WorldWideScience

Sample records for alloy-ts5

  1. Influence of iron and beryllium additions on heat resistance of silicide coatings on TsMB-30 molybdenum alloy

    International Nuclear Information System (INIS)

    Zajtseva, A.L.; Fedorchuk, N.M.; Lazarev, Eh.M.; Korotkov, N.A.

    1985-01-01

    Alloying of titanium modified silicide coatings on TsMB-30 molybdenum alloy with iron or beryllium is stated to improve their protective properties. Coatings with low content of alloying elements have the best protective properties. Service life of coatings is determined by the formed oxide film and phase transformations taking place in the coating

  2. TS-1 and TS-2 transient overpower tests on FFTF fuel

    International Nuclear Information System (INIS)

    Pitner, A.L.; Ferrell, P.C.; Culley, G.E.; Weber, E.T.

    1985-01-01

    The TS-1 and TS-2 TREAT transient experiments subjected a low burnup (2 MWd/kg) and a medium burnup (58 MWd/kg), respectively, FFTF irradiated fuel pin to unprotected 5 cents/s overpower transient conditions. The fuel pin failure response was similar in the two tests, which demonstrated a large margin to failure (P/P 0 > 3) and a favorable upper level failure location. Thus, for these transient conditions, burnup effects on transient performance appeared to be minimal in the range tested. Pin disruption in the medium burnup TS-2 test was more severe due to the higher fission gas pressurization, but failure occurred at only a 5% lower power level than for the low burnup TS-1 fuel pin. Both tests exhibited axial extrusion of molten fuel to the region above the fuel column several seconds before pin failure, demonstrating a potentially beneficial inherent safety mechanism to delay failure and mitigate accident consequences

  3. Influence of alloy microstructure on the microshear bond strength of basic alloys to a resin luting cement.

    Science.gov (United States)

    Bauer, José; Costa, José Ferreira; Carvalho, Ceci Nunes; Souza, Douglas Nesadal de; Loguercio, Alessandro Dourado; Grande, Rosa Helena Miranda

    2012-01-01

    The aim of this study was to evaluate the influence of microstructure and composition of basic alloys on their microshear bond strength (µSBS) to resin luting cement. The alloys used were: Supreme Cast-V (SC), Tilite Star (TS), Wiron 99 (W9), VeraBond II (VBII), VeraBond (VB), Remanium (RM) and IPS d.SIGN 30 (IPS). Five wax patterns (13 mm in diameter and 4mm height) were invested, and cast in a centrifugal casting machine for each basic alloy. The specimens were embedded in resin, polished with a SiC paper and sandblasted. After cleaning the metal surfaces, six tygon tubes (0.5 mm height and 0.75 mm in diameter) were placed on each alloy surface, the resin cement (Panavia F) was inserted, and the excess was removed before light-curing. After storage (24 h/37°C), the specimens were subjected to µSBS testing (0.5 mm/min). The data were subjected to a one-way repeated measures analysis of variance and Turkey's test (α=0.05). After polishing, their microstructures were revealed with specific conditioners. The highest µSBS (mean/standard deviation in MPa) were observed in the alloys with dendritic structure, eutectic formation or precipitation: VB (30.6/1.7), TS (29.8/0.9), SC (30.6/1.7), with the exception of IPS (31.1/0.9) which showed high µSBS but no eutectic formation. The W9 (28.1/1.5), VBII (25.9/2.0) and RM (25.9/0.9) showed the lowest µSBS and no eutectic formation. It seems that alloys with eutectic formation provide the highest µSBS values when bonded to a light-cured resin luting cement.

  4. TS gene polymorphisms are not good markers of response to 5-FU therapy in stage III colon cancer patients.

    Science.gov (United States)

    Fariña-Sarasqueta, A; Gosens, M J E M; Moerland, E; van Lijnschoten, I; Lemmens, V E P P; Slooter, G D; Rutten, H J T; van den Brule, Adriaan J C

    2011-08-01

    Although the predictive and prognostic value of thymidylate synthase (TS) expression and gene polymorphism in colon cancer has been widely studied, the results are inconclusive probably because of methodological differences. With this study, we aimed to elucidate the role of TS gene polymorphisms genotyping in therapy response in stage III colon carcinoma patients treated with 5-FU adjuvant chemotherapy. 251 patients diagnosed with stage III colon carcinoma treated with surgery followed by 5-FU based adjuvant therapy were selected. The variable number of tandem repeats (VNTR) and the single nucleotide polymorphism (SNP) in the 5'untranslated region of the TS gene were genotyped. There was a positive association between tumor T stage and the VNTR genotypes (p = 0.05). In both univariate and multivariate survival analysis no effects of the studied polymorphisms on survival were found. However, there was an association between both polymorphisms and age. Among patients younger than 60 years, the patients homozygous for 2R seemed to have a better overall survival, whereas among the patients older than 67 this longer survival was seen by the carriers of other genotypes. We conclude that the TS VNTR and SNP do not predict response to 5-FU therapy in patients with stage III colon carcinoma. However, age appears to modify the effects of TS polymorphisms on survival.

  5. Phase decomposition in a mechanically alloyed Cu-44.5 at%Ni-22.5 at%Fe alloy during isothermal aging

    International Nuclear Information System (INIS)

    Lopez-Hirata, Victor M.; Saucedo-Munoz, Maribel L.; Diaz-Barriga-Arceo, Lucia G.

    2006-01-01

    A supersaturated solid solution of Cu-44.5 at%Ni-22.5 at%Fe alloy was produced by ball milling of a pure chemical elemental mixture for 1080 ks. An fcc supersaturated solid solution with a grain size of about 20 nm was obtained after milling. This alloy was subsequently aged at 803, 898 and 1003 K for different times. The growth kinetics of the modulation wavelength was determined from the X-ray diffraction results and followed the Lifshitz-Slyozov-Wagner theory for a diffusion-controlled coarsening in the MA alloy after aging. The growth kinetics of composition modulation wavelength for the MA alloy was faster at 803 and 898 K than that for the same alloy composition obtained by a conventional processing and then aged at the same temperatures. The activation energy for the decomposed phase coarsening process in the MA alloy was lower than that corresponding to the conventionally-processed alloy. (author)

  6. Taylor Series-Based Long-Term Creep-Life Prediction of Alloy 617

    International Nuclear Information System (INIS)

    Yin, Song Nan; Kim, Woo Gon; Kim, Yong Wan; Park, Jae Young; Kim, Soen Jin

    2010-01-01

    In this study, a Taylor series (T-S) model based on the Arrhenius, McVetty, and Monkman-Grant equations was developed using a mathematical analysis. In order to reduce fitting errors, the McVetty equation was transformed by considering the first three terms of the Taylor series equation. The model parameters were accurately determined by a statistical technique of maximum likelihood estimation, and this model was applied to the creep data of alloy 617. The T-S model results showed better agreement with the experimental data than other models such as the Eno, exponential, and L-M models. In particular, the T-S model was converted into an isothermal Taylor series (IT-S) model that can predict the creep strength at a given temperature. It was identified that the estimations obtained using the converted ITS model was better than that obtained using the T-S model for predicting the long-term creep life of alloy 617

  7. Improvement of antiscuff properties and thermal stability of alloys of the Fe-Cr-Ni-Si system used for building-up of fittings

    International Nuclear Information System (INIS)

    Luzhanskij, I.B.; Runov, A.E.; Gel'man, A.S.; Stepin, V.S.

    1978-01-01

    Studied was the influence of the system and the degree of alloying of alloys of the Fe-Cr-Ni-Si system on their operational characteristics in the operation mode of the energy armature of superhigh parameters. The TsN18 alloy has been developed (containing 0.1 to 0.2% C; 3.5 to 6.0% Si; 0.5 to 3.0% Mn; 16 to 17% Cr; 10.5 to 12% Ni; 1.5 to 3% Mo; the balance being Fe), bombining a high resistance to scuffing with a fairly high heat resistance; the alloy lending itself to building up and to machining. The dependence of the wear resistance of the alloys of the Fe-Cr-Ni-Si system on two factors has been established; namely, - the antifriction characteristics of the film of secondary structures, and physico-mechanical properties of the alloy

  8. Improving tribological properties of Ti-5Zr-3Sn-5Mo-15Nb alloy by double glow plasma surface alloying

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Lili; Qin, Lin, E-mail: qinlin@tyut.edu.cn; Kong, Fanyou; Yi, Hong; Tang, Bin

    2016-12-01

    Highlights: • The Mo alloyed layers were successfully prepared on TLM surface by DG-PSA. • The surface microhardness of TLM is remarkably enhanced by Mo alloying. • The TLM samples after Mo alloying exhibit good wettability. • The Mo alloyed TLM samples show excellent tribological properties. - Abstract: Molybdenum, an alloying element, was deposited and diffused on Ti-5Zr-3Sn-5Mo-15Nb (TLM) substrate by double glow plasma surface alloying technology at 900, 950 and 1000 °C. The microstructure, composition distribution and micro-hardness of the Mo modified layers were analyzed. Contact angles on deionized water and wear behaviors of the samples against corundum balls in simulated human body fluids were investigated. Results show that the surface microhardness is significantly enhanced after alloying and increases with treated temperature rising, and the contact angles are lowered to some extent. More importantly, compared to as-received TLM alloy, the Mo modified samples, especially the one treated at 1000 °C, exhibit the significant improvement of tribological properties in reciprocating wear tests, with lower specific wear rate and friction coefficient. To conclude, Mo alloying treatment is an effective approach to obtain excellent comprehensive properties including optimal wear resistance and improved wettability, which ensure the lasting and safety application for titanium alloys as the biomedical implants.

  9. Influence of dissolved hydrogen on aluminum-lithium alloy fracture behavior

    Science.gov (United States)

    Rivet, F. C.; Swanson, R. E.

    1989-01-01

    The objective of this work is to study the effects of dissolved hydrogen on the mechanical properties of 2090 and 2219 alloys. Prior to mechanical testing, potentiostatic and potentiodynamic tests were performed using NaCl/HCl solutions varying in pH from 1.5 to 7.5 (3.5 pct NaCl in deionized water). After analysis of the potentiodynamic curve for each solution, several potentiostatic experiments were conducted for various times (from 10 minutes to several hours) with a cathodic overpotential of 300 mV. These experiments were performed to select charging conditions. It is shown that the fracture of L-S and T-S orientations proceeds via slipping of layers in the S-T direction. The T-S and L-S orientations fractured with substantially higher propagation energy that the L-T and T-L orientations, due in large part to the extensive delamination propagation of the fracture.

  10. Fatigue crack growth rates and fracture toughness of rapidly solidified Al-8.5 pct Fe-1.2 pct V-1.7 pct Si alloys

    International Nuclear Information System (INIS)

    Hariprasad, S.; Sastry, S.M.L.; Jerina, K.L.

    1994-01-01

    The room-temperature fatigue crack growth rates (FCGR) and fracture toughness were evaluated for different crack plane Orientations of an Al-8.5 pct Fe-1.2 pct V-1.7 pct Si alloy produced by planar flow casting (PFC) and atomized melt deposition (AMD) processes. For the alloy produced by the PFC process, properties were determined in six different orientations, including the short transverse directions S-T and S-L. Diffusion bonding and adhesive bonding methods were used to prepare specimens for determining FCGR and fracture toughness in the short transverse direction. Interparticle boundaries control fracture properties in the alloy produced by PFC. Fracture toughness of the PFC alloy varies from 13.4 MPa√ bar m to 30.8 MPa√ bar m, depending on the orientation of the crack plane relative to the interparticle boundaries. Fatigue crack growth resistance and fracture toughness are greater in the L-T, L-S, and T-S directions than in the T-L, S-T, and S-L orientations. The alloy produced by AMD does not exhibit anisotropy in fracture toughness and fatigue crack growth resistance in the as-deposited condition or in the extruded condition. The fracture toughness varies from 17.2 MPa√ bar m to 18.5 MPa√ bar m for the as-deposited condition and from 19.8 MPa√ bar m to 21.0 MPa√ bar m for the extruded condition. Fracture properties are controlled by intrinsic factors in the alloy produced by AMD. Fatigue crack growth rates of the AMD alloy are comparable to those of the PFC alloy in the L-T orientation. The crack propagation modes were studied by optical metallographic examination of crack-microstructure interactions and scanning electron microscopy of the fracture surfaces

  11. Development of cube textured Ni-W alloy substrates used for coated conductors

    DEFF Research Database (Denmark)

    Suo, Hongli; Ma, Lin; Gao, Mangmang

    2014-01-01

    It is considered as a challenge for RABiTS route to get cube textured Ni-W alloy substrates with high mechanical and magnetic properties for coated conductors. The works of our group in recent years are summarized about different Ni-W substrates with high W content and composite tapes made by RABiTS...

  12. Damping characteristics of a Ti40.5Ni49.5Zr10 shape memory alloy

    International Nuclear Information System (INIS)

    Hsieh, S.F.; Wu, S.K.

    2005-01-01

    Ti 40.5 Ni 49.5 Zr 10 alloy undergoes B2-bar B19' martensitic transformation. Damping capacities of B19' and B2 phases of this alloy are lower than those of Ti 51 Ni 49 alloy due to Zr atoms solid-soluted hardening. Transformation temperatures of this alloy decrease, but transformation peak heights Q max -1 increase with increasing aging time at 300 o C due to the formation of finer (001) M twins for specimens aged longer. The Q max -1 peaks of the slightly cold-rolled Ti 40.5 Ni 49.5 Zr 10 alloy are higher than those of the as-annealed alloy, which may be because the thinner twins are induced by small deformation

  13. Gas atomization of Cu-modified AB5 metal hydride alloys

    International Nuclear Information System (INIS)

    Young, K.; Ouchi, T.; Banik, A.; Koch, J.; Fetcenko, M.A.; Bendersky, L.A.; Wang, K.; Vaudin, M.

    2011-01-01

    Research highlights: → The gas atomization process together with a hydrogen annealing process was demonstrated on AB5 alloys. → The method was found to be effective in restoring the original cycle life sacrificed by the incorporation of copper in the alloy formula as a means of improving the low temperature performance of AB 5 alloys. → The new process also improves high rate, low temperature, and charge retention performances for both Cu-free and Cu-containing AB 5 alloys. - Abstract: Gas atomization together with a hydrogen annealing process has been proposed as a method to achieve improved low-temperature performance of AB 5 alloy electrodes in Ni/MH batteries and restore the original cycle life which was sacrificed by the incorporation of copper in the alloy formula. While the gas atomization process reduces the lattice constant aspect ratio c/a of the Cu-containing alloys, the addition of a hydrogen annealing step recovers this property, although it is still inferior to the conventionally prepared annealed Cu-free alloy. This observation correlates very well with the cycle life performance. In addition to extending the cycle life of the Cu-containing metal hydride electrode, processing by gas atomization with additional hydrogen annealing improves high-rate, low-temperature, and charge retention performances for both Cu-free and Cu-containing AB 5 alloys. The degradation mechanisms of alloys made by different processes through cycling are also discussed.

  14. A Comparison of Tropical Storm (TS) and Non-TS Gust Factors for Assessing Peak Wind Probabilities at the Eastern Range

    Science.gov (United States)

    Merceret, Francis J.; Crawford, Winifred C.

    2010-01-01

    Peak wind speed is an important forecast element to ensure the safety of personnel and flight hardware at Kennedy Space Center (KSC) and the Cape Canaveral Air Force Station (CCAFS) in East-Central Florida. The 45th Weather Squadron (45 WS), the organization that issues forecasts for the KSC/CCAFS area, finds that peak winds are more difficult to forecast than mean winds. This difficulty motivated the 45 WS to request two independent studies. The first (Merceret 2009) was the development of a reliable model for gust factors (GF) relating the peak to the mean wind speed in tropical storms (TS). The second (Lambert et al. 2008) was a climatological study of non-TS cool season (October-April) mean and peak wind speeds by the Applied Meteorology Unit (AMU; Bauman et al. 2004) without the use of GF. Both studies presented their statistics as functions of mean wind speed and height. Most of the few comparisons of TS and non-TS GF in the literature suggest that non-TS GF at a given height and mean wind speed are smaller than the corresponding TS GF. The investigation reported here converted the non-TS peak wind statistics calculated by the AMU to the equivalent GF statistics and compared them with the previous TS GF results. The advantage of this effort over all previously reported studies of its kind is that the TS and non-TS data were taken from the same towers in the same locations. This eliminates differing surface attributes, including roughness length and thermal properties, as a major source of variance in the comparison. The goal of this study is two-fold: to determine the relationship between the non-TS and TS GF and their standard deviations (GFSD) and to determine if models similar to those developed for TS data in Merceret (2009) could be developed for the non-TS environment. The results are consistent with the literature, but include much more detailed, quantitative information on the nature of the relationship between TS and non-TS GF and GFSD as a function

  15. Machinability of zinc-aluminum alloy5; zamzk5; alloy produced by powder metallurgy

    International Nuclear Information System (INIS)

    Adnan, I.O.; Momani, M.A.A.

    2007-01-01

    Powder metallurgy process (P/M) is repeatedly reported as a near-net or net-shape manufacturing process with the ability of producing parts of complicated or intricate shapes with high required dimensional accuracy and high surface quality. However, some finishing and machining operations are sometimes necessary and must be done to meet dimensional tolerances or accommodate design features that can be achieved during compaction such as transverse holes, undercuts and threads. Therefore, it is necessary to study the machinability of P/M products. ZAMAK5 alloy is widely used in engineering applications in the automobile industry, particularly in the manufacturing of bushes and recently self -lubricated bearings which are manufactured by the P/M process. Therefore it is anticipated that studying the machinability of this alloy as produced by the powder metallurgy process is worthwhile investigating. In this paper, the machinability of ZAMAK5, alloy produced by powder metallurgy, under different cutting conditions of speed, depth of cut and feed rate is carried out. Surface roughness was used as a criterion for assessing machinability at the different conditions. It was found that specimens compacted at 475 MPa and having 1% addition of zinc stearates as a binder and lubricant gave better surface quality than those produced at 550 MPa compacting pressure,whereas at 1.5% addition of zinc stearates produced worse surface quality (i.e. Higher surface roughness than in case of 475 MPa compacting pressure). On the whole, the results of the experimental work revealed that the surface roughness at the different cutting conditions remained within the accepted level in industry, less than 2 microns. (author)

  16. Structure and grindability of cast Ti-5Cr-xFe alloys

    International Nuclear Information System (INIS)

    Hsu, H.-C.; Pan, C.-H.; Wu, S.-C.; Ho, W.-F.

    2009-01-01

    The purpose of this study was to investigate the structure, microhardness and grindability of Ti-5Cr and a series of ternary Ti-5Cr-xFe alloys with 0.1, 0.5, 1, 3 and 5 wt.% Fe, respectively. This study evaluated the phase and structure of Ti-5Cr and Ti-5Cr-xFe alloys, using an X-ray diffraction (XRD) for phase analysis and optical microscope for microstructure of the etched alloys. In addition, grindability was evaluated by measuring the amount of metal volume removed after grinding for 1 min at each of the four rotational speeds of the wheel (500, 750, 1000 or 1200 m/min), with the goal of developing a titanium alloy with better machinability than commercially pure titanium (c.p. Ti). The results showed that the structure of Ti-5Cr-xFe alloys is sensitive to the Fe content. With Fe contents higher than 0.5 wt.%, the equi-axed β phase is entirely retained, while ω phase was found in the Ti-5Cr, Ti-5Cr-0.1Fe, Ti-5Cr-0.5Fe and Ti-5Cr-1Fe alloys. The largest quantity of ω phase and highest microhardness were found in Ti-5Cr-0.5Fe and Ti-5Cr-1Fe alloys. The grinding rates of the Ti-5Cr and Ti-5Cr-xFe alloys showed a similar tendency to the microhardness. The Ti-5Cr, Ti-5Cr-0.1Fe, Ti-5Cr-0.5Fe and Ti-5Cr-1Fe alloys exhibited the best grindability, especially at 500, 750 and 1000 m/min. Furthermore, the grindability of the tested metals increased in proportion to grinding speed up to 1000 m/min, with a decrease after 1200 m/min. This study concluded that Fe may be used to harden titanium and improve the grindability

  17. Grain refinement of Al-Si9.8-Cu3.4 alloy by novel Al-3.5FeNb-1.5C master alloy and its effect on mechanical properties

    Science.gov (United States)

    Apparao, K. Ch; Birru, Anil Kumar

    2018-01-01

    A novel Al-3.5FeNb-1.5C master alloy with uniform microstructure was prepared using a melt reaction process for this study. In the master alloy, basic intermetallic particles such as NbAl3, NbC act as heterogeneous nucleation substrates during the solidification of aluminium. The grain refining performance of the novel master alloy on Al-Si9.8-Cu3.4 alloy has also been investigated. It is observed that the addition of 0.1 wt.% of Al-3.5FeNb-1.5C master alloy can induce very effective grain refinement of the Al-Si9.8-Cu3.4 alloy. The average grain size of α-Al is reduced to 22.90 μm from about 61.22 μm and most importantly, the inoculation of Al-Si9.8-Cu3.4 alloy with FeNb-C is not characterised by any visible poisoning effect, which is the drawback of using commercial Al-Ti-B master alloys on aluminium cast alloys. Therefore, the mechanical properties of the Al-Si9.8-Cu3.4 alloy have been improved obviously by the addition of the 0.1 wt.% of Al-3.5FeNb-1.5C master alloy, including the yield strength and elongation.

  18. Mechanical properties and microstructure of Ti-35.5Nb-5.7Ta beta alloy.

    Science.gov (United States)

    Bartakova, S; Prachar, P; Dvorak, I; Hruby, V; Vanek, J; Pospichal, M; Svoboda, E; Martikan, A; Konecna, H; Sedlak, I

    2015-01-01

    Titanium and titanium alloys represent generally accepted metallic biomaterials for clinical dentistry and dental implantology. In this paper, we present a Ti-35.5Nb-5.7Ta alloy with a special respect to its microstructure and mechanical characteristics, such as Young modulus of elasticity. Three thermal treatments differing in temperature and time of annealing were used during the Ti-35.5Nb-5.7Ta processing in order to evaluate the effects of ageing, melting annealing, and annealing on mechanical characteristics and microstructure. Using microscopy, the alloy was analyzed and the differences in shares of beta phase grains, alpha particles and precipitates evaluated. The three thermal treatments were evaluated also from technological point of view. The following thermal treatment was found optimal for the Ti-35.5Nb-5.7Ta alloy: melting annealing at 800 °C for 0.5 hour followed by a cold swaging with a 52-79 % deformation, and final hardening at 500 °C for 2 hours in water(Tab. 2, Fig. 3, Ref. 24).

  19. Gd{sub 90}Co{sub 2.5}Fe{sub 7.5} alloy displaying enhanced magnetocaloric properties

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, V., E-mail: virgil12@nist.gov [Materials Science and Engineering Division, NIST, Gaithersburg, MD 20899-8552 (United States); Shull, R.D., E-mail: robert.shull@nist.gov [Materials Science and Engineering Division, NIST, Gaithersburg, MD 20899-8552 (United States); Kletetschka, G., E-mail: kletetschka@gmail.com [Faculty of Science, Charles University, Prague 12843 (Czech Republic); Institute of Geology, Academy of Science of the Czech Republic, v.v.i., Prague 16500 (Czech Republic); Stutzman, P.E., E-mail: paul.stutzman@nist.gov [Materials and Structural Systems Division, NIST, Gaithersburg, MD 20899-861 (United States)

    2015-02-15

    Highlights: • The Gd{sub 90}Co{sub 2.5}Fe{sub 7.5} alloy displays superior magnetocaloric properties than Gd. • Alloy’s superior properties at relatively low field values: 400, 800 kA/m (0.5, 1 T). • We proposed two possible mechanisms for the Gd-based alloy enhanced properties. • We indicated a pathway for further improving the alloy magnetocaloric properties. - Abstract: We report on the discovery of a new Gd{sub 90}Co{sub 2.5}Fe{sub 7.5} alloy exhibiting superior magnetocaloric properties compared to those of gadolinium. We present magnetically-derived entropy change, ΔS{sub M}, computed from magnetic data, and thermally-derived temperature change, ΔT{sub ad}, obtained from direct thermal measurements together with their respective MCE peaks for the alloy and gadolinium. The MCE peaks of the alloy are taller and broader than the corresponding MCE peaks of gadolinium. Correspondingly, the refrigeration capacity (RC) values of the alloy computed from magnetic and thermal MCEs for field changes, ΔH, of 400 kA/m (0.5 T) and 800 kA/m (1 T) are about 20% larger than those of gadolinium. Two possible mechanisms are proposed to account for the improved magnetocaloric properties of gadolinium alloyed with small amounts of Co and Fe, thereby pointing out a different methodology to use in the search for improved low field magnetic refrigerants.

  20. [Construction of a system for proper TS-1 application].

    Science.gov (United States)

    Azuma, Sayaka; Morimoto, Shigefumi; Kagawa, Kunihiko; Katada, Yoshinori; Hasegawa, Kenji; Tabuse, Katsuyoshi

    2010-03-01

    TS-1 is an oral anti-tumor drug, which contains 5-chloro-2, 4-dihydroxypyridine (CDHP), a compound mainly excreted in urine. Since the CDHP concentration is increased among patients with impaired renal function, the frequency of side effects of TS-1 increases in such patients. Therefore, we constructed a computer-aided system that enables prompt monitoring of creatinine clearance (Ccr) calculated from the serum creatinine levels of patients prescribed TS-1 at the time pharmacists prepare the medicine. With this system, we found two cases who were prescribed TS-1, despite their decreased Ccr. One was a patient whose estimated Ccr was less than 30 mL/min/m2. With such renal malfunction, pharmacokinetics of the drug was considerably changed compared with normal control, and the dosage should be reduced. The other case presented with severe jaundice and had only a mild decrease of renal function (Ccr: 50 mL/min/m2). So we measured the concentration of uracil in the urine and performed a drug lymphocyte stimulation test for further investigation of concomitant affecting factors. Our system is useful because it can show pharmacists both the dosage TS-1 patients take and their renal function at a glance in real time. This system can be adapted for every medicine which might accumulate in patients with renal dysfunction.

  1. TS/EL ELECTRICAL WORK REQUEST FORM

    CERN Multimedia

    TS Department

    2008-01-01

    To facilitate the processing of requests for minor electrical installation work to be carried out by the TS/EL group, a new procedure designed to improve contacts and exchange of information with customers has been set up. The procedure comprises a check to determine whether the TS/EL or the TS/FM group is responsible for the area where the electrical work is to be done. If the work is to be performed by the EL group, an on-line request form must be completed. The following steps must be completed: On a web browser, use the link http://ts-dep.web.cern.ch/ts-dep/groups/el/el.htm In the left-hand menu choose ‘Demande de Travaux Electriques’ Enter the building number to check which group to contact and click ‘FIND’ If the area is: Under FM’s responsibility:\tCall 77777 Under EL’s responsibility:\tClick the link to the work form, complete it and send it (click ‘ENVOYER’) IMPORTANT This form is for minor electrical installation requests only. Please call 72201 in t...

  2. Assessment of TS-1, a thick cane mutant

    International Nuclear Information System (INIS)

    Shama Rao, H.K.

    1979-01-01

    A true breeding thick cane mutant TS-1, induced by radiations, was obtained in variety Co-419. TS-1 was found to be superior to Co-419 with respect to cane size, weight, yield and juice quality. The thick canes of TS-1 were found to be solid even at 14 months age and so also their ratoons. The tillering habit of TS-1 has a definite advantage over other varieties with respect to easy intercultural field operations. TS-1 is now being tested under various agroclimatic zones in Karnataka, Maharashtra and U.P. (auth.)

  3. Tensile properties of V-5Cr-5Ti alloy after exposure in air environment

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Soppet, W.K. [Argonne National Lab., IL (United States)

    1997-04-01

    Oxidation studies were conducted on V-5Cr-5Ti alloy specimens in an air environment to evaluate the oxygen uptake behavior of the alloy as a function of temperature and exposure time. The oxidation rates, calculated from parabolic kinetic measurements of thermogravimetric testing and confirmed by microscopic analysis of cross sections of exposed specimens, were 5, 17, and 27 {mu}m per year after exposure at 300, 400, and 500{degrees}C, respectively. Uniaxial tensile tests were conducted at room temperature and at 500{degrees}C on preoxidized specimens of the alloy to examine the effects of oxidation and oxygen migration on tensile strength and ductility. Correlations were developed between tensile strength and ductility of the oxidized alloy and microstructural characteristics such as oxide thickness, depth of hardened layer, depth of intergranular fracture zone, and transverse crack length.

  4. Inhibiting the corrosion of MNZh 5-1 alloy in neutral solutions of 5-chloro-1,2,3-benzotrialzol

    Science.gov (United States)

    Kuznetsov, Yu. I.; Agafonkina, M. O.; Andreeva, N. P.; Arkhipushkin, I. A.; Kazansky, L. P.

    2017-11-01

    The adsorption and protective properties of 5-chloro-1,2,3-benzotriazol (5-chloro-BTA) are studied in relation to MNZh 5-1 alloy in a chloride borate buffer solution with pH 7.4. It is shown that this inhibitor can stabilize the passive state of the alloy at a concentration of 0.12 mmol/g. The adsorption of 5-chloro-BTA on a surface of MNZh 5-1 alloy is polymolecular; the free energy of adsorption is about 80 kJ/mol. The advantages of adsorption and protective properties of 5-chloro-BTA compared to BTA on both MNZh 5-1 alloy and the metals contained in the alloy (Ni, Cu) are shown. XPS data indicate a 5-chloro-BTA monolayer formed on the surface of the alloy. This monolayer was composed of inhibitor molecules, which are normally oriented toward a surface and are not removed during ultrasonic washing of the electrode.

  5. Transcutaneous Spinal Direct Current Stimulation (tsDCS

    Directory of Open Access Journals (Sweden)

    Filippo eCogiamanian

    2012-07-01

    Full Text Available In the past ten years renewed interest has centered on non-invasive transcutaneous weak direct currents applied over the scalp to modulate cortical excitability (brain polarization or transcranial direct current stimulation, tDCS. Extensive literature shows that tDCS induces marked changes in cortical excitability that outlast stimulation.Aiming at developing a new, non invasive, approach to spinal cord neuromodulation we assessed the after-effects of thoracic transcutaneous spinal DC stimulation (tsDCS on somatosensory potentials (SEPs evoked in healthy subjects by posterior tibial nerve (PTN stimulation. Our findings showed that thoracic anodal tsDCS depresses the cervico-medullary PTN-SEP component (P30 without eliciting adverse effects. tsDCS also modulates post-activation H-reflex dynamics. Later works further confirmed that transcutaneous electric fields modulate spinal cord function. Subsequent studies in our laboratory showed that tsDCS modulates the flexion reflex in the human lower limb. Besides influencing the laser evoked potentials, tsDCS increases pain tolerance in healthy subjects. Hence, though the underlying mechanisms remain speculative, tsDCS modulates activity in lemniscal, spinothalamic and segmental motor systems.Here we review currently available experimental evidence that non-invasive spinal cord stimulation influences spinal function in humans and argue that, by focally modulating spinal excitability, tsDCS could provide a novel therapeutic tool complementary to drugs and invasive spinal cord stimulation in managing various pathologic conditions, including pain.

  6. Hot rolling effect on the characters of Zr-0.6Nb-0.5Fe-0.5Cr alloy

    International Nuclear Information System (INIS)

    Sungkono; Siti Aidah

    2015-01-01

    Characters of Zr-0.6Nb-0.5Fe-0.5Cr alloy after hot rolling have been studied. The objective of this research was to obtain of hot rolling effect on the characteristics of microstructures, hardness and phases formed in Zr-0.6Nb-0.5Fe-0.5Cr alloy. The hot rolling process of alloy carried out at temperature of 800 °C with retention time of 1.5 and 2 hours and a thickness reduction between 5 to 25 %. The results of this experiment showed that the Zr-0.6Nb-0.5Fe-0.5Cr alloy has Widmanstaetten structure with microstructure evolving into deformed columnar grains and deformed elongated grains with increasing thickness reduction. Besides, the longer the retention time at temperature of 800 °C is the larger are the grain structures and formation of α-Zr and Zr_3Fe phase. The hardness of Zr-0.6Nb-0.5Fe-0.5Cr alloy has same trends i.e the larger thickness reduction gives higher hardness. The Zr-0.6Nb-0.5Fe-0.5Cr alloy can under go hot rolling deformation at a thickness reduction of 25 % and the formation of α-Zr and Zr_3Fe can increased of hardness and strength of Zr-0.6 Nb-0.5 Fe-0.5 Cr alloy. (author)

  7. Thermal conductivity of Cu–4.5 Ti alloy

    Indian Academy of Sciences (India)

    The thermal conductivity (TC) of peak aged Cu–4.5 wt% Ti alloy was measured at different temperatures and studied its variation with temperature. It was found that TC increased with increasing temperature. Phonon and electronic components of thermal conductivity were computed from the results. The alloy exhibits an ...

  8. Pressure dependence of resistivity and magnetic properties in a Mn1.9Cr0.1Sb alloy

    Directory of Open Access Journals (Sweden)

    D. V. Maheswar Repaka

    2017-12-01

    Full Text Available We report magnetic-field and hydrostatic pressure dependent electrical resistivity and magnetic properties of a Mn1.9Cr0.1Sb alloy. Upon cooling, the magnetization of Mn1.9Cr0.1Sb exhibits a first-order ferrimagnetic to antiferromagnetic transition at the exchange inversion temperature, TS = 261 K under a 0.1 T magnetic field. Our experimental results show that TS decreases with increasing magnetic field but increase with increasing hydrostatic pressure. The pressure induced transition is accompanied by a large positive baro-resistance of 30.5% for a hydrostatic pressure change of 0.69 GPa. These results show that the lattice parameters as well as the bond distance between Mn-Mn atoms play a crucial role in the magnetic and electronic transport properties of Mn1.9Cr0.1Sb. This sample also exhibits a large inverse magnetocaloric effect with a magnetic entropy change of ΔSm = +6.75 J/kg.K and negative magnetoresistance (44.5% for a field change of 5 T at TS in ambient pressure which may be useful for magnetic cooling and spintronics applications.

  9. Structure and mechanical properties of as-cast Ti-5Nb-xFe alloys

    International Nuclear Information System (INIS)

    Hsu, Hsueh-Chuan; Hsu, Shih-Kuang; Wu, Shih-Ching; Lee, Chih-Jhan; Ho, Wen-Fu

    2010-01-01

    In this study, as-cast Ti-5Nb and a series of Ti-5Nb-xFe alloys were investigated and compared with commercially pure titanium (c.p. Ti) in order to determine their structure and mechanical properties. The series of Ti-5Nb-xFe alloys contained an iron content ranging from 1 to 5 mass% and were prepared by using a commercial arc-melting vacuum-pressure casting system. Additionally, X-ray diffraction (XRD) for phase analysis was conducted with a diffractometer, and three-point bending tests were performed to evaluate the mechanical properties of all specimens. The fractured surfaces were observed by using scanning electron microscopy (SEM). The experimental results indicated that these alloys possessed a range of different structures and mechanical properties dependent upon the various additions of Fe. With an addition of 1 mass% Fe, retention of the metastable β phase began. However, when 4 mass% Fe or greater was added, the β phase was entirely retained with a bcc crystal structure. Moreover, the ω phase was only detected in the Ti-5Nb-2Fe, Ti-5Nb-3Fe and Ti-5Nb-4Fe alloys. The largest quantity of ω phase and the highest bending modulus were found in the Ti-5Nb-3Fe alloy. The Ti-5Nb-2Fe alloy had the lowest bending modulus, which was lower than that of c.p. Ti by 20%. This alloy exhibited the highest bending strength/modulus ratio of 26.7, which was higher than that of c.p. Ti by 214%, and of the Ti-5Nb alloy (14.4 ) by 85%. Additionally, the elastically recoverable angles of the ductile Ti-5Nb-1Fe (19.9 o ) and Ti-5Nb-5Fe (29.5 o ) alloys were greater than that of c.p. Ti (2.7 o ) by as much as 637% and 993%, respectively. Furthermore, the preliminary cell culturing results revealed that the Ti-5Nb-xFe alloys were not only biocompatible, but also supported cell attachment.

  10. Structure and mechanical properties of as-cast Ti-5Nb-xFe alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsueh-Chuan; Hsu, Shih-Kuang; Wu, Shih-Ching [Department of Dental Laboratory Technology, Central Taiwan University of Science and Technology, Taichung 40605, Taiwan (China); Institute of Biomedical Engineering and Material Science, Central Taiwan University of Science and Technology, Changhua 51591, Taiwan (China); Lee, Chih-Jhan [Department of Materials Science and Engineering, Da-Yeh University, Changhua 51591, Taiwan (China); Ho, Wen-Fu, E-mail: fujii@mail.dyu.edu.tw [Department of Materials Science and Engineering, Da-Yeh University, Changhua 51591, Taiwan (China)

    2010-09-15

    In this study, as-cast Ti-5Nb and a series of Ti-5Nb-xFe alloys were investigated and compared with commercially pure titanium (c.p. Ti) in order to determine their structure and mechanical properties. The series of Ti-5Nb-xFe alloys contained an iron content ranging from 1 to 5 mass% and were prepared by using a commercial arc-melting vacuum-pressure casting system. Additionally, X-ray diffraction (XRD) for phase analysis was conducted with a diffractometer, and three-point bending tests were performed to evaluate the mechanical properties of all specimens. The fractured surfaces were observed by using scanning electron microscopy (SEM). The experimental results indicated that these alloys possessed a range of different structures and mechanical properties dependent upon the various additions of Fe. With an addition of 1 mass% Fe, retention of the metastable {beta} phase began. However, when 4 mass% Fe or greater was added, the {beta} phase was entirely retained with a bcc crystal structure. Moreover, the {omega} phase was only detected in the Ti-5Nb-2Fe, Ti-5Nb-3Fe and Ti-5Nb-4Fe alloys. The largest quantity of {omega} phase and the highest bending modulus were found in the Ti-5Nb-3Fe alloy. The Ti-5Nb-2Fe alloy had the lowest bending modulus, which was lower than that of c.p. Ti by 20%. This alloy exhibited the highest bending strength/modulus ratio of 26.7, which was higher than that of c.p. Ti by 214%, and of the Ti-5Nb alloy (14.4 ) by 85%. Additionally, the elastically recoverable angles of the ductile Ti-5Nb-1Fe (19.9{sup o}) and Ti-5Nb-5Fe (29.5{sup o}) alloys were greater than that of c.p. Ti (2.7{sup o}) by as much as 637% and 993%, respectively. Furthermore, the preliminary cell culturing results revealed that the Ti-5Nb-xFe alloys were not only biocompatible, but also supported cell attachment.

  11. The complex structure of liquid Cu{sub 6}Sn{sub 5} alloy

    Energy Technology Data Exchange (ETDEWEB)

    Qin Jingyu; Gu Tingkun; Bian Xiufang [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Southern Campus, Jinan 250061 (China); Liu Hui [Shandong High Performance Computing Center, Shandong University, Southern Campus, Jinan 250061 (China)

    2009-04-15

    By applying ab initio molecular dynamics simulation to liquid Cu{sub 6}Sn{sub 5} alloy, the hetero-coordination tendency is discovered by Bathia-Thornton partial correlation functions and a chemical short-range parameter. However the local structural environment of Sn in l-Cu{sub 6}Sn{sub 5} alloy resembles that of liquid Sn by Voronoi analysis. A new feature, i.e. a subpeak in between the first and second peaks, is discovered by the present method which implies that topologically disordered {beta}-Sn-type structural units may exist in l-Cu{sub 6}Sn{sub 5} alloy. The local density states of electrons show that both Cu-Sn and Sn-Sn bonding exist in l-Cu{sub 6}Sn{sub 5} alloy. This work suggests that chemical short-range order between unlike atoms and self-coordination between Sn atoms coexists in l-Cu{sub 6}Sn{sub 5} alloy.

  12. Corrosion protection of Mg-5Li alloy with epoxy coatings containing polyaniline

    International Nuclear Information System (INIS)

    Shao Yawei; Huang Hui; Zhang Tao; Meng Guozhe; Wang Fuhui

    2009-01-01

    The protective ability of epoxy coating containing polyaniline (PANI coating) on Mg-5Li alloy in 3.5% NaCl aqueous solution has been studied by means of EIS and electrochemical noise measurements (EN). The results of EN and EIS revealed that the PANI coating protected Mg-5Li alloy from corrosion perfectly. XPS results indicated that the presence of polyaniline changed the chemical structure of the corrosion film on the alloy surface. An analysis of the electrochemical noise data based on stochastic analysis indicated that the corrosion growth probability of Mg-5Li alloy beneath the coating was decreased by the addition of polyaniline.

  13. Phase I study of concurrent radiotherapy with TS-1 and vitamin A (TAR therapy) for head and neck cancer

    International Nuclear Information System (INIS)

    Nakashima, Torahiko; Kuratomi, Yuichiro; Yamamoto, Tomoya; Masuda, Muneyuki; Hirakawa, Naoya; Nakamura, Kazumasa; Shioyama, Yoshiyuki; Umezaki, Toshiro; Komune, Shizuo

    2005-01-01

    The triple combination of 5-fluorouracil (5-FU), vitamin A and radiation (FAR therapy) has been effectively used to treat head and neck cancer. The biological anti-tumor effect of 5-FU depends on the activity of its metabolizing enzyme, dihydropyrimidine dehydrogenase (DPD). TS-1 is a novel oral DPD inhibitory fluoropyrimidine (DIF). To improve the anti-tumor effect of FAR therapy, we have applied TS-1 in place of 5-FU injection in the combination of Vitamin A and radiation (TAR therapy). In this study, we have examined the appropriate duration of TS-1 medication and the clinical efficacy and safety of TAR therapy. TS-1 was administered orally at a dose of 65 mg/m 2 twice a day. Vitamin A (Retinol Palmitate: 50,000 U/day) was administered intra-musculary on each day of radiation. Radiation was given (1.5∼2 Gy/day: 5 days/week) for 30∼40 Gy. The levels were divided according to the length of TS-1 application as follows: level 1, 2 weeks; level 2, 3 weeks; level 4, 4 weeks. Grade 4 toxicity of anorexia was observed in one case of level 3. We decided that level 2 (3 weeks of TS-1 administration) was the appropriate length of TS-1 application. TAR therapy is a useful concurrent chemo-radiotherapy which might improve the response rate and quality of life (QOL) of patients with head and neck squamous cell carcinoma (HNSCC). (author)

  14. High damping Fe-Mn martensitic alloys for engineering applications

    International Nuclear Information System (INIS)

    Baik, S.-H.

    2000-01-01

    Conventional methods for reducing vibration in engineering designs (i.e. by stiffening or detuning) may be undesirable or inadequate in conditions where size or weight must be minimized or where complex vibration spectra exist. Alloys which combine high damping capacity with good mechanical properties can provide attractive technical and economic solutions to problems involving seismic, shock and vibration isolation. To meet these trends, we have developed a new high damping Fe-17%Mn alloy. Also, the alloy has advantages of good mechanical properties and is more economical than any other known damping alloys (a quarter the cost of non-ferrous damping alloy). Thus, the high damping Fe-17%Mn alloy can be widely applied to household appliances, automobiles, industrial facilities and power plant components with its excellent damping capacity (SDC, 30%) and mechanical property (T.S. 700 MPa). It is the purpose of this paper to introduce the characterization of the high damping Fe-17%Mn alloy and the results of retrofit of several such applications. (orig.)

  15. Magnetic properties of three pseudobinary RCo5 alloy systems

    International Nuclear Information System (INIS)

    Heinrich, J.P.

    1976-01-01

    The field dependence of the magnetization was measured in the magnetically easy and hard directions as a function of composition and temperature in the pseudobinary systems Pr/sub x-/ Sm/sub 1-x/Co 5 , Y/sub x/Nd/sub 1-x/Co 5 , and Gd/sub x/Nd/sub 1-x/Co 5 . The saturation magnetization was determined and the anisotropy constants K 1 and K 2 were calculated from hard direction magnetization data. It was assumed that the net magnetization and anisotropy of the alloys could be divided into components representing the cobalt-cobalt, rare earth-cobalt, and rare earth-rare earth interactions. Data on YCo 5 was employed to account for the effect of the first interaction and the remaining two interactions were separated by means of some simple and physically reasonable assumptions. The resulting rare earth-rare earth magnetization and anisotropy data was then tested to see if it could be described by the single ion model. It was concluded that the single ion model did not describe the rare earth-rare earth interaction well in these alloys. This conclusion is in agreement with published results on light rare earth metals and alloys. It was further observed that some of the characteristics of the rare earth-rare earth interaction could be accounted for by assuming the existence of a band-type interaction between the rare earth atoms. All the alloys which contained Nd were found to exhibit low-temperature magnetization anomalies which were thought to be due to the existence of relatively strong basal plane anisotropy in these alloys

  16. TS-1 supported highly dispersed sub-5 nm gold nanoparticles toward direct propylene epoxidation using H2 and O2

    Science.gov (United States)

    Li, Naixu; Chen, Yong; Shen, Quanhao; Yang, Bin; Liu, Ming; Wei, Lingfei; Tian, Wei; Zhou, Jiancheng

    2018-05-01

    We report a simple and efficient method for the preparation of highly dispersed Au nanoparticles (< 5 nm) on TS-1 substrate. The synthesis relies on the use of NaBH4 as a reductant for rapid Au atom generation, as well as PVA as a capping agent confining the particle size and dispersion. The samples were characterized by N2 physisorption, inductively coupled plasma mass spectrometry, power X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, CO pulse chemisorption and thermogravimetric analysis. The size of Au particles can be controlled in the range of 3-5 nm. The supported catalyst shows both good activity and selectivity for propylene oxide (PO) generation from direct propylene epoxidation. An optimal performance with PO formation rate of 102.94 gPO h-1 kg-1cat and selectivity of 84.83% is achieved over 2.0 wt% Au/TS-1 catalyst, which is prepared by controlling PVA/Au3+ mass ratio of 1.5/1 and NaBH4/Au3+ mole ratio of 5/1. After 50 h test at 200 °C, no significant decrement of both catalytic activity and PO selectivity can be observed, indicating the excellent thermally stability of the catalyst. Furthermore, a possible reaction mechanism is described on basis of the previous researches and our experimental results.

  17. Characters of alloy Zr-0.4%Mo-0.5%Fe-0.5%Cr post heat treatment and cold rolling

    International Nuclear Information System (INIS)

    Sungkono; Siti Aidah

    2014-01-01

    Research and development of Zr-Mo-Fe-Cr alloys aimed to obtain PWR fuel element structure material with high burn up. In this study of the Zr-0.4%Mo-0.5%Fe-0.5%Cr alloys was prepared from zirconium sponge, molybdenum, iron and chromium powder. The alloy were heat treated at varying temperatures of 650 and 750 °C and retention time of 1, 1.5 and 2 hours. The objectives of this research was to obtain effect of thickness reduction on the character of Zr-0.4%Mo-0.5%Fe-0.5%Cr alloy. The results of this experiment showed that the microstructures of Zr-0.4%Mo-0.5%Fe-0.5%Cr alloy after heat treatment and cold rolling exhibits that the higher of the thickness reduction has applied on the alloy caused the microstructure to evolve from deformed equiaxial grains into flat bar grains and then into deformed flat bar grains. However, the higher of the temperature and the retention time then the larger grain structures so that the cold rolling causes the shape of the grains structure into a flat bar with a relatively larger size which affects the lower hardness. The Zr-0.4%Mo-0.5%Fe-0.5%Cr alloy after heat treatment (650-750°C; 1.5-2 hours) can undergo cold deformation without cracking at a thickness reduction between 5 to 15%. (author)

  18. Electromagnetic noise spectrum at John TS [transmission station

    International Nuclear Information System (INIS)

    Hatanaka, G.K.

    1992-01-01

    Canadian National (CN) is proposing the development of a commercial office tower on a site directly south of John Transmission Station (TS). CN is concerned about the potential effects of fields originating from John TS and other nearby sources on the operation of sensitive equipment and occupants of the building. Potential equipment and tenants might include data processing equipment and television and radio broadcasting companies. A study was conducted to characterize the severity of the electromagnetic environment at the site in order to address these concerns. Measurements of the electromagnetic spectrum from 100 kHz to 300 MHz were performed from a mobile test facility that features a 5 kW diesel generator and an extendible antenna mast. Peak measurements were made using a selectable measurement time of 0.05 s. It was found that the highest noise levels result from micro-gap discharges under dry weather conditions. The micro-gap discharges are characteristic of defect noise sources associated with substation hardware. At 0.5 MHz the noise levels are typical of median noise levels expected for the International Radio Consultive Committee (CCIR) defined business environment. At 74 MHz the noise levels are more severe than the expected levels for this type of environment. However, levels more representative of the business environment will be achieved by eliminating the micro-gap noise sources attributed to John TS. 6 refs., 11 figs., 2 tabs

  19. The studies of the martensite transformations in a Ti36.5Ni48.5Hf15 alloy

    International Nuclear Information System (INIS)

    Han, S.; Jin, S.; Chinese Academy of Sciences, Beijing; Zou, W.; Zhang, Z.; Yang, D.

    1995-01-01

    In recent years, high temperature shape memory alloy (SMA) has attracted much interest by many groups of researchers. Many kinds of alloys, such as TiNiPd and NiAL alloys were reported to have shape memory effect in high temperatures. But for different kinds of reasons, these alloys were not put to practical use. TiNi alloys have been considered the best shape memory materials until now. Adding a third element whose characteristics are similar to Ti or Ni in TiNi binary alloys can produce a new style SMA, which has been done in many cases. In most circumstances, Ni was substituted and only a few investigations on the TiNi alloys was Ti replaced. But in recent years, many investigators have given more attention to this subject. In 1976, Eckelmeyer showed that Zr was one of the element that can raise the phase transformation temperatures of TiNi alloys. In 1990, Krupp obtained a patent on TiNiZr SMA with high transformation temperatures for TiNi alloys. J.H. Mulder also published his work on TiNiZr alloys in 1992. In their previous work, a new type of high temperature SMA Ti 36.5 Ni 48.5 Hf 15 alloy were investigated in more detail by DSC measurement, TEM and high-resolution observations

  20. Diffusion of hydrogen interstitials in Zr based AB2 and mischmetal based AB5 alloys

    International Nuclear Information System (INIS)

    Mani, N; Ravi, N; Ramaprabhu, S

    2005-01-01

    The Zr based AB 2 alloys ZrMnFe 0.5 Ni 0.5 , ZrMnFe 0.5 Co 0.5 and mischmetal (Mm) based AB 5 alloy MmNi 3.5 Al 0.5 Fe 0.5 Co 0.5 have been prepared and characterized by means of powder x-ray diffractograms. The hydrogen absorption kinetics of these alloys have been studied in the temperature and pressure ranges 450-650 0 C and 10-100 mbar respectively with a maximum H to host alloy formula unit ratio of 0.01, using a pressure reduction technique. The diffusion coefficient of the hydrogen interstitials has been determined from hydrogen absorption kinetics experiments. The dependence of the diffusion coefficient on the alloy content has been discussed. For Mm based MmNi 3.5 Al 0.5 Fe 0.5 Co 0.5 alloy, the diffusion coefficient is about an order of magnitude higher than that of the Zr based alloys

  1. Comparative genomic analysis reveals a novel mitochondrial isoform of human rTS protein and unusual phylogenetic distribution of the rTS gene

    Directory of Open Access Journals (Sweden)

    McGuire John J

    2005-09-01

    Full Text Available Abstract Background The rTS gene (ENOSF1, first identified in Homo sapiens as a gene complementary to the thymidylate synthase (TYMS mRNA, is known to encode two protein isoforms, rTSα and rTSβ. The rTSβ isoform appears to be an enzyme responsible for the synthesis of signaling molecules involved in the down-regulation of thymidylate synthase, but the exact cellular functions of rTS genes are largely unknown. Results Through comparative genomic sequence analysis, we predicted the existence of a novel protein isoform, rTS, which has a 27 residue longer N-terminus by virtue of utilizing an alternative start codon located upstream of the start codon in rTSβ. We observed that a similar extended N-terminus could be predicted in all rTS genes for which genomic sequences are available and the extended regions are conserved from bacteria to human. Therefore, we reasoned that the protein with the extended N-terminus might represent an ancestral form of the rTS protein. Sequence analysis strongly predicts a mitochondrial signal sequence in the extended N-terminal of human rTSγ, which is absent in rTSβ. We confirmed the existence of rTS in human mitochondria experimentally by demonstrating the presence of both rTSγ and rTSβ proteins in mitochondria isolated by subcellular fractionation. In addition, our comprehensive analysis of rTS orthologous sequences reveals an unusual phylogenetic distribution of this gene, which suggests the occurrence of one or more horizontal gene transfer events. Conclusion The presence of two rTS isoforms in mitochondria suggests that the rTS signaling pathway may be active within mitochondria. Our report also presents an example of identifying novel protein isoforms and for improving gene annotation through comparative genomic analysis.

  2. Comparative genomic analysis reveals a novel mitochondrial isoform of human rTS protein and unusual phylogenetic distribution of the rTS gene

    Science.gov (United States)

    Liang, Ping; Nair, Jayakumar R; Song, Lei; McGuire, John J; Dolnick, Bruce J

    2005-01-01

    Background The rTS gene (ENOSF1), first identified in Homo sapiens as a gene complementary to the thymidylate synthase (TYMS) mRNA, is known to encode two protein isoforms, rTSα and rTSβ. The rTSβ isoform appears to be an enzyme responsible for the synthesis of signaling molecules involved in the down-regulation of thymidylate synthase, but the exact cellular functions of rTS genes are largely unknown. Results Through comparative genomic sequence analysis, we predicted the existence of a novel protein isoform, rTS, which has a 27 residue longer N-terminus by virtue of utilizing an alternative start codon located upstream of the start codon in rTSβ. We observed that a similar extended N-terminus could be predicted in all rTS genes for which genomic sequences are available and the extended regions are conserved from bacteria to human. Therefore, we reasoned that the protein with the extended N-terminus might represent an ancestral form of the rTS protein. Sequence analysis strongly predicts a mitochondrial signal sequence in the extended N-terminal of human rTSγ, which is absent in rTSβ. We confirmed the existence of rTS in human mitochondria experimentally by demonstrating the presence of both rTSγ and rTSβ proteins in mitochondria isolated by subcellular fractionation. In addition, our comprehensive analysis of rTS orthologous sequences reveals an unusual phylogenetic distribution of this gene, which suggests the occurrence of one or more horizontal gene transfer events. Conclusion The presence of two rTS isoforms in mitochondria suggests that the rTS signaling pathway may be active within mitochondria. Our report also presents an example of identifying novel protein isoforms and for improving gene annotation through comparative genomic analysis. PMID:16162288

  3. Microstructure and bio-corrosion behaviour of Mg-5Zn-0.5Ca -xSr alloys as potential biodegradable implant materials

    Science.gov (United States)

    Yan, Li; Zhou, Jiaxing; Sun, Zhenzhou; Yang, Meng; Ma, Liqun

    2018-04-01

    Magnesium alloys are widely studied as biomedical implants owing to their biodegradability. In this work, novel Mg-5Zn-0.5Ca-xSr (x = 0, 0.14, 0.36, 0.50, 0.70 wt%) alloys were prepared as biomedical materials. The influence of strontium (Sr) addition on the microstructure, corrosion properties and corrosion morphology of the as-cast Mg-5Zn-0.5Ca-xSr alloys is investigated by a variety of techniques such as scanning electron microscopy, x-ray diffraction, and electrochemical measurements. The Sr-free alloy is composed of three phases, namely, α-Mg, CaMg2 and Ca2Mg6Zn3, while the alloys with the Sr addition consist of α-Mg, CaMg2 and Ca2Mg6Zn3 and Mg17Sr2. Corrosion experiments in Hank’s solution show that the addition of a small amount of Sr can improve the corrosion resistance of the Mg-5Zn-0.5Ca alloy. The corrosion products include Mg(OH)2, Zn(OH)2, Ca(OH)2, and HA (Ca5(PO4)3(OH)). Mg-5Zn-0.5Ca-0.36Sr alloy has the minimum weight loss rate (0.68 mm/a), minimal hydrogen evolution (0.08 ml/cm2/d) and minimum corrosion current density (7.4 μA/cm2), indicating that this alloy shows the best corrosion resistance.

  4. Fabrication of nano ZrO2 dispersed novel W79Ni10Ti5Nb5 alloy by mechanical alloying and pressureless sintering

    Science.gov (United States)

    Sahoo, R. R.; Patra, A.; Karak, S. K.

    2017-02-01

    A high energy planetary ball-mill was employed to synthesize tungsten (W) based alloy with nominal composition of W79Ni10Ti5Nb5(ZrO2)1 (in wt. %) for 20 h with chrome steel as grinding media, toluene as process control agent (PCA) along with compaction at 500 MPa pressure for 5 mins and sintering at 1500°C for 2 h using Ar atmosphere. X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), elemental mapping and Transmission electron microscopy (TEM) was used to study the phase formation, microstructure of both milled powder and consolidated alloy. The crystallite size of W in W79Ni10Ti5Nb5(ZrO2)1 powder was 37 nm, 14.7 nm at 10 h and 20 h of milling respectively and lattice strain enhances to 0.54% at 20 h of milling. The crystallite size reduction is more at 10 h of milling and the rate drop beyond 10 to 20 h of milling. The intense improvement in dislocation density was evident upto 10 h of milling and the rate decreases between 10 to 20 h of milling. Increase in the lattice parameter of tungsten in W79Ni10Ti5Nb5(ZrO2)1 alloy upto 0.09% was observed at 10 h of milling owing to severe stress assisted deformation followed by contraction upto 0.07% at 20 h of milling due to formation of solid solution. The large spherical particles at 0 h of milling transformed to elongated shape at 10 h of milling and finer morphology at 20 h of milling. The average particle size reduced from 100 µm to 4.5 µm with the progress of milling from 0 to 20 h. Formation of fine polycrystallites of W was revealed by bright field TEM analysis and the observed crystallite size from TEM study was well supported by the evaluated crystallite size from XRD. XRD pattern and SEM micrograph of sintered alloy revealed the formation of NbNi, Ni3Ti intermetallic phases. Densification of 91.5% was attained in the 20 h milled and sintered alloy. Mechanical behaviour of the sintered product was evaluated by hardness and wear study. W79Ni10Ti5Nb5(ZrO2)1 alloy

  5. Molecular Cloning of a cDNA Encoding for Taenia solium TATA-Box Binding Protein 1 (TsTBP1) and Study of Its Interactions with the TATA-Box of Actin 5 and Typical 2-Cys Peroxiredoxin Genes.

    Science.gov (United States)

    Rodríguez-Lima, Oscar; García-Gutierrez, Ponciano; Jiménez, Lucía; Zarain-Herzberg, Ángel; Lazzarini, Roberto; Landa, Abraham

    2015-01-01

    TATA-box binding protein (TBP) is an essential regulatory transcription factor for the TATA-box and TATA-box-less gene promoters. We report the cloning and characterization of a full-length cDNA that encodes a Taenia solium TATA-box binding protein 1 (TsTBP1). Deduced amino acid composition from its nucleotide sequence revealed that encodes a protein of 238 residues with a predicted molecular weight of 26.7 kDa, and a theoretical pI of 10.6. The NH2-terminal domain shows no conservation when compared with to pig and human TBP1s. However, it shows high conservation in size and amino acid identity with taeniids TBP1s. In contrast, the TsTBP1 COOH-terminal domain is highly conserved among organisms, and contains the amino acids involved in interactions with the TATA-box, as well as with TFIIA and TFIIB. In silico TsTBP1 modeling reveals that the COOH-terminal domain forms the classical saddle structure of the TBP family, with one α-helix at the end, not present in pig and human. Native TsTBP1 was detected in T. solium cysticerci´s nuclear extract by western blot using rabbit antibodies generated against two synthetic peptides located in the NH2 and COOH-terminal domains of TsTBP1. These antibodies, through immunofluorescence technique, identified the TBP1 in the nucleus of cells that form the bladder wall of cysticerci of Taenia crassiceps, an organism close related to T. solium. Electrophoretic mobility shift assays using nuclear extracts from T. solium cysticerci and antibodies against the NH2-terminal domain of TsTBP1 showed the interaction of native TsTBP1 with the TATA-box present in T. solium actin 5 (pAT5) and 2-Cys peroxiredoxin (Ts2-CysPrx) gene promoters; in contrast, when antibodies against the anti-COOH-terminal domain of TsTBP1 were used, they inhibited the binding of TsTBP1 to the TATA-box of the pAT5 promoter gene.

  6. Crystallization behavior and the thermal properties of Zr63Al7.5Cu17.5Ni10B2 bulk amorphous alloy

    International Nuclear Information System (INIS)

    Jang, J.S.C.; Chang, L.J.; Jiang, Y.T.; Wong, P.W.

    2003-01-01

    The ribbons of amorphous Zr 63 Al 7.5 Cu 17.5 Ni 10 B 2 alloys with 0.1 mm thickness were prepared by melt spinning method. The thermal properties and micro structural development during the annealing of amorphous alloy have been investigated by a combination of differential thermal analysis, differential scanning calorimetry, high-temperature optical microscope, X-ray diffractometry and TEM. The glass transition temperature for the Zr 63 Al 7.5 Cu 17.5 Ni 10 B 2 alloys are measured about 645 K (372 C). This alloy also obtains a large temperature interval ΔT x about 63 K. Meanwhile, the calculated T rg for Zr 63 Al 7.5 Cu 17.5 Ni 10 B 2 alloy presents the value of 0.57. The activation energy of crystallization for the alloy Zr 63 Al 7.5 Cu 17.5 Ni 10 B 2 was about 370± 10 kJ/mole as determined by the Kissinger and Avrami plot, respectively. These values are about 20% higher than the activation energy of crystallization for the Zr 65 Al 7.5 Cu 17.5 Ni 10 alloy (314 kJ/mol.). This implies that the boron additions exhibit the effect of improving the thermal stability for the Zr-based alloy. The average value of the Avrami exponent n were calculated to be 1.75±0.15 for Zr 63 Al 7.5 Cu 17.5 Ni 10 B 2 alloy. This indicates that this alloy presents a crystallization process with decreasing nucleation rate. (orig.)

  7. Shape memory and superelastic behavior of Ti-7.5Nb-4Mo-1Sn alloy

    International Nuclear Information System (INIS)

    Zhang, D.C.; Lin, J.G.; Jiang, W.J.; Ma, M.; Peng, Z.G.

    2011-01-01

    Research highlights: → A Ti-based shape memory alloy, Ti-7.5Nb-4Mo-1Sn, was designed. → The martensitic transformation start temperature of the alloy, M s , is 261 K. → The alloy exhibits good shape memory and superelastic behaviors. → The alloy also shows a good superelastic stability at room temperature. → The Ti-5Mo-7.5Nb-1Sn alloy has a potential application as a biomedical material. -- Abstract: In the present work, a Ti-based shape memory alloy with the composition of Ti-7.5Nb-4Mo-1Sn was designed based on the d-electron orbit theory. The shape memory and superelastic behavior of the alloy were investigated. It is found that the martensitic transformation temperature of the alloy is near 261 K. The tensile and the thermal cycling testing results show that the alloy exhibits the stable shape memory effect and superelasticity at room temperature. The maximum recovered strain of the alloy is 4.83%.

  8. Electrode characteristics of the (Mm)Ni 5-based hydrogen storage alloys

    Energy Technology Data Exchange (ETDEWEB)

    Han, Dong Soo; Choi, Seung Jun; Chang, Min Ho; Choi, Jeon; Park, Choong Nyun [Chonnam National University, Kwangju (Korea, Republic of)

    1995-06-01

    The MmNi-based alloy electrode was studied for use a negative electrode in Ni-MH battery. Alloys with MmNi{sub 5}-{sub x} M{sub x}(M=Co,Al,Mn) composition were synthesized, and their electrode characteristics of activation rate, temperature dependence, electrode capacity and cycle life were investigated. With increasing Al content and decreasing Mn content in the alloys, the discharge capacity increased while the cycle life decreased. As x in MmNi{sub 5}-{sub x} M{sub x} increased from 1.5 to 2.0, decreasing the Ni content, the discharge capacity, the low temperature property and the rate capability decreased. However its cycle life was improved. Increasing Co content resulted in a prolonged cycle life and decrease of high rate discharge capacity. It can be concluded that the most promising alloy in view of discharge capacity and cycle life is MmNi{sub 3}.5 Co{sub 0}.7 Al{sub 0}.5 Mn{sub 0}.3. (author). 9 refs., 9 figs., 1 tab.

  9. Production and mechanical properties of Ti-5Al-2.5Fe-xCu alloys for biomedical applications.

    Science.gov (United States)

    Yamanoglu, Ridvan; Efendi, Erdinc; Kolayli, Fetiye; Uzuner, Huseyin; Daoud, Ismail

    2018-01-30

    In this study, the mechanical, antibacterial properties and cell toxicity response of Ti-5Al2.5Fe alloy with different copper contents were investigated. The alloys were prepared by high-energy ball milling using elemental Ti, Al, Fe, and Cu powders and consolidated by a uniaxial vacuum hot press. Staphylococcus aureus strain ATCC 29213 and Escherichia coli strain ATCC 25922 were used to determine the antibacterial properties of the sintered alloys. The in vitro cytotoxicity of the samples was evaluated with HeLa (ATTC, CCL-2) cells using thiazolyl blue tetrazolium bromide. The mechanical behavior of the samples was determined as a function of hardness and bending tests and analyzed by scanning electron microscopy, energy dispersive x-ray spectroscopy, optical microscopy and x-ray diffraction (XRD). The results showed that the Cu content significantly improved the antibacterial properties. Cu addition prevented the formation of E. coli and S. aureus colonies on the surface of the samples. All samples exhibited very good cell biocompatibility. The alloys with different copper contents showed different mechanical properties, and the results were correlated by microstructural and XRD analyses in detail. Our results showed that Cu has a great effect on the Ti5Al2.5Fe alloy and the alloy is suitable for biomedical applications with enhanced antibacterial activity.

  10. Enhancing pitting corrosion resistance of AlxCrFe1.5MnNi0.5 high-entropy alloys by anodic treatment in sulfuric acid

    International Nuclear Information System (INIS)

    Lee, C.P.; Chen, Y.Y.; Hsu, C.Y.; Yeh, J.W.; Shih, H.C.

    2008-01-01

    High-entropy alloys are a newly developed family of multi-component alloys that comprise various major alloying elements. Each element in the alloy system is present in between 5 and 35 at.%. The crystal structures and physical properties of high-entropy alloys differ completely from those of conventional alloys. The electrochemical impedance spectra (EIS) of the Al x CrFe 1.5 MnNi 0.5 (x = 0, 0.3, 0.5) alloys, obtained in 0.1 M HCl solution, clearly revealed that the corrosion resistance values were determined to increase from 21 to 34 Ωcm 2 as the aluminum content increased from 0 to 0.5 mol, and were markedly lower than that of 304 stainless steel (243 Ωcm 2 ). At passive potential, the corresponding current declined with the anodizing time accounting, causing passivity by the growth of the multi-component anodized film in H 2 SO 4 solution. X-ray photoelectron spectroscopy (XPS) analyses revealed that the surface of anodized Al 0.3 CrFe 1.5 MnNi 0.5 alloy formed aluminum and chromium oxide film which was the main passivating compound on the alloy. This anodic treatment increased the corrosion resistance in the EIS measurements of the CrFe 1.5 MnNi 0.5 and Al 0.3 CrFe 1.5 MnNi 0.5 alloys by two orders of magnitude. Accordingly, the anodic treatment of the Al x CrFe 1.5 MnNi 0.5 alloys optimized their surface structures and minimized their susceptibility to pitting corrosion

  11. Effect of heat treatment on the microstructures and mechanical properties of Al-5.5Zn-2.5Mg alloy

    Energy Technology Data Exchange (ETDEWEB)

    Acer, Emine [Erciyes University, Institute of Science, Department of Physics, Kayseri (Turkey); Çadırlı, Emin [Niğde University, Faculty of Arts and Sciences, Department of Physics, Niğde (Turkey); Erol, Harun [Erciyes University, Institute of Science, Department of Physics, Kayseri (Turkey); Karatekin University Faculty of Arts and Sciences, Department of Physics, Çankırı (Turkey); Kırındı, Talip [Kırıkkale University, Faculty of Education, Department of Elementary Education, Kırıkkale (Turkey); Gündüz, Mehmet, E-mail: gunduz@erciyes.edu.tr [Erciyes University, Faculty of Science, Department of Physics, Kayseri (Turkey)

    2016-04-26

    The Al-5.5 Zn-2.5 Mg (wt%) ternary alloy was prepared using a vacuum melting furnace and a casting furnace. Microstructural and mechanical properties of the alloy were investigated as-cast and under heat-treated conditions. To investigate the effect of heat treatment, numerous designed Al-5.5 Zn-2.5 Mg samples were homogenized under different conditions and then aged under different regimes. The effects of heat treatment on the microstructures were examined by OM, SEM, and TEM, and mechanical properties of the Al-Zn-Mg alloy were studied. A good combination of high microhardness and reasonable tensile strength were obtained by successive and suitable heat treatments. After aging for 24 h at 150°C, the peak microhardnes and tensile strength values were achieved as 157 MPa and 188.8 MPa, respectively. The microscopic fracture surfaces of the aged samples under different homogenization and aging conditions were observed using scanning electron microscopy. Fractographic analysis of the tensile fracture surfaces shows that the type of fracture changed significantly from ductile to more ductile depending on the aging regime.

  12. Structure and Mechanical Properties of As-Cast Ti–5Sn–xMo Alloys

    Science.gov (United States)

    Yu, Hsing-Ning; Hsu, Hsueh-Chuan; Wu, Shih-Ching; Hsu, Shih-Kuang; Ho, Wen-Fu

    2017-01-01

    Ti–5Sn–xMo (x = 0, 1, 3, 5, 7.5, 10, 12.5, 15, 17.5, and 20 wt %) alloys were designed and prepared for application as implant materials with superior mechanical properties. The results demonstrated that the crystal structure and mechanical properties of Ti–5Sn–xMo alloys are highly affected by their Mo content. The as-cast microstructures of Ti–5Sn–xMo alloys transformed in the sequence of phases α′ → α″ → β, and the morphologies of the alloys changed from a lath structure to an equiaxed structure as the Mo content increased. The α″-phase Ti–5Sn–7.5Mo (80 GPa) and β-phase Ti–5Sn–10Mo (85 GPa) exhibited relatively low elastic moduli and had excellent elastic recovery angles of 27.4° and 37.8°, respectively. Furthermore, they exhibited high ductility and moderate strength, as evaluated using the three-point bending test. Search for a more suitable implant material by this study, Ti–5Sn–xMo alloys with 7.5 and 10 wt % Mo appear to be promising candidates because they demonstrate the optimal combined properties of microhardness, ductility, elastic modulus, and elastic recovery capability. PMID:28772820

  13. Influences of Gd on the microstructure and strength of Mg-4.5Zn alloy

    International Nuclear Information System (INIS)

    Yang Jie; Xiao Wenlong; Wang Lidong; Wu Yaoming; Wang Limin; Zhang Hongjie

    2008-01-01

    Microstructure and mechanical properties of peak-aged Mg-4.5Zn-xGd (x 0, 0.5, 1.0 and 1.5 wt.%) alloys have been investigated. The results showed that the grain size of the alloys was refined gradually with increasing Gd. Mg 5 Gd and Mg 3 Gd 2 Zn 3 phases were found in the Gd-containing alloys. The strengths were greatly improved with Gd additions, and the highest strength level was obtained in the Mg-4.5Zn-1.5Gd alloy, in which the ultimate tensile strength and yield strength were 231 MPa and 113 MPa, respectively. Through comparing with the Mg-4.5Zn alloy, the increments of ultimate tensile strength and yield strength were 22 MPa and 56 MPa, respectively. The improved strength was mainly correlated to the grain refining effect, the strengthening effect of the Mg 5 Gd and Mg 3 Gd 2 Zn 3 phases and also the hardening effect of the solutioned Gd atoms

  14. Mechanical alloying of Cu-xCr (x = 3, 5 and 8 wt.%) alloys

    International Nuclear Information System (INIS)

    Aguilar, C.; Ordonez, S.; Guzman, D.; Rojas, P.A.

    2010-01-01

    This work studies the structural evolution of Cu-xCr (x = 3, 5 and 8 wt.%) alloys processed by mechanical alloying using X-ray diffraction profiles, scanning microscopy and microhardness analysis. X-ray diffraction analysis using the modified Williamson-Hall and Warren-Averbach methods were used to determine structural properties, such as crystallite size, stacking fault probability and energy, dislocation density, lattice parameters and crystallite size distribution of metallic powder as a function of Cr amount and milling time. Lattice defects increase the Gibbs free energy and the Gibbs free energy curves shift upward, therefore the solubility limit change.

  15. Move of Purchasing Offices TS – AB* – AT*

    CERN Multimedia

    FI Department

    2008-01-01

    The TS – AB* - AT* Purchasing Offices and the Purchasing Pool have moved to Building 5 – 2nd and *3rd floors. The phone and fax numbers are unchanged. We apologize for any inconvenience caused by the move. Thank you for your understanding. Finance Department – Purchasing Service.

  16. The microstructure of Mg–4Zn–2Al–0.5Ca aged alloy

    International Nuclear Information System (INIS)

    Lin Xiaoping; Dong Yun; Ye Jie; Song Boyang

    2012-01-01

    Highlights: ► The microstructure of Mg–4Zn–2Al–0.5Ca aged alloy was investigated by TEM. ► Edge dislocations, ordered zones and moiré fringes are found in alloy. ► Ca can improve the thermal stability of precipitates. - Abstract: In this study, we investigated the microstructure of a new Mg–4Zn–2Al–0.5Ca aged alloy with TEM and HRTEM. The age hardening process of Mg–4Zn–2Al–0.5Ca alloy aged at 120 °C or 160 °C follows a similar pattern: a period of fluctuation of hardness present before the alloy reaches its maximum hardness. The atomic arrangement is different in different areas of the microstructure possibly due to the difference of the segregated degree of the solute atoms in the alloy. The microstructure of alloy aged at 120 °C for 230 h consists of cellular textures, ordered zone, elongated precipitates and disc-like precipitates, while the microstructure of the alloy aged at 160 °C for 32 h consists of edge dislocations, ordered zones and moiré fringe. No MgZn precipitates are found in the peak aged microstructures of alloys aged at 120 °C and 160 °C. It is reasonable to believe that Ca is a particularly effective trace addition in improving the thermal stability of precipitation in Mg–4Zn–2Al alloy aged at 120 °C and 160 °C.

  17. Movable Thomson scattering system based on optical fiber (TS-probe)

    International Nuclear Information System (INIS)

    Narihara, K.; Hayashi, H.

    2009-01-01

    This paper proposes a movable compact Thomson scattering (TS) system based on optical fibers (TS-probe). A TS-probe consists of a probe head, optical fiber, a laser-diode, polychromators and lock-in amplifiers. A laser beam optics and light collection optics are mounted rigidly on a probe head with a fixed scattering position. Laser light and scattered light are transmitted by flexible optical fibers, enabling us to move the TS-prove head freely during plasma discharge. The light signal scattered from an amplitude-modulated laser is detected against the plasma light based on the principle of the lock-in amplifier. With a modulated laser power of 300W, the scattered signal from a sheet plasma of 15 mm depth and n e -10 19 m -3 will be measured with 10% accuracy by setting the integrating time to 0.1 s. The TS-probe head is like a 1/20 model of the currently operating LHD-TS. (author)

  18. Effects of scandium and zirconium combination alloying on as-cast microstructure and mechanical properties of Al-4Cu-1.5Mg alloy

    Directory of Open Access Journals (Sweden)

    Xiang Qingchun

    2011-02-01

    Full Text Available The influences of minor scandium and zirconium combination alloying on the as-cast microstructure and mechanical properties of Al-4Cu-1.5Mg alloy have been experimentally investigated. The experimental results show that when the minor elements of scandium and zirconium are simultaneously added into the Al-4Cu-1.5Mg alloy, the as-cast microstructure of the alloy is effectively modified and the grains of the alloy are greatly refined. The coarse dendrites in the microstructure of the alloy without Sc and Zr additions are refined to the uniform and fine equiaxed grains. As the additions of Sc and Zr are 0.4% and 0.2%, respectively, the tensile strength, yield strength and elongation of the alloy are relatively better, which are 275.0 MPa, 176.0 MPa and 8.0% respectively. The tensile strength is increased by 55.3%, and the elongation is nearly raised three times, compared with those of the alloy without Sc and Zr additions.

  19. Development of advanced NI alloy substrates with high percentage of cube texture for biaxially oriented YBCO coated tapes

    International Nuclear Information System (INIS)

    HongLi Suo; Yue Zhao; MangMang Gao; Min Liu; YongHua Zhu; PeiKuo Gao; JianHong Wang; Lin Ma; RuiFen Fan; Yuan Ji; MeiLing Zhou

    2009-01-01

    The improvement of mechanical and magnetic properties of textured NiW alloy tapes is considered as a main challenge for RABiTS substrates in coated conductors. The present paper summaries the successful development of several textured NiW substrate tapes with high W contents as well as advanced NiW composite substrates with high strength and reduced magnetization in our previous works. The fabrication process of these tapes and their characterizations are presented in detail. The results on the texture quality and mechanical properties as well as on the magnetic behaviour of these tapes are promising in view of the future application in coated conductor and constitute an alternative to the well known Ni5W alloy substrates. (au)

  20. Influence of 45S5 Bioglass addition on microstructure and properties of ultrafine grained (Mg-4Y-5.5Dy-0.5Zr) alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, K., E-mail: kamil.kowalski@put.poznan.pl [Institute of Materials Science and Engineering, Poznan University of Technology, Jana Pawla II 24, 61-138 Poznan (Poland); Jurczyk, M.U. [Division of Mother’s and Child’s Health, Poznan University of Medical Sciences, Polna 33, 60-535 Poznan (Poland); Wirstlein, P.K. [Department of Gynecology and Obstetrics, Division of Reproduction, Poznan University of Medical Sciences, Polna 33, 60-535 Poznan (Poland); Jakubowicz, J.; Jurczyk, M. [Institute of Materials Science and Engineering, Poznan University of Technology, Jana Pawla II 24, 61-138 Poznan (Poland)

    2017-05-15

    Highlights: • Ultrafine grained composites were formed by consolidating mechanically alloyed powders. • Mechanical properties were sensitive to the content of 45S5 Bioglass in Mg-4Y-5.5Dy-0.5Zr alloy. • Fluoride treated composites displayed superior corrosion resistance in Ringer solution. • Composites modified with MgF{sub 2} have a higher degree of biocompatibility in comparison with the unmodified reference material. - Abstract: Bulk samples of an ultrafine grained (Mg-4Y-5.5Dy-0.5Zr)-x wt% 45S5 Bioglass (x = 0, 5) and (Mg-4Y-5.5Dy-0.5Zr)-5 wt% 45S5 Bioglass-1 wt% Ag composites have been synthesized by consolidating mechanically alloyed powders. The influence of the chemical composition on the microstructure, mechanical properties and corrosion behavior of bulk composites were studied. The sintering of (Mg-4Y-5.5Dy-0.5Zr)-5 wt% 45S5 Bioglass powders led to the formation of a bulk composite with grain size of approx. 95 nm. The corrosion behavior of Mg-based composites before and after hydrofluoric acid treatment was also investigated. The ultrafine grained (Mg-4Y-5.5Dy-0.5Zr)-5 wt% 45S5 Bioglass composite was more corrosion resistant than the bulk Mg-4Y-5.5Dy-0.5Zr alloy after HF treatment. The in vitro biocompatibility of synthesized composites was evaluated and compared with microcrystalline magnesium. Magnesium, (Mg-4Y-5.5Dy-0.5Zr)-5 wt% 45S5 Bioglass and (Mg-4Y-5.5Dy-0.5Zr)-5 wt% 45S5 Bioglass-1 wt% Ag composites modified with MgF{sub 2} have a higher degree of biocompatibility in comparison with the unmodified reference material.

  1. The TS 600: automatic control system for eddy currents

    International Nuclear Information System (INIS)

    Poulet, J.P.

    1986-10-01

    In the scope of fabrication and in service inspection of the PWR steam generator tubing bendle, FRAMATOME developed an automatic Eddy Current testing system: TS600. Based on a mini-computer, TS600 allows to digitize, to store and to process data in various ways, so it is possible to perform several kinds of inspection: conventional inservice inspection, roll area profilometry...... TS600 can also be used to develop new methods of examination [fr

  2. Scandium effect on mechanical properties of Al-6.5 % Mg alloy

    International Nuclear Information System (INIS)

    Drits, M.E.; Toropova, L.S.; Bykov, Yu.G.

    1982-01-01

    Quantitative evaluation of influence of small scandium additions (up to 0.5 wt%) on properties of Al-6.5% Mg binary alloy are carried out depending on test temperature in the range of -196 to 310 deg C. Alloys were tested on ''Instron'' machine at 1.3x10 - 3 s - 1 strain rate. Scandium additions are shown to increase plasticity at -196 deg C. Yield strength also increases with introduction of 0.2% Sc if deformation temperature does not exceed 250 deg C. The growth of ultimate strength is less significant. Elevated strength properties of alloys with scandium additions can be explained by a fine-grained structure

  3. Digastric Muscle Phenotypes of the Ts65Dn Mouse Model of Down Syndrome.

    Directory of Open Access Journals (Sweden)

    Tiffany J Glass

    Full Text Available Down syndrome is frequently associated with complex difficulties in oromotor development, feeding, and swallowing. However, the muscle phenotypes underlying these deficits are unclear. We tested the hypotheses that the Ts65Dn mouse model of DS has significantly altered myosin heavy chain (MyHC isoform profiles of the muscles involved in feeding and swallowing, as well as reductions in the speed of these movements during behavioral assays. SDS-PAGE, immunofluorescence, and qRT-PCR were used to assess MyHC isoform expression in pertinent muscles, and functional feeding and swallowing performance were quantified through videofluoroscopy and mastication assays. We found that both the anterior digastric (ADG and posterior digastric (PDG muscles in 11-day old and 5-6 week old Ts65Dn groups showed significantly lower MyHC 2b protein levels than in age-matched euploid control groups. In videofluoroscopic and videotape assays used to quantify swallowing and mastication performance, 5-6 week old Ts65Dn and euploid controls showed similar swallow rates, inter-swallow intervals, and mastication rates. In analysis of adults, 10-11 week old Ts65Dn mice revealed significantly less MyHC 2b mRNA expression in the posterior digastric, but not the anterior digastric muscle as compared with euploid controls. Analysis of MyHC 2b protein levels across an adult age range (10-53 weeks of age revealed lower levels of MyHC 2b protein in the PDG of Ts65Dn than in euploids, but similar levels of MyHC 2b in the ADG. Cumulatively, these results indicate biochemical differences in some, but not all, muscles involved in swallowing and jaw movement in Ts65Dn mice that manifest early in post-natal development, and persist into adulthood. These findings suggest potential utility of this model for future investigations of the mechanisms of oromotor difficulties associated with Down syndrome.

  4. Influence of thermo hydrogen treatment on microstructure and mechanical properties of Ti-5Al-2.5Sn ELI alloy

    Directory of Open Access Journals (Sweden)

    Ya-fei Ren

    2017-01-01

    Full Text Available Thermo hydrogen treatment (THT of titanium is a process in which hydrogen is used as a temporary alloying element in titanium alloys. It is an attractive approach for controlling the microstructure and thereby improving the final mechanical properties. In the present study, the microstructure of the original (non-hydrogenated sample has only α phase and the grains is coarse with an average size of ~ 650 μm. While the grain size of thermo hydrogen treated Ti-5Al-2.5Sn ELI alloy became finer and the mechanical properties were improved significantly. When the hydrogen content of the hydrogenated Ti-5Al-2.5Sn ELI alloy is 0.321wt.%, β phase and δ titanium hydride appear. Also the average grain size decreases to 450 μm. When the hydrogen content is 0.515wt.%, the grain size decreases to 220 μm. The mechanical properties were tested after dehydrogenation, and the mechanical properties improved significantly compared to the unhydrogenated specimens. The tensile strength of the Ti-5Al-2.5Sn ELI alloy improved by 17.7% when the hydrogen content increased to 0.920wt.%, at the same time the percentage reduction of area (Z increased by 33% and the impact toughness increased by 37%.

  5. The effect of molybdenum on the corrosion behaviour of the high-entropy alloys Co1.5CrFeNi1.5Ti0.5Mox in aqueous environments

    International Nuclear Information System (INIS)

    Chou, Y.L.; Yeh, J.W.; Shih, H.C.

    2010-01-01

    The purpose of this study is to investigate the electrochemical properties of the Co 1.5 CrFeNi 1.5 Ti 0.5 Mo x high-entropy alloys in three aqueous environments which simulate acidic, marine, and basic environments at ambient temperature (∼25 o C). The potentiodynamic polarisation curves of the Co 1.5 CrFeNi 1.5 Ti 0.5 Mo x alloys, obtained in aqueous solutions of H 2 SO 4 and NaOH, clearly revealed that the corrosion resistance of the Mo-free alloy was superior to that of the Mo-containing alloys. On the other hand, the lack of hysteresis in cyclic polarisation tests and SEM micrographs confirmed that the Mo-containing alloys are not susceptible to pitting corrosion in NaCl solution.

  6. Bimodal microstructure and deformation of cryomilled bulk nanocrystalline Al-7.5Mg alloy

    International Nuclear Information System (INIS)

    Lee, Z.; Witkin, D.B.; Radmilovic, V.; Lavernia, E.J.; Nutt, S.R.

    2005-01-01

    The microstructure, mechanical properties and deformation response of bimodal structured nanocrystalline Al-7.5Mg alloy were investigated. Grain refinement was achieved by cryomilling of atomized Al-7.5Mg powders, and then cryomilled nanocrystalline powders blended with 15 and 30% unmilled coarse-grained powders were consolidated by hot isostatic pressing followed by extrusion to produce bulk nanocrystalline alloys. Bimodal bulk nanocrystalline Al-7.5Mg alloys, which were comprised of nanocrystalline grains separated by coarse-grain regions, show balanced mechanical properties of enhanced yield and ultimate strength and reasonable ductility and toughness compared to comparable conventional alloys and nanocrystalline metals. The investigation of tensile and hardness test suggests unusual deformation mechanisms and interactions between ductile coarse-grain bands and nanocrystalline regions

  7. Stress corrosion of the alloy U-7.5 Nb-2.5 Zr

    International Nuclear Information System (INIS)

    Lepoutre, D.; Nomine, A.M.; Miannay, D.

    1983-09-01

    Oxide formed on U-7.5 Nb-2.5 Zr at room temperature during stress corrosion cracking in oxygen is identical to the natural oxide of the alloy. It is formed by UO 2 with Nb and Zr and is associated with an increased Nb content at the interface. This oxide would be responsible for cracking [fr

  8. Uranium-molybdenum alloys containing 0,5 to 3 per cent by weight of molybdenum

    International Nuclear Information System (INIS)

    Lehmann, J.

    1959-01-01

    The following properties have been determined in the new cast state of uranium alloys containing 0.5-1-1.8-2 and 3.5 per cent of molybdenum: micro-graphical aspect, crystalline structure, thermal expansion, the mechanical characteristics, behaviour when subjected to cyclic temperature variations, and heat treatment. The transformation curves have been established for continuous cooling at rates varying between 2.5 and 200 deg. C per minute, using a dilatation method for the alloys containing 1.0, 2.0 and 3.0 per cent Mo. T.T.T. curves have been traced for 0.5 and 1.0 per cent Mo alloys and the Ms points determined for alloys containing 2.0 and 3.0 par cent Mo. In this way it has been possible to show the different results of transformation, brought about either by nucleation and diffusion or by shear - the alloy containing 1 per cent Mo, give two martensites α' and α'' and the alloys containing 2 and 3 per cent Mo give one martensite with a band structure. (author) [fr

  9. Microstructure and grain refining performance of melt-spun Al-5Ti-1B master alloy

    International Nuclear Information System (INIS)

    Zhang Zhonghua; Bian Xiufang; Wang Yan; Liu Xiangfa

    2003-01-01

    In the present work, the microstructure and grain refining performance of the melt-spun Al-5Ti-1B (wt%) master alloy have been investigated, using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and grain refining tests. It has been found that the microstructure of the melt-spun Al-5Ti-1B master alloy is mainly composed of two phases: metastable, supersaturated α-Al solid solution and uniformly dispersed TiB 2 particles, quite different from that of the rod-like alloy consisting of three phases: α-Al, blocky TiAl 3 , and clusters of TiB 2 particles. Quenching temperatures and wheel speeds (cooling rates), however, have no obvious effect on the microstructure of the melt-spun Al-5Ti-1B alloy. Grain refining tests show that rapid solidification has a significant effect on the grain refining performance of Al-5Ti-1B alloy and leads to the great increase of nucleation rate of the alloy. Nevertheless, the melt-spun Al-5Ti-1B master alloy prepared at different wheel speeds and quenching temperatures possesses the similar grain refining performance. The reasons for the microstructure formation and the improvement of the grain refining performance of the melt-spun Al-5Ti-1B master alloy have been also discussed

  10. Mössbauer study of alloy Fe{sub 67.5}Ni{sub 32.5}, prepared by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Benitez Rodríguez, Edson Daniel, E-mail: edbenitezr@ut.edu.co; Bustos Rodríguez, Humberto; Oyola Lozano, Dagoberto; Rojas Martínez, Yebrail Antonio [University of Tolima, Department of Physics (Colombia); Pérez Alcázar, German Antonio [University of Valle, Department of Physics (Colombia)

    2015-06-15

    We present the study of effect of the particle size on the structural and magnetic properties of the Fe{sub 67.5}Ni{sub 32.5} alloy, prepared by mechanical alloying (MA). After milling the powders during 10 hours they were separated by sieving using different meshes. The refinement of the X-ray patterns showed the coexistence of the BCC (Body Centered Cubic) and the FCC (Face Centered Cubic) phases in all samples with lattice parameters and crystallite sizes independent of the mean particle size. However, big particles presented bigger volumetric fraction of BCC grains. The Mossbauer spectra were fitted with a broad sextet corresponding to the ferromagnetic BCC phase, a hyperfine magnetic field distribution and a broad singlet which correspond to the ferromagnetic and paramagnetic sites of the FCC phase, respectively. Hysteresis loops showed a magnetically, soft behavior for all the samples, however, the saturation magnetization values are smaller for the original powder and for the powders with small, mean, particle size due to the dipolar magnetic interaction and the smaller mean magnetic moment, respectively. These effects were proved by Henkel plots that were made to the samples.

  11. The Mechanical Properties of AlSi17Cu5 Cast Alloy after Overheating and Modification of CuP Master Alloy

    Directory of Open Access Journals (Sweden)

    Piątkowski J.

    2013-09-01

    Full Text Available The paper presents the results of studies on the effect of the AlSi17Cu5 alloy overheating to atemperature of 920°C and modification with phosphorus (CuP10 on the resultingmechanical (HB, Rm, R0.2 and plastic (A5 and Z properties. It has been shown that, so-called, "timethermal treatment" (TTT of an alloy in the liquid state, consisting inoverheating the metal to about 250°C above Tliq,holding at this temperature by 30 minutes improvesthe mechanical properties. It has also been found that overheating of alloy above Tliq.enhances the process of modification, resulting in the formation of fine-grain structure. The primary silicon crystals uniformly distributed in the eutectic and characteristics ofthe α(Al solution supersaturated with alloying elements present in the starting alloy composition (Cu, Fe provide not only an increase of strength at ambient temperature but also at elevated temperature (250°C.

  12. Rare earth conversion coating on Mg-8.5Li alloys

    International Nuclear Information System (INIS)

    Yang Xiaowei; Wang Guixiang; Dong Guojun; Gong Fan; Zhang Milin

    2009-01-01

    The conversion coating formed by immersion in a solution containing rare earth salt on Mg-8.5Li alloy was studied and the corrosion resistance was evaluated as well. The surface morphology was observed by scanning electron microscopy (SEM), and the chemical composition was characterized by X-ray photoelectron spectroscopy (XPS). The corrosion behaviors of Mg-8.5Li alloy and conversion coating were assessed by means of potentiodynamic polarization curves, electrochemical impedance spectra (EIS) and immersion tests. The experimental results indicated that the coating with cracked morphology was homogeneous. It was mainly composed of La 2 O 3 , CeO 2 , Mn 2 O 3 and MnO 2 as detected by XPS. The results of electrochemical measurements and immersion tests revealed that the rare earth conversion coating possessed better corrosion resistance than bare alloy and chromate conversion coating.

  13. Grain refining of Al-4.5Cu alloy by adding an Al-30TiC master alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Kazuaki [Toyota Motor Corp., Shizuoka (Japan). Materials Engineering Div. III; Flemings, M.C. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering

    1998-06-01

    A particulate Al-30 wt pct TiC composite was employed as a grain refiner for the Al-4.5 wt pct Cu alloy. The composite contains submicron TiC particles. The addition of the TiC grain refiner to the metal alloy in the amount of 0.1 Ti wt pct effected a remarkable reduction in the average grain size in Al-4.5 wt pct Cu alloy castings. With the content of over 0.2 Ti wt pct, the grain refiner maintained its refining effectiveness even after a 3,600-second holding time at 973 K. The TiC particles in the resulting castings were free of interfacial phases. It is concluded that the TiC are the nucleating agents and that they are resistant to the fading effect encountered with most grain refiners.

  14. Synthesis of mesoporous TS-1 using a hybrid SiO2–TiO2 xerogel for catalytic oxidative desulfurization

    International Nuclear Information System (INIS)

    Yang, Seung-Tae; Jeong, Kwang-Eun; Jeong, Soon-Yong; Ahn, Wha-Seung

    2012-01-01

    Graphical abstract: Display Omitted Highlights: ► Meso-TS-1 catalyst was synthesized using a SiO 2 –TiO 2 xerogel with an organosilane precursor. ► Hierarchical pore structure was confirmed by characterization of the materials. ► Catalytic activity was tested using oxidative desulfurization of the model sulfur compounds. ► Meso-TS-1 demonstrated significantly improved catalytic activity than TS-1. -- Abstract: Mesoporous TS-1 (M-TS-1) was synthesized using a hybrid SiO 2 –TiO 2 xerogel combined with an organosilane precursor. Prepared samples were characterized by XRD, UV–vis spectroscopy, SEM, and N 2 adsorption–desorption measurement. M-TS-1, prepared in 2 days, showed high crystallinity and the best textural properties among the samples. The N 2 adsorption–desorption isotherms of M-TS-1 exhibited a hysteresis loop at pressure higher than P/P 0 = 0.4, clearly indicating the existence of mesopores. M-TS-1 has significantly larger mesopore volume (0.48 cm 3 /g) than that of conventional TS-1 (0.07 cm 3 /g), and showed a narrow peak centered at ca. 6.3 nm. In the oxidative desulfurization reaction, M-TS-1 was more active than conventional TS-1 at the same Ti-loading; M-TS-1 produced a dibenzothiophene (DBT) conversion of 96%, whereas conventional TS-1 produced a final DBT conversion of 5.6% after a reaction time of 180 min. Oxidative desulfurization over TS-1 was influenced both by electron density and steric hindrance in the sulfur compounds tested.

  15. Mechanical and electrochemical characterization of Ti-12Mo-5Zr alloy for biomedical application

    International Nuclear Information System (INIS)

    Zhao Changli; Zhang Xiaonong; Cao Peng

    2011-01-01

    Highlights: → A new β metastable titanium alloy with composition of Ti-12Mo-5Zr that comprised of non-toxic elements Mo and Zr has been developed. → The elastic modulus of the Ti-12Mo-5Zr alloy is as low as 64 GPa, which is much lower than those of pure Ti and Ti-6Al-4V alloy. → The Ti-12Mo-5Zr alloy has moderate strength and much higher microhardness as compared with Ti-6Al-4V, which showing better mechanical biocompatibility. → The corrosion resistance is much higher than that of Ti-6Al-4V in a simulated body fluid (Hank's solution). - Abstract: We have fabricated a new β metastable titanium alloy that comprised of non-toxic elements Mo and Zr. Ingot with composition of Ti-12Mo-5Zr is prepared by melting pure metals in a vacuum non-consumable arc melting furnace. The alloy is then homogenized and solution treated under different temperature. The alloy is characterized by optical microscopy, X-ray diffraction, tensile tests and found to have an acicular martensitic α'' + β structure and dominant β phase for the 1053 K and 1133 K solution treatment samples, respectively. The elastic modulus of the latter is about 64 GPa, which is much lower than those of pure Ti and Ti-6Al-4V alloy. In addition, it had moderate strength and much higher microhardness as compared with Ti-6Al-4V alloy. The results show better mechanical biocompatibility of this alloy, which will avoid stress shielding and thus prevent bone resorption in orthopedic implants applications. As long-term stability in biological environment is required, we have also evaluated the electrochemical behavior in a simulated body fluid (Hank's solution). Potentiodynamic polarization curves exhibits that the 1133 K solution treatment Ti-12Mo-5Zr sample has better corrosion properties than Ti-6Al-4V and is comparable to the pure titanium. The good corrosion resistance combined with better mechanical biocompatibility makes the Ti-12Mo-5Zr alloy suitable for use as orthopedic implants.

  16. Crack propagation behavior of Ti-5Ta alloy in boiling nitric acid solution

    International Nuclear Information System (INIS)

    Motooka, Takafumi; Kiuchi, Kiyoshi

    1999-05-01

    The crack propagation behavior of Ti-5Ta alloy both in boiling nitric acid solution and in air at room temperature has been investigated. The crack growth rate of Ti-5Ta alloy was measured as a function of the stress intensity factor range. After the tests, the fracture surface morphology was observed by a scanning electron microscope and the crystallographic orientation was examined by X-ray diffraction analysis. Difference in the crack growth behavior was not observed in both environments. The crack growth rate in boiling nitric acid solution was similar to that in air at room temperature. Moreover, the crystallographic orientation of Ti-5Ta alloy had little effect on the fatigue behavior, because this alloy does not have the susceptibility to SCC in nitric acid solution. (author)

  17. Evaluation of Cracking Causes of AlSi5Cu3 Alloy Castings

    Directory of Open Access Journals (Sweden)

    Eperješi Š.

    2014-10-01

    Full Text Available Recently, the castings made from aluminum-silicon alloys by pressure die casting are increasingly used in the automotive industry. In practice, on these castings are high demands, mainly demands on quality of their structure, operating life and safety ensuring of their utilization. The AlSi5Cu3 alloy castings are widely used for production of car components. After the prescribed tests, the cracks and low mechanical properties have been identified for several castings of this alloy, which were produced by low pressure casting into a metal mould and subsequent they were heat treated. Therefore, analyses of the castings were realized to determine the causes of these defects. Evaluation of structure of the AlSi5Cu3 alloy and causes of failure were the subjects of investigation presented in this article.

  18. Phase transformation and microstructure evolution of the deformed Ti-30Zr-5Nb shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Wentao, E-mail: wtqu@xsyu.edu.cn [School of Mechanical Engineering, Xi' an Shiyou University, Xi' an 710065 (China); Sun, Xuguang; Yuan, Bifei [School of Mechanical Engineering, Xi' an Shiyou University, Xi' an 710065 (China); Xiong, Chengyang [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Li, Yan, E-mail: liyan@buaa.edu.cn [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Nie, Yongsheng [Lanzhou Seemine SMA Co. Ltd., Lanzhou 730010 (China)

    2017-04-15

    The phase transformation and microstructures of the deformed Ti-30Zr-5Nb shape memory alloy were investigated. The X-ray diffraction measurements indicated that the Ti-30Zr-5Nb alloy was composed of a single orthorhombic α″-martensite phase. The alloy exhibited one yielding behavior in the tensile test, with a critical stress of ~ 600 MPa and a tensile strain of approximately 15%. A shape memory recovery accompanied by a permanent strain was exhibited in the deformed alloys when heated at 873 K. The permanent strain increased with increasing pre-strain. The microstructure evolution of the deformed alloy was investigated by transmission electron microscopy. The results showed that the martensite reorientation occurred and the dislocations were generated during deformation. The alloy displayed a reversible martensite transformation start temperature as high as 763 K. However, no strain-induced martensite stabilization was found in the deformed alloy with different pre-strain levels, potentially because the large chemical energy of the Ti-30Zr-5Nb alloy depressed the effects of the elastic energy and the dissipative energy. - Highlights: • Ti-30Zr-5Nb alloy is composed of single orthorhombic α″-martensite phase with M{sub s} of 721 K. • No martensite stabilization has been found in Ti-30Zr-5Nb alloy with different pre-strain. • Ti-30Zr-5Nb shows the maximum shape memory effect of 2.75% with a pre-strain of 8%.

  19. Summary on out-of-pile and in-pile properties of M5 alloy

    International Nuclear Information System (INIS)

    Zhao Wenjin

    2001-01-01

    The out-of-pile and in-pile corrosion, mechanical properties, microstructure,hydrogen absorption, creep and growth resistances of M5 alloy using as PWR fuel rod cladding materials developed by FRAMATOME in France has been summarized with reference to the literatures. The results obtained from in-pile irradiation tests show that the corrosion and hydrogen absorption resistances, creep and irradiation growth resistances of M5 alloy cladding are superior to that of the optimized Zircaloy-4. It could be estimated that the M5 alloy enables rod burnups close to 65GWd/tU to be reached

  20. Analysis of Microstructure and Sliding Wear Behavior of Co1.5CrFeNi1.5Ti0.5 High-Entropy Alloy

    Science.gov (United States)

    Lentzaris, K.; Poulia, A.; Georgatis, E.; Lekatou, A. G.; Karantzalis, A. E.

    2018-04-01

    Α Co1.5CrFeNi1.5Ti0.5 high-entropy alloy (HEA) of the well-known family of CoCrFeNiTi has been designed using empirical parameters. The aim of this design was the production of a HEA with fcc structure that gives ductile behavior and also high strength because of the solid solution effect. The VEC calculations (8.1) supported the fcc structure while the δ factor calculations (4.97) not being out of the limit values, advised a significant lattice distortion. From the other hand, the ΔΗ mix calculations (- 9.64 kJ/mol) gave strong indications that no intermetallic would be formed. In order to investigate its potential application, the Co1.5CrFeNi1.5Ti0.5 HEA was prepared by vacuum arc melting and a primary assessment of its surface degradation response was conducted by means of sliding wear testing using different counterbody systems for a total sliding distance of 1000 m. An effort to correlate the alloy's wear response with the microstructural characteristics was attempted. Finally, the wear behavior of the Co1.5CrFeNi1.5Ti0.5 HEA was compared with that of two commercially used wear-resistant alloys. The results obtained provided some first signs of the high-entropy alloys' better wear performance when tested under sliding conditions against a steel ball.

  1. Anomalous Hall effect in ion-beam sputtered Co2FeAl full Heusler alloy thin films

    Science.gov (United States)

    Husain, Sajid; Kumar, Ankit; Akansel, Serkan; Svedlindh, Peter; Chaudhary, Sujeet

    2017-11-01

    Investigations of temperature dependent anomalous Hall effect and longitudinal resistivity in Co2FeAl (CFA) thin films grown on Si(1 0 0) at different substrate temperature Ts are reported. The scaling of the anomalous Hall conductivity (AHC) and the associated phenomenological mechanisms (intrinsic and extrinsic) are analyzed vis-à-vis influence of Ts. The intrinsic contribution to AHC is found to be dominating over the extrinsic one. The appearance of a resistivity minimum at low temperature necessitates the inclusion of quantum corrections on account of weak localization and electron-electron scattering effects whose strength reduces with increase in Ts. The study establishes that the optimization of Ts plays an important role in the improvement of atomic ordering which indicates the higher strength of spin-orbit coupling and leads to the dominant intrinsic contribution to AHC in these CFA full Heusler alloy thin films.

  2. Cell cycle phase dependent emergence of thymidylate synthase studied by monoclonal antibody (M-TS-4).

    Science.gov (United States)

    Shibui, S; Hoshino, T; Iwasaki, K; Nomura, K; Jastreboff, M M

    1989-05-01

    A method of identifying thymidylate synthase (TS) at the cellular level was developed using anti-TS monoclonal antibody (M-TS-4), a monoclonal antibody created against purified TS from a HeLa cell line. In HeLa cells and four human glioma cell lines (U-251, U-87, 343-MGA, and SF-188), TS was identified primarily in the cytoplasm. Autoradiographic and flow cytometric studies showed that TS appeared mainly in the G1 phase and subsided early in the S phase; thus, the G1 phase can be divided into TS-positive and -negative fractions. Nuclear TS was not demonstrated unequivocally with M-TS-4, and the relationship between nuclear TS and DNA synthesis could not be determined. Although the percentage of TS-positive cells was larger than the S-phase fraction measured by autoradiography after a pulse of tritiated thymidine or by the immunoperoxidase method using BUdR, the ratios were within a similar range (1.2-1.4) in all cell lines studied. Therefore, the S-phase fraction can be estimated indirectly from the percentage of TS-positive cells measured by M-TS-4. Because the emergence of TS detected by our method is cell cycle dependent, M-TS-4 may be useful for biochemical studies of TS and for cytokinetic analysis.

  3. Annex 5 - Fabrication of U-Al alloy

    International Nuclear Information System (INIS)

    Drobnjak, Dj.; Lazarevic, Dj.; Mihajlovic, A.

    1961-01-01

    Alloy U-Al with low content of aluminium is often used for fabrication of fuel elements because it is stable under moderate neutron flux density. Additionally this type of alloys show much better characteristics than pure uranium under reactor operating conditions (temperature, mechanical load, corrosion effect of water). This report contains the analysis of the phase diagram of U-Al alloy with low content of aluminium, applied procedure for alloying and casting with detailed description of equipment. Characteristics of the obtained alloy are described and conclusions about the experiment and procedure are presented [sr

  4. Comparing the dynamic and thermodynamic behaviors of Al{sub 86}Ni{sub 9}-La{sub 5}/(La{sub 0.5}Ce{sub 0.5}){sub 5} amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Li, G.H. [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Wang, W.M. [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China)], E-mail: weiminw@sdu.edu.cn; Bian, X.F.; Zhang, J.T.; Li, R.; Wang, L. [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China)

    2009-06-10

    The dynamic viscosities and thermodynamic dilatometric behaviors of Al{sub 86}Ni{sub 9}La{sub 5} and Al{sub 86}Ni{sub 9}(La{sub 0.5}Ce{sub 0.5}){sub 5} amorphous alloys were investigated using viscometer, differential scanning calorimetry (DSC) and conventional dilatometer. Comparing with Al{sub 86}Ni{sub 9}La{sub 5} alloy, Al{sub 86}Ni{sub 9}(La{sub 0.5}Ce{sub 0.5}){sub 5} alloy exhibits a larger viscosity and a larger average thermal expansion coefficient in the linear expansion zone ({alpha}{sub exp}). The viscosity and thermal expansion data suggest that the partial substitution La by Ce decreases the quantity of free volume in Al-Ni-La system by improving the continuous degree of atomic size, which leads to the improvement of glass forming ability.

  5. Characteristics of hydrostatically extruded Zr-2.5Nb alloy

    International Nuclear Information System (INIS)

    Jie, Z.; Jiaqi, D.; Tieqi, Y.; Wenxian, H.; Yan, L.; Yunxia, Z.; Zhenhe, L.

    1984-01-01

    Hydrostatic extrusion is a new production technology. Zr-2.5Nb alloy tubes cold hydrostatically extruded possess excellent mechanical properties similar to heat-treated tubes and better than cold-worked tubes. Examination by transmission electron microscope shows that the alloy is of a uniform cell substructure containing the (α + β) phases, which is one of important factors improving properties of the alloy. The study of texture, stress, and reorientation of the hydride shows that hydrostatically extruded tubes with basal plane normals in the radial direction have obviously higher hydride reorientation threshold stress than tubes with basal plane normals in the circumferential direction. Moreover, investigation of fracture toughness reveals that hydride distributed perpendicular to the crack propagation direction restrains further propagation of the crack. It is favorable for preserving the fracture resistance of the material

  6. Microstructure and mechanical properties of a novel near-α titanium alloy Ti6.0Al4.5Cr1.5Mn

    International Nuclear Information System (INIS)

    Wang, Hong-bin; Wang, Shu-sen; Gao, Peng-yue; Jiang, Tao; Lu, Xiong-gang; Li, Chong-he

    2016-01-01

    Based on previous Ti-Al-Cr-Mn quaternary system thermodynamic database, a novel near-α titanium alloy Ti-6.0Al-4.5Cr-1.5Mn alloy was designed and successfully prepared by the water-cooled copper crucible. Microscopic observation showed that both as-cast and annealing status consist of α phase, which coincides with the theoretical expectation. The mechanical properties at room temperature were measured and this alloy possesses good mechanical properties, its average yield-strength reaches 1051.5 MPa and tensile-strength is up to 1091.2 MPa while its average elongation is just 8.3%. Compared with the TA15, it has better mechanical strength and worse elongation. In the new alloy Laves phase Cr 2 Ti were detected by XRD pattern and TEM, which may cause the alloy's poor plasticity.

  7. Microstructure and mechanical properties of a novel near-α titanium alloy Ti6.0Al4.5Cr1.5Mn

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong-bin [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Shanghai Special Casting Engineering Technology Research Center, Shanghai 201605 (China); Wang, Shu-sen; Gao, Peng-yue; Jiang, Tao [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Lu, Xiong-gang; Li, Chong-he [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Shanghai Special Casting Engineering Technology Research Center, Shanghai 201605 (China)

    2016-08-30

    Based on previous Ti-Al-Cr-Mn quaternary system thermodynamic database, a novel near-α titanium alloy Ti-6.0Al-4.5Cr-1.5Mn alloy was designed and successfully prepared by the water-cooled copper crucible. Microscopic observation showed that both as-cast and annealing status consist of α phase, which coincides with the theoretical expectation. The mechanical properties at room temperature were measured and this alloy possesses good mechanical properties, its average yield-strength reaches 1051.5 MPa and tensile-strength is up to 1091.2 MPa while its average elongation is just 8.3%. Compared with the TA15, it has better mechanical strength and worse elongation. In the new alloy Laves phase Cr{sub 2}Ti were detected by XRD pattern and TEM, which may cause the alloy's poor plasticity.

  8. Low-cycle fatigue of welded joints of alloy AMg5

    International Nuclear Information System (INIS)

    Modestova, R.V.; Borisenko, V.A.; Parfenova, I.N.; Stepanov, S.V.

    1986-01-01

    The authors study the low-cycle fatigue of welded joints of aluminum alloy AMg5 in order to determine the cyclic strength coefficient of welded seams. Tests were carried out on cylindrical specimens of the parent metal, welded specimens, and models of welded vessels. The average values of mechanical properties of the specimens and the parent metal are shown. It is shown that when designing welded vessels of aluminum alloy AMg5, the permissible amplitudes of conventional compressive stresses are recommended to be determined as the lower of the two values calculated using the equations presented

  9. Hypocellularity in the Murine Model for Down Syndrome Ts65Dn Is Not Affected by Adult Neurogenesis

    Science.gov (United States)

    López-Hidalgo, Rosa; Ballestín, Raul; Vega, Jessica; Blasco-Ibáñez, José M.; Crespo, Carlos; Gilabert-Juan, Javier; Nácher, Juan; Varea, Emilio

    2016-01-01

    Down syndrome (DS) is caused by the presence of an extra copy of the chromosome 21 and it is the most common aneuploidy producing intellectual disability. Neural mechanisms underlying this alteration may include defects in the formation of neuronal networks, information processing and brain plasticity. The murine model for DS, Ts65Dn, presents reduced adult neurogenesis. This reduction has been suggested to underlie the hypocellularity of the hippocampus as well as the deficit in olfactory learning in the Ts65Dn mice. Similar alterations have also been observed in individuals with DS. To determine whether the impairment in adult neurogenesis is, in fact, responsible for the hypocellularity in the hippocampus and physiology of the olfactory bulb, we have analyzed cell proliferation and neuronal maturation in the two major adult neurogenic niches in the Ts656Dn mice: the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ). Additionally, we carried out a study to determine the survival rate and phenotypic fate of newly generated cells in both regions, injecting 5′BrdU and sacrificing the mice 21 days later, and analyzing the number and phenotype of the remaining 5′BrdU-positive cells. We observed a reduction in the number of proliferating (Ki67 positive) cells and immature (doublecortin positive) neurons in the subgranular and SVZ of Ts65Dn mice, but we did not observe changes in the number of surviving cells or in their phenotype. These data correlated with a lower number of apoptotic cells (cleaved caspase 3 positive) in Ts65Dn. We conclude that although adult Ts65Dn mice have a lower number of proliferating cells, it is compensated by a lower level of cell death. This higher survival rate in Ts65Dn produces a final number of mature cells similar to controls. Therefore, the reduction of adult neurogenesis cannot be held responsible for the neuronal hypocellularity in the hippocampus or for the olfactory learning deficit of Ts65Dn mice

  10. Adiabatic shear localization in a near beta Ti–5Al–5Mo–5 V–1Cr–1Fe alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bingfeng, E-mail: biw009@ucsd.edu [School of Materials Science and Engineering, Central South University, Changsha 410083, Hunan (China); Key Lab of Nonferrous Materials, Ministry of Education, Central South University, Changsha 410083, Hunan (China); Department of Mechanical and Aerospace Engineering, University of California, San Diego (United States); Sun, Jieying; Wang, Xiaoyan; Fu, Ao [School of Materials Science and Engineering, Central South University, Changsha 410083, Hunan (China)

    2015-07-15

    Adiabatic shear localization plays an important role in the deformation and failure of near beta Ti–5Al–5Mo–5 V–1Cr–1Fe alloy used in aircraft's gear at high rate deformation. Hat shaped specimens with different nominal shear strains are used to induce the formation of an adiabatic shear band under controlled shock-loading experiments. When the nominal shear strain is about 0.68, unstable shear deformation of the alloy emerges after the true flow stress reaches 1100 MPa, the first vibration peak during the split Hopkinson pressure bar testing, and the whole process lasts about 62 μs. The microstructures within the shear band in the Ti–5Al–5Mo–5V–1Cr–1Fe alloy are investigated by means of optical microscopy, scanning electron microscopy and transmission electron microscopy. Phase transformation occurs in the shear band when the nominal shear strain increases to 0.68. A number of equiaxed grains with sizes 50–200 nm and alpha″-phase are in the center of the shear band. Kinetic calculations indicate that during the deformation process, the recrystallized nanosized grains can be formed in the shear band by way of the subgrain boundaries rotation, and the alpha″ phase transformation start after the subgrain boundaries rotated to 30°.

  11. SAS4A and FPIN2X validation for slow ramp TOP accidents: experiments TS-1 and TS-2

    International Nuclear Information System (INIS)

    Hill, D.J.

    1986-01-01

    The purpose of this paper is to present further results in the series of experimental analyses being performed using SAS4A and FPIN2X in order to provide a systematic validation of these codes. The two experiments discussed here, TS-1 and TS-2, were performed by Westinghouse Hanford/Hanford Engineering Development Laboratory (WHC/HEDL) in the Transient Reactor Test (TREAT) Facility. They were slow ramp transient overpowers (TOPs) of ∼ 5 cent/s equivalent Fast Flux Test Facility (FFTF) ramp rate, single-pin experiments in flowing sodium loops. The good agreement found here adds significantly to the experimental data base that provides the foundation for SAS4A and FPIN2X validation. It also shows that prefailure internal fuel motion is a phenomenon that has to be correctly accounted for, not only as a potential inherent safety mechanism, but also before any accurate prediction of fuel failure and subsequent fuel motion and the associated reactivity effects can be made. This is also true for metal-fueled pins. This capability is provided by PINACLE, which is being incorporated into SAS4A

  12. Mechanical property and conductivity changes in several copper alloys after 13.5 dpa neutron irradiation

    International Nuclear Information System (INIS)

    Ames, M.; Kohse, G.; Lee, T.S.; Grant, N.J.; Harling, O.K.

    1986-01-01

    A scoping experiment in which 25 different copper materials of 17 alloy compositions were irradiated to approx.13.5 dpa approx.400 0 C in a fast reactor is described. The materials include rapidly solidified (RS) alloys, with and without oxide dispersion strengthening, as well as conventionally processed alloys. Immersion density (swelling), electrical conductivity (which can be related to thermal conductivity), and yield stress and ductility by miniature disk bend testing have been measured before and after irradiation. It was found, in general, that the Rs alloys are stable under irradiation to 13.5 dpa, showing small conductivity changes and little or no swelling. Reduction of strength and ductility, in post-irradiation tests at the irradiation temperature, are not generally observed. Some conventionally processed alloys also performed well, although irradiation softening and swelling of several percent were observed in some cases, and pure copper swelled in excess of 5%. It is concluded that a number of copper alloys should receive further study, and that higher dose irradiations will be required to establish the limits of swelling suppression in these alloys

  13. Heat treatment effects on tensile properties of V-(4-5) wt.% Cr-(4-5) wt.% Ti alloys

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Soppet, W.K. [Argonne National Lab., IL (United States)

    1997-08-01

    Effects of thermomechanical treatments on microstructures and mechanical properties are of interest for long term application of V-Cr-Ti alloys in fusion reactor systems. Influence of thermal annealing at 1050{degrees}C on stress/strain behavior, maximum engineering strength, and uniform and total elongation were evaluated. The results show that multiple annealing has minimal effect on the tensile properties of V-(4-5)Cr-(4-5)Ti alloys tested at room temperature and at 500{degrees}C.

  14. Obtaining of U-2.5Zr7.5Nb and U-3Zr-9Nb alloys by sintering process

    International Nuclear Information System (INIS)

    Mazzeu, Thiago de Oliveira; Paula, Joao Bosco de; Ferraz, Wilmar Barbosa; Santos, Ana Maria Matildes dos; Brina, Jose Giovanni Mascarenhas

    2011-01-01

    The development of metallic fuels with low enrichment to be used in research and test reactors, as well in the future pressurized water reactors, focuses on the search for uranium alloys of high density. Alloying elements such as Zr, Nb and Mo are added to uranium to improve fuel performance in reactors. In this context, the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) in Belo Horizonte is developing the U-2.5Zr-7.5Nb and U- 3Zr-9Nb (weight %) alloys by the innovative process of sintering that utilizes raw materials in the form of powders. The powders were pressed at 400MPa and then sintered under a vacuum of about 5 x 10-6 Torr at temperatures ranging from 1050 deg to 1300 deg C. The densities of the alloys were measured geometrically and by hydrostatic method using water. The microstructures of the pellets were observed by scanning electron microscopy (SEM) and the elements of alloying were identified by energy dispersive X-ray spectroscopy (SEM/EDS) analysis. The obtained results showed a small increasing density with rising sintering temperature. The highest density achieved was approximately 80% of theoretical density. It was also qualitatively observed that the superficial oxidation of the pellets increased with increasing sintering temperature thus avoiding the fusion of the alloys at higher temperatures. (author)

  15. The Influence of Aluminum on the Microstructure and Hardness of Mg-5Si-7Sn Alloy

    Directory of Open Access Journals (Sweden)

    Rzychoń T.

    2016-03-01

    Full Text Available Magnesium alloys due the low density and good mechanical properties are mainly used in the automotive and aerospace industry. In recent years, magnesium alloys are extensively developed for use in high temperatures (above 120°C. Among these alloys, magnesium alloys containing tin and silicon have large possibilities of application due to the formation of thermally stable intermetallic Mg2Sn and Mg2Si. In this paper the influence of aluminum and heat treatment on the on the microstructure and hardness of Mg-7Sn-5Si alloy is reported. It was found that the microstructure of Mg-7Sn-5Si alloy consist of α-Mg solid solution, Mg2Sn and Mg2Si compounds. Addition of 2 wt% of Al to Mg-7Sn-5Si alloy causes the formation of Al2Sn phase. Moreover, Al dissolves in the α-Mg solid solution. The solution heat-treatment of tested alloys at 500°C for 24 h causes the dissolve the Mg2Sn phase in the α-Mg matrix and spheroidization of Mg2Si compound. The Mg2Si primary crystals are stable at solution temperature. After ageing treatment the precipitation process of equilibrium Mg2Sn phase was found in both alloys. The addition of aluminum has a positive effect on the hardness of Mg-7Sn-5Si alloy. In case of Mg-5Si-7Sn-2Al alloy the highest hardness was obtained for sample aged for 148 h at 250°C (88 HV2, while in case of Al-free alloy the highest hardness is 70 HV for material aged for 148 h at 250°C.

  16. Control of segregation in squeeze cast Al-4.5Cu binary alloy

    Energy Technology Data Exchange (ETDEWEB)

    Durrant, G. [Oxford Univ. (United Kingdom). Dept. of Materials; Gallerneault, M. [Alcan International Ltd., Kingston, ON (Canada); Cantor, B. [Oxford Univ. (United Kingdom). Dept. of Materials

    1997-10-01

    The high pressure applied in squeeze casting allows Al alloys of wrought composition to be cast to near net-shape, although their long freezing range leads to the segregation of alloying elements. In this paper we present results on the squeeze casting and gravity casting of a model Al-4.5 wt%Cu alloy. Squeeze cast Al-4.5Cu has a normal segregation pattern with eutectic macrosegregates towards the centre of the billet, whereas gravity cast material has a typical inverse segregation pattern. Normal segregation in squeeze cast Al-4.5Cu is due to large temperature gradients during solidification. Segregation can be minimized by releasing the applied pressure during solidification to allow backflow of the interdendritic fluid, or by the addition of grain refiner to remove the large columnar dendritic growth structure. (orig.)

  17. Instability of TiC and TiAl3 compounds in Al-10Mg and Al-5Cu alloys by addition of Al-Ti-C master alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The performance of Al-Ti-C master alloy in refining Al-10Mg and A1-5Cu alloys was studied by using electron probe micro-analyzer (EPMA) and X-ray diffractometer (XRD) analysis.The results indicate that there are obvious fading phenomena in both Al-10Mg and Al-5Cu alloys with the addition of Al-5Ti-0.4C refiner which contains TiC and TiAl3 compounds.Mg element has no influence on the stability of TiC and TiAl3, while TiC particles in Al-10Mg alloy react with Al to form Al4C3 particles, resulting in the refinement fading.However, TiC particles are relatively stable in Al-5Cu alloy, while TiAl3 phase reacts with Al2Cu to produce a new phase Ti(Al, Cu)2, which is responsible for the refinement fading in Al-5Cu alloy.These indicate that the refinement fading will not occur only when both the TiC particles and TiAl3 compound of Al-Ti-C refiner are stable in Al alloys.

  18. Corrosion of Zn5Al and Zn55Al alloys with cerium, praseodymium and neodymium

    International Nuclear Information System (INIS)

    Alikhanova, S.D.

    2017-01-01

    The present work is devoted to corrosion of Zn5Al and Zn55Al alloys with cerium, praseodymium and neodymium. The purpose of present work is elaboration of optimal composition of zinc-aluminium alloys Zn5Al and Zn55Al alloyed by rare-earth metals of cerium subgroup which are used as anode covers for protection of steel from corrosion. Therefore, the regularities of change of corrosion-electrochemical properties in various corrosive mediums have been determined; processes mechanisms of high temperature oxidation of alloys in solid state have been studied; in the products of alloys oxidation their phase components have been defined and their role in the corrosion process have been revealed; the optimal compositions of zinc-aluminium alloys alloyed by rare earth metals, which are protected by two patents of the Republic of Tajikistan have been elaborated.

  19. Surface alloying in Sn/Au(111) at elevated temperature

    Science.gov (United States)

    Sadhukhan, Pampa; Singh, Vipin Kumar; Rai, Abhishek; Bhattacharya, Kuntala; Barman, Sudipta Roy

    2018-04-01

    On the basis of x-ray photoelectron spectroscopy, we show that when Sn is deposited on Au(111) single crystal surface at a substrate temperature TS=373 K, surface alloying occurs with the formation of AuSn phase. The evolution of the surface structure and the surface morphology has been studied by low energy electron diffraction and scanning tunneling microscopy, respectively as a function of Sn coverage and substrate temperatures.

  20. Tegafur/gimeracil/oteracil (TS-1 induced Stevens–Johnson syndrome: Case report

    Directory of Open Access Journals (Sweden)

    Satoko Minakawa

    2013-09-01

    Full Text Available TS-1 is an oral fluoropyrimidine anticancer drug that contains tegafur, gimeracil, and oteracil. A 78-year-old Japanese male who was diagnosed with carcinoma of the oral floor (rT4aN0M0 was prescribed a standard dose of TS-1 (80 mg/day. On Day 8 after administration of TS-1, an eruption developed. There was erythema, along with vesicles and erosions involving the lip, face, neck, trunk, limbs, and genitals. The drug-induced lymphocyte stimulation test (DLST for TS-1 was negative on the 23rd day, but positive on the 43rd day (20 days after discontinuing prednisolone. The condition was diagnosed as Stevens–Johnson syndrome due to TS-1 because of the clinical course and laboratory results. This case and 24 cases previously reported in the literature were analyzed. The types of drug eruption were drug-related lupus (9 cases, acral erythema (7 cases, scleroderma-like skin lesion (2 cases, Stevens–Johnson syndrome (2 cases, lichenoid eruption (1 case, purpura (1 case, lichen planus (1 case, erythema multiforme (1 case, hypopigmentation (1 case and toxic epidermal necrolysis (1 case, respectively. In view of the increasing usage of TS-1 in several common cancers, clinicians should be aware of drug eruptions due to TS-1.

  1. Enhancing pitting corrosion resistance of Al{sub x}CrFe{sub 1.5}MnNi{sub 0.5} high-entropy alloys by anodic treatment in sulfuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.P.; Chen, Y.Y.; Hsu, C.Y.; Yeh, J.W. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China); Shih, H.C. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China); Institute of Materials Science and Nanotechnology, Chinese Culture University, Taipei 111, Taiwan (China)], E-mail: hcshih@mx.nthu.edu.tw

    2008-12-01

    High-entropy alloys are a newly developed family of multi-component alloys that comprise various major alloying elements. Each element in the alloy system is present in between 5 and 35 at.%. The crystal structures and physical properties of high-entropy alloys differ completely from those of conventional alloys. The electrochemical impedance spectra (EIS) of the Al{sub x}CrFe{sub 1.5}MnNi{sub 0.5} (x = 0, 0.3, 0.5) alloys, obtained in 0.1 M HCl solution, clearly revealed that the corrosion resistance values were determined to increase from 21 to 34 {omega}cm{sup 2} as the aluminum content increased from 0 to 0.5 mol, and were markedly lower than that of 304 stainless steel (243 {omega}cm{sup 2}). At passive potential, the corresponding current declined with the anodizing time accounting, causing passivity by the growth of the multi-component anodized film in H{sub 2}SO{sub 4} solution. X-ray photoelectron spectroscopy (XPS) analyses revealed that the surface of anodized Al{sub 0.3}CrFe{sub 1.5}MnNi{sub 0.5} alloy formed aluminum and chromium oxide film which was the main passivating compound on the alloy. This anodic treatment increased the corrosion resistance in the EIS measurements of the CrFe{sub 1.5}MnNi{sub 0.5} and Al{sub 0.3}CrFe{sub 1.5}MnNi{sub 0.5} alloys by two orders of magnitude. Accordingly, the anodic treatment of the Al{sub x}CrFe{sub 1.5}MnNi{sub 0.5} alloys optimized their surface structures and minimized their susceptibility to pitting corrosion.

  2. On the Correlation between Morphology of alpha and Its Crystallographic Orientation Relationship with TiB and Beta in Boron Containing Ti-5Al-5Mo-5V-3Cr-0.5Fe Alloy (Preprint)

    Science.gov (United States)

    2012-01-01

    orientation microscopy studies on a boron containing version of the commercial Ti- 5Al-5Mo-5V-3Cr-0.5Fe ( Ti5553 ) alloy. 15. SUBJECT TERMS Ti5553 ...of the commercial Ti-5Al-5Mo-5V-3Cr-0.5Fe ( Ti5553 ) alloy. Keywords: Ti5553 , TiB, EBSD, crystallography, orientation relationship. Paper There has...absence of orientation relationships between the α, β and TiB phases, on the morphology of α nucleating from TiB in the Ti5553 alloy.. The base

  3. Strain-softening behavior of an Fe-6.5 wt%Si alloy during warm deformation and its applications

    International Nuclear Information System (INIS)

    Fu Huadong; Zhang Zhihao; Yang Qiang; Xie Jianxin

    2011-01-01

    Research highlights: → An Fe-6.5 wt%Si alloy exhibits strain-softening behavior after large deformation. → The decrease of the order degree is responsible for the strain-softening behavior. → The strain-softening behavior of Fe-6.5 wt%Si alloy can be applied in cold rolling. → An Fe-6.5 wt%Si thin strip with thickness of 0.20 mm is fabricated by cold rolling. - Abstract: An Fe-6.5 wt%Si alloy with columnar grains was compressed at a temperature below its recrystallization temperature. The Vickers hardness and structure of the alloy before and after deformation were investigated. The results showed that with an increase in the degree of deformation, Vickers hardness of the alloy initially increased rapidly and then decreased slowly, indicating that the alloy had a strain-softening behavior after a large deformation. Meanwhile, the work-hardening exponent of the alloy decreased significantly. Transmission electron microscopy confirmed that the decrease of the order degree was responsible for the strain-softening behavior of the deformed alloy. Applying its softening behavior, the Fe-6.5 wt%Si alloy with columnar grains was rolled at 400 deg. C and then at room temperature. An Fe-6.5 wt%Si thin strip with thickness of 0.20 mm was fabricated. The surface of the strip was bright and had no obvious edge cracks.

  4. Effect of Al-5Ti-0.62C-0.2Ce Master Alloy on the Microstructure and Tensile Properties of Commercial Pure Al and Hypoeutectic Al-8Si Alloy

    Directory of Open Access Journals (Sweden)

    Wanwu Ding

    2017-06-01

    Full Text Available Al-5Ti-0.62C-0.2Ce master alloy was synthesized by a method of thermal explosion reaction in pure molten aluminum and used to modify commercial pure Al and hypoeutectic Al-8Si alloy. The microstructure and tensile properties of commercial pure Al and hypoeutectic Al-8Si alloy with different additions of Al-5Ti-0.62C-0.2Ce master alloy were investigated. The results show that the Al-5Ti-0.62C-0.2Ce alloy was composed of α-Al, granular TiC, lump-like TiAl3 and block-like Ti2Al20Ce. Al-5Ti-0.62C-0.2Ce master alloy (0.3 wt %, 5 min can significantly refine macro grains of commercial pure Al into tiny equiaxed grains. The Al-5Ti-0.62C-0.2Ce master alloy (0.3 wt %, 30 min still has a good refinement effect. The tensile strength and elongation of commercial pure Al modified by the Al-5Ti-0.62C-0.2Ce master alloy (0.3 wt %, 5 min increased by roughly 19.26% and 61.83%, respectively. Al-5Ti-0.62C-0.2Ce master alloy (1.5 wt %, 10 min can significantly refine both α-Al grains and eutectic Si of hypoeutectic Al-8Si alloy. The dendritic α-Al grains were significantly refined to tiny equiaxed grains. The morphology of the eutectic Si crystals was significantly refined from coarse needle-shape or lath-shape to short rod-like or grain-like eutectic Si. The tensile strength and elongation of hypoeutectic Al-8Si alloy modified by the Al-5Ti-0.62C-0.2Ce master alloy (1.5 wt %, 10 min increased by roughly 20.53% and 50%, respectively. The change in mechanical properties corresponds to evolution of the microstructure.

  5. Creep deformation behaviour and microstructural changes in Zr-2.5% Nb alloy

    International Nuclear Information System (INIS)

    Chaudhuri, S.; Singh, R.; Ghosh, R.N.; Sinha, T.K.; Banerjee, S.

    2002-01-01

    Cold worked and stress relieved Zr-2.5% Nb alloy is a well-known material used as pressure tubes in Pressurised Heavy Water Reactors. The pressure tubes, made of a typical Zr-alloy, consisting of 2.54% Nb, 0.1175% oxygen and less than 100 ppm impurities, are expected to withstand 9.5 MPa to 12.5 MPa pressure at 250 degC to 310 degC under fast neutron fluxes of 3.5 x 10 17 nm -2 s -1 . These tubes are made by hot extrusion at 780 degC with an extrusion ratio 8.3:1 and 40% cold pilgering followed by annealing at 550 degC for 3 hours and subsequently by 20-30% cold pilgering and stress relieving at 400 degC for 24 hours. The microstructure of such cold worked and stress relieved alloy consists of Β-Zr precipitates in the matrix of elongated Α-Zr grains. Although various factors such as irradiation creep, thermal creep, irradiation growth etc are responsible for limiting the life of pressure tubes; the thermal creep contributes significantly in overall creep deformation. Keeping this in view as well as due to non-availability of adequate published information including creep database on this alloy, an extensive investigation on the thermal creep behaviour of indigenously produced Zr-2.5% Nb alloy was undertaken. The creep tests in air using Mayes' creep testing machines were carried out in the temperature range of 300 degC to 450 degC under stresses in the range of 50 to 550 MPa. Analysis of data revealed that the mechanism of creep deformation remains the same in this range

  6. M5TM alloy high burnup behavior and worldwide licensing

    International Nuclear Information System (INIS)

    Mardon, J.P.; Hoffmann, P.B.; Garner, G.L.

    2005-01-01

    The in-reactor behavior of advanced PWR Zirconium alloys at burnups equal to or below licensing limits has been widely reported. Specifically, the advanced alloy M5 has demonstrated impressive improvements over Zircaloy-4 for fuel rod cladding and fuel assembly structural components. To demonstrate superiority of the alloy at burnups beyond current licensing limits, M5 has been operated in PWR at burnups exceeding 71 GWd/tU in the United States and 78 GWd/tU in Europe. Two extensive irradiation programs have been performed in the United States to demonstrate alloy M5 performance beyond current licensing limits. Four M5 TM fuel rods were exposed to four 24-month cycles in a 15x15 reactor beginning in 1995. Additionally, one 17x17 lead assembly containing M5 fuel rods and guide tubes was operated for four 18-month cycles beginning from 1997. Post-irradiation examinations (PIE) performed after all four cycles in the 15x15 demonstration program revealed excellent performance in the licensed burnup and in the high burnup stages of the experience. Examination of the 4th cycle 17x17 assembly will be accomplished in two stages the first of which is scheduled for June 2005. Moreover, several irradiation campaigns have been performed in Europe in order to confirm the excellent M5 in-pile behavior in demanding PWRs irradiation conditions with regard to void fraction, heat flux, lithium content and temperature. Results from the high burnup fuel examinations verify that the excellent performance achieved up to 62 GWd/tU was continued into higher burnup. The results of high burnup PIE campaigns for European and American PWR's are presented in this paper. Measured performance indicators include fuel assembly dimensional stability parameters (assembly length, fuel rod length, assembly bow, fuel rod bow, fuel rod radial creep and spacer grid width), oxidation measurements (fuel rod and guide tube) and hydrogen pick-up data (fuel rod). In the framework of PCI studies, power ramp

  7. Development and characterization of monolithic fuel miniplate alloy U-2.5Zr-7.5Nb, coated in zircaloy

    International Nuclear Information System (INIS)

    Machado, Geraldo Correa

    2014-01-01

    The autocthonal production of nuclear fuel in Brazil for test and research reactors is restricted to MTR (Material Test Reactor) fuel type dispersion plate, using U3Si2 alloy, coated and dispersed in aluminum, developed by IPEN-SP for use in IEA-R1 reactor. Moreover, the UO 2 fuel rod type for power reactors is manufactured by Rezende (RJ) with a German technology by INB under license. Currently, Brazil is performing two programs of developing reactors. Currently, Brazil is developing two reactors. One of them is the development, by CNEN, the Brazilian Multipurpose Reactor (RMB), for testing, research and radioisotope production. The other one is the development a power reactor for naval propulsion, conducted by the Brazilian Navy. This dissertation presents the development and characterization of monolithic fuel miniplate alloy U-2.5Zr-7.5Nb, coated in zircaloy (ZRY), on a laboratory scale. Due to its innovative features and properties, this fuel can be used as fuel in both test reactors, research and producing radioisotopes for power reactors as small and medium sizes. Thus, this high potential fuel can be used in domestic reactors currently under development. The development of monolithic fuel plate type is made using the technique called 'picture-frame' where a sandwich composed of a monolith alloy U-2.5Zr- 7.5Nb coupled to a frame and coated sheets of Zry is obtained. The alloy U-2.5Zr-7.5Nb was obtained by melting in an induction furnace and then was cast into rectangular ingots of graphite, thus achieving an ingot with approximate dimensions of 170 x 50 x 60 mm. The obtained ingot was hot rolled at 850 ºC, with a 50 % reduction in thickness, in order to refine the raw structure of fusion. Samples cut from the alloy U-2.5Zr-7.5Nb, with dimensions 20 x 20 x 6 mm were placed in frames and plates Zry and joined by TIG (Tungsten Inert Gas) under an atmosphere of argon, obtaining a set of 10 mm thick, 45 mm wide and 100 mm long. The sandwiches were hot rolled to

  8. Magnesium Alloy WE43 and WE43-T5 - Mechanical and Thermal Properties

    Science.gov (United States)

    Xiang, Chongchen

    Magnesium alloys are promising in aerospace, automotive and electronic industries due to low density, high specific strength and excellent machinability. A rare earth element alloy (WE43) is studied in as cast and heat treated conditions. Multiscale characterization is conducted to understand the nanomechanical response using a nanoindentor and microscale behavior using tensile tests. Further, compressive characterization is conducted across six orders of strain rate magnitudes from 10-3 to 3x103 s -1 under the range of liquid nitrogen (-196°C) to room temperature (25°C). Based on the results, a constitutive model is developed to estimate the plastic behavior of as-cast WE43 and WE43-T5 at different strain rates and under different temperatures. In addition, dynamic properties are studied using a dynamic mechanical analyzer at 1-100 Hz loading frequencies and the temperature range from 35°C to 500°C. Only Yttrium-rich cuboidal phase and zirconium-rich phase were present in WE43-T5 alloy and the eutectic phase was absent. Also, the grain size was reduced due to the hot rolling process. The difference in microstructure reflects into the mechanical properties. WE43-T5 specimens have improved mechanical properties over the as-cast alloy. Two transition temperatures are found at 210 and 250°C based on the storage and loss moduli results. The Mg24Y5 peak is found in the high temperature x-ray diffraction results along with a new Mg12Nd peak at those two temperature points. The corrosion behavior, studied by 7-day immersion in 3.5% NaCl solution, shows that the heat treated alloy has significantly lower corrosion rate than the as-cast alloy due to the absence of the eutectic mixture in the microstructure. With rapidly growing applications of magnesium alloys, particularly with rare earth elements, this study is expected to provide critical data and structure-property correlations that will help the scientific community.

  9. Effect of Heat Treatment on Corrosion Behaviors of Mg-5Y-1.5Nd Alloys

    Directory of Open Access Journals (Sweden)

    Xiumin Ma

    2016-01-01

    Full Text Available Corrosion behavior of Mg-5Y-1.5Nd alloy was investigated after heat treatment. The microstructure and precipitation were studied by scanning electron microscope (SEM and energy dispersive spectrometer (EDS. The weight loss rates of different samples were arranged as T6-24 h>T6-6 h>T6-14 h>as-cast>T4. The open circuit potential (OCP showed that T4 sample had a more positive potential than that of other samples. The potentiodynamic polarization curves showed that the T6-24 h sample had the highest corrosion current density of 245.362 μA·cm−2, whereas the T4 sample had the lowest at 52.164 μA·cm−2. The EIS results confirmed that the heat treatment reduced the corrosion resistance for Mg-5Y-1.5Nd alloy, because the precipitations acted as the cathode of electrochemical reactions to accelerate the corrosion process. The corrosion rates of different samples were mainly determined by the amount and distribution of the precipitations. The precipitations played dual roles that depended on the amount and distribution. The presence of the phase in the alloys could deteriorate the corrosion performance as it could act as an effective galvanic cathode. Otherwise, a fine and homogeneous phase appeared to be a better anticorrosion barrier.

  10. Effect of electrical discharge machining on uranium-0.75 titanium and tungsten-3.5 nickel-1.5 iron alloys

    International Nuclear Information System (INIS)

    Anderson, R.C.

    1976-06-01

    It was found that U--0.75 Ti alloy cracked if the EDM parameters were out of control, and precipitation of carbides adjacent to the EDM surface took place during subsequent solution quenching. Cracks form in the ''recast'' layer when solution-quenched U--0.75 Ti alloy undergoes EDM, and the cracks propagated during subsequent nickel plating. If the recast layer was removed prior to nickel plating, only a slight loss in strength resulted, compared to conventional machining. W--3.5 Ni--1.5 Fe alloy also sustained some surface damage during EDM and also experienced a small loss in strength compared to conventionally machined material. 12 figures, 4 tables

  11. CATALYTIC PERFORMANCES OF Fe2O3/TS-1 CATALYST IN PHENOL HYDROXYLATION REACTION

    Directory of Open Access Journals (Sweden)

    Didik Prasetyoko

    2010-07-01

    Full Text Available Hydroxylation reaction of phenol into diphenol, such as hydroquinone and catechol, has a great role in many industrial applications. Phenol hydroxylation reaction can be carried out using Titanium Silicalite-1 (TS-1 as catalyst and H2O2 as an oxidant. TS-1 catalyst shows high activity and selectivity for phenol hydroxylation reaction. However, its hydrophobic sites lead to slow H2O2 adsorption toward the active site of TS-1. Consequently, the reaction rate of phenol hydroxylation reaction is tends to be low. Addition of metal oxide Fe2O3 enhanced hydrophilicity of TS-1 catalyst. Liquid phase catalytic phenol hydroxylation using hydrogen peroxide as oxidant was carried out over iron (III oxide-modified TS-1 catalyst (Fe2O3/TS-1, that were prepared by impregnation method using iron (III nitrate as precursor and characterized by X-ray diffraction, infrared spectroscopy, nitrogen adsorption, pyridine adsorption, and hydrophilicity techniques. Catalysts 1Fe2O3/TS-1 showed maximum catalytic activity of hydroquinone product. In this research, the increase of hydroquinone formation rate is due to the higher hydrophilicity of Fe2O3/TS-1 catalysts compare to the parent catalyst, TS-1.   Keywords: Fe2O3/TS-1, hydrophilic site, phenol hydroxylation

  12. Synthesis of mesoporous TS-1 using a hybrid SiO{sub 2}–TiO{sub 2} xerogel for catalytic oxidative desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung-Tae [Department of Chemical Engineering, Inha University, Incheon 402-751 (Korea, Republic of); Jeong, Kwang-Eun; Jeong, Soon-Yong [Research Center for Green Catalysis, Division of Green Chemistry and Engineering Research, Korea Research Institute of Chemical Technology, P.O. Box 107, 141 Gajeong-ro, Yuseong, Daejeon 305-600 (Korea, Republic of); Ahn, Wha-Seung, E-mail: whasahn@inha.ac.kr [Department of Chemical Engineering, Inha University, Incheon 402-751 (Korea, Republic of)

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ► Meso-TS-1 catalyst was synthesized using a SiO{sub 2}–TiO{sub 2} xerogel with an organosilane precursor. ► Hierarchical pore structure was confirmed by characterization of the materials. ► Catalytic activity was tested using oxidative desulfurization of the model sulfur compounds. ► Meso-TS-1 demonstrated significantly improved catalytic activity than TS-1. -- Abstract: Mesoporous TS-1 (M-TS-1) was synthesized using a hybrid SiO{sub 2}–TiO{sub 2} xerogel combined with an organosilane precursor. Prepared samples were characterized by XRD, UV–vis spectroscopy, SEM, and N{sub 2} adsorption–desorption measurement. M-TS-1, prepared in 2 days, showed high crystallinity and the best textural properties among the samples. The N{sub 2} adsorption–desorption isotherms of M-TS-1 exhibited a hysteresis loop at pressure higher than P/P{sub 0} = 0.4, clearly indicating the existence of mesopores. M-TS-1 has significantly larger mesopore volume (0.48 cm{sup 3}/g) than that of conventional TS-1 (0.07 cm{sup 3}/g), and showed a narrow peak centered at ca. 6.3 nm. In the oxidative desulfurization reaction, M-TS-1 was more active than conventional TS-1 at the same Ti-loading; M-TS-1 produced a dibenzothiophene (DBT) conversion of 96%, whereas conventional TS-1 produced a final DBT conversion of 5.6% after a reaction time of 180 min. Oxidative desulfurization over TS-1 was influenced both by electron density and steric hindrance in the sulfur compounds tested.

  13. Not in Traffic Surveillance (NiTS)

    Data.gov (United States)

    Department of Transportation — The Not-in-Traffic Surveillance (NiTS) system is a virtual data collection system designed to provide counts and details regarding fatalities and injuries that occur...

  14. Microstructure and Mechanical Properties of TIG Weld Joint of ZM5 Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    QIN Ren-yao

    2016-06-01

    Full Text Available The ZM5 magnesium alloy plates were welded by TIG welding method. The microstructural characteristics and mechanical properties of ZM5 magnesium alloy joint were studied by optical microscopy, microhardness and tensile testers. The results show that the TIG weld joint of ZM5 magnesium alloy is composed of heat affected zone, partially melted zone and weld metal. The heat affected zone is consisted of primary α-Mg phase and eutectic phase that is composed of eutectic α-Mg and eutectic β-Mg17Al12 phase and mainly precipitated at grain boundaries. In the partially melted zone, the eutectic phase is not only increasingly precipitated at grain boundaries, but also dispersed in grains, and the growth of the β-Mg17Al12 phase is obviously observed. The microstructure in the weld is the typical dendritic morphology. The dendrites are considered as primary α-Mg phase, and the interdendritic regions are α+β eutectic phase. The difference in the microstructure of the heat affected zone, partially melted zone and weld results in their various microhardness values, and leads to the smaller tensile strength and ductility in the ZM5 alloy weld joint than parent metal.

  15. Pressure effects on Al89La6Ni5 amorphous alloy crystallization

    DEFF Research Database (Denmark)

    Zhuang, Yanxin; Jiang, Jianzhong; Zhou, T. J.

    2000-01-01

    The pressure effect on the crystallization of the Al89La6Ni5 amorphous alloy has been investigated by in situ high-pressure and high-temperature x-ray powder diffraction using synchrotron radiation. The amorphous alloy crystallizes in two steps in the pressure range studied (0-4 GPa). The first p...

  16. T.S. Eliot i nordisk efterkrigstidsdigtning

    DEFF Research Database (Denmark)

    Larsen, Peter Stein

    2009-01-01

    andet indkredses den særlige fascinationskraft ved Eliots æstetik, som den kommer til udtryk i The Waste Land (1922), nemlig at der er tale om en uhyre sofistikeret brug af montageformen. For det tredje peges der gennem et par digtlæsninger på, hvordan Eliots montage-æstetik kan følges i nordisk poesi......Hvad er årsagen til, at T.S. Eliot måske mere end nogen anden digter har haft indflydelse på nordiske digtere i det 20. århundrede? Dette vil blive undersøgt i tre tempi i denne artikel. For det første gives der et generelt rids af, hvor man finder T.S. Eliots aftryk i nordisk litteratur. For det...

  17. Microstructure, corrosion resistance and cytocompatibility of Mg-5Y-4Rare Earth-0.5Zr (WE54) alloy

    Energy Technology Data Exchange (ETDEWEB)

    Smola, Bohumil, E-mail: bohumil.smola@mff.cuni.cz [Charles University Prague, Faculty of Mathematics and Physics, Ke Karlovu 5, 121 16 Praha 2 (Czech Republic); Joska, Ludek [Institute of Chemical Technology Prague, Faculty of Chemical Technology, Technicka 5, 166 28 Praha 6 (Czech Republic); Brezina, Vitezslav [University of South Bohemia, Institute of Physical Biology, Zamek 136, 373 33 Nove Hrady (Czech Republic); Stulikova, Ivana [Charles University Prague, Faculty of Mathematics and Physics, Ke Karlovu 5, 121 16 Praha 2 (Czech Republic); Hnilica, Frantisek [Czech Technical University in Prague, Faculty of Mechanical Engineering, Karlovo namesti 13, 121 35 Praha 2 (Czech Republic)

    2012-05-01

    Conventionally cast Mg-5Y-4Rare Earth-0.5Zr alloy (WE54) was solution treated (525 Degree-Sign C/8 h - T4) and one part subsequently aged (200 Degree-Sign C/16 h - T6). Powder from the cast WE54 alloy prepared by gas atomizing was consolidated by extrusion at 250 Degree-Sign C or 400 Degree-Sign C. Dense triangular arrangement of prismatic plates of transient D0{sub 19} and C-base centered orthorhombic phases precipitated in the {alpha}-Mg matrix during the T6 treatment. Both alloys prepared by powder metallurgy exhibit similar microstructure consisting of {approx} 4-6 {mu}m {alpha}-Mg matrix fibers surrounded by particles of the equilibrium Mg{sub 5}(Y, Nd) phase and of oxides. Open circuit potential and polarization resistance in the isotonic saline (9 g/l NaCl/H{sub 2}O) were monitored for 24 h. The corrosion rate of the T4 and T6 treated alloys was about 80 times lower than that of commercial Mg. Both alloys prepared by powder metallurgy exhibited approximately 8 times higher corrosion resistance than commercial Mg. The human MG-63 osteoblast-like cells spreading and division in the extracts (0.28 g in 28 ml of EMEM) of all 4 alloys were monitored by cinemicrography for 24 h. The MG-63 cells proliferate without cytotoxicity in all extracts. - Highlights: Black-Right-Pointing-Pointer T6 treated WE54 alloy exhibit dense triangular arrangement of {beta} Double-Prime and {beta} Prime phase prismatic plates. Black-Right-Pointing-Pointer Microstructure of PM prepared WE54 alloy consists of {alpha}-Mg phase cells surrounded by {beta} phase particles. Black-Right-Pointing-Pointer PM produced WE54 corroded 10 times faster in physiological solution thanT4 and T6 treated WE54. Black-Right-Pointing-Pointer MG63 cell spreading in EMEM extracts of PM prepared WE54 is comparable to that in control EMEM. Black-Right-Pointing-Pointer Cell mitosis is enhanced in PM WE54 extracts compared to the control and extracts of T4 and T6 WE54.

  18. Electrical and Thermal Conductivity and Conduction Mechanism of Ge2Sb2Te5 Alloy

    Science.gov (United States)

    Lan, Rui; Endo, Rie; Kuwahara, Masashi; Kobayashi, Yoshinao; Susa, Masahiro

    2018-06-01

    Ge2Sb2Te5 alloy has drawn much attention due to its application in phase-change random-access memory and potential as a thermoelectric material. Electrical and thermal conductivity are important material properties in both applications. The aim of this work is to investigate the temperature dependence of the electrical and thermal conductivity of Ge2Sb2Te5 alloy and discuss the thermal conduction mechanism. The electrical resistivity and thermal conductivity of Ge2Sb2Te5 alloy were measured from room temperature to 823 K by four-terminal and hot-strip method, respectively. With increasing temperature, the electrical resistivity increased while the thermal conductivity first decreased up to about 600 K then increased. The electronic component of the thermal conductivity was calculated from the Wiedemann-Franz law using the resistivity results. At room temperature, Ge2Sb2Te5 alloy has large electronic thermal conductivity and low lattice thermal conductivity. Bipolar diffusion contributes more to the thermal conductivity with increasing temperature. The special crystallographic structure of Ge2Sb2Te5 alloy accounts for the thermal conduction mechanism.

  19. Electrical and Thermal Conductivity and Conduction Mechanism of Ge2Sb2Te5 Alloy

    Science.gov (United States)

    Lan, Rui; Endo, Rie; Kuwahara, Masashi; Kobayashi, Yoshinao; Susa, Masahiro

    2017-11-01

    Ge2Sb2Te5 alloy has drawn much attention due to its application in phase-change random-access memory and potential as a thermoelectric material. Electrical and thermal conductivity are important material properties in both applications. The aim of this work is to investigate the temperature dependence of the electrical and thermal conductivity of Ge2Sb2Te5 alloy and discuss the thermal conduction mechanism. The electrical resistivity and thermal conductivity of Ge2Sb2Te5 alloy were measured from room temperature to 823 K by four-terminal and hot-strip method, respectively. With increasing temperature, the electrical resistivity increased while the thermal conductivity first decreased up to about 600 K then increased. The electronic component of the thermal conductivity was calculated from the Wiedemann-Franz law using the resistivity results. At room temperature, Ge2Sb2Te5 alloy has large electronic thermal conductivity and low lattice thermal conductivity. Bipolar diffusion contributes more to the thermal conductivity with increasing temperature. The special crystallographic structure of Ge2Sb2Te5 alloy accounts for the thermal conduction mechanism.

  20. Magnetic properties analysis of intermetallic alloys Rni5 (R = Rare Earths)

    International Nuclear Information System (INIS)

    Barthem, V.M.T.S.

    1988-01-01

    SmNi 5 and TmNi 5 alloys were analysed by magnetization measures, susceptibility, resistivity and only for TmNi 5 by magnetostriction and thermal expansion. The results are distinguished by powerful magnetic anisotropy of these materials. (C.G.C.) [pt

  1. Microstructural evolution of direct chill cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy during solution treatment

    OpenAIRE

    He Kezhun; Yu Fuxiao; Zhao Dazhi

    2011-01-01

    Heat treatment has important influence on the microstructure and mechanical properties of Al-Si alloys. The most common used heat treatment method for these alloys is solution treatment followed by age-hardening. This paper investigates the microstructural evolution of a direct chill (DC) cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy after solution treated at 500, 510, 520 and 530℃, respectively for different times. The major phases observed in the as-cast alloy are α-aluminum dendrite, primary Si p...

  2. Reconstitution of Qbeta RNA replicase from a covalently bonded elongation factor Tu-Ts complex

    DEFF Research Database (Denmark)

    Brown, S; Blumenthal, T

    1976-01-01

    of these polypeptides, protein synthesis elongation factors EF-Tu and EF-Ts, can be covalently crosslinked with dimethyl suberimidate to form a complex which lacks the ability to catalyze the known host functions catalyzed by the individual elongation factors. Using a previously developed reconstitution system we have...... examined the effects of crosslinking the EF-Tu-Ts complex on reconstituted replicase activity. Renaturation is significantly more efficient when exogenously added native EF-Tu-Ts is crosslinked than when it is not. Crosslinked EF-Tu-Ts can be purified from a crude crosslinked postribosomal supernatant...... by its ability to replace EF-Tu and EF-Ts in the renaturation of denatured Qbeta replicase. A sample of Qbeta replicase with crosslinked EF-Tu-Ts replacing the individual elongation factors was prepared. Although it lacked EF-Tu and EF-Ts activities, it could initiate transcription of both poly...

  3. Processing and characterization of AlCoFeNiXTi0,5 (X = Mn, V) high entropy alloys

    International Nuclear Information System (INIS)

    Triveno Rios, C.; Kiminami, C.S.

    2014-01-01

    The microstructure of high entropy alloys consists of solid solution phases with FC and BCC simple structures, contrary to classical metallurgy where they form complex structures of intermetallic compounds. Because of this they have several attractive properties for engineering applications. In this work the AlCoFeNiMnTi 0,5 and AlCoFeNiVTi 0,5 alloys were processed by melting arc. Since the main objective was the microstructural and mechanical characterization of ingots as-cast. The alloys were characterized by scanning electron microscopy, X-ray diffraction, microhardness and cold compression test. The results showed that the microstructure consists mainly of dendrites and interdendritic regions consisting of metastable crystalline phases. It was also observed that the AlCoFeNiVTi 0,5 alloy showed better mechanical properties than the AlCoFeNiMnTi 0,5 alloy. This may be associated with differences in the parameters of formation of simple solid solution phases between the two alloys. (author)

  4. Microstructure and Hot Deformation Behavior of Fe-20Cr-5Al Alloy

    OpenAIRE

    Jung-Ho Moon; Tae Kwon Ha

    2014-01-01

    High temperature deformation behavior of cast Fe-20Cr-5Al alloy has been investigated in this study by performing tensile and compression tests at temperatures from 1100 to 1200oC. Rectangular ingots of which the dimensions were 300×300×100 in millimeter were cast using vacuum induction melting. Phase equilibrium was calculated using the FactSage®, thermodynamic software and database. Tensile strength of cast Fe-20Cr-5Al alloy was 4 MPa at 1200oC. With temperature decreas...

  5. Effect of heat treatments on the microstructure and mechanical properties of an extruded Mg{sub 95.5}Y{sub 3}Zn{sub 1.5} alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huan; Xue, Feng, E-mail: xuefeng@seu.edu.cn; Bai, Jing; Sun, Yangshan

    2013-11-15

    The microstructure and mechanical properties of the extruded Mg{sub 95.5}Y{sub 3}Zn{sub 1.5} alloy under different heat treatment were systematically investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and an electronic universal testing machine. The results show that the as-extruded alloy is composed of 18R LPSO stripes and α-Mg matrix with stacking faults (SFs) in it. The fine 14H LPSO lamellas are formed in α-Mg matrix near the areas of SFs during solution treatment at 500 °C for 8 h. A great number of fine β′ phases are precipitated in the α-Mg matrix of T6-treated (aging of the T4-treated alloy at 225 °C for 24 h) and T5-treated (aging of the as-extruded alloy at 225 °C for 32 h) alloys. Moreover, the SFs which were first observed in extruded alloy are retained in T5-staged specimen, and exhibit a cross arrangement with β′ precipitates. The absence of 14H LPSO phase in T5-treated alloy indicates that the 14H structure cannot be formed during aging at 225 °C. Tensile tests reveal that the presence of 14H lamellas improves the ductility of the alloy, but decreases the strength, suggesting that the 18R LPSO stripes are more effective in strengthening the alloy than 14H LPSO lamellas. The T6-staged alloy exhibits superior comprehensive mechanical properties with ultimate tensile strength of 358 MPa, tensile yield strength of 226 MPa and elongation of 6.1% at room temperature.

  6. T-S Fuzzy Modelling and H∞ Attitude Control for Hypersonic Gliding Vehicles

    Directory of Open Access Journals (Sweden)

    Weidong Zhang

    2017-01-01

    Full Text Available This paper addresses the T-S fuzzy modelling and H∞ attitude control in three channels for hypersonic gliding vehicles (HGVs. First, the control-oriented affine nonlinear model has been established which is transformed from the reentry dynamics. Then, based on Taylor’s expansion approach and the fuzzy linearization approach, the homogeneous T-S local modelling technique for HGVs is proposed. Given the approximation accuracy and controller design complexity, appropriate fuzzy premise variables and operating points of interest are selected to construct the T-S homogeneous submodels. With so-called fuzzy blending, the original plant is transformed into the overall T-S fuzzy model with disturbance. By utilizing Lyapunov functional approach, a state feedback fuzzy controller has been designed based on relaxed linear matrix inequality (LMI conditions to stable the original plants with a prescribed H∞ performance of disturbance. Finally, numerical simulations are performed to demonstrate the effectiveness of the proposed H∞ T-S fuzzy controller for the original attitude dynamics; the superiority of the designed T-S fuzzy controller compared with other local controllers based on the constructed fuzzy model is shown as well.

  7. LIDAR TS for ITER core plasma. Part II: simultaneous two wavelength LIDAR TS

    Science.gov (United States)

    Gowers, C.; Nielsen, P.; Salzmann, H.

    2017-12-01

    We have shown recently, and in more detail at this conference (Salzmann et al) that the LIDAR approach to ITER core TS measurements requires only two mirrors in the inaccessible port plug area of the machine. This leads to simplified and robust alignment, lower risk of mirror damage by plasma contamination and much simpler calibration, compared with the awkward and vulnerable optical geometry of the conventional imaging TS approach, currently under development by ITER. In the present work we have extended the simulation code used previously to include the case of launching two laser pulses, of different wavelengths, simultaneously in LIDAR geometry. The aim of this approach is to broaden the choice of lasers available for the diagnostic. In the simulation code it is assumed that two short duration (300 ps) laser pulses of different wavelengths, from an Nd:YAG laser are launched through the plasma simultaneously. The temperature and density profiles are deduced in the usual way but from the resulting combined scattered signals in the different spectral channels of the single spectrometer. The spectral response and quantum efficiencies of the detectors used in the simulation are taken from catalogue data for commercially available Hamamatsu MCP-PMTs. The response times, gateability and tolerance to stray light levels of this type of photomultiplier have already been demonstrated in the JET LIDAR system and give sufficient spatial resolution to meet the ITER specification. Here we present the new simulation results from the code. They demonstrate that when the detectors are combined with this two laser, LIDAR approach, the full range of the specified ITER core plasma Te and ne can be measured with sufficient accuracy. So, with commercially available detectors and a simple modification of a Nd:YAG laser similar to that currently being used in the design of the conventional ITER core TS design mentioned above, the ITER requirements can be met.

  8. Microstructure and mechanical behavior of superelastic Ti-24Nb-0.5O and Ti-24Nb-0.5N biomedical alloys.

    Science.gov (United States)

    Ramarolahy, A; Castany, P; Prima, F; Laheurte, P; Péron, I; Gloriant, T

    2012-05-01

    In this study, the microstructure and the mechanical properties of two new biocompatible superelastic alloys, Ti-24Nb-0.5O and Ti-24Nb-0.5N (at.%), were investigated. Special attention was focused on the role of O and N addition on α(″) formation, supereleastic recovery and mechanical strength by comparison with the Ti-24Nb and Ti-26Nb (at.%) alloy compositions taken as references. Microstructures were characterized by optical microscopy, X-ray diffraction and transmission electron microscopy before and after deformation. The mechanical properties and the superelastic behavior were evaluated by conventional and cyclic tensile tests. High tensile strength, low Young's modulus, rather high superelastic recovery and excellent ductility were observed for both superelastic Ti-24Nb-0.5O and Ti-24Nb-0.5N alloys. Deformation twinning was shown to accommodate the plastic deformation in these alloys and only the {332} twinning system was observed to be activated by electron backscattered diffraction analyses. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Dual-tuning effects of In, Al, and Ti on the thermodynamics and kinetics of Mg85In5Al5Ti5 alloy synthesized by plasma milling

    International Nuclear Information System (INIS)

    Cao, Zhijie; Ouyang, Liuzhang; Wu, Yuyu; Wang, Hui; Liu, Jiangwen; Fang, Fang; Sun, Dalin; Zhang, Qingan; Zhu, Min

    2015-01-01

    Highlights: • Mg 85 In 5 Al 5 Ti 5 alloy catalyzed with in-situ formed MgF 2 was prepared by P-milling. • Reaction mechanism of Mg 85 In 5 Al 5 Ti 5 alloy was presented. • Further destabilization of Mg was realized (65.2 kJ/mol H 2 ). • Dual tuning of the thermodynamic and kinetic properties of MgH 2 was realized. - Abstract: The dehydrogenation enthalpy change of MgH 2 by reversibly forming an Mg 0.95 In 0.05 solid solution offers a new method for tuning the thermodynamics of Mg-based alloys. In order to further lower the stability of MgH 2 , Al has been introduced into Mg(In) solid solution. At the same time, to solve the problem of sluggish kinetic properties of Mg–In solid–solution systems and to lower the dehydrogenation activation energy, Ti has also been added. It has been demonstrated that the Mg 85 In 5 Al 5 Ti 5 alloy synthesized by plasma milling (P-milling) shows both enhanced dehydriding thermodynamics and kinetics. This technique could be used to synthesize Mg(In, Al) ternary solid solution incorporating the Ti catalyst in only one step, making it much more efficient than the two-step method. Compared with Mg-based solid solutions, the addition of Ti and in-situ synthesized MgF 2 improved the kinetics and the introduction of In as well as Al imparted enhanced thermodynamics to the Mg 85 In 5 Al 5 Ti 5 system. The dehydrogenation enthalpy change and activation energy were lowered to 65.2 kJ/(mol H 2 ) and 125.2 kJ/mol, respectively, for the Mg 85 In 5 Al 5 Ti 5 alloy

  10. Synthesis of Mo5SiB2 based nanocomposites by mechanical alloying and subsequent heat treatment

    International Nuclear Information System (INIS)

    Abbasi, A.R.; Shamanian, M.

    2011-01-01

    Research highlights: → α-Mo-Mo 5 SiB 2 nanocomposite was produced after 20 h milling of Mo-Si-B powders. → Heat treatment of 5 h MAed powders led to the formation of boride phases. → Heat treatment of 10 h MAed powders led to the formation of Mo 5 SiB 2 phase. → By increasing heat treatment time, quantity of Mo 5 SiB 2 phase increased. → 5 h heat treatment of 20 h MAed powders led to the formation of Mo 5 SiB 2 -based composite. - Abstract: In this study, systematic investigations were conducted on the synthesis of Mo 5 SiB 2 -based alloy by mechanical alloying and subsequent heat treatment. In this regard, Mo-12.5 mol% Si-25 mol% B powder mixture was milled for different times. Then, the mechanically alloyed powders were heat treated at 1373 K for 1 h. The phase transitions and microstructural evolutions of powder particles during mechanical alloying and heat treatment were studied by X-ray diffractometry and scanning electron microscopy. The results showed that the phase evolutions during mechanical alloying and subsequent heat treatment are strongly dependent on milling time. After 10 h of milling, a Mo solid solution was formed, but, no intermetallic phases were detected at this stage. However, an α-Mo-Mo 5 SiB 2 nanocomposite was formed after 20 h of milling. After heat treatment of 5 h mechanically alloyed powders, small amounts of MoB and Mo 2 B were detected and α-Mo-MoB-Mo 2 B composite was produced. On the other hand, heat treatment of 10 h and 20 h mechanically alloyed powders led to the formation of an α-Mo-Mo 5 SiB 2 -MoSi 2 -Mo 3 Si composite. At this point, there is a critical milling time (10 h) for the formation of Mo 5 SiB 2 phase after heat treatment wherein below that time, boride phase and after that time, Mo 5 SiB 2 phase are formed. In the case of 20 h mechanically alloyed powders, by increasing heat treatment time, not only the quantity of α-Mo was reduced and the quantity of Mo 5 SiB 2 was increased, but also new boride

  11. Low cost AB{sub 5}-type hydrogen storage alloys for a nickel-metal hydride battery

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Lijun [General Res. Inst. for Non-Ferrous Metals, Beijing (China); Zhan Feng [General Res. Inst. for Non-Ferrous Metals, Beijing (China); Bao Deyou [General Res. Inst. for Non-Ferrous Metals, Beijing (China); Qing Guangrong [General Res. Inst. for Non-Ferrous Metals, Beijing (China); Li Yaoquan [General Res. Inst. for Non-Ferrous Metals, Beijing (China); Wei Xiuying [General Res. Inst. for Non-Ferrous Metals, Beijing (China)

    1995-12-15

    The studies have been carried out on utilizing Ml(NiAl){sub 5}-based alloys as a low cost negative battery electrode. The replacement of nickel by copper improved the cycle lifetime to some extent without a decrease in capacity. Using Ml(NiAlCu){sub 5} alloys, hydrogen storage alloys with good overall characteristics and low cost were obtained through substituting cobalt or silicon for nickel. The discharge capacity was further increased by increasing the lanthanum content in lanthanum-rich mischmetal. (orig.)

  12. Zirconium hydrides and Fe redistribution in Zr-2.5%Nb alloy under ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Idrees, Y.; Yao, Z. [Department of Mechanical and Materials Engineering, Queen' s University, Kingston, ON, Canada, K7L 3N6 (Canada); Cui, J.; Shek, G.K. [Kinetrics, Mississauga, ON (Canada); Daymond, M.R., E-mail: daymond@queensu.ca [Department of Mechanical and Materials Engineering, Queen' s University, Kingston, ON, Canada, K7L 3N6 (Canada)

    2016-11-15

    Zr-2.5%Nb alloy is used to fabricate the pressure tubes of the CANDU reactor. The pressure tube is the primary pressure boundary for coolant in the CANDU design and is susceptible to delayed hydride cracking, reduction in fracture toughness upon hydride precipitation and potentially hydride blister formation. The morphology and nature of hydrides in Zr-2.5%Nb with 100 wppm hydrogen has been investigated using transmission electron microscopy. The effect of hydrides on heavy ion irradiation induced decomposition of the β phase has been reported. STEM-EDX mapping was employed to investigate the distribution of alloying elements. The results show that hydrides are present in the form of stacks of different sizes, with length scales from nano- to micro-meters. Heavy ion irradiation experiments at 250 °C on as-received and hydrided Zr-2.5%Nb alloy, show interesting effects of hydrogen on the irradiation induced redistribution of Fe. It was found that Fe is widely redistributed from the β phase into the α phase in the as-received material, however, the loss of Fe from the β phase and subsequent precipitation is retarded in the hydrided material. This preliminary work will further the current understanding of microstructural evolution of Zr based alloys in the presence of hydrogen. - Graphical abstract: STEM HAADF micrographs at low magnification showing the hydride structure in Zr-2.5Nb alloy.

  13. Giant magnetocaloric effect in Gd5(Si2Ge2 alloy with low purity Gd

    Directory of Open Access Journals (Sweden)

    Cleber Santiago Alves

    2004-12-01

    Full Text Available Gd5(Ge1-xSi x, x < 4 based alloys are potential candidates for magnetic refrigeration in the range ~20 - ~290 K. However, one of the greatest obstacles for the use of that technology in large scale is the utilization of high pure Gd metal (99.99 wt. (% to produce the GdGeSi alloys, since the impurity elements decrease the intensity of the magnetocaloric effect (EMC¹. In this work, we prove that annealing of the Gd5Ge2Si2 can promote remarkable values for the EMC in comparison to those obtained for the alloy with high pure Gd. Also, the as cast alloy and the annealed alloy are not monophasic, but have at least two crystalline phases in their microstructure. Results for X-ray analysis, optical and electronic microscopy and magnetization measurements are reported.

  14. A novel concurrent chemoradiotherapy with TS-1/nedaplatin for esophageal cancer showing better quality of life durning treatment

    International Nuclear Information System (INIS)

    Miyazaki, Aya; Inaba, Hiroyuki; Tsuda, Takashi; Itoh, Fumio

    2005-01-01

    Concurrent chemoradiotherapy (CRT) for esophageal cancer is expected to achieve adequate quality of life (QOL) and to improve the survival of patients. As a QOL-oriented therapy for esophageal cancer, concurrent CRT with tegafur·gimestat·otastat potassium (TS-1)/nedaplatin (CDGP) was developed and evaluated. Between June 2001 and September 2002, 18 patients with esophageal cancer were enrolled in a clinical study of concurrent CRT with TS-1/CDGP. To evaluate the impact of treatment on the QOL, the patients were asked to answer QOL Questionnaire for Cancer Patients Treated with Anticancer Drugs (QOL-ACD) before and after therapy. The response rate was 66.7%, with a complete response occurring in 9 (50.0%) of the 18 patients. Patients with improved global, functional, or mental QOL after therapy showed or tended to show a significant, longer survival. Compared to patients previously treated by the same regimen with 5-fluorouracil (5-FU) instead of TS-1, those receiving the present therapy were able to leave hospital more frequently during treatment. TS-1/CDGP-based CRT for esophageal cancer exhibited comparable antitumor activity and survival benefit as with standard 5-FU/cisplatin (CDDP)-based CRT without causing serious side-effects. The patients receiving the present therapy seemed to have a better chance of maintaining their QOL. (author)

  15. Evaluation of the egg transmission and pathogenicity of Mycoplasma gallisepticum isolates genotyped as ts-11.

    Science.gov (United States)

    Armour, Natalie K; Ferguson-Noel, Naola

    2015-01-01

    Live Mycoplasma gallisepticum vaccines are used for the control of respiratory disease, egg production losses and egg transmission associated with M. gallisepticum infection in long-lived poultry. The first field case of apparent increased virulence and vertical transmission of ts-11, a live M. gallisepticum vaccine, has been reported. In that study a M. gallisepticum isolate from the broiler progeny of ts-11-vaccinated breeders was genotyped as ts-11 by sequence analysis of four different genetic targets and Random Amplified Polymorphic DNA and found to be significantly more virulent than ts-11 vaccine. The objective of the current study was to evaluate the rate of egg transmission and pathogenicity of ts-11 vaccine and isolates recovered from ts-11-vaccinated breeders (K6222B) and their broiler progeny (K6216D) which had been genotyped as ts-11. Groups of 28-week-old specific pathogen-free chickens at 87% average weekly egg production were inoculated with sterile broth media (negative controls), ts-11 vaccine, K6222B, K6216D or R strain (positive controls) by eye-drop and aerosol. K6216D transmitted via the egg at an average rate of 4.0% in the third and fourth weeks post-infection, while egg transmission of K6222B and ts-11 vaccine was not detected. M. gallisepticum was isolated from the air sacs, ovaries and oviducts of hens infected with K6216D and K6222B, but not from those infected with ts-11 vaccine. K6216D and K6222B both induced respiratory signs and significantly more tracheal colonization and more severe tracheal and air sac lesions than ts-11 vaccine (P ≤ 0.05). There were no substantial differences in the egg production of ts-11, K6216D and K6222B infected groups. These results provide the first conclusive evidence of transovarian transmission of an isolate genotyped as ts-11 and indicate that isolates genotyed as ts-11 vary in their virulence and ability to transmit via the egg.

  16. Operation and consolidation: lifetime of equipment and priorities TS

    CERN Document Server

    Béjar-Alonso, Isabel

    2008-01-01

    Since 1999 the TS department has benchmarked his services with the industry and other research laboratories and has prepared several consolidation plans. An evaluation of the results obtained from the different consolidation plans will be summarized. The difference between the projects achieved and those planned will be analyzed. The impact of the differed consolidation and of the maintenance backlog will be analyzed in order to present the future TS consolidation strategy

  17. The rate of charge tunneling is insensitive to polar terminal groups in self-assembled monolayers in Ag(TS)S(CH2)(n)M(CH2)(m)T//Ga2O3/EGaIn junctions.

    Science.gov (United States)

    Yoon, Hyo Jae; Bowers, Carleen M; Baghbanzadeh, Mostafa; Whitesides, George M

    2014-01-08

    This paper describes a physical-organic study of the effect of uncharged, polar, functional groups on the rate of charge transport by tunneling across self-assembled monolayer (SAM)-based large-area junctions of the form Ag(TS)S(CH2)(n)M(CH2)(m)T//Ga2O3/EGaIn. Here Ag(TS) is a template-stripped silver substrate, -M- and -T are "middle" and "terminal" functional groups, and EGaIn is eutectic gallium-indium alloy. Twelve uncharged polar groups (-T = CN, CO2CH3, CF3, OCH3, N(CH3)2, CON(CH3)2, SCH3, SO2CH3, Br, P(O)(OEt)2, NHCOCH3, OSi(OCH3)3), having permanent dipole moments in the range 0.5 < μ < 4.5, were incorporated into the SAM. A comparison of the electrical characteristics of these junctions with those of junctions formed from n-alkanethiolates led to the conclusion that the rates of charge tunneling are insensitive to the replacement of terminal alkyl groups with the terminal polar groups in this set. The current densities measured in this work suggest that the tunneling decay parameter and injection current for SAMs terminated in nonpolar n-alkyl groups, and polar groups selected from common polar organic groups, are statistically indistinguishable.

  18. Do's and Don'ts for Liposuction

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Do's and don’ts for liposuction Don’t ...

  19. Experiments in a boundary layer subjected to free stream turbulence. Part 2: The role of TS waves in the transition process

    International Nuclear Information System (INIS)

    Boiko, A.V.; Westin, K.J.A.; Klingmann, B.G.B.; Kozlov, V.V.; Alfredsson, P.H.

    1993-12-01

    The natural occurrence of Tollmien-Schlichting (TS) waves has so far only been observed in boundary layers subjected to moderate levels of free stream turbulence (Tu <1%), due to the difficulty in detecting small-amplitude waves in highly perturbed boundary layers. By introducing controlled oscillations with a vibrating ribbon, it is possible to study small amplitude waves using phase-selective filtering techniques. In the present work, the effect of TS-waves on the transition is studied at Tu = 1.5%. It is demonstrated that TS-waves can exist and develop in a similar way as in an undisturbed boundary layer. It is also found that TS-waves with quite small amplitudes are involved in nonlinear interactions which lead to a regeneration of TS-waves in the whole unstable frequency band. This results in a significant increase in the number of turbulent spots, which promote the onset of turbulence. 28 refs

  20. Identification and characterization of a Bacillus subtilis strain TS06 ...

    African Journals Online (AJOL)

    Replant disease is a major limitation for strawberry production in greenhouse. Bio-control may be a good way to cope with the replant diseases. Here, we report identification and characterization of a bacterial strain TS06 that may be used as a bio-control agent against the replant diseases in strawberry. TS06 was identified ...

  1. Microstructural studies of suck cast (Zr-SS)-3 and 5 AI alloys for nuclear metallic waste form

    International Nuclear Information System (INIS)

    Kumar, P.; Das, N.; Sengupta, P.; Arya, A.; Dey, G.K.

    2015-01-01

    Management of radioactive metallic waste using 'alloy melting route' is currently being investigated. For disposal of Zr and SS base nuclear metallic wastes, Zr-stainless steel (SS) hybrid alloys are being considered as baseline alloys for developing metallic-waste-form (MWF) alloys. In this context Zr-16 wt. %55 has been selected for MWF alloy in our previous study. In present study, to include amorphous phase in this alloy, 3 and 5 wt. % Al has been added in order to improve desirable properties and useful features of MWF and the two alloys have been prepared by suck casting techniques. Microstructure of these alloys have been investigated by optical and electron microscopy which shows occurrence of two different phases, e.g. dark grey and white phases, in (Zr-16 SS)-3 Al and three different phases, e.g. grey, dark grey and white phases in (Zr-16 SS)-5 AI. Electron diffraction and X-ray diffraction (XRD) analyses of these two alloy specimens revealed the occurrence of Zr (Fe, Cr, AI) (dark grey) and Zr 2 (Fe, Cr, AI) (white) phases in (Zr-16 SS)-3 Al whereas, Zr (Fe, Cr, AI) (dark grey), Zr 2 (Fe, Cr, AI) (grey) and Zr 3 (Fe, Cr, AI) (white) phases were found in (Zr-16 SS)-5 AI. In addition, presence of amorphous phase was indicated by XRD analysis that could be confirmed by transmission electron microscopy of these two alloys. (author)

  2. CaTs Lab (CHAOS and Thermal Sciences Laboratory)

    Science.gov (United States)

    Teate, Anthony A.

    2002-01-01

    The CHAOS and Thermal Sciences Laboratory (CaTs) at James Madison University evolved into a noteworthy effort to increase minority representation in the sciences and mathematics. Serving ten students and faculty directly, and nearly 50 students indirectly, CaTs, through recruitment efforts, workshops, mentoring programs, tutorial services and research and computational laboratories, fulfilled its intent to initiate an academically enriched research program aimed at strengthening the academic and self-actualization skills of undergraduate students with potential to pursue doctoral study in the sciences. The stated goal of the program was to increase by 5% the number of enrolled mathematics and science students into the program. Success far exceeded the program goals by producing 100% graduation rate of all supported recipients during its tenure, with 30% of the students subsequently in pursuit of graduate degrees. Student retention in the program exceeded 90% and faculty participation exceeded the three members involved in mentoring and tutoring, gaining multi-disciplinary support. Aggressive marketing of the program resulted in several paid summer internships and commitments from NASA and an ongoing relationship with CHROME, a nationally recognized organization which focuses on developing minority students in the sciences and mathematics. Success of the program was only limited by the limited fiscal resources at NASA which resulted in phasing out of the program.

  3. Electrochemical Corrosion Behavior of Oxidation Layer on Fe30Mn5Al Alloy

    Directory of Open Access Journals (Sweden)

    ZHU Xue-mei

    2017-08-01

    Full Text Available The Fe30Mn5Al alloy was oxidized at 800℃ in air for 160h, the oxidation-induced layer about 15μm thick near the scale-metal interface was induced to transform to ferrite and become enriched in Fe and depletion in Mn. The effect of the oxidation-induced Mn depletion layer on the electrochemical corrosion behavior of Fe30Mn5Al alloy was evaluated. The results show that in 1mol·L-1 Na2SO4 solution, the anodic polarization curve of the Mn depletion layer exhibits self-passivation, compared with Fe30Mn5Al austenitic alloy, and the corrosion potential Evs SCE is increased to -130mV from -750mV and the passive current density ip is decreased to 29μA/cm2 from 310μA/cm2. The electrochemical impedance spectroscopy(EIS of the Mn depletion layer has the larger diameter of capacitive arc, the higher impedance modulus|Z|, and the wider phase degree range, and the fitted polarization resistant Rt is increased to 9.9kΩ·cm2 from 2.7kΩ·cm2 by using an equivalent electric circuit of Rs-(Rt//CPE. The high insulation of the Mn depletion layer leads to an improved corrosion resistance of Fe30Mn5Al austenitic alloy.

  4. In search of zero thermal expansion anisotropy in Mo{sub 5}Si{sub 3} by strategic alloying

    Energy Technology Data Exchange (ETDEWEB)

    Dharmawardhana, C.C., E-mail: ccdxz8@mail.umkc.edu; Sakidja, R., E-mail: sakidjar@umkc.edu; Aryal, S.; Ching, W.Y.

    2015-01-25

    Highlights: • For the first time, theoretical prediction of achieving isotropic thermal expansion anisotropy (TEA) for T1 phase Mo{sub 5}Si{sub 3} by alloying with a mere 17.5% Al substitution on the Si sites. Most effective alloying proposed for the said system up to date. • The theoretical approach is verified by simulating the experimentally observed unusual TEA behaviour for (Mo,V){sub 5}Si{sub 3} alloys as a function of percent alloying. • The 2nd order and 3rd order elastic constants we explain the origin of the TEA in T1 phase for Mo{sub 5}Si{sub 3} system and how Al effect in reducing the TEA. • We use directional dependent phonon density of state, a novel approach, to identify the origin of the anisotropy and show this method of analysis could be used for other intermetallic alloys as well. - Abstract: Reducing the thermal expansion anisotropy (TEA) of alloy compounds is one of the most important issues for their potential applications in high temperature environment. The Mo{sub 5}Si{sub 3} (T1 phase) is known to be an important intermetallic compound with high melting temperature. Unfortunately, its large TEA renders it unsuitable for high temperature structural/coating applications. Many attempts have been made in the past to reduce TEA by substituting Mo by other transition metal ions such as V with little success and some unexpected observations. Here we use accurate ab initio molecular dynamics (AIMD) simulations to obtain the TEA from thermal expansion coefficients for two T1 phase alloy systems (Mo,V){sub 5}Si{sub 3} and Mo{sub 5}(Si,Al){sub 3}. We demonstrate that strategic alloying with Al substituting Si can achieve zero TEA for T1 phase. The microscopic origin of this outstanding thermomechanical properties in this alloy is explained by the calculation of higher order elastic constants in conjunction with atom and direction-resolved phonon density of states.

  5. Solid solution in Al-4.5 wt% Cu produced by mechanical alloying

    International Nuclear Information System (INIS)

    Fogagnolo, J.B.; Amador, D.; Ruiz-Navas, E.M.; Torralba, J.M.

    2006-01-01

    Mechanical alloying has been used to produce oxide dispersion strengthened alloys, intermetallic compounds, aluminium alloys and to obtain nanostructured and amorphous materials, as well as to extend the solid solution limit. In this work, Al and Cu elemental powders were subjected to high-energy milling to produce Al-4.5 wt% Cu powder alloy. The powders obtained were characterized by scanning electron microscopy, X-ray diffraction (XRD) and differential scanning calorimetry (DSC), aiming to explore if the copper is present in solid solution or as small particles after high-energy milling. Related to the formation of a supersaturated solid solution, the results of scanning electron microscopy and X-ray diffraction are non-conclusive: the copper could be dispersed with a very small size, undetectable to both techniques. The Al 2 Cu precipitation at temperatures between 160 and 230 deg. C, verified by DSC and XRD analyses, substantiated that mechanical alloying had produced a supersaturated solid solution of copper in aluminium. The crystallite size as a function of milling time and annealing temperature was also determined by X-ray techniques

  6. The growth temperature and measurement temperature dependences of soft magnetic properties and effective damping parameter of (FeCo-Al alloy thin films

    Directory of Open Access Journals (Sweden)

    Yusuke Ariake

    2018-05-01

    Full Text Available The soft magnetic properties and effective damping parameters of Fe73Co25Al2 alloy thin films are discussed. The effective damping parameter αeff measured by ferromagnetic resonance for the 10 nm-thick sample is nearly constant (≈0.004 ± 0.0008 for a growth temperature Ts from ambient to 200 °C, and then tends to decrease for higher temperatures and αeff is 0.002 ± 0.0004 at Ts = 300 °C. For the 80 nm-thick sample, the αeff seems to increase with Ts from αeff = 0.001 ± 0.0002 at Ts = ambient to αeff = 0.002 ± 0.0004. The αeff is found nearly constant (αeff = 0.004 ± 0.0008 over a temperature range from 10 to 300 K for the 10 nm films with the different Ts (ambient, 100 and 200 °C. Together with an increasing non-linearity of the frequency dependence of the linewidth at low Ts, extrinsic contributions such as two-magnon scattering dominate the observed temperature dependence of effective damping and linewidth.

  7. Thermal conductivity of Cu–4⋅5 Ti alloy

    Indian Academy of Sciences (India)

    Unknown

    Abstract. The thermal conductivity (TC) of peak aged Cu–4⋅5 wt% Ti alloy was measured at different tem- peratures and studied its variation with temperature. It was found that TC increased with increasing tem- perature. Phonon and electronic components of thermal conductivity were computed from the results. The.

  8. Dynamic Shear Deformation and Failure of Ti-6Al-4V and Ti-5Al-5Mo-5V-1Cr-1Fe Alloys.

    Science.gov (United States)

    Ran, Chun; Chen, Pengwan

    2018-01-05

    To study the dynamic shear deformation and failure properties of Ti-6Al-4V (Ti-64) alloy and Ti-5Al-5Mo-5V-1Cr-1Fe (Ti-55511) alloy, a series of forced shear tests on flat hat shaped (FHS) specimens for the two investigated materials was performed using a split Hopkinson pressure bar setup. The evolution of shear deformation was monitored by an ultra-high-speed camera (Kirana-05M). Localized shear band is induced in the two investigated materials under forced shear tests. Our results indicate that severe strain localization (adiabatic shear) is accompanied by a loss in the load carrying capacity, i.e., by a sudden drop in loading. Three distinct stages can be identified using a digital image correlation technique for accurate shear strain measurement. The microstructural analysis reveals that the dynamic failure mechanisms for Ti-64 and Ti-55511 alloys within the shear band are of a cohesive and adhesive nature, respectively.

  9. Effect of Bi-content on hardness and micro-creep behavior of Sn-3.5Ag rapidly solidified alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kamal, M. [Metal Physics Laboratory, Faculty of Science, Mansoura University (Egypt); Gouda, El Said [Metal Physics Laboratory, Department of Solid State Physics, Physics Division, National Research Center, Dokki, Giza (Egypt); Marei, L.K. [Faculty of Petroleum and Mining Engineering, Suez Canal University, Suez (Egypt)

    2009-12-15

    In the present paper, the influence of 1, 3, 5 and 10 % Bi (weight %) as ternary additions on structure, melting and mechanical properties of rapidly solidified Sn-3.5Ag alloy has been investigated. The effect of Bi was discussed based on the experimental results. The experimental results showed that the alloys of Sn-3.5Ag, Sn-3.5Ag-1Bi and Sn-3.5Ag-3Bi are composed of two phases; Ag{sub 3}Sn IMC embedded in Sn matrix phase, which indicated that the solubility of Bi phase in Sn-matrix was extended to 3 % as a result of rapid solidification. Bi precipitation in Sn matrix was only observed in Sn-3.5Ag-5Bi and Sn-3.5Ag-10Bi alloys. Also, addition of Bi decreased continuously the melting point of the eutectic Sn-3.5Ag alloy to 202.6 C at 10 % Bi. Vickers hardness of Sn-3.5Ag rapidly solidified alloy increased with increasing Bi content up to 3 % due to supersaturated solid solution strengthening hardening mechanism of Bi phase in Sn matrix, while the alloys contain 5 and 10 % Bi exhibited lower values of Vickers hardness. The lower values can be attributed to the precipitation of Bi as a secondary phase which may form strained regions due to the embrittlement of Bi atom. In addition, the effect of Bi addition on the micro-creep behavior of Sn-3.5Ag alloy as well as the creep rate have been described and has been calculated at room temperature. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Molybdate and molybdate/permanganate conversion coatings on Mg-8.5Li alloy

    International Nuclear Information System (INIS)

    Wang Guixiang; Zhang Milin; Wu Ruizhi

    2012-01-01

    A novel environment-friendly conversion coating for Mg-8.5Li alloy was obtained by immersing in a solution of molybdate. The concentration of ammonium molybdate and the addition of potassium permanganate were discussed in this experiment. The surface morphology of the conversion coatings was observed by scanning electron microscopy (SEM), and the chemical composition was investigated by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The corrosion resistance of Mg-8.5Li alloy and conversion coatings were investigated by means of potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurement. The results showed that the coatings with cracked morphology were homogeneous and uniform. The conversion coatings were mainly composed of metal-oxide as detected by XPS. The results of electrochemical measurement and weight loss measurement revealed that the molybdate conversion coating had better corrosion resistance than bare alloy and chromate conversion coating, and the molybdate/permanganate conversion coating had lower corrosion current density and higher coating resistance than the molybdate conversion coating.

  11. Molybdate and molybdate/permanganate conversion coatings on Mg-8.5Li alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wang Guixiang, E-mail: wgx0357@126.com [Key Laboratory of Superlight Material and Surface Technology, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Zhang Milin; Wu Ruizhi [Key Laboratory of Superlight Material and Surface Technology, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China)

    2012-01-15

    A novel environment-friendly conversion coating for Mg-8.5Li alloy was obtained by immersing in a solution of molybdate. The concentration of ammonium molybdate and the addition of potassium permanganate were discussed in this experiment. The surface morphology of the conversion coatings was observed by scanning electron microscopy (SEM), and the chemical composition was investigated by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The corrosion resistance of Mg-8.5Li alloy and conversion coatings were investigated by means of potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurement. The results showed that the coatings with cracked morphology were homogeneous and uniform. The conversion coatings were mainly composed of metal-oxide as detected by XPS. The results of electrochemical measurement and weight loss measurement revealed that the molybdate conversion coating had better corrosion resistance than bare alloy and chromate conversion coating, and the molybdate/permanganate conversion coating had lower corrosion current density and higher coating resistance than the molybdate conversion coating.

  12. Microstructures and mechanical responses of powder metallurgy non-combustive magnesium extruded alloy by rapid solidification process in mass production

    International Nuclear Information System (INIS)

    Kondoh, Katsuyoshi; Hamada, EL-Sayed Ayman; Imai, Hisashi; Umeda, Junko; Jones, Tyrone

    2010-01-01

    Spinning Water Atomization Process (SWAP), which was one of the rapid solidification processes, promised to produce coarse non-combustible magnesium alloy powder with 1-4 mm length, having fine α-Mg grains and Al 2 Ca intermetallic compounds. It had economical and safe benefits in producing coarse Mg alloy powders with very fine microstructures in the mass production process due to its extreme high solidification rate compared to the conventional atomization process. AMX602 (Mg-6%Al-0.5%Mn-2%Ca) powders were compacted at room temperature. Their green compacts with a relative density of about 85% were heated at 573-673 K for 300 s in Ar gas atmosphere, and immediately consolidated by hot extrusion. Microstructure observation and evaluation of mechanical properties of the extruded AMX602 alloys were carried out. The uniform and fine microstructures with grains less than 0.45-0.8 μm via dynamic recrystallization during hot extrusion were observed, and were much small compared to the extruded AMX602 alloy fabricated by using cast ingot. The extremely fine intermetallic compounds 200-500 nm diameter were uniformly distributed in the matrix of powder metallurgy (P/M) extruded alloys. These microstructures caused excellent mechanical properties of the wrought alloys. For example, in the case of AMX602 alloys extruded at 573 K, the tensile strength (TS) of 447 MPa, yield stress (YS) of 425 MPa and 9.6% elongation were obtained.

  13. Precursor effect on the property and catalytic behavior of Fe-TS-1 in butadiene epoxidation

    Science.gov (United States)

    Wu, Mei; Zhao, Huahua; Yang, Jian; Zhao, Jun; Song, Huanling; Chou, Lingjun

    2017-11-01

    The effect of iron precursor on the property and catalytic behavior of iron modified titanium silicalite molecular sieve (Fe-TS-1) catalysts in butadiene selective epoxidation has been studied. Three Fe-TS-1 catalysts were prepared, using iron nitrate, iron chloride and iron sulfate as precursors, which played an important role in adjusting the textural properties and chemical states of TS-1. Of the prepared Fe-TS-1 catalysts, those modified by iron nitrate (FN-TS-1) exhibited a significant enhanced performance in butadiene selective epoxidation compared to those derived from iron sulfate (FS-TS-1) or iron chloride (FC-TS-1) precursors. To obtain a deep understanding of their structure-performance relationship, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Temperature programmed desorption of NH3 (NH3-TPD), Diffuse reflectance UV-Vis spectra (DR UV-Vis), Fourier transformed infrared spectra (FT-IR) and thermal gravimetric analysis (TGA) were conducted to characterize Fe-TS-1 catalysts. Experimental results indicated that textural structures and acid sites of modified catalysts as well as the type of Fe species influenced by the precursors were all responsible for the activity and product distribution.

  14. Casting defects and mechanical properties of high pressure die cast Mg-Zn-Al-RE alloys

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Wenlong; Easton, Mark A.; Zhu, Suming; Nie, Jianfeng [CAST Cooperative Research Centre, Department of Materials Engineering Monash University, Melbourne, VIC (Australia); Dargusch, Matthew S. [School of Mechanical and Mining Engineering, University of Queensland, Brisbane, QLD (Australia); Gibson, Mark A. [CSIRO Process Science and Engineering, Melbourne, VIC (Australia); Jia, Shusheng [Key Laboratory of Automobile Materials, Ministry of Education, Department of Materials Science and Engineering Jilin University, Changchun (China)

    2012-02-15

    The die casting defects and tensile properties of high pressure die cast (HPDC) Mg-Zn-Al-RE alloys with various combinations of Zn and Al were studied. The results show that die casting defects in Mg-Zn-Al-RE alloys are affected by the percentage of Zn and Al contents. The hot tearing susceptibility (HTS) of Mg-Zn-Al-RE alloys tends to increase with increasing Zn content up to 6 wt%, while a further increase of Al and/or Zn content reduces the HTS. In tensile tests, the yield strength (YS) is generally improved by increasing Zn or Al content, whereas the tensile strength (TS) and ductility appear to depend largely on the presence of casting defects. Compared with Mg-Zn-Al alloys, the mechanical properties of the Mg-Zn-Al-RE alloy are significantly improved. The Mg-4Zn-4Al-4RE alloy is found to have few casting defects and the optimal tensile properties. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Review of $V_{cb}$ and $V_{td}/V_{ts}$

    OpenAIRE

    Forty, Roger W

    1997-01-01

    The current experimental status of the CKM matrix element V_cb and the ratio V_td/V_ts is reviewed. Knowledge of these elements has a strong impact on the unitarity triangle, of interest for studies of CP violation in the B system. The measurements of V_cb from both inclusive semileptonic b decays and the exclusive channel B -> D* l nu are reaching high precision. For V_td/V_ts the strongest upper limit is derived from studies of B-Bbar mixing.

  16. Corrosion behavior of novel imitation-gold copper alloy with rare earth in 3.5% NaCl solution

    International Nuclear Information System (INIS)

    Chen, J.L.; Li, Z.; Zhu, A.Y.; Luo, L.Y.; Liang, J.

    2012-01-01

    Highlights: → The design alloy has better anti-tarnish property than that of H7211 alloy during salt-spray test. → The corrosion rate of design alloy is much lower than that of H7211 alloy as immersed in NaCl solution. → In the low frequency region, the capacitive behavior normally faded and diffusion process had a key role. → In the medium frequency region, the Bode pattern showed a capacitive behavior. -- Abstract: A novel imitation-gold copper alloy with rare earth was designed and prepared. The corrosion behavior of the alloy immersed in 3.5% NaCl solution and its anti-tarnish property in the salt spray for different days has been studied. The designed alloy (CuZnAlNiMeRe) has more excellent anti-tarnish property and lower corrosion rate than those of currency coinage materials of H7211 alloy (used in China). A uniform and compact of corrosion film has been formed after the designed alloy immersed in 3.5% NaCl solution. The corrosion current densities I corr of the alloy decreased while the polarization resistance R p increased with time. The capacitance of the corrosion product film C film of the alloy decreased while the charge transfer resistance R ct . The Warburg diffusion impedance W R and the resistance of the equivalent circuit R increased with time.

  17. Transport of UF6 in compliance with TS-R-1

    International Nuclear Information System (INIS)

    Dekker, B.G.

    2004-01-01

    The IAEA Regulations TS-R-1 (ST-1, Revised) 1996 Edition include requirements for packages containing uranium hexafluoride (UF6); these are the first and only substance-specific requirements in the IAEA regulations. These requirements have already particularly affected, and will further affect, the transport of non-fissile and fissile excepted UF 6 and the packages used for these transports. Non-fissile and fissile excepted UF6 (ASTM C 787) has been transported worldwide for decades in a safe and reliable manner, using internationally standardised packages. Under the auspices of the World Nuclear Transport Institute (WNTI), an industry working group has been evaluating the existing packages against the requirements in TS-R-1. As new requirements came into effect, there were new challenges for the use of these standard packages, including the free drop test and the thermal requirements. In close cooperation with the WNTI HEXT Industry Working Group, a consortium of UF6 producers/users has worked together on the design and development, testing and certification of technical solutions for modification and optimisation of the existing packages to comply with TS-R-1. This paper reviews the existing standard packages against the requirements in TS-R-1. An update is also given describing the enhancements to the standard packages that have been designed and developed recently. The paper also describes how these solutions have been tested and certified, as well as the status of implementation. Finally, a review is made of the options that are available internationally to transport UF6 in compliance with TS-R-1. (author)

  18. Porosity in fiber laser formation of 5A06 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yang Chun; Wang, Chun Ming; Hu, Xi Yuan; Wang, Jun; Yu, Sheng Fu [HUST, Wuhan (China)

    2010-05-15

    The mechanism of porosity formation and its suppression methods in laser formation of aluminum alloy have been studied using a 4kW fiber laser to weld 5A06 aluminum alloy with SAl-Mg5 filler. It was found that the porosity formation is closely related to the stability of the keyhole and fluctuation of the molten pool in the laser welding aluminum alloy. The filling wire increased the instability of the keyhole and weld pool, thus further increasing the amount of gas cavities in the joint. Prefabrication of a suitable gap for the butt joint can provide a natural passage for the flow of the liquid metal, which can weaken, and even completely eliminate the disturbance of the filling wire on the formation of keyhole. The gap can also provide a passage for the escape of the bubble. Thus, this method can greatly decrease the sheet's susceptibility to porosity. Moreover, for a thin sheet, if the power of the laser is sufficient to form a keyhole with stable penetration through the weld sheet, a weld bead without porosity can also be obtained because closing the keyhole is almost impossible

  19. Porosity in fiber laser formation of 5A06 aluminum alloy

    International Nuclear Information System (INIS)

    Yu, Yang Chun; Wang, Chun Ming; Hu, Xi Yuan; Wang, Jun; Yu, Sheng Fu

    2010-01-01

    The mechanism of porosity formation and its suppression methods in laser formation of aluminum alloy have been studied using a 4kW fiber laser to weld 5A06 aluminum alloy with SAl-Mg5 filler. It was found that the porosity formation is closely related to the stability of the keyhole and fluctuation of the molten pool in the laser welding aluminum alloy. The filling wire increased the instability of the keyhole and weld pool, thus further increasing the amount of gas cavities in the joint. Prefabrication of a suitable gap for the butt joint can provide a natural passage for the flow of the liquid metal, which can weaken, and even completely eliminate the disturbance of the filling wire on the formation of keyhole. The gap can also provide a passage for the escape of the bubble. Thus, this method can greatly decrease the sheet's susceptibility to porosity. Moreover, for a thin sheet, if the power of the laser is sufficient to form a keyhole with stable penetration through the weld sheet, a weld bead without porosity can also be obtained because closing the keyhole is almost impossible

  20. Low temperature study of mechanically alloyed Fe{sub 67.5}Ni{sub 32.5} Invar sample

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, J.L. [Departamento de Física, Universidad del Valle, A. A. 25360, Cali (Colombia); Valderruten, J.F. [Departamento de Ingeniería, Universidad Cooperativa de Colombia, Bucaramanga (Colombia); Pérez Alcázar, G.A., E-mail: gpgeperez@gmail.com [Departamento de Física, Universidad del Valle, A. A. 25360, Cali (Colombia); Colorado, H.D. [Departamento de Física, Universidad del Valle, A. A. 25360, Cali (Colombia); Romero, J.J. [Instituto de Microelectrónica de Madrid, CNM, CSIC, C/Isaac Newton 8, Tres Cantos, 28760 Madrid (Spain); González, J.M. [Unidad Asociada ICMM-IMA, Apdo. 155, Las Rozas, 28230 Madrid (Spain); Greneche, J.M. [LUNAM, Université du Maine, Institut des Molécules et Matériaux du Mans, UMR CNRS 6283, 72085 Le Mans, Cedex 9 (France); Marco, J.F. [Instituto de Química-Física ' ' Rocasolano' ' , CSIC, C/Serrano 119, 28006 Madrid (Spain)

    2015-07-01

    The study at low temperatures of powder of the Invar alloy, Fe{sub 67.5}Ni{sub 32.5}, produced by mechanical alloying, shows that the sample presents two structural phases, the Fe–Ni BCC and the Fe–Ni FCC. The {sup 57}Fe Mössbauer spectra obtained in this sample at different temperatures were fitted considering two hyperfine magnetic field distributions. The first one having the larger mean field and only one peak (at ca. 35 T, varying with T), is associated with the BCC phase, and the second one, presenting several broad peaks (distributed between 10 and 35 T), is associated to the FCC phase. A singlet, which is associated to low spin Fe sites of the FCC phase, was also considered. The mean hyperfine magnetic field of the BCC phase increases monotonically as temperature decreases, while that of the FCC phase presents an anomaly near 75 K. The real part of the ac magnetic susceptibility temperature scans presents a peak whose position increases from 31 to 39 K, when the ac field frequency increases from 100 to 5000 Hz. These results permit to associate the detected anomaly to the occurrence of a reentrant spin glass transition. - Highlights: • XRD detect the BCC and FCC nanocrystalline phases in the Invar Fe{sub 67.5}Si{sub 32.5}. • Mössbauer spectra were fitted with two HMFDs and a singlet. • The MHMF and the isomer shift of the FCC structure present a kink near 61 K. • Magnetic susceptibility proved that this anomaly corresponds to a RSG- F transition. • The Invar composition of the MA Fe{sub 67.5}Si{sub 32.5} alloy presents the frustration phenomena.

  1. Determination of activation energy of hydrogen diffusion in Zr-2.5%Nb alloy

    International Nuclear Information System (INIS)

    Chandra, Komal; Kulkarni, A.S.; Ramanjaneyulu, P.S.; Yadav, C.S.; Saxena, M.K.; Tomar, B.S.; Ramakumar, K.L.; Sunil, Sourav; Singh, R.N.

    2013-01-01

    The present paper describes the study on the determination of diffusion coefficient of hydrogen in Zr-2.5%Nb alloy. Hydrogen was charged on Zr-2.5% Nb alloy electrolytically. After annealing at required temperature, hydrogen concentration at various depths from the charged end was determined employing hot vacuum extraction-quadrupole mass spectrometer (HVE-QMS). The depth profile was used to obtain the diffusion coefficient employing Fick's second law of diffusion. From the Arrhenius relation between diffusion coefficient and temperature, activation energy of hydrogen diffusion was calculated. (author)

  2. Biochemical characterization of the triticale TsPAP1, a new type of plant prolyl aminopeptidase, and its impact on proline content and flowering time in transgenic Arabidopsis plants.

    Science.gov (United States)

    Zdunek-Zastocka, Edyta; Grabowska, Agnieszka; Branicki, Tomasz; Michniewska, Beata

    2017-07-01

    Proline aminopeptidase (PAP, EC 3.4.11.5) is the only enzyme that effectively releases proline from the N-termini of peptides. The amino acid sequence of the PAP from Triticosecale, TsPAP1, comprises conserved regions, characteristic of the monomeric forms of PAP found in bacteria but not yet identified in plants. Therefore, we aimed to obtain and biochemically characterize the TsPAP1 protein. The recombinant TsPAP1 protein was received through heterologous expression of the TsPAP1 coding sequence in a bacterial expression system and purified with affinity chromatography. Gel filtration chromatography and SDS electrophoresis revealed that TsPAP1 is a monomer with a molecular mass of 37.5 kDa. TsPAP1 prefers substrates with proline at the N-terminus but is also capable of hydrolyzing β-naphthylamides of hydroxyproline and alanine. Among the peptides tested, the most preferred were di- and tripeptides, especially those with glycine in the Y position. The use of diagnostic inhibitors indicated that TsPAP1 is a serine peptidase; however, further characterization revealed that the SH residues are also important for maintaining its activity. To examine the role of TsPAP1 under physiological conditions, we developed transgenic Arabidopsis plants overexpressing TsPAP1. Compared with wild-type plants, the transgenic lines accumulated more proline, flowered an average of 3.5 days earlier, and developed more siliques than did untransformed controls. Our paper is the first to describe the biochemical properties of a novel monomeric plant PAP and contributes to the functional characterization of PAP proteins in plants. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Volatility of V15Cr5Ti fusion reactor alloy

    International Nuclear Information System (INIS)

    Neilson, R.M. Jr.

    1986-01-01

    One potential hazard from the presence of activation products in fusion facilities is accidental oxidation-driven volatility of those activation products. Scoping experiments were conducted to investigate the oxidation and elemental volatility of candidate fusion reactor alloy V15Cr5Ti as a function of time, temperature, and test atmosphere. Experiments in air and in argon carrier gases containing 10 4 to 10 1 Pa (10 -1 to 10 -4 atm) oxygen were conducted to investigate the lower oxygen partial pressure limit for the formation of a low melting point (approximately 650 0 C), high volatility, oxide layer and its formation rate. Experiments to determine the elemental volatility of alloy constituents in air at temperatures of 700 0 C to greater than 1600 0 C. Some of these volatility experiments used V15Cr5Ti that was arc-remelted to incorporate small quantities (<0.1 wt. %) of Sc and Ca. Incorporation of Sc and Ca in test specimens permitted volatility measurement of radioactive constituents present only after activation of V15Cr5Ti

  4. Microstructures and mechanical properties of squeeze cast Al–5.0Cu–0.6Mn alloys with different Fe content

    International Nuclear Information System (INIS)

    Zhang, WeiWen; Lin, Bo; Zhang, DaTong; Li, YuanYuan

    2013-01-01

    Highlights: • The effect of Fe-rich phases on squeeze cast Al–Cu alloys with high Fe content. • Four kinds of Fe-rich phases may present in Al–Cu alloys. • There is great tolerance to Fe impurities in squeeze cast Al–Cu alloys. - Abstract: The microstructures and mechanical properties of gravity die cast and squeeze cast Al–5.0 wt% Cu–0.6 wt% Mn alloys with different Fe content have been studied using tensile test, optical microscope, scanning electron microscope, electron probe micro-analyzer and image analysis. The results show that four kinds of Fe-rich intermetallics may present in the final microstructures of the alloys: Chinese script α-Fe (Al 15 (FeMn) 3 (CuSi) 2 ) and Al 6 (FeMn), needle-like β-Fe(Al 7 Cu 2 Fe) and Al 3 (FeMn) when the Fe content increases from 0.1 wt% to 1.5 wt%. In the gravity die cast alloy with 0.5 wt% Fe, the Chinese script α-Fe presents as the main Fe-rich intermetallics, and a few needle-like β-Fe also exist. When the Fe content increases to 1.0 wt%, the main Fe-rich intermetallics change to needle-like Al 3 (FeMn) and Chinese-script Al 6 (FeMn). The needle-like β-Fe disappears when the Fe content is 0.5 wt% in the squeeze cast alloy with an applied pressure of 75 MPa. Furthermore, the secondary dendritic arm spacing of α(Al), the percentage of porosity and the volume fraction of the second intermetallics decrease distinctly in the squeeze cast alloy compared to the gravity die cast alloy. There is a peak value of ultimate strength and yield strength for the alloy with 0.5 wt% Fe. The elongations of the alloys decrease gradually with increasing Fe content and the elongation of the squeeze cast alloys is two times more than that of the gravity die cast alloys

  5. Enhancement of the electrochemical behaviour and biological performance of Ti–25Ta–5Zr alloy by thermo-mechanical processing

    Energy Technology Data Exchange (ETDEWEB)

    Cimpean, Anisoara [Department of Biochemistry and Molecular Biology, University of Bucharest, Spl. Independentei, 91-95, 050095 Bucharest (Romania); Vasilescu, Ecaterina; Drob, Paula [Department of Electrochemistry and Corrosion, Institute of Physical Chemistry “Ilie Murgulescu” of Romanian Academy, Spl. Independentei 202, 060021 Bucharest (Romania); Cinca, Ion, E-mail: ion_cinca@hotmail.com [Faculty of Material Science and Engineering, Politehnica University, Spl. Independentei 313, 060042 Bucharest (Romania); Vasilescu, Cora; Anastasescu, Mihai [Department of Electrochemistry and Corrosion, Institute of Physical Chemistry “Ilie Murgulescu” of Romanian Academy, Spl. Independentei 202, 060021 Bucharest (Romania); Mitran, Valentina [Department of Biochemistry and Molecular Biology, University of Bucharest, Spl. Independentei, 91-95, 050095 Bucharest (Romania); Drob, Silviu Iulian [Department of Electrochemistry and Corrosion, Institute of Physical Chemistry “Ilie Murgulescu” of Romanian Academy, Spl. Independentei 202, 060021 Bucharest (Romania)

    2014-05-01

    A new Ti–25Ta–5Zr alloy based only on non-toxic and non-allergic elements was elaborated in as-cast and thermo-mechanical processed, recrystallized states (XRD and SEM) in order to be used as candidate material for implant applications. Its long-term interactions with Ringer–Brown and Ringer solutions of different pH values and its cytocompatibility were determined. The thermo-mechanically processed alloy has nobler electrochemical behaviour than as-cast alloy due to finer microstructure obtained after the applied treatment. Corrosion and ion release rates presented the lowest values for the treated alloy. Nyquist and Bode plots displayed higher impedance values and phase angles for the processed alloy, denoting a more protective passive film. SEM micrographs revealed depositions from solutions that contain calcium, phosphorous and oxygen ions (EDX analysis), namely calcium phosphate. An electric equivalent circuit with two time constants was modelled. Cell culture experiments with MC3T3-E1 pre-osteoblasts demonstrated that thermo-mechanically processed Ti–25Ta–5Zr alloy supports a better cell adhesion and spreading, and enhanced cell proliferation. Altogether, these data indicate that thermo-mechanical treatment endows the alloy with improved anticorrosion and biological performances. - Highlights: • Ti–25Ta–5Zr alloy exhibited noble electrochemical, passive behaviour in simulated biofluids. • An electric equivalent circuit with two time constants was modelled. • Corrosion rates show the lowest values for the recrystallized Ti–25Ta–5Zr alloy. • In vitro tests revealed good cytocompatibility of as-cast and processed alloy. • Recrystallized treatment endows the alloy with superior biological performances.

  6. Enhancement of the electrochemical behaviour and biological performance of Ti–25Ta–5Zr alloy by thermo-mechanical processing

    International Nuclear Information System (INIS)

    Cimpean, Anisoara; Vasilescu, Ecaterina; Drob, Paula; Cinca, Ion; Vasilescu, Cora; Anastasescu, Mihai; Mitran, Valentina; Drob, Silviu Iulian

    2014-01-01

    A new Ti–25Ta–5Zr alloy based only on non-toxic and non-allergic elements was elaborated in as-cast and thermo-mechanical processed, recrystallized states (XRD and SEM) in order to be used as candidate material for implant applications. Its long-term interactions with Ringer–Brown and Ringer solutions of different pH values and its cytocompatibility were determined. The thermo-mechanically processed alloy has nobler electrochemical behaviour than as-cast alloy due to finer microstructure obtained after the applied treatment. Corrosion and ion release rates presented the lowest values for the treated alloy. Nyquist and Bode plots displayed higher impedance values and phase angles for the processed alloy, denoting a more protective passive film. SEM micrographs revealed depositions from solutions that contain calcium, phosphorous and oxygen ions (EDX analysis), namely calcium phosphate. An electric equivalent circuit with two time constants was modelled. Cell culture experiments with MC3T3-E1 pre-osteoblasts demonstrated that thermo-mechanically processed Ti–25Ta–5Zr alloy supports a better cell adhesion and spreading, and enhanced cell proliferation. Altogether, these data indicate that thermo-mechanical treatment endows the alloy with improved anticorrosion and biological performances. - Highlights: • Ti–25Ta–5Zr alloy exhibited noble electrochemical, passive behaviour in simulated biofluids. • An electric equivalent circuit with two time constants was modelled. • Corrosion rates show the lowest values for the recrystallized Ti–25Ta–5Zr alloy. • In vitro tests revealed good cytocompatibility of as-cast and processed alloy. • Recrystallized treatment endows the alloy with superior biological performances

  7. Effect of mushy state rolling on age-hardening and tensile behavior of Al-4.5Cu alloy and in situ Al-4.5Cu-5TiB2 composite

    International Nuclear Information System (INIS)

    Siddhalingeshwar, I.G.; Herbert, M.A.; Chakraborty, M.; Mitra, R.

    2011-01-01

    Research highlights: → Mushy state rolling of composites reduces peak-aging times to ∼7.5-10% of that of as-cast alloy. → Uniform Cu atom distribution achieved in matrices by mushy state rolling enhances aging kinetics. → Uniform precipitate distribution obtained by mushy state rolling leads to higher microhardness. → Peak-age tensile strength and strain hardening rates are found to increase on mushy state rolling. - Abstract: The effect of mushy state rolling on aging kinetics of stir-cast Al-4.5Cu alloy and in situ Al-4.5Cu-5TiB 2 composite and their tensile behavior in solution-treated (495 deg. C) or differently aged (170 deg. C) conditions, has been investigated. As-cast or pre-hot rolled alloy and composite samples were subjected to single or multiple mushy state roll passes to 5% thickness reduction at temperatures for 20% liquid content. Peak-aging times of mushy state rolled composite matrices have been found as ∼7.5-10% of that of as-cast alloy. Such enhancement in aging kinetics is attributed to homogeneity in Cu atom distribution as well as increase in matrix dislocation density due to thermal expansion coefficient mismatch between Al and TiB 2 , matrix grain refinement and particle redistribution, achieved by mushy state rolling. Uniform precipitate distribution in mushy state rolled composite matrices leads to greater peak-age microhardness with higher yield and ultimate tensile strengths than those in as-cast alloy and composite.

  8. Thermo-physical characterization of the Fe_6_7Mo_6Ni_3_._5Cr_3_._5P_1_2C_5_._5B_2_._5 bulk metallic glass forming alloy

    International Nuclear Information System (INIS)

    Bochtler, Benedikt; Gross, Oliver; Gallino, Isabella; Busch, Ralf

    2016-01-01

    The iron-phosphorus based bulk metallic glass forming alloy Fe_6_7Mo_6Ni_3_._5Cr_3_._5P_1_2C_5_._5B_2_._5 is characterized with respect to its thermophysical properties, crystallization and relaxation behavior, as well as its viscosity. The alloy provides a high critical casting thickness of 13 mm, thus allowing for the casting of amorphous parts with a considerable size. Calorimetric measurements reveal the characteristic transformation temperatures, transformation enthalpies, and the specific heat capacity. The analyses show that no stable supercooled liquid region exists upon heating. The specific heat capacity data are used to calculate the enthalpy, entropy, and Gibbs free energy differences between the crystalline and the supercooled liquid state. The crystallization behavior of amorphous samples upon heating is analyzed by differential scanning calorimetry and X-ray diffraction, and a time-temperature-transformation diagram is constructed. Dilatometry is used to determine the thermal expansion behavior. The equilibrium viscosity below the glass transition as well as volume relaxation behavior are measured by three-point beam bending and dilatometry, respectively, to assess the kinetic fragility. With a kinetic fragility parameter of D* = 21.3, the alloy displays a rather strong liquid behavior. Viscosity above the melting point is determined using electromagnetic levitation in microgravity on a reduced gravity aircraft in cooperation with the German Aerospace Center (DLR). These high-temperature viscosity data are compared with the low-temperature three-point beam bending measurements. The alloy displays a strong liquid behavior at low temperatures and a fragile behavior at high temperatures. These results are analogous to the ones observed in several Zr-based bulk metallic glass forming liquids, indicating a strong to fragile liquid-liquid transition in the undercooled liquid, which is obscured by crystallization.

  9. Effect of zirconium addition on the ductility and toughness of cast zinc-aluminum alloy5, zamak5, grain refined by titanium plus boron

    International Nuclear Information System (INIS)

    Adnan, I.O.

    2007-01-01

    Zinc-aluminum casting alloys are frequently employed in design. They are inexpensive and have mechanical properties in many respects superior to aluminum and copper alloys. Common applications of zinc-aluminum alloys are in the automobile industry for manufacturing carburetors bodies, fuel pump bodies, driving wheels and door handles. They are mainly used for die casting due to their low melting points which ranges from 375 to 487 degree C, good fluidity, pollution free melting in addition to their high corrosion resistance. Against these advantages there exists the deficiency as these alloys solidify in a coarse dentititic structure which tends to deteriorate the mechanical properties and impact strength. It was found that addition of some rare earth materials e.g. titanium or titanium plus boron results in modifying its structure into a petal-like or nodular type. The available literature reveals that most of the published work is directed towards the metallurgical aspects and little or no work is published on the effect of those elements on its mechanical strength, ductility, toughness and impact strength. In this paper, the effect of addition of Zirconium on the microstructure, mechanical behavior, hardness, ductility and impact strength of zinc-aluminum alloy5, Zamak5, is investigated. It was found that addition of Ti+B or Zr or Ti+B+Zr resulted in modifying the coarse dentritic structure of the Zamak5 alloy into a fine nodular one. Further more, addition of any of these elements alone or together resulted in enhancement of the mechanical strength, hardness, ductility, toughness and impact strength of this alloy, for example an increase of 11% in hardness was achieved in case of Zr addition and 100% increase of ductility and 12.5% increase in impact strength were achieved in case of Ti+B addition. (author)

  10. ChemTS: an efficient python library for de novo molecular generation

    Science.gov (United States)

    Yang, Xiufeng; Zhang, Jinzhe; Yoshizoe, Kazuki; Terayama, Kei; Tsuda, Koji

    2017-12-01

    Automatic design of organic materials requires black-box optimization in a vast chemical space. In conventional molecular design algorithms, a molecule is built as a combination of predetermined fragments. Recently, deep neural network models such as variational autoencoders and recurrent neural networks (RNNs) are shown to be effective in de novo design of molecules without any predetermined fragments. This paper presents a novel Python library ChemTS that explores the chemical space by combining Monte Carlo tree search and an RNN. In a benchmarking problem of optimizing the octanol-water partition coefficient and synthesizability, our algorithm showed superior efficiency in finding high-scoring molecules. ChemTS is available at https://github.com/tsudalab/ChemTS.

  11. Influence of heat treatment on the mechanical and electrical characteristics of Ni0.5Ti0.5 alloy prepared by electron-beam melting

    International Nuclear Information System (INIS)

    Ammar, A.H.; Al-Buhairi, M.; Farag, A.A.M.; Al-Wajeeh, N.M.M.

    2013-01-01

    Nickel titanium alloys (Ni 0.5 Ti 0.5 ) were successfully produced from elemental Ni/Ti powders by electron-beam melting method and then subjected to annealing and aging treatment. Microstructure of the alloys was examined by XRD and SEM. The mechanical properties of the alloyed surface were examined. The microhardness was studied as a function of annealing temperature and time. It was found that the microhardness decreases with increasing annealing temperature until 660 °C after which the microhardness increases. Electrical resistance measurements were carried out in order to study the transformation behavior. The electrical measurements point out the importance of temperature dependence of Ni 0.5 Ti 0.5 electrical resistance for the identification of particular transformation. The influence of aging on the development of electrical resistivity was also investigated

  12. Kunstisuvi 1999 / Sirje Eelma, Rait Prääts

    Index Scriptorium Estoniae

    Eelma, Sirje, 1950-

    1999-01-01

    12. juunist näitus "Rahvusvaheline väikegraafika ja eesti väikeskulptuur" Kuressaare Raegaleriis. Koostajad ja kujundajad Sirje Eelma, Terje Ojaver. 19. juunist Haapsalu Linnagaleriis ja lisaruumides väljapanek "Motiiv". Koostajad Agur Kruusing, Sirje Eelma, Rait Prääts, kujundaja Agur Kruusing. Pärnu Linnagaleriis näitus "Minimaal". Koostaja ja kujundaja Rait Prääts. Muuseumiaidas eesti noorema kunsti väljapanek "Voolab". Koostaja Karol Kallas. Juuli lõpul Selgase dolomiidipäevad Kuressaares. Pärast põhinäituste lõppemist valiknäitus Paide Vallitornis

  13. Atomic and magnetic correlations in a copper - 5% manganese alloy

    Energy Technology Data Exchange (ETDEWEB)

    Murani, A P; Schaerpf, O; Andersen, K [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Raphel, R [Centre National de la Recherche Scientifique (CNRS), 38 - Grenoble (France)

    1997-04-01

    Interest in magnetism of Cu-Mn alloys has been revived and sustained by a number of very interesting neutron investigations on single-crystal samples which show `spin-density wave` (SDW) peaks at incommensurate wave-vectors. Recently such peaks have been observed even in very dilute samples with Mn concentration as low as {approx} 0.5 at.%. The proposed interpretation by the authors that these peaks represent incommensurate antiferromagnetic ordering, therefore, questions the widely-held view that at low enough temperatures the solute spins in this and similar alloys freeze with random or quasi-random orientations, forming a spin-glass state. Atomic and magnetic correlations have been investigated in a single crystal of Cu-5 at.% Mn within the first Brillouin zone using polarised neutrons and making use of the multi-angle three-dimensional polarisation analysis capability of the D7 spectrometer as a firs step in our aim to shed further light on the phenomenon. (author). 6 refs.

  14. Passivation behavior of AB{sub 5}-type hydrogen storage alloys for battery electrode application

    Energy Technology Data Exchange (ETDEWEB)

    Meli, F. [Fribourg Univ. (Switzerland). Inst. de Physique; Sakai, T. [Fribourg Univ. (Switzerland). Inst. de Physique; Zuettel, A. [Fribourg Univ. (Switzerland). Inst. de Physique; Schlapbach, L. [Fribourg Univ. (Switzerland). Inst. de Physique

    1995-04-15

    In many applications, AB{sub 5} type hydrogen storage alloys show passivation behavior, i.e. when fully discharged, metal hydride electrodes show (especially at higher temperatures) a decrease in activity and therefore a decrease in capacity at normal discharge currents for ensuing cycles. Passivation may continue to the point where activity becomes so low that the capacity is no longer accessible. Electrochemical measurements were taken of two different AB{sub 5}-type alloys, one with manganese and one without manganese (LaNi{sub 3.4}Co{sub 1.2}Al{sub 0.4} and LaNi{sub 3.4}Co{sub 1.2}Al{sub 0.3}Mn{sub 0.1}). Both alloys showed passivation behavior after remaining in the discharged state. The alloy with manganese showed a stronger tendency to passivation which is in contradiction with earlier observations. Photoelectron spectroscopic analysis together with sputter depth profiling was used to investigate the surface composition of samples which had undergone different surface pretreatments. Surface analysis of electrodes in the passivated state shows a lower content of metallic nickel and a thicker nickel surface oxide film. We attribute the low electrochemical kinetics of the alloys after passivation to the loss of metallic nickel and/or cobalt at the electrode-electrolyte interface. ((orig.))

  15. The chemical phenol extraction of intermetallic particles from casting AlSi5Cu1Mg alloy.

    Science.gov (United States)

    Mrówka-Nowotnik, G; Sieniawski, J; Nowotnik, A

    2010-03-01

    This paper presents a chemical extraction technique for determination of intermetallic phases formed in the casting AlSi5Cu1Mg aluminium alloy. Commercial aluminium alloys contain a wide range of intermetallic particles that are formed during casting, homogenization and thermomechanical processing. During solidification, particles of intermetallics are dispersed in interdendritic spaces as fine primary phases. Coarse intermetallic compounds that are formed in this aluminium alloy are characterized by unique atomic arrangement (crystallographic structure), morphology, stability, physical and mechanical properties. The volume fraction, chemistry and morphology of the intermetallics significantly affect properties and material behaviour during thermomechanical processing. Therefore, accurate determination of intermetallics is essential to understand and control microstructural evolution in Al alloys. Thus, in this paper it is shown that chemical phenol extraction method can be applied for precise qualitative evaluation. The results of optical light microscopy LOM, scanning electron microscopy SEM and X-ray diffraction XRD analysis reveal that as-cast AlSi5Cu1Mg alloy contains a wide range of intermetallic phases such as Al(4)Fe, gamma- Al(3)FeSi, alpha-Al(8)Fe(2)Si, beta-Al(5)FeSi, Al(12)FeMnSi.

  16. BlendCAC: A BLockchain-ENabled Decentralized Capability-based Access Control for IoTs

    OpenAIRE

    Xu, Ronghua; Chen, Yu; Blasch, Erik; Chen, Genshe

    2018-01-01

    The prevalence of Internet of Things (IoTs) allows heterogeneous embedded smart devices to collaboratively provide smart services with or without human intervention. While leveraging the large scale IoT based applications like Smart Gird or Smart Cities, IoTs also incur more concerns on privacy and security. Among the top security challenges that IoTs face, access authorization is critical in resource sharing and information protection. One of the weaknesses in today's access control (AC) is ...

  17. A Federated Capability-based Access Control Mechanism for Internet of Things (IoTs)

    OpenAIRE

    Xu, Ronghua; Chen, Yu; Blasch, Erik; Chen, Genshe

    2018-01-01

    The prevalence of Internet of Things (IoTs) allows heterogeneous embedded smart devices to collaboratively provide intelligent services with or without human intervention. While leveraging the large-scale IoT-based applications like Smart Gird and Smart Cities, IoT also incurs more concerns on privacy and security. Among the top security challenges that IoTs face is that access authorization is critical in resource and information protection over IoTs. Traditional access control approaches, l...

  18. Characterization of a High Strength, Refractory High Entropy Alloy, AlMo0.5NbTa0.5TiZr

    Science.gov (United States)

    Jensen, Jacob

    High entropy alloys (HEAs) are a relatively new class of materials that have garnered significant interest over the last decade due to their intriguing balance of properties including high strength, toughness, and corrosion resistance. In contrast to conventional alloy systems, HEAs are based on four or more principal elements with near equimolar concentrations and tend to have simple microstructures due to the preferential formation of solid solution phases. HEAs appear to offer new pathways to lightweighting in structural applications, new alloys for elevated temperature components, and new magnetic materials, but more thorough characterization studies are needed to assess the viability of the recently developed multicomponent materials. One such HEA, AlMo0.5NbTa0.5TiZr, was selected to be the basis for this characterization study in part due to its strength at elevated temperatures (sigma0.2 = 1600 MPa at T = 800 °C) and low density compared with commercially available Ni-based superalloys. The refractory element containing HEA composition was developed in order to balance the high temperature strength of the refractory elements with the desirable properties achieved by the high entropy alloying design approach for potential use in aerospace thermal protection and structural applications. Ingots of AlMo0.5NbTa0.5TiZr were cast by vacuum arc melting followed by hot isostatic pressing (HIP) and homogenization at 1400 °C for 24 hrs with a furnace cool of 10 °C/min. The resulting microstructure was characterized at multiple length scales using x-ray diffraction (XRD), scanning transmission electron microscopy (SEM), conventional and scanning transmission electron microscopy (TEM and STEM), and x-ray energy dispersive spectroscopy (XEDS). The microstructure was found to consist of a periodic, coherent two phase mixture, where a disordered bcc phase is aligned orthogonally in an ordered B2 phase. Through microstructural evolution heat treatment studies, the

  19. Low cycle fatigue behaviour of Ti-6Al-5Zr-0.5Mo-0.25Si alloy at room temperature

    International Nuclear Information System (INIS)

    Nag, Anil Kumar; Praveen, K.V.U.; Singh, Vakil

    2006-01-01

    Low cycle fatigue (LCF) behaviour of the near α titanium alloy, Ti-6Al-5Zr-0.5Mo-0.25Si (LT26A), was investigated in the (α+ β) as well as β treated conditions at room temperature. LCF tests were carried out under total strain controlled mode in the range of Δε t /2: from ± 0.60% to ± 1.40%. The alloy shows cyclic softening in both the conditions. Also it exhibits dual slope Coffin-Manson (C-M) relationship in both the treated conditions. (author)

  20. Computer aided cooling curve analysis for Al-5Si and Al-11Si alloys ...

    African Journals Online (AJOL)

    The effect of grain refiner, modifier, and combination of grain refiner cum modifier was studied on Al-5Si and Al-11Si alloys using computer aided cooling curve analysis. For combined grain refinement and modification effect, Al-Ti-B-Sr single master alloy was developed that acted as both grain refiner and modifier.

  1. Measurement of the CKM matrix element |V_ts

    CERN Document Server

    Unverdorben, Christopher Gerhard

    This is the first direct measurement of the CKM matrix element |V_ts|, using data collected by the ATLAS detector in 2012 at √s=8 TeV pp-collisions with a total integrated luminosity of 20.3 fb⁻¹. The analysis is based on 112171 reconstructed tt̅ candidate events in the lepton+jets channel, having a purity of 90.0 %. 183 tt̅→WWbs̅ decays are expected (charge conjugation implied), which are available for the extraction of the CKM matrix element |V_ts|². To identify these rare decays, several observables are examined, such as the properties of jets, tracks and of b-quark identification algorithms. Furthermore, the s-quark hadrons K0s are considered, reconstructed by a kinematic fit. The best observables are combined in a multivariate analysis, called "boosted decision trees". The responses from Monte Carlo simulations are used as templates for a fit to data events yielding a significance value of 0.7σ for t→s+W decays. An upper limit of |V_ts|² < 1.74 % at 95 % confidence level is set, includi...

  2. Effect of Thermomechanical Processing on the Microstructure, Properties, and Work Behavior of a Ti50.5 Ni29.5 Pt20 High-Temperature Shape Memory Alloy

    Science.gov (United States)

    Noebe, Ronald; Draper, Susan; Gaydosh, Darrell; Garga, Anita; Lerch, Brad; Penney, Nicholas; Begelow, Glen; Padula, Santo, II; Brown, Jeff

    2006-01-01

    TiNiPt shape memory alloys are particularly promising for use as solid state actuators in environments up to 300 C, due to a reasonable balance of properties, including acceptable work output. However, one of the challenges to commercializing a viable high-temperature shape memory alloy (HTSMA) is to establish the appropriate primary and secondary processing techniques for fabrication of the material in a required product form such as rod and wire. Consequently, a Ti(50.5)Ni(29.5)Pt20 alloy was processed using several techniques including single-pass high-temperature extrusion, multiple-pass high-temperature extrusion, and cold drawing to produce bar stock, thin rod, and fine wire, respectively. The effects of heat treatment on the hardness, grain size, room temperature tensile properties, and transformation temperatures of hot- and cold-worked material were examined. Basic tensile properties as a function of temperature and the strain-temperature response of the alloy under constant load, for the determination of work output, were also investigated for various forms of the Ti(50.5)Ni(29.5)Pt20 alloy, including fine wire.

  3. New Quality Assessment Criterion of AlSi5Cu1 Alloy

    Directory of Open Access Journals (Sweden)

    M. Wierzbińska

    2007-07-01

    Full Text Available The paper presents the discussion of the results of mechanical testing for aluminium foundry alloy AlSi5Cu1Mg for high-loaded machine elements. Values of yield strength (Rp0.2, tensile strength (Rm, elongation(A5 and hardness (HB are usually considered as the primary quality assessment criterion for a manufacturing process. It was concluded, that this criterion, A5 index particularly, is unsatisfactory to estimate the plasticity of the alloy and its crack resistance in the presence of sharp-pointed stress concentrators or microcracks. More adequate parameter is plane strain fracture toughness KIc. However, size of the samples appeared to be twice as large as would be needed to fulfill requirements of test conditions, and the test itself is laborious and time-consuming that it becomes impractical as a acceptance test. Therefore, substitute test for quality assessment – determination of tensile strength in the presence of a sharp notch kmR was applied. The comparative analysis of kmR/Rp0.2 ratio, as a more enhanced fatigue resistance criterion than kmR and plane strain fracture toughness KIc of the alloy was performed. It was assumed that kmR/Rp0.2 parameter has good correlation with the critical stress intensity factor KIc Thus, under manufacturing process conditions, being unable to carry out KIc test, it may be successfully replaced by kmR test.

  4. In vitro metal ion release and biocompatibility of amorphous Mg67Zn28Ca5 alloy with/without gelatin coating

    International Nuclear Information System (INIS)

    Chan, W.Y.; Chian, K.S.; Tan, M.J.

    2013-01-01

    Amorphous zinc-rich Mg–Zn–Ca alloys have exhibited good tissue compatibility and low hydrogen evolution in vivo. However, suboptimal cell–surface interaction on magnesium alloy surface observed in vitro could lead to reduced integration with host tissue for regenerative purpose. This study aims to improve cell–surface interaction of amorphous Mg 67 Zn 28 Ca 5 alloy by coating a gelatin layer by electrospinning. Coated/uncoated alloys were immersed and extracted for 3 days under different CO 2 . The immersion results showed that pH and metal ion release in the alloy extracts were affected by gelatin coating and CO 2 , suggesting their roles in alloy biocorrosion and a mechanism has been proposed for the alloy–CO 2 system with/without coating. Cytotoxicity results are evident that gelatin-coated alloy with 2-day crosslinking not only exhibited no indirect cytotoxicity, but also supported attachment of L929 and MG63 cell lines around/on the alloy with high viability. Therefore, amorphous Mg 67 Zn 28 Ca 5 alloy coated with gelatin by electrospinning technique provides a useful method to improve alloy biocompatibility. - Highlights: • Electrospinning is a new method to coat amorphous Mg 67 Zn 28 Ca 5 alloy with gelatin. • Gelatin-coated alloy has differential effect on pH and ion release at various CO 2 . • L929 cell proliferation correlates with Mg 2+ level in alloy extracts. • Biomimetic gelatin coating significantly improves cell–surface interaction

  5. Microstructures and phase transformations of Ti-30Zr-xNb (x = 5, 7, 9, 13 at.%) shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Wentao; Sun, Xuguang; Yuan, Bifei [School of Mechanical Engineering, Xi' an Shiyou University, Xi' an 710065 (China); Xiong, Chengyang; Zhang, Fei [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Li, Yan, E-mail: liyan@buaa.edu.cn [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Sun, Baohui [Lanzhou Seemine SMA Co. Ltd., Lanzhou 730010 (China)

    2016-12-15

    The microstructures, phase transformations and shape memory properties of Ti-30Zr-xNb (x = 5, 7, 9, 13 at.%) alloys were investigated. The X-ray diffraction and transmission electron microscopy observations showed that the Ti-30Zr-5Nb, Ti-30Zr-7/9Nb and Ti-30Zr-13Nb alloys were composed of the hcp α′-martensite, orthorhombic α″-martensite and β phases, respectively. The results indicated the enhanced β-stabilizing effect of Nb in Ti-30Zr-xNb alloys than that in Ti-Nb alloys due to the high content of Zr. The differential scanning calorimetry test indicated that the Ti-30Zr-5Nb alloy displayed a reversible transformation with a high martensitic transformation start temperature of 776 K and a reverse martensitic transformation start temperature (A{sub s}) of 790 K. For the Ti-30Zr-7Nb and Ti-30Zr-9Nb alloys, the martensitic transformation temperatures decreased with the increasing Nb content. Moreover, an ω phase transformation occurred in the both alloys upon heating at a temperature lower than the corresponding A{sub s}, which is prompted by more addition of Nb. Although the critical stress in tension of the three martensitic alloys decreased with increasing Nb content, the Ti-30Zr-9Nb alloy showed a critical stress of as high as 300 MPa. Among all the alloys, the Ti-30Zr-9Nb alloy exhibited the maximum shape memory effect of 1.61%, due to the lowest critical stress for the martensite reorientation. - Highlights: •Ti-30Zr-5Nb alloy is composed of hcp α′-martensite with the M{sub s} of 776 K. •Ti-30Zr-7Nb and Ti-30Zr-9Nb alloys are predominated by orthorhombic α″-martensite. •Ti-30Zr-13Nb alloy consists of a single β phase due to the β-stabilizing effect of Nb. •The martensitic transformation temperatures decrease with increasing Nb content. •Ti-30Zr-9Nb alloy shows the maximum shape memory effect of 1.61%.

  6. Advanced high temperature superconductor film-based process using RABiTS

    International Nuclear Information System (INIS)

    Goyal, A.; Hawsey, R.A.; Hack, J.; Moon, D.

    2000-01-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Research Corporation (Contractor), Managing contractor for Oak Ridge National Laboratory (ORNL) and Midwest Superconductivity, Inc. (MSI) and Westinghouse Science and Electric Company (WEC) was to develop the basis for a commercial process for the manufacturing of superconducting tape based on the RABiTS technology developed at ORNL. The chosen method for deposition of YBCO films on RABiTS was Metal Organic chemical Vapor Deposition (MOCVD)

  7. Ductility of Mo–12Si–8.5B alloys doped with lanthanum oxide by the liquid–liquid doping method

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wenhu [School of Materials Science & Engineering, Xi’an University of Technology, Xi’an 710048 (China); School of Materials Science & Engineering, Shaanxi University of Technology, Hanzhong 723000 (China); Zhang, Guojun, E-mail: zhangguojun@xaut.edu.cn [School of Materials Science & Engineering, Xi’an University of Technology, Xi’an 710048 (China); Wang, Shixiong [School of Materials Science & Engineering, Xi’an University of Technology, Xi’an 710048 (China); Li, Bin; Sun, Jun [State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049 (China)

    2015-09-05

    Highlights: • Alloys doping lanthanum oxide by L–L doped method were prepared by hot pressing. • The compression strength of alloys are superior. • The fracture toughness of alloys is improved by L–L doped method. - Abstract: Mo–12Si–8.5B (Mo–Si–B) alloys doped with different mass fractions (0.3 wt%, 0.6 wt%, and 0.9 wt%) of lanthanum oxide (La{sub 2}O{sub 3}) were prepared by liquid–liquid (L–L) doping, mechanical alloying and hot pressing sintering techniques. The observation of the microstructures of the Mo–Si–B alloys reveals that the grain sizes of the alloys were refined with the increase in La{sub 2}O{sub 3} doping. The fracture toughness values of the alloys of over 10 MPa m{sup 1/2} reveal that the addition of La{sub 2}O{sub 3} via the L–L doping method can obviously improve the alloy fracture toughness compared to the alloys doped with La{sub 2}O{sub 3} via the solid–solid (S–S) doping method. In addition, compression tests indicate that the compression strength of the alloys was improved compared to Mo–12Si–8.5B alloys.

  8. Characterization of structures and novel magnetic response of Fe87.5Si7Al5.5 alloy processed by ball milling

    International Nuclear Information System (INIS)

    Duan, Yuping; Gu, Shuchao; Zhang, Zhonglun; Wen, Ming

    2012-01-01

    Highlights: ► The water atomized Fe 87.5 Si 7 Al 5.5 (Wt.%) alloy was processed by ball-milling. ► The microstructure and magnetic properties of alloy changed following milling. ► The powders milled for 10 h have the largest M s and strongest reflection loss. ► The permeability of the powders milled for 2 h is the largest. ► The charge exchange between Fe and Si is discussed base on first-principles. - Abstract: The water atomized Fe 87.5 Si 7 Al 5.5 (Wt.%) alloy was processed by a high-energy planetary ball-milling. The characterization of morphology, microstructure, and electromagnetic properties were measured by scanning electron microscope (SEM), X-ray diffractometer, vibrating sample magnetometer (VSM), vector network analyzer and the first principle method. The analysis results showed that the powders shape became flaky from fusiform. The powders showed a reduction of the average grain size and the increase of the internal strain, and then presented an adverse variation trend after 55 h milling. The powders that milled 10 h had the largest saturation magnetization M S (131 emu/g). The value μ′ of the powders decreased with increasing milling time at relatively lower frequency (2–8 GHz), but opposite variation tendency happened at higher frequency (8–18 GHz). Also, only short time milling can enhance the value of μ″ in the test frequency. The powders after 10 h milling showed excellent microwave absorption (RL < −10 dB) at the frequency 9.0–15.6 GHz and the absorption peak shifted regularly to the high frequency as the increased milling time. Furthermore, the effect of charge exchange between the Fe and Si on the saturation magnetization in the ball-milling process was also investigated by using density functional theory (DFT) of first principle.

  9. Influence of phase composition on microstructure and properties of Mg-5Al-0.4Mn-xRE (x = 0, 3 and 5 wt.%) alloys

    International Nuclear Information System (INIS)

    Braszczyńska-Malik, K.N.; Grzybowska, A.

    2016-01-01

    The microstructure and mechanical properties investigations of two AME503 and AME505 experimental alloys in as-cast conditions were presented. The investigated materials were fabricated on the basis of the AM50 commercial magnesium alloy with 3 and 5 wt.% cerium rich mischmetal. In the as-cast condition, both experimental alloys were mainly composed of α-Mg, Al_1_1RE_3 and Al_1_0RE_2Mn_7 intermetallic phases. Additionally, due to non-equilibrium solidification conditions, a small amount of α + γ divorced eutectic and Al_2RE intermetallic phase were revealed. The obtained results also show a significant influence of rare earth elements on Brinell hardness, tensile and compression properties at ambient temperature and especially on creep properties at 473 K. Improved alloy properties with a rise in rare earth elements mass fraction results from an increase in Al_1_1RE_3 phase volume fraction and suppression of α + γ eutectic volume fraction in the alloy microstructure. Additionally, the influence of rare earth elements on the dendrite arm space value was discussed. The presented results also proved the thermal stability of the intermetallic phases during creep testing. - Highlights: • Two different Mg-5Al-0.4Mn alloys containing 3 and 5 wt.% of rare earth elements were fabricated. • Addition of rare earth elements leads to a reduction of dendrite arm spaces. • Mechanical properties depend on the phase composition of the alloys. • The increase of the rare earth elements content causes rise of the creep resistance.

  10. Deep-HiTS: Rotation Invariant Convolutional Neural Network for Transient Detection

    Science.gov (United States)

    Cabrera-Vives, Guillermo; Reyes, Ignacio; Förster, Francisco; Estévez, Pablo A.; Maureira, Juan-Carlos

    2017-02-01

    We introduce Deep-HiTS, a rotation-invariant convolutional neural network (CNN) model for classifying images of transient candidates into artifacts or real sources for the High cadence Transient Survey (HiTS). CNNs have the advantage of learning the features automatically from the data while achieving high performance. We compare our CNN model against a feature engineering approach using random forests (RFs). We show that our CNN significantly outperforms the RF model, reducing the error by almost half. Furthermore, for a fixed number of approximately 2000 allowed false transient candidates per night, we are able to reduce the misclassified real transients by approximately one-fifth. To the best of our knowledge, this is the first time CNNs have been used to detect astronomical transient events. Our approach will be very useful when processing images from next generation instruments such as the Large Synoptic Survey Telescope. We have made all our code and data available to the community for the sake of allowing further developments and comparisons at https://github.com/guille-c/Deep-HiTS. Deep-HiTS is licensed under the terms of the GNU General Public License v3.0.

  11. Embrittlement of the alloy U 7.5 Nb 2.5 Zr by gaseous oxygen and hydrogen

    International Nuclear Information System (INIS)

    Lepoutre, D.; Nomine, A.M.; Miannay, D.

    1981-04-01

    Embrittlement of the alloy uranium 7.5 niobium 2.5 zirconium in gaseous oxygen and hydrogen versus stress intensity, temperature and pressure is studied using rupture mechanics. Cracking speed is determined. In oxygen, only cracks are produced and embrittlement is due to oxidation. In hydrogen at high pressure an hydride is formed and at low pressure cracks are produced but the mechanism is not identified [fr

  12. Arc Security System Based on Harmonics Detection for the TS ICRH Transmitter

    International Nuclear Information System (INIS)

    Berger-by, G.; Beaumont, B.; Lombard, G.; Millon, L.; Mollard, P.; Volpe, D.

    2006-01-01

    Since 1999 and with the help of I.P.P. (Institut fuer Plasmaphysik) Garching, we have tested in the Tore Supra (T.S.) ICRH transmitter, arcs security systems based on harmonics detection in a frequency band lower than the generator frequency. These systems have been designed for ASDEX in order to discriminate between the arcs and the ELMS mismatches during H-mode plasmas; they have been supplied to T.S. by a loan contract by I.P.P. The first tests done in T.S. were very successful and have permitted in 2000 to build a prototype matching T.S. technical requirements. These systems have some advantages in comparison with traditional securities which are based on use of a level on the V r /V f (Reflected to Forward voltage ratio) calculation . They do not use calculation, calibration with frequency or level. They can use RF signals from directional couplers or probes, so they are fully independent of the measurement systems. The detection bandwidth (4 MHz-35 MHz on TS) is independent of the antennae working frequencies. The detection principle is therefore insensitive to the crosstalk between the antennae and to the antennae coupling variations. The RF arc security box is installed in the generator hall which can be located far from the torus hall and the antennae (about 50 m on T.S.) a feature which is very relevant for the ITER transmitters. In 2001 we have built 3 systems based on our prototype in order to improve the protection of the 3 ICRH generators and antennae. These systems use industrial pass-band filters and a very sensitive linear detection (- 60 dBm) in order to facilitate the adjustment. Optical fibbers are used to transfer, with a very high immunity, the trip information to the generator electronic pilot. To guarantee safe operation, a checking test of the entire security chain is performed with a 10 MHz RF oscillator before each plasma start. The RF principle used on T.S. ICRH transmitter and its electronic interactions with the VME command control of

  13. Intergranular corrosion in AA5XXX aluminum alloys with discontinuous precipitation at the grain boundaries

    Science.gov (United States)

    Bumiller, Elissa

    The US Navy currently uses AA5xxx aluminum alloys for structures exposed to a marine environment. These alloys demonstrate excellent corrosion resistance over other aluminum alloys (e.g., AA2xxx or AA7xxx) in this environment, filling a niche in the marine structures market when requiring a light-weight alternative to steel. However, these alloys are susceptible to localized corrosion; more specifically, intergranular corrosion (IGC) is of concern. IGC of AA5xxx alloys due to the precipitation of beta phase on the grain boundaries is a well-established phenomenon referred to as sensitization. At high degrees of sensitization, the IGC path is a continuous anodic path of beta phase particles. At lower degrees of sensitization, the beta phase coverage at the grain boundaries is not continuous. The traditional ranges of susceptibility to IGC as defined by ASTM B928 are in question due to recent studies. These studies showed that even at mid range degrees of sensitization where the beta phase is no longer continuous, IGC may still occur. Previous thoughts on IGC of these alloy systems were founded on the idea that once the grain boundary precipitate became discontinuous the susceptibility to IGC was greatly reduced. Additionally, IGC susceptibility has been defined metallurgically by compositional gradients at the grain boundaries. However, AA5xxx alloys show no compositional gradients at the grain boundaries, yet are still susceptible to IGC. The goal of this work is to establish criteria necessary for IGC to occur given no continuous beta phase path and no compositional gradient at the grain boundaries. IGC performance of the bulk alloy system AA5083 has been studied along with the primary phases present in the IGC system: alpha and beta phases using electrochemistry and modeling as the primary tools. Numerical modeling supports that at steady-state the fissure tip is likely saturated with Mg in excess of the 4% dissolved in the matrix. By combining these results

  14. Silicon Alloying On Aluminium Based Alloy Surface

    International Nuclear Information System (INIS)

    Suryanto

    2002-01-01

    Silicon alloying on surface of aluminium based alloy was carried out using electron beam. This is performed in order to enhance tribological properties of the alloy. Silicon is considered most important alloying element in aluminium alloy, particularly for tribological components. Prior to silicon alloying. aluminium substrate were painted with binder and silicon powder and dried in a furnace. Silicon alloying were carried out in a vacuum chamber. The Silicon alloyed materials were assessed using some techniques. The results show that silicon alloying formed a composite metal-non metal system in which silicon particles are dispersed in the alloyed layer. Silicon content in the alloyed layer is about 40% while in other place is only 10.5 %. The hardness of layer changes significantly. The wear properties of the alloying alloys increase. Silicon surface alloying also reduced the coefficient of friction for sliding against a hardened steel counter face, which could otherwise be higher because of the strong adhesion of aluminium to steel. The hardness of the silicon surface alloyed material dropped when it underwent a heating cycle similar to the ion coating process. Hence, silicon alloying is not a suitable choice for use as an intermediate layer for duplex treatment

  15. Mossbauer studies of amorphous Fe73.5Cu1Nb3Si13.5B9 alloy

    DEFF Research Database (Denmark)

    Jiang, Jianzhong

    1996-01-01

    This paper reports a Mossbauer study of amorphous Fe73.5Cu1Nb3Si13.5B9 alloy between 10 and 673 K. The Curie temperature Tc is found to be 620-+ 1 K. The temperature dependence of the reduced average hyperfine field can be explained on the basis of Handrich's model of amorphous ferromagnetism...

  16. Microstructures and mechanical properties of heat-treated Al–5.0Cu–0.5Fe squeeze cast alloys with different Mn/Fe ratio

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weiwen, E-mail: mewzhang@scut.edu.cn; Lin, Bo; Fan, Jianlei; Zhang, Datong; Li, Yuanyuan

    2013-12-20

    The Al–5.0 wt% Cu–0.5 wt% Fe alloys with different Mn/Fe ratio were prepared by squeeze casting. Various test techniques, including tensile test, image analysis, scanning electron microscope (SEM), X-ray diffraction (XRD), electron probe micro-analyzer (EPMA) and transmission electron microscopy (TEM) were used to examine the microstructures and mechanical properties of the alloys in T5 heat-treated condition. The results show that the β-Fe (Al{sub 7}Cu{sub 2}Fe) is stable and its needle-like morphology is maintained after T5 heat treatment. However, the Chinese script Al{sub m}Fe, α-Fe or Al{sub 6}(FeMn) partially transform to a new Chinese script Cu-rich α(CuFe) (Al{sub 7}Cu{sub 2}Fe or Al{sub 7}Cu{sub 2}(FeMn)), which is harmful to the mechanical properties of the alloys due to the decrease of the Cu content in α(Al) matrix. The optimal Mn/Fe ratio is determined by the morphology of Fe-rich intermetallics, volume fraction of θ′ and T (Al{sub 20}Cu{sub 2}Mn{sub 3}), size of α(Al) dendrite and porosity. Excessive Mn/Fe ratio will deteriorate the mechanical properties of the alloys due to the increase of the total amount of porosity and the Fe-rich intermetallics. When the Mn/Fe ratio is 1.6 and 1.2 for the applied pressure of 0 MPa and 75 MPa, respectively, the needle-like β-Fe phase is completely converted to the Chinese script Fe-rich intermetallics. The ultimate tensile strength, yield strength and elongation of the T5 heat-treated alloy with the Mn/Fe ratio of 1.2 and applied pressure of 75 MPa reach 395 MPa, 335 MPa and 14%, respectively.

  17. Microstructures and mechanical properties of heat-treated Al–5.0Cu–0.5Fe squeeze cast alloys with different Mn/Fe ratio

    International Nuclear Information System (INIS)

    Zhang, Weiwen; Lin, Bo; Fan, Jianlei; Zhang, Datong; Li, Yuanyuan

    2013-01-01

    The Al–5.0 wt% Cu–0.5 wt% Fe alloys with different Mn/Fe ratio were prepared by squeeze casting. Various test techniques, including tensile test, image analysis, scanning electron microscope (SEM), X-ray diffraction (XRD), electron probe micro-analyzer (EPMA) and transmission electron microscopy (TEM) were used to examine the microstructures and mechanical properties of the alloys in T5 heat-treated condition. The results show that the β-Fe (Al 7 Cu 2 Fe) is stable and its needle-like morphology is maintained after T5 heat treatment. However, the Chinese script Al m Fe, α-Fe or Al 6 (FeMn) partially transform to a new Chinese script Cu-rich α(CuFe) (Al 7 Cu 2 Fe or Al 7 Cu 2 (FeMn)), which is harmful to the mechanical properties of the alloys due to the decrease of the Cu content in α(Al) matrix. The optimal Mn/Fe ratio is determined by the morphology of Fe-rich intermetallics, volume fraction of θ′ and T (Al 20 Cu 2 Mn 3 ), size of α(Al) dendrite and porosity. Excessive Mn/Fe ratio will deteriorate the mechanical properties of the alloys due to the increase of the total amount of porosity and the Fe-rich intermetallics. When the Mn/Fe ratio is 1.6 and 1.2 for the applied pressure of 0 MPa and 75 MPa, respectively, the needle-like β-Fe phase is completely converted to the Chinese script Fe-rich intermetallics. The ultimate tensile strength, yield strength and elongation of the T5 heat-treated alloy with the Mn/Fe ratio of 1.2 and applied pressure of 75 MPa reach 395 MPa, 335 MPa and 14%, respectively

  18. Simultaneous and multi-criteria optimization of TS requirements and maintenance at NPPs

    International Nuclear Information System (INIS)

    Martorell, S.; Sanchez, A.; Carlos, S.; Serradell, V.

    2002-01-01

    One of the main concerns of the nuclear industry is to improve the availability of safety-related systems at nuclear power plants (NPPs) to achieve high safety levels. The development of efficient testing and maintenance has been traditionally one of the different ways to guarantee high levels of systems availability, which are implemented at NPP through technical specification and maintenance requirements (TS and M). On the other hand, there is a widely recognized interest in using the probabilistic risk analysis (PRA) for risk-informed applications aimed to emphasize both effective risk control and effective resource expenditures at NPPs. TS and M-related parameters in a plant are associated with controlling risk or with satisfying requirements, and are candidate to be evaluated for their resource effectiveness in risk-informed applications. The resource versus risk-control effectiveness principles formally enter in optimization problems where the cost or the burden for the plant staff is to be minimized while the risk or the availability of the safety equipment is constrained to be at a given level, and vice versa. Optimization of TS and M has been found interesting from the very beginning. However, the resolution of such a kind of optimization problem has been limited to focus on only individual TS and M-related parameters (STI, AOT, PM frequency, etc.) and/or adopting an individual optimization criterion (availability, costs, plant risks, etc.). Nevertheless, a number of reasons exist (e.g. interaction, similar scope, etc.) that justify the growing interest in the last years to focus on the simultaneous and multi-criteria optimization of TS and M. In the simultaneous optimization of TS and M-related parameters based on risk (or unavailability) and cost, like in many other engineering optimization problems, one normally faces multi-modal and non-linear objective functions and a variety of both linear and non-linear constraints. Genetic algorithms (GAs) have

  19. Study of the compression and wear-resistance properties of freeze-cast Ti and Ti‒5W alloy foams for biomedical applications.

    Science.gov (United States)

    Choi, Hyelim; Shil'ko, Serge; Gubicza, Jenő; Choe, Heeman

    2017-08-01

    Ti and Ti‒5wt% W alloy foams were produced by freeze-casting process and their mechanical behaviors were compared. The Ti‒5W alloy foam showed a typical acicular Widmanstätten α/β structure with most of the W dissolved in the β phase. An electron-probe microanalysis revealed that approximately 2wt% W was uniformly dissolved in the Ti matrix of Ti‒5W alloy foam with few partially dissolved W particles. The compressive-yield strength of Ti‒5W alloy foam (~323MPa) was approximately 20% higher than that of the Ti foam (~256MPa) owing to the solid-solution-strengthening effect of W in the Ti matrix, which also resulted in a dramatic improvement in the wear resistance of Ti‒5W alloy foam. The compressive behaviors of the Ti and Ti‒5W alloy foams were predicted by analytical models and compared with the experimental values. Compared with the Gibson-Ashby and cellular-lattice-structure-in-square-orientation models of porous materials, the orientation-averaging method provided prediction results that are much more accurate in terms of both the Young's modulus and the yield strength of the Ti and Ti‒5W alloy foams. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Evaluation of mechanical properties in stainless alloy ferritic with 5 % molybdenum; Avaliacao das propriedades mecanicas em ligas inoxidaveis ferriticas com 5% de molibdenio

    Energy Technology Data Exchange (ETDEWEB)

    Lima Filho, V.X.; Gomes, F.H.F.; Guimaraes, R.F.; Saboia, F.H.C.; Abreu, H.F.G. de [Instituto Federal de Educacao, Ciencia e Tecnologia do Ceara (IFCE). Campus Maracanau, CE (Brazil)], e-mail: venceslau@ifce.edu.br

    2010-07-01

    The deterioration of equipment in the oil industry is caused by high aggressiveness in processing the same. One solution to this problem would increase the content of molybdenum (Mo) alloys, since this improves the corrosion resistance. As the increase of Mo content causes changes in mechanical properties, we sought to evaluate the mechanical properties of alloys with 5% Mo and different levels of chromium (Cr). Were performed metallography and hardness measurement of the alloys in the annealed condition. Subsequent tests were performed tensile and Charpy-V, both at room temperature. The results showed that 2% difference in the content of Cr did not significantly alter the mechanical properties of alloys. The alloys studied had higher values in measured properties when compared to commercial ferritic alloys with similar percentages of Cr. The high content of Mo resulted in a brittle at room temperature but ductile at temperatures above 70 degree C. (author)

  1. Annex 5 - Fabrication of U-Al alloy; Prilog 5 - Dobijanje legure U-Al

    Energy Technology Data Exchange (ETDEWEB)

    Drobnjak, Dj; Lazarevic, Dj; Mihajlovic, A [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    Alloy U-Al with low content of aluminium is often used for fabrication of fuel elements because it is stable under moderate neutron flux density. Additionally this type of alloys show much better characteristics than pure uranium under reactor operating conditions (temperature, mechanical load, corrosion effect of water). This report contains the analysis of the phase diagram of U-Al alloy with low content of aluminium, applied procedure for alloying and casting with detailed description of equipment. Characteristics of the obtained alloy are described and conclusions about the experiment and procedure are presented. Sistem U-Al sa niskim sadrzajem aluminijuma jedan je od cesto koriscenih za izradu gorivnih elemenata, jer je dovoljno stabilan pri umerenim gustinama fluksa. Pored toga, u uslovima karakteristicnim za rad nuklearnog reaktora (temperatura, gradijent temperature, mehanicka naprezanja, koroziono dejstvo vode) legure ovog sistema pokazuju daleko bolja svojstva od nelegiranog urana. Referat sadrzi analizu dijagrama stanja U-Al legure sa niskim sadrzajem aluminijuma, primenjeni postupak legiranja i livenja sa opisom pojedinih uredjaja i operacija. Takodje su opisana svojstva dobijene legure i dat je zakljucak o eksperimentu i tehnici rada (author)

  2. Tensile properties of aluminized V-5Cr-5Ti alloy after exposure in air environment

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Soppet, W.K. [Argonne National Lab., IL (United States)

    1997-08-01

    The objectives of this task are to (a) develop procedures to modify surface regions of V-Cr-Ti alloys in order to minimize oxygen uptake by the alloys when exposed to environments that contain oxygen, (b) evaluate the oxygen uptake of the surface-modified V-Cr-Ti alloys as a function of temperature an oxygen partial pressure in the exposure environment, (c) characterize the microstructures of oxide scales and oxygen trapped at the grain boundaries of the substrate alloys, and (d) evaluate the influence of oxygen uptake on the tensile properties of the modified alloys at room and elevated temperatures.

  3. TS WEBSITE AND SOCIAL MEDIA ANALYTICS- DECEMBER 2016

    Data.gov (United States)

    Department of Veterans Affairs — This PowerPoint included accomplishments reached in December 2016, along with how many TS users and Pulse users there are currently. Not only does this PowerPoint...

  4. TS WEBSITE AND SOCIAL MEDIA ANALYTICS NOVEMBER 2016

    Data.gov (United States)

    Department of Veterans Affairs — This PowerPoint included accomplishments reached in November 2016, along with how many TS users and Pulse users there are currently. Not only does this PowerPoint...

  5. TS LOOP ALCOVE VENTILATION ANALYSIS

    International Nuclear Information System (INIS)

    T.M. Lahnalampi

    2000-01-01

    The scope of this analysis is to examine the existing, constructor installed, physical ventilation installations located in each of the Exploratory Studies Facility (ESF) Topopah Springs (TS) Loop Alcoves No.1, No.2, No.3, No.4, No.6, and No.7. Alcove No.5 is excluded from the scope of this analysis since it is an A/E design system. Each ventilation installation will be analyzed for the purpose of determining if requirements for acceptance into the A/E design technical baseline have been met. The ventilation installations will be evaluated using Occupational Safety and Health Administration (OSHA) standards and Exploratory Studies Facility Design Requirements (ESFDR) (YMP 1997) requirements. The end product will be a technical analysis that will define ventilation installation compliance issues, any outstanding field changes, and use-as-is design deviations that are required to bring the ventilation installations into compliance with requirements for acceptance into the A/E design technical baseline. The analysis will provide guidance for alcove ventilation component design modifications to be developed to correct any deficient components that do not meet minimum requirements and standards

  6. Transformation behavior and shape memory characteristics of thermo-mechanically treated Ti–(45−x)Ni–5Cu–xV (at%) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jae-young; Chun, Su-jin [Division of Materials Scince and Engineering and ERI, Gyeongsang National University, 501 Jinjudaero, Jinju, Gyeongnam 660-701 (Korea, Republic of); Choi, Eunsoo [Department of Civil Engineering, Hongik University, Seoul (Korea, Republic of); Liu, Yinong; Yang, Hong [School of Mechanical Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Nam, Tae-hyun, E-mail: tahynam@gnu.ac.kr [Division of Materials Scince and Engineering and ERI, Gyeongsang National University, 501 Jinjudaero, Jinju, Gyeongnam 660-701 (Korea, Republic of)

    2012-10-15

    Transformation behavior, shape memory characteristics and superelasticity of thermo-mechanically treated Ti–(45−x)Ni–5Cu–xV (at%) (x = 0.5–2.0) alloys were investigated by means of differential scanning calorimetry, transmission electron microscopy, X-ray diffractions, thermal cycling tests under constant load and tensile tests. The B2–B19′ transformation occurred when V content was 0.5 at%, above which the B2–B19–B19′ transformation occurred. The B2–B19 transformation was not separated clearly from the B19–B19′ transformation. Thermo-mechanically treated Ti–(45−x)Ni–5Cu–xV alloys showed perfect shape memory effect and transformation hysteresis(ΔT) of Ti–43.5Ni–5.0Cu–1.5V and Ti–43.0Ni–5.0Cu–2.0V alloys was about 9 K which was much smaller than that of a Ti–44.5Ni–5.0Cu–0.5V alloy(23.3 K). More than 90% of superelastic recovery ratio was observed in all specimens and transformation hysteresis (Δσ) of a Ti–44.5Ni–5.0Cu–0.5V alloy was about 70 MPa, which was much larger than that of a Ti–43.0Ni–5.0Cu–2.0V alloy (35 MPa).

  7. Al and Si Alloying Effect on Solder Joint Reliability in Sn-0.5Cu for Automotive Electronics

    Science.gov (United States)

    Hong, Won Sik; Oh, Chulmin; Kim, Mi-Song; Lee, Young Woo; Kim, Hui Joong; Hong, Sung Jae; Moon, Jeong Tak

    2016-12-01

    To suppress the bonding strength degradation of solder joints in automotive electronics, we proposed a mid-temperature quaternary Pb-free Sn-0.5Cu solder alloy with minor Pd, Al, Si and Ge alloying elements. We manufactured powders and solder pastes of Sn-0.5Cu-(0.01,0.03)Al-0.005Si-(0.006-0.007)Ge alloys ( T m = 230°C), and vehicle electronic control units used for a flame-retardant-4 printed circuit board with an organic solderability preservative finish were assembled by a reflow soldering process. To investigate the degradation properties of solder joints used in engine compartments, thermal cycling tests were conducted from -40°C to 125°C (10 min dwell) for 1500 cycles. We also measured the shear strength of the solder joints in various components and observed the microstructural evolution of the solder joints. Based on these results, intermetallic compound (IMC) growth at the solder joints was suppressed by minor Pd, Al and Si additions to the Sn-0.5Cu alloy. After 1500 thermal cycles, IMC layers thicknesses for 100 parts per million (ppm) and 300 ppm Al alloy additions were 6.7 μm and 10 μm, compared to the as-reflowed bonding thicknesses of 6 μm and 7 μm, respectively. Furthermore, shear strength degradation rates for 100 ppm and 300 ppm Al(Si) alloy additions were at least 19.5%-26.2%. The cause of the improvement in thermal cycling reliability was analyzed using the (Al,Cu)-Sn, Si-Sn and Al-Sn phases dispersed around the Cu6Sn5 intermetallic at the solder matrix and bonding interfaces. From these results, we propose the possibility of a mid-temperature Sn-0.5Cu(Pd)-Al(Si)-Ge Pb-free solder for automotive engine compartment electronics.

  8. Severe plastic deformation of α+β Ti-5Ta-1.8Nb alloy by cryo-rolling

    International Nuclear Information System (INIS)

    Dasgupta, Arup; Parida, Pradyumna Kumar; Saroja, S.; Vijayalakshmi, M.

    2010-01-01

    The α-β (β ∼ 8%) Ti5Ta1.8Nb alloy is under development at IGCAR for reprocessing applications owing to its superior corrosion resistance and weldability. A possible method to strengthen the alloy is to engineer the grain size to finer dimensions through severe plastic deformation (SPD). A detailed analysis of the study of evolution of microstructure and micro-texture in the SPD Ti-Ta-Nb alloy is presented

  9. Porous anodic film formation on an Al-3.5 wt% Cu alloy

    Energy Technology Data Exchange (ETDEWEB)

    Paez, M.A.; Bustos, O.; Thompson, G.E.; Skeldon, P.; Shimizu, K.; Wood, G.C.

    2000-03-01

    Anodic film growth has been undertaken on an electropolished Al-3.5 wt % Cu alloy to determine the influence of copper in solid solution on the anodizing behavior. At the commencement of anodizing of the electropolished alloy, in the presence of interfacial enrichment of copper, Al{sup 3+} and Cu{sup 2+} ions egress and O{sup 2{minus}} ion ingress proceed; film growth occurs at the alloy/film interface though O{sup 2{minus}} ion ingress, with outwardly mobile Al{sup 3+} and Cu{sup 2+} ions ejected at the film/electrolyte interface, and field-assisted dissolution proceeding at the bases of pores. Oxidation of copper, in the presence of the enriched layer, is also associated with O{sub 2} gas generation, leading to development of oxygen-filled voids. As a result of significant pressures in the voids, film rupture proceeds, with electrolyte access to the alloy, dissolution of the enriched interfacial layer and re-anodizing. The consequence of such processes in the development of anodic films of increased porosity and reduced efficiency of film formation compared with anodizing of superpure aluminum under similar conditions.

  10. TsAg5, a Taenia solium cysticercus protein with a marginal trypsin-like activity in the diagnosis of human neurocysticercosis.

    Science.gov (United States)

    Rueda, Analiz; Sifuentes, Cecilia; Gilman, Robert H; Gutiérrez, Andrés H; Piña, Ruby; Chile, Nancy; Carrasco, Sebastián; Larson, Sandra; Mayta, Holger; Verástegui, Manuela; Rodriguez, Silvia; Gutiérrez-Correa, Marcel; García, Héctor H; Sheen, Patricia; Zimic, Mirko

    2011-12-01

    Neurocysticercosis is an endemic parasitic disease caused by Taenia solium larva. Although the mechanism of infection is not completely understood, it is likely driven by proteolytic activity that degrades the intestinal wall to facilitate oncosphere penetration and further infection. We analyzed the publicly available T. solium EST/DNA library and identified two contigs comprising a full-length cDNA fragment very similar to Echinococcus granulosus Ag5 protein. The T. solium cDNA sequence included a proteolytic trypsin-like-domain in the C-terminal region, and a thrombospondin type-1 adherence-domain in the N-terminal region. Both the trypsin-like and adherence domains were expressed independently as recombinant proteins in bacterial systems. TsAg5 showed marginal trypsin-like activity and high sequence similarity to Ag5. The purified antigens were tested in a Western immunoblot assay to diagnose human neurocysticercosis. The sensitivity of the trypsin-like-domain was 96.36% in patients infected with extraparenchymal cysts, 75.44% in patients infected with multiple cysts, and 39.62% in patients with a single cyst. Specificity was 76.70%. The thrombospondin type-1 adherence-domain was not specific for neurocysticercosis. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Magnetic properties and EXAFS study of nanocrystalline Fe2Mn0.5Cu0.5Al synthesized using mechanical alloying technique

    International Nuclear Information System (INIS)

    Nanto, Dwi; Yang, Dong-Seok; Yu, Seong-Cho

    2014-01-01

    Nanocrystalline Fe 2 Mn 0.5 Cu 0.5 Al has been synthesized by the mechanical alloying technique and studied as a function of milling time. Alloy nature of Fe 2 Mn 0.5 Cu 0.5 Al was observed in a sample milled for 96 h. The magnetic saturation is 4.0 μ B /f.u., which coincidently follows Slater–Pauling rule at 5 K. Nanocrystalline Fe 2 Mn 0.5 Cu 0.5 Al has enhanced saturate magnetization compared to any other fabrication of Fe 2 MnAl reported. Cu element plays an important role in site competes with other elements and may result in the enhancement of saturate magnetization. In accordance to the magnetic results and EXAFS pattern, it was revealed that the dynamics of magnetic properties were confirmed as structural changes of nanocrystalline Fe 2 Mn 0.5 Cu 0.5 Al

  12. The optical, vibrational, structural and elasto-optic properties of Zn_0_._2_5Cd_0_._7_5S_ySe_1_-_y quaternary alloys

    International Nuclear Information System (INIS)

    Paliwal, U.; Swarkar, C. B.; Sharma, M. D.; Joshi, K. B.

    2016-01-01

    The optical, vibrational, structural and elasto-optic properties of quaternary II-VI alloys Zn_0_._2_5Cd_0_._7_5S_0_._2_5Se_0_._7_5, Zn_0_._2_5Cd_0_._7_5S_0_._5_0Se_0_._5_0 and Zn_0_._2_5Cd_0_._7_5S_0_._7_5Se_0_._2_5 are presented. Within the empirical pseudopotential method (EPM) the disorder effects are modeled via modified virtual crystal approximation (MVCA). The computed bandgaps and the refined form factors are utilized to evaluate optical, vibrational, structural and elasto-optic properties. The refractive index (n), static (ε_0) and high frequency dielectric (ε_∞) constants are calculated to reveal optical behavior of alloys. The longitudinal ω_L_O(0) and transverse ω_T_O(0) optical frequencies are obtained to see vibrational characteristics. Moreover, the elastic constants (c_i_j) and bulk moduli (B) are computed by combining the EPM with Harrison bond orbital model. The elasto-optic nature of alloys is examined by computing the photo-elastic constants. These values are significant with regard to the opto-electronic applications especially when no experimental data are available on this system.

  13. Highlighting micrographic structures of uranium alloys containing 0.5 to 10 per cent wt molybdenum

    International Nuclear Information System (INIS)

    Laniesse, J.; Bouleau, M.

    1959-02-01

    The authors report a study which aimed at determining for different uranium molybdenum alloys and with respect to their molybdenum content a polishing method which allows a relatively simple grain examination in the as-cast condition, an as perfect as possible resolution of eutectic decompositions, and the appropriate conditions to highlight structures (beta-alpha and gamma-alpha martensite transformations, beta phase retention and decomposition, transient structures, eutectoid decomposition, and so on). Alloys differ by their molybdenum content: from 0.5 to 1 per cent wt, 1.5 to 3 per cent wt, 5 to 10 per cent wt

  14. Study of phase transformation of U-2,5Zr-7,5Nb e U-3Zr-9Nb alloys for application in advanced nuclear fuel

    International Nuclear Information System (INIS)

    Pais, Rafael Witter Dias

    2015-01-01

    Metal fuels are relevant in the nuclear area due to the versatility of its use in the nuclear fuel cycle. Among the alloys of uranium investigated with high potential for use in nuclear power reactors, U-Zr-Nb alloys appear as an important alternative because of their superior physico-chemical and metallurgical properties. These alloys have also potential for use in nuclear testing, research and production radioisotopes of high performance nuclear reactors. Therefore, the development of these alloys is strategic since they are planned to be used in national reactors as RMB (Brazilian Multipurpose Reactor) and LABGENE (Electrical Generation Core Laboratory), currently under development in Brazil. In this work it was realized a extensive study in the scope of the manufacturing, heat treatment and phase transformations of U-2,5Zr-7,5Nb (m/m%) and U-3ZR-9NB (m/m%) fuel alloys. Ingots of both alloys were produced employing a specific methodology developed in this study. This methodology comprised the melting process in a vacuum induction furnace at high temperatures (1500 °C) and thermal-mechanical processing to break the as-cast structure. Samples with typical dimensions (17 x 7 x 2.5 mm) free from macrostructural defects were homogenized at 1000 °C in vacuum of 10 -5 torr for 17.5 hours with a 10°C/min cooling rate until to 820 °C and, subsequently, quenched in water. The samples, randomly selected, were subjected to isothermal treatment tests under different conditions of time and temperature. Isothermal treatments for transformation and retention phases were carried out in a special assembly designed for this work. After the tests, the samples were characterized by the usual phase characterization techniques with particular emphasis for the X-ray diffraction technique. In this way, the Rietveld refinement method was applied. In the case of uranium based alloys it is quite challenging due to the lack of data in the literature. In this work a strategy for the

  15. Cloning and Characterization of EF-Tu and EF-Ts from Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Stephanie O. Palmer

    2013-01-01

    Full Text Available We have cloned genes encoding elongation factors EF-Tu and EF-Ts from Pseudomonas aeruginosa and expressed and purified the proteins to greater than 95% homogeneity. Sequence analysis indicated that P. aeruginosa EF-Tu and EF-Ts are 84% and 55% identical to E. coli counterparts, respectively. P. aeruginosa EF-Tu was active when assayed in GDP exchange assays. Kinetic parameters for the interaction of EF-Tu with GDP in the absence of EF-Ts were observed to be = 33 μM, = 0.003 s−1, and the specificity constant was  s−1 μM−1. In the presence of EF-Ts, these values were shifted to = 2 μM, = 0.005 s−1, and the specificity constant was  s−1 μM−1. The equilibrium dissociation constants governing the binding of EF-Tu to GDP ( were 30–75 nM and to GTP ( were 125–200 nM. EF-Ts stimulated the exchange of GDP by EF-Tu 10-fold. P. aeruginosa EF-Tu was active in forming a ternary complex with GTP and aminoacylated tRNA and was functional in poly(U-dependent binding of Phe-tRNAPhe at the A-site of P. aeruginosa ribosomes. P. aeruginosa EF-Tu was active in poly(U-programmed polyphenylalanine protein synthesis system composed of all P. aeruginosa components.

  16. Filler metal alloy for welding cast nickel aluminide alloys

    Science.gov (United States)

    Santella, M.L.; Sikka, V.K.

    1998-03-10

    A filler metal alloy used as a filler for welding cast nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and cast in copper chill molds. 3 figs.

  17. Evaluation of the Airborne CASI/TASI Ts-VI Space Method for Estimating Near-Surface Soil Moisture

    Directory of Open Access Journals (Sweden)

    Lei Fan

    2015-03-01

    Full Text Available High spatial resolution airborne data with little sub-pixel heterogeneity were used to evaluate the suitability of the temperature/vegetation (Ts/VI space method developed from satellite observations, and were explored to improve the performance of the Ts/VI space method for estimating soil moisture (SM. An evaluation of the airborne ΔTs/Fr space (incorporated with air temperature revealed that normalized difference vegetation index (NDVI saturation and disturbed pixels were hindering the appropriate construction of the space. The non-disturbed ΔTs/Fr space, which was modified by adjusting the NDVI saturation and eliminating the disturbed pixels, was clearly correlated with the measured SM. The SM estimations of the non-disturbed ΔTs/Fr  space using the evaporative fraction (EF and temperature vegetation dryness index (TVDI were validated by using the SM measured at a depth of 4 cm, which was determined according to the land surface types. The validation results show that the EF approach provides superior estimates with a lower RMSE (0.023 m3·m−3 value and a higher correlation coefficient (0.68 than the TVDI. The application of the airborne ΔTs/Fr  space shows that the two modifications proposed in this study strengthen the link between the ΔTs/Fr space and SM, which is important for improving the precision of the remote sensing Ts/VI space method for monitoring SM.

  18. Large magnetoresistance in a directionally solidified Ni44.5Co5.1Mn37.1In13.3 magnetic shape memory alloy

    Science.gov (United States)

    Li, Zongbin; Hu, Wei; Chen, Fenghua; Zhang, Mingang; Li, Zhenzhuang; Yang, Bo; Zhao, Xiang; Zuo, Liang

    2018-04-01

    Polycrystalline Ni44.5Co5.1Mn37.1In13.3 alloy with coarse columnar-shaped grains and 〈0 0 1〉A preferred orientation was prepared by directional solidification. Due to the strong magnetostructural coupling, inverse martensitic transformation can be induced by the magnetic field, resulting in large negative magnetoresistance up to -58% under the field of 3 T. Such significant field controlled functional behaviors should be attributed to the coarse grains and strong preferred orientation in the directionally solidified alloy.

  19. The effects of Mg addition on the microstructure and mechanical properties of thixoformed Al–5%Si–Cu alloys

    International Nuclear Information System (INIS)

    Salleh, M.S.; Omar, M.Z.; Syarif, J.

    2015-01-01

    Highlights: • The average globule size of α-Al decreased when Mg amount is increased. • T6 heat treatment has increased the strength of the thixoformed alloys. • The elongation after T6 heat treatment is even significantly improved. • Thixoformed alloy with high Mg content shows a brittle type fracture. • Thixoformed alloy in T6 condition shows a ductile type fracture. - Abstract: In this study, the effects of different amounts of magnesium (Mg) on the microstructures and tensile properties of thixoformed Al–5%Si–Cu alloys were investigated. Three different alloys containing various amounts of Mg (0.5, 0.8 and 1.2 wt%) were prepared through the cooling slope casting technique, before they were thixoformed using a compression press. Several of the thixoformed samples were then treated with a T6 heat treatment, that is, solution treatment at 525 °C for 8 h, quenching in warm water at 60 °C, followed by aging at 155 °C for 4 h. All of the samples were then characterised by optical microscopy (OM), scanning electron microscopy (SEM) energy dispersive X-ray (EDX) spectroscopy and X-ray diffraction (XRD) analysis as well as by tensile tests. The results revealed that magnesium was able to refine the size of α-Al globules and the eutectic silicon in the samples. It was also observed that a compact π-Al 9 FeMg 3 Si 5 phase was formed when the magnesium content was 0.8 wt% and 1.2 wt%. The mechanical properties of the thixoformed alloys improved significantly after the T6 heat treatment. The highest attainment was recorded by the latter alloy (i.e. with 1.2 wt%Mg) with its ultimate tensile strength (UTS) as high as 306 MPa, yield strength (YS), 264 MPa, and elongation to fracture of 1.8%. The fracture of thixoformed alloy with a low Mg content (0.5 wt%) showed a combination of dimple and cleavage fracture, whereas in the alloy that contained the highest Mg content (1.2 wt%), cleavage fracture was observed

  20. On the correlation between the morphology of α and its crystallographic orientation relationship with TiB and β in boron-containing Ti–5Al–5Mo–5V–3Cr–0.5Fe alloy

    International Nuclear Information System (INIS)

    Nandwana, P.; Nag, S.; Hill, D.; Tiley, J.; Fraser, H.L.; Banerjee, R.

    2012-01-01

    While the role of borides on the microstructure of titanium alloys has been discussed in many previous reports, this paper presents the first experimental evidence of (i) the three-dimensional geometry of α precipitates confirming their equiaxed morphology, as determined by reconstruction of serially sectioned scanning electron microscopy images; and (i) the influence of the crystallographic orientation relationship between β, TiB and α phases on the morphology of α precipitates, investigated via detailed orientation microscopy studies on a boron-containing version of the commercial Ti–5Al–5Mo–5V–3Cr–0.5Fe alloy Ti5553.

  1. Some aspects of thermally induced martensite in Fe-30% Ni-5% Cu alloy

    International Nuclear Information System (INIS)

    Guener, M.; Gueler, E.; Yasar, E.; Aktas, H.

    2007-01-01

    Kinetical, morphological, crystallographical and several thermal properties of thermally induced martensite in the austenite phase of Fe-30% Ni-5% Cu alloy were investigated. Scanning electron microscope (SEM), transmission electron microscope (TEM) and differential scanning calorimetry (DSC) techniques were used during study. Kinetics of the transformation was found to be as athermal type. SEM and TEM observations revealed α' (BCC) martensite formation in the austenite phase of alloy by thermal effect. These thermally induced α' martensites exhibited a thin plate-like morphology with twinnings

  2. Synthesis by mechanical alloying and characterization of 95.5Sn/4.0Ag/0.5Cu, (wt%) nanopowder

    International Nuclear Information System (INIS)

    Barreto, Karen Lyn Lima; Manzato, Lizandro; Rivera, Jose Anglada; Oliveira, Marceli Falcao de

    2010-01-01

    This work aims at sintering and characterizing the 95.5Sn/4.0Ag/0.5Cu (wt%) nanopowder, produced by high energy milling. The nano-sized particles reduce the melting point of this solder, which is usually higher for such alloys, for example, when compared with the usual 63Sn/37Pb (wt%) solder. The alloy was processed in a Spex mill with the following parameters: (I) different times of milling, 12, 24 and 48 hours. (II) the ratio of ball/mass powder of 40:1 and (II) hydrogen milling atmosphere. The microstructural evolution during milling was studied by X-ray diffraction and differential calorimetry. Combining these three variables, after grinding, a reduction of the particle size and the melting point of the solder were observed. This material is promising for applications in microelectronics packaging as a lead free solder. (author)

  3. Influence of heat treatment on the mechanical and electrical characteristics of Ni{sub 0.5}Ti{sub 0.5} alloy prepared by electron-beam melting

    Energy Technology Data Exchange (ETDEWEB)

    Ammar, A.H. [Thin Film Laboratory, Physics Department, Faculty of Education, Ain Shams University (Egypt); Physics Department, Faculty of Science and Arts, Al-Ola, Taibah University (Saudi Arabia); Al-Buhairi, M. [Physics Department, Faculty of Science, Taiz University (Yemen); Farag, A.A.M., E-mail: alaafaragg@yahoo.com [Thin Film Laboratory, Physics Department, Faculty of Education, Ain Shams University (Egypt); Al-Wajeeh, N.M.M. [Physics Department, Faculty of Science, Taiz University (Yemen)

    2013-06-15

    Nickel titanium alloys (Ni{sub 0.5}Ti{sub 0.5}) were successfully produced from elemental Ni/Ti powders by electron-beam melting method and then subjected to annealing and aging treatment. Microstructure of the alloys was examined by XRD and SEM. The mechanical properties of the alloyed surface were examined. The microhardness was studied as a function of annealing temperature and time. It was found that the microhardness decreases with increasing annealing temperature until 660 °C after which the microhardness increases. Electrical resistance measurements were carried out in order to study the transformation behavior. The electrical measurements point out the importance of temperature dependence of Ni{sub 0.5}Ti{sub 0.5} electrical resistance for the identification of particular transformation. The influence of aging on the development of electrical resistivity was also investigated.

  4. VANADIUM ALLOYS

    Science.gov (United States)

    Smith, K.F.; Van Thyne, R.J.

    1959-05-12

    This patent deals with vanadium based ternary alloys useful as fuel element jackets. According to the invention the ternary vanadium alloys, prepared in an arc furnace, contain from 2.5 to 15% by weight titanium and from 0.5 to 10% by weight niobium. Characteristics of these alloys are good thermal conductivity, low neutron capture cross section, good corrosion resistance, good welding and fabricating properties, low expansion coefficient, and high strength.

  5. Effect of Si, Mn, Sn on Tensile and Corrosion Properties of Mg-4Zn-0.5Ca Alloys for Biodegradable Implant Materials

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Dae Hyun; Nam, Ji Hoon; Lee, Byeong Woo; Park, Ji Yong; Shin, Hyun Jung; Park, Ik Min [Pusan National University, Busan (Korea, Republic of)

    2015-03-15

    Effect of elements Si, Mn, Sn on tensile and corrosion properties of Mg-4Zn-0.5Ca alloys were investigated. The results of tensile properties show that the yield strength, ultimate tensile strength and elongation of Mg-4Zn-0.5Ca alloy increased significantly with the addition of 0.6 wt% Mn. This is considered the grain refinement effect due to addition of Mn. However addition of 0.6 wt% Si decreased yield strength, ultimate tensile strength and elongation. The bio-corrosion behavior of Mg-4Zn-0.5Ca-X alloys were investigated using immersion tests and potentiodynamic polarization test in Hank's solution. Immersion test showed that corrosion rate of Mg-4Zn-0.5Ca-0.6Mn alloy was the lowest rate and addition of 1.0 wt% Sn accelerated corrosion rate due to micro-galvanic effect in α-Mg/CaMgSn phases interface. And corrosion potential (E{sub c}orr) of Mg-4Zn-0.5Ca-0.6Mn alloy was the most noble among Mg-4Zn-0.5Ca-X alloys.

  6. Formation of long-period stacking ordered structures in Mg88M5Y7 (M = Ti, Ni and Pb) casting alloys

    International Nuclear Information System (INIS)

    Jin, Qian-Qian; Fang, Can-Feng; Mi, Shao-Bo

    2013-01-01

    Highlights: •Apart from 18R-LPSO, 14H-LPSO structure was determined in the Mg-Ni-Y alloys. •The appearance of twin-related structure in 18R-LPSO structure results from the stacking faults in the stacking sequence of the closely packed planes. •A new (Pb, Mg) 2 Y phase with a body-centered orthorhombic structure was determined in the Mg-Pb-Y alloy. •No LPSO structures were found in the Mg-Pb-Y and Mg-Ti-Y casting alloys. -- Abstract: Formation of long-period stacking ordered (LPSO) structures is investigated in Mg 88 M 5 Y 7 (M = Ti, Ni and Pb) casting alloys by means of electron microscopy and X-ray diffraction. In the Mg 88 Ni 5 Y 7 casting alloy, 14H-LPSO structure is observed in a small amount, which coexists with 18R-LPSO structure. The appearance of stacking faults in 18R-LPSO structure results in twin-related structure in the stacking sequence of the closely packed planes. A new (Pb, Mg) 2 Y phase with a body-centered orthorhombic structure is determined in the Mg 88 Pb 5 Y 7 alloy. No LPSO structures are found in the Mg 88 Pb 5 Y 7 and Mg 88 Ti 5 Y 7 casting alloys. In terms of the atomic radius and heat of mixing, the formation ability of LPSO structure in the present alloys is discussed

  7. Creep and stress rupture behaviour of zircaloy-2 and Zr-2.5% Nb alloy tubes at 573 K

    International Nuclear Information System (INIS)

    Laha, K.; Bhanu Sankara Rao, K.; Chandravathi, K.S.; Mannan, S.L.

    1992-01-01

    Zirconium alloys are extensively used for coolant tubes of pressurised heavy water reactors. The choice of these materials is based on their good corrosion resistance in water, low capture cross section for thermal neutrons and good mechanical properties. In this paper the results of an investigation performed on the creep and rupture behaviour of indigenously produced zircaloy-2 and Zr-2.5% Nb alloy are presented. Samples for creep testing were cut longitudinally from finished pressure tubes. Creep rupture tests were carried out in air under constant load conditions at 300 C employing five stress levels in the range 300-360 MPa. Zr-2.5% Nb alloy displayed higher rupture lives at all stress levels compared to zircaloy-2. Steady state creep rate of Zr-2.5%Nb was lower than that zircaloy-2 at identical stress levels. In the stress range of the experiments, the dependence of the steady state creep rate (ε s ) on applied stress (σ) for both the alloys could be represented by a power law, ε s =A σ n The stress sensitivity (n) for Zr-2.5% Nb was lower than that of zircaloy-2. For both the alloys the time to creep rupture t r was found related to the steady state creep rate through the modified Monkman-Grant relation (ε s ) α . t r = constant. Similar value of α was obtained for both the materials. Zr-2.5%Nb exhibited higher ductility (% elongation to rupture) compared to zircaloy-2 at stress levels ≥ 320 MPa. At lower stresses significant difference in ductility was not noticed. Percentage reduction in area was lower in Zr-2.5%Nb at all stress levels indicating better resistance for necking. The time for onset of tertiary was longer for Zr-2.5% Nb alloy. The proportion of life spent by Zr-2.5% Nb in steady state creep regime was higher compared to that of zircaloy-2. Metallographic investigations on longitudinal sections in both the alloys showed large number of intragranular pores close to the fracture surface. A few number of cracks which are characteristic of

  8. Konstantin Päts ja NSV Liidu Tallinna saatkond / Magnus Ilmjärv

    Index Scriptorium Estoniae

    Ilmjärv, Magnus, 1961-

    1999-01-01

    Järg Sep/13,14,15,16,17,18,20,21,22,22 lk. 17,21,17,18,18,16,17,21,18,14. Päts kui Nõukogude saatkonna lobitegija. Välisminister Pusta kangutamine. Pätsi info venelastele J. Tõnissoni kohta. Balti riikide vahelise koostöö takistamine. J. Puhk tõmmati venelaste mõjusfääri. Päts nõuab Eesti valitsuselt uut kaubanduslepingut venelastega

  9. ERCC1 and TS Expression as Prognostic and Predictive Biomarkers in Metastatic Colon Cancer.

    Directory of Open Access Journals (Sweden)

    Michel B Choueiri

    Full Text Available In patients with metastatic colon cancer, response to first line chemotherapy is a strong predictor of overall survival (OS. Currently, oncologists lack diagnostic tests to determine which chemotherapy regimen offers the greatest chance for response in an individual patient. Here we present the results of gene expression analysis for two genes, ERCC1 and TS, measured with the commercially available ResponseDX: Colon assay (Response Genetics, Los Angeles, CA in 41 patients with de novo metastatic colon cancer diagnosed between July 2008 and August 2013 at the University of California, San Diego. In addition ERCC1 and TS expression levels as determined by RNAseq and survival data for patients in TCGA were downloaded from the TCGA data portal. We found that patients with low expression of ERCC1 (n = 33 had significantly longer median OS (36.0 vs. 10.1 mo, HR 0.29, 95% CI .095 to .84, log-rank p = 9.0x10-6 and median time to treatment to failure (TTF following first line chemotherapy (14.1 vs. 2.4 mo, HR 0.17, 95% CI 0.048 to 0.58, log-rank p = 5.3x10-4 relative to those with high expression (n = 4. After accounting for the covariates age, sex, tumor grade and ECOG performance status in a Cox proportional hazard model the association of low ERCC1 with longer OS (HR 0.18, 95% CI 0.14 to 0.26, p = 0.0448 and TTF (HR 0.16, 95% CI 0.14 to 0.21, p = 0.0053 remained significant. Patients with low TS expression (n = 29 had significantly longer median OS (36.0 vs. 14.8 mo, HR 0.25, 95% CI 0.074 to 0.82, log-rank p = 0.022 relative to those with high expression (n = 12. The combined low expression of ERCC1/TS was predictive of response in patients treated with FOLFOX (40% vs. 91%, RR 2.3, Fisher's exact test p = 0.03, n = 27, but not with FOLFIRI (71% vs. 71%, RR 1.0, Fisher's exact test p = 1, n = 14. Overall, these findings suggest that measurement of ERCC1 and TS expression has potential clinical utility in managing patients with metastatic colorectal

  10. Modern quantitative microstructure analysis on the example of aicu5mg1 alloys

    Directory of Open Access Journals (Sweden)

    Zlatičanin Biljana V.

    2002-01-01

    Full Text Available Using an automatic, QUANTIMET 500 MC, device for quantitative picture analysis and applying linear method of measurement on the example of AlCu5Mg1 alloys, the grain size (min, max and medium values, as well as relative standard measuring errors (RSE, dendrite arm spacing (DAS and length eutectic (Le and also distribution by size (histogram and volume participation of -hard solution and eutectic have been determined. We have also studied the influence of grain-refining additives AlTi5B1 for the same chemical composition of the aluminium-capper-magnesium alloy. It has been concluded that with the increase of titanium content, the mean value of grain size decreases. We have also examined hardness and pressure strength.

  11. Photocatalytic hydrogen generation over Eosin Y-Sensitized TS-1 zeolite

    International Nuclear Information System (INIS)

    Zhang Xiaojie; Jin Zhiliang; Li Yuexiang; Li Shuben; Lu Gongxuan

    2008-01-01

    Eosin Y-sensitized TS-1 zeolite was studied for the photo-reduction of water into hydrogen driven by visible light (λ ≥ 420 nm). The optimal pH and weight ratio between Eosin Y and TS-1 zeolite is 7 and 1/8, respectively. In the presence of triethanolamine (TEA) as an electron donor, the highest rate of hydrogen generation and apparent quantum efficiency are 34 μmol h -1 and 9.4%, respectively, under visible light irradiation (λ ≥ 420 nm). Short-term stability test indicates that the catalyst is rather stable during 50 h photoreaction

  12. Photocatalytic hydrogen generation over Eosin Y-Sensitized TS-1 zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xiaojie [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Zhong Road 18, Lanzhou 730000 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100101 (China); Jin Zhiliang [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Zhong Road 18, Lanzhou 730000 (China); Li Yuexiang [Department of Chemistry, Nanchang University, Nanjing Road 245, Nanchang 330047 (China); Li Shuben [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Zhong Road 18, Lanzhou 730000 (China); Lu Gongxuan [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Zhong Road 18, Lanzhou 730000 (China)], E-mail: gxlu@lzb.ac.cn

    2008-05-30

    Eosin Y-sensitized TS-1 zeolite was studied for the photo-reduction of water into hydrogen driven by visible light ({lambda} {>=} 420 nm). The optimal pH and weight ratio between Eosin Y and TS-1 zeolite is 7 and 1/8, respectively. In the presence of triethanolamine (TEA) as an electron donor, the highest rate of hydrogen generation and apparent quantum efficiency are 34 {mu}mol h{sup -1} and 9.4%, respectively, under visible light irradiation ({lambda} {>=} 420 nm). Short-term stability test indicates that the catalyst is rather stable during 50 h photoreaction.

  13. Preparation and electrochemical properties of La_0_._7_0Mg_xNi_2_._4_5Co_0_._7_5Al_0_._3_0 (x = 0, 0.30, 0.33, 0.36, 0.39) hydrogen storage alloys

    International Nuclear Information System (INIS)

    Tian, Xiao; Wei, Wei; Duan, Ruxia; Zheng, Xinyao; Zhang, Huaiwei; Tegus, O.; Li, Xingguo

    2016-01-01

    The as-cast alloy with the composition of La_0_._7_0Ni_2_._4_5Co_0_._7_5Al_0_._3_0 was prepared by vacuum arc melting. La–Mg–Ni-based La_0_._7_0Mg_xNi_2_._4_5Co_0_._7_5Al_0_._3_0 hydrogen storage alloy has been synthesized by high-energy vibratory milling blending of the La_0_._7_0Ni_2_._4_5Co_0_._7_5Al_0_._3_0 as-cast alloy and elemental Mg, followed by an isothermal annealing. The microstructures and electrochemical properties of the La_0_._7_0Ni_2_._4_5Co_0_._7_5Al_0_._3_0 and La_0_._7_0Mg_xNi_2_._4_5Co_0_._7_5Al_0_._3_0 alloys were investigated by XRD, SEM and electrochemical measurements. The XRD analysis and Rietveld refinement showed that the as-cast La_0_._7_0Ni_2_._4_5Co_0_._7_5Al_0_._3_0 alloy consists of single LaNi_5 phase, whereas the La_0_._7_0Mg_xNi_2_._4_5Co_0_._7_5Al_0_._3_0 alloys contain the LaNi_5 and (La, Mg)_2Ni_7. The electrochemical measurements indicated that the maximum discharge capacity and discharge potential characteristic of the La_0_._7_0Mg_xNi_2_._4_5Co_0_._7_5Al_0_._3_0 alloys increases first and then decreases with increasing x. The maximum discharge capacity and discharge potential characteristic of alloy reaches the optimum when x is 0.36. The cyclic stability of the La_0_._7_0Mg_xNi_2_._4_5Co_0_._7_5Al_0_._3_0 alloy with a smaller quantity of Mg is better than that of the alloy with a larger quantity of Mg. - Highlights: • La–Mg–Ni-based alloy was synthesized by melting, milling and subsequent annealing. • Mg atoms exist in the La_2Ni_7 phase prior to LaNi_5 phase. • The La_0_._7_0Mg_xNi_2_._4_5Co_0_._7_5Al_0_._3_0 alloys consist of the LaNi_5 and (La, Mg)_2Ni_7. • The more Mg element the alloys contain, the easier aggregation Mg atom is. • The C_m_a_x of La_0_._7_0Mg_xNi_2_._4_5Co_0_._7_5Al_0_._3_0 alloy first increases and then decreases with rising x.

  14. Enhancement by Nalidixic Acid of the Thermal Susceptibility of the Ts-7 Mutant of Escherichia Coli TAU-Bar

    Science.gov (United States)

    Nishida, Mikio; Mishima, Yukio; Kawada, Jun; Yielding, K. Lemone

    1975-01-01

    Nadilidixic acid at 5 × 10−6 M produced a substantial increase in thermal susceptibility of Ts-7, suggesting either that the thermal and nalidixic acid targets are identical or closely interdependent. PMID:1101825

  15. Effect of cold rolling on the microstructural evolution of new β-typed Ti–6Mo–6V–5Cr–3Sn–2.5Zr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Gwnaghyo; Lee, Kwangmin, E-mail: kmlee@jnu.ac.kr

    2017-01-15

    A Ti–6Mo–6V–5Cr–3Sn–2.5Zr (wt.%) alloy was designed as a new metastable β-Ti alloy. The effect that cold rolling had on the microstructural evolution of the material was investigated via optical microscopy (OM), X-ray diffraction (XRD), electron back-scattered diffraction (EBSD) and transmission electron microscopy (TEM) measurements. A single β phase formed in the alloy after solution treatment at 780 °C for 30 min followed by water quenching. The solution-treated alloy was cold rolled with thickness reductions of 10%, 30%, 50% and 70%, and the hardness values increased as the thickness of the specimen decreased. The textures of the cold rolled specimen were characterized according to the 〈110〉 partial parallel to the rolling direction as the rolling reduction increased. The crystallographic orientation showed principal α-fiber textures for (111)〈110〉 and (112)〈110〉. The cold deformation led to the appearance of martensite α″ phases, particularly stress-induced martensite (SIM) α″ phases. - Highlights: • Effect of cold rolling on new β-typed Ti-6Mo-6V-5Cr-3Sn-2.5Zr alloy was studied. • A single β phase was obtained after solution treatment at 780 °C for 30 min. • α-Fiber textures became dominated with the increase in cold rolling reduction. • A stress-induced α″ martensite was caused by cold rolling.

  16. Effects of aging time on the mechanical properties of Sn–9Zn–1.5Ag–xBi lead-free solder alloys

    International Nuclear Information System (INIS)

    Liu, Chih-Yao; Hon, Min-Hsiung; Wang, Moo-Chin; Chen, Ying-Ru; Chang, Kuo-Ming; Li, Wang-Long

    2014-01-01

    Highlights: • The microstructure of these solder alloys are composed of Sn-rich phase and Ag 3 Sn. • The grain size of Sn–9Zn–1.5Ag–xBi solder alloys increases with rose aging time. • The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloys. • TEM observed that Bi appears as oblong shape fine particles. -- Abstract: The effects of aging time on the mechanical properties of the Sn–9Zn–1.5Ag–xBi lead-free solder alloys are investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive spectrometry (EDS) and a universal testing machine. The experimental results show that the microstructure of Sn–9Zn–1.5Ag–xBi solder alloys is composed of Sn-rich phase and AgZn 3 . No other intermetallic compounds (IMCs) with Bi content was observed in the solder matrix for Sn–9Zn–1.5Ag solder alloys with various Bi contents before and after aging at 150 °C for different durations. The lattice parameter increases significantly with increasing aging time or Bi addition. The size of Sn-rich grain increased gradually with aging time increased, but decreases with Bi content increases. The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloy before aging

  17. Effects of aging time on the mechanical properties of Sn–9Zn–1.5Ag–xBi lead-free solder alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chih-Yao [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Hon, Min-Hsiung [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Road, Kaohsiung 80782, Taiwan (China); Wang, Moo-Chin, E-mail: mcwang@kmu.edu.tw [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, Kaohsiung 80728, Taiwan (China); Chen, Ying-Ru; Chang, Kuo-Ming; Li, Wang-Long [Institute of Nanotechnology and Microsystems Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China)

    2014-01-05

    Highlights: • The microstructure of these solder alloys are composed of Sn-rich phase and Ag{sub 3}Sn. • The grain size of Sn–9Zn–1.5Ag–xBi solder alloys increases with rose aging time. • The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloys. • TEM observed that Bi appears as oblong shape fine particles. -- Abstract: The effects of aging time on the mechanical properties of the Sn–9Zn–1.5Ag–xBi lead-free solder alloys are investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive spectrometry (EDS) and a universal testing machine. The experimental results show that the microstructure of Sn–9Zn–1.5Ag–xBi solder alloys is composed of Sn-rich phase and AgZn{sub 3}. No other intermetallic compounds (IMCs) with Bi content was observed in the solder matrix for Sn–9Zn–1.5Ag solder alloys with various Bi contents before and after aging at 150 °C for different durations. The lattice parameter increases significantly with increasing aging time or Bi addition. The size of Sn-rich grain increased gradually with aging time increased, but decreases with Bi content increases. The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloy before aging.

  18. The influences of rare earth content on the microstructure and mechanical properties of Mg-7Zn-5Al alloy

    International Nuclear Information System (INIS)

    Xiao, Wenlong; Shen, Yusen; Wang, Lidong; Wu, Yaoming; Cao, Zhanyi; Jia, Shusheng; Wang, Limin

    2010-01-01

    The influences of rare earth (RE) on the microstructure and mechanical properties of Mg-7Zn-5Al alloy were studied. The results indicate that both the dendrite and grain size of the alloy can be refined by low RE addition. The Al 2 REZn 2 phase will be formed with increasing the RE content, however the high RE addition results in the grain coarsening in the alloy due to the decrease of the contribution of Al and Zn solutes on the grain refinement. The strengthening and weakening mechanisms caused by RE addition only lead to the obviously improve on the room temperature ultimate tensile strength. The mechanical properties of the studied alloys can be improved by aging treatment, and the aged Mg-7Zn-5Al-2RE alloy exhibits optimal mechanical properties at room temperature.

  19. The effects of Mg addition on the microstructure and mechanical properties of thixoformed Al–5%Si–Cu alloys

    Energy Technology Data Exchange (ETDEWEB)

    Salleh, M.S., E-mail: shukor@utem.edu.my [Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Selangor (Malaysia); Department of Manufacturing Process, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka (Malaysia); Omar, M.Z., E-mail: zaidi@eng.ukm.my [Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Selangor (Malaysia); Syarif, J., E-mail: syarif@eng.ukm.my [Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Selangor (Malaysia)

    2015-02-05

    Highlights: • The average globule size of α-Al decreased when Mg amount is increased. • T6 heat treatment has increased the strength of the thixoformed alloys. • The elongation after T6 heat treatment is even significantly improved. • Thixoformed alloy with high Mg content shows a brittle type fracture. • Thixoformed alloy in T6 condition shows a ductile type fracture. - Abstract: In this study, the effects of different amounts of magnesium (Mg) on the microstructures and tensile properties of thixoformed Al–5%Si–Cu alloys were investigated. Three different alloys containing various amounts of Mg (0.5, 0.8 and 1.2 wt%) were prepared through the cooling slope casting technique, before they were thixoformed using a compression press. Several of the thixoformed samples were then treated with a T6 heat treatment, that is, solution treatment at 525 °C for 8 h, quenching in warm water at 60 °C, followed by aging at 155 °C for 4 h. All of the samples were then characterised by optical microscopy (OM), scanning electron microscopy (SEM) energy dispersive X-ray (EDX) spectroscopy and X-ray diffraction (XRD) analysis as well as by tensile tests. The results revealed that magnesium was able to refine the size of α-Al globules and the eutectic silicon in the samples. It was also observed that a compact π-Al{sub 9}FeMg{sub 3}Si{sub 5} phase was formed when the magnesium content was 0.8 wt% and 1.2 wt%. The mechanical properties of the thixoformed alloys improved significantly after the T6 heat treatment. The highest attainment was recorded by the latter alloy (i.e. with 1.2 wt%Mg) with its ultimate tensile strength (UTS) as high as 306 MPa, yield strength (YS), 264 MPa, and elongation to fracture of 1.8%. The fracture of thixoformed alloy with a low Mg content (0.5 wt%) showed a combination of dimple and cleavage fracture, whereas in the alloy that contained the highest Mg content (1.2 wt%), cleavage fracture was observed.

  20. Corelation between the crystallisation process and change in thermoelectromotive force for the amorphous alloy Fe89.8Ni1.5Si5.2B3C0.5

    Directory of Open Access Journals (Sweden)

    Maričić Aleksa M.

    2003-01-01

    Full Text Available Thermal and kinetic analyses of the structural changes for the amorphous alloy Fe89.8Ni1.5Si5.2B3C0.5, during the processes of non-isothermal heating and isothermal annealing, have been performed. The crystallisation process has been investigated using the method of differential scanning calorimetry (DSC. It is determined that this alloy crystalizes through three different stages. Changes in the electronic structure of the amorphous tape, for the temperature range 20 to 700ºC have been studied. This was achieved by measuring the thermoelectromotive force (TEMS, of the thermo pair made of two tapes with same chemical structure of the alloy FeNiSiBC, but different atomic structure: one is in the crystal state (CL and the other is in the amorphous state (AM. Analysis of the temperature dependence of the electromotive force has shown the following: the investigated alloy is thermically stable up to 450ºC and changes in the atomic structure as well as equalising of the free electron density in both parts of the thermo pair AM-CL, take place in the temperature range from 450 to 550ºC. Kinetic parameters of the process were determined by measuring time dependence of the TEMS in isothermic conditions at the temperatures 450, 480 and 510ºC.

  1. Bureau de documentation TS/EL/DO

    CERN Document Server

    Dujardin, M

    2004-01-01

    Le bureau de documentation a comme responsabilité de fournir et manager toute la documentation nécessaire au groupe TS-EL. Ce travail utilise des outils CAO (EUCLID- AUTOCAD) et de gestion de base de donnés ORACLE (GESMAR,EDMS) largement utilisé dans le département TS mais aussi des applications métiers tel que le transfert des donnés CAO vers les bases de données, le cheminement automatique ou la schématique électrique. La section se concentre sur des études de grands ensembles et l'intégration 3D des équipements électriques. Les études de services généraux sont généralement sous-traitées. Le projet LHC occupe actuellement la quasi totalité de nos ressources. Pour mener à bien les études électriques du LHC, caractérisées par une définition tardive des besoins et de nombreuses modifications, une structure souple et réactive a été mis en place : Une cellule CAO 3D EUCLID, en charge des layouts d'équipements et des cheminements, en relation avec l'intégration, et une cellule d'é...

  2. Preparation and characterization of Ti-15Zr-12.5Mo alloy for use as biomaterial

    International Nuclear Information System (INIS)

    Lourenco, M.L.; Correa, D.R.N.; Grandini, C.R.

    2014-01-01

    Titanium alloys exhibit favorable properties for biomedical applications. With the zirconium and molybdenum addition, the microstructure and mechanical properties can be changed. Moreover, these alloying elements have certified non-toxicity. The aim of this paper is to prepare and characterize the microstructure and some mechanical properties of Ti-15Zr-12,5Mo (wt%). The alloy was produced by arc-melting and heat treated at 1000 °C for 24 h. Chemical analysis was made by ICP-OES, EDS and density measurements. The crystalline structure and microstructure were analyzed by X-ray diffraction, optical and scanning electron microscopy. An analysis of the mechanical properties was evaluated by Vickers microhardness measurements. The alloy presented a β-type structure (bcc crystalline structure), with the formation of typical equiaxial grains, with higher hardness value than the cp-Ti. (author)

  3. Microstructural evolution of direct chill cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy during solution treatment

    Directory of Open Access Journals (Sweden)

    He Kezhun

    2011-08-01

    Full Text Available Heat treatment has important influence on the microstructure and mechanical properties of Al-Si alloys. The most common used heat treatment method for these alloys is solution treatment followed by age-hardening. This paper investigates the microstructural evolution of a direct chill (DC cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy after solution treated at 500, 510, 520 and 530℃, respectively for different times. The major phases observed in the as-cast alloy are α-aluminum dendrite, primary Si particle, eutectic Si, Al7Cu4Ni, Al5Cu2Mg8Si6, Al15(Cr, Fe, Ni, Cu4Si2 and Al2Cu. The Al2Cu phase dissolves completely after being solution treated for 2 h at 500℃, while the eutectic Si, Al5Cu2Mg8Si6 and Al15(Cr, Fe, Ni, Cu4Si2 phases are insoluble. In addition, the Al7Cu4Ni phase is substituted by the Al3CuNi phase. The α-aluminum dendrite network disappears when the solution temperature is increased to 530℃. Incipient melting of the Al2Cu-rich eutectic mixture occurrs at 520℃, and melting of the Al5Cu2Mg8Si6 and Al3CuNi phases is observed at a solution temperature of 530℃. The void formation of the structure and deterioration of the mechanical properties are found in samples solution treated at 530℃.

  4. The Microstructure And Mechanical Properties Of The AlSi17Cu5 Alloy After Heat Treatment

    Directory of Open Access Journals (Sweden)

    Piątkowski J.

    2015-09-01

    Full Text Available In the paper results of the microstructure and mechanical properties (HB, Rm and R0,2 of AlSi17Cu5 alloy, subjected by solution heat treatment (500ºC/6h/woda and aging (200ºC/16h/piec are presented. In next step the alloy was modified and heated significantly above the Tliq temperature (separately and together. It was found that the increase in the strength properties of the tested alloy after heat treatment compared to alloys without solution heat treatment and aging was due to precipitation hardening. The applied aging treatment of ingots (preceded by solution heat treatment, causes not only increase in concentration in α(Al solid solution, but also a favorable change of the primary Si crystals morphology. During stereological measurements significant size reduction and change in the morphology of hypereutectic silicon crystals ware found. This effects can be further enhanced by overheating the alloy to a temperature of 920ºC and rapid cooling before casting of the alloy.

  5. The influence of alloying elements in aluminium on the grain refinement with ALTI5B1

    Directory of Open Access Journals (Sweden)

    Naglič I.

    2009-07-01

    Full Text Available This work deals with the influence of alloying elements in aluminium on the grain refinement with various additions of AlTi5B1. Grain-refinement tests were made at a cooling rate of 15 °C/s. The results revealed that in both aluminium and an Al-Fe alloy the grain size decreases with increasing additions of the AlTi5B1 grain refiner. We found that for the same boron content the grain size was smaller in the case of the Al-Fe alloy. The difference in the grain sizes for the same content of boron was approximately 15 μm; this is considerably smaller than the difference between the grain sizes in samples with the same difference of growth-restricting factor made at slower cooling rates.

  6. Production of SmCo5 alloy by calciothermic reduction of samarium oxide

    International Nuclear Information System (INIS)

    Krishnan, T.S.; Gupta, C.K.

    1988-01-01

    Among the established permanent magnets, SmCo 5 magnet occupies the foremost position as it offers a unique combination of high energy product, coercivity and curie temperature. The SmCo 5 magnets are thus extensively used for high field applications. These are also best suited for use in environments where high demagnetizing field and high temperature are operative. Also, for applications where high performance and miniaturization are the over-riding considerations, the choice again falls on SmCo 5 magnets. The main deterrent to the widespread use of SmCo 5 magnet is its high cost. Both samarium and cobalt metals are high priced, and the magnets prepared from their directly melted alloy are thus naturally very expensive. An alternate process involving calcium reduction of their oxide intermediates has, therefore, been studied and the alloy prepared by this process has been evaluated and found satisfactory for magnet production. The process essentially involves compaction of the charge mix containing samarium oxide, cobalt oxide (or metal) and calcium metal and reduction of the charge compact at 1000-1300 degrees C in hydrogen atmosphere, followed by water and acid leaching, drying and classification

  7. Phase Composition of a CrMo0.5NbTa0.5TiZr High Entropy Alloy: Comparison of Experimental and Simulated Data

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    2013-09-01

    Full Text Available Microstructure and phase composition of a CrMo0.5NbTa0.5TiZr high entropy alloy were studied in the as-solidified and heat treated conditions. In the as-solidified condition, the alloy consisted of two disordered BCC phases and an ordered cubic Laves phase. The BCC1 phase solidified in the form of dendrites enriched with Mo, Ta and Nb, and its volume fraction was 42%. The BCC2 and Laves phases solidified by the eutectic-type reaction, and their volume fractions were 27% and 31%, respectively. The BCC2 phase was enriched with Ti and Zr and the Laves phase was heavily enriched with Cr. After hot isostatic pressing at 1450 °C for 3 h, the BCC1 dendrites coagulated into round-shaped particles and their volume fraction increased to 67%. The volume fractions of the BCC2 and Laves phases decreased to 16% and 17%, respectively. After subsequent annealing at 1000 °C for 100 h, submicron-sized Laves particles precipitated inside the BCC1 phase, and the alloy consisted of 52% BCC1, 16% BCC2 and 32% Laves phases. Solidification and phase equilibrium simulations were conducted for the CrMo0.5NbTa0.5TiZr alloy using a thermodynamic database developed by CompuTherm LLC. Some discrepancies were found between the calculated and experimental results and the reasons for these discrepancies were discussed.

  8. Characterization of the shape memory properties of a Ni45.3Ti39.7Hf10Pd5 alloy

    International Nuclear Information System (INIS)

    Acar, E.; Karaca, H.E.; Tobe, H.; Noebe, R.D.; Chumlyakov, Y.I.

    2013-01-01

    Highlights: •Ni 45.3 Ti 39.7 Hf 10 Pd 5 alloys have transformation strain of up to 4.6% and work output of up to 29 J cm −3 . •The alloy showed good superelastic behavior at 90 °C with recoverable strain of 4.3%. •The alloy exhibited 1.6% two-way shape memory strain after a simple training procedure. •The formation of 〈0 1 1〉 type II twins in martensite plates results in large transformation strain. -- Abstract: The load-biased shape memory and superelastic responses of a Ni 45.3 Ti 39.7 Hf 10 Pd 5 polycrystalline alloy were investigated in compression. Transformation strain of up to 4.6% and work output of up to 29 J cm −3 were determined from load-biased thermal cycling experiments. The alloy showed good superelastic behavior at 90 o C with recoverable strain of over 4%. It was also determined that the Ni 45.3 Ti 39.7 Hf 10 Pd 5 alloy could develop two-way shape memory strain of 1.6% without an intense training process. Transmission electron microscopy (TEM) revealed that the internal twins formed in the martensite variants were 〈0 1 1〉 type II twins

  9. REAC/TS radiation accident registry. Update of accidents in the United States

    International Nuclear Information System (INIS)

    Ricks, R.C.; Berger, M.E.; Holloway, E.C.; Goans, R.E.

    2000-01-01

    Serious injury due to ionizing radiation is a rare occurrence. From 1944 to the present, 243 US accidents meeting dose criteria for classification as serious are documented in the REAC/TS Registry. Thirty individuals have lost their lives in radiation accidents in the United States. The Registry is part of the overall REAC/TS program providing 24-hour direct or consultative assistance regarding medical and heath physics problems associated with radiation accidents in local, national, and international incidents. The REAC/TS Registry serves as a repository of medically important information documenting the consequences of these accidents. Registry data are gathered from various sources. These include reports from the World Heath Organization (WHO), International Atomic Energy Agency (IAEA), US Nuclear Regulatory Commission (US NRC), state radiological health departments, medical/health physics literature, personal communication, the Internet, and most frequently, from calls for medical assistance to REAC/TS, as part of our 24-hour medical assistance program. The REAC/TS Registry for documentation of radiation accidents serves several useful purposes: 1) weaknesses in design, safety practices, training or control can be identified, and trends noted; 2) information regarding the medical consequences of injuries and the efficacy of treatment protocols is available to the treating physician; and 3) Registry case studies serve as valuable teaching tools. This presentation will review and summarize data on the US radiation accidents including their classification by device, accident circumstances, and frequency by respective states. Data regarding accidents with fatal outcomes will be reviewed. The inclusion of Registry data in the IAEA's International Reporting System of Radiation Events (RADEV) will also be discussed. (author)

  10. Replacing -CH2CH2- with -CONH- does not significantly change rates of charge transport through Ag(TS)-SAM//Ga2O3/EGaIn junctions.

    Science.gov (United States)

    Thuo, Martin M; Reus, William F; Simeone, Felice C; Kim, Choongik; Schulz, Michael D; Yoon, Hyo Jae; Whitesides, George M

    2012-07-04

    This paper describes physical-organic studies of charge transport by tunneling through self-assembled monolayers (SAMs), based on systematic variations of the structure of the molecules constituting the SAM. Replacing a -CH(2)CH(2)- group with a -CONH- group changes the dipole moment and polarizability of a portion of the molecule and has, in principle, the potential to change the rate of charge transport through the SAM. In practice, this substitution produces no significant change in the rate of charge transport across junctions of the structure Ag(TS)-S(CH(2))(m)X(CH(2))(n)H//Ga(2)O(3)/EGaIn (TS = template stripped, X = -CH(2)CH(2)- or -CONH-, and EGaIn = eutectic alloy of gallium and indium). Incorporation of the amide group does, however, increase the yields of working (non-shorting) junctions (when compared to n-alkanethiolates of the same length). These results suggest that synthetic schemes that combine a thiol group on one end of a molecule with a group, R, to be tested, on the other (e.g., HS~CONH~R) using an amide-based coupling provide practical routes to molecules useful in studies of molecular electronics.

  11. The influence of laser alloying on the structure and mechanical properties of AlMg5Si2Mn surface layers

    Science.gov (United States)

    Pakieła, W.; Tański, T.; Brytan, Z.; Labisz, K.

    2016-04-01

    The goal of this paper was focused on investigation of microstructure and properties of surface layer produced during laser surface treatment of aluminium alloy by high-power fibre laser. The performed laser treatment involves remelting and feeding of Inconel 625 powder into the aluminium surface. As a base metal was used aluminium alloy AlMg5Si2Mn. The Inconel powder was injected into the melt pool and delivered by a vacuum feeder at a constant rate of 4.5 g/min. The size of Inconel alloying powder was in the range 60-130 µm. In order to remelt the aluminium alloy surface, the fibre laser of 3 kW laser beam power has been used. The linear laser scan rate of the beam was set 0.5 m/min. Based on performed investigations, it was possible to obtain the layer consisting of heat-affected zone, transition zone and remelted zone, without cracks and defects having much higher hardness value compared to the non-alloyed material.

  12. Effect of the milling time on thermal stability of mechanically alloyed Mg{sub 5}0 Ni{sub 5}0 amorphous alloy; Efecto del tiempo de molienda sobre la estabilidad termica del amorfo Mg{sub 5}0 Ni:50 producido mediante aleado mecanico

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, D.; Ordonez, S.; Serafini, D.; Rojas, P.; Aguilar, C.; Santander, M.; Navea, L.

    2009-07-01

    In order to study the relationship between the milling time used in the production of Mg{sub 5}0Ni{sub 5}0 amorphous alloy and its thermal stability, seven amorphous alloys were produced by milling for 20, 25, 30, 35, 40, 50 and 60 h each sample. The obtained powders were morphological and structurally characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The thermal stability of amorphous alloys was study by differential scanning calorimetry (DSC). Based on the obtained results, it can be concluded that the increase in the added energy when milling for longer time causes the homogenization of the microstructure with an increase in amorphous phase, which dissolves a large amount of nickel in its structure. Therefore, the simultaneous crystallization of the Mg{sub 2}Ni and MgNi{sub 2} intermetallic compounds at 345 degree centigrade can be explained. (Author) 19 refs.

  13. Corrosion Behavior of High Pressure Die Cast Al-Ni and Al-Ni-Ca Alloys in 3.5% NaCl Solution

    Energy Technology Data Exchange (ETDEWEB)

    Arthanari, Srinivasan; Jang, Jae Cheol; Shin, Kwang Seon [Seoul National University, Seoul (Korea, Republic of)

    2017-06-15

    In this investigation corrosion behavior of newly developed high-pressure die cast Al-Ni (N15) and Al-Ni-Ca (NX1503) alloys was studied in 3.5% NaCl solution. The electrochemical corrosion behavior was evaluated using open circuit potential (OCP) measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. Potentiodynamic polarization results validated that NX1503 alloy exhibited lower corrosion current density (i{sub corr}) value (5.969 μA/cm{sup 2}) compared to N15 (7.387 μA/cm{sup 2}). EIS-Bode plots revealed a higher impedance (|Z|) value and maximum phase angle value for NX1503 than N15 alloy. Equivalent circuit curve fitting analysis revealed that surface layer (R{sub 1}) and charge transfer resistance (R{sub ct}) values of NX1503 alloy was higher compared to N15 alloy. Immersion corrosion studies were also conducted for alloys using fishing line specimen arrangement to simultaneously measure corrosion rates from weight loss (P{sub W}) and hydrogen volume (P{sub H}) after 72 hours and NX1503 alloy had lower corrosion rate compared to N15 alloy. The addition of Ca to N15 alloy significantly reduced the Al{sub 3}Ni intermetallic phase and further grain refinement may be attributed for reduction in the corrosion rate.

  14. Phase Composition of a CrMo0.5NbTa0.5TiZr High Entropy Alloy: Comparison of Experimental and Simulated Data

    OpenAIRE

    Fan Zhang; Oleg N. Senkov; Jonathan D. Miller

    2013-01-01

    Microstructure and phase composition of a CrMo0.5NbTa0.5TiZr high entropy alloy were studied in the as-solidified and heat treated conditions. In the as-solidified condition, the alloy consisted of two disordered BCC phases and an ordered cubic Laves phase. The BCC1 phase solidified in the form of dendrites enriched with Mo, Ta and Nb, and its volume fraction was 42%. The BCC2 and Laves phases solidified by the eutectic-type reaction, and their volume fractions were 27% and 31%, respectively....

  15. [Case report: a recurrent gastric cancer in the terminal stage, associated with obstructive jaundice which responded significantly to oral administration of TS-1].

    Science.gov (United States)

    Tasaka, K; Tomofuzi, Y; Sugihara, Z; Fukuda, H

    2001-10-01

    TS-1, a novel oral formation of 5-fluorouracil that consists of 1M tegafur (5-FU), 0.4M CDHP and 1M Oxo, is reported to achieve a higher response rate of 49% in patients with advanced gastric cancer in a late phase II study. We report a case of recurrent gastric cancer that responded significantly to the short-term administration of TS-1. A 73-year-old man, who had undergone a curative distal gastrectomy with D2 lymphadenectomy 2 years earlier, had presented with obstructive jaundice resulting from cancerous lymphadenopathy. PTCD was performed for drainage, but cholestasis disappeared completely through the two courses of oral administration of TS-1. The serum level of transaminase and bilirubin remained within normal limits, even with PTCD unequipped, until the patient died of the original disease. The adverse effects observed with the drug were anemia (grade 1) and skin pigmentation (grade 2), both of which improved soon after discontinuing the medication. In conclusion, TS-1 may be well-tolerable and effective in some cases of terminal-stage and/or recurrent gastric cancer, especially those associated with obstructive jaundice arising from the cancerous lymphadenopathy, in that patient QOL can be maintained to a much greater extent.

  16. Electrochemical characterization of melt spun AB{sub 5} alloys for metal hydride batteries

    Energy Technology Data Exchange (ETDEWEB)

    Brateng, Randi

    2003-05-01

    This thesis is part of a larger research project where two metal hydride forming AB{sub 5} type alloys have been investigated. A slightly non-stoichiometric alloy with mischmetal on A-site and nickel, cobalt, manganese and aluminium on B-site has been characterized. The composition of this material, which will be referred to as Mm(NiCoMnA1){sub 5.15}, is close to the normal battery composition. The other alloy characterized is LaNi{sub 5} based, where nickel is partly substituted with tin. This material will later be referred to as La(NiSn){sub 5}. These materials were produced by melt spinning to vary the cooling rate during solidification. The main purpose of the study has been to characterize the electrochemical properties related to battery performance. The production as well as the metallurgical and structural characterization of the materials were performed in another part of the project. For Mm(NiCoMnA1){sub 5.15} the unit cell volume was dependent on the cooling rate before heat treatment, while the unit cell volume was almost independent of the cooling rate for La(NiSn){sub 5}. For both alloy compositions, the electrochemical properties seemed to change with varying cooling rate. The desorption equilibrium potential, the discharge capacity when discharging at a low current and the deterioration rate were found to be reduced with decreasing unit cell volume and increased with increasing unit cell volume, before heat treatment of Mm(NiCoMnA1){sub 5.15}. The self discharge rate was observed to be inversely proportional to the unit cell volume for this material. For not heat treated La(NiSn){sub 5}, produced at different cooling rates, the desorption equilibrium potential decreased when the self discharge rate and the discharge capacity increased after cycling for 300 cycles. The deterioration rate decreased when the desorption equilibrium potential was reduced for La(NiSn){sub 5}. The electrochemical parameters both before and after heat treatment of La

  17. Synthesis and characterization of Ti-27.5Nb alloy made by CLAD® additive manufacturing process for biomedical applications

    International Nuclear Information System (INIS)

    Fischer, M.; Laheurte, P.; Acquier, P.; Joguet, D.; Peltier, L.; Petithory, T.; Anselme, K.; Mille, P.

    2017-01-01

    Biocompatible beta-titanium alloys such as Ti-27.5(at.%)Nb are good candidates for implantology and arthroplasty applications as their particular mechanical properties, including low Young's modulus, could significantly reduce the stress-shielding phenomenon usually occurring after surgery. The CLAD® process is a powder blown additive manufacturing process that allows the manufacture of patient specific (i.e. custom) implants. Thus, the use of Ti-27.5(at.%)Nb alloy formed by CLAD® process for biomedical applications as a mean to increase cytocompatibility and mechanical biocompatibility was investigated in this study. The microstructural properties of the CLAD-deposited alloy were studied with optical microscopy and electron back-scattered diffraction (EBSD) analysis. The conservation of the mechanical properties of the Ti-27.5Nb material after the transformation steps (ingot-powder atomisation-CLAD) were verified with tensile tests and appear to remain close to those of reference material. Cytocompatibility of the material and subsequent cell viability tests showed that no cytotoxic elements are released in the medium and that viable cells proliferated well. - Highlights: • Biomimetic implants can be provided from additive manufacturing with beta-titanium alloys. • We studied the properties of a Ti-Nb alloy elaborated with a laser deposition process. • TiNb alloy processed by LMD consists of only beta phase due to rapid cooling. • No preferential crystallographic texture is observed with EBSD analyses. • TiNb samples showed a combination of high strength and low Young's modulus.

  18. Synthesis and characterization of Ti-27.5Nb alloy made by CLAD® additive manufacturing process for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, M. [LEM3, Université de Lorraine, Ile du Saulcy, 57045 Metz (France); Laheurte, P., E-mail: pascal.laheurte@univ-lorraine.fr [LEM3, Université de Lorraine, Ile du Saulcy, 57045 Metz (France); Acquier, P. [IREPA Laser, Institut Carnot Mica, Parc d' Innovation, 67400 Illkirch (France); Joguet, D. [LERMPS, Université de Technologie de Belfort Montbéliard, Sevenans, 90010 Belfort (France); Peltier, L. [LEM3, Ecole Nationale Supérieure d' Arts et Métiers, 57078 Metz (France); Petithory, T.; Anselme, K. [IS2M, CNRS UMR7361, Université de Haute-Alsace, 68057 Mulhouse (France); Mille, P. [LGECO Institut National des Sciences Appliquées, 67000 Strasbourg (France)

    2017-06-01

    Biocompatible beta-titanium alloys such as Ti-27.5(at.%)Nb are good candidates for implantology and arthroplasty applications as their particular mechanical properties, including low Young's modulus, could significantly reduce the stress-shielding phenomenon usually occurring after surgery. The CLAD® process is a powder blown additive manufacturing process that allows the manufacture of patient specific (i.e. custom) implants. Thus, the use of Ti-27.5(at.%)Nb alloy formed by CLAD® process for biomedical applications as a mean to increase cytocompatibility and mechanical biocompatibility was investigated in this study. The microstructural properties of the CLAD-deposited alloy were studied with optical microscopy and electron back-scattered diffraction (EBSD) analysis. The conservation of the mechanical properties of the Ti-27.5Nb material after the transformation steps (ingot-powder atomisation-CLAD) were verified with tensile tests and appear to remain close to those of reference material. Cytocompatibility of the material and subsequent cell viability tests showed that no cytotoxic elements are released in the medium and that viable cells proliferated well. - Highlights: • Biomimetic implants can be provided from additive manufacturing with beta-titanium alloys. • We studied the properties of a Ti-Nb alloy elaborated with a laser deposition process. • TiNb alloy processed by LMD consists of only beta phase due to rapid cooling. • No preferential crystallographic texture is observed with EBSD analyses. • TiNb samples showed a combination of high strength and low Young's modulus.

  19. The tensile properties and high cyclic fatigue characteristics of Mg-5Li-3Al-1.5Zn-2RE alloy

    International Nuclear Information System (INIS)

    Li Tingqu; Liu Yongbing; Cao Zhanyi; Jiang Dongmei; Cheng Liren

    2010-01-01

    Research highlights: → The PLC phenomenon was observed during tensile deformation in LAZ531-2RE alloy. → The negative SRS in high strain rate regime can be explained by the DSA mechanism. → The higher ductility may be associated with finer-grained microstructure and Li addition. → Fatigue crack propagation was characterized by striation-like features. - Abstract: The tensile and fatigue properties of the Mg-5Li-3Al-1.5Zn-2RE (LAZ531-2RE) alloy were presented. The alloy was prepared by hot extrusion after vacuum casting. The Portevin-Le Chatelier (PLC) phenomenon was observed during tensile deformation. The PLC effect was attributed to the dynamic interaction between solute atoms (Li) and dislocation movement. The abnormal negative strain rate sensitivity (SRS) in high strain rate regime can be explained by the dynamic strain ageing (DSA) mechanism. The higher ductility may be associated with finer-grained microstructure and Li addition. Fatigue crack propagation was characterized by striation-like features. The smaller spacing of fatigue striations and larger fatigue crack propagation zone at the lower total strain amplitude gave rise to a longer fatigue life.

  20. Solubility of hydrogen in LaNi{sub 5}-, LaCo{sub 5}- und LaNi{sub 5-x}Co{sub x}-alloys; Die Wasserstoff-Loeslichkeit in LaNi{sub 5}-, LaCo{sub 5}- und LaNi{sub 5-x}Co{sub x}-Legierungen

    Energy Technology Data Exchange (ETDEWEB)

    Schlotfeld, K.

    2004-07-01

    Hydrogen absorption isotherms of the alloys LaNi{sub 5}, LaNi{sub 4}Co, LaNi{sub 3}Co{sub 2} and LaCo{sub 5} were measured with an electronic microbalance between 313 and 533 K and between 0.01 and 120 bar. The unit cells of the binary alloys LaNi{sub 5} and LaCo{sub 5} contain a large number of interstitial sites of various kinds, which have to be considered for the occupation with hydrogen. Initially, the larger sites, which require the lowest energy, are filled. At rising concentrations the smaller sites associated with higher energy are successively entered. However, even at the highest hydrogen pressures of 1000 bar applied so far, most interstitial sites remain empty, due to an empirical rule which is theoretically well understood, that the dissolved hydrogen atoms cannot approach each other closer than the minimal distance of 0.21 nm. These conditions lead to a maximal hydrogen/metal ratio of 1.5 at 1000 bar and of roughly 1.2 at 150 bar. A statistical description of the two binary alloys has already been presented by Brodowsky, Yasuda, and Itagaki, which includes the energy differences of hydrogen in the various classes of sites. For the interpretation of the miscibility gaps below a critical temperature the influence of the volume expansion of the dissolved hydrogen on the excess functions was taken into account, similarly the shift of the Fermi energy of the system. In the ternary alloys, there is the complication that the energy of the sites is not is not equal within each group but that the levels have a distribution according to the number of Ni or Co atoms, respectively, around a particular interstitial site. Although this splitting up of the energy levels could not be treated quantitatively, it was very evident in the juxtaposition of the absorption isotherms of the various alloys. The measurements have shown, that the plateau pressure, which is important for the practical application of these alloys, is lowered in steps in the transition from La

  1. Nano ZrO{sub 2} particles in nanocrystalline Fe–14Cr–1.5Zr alloy powders

    Energy Technology Data Exchange (ETDEWEB)

    Xu, W.Z.; Li, L.L.; Saber, M.; Koch, C.C.; Zhu, Y.T., E-mail: ytzhu@ncsu.edu; Scattergood, R.O.

    2014-09-15

    Here we report on the formation of nano ZrO{sub 2} particles in Fe–14Cr–1.5Zr alloy powders synthesized by mechanical alloying. The nano ZrO{sub 2} particles were found uniformly dispersed in the ferritic matrix powders with an average size of about 3.7 nm, which rendered the alloy powders so stable that it retained nanocrystalline structure after annealing at 900 °C for 1 h. The ZrO{sub 2} nanoparticles have a tetragonal crystal structure and the following orientation relationship with the matrix: (0 0 2){sub ZrO2}//(0 0 2){sub Matrix} and [0 1 0]{sub ZrO2}//[1 2 0]{sub Matrix}. The size and dispersion of the ZrO{sub 2} particles are comparable to those of Y–Ti–O enriched oxides reported in irradiation-resistant ODS alloys. This suggests a potential application of the new alloy powders for nuclear energy applications.

  2. Process development for fabrication of Ag-15% In-5% Cd alloys and rods for the control rods of IPEN critical unit

    International Nuclear Information System (INIS)

    Figueredo, A.M. de.

    1985-12-01

    The development of two process at the Nuclear and Energetic Research Institute (IPEN-Brazil) are described. - the production of Ag-15% In-5%. Cd alloys with nuclear grade. The fabrication of rods from Ag-15% In-5% Cd alloy for use at the critical unit. The methods for quality control of alloy and rod are presented, and main problems are identified. (C.G.C.)

  3. Magnetic and magnetocaloric properties of the alloys Mn2-xFexP0.5As0.5 (0⩽x⩽0.5)

    Science.gov (United States)

    Gribanov, I. F.; Golovchan, A. V.; Varyukhin, D. V.; Val'kov, V. I.; Kamenev, V. I.; Sivachenko, A. P.; Sidorov, S. L.; Mityuk, V. I.

    2009-10-01

    The results of investigations of the magnetic and magnetocaloric properties of alloys from the system Mn2-xFexP0.5As0.5 (0⩽x⩽0.5) are presented. The magnetization measurements are performed in the temperature interval 4.2-700K in magnetic fields up to 8T. The entropy changes ΔS with the magnetic field changing from 0 to 2, 4, 5, and 8T are determined from the magnetization isotherms obtained near temperatures of the spontaneous appearance of the ferromagnetic state (TC,TAF -FM1), and the curves ΔS(T0) are constructed. It is found that TC and TAF-FM1 decrease monotonically with increasing manganese concentration and that the ferromagnetic phase is completely suppressed in Mn1.5Fe0.5P0.5As0.5. It is found that the concentration dependences of the maximum entropy jump (and the corresponding cold-storage capacity) and the magnitudes of the ferromagnetic moment of the unit cell with maxima for x =0.9 and 0.8 show extremal behavior. The data obtained are compared with the ferromagnetic moments calculated from first principles by the Korringa-Kohn-Rostoker method using the coherent-potential approximation (KKR-CPA)—the discrepancy for 0.5⩽x⩽0.7 is attributed to the appearance of an antiferromagnetic component of the magnetic structure. It is concluded that the alloys Mn2-xFexP0.5As0.5 have promise for use in magnetic refrigerators operating at room temperature.

  4. Internal friction and mechanical properties of Zr - 2.5% Nb alloy after programme loading

    International Nuclear Information System (INIS)

    Gindin, I.A.; Chirkina, L.A.; Okovit, V.S.; Netesov, V.M.

    1984-01-01

    Temperature dependence of internal friction in the range 20-600 deg C of the alloy Zr-2.5% Nb in the initial state after programmed loading up to 0.1% of residual elongation and static deformation to the same deformation degree has been studied. It is shown, that the programmed loading promotes the decrease in relaxation rate at 20 and 200 deg C and the increase of strength characteristics of the alloy without the decrease in plasticity margin to fracture in the range 20-400 deg C

  5. Microstructure, mechanical property and in vitro biocorrosion behavior of single-phase biodegradable Mg–1.5Zn–0.6Zr alloy

    Directory of Open Access Journals (Sweden)

    Tao Li

    2014-06-01

    Full Text Available The microstructure, mechanical property, and in vitro biocorrosion behavior of as-cast single-phase biodegradable Mg–1.5Zn–0.6Zr alloy were investigated and compared with a commercial as-cast AZ91D alloy. The results show that the Mg–1.5Zn–0.6Zr alloy had a single-phase solid solution structure, with an average grain size of 34.7 ± 13.1 μm. The alloy exhibited ultimate tensile strength of 168 ± 2.0 MPa, yield strength of 83 ± 0.6 MPa, and elongation of 9.1 ± 0.6%. Immersion tests and electrochemical measurements reveal that the alloy displayed lower biocorrosion rate and more uniform corrosion mode than AZ91D in Hank's solution. The elimination of intensive galvanic corrosion reactions and the formation of a much more compact and uniform corrosion film mainly account for the better biocorrosion properties of the Mg–1.5Zn–0.6Zr alloy than AZ91D.

  6. Internal friction and Young's modulus measurements in Zr-2.5Nb alloy doped with hydrogen

    International Nuclear Information System (INIS)

    Ritchie, I.G.; Pan, Z.-L.

    1992-01-01

    The presence of hydrides is an important factor in assessing the potential for delayed hydride cracking in Zr-2.5Nb alloys, and consequently, the terminal solid solubility (TSS) of hydrogen in the material is an important parameter. In pure zirconium doped with hydrogen, the TSS is marked by a dissolution peak of internal friction on heating and a truncated precipitation peak associated with hydride nucleation on cooling. These phenomena occur only at low frequencies and are accompanied in torsion pendulum studies by autotwisting of the sample (or zero-point drift) that stops abruptly at the TSS. Neither the dissolution/precipitation peaks nor the autotwisting phenomena are observed in Zr-2.5Nb. However, the TSS is also marked by an abrupt change in the slope of Young's modulus as a function of temperature. This phenomenon is observed regardless of the frequency (in the range 1 Hz to 120 kHz) and in both pure zirconium and Zr-2.5Nb alloys. The reasons for the absence of the dissolution/precipitation peak in Zr-2.5Nb alloys are discussed and the use of Young's modulus changes to investigate the TSS of hydrogen and the hysteresis between heat-up and cool-down TSS curves is demonstrated. (author)

  7. T.S. ELIOT'S MISREADING OF SOME LITERARY SOURCES IN THE WASTE LAND

    Directory of Open Access Journals (Sweden)

    Liem Satya Limanta

    2002-01-01

    Full Text Available A poet cannot be a poet at all if he is not connected with all the poetic tradition before him. This is T.S. Eliot's dictum which he stated in Tradition and the Individual Talent and which he practiced in his work The Waste Land. T.S. Eliot showed his relationship with the past through all the quotations and allusions to mythical, literary, and religious works. His reading of those sources according to Paul de Man cannot avoid misreading or misinterpretation. Harold Bloom has tried to build up a theory of misreading, which he prefers to call misprision, especially applied to and done by poets in The Anxiety of Influence. Throughout this article I shall show how T.S. Eliot has applied some of the ways Bloom describes in reading some of the literary sources, and by so doing Eliot has given new meaning to them.

  8. Characteristics of mechanical alloying of Zn-Al-based alloys

    International Nuclear Information System (INIS)

    Zhu, Y.H.; Hong Kong Polytechnic; Perez Hernandez, A.; Lee, W.B.

    2001-01-01

    Three pure elemental powder mixtures of Zn-22%Al-18%Cu, Zn-5%Al-11%Cu, and Zn-27%Al-3%Cu (in wt.%) were mechanically alloyed by steel-ball milling processing. The mechanical alloying characteristics were investigated using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy techniques. It was explored that mechanical alloying started with the formation of phases from pure elemental powders, and this was followed by mechanical milling-induced phase transformation. During mechanical alloying, phases stable at the higher temperatures formed at the near room temperature of milling. Nano-structure Zn-Al-based alloys were produced by mechanical alloying. (orig.)

  9. Agent Based Fuzzy T-S Multi-Model System and Its Applications

    Directory of Open Access Journals (Sweden)

    Xiaopeng Zhao

    2015-11-01

    Full Text Available Based on the basic concepts of agent and fuzzy T-S model, an agent based fuzzy T-S multi-model (ABFT-SMM system is proposed in this paper. Different from the traditional method, the parameters and the membership value of the agent can be adjusted along with the process. In this system, each agent can be described as a dynamic equation, which can be seen as the local part of the multi-model, and it can execute the task alone or collaborate with other agents to accomplish a fixed goal. It is proved in this paper that the agent based fuzzy T-S multi-model system can approximate any linear or nonlinear system at arbitrary accuracy. The applications to the benchmark problem of chaotic time series prediction, water heater system and waste heat utilizing process illustrate the viability and the efficiency of the mentioned approach. At the same time, the method can be easily used to a number of engineering fields, including identification, nonlinear control, fault diagnostics and performance analysis.

  10. Study of polarization curves from AlSi12, AlSi5Mg and AlMg5 alloys due to corrosion problems in telecomunication equipment

    International Nuclear Information System (INIS)

    Silva, J.R.A. da

    1984-01-01

    The corrosion behaviour of three aluminium based alloys (AlSi 12, AlMg5 and AlSi 5Mg) when exposed to aqueous media containing chloride is investigated; these alloys are used in the manufacturing of telecomunication equipment. Accelerated corrosion testing and salt spray tests were carried out. The results include polarization curves obtained with three kinds of aqueous solutions (the first containing only 3% NaCl and the others, 3% NaCl and small amounts of Fe 3+ and Cu 2+ ions). (C.L.B.) [pt

  11. Compatibility of heat resistant alloys with boron carbide, 5

    International Nuclear Information System (INIS)

    Baba, Shinichi; Kurasawa, Toshimasa; Endow, Taichi; Someya, Hiroyuki; Tanaka, Isao.

    1986-08-01

    This paper includes an experimental result of out-of-pile compatibility and capsule design for irradiation test in Japan Materials Testing Reactor (JMTR). The compatibility between sheath material and neutron absorber materials for control rod devices (CRD) was examined for potential use in a very high temperature reactor (VHTR) which is under development at JAERI. The purpose of the compatibility tests are preliminary evaluation of safety prior to irradiation tests. Preliminary compatibility evaluation was concerned with three items as follows : 1) Lithium effects on the penetrating reaction of Incoloy 800H alloy in contact with a mixture of boronated graphite and lithium hydroxide powders, 2) Short term tensile properties of Incoloy 800H and Hastelloy XR alloy reacted with boronated graphite and fracture mode analysis, 3) Reaction behavior of both alloys under transient power conditions of a VHTR. It was clear that the reaction rate constant of the Incoloy 800H alloy was accelerated by doping lithium hydroxide into the boron carbide and graphite powder. The mechanical properties of Incoloy 800H and Hastelloy XR alloy reacted with boronated graphite were decreased. Ultimate tensile strength and tensile ductilities at temperatures over 850 deg C were reduced, but there was no change in the proof (yield) stress. Both alloys exhibited a brittle intergranular fracture mode during transient power conditions of a VHTR and also exhibited severe penetration. Irradiation capsules for compatibility test were designed to simulate three irradiation conditions of VHTR: 1) steady state for VHTR, 2) Transient power condition, 3) Service limited life of CRD. Capsule irradiation experiments have been carried out satisfactorily and thus confirm the validity of the capsule design procedure. (author)

  12. Investigation on the microstructure and mechanical properties of a cast Mg-6Zn-5Al-4RE alloy

    International Nuclear Information System (INIS)

    Xiao Wenlong; Jia Shusheng; Wang Jun; Wang, Jianli; Wang Limin

    2008-01-01

    Mg-6Zn-5Al-4RE (RE = Mischmetal, mass%) alloy was prepared by metal mould casting method. The microstructure and mechanical properties of the as-cast and heat-treated alloys were investigated. The results show that the phase compositions of the as-cast state alloy are supersaturated solid solution α-Mg, lamellar β-Al 12 Mg 17 , polygonal Al 3 RE and cluster Al 2 REZn 2 phases. The mechanical properties, especially the ultimate tensile strength and elongation of the alloy were significantly improved by the heat treatment. Fracture surface of tensile specimens was analyzed by optical microscope and scanning electron microscope

  13. Effect of helium on swelling and microstructural evolution in ion-irradiated V-15Cr-5Ti alloy

    International Nuclear Information System (INIS)

    Loomis, B.A.; Kestel, B.J.; Gerber, S.B.; Ayrault, G.

    1986-03-01

    An investigation was made on the effects of implanted helium on the swelling and microstructural evolution that results from energetic single- and dual-ion irradiation of the V-15Cr-5Ti alloy. Single-ion irradiations were utilized for a simulated production of the irradiation damage that might be expected from neutron irradiation of the alloy in a reactor with a fast neutron energy spectrum (E > 0.1 MeV). Dual-ion irradiations were utilized for a simulated production of the simultaneous creation of helium atoms and irradiation damage in the alloy in the MFR environment. Experimental results are also presented on the radiation-induced segregation of the constituent atoms in the single- and dual-ion irradiated alloy

  14. Study on the surface reaction of LaNi{sub 5} alloy during discharge process in KOH solution

    Energy Technology Data Exchange (ETDEWEB)

    Tan Zuxian [Department of Chemistry, Wuhan University, Wuhan 430072 (China); Yang Yifu [Department of Chemistry, Wuhan University, Wuhan 430072 (China)]. E-mail: yang-y-f1@vip.sina.com; Jiang Fengshan [Department of Chemistry, Wuhan University, Wuhan 430072 (China); Shao Huixia [Department of Chemistry, Wuhan University, Wuhan 430072 (China)

    2006-10-05

    A new method for studying surface reaction of LaNi{sub 5} absorbing alloy in KOH solution (pH 12) was established. It is based on tip-substrate voltammetry of scanning electrochemical microscopy (SECM) where the tip faradic current is recorded while scanning the substrate potential. The Pt electrode is selected as tip electrode, and the Pt oxide formation-reduction is used as a pH-dependent reaction while the tip potential is held at a constant value. As substrate surface reactions proceed, the pH of solution can be changed, and then the tip faradic current is recorded. The mechanism of discharge process of LaNi{sub 5} alloy was analyzed by comparing the tip current (I {sub tip}) versus substrate potential (E {sub sub}) curve, which reflects the exchange of H{sup +} or OH{sup -} between the alloy surface and the solution, with the substrate current (I {sub sub}) versus substrate potential (E {sub sub}) curve, which reflects the exchange of electron on the LaNi{sub 5} alloy surface. The results showed that the OH{sup -} adsorption process is occurred before the electron transfer process during discharge process, and the adsorptive OH{sup -} helps the oxidation of adsorbed hydrogen atom on the alloy surface. A quantitative assessment for the maximum changes of pH during discharge process is also proposed, and the variation as large as 2.65 pH unit was detected.

  15. Study on the surface reaction of LaNi{sub 5} alloy during discharge process in KOH solution

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Zuxian; Yang, Yifu; Jiang, Fengshan; Shao, Huixia [Wuhan University, Wuhan (China). Department of Chemistry

    2006-10-05

    A new method for studying surface reaction of LaNi{sub 5} absorbing alloy in KOH solution (pH 12) was established. It is based on tip-substrate voltammetry of scanning electrochemical microscopy (SECM) where the tip faradic current is recorded while scanning the substrate potential. The Pt electrode is selected as tip electrode, and the Pt oxide formation-reduction is used as a pH-dependent reaction while the tip potential is held at a constant value. As substrate surface reactions proceed, the pH of solution can be changed, and then the tip faradic current is recorded. The mechanism of discharge process of LaNi{sub 5} alloy was analyzed by comparing the tip current (I{sub tip}) versus substrate potential (E{sub sub}) curve, which reflects the exchange of H{sup +} or OH{sup -} between the alloy surface and the solution, with the substrate current (I{sub sub}) versus substrate potential (E{sub sub}) curve, which reflects the exchange of electron on the LaNi{sub 5} alloy surface. The results showed that the OH{sup -} adsorption process is occurred before the electron transfer process during discharge process, and the adsorptive OH{sup -} helps the oxidation of adsorbed hydrogen atom on the alloy surface. A quantitative assessment for the maximum changes of pH during discharge process is also proposed, and the variation as large as 2.65 pH unit was detected. (author)

  16. Metallurgical characterization of melt-spun ribbons of U-5.4 wt%Nb alloy

    Science.gov (United States)

    Ma, Rong; Ren, Zhiyong; Tang, Qingfu; Chen, Dong; Liu, Tingyi; Su, Bin; Wang, Zhenhong; Luo, Chao

    2018-06-01

    The microstructures and micro-mechanical properties of the melt-spun ribbons of U-5.4 wt%Nb alloy were characterized using optical microscopy, scanning electron microscopy, X-ray diffraction and nanoindentation. Observed variations in microstructures and properties are related to the changes in ribbon thicknesses and cooling rates. The microstructures of the melt-spun ribbon consist of fine-scale columnar grains (∼1 μm) adjacent to the chill surface and coarse cellular grains in the remainder of the ribbon. In addition, the formation of inclusions in the ribbon is suppressed kinetically due to the high cooling rate during melt spinning. Compared with the water-quenched specimen prepared by traditional gravity casting and solution heat treatment, the elastic modulus values of the U-5.4 wt%Nb alloy were examined to vary with grain size and exhibited diverse energy dissipation capacities.

  17. Effect of Ce-rich rare earth on microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb magnesium alloy

    Directory of Open Access Journals (Sweden)

    You Zhiyong

    2012-05-01

    Full Text Available To improve the comprehensive mechanical properties of Mg-10Zn-5Al-0.1Sb magnesium alloy, different amount of Ce-rich rare earth (RE was added to the alloy, and the effect of RE addition on the microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb alloy was investigated by means of Brinell hardness measurement, scanning electron microscopy (SEM, energy dispersive spectroscope (EDS and X-ray diffraction (XRD. The results show that an appropriate amount of Ce-rich rare earth addition can make the Al4Ce phase particles and CeSb phase disperse more evenly in the alloy. These phases refine the alloy抯 matrix and make the secondary phases [t-Mg32(Al,Zn49 phase and f-Al2Mg5Zn2 phase] finer and more dispersive, therefore significantly improve the mechanical properties of the Mg-10Zn-5Al-0.1Sb alloy. When the RE addition is 1.0 wt.%, the tensile strengths of the alloy both at room temperature and 150 篊 reach the maximum values while the impact toughness is slightly lower than that of the matrix alloy. The hardness increases with the increase of RE addition.

  18. Bulk glass formation and crystallization in Zr54.5Cu20Al10Ni8Ti7.5 alloy

    International Nuclear Information System (INIS)

    Neogy, S.; Tewari, R.; Srivastava, D.; Dey, G.K.; Kumar, V.; Ranganathan, S.

    2006-01-01

    The present work was aimed at fabrication, characterization and crystallization of Zr 54.5 Cu 20 Al 10 Ni 8 Ti 7.5 bulk metallic glass. The glass forming alloy was made by arc melting and then subjected to copper mold casting into 3 mm diameter bulk glass rods. The as-cast microstructure was characterized by optical microscopy and transmission electron microscopy (TEM)

  19. In vitro metal ion release and biocompatibility of amorphous Mg{sub 67}Zn{sub 28}Ca{sub 5} alloy with/without gelatin coating

    Energy Technology Data Exchange (ETDEWEB)

    Chan, W.Y., E-mail: chan.wing.yue@sgh.com.sg [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore); Department of Plastic, Reconstructive and Aesthetic Surgery, Singapore General Hospital (Singapore); Chian, K.S.; Tan, M.J. [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore)

    2013-12-01

    Amorphous zinc-rich Mg–Zn–Ca alloys have exhibited good tissue compatibility and low hydrogen evolution in vivo. However, suboptimal cell–surface interaction on magnesium alloy surface observed in vitro could lead to reduced integration with host tissue for regenerative purpose. This study aims to improve cell–surface interaction of amorphous Mg{sub 67}Zn{sub 28}Ca{sub 5} alloy by coating a gelatin layer by electrospinning. Coated/uncoated alloys were immersed and extracted for 3 days under different CO{sub 2}. The immersion results showed that pH and metal ion release in the alloy extracts were affected by gelatin coating and CO{sub 2}, suggesting their roles in alloy biocorrosion and a mechanism has been proposed for the alloy–CO{sub 2} system with/without coating. Cytotoxicity results are evident that gelatin-coated alloy with 2-day crosslinking not only exhibited no indirect cytotoxicity, but also supported attachment of L929 and MG63 cell lines around/on the alloy with high viability. Therefore, amorphous Mg{sub 67}Zn{sub 28}Ca{sub 5} alloy coated with gelatin by electrospinning technique provides a useful method to improve alloy biocompatibility. - Highlights: • Electrospinning is a new method to coat amorphous Mg{sub 67}Zn{sub 28}Ca{sub 5} alloy with gelatin. • Gelatin-coated alloy has differential effect on pH and ion release at various CO{sub 2}. • L929 cell proliferation correlates with Mg{sup 2+} level in alloy extracts. • Biomimetic gelatin coating significantly improves cell–surface interaction.

  20. Influence of structural disorder on the optical and transport properties of Co sub 0 sub . sub 5 sub 0 Ti sub 0 sub . sub 5 sub 0 alloy films

    CERN Document Server

    Kim, K W; Rhee, J Y; Kudryavtsev, Y V; Ri, H C

    2000-01-01

    Co sub 0 sub . sub 5 sub 0 Ti sub 0 sub . sub 5 sub 0 alloy films with a total thickness of about 100 nm were prepared by flash evaporation of the crushed alloy powders onto heated (730 K for the ordered state) and LN sub 2 -cooled (150 K for the disordered state) substrates. Structural analysis of the films was performed by suing transmission electron microscopy. The optical conductivity (OC) of the samples was measured at room temperature in a spectral range of 265 -2500 nm (4.7 - 0.5 eV). The resistivity measurements were carried out by using the four-probe technique in a temperature range of 4.2 - 300 K. The experimental OC spectra for the Co sub 0 sub . sub 5 sub 0 Ti sub 0 sub . sub 5 sub 0 alloys show the most significant change in the infrared region upon the order-disorder transformation. The structural disorder in the Co sub 0 sub . sub 5 sub 0 Ti sub 0 sub . sub 5 sub 0 alloy film leads to a change in the sign of the temperature coefficient of the resistivity from positive to negative. The observed...

  1. Twin relationships of 5M modulated martensite in Ni-Mn-Ga alloy

    International Nuclear Information System (INIS)

    Li Zongbin; Zhang Yudong; Esling, Claude; Zhao Xiang; Zuo Liang

    2011-01-01

    Highlights: → We determine orientation relationships of 5M modulated martensite in NiMnGa alloy. → Accurate EBSD mapping is performed using monoclinic superstructure. → Four distinct variants mutually twin-related to each other are revealed. → Three twinning types and full twinning elements are identified. → Twin interfaces do coincide with respective twinning planes. - Abstract: For Ni-Mn-Ga ferromagnetic shape memory alloys, the characteristic features of modulated martensite (including the number/shape of constituent variants, the inter-variant orientation relationship and the geometrical distribution of variant interfaces) determine the attainability of the shape memory effect. In the present work, a comprehensive microstructural and crystallographic investigation has been conducted on a bulk polycrystalline Ni 50 Mn 28 Ga 22 alloy. As a first attempt, the orientation measurements by electron backscatter diffraction (EBSD) - using the precise information on the commensurate 5M modulated monoclinic superstructure (instead of the conventionally simplified non-modulated tetragonal structure) - were successfully performed to identify the crystallographic orientations on an individual basis. Consequently, the morphology of modulated martensite, the orientation relationships between adjacent variants and the characters of twin interfaces were unambiguously determined. With the thus-obtained full-featured image on the configuration of martensitic variants, the possibility of microstructural modification by proper mechanical 'training' was further discussed. This new effort makes it feasible to explore the crystallographic/microstructural correlations in modulated martensite with high statistical reliability, which in turn provides useful guidance for optimizing the microstructure and shape memory performance.

  2. Three-dimensional rigid multiphase networks providing high-temperature strength to cast AlSi10Cu5Ni1-2 piston alloys

    International Nuclear Information System (INIS)

    Asghar, Z.; Requena, G.; Boller, E.

    2011-01-01

    The three-dimensional (3-D) architecture of rigid multiphase networks present in AlSi10Cu5Ni1 and AlSi10Cu5Ni2 piston alloys in as-cast condition and after 4 h spheroidization treatment is characterized by synchrotron tomography in terms of the volume fraction of rigid phases, interconnectivity, contiguity and morphology. The architecture of both alloys consists of α-Al matrix and a rigid long-range 3-D network of Al 7 Cu 4 Ni, Al 4 Cu 2 Mg 8 Si 7 , Al 2 Cu, Al 15 Si 2 (FeMn) 3 and AlSiFeNiCu aluminides and Si. The investigated architectural parameters of both alloys studied are correlated with room-temperature and high-temperature (300 deg. C) strengths as a function of solution treatment time. The AlSi10Cu5Ni1 and AlSi10Cu5Ni2 alloys behave like metal matrix composites with 16 and 20 vol.% reinforcement, respectively. Both alloys have similar strengths in the as-cast condition, but the AlSi10Cu5Ni2 is able to retain ∼15% higher high temperature strength than the AlSi10Cu5Ni1 alloy after more than 4 h of spheroidization treatment. This is due to the preservation of the 3-D interconnectivity and the morphology of the rigid network, which is governed by the higher degree of contiguity between aluminides and Si.

  3. A Combination of TsHARP and Thin Plate Spline Interpolation for Spatial Sharpening of Thermal Imagery

    Directory of Open Access Journals (Sweden)

    Xuehong Chen

    2014-03-01

    Full Text Available There have been many studies and much attention paid to spatial sharpening for thermal imagery. Among them, TsHARP, based on the good correlation between vegetation index and land surface temperature (LST, is regarded as a standard technique because of its operational simplicity and effectiveness. However, as LST is affected by other factors (e.g., soil moisture in the areas with low vegetation cover, these areas cannot be well sharpened by TsHARP. Thin plate spline (TPS is another popular downscaling technique for surface data. It has been shown to be accurate and robust for different datasets; however, it has not yet been attempted in thermal sharpening. This paper proposes to combine the TsHARP and TPS methods to enhance the advantages of each. The spatially explicit errors of these two methods were firstly estimated in theory, and then the results of TPS and TsHARP were combined with the estimation of their errors. The experiments performed across various landscapes and data showed that the proposed combined method performs more robustly and accurately than TsHARP.

  4. Grain refining mechanism of Al-containing Mg alloys with the addition of Mn-Al alloys

    International Nuclear Information System (INIS)

    Qin, Gaowu W.; Ren Yuping; Huang Wei; Li Song; Pei Wenli

    2010-01-01

    Graphical abstract: Display Omitted Research highlights: The ε-AlMn phase acts as the heterogeneous nucleus of α-Mg phase during the solidification of the AZ31 Mg alloy, not the γ-Al 8 Mn 5 phase. The grain refinement effect is very clear with the addition of only 0.5 wt% Mn-28Al alloy (pure ε-AlMn). The grain refinement does not deteriorate up to the holding time of 60 min at 740 o C. - Abstract: The effect of manganese on grain refinement of Al-containing AZ31 Mg alloy has been investigated by designing a series of Mn-Al alloys composed of either pure ε-AlMn, γ 2 -Al 8 Mn 5 or both of them using optical microscopy and X-ray diffraction. It is experimentally clarified that the grain refinement of the AZ31 Mg alloy is due to the existence of the ε-AlMn phase in the Mn-Al alloys, not the γ 2 -Al 8 Mn 5 phase. The grain size of AZ31 Mg alloy is about 91 μm without any addition of Mn-Al alloys, but remarkably decreases to ∼55 μm with the addition of either Mn-34 wt% Al or Mn-28 wt% Al. With a minor addition of 0.5 wt% Mn-28Al alloy, the grain size of AZ31 alloy decreases to ∼53 μm, and the Mn-28Al alloy can be active as grain refiner for holding time up to 60 min for the melt AZ31 alloy at 750 o C.

  5. A new hardware and software developed for copper alloy analyser type XRFA-5

    International Nuclear Information System (INIS)

    Lakatos, T.; Kovacs, P.; Szadai, J.; Szekely, G.

    1991-01-01

    In the production of copper alloys a large amount of waste of unknown origin and composition is melted, and rapid analysis of the melt is important. A copper alloy analyzer based on the energy-dispersive x-ray fluorescence was developed in ATOMKI earlier for copper smelting plants in Hungary. The equipment has recently been upgraded by its connection to IBM PC/AT computer. A digital signal processor and analyzer module, a new software tool for the automatic determination of eight elements, and a stand-alone analyzer program DISIP was developed. The upgraded analyzer type XRFA-5.01 is presented briefly. (R.P.) 3 refs

  6. Evaluation of Pb–17Li compatibility of ODS Fe-12Cr-5Al alloys

    Energy Technology Data Exchange (ETDEWEB)

    Unocic, Kinga A., E-mail: unocicka@ornl.gov; Hoelzer, David T.

    2016-10-15

    The Dual Coolant Lead Lithium (DCLL: eutectic Pb–17Li and He) blanket concept requires improved Pb–17Li compatibility with ferritic steels in order to demonstrate acceptable performance in fusion reactors. As an initial step, static Pb-17at.%Li (Pb-17Li) capsule experiments were conducted on new oxide dispersion strengthened (ODS) FeCrAl alloys ((1) Y{sub 2}O{sub 3} (125Y), (2) Y{sub 2}O{sub 3} + ZrO{sub 2} (125YZ), (3) Y{sub 2}O{sub 3} + HfO{sub 2} (125YH), and (4) Y{sub 2}O{sub 3} + TiO{sub 2} (125YT)) produced at ORNL via mechanical alloying (MA). Tests were conducted in static Pb–17Li for 1000 h at 700 °C. Alloys showed promising compatibility with Pb–17Li with small mass change after testing for 125YZ, 125YH and 125YT, while the 125Y alloy experienced the highest mass loss associated with some oxide spallation and subsequent alloy dissolution. X-ray diffraction methods identified the surface reaction product as LiAlO{sub 2} on all four alloys. A small decrease (∼1 at.%) in Al content beneath the oxide scale was observed in all four ODS alloys, which extended 60 μm beneath the oxide/metal interface. This indicates improvements in alloy dissolution by decreasing the amount of Al loss from the alloy. Scales formed on 125YZ, 125YH and 125YT were examined via scanning transmission electron microscopy (S/TEM) and revealed incorporation of Zr-, Hf-, and Ti-rich precipitates within the LiAlO{sub 2} product, respectively. This indicates an inward scale growth mechanism. Future work in flowing Pb–17Li is needed to further evaluate the effectiveness of this strategy in a test blanket module. - Highlights: • Investigation of Pb-17Li compatibility of new ODS Fe-12Cr5Al. • Promising small mass change after static Pb-17Li exposure. • LiAlO{sub 2} formed on the surface during Pb-17Li exposure. • Oxide precipitates incorporated within the LiAlO{sub 2} product. • An inward scale growth mechanism was identified.

  7. Study of the glass forming ability of Cu60Zr32,5Ti7,5 alloy by molecular dynamics

    International Nuclear Information System (INIS)

    Schimidt, C.S.; Lima, L.V.; Bastos, I.N.; Aliaga, L.C.R.

    2016-01-01

    This article presents the results of molecular dynamics simulation of Cu 60 Zr 32.5 Ti 7.5 alloy through the open source code LAMMPS. Amorphous samples were produced by quenching the metallic molten from 2300K to 200K at cooling rates of 50, 5 and 0.5K/ps. The pair distribution functions of both the liquid and solid were calculated and compared at different temperatures. The topology of short-range order was analyzed using the Voronoi tessellation method, which determined the presence of Cu-centered icosahedral clusters as the prevailing in the amorphous state at 300K. Moreover, the sample was submitted to uniaxial tensile tests at strain rate of 10ps -1 , in order to investigate the mechanical behavior of the metallic glass. The result of the stress-strain curve showed that applied loads lead to the plastic regime. However, the presences of shear bands, typical in the experimental testing, were not observed. Moreover, the evolution of the viscosity above the glass transition temperature and the fragility of the alloy were determined. The solidus and liquidus temperatures were determined and a good agreement with experimental data was found. (author)

  8. Effect of Cooling Rate and Chemical Modification on the Tensile Properties of Mg-5wt% Si Alloy

    Science.gov (United States)

    Mirshahi, Farshid; Meratian, Mahmood; Zahrani, Mohsen Mohammadi; Zahrani, Ehsan Mohammadi

    Hypereutectic Mg-Si alloys are a new class of light materials usable for aerospace and other advanced engineering applications. In this study, the effects of both cooling rate and bismuth modification on the micro structure and tensile properties of hypereutectic Mg-5wt% Si alloy were investigated. It was found that the addition of 0.5% Bi, altered the morphology of primary Mg2Si particles from bulky to polygonal shape and reduced their mean size from more than 70 μm to about 30 (am. Also, the tensile strength and elongation of the modified alloy increased about 10% and 20%, respectively, which should be ascribed to the modification of Mg2Si morphology and more uniform distribution of the primary particles. Moreover, an increase in tensile strength value with increase in cooling rate were observed which is attributed to finer micro structure of alloy in higher cooling rates. It was observed that Bi addition is significantly more effective in refining the morphology of primary Mg2Si particles than applying faster cooling rates.

  9. Effect of CaO on Hot Workability and Microstructure of Mg-9.5Zn-2Y Alloy

    Science.gov (United States)

    Kwak, Tae-yang; Kim, Daeguen; Yang, Jaehack; Yoon, Young-ok; Kim, Shae K.; Lim, Hyunkyu; Kim, Woo Jin

    Mg-Zn-Y system alloys have been a great interest because Mg-Zn-Y alloys with I-phase exhibited high ductility at room and elevated temperatures. According to our preliminary experiments, the addition of CaO improved strength, but the process window became narrow. Therefore, the aim of current work was to find optimum extrusion conditions for CaO added Mg-Zn-Y alloys by processing maps. The 0.3 wt.% of CaO added Mg-9.5Zn-2Y (Mg95.6Zn3.8Y0.6) alloy was prepared by casting into steel mold and homogenizing. Hot compression test were performed in the Gleeble machine at temperature range of 250-400 °C with various strain rates. The alloys were extruded with a reduction ratio of 20:1. To analyze the microstructure and texture, optical micrograph, scanning electron microscope and electron backscattered diffraction were used. Moreover, we investigated the effects of metallic Ca addition in this alloy to compare with the addition of CaO.

  10. Near total magnetic moment compensation with high Curie temperature in Mn2V0.5Co0.5Z (Z  =  Ga,Al) Heusler alloys

    Science.gov (United States)

    Midhunlal, P. V.; Arout Chelvane, J.; Arjun Krishnan, U. M.; Prabhu, D.; Gopalan, R.; Kumar, N. Harish

    2018-02-01

    Mn2V1-x Co x Z (Z  =  Ga,Al and x  =  0, 0.25, 0.5, 0.75, 1) Heusler alloys have been synthesized to investigate the effect of Co substitution at the V site on the magnetic moment and Curie temperature of half-metallic ferrimagnets Mn2VGa and Mn2VAl. Near total magnetic moment compensation was achieved with high Curie temperature for x  =  0.5 composition. The Co substituted alloys show a non linear decrease in lattice parameter without altering the crystal structure of the parent alloys. The end members Mn2VGa and Mn2CoGa have the saturation magnetization of 1.80 µ B/f.u. and 2.05 µ B/f.u. respectively whereas for the Mn2V0.5Co0.5Ga alloy, a near total magnetic moment compensation (0.10 µ B/f.u.) was observed due to the ferrimagnetic coupling of Mn with parallelly aligned V and Co. The Co substituted Mn2VAl has also shown a similar trend with compensated magnetic moment value of 0.06 µ B/f.u. for x  =  0.5. The Curie temperatures of the alloys including the x  =  0.5 composition are well above the room temperature (more than 650 K) which is in sharp contrast to the earlier reported values of 171 K for the (MnCo)VGa and 105 K for the (MnCo)VAl (substitution at the Mn site). The observed T C values are highest among the Mn2V based fully compensated ferrimagnets. The magnetic moment compensation without significant reduction in T C indicates that the V site substitution of Co does not weaken the magnetic interaction in Mn2VZ (Z  =  Ga,Al) alloys which is contrary to the earlier experimental reports on Mn site substitution.

  11. Les coûts du diabète sur 10 ans au Canada : intégration des coûts en soins de santé imputables au diabète à un modèle de prédiction de son incidence

    Directory of Open Access Journals (Sweden)

    Anja Bilandzic

    2017-01-01

    Full Text Available Introduction : Notre objectif était d’estimer les coûts de santé directs liés au traitement du diabète au Canada sur 10 ans, à l’aide de données de sondages nationaux et d’un outil de prévision du risque de diabète, ainsi que les coûts par personne. Méthodologie : Nous avons utilisé le Diabetes Population Risk Tool pour estimer le nombre de nouveaux cas de diabète chez les personnes âgées de 20 ans et plus sur 10 ans (jusqu'en 2022 à l’aide des données de 2011 et de 2012 de l’Enquête sur la santé dans les collectivités canadiennes. Nous avons évalué les coûts liés au diabète à partir d’une étude de cohorte faisant appel à l’appariement par score de propension, en utilisant la base de données sur le diabète de l’Ontario ainsi que d’autres données administratives. Nous avons calculé les coûts totaux en utilisant les coûts associés aux nouveaux cas, en tenant compte du sexe, de l’année du diagnostic et des taux de mortalité annuels dus à la maladie. Résultats : D'après nos calculs, le risque de développer le diabète sur 10 ans s’élevait pour la population canadienne en 2011-2012 à 9,98 %, soit 2,16 millions de nouveaux cas. Les coûts totaux en soins de santé imputables au diabète pendant cette période sont de 15,36 milliards (7,55 milliards pour les femmes et 7,81 milliards pour les hommes. Ce sont les hospitalisations de courte durée qui constituent la majeure partie de ces coûts (43,2 %. Des interventions menées au sein de la population entraînant une perte de poids de 5 % au sein de la population permettraient de réduire les coûts des soins de santé de 2,03 milliards de dollars. Une réduction du risque de 30 % obtenue grâce à des interventions auprès des personnes à plus haut risque de développer le diabète (c.-à-d. les 10 % au sommet du groupe à risque le plus élevé entraînerait des économies de l’ordrede 1,48 million de dollars. Conclusion : D'ici 2022

  12. The Effects of Antimony Addition on the Microstructural, Mechanical, and Thermal Properties of Sn-3.0Ag-0.5Cu Solder Alloy

    Science.gov (United States)

    Sungkhaphaitoon, Phairote; Plookphol, Thawatchai

    2018-02-01

    In this study, we investigated the effects produced by the addition of antimony (Sb) to Sn-3.0Ag-0.5Cu-based solder alloys. Our focus was the alloys' microstructural, mechanical, and thermal properties. We evaluated the effects by means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), differential scanning calorimetry (DSC), and a universal testing machine (UTM). The results showed that a part of the Sb was dissolved in the Sn matrix phase, and the remaining one participated in the formation of intermetallic compounds (IMCs) of Ag3(Sn,Sb) and Cu6(Sn,Sb)5. In the alloy containing the highest wt pct Sb, the added component resulted in the formation of SnSb compound and small particle pinning of Ag3(Sn,Sb) along the grain boundary of the IMCs. Our tests of the Sn-3.0Ag-0.5Cu solder alloys' mechanical properties showed that the effects produced by the addition of Sb varied as a function of the wt pct Sb content. The ultimate tensile strength (UTS) increased from 29.21 to a maximum value of 40.44 MPa, but the pct elongation (pct EL) decreased from 48.0 to a minimum 25.43 pct. Principally, the alloys containing Sb had higher UTS and lower pct EL than Sb-free solder alloys due to the strengthening effects of solid solution and second-phase dispersion. Thermal analysis showed that the alloys containing Sb had a slightly higher melting point and that the addition amount ranging from 0.5 to 3.0 wt pct Sb did not significantly change the solidus and liquidus temperatures compared with the Sb-free solder alloys. Thus, the optimal concentration of Sb in the alloys was 3.0 wt pct because the microstructure and the ultimate tensile strength of the SAC305 solder alloys were improved.

  13. Thermal expansion and elastic moduli of the silicide based intermetallic alloys Ti5Si3(X) and Nb5Si3

    International Nuclear Information System (INIS)

    Zhang, L.; Wu, J.

    1997-01-01

    Silicides are among those potential candidates for high temperature application because of their high melting temperature, low density and good oxidation resistance. Recent interest is focused on molybdenum silicides and titanium silicides. Extensive investigation has been carried out on MoSi 2 , yet comparatively less work was performed on titanium silicides such as Ti 5 Si 3 and Ti 3 and TiSi 2 which are of lower density than MoSi 2 . Fundamental understanding of the titanium silicides' properties for further evaluation their potential for practical application are thus needed. The thermal expansion coefficients and elastic moduli of intermetallic compounds are two properties important for evaluation as a first step. The thermal expansion determines the possible stress that might arise during cooling for these high melting point compounds, which is crucial to the preparation of defect free specimens; and the elastic moduli are usually reflections of the cohesion in crystal. In Frommeyer's work and some works afterwards, the coefficients of thermal expansion were measured on both polycrystalline and single crystal Ti 5 Si 3 . The elastic modulus of polycrystalline Ti 5 Si 3 was measured by Frommeyer and Rosenkranz. However, in the above works, the referred Ti 5 Si 3 was the binary one, no alloying effect has been reported on this matter. Moreover, the above parameters (coefficient of thermal expansion and elastic modulus) of Nb 5 Si 3 remain unreported so far. In this paper, the authors try to extend the knowledge of alloyed Ti 5 Si 3 compounds with Nb and Cr additions. Results on the coefficients of thermal expansion and elastic moduli of Ti 5 Si 3 compounds and Nb 5 Si 3 are presented and the discussion is focused on the alloying effect

  14. Moessbauer and X-ray Study of Fe1-xAlx, 0.2≤x≤0.5, Samples Produced by Mechanical Alloying

    International Nuclear Information System (INIS)

    Oyola Lozano, D.; MartInez, Y. Rojas; Bustos, H.; Perez Alcazar, G. A.

    2004-01-01

    In this work we report the magnetic and structural properties obtained by Moessbauer spectroscopy and X-ray diffraction, of the Fe 1-x Al x , 0.2≤x≤0.5, alloys produced by mechanical alloying. Alloys with x=0.2, 0.3, 0.4 and 0.5, were for milled 12, 24, 36, and 48 hours. All the obtained alloys are in the bcc phase. The obtained Moessbauer spectra are characteristic of disordered ferromagnetic system. The lattice parameter remains nearly constant (∼2.91 A) for all the milling times and compositions. The mean grain sizes in the (110) and (211) direction are nearly constants with the milling time but vary from 15.5 to 11 nm and from 10.5 to 8.5 nm when Al content grow between x=0.2 to x=0.4, respectively. The difference between the mean grain sizes in these two directions shows that the grains are of prolate spheroid form.

  15. Morphological characteristic of the conventional and melt-spun Al-10Ni-5.6Cu (in wt.%) alloy

    Energy Technology Data Exchange (ETDEWEB)

    Karakoese, Ercan [Erciyes University, Institute of Science and Technology, Department of Physics, 38039 Kayseri (Turkey); Keskin, Mustafa, E-mail: keskin@erciyes.edu.tr [Erciyes University, Faculty of Arts and Sciences, Department of Physics, 38039 Kayseri (Turkey)

    2009-12-15

    The Al-10Ni-5.6Cu alloy was prepared by conventional casting and further processed melt-spinning technique. The resulting conventional cast and melt-spun ribbons were characterized using X-ray diffraction, optical microscopy, scanning electron microscopy together with energy dispersive spectroscopy, differential scanning calorimetry and microhardness techniques. The X-ray diffraction analysis indicated that ingot samples were {alpha}-Al, intermetallic Al{sub 3}Ni and Al{sub 2}Cu phases. The optical microscopy and scanning electron microscopy results show that the microstructures of rapidly solidified ribbons are clearly different from their ingot alloy. Al-10Ni-5.6Cu ribbons reveal a very fine cellular structure with intermetallic Al{sub 3}Ni particles. Moreover, at high solidification rates the melt-spun ribbons have a polygonal structure dispersed in a supersaturated aluminum matrix. The differential scanning calorimetry measurements revealed that exothermic reaction was between 290 deg. C and 440 deg. C which are more pronounced in the ternary Al-10Ni-5.6Cu alloy.

  16. Morphological characteristic of the conventional and melt-spun Al-10Ni-5.6Cu (in wt.%) alloy

    International Nuclear Information System (INIS)

    Karakoese, Ercan; Keskin, Mustafa

    2009-01-01

    The Al-10Ni-5.6Cu alloy was prepared by conventional casting and further processed melt-spinning technique. The resulting conventional cast and melt-spun ribbons were characterized using X-ray diffraction, optical microscopy, scanning electron microscopy together with energy dispersive spectroscopy, differential scanning calorimetry and microhardness techniques. The X-ray diffraction analysis indicated that ingot samples were α-Al, intermetallic Al 3 Ni and Al 2 Cu phases. The optical microscopy and scanning electron microscopy results show that the microstructures of rapidly solidified ribbons are clearly different from their ingot alloy. Al-10Ni-5.6Cu ribbons reveal a very fine cellular structure with intermetallic Al 3 Ni particles. Moreover, at high solidification rates the melt-spun ribbons have a polygonal structure dispersed in a supersaturated aluminum matrix. The differential scanning calorimetry measurements revealed that exothermic reaction was between 290 deg. C and 440 deg. C which are more pronounced in the ternary Al-10Ni-5.6Cu alloy.

  17. Corrosion behavior of Mg–5Al based magnesium alloy with 1 wt.% Sn, Mn and Zn additions in 3.5 wt.% NaCl solution

    Directory of Open Access Journals (Sweden)

    Nguyen Dang Nam

    2014-06-01

    Full Text Available The corrosion properties of four Mg–5Al alloys with M-alloying elements (tin, manganese and zinc in a 3.5 wt.% NaCl solution were examined using electrochemical tests and surface analyses. The electrochemical results indicated that the addition of 1 wt.% M metal decreased the corrosion rate and hydrogen evolution rate of the Mg–5Al specimens. Moreover, the addition of 1Zn resulted in having the best corrosion resistance due to the interaction of Zn oxide with Mg and Al oxides which acted as a corrosion barrier.

  18. Grain refining mechanism of Al-containing Mg alloys with the addition of Mn-Al alloys

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Gaowu W., E-mail: qingw@smm.neu.edu.c [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Wenhu Road 3-11, Heping District, Shenyang 110004, Liaoning Province (China); Ren Yuping; Huang Wei; Li Song; Pei Wenli [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Wenhu Road 3-11, Heping District, Shenyang 110004, Liaoning Province (China)

    2010-10-08

    Graphical abstract: Display Omitted Research highlights: The {epsilon}-AlMn phase acts as the heterogeneous nucleus of {alpha}-Mg phase during the solidification of the AZ31 Mg alloy, not the {gamma}-Al{sub 8}Mn{sub 5} phase. The grain refinement effect is very clear with the addition of only 0.5 wt% Mn-28Al alloy (pure {epsilon}-AlMn). The grain refinement does not deteriorate up to the holding time of 60 min at 740 {sup o}C. - Abstract: The effect of manganese on grain refinement of Al-containing AZ31 Mg alloy has been investigated by designing a series of Mn-Al alloys composed of either pure {epsilon}-AlMn, {gamma}{sub 2}-Al{sub 8}Mn{sub 5} or both of them using optical microscopy and X-ray diffraction. It is experimentally clarified that the grain refinement of the AZ31 Mg alloy is due to the existence of the {epsilon}-AlMn phase in the Mn-Al alloys, not the {gamma}{sub 2}-Al{sub 8}Mn{sub 5} phase. The grain size of AZ31 Mg alloy is about 91 {mu}m without any addition of Mn-Al alloys, but remarkably decreases to {approx}55 {mu}m with the addition of either Mn-34 wt% Al or Mn-28 wt% Al. With a minor addition of 0.5 wt% Mn-28Al alloy, the grain size of AZ31 alloy decreases to {approx}53 {mu}m, and the Mn-28Al alloy can be active as grain refiner for holding time up to 60 min for the melt AZ31 alloy at 750 {sup o}C.

  19. Evaluation of Surface Mechanical Properties and Grindability of Binary Ti Alloys Containing 5 wt % Al, Cr, Sn, and V

    Directory of Open Access Journals (Sweden)

    Hae-Soon Lim

    2017-11-01

    Full Text Available This study aimed to investigate the relationship between the surface mechanical properties and the grindability of Ti alloys. Binary Ti alloys containing 5 wt % concentrations of Al, Cr, Sn, or V were prepared using a vacuum arc melting furnace, and their surface properties and grindability were compared to those of commercially pure Ti (cp-Ti. Ti alloys containing Al and Sn had microstructures that consisted of only α phase, while Ti alloys containing Cr and V had lamellar microstructures that consisted of α + β phases. The Vickers microhardness of Ti alloys was increased compared to those of cp-Ti by the solid solution strengthening effect. Among Ti alloys, Ti alloy containing Al had the highest Vickers microhardness. At a low SiC wheel speed of 5000 rpm, the grinding rates of Ti alloys showed an increasing tendency as the hardness values of Ti alloys decreased. At a high SiC wheel speed of 10,000 rpm, the grinding rates of Ti alloys showed an increasing tendency as the tensile strength values increased. The Ti alloy containing Al, which showed the lowest tensile strength, had the lowest grinding rate. The grinding ratios of the Ti alloys were higher than those of cp-Ti at both wheel revolution speeds of 5000 and 10,000 rpm. The grinding ratio of the Ti alloy containing Al was significantly increased at 10,000 rpm (p < 0.05.

  20. Effect of Co on Si and Fe-containing intermetallic compounds (IMCs) in Al–20Si–5Fe alloys

    International Nuclear Information System (INIS)

    Fatih Kilicaslan, M.; Yilmaz, Fikret; Hong, Soon-Jik; Uzun, Orhan

    2012-01-01

    The effects of cobalt addition on microstructure and mechanical properties of Al–20Si–5Fe–XCo (X=0, 1, 3, and 5) alloys were reported in this study. The alloys were produced by both conventional sand casting and melt-spinning at 20 m/s disk velocity. Microstructures of the samples were investigated using X-ray diffractometry (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Vickers micro-hardness tester was used for hardness measurements. Results showed that Co addition can alter morphology of Fe-bearing intermetallic compounds (IMCs) from long rod/needle-like structures to short rod-like ones, and lead to a more homogenous distribution in the microstructure. Addition of 5 wt% Co leads to a decrease in average size of the primary silicon phases in as-cast Al–Si alloys. In melt-spun alloys, with the addition of Co, the microstructure became finer and more homogenously distributed, while thickness of the featureless zone has seen great increase. The optimum Fe to Co ratio was found to be 1 for suppressing the undesirable effect of Fe-bearing acicular/needle-like intermetallic compounds.

  1. Effect of Co on Si and Fe-containing intermetallic compounds (IMCs) in Al-20Si-5Fe alloys

    Energy Technology Data Exchange (ETDEWEB)

    Fatih Kilicaslan, M. [Department of Physics, Faculty of Art and Science, Kastamonu University, Kastamonu (Turkey); Yilmaz, Fikret [Department of Physics, Faculty of Art and Science, Gaziosmanpasa University, Tokat (Turkey); Hong, Soon-Jik, E-mail: hongsj@kongju.ac.kr [Division of Advanced Materials Engineering, Institute for Rare Metals, Kongju National University, Cheonan 331717 (Korea, Republic of); Uzun, Orhan, E-mail: orhan.uzun@gop.edu.tr [Department of Physics, Faculty of Art and Science, Gaziosmanpasa University, Tokat (Turkey)

    2012-10-30

    The effects of cobalt addition on microstructure and mechanical properties of Al-20Si-5Fe-XCo (X=0, 1, 3, and 5) alloys were reported in this study. The alloys were produced by both conventional sand casting and melt-spinning at 20 m/s disk velocity. Microstructures of the samples were investigated using X-ray diffractometry (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Vickers micro-hardness tester was used for hardness measurements. Results showed that Co addition can alter morphology of Fe-bearing intermetallic compounds (IMCs) from long rod/needle-like structures to short rod-like ones, and lead to a more homogenous distribution in the microstructure. Addition of 5 wt% Co leads to a decrease in average size of the primary silicon phases in as-cast Al-Si alloys. In melt-spun alloys, with the addition of Co, the microstructure became finer and more homogenously distributed, while thickness of the featureless zone has seen great increase. The optimum Fe to Co ratio was found to be 1 for suppressing the undesirable effect of Fe-bearing acicular/needle-like intermetallic compounds.

  2. Development and characterization of monolithic fuel miniplate alloy U-2.5Zr-7.5Nb, coated in zircaloy; Desenvolvimento e caracterizacao do combustivel nuclear tipo placa monolitico da liga U-2,5Zr-7,5Nb revestido em zircaloy

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Geraldo Correa

    2014-06-01

    The autocthonal production of nuclear fuel in Brazil for test and research reactors is restricted to MTR (Material Test Reactor) fuel type dispersion plate, using U3Si2 alloy, coated and dispersed in aluminum, developed by IPEN-SP for use in IEA-R1 reactor. Moreover, the UO{sub 2} fuel rod type for power reactors is manufactured by Rezende (RJ) with a German technology by INB under license. Currently, Brazil is performing two programs of developing reactors. Currently, Brazil is developing two reactors. One of them is the development, by CNEN, the Brazilian Multipurpose Reactor (RMB), for testing, research and radioisotope production. The other one is the development a power reactor for naval propulsion, conducted by the Brazilian Navy. This dissertation presents the development and characterization of monolithic fuel miniplate alloy U-2.5Zr-7.5Nb, coated in zircaloy (ZRY), on a laboratory scale. Due to its innovative features and properties, this fuel can be used as fuel in both test reactors, research and producing radioisotopes for power reactors as small and medium sizes. Thus, this high potential fuel can be used in domestic reactors currently under development. The development of monolithic fuel plate type is made using the technique called 'picture-frame' where a sandwich composed of a monolith alloy U-2.5Zr- 7.5Nb coupled to a frame and coated sheets of Zry is obtained. The alloy U-2.5Zr-7.5Nb was obtained by melting in an induction furnace and then was cast into rectangular ingots of graphite, thus achieving an ingot with approximate dimensions of 170 x 50 x 60 mm. The obtained ingot was hot rolled at 850 ºC, with a 50 % reduction in thickness, in order to refine the raw structure of fusion. Samples cut from the alloy U-2.5Zr-7.5Nb, with dimensions 20 x 20 x 6 mm were placed in frames and plates Zry and joined by TIG (Tungsten Inert Gas) under an atmosphere of argon, obtaining a set of 10 mm thick, 45 mm wide and 100 mm long. The sandwiches were

  3. T5 heat treatment of semi-solid metal processed aluminium alloy F357

    CSIR Research Space (South Africa)

    Moller, H

    2009-04-01

    Full Text Available The T5 heat treatment of semi-solid metal (SSM) processed alloy F357 was investigated by considering the effects of cooling rate and natural aging after casting, as well as artificial aging parameters on tensile properties. In addition, the tensile...

  4. Enhanced catalytic oxidation by hierarchically structured TS-1 zeolite

    NARCIS (Netherlands)

    Xin, H.; Zhao, Jiao; Zhao, J.; Xu, S.; Li, Junping; Zhang, Weiping; Guo, X.; Hensen, E.J.M.; Yang, Q.; Li, Can

    2010-01-01

    A TS-1 zeolite with a disordered network of mesopores penetrating the microporous crystalline zeolite framework was successfully synthesized by a one-pot carbon hard-templating synthesis approach. Besides conventional methods to characterize the mesoporosity, the use of variable-temperature 129Xe

  5. Gemcitabine-Based Chemogene Therapy for Pancreatic Cancer Using Ad-dCK::UMK GDEPT and TS/RR siRNA Strategies

    Directory of Open Access Journals (Sweden)

    Soukaina Réjiba

    2009-07-01

    Full Text Available Gemcitabine is a first-line agent for advanced pancreatic cancer therapy. However, its efficacy is often limited by its poor intracellular metabolism and chemoresistance. To exert its antitumor activity, gemcitabine requires to be converted to its active triphosphate form. Thus, our aim was to improve gemcitabine activation using gene-directed enzyme prodrug therapy based on gemcitabine association with the deoxycytidine kinase::uridine monophosphate kinase fusion gene (dCK::UMK and small interference RNA directed against ribonucleotide reductase (RRM2 and thymidylate synthase (TS. In vitro, cytotoxicity was assessed by 3-[4,5-dimethylthiazol-2-yl]-3,5-diphenyl tetrazolium bromide and [3H]thymidine assays. Apoptosis-related gene expression and activity were analyzed by reverse transcription-polymerase chain reaction, Western blot, and ELISA. For in vivo studies, the treatment efficacy was evaluated on subcutaneous and orthotopic pancreatic tumor models. Our data indicated that cell exposure to gemcitabine induced a down-regulation of dCK expression and up-regulation of TS and RR expression in Panc1-resistant cells when compared with BxPc3- and HA-hpc2-sensitive cells. The combination of TS/RRM2 small interference RNA with Ad-dCK::UMK induced a 40-fold decrease of gemcitabine IC50 in Panc1 cells. This strong sensitization was associated to apoptosis induction with a remarkable increase in TRAIL expression and a diminution of gemcitabine-induced nuclear factor-κB activity. In vivo, the gemcitabine-based tritherapy strongly reduced tumor volumes and significantly prolonged mice survival. Moreover, we observed an obvious increase of apoptosis and decrease of cell proliferation in tumors receiving the tritherapy regimens. Together, these findings suggest that simultaneous TS/RRM2-gene silencing and dCK::UMK gene overexpression markedly improved gemcitabine's therapeutic activity. Clearly, this combined strategy warrants further investigation.

  6. Long-term oxidation of Zr-2.5 wt% Nb alloy

    International Nuclear Information System (INIS)

    Cox, B.

    1976-09-01

    A long-term study of the oxidation of Zr-2.5 wt% Nb alloys in water, steam, air and fused nitrate/nitrite salt has been carried out as a function of material batch, degree of cold-work, and heat treatment. Examination after oxidation was by weight gain, optical microscopy, replica electron microscopy, scanning electron microscopy, oxide impedance measurements, mercury porosimetry and metallographic sectioning. The results are compared with other published work and some hypothetical oxidation mechanisms are proposed and discussed. (author)

  7. Improvement of magnetocaloric properties of Gd-Ge-Si alloys by alloying with iron

    Directory of Open Access Journals (Sweden)

    Erenc-Sędziak T.

    2013-01-01

    Full Text Available The influence of annealing of Gd5Ge2Si2Fex alloys at 1200°C and of alloying with various amount of iron on structure as well as thermal and magnetocaloric properties is investigated. It was found that annealing for 1 to 10 hours improves the entropy change, but reduces the temperature of maximum magnetocaloric effect by up to 50 K. Prolonged annealing of the Gd5Ge2Si2 alloy results in the decrease of entropy change due to the reduction of Gd5Ge2Si2 phase content. Addition of iron to the ternary alloy enhances the magnetocaloric effect, if x = 0.4 – 0.6, especially if alloying is combined with annealing at 1200°C: the peak value of the isothermal entropy change from 0 to 2 T increases from 3.5 to 11 J/kgK. Simultaneously, the temperature of maximum magnetocaloric effect drops to 250 K. The changes in magnetocaloric properties are related to the change in phase transformation from the second order for arc molten ternary alloy to first order in the case of annealed and/or alloyed with iron. The results of this study indicate that the minor addition of iron and heat treatment to Gd-Ge-Si alloys may be useful in improving the materials’ magnetocaloric properties..

  8. Effect of preparation techniques on creep characteristics of the Zr-2. 5% Nb alloy at temperatures of 673 to 823 K

    Energy Technology Data Exchange (ETDEWEB)

    Pahutova, M; Kreici, J; Polesna, M [Ceskoslovenska Akademie Ved, Brno. Ustav Fyzikalni Metalurgie

    1976-01-01

    The effect of the initial raw material - zirconium sponge or zirconium iodide - on some creep and stres-strain properties was studied on Zr-2.5%Nb alloy by a stress-strain test at constant crosshead speed and by strain-rate sensitivity testing. Dependence of the creep characteristics on cooling conditions after solution treatment was examined. Alloy made from Zr-sponge was used for measurement of steady-state creep rate on time to fracture dependence and steady-state creep rate on time to fracture with respect to the angle between rolling direction of alloy sheets and tensile axis. Transmission electron microscopy was used for structure study of both alloys after different heat treatment. Higher creep strength of the alloy made from iodide zirconium (after respective heat treatment) than that of the alloy made from Zr-sponge is discussed. Oxygen content and its effect on structural changes during heat treatment seems to be responsible for higher creep strength of the first alloy. On the other hand the difference of respective creep strengths is not so significant as to justify production of Zr-2.5%Nb alloy and perhaps of future high-strength Zr alloys (for applications in structural components in reactors in the temperature range of 673 to 773 K) from iodide zirconium. Results of creep and stress-strain (short time) testing are briefly discussed.

  9. A Solution-Based Temperature Sensor Using the Organic Compound CuTsPc

    Directory of Open Access Journals (Sweden)

    Shahino Mah Abdullah

    2014-06-01

    Full Text Available An electrochemical cell using an organic compound, copper (II phthalocyanine-tetrasulfonic acid tetrasodium salt (CuTsPc, has been fabricated and investigated as a solution-based temperature sensor. The capacitance and resistance of the ITO/CuTsPc solution/ITO chemical cell has been characterized as a function of temperature in the temperature range of 25–80 °C. A linear response with minimal hysteresis is observed. The fabricated temperature sensor has shown high consistency and sensitive response towards a specific range of temperature values.

  10. ENVIRONMENTAL TECHNOLOGY VERIFICATION: JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT: TRITON SYSTEMS, LLC SOLID BOWL CENTRIFUGE, MODEL TS-5000

    Science.gov (United States)

    Verification testing of the Triton Systems, LLC Solid Bowl Centrifuge Model TS-5000 (TS-5000) was conducted at the Lake Wheeler Road Field Laboratory Swine Educational Unit in Raleigh, North Carolina. The TS-5000 was 48" in diameter and 30" deep, with a bowl capacity of 16 ft3. ...

  11. Giant elastocaloric effect covering wide temperature range in columnar-grained Cu71.5Al17.5Mn11 shape memory alloy

    Directory of Open Access Journals (Sweden)

    Sheng Xu

    2016-10-01

    Full Text Available The elastocaloric effect in a columnar-grained Cu71.5Al17.5Mn11 shape memory alloy fabricated by directional solidification was investigated. A large entropy change of 25.0 J/kg K generated by the reversible martensitic transformation was demonstrated. The adiabatic temperature change of 12-13 K was directly measured, covering a wide temperature range of more than 100 K. The low applied stress with a specific elastocaloric ability of 100.8 K/GPa was identified and the potentially attainable operational temperature window as wide as more than 215 K was also discussed. The outstanding elastocaloric refrigeration capability, together with the low applying stress and uniform phase transformation, makes the columnar-grained Cu–Al–Mn shape memory alloy a promising material for solid-state refrigeration.

  12. Electrical Resistance of Ag-TS-S(CH2)(n-1)CH3//Ga2O3/EGaln Tunneling Junctions

    NARCIS (Netherlands)

    Cademartiri, Ludovico; Thuo, Martin M.; Nijhuis, Christian A.; Reus, William F.; Tricard, Simon; Barber, Jabulani R.; Sodhi, Rana N. S.; Brodersen, Peter; Kim, Choongik; Chiechi, Ryan C.; Whitesides, George M.

    2012-01-01

    Tunneling junctions having the structure Ag-TS-S(CH2)(n-1)CH3//Ga2O3/EGaIn allow physical-organic studies of charge transport across self-assembled monolayers (SAMs). In ambient conditions, the surface of the liquid metal electrode (EGaIn, 75.5 wt % Ga, 24.5 wt % In, mp 15.7 degrees C) oxidizes and

  13. Effects of strontium on microstructure and mechanical properties of as-cast Mg-5 wt.%Sn alloy

    International Nuclear Information System (INIS)

    Liu, Hongmei; Chen, Yungui; Zhao, Haofeng; Wei, Shanghai; Gao, Wei

    2010-01-01

    The strontium (Sr) addition to the Mg-5 wt.%Sn alloy results in grain refinement and the formation of a rod-shaped and a bone-shaped MgSnSr intermetallic phase which are mainly straddle on the grain boundaries. The yield strength is improved, while the tensile strength and elongation first increased, and then decreased with a large addition of Sr. Optimum mechanical properties at ambient temperature are obtained at a content of 2.14 wt.%Sr. Tensile properties of the alloys at elevated temperatures are also improved, and the decrease of strength at elevated temperature slowed down with increasing Sr addition, indicating that Sr can improve the thermal stability of Mg-Sn alloys.

  14. Microstructure and Tribological Properties of AlCoCrFeNiTi0.5 High-Entropy Alloy in Hydrogen Peroxide Solution

    Science.gov (United States)

    Yu, Y.; Liu, W. M.; Zhang, T. B.; Li, J. S.; Wang, J.; Kou, H. C.; Li, J.

    2014-01-01

    Microstructure and tribological properties of an AlCoCrFeNiTi0.5 high-entropy alloy in high-concentration hydrogen peroxide solution were investigated in this work. The results show that the sigma phase precipitates and the content of bcc2 decrease during the annealing process. Meanwhile, the complex construction of the interdendrite region changes into simple isolated-island shape, and much more spherical precipitates are formed. Those changes of microstructure during the annealing process lead to the increase of hardness of this alloy. In the testing conditions, the AlCoCrFeNiTi0.5 alloy shows smoother worn surfaces and steadier coefficient of friction curves than does the 1Cr18Ni9Ti stainless steel, and SiC ceramic preserves better wear resistance than ZrO2 ceramic. After annealing, the wear resistance of the AlCoCrFeNiTi0.5 alloy increases coupled with SiC counterface but decreases with ZrO2 counterface.

  15. Microstructure, mechanical property and in vitro biocorrosion behavior of single-phase biodegradable Mg–1.5Zn–0.6Zr alloy

    OpenAIRE

    Tao Li; Yong He; Hailong Zhang; Xitao Wang

    2014-01-01

    The microstructure, mechanical property, and in vitro biocorrosion behavior of as-cast single-phase biodegradable Mg–1.5Zn–0.6Zr alloy were investigated and compared with a commercial as-cast AZ91D alloy. The results show that the Mg–1.5Zn–0.6Zr alloy had a single-phase solid solution structure, with an average grain size of 34.7 ± 13.1 μm. The alloy exhibited ultimate tensile strength of 168 ± 2.0 MPa, yield strength of 83 ± 0.6 MPa, and elongation of 9.1 ± 0.6%. Immersion tests and electroc...

  16. Effects of additions on AB{sub 5}-type hydrogen storage alloy in MH-Ni battery application

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiangdong; Feng, Hongwei; Tian, Xiao; Chi, Bo; Yan, Shufang [School of Material Science and Engineering, Inner Mongolia University of Technology, Hohhot 010051 (China); Xu, Jin [Zhanjiang University of Radio and Television, Zhanjiang 524003 (China)

    2009-09-15

    The AB{sub 5}-type hydrogen storage alloy of Mm{sub 0.3}Ml{sub 0.7}Ni{sub 3.55}Co{sub 0.75}Mn{sub 0.4}Al{sub 0.3} were synthesized and mixed with PVA (Polyvinyl Alcohol) or different percentage Ni powder as the test samples. The cycle stabilities of the composites were tested in 6 M KOH electrolyte through electrochemical method. The results indicated that all the samples with Ni powder have better cycle stabilities and flatter discharge voltage platform. The sample of Mm{sub 0.3}Ml{sub 0.7}Ni{sub 3.55}Co{sub 0.7}5Mn{sub 0.4}Al{sub 0.3} + 200 wt.% Ni has the highest capacity conservation rate of 80.5% and the longest discharge time of 5.2 h. The SEM images show that the particle diameters of the alloy decreased by 2 {mu}m and the surface smoothed without sharp edges after adding Ni powder. It can be presumed that adding Ni can improve the cycle stability of the alloy of Mm{sub 0.3}Ml{sub 0.7}Ni{sub 3.55}Co{sub 0.7}5Mn{sub 0.4}Al{sub 0.3} in the alkaline electrolyte and enhance the reaction rate in the charge/discharge cycles. (author)

  17. Development of an Operational TS Dataset Production System for the Data Assimilation System

    Science.gov (United States)

    Kim, Sung Dae; Park, Hyuk Min; Kim, Young Ho; Park, Kwang Soon

    2017-04-01

    An operational TS (Temperature and Salinity) dataset production system was developed to provide near real-time data to the data assimilation system periodically. It collects the latest 15 days' TS data of the north western pacific area (20°N - 55°N, 110°E - 150°E), applies QC tests to the archived data and supplies them to numerical prediction models of KIOST (Korea Institute of Ocean Science and Technology). The latest real-time TS data are collected from Argo GDAC and GTSPP data server every week. Argo data are downloaded from /latest_data directory of Argo GDAC. Because many duplicated data exist when all profile data are extracted from all Argo netCDF files, DB system is used to avoid duplication. All metadata (float ID, location, observation date and time, etc) of all Argo floats is stored into Database system and a Matlab program was developed to manipulate DB data, to check the duplication and to exclude duplicated data. GTSPP data are downloaded from /realtime directory of GTSPP data service. The latest data except ARGO data are extracted from the original data. Another Matlab program was coded to inspect all collected data using 10 QC tests and produce final dataset which can be used by the assimilation system. Three regional range tests to inspect annual, seasonal and monthly variations are included in the QC procedures. The C program was developed to provide regional ranges to data managers. It can calculate upper limit and lower limit of temperature and salinity at depth from 0 to 1550m. The final TS dataset contains the latest 15 days' TS data in netCDF format. It is updated every week and transmitted to numerical modeler of KIOST for operational use.

  18. The pseudoelasticity of a Ni45Ti50Cu5 alloy

    International Nuclear Information System (INIS)

    Ranucci, T.; Airoldi, G.

    2000-01-01

    Since several years the Ni (50-X) Ti 50 Cu X alloys are attentively considered for the interesting features related to the B2=>B19' transformation involved in the pseudoelastic behavior. In contrast with the binary NiTi, where two martensitic transformations, B2=>R-phase and R-phase=>B19' can overlap, in the ternary alloy a single transformation is expected with a narrower hysteresis. The pseudoelastic behavior of a Ni 45 Ti 50 Cu 5 is here thoroughly investigated both as a function of different thermal treatments and of the maximum applied strain. The minimum hysteresis width of the pseudoelastic cycle appears for a thermal treatment of 450 C and decreases with stress cycling. The stress induced transformation involves, however, a single process whenever the maximum applied strain is smaller than the transformation strain. When the attained strain exceeds the transformation strain, another transformation sets in as supported by electrical resistance measurements performed concomitantly to stress-strain tests. (orig.)

  19. Artifacts in MRI of the temporomandibular joint caused by dental alloys: a phantom study at 1.5 T

    International Nuclear Information System (INIS)

    Fellner, C.; Erlangen-Nuernberg Univ., Erlangen; Behr, M.; Fellner, F.; Held, P.; Handel, G.; Feuerbach, S.

    1997-01-01

    Purpose: The influence of dental alloys on MRI of the temporomandibular joint was studied using a phantom model for this joint. Methods: At 1,5 T, 15 dental alloys and 14 of their most important components were investigated acquiring sagittal (FOV: 150 mm) and transverse (FOV: 250 mm) T 1 -weighted SE additionally. The artifacts were assessed qualitatively as well as quantitatively, and the samples were subdivided into four artifact categories. Results: Ag, Cu, Ga, In, Ti, Sn, Zn, amalgan, the precious alloys, the Au-Pd and Ag-Pd alloys showed no artifacts (category I). Minimal artifacts below 10 mm on transverse images (category II) were found for Cr, Pd, Pt and for the Ni-Cr alloy. Mn and the remaining non-precious alloys induced artifacts up to 30 mm (category III). Significant artifacts - more than 30 mm - (category IV) were to be more susceptible for artifacts than T 1 -weighted SE and FLASH techniques. Conclusions: In contrast to dental alloys for fixed prosthodontics, Ni-Cr- or 18/8 wires used for orthodontic bands can influence not only the image quality, but also the diagnostic reliability of MRI of the temporomandibular joint. (orig.) [de

  20. Microstructural characterization of a rapidly solidified ultrahigh strength Al94.5Cr3Co1.5Ce1 alloy

    International Nuclear Information System (INIS)

    Ping, D.H.; Hono, K.; Inoue, A.

    2000-01-01

    The microstructure of a rapidly solidified Al 94.5 Cr 3 Co 1.5 Ce 1 alloy has been examined in detail by means of high resolution transmission electron microscopy (HRTEM) and atom probe field ion microscopy (APFIM). In the as-quenched microstructure, nanoscale particles of a solute-enriched amorphous phase and an Al-Cr compound are dispersed in randomly oriented fine grains of α-Al ( 200nm ). The interface between the Al grains and the amorphous particles is not smooth but irregular with atomic protrusions and concavities, suggesting that interfacial instability occurs during the solidification process. Nanoscale amorphous particles are formed as a result of solute trapping within the rapidly grown Al grains. After annealing at 400 C for 15 minutes grain growth occurs, and the interface of the Al grains is smoothed. The amorphous region trapped within the grains if crystallized to an Al-Cr compound, but no icosahedral phase has been confirmed. The APFIM results have revealed that Cr and Ce atoms have a similar partitioning behavior, i.e., they are rejected from the α-Al phase and partitioned into the trapped amorphous regions. On the other hand, Co atoms are not partitioned between the two phases in the as-quenched state but are partitioned into the α-Al grains in the annealed alloys being rejected from the Al compounds and finally form Al-Co compounds. Based on these microstructural characterization results, the origins of high strength of this alloy are discussed

  1. Neutron-absorbing alloys

    International Nuclear Information System (INIS)

    Portnoi, K.I.; Arabei, L.B.; Gryaznov, G.M.; Levi, L.I.; Lunin, G.L.; Kozhukhov, V.M.; Markov, J.M.; Fedotov, M.E.

    1975-01-01

    A process is described for the production of an alloy consiting of 1 to 20% In, 0.5 to 15% Sm, and from 3 to 18% Hf, the balance being Ni. Such alloys show a good absorption capacity for thermal and intermediate neutrons, good neutron capture efficiency, and good corrosion resistance, and find application in nuclear reactor automatic control and safety systems. The Hf provides for the maintenance of a reasonably high order of neutron capture efficiency throughout the lifetime of a reactor. The alloys are formed in a vacuum furnace operating with an inert gas atmosphere at 280 to 300 mm.Hg. They have a corrosion resistance from 3 to 3.5 times that of the Ag-based alloys commonly employed, and a neutron capture efficiency about twice that of the Ag alloys. Castability and structural strength are good. (U.K.)

  2. Study of the Integration of the CNU-TS-1 Mobile Tunnel Monitoring System.

    Science.gov (United States)

    Du, Liming; Zhong, Ruofei; Sun, Haili; Zhu, Qiang; Zhang, Zhen

    2018-02-01

    A rapid, precise and automated means for the regular inspection and maintenance of a large number of tunnels is needed. Based on the depth study of the tunnel monitoring method, the CNU-TS-1 mobile tunnel monitoring system (TS1) is developed and presented. It can efficiently obtain the cross-sections that are orthogonal to the tunnel in a dynamic way, and the control measurements that depend on design data are eliminated. By using odometers to locate the cross-sections and correcting the data based on longitudinal joints of tunnel segment lining, the cost of the system has been significantly reduced, and the interval between adjacent cross-sections can reach 1-2 cm when pushed to collect data at a normal walking speed. Meanwhile, the relative deformation of tunnel can be analyzed by selecting cross-sections from original data. Through the measurement of the actual tunnel, the applicability of the system for tunnel deformation detection is verified, and the system is shown to be 15 times more efficient than that of the total station. The simulation experiment of the tunnel deformation indicates that the measurement accuracy of TS1 for cross-sections is 1.1 mm. Compared with the traditional method, TS1 improves the efficiency as well as increases the density of the obtained points.

  3. Study of the Integration of the CNU-TS-1 Mobile Tunnel Monitoring System

    Directory of Open Access Journals (Sweden)

    Liming Du

    2018-02-01

    Full Text Available A rapid, precise and automated means for the regular inspection and maintenance of a large number of tunnels is needed. Based on the depth study of the tunnel monitoring method, the CNU-TS-1 mobile tunnel monitoring system (TS1 is developed and presented. It can efficiently obtain the cross-sections that are orthogonal to the tunnel in a dynamic way, and the control measurements that depend on design data are eliminated. By using odometers to locate the cross-sections and correcting the data based on longitudinal joints of tunnel segment lining, the cost of the system has been significantly reduced, and the interval between adjacent cross-sections can reach 1–2 cm when pushed to collect data at a normal walking speed. Meanwhile, the relative deformation of tunnel can be analyzed by selecting cross-sections from original data. Through the measurement of the actual tunnel, the applicability of the system for tunnel deformation detection is verified, and the system is shown to be 15 times more efficient than that of the total station. The simulation experiment of the tunnel deformation indicates that the measurement accuracy of TS1 for cross-sections is 1.1 mm. Compared with the traditional method, TS1 improves the efficiency as well as increases the density of the obtained points.

  4. Impact of beryllium additions on thermal and mechanical properties of conventionally solidified and melt-spun Al–4.5 wt.%Mn–x wt.%Be (x = 0, 1, 3, 5) alloys

    International Nuclear Information System (INIS)

    Öz, Turan; Karaköse, Ercan; Keskin, Mustafa

    2013-01-01

    Highlights: • Thermal and mechanical properties of Al–Mn–Be alloys were investigated. • IQC Al–Mn–Be alloys were synthesized by the CS and MS techniques. • The volume fraction of IQC increases continuously with Be content. • The melting points of the QC i-phase were determined between 652 °C and 675 °C. • The maximum H V and σ values were found to be 124 kg/mm 2 and 458 MPa with the addition of 5% Be. - Abstract: The influence of beryllium (Be) addition on the quasicrystal-forming ability, thermal and mechanical properties of Al–4.5 wt.%Mn–x wt.%Be (x = 0, 1, 3, 5) alloys was investigated in this study. Quasicrystalline Al–Mn–Be alloys were synthesized by the conventionally casting and melt spinning techniques. The microstructures of the samples were characterized by scanning electron microscopy (SEM) and the phase composition was identified by X-ray diffractometry (XRD). The phase transition during the solidification process was studied by differential scanning calorimetry (DSC) and differential thermal analysis (DTA) under an Ar atmosphere. The mechanical properties of the conventionally solidified (CS) and melt-spun (MS) samples were measured by a Vickers micro-hardness indenter and tensile-strength tests. The Al–4.5 wt.%Mn alloy has a hexagonal structure and minor dendritic icosahedral quasicrystalline phase (IQC) precipitates surrounded by an α-Al matrix. Addition of Be into the Al–4.5 wt.%Mn alloy generates intermetallic Be 4 AlMn and IQC phases with the extinction of the hexagonal phase, and the fraction of IQC increases continuously with the increase in Be content. A considerable improvement in microhardness and tensile strength values was observed due to the addition of Be in different percentages into the composition

  5. Experimental Study of Laser - enhanced 5A03 Aluminum Alloy and Its Stress Corrosion Resistance

    Science.gov (United States)

    Wang, Guicheng; Chen, Jing; Pang, Tao

    2018-02-01

    Based on the study of improving the stress corrosion resistance of 5A03 aluminum alloy for ship, this paper mainly studied the tensile test, surface morphology and residual stress under laser shock, high temperature and stress corrosion. It is found that the residual compressive stress and the grain refinement on the surface of the material during the heat strengthening process increase the breaking strength of the sample in the stress corrosion environment. Appropriate high temperature maintenance helps to enhance the effect of deformation strengthening. In the 300°C environment insulation, due to recrystallization of the material, the performance decreased significantly. This study provides an experimental basis for effectively improving the stress corrosion resistance of 5A03 aluminum alloy.

  6. Effects of torsional oscillation on tensile behavior of Sn–3.5 wt% Ag alloy with and without adding ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sobhy, M., E-mail: miladsobhym@yahoo.com

    2014-07-29

    Stress–strain characteristics of both Sn–3.5 wt% Ag and Sn–3.5 wt% Ag–0.3 wt% ZnO alloys were investigated using tensile testing machine. Different superimposed torsional oscillation frequencies ranging from 0 to 1.3 Hz at different deformation temperatures ranging from 303 to 363 K were performed. X-ray diffraction (XRD), transition electron microscopy (TEM) and optical microscopy were used to investigate the microstructures of both alloys. The mechanical parameters such as Young's modulus Y, yield stress σ{sub y}, fracture stress σ{sub f}, work hardening coefficient χ{sub p} and fracture strain ε{sub f} were calculated. The fracture stress of both alloys decreases with increasing the superimposed frequency of torsional oscillations as well as deformation temperatures. The fracture strain behaves in a different manner i.e. it increases with increasing the deformation temperature in the alloy containing ZnO nanoparticles while decreases in the alloy free from ZnO nanoparticles. With respect to the effect of the frequency of the superimposed torsional deformation, the fracture strain increases in both alloys.

  7. AHP 40: NAMUYI TIBETAN pha⁵⁴ tsə⁵⁴ RITUALS AND ORAL CHANTS

    Directory of Open Access Journals (Sweden)

    Libu Lakhi (Li Jianfu

    2016-02-01

    Full Text Available sa54 da54 (b. 1939 is a Namuyi pha54 tsə54 - a traditional Namuyi religious practitioner/ specialist - who chants and conducts religious rituals. He lives and practices in Liangshan Yi Autonomous Prefecture, Sichuan Province, China. This article introduces pha54 tsə54 sa54 da54 and the many hours of his oral materials recorded by Libu Lakhi in 2009 that are archived at http://tinyurl.com/lgf3row. In addition, aspects of Namuyi religion are described, including terms of mountain deities, ill omens and taboos, the pha54 tsə54, sa54 da54, chants, and a personal account of a ritual done in Dashui Village, Minsheng Township, Xichang City, Sichuan Province in March 2013. An appendix, seven photographs, and a diagram provide additional detail.

  8. Comparative study on microstructures and mechanical properties of the heat-treated Al–5.0Cu–0.6Mn–xFe alloys prepared by gravity die casting and squeeze casting

    International Nuclear Information System (INIS)

    Lin, Bo; Zhang, WeiWen; Lou, ZhaoHui; Zhang, DaTong; Li, YuanYuan

    2014-01-01

    Highlights: • Only two kind Fe-rich intermetallics are found in the heat-treated Al–5.0Cu–0.6Mn–xFe alloys. • Squeeze cast Al–5.0Cu–0.6Mn alloys containing 1.5% Fe have desirable mechanical properties. • The difference between gravity die cast and squeeze cast Al–5.0Cu–0.6Mn–xFe alloys. - Abstract: The Al–5.0 wt% Cu–0.6 wt% Mn alloys with different Fe contents were prepared by gravity die casting and squeeze casting. The difference in microstructures and mechanical properties of the T5 heat-treated alloys was examined by tensile test, optical microscopy, deep etching technique, scanning electron microscope and electron probe micro-analyzer. The results show that both β-Fe and α (CuFe) are observed in T5 heat-treated gravity die cast alloy and only α (CuFe) appears in the squeeze cast alloy when the Fe content is 0.5 wt%. When the Fe content is more than 1.0 wt%, the main Fe-rich intermetallics is α (CuFe) in both squeeze cast and gravity die cast alloys. The mechanical properties of both the gravity die cast and squeeze cast alloys decrease gradually with the increase of Fe content due to the decreased volume fraction of precipitation particles, the increased volume fraction of Fe-rich intermetallics and the increased size of α (Al) dendrites. The squeeze cast alloys with different Fe contents have superior mechanical properties compared to the gravity die cast alloys, which is mainly attributed to the reduction of porosity and refinement of Fe-rich intermetallics and α (Al) dendrite. In particularly, the elongation of the squeeze cast alloys is less sensitive to the Fe content than that of the gravity die cast alloys. An elongation level of 13.7% is obtained in squeeze cast alloy even when the Fe content is as high as 1.5%, while that of the gravity die cast alloy is only 5.3%

  9. Pre- and post-natal melatonin administration partially regulates brain oxidative stress but does not improve cognitive or histological alterations in the Ts65Dn mouse model of Down syndrome.

    Science.gov (United States)

    Corrales, Andrea; Parisotto, Eduardo B; Vidal, Verónica; García-Cerro, Susana; Lantigua, Sara; Diego, Marian; Wilhem Filho, Danilo; Sanchez-Barceló, Emilio J; Martínez-Cué, Carmen; Rueda, Noemí

    2017-09-15

    Melatonin administered during adulthood induces beneficial effects on cognition and neuroprotection in the Ts65Dn (TS) mouse model of Down syndrome. Here, we investigated the effects of pre- and post-natal melatonin treatment on behavioral and cognitive abnormalities and on several neuromorphological alterations (hypocellularity, neurogenesis impairment and increased oxidative stress) that appear during the early developmental stages in TS mice. Pregnant TS females were orally treated with melatonin or vehicle from the time of conception until the weaning of the offspring, and the pups continued to receive the treatment from weaning until the age of 5 months. Melatonin administered during the pre- and post-natal periods did not improve the cognitive impairment of TS mice as measured by the Morris Water maze or fear conditioning tests. Histological alterations, such as decreased proliferation (Ki67+ cells) and hippocampal hypocellularity (DAPI+ cells), which are typical in TS mice, were not prevented by melatonin. However, melatonin partially regulated brain oxidative stress by modulating the activity of the primary antioxidant enzymes (superoxide dismutase in the cortex and catalase in the cortex and hippocampus) and slightly decreasing the levels of lipid peroxidation in the hippocampus of TS mice. These results show the inability of melatonin to prevent cognitive impairment in TS mice when it is administered at pre- and post-natal stages. Additionally, our findings suggest that to induce pro-cognitive effects in TS mice during the early stages of development, in addition to attenuating oxidative stress, therapies should aim to improve other altered processes, such as hippocampal neurogenesis and/or hypocellularity. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Phase stability and tensile properties of Co-free Al0.5CrCuFeNi2 high-entropy alloys

    International Nuclear Information System (INIS)

    Ng, Chun; Guo, Sheng; Luan, Junhua; Wang, Qing; Lu, Jian; Shi, Sanqiang; Liu, C.T.

    2014-01-01

    Highlights: • The solid solution phase in the high-entropy alloy was confirmed to be metastable. • The alloy exhibited microstructural and mechanical stability against annealing. • Only as-cast alloys showed sufficient tensile plasticity. • A large variability of the measured tensile properties was recorded. • The alloys showing slip banding behavior did not necessarily have tensile ductility. -- Abstract: High-entropy alloys (HEAs) are becoming new research frontiers in the metallic materials field. The phase stability of HEAs is of critical significance, but a convincing understanding on it has been somewhat held back by the slow diffusion kinetics, which prevents the completion of diffusion assisted phase transformations toward the equilibrium state. Here a unique methodology, combining both the thermomechanical treatments and thermodynamic calculations, was employed to reveal the phase stability of HEAs, exemplified using the newly developed Al 0.5 CrCuFeNi 2 alloy. The metastable nature of the solid solution phases in this high-entropy alloy was uncovered through thermomechanical treatments induced phase transformations, and supported by the thermodynamic calculations. Meanwhile, the tensile properties for both the as-cast and thermomechanically treated alloys were measured, and correlated to their indentation behavior

  11. Aleksandr Gol’ts, Armiia Rossii: 11 poteriannykh let, Moscow: Zakharov, 2004, 224 pp.

    Directory of Open Access Journals (Sweden)

    Richard F. Staar

    2004-07-01

    Full Text Available Specialist of military questions, Aleksandr Gol’ts worked for Red Star (Krasnaia Zvezda, the newspaper of the Russian Ministry of Defense, before joining various prestigious magazines such as Itogi. He is considered one of the most prominent journalist on military matters in Russia today. His book, “The Russian Army : 11 lost years”, is dedicated to military reforms in post-Soviet Russia. With his extensive knowledge of institutional realities of the military establishment, Gol’ts provides a...

  12. Corrosion of aluminum alloys as a function of alloy composition

    International Nuclear Information System (INIS)

    Johnson, A.B. Jr.

    1969-10-01

    A study was initiated which included nineteen aluminum alloys. Tests were conducted in high purity water at 360 0 C and flow tests (approx. 20 ft/sec) in reactor process water at 130 0 C (TF-18 loop tests). High-silicon alloys and AlSi failed completely in the 360 0 C tests. However, coupling of AlSi to 8001 aluminum suppressed the failure. The alloy compositions containing iron and nickel survived tht 360 0 C autoclave exposures. Corrosion rates varied widely as a function of alloy composition, but in directions which were predictable from previous high-temperature autoclave experience. In the TF-18 loop flow tests, corrosion penetrations were similar on all of the alloys and on high-purity aluminum after 105 days. However, certain alloys established relatively low linear corrosion rates: Al-0.9 Ni-0.5 Fe-0.1 Zr, Al-1.0 Ni-0.15 Fe-11.5 Si-0.8 Mg, Al-1.2 Ni-1.8 Fe, and Al-7.0 Ni-4.8 Fe. Electrical polarity measurements between AlSi and 8001 alloys in reactor process water at temperatures up to 150 0 C indicated that AlSi was anodic to 8001 in the static autoclave system above approx. 50 0 C

  13. Iron-based amorphous alloys and methods of synthesizing iron-based amorphous alloys

    Science.gov (United States)

    Saw, Cheng Kiong; Bauer, William A.; Choi, Jor-Shan; Day, Dan; Farmer, Joseph C.

    2016-05-03

    A method according to one embodiment includes combining an amorphous iron-based alloy and at least one metal selected from a group consisting of molybdenum, chromium, tungsten, boron, gadolinium, nickel phosphorous, yttrium, and alloys thereof to form a mixture, wherein the at least one metal is present in the mixture from about 5 atomic percent (at %) to about 55 at %; and ball milling the mixture at least until an amorphous alloy of the iron-based alloy and the at least one metal is formed. Several amorphous iron-based metal alloys are also presented, including corrosion-resistant amorphous iron-based metal alloys and radiation-shielding amorphous iron-based metal alloys.

  14. Electrochemical hydrogen storage of Ti-V-based body-centered-cubic phase alloy surface-modified with AB5 nanoparticles

    International Nuclear Information System (INIS)

    Yu, X.B.; Walker, G.S.; Grant, D.M.; Wu, Z.; Xia, B.J.; Shen, J.

    2005-01-01

    A composite of Ti-V-based bcc phase alloy surface-modified with AB 5 nanoparticles was prepared by ball milling. The composite showed significantly improved electrochemical hydrogen release capacities. For example, the 30 min ball milled Ti-30V-15Mn-15Cr+10 wt %AB 5 showed a discharge capacity in the first cycle, at 353 K, of 886 mA h g -1 , corresponding to 3.38 wt % of hydrogen, with a 45 mA g -1 discharge current. It is thought that this high capacity is due to the enhanced electrochemical-catalytic activity from the alloy surface covered with AB 5 nanoparticles, which not only have better charge-discharge capacity themselves, acting as both an electrocatalyst and a microcurrent collector, but also result in the greatly enhanced hydrogen atomic diffusivities in the nanocrystalline relative to their conventional coarse-grained counterparts. These results provide new insight for use of Ti-V-based bcc phase alloy for high-energy batteries

  15. Microstructural-Scale Model for Surfaces Spreading of Intergranular Corrosion in Sensitized Stainless Steels and Aluminum-Magnesium (AA5XXX) Alloys

    Science.gov (United States)

    Jain, Swati

    Components from AA5XXX (Al-Mg alloys with more than 3 wt% Mg) alloys are X attractive due to availability of low cost, high strength to weight ratio and good weldability. Therefore, these alloys have potential applications in Naval ships. However, these alloys become susceptible to IGC (intergranular corrosion) due to beta-phase precipitation due to improper heat treatment or inadvertent thermal exposure. Stainless steels may also become susceptible due to carbide precipitation and chromium depletion on grain boundaries. IGC susceptibility depends on the interplay between the metallurgical conditions, electrochemical conditions, and chemical conditions. Specific combinations cause IGC while others do not. The objective of this study is to investigate the conditions which bring about surface spreading of IGC in these alloy classes. To accomplish this goal, a microstructure scale model was developed with experimental inputs to understand the 2-D IGC spreading in stainless steels and AA5XXX alloys. The conditions strongly affecting IGC spreading were elucidated. Upon natural and artificial aging, the stainless steels become susceptible to intergranular corrosion because of chromium depletion in the grain boundaries. After aging Al-Mg (AA5XXX) alloys show susceptibility due to the precipitation of the beta-phase (Al3Mg7) in the grain boundaries. Chromium depleted grain boundaries in stainless steels are anodically more active as compared to the interior of the grains. (3-phase rich grain boundaries have lower OCP (open circuit potential) and pitting potentials as compared to the Al-Mg solid solutions. A new approach to modeling the IGC surface spreading in polycrystalline materials that is presented. This model is the first to couple several factors into one granular scale model that illustrates the way in which they interact and IGC occurs. It sheds new information on conditions which cause IGC spreading in two alloy classes and describes a new theory for the critical

  16. Effect of reduction ratio on annealing texture and r-value directionality for a cold-rolled Al-5% Mg alloy

    International Nuclear Information System (INIS)

    Choi, Shi-Hoon; Choi, Jae-Kwon; Kim, Hyoung-Wook; Kang, Seok-Bong

    2009-01-01

    The evolution of the macrotexture and r-value directionality of cold-rolled Al-5% Mg alloys during annealing at various temperatures was investigated to seek an optimum annealing condition to improve the formability of TRBs. The change of volume fractions for the typical texture components of Al-5% Mg alloys was calculated using a misorientation approach in 3-D Euler space. A visco-plastic self-consistent (VPSC) polycrystal model was used to predict r-value directionality of the cold-rolled and annealed Al-5% Mg alloys. The electron backscatter diffraction (EBSD) technique was used to investigate a rapid change of the initial deformation texture in the specimen deformed by a reduction of 9% during annealing. The results showed that an optimum annealing temperature for achieving the low planar anisotropy was strongly dependent on the rolling reduction ratio.

  17. Phase Transformation Behavior of Oxide Particles Formed in Mechanically Alloyed Fe-5Y{sub 2}O{sub 3} Powder

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ga Eon; Choi, Jung-Sun; Noh, Sanghoon; Kang, Suk Hoon; Choi, Byoung Kwon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Deajeon (Korea, Republic of); Kim, Young Do [Hanyang University, Seoul (Korea, Republic of)

    2017-05-15

    The phase transformation behavior of the oxides formed in mechanically alloyed Fe-5Y{sub 2}O{sub 3} powder is investigated. Non-stoichiometric Y-rich and Fe-rich oxides with sizes of less than 300 nm are observed in the mechanically alloyed powder. The diffusion and redistribution reactions of the elements in these oxides during heating of the powder above 800 ℃ were observed, and these reactions result in the formation of a Y{sub 3}Fe{sub 5}O{sub 12} phase after heating at 1050 ℃. Thus, it is considered that the Y{sub 2}O{sub 3} powder and some Fe powder are formed from the non-stoichiometric Y-rich and Fe-rich oxides after the mechanical alloying process, and a considerable energy accumulated during the mechanical alloying process leads to a phase transformation of the Y-rich and Fe-rich oxides to Y{sub α}Fe{sub β}O{sub γ}-type phase during heating.

  18. Thermo-mechanical processing of a Ti 49.5Al 1.25Ag alloy

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, A.; Viana, F.; Vieira, M.F.; Santos, H.M.C. [GMM/IMAT, Dept. de Engenharia Metalurgica e de Materiais, FEUP, Porto (Portugal)

    2002-07-01

    Gamma titanium aluminide is an important candidate to several applications in the aerospace and automotive industries. The great drawback of these alloys is its low ductility at room temperature. This work is part of a study that intends to increase the ductility of gamma titanium aluminide through the addition of alloying elements. In this paper the effects of the heat treatment and the deformation processing on the microstructure of a Ti 49.5Al 1.25Ag are described. The alloy was produced by arc melting, under an argon atmosphere, using a water-cooled copper crucible. The as-cast samples were heat treated at 1300 and 1400 C. Encapsulated samples were deformed by double forging and multiple step rolling. The as-cast {gamma}-TiAl alloy presented an extended degree of segregation, have been detected three microconstituents: lamellar dendrites, interdendritic Al enriched {gamma}-phase and a number of Ag rich particles located at the dendritic/interdendritic interface. The heat treatment at 1400 C for 6 hours allowed the elimination of the as-cast microstructure and its replacement by a fully lamellar one. The thermomechanical processing produced non-homogenous microstructures of deformed lamellar grains and recrystallized gamma grains. The microstructure changes occurring during the several stages of the processing were characterized using optical and scanning electron microscopy. The modification of the chemical composition of the phases was determined using SEM-EDS facilities. (orig.)

  19. The impact of ISO/TS 16949 on automotive industries and created organizational capabilities from its implementation

    Directory of Open Access Journals (Sweden)

    Bakhtiar Ostadi

    2010-12-01

    Full Text Available ISO/TS 16949 is an ISO Technical Specification. ISO/TS 16949 achieves the objectives which are continually to improve the production of automobile parts and related services, and to strengthen the international competition for the automotive industry and its suppliers. By applying this quality system standard, automotive manufacturers could offer superior products and good services to customers. The more the companies know about the benefits if quality management systems such as ISO/TS 16949, better they can seek interest and determine indices of these systems. So, this standard has been implemented in companies considering a number of benefits. In this paper, we carry out an empirical study in order to verify the importance these benefits and ranking them based on the value of importance. Finally, the study tends to provide a reference guide considering benefits assessment and created organizational capabilities from this standard for the automotive industry in pursuing ISO/TS 16949 and procuring maximum benefit from the results.

  20. Research on low strain magnetic mechanical hysteresis damping performance of Fe-15Cr-3Mo-0.5Si alloy

    International Nuclear Information System (INIS)

    Wang, Hui; Huang, Huawei; Hong, Xiaofeng; Yin, Changgeng; Huang, Zhaohua; Chen, Le

    2015-01-01

    Highlights: • Heat treatment system has a great effect on the alloy damping performance. • Damping performance does not improve monotonously with temperature. • Furnace cooling is higher than that of alloy after air cooling. • There is an optimum annealing temperature and grain size to obtain high damping. - Abstract: This paper studies the preparation of Fe-15Cr-3Mo-0.5Si alloy by using vacuum induction melting furnace and vacuum annealing furnace, the damping performance of which in different heat treatment states is tested with dynamic mechanical thermal analyzer (DMA). Through microstructure observation with metallographic microscope (OM), grain boundary observation with scanning electron microscopy (SEM), phase structure analysis with X-ray diffraction (XRD) and internal stress of S-B model analysis, the effect law of annealing temperature, types of cooling, holding time and grain sizes on the damping performance of alloy and the related mechanism can be concluded as follows. The annealing temperature and grain sizes have a significant impact on the damping strain amplitude as well as the magnetic and mechanical damping performance of this ferromagnetic alloy. Proper annealing temperature and grain size is the necessary condition to get high damping performance of the alloy. It is not conducive to improvement of the damping performance if the annealing temperature is too high or too low and the grain size is too small or too large. For Fe-15Cr-3Mo-0.5Si alloy, within the range of the low strain amplitude, alloy damping performance does not improve monotonously with the increase of the annealing temperature and grain size. The maximum value appears at the annealing temperature of 1100 °C/1 h with the grain size of about 300 μm. At high annealing temperature of 1100 °C, the damping performance of alloy in the slow cooling furnace is higher than that with air cooling treatment. The extension or shortening of the holding time, to a certain extent

  1. Research on low strain magnetic mechanical hysteresis damping performance of Fe-15Cr-3Mo-0.5Si alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hui, E-mail: qinghe5525@163.com; Huang, Huawei; Hong, Xiaofeng; Yin, Changgeng; Huang, Zhaohua; Chen, Le

    2015-02-15

    Highlights: • Heat treatment system has a great effect on the alloy damping performance. • Damping performance does not improve monotonously with temperature. • Furnace cooling is higher than that of alloy after air cooling. • There is an optimum annealing temperature and grain size to obtain high damping. - Abstract: This paper studies the preparation of Fe-15Cr-3Mo-0.5Si alloy by using vacuum induction melting furnace and vacuum annealing furnace, the damping performance of which in different heat treatment states is tested with dynamic mechanical thermal analyzer (DMA). Through microstructure observation with metallographic microscope (OM), grain boundary observation with scanning electron microscopy (SEM), phase structure analysis with X-ray diffraction (XRD) and internal stress of S-B model analysis, the effect law of annealing temperature, types of cooling, holding time and grain sizes on the damping performance of alloy and the related mechanism can be concluded as follows. The annealing temperature and grain sizes have a significant impact on the damping strain amplitude as well as the magnetic and mechanical damping performance of this ferromagnetic alloy. Proper annealing temperature and grain size is the necessary condition to get high damping performance of the alloy. It is not conducive to improvement of the damping performance if the annealing temperature is too high or too low and the grain size is too small or too large. For Fe-15Cr-3Mo-0.5Si alloy, within the range of the low strain amplitude, alloy damping performance does not improve monotonously with the increase of the annealing temperature and grain size. The maximum value appears at the annealing temperature of 1100 °C/1 h with the grain size of about 300 μm. At high annealing temperature of 1100 °C, the damping performance of alloy in the slow cooling furnace is higher than that with air cooling treatment. The extension or shortening of the holding time, to a certain extent

  2. Nuclear Magnetic Resonance (NMR) study of the nanocrystalline alloy Fe73.5 Cu1 Nb3 Si13.5 B9

    International Nuclear Information System (INIS)

    Aliaga-Guerra, D.; Iannarella, L.; Fontes, M.B.; Guimaraes, A.P.; Skorvanek, I.

    1994-05-01

    Nanocrystalline Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 alloys were studied with spin echo NMR at 4.2 K, from 15 to 100 MHz. Several lines are observed, with signals from domains and domain walls. Signals at 50-90 MHz appear to arise from 93 Nb nuclei in the amorphous matrix and in the interface of the crystallites. (author). 5 refs, 3 figs

  3. In situ hydrothermal synthesis of a novel hierarchically porous TS-1/modified-diatomite composite for methylene blue (MB) removal by the synergistic effect of adsorption and photocatalysis.

    Science.gov (United States)

    Yuan, Weiwei; Yuan, Peng; Liu, Dong; Yu, Wenbin; Laipan, Minwang; Deng, Liangliang; Chen, Fanrong

    2016-01-15

    Hierarchically porous TS-1/modified-diatomite composites with high removal efficiency for methylene blue (MB) were prepared via a facile in situ hydrothermal route. The surface charge state of the diatomite was modified to enhance the electrostatic interactions, followed by in situ hydrothermal coating with TS-1 nanoparticles. The zeolite loading amount in the composites could be adjusted by changing the hydrothermal time. The highest specific surface area and micropore volume of the obtained composites were 521.3m(2)/g and 0.254cm(3)/g, respectively, with an optimized zeolite loading amount of 96.8%. Based on the synergistic effect of efficient adsorption and photocatalysis resulting from the newly formed hierarchically porous structure and improved dispersion of TS-1 nanoparticles onto diatomite, the composites' removal efficiency for MB reached 99.1% after 2h of photocatalytic reaction, even higher than that observed using pure TS-1 nanoparticles. Moreover, the superior MB removal kinetics of the composites were well represented by a pseudo-first-order model, with a rate constant (5.28×10(-2)min(-1)) more than twice as high as that of pure TS-1 nanoparticles (2.43×10(-2)min(-1)). The significant dye removal performance of this novel TS-1/modified-diatomite composite indicates that it is a promising candidate for use in waste water treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. The effect of preparation techniques on creep characteristics of the Zr-2.5% Nb alloy at temperatures of 673 to 823 K

    International Nuclear Information System (INIS)

    Pahutova, M.; Krejci, J.; Polesna, M.

    1976-01-01

    The effect of the initial raw material - zirconium sponge or zirconium iodide - on some creep and stres-strain properties was studied on Zr-2.5%Nb alloy by a stress-strain test at constant crosshead speed and by strain-rate sensitivity testing. Dependence of the creep characteristics on cooling conditions after solution treatment was examined. Alloy made from Zr-sponge was used for measurement of steady-state creep rate on time to fracture dependence and steady-state creep rate on time to fracture with respect to the angle between rolling direction of alloy sheets and tensile axis. Transmission electron microscopy was used for structure study of both alloys after different heat treatment. Higher creep strength of the alloy made from iodide zirconium (after respective heat treatment) than that of the alloy made from Zr-sponge is discussed. Oxygen content and its effect on structural changes during heat treatment seems to be responsible for higher creep strength of the first alloy. On the other hand the difference of respective creep strengths is not so significant as to justify production of Zr-2.5%Nb alloy and perhaps of future high-strength Zr alloys (for applications in structural components in reactors in the temperature range of 673 to 773 K) from iodide zirconium. Results of creep and stress-strain (short time) testing are briefly discussed. (author)

  5. "Cremaster' tsükkel" : Matthew Barney avastusretk kunsti ja filmikunsti vahealal / Miriam Dagan ; tõlk. Epp Aareleid

    Index Scriptorium Estoniae

    Dagan, Miriam

    2007-01-01

    Ameerika kunstniku ja režissööri kunstnikufilmidest "Cremaster' tsükkel" (1994-2002). Viie tsükli põhisündmusest. Viienda filmi rekvisiitor oli Meeli Salumäe, Kostabi Maailma assistent New Yorgis

  6. Coercivity enhancement of NdFeB sintered magnets by low melting point Dy{sub 32.5}Fe{sub 62}Cu{sub 5.5} alloy modification

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Liping; Ma, Tianyu, E-mail: maty@zju.edu.cn; Zhang, Pei; Jin, Jiaying; Yan, Mi, E-mail: mse_yanmi@zju.edu.cn

    2014-04-15

    To improve coercivity without sacrificing other magnetic performance of NdFeB sintered magnets, a low melting point Dy{sub 32.5}Fe{sub 62}Cu{sub 5.5} alloy was introduced as an intergranular additive. Magnetic properties and microstructure of the magnets with different Dy{sub 32.5}Fe{sub 62}Cu{sub 5.5} contents were studied. At the optimum addition of 3 wt%, coercivity H{sub cj} was enhanced from 12.7 to 15.2 kOe, the maximum magnetic energy product (BH){sub max} was simultaneously increased from 46.6 to 47.8 MG Oe, accompanied by a slight reduction in remanence B{sub r}. Further investigation on microstructure and grain boundary composition indicated that the enhanced H{sub cj} and (BH){sub max} could be attributed to the refined and uniform 2:14:1 phase grains, continuous grain boundaries and a (Nd,Dy){sub 2}Fe{sub 14}B hardening shell surrounding the 2:14:1 phase grains. - Highlights: • Low melting-point Dy{sub 32.5}Fe{sub 62}Cu{sub 5.5} alloy was introduced to NdFeB magnets. • The doped magnet exhibits enhanced coercivity and maximum energy product. • (Nd,Dy){sub 2}Fe{sub 14}B shell was expected to form in the surface of Nd{sub 2}Fe{sub 14}B grains. • The continuous grain boundary layer formed between neighboring Nd{sub 2}Fe{sub 14}B grains.

  7. Surface modification of 5083 Al alloy by electrical discharge alloying processing with a 75 mass% Si-Fe alloy electrode

    Energy Technology Data Exchange (ETDEWEB)

    Stambekova, Kuralay [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Rd., Taichung 40227, Taiwan (China); Lin, Hung-Mao [Department of Mechanical Engineering, Far East University, No. 49, Zhonghua Rd., Xinshi Dist., Tainan City 74448, Taiwan (China); Uan, Jun-Yen, E-mail: jyuan@dragon.nchu.edu.tw [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Rd., Taichung 40227, Taiwan (China)

    2012-03-01

    This study experimentally investigates the surface modification of 5083 Al alloy by the electrical discharge alloying (EDA) process with a Si-Fe alloy as an electrode. Samples were analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), micro-hardness and corrosion resistance tests. The micro-hardness of EDA alloyed layer was evidently higher than that of the base metal (5083 Al alloy). The TEM results show that the matrix of the alloyed layer has an amorphous-like structure; the matrix contains fine needle-like Si particles, block-like Si particles and nano-size Al{sub 4.5}FeSi and Al{sub 13}Fe{sub 4} particles. The TEM results support experimental results for the high hardness of the alloyed layer. Moreover, the EDA alloyed layer with composite microstructures has good corrosion resistance in NaCl aqueous solution.

  8. Effect of Copper and Silicon on Al-5%Zn Alloy as a Candidate Low Voltage Sacrificial Anode

    Science.gov (United States)

    Pratesa, Yudha; Ferdian, Deni; Togina, Inez

    2017-05-01

    One common method used for corrosion protection is a sacrificial anode. Sacrificial anodes that usually employed in the marine environment are an aluminum alloy sacrificial anode, especially Al-Zn-In. However, the electronegativity of these alloys can cause corrosion overprotection and stress cracking (SCC) on a high-strength steel. Therefore, there is a development of the sacrificial anode aluminum low voltage to reduce the risk of overprotection. The addition of alloying elements such as Cu, Si, and Ge will minimize the possibility of overprotection. This study was conducted to analyze the effect of silicon and copper addition in Al-5Zn. The experiment started from casting the sacrificial anode aluminum uses electrical resistance furnace in a graphite crucible in 800°C. The results alloy was analyzed using Optical emission spectroscopy (OES), Differential scanning calorimetry, electrochemical impedance spectroscopy, and metallography. Aluminum alloy with the addition of a copper alloy is the most suitable and efficient to serve as a low-voltage sacrificial anode aluminum. Charge transfer resistivity of copper is smaller than silicon which indicates that the charge transfer between the metal and the electrolyte is easier t to occur. Also, the current potential values in coupling with steel are also in the criteria range of low-voltage aluminum sacrificial anodes.

  9. Analysing the strength of friction stir welded dissimilar aluminium alloys using Sugeno Fuzzy model

    Science.gov (United States)

    Barath, V. R.; Vaira Vignesh, R.; Padmanaban, R.

    2018-02-01

    Friction stir welding (FSW) is a promising solid state joining technique for aluminium alloys. In this study, FSW trials were conducted on two dissimilar plates of aluminium alloy AA2024 and AA7075 by varying the tool rotation speed (TRS) and welding speed (WS). Tensile strength (TS) of the joints were measured and a Sugeno - Fuzzy model was developed to interconnect the FSW process parameters with the tensile strength. From the developed model, it was observed that the optimum heat generation at WS of 15 mm.min-1 and TRS of 1050 rpm resulted in dynamic recovery and dynamic recrystallization of the material. This refined the grains in the FSW zone and resulted in peak tensile strength among the tested specimens. Crest parabolic trend was observed in tensile strength with variation of TRS from 900 rpm to 1200 rpm and TTS from 10 mm.min-1 to 20 mm.min-1.

  10. The Prediction of the Gas Utilization Ratio based on TS Fuzzy Neural Network and Particle Swarm Optimization.

    Science.gov (United States)

    Zhang, Sen; Jiang, Haihe; Yin, Yixin; Xiao, Wendong; Zhao, Baoyong

    2018-02-20

    Gas utilization ratio (GUR) is an important indicator that is used to evaluate the energy consumption of blast furnaces (BFs). Currently, the existing methods cannot predict the GUR accurately. In this paper, we present a novel data-driven model for predicting the GUR. The proposed approach utilized both the TS fuzzy neural network (TS-FNN) and the particle swarm algorithm (PSO) to predict the GUR. The particle swarm algorithm (PSO) is applied to optimize the parameters of the TS-FNN in order to decrease the error caused by the inaccurate initial parameter. This paper also applied the box graph (Box-plot) method to eliminate the abnormal value of the raw data during the data preprocessing. This method can deal with the data which does not obey the normal distribution which is caused by the complex industrial environments. The prediction results demonstrate that the optimization model based on PSO and the TS-FNN approach achieves higher prediction accuracy compared with the TS-FNN model and SVM model and the proposed approach can accurately predict the GUR of the blast furnace, providing an effective way for the on-line blast furnace distribution control.

  11. Microstructure, mechanical properties and stretch formability of Mg-3Al-0.5Ca-0.2Gd alloy processed at various finish rolling temperatures

    Science.gov (United States)

    Kang, Qiang; Jiang, Haitao; Zhang, Yun

    2018-04-01

    Effects of various finish rolling temperatures on the microstructure, texture, mechanical properties and stretch formability of rolled and annealed Mg-3Al-0.5Ca-0.2Gd (wt%) alloy were investigated in this paper, and it was found that compared with grain size and second phase particles, the basal textures, tensile properties and stretch formability Mg-3Al-0.5Ca-0.2Gd alloy are more sensitive to the increasing finishing rolling temperature. For the rolled and annealed Mg-3Al-0.5Ca-0.2Gd alloy, their grains barely grow up and second phase particles are slightly coarsened, while their basal poles are obviously weakened and tilted with increasing finish rolling temperature. Consequently, the weakened and RD-tilted basal textures are beneficial to the gradually improved elongation and stretch formability of Mg-3Al-0.5Ca-0.2Gd alloy. It is investigated that the gradually activated non-basal slips, e. g. 〈c 〉, 〈c + a〉 dislocations due to the increasing finish rolling temperature could contribute to the weakened RD-tilted textures in rolled and annealed Mg-3Al-0.5Ca-0.2Gd alloy.

  12. Investigation of phase transformations of U2.5Zr7.5Nb and U3Zr9Nb alloys aging at 600 deg C

    International Nuclear Information System (INIS)

    Cantagalli, Natalia Mattar; Tanure, Leandro Paulo de Almeida Reis; Braga, Daniel Martins; Santos, Ana Maria Matildes dos; Ferraz, Wilmar Barbosa

    2009-01-01

    Investigation has been made of the effects of high-temperature aging (600 deg C) on the phase transformations in the U2.5Zr7.5Nb and U3Zr9Nb alloys. These alloys have been produced with vacuum induction melting (VIM) furnace in cast ingots. The ingots were homogenized at 1000 deg C for 24 hours in vacuum of -4 torr, and cooled to room temperature at a rate of 3 deg C/min. Specimens from these homogeneous materials, cut in 3 mm high and 10 mm diameter, were reheated to γ phase at 850 deg C, for 1 hour, and aging at 600 deg C at different times from 0.5 to 24 hours. The phases decomposition were characterized by X-ray diffraction (XRD), metallographic, micro-probe analyze by energy dispersive spectrometry (EDS) and microhardness methods. It was verified that the decomposition of the δ phase proceeds in two steps. The first is a discontinuous precipitation of a lamellar two-phase aggregate composed of alpha solid solution and a metastable gamma phase. The metastable gamma phase has a constant composition at given temperature. After longer annealing, it decomposes eutectoidally into the equilibrium (α + δ 2 ) phases mixture. During this process a modification of the original lamellar microstructure takes place. The obtained metastable phases of these alloys of different compositions were analyzed in relation to their constitution, heat treatability and micrographic features and the results confronted with available distinct uranium alloys data from literature. (author)

  13. Synthesize and microstructure characterization of Ni43Mn41Co5Sn11 Heusler alloy

    International Nuclear Information System (INIS)

    Elwindari, Nastiti; Manaf, Azwar

    2016-01-01

    The ferromagnetic heusler alloys are promising materials in many technical applications due to their multifunctional properties such as shape memory effect, magnetocaloric effect, giant magnetoresistance, etc. In this work, synthesize and characterization of polycrystalline Ni 43 Mn 41 Co 5 Sn 11 (NMCS) alloy are reported. Alloy preparation was conducted by melting the constitute elements under an innert Argon (Ar) atmosphere in a vacuum mini arc-melting furnace. Homogenization of the microstructure of the as-cast ingot was obtained after annealing process at 750°C for 48 hours. It is shown that the dendrites structure has changed to equaixed grains morphology after homogenization. Microstructure characteristics of material by x-ray diffraction revealed that the alloy has a L 21 -type cubic crystal structure as the main phase at room temperature. In order to induce the shape anisotropy, a forging treatment was applied to show the shape orientation of material. Various enhancements of magnetic properties in a longitudinal direction were observed at various degree of anisotropy. The microstructure changes of as-cast NMCS and effects of homogenization treatments as studied by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) are discussed in details.

  14. 77 FR 43817 - Notice of Submission for OMB Review; Office of Postsecondary Education; Talent Search (TS) Annual...

    Science.gov (United States)

    2012-07-26

    ...; Talent Search (TS) Annual Performance Report SUMMARY: The Talent Search program provides Federal... Records Management Services, Office of Management, publishes this notice containing proposed information... records. Title of Collection: Talent Search (TS) Annual Performance Report. OMB Control Number: Pending...

  15. Tensile properties of Zr-2.5 Nb pressure tube alloy between 25 and 800 degC

    International Nuclear Information System (INIS)

    Singh, R.N.; Kishore, R.; Sinha, T.K.; Banerjee, S.

    2000-10-01

    Tensile properties of zirconium-2.5 wt. % niobium pressure tube material were evaluated by uniaxial tension tests at temperatures between 25 and 800 degC and under strain-rates varying from 3.3 x 10 -5 to 3.3 x 10 -3 /s. Tests were carried out on specimens fabricated from the sections of finished (autoclaved) tubes as well as on those machined from the sections of cold worked (2 nd pilgered) tubes. Moreover, specimens fabricated from finished tubes belonging to twenty different heats were tested at 300 degC to study the heat to heat variation in tensile properties of this alloy. In order to study the effect of the crystallographic texture on the tensile properties, specimens oriented in longitudinal as well as, in transverse directions of the tubes were also tested. Results showed that both yield and ultimate tensile strengths of this alloy decreased monotonically with increasing test temperatures, with a rapid fall in strengths above a temperature of 350 degC (623 K). The tensile ductility did not change appreciably up to 400 degC (673K) but increased rapidly above this temperature. The observed results on the temperature dependence of the strength and ductility indicated the possible occurrence of dynamic strain-ageing in this alloy in the temperature range of 200-300 degC (473 to 573 K). The transverse specimens showed higher strengths and lower ductility as compared to those of the longitudinal specimens up to a temperature of 350 degC (623 K). Above 350 degC, the difference in the strengths and the ductility of the two types of the specimens, became negligibly small indicating that the texture did not appreciably influence the tensile properties of this alloy at temperatures exceeding 350 degC. The alloy developed extensive superplasticity (ductility exceeding 100 %), when tested in the temperature range of 650-800 degC. Maximum ductility values of 650 % for longitudinal and 900 % for the transverse orientation with strain-rate sensitivity (m) exceeding 0.5

  16. Microstructure and properties of hot extruded Mg-3Zn-Y-xCu (x = 0, 1, 3, 5) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bao-sheng; Kuang, Ya-fei; Fang, Da-qing; Chai, Yue-sheng [Taiyuan Univ. of Science and Technology (China). College of Materials Science and Engineering; Taiyuan Univ. of Science and Technology (China). Engineering Research Center for Magnesium Alloys of Shanxi Province; Zhang, Yue-zhong [Taiyuan Univ. of Science and Technology (China). Engineering Research Center for Magnesium Alloys of Shanxi Province; Taiyuan Univ. of Science and Technology (China). College of Chemical and Biological Engineering

    2017-04-15

    In petroleum drilling engineering, materials with high strength and rapid degradation are required for degradable fracturing ball applications. In this work, the microstructure, mechanical properties, and corrosion behavior of extruded Mg-3Zn-Y-xCu (x = 0, 1, 3, 5 weight percent) alloys are investigated using optical microscopy, scanning electronic microscopy equipped with energy dispersive X-ray spectroscopy, X-ray diffraction, transmission electronic microscopy, compression tests, electrochemical measurements, and hydrogen evolution tests, to explore their potential as excellent candidate alloys for degradable fracturing ball applications. It is found that the Mg-3Zn-Y alloy is mainly composed of α-Mg, Mg{sub 3}Zn{sub 3}Y{sub 2}, and Mg{sub 3}Zn{sub 6}Y phases. After Cu addition, a new MgZnCu phase is formed, while the Mg{sub 3}Zn{sub 3}Y{sub 2} phase disappears. The Mg-3Zn-Y-3Cu alloy shows the highest compressive strength (473 MPa) and yield strength (402 MPa), mainly attributed to the combined effect of the fine-grain and dispersed precipitation of Mg{sub 3}Zn{sub 6}Y and MgZnCu. The corrosion rate of Mg-3Zn-Y-3Cu reaches 0.41 mm day{sup -1} in 3.5 wt.% KCl solution. Consequently, Mg-3Zn-Y-3Cu alloy is a suitable degradable fracturing ball-seat material.

  17. Superconductivity in REO0.5F0.5BiS2 with high-entropy-alloy-type blocking layers

    Science.gov (United States)

    Sogabe, Ryota; Goto, Yosuke; Mizuguchi, Yoshikazu

    2018-05-01

    We synthesized new REO0.5F0.5BiS2 (RE: rare earth) superconductors with high-entropy-alloy-type (HEA-type) REO blocking layers. The lattice constant a systematically changed in the HEA-type samples with the RE concentration and the RE ionic radius. A sharp superconducting transition was observed in the resistivity measurements for all the HEA-type samples, and the transition temperature of the HEA-type samples was higher than that of typical REO0.5F0.5BiS2. The sharp superconducting transition and the enhanced superconducting properties of the HEA-type samples may indicate the effectiveness of the HEA states of the REO blocking layers in the REO0.5F0.5BiS2 system.

  18. High-temperature deformation of a mechanically alloyed niobium-yttria alloy

    International Nuclear Information System (INIS)

    Chou, I.; Koss, D.A.; Howell, P.R.; Ramani, A.S.

    1997-01-01

    Mechanical alloying (MA) and hot isostatic pressing have been used to process two Nb alloys containing yttria particles, Nb-2 vol.%Y 2 O 3 and Nb-10 vol.%Y 2 O 3 . Similar to some thermomechanically processed nickel-based alloys, both alloys exhibit partially recrystallized microstructures, consisting of a 'necklace' of small recrystallized grains surrounding much larger but isolated, unrecrystallized, cold-worked grains. Hot compression tests from 1049 to 1347 C (0.5-0.6T MP ) of the 10% Y 2 O 3 alloy show that MA material possesses a much higher yield and creep strength than its powder-blended, fully recrystallized counterpart. In fact, the density-compensated specific yield strength of the MA Nb-10Y 2 O 3 exceeds that of currently available commercial Nb alloys. (orig.)

  19. Effects of solution heat treatment on the microstructure and hardness of Mg-5Li-3Al-2Zn-2Cu alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li Jiqing; An Jiangmin; Qu Zhikun [Key Laboratory of Superlight Materials and Surface Technology (Harbin Engineering University), Ministry of Education, Harbin 150001 (China); Wu Ruizhi, E-mail: Ruizhiwu2006@yahoo.com [Key Laboratory of Superlight Materials and Surface Technology (Harbin Engineering University), Ministry of Education, Harbin 150001 (China); Zhang Jinghuai; Zhang Milin [Key Laboratory of Superlight Materials and Surface Technology (Harbin Engineering University), Ministry of Education, Harbin 150001 (China)

    2010-10-15

    The microstructure and hardness of Mg-5Li-3Al-2Zn-2Cu alloy were investigated both in the as-cast condition and after solution heat treatment at 330-390 deg. C for 5 h. The as-cast alloy contains a microstructure consisting of {alpha}-Mg matrix, AlLi phase, AlCuMg phase and Al{sub 2}Cu phase. After the solution heat treament, the AlLi phase was dissolved into the matrix, however, the AlCuMg and Al{sub 2}Cu phases were not dissolved. With the increase of solution temperature, almost all the AlLi phase was dissolved, and the effects of solution strengthening of Al and Li atoms in the alloy increase, which results in the gradual increase of the Brinell hardness of the solution-treated alloy.

  20. WC-3015 alloy (high-temperature alloy)

    International Nuclear Information System (INIS)

    Anon.

    1974-01-01

    WC-3015 Nb alloy containing 28 to 30 Hf, 1 to 2 Zr, 13 to 16 W, 0 to 4 Ta, 0 to 5 Ti, 0.07 to 0.33 C, less than or equal to 0.02 N, less than or equal to 0.03 O, less than or equal to 0.001 H was developed for use at high temperature in oxidizing environments. Its composition can be tailored to meet specific requirements. When WC-3015 is exposed to O at elevated temperature, Hf and Nb oxidized preferentially and HfO 2 dissolves in Nb 2 O 5 to form 6HfO-Nb 2 O 5 . This complex oxide has a tight cubic lattice which resists the diffusion of O into the substrate. During 24-h exposure to air at 2400 0 F, the alloy oxidizes to a depth of approximately 0.035 in. with a surface recession of 0 to 0.004 in. Oxidation resistance of WC-3015 welds and base material can be further enhanced greatly by applying silicide coatings. WC-3015 alloy can be machined by conventional and electrical-discharge methods. It can be hot worked readily by extrusion, forging or rolling. Cold working can be used at room or elevated temperature. It can be welded by the electron-beam or Tig processes. Physical constants, typical mechanical properties at 75 to 2400 0 F, and effects of composition and heat treatment on tensile and stress-rupture properties of the alloy are tabulated

  1. The variation of work hardening characteristics of Al-5 wt% Mg alloy during phase transition

    International Nuclear Information System (INIS)

    Mahmoud, M.A.; Sobhy, M.; Abd El-Rehim, A.F.; Abdel Rahman, R.M.

    2010-01-01

    The aim of this study is to investigate the effect of aging conditions on the stress-strain behavior along with microstructure changes of the Al-5 wt% Mg alloy. Following solid solution treatment and aging of specimens at temperatures ranging from 373 to 573 K for various aging times (1/4 to 4 h), stress-strain tests were performed at different testing temperatures (313-343 K). The work hardening parameters (σ y , σ f , χ p and Y) were found to decrease continuously with pre-aging times at all aging and testing temperatures, where the softening parameters (ε f and L) oppose this behavior. The variation in stress-strain parameters with increasing aging temperatures and aging times was explained on the basis of structural transformations taking place in the Al-Mg alloy. A precipitate-dislocation intersections mechanism was assumed as the rate-controlling mechanism for alloy.

  2. A novel stabilization condition for T-S polynomial fuzzy system with time-delay:A sum-of-squares approach

    OpenAIRE

    Tsai, Shun Hung; Chen, Yu-An; Chen, Yu-Wen; Lo, Ji-Chang; Lam, Hak-Keung

    2017-01-01

    A novel stabilization problem for T-S polynomial fuzzy system with time-delay is investigated in this paper. Firstly, a polynomial fuzzy controller for T-S polynomial fuzzy system with time-delay is proposed. In addition, based on polynomial Lyapunov-Krasovskii function and the developed polynomial slack variable matrices, a novel stabilization condition for T-S polynomial fuzzy system with time-delay is presented in terms of sum-of-square (SOS) form. Lastly, nonlinear system with time-delay ...

  3. Adrenalectomy for Cushing's syndrome: do's and don'ts.

    Science.gov (United States)

    Paduraru, D N; Nica, A; Carsote, M; Valea, A

    2016-01-01

    Aim. To present specific aspects of adrenalectomy for Cushing's syndrome (CS) by introducing well established aspects ("do's") and less known aspects ("don'ts"). Material and Method. This is a narrative review. Results. The "do's" for laparoscopic adrenalectomy (LA) are the following: it represents the "gold standard" for secretor and non-secretor adrenal tumors and the first line therapy for CS with an improvement of cardio-metabolic co-morbidities; the success rate depending on the adequate patients' selection and the surgeon's skills. The "don'ts" are large (>6-8 centimeters), locally invasive, malignant tumors requiring open adrenalectomy (OA). Robotic adrenalectomy is a new alternative for LA, with similar safety and conversion rate and lower pain drugs use. The "don'ts" are the following: lack of randomized controlled studies including oncologic outcome, different availability at surgical centers. Related to the sub-types of CS, the "do's" are the following: adrenal adenomas which are cured by LA, while adrenocortical carcinoma (ACC) requires adrenalectomy as first line therapy and adjuvant mitotane therapy; synchronous bilateral adrenalectomy (SBA) is useful for Cushing's disease (only cases refractory to pituitary targeted therapy), for ectopic Cushing's syndrome (cases with unknown or inoperable primary site), and for bilateral cortisol producing adenomas. The less established aspects are the following: criteria of skilled surgeon to approach ACC; the timing of surgery in subclinical CS; the need for adrenal vein catheterization (which is not available in many centers) to avoid unnecessary SBA. Conclusion. Adrenalectomy for CS is a dynamic domain; LA overstepped the former OA area. The future will improve the knowledge related to RA while the cutting edge is represented by a specific frame of intervention in SCS, children and pregnant women. Abbreviations: ACC = adrenocortical carcinoma, ACTH = Adrenocorticotropic Hormone, CD = Cushing's disease, CS

  4. Microstrucural characterization of gas atomized Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} and Fe{sub 97}Si{sub 3} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Escorial, A., E-mail: age@cenim.csic.es [CENIM-CSIC, Avda. Gregorio del Amo, 8, 28040 Madrid (Spain); Lieblich, M. [CENIM-CSIC, Avda. Gregorio del Amo, 8, 28040 Madrid (Spain); Lopez, M.; Marin, P. [Instituto de Magnetismo Aplicado, P.O. Box 155, 28230 Madrid (Spain)

    2011-06-15

    Research highlights: > Two FeSi-base alloys as precursors for small dimension soft magnets. > Small particles rapidly solidified by gas atomisation. > Increase effective magnetic anisotropy constant by alloying segregation. > Magnetic hardenning due to volume decrease. - Abstract: Powder particles of Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} and Fe{sub 97}Si{sub 3} soft magnetic alloys have been prepared by gas atomization. The gas atomized powder was microstructurally characterized and the dependence of coercivity with the composition and powder particle size investigated. As-atomized powder particles of both compositions were constituted by a bcc {alpha}-Fe (Si) solid solution. The Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} powder particles presented a grain microstructure with dendrite structure, which dendrite arms were enriched in Nb. The coercivity increased as the particle size decreased, with a minimum coercivity, of 5 Oe, measured in the Fe{sub 97}Si{sub 3} alloy in the range of 50-100 {mu}m powder particle size. The coercive fields were quite higher in the Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} than in the Fe{sub 97}Si{sub 3} powder, due to the Nb addition, which produced a phase segregation that leads to a noticeable magnetic hardening.

  5. Moessbauer and X-ray Study of Fe{sub 1-x}Al{sub x}, 0.2{<=}x{<=}0.5, Samples Produced by Mechanical Alloying

    Energy Technology Data Exchange (ETDEWEB)

    Oyola Lozano, D., E-mail: doyola@ut.edu.co; MartInez, Y. Rojas; Bustos, H.; Perez Alcazar, G. A. [Universidad del Tolima, Departamento de Fisica (Colombia)

    2004-12-15

    In this work we report the magnetic and structural properties obtained by Moessbauer spectroscopy and X-ray diffraction, of the Fe{sub 1-x}Al{sub x}, 0.2{<=}x{<=}0.5, alloys produced by mechanical alloying. Alloys with x=0.2, 0.3, 0.4 and 0.5, were for milled 12, 24, 36, and 48 hours. All the obtained alloys are in the bcc phase. The obtained Moessbauer spectra are characteristic of disordered ferromagnetic system. The lattice parameter remains nearly constant ({approx}2.91 A) for all the milling times and compositions. The mean grain sizes in the (110) and (211) direction are nearly constants with the milling time but vary from 15.5 to 11 nm and from 10.5 to 8.5 nm when Al content grow between x=0.2 to x=0.4, respectively. The difference between the mean grain sizes in these two directions shows that the grains are of prolate spheroid form.

  6. Effect of Mn and Fe on the Formation of Fe- and Mn-Rich Intermetallics in Al–5Mg–Mn Alloys Solidified Under Near-Rapid Cooling

    Science.gov (United States)

    Liu, Yulin; Huang, Gaoren; Sun, Yimeng; Zhang, Li; Huang, Zhenwei; Wang, Jijie; Liu, Chunzhong

    2016-01-01

    Mn was an important alloying element used in Al–Mg–Mn alloys. However, it had to be limited to a low level (Al–5Mg–Mn alloy with low Fe content (Al6(Fe,Mn) was small in size and amount. With increasing Mn content, intermetallic Al6(Fe,Mn) increased, but in limited amount. In high-Fe-containing Al–5Mg–Mn alloys (0.5 wt % Fe), intermetallic Al6(Fe,Mn) became the dominant phase, even in the alloy with low Mn content (0.39 wt %). Cooling rate played a critical role in the refinement of the intermetallics. Under near-rapid cooling, intermetallic Al6(Fe,Mn) was extremely refined. Even in the high Mn and/or high-Fe-containing alloys, it still demonstrated fine Chinese script structures. However, once the alloy composition passed beyond the eutectic point, the primary intermetallic Al6(Fe,Mn) phase displayed extremely coarse platelet-like morphology. Increasing the content of Fe caused intermetallic Al6(Fe,Mn) to become the primary phase at a lower Mn content. PMID:28787888

  7. Effect of Mn and Fe on the Formation of Fe- and Mn-Rich Intermetallics in Al-5Mg-Mn Alloys Solidified Under Near-Rapid Cooling.

    Science.gov (United States)

    Liu, Yulin; Huang, Gaoren; Sun, Yimeng; Zhang, Li; Huang, Zhenwei; Wang, Jijie; Liu, Chunzhong

    2016-01-29

    Mn was an important alloying element used in Al-Mg-Mn alloys. However, it had to be limited to a low level (Al-5Mg-Mn alloy with low Fe content (Al₆(Fe,Mn) was small in size and amount. With increasing Mn content, intermetallic Al₆(Fe,Mn) increased, but in limited amount. In high-Fe-containing Al-5Mg-Mn alloys (0.5 wt % Fe), intermetallic Al₆(Fe,Mn) became the dominant phase, even in the alloy with low Mn content (0.39 wt %). Cooling rate played a critical role in the refinement of the intermetallics. Under near-rapid cooling, intermetallic Al₆(Fe,Mn) was extremely refined. Even in the high Mn and/or high-Fe-containing alloys, it still demonstrated fine Chinese script structures. However, once the alloy composition passed beyond the eutectic point, the primary intermetallic Al₆(Fe,Mn) phase displayed extremely coarse platelet-like morphology. Increasing the content of Fe caused intermetallic Al₆(Fe,Mn) to become the primary phase at a lower Mn content.

  8. Registration of melting and crystallization process of MCMgLi8Ca5 alloy with use of ATND method

    Directory of Open Access Journals (Sweden)

    J. Pezda

    2009-04-01

    Full Text Available Among lightweight metal alloys, magnesium is the lightest structural material with density of 1.74 g/cm3, having many attractive physical and mechanical properties combined with processing advantages. Therefore, it represents very attractive material for large amountof applications starting from automotive industry as the main user, up to other industry fields like sports, robotic electronics, armaments, and textile ones, or production of audio-video equipment. Furthermore, addition of lithium, that has density of 0,53 g/cm3, reduces density of the resulting Mg-Li alloys to the same level as polymeric materials. On metallic matrix of magnesium alloys with lithium are also manufactured composites reinforced with e.g. ceramic fiber, which are used as a lightweight and resistant structure materials. Therefore, Mg-Li alloys become an alternative material assuring low density, improved ductility and corrosion resistance.The paper presents an attempt of implementation of the ATND method to monitoring of crystallization process of MCMgLi8Ca5 alloys.Investigated magnesium alloys were produced in the Foundry Research Institute. Registration of melting and crystallization processes wasmade with use of the ATND method. Results of the preliminary tests are shown in a graphical form.

  9. Development of heat treated Zr-2.5% Nb alloy tubes for pressure tubes

    International Nuclear Information System (INIS)

    Saibaba, N.; Jha, S.K.; Tonpe, S.

    2011-01-01

    Zr-2.5% Nb alloy is the candidate material for pressure tubes of Pressurized Heavy Water Reactors (PHWR), and are manufactured in cold working condition while heat treated pressure tubes are used in RBMK and FUGEN type of reactors. The diametral creep of these tubes is the life limiting factor. This paper presents the extensive work carried out for the optimization of process parameters to manufacture heat treated Zr-2.5% Nb pressure tubes. Extensive dilactometry study was carried out to establish the transus temperature for the alloy and the effect of soaking temperature and cooling rate on the microstructure was characterized. On the basis of the study, water quenching (at 883 deg C) in the a b region with 20-25% primary a phase was selected, further cold worked, aged and finally autoclaved. Mechanical properties of the finished tubes were found to be comparable to the cold worked route. Large number of full sized tubes of about 700 - 800 mm long was produced to establish the repeatability. (author)

  10. Atomistic study on the interaction of nitrogen and Mg lattice and the nitride formation in nanocrystalline Mg alloys synthesized using cryomilling process

    International Nuclear Information System (INIS)

    Nezafati, Marjan; Giri, Anit; Hofmeister, Clara; Cho, Kyu; Schneider, Matthew M.; Zhou, Le; Sohn, Yongho; Kim, Chang-Soo

    2016-01-01

    Cryomilling is a broadly applied technique to synthesize nanostructured alloys and composites through powder metallurgy (PM) processing. Understanding the interactions between liquid nitrogen and the nanostructured metal powder is important as it can potentially impact the mechanical performance of these materials. In this study, we performed a series of ab initio density functional theory (DFT) computations to examine the interactions of liquid nitrogen and Mg-based matrices and the formation of Mg-nitrides. The diffusion energy barriers of nitrogen in the Mg and/or Mg-Al alloys were systematically quantified by calculating the transition state (TS) for the displacement of nitrogen between two neighboring equivalent positions. The TS calculation results indicate that diffusion of N atoms is much easier than that of N 2  molecule in the Mg matrix. It is predicted that at least ∼0.4 eV is required to overcome the diffusion energy barrier in the Mg matrix. We also quantified the formation energy of Mg nitride in the matrix. The presence of Mg nitride was demonstrated experimentally using transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS). In conjunction with the DFT computations and TEM/EELS analysis, we performed analytical calculations for the strain energy introduced during cryomilling to examine the impacts of processing parameters.

  11. Microstructures and room temperature fracture toughness of Nb/Nb5Si3 composites alloyed with W, Mo and W–Mo fabricated by spark plasma sintering

    International Nuclear Information System (INIS)

    Xiong, Bowen; Cai, Changchun; Wang, Zhenjun

    2014-01-01

    Highlights: • Microstructure of Nb/Nb 5 Si 3 composite alloyed with W and Mo is change obviously. • W and Mo elements can solid solution in Nb and Nb 5 Si 3 phase respectively. • Alloyed with W and Mo together, the solid solubility of Nb 5 Si 3 phases is undetected. • The Nb/Nb 5 Si 3 composite alloyed with W and Mo together has high fracture toughness. - Abstract: Microstructures and room temperature fracture toughness of Nb/Nb 5 Si 3 composites alloyed with W, Mo and W–Mo fabricated by spark plasma sintering were investigated. The microstructures were examined using scanning electron microscope (SEM). X-ray diffraction (XRD) was performed on the bulk specimens for identification of phases. The chemical species were analyzed using electron-probe micro-analysis (EPMA). Results indicated that the microstructures of Nb/Nb 5 Si 3 composites alloyed with W or Mo is unaltered, including primary Nb and eutectic mixtures of Nb and Nb 5 Si 3 , and the coarse and fine eutectic mixtures. The W and Mo elements solid solution in Nb and Nb 5 Si 3 phase are detected. But that alloyed with W and Mo together, The microstructures are change obviously, including Nb phase, the solid solubility phases of W and Mo atoms in Nb, and the solid solubility phases of Nb atoms in W are also found, but the solid solubility phenomenon of Nb 5 Si 3 phases is not detected. The microhardness of Nb and Nb 5 Si 3 phases increases obviously because of solid solution strengthening. The Nb/Nb 5 Si 3 composite alloyed with W and Mo together hashing high fracture toughness is attributable to the big eutectic Nb and interface of eutectic phases, which can bear large deformation to absorb the crack energy and form the decohesion between eutectic phases

  12. Effect of texture on creep deformation behavior of Zr-2.5Nb alloy

    International Nuclear Information System (INIS)

    Guguloth, Krishna; Swaminathan, J.; Mitra, Rahul; Ghosh, R.N.; Singh, R.N.; Chakravartty, J.K.

    2016-01-01

    Zr-2.5%Nb alloys are extensively used as high temperature pressure tubes in nuclear reactor. Therefore creep behavior of this alloy is of considerable importance. The paper presents creep strain-time plots on two sets of specimens made from two as received pressure tubes having different diameters. These tubes were reported to have undergone different processing routes; both tubes were autoclaved at the same temperature in the steam atmosphere. A comparison of the creep strain-time plots of the two sets of specimen under identical test conditions showed a marked difference. The chemical composition and the microstructure of the two sets of samples were also found to be similar. Therefore X-ray diffraction patterns were taken from the two tubes. The ratio of intensity of two prominent reflections from 0002 and 1120 planes of alpha Zr in the case of 90mm tube was found to be 1.79; whereas that from the 110mm tube was 0.25. This suggests that in the case of 110mm tube most of the basal planes were less favorably oriented with respect to the loading axis. This is the reason why creep strength of 110mm tube was found to be higher. The paper also describes how the effect of texture can be incorporated in evaluating the creep behavior of Zr-Nb alloy. This suggests that a relatively larger volume of creep test data on Zr-2.5Nb pressure tube is necessary to account for the effect texture so that a reliable estimate of its creep life could be obtained. (author)

  13. Interstitial lung disease caused by TS-1: a case of long-term drug retention as a fatal adverse reaction.

    Science.gov (United States)

    Park, Joong-Min; Hwang, In Gyu; Suh, Suk-Won; Chi, Kyong-Choun

    2011-12-01

    TS-1 is an oral anti-cancer agent for gastric cancer with a high response rate and low toxicity. We report a case of long-term drug retention of TS-1 causing interstitial lung disease (ILD) as a fatal adverse reaction. A 65-year-old woman underwent a total gastrectomy with pathologic confirmation of gastric adenocarcinoma. She received 6 cycles of TS-1 and low-dose cisplatin for post-operative adjuvant chemotherapy followed by single-agent maintenance therapy with TS-1. After 8 months, the patient complained of a productive cough with sputum and mild dyspnea. A pulmonary evaluation revealed diffuse ILD in the lung fields, bilaterally. In spite of discontinuing chemotherapy and the administration of corticosteroids, the pulmonary symptoms did not improve, and the patient died of pulmonary failure. TS-1-induced ILD can be caused by long-term drug retention that alters the lung parenchyma irreversibly, the outcome of which can be life-threatening. Pulmonary evaluation for early detection of disease is recommended.

  14. Microstructure and Tensile Properties of Sn-1Ag-0.5Cu Solder Alloy Bearing Al for Electronics Applications

    Science.gov (United States)

    Shnawah, Dhafer Abdul-Ameer; Said, Suhana Binti Mohd; Sabri, Mohd Faizul Mohd; Badruddin, Irfan Anjum; Hoe, Teh Guan; Che, Fa Xing; Abood, Adnan Naama

    2012-08-01

    This work investigates the effects of 0.1 wt.% and 0.5 wt.% Al additions on bulk alloy microstructure and tensile properties as well as on the thermal behavior of Sn-1Ag-0.5Cu (SAC105) lead-free solder alloy. The addition of 0.1 wt.% Al reduces the amount of Ag3Sn intermetallic compound (IMC) particles and leads to the formation of larger ternary Sn-Ag-Al IMC particles. However, the addition of 0.5 wt.% Al suppresses the formation of Ag3Sn IMC particles and leads to a large amount of fine Al-Ag IMC particles. Moreover, both 0.1 wt.% and 0.5 wt.% Al additions suppress the formation of Cu6Sn5 IMC particles and lead to the formation of larger Al-Cu IMC particles. The 0.1 wt.% Al-added solder shows a microstructure with coarse β-Sn dendrites. However, the addition of 0.5 wt.% Al has a great effect on suppressing the undercooling and refinement of the β-Sn dendrites. In addition to coarse β-Sn dendrites, the formation of large Sn-Ag-Al and Al-Cu IMC particles significantly reduces the elastic modulus and yield strength for the SAC105 alloy containing 0.1 wt.% Al. On the other hand, the fine β-Sn dendrite and the second-phase dispersion strengthening mechanism through the formation of fine Al-Ag IMC particles significantly increases the elastic modulus and yield strength of the SAC105 alloy containing 0.5 wt.% Al. Moreover, both 0.1 wt.% and 0.5 wt.% Al additions worsen the elongation. However, the reduction in elongation is much stronger, and brittle fracture occurs instead of ductile fracture, with 0.5 wt.% Al addition. The two additions of Al increase both solidus and liquidus temperatures. With 0.5 wt.% Al addition the pasty range is significantly reduced and the differential scanning calorimetry (DSC) endotherm curve gradually shifts from a dual to a single endothermic peak.

  15. Magnetocaloric effect of Gd 5 Si 2 Ge 2 alloys in low magnetic field

    Indian Academy of Sciences (India)

    The magnetocaloric effect (MCE) is studied by measuring magnetic entropy change ( M) and adiabatic temperature change ( ad) in a magnetic field of 1.5 T using a vibrating sample magnetometer (VSM) and a home-made magnetocaloric effect measuring apparatus, respectively. The maximum M of the alloys ...

  16. Effect of Zn on the microstructure and mechanical properties of as-cast Mg–7Gd–3Y–1Nd–0.5Zr alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, M.; Zhang, K., E-mail: zhkui@grinm.com; Li, X.G.; Yuan, J.W.; Li, Y.J.; Ma, M.L.; Shi, G.L.; Li, T.; Liu, J.B.

    2015-06-25

    The microstructure and mechanical properties of as-cast Mg–7Gd–3Y–1Nd–xZn–0.5Zr (x=0, 0.5, 1 and 2 wt%) alloys have been investigated by optical microscopy (OM), scanning electron microscopy equipped with energy dispersive spectrum, transmission electron microscopy (TEM), X-ray diffraction and tensile tests at room temperature (RT). Experimental results reveal that the microstructure of the alloy without Zn contains α-Mg and Mg{sub 5}RE phase, the microstructure of the alloy with 0.5% Zn consists of α-Mg, (Mg, Zn){sub 3}RE phase, Mg{sub 5}(RE, Zn) phase and stacking fault. The addition of 1% and 2% Zn results in the disappearance of the Mg{sub 5}(RE, Zn) phase, but the stacking fault can be seen more clearly. Moreover, a new block-like long period stacking ordered (LPSO) phase is observed in grain boundaries with increasing Zn content up to 2%. TEM analyses indicate that the Mg{sub 5}RE, (Mg, Zn){sub 3}RE and Mg{sub 5}(RE, Zn) phases have a face-centered cubic (f.c.c.) structure with lattice constants of 2.22 nm, 0.73 nm and 2.23 nm, respectively. The new block-like LPSO phase belongs to 10H-type. The tensile tests at RT exhibit that the alloy containing 1% Zn shows the optimal mechanical properties and the ultimate tensile strength (UTS), yield strength (YS) and elongation are 187 MPa, 145 MPa and 3.1%, respectively. As indicated by fracture analyses, the fracture modes of the alloys with 0% and 0.5% Zn are typically intercrystalline fracture, whereas both intercrystalline and transcrystalline fractures are observed in the alloys with 1% and 2% Zn.

  17. Amorphous and nanocrystalline fraction calculus for the Fe{sub 73.5}Si{sub 3.5}Ge{sub 10}Nb{sub 3}B{sub 9}Cu{sub 1} alloy

    Energy Technology Data Exchange (ETDEWEB)

    Muraca, D. [Laboratorio de Solidos Amorfos, Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires (Argentina); Moya, J. [Laboratorio de Solidos Amorfos, Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires (Argentina); Carrera del Investigador, CONICET (Argentina); Cremaschi, V.J. [Laboratorio de Solidos Amorfos, Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires (Argentina) and Carrera del Investigador, CONICET (Argentina)]. E-mail: vcremas@fi.uba.ar; Sirkin, H.R.M. [Laboratorio de Solidos Amorfos, Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires (Argentina); Carrera del Investigador, CONICET (Argentina)

    2007-09-01

    We studied the relationship between the saturation magnetization (M {sub S}) of the Fe{sub 73.5}Si{sub 3.5}Ge{sub 10}Nb{sub 3}B{sub 9}Cu{sub 1} alloy and its nanocrystalline structure. Amorphous ribbons obtained by the melt spinning technique were heat-treated for 1 h at different temperatures. The optimal treatment to obtain a homogeneous structure of Fe{sub 3}(Si,Ge) nanocrystals with a grain size of around 10 nm embedded in an amorphous matrix involved heating at 540 C for 1 h. We calculated the magnetic contribution of the nanocrystals to the heat treated alloy using a linear model and measured the M {sub S} of the Fe{sub 73.5}Si{sub 3.5}Ge{sub 10}Nb{sub 3}B{sub 9}Cu{sub 1} nanocrystalline and of an amorphous alloy of the same composition of the amorphous matrix: Fe{sub 58}Si{sub 0.5}Ge{sub 3.5}Cu{sub 3}Nb{sub 9}B{sub 26}. Using experimental data and theoretical calculations, we obtained the amorphous and crystalline fraction of the heat-treated ribbons.

  18. Nickel alloys and high-alloyed special stainless steels. Properties, manufacturing, applications. 4. compl. rev. ed.

    International Nuclear Information System (INIS)

    Heubner, Ulrich; Kloewer, Jutta; Alves, Helena; Behrens, Rainer; Schindler, Claudius; Wahl, Volker; Wolf, Martin

    2012-01-01

    This book contains the following eight topics: 1. Nickel alloys and high-alloy special stainless steels - Material overview and metallurgical principles (U. Heubner); 2. Corrosion resistance of nickel alloys and high-alloy special stainless steels (U. Heubner); 3. Welding of nickel alloys and high-alloy special stainless steels (T. Hoffmann, M. Wolf); 4. High-temperature materials for industrial plant construction (J. Kloewer); 5. Nickel alloys and high-alloy special stainless steels as hot roll clad composites-a cost-effective alternative (C. Schindler); 6. Selected examples of the use of nickel alloys and high-alloy special stainless steels in chemical plants (H. Alves); 7. The use of nickel alloys and stainless steels in environmental engineering (V. Wahl); 8: Nickel alloys and high-alloy special stainless steels for the oil and gas industry (R. Behrens).

  19. Study of the corrosion behavior and the corrosion films formed on the surfaces of Mg–xSn alloys in 3.5 wt.% NaCl solution

    International Nuclear Information System (INIS)

    Wang, Jingfeng; Li, Yang; Huang, Song; Zhou, Xiaoen

    2014-01-01

    Highlights: • Corrosion of four cast Mg–xSn alloys in 3.5 wt.% NaCl solution was investigated. • Both Mg(OH) 2 /SnO 2 corrosion product film and Mg(OH) 2 /MgSnO 3 clusters formed on Mg–1.5Sn. • Compact Mg(OH) 2 /MgSnO 3 film suppressed the cathodic effect of the impurity inclusions. • Mg–xSn (x = 0.5, 1.0, 2.0 wt.%) alloys only formed loose Mg(OH) 2 /SnO 2 corrosion product film. - Abstract: The corrosion behavior and the corrosion films formed on the surfaces of Mg–xSn (x = 0.5, 1.0, 1.5, and 2.0 wt.%) alloys in 3.5 wt.% NaCl solution were investigated by immersion tests, electrochemical measurements, corrosion morphology observations, and X-ray diffraction analysis. Immersion tests and electrochemical measurements illustrated that the best corrosion resistance was reported for the Mg–1.5Sn alloy. Both Mg(OH) 2 /SnO 2 corrosion product film and Mg(OH) 2 /MgSnO 3 clusters formed on Mg–1.5Sn alloy surface. Mg(OH) 2 /MgSnO 3 clusters were compact and suppressed the cathodic effect of the impurity inclusions greatly. The Mg–xSn (x = 0.5, 1.0, and 2.0 wt.%) alloys only formed loose Mg(OH) 2 /SnO 2 corrosion product film during the corrosion process

  20. Study on improved tribological properties by alloying copper to CP-Ti and Ti–6Al–4V alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Song [Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Ma, Zheng [Institute of Metal Research, Chinese Academy of Science, Shenyang 110016 (China); Liao, Zhenhua [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Song, Jian [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Yang, Ke [Institute of Metal Research, Chinese Academy of Science, Shenyang 110016 (China); Liu, Weiqiang, E-mail: weiqliu@hotmail.com [Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China)

    2015-12-01

    Copper alloying to titanium and its alloys is believed to show an antibacterial performance. However, the tribological properties of Cu alloyed titanium alloys were seldom studied. Ti–5Cu and Ti–6Al–4V–5Cu alloys were fabricated in the present study in order to further study the friction and wear properties of titanium alloys with Cu additive. The microstructure, composition and hardness were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and hardness tester. The tribological behaviors were tested with ZrO{sub 2} counterface in 25% bovine serum using a ball-on-disc tribo-tester. The results revealed that precipitations of Ti{sub 2}Cu intermetallic compounds appeared in both Ti–5Cu and Ti–6Al–4V–5Cu alloys. The tribological results showed an improvement in friction and wear resistance for both Ti–5Cu and Ti–6Al–4V–5Cu alloys due to the precipitation of Ti{sub 2}Cu. The results also indicated that both CP-Ti and Ti–5Cu behaved better wear resistance than Ti–6Al–4V and Ti–6Al–4V–5Cu due to different wear mechanisms when articulated with hard zirconia. Both CP-Ti and Ti–5Cu revealed dominant adhesive wear with secondary abrasive wear mechanism while both Ti–6Al–4V and Ti–6Al–4V–5Cu showed severe abrasive wear and cracks with secondary adhesive wear mechanism due to different surface hardness integrated by their microstructures and material types. - Highlights: • Ti–5Cu and Ti–6Al–4V–5Cu alloys were fabricated with Cu additive. • Precipitations of Ti{sub 2}Cu intermetallic compounds appeared after alloying Cu. • The precipitation of Ti{sub 2}Cu improved both friction and wear resistance. • Plowing was the dominant material removal force with severe plowing phenomenon. • Different dominant and secondary wear mechanisms appeared with different hardness.

  1. Theatrical Style and the Work of T.S. Eliot.

    Science.gov (United States)

    Harris, Warren Meredith

    This study examines T.S. Eliot's intentions for the staging of his plays, as revealed in the texts themselves and in related documents. His plays reflect his basically naturalistic conception of the stage environment and the acting; two of the plays, "Sweeney Agonistes," which was unfinished, and "The Family Reunion," demonstrate his inability to…

  2. Influence of Al addition on the thermal stability and mechanical properties of Fe76.5-xCu1Si13.5b9Alx amorphous alloys

    Directory of Open Access Journals (Sweden)

    Sun Y.Y.

    2012-01-01

    Full Text Available This paper fabricated Fe76.5-xCu1Si13.5B9Alx (x=0,1,2,3,5,7 at.% amorphous ribbons using singleroller melt-spinning method. The effect of Al content on the thermal stability and mechanical properties was investigated. The results indicated that Al addition have little effect on the amorphous formation ability of the alloys. On the other hand, increasing the Al content can substantially increase Tx2, which corresponds to the crystallization of Fe borides. Nanoindentation tests indicated that hardness of the alloys increase slightly with increasing the Al content, and Young’s modulus has a complicated relationship with the Al content.

  3. Synthesis and characterization of Ti-27.5Nb alloy made by CLAD® additive manufacturing process for biomedical applications.

    Science.gov (United States)

    Fischer, M; Laheurte, P; Acquier, P; Joguet, D; Peltier, L; Petithory, T; Anselme, K; Mille, P

    2017-06-01

    Biocompatible beta-titanium alloys such as Ti-27.5(at.%)Nb are good candidates for implantology and arthroplasty applications as their particular mechanical properties, including low Young's modulus, could significantly reduce the stress-shielding phenomenon usually occurring after surgery. The CLAD® process is a powder blown additive manufacturing process that allows the manufacture of patient specific (i.e. custom) implants. Thus, the use of Ti-27.5(at.%)Nb alloy formed by CLAD® process for biomedical applications as a mean to increase cytocompatibility and mechanical biocompatibility was investigated in this study. The microstructural properties of the CLAD-deposited alloy were studied with optical microscopy and electron back-scattered diffraction (EBSD) analysis. The conservation of the mechanical properties of the Ti-27.5Nb material after the transformation steps (ingot-powder atomisation-CLAD) were verified with tensile tests and appear to remain close to those of reference material. Cytocompatibility of the material and subsequent cell viability tests showed that no cytotoxic elements are released in the medium and that viable cells proliferated well. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Uniform nanocrystalline AB{sub 5}-type hydrogen storage alloy: Preparation and properties as negative materials of Ni/MH battery

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Dongsheng; Li, Weishan; Hu, Shejun [Department of Chemistry, South China Normal University, 510631 (China); Xiao, Fangming; Tang, Renheng [Guangzhou Institute for Nonferrous Metal Research, 510651 (China)

    2006-05-15

    AB{sub 5}-type nanocrystalline hydrogen storage alloy was prepared by a twin-roll process. X-ray diffraction (XRD), scanning electron microscope (SEM), pressure-composition isotherms (PCT), and charge-discharge cycling were used to characterize its performances. The alloy has a hexagonal CaCu{sub 5}-type structure and a uniform crystallite size of about 40nm. It shows good high-rate discharge ability (HRD). The initial discharge capacity of the alloy is high up to 312mAh/g, and its capacity loss is low, only about 20% after 400 cycles under 640mA/g. At the discharge current density of 2000mA/g, the high-rate discharge ability (HRD) is 90% and the discharge capacity 211mAh/g after 400 cycles, 85% of the initial capacity. (author)

  5. VISIT-TS: A multimedia tool for population studies on tic disorders [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    M. Jonathan Vachon

    2016-10-01

    Full Text Available Population-based assessment of Tourette syndrome (TS and other tic disorders produces a paradox. On one hand, ideally diagnosis of tic disorders requires expert observation. In fact, diagnostic criteria for TS explicitly require expert assessment of tics for a definite diagnosis. On the other hand, large-scale population surveys with expert assessment of every subject are impracticable. True, several published studies have successfully used expert assessment to find tic prevalence in a representative population (e.g. all students in a school district. However, extending these studies to larger populations is daunting. We created a multimedia tool to demonstrate tics to a lay audience, discuss their defining and common attributes, and address features that differentiate tics from other movements and vocalizations. A first version was modified to improve clarity and to include a more diverse group in terms of age and ethnicity. The result is a tool intended for epidemiological research. It may also provide additional benefits, such as more representative minority recruitment for other TS studies and increased community awareness of TS.

  6. Teacher Salary Comparisons--Inter-City Differences: 2010-11 and 2011-12. BCTF Research Report. Section I. 2012-TS-02

    Science.gov (United States)

    White, Margaret

    2012-01-01

    This research report, which is an update of research report 2011-TS-03, shows the salary difference for each step of British Columbia's (BC) Category 5 or comparable qualifications. Salaries for Vancouver public school teachers are compared to teacher salaries in Toronto (elementary), Ottawa (secondary), and Edmonton. Salaries for Prince George…

  7. Preparation, heat treatment, and mechanical properties of the uranium-5 weight percent chromium eutectic alloy

    International Nuclear Information System (INIS)

    Townsend, A.B.

    1980-10-01

    The eutectic alloy of uranium-5 wt % chromium (U-5Cr) was prepared from high-purity materials and cast into 1-in.-thick ingots. This material was given several simple heat treatments, the mechanical properties of these heat-treated samples were determined; and the microstructure was examined. Some data on the melting point and transformation temperatures were obtained

  8. Processing and characterization of AlCoFeNiXTi{sub 0,5} (X = Mn, V) high entropy alloys; Processamento e caracterizacao de ligas de alta entropia AlCoFeNixTi{sub 0,5} (X = Mn, V)

    Energy Technology Data Exchange (ETDEWEB)

    Triveno Rios, C., E-mail: carlos.triveno@ufabc.edu.br [Universidade Federal do ABC (CECS/UFABC), Santo Andre, SP (Brazil). Engenharia de Materiais; Lopes, E.S.N.; Caram, R. [Universidade Estadual de Campinas (FEM/DEMA/UNICAMP), Campinas, SP (Brazil); Kiminami, C.S. [Universidade Federal de Sao Carlos (DEMa/UFSCar), Sao Carlos, SP (Brazil). Departamento de Engenharia de Materiais

    2014-07-01

    The microstructure of high entropy alloys consists of solid solution phases with FC and BCC simple structures, contrary to classical metallurgy where they form complex structures of intermetallic compounds. Because of this they have several attractive properties for engineering applications. In this work the AlCoFeNiMnTi{sub 0,5} and AlCoFeNiVTi{sub 0,5} alloys were processed by melting arc. Since the main objective was the microstructural and mechanical characterization of ingots as-cast. The alloys were characterized by scanning electron microscopy, X-ray diffraction, microhardness and cold compression test. The results showed that the microstructure consists mainly of dendrites and interdendritic regions consisting of metastable crystalline phases. It was also observed that the AlCoFeNiVTi{sub 0,5} alloy showed better mechanical properties than the AlCoFeNiMnTi{sub 0,5} alloy. This may be associated with differences in the parameters of formation of simple solid solution phases between the two alloys. (author)

  9. PLUTONIUM-ZIRCONIUM ALLOYS

    Science.gov (United States)

    Schonfeld, F.W.; Waber, J.T.

    1960-08-30

    A series of nuclear reactor fuel alloys consisting of from about 5 to about 50 at.% zirconium (or higher zirconium alloys such as Zircaloy), balance plutonium, and having the structural composition of a plutonium are described. Zirconium is a satisfactory diluent because it alloys readily with plutonium and has desirable nuclear properties. Additional advantages are corrosion resistance, excellent fabrication propenties, an isotropie structure, and initial softness.

  10. Effects of different casting mould cooling rates on microstructure and properties of sand-cast Al-7.5Si-4Cu alloy

    Directory of Open Access Journals (Sweden)

    Liu Guanglei

    2013-11-01

    Full Text Available In this work, Al-7.5Si-4Cu alloy melt modified by Al-10Sr, RE and Al-5Ti-B master alloys was poured into multi-step moulds made from three moulding sands, including quartz, alumina and chromite, to investigate comparatively the effects of different cooling rates of the casting mould on the alloy's microstructures and mechanical properties. The results show that with an increase in wall thickness, the cooling rate decreases, the dendrite arm spacing (DAS increases significantly and the mechanical properties decrease steadily. The elongation is more sensitive to the cooling rate than the tensile strength. No obvious trend of the effect of wall thickness on hardness of the alloy was found. When the cooling rate is at its greatest, the microstructures and mechanical properties are the best when using chromite sand. The improvement of the properties is mainly attributed to the decrease of the DAS, the grain refinement and the metamorphic effect. Each of the three has a strong impact on the microstructures. Furthermore, a series of fitting models was established based on the data of the DAS to predict the mechanical properties of the multivariate sand-cast Al-7.5Si-4Cu alloy.

  11. Evidence of a novel aggrecan-degrading activity in cartilage: Studies of mice deficient in both ADAMTS-4 and ADAMTS-5.

    Science.gov (United States)

    Rogerson, Fraser M; Stanton, Heather; East, Charlotte J; Golub, Suzanne B; Tutolo, Leonie; Farmer, Pamela J; Fosang, Amanda J

    2008-06-01

    To characterize aggrecan catabolism and the overall phenotype in mice deficient in both ADAMTS-4 and ADAMTS-5 (TS-4/TS-5 Delta-cat) activity. Femoral head cartilage from the joints of TS-4/TS-5 Delta-cat mice and wild-type mice were cultured in vitro, and aggrecan catabolism was stimulated with either interleukin-1alpha (IL-1alpha) or retinoic acid. Total aggrecan release was measured, and aggrecanase activity was examined by Western blotting using neoepitope antibodies for detecting cleavage at EGE 373-374 ALG, SELE 1279-1280 GRG, FREEE 1467-1468 GLG, and AQE 1572-1573 AGEG. Aggrecan catabolism in vivo was examined by Western blotting of cartilage that had been extracted immediately ex vivo. TS-4/TS-5 Delta-cat mice were viable, fertile, and phenotypically normal. TS-4/TS-5 Delta-cat cartilage explants did not release aggrecan in response to IL-1alpha, and there was no detectable increase in aggrecanase neoepitopes. TS-4/TS-5 Delta-cat cartilage explants released aggrecan in response to retinoic acid. There was no retinoic acid-stimulated cleavage at either EGE 373-374 ALG or AQE 1572-1573 AGEG. There was a low level of cleavage at SELE 1279-1280 GRG and major cleavage at FREEE 1467-1468 GLG. Ex vivo, cleavage at FREEE 1467-1468 GLG was substantially reduced, but still present, in TS-4/TS-5 Delta-cat mouse cartilage compared with wild-type mouse cartilage. An aggrecanase other than ADAMTS-4 and ADAMTS-5 is expressed in mouse cartilage and is up-regulated by retinoic acid but not IL-1alpha. The novel aggrecanase appears to have different substrate specificity from either ADAMTS-4 or ADAMTS-5, cleaving E-G bonds but not E-A bonds. Neither ADAMTS-4 nor ADAMTS-5 is required for normal skeletal development or aggrecan turnover in cartilage.

  12. Deformation Behavior of Reverse Deep Drawing of 5A06 Aluminum Alloy Plate

    Directory of Open Access Journals (Sweden)

    ZHANG Zhi-chao

    2017-09-01

    Full Text Available The limit drawing ratio is influenced by the bending and unbending effect during reverse deep drawing of plate. The 5A06 aluminum alloy plate widely applied in aerospace industry was used, and the reverse deep drawing of the 4.5mm thick plate was investigated experimentally and numerically. The stress and strain distributions of plate were analyzed, the deformation behaviour was discussed for three types of cross section of die during the reverse deep drawing process; moreover, the changing rule of strain paths with the die profile was also discussed. Results show that a maximum radial stress is induced by the bending effect at the transient region between the inside die radius and straight wall, where a radial stress and strain gradient along the thickness direction appears and the fracture is easy to occur. For the semi-circle profiled die structure, the limited punch stroke is 203mm which is increased by 40% than that for the die with a planar profile section. The semi-circle profiled die structure can reduce the bending effect, effectively reduce the stress gradient and the maximum stress value in the transient region, and is helpful to improve the limit drawing ratio of the 5A06 aluminum alloy plate.

  13. Microstructures and microhardness evolutions of melt-spun Al–8Ni–5Nd–4Si alloy

    International Nuclear Information System (INIS)

    Karaköse, Ercan; Keskin, Mustafa

    2012-01-01

    Al–Ni–Nd–Si alloy with nominal composition of Al–8 wt.%Ni–5 wt.%Nd–4 wt.%Si was rapidly solidified by using melt-spinning technique to examine the influence of the cooling rate/conditions on microstructure and mechanical properties. The resulting conventional cast (ingot) and melt-spun ribbons were characterized by X-ray diffraction, optical microscopy, scanning electron microscopy together with energy dispersive spectroscopy, differential scanning calorimetry, differential thermal analysis and Vickers microhardness tester. The ingot alloys consists of four phases namely α-Al, intermetallic Al 3 Ni, Al 11 Nd 3 and fcc Si. Melt-spun ribbons are completely composed of α-Al phase. The optical microscopy and scanning electron microscopy results show that the microstructures of rapidly solidified ribbons are clearly different from their ingot alloy. The change in microhardness is discussed based on the microstructural observations. - Highlights: ► Rapid solidification allows a reduction in grain size, extended solid solution ranges. ► We observed the matrix lattice parameter increases with increasing wheel speed. ► Melt-spun ribbons consist of partly amorphous phases embedded in crystalline phases. ► The solidification rate is high enough to retain most of alloying elements in the Al matrix. ► The rapid solidification has effect on the phase constitution.

  14. Equilibrium phase of high-entropy FeCoNiCrCu0.5 alloy at elevated temperature

    International Nuclear Information System (INIS)

    Lin, C.-M.; Tsai, H.-L.

    2010-01-01

    The phase transformations of FeCoNiCrCu 0.5 alloy with the as-cast structure and heat-treated structures were studied. The as-cast alloy specimens were first heated at 1050 o C with a holding time of 1 h. Serial heat-treatment processes at 350 o C, 500 o C, 650 o C, 800 o C, 950 o C, 1100 o C, 1250 o C and 1350 o C with a holding time of 24 h were then carried out to understand the phase evolution and the relationship between the microstructure and the hardness of the specimens. The microstructures were investigated and chemical analyses performed by optical microscopy (OM), scanning elector microscopy (SEM), X-ray diffractometer (XRD) and transmission elector microscopy (TEM). The results show that FCC peaks were observed from the X-ray diffraction of the as-cast specimens and a precipitate phase was present in the specimens that had been heated to 950 o C. The hardness of the FeCoNiCrCu 0.5 alloy remained unchanged in the specimens that underwent various heat treatments that were applied in this study.

  15. The effect of minor alloying elements on oxidation and hydrogen pickup in Zr-2.5Nb

    International Nuclear Information System (INIS)

    Ploc, R.A.

    2002-01-01

    In CANDU reactors, fuel and coolant are contained in horizontal pressure tubes made of Zr-2.5 wt% Nb alloy. In the past decade, the effect of more than 20 impurity elements, in various concentrations, on oxidation and deuterium pickup (at 300 o C, pD = 10.5, Li 2 O) have been investigated in over 70 Zr-2.5Nb alloys. The studies were performed using non-consumable arc-melted alloy logs that were rolled and made into corrosion coupons and corroded in autoclaves. This study represents one of the largest collections of previously unpublished data on the effect of impurity elements on oxide film growth and deuterium pickup in a zirconium alloy. Elements such as Al, Ti, Mn, and Pt, to name but a few, were found to significantly accelerate the corrosion process. Some elements, such as tin, had a positive effect on oxidation (lowers the rate of oxide film development) and a negative effect on hydrogen pickup (increases pickup). Three parameters were important to the corrosion process, namely, microstructure, surface finish, and synergistic interactions between the impurity elements. The above studies culminated in two response surface analyses (RSA). The first was conducted on the effect of C and Fe on oxygen and deuterium pickup in Zr-2.5Nb drop castings corroded at 325 o C in CANDU conditions. The second study was performed in autoclaves at 300 o C on the affect of four impurity elements, C, Fe, Cr, and Si, in Zr-2.5Nb micro-tubes, which possess the same microstructure as full-size pressure tubes. The first RSA revealed a quadratic dependence of corrosion on C and Fe concentrations, with an optimum resistance at about 30 ppm (wt) C and 1100 ppm (wt) Fe. This has been partially confirmed by out-reactor corrosion of Zr-2.5Nb-Fe micro-pressure tubes. Trends in- and out-reactor were similar for oxidation but different in magnitude for deuterium pickup. There is no linear dependence on the Fe concentration in-reactor, implying that Fe and C form a complex. The second RSA

  16. The effect of minor alloying elements on oxidation and hydrogen pickup in Zr-2.5Nb

    International Nuclear Information System (INIS)

    Ploc, R.A.

    2002-01-01

    In CANDU reactors, fuel and coolant are contained in horizontal pressure tubes made of Zr-2.5 wt% Nb alloy. In the past decade, the effect of more than 20 impurity elements, in various concentrations, on oxidation and deuterium pickup (at 300 deg C, pD = 10.5, Li 2 O) have been investigated in over 70 Zr-2.5Nb alloys. The studies were performed using non-consumable arc-melted alloy logs that were rolled and made into corrosion coupons and corroded in autoclaves. This study represents one of the largest collections of previously unpublished data on the effect of impurity elements on oxide film growth and deuterium pickup in a zirconium alloy. Elements such as Al, Ti, Mn, and Pt, to name but a few, were found to significantly accelerate the corrosion process. Some elements, such as tin, had a positive effect on oxidation (lowers the rate of oxide film development) and a negative effect on hydrogen pickup (increases pickup). Three parameters were important to the corrosion process, namely, microstructure, surface finish, and synergistic interactions between the impurity elements. The above studies culminated in two response surface analyses (RSA). The first was conducted on the effect of C and Fe on oxygen and deuterium pickup in Zr-2.5Nb drop castings corroded at 325 deg C in CANDU conditions. The second study was performed in autoclaves at 300 deg C on the affect of four impurity elements, C, Fe, Cr, and Si, in Zr-2.5Nb micro-tubes, which possess the same microstructure as full-size pressure tubes. The first RSA revealed a quadratic dependence of corrosion on C and Fe concentrations, with an optimum resistance at about 30 ppm (wt) C and 1100 ppm (wt) Fe. This has been partially confirmed by out-reactor corrosion of Zr-2.5Nb-Fe micro-pressure tubes. Trends in- and out-reactor were similar for oxidation but different in magnitude for deuterium pickup. There is no linear dependence on the Fe concentration in-reactor, implying that Fe and C form a complex. The second

  17. A hybrid GA-TS algorithm for open vehicle routing optimization of coal mines material

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.W.; Ding, C.; Zhu, K.J. [China University of Geoscience, Wuhan (China)

    2011-08-15

    In the open vehicle routing problem (OVRP), the objective is to minimize the number of vehicles and the total distance (or time) traveled. This study primarily focuses on solving an open vehicle routing problem (OVRP) by applying a novel hybrid genetic algorithm and the Tabu search (GA-TS), which combines the GA's parallel computing and global optimization with TS's Tabu search skill and fast local search. Firstly, the proposed algorithm uses natural number coding according to the customer demands and the captivity of the vehicle for globe optimization. Secondly, individuals of population do TS local search with a certain degree of probability, namely, do the local routing optimization of all customer sites belong to one vehicle. The mechanism not only improves the ability of global optimization, but also ensures the speed of operation. The algorithm was used in Zhengzhou Coal Mine and Power Supply Co., Ltd.'s transport vehicle routing optimization.

  18. Short-lived non-coding transcripts (SLiTs): Clues to regulatory long non-coding RNA.

    Science.gov (United States)

    Tani, Hidenori

    2017-03-22

    Whole transcriptome analyses have revealed a large number of novel long non-coding RNAs (lncRNAs). Although the importance of lncRNAs has been documented in previous reports, the biological and physiological functions of lncRNAs remain largely unknown. The role of lncRNAs seems an elusive problem. Here, I propose a clue to the identification of regulatory lncRNAs. The key point is RNA half-life. RNAs with a long half-life (t 1/2 > 4 h) contain a significant proportion of ncRNAs, as well as mRNAs involved in housekeeping functions, whereas RNAs with a short half-life (t 1/2 regulatory ncRNAs and regulatory mRNAs. This novel class of ncRNAs with a short half-life can be categorized as Short-Lived non-coding Transcripts (SLiTs). I consider that SLiTs are likely to be rich in functionally uncharacterized regulatory RNAs. This review describes recent progress in research into SLiTs.

  19. Grindability of cast Ti-Cu alloys.

    Science.gov (United States)

    Kikuchi, Masafumi; Takada, Yukyo; Kiyosue, Seigo; Yoda, Masanobu; Woldu, Margaret; Cai, Zhuo; Okuno, Osamu; Okabe, Toru

    2003-07-01

    The purpose of the present study was to evaluate the grindability of a series of cast Ti-Cu alloys in order to develop a titanium alloy with better grindability than commercially pure titanium (CP Ti), which is considered to be one of the most difficult metals to machine. Experimental Ti-Cu alloys (0.5, 1.0, 2.0, 5.0, and 10.0 mass% Cu) were made in an argon-arc melting furnace. Each alloy was cast into a magnesia mold using a centrifugal casting machine. Cast alloy slabs (3.5 mm x 8.5 mm x 30.5 mm), from which the hardened surface layer (250 microm) was removed, were ground using a SiC abrasive wheel on an electric handpiece at four circumferential speeds (500, 750, 1000, or 1250 m/min) at 0.98 N (100 gf). Grindability was evaluated by measuring the amount of metal volume removed after grinding for 1min. Data were compared to those for CP Ti and Ti-6Al-4V. For all speeds, Ti-10% Cu alloy exhibited the highest grindability. For the Ti-Cu alloys with a Cu content of 2% or less, the highest grindability corresponded to an intermediate speed. It was observed that the grindability increased with an increase in the Cu concentration compared to CP Ti, particularly for the 5 or 10% Cu alloys at a circumferential speed of 1000 m/min or above. By alloying with copper, the cast titanium exhibited better grindability at high speed. The continuous precipitation of Ti(2)Cu among the alpha-matrix grains made this material less ductile and facilitated more effective grinding because small broken segments more readily formed.

  20. The microstructures and electrochemical performances of La0.6Gd0.2Mg0.2Ni3.0Co0.5-xAlx (x=0-0.5) hydrogen storage alloys as negative electrodes for nickel/metal hydride secondary batteries

    Science.gov (United States)

    Li, Rongfeng; Xu, Peizhen; Zhao, Yamin; Wan, Jing; Liu, Xiaofang; Yu, Ronghai

    2014-12-01

    La0.6Gd0.2Mg0.2Ni3.0Co0.5-xAlx (x = 0-0.5) hydrogen storage alloys were prepared by induction melting followed by annealing treatment at 1173 K for 8 h. The effects of substitution Al for Co on the microstructures and electrochemical performances were studied systematically. The structure analyses show that all alloys consist of multiphase structures such as (La, Mg)2Ni7 phase, (La, Mg) Ni3 phase and LaNi5 phase. The abundance of (La, Mg)2Ni7 phase decreases while the abundance of LaNi5 phase and (La, Mg)Ni3 phase increases directly as the Al content increasing. The electrochemical tests show that the maximum discharge capacity of alloy electrodes are almost unchanged when x ≤ 0.2 while the cyclic stability of the alloy electrode are improved significantly after proper amount of Al substitution for Co. The alloy electrode with x = 0.1 exhibits the better balance between discharge capacity and cycling life than any others. Moreover, at the discharge current density of 900 mA g-1, the high rate dischargeability (HRD) of the alloy electrodes decreases with increasing Al substitution and the relative analyses reveal that the charge transfer on alloy surface is more important than the hydrogen diffusion in alloy bulk for the kinetic properties of the alloy electrodes.

  1. Microstructures and mechanical properties of Cu-Sn alloy subjected to elevated-temperature heat deformation

    Science.gov (United States)

    Hui, Jun; Feng, Zaixin; Fan, Wenxin; Wang, Pengfei

    2018-04-01

    Cu-Sn alloy was subjected to elevated-temperature isothermal compression with 0.01 s‑1 strain rate and 500 ∼ 700 °C temperature range. The thermal compression curve reflected a competing process of work hardening versus dynamic recovery (DRV) and recrystallization, which exhibited an obvious softening trend. Meanwhile, high-temperature deformation and microstructural features in different regions of the alloy was analyzed through EBSD. The results show that grains grow as the temperature rises, competition among recrystallization, substructural, and deformation regions tends to increase with the increase of temperature, and distribution frequency of recrystallization regions gradually increases and then drops suddenly at 650 °C. At 500 ∼ 550 °C, preferentially oriented texturing phenomenon occurs, low angle boundaries(LABs) are gradually transformed into high angle boundaries (HABs) and the Σ (CSL) boundaries turn gradually into Σ3 boundaries. In tensile test of tin bronze, elongation at break increases slowly, whereas yield strength (YS) and ultimate tensile strength (TS) decrease gradually.

  2. Attentional function and basal forebrain cholinergic neuron morphology during aging in the Ts65Dn mouse model of Down syndrome.

    Science.gov (United States)

    Powers, Brian E; Velazquez, Ramon; Kelley, Christy M; Ash, Jessica A; Strawderman, Myla S; Alldred, Melissa J; Ginsberg, Stephen D; Mufson, Elliott J; Strupp, Barbara J

    2016-12-01

    Individuals with Down syndrome (DS) exhibit intellectual disability and develop Alzheimer's disease-like neuropathology during the third decade of life. The Ts65Dn mouse model of DS exhibits key features of both disorders, including impairments in learning, attention and memory, as well as atrophy of basal forebrain cholinergic neurons (BFCNs). The present study evaluated attentional function in relation to BFCN morphology in young (3 months) and middle-aged (12 months) Ts65Dn mice and disomic (2N) controls. Ts65Dn mice exhibited attentional dysfunction at both ages, with greater impairment in older trisomics. Density of BFCNs was significantly lower for Ts65Dn mice independent of age, which may contribute to attentional dysfunction since BFCN density was positively associated with performance on an attention task. BFCN volume decreased with age in 2N but not Ts65Dn mice. Paradoxically, BFCN volume was greater in older trisomic mice, suggestive of a compensatory response. In sum, attentional dysfunction occurred in both young and middle-aged Ts65Dn mice, which may in part reflect reduced density and/or phenotypic alterations in BFCNs.

  3. A green surfactant-assisted synthesis of hierarchical TS-1 zeolites with excellent catalytic properties for oxidative desulfurization.

    Science.gov (United States)

    Du, Shuting; Li, Fen; Sun, Qiming; Wang, Ning; Jia, Mingjun; Yu, Jihong

    2016-02-25

    Hierarchical TS-1 zeolites with uniform intracrystalline mesopores have been successfully synthesized through the hydrothermal method by using the green and cheap surfactant Triton X-100 as the mesoporous template. The resultant materials exhibit remarkably enhanced catalytic activity in oxidative desulfurization reactions compared to the conventional TS-1 zeolite.

  4. Microstructure of AlSi17Cu5 alloy after overheating over liquidus temperature

    Directory of Open Access Journals (Sweden)

    J. Piątkowski

    2015-01-01

    Full Text Available The paper presents microstructure tests of alloy AlSi17Cu5. In order to disintegrate the primary grain of silicon the so-called time-temperature transformation TTT was applied which was based on overheating the liquid alloy way over the temperature Tliq., soaking in it for 30 minutes and casting it to a casting mould. It was found that such process causes the achievement of fine-crystalline structure and primary silicon crystals take up the form of pentahedra or frustums of pyramids. With the use of X-ray microanalysis and X-ray diffraction analysis the presence of intermetallic phases Al2Cu, Al4Cu9 which are the ingredients of eutectics α - AlCu - β and phase Al9Fe2Si which is a part of eutectic α - AlFeSi - β was confirmed.

  5. Effect of different post-treatments on the bioactivity of alkali-treated Ti-5Si alloy.

    Science.gov (United States)

    Hsu, Hsueh-Chuan; Wu, Shih-Ching; Hsu, Shih-Kuang; Liao, Yi-Hang; Ho, Wen-Fu

    2017-01-01

    As titanium (Ti) alloys are bioinert, various chemically-modified Ti surface has been developed to promote bioactivity and bone ingrowth. In this study, various post treatments (water aging, hydrothermal, and heat treatments) were applied to NaOH-treated Ti-5Si to improve its bioactivity. The bioactivity of surface-modified Ti-5Si was access by using the apatite formation ability of Ti-5Si surfaces soaking in a simulated body fluid (SBF). The results showed that the NaOH-treated surface formed a porous network structure composed of sodium titanate hydrogel, which was changed to sodium titanate after subsequent post treatments, whereas sodium titanate, anatase and rutile phases were found on the Ti-5Si surfaces after heat treatment. After immersion in SBF for 14 days, compact apatite layers were observed on the surfaces of all the Ti-5Si tested. The results of XRD and FTIR indicated that the apatite deposited on the Ti-5Si substrate with various surface modified conditions was carbonate-substituted hydroxyapatite. The apatite-forming ability of the surface of the Ti-5Si was excellent, even though Ti-5Si was not subjected to surface modifications. As a result, the bioactivity of Ti-5Si alloy was verified by the apatite-forming ability, making it suitable for use in orthopedic and dental implants.

  6. Heterogeneous nucleation of Mg2Si on Sr11Sb10 nucleus in Mg–x(3.5, 5 wt.%)Si–1Al alloys

    International Nuclear Information System (INIS)

    Wang, Hui-Yuan; Chen, Lei; Liu, Bo; Li, Xiao-Ran; Wang, Jin-Guo; Jiang, Qi-Chuan

    2012-01-01

    After combined additions of Sr and Sb, most primary Mg 2 Si crystals in Mg–3.5Si–1Al and Mg–5Si–1Al alloys transformed from equiaxed-dendritic shapes to octahedral morphologies; while eutectic phases also changed from Chinese script to short rod-shapes. The mechanisms of complex modification of Sr and Sb were attributed to the heterogeneous nucleation of primary Mg 2 Si on Sr 11 Sb 10 nucleus, together with change in growth manners caused by incorporation of Sb in Mg 2 Si crystals. -- Highlights: ► The Sr 11 Sb 10 is the heterogeneous nucleation of primary Mg 2 Si in Mg–3.5Si–1Al alloys. ► Some Sb atoms were incorporated by substituting Si which changed growth manners of primary Mg 2 Si. ► Primary Mg 2 Si transformed from equiaxed-dendritic to octahedral after modification. ► Eutectic phases changed from Chinese script to short rod-shapes after modification.

  7. The role of magnesium in the electrochemical behaviour of 5XXX aluminium-magnesium alloys

    NARCIS (Netherlands)

    Flores Ramirez, J.R.

    2006-01-01

    An investigation concerning the effects of magnesium on the intergranular corrosion susceptibility of AA5XXX aluminium alloys was carried out. In the present work, magnesium is found to be highly mobile in the bulk metal as well as in the aluminium oxide. This mobility is also found to be dependent

  8. Temperature-sensitive mutants of influenza A virus. XIV. Production and evaluation of influenza A/Georgia/74-ts-1[E] recombinant viruses in human adults.

    Science.gov (United States)

    Richman, D D; Murphy, B R; Belshe, R B; Rusten, H M; Chanock, R M; Blacklow, N R; Parrino, T A; Rose, F B; Levine, M M; Caplan, E

    1977-08-01

    The two temperature-sensitive (ts) lesions present in influenza A/Hong Kong/68-ts-1[E] (H3N2 68) virus were transferred via genetic reassortment to influenza A/Georgia/74 (H3N2 74) wild-type virus. A recombinant clone possessing both ts lesions and the shutoff temperature of 38 C of the Hong Kong/68 ts donor and the two surface antigens of the Georgia/74 wild-type virus was administered to 32 seronegative adult volunteers. Thirty-one volunteers were infected, of whom only five experienced mild afebrile upper respiratory tract illness. The wild-type recipient virus was a cloned population that induced illness in five of six infected volunteers. Therfore, the attenuation exhibited by the Georgia/74-ts-1[E] virus could reasonably be assumed to be due to the acquisition of the two ts-1[E] lesions by the Georgia/74 wild-type virus. The serum and nasal wash antibody responses of the ts-1[E] vaccinees were equivalent to those of the volunteers who received wild-type virus. The two ts lesions present in the Hong Kong/68-ts-1[E] virus have now been transferred three times to a wild-type virus bearing a new hemagglutinin, and in each instance the new ts recombination exhibited a similar, satisfactory level of attenuation and antigenicity for adults. It seems likely that the transfer of the ts-1[E] lesions to any new influenza virus will regularly result in attenuation of a recombinat virus possessing the new surface antigens.

  9. Effects of air melting on Fe/0.3/3Cr/0.5Mo/2Mn and Fe/0.3C/3Cr/0.5Mo/2Ni structural alloy steels

    International Nuclear Information System (INIS)

    Steinberg, B.

    1979-06-01

    Changing production methods of a steel from vacuum melting to air melting can cause an increase in secondary particles, such as oxides and nitrides, which may have detrimental effects on the mechanical properties and microstructure of the alloy. In the present study a base alloy of Fe/0.3C/3Cr/0.5Mo with either 2Mn or 2Ni added was produced by air melting and its mechanical properties and microstructure were compared to an identical vacuum melted steel. Significant differences in mechanical behavior, morphology, and volume fraction of undissolved inclusions have been observed as a function of composition following air melting. For the alloy containing manganese, all properties remained very close to vacuum melted values but the 2Ni alloy displayed a marked loss in Charpy impact toughness and plane strain fracture toughness. This loss is attributed to an increase in volume fraction of secondary particles in the nickel alloy, as opposed to both the Mn alloy and vacuum melted alloys, as well as to substaintially increased incidence of linear coalescence of voids. Microstructural features are discussed

  10. Study on improved tribological properties by alloying copper to CP-Ti and Ti-6Al-4V alloy.

    Science.gov (United States)

    Wang, Song; Ma, Zheng; Liao, Zhenhua; Song, Jian; Yang, Ke; Liu, Weiqiang

    2015-12-01

    Copper alloying to titanium and its alloys is believed to show an antibacterial performance. However, the tribological properties of Cu alloyed titanium alloys were seldom studied. Ti-5Cu and Ti-6Al-4V-5Cu alloys were fabricated in the present study in order to further study the friction and wear properties of titanium alloys with Cu additive. The microstructure, composition and hardness were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and hardness tester. The tribological behaviors were tested with ZrO2 counterface in 25% bovine serum using a ball-on-disc tribo-tester. The results revealed that precipitations of Ti2Cu intermetallic compounds appeared in both Ti-5Cu and Ti-6Al-4V-5Cu alloys. The tribological results showed an improvement in friction and wear resistance for both Ti-5Cu and Ti-6Al-4V-5Cu alloys due to the precipitation of Ti2Cu. The results also indicated that both CP-Ti and Ti-5Cu behaved better wear resistance than Ti-6Al-4V and Ti-6Al-4V-5Cu due to different wear mechanisms when articulated with hard zirconia. Both CP-Ti and Ti-5Cu revealed dominant adhesive wear with secondary abrasive wear mechanism while both Ti-6Al-4V and Ti-6Al-4V-5Cu showed severe abrasive wear and cracks with secondary adhesive wear mechanism due to different surface hardness integrated by their microstructures and material types. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Mechanical and bio-corrosion properties of quaternary Mg–Ca–Mn–Zn alloys compared with binary Mg–Ca alloys

    International Nuclear Information System (INIS)

    Bakhsheshi-Rad, H.R.; Idris, M.H.; Abdul-Kadir, M.R.; Ourdjini, A.; Medraj, M.; Daroonparvar, M.; Hamzah, E.

    2014-01-01

    Highlights: • Quaternary alloy show better mechanical and corrosion properties than binary alloy. • Mg–2Ca–0.5Mn–2Zn alloy showed suitable mechanical properties for bone application. • The improved corrosion resistance with addition of Mn and Zn into the Mg–Ca alloy. • Formation of protective surface film Mn-containing magnesium on quaternary alloy. • Secondary phases have strong effect on micro-galvanic corrosion of Mg alloys. - Abstract: Binary Mg–xCa alloys and the quaternary Mg–Ca–Mn–xZn were studied to investigate their bio-corrosion and mechanical properties. The surface morphology of specimens was characterized by X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results of mechanical properties show that the yield strength (YS), ultimate tensile strength (UTS) and elongation of quaternary alloy increased significantly with the addition of zinc (Zn) up to 4 wt.%. However, further addition of Zn content beyond 4 wt.% did not improve yield strength and ultimate tensile strength. In contrast, increasing calcium (Ca) content has a deleterious effect on binary Mg–Ca alloys. Compression tests of the magnesium (Mg) alloys revealed that the compression strength of quaternary alloy was higher than that of binary alloy. However, binary Mg–Ca alloy showed higher reduction in compression strength after immersion in simulated body fluid. The bio-corrosion behaviour of the binary and quaternary Mg alloys were investigated using immersion tests and electrochemical tests. Electrochemical tests shows that the corrosion potential (E corr ) of binary Mg–2Ca significantly shifted toward nobeler direction from −1996.8 to −1616.6 mV SCE with the addition of 0.5 wt.% manganese (Mn) and 2 wt.% Zn content. However, further addition of Zn to 7 wt.% into quaternary alloy has the reverse effect. Immersion tests show that the quaternary

  12. Evaluation of wrought Zn-Al alloys (1, 3, and 5 wt % Al) through mechanical and in vivo testing for stent applications.

    Science.gov (United States)

    Bowen, Patrick K; Seitz, Jan-Marten; Guillory, Roger J; Braykovich, Jacob P; Zhao, Shan; Goldman, Jeremy; Drelich, Jaroslaw W

    2018-01-01

    Special high grade zinc and wrought zinc-aluminum (Zn-Al) alloys containing up to 5.5 wt % Al were processed, characterized, and implanted in rats in search of a new family of alloys with possible applications as bioabsorbable endovascular stents. These materials retained roll-induced texture with an anisotropic distribution of the second-phase Al precipitates following hot-rolling, and changes in lattice parameters were observed with respect to Al content. Mechanical properties for the alloys fell roughly in line with strength (190-240 MPa yield strength; 220-300 MPa ultimate tensile strength) and elongation (15-30%) benchmarks, and favorable elastic ranges (0.19-0.27%) were observed. Intergranular corrosion was observed during residence of Zn-Al alloys in the murine aorta, suggesting a different corrosion mechanism than that of pure zinc. This mode of failure needs to be avoided for stent applications because the intergranular corrosion caused cracking and fragmentation of the implants, although the composition of corrosion products was roughly identical between non- and Al-containing materials. In spite of differences in corrosion mechanisms, the cross-sectional reduction of metals in murine aorta was nearly identical at 30-40% and 40-50% after 4.5 and 6 months, respectively, for pure Zn and Zn-Al alloys. Histopathological analysis and evaluation of arterial tissue compatibility around Zn-Al alloys failed to identify areas of necrosis, though both chronic and acute inflammatory indications were present. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 245-258, 2018. © 2017 Wiley Periodicals, Inc.

  13. Phase Transformation and Hydrogen Storage Properties of an La7.0Mg75.5Ni17.5 Hydrogen Storage Alloy

    Directory of Open Access Journals (Sweden)

    Lin Hu

    2017-10-01

    Full Text Available X-ray diffraction showed that an La7.0Mg75.5Ni17.5 alloy prepared via inductive melting was composed of an La2Mg17 phase, an LaMg2Ni phase, and an Mg2Ni phase. After the first hydrogen absorption/desorption process, the phases of the alloy turned into an La–H phase, an Mg phase, and an Mg2Ni phase. The enthalpy and entropy derived from the van’t Hoff equation for hydriding were −42.30 kJ·mol−1 and −69.76 J·K−1·mol−1, respectively. The hydride formed in the absorption step was less stable than MgH2 (−74.50 kJ·mol−1 and −132.3 J·K−1·mol−1 and Mg2NiH4 (−64.50 kJ·mol−1 and −123.1 J·K−1·mol−1. Differential thermal analysis showed that the initial hydrogen desorption temperature of its hydride was 531 K. Compared to Mg and Mg2Ni, La7.0Mg75.5Ni17.5 is a promising hydrogen storage material that demonstrates fast adsorption/desorption kinetics as a result of the formation of an La–H compound and the synergetic effect of multiphase.

  14. Ultrasonic Characterization of Microstructural Changes in Ti-10V-4.5Fe-1.5Al β-Titanium Alloy

    Science.gov (United States)

    Viswanath, A.; Kumar, Anish; Jayakumar, T.; Purnachandra Rao, B.

    2015-08-01

    Ultrasonic measurements have been carried out in Ti-10V-4.5Fe-1.5Al β-titanium alloy specimens subjected to β annealing at 1173 K (900 °C) for 1 hour followed by heat treatment in the temperature range of 823 K to 1173 K (550 °C to 900 °C) at an interval of 50 K (50 °C) for 1 hour, followed by water quenching. Ultrasonic parameters such as ultrasonic longitudinal wave velocity, ultrasonic shear wave velocity, shear anisotropy parameter, ultrasonic attenuation, and normalized nonlinear ultrasonic parameter have been correlated with various microstructural changes to understand the interaction of the propagating ultrasonic wave with microstructural features in the alloy. Simulation studies using JMatPro® software and X-ray diffraction measurements have been carried out to estimate the α-phase volume fraction in the specimens heat treated below the β-transus temperature (BTT). It is found that the α-phase (HCP) volume fraction increases from 0 to 52 pct, with decrease in the temperature from 1073 K to 823 K (800 °C to 550 °C). Ultrasonic longitudinal and shear wave velocities are found to increase with decrease in the heat treatment temperature below the BTT, and they exhibited linear relationships with the α-phase volume fraction. Thickness-independent ultrasonic parameters, Poisson's ratio, and the shear anisotropy parameter exhibited the opposite behavior, i.e., decrease with increase in the α-phase consequent to decrease in the heat treatment temperature from 1073 K to 823 K (800 °C to 550 °C). Ultrasonic attenuation is found to decrease from 0.7 dB/mm for the β-annealed specimen to 0.23 dB/mm in the specimen heat treated at 823 K (550 °C) due to the combined effect of the decrease in the β-phase (BCC) with higher damping characteristics and the reduction in scattering due to randomization of β grains with the precipitation of α-phase. Normalized nonlinear ultrasonic parameter is found to increase with increase in the α-phase volume fraction

  15. Microstructural evolution in decomposition of amorphous Zr41Ti14Cu12.5Ni10Be22.5 alloy, as investigated by small-angle neutron scattering

    International Nuclear Information System (INIS)

    Liu Junming; Hahn-Meitner-Inst. Berlin, Bereich, NM; Nanjing Univ.

    1997-01-01

    Small angle neutron scattering (SANS) has been applied to investigate decomposition kinetics and microstructural evolution in amorphous Zr 41 Ti 14 Cu 12.5 Ni 10 Be 22.5 . It is detected that immediately after the alloy is submitted into the supercooled liquid range, phase separation develops rapidly in the early stage, leaving a sluggish coarsening stage. The decomposed alloy finally achieves a roughly regular microstructure which consists of one particle-like supercooled liquid phase embedded in the similarly disordered matrix. The morphology of the particles as a function of time is evaluated, predicting a bar-like pattern. Strong temperature dependence of the phase separation is observed. (orig.)

  16. Emotion of Physiological Signals Classification Based on TS Feature Selection

    Institute of Scientific and Technical Information of China (English)

    Wang Yujing; Mo Jianlin

    2015-01-01

    This paper propose a method of TS-MLP about emotion recognition of physiological signal.It can recognize emotion successfully by Tabu search which selects features of emotion’s physiological signals and multilayer perceptron that is used to classify emotion.Simulation shows that it has achieved good emotion classification performance.

  17. AlSi17Cu5Mg alloy as future material for castings of pistons for internal combustion engines

    Directory of Open Access Journals (Sweden)

    J. Piątkowski

    2015-07-01

    Full Text Available The paper presents chosen properties and microstructure of AlSi17Cu5Mg alloy as future material for casting pistons in automotive industry. Tests were conducted to elaborate technology of preparation, assessment of crystallisation parameters and shaping the primary structure of the silumin with the aim to improve the working parameters and the functioning efficiency in cylinder-piston system. Refinement of Si crystals, achieved due to overheating above the temperature Tliq. causes that the alloy reaches satisfactory properties in working chamber of the engine are optimised. Such condition of material characteristics causes that hypereutectic silumins, for chosen applications in transport, may serve as an alternative to Al - Si alloys of hypoeutectic and near - eutectic type.

  18. A survey of the mechanical properties of uranium alloys U-5Mo-3Nb wt.% and U-3Mo-3Nb wt.%

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, G.

    1969-04-15

    In a continuing program on the development of soft and ductile uranium alloys for armament applications, two compositions were studied. These gamma extruded uranium alloys were U-5Mo-3Nb wt.% and U-3Mo-3Nb wt.%. This study was carried out to determine the influence of tempering heat treatments associated with extrusion on the ductility of these uranium alloys. The mechanical properties of both alloys were measured in the extruded condition, in the extruded and annealed condition and in the quenched and tempered condition. A maximum elongation of 13.7% in tension with a low amount of work hardening was obtained for the U-3Mo-3Nb wt.% alloy after 1 1/2 hours anneal at 1200 deg F (650 deg C) followed by a rapid cooling in water at 70 deg F (21 deg C). A maximum elongation of 17.3% with a large amount of work hardening was obtained for alloy U-5Mo-3Nb wt.% after vacuum annealing, normalizing, gamma phase solubilizing at 1500 deg F (815 deg C) and quenching in water at 700 deg F (210 deg C). The maximum ductility achieved in these two alloys by our approaches is low compared with the ductility of Armco Iron employed for the same applications in the field of ballistics.

  19. Function and structure in phage Qbeta RNA replicase. Association of EF-Tu-Ts with the other enzyme subunits

    DEFF Research Database (Denmark)

    Blumenthal, T; Young, R A; Brown, S

    1976-01-01

    alters its quaternary structure: the EF-Tu-Ts cannot be covalently attached to the other enzyme subunits with bifunctional cross-linking reagents in the presence of RNA. This conformational change is not influenced by ionic strength. The addition of Qbeta RNA to the enzyme, does not result in the release...... for one another increases with increasing ionic strength. The enzyme is capable of initiation of RNA synthesis with synthetic templates only when in the low ionic strength conformation. Elongation of initiated polynucleotide chains is not affectedby ionic strength. Addition of Qbeta RNA to the enzyme also...... of EF-Tu-Ts from the other enzyme subunits: whereas free EF-Tu-Ts binds GDP independently of salt concentration, this binding by Qbeta replicase is sensitive to high ionic strength and remains so in the presence of Qbeta RNA. Furthermore, RNA does not allow the release of EF-Ts from EF-Tu by GTP...

  20. The Development of the Low-Cost Titanium Alloy Containing Cr and Mn Alloying Elements

    Science.gov (United States)

    Zhu, Kailiang; Gui, Na; Jiang, Tao; Zhu, Ming; Lu, Xionggang; Zhang, Jieyu; Li, Chonghe

    2014-04-01

    The α + β-type Ti-4.5Al-6.9Cr-2.3Mn alloy has been theoretically designed on the basis of assessment of the Ti-Al-Cr-Mn thermodynamic system and the relationship between the molybdenum equivalent and mechanical properties of titanium alloys. The alloy is successfully prepared by the split water-cooled copper crucible, and its microstructures and mechanical properties at room temperature are investigated using the OM, SEM, and the universal testing machine. The results show that the Ti-4.5Al-6.9Cr-2.3Mn alloy is an α + β-type alloy which is consistent with the expectation, and its fracture strength, yield strength, and elongation reach 1191.3, 928.4 MPa, and 10.7 pct, respectively. Although there is no strong segregation of alloying elements under the condition of as-cast, the segregation of Cr and Mn is obvious at the grain boundary after thermomechanical treatment.

  1. Effect of heat treatment and impurity concentration on some mechanical properties V-15Cr-5Ti alloy

    International Nuclear Information System (INIS)

    Loomis, B.A.; Kestel, B.J.; Diercks, D.R.

    1986-03-01

    The effects of heat treatment and O, N, C, Si, and S impurity level on the yield strength, ductility, and fracture mode for specimens from four different heats of the V-15Cr-5Ti alloy are presented. The heat treatments for the alloy consisted of annealing as-rolled material for one hour at either 950, 1050, 1125, or 1200 0 C. The total oxygen, nitrogen, and carbon impurity concentration ranged from 400 to 1200 wppm. The Si concentration ranged from 300 to 1050 wppm, and the S concentration ranged from 440 to 1100 wppm. The yield strength and ductility for the alloy, regardless of impurity concentration, exhibited minimum and maximum values, respectively, for the 1125 0 C anneal. The primary mode of failure for the tensile specimens was transgranular fracture

  2. Hematopoietic Stem Cells from Ts65Dn Mice Are Deficient in the Repair of DNA Double-Strand Breaks.

    Science.gov (United States)

    Wang, Yingying; Chang, Jianhui; Shao, Lijian; Feng, Wei; Luo, Yi; Chow, Marie; Du, Wei; Meng, Aimin; Zhou, Daohong

    2016-06-01

    Down syndrome (DS) is a genetic disorder caused by the presence of an extra partial or whole copy of chromosome 21. In addition to musculoskeletal and neurodevelopmental abnormalities, children with DS exhibit various hematologic disorders and have an increased risk of developing acute lymphoblastic leukemia and acute megakaryocytic leukemia. Using the Ts65Dn mouse model, we investigated bone marrow defects caused by trisomy for 132 orthologs of the genes on human chromosome 21. The results showed that, although the total bone marrow cellularity as well as the frequency of hematopoietic progenitor cells (HPCs) was comparable between Ts65Dn mice and their age-matched euploid wild-type (WT) control littermates, human chromosome 21 trisomy led to a significant reduction in hematopoietic stem cell (HSC) numbers and clonogenic function in Ts65Dn mice. We also found that spontaneous DNA double-strand breaks (DSBs) were significantly increased in HSCs from the Ts65Dn mice, which was correlated with the significant reduction in HSC clonogenic activity compared to those from WT controls. Moreover, analysis of the repair kinetics of radiation-induced DSBs revealed that HSCs from Ts65Dn mice were less proficient in DSB repair than the cells from WT controls. This deficiency was associated with a higher sensitivity of Ts65Dn HSCs to radiation-induced suppression of HSC clonogenic activity than that of euploid HSCs. These findings suggest that an additional copy of genes on human chromosome 21 may selectively impair the ability of HSCs to repair DSBs, which may contribute to DS-associated hematological abnormalities and malignancies.

  3. Electrodeposition of Al-Ta alloys in NaCl-KCl-AlCl{sub 3} molten salt containing TaCl{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Kazuki; Matsushima, Hisayoshi; Ueda, Mikito, E-mail: mikito@eng.hokudai.ac.jp

    2016-12-01

    Highlights: • Electrodeposition of Al-Ta alloys in an AlCl{sub 3}-NaCl-KCl-TaCl{sub 5} melt was carried out. • We were obtained 72 at% Ta-Al alloy at 0.3 V. • Amorphous Ta-Al was formed in high Ta concentration. - Abstract: To form Al-Ta alloys for high temperature oxidation resistance components, molten salt electrolysis was carried out in an AlCl{sub 3}-NaCl-KCl melt containing TaCl{sub 5} at 423 K. The voltammogram showed two cathodic waves at 0.45 V and 0.7 V vs. Al/Al(III), which may correspond to reduction from Ta(V) to Ta(III) and from Ta(III) to tantalum metal, respectively. Electrodeposits of Al and Ta were obtained in the range from −0.05 to 0.3 V and the highest concentration of Ta in the electrodeposit was 72 at% at 0.3 V. With increasing Ta content in the alloy, the morphology of the electrodeposits became powdery and the particle size smaller.

  4. HRTEM study of the nanocrystalline Al85Y10Ni5 alloy

    International Nuclear Information System (INIS)

    Kozubowski, J.A.; Latuch, J.

    1999-01-01

    Nanocrystalline alloy Al 85 Y 10 Ni 5 obtained by annealing of the amorphous ribbons formed by melt spinning was studied by transmission electron microscopy and energy dispersive X-ray spectroscopy (EDS). The combined use of electron diffraction, electron microscopy and EDS has revealed the presence of several nano-phases: separate grains of Al(Y) and Al(N) solid solutions Al 3 Y grains and an unidentified phase of composition close to Al 3 (Ni,Y). (author)

  5. Tie-down assessment of radioactive material packages on conveyances approach to competent authority approval applications in accordance with TS-R 1 (June 2000) and TS-G-1.1 (June 2002)

    Energy Technology Data Exchange (ETDEWEB)

    Read, J.; Owen, S.; Tso, C.F. [Arup, London (United Kingdom)

    2004-07-01

    This paper summarizes the authors' findings, during carrying out many package tie-down assessments, regarding the approach to the assessment process, and the issues that may arise. The current regulatory framework, as outlined in the abstract, is considered and possible areas for further development or research are discussed. The safe transport of a package containing radioactive material requires a secure system of retention on the conveyance during transport. The requirements for the assessment of this tie-down system are covered by International Atomic Energy Authority (IAEA) Regulations, and by the specific regulatory and guidance materials applying in the country of application. The IAEA regulations have recently been updated in TS-R-1 (June 2000) [1] and TS-G-1.1 (June 2002) [2]. In particular, Appendix V of reference [2] specifically covers 'Package Stowage and Retention during Transport'. In the United Kingdom the Transport Container Standardisation Committee (TCSC) provides guidance on the application of the IAEA regulations in TCSC 1006 ''The securing of Radioactive Materials on Conveyances'' [3], and this document has also been revised in December 2003. The basic requirement of the IAEA regulations is to maintain the integrity of the components of the package and its retention systems during routine operations (TS-R-1 Para 612). In accident conditions the package is permitted and may be required as part of the design (the weak-link approach as discussed later in this paper) to separate from the conveyance, while preserving the package integrity. Any tie-down attachments on the package shall be so designed that, under normal and accident conditions of transport, the forces in those attachments shall not impair the ability of the package to meet the requirements of the Regulations. (TS-R-1 Para 636).

  6. Tie-down assessment of radioactive material packages on conveyances approach to competent authority approval applications in accordance with TS-R 1 (June 2000) and TS-G-1.1 (June 2002)

    International Nuclear Information System (INIS)

    Read, J.; Owen, S.; Tso, C.F.

    2004-01-01

    This paper summarizes the authors' findings, during carrying out many package tie-down assessments, regarding the approach to the assessment process, and the issues that may arise. The current regulatory framework, as outlined in the abstract, is considered and possible areas for further development or research are discussed. The safe transport of a package containing radioactive material requires a secure system of retention on the conveyance during transport. The requirements for the assessment of this tie-down system are covered by International Atomic Energy Authority (IAEA) Regulations, and by the specific regulatory and guidance materials applying in the country of application. The IAEA regulations have recently been updated in TS-R-1 (June 2000) [1] and TS-G-1.1 (June 2002) [2]. In particular, Appendix V of reference [2] specifically covers 'Package Stowage and Retention during Transport'. In the United Kingdom the Transport Container Standardisation Committee (TCSC) provides guidance on the application of the IAEA regulations in TCSC 1006 ''The securing of Radioactive Materials on Conveyances'' [3], and this document has also been revised in December 2003. The basic requirement of the IAEA regulations is to maintain the integrity of the components of the package and its retention systems during routine operations (TS-R-1 Para 612). In accident conditions the package is permitted and may be required as part of the design (the weak-link approach as discussed later in this paper) to separate from the conveyance, while preserving the package integrity. Any tie-down attachments on the package shall be so designed that, under normal and accident conditions of transport, the forces in those attachments shall not impair the ability of the package to meet the requirements of the Regulations. (TS-R-1 Para 636)

  7. Microstructures and microhardness evolutions of melt-spun Al-8Ni-5Nd-4Si alloy

    Energy Technology Data Exchange (ETDEWEB)

    Karakoese, Ercan, E-mail: ekarakose@karatekin.edu.tr [Karatekin University, Faculty of Sciences, Department of Physics, 18100 Cank Latin-Small-Letter-Dotless-I r Latin-Small-Letter-Dotless-I (Turkey); Keskin, Mustafa [Erciyes University, Faculty of Sciences, Department of Physics, 38039 Kayseri (Turkey)

    2012-03-15

    Al-Ni-Nd-Si alloy with nominal composition of Al-8 wt.%Ni-5 wt.%Nd-4 wt.%Si was rapidly solidified by using melt-spinning technique to examine the influence of the cooling rate/conditions on microstructure and mechanical properties. The resulting conventional cast (ingot) and melt-spun ribbons were characterized by X-ray diffraction, optical microscopy, scanning electron microscopy together with energy dispersive spectroscopy, differential scanning calorimetry, differential thermal analysis and Vickers microhardness tester. The ingot alloys consists of four phases namely {alpha}-Al, intermetallic Al{sub 3}Ni, Al{sub 11}Nd{sub 3} and fcc Si. Melt-spun ribbons are completely composed of {alpha}-Al phase. The optical microscopy and scanning electron microscopy results show that the microstructures of rapidly solidified ribbons are clearly different from their ingot alloy. The change in microhardness is discussed based on the microstructural observations. - Highlights: Black-Right-Pointing-Pointer Rapid solidification allows a reduction in grain size, extended solid solution ranges. Black-Right-Pointing-Pointer We observed the matrix lattice parameter increases with increasing wheel speed. Black-Right-Pointing-Pointer Melt-spun ribbons consist of partly amorphous phases embedded in crystalline phases. Black-Right-Pointing-Pointer The solidification rate is high enough to retain most of alloying elements in the Al matrix. Black-Right-Pointing-Pointer The rapid solidification has effect on the phase constitution.

  8. The Effect of Deep Cryogenic Treatment on the Corrosion Behavior of Mg-7Y-1.5Nd Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    Quantong Jiang

    2017-10-01

    Full Text Available The effect of quenching on the corrosion resistance of Mg-7Y-1.5Nd alloy was investigated. The as-cast alloy was homogenized at 535 °C for 24 h, followed by quenching in air, water, and liquid nitrogen. Then, all of the samples were peak-aged at 225 °C for 14 h. The microstructures were studied by scanning electron microscopy, energy-dispersive spectrometry, and X-ray diffraction. Corrosion behavior was analyzed by using weight loss rate and gas collection. Electrochemical characterizations revealed that the T4-deep cryogenic sample displayed the strongest corrosion resistance among all of the samples. A new square phase was discovered in the microstructure of the T6-deep cryogenic sample; this phase was hugely responsible for the corrosion property. Cryogenic treatment significantly improved the corrosion resistance of Mg-7Y-1.5Nd alloy.

  9. Nickel base alloys

    International Nuclear Information System (INIS)

    Gibson, R.C.; Korenko, M.K.

    1980-01-01

    Nickel based alloy, the characteristic of which is that it mainly includes in percentages by weight: 57-63 Ni, 7-18 Cr, 10-20 Fe, 4-6 Mo, 1-2 Nb, 0.2-0.8 Si, 0.01-0.05 Zr, 1.0-2.5 Ti, 1.0-2.5 Al, 0.02-0.06 C and 0.002-0.015 B. The aim is to create new nickel-chromium alloys, hardened in a solid solution and by precipitation, that are stable, exhibit reduced swelling and resistant to plastic deformation inside the reactor. These alloys of the gamma prime type have improved mechanical strengthm swelling resistance, structural stability and welding properties compared with Inconel 625 [fr

  10. Low cycle fatigue behaviour of Ti–6Al–5Zr–0⋅5Mo–0⋅25Si alloy at ...

    Indian Academy of Sciences (India)

    Unknown

    condition as compared to the β treated one is in conformity with the higher degree of softening in the former one, as indicated by the stress-response curves in figures 3a and b. Some investigators have reported cross over in the cyclic and monotonic stress–strain curves above 1⋅5% of total strain in the near-α titanium alloy, ...

  11. Air oxidation of Zircaloy-4, M5 (registered) and ZIRLOTM cladding alloys at high temperatures

    International Nuclear Information System (INIS)

    Steinbrueck, M.; Boettcher, M.

    2011-01-01

    The paper presents the results of isothermal and transient oxidation experiments of the advanced cladding alloys M5 (registered) and ZIRLO TM in comparison to Zircaloy-4 in air at temperatures from 973 to 1853 K. Generally, oxidation in air leads to a strong degradation of the cladding material. The main mechanism of this process is the formation of zirconium nitride and its re-oxidation. From the point of view of safety, the barrier effect of the fuel cladding is lost much earlier than during accident transients with a steam atmosphere only. Comparison of the three alloys investigated reveals a qualitatively similar, but quantitatively varying oxidation behavior in air. The mainly parabolic oxidation kinetics, where applicable, is comparable for the three alloys. Strong differences of up to 500% in oxidation rates were observed after transition to linear kinetics at temperatures below 1300 K. The paper presents kinetic rate constants as well as critical times and oxide scale thicknesses at the point of transition from parabolic to linear kinetics.

  12. Effect of rapid solidification on the microstructure and mechanical properties of hot-pressed Al-20Si-5Fe alloys

    International Nuclear Information System (INIS)

    Rajabi, M.; Vahidi, M.; Simchi, A.; Davami, P.

    2009-01-01

    The aim of this work is to study the effect of cooling rate and subsequent hot consolidation on the microstructural features and mechanical strength of Al-20Si-5Fe-2X (X = Cu, Ni and Cr) alloys. Powder and ribbons were produced by gas atomization and melt spinning processes at two different cooling rates of 1 x 10 5 K/s and 5 x 10 7 K/s. The microstructure of the products was examined using optical microscopy, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The particles were consolidated by hot pressing at 400 deg. C/250 MPa/1 h under a high purity argon atmosphere and the microstructure, hardness and compressive strength of the compacts were evaluated. Results showed a profound effect of the cooling rate, consolidation stage, and transition metals on the microstructure and mechanical strength of Al-20Si-5Fe alloys. While microstructural refining was obtained at both cooling rates, the microstructure of the atomized powder exhibited the formation of fine primary silicon (∼ 1 μm), eutectic Al-Si phase with eutectic spacing of ∼ 300 nm, and δ-iron intermetallic. Supersaturated Al matrix containing 5-7 at.% silicon and nanometric Si precipitates (20-40 nm) were determined in the microstructure of the melt-spun ribbons. The hot consolidation resulted in coarsening of Si particles in the atomized particles, and precipitation of Si and Fe-containing intermetallics from the supersaturated Al matrix in the ribbons. The consolidated ribbons exhibited higher mechanical strength compared to the atomized powders, particularly at elevated temperatures. The positive influence of the transition metals on the thermal stability of the Al-20Si-5Fe alloy was noticed, particularly in the Ni-containing alloy.

  13. Crystallisation kinetics of amorphous Fe72.5-xCu1Nb4.5Si10+x+yB12-y alloy

    International Nuclear Information System (INIS)

    Miglierini, M.; Lipka, J.; Sitek, J.

    1994-01-01

    Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 and Fe 72.5-x Cu 1 Nb 4.5 Si 10+x+y B 12-y alloys are compared from the point of view of crystallisation behaviour and changes in the short-range order in the amorphous reminder. The increase in Nb to 4.5 at.% in the latter system slows down the formation of nanocrystals to approximately 40% even after 16 hours of anneal at 550 C for x = 0.5, y = 3. Segregation-induced changes in the short-range order are manifested via hyperfine field distributions corresponding to the amorphous reminder. (orig.)

  14. Investigating the optical modes of InxGa1xN alloy and In0.5Ga0.5N/GaN MQW in far-infrared reflectivity spectra

    International Nuclear Information System (INIS)

    Mirjalili, G.; Amraei, R.

    2006-01-01

    Optical properties of In x Ga 1 x N alloy and In 0 .5Ga 0 .5N/GaN multi quantum wells have been investigated in the region of far infrared. Far-IR reflectivity spectra of In 0 .5Ga 0 .5N/GaN multi quantum wells on GaAs substrate have been obtained by oblique incidence p- and s- polarization light using effective medium approximation. The spectra and the dielectric functions response give a good information about the phonon and plasmon contribution in doped MQW as well as the mole fraction of compounds in the alloys. The changes in position of optical modes are good tools for measurement of the amount of free carrier and the amount of mole fraction in the samples. During study of In x Ga 1 x N reflectivity spectra, two distinct reststrahl bands with frequency near those of pure InN and GaN were observed over entire composition range. Each band shifts to lower frequencies and decreases in amplitude as the concentration of corresponding compound in alloy decreased. Analysis of dielectric function gives the TO-like and LO-like mode frequencies. The changes in LO mode frequencies, due to coupling of phonon-plasmon, have been observed

  15. Influence of micro-additions of bismuth on structures, mechanical and electrical transport properties of rapidly solidified Sn-3.5% Ag Alloy from melt

    International Nuclear Information System (INIS)

    El Bahay, M.M.; Mady, H.A.

    2005-01-01

    The present study was undertaken to investigate the influence of the Bi addition in the Sn-3.5 Ag rapidly solidified binary system for use as a Pb-free solder. The resulting properties of the binary system were extended to the Sn based ternary systems Sn 9 6.5-X Ag 3 .5 Bi x (0≤ X ≤ 2.5) solder. The structure and electrical resistivity of rapidly solidified (melt spun) alloys have been investigated. With the addition of up to 2.5 mass % Bi, the melting temperature decreases from 221.1 to 214.8 degree C. Wetting contact angle of the six alloys on Cu Zn 3 0 substrate are carried out at 573 K. Microhardness evaluations were also performed on the Sn-Ag-Bi alloys. The measured values and other researcher's results were compared with the calculated data

  16. TS-05: 150 lines of java with high architectural complexity

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    2005-01-01

    In the short time span available in a software architecture course, it is difficult to find a software system that is both interesting from an architectural perspective and so small that it does not overwhelm the students.We present TS-05 which is a bare 150 line Java "toy-system" that never...

  17. HAfTs are novel lncRNA transcripts from aflatoxin exposure.

    Directory of Open Access Journals (Sweden)

    B Alex Merrick

    Full Text Available The transcriptome can reveal insights into precancer biology. We recently conducted RNA-Seq analysis on liver RNA from male rats exposed to the carcinogen, aflatoxin B1 (AFB1, for 90 days prior to liver tumor onset. Among >1,000 differentially expressed transcripts, several novel, unannotated Cufflinks-assembled transcripts, or HAfTs (Hepatic Aflatoxin Transcripts were found. We hypothesized PCR-cloning and RACE (rapid amplification of cDNA ends could further HAfT identification. Sanger data was obtained for 6 transcripts by PCR and 16 transcripts by 5'- and 3'-RACE. BLAST alignments showed, with two exceptions, HAfT transcripts were lncRNAs, >200nt without apparent long open reading frames. Six rat HAfT transcripts were classified as 'novel' without RefSeq annotation. Sequence alignment and genomic synteny showed each rat lncRNA had a homologous locus in the mouse genome and over half had homologous loci in the human genome, including at least two loci (and possibly three others that were previously unannotated. While HAfT functions are not yet clear, coregulatory roles may be possible from their adjacent orientation to known coding genes with altered expression that include 8 HAfT-gene pairs. For example, a unique rat HAfT, homologous to Pvt1, was adjacent to known genes controlling cell proliferation. Additionally, PCR and RACE Sanger sequencing showed many alternative splice variants and refinements of exon sequences compared to Cufflinks assembled transcripts and gene prediction algorithms. Presence of multiple splice variants and short tandem repeats found in some HAfTs may be consequential for secondary structure, transcriptional regulation, and function. In summary, we report novel, differentially expressed lncRNAs after exposure to the genotoxicant, AFB1, prior to neoplastic lesions. Complete cloning and sequencing of such transcripts could pave the way for a new set of sensitive and early prediction markers for chemical

  18. Delayed hydride cracking behavior of Zr-2.5Nb alloy pressure tubes for PHWR700

    Energy Technology Data Exchange (ETDEWEB)

    Sunil, S.; Bind, A.K.; Khandelwal, H.K.; Singh, R.N., E-mail: rnsingh@barc.gov.in; Chakravartty, J.K.

    2015-11-15

    In order to attain improved in-reactor performance few prototypes pressure tubes of Zr-2.5Nb alloy were manufactured by employing forging to break the cast structure and to obtain more homogeneous microstructure. Both double forging and single forging were employed. The forged material was further processed by employing hot extrusion, cold pilgering and autoclaving. A detailed characterization in terms of mechanical properties and microstructure of the prototype tubes were carried for qualifying it for intended use as pressure tubes in PHWR700 reactors. In this work, Delayed Hydride Cracking (DHC) behavior of the forged Zr-2.5Nb pressure tube material characterized in terms of DHC velocity and threshold stress intensity factor associated with DHC (K{sub IH}) was compared with that of conventionally manufactured material in the temperature range of 200–283 °C. Activation energy associated with the DHC in this alloy was found to be ∼60 kJ/mol for the forged materials.

  19. Structural and magnetic properties of Fe76P5(Si0.3B0.5C0.2)19 amorphous alloy

    International Nuclear Information System (INIS)

    Lavorato, G.C.; Fiore, G.; Tiberto, P.; Baricco, M.; Sirkin, H.; Moya, J.A.

    2012-01-01

    Highlights: ► Fe 76 P 5 (Si 0.3 B 0.5 C 0.2 ) 19 amorphous alloy in ribbons and 1 mm and 2 mm rod samples. ► Good glass forming ability with ΔT = 50 K and γ = 0.37 and off-eutectic composition. ► Good soft magnetic properties with magnetization saturation of 1.44 T. ► Geometrical factors are the primary causes of magnetic losses in frequencies above 10 Hz. - Abstract: Recently, bulk amorphous alloys were produced in the Fe–B–Si–P–C system with high glass forming ability, excellent magnetic properties and the advantage of containing no expensive glass-forming elements, such as Ga, Y, Cr or Nb, having, therefore, a good perspective of commercial applications. In the present work, the Fe 76 P 5 (Si 0.3 B 0.5 C 0.2 ) 19 amorphous alloy prepared by two quenching techniques has been studied. Amorphous ribbons of about 40 μm thick were obtained by planar-flow casting together with cylinders having 1 and 2 mm diameter produced by copper mold injection casting. All the samples appear fully amorphous after X-ray diffraction analysis. A comprehensive set of thermal data (glass, crystallization, melting and liquidus temperatures) were obtained as well as a description of the melting and solidification processes. Mechanical microhardness tests showed that the samples have a hardness of 9.7 ± 0.3 GPa. Good soft-magnetic properties were obtained, including a high magnetization of 1.44 T and a low coercivity (4.5 A/m for ribbons and 7.5 A/m in the case of 1 mm rod samples, both in as-cast state). Thermomagnetic studies showed a Curie temperature around 665 K and the precipitation of new magnetic phases upon temperatures of 1000 K. Furthermore, the frequency dependence of magnetic losses at a fixed peak induction was studied. The results suggest the occurrence of a fine magnetic domain structure in bulk samples. The good soft magnetic properties of the bulk metallic glass obtained by copper mold casting for this particular Fe-based composition suggests possible

  20. Martensitic transformation and mechanical properties of Ni{sub 49+x}Mn{sub 36–x}In{sub 15} (x=0, 0.5, 1.0, 1.5 and 2.0) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Le; Mehta, Abhishek [Department of Materials Science and Engineering and Advanced Materials Processing and Analysis Center, University of Central Florida, Orlando, FL, 32816 (United States); Giri, Anit [TKC Global, 13873 Park Center Road, Herndon, VA 20171 (United States); Weapons and Materials Research Directorate, US Army Research Laboratory, Aberdeen Proving Ground, MD 21005 (United States); Cho, Kyu [Weapons and Materials Research Directorate, US Army Research Laboratory, Aberdeen Proving Ground, MD 21005 (United States); Sohn, Yongho, E-mail: Yongho.Sohn@ucf.edu [Department of Materials Science and Engineering and Advanced Materials Processing and Analysis Center, University of Central Florida, Orlando, FL, 32816 (United States)

    2015-10-14

    Five polycrystalline Ni{sub 49+x}Mn{sub 36–x}In{sub 15} (x=0, 0.5, 1.0, 1.5 and 2) alloys were prepared by triple arc-melting and examined to understand their martensitic transformation and mechanical properties. Martensitic transformation temperatures were determined by differential scanning calorimetry (DSC) and observed to increase with increasing Ni content. Powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed that Ni{sub 49}Mn{sub 36}In{sub 15} is austenitic at room temperature while modulated 7M martensitic structure was observed in other alloys. Different twinning relationships between martensitic variants were revealed by TEM. Reduced elastic modulus and hardness were measured by nanoindentation. For the martensites, the reduced elastic modulus increased as the e/a increases, while hardness did not vary. The austenitic phase exhibited a lower reduced elastic modulus and hardness. A larger scatter in the reduced elastic modulus and hardness was observed for the martensitic phase in conjunction with variants of different orientation. The martensitic transformation behavior and nanoindentation results were also compared with Ni{sub 53+x}Mn{sub 22–x}Ga{sub 25} (x=0.5, 1.0, 1.8 and 2.5) alloys. For both Ni–Mn–In and Ni–Mn–Ga alloys, the martensitic transformation temperature and reduced elastic modulus increased as the e/a ratio increased.

  1. The effect of neodymium on the microcracks generated on the Al–17.5Si alloy surface treated by high current pulsed electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Liang; Gao, Bo, E-mail: gaob@smm.neu.edu.cn; Zhu, Guanglin; Hao, Yi; Sun, Shuchen; Tu, Ganfeng

    2016-02-28

    Graphical abstract: SEM results demonstrate that microcracks are remarkably removed from the Al–17.5Si alloy surface after HCPEB treatment due to Nd element, and they decrease in length at high pulse number, showing a decrease in the stress concentration in the primary Si phase during the cooling process of HCPEB, as shown in Fig. 1. Therefore, the microcrack elimination is attributed to reducing the stress concentration. - Highlights: • The main highlights in this paper are summarized as follows: (1) After adding rare earth Nd, the microcracks are remarkably removed from an Al–17.5Si alloy surface by HCPEB, resulting in an improved corrosion resistance of the alloy surface. (2) A site-fixed observation of SEM is first proposed in HCPEB-treated technology, and a microcrack evolution with increasing pulsed numbers is observed for alloy surfaces using this method. (3) The elimination mechanism of microcracks with rare earth Nd is first presented in the present work. (4) Compound modification of rare earth Nd and HCPEB technology on the Al–17.5Si alloy is first investigated. - Abstract: In the present work, the effect of Nd on the microcracks generated on an Al–17.5Si alloy surface by a high current pulsed electron beam (HCPEB) was investigated. By a newly proposed site-fixed observation, the propagation of microcracks with increasing pulsed numbers first increases and then decreases due to the Nd element. The crack density decreases from 0.0669 mm/mm{sup 2} of 5 pulses to 0.00687 mm/mm{sup 2} of 50 pulses. EPMA analysis results indicate that Nd is uniformly distributed on the HCPEB-treated alloy surface. Nano-silicon particles and nano-Al cellular structures were formed by TEM observation, showing grain refinement of the alloy surface. The microcrack elimination is attributed to a decrease in the stress concentration in the primary Si phase during the cooling process of HCPEB. The electrochemical measurement shows that the corrosion current density

  2. The investigation of topological phase of Gd1-xYxAuPb (x = 0, 0.25, 0.5, 0.75, 1) alloys under hydrostatic pressure

    Science.gov (United States)

    Saeidi, Parviz; Nourbakhsh, Zahra

    2018-04-01

    Topological phase of Gd1-xYxAuPb (x = 0, 0.25, 0.5, 0.75, 1) alloys have been studied utilizing density function theory by WIEN2k code. The generalized gradient approximation (GGA), generalized gradient approximation plus Hubbard parameter (GGA + U), Modified Becke and Johnson (MBJ) and GGA Engel-vosko in the presence of spin orbit coupling have been used to investigate the topological band structure of Gd1-xYxAuPb alloys at zero pressure. The topological phase and band order of these alloys within GGA and GGA + U approaches under hydrostatic pressure are also investigated. We find that under hydrostatic pressure in some percentages of Gd1-xYxAuPb (x = 0, 0.25, 0.5, 0.75, 1) alloys in both GGA and GGA + U approaches, the trivial topological phase is converted into nontrivial topological phase. In addition, the band inversion strength versus lattice constant of these alloys is studied. Moreover, the schematic plan is represented in order to show the trivial and nontrivial topological phase of Gd1-xYxAuPb (x = 0, 0.25, 0.5, 0.75, 1) alloys in both GGA and GGA + U approaches.

  3. Preparation of Copper and Chromium Alloyed Layers on Pure Titanium by Plasma Surface Alloying Technology

    Science.gov (United States)

    He, Xiaojing; Li, Meng; Wang, Huizhen; Zhang, Xiangyu; Tang, Bin

    2015-05-01

    Cu-Cr alloyed layers with different Cu and Cr contents on pure titanium were obtained by means of plasma surface alloying technology. The microstructure, chemical composition and phase composition of Cu-Cr alloyed layers were analyzed by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD), respectively. The experimental results demonstrate that the alloyed layers are bonded strongly to pure titanium substrate and consist of unbound Ti, CuTi, Cu3Ti, CuTi3 and Cr2Ti. The thickness of Cu5Cr5 and Cu7Cr3 alloyed layer are about 18 μm and 28 μm, respectively. The antibacterial properties against gram-negative Escherichia coli (E.coli, ATCC10536) and gram-positive Staphylococcus aureus (S. aureus, ATCC6538) of untreated pure titanium and Cu-Cr alloyed specimen were investigated by live/dead fluorescence staining method. The study shows that Cu-Cr alloyed layers exhibit excellent antibacterial activities against both E.coli and S.aureus within 24 h, which may be attributed to the formation of Cu-containing phases.

  4. Preparation of a high strength Al–Cu–Mg alloy by mechanical alloying and press-forming

    International Nuclear Information System (INIS)

    Tang Huaguo; Cheng Zhiqiang; Liu Jianwei; Ma Xianfeng

    2012-01-01

    Highlights: ► A high strength aluminum alloy of Al–2 wt.%Mg–2 wt.%Cu has been prepared by mechanical alloying and press-forming. ► The alloy only consists of solid solution α-Al. ► The grains size of α-Al was about 300 nm–5 μm. ► The solid solution strengthening and the grain refinement strengthening are the main reasons for such a high strength. - Abstract: A high strength aluminum alloy, with the ratio of 96 wt.%Al–2 wt.%Mg–2 wt.%Cu, has been prepared by mechanical alloying and press-forming. The alloy exhibited a high tensile strength of 780 MPa and a high microhardness of 180 HV. X-ray diffraction characterizations confirmed that the alloy only consists of a solid solution α-Al. Microstructure characterizations revealed that the grain size of α-Al was about 300 nm–5 μm. The solid solution strengthening and the grain refinement strengthening were considered to be the reason for such a high strength.

  5. Preparation of a high strength Al-Cu-Mg alloy by mechanical alloying and press-forming

    Energy Technology Data Exchange (ETDEWEB)

    Tang Huaguo [State Key Laboratory of Rare Earth Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Cheng Zhiqiang [College of Resources and Environment, Jilin Agricultural University, Changchun 130118 (China); Liu Jianwei [State Key Laboratory of Rare Earth Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Ma Xianfeng, E-mail: xfma@ciac.jl.cn [State Key Laboratory of Rare Earth Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2012-07-30

    Highlights: Black-Right-Pointing-Pointer A high strength aluminum alloy of Al-2 wt.%Mg-2 wt.%Cu has been prepared by mechanical alloying and press-forming. Black-Right-Pointing-Pointer The alloy only consists of solid solution {alpha}-Al. Black-Right-Pointing-Pointer The grains size of {alpha}-Al was about 300 nm-5 {mu}m. Black-Right-Pointing-Pointer The solid solution strengthening and the grain refinement strengthening are the main reasons for such a high strength. - Abstract: A high strength aluminum alloy, with the ratio of 96 wt.%Al-2 wt.%Mg-2 wt.%Cu, has been prepared by mechanical alloying and press-forming. The alloy exhibited a high tensile strength of 780 MPa and a high microhardness of 180 HV. X-ray diffraction characterizations confirmed that the alloy only consists of a solid solution {alpha}-Al. Microstructure characterizations revealed that the grain size of {alpha}-Al was about 300 nm-5 {mu}m. The solid solution strengthening and the grain refinement strengthening were considered to be the reason for such a high strength.

  6. The quasicrystalline phase formation in Al-Cu-Cr alloys produced by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Sviridova, T.A.; Shevchukov, A.P.; Shelekhov, E.V. [National University of Science and Technology ' MISIS' , Moscow 119049 (Russian Federation); Diakonov, D.L. [Bardin Central Research Institute for the Iron and Steel Industry, Moscow 105005 (Russian Federation); Tcherdyntsev, V.V.; Kaloshkin, S.D. [National University of Science and Technology ' MISIS' , Moscow 119049 (Russian Federation)

    2011-06-15

    Research highlights: > Formation of decagonal quasicrystalline phase in Al-Cu-Cr alloys. > Obtained decagonal phase belongs to D{sub 3} family of decagonal quasicrystals. > Decagonal phase has 1.26 nm periodicity along 10-fold axis. > Alloys were produced by combination of mechanical alloying and subsequent annealing. > Phase composition of as-milled powders depending on annealing temperature. - Abstract: Almost single-phase decagonal quasicrystal with periodicity of 1.26 nm along 10-fold axis was produced in Al{sub 69}Cu{sub 21}Cr{sub 10} and Al{sub 72.5}Cu{sub 16.5}Cr{sub 11} alloys using combination of mechanical alloying (MA) and subsequent annealing. Phase transformations of as-milled powders depending on annealing temperature in the range of 200-800 deg. C are examined. Since the transformations can be explained based on kinetic and thermodynamic reasons it seems that applied technique (short preliminary MA followed by the annealing) permits to produce the equilibrium phases rather than metastable ones.

  7. In-situ thermal analysis and macroscopical characterization of Mg–xCa and Mg–0.5Ca–xZn alloy systems

    International Nuclear Information System (INIS)

    Farahany, Saeed; Bakhsheshi-Rad, Hamid Reza; Idris, Mohd Hasbullah; Abdul Kadir, Mohammed Rafiq; Lotfabadi, Amir Fereidouni; Ourdjini, Ali

    2012-01-01

    Highlights: ► The effect of Ca and Zn addition on Mg–Ca and Mg–Ca–Zn were investigated. ► Ca and Zn addition decreased solid fraction at coherency point. ► T N –T DCP increased by adding Ca and Zn in Mg–Ca and Mg–Ca–Zn, respectively. ► Three reactions were detected when Zn/Ca atomic ratio less than 1.25 in Mg–Ca–Zn. ► A new peak Mg 51 Zn 20 was identified in Mg–0.5Ca–9Zn in addition of other peaks. - Abstract: This research described the identification phases by thermal analysis and microscopy inspection of Mg–xCa and Mg–0.5%Ca–xZn alloys that were solidified at slow cooling rate. Analysis of cooling curve after Ca addition shows the evolution of the Mg 2 Ca intermetallic phase at around 520 °C in addition to α-Mg phase. First derivative curves of alloys after the addition of Zn to Mg–0.5Ca alloy reveals three peaks related to α-Mg, Mg 2 Ca and Ca 2 Mg 6 Zn 3 for alloys that have Zn/Ca atomic ratio less than 1.23. The peak of Mg 2 Ca reaction on the first derivative curves disappeared for alloys containing Zn/Ca ratio more than 1.23. A new peak was also observed at 330 °C for Mg–0.5Ca–9Zn which was identified as Mg 51 Zn 20 . Solid fraction at coherency point decreased with increasing Ca and Zn elements. However, coherency time and difference between the nucleation and coherency temperatures (T N –T DCP ) increased by adding Ca and Zn in Mg–Ca and Mg–Ca–Zn systems.

  8. A sulfidation-resistant nickel-base alloy

    International Nuclear Information System (INIS)

    Lai, G.Y.

    1989-01-01

    For applications in mildly to moderately sulfidizing environments, stainless steels, Fe-Ni-Cr alloys (e.g., alloys 800 and 330), and more recently Fe-Ni-Cr-Co alloys (e.g., alloy 556) are frequently used for construction of process equipment. However, for many highly sulfidizing environments, few existing commercial alloys have adequate performance. Thus, a new nickel-based alloy containing 27 wt.% Co, 28 wt.% Cr, 4 wt.% Fe, 2.75 wt.% Si, 0.5 wt.% Mn and 0.05 wt.% C (Haynes alloy HR-160) was developed

  9. Cap casting and enveloped casting techniques for Zr55Cu30Ni5Al10 glassy alloy rod with 32 mm in diameter

    International Nuclear Information System (INIS)

    Yokoyama, Yoshihiko; Inoue, Akihisa; Mund, Enrico; Schultz, Ludwig

    2009-01-01

    In order to produce centimetre-sized bulk glassy alloys (BMGs), various cast techniques have been developed. We succeed in the development of cap casting and enveloped casting technique to accomplish the fabrication of centimetre sized BMGs. The former has an advantage to increase cooling rate and the later has an advantage to joint another materials instead of welding. This paper presents the production of a glassy Zr 55 Cu 30 Ni 5 Al 10 alloy rod with a diameter of 32 mm and joined glassy Zr 55 Cu 30 Ni 5 Al 10 alloy parts with another materials for industrial applications.

  10. Elongation factor Ts directly facilitates the formation and disassembly of the Escherichia coli elongation factor Tu·GTP·aminoacyl-tRNA ternary complex.

    Science.gov (United States)

    Burnett, Benjamin J; Altman, Roger B; Ferrao, Ryan; Alejo, Jose L; Kaur, Navdep; Kanji, Joshua; Blanchard, Scott C

    2013-05-10

    Aminoacyl-tRNA (aa-tRNA) enters the ribosome in a ternary complex with the G-protein elongation factor Tu (EF-Tu) and GTP. EF-Tu·GTP·aa-tRNA ternary complex formation and decay rates are accelerated in the presence of the nucleotide exchange factor elongation factor Ts (EF-Ts). EF-Ts directly facilitates the formation and disassociation of ternary complex. This system demonstrates a novel function of EF-Ts. Aminoacyl-tRNA enters the translating ribosome in a ternary complex with elongation factor Tu (EF-Tu) and GTP. Here, we describe bulk steady state and pre-steady state fluorescence methods that enabled us to quantitatively explore the kinetic features of Escherichia coli ternary complex formation and decay. The data obtained suggest that both processes are controlled by a nucleotide-dependent, rate-determining conformational change in EF-Tu. Unexpectedly, we found that this conformational change is accelerated by elongation factor Ts (EF-Ts), the guanosine nucleotide exchange factor for EF-Tu. Notably, EF-Ts attenuates the affinity of EF-Tu for GTP and destabilizes ternary complex in the presence of non-hydrolyzable GTP analogs. These results suggest that EF-Ts serves an unanticipated role in the cell of actively regulating the abundance and stability of ternary complex in a manner that contributes to rapid and faithful protein synthesis.

  11. Thermal, mechanics and electrical characterization of the Al-0,6%Mg-08%Si alloy refined and modified with different copper contents; Caracterizacao termica, mecanica e eletrica da liga Al-0,6% Mg-0,8% Si refinada e modificada com diferentes teores de cobre

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, E.S. [Universidade Federal do Para (UFPA), Belem, PA (Brazil)], Email: mmanufreitas@gmail.com; Marques, P.R.R.; Santos, W.L.R.; Kamizono, K.A.; Quaresma, J. Maria V.

    2009-07-01

    The aluminum, magnesium and silicon alloys form a very important group, utilized as casted form and worked alloys, especially in 6201 alloy series. These alloys show applicability on cables and wires fabrication to electrical energy transmission. The present work analyzes the copper content variation and its influence in electrical conductivity, tensile strength and in studied alloy ductility. The refined Al-0,6% Mg-0,8% Si studied alloy was modified with the following contents: [0,05; 0,10; 0,20 e 0,30]% Cu and unidirectional solidified. The test specimen were machined to 10 mm diameter and rolled to 3,98 mm, whose deformation rate was 60,2%. The obtained wires were mechanical, electrical and structural characterized and the mechanical and electrical characterization results were associated to fractures of evaluated micro cavities. The highest observation was the Cu content in alloy increases the TS, decreases electrical conductivity and increases liquidus isotherm's velocity, forming micro cavities. (author)

  12. Corrosion of high-density sintered tungsten alloys

    International Nuclear Information System (INIS)

    Batten, J.J.; Moore, B.T.

    1989-01-01

    In comparative corrosion tests, the corrosion resistance of an Australian tungsten alloy (95% W, 3.5% Ni, 1.5% Fe) was found to be superior to three other tungsten alloys and, under certain conditions, even more corrosion-resistant than pure tungsten. Corrosion resistance was evaluated after immersion in both distilled water and 5% sodium chloride solutions, and in cyclic humidity and salt mist environments. For all but the Australian alloy, the rate of corrosion in sodium chloride solution was markedly less than that in distilated water. In all cases, alloys containing copper had the greatest corrosion rates. Corrosion mechanisms were investigated using a scanning electron microscope, analysis of corrosion products and galvanic corrosion studies. For the alloys, corrosion was attributed primarily to a galvanic reaction. Whether the tungsten or binder phase of the alloy became anodic, and thus was attacked preferentially, depended upon alloy composition and corrosion environment. 16 refs., 4 tabs., 4 figs

  13. Experimental Studies on Al (5.7% Zn) Alloy based Hybrid MMC

    Science.gov (United States)

    Shivaprakash, Y. M.; Ramu, H. C.; Chiranjivee; Kumar, Roushan; Kumar, Deepak

    2018-02-01

    In this investigation, an attempt is made to disperse SiC (20-25 microns) and Gr (15-20 microns) in the aluminium alloy having Zn, Mg and coper as major alloying elements. The composite is further subjected to mechanical testing to determine various properties like hardness, tensile strength and wear resistance. The alloy and composite samples were tested in the un heat treated conditions. All the tests were done at the laboratory conditions as per ASTM standards. The Pin-On-Disc tribometer is used to test the two-body abrasive sliding wear behaviour in dry conditions. The wear pattern is analysed by the optical images of worn surface taken in an inverted metallurgical microscope. The calculated density is found to be reducing as the SiC and Gr quantity is increased in the base alloy. The as cast Al alloy was found to be having highest hardness. The introduction of SiC tend to increase the hardness and UTS, since Gr is also introduced simultaneously which tends to reduce the hardness and UTS of composite. The composite having highest quantity of Gr showed superior wear resistance which is mainly because the Gr particulates provide an inbuilt lubricating properties to composite. The analysis of images of worn surface showed the abrasive and delamination pattern of wear. The composites developed in the present work can be used in the automobile and aerospace parts that are light in weight and require self-lubricating properties to enhance the wear resistance.

  14. Tensile strength/yield strength (TS/YS) ratios of high-strength steel (HSS) reinforcing bars

    Science.gov (United States)

    Tavio, Anggraini, Retno; Raka, I. Gede Putu; Agustiar

    2018-05-01

    The building codes such as American Concrete Institute (ACI) 318M-14 and Standard National Indonesia (SNI) 2847:2013 require that the ratio of tensile strength (TS) and yield strength (YS) should not less than 1.25. The requirement is based on the assumption that a capability of a structural member to develop inelastic rotation capacity is a function of the length of the yield region. This paper reports an investigation on various steel grades, namely Grades 420, 550, 650, and 700 MPa, to examine the impact of different TS/YS ratios if it is less or greater than the required value. Grades 550, 650, and 700 MPa were purposely selected with the intention to examine if these higher grades are still promising to be implemented in special structural systems since they are prohibited by the building codes for longitudinal reinforcement, whereas Grade 420 MPa bars are the maximum limit of yield strength of reinforcing bars that is allowable for longitudinal reinforcement of special structural systems. Tensile tests of these steel samples were conducted under displacement controlled mode to capture the complete stress-strain curves and particularly the post-yield response of the steel bars. From the study, it can be concluded that Grade 420 performed higher TS/YS ratios and they were able to reach up to more than 1.25. However, the High Strength Still (HSS) bars (Grades 550, 600, and 700 MPa) resulted in lower TS/YS ratios (less than 1.25) compared with those of Grade 420 MPa.

  15. Determination of impurities in uranium--niobium (7.5%)--zirconium (2.5%) alloy

    Energy Technology Data Exchange (ETDEWEB)

    Arragon, Y

    1973-10-01

    The determination of 11 impurities in uranium--niobium-- zirconium alloys was studied. Elements of which the alloy is composed are considered and information is given on the determination of niobium by niobic acid precipitation. Selective elimination of the three components is discussed. Two liquid-liquid extractions are used. The nioblum is separated by methylisobutylketone in a hydrochloric --hydrofluoric medium and the zirconium and uranium by tributyl phosphate in a nitric medium. The determination of trace elements using electrochemical methods is discussed. Anodic re-dissolution polarography or square wave polarography enabled six elements (cadmium, copper, lead, zinc, bismuth, and thallium) to be determined in a carbonate medium together with aluminium in tetraethylammonium perchlorate, molybdenum in nitric acid, ammonium nitrate, and tungsten in hydrochloric acid with added double sodium and potassium tartrate. Fluorine was determined using ionometric techniques with a specific electrode and carbon was titrated by conductometry after combustion of the sample in an oxygen current. (auth)

  16. Growth dependent magnetization reversal in Co2MnAl full Heusler alloy thin films

    Science.gov (United States)

    Barwal, Vineet; Husain, Sajid; Behera, Nilamani; Goyat, Ekta; Chaudhary, Sujeet

    2018-02-01

    Angular dependent magnetization reversal has been investigated in Co2MnAl (CMA) full Heusler alloy thin films grown on Si(100) at different growth temperatures (Ts) by DC-magnetron sputtering. An M -shaped curve is observed in the in-plane angular (0°-360°) dependent coercivity (ADC) by magneto-optical Kerr effect measurements. The dependence of the magnetization reversal on Ts is investigated in detail to bring out the structure-property correlation with regards to ADC in these polycrystalline CMA thin films. This magnetization reversal ( M -shaped ADC behavior) is well described by the two-phase model, which is a combination of Kondorsky (domain wall motion) and Stoner Wohlfarth (coherent rotation) models. In this model, magnetization reversal starts with depinning of domain walls, with their gradual displacement explained by the Kondorsky model, and at a higher field (when the domain walls merge), the system follows coherent rotation before reaching its saturation following the Stoner Wohlfarth model. Further, the analysis of angular dependent squareness ratio (Mr/Ms) indicates that our films clearly exhibited twofold uniaxial anisotropy, which is related to self-steering effect arising due to the obliquely incident flux during the film-growth.

  17. Study of phase transformation of U-2,5Zr-7,5Nb e U-3Zr-9Nb alloys for application in advanced nuclear fuel; Estudo das transformacoes de fases nas ligas U-2,5Zr-7,5Nb e U-3Zr-9Nb para aplicacao em combustivel nuclear avancado

    Energy Technology Data Exchange (ETDEWEB)

    Pais, Rafael Witter Dias

    2015-07-01

    Metal fuels are relevant in the nuclear area due to the versatility of its use in the nuclear fuel cycle. Among the alloys of uranium investigated with high potential for use in nuclear power reactors, U-Zr-Nb alloys appear as an important alternative because of their superior physico-chemical and metallurgical properties. These alloys have also potential for use in nuclear testing, research and production radioisotopes of high performance nuclear reactors. Therefore, the development of these alloys is strategic since they are planned to be used in national reactors as RMB (Brazilian Multipurpose Reactor) and LABGENE (Electrical Generation Core Laboratory), currently under development in Brazil. In this work it was realized a extensive study in the scope of the manufacturing, heat treatment and phase transformations of U-2,5Zr-7,5Nb (m/m%) and U-3ZR-9NB (m/m%) fuel alloys. Ingots of both alloys were produced employing a specific methodology developed in this study. This methodology comprised the melting process in a vacuum induction furnace at high temperatures (1500 °C) and thermal-mechanical processing to break the as-cast structure. Samples with typical dimensions (17 x 7 x 2.5 mm) free from macrostructural defects were homogenized at 1000 °C in vacuum of 10{sup -5} torr for 17.5 hours with a 10°C/min cooling rate until to 820 °C and, subsequently, quenched in water. The samples, randomly selected, were subjected to isothermal treatment tests under different conditions of time and temperature. Isothermal treatments for transformation and retention phases were carried out in a special assembly designed for this work. After the tests, the samples were characterized by the usual phase characterization techniques with particular emphasis for the X-ray diffraction technique. In this way, the Rietveld refinement method was applied. In the case of uranium based alloys it is quite challenging due to the lack of data in the literature. In this work a strategy for the

  18. PFCRT and DHFR-TS Sequences for Monitoring Drug Resistance in ...

    African Journals Online (AJOL)

    Erah

    from falciparum malaria isolates collected in Adzopé City, Côte d'Ivoire in 2007. Methods: Blood ... performed using specific primers of pfcrt and dhfr-ts. During the study .... The following mixture was prepared to a final volume of 50 ..... following the withdrawal of these anti- malarials as ... Malaria vaccines in Africa. Acta Trop.

  19. Preparation, crystallography, magnetic and magnetothermal properties of Ce5SixGe4-x alloys

    Energy Technology Data Exchange (ETDEWEB)

    Vijayaraghavan, Rangarajan [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    An investigation of the crystal structure and the phase relationships in the Ce5Si4-xGex system has been carried out. The crystal structures of the single phase intermetallics were characterized using X-ray powder diffraction and subsequent refinement employing the Rietveld analysis technique was performed. The intermetallic system was found to crystallize in three distinct crystal structures. The Ce5Si4-based solid solution extends from x = 0 to x = 2.15 and it was found to crystallize in the well-known Zr5Si4-type tetragonal structure. The germanium rich alloys, where 3.1 ≤} x ≤ 4, crystallized in the Sm5Ge4-type orthorhombic structure. The crystal structure of the intermediate phase, when 2.35 ≤ x ≤ 2.8, was found out to be of the Gd5Si2Ge2-type monoclinic structure. Microhardness tests were conducted on the samples in order to probe the trend in mechanical properties in this alloy system as a function of Ge concentration. The magnetic, thermal and magnetocaloric properties of the Ce5Si4-xGex alloy system have been investigated for x = 0, 1.0, 1.8, 2.5, 2.8, 3.5, 3.8 and 4.0. The phases with x = 0, 1.0 and 1.8 crystallize in the tetragonal Zr5Si4 structure and those with x = 2.5, 2.8 form in the Gd5Si2Ge2-type monoclinic structure. The alloys with x = 3.5, 3.8 and 4.0 crystallize in the Sm5Ge4-type orthorhombic structure. The Curie temperature of the tetragonal phases increases with increasing Ge content. The ordering temperatures of the monoclinic and orthorhombic phases remain nearly unaffected by the composition, with the Curie temperatures of the latter slightly higher than those of the former. All the alloys display evidence of antiferromagnetic interactions in the ground state. The orthorhombic and the

  20. LHC optics determination with proton tracks measured in the CT-PPS detectors in 2016, before TS2

    CERN Document Server

    Nemes, F

    2017-01-01

    Novel optics estimation methods have been developed for the CMS-TOTEM Precision Proton Spectrometer (CT-PPS), in order to determine the horizontal dispersion function $D_{x}$ and the orbit between IP5 and the Roman Pot detectors. The tools have been successfully applied at $\\sqrt{s} = $13 TeV collision energy and $\\beta^{*} = $0.4 m optics with $\\alpha = 370\\,\\mu$rad horizontal crossing angle (settings valid in 2016 before Technical Stop 2 - TS2).

  1. Effect of Al content on structure and mechanical properties of the Al{sub x}CrNbTiVZr (x = 0; 0.25; 0.5; 1) high-entropy alloys

    Energy Technology Data Exchange (ETDEWEB)

    Yurchenko, N.Yu. [Laboratory of Bulk Nanostructured Materials, Belgorod State University, Belgorod 308015 (Russian Federation); Stepanov, N.D., E-mail: stepanov@bsu.edu.ru [Laboratory of Bulk Nanostructured Materials, Belgorod State University, Belgorod 308015 (Russian Federation); Shaysultanov, D.G. [Laboratory of Bulk Nanostructured Materials, Belgorod State University, Belgorod 308015 (Russian Federation); Tikhonovsky, M.A. [National Science Center “Kharkov Institute of Physics and Technology”, NAS of Ukraine, Kharkov, 61108 (Ukraine); Salishchev, G.A. [Laboratory of Bulk Nanostructured Materials, Belgorod State University, Belgorod 308015 (Russian Federation)

    2016-11-15

    In present study, structure and mechanical properties of the Al{sub x}CrNbTiVZr (x = 0; 0.25; 0.5; 1) high-entropy alloys after arc melting and annealing at 1200 °C for 24 h are investigated. The CrNbTiVZr alloy is composed of body centered cubic (bcc) and C15 (face centered cubic) Laves phases while the Al{sub x}CrNbTiVZr (x = 0.25; 0.5; 1) alloys consist of bcc and two C14 (hexagonal close packed) Laves phases with different chemical compositions. Thermodynamic modeling predicts existence of two phases – bcc and C15 Laves phase and broadening of single bcc phase field due to Al addition. The density of the alloys decreases with the increase of Al content. The alloys are found to be extremely brittle at room temperature and 600 °C. The alloys have high strength at temperatures of 800–1000 °C. For example, yield strength at 800 °C increases from 440 MPa for the CrNbTiVZr alloy to 1250 MPa for the AlCrNbTiVZr alloy. The experimental phase composition of the Al{sub x}CrNbTiVZr alloys is compared with predicted equilibrium phases and the factors governing the transformation of C15 to C14 Laves phases due to Al addition to the CrNbTiVZr alloy analyzed. Specific properties of the alloys are compared with other high-entropy alloys and commercial Ni-based superalloys. - Highlights: •Al{sub x}CrNbTiVZr (x = 0; 0.25; 0.5; 1) alloys are arc melted and annealed at 1200 °C. •The CrNbTiVZr alloy has bcc and C15 Laves phases. •The Al-containing alloys are composed of bcc and two C14 Laves phases. •The alloys demonstrate high specific strength at temperatures of 800 °C and 1000 °C. •The strength of the alloys increases in proportion with increase of Al content.

  2. Effect of cobalt on microstructure and properties of AlCr1.5CuFeNi2Cox high-entropy alloys

    Science.gov (United States)

    Kukshal, Vikas; Patnaik, Amar; Bhat, I. K.

    2018-04-01

    The present paper investigates the effect of Co addition on the alloying behaviour, microstructure and the resulting properties of cast AlCr1.5CuFeNi2Cox high-entropy alloys intended to be used for high temperature applications. The elements Al, Cr, Cu, Fe, Ni and Co (Purity > 99) weighing approximately 800 g was melted in a high temperature vacuum induction furnace. The microstructure, phase transformation, density, microhardness and compressive strength of the samples were analysed using x-ray diffraction (XRD), scanning electron microscopes (SEM), Vickers microhardness tester and universal Testing machine. The crystalline structure of the alloys exhibits simple FCC and BCC phases. The microstructures investigation of the alloys shows the segregation of copper in the interdendritic region resulting in Cu-rich FCC phase. The addition of Co further enhances the formation of FCC phase resulting in the decrease in micro hardness value of the alloys, which varies from 471 HV to 364 HV with increase in the cobalt content from x = 0 to x = 1 (molar ratio). The similar decreasing trend is also observed for the compressive strength of the alloys.

  3. Automotive standard ISO/TS 16949 as a quality determinant

    Directory of Open Access Journals (Sweden)

    Joanna Rosak-Szyrocka

    2016-03-01

    Full Text Available The main aim of this paper is to present the standard ISO/TS 16949. In the modern world of competition, quality is one of the most important factors. Modern organizations should gamble on quality, regardless of the type of business, because it is the basic form of running a business effectively. It is not only a factor of market success, but also an indication of organizational culture.

  4. The terminal solid solubility of hydrogen and deuterium in Zr-2.5Nb alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ritchie, I G; Pan, Z L; Puls, M P [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

    1997-02-01

    The presence of hydrides in zirconium based alloys is an important factor in assessing the potential for delayed hydride cracking in pressure tubes and the embrittlement of other in-core components fabricated from these alloys. Consequently, the terminal solid solubility (TSS) of hydrogen in the zirconium alloys used in the Nuclear Industry is an important parameter. However, at the low hydrogen concentrations found in practice, the TSS is difficult to measure accurately and even the measurements of hydrogen concentrations by standard techniques are notoriously difficult to make reproducibly at the nominal levels found in pressure tube materials. The presence of hydrides, their dissolution and nucleation gives rise to a number of internal friction phenomena and changes in Young`s modulus that can be useful from the practical point of view. These phenomena can be used to establish expressions for the TSS as a function of temperature, the hysteresis between dissolution and nucleation and hydrogen supercharging from the gas phase. In particular, such studies show that the hysteresis between the TSS measured during heating and cooling is particularly sensitive to the thermal history of the sample. This paper reviews the phenomena involved and presents some recent results on Zr-2.5Nb pressure tube material. (author). 28 refs, 17 figs, 6 tabs.

  5. In vitro bio-functional performances of the novel superelastic beta-type Ti–23Nb–0.7Ta–2Zr–0.5N alloy

    International Nuclear Information System (INIS)

    Ion, Raluca; Gordin, Doina-Margareta; Mitran, Valentina; Osiceanu, Petre; Dinescu, Sorina; Gloriant, Thierry; Cimpean, Anisoara

    2014-01-01

    The materials used for internal fracture fixations and joint replacements are mainly made of metals which still face problems ranging from higher rigidity than that of natural bone to leaching cytotoxic metallic ions. Beta (β)-type titanium alloys with low elastic modulus made from non-toxic and non-allergenic elements are desirable to reduce stress shielding effect and enhance bone remodeling. In this work, a new β-type Ti–23Nb–0.7Ta–2Zr–0.5N alloy with a Young's modulus of approximately 50 GPa was designed and characterized. The behavior of MC3T3-E1 pre-osteoblasts on the new alloy, including adhesion, proliferation and differentiation, was evaluated by examining the cytoskeleton, focal adhesion formation, metabolic activity and extracellular matrix mineralization. Results indicated that the pre-osteoblast cells exhibited a similar degree of attachment and growth on Ti–23Nb–0.7Ta–2Zr–0.5N and Ti–6Al–4V. However, the novel alloy proved to be significantly more efficient in sustaining mineralized matrix deposition upon osteogenic induction of the cells than Ti–6Al–4V control. Further, the analysis of RAW 264.7 macrophages cytokine gene and protein expression indicated no significant inflammatory response. Collectively, these findings suggest that the Ti–23Nb–0.7Ta–2Zr–0.5N alloy, which has an increased mechanical biocompatibility with bone, allows a better osteogenic differentiation of osteoblast precursor cells than Ti–6Al–4V and holds great potential for future clinical prosthetic applications. - Highlights: • A new low modulus (∼ 50 GPa) β-type Ti–23Nb–0.7Ta–2Zr–0.5N alloy was synthesized. • In vitro response of MC3T3-E1 pre-osteoblasts and RAW 264.7 macrophages was studied. • Cellular response to Ti–23Nb–0.7Ta–2Zr–0.5N and Ti6Al4V was almost identical. • Ti–23Nb–0.7Ta–2Zr–0.5N alloy is more efficient in sustaining matrix mineralization. • No significant inflammatory response was

  6. In vitro bio-functional performances of the novel superelastic beta-type Ti–23Nb–0.7Ta–2Zr–0.5N alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ion, Raluca [University of Bucharest, Department of Biochemistry and Molecular Biology, 91–95 Spl. Independentei, 050095, Bucharest (Romania); Gordin, Doina-Margareta [INSA Rennes, UMR CNRS 6226 SCR/Chimie-Métallurgie, 20 avenue des Buttes de Coësmes, F-35043 Rennes Cedex (France); Mitran, Valentina [University of Bucharest, Department of Biochemistry and Molecular Biology, 91–95 Spl. Independentei, 050095, Bucharest (Romania); Osiceanu, Petre [Institute of Physical Chemistry “Ilie Murgulescu”, 202 Spl. Independentei, 060021 Bucharest (Romania); Dinescu, Sorina [University of Bucharest, Department of Biochemistry and Molecular Biology, 91–95 Spl. Independentei, 050095, Bucharest (Romania); Gloriant, Thierry [INSA Rennes, UMR CNRS 6226 SCR/Chimie-Métallurgie, 20 avenue des Buttes de Coësmes, F-35043 Rennes Cedex (France); Cimpean, Anisoara, E-mail: anisoara.cimpean@bio.unibuc.ro [University of Bucharest, Department of Biochemistry and Molecular Biology, 91–95 Spl. Independentei, 050095, Bucharest (Romania)

    2014-02-01

    The materials used for internal fracture fixations and joint replacements are mainly made of metals which still face problems ranging from higher rigidity than that of natural bone to leaching cytotoxic metallic ions. Beta (β)-type titanium alloys with low elastic modulus made from non-toxic and non-allergenic elements are desirable to reduce stress shielding effect and enhance bone remodeling. In this work, a new β-type Ti–23Nb–0.7Ta–2Zr–0.5N alloy with a Young's modulus of approximately 50 GPa was designed and characterized. The behavior of MC3T3-E1 pre-osteoblasts on the new alloy, including adhesion, proliferation and differentiation, was evaluated by examining the cytoskeleton, focal adhesion formation, metabolic activity and extracellular matrix mineralization. Results indicated that the pre-osteoblast cells exhibited a similar degree of attachment and growth on Ti–23Nb–0.7Ta–2Zr–0.5N and Ti–6Al–4V. However, the novel alloy proved to be significantly more efficient in sustaining mineralized matrix deposition upon osteogenic induction of the cells than Ti–6Al–4V control. Further, the analysis of RAW 264.7 macrophages cytokine gene and protein expression indicated no significant inflammatory response. Collectively, these findings suggest that the Ti–23Nb–0.7Ta–2Zr–0.5N alloy, which has an increased mechanical biocompatibility with bone, allows a better osteogenic differentiation of osteoblast precursor cells than Ti–6Al–4V and holds great potential for future clinical prosthetic applications. - Highlights: • A new low modulus (∼ 50 GPa) β-type Ti–23Nb–0.7Ta–2Zr–0.5N alloy was synthesized. • In vitro response of MC3T3-E1 pre-osteoblasts and RAW 264.7 macrophages was studied. • Cellular response to Ti–23Nb–0.7Ta–2Zr–0.5N and Ti6Al4V was almost identical. • Ti–23Nb–0.7Ta–2Zr–0.5N alloy is more efficient in sustaining matrix mineralization. • No significant inflammatory response was

  7. A new insight into high-strength Ti62Nb12.2Fe13.6Co6.4Al5.8 alloys with bimodal microstructure fabricated by semi-solid sintering.

    Science.gov (United States)

    Liu, L H; Yang, C; Kang, L M; Qu, S G; Li, X Q; Zhang, W W; Chen, W P; Li, Y Y; Li, P J; Zhang, L C

    2016-03-31

    It is well known that semi-solid forming could only obtain coarse-grained microstructure in a few alloy systems with a low melting point, such as aluminum and magnesium alloys. This work presents that semi-solid forming could also produce novel bimodal microstructure composed of nanostructured matrix and micro-sized (CoFe)Ti2 twins in a titanium alloy, Ti62Nb12.2Fe13.6Co6.4Al5.8. The semi-solid sintering induced by eutectic transformation to form a bimodal microstructure in Ti62Nb12.2Fe13.6Co6.4Al5.8 alloy is a fundamentally different approach from other known methods. The fabricated alloy exhibits high yield strength of 1790 MPa and plastic strain of 15.5%. The novel idea provides a new insight into obtaining nano-grain or bimodal microstructure in alloy systems with high melting point by semi-solid forming and into fabricating high-performance metallic alloys in structural applications.

  8. Creep of titanium--silicon alloys

    International Nuclear Information System (INIS)

    Paton, N.E.; Mahoney, M.W.

    1976-01-01

    Operative creep mechanisms in laboratory melts of Ti-5Zr-0.5Si and Ti-5Zr-0.5Si have been investigated as a function of microstructure, creep stress, and temperature. From creep rate data and transmission electron microscopy results, it has been shown that an important creep strengthening mechanism at 811 0 K in Si-bearing Ti alloys is clustering of solute atoms on dislocations. All of the alloys investigated showed anomalously high apparent activation energies and areas for creep and a high exponent (n) in the Dorn equation. In addition, the effect of heat treatment was investigated and it is shown that the highest creep strength was obtained by using a heat treatment which retained the maximum amount of silicon in solution. This is consistent with the proposed creep strengthening mechanism. An investigation of the creep behavior of several other Si containing alloys including two commercial alloys, Ti-11 and IMI-685 indicated similar results. 12 fig., 6 tables

  9. Hysteresis properties of conventionally annealed and Joule-heated nanocrystalline Fe73.5Cu1Nb3Si13.5B9 alloys

    International Nuclear Information System (INIS)

    Tiberto, P.; Basso, V.; Beatrice, C.; Bertotti, G.

    1996-01-01

    The dependence of magnetic properties on the thermal treatment used to induce the amorphous-to-nanocrystalline transformation in Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 alloy has been studied. Quasi-static hysteresis loops and initial permeability measurements were performed on nanocrystalline samples obtained by conventional annealing and Joule heating. A comparison between the magnetic properties of nanocrystalline samples obtained by the two heating procedures is presented. (orig.)

  10. Relaxation resistance of heat resisting alloys with cobalt

    International Nuclear Information System (INIS)

    Borzdyka, A.M.

    1977-01-01

    Relaxation resistance of refractory nickel-chromium alloys containing 5 to 14 % cobalt is under study. The tests involve the use of circular samples at 800 deg to 850 deg C. It is shown that an alloy containing 14% cobalt possesses the best relaxation resistance exceeding that of nickel-chromium alloys without any cobalt by a factor of 1.5 to 2. The relaxation resistance of an alloy with 5% cobalt can be increased by hardening at repeated loading

  11. Observations of a Cast Cu-Cr-Zr Alloy

    Science.gov (United States)

    Ellis, David L.

    2006-01-01

    Prior work has demonstrated that Cu-Cr-Nb alloys have considerable advantages over the copper alloys currently used in regeneratively cooled rocket engine liners. Observations indicated that Zr and Nb have similar chemical properties and form very similar compounds. Glazov and Zakharov et al. reported the presence of Cr2Zr in Cu-Cr-Zr alloys with up to 3.5 wt% Cr and Zr though Zeng et al. calculated that Cr2Zr could not exist in a ternary Cu-Cr-Zr alloy. A cast Cu-6.15 wt% Cr-5.25 wt% Zr alloy was examined to determine if the microstructure developed would be similar to GRCop-84 (Cu-6.65 wt% Cr-5.85 wt% Nb). It was observed that the Cu-Cr-Zr system did not form any Cr2Zr even after a thermal exposure at 875 C for 176.5 h. Instead the alloy consisted of three phases: Cu, Cu5Zr, and Cr.

  12. Role of nano-precipitation on the microstructure and shape memory characteristics of a new Ni_5_0_._3Ti_3_4_._7Zr_1_5 shape memory alloy

    International Nuclear Information System (INIS)

    Evirgen, A.; Karaman, I.; Pons, J.; Santamarta, R.; Noebe, R.D.

    2016-01-01

    The microstructure and shape memory characteristics of the Ni_5_0_._3Ti_3_4_._7Zr_1_5 shape memory alloy were investigated as a function of aging heat treatments that result in nanometer to submicron size precipitates. Microstructure–property relationships were developed by characterizing samples using transmission electron microscopy, differential scanning calorimetry, and load-biased thermal cycling experiments. The precipitate size was found to strongly influence the martensitic transformation–precipitate interactions and ultimately the shape memory characteristics of the alloy. Aging treatments resulting in relatively fine precipitates, which are not an obstacle to twin boundaries and easily bypassed by martensite variants, exhibited higher transformation strain, lower transformation thermal hysteresis, and better thermal and dimensional stability compared to samples with relatively large precipitates. When precipitate dimensions approached several hundred nanometers in size they acted as obstacles to martensite growth, limiting martensite variant and twin size resulting in reduced functional and structural properties. Aging heat treatments were also shown to result in a wide range of transformation temperatures, increasing them above 100 °C in some cases, and affected the stress dependence of the transformation hysteresis and the stress versus transformation temperature relationships for the Ni_5_0_._3Ti_3_4_._7Zr_1_5 alloy.

  13. Electrical Resistance Alloys and Low-Expansion Alloys

    DEFF Research Database (Denmark)

    Kjer, Torben

    1996-01-01

    The article gives an overview of electrical resistance alloys and alloys with low thermal expansion. The electrical resistance alloys comprise resistance alloys, heating alloys and thermostat alloys. The low expansion alloys comprise alloys with very low expansion coefficients, alloys with very low...... thermoelastic coefficients and age hardenable low expansion alloys....

  14. Fabrication and Magnetic Properties of Co₂MnAl Heusler Alloys by Mechanical Alloying.

    Science.gov (United States)

    Lee, Chung-Hyo

    2018-02-01

    We have applied mechanical alloying (MA) to produce nanocrystalline Co2MnAl Heusler alloys using a mixture of elemental Co50Mn25Al25 powders. An optimal milling and heat treatment conditions to obtain a Co2MnAl Heusler phase with fine microstructure were investigated by X-ray diffraction, differential scanning calorimeter and vibrating sample magnetometer measurements. α-(Co, Mn, Al) FCC phases coupled with amorphous phase are obtained after 3 hours of MA without any evidence for the formation of Co2MnAl alloys. On the other hand, a Co2MnAl Heusler alloys can be obtained by the heat treatment of all MA samples up to 650 °C. X-ray diffraction result shows that the average grain size of Co2MnAl Heusler alloys prepared by MA for 5 h and heat treatment is in the range of 95 nm. The saturation magnetization of MA powders decreases with MA time due to the magnetic dilution by alloying with nonmagnetic Mn and Al elements. The magnetic hardening due to the reduction of the grain size with ball milling is also observed. However, the saturation magnetization of MA powders after heat treatment increases with MA time and reaches to a maximum value of 105 emu/g after 5 h of MA. It can be also seen that the coercivity of 5 h MA sample annealed at 650 °C is fairly low value of 25 Oe.

  15. Anomalous grain growth in nanocrystalline Fe73.5Cu1Nb3Su13.5B9 alloys

    DEFF Research Database (Denmark)

    Jiang, Jianzhong

    1997-01-01

    The grain growth of the FeSi phase during the crystallization process of the amorphous Fe73.5Cu1Nb3Si13.5B9 alloy was studied using transmission electron microscopy and x-ray diffractometry. An anomalous grain growth behaviour of the FeSi phase in the samples annealed in temperature range from 743...... to 823 K for one hour was observed, i.e. the grain size of the FeSi phase slightly decreases when the annealing temperature increases from 743 K ot 823 K. The mechanism of the anomalous grain growth may be due to the different nucleation and volume diffusion rates in the samples anneales at low and high...

  16. Effect of Nd on the corrosion behaviour of AM50 and AZ91D magnesium alloys in 3.5 wt.% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Arrabal, R., E-mail: raularrabal@quim.ucm.es [Departamento de Ciencia de Materiales, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain); Pardo, A.; Merino, M.C.; Mohedano, M.; Casajus, P. [Departamento de Ciencia de Materiales, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain); Paucar, K. [Gabinete de Corrosion, Facultad de Ingenieria Quimica y Textil, Universidad Nacional de Ingenieria, Cod. Postal 25, Lima (Peru); Garces, G. [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Nd addition modified the microstructure of AM50 and AZ91D magnesium alloys. Black-Right-Pointing-Pointer Volume of {beta}-Mg{sub 17}Al{sub 12} phase was reduced and Al{sub 2}Nd/Al-Mn-Nd particles were formed. Black-Right-Pointing-Pointer Nd-containing intermetallics revealed lower potential than Al-Mn inclusions. Black-Right-Pointing-Pointer 0.7-0.8 wt.% Nd reduced the corrosion rate of AM50 and AZ91D alloys by 90%. - Abstract: The corrosion performance of AM50 and AZ91D alloys containing up to 1.5 wt.% Nd was investigated by electrochemical and gravimetric measurements in 3.5 wt.% NaCl at 22 Degree-Sign C. The alloys were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and surface potential maps. In Nd-containing alloys, formation of Al{sub 2}Nd and Al-Mn-Nd intermetallic compounds reduced the volume fraction and modified the morphology of the {beta}-Mg{sub 17}Al{sub 12} phase. The addition of Nd improved the corrosion resistance of the alloys due to increased passivity of the surface film and suppression of micro-galvanic couples.

  17. Experimental data report for Test TS-2 reactivity initiated accident test in NSRR with pre-irradiated BWR fuel rod

    International Nuclear Information System (INIS)

    Nakamura, Takehiko; Yoshinaga, Makio; Sobajima, Makoto; Fujishiro, Toshio; Kobayashi, Shinsho; Yamahara, Takeshi; Sukegawa, Tomohide; Kikuchi, Teruo

    1993-02-01

    This report presents experimental data for Test TS-2 which was the second test in a series of Reactivity Initiated Accident (RIA) condition test using pre-irradiated BWR fuel rods, performed at the Nuclear Safety Research Reactor (NSRR) in February, 1990. Test fuel rod used in the Test TS-2 was a short sized BWR (7x7) type rod which was fabricated from a commercial rod irradiated at Tsuruga Unit 1 power reactor. The fuel had an initial enrichment of 2.79% and a burnup of 21.3Gwd/tU (bundle average). A pulse irradiation of the test fuel rod was performed under a cooling condition of stagnant water at atmospheric pressure and at ambient temperature which simulated a BWR's cold start-up RIA event. The energy deposition of the fuel rod in this test was evaluated to be 72±5cal/g·fuel (66±5cal/g·fuel in peak fuel enthalpy) and no fuel failure was observed. Descriptions on test conditions, test procedures, transient behavior of the test rod during the pulse irradiation, and, results of pre and post pulse irradiation examinations are described in this report. (author)

  18. Formation of SmFe5(0001) ordered alloy thin films on Cu(111) single-crystal underlayers

    International Nuclear Information System (INIS)

    Yabuhara, Osamu; Ohtake, Mitsuru; Nukaga, Yuri; Futamoto, Masaaki; Kirino, Fumiyoshi

    2010-01-01

    SmFe 5 (0001) single-crystal thin films are prepared by molecular beam epitaxy employing Cu(111) single-crystal underlayers on MgO(111) substrates. The Cu atoms diffuse into the Sm-Fe layer and substitute the Fe sites in SmFe 5 structure forming an alloy compound of Sm(Fe,Cu) 5 . The Sm(Fe,Cu) 5 film is more Cu enriched with increasing the substrate temperature. The Cu underlayer plays an important role in assisting the formation of the ordered phase.

  19. Thermoelectric properties of p-type pseudo-binary (Ag0.365Sb0.558Te) x -(Bi0.5Sb1.5Te3)1-x (x=0-1.0) alloys prepared by spark plasma sintering

    International Nuclear Information System (INIS)

    Cui, J.L.; Xue, H.F.; Xiu, W.J.; Jiang, L.; Ying, P.Z.

    2006-01-01

    In this paper, pseudo-binary (Ag 0.365 Sb 0.558 Te) x -(Bi 0.5 Sb 1.5 Te 3 ) 1- x (x=0-1.0) alloys were prepared using spark plasma sintering technique, and the composition-dependent thermoelectric properties were evaluated. Electrical conductivities range from 7.9x10 4 to 15.6x10 4 Ω -1 m -1 at temperatures of 507 and 318 K, respectively, being about 3.0 and 8.5 times those of Bi 0.5 Sb 1.5 Te 3 alloy at the corresponding temperatures. The optimal dimensionless figure of merit (ZT) of the sample with molar fraction x=0.025 reaches 1.1 at 478 K, whereas that of the ternary Bi 0.5 Sb 1.5 Te 3 alloy is 0.58 near room temperature. The results also reveal that a direct introduction of Ag 0.365 Sb 0.558 Te in the Bi-Sb-Te system is much more effective to the property improvement than naturally precipitated Ag 0.365 Sb 0.558 Te in the Ag-doped Ag-Bi-Sb-Te system. - Graphical abstract: The temperature dependence of the dimensionless thermoelectric figure of merit ZT for different (Ag 0.365 Sb 0.558 Te) x -(Bi 0.5 Sb 1.5 Te 3 ) 1- x (x=0-1.0) alloys prepared by spark plasma sintering

  20. Microstructure, mechanical properties, in vitro degradation and cytotoxicity evaluations of Mg-1.5Y-1.2Zn-0.44Zr alloys for biodegradable metallic implants.

    Science.gov (United States)

    Fan, Jun; Qiu, Xin; Niu, Xiaodong; Tian, Zheng; Sun, Wei; Liu, Xiaojuan; Li, Yangde; Li, Weirong; Meng, Jian

    2013-05-01

    Mg-1.5Y-1.2Zn-0.44Zr alloys were newly developed as degradable metallic biomaterials. A comprehensive investigation of the microstructure, mechanical properties, in vitro degradation assessments and in vitro cytotoxicity evaluations of the as-cast state, as-heat treated state and as-extruded state alloys was done. The microstructure observations show that the Mg-1.5Y-1.2Zn-0.44Zr alloys are mainly composed of the matrix α-Mg phases and the Mg12ZnY secondary phases (LPS structure). The hot extrusion method significantly refined the grains and eliminated the defects of both as-cast and heat treated alloys and thereby contributed to the better mechanical properties and biodegradation resistance. The values of tensile strength and tensile yield strength of the alloy in the as-extruded condition are about 236 and 178 MPa respectively, with an excellent elongation of 28%. Meanwhile, the value of compressive strength is about 471 MPa and the value of bending strength is about 501 MPa. The superior bending strength further demonstrates the excellent ductility of the hot extruded alloys. The results of immersion tests and electrochemical measurements in the SBF indicate that a protective film precipitated on the alloy's surface with the extension of degradation. The protective film contains Mg(OH)2 and hydroxyapatite (HA) which can reinforce osteoblast activity and promote good biocompatibility. No significant cytotoxicity towards L-929 cells was detected and the immersion extracts of alloy samples could enhance the cell proliferation with time in the cytotoxicity evaluations, implying that the Mg-1.5Y-1.2Zn-0.44Zr alloys have the potential to be used for biomedical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. A highly Conserved Aspartic Acid Residue of the Chitosanase from Bacillus Sp. TS Is Involved in the Substrate Binding.

    Science.gov (United States)

    Zhou, Zhanping; Zhao, Shuangzhi; Liu, Yang; Chang, Zhengying; Ma, Yanhe; Li, Jian; Song, Jiangning

    2016-11-01

    The chitosanase from Bacillus sp. TS (CsnTS) is an enzyme belonging to the glycoside hydrolase family 8. The sequence of CsnTS shares 98 % identity with the chitosanase from Bacillus sp. K17. Crystallography analysis and site-direct mutagenesis of the chitosanase from Bacillus sp. K17 identified the important residues involved in the catalytic interaction and substrate binding. However, despite progress in understanding the catalytic mechanism of the chitosanase from the family GH8, the functional roles of some residues that are highly conserved throughout this family have not been fully elucidated. This study focused on one of these residues, i.e., the aspartic acid residue at position 318. We found that apart from asparagine, mutation of Asp318 resulted in significant loss of enzyme activity. In-depth investigations showed that mutation of this residue not only impaired enzymatic activity but also affected substrate binding. Taken together, our results showed that Asp318 plays an important role in CsnTS activity.

  2. Austenitic alloys Fe-Ni-Cr dominating

    International Nuclear Information System (INIS)

    Gibson, R.C.; Korenko, M.K.

    1980-01-01

    Austenitic alloy essentially comprising 42 to 48% nickel, 11 to 13% chromium, 2.6 to 3.4% niobium, 0.2 to 1.2% silicon, 0.5 to 1.5% vanadium, 2.6 to 3.4% molybdenum, 0.1 to 0.3% aluminium, 0.1 to 0.3% titanium, 0.02 to 0.05% carbon, 0.002 to 0.015% boron, up to 0.06% zirconium, the balance being iron. The characteristic of this alloy is a conventional elasticity limit to within 2% of at least 450 MPa, with a maximum tensile strength of at least 500 MPa at a test temperature of 650 0 C after immersion annealing at 1038 0 C and 30% hardening. To this effect the invention concerns Ni-Cr-Fe high temperature alloys possessing excellent mechanical strength characteristics, that can be obtained with lower levels of nickel and chromium than those used in alloys of this kind in the present state of the technique, a higher amount of niobium than in the previous alloys and with the addition of 0.5 to 1.5% vanadium [fr

  3. The effect of texture on delayed hydride cracking in Zr-2.5Nb alloy

    Energy Technology Data Exchange (ETDEWEB)

    Resta Levi, R.; Sagat, S

    1999-09-01

    Pressure tubes for CANDU reactors are made of Zr-2.5Nb alloy. They are produced by hot extrusion followed by cold work, which results in a material with a pronounced crystallographic texture with basal plane normals of its hexagonal structure around the circumferential direction. Under certain conditions, this material is susceptible to a cracking mechanism called delayed hydride cracking (DHC). Our work investigated the susceptibility of Zr-2.5Nb alloy pressure tube to DHC in this pressure tube material, in terms of crystallographic texture and grain shape. The results are presented in terms of crack velocity obtained on different planes and directions of the pressure tube. The results show that it is more difficult for a crack to propagate at right angles to crystallographic basal planes (which are close to the precipitation habit plane of hydrides) than for it to propagate parallel to the basal plane. However, if the cracking plane is oriented parallel to preexisting hydrides (hydrides formed as a result of the manufacturing process), the crack propagates along these hydrides easily, even if the hydride habit planes are not oriented favourably. (author)

  4. Virtual thermal expansion coefficient of Cu precipitated in the Fe95Cu5 alloy

    International Nuclear Information System (INIS)

    Koeszegi, L.; Somogyvari, Z.

    1999-01-01

    Complete text of publication follows. Precipitations on grain boundaries play very important role in the formation of material's characteristics like embrittlement, durability etc. It was already shown [1] that Cu precipitations are under different stress conditions than the bulk material. The situation is more complicated in the case when a construction is exposed to temperature changes as well. In that case not only the residual stresses during the fabrication but the different thermal expansion coefficients can produce additional problems. This situation was modelled using Fe 95 Cu 5 alloy where Cu precipitates on the grain boundaries. The alloy was produced by high-frequency melting and an extra heat treatment was used to produce a quasi-equilibrium state. Pure Cu was also measured to compare the behaviours. Cu(111) Bragg peak was measured at different temperatures by high resolution neutron diffraction. The measurements were carried out on the G5-2 spectrometer at LLB in Saclay. Measurements show that not only residual stress can be recognised on the Cu precipitates but the thermal expansion coefficient of these precipitates definitly differ from the ones of pure Cu. (author)

  5. Microstructure and Mechanical Properties of Al-5Mg-0.8Mn Alloys with Various Contents of Fe and Si Cast under Near-Rapid Cooling

    Directory of Open Access Journals (Sweden)

    Yulin Liu

    2017-10-01

    Full Text Available Al-5Mg-0.8Mn alloys (AA5083 with various iron and silicon contents were cast under near-rapid cooling and rolled into sheets. The aim was to study the feasibility of minimizing the deteriorating level of the harmful Fe-rich phases on the mechanical properties through refining the intermetallics by significantly increasing the casting rate. The results showed that the size and density of the intermetallic particles that remained in the hot bands and the cold rolled sheets increased as the contents of iron and silicon in the alloys were increased. However, the increment of the particle sizes was limited due to the significant refinement of the intermetallics formed during casting under near-rapid cooling. The mechanical properties of the alloys reduced as the contents of iron and silicon in the alloys increased. However, the decrement of tensile strengths and ductility was quite small. Therefore, higher contents of iron and silicon could be used in the Al-5Mg-0.8Mn alloy (AA5083 alloy when the material is cast under near-rapid cooling, such as in the continuous strip casting process.

  6. REAC/TS Radiation Accident Registry: An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Doran M. Christensen, DO, REAC/TS Associate Director and Staff Physician Becky Murdock, REAC/TS Registry and Health Physics Technician

    2012-12-12

    Over the past four years, REAC/TS has presented a number of case reports from its Radiation Accident Registry. Victims of radiological or nuclear incidents must meet certain dose criteria for an incident to be categorized as an “accident” and be included in the registry. Although the greatest numbers of “accidents” in the United States that have been entered into the registry involve radiation devices, the greater percentage of serious accidents have involved sealed sources of one kind or another. But if one looks at the kinds of accident scenarios that have resulted in extreme consequence, i.e., death, the greater share of deaths has occurred in medical settings.

  7. Study of magnetic hardening in Sm(Co/sub 1-x/Cu/sub x/)/sub 5/ alloy

    International Nuclear Information System (INIS)

    Awan, M.S.; Bhatti, A.S.; Farooque, M.

    2008-01-01

    Magnetic hardening has been examined in the samarium (Sm), cobalt (Co) and copper (Cu) fused permanent magnets by correlating the magnetic properties with annealing temperature and microstructure of the samples. For the Sm(Co/sub 1-x/Cu/sub x/)/sub 5/ system, with various copper contents (x=0, 0.2, 0.3, 0.4 and 0.5) the shape of initial magnetization curve indicated that the magnetic hardening process involved in these types of magnets consists of domain wall pinning type. This is consistent with the microstructure studies which show the existence of nonmagnetic Cu-rich precipitates in the Co-rich matrix. Copper substituted samples were annealed in the temperature range (300 -1000) degree C for 3h under the protective atmosphere of argon (Ar) gas. Both cast and annealed samples prepared by tri-arc melting technique exhibit two-phase microstructure responsible for enhanced magnetic properties. Metallographic and surface studies were carried out using a digital optical microscope (OM). X-ray diffraction (XRD) studies confirmed that the alloys solidefied in the hexagonal crystal structure. The lattice parameters and unit cell volume increase with increasing Cu content. Scanning electron microscope (SEM) coupled with energy dispersive X-ray (EDX) was used to examine the surface morphology, compositional variations, elemental segregations, formation and effect of annealing on the different phases. Later these parameters were related to the magnetic properties. Copper-rich phase precipitates in the Co- rich matrix may serves as the pinning centers for the domain wall motion. Introduction of these pinning centers improved the magnetic hardening of the alloy. Annealing the Cu-substituted alloy further improved the magnetic properties. During annealing, diffusion of copper played the key role for enhanced magnetic properties. It was found that both Cu substitution and subsequent annealing are the dominating factors determining the magnetic properties of these magnetic

  8. Effect of Mn and Fe on the Formation of Fe- and Mn-Rich Intermetallics in Al–5Mg–Mn Alloys Solidified Under Near-Rapid Cooling

    Directory of Open Access Journals (Sweden)

    Yulin Liu

    2016-01-01

    Full Text Available Mn was an important alloying element used in Al–Mg–Mn alloys. However, it had to be limited to a low level (<1.0 wt % to avoid the formation of coarse intermetallics. In order to take full advantage of the benefits of Mn, research was carried out to investigate the possibility of increasing the content of Mn by studying the effect of cooling rate on the formation of Fe- and Mn-rich intermetallics at different content levels of Mn and Fe. The results indicated that in Al–5Mg–Mn alloy with low Fe content (<0.1 wt %, intermetallic Al6(Fe,Mn was small in size and amount. With increasing Mn content, intermetallic Al6(Fe,Mn increased, but in limited amount. In high-Fe-containing Al–5Mg–Mn alloys (0.5 wt % Fe, intermetallic Al6(Fe,Mn became the dominant phase, even in the alloy with low Mn content (0.39 wt %. Cooling rate played a critical role in the refinement of the intermetallics. Under near-rapid cooling, intermetallic Al6(Fe,Mn was extremely refined. Even in the high Mn and/or high-Fe-containing alloys, it still demonstrated fine Chinese script structures. However, once the alloy composition passed beyond the eutectic point, the primary intermetallic Al6(Fe,Mn phase displayed extremely coarse platelet-like morphology. Increasing the content of Fe caused intermetallic Al6(Fe,Mn to become the primary phase at a lower Mn content.

  9. The structural representation and properties of mutually incommensurate composite crystal (BiS)xTS2 (T=Ti, V, Nb and Ta)

    International Nuclear Information System (INIS)

    Gotoh, Y.; Fujihisa, H.; Takeya, S.; Yamaguchi, I.

    2006-01-01

    The structural representation of mutually incommensurate composite crystal, (BiS) x TS 2 (T=Ti, V, Nb and Ta), with layered substructures has been described by superspace group approach. The incommensurate composite structures of (BiS) x TS 2 have been successfully characterized by the single-crystal X-ray-diffraction method. Temperature dependences of in-plane electrical resistivity of single composite crystals of (BiS) x TS 2 have been obtained by a standard d.c. four probe method in the range of 1.7-300 K. It has been found that the electronic transport properties of (BiS) x TS 2 compounds show metallic behavior below room temperature. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  10. Thermal isocreep curves obtained during multi-axial creep tests on recrystallized Zircaloy-4 and M5alloy

    International Nuclear Information System (INIS)

    Rautenberg, M.; Poquillon, D.; Pilvin, P.; Grosjean, C.; Cloué, J.M.; Feaugas, X.

    2014-01-01

    Zirconium alloys are widely used in the nuclear industry. Several components, such as cladding or guide tubes, undergo strong mechanical loading during and after their use inside the pressurized water reactors. The current requirements on higher fuel performances lead to the developing on new Zr based alloys exhibiting better mechanical properties. In this framework, creep behaviors of recrystallized Zircaloy-4 and M5™, have been investigated and then compared. In order to give a better understanding of the thermal creep anisotropy of Zr-based alloys, multi-axial creep tests have been carried out at 673 K. Using a specific device, creep conditions have been set using different values of β = σ zz /σ θθ , σ zz and σ θθ being respectively the axial and hoop creep stresses. Both axial and hoop strains are measured during each test which is carried out until stationary creep is stabilized. The steady-state strain rates are then used to build isocreep curves. Considering the isocreep curves, the M5alloy shows a largely improved creep resistance compared to the recrystallized Zircaloy-4, especially for tubes under high hoop loadings (0 < β < 1). The isocreep curves are then compared with simulations performed using two different mechanical models. Model 1 uses a von Mises yield criterion, the model 2 is based on a Hill yield criterion. For both models, a coefficient derived from Norton law is used to assess the stress dependence

  11. Fracture characteristics of uranium alloys by scanning electron microscopy

    International Nuclear Information System (INIS)

    Koger, J.W.; Bennett, R.K. Jr.

    1976-10-01

    The fracture characteristics of uranium alloys were determined by scanning electron microscopy. The fracture mode of stress-corrosion cracking (SCC) of uranium-7.5 weight percent niobium-2.5 weight percent zirconium (Mulberry) alloy, uranium--niobium alloys, and uranium--molybdenum alloys in aqueous chloride solutions is intergranular. The SCC fracture surface of the Mulberry alloy is characterized by very clean and smooth grain facets. The tensile-overload fracture surfaces of these alloys are characteristically ductile dimple. Hydrogen-embrittlement failures of the uranium alloys are brittle and the fracture mode is transgranular. Fracture surfaces of the uranium-0.75 weight percent titanium alloys are quasi cleavage

  12. Fabrication of nanocrystalline alloys Cu–Cr–Mo super satured solid solution by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, C., E-mail: claudio.aguilar@usm.cl [Departamento de Ingeniería Metalúrgica y Materiales, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Guzmán, D. [Departamento de Ingeniería en Metalurgia, Facultad de Ingeniería, Universidad de Atacama y Centro Regional de Investigación y Desarrollo Sustentable de Atacama (CRIDESAT), Av. Copayapu 485, Copiapó (Chile); Castro, F.; Martínez, V.; Cuevas, F. de las [Centro de Estudios e Investigaciones Técnicas de Gipuzkoa, Paseo de Manuel Lardizábal, N° 15, 20018 San Sebastián (Spain); Lascano, S. [Departamento de Ingeniería Mecánica, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Muthiah, T. [Departamento de Ingeniería Metalúrgica y Materiales, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile)

    2014-08-01

    This work discusses the extension of solid solubility of Cr and Mo in Cu processed by mechanical alloying. Three alloys processed, Cu–5Cr–5Mo, Cu–10Cr–10Mo and Cu–15Cr–15Mo (weight%) using a SPEX mill. Gibbs free energy of mixing values 10, 15 and 20 kJ mol{sup −1} were calculated for these three alloys respectively by using the Miedema's model. The crystallite size decreases and dislocation density increases when the milling time increases, so Gibbs free energy storage in powders increases by the presence of crystalline defects. The energy produced by crystallite boundaries and strain dislocations were estimated and compared with Gibbs free energy of mixing values. The energy storage values by the presence of crystalline defects were higher than Gibbs free energy of mixing at 120 h for Cu–5Cr–5Mo, 130 h for Cu–10Cr–10Mo and 150 h for Cu–15Cr–15Mo. During milling, crystalline defects are produced that increases the Gibbs free energy storage and thus the Gibbs free energy curves are moved upwards and hence the solubility limit changes. Therefore, the three alloys form solid solutions after these milling time, which are supported with the XRD results. - Highlights: • Extension of solid solution Cr and Mo in Cu achieved by mechanical alloying. • X-ray characterization of Cu–Cr–Mo system processed by mechanical alloying. • Thermodynamics analysis of formation of solid solution of the Cu–Cr–Mo system.

  13. Surface treatment of new type aluminum lithium alloy and fatigue crack behaviors of this alloy plate bonded with Ti–6Al–4V alloy strap

    International Nuclear Information System (INIS)

    Sun, Zhen-Qi; Huang, Ming-Hui; Hu, Guo-Huai

    2012-01-01

    Highlights: ► A new generation aluminum lithium alloy which special made for Chinese commercial plane was investigated. ► Pattern of aluminum lithium alloy and Ti alloy were shown after anodization. ► Crack propagation of samples bonded with different wide Ti straps were studied in this paper. -- Abstract: Samples consisting of new aluminum lithium alloy (Al–Li alloy) plate developed by the Aluminum Company of America and Ti–6Al–4V alloy (Ti alloy) plate were investigated. Plate of 400 mm × 140 mm × 2 mm with single edge notch was anodized in phosphoric solution and Ti alloy plate of 200 mm × 20 (40) mm × 2 mm was anodized in alkali solution. Patterns of two alloys were studied at original/anodized condition. And then, aluminum alloy and Ti alloy plates were assembled into a sample with FM 94 film adhesive. Fatigue crack behaviors of the sample were investigated under condition of nominal stress σ = 36 MPa and 54 MPa, stress ratio of 0.1. Testing results show that anodization treatment modifies alloys surface topography. Ti alloy bonding to Al–Li alloy plate effectively retards crack growth than that of Al–Li alloy plate. Fatigue life of sample bonded with Ti alloy strap improves about 62.5% than that of non-strap plate.

  14. Evidence of eutectic crystallization and transient nucleation in Al89La6Ni5 amorphous alloy

    International Nuclear Information System (INIS)

    Zhuang, Y. X.; Jiang, J. Z.; Lin, Z. G.; Mezouar, M.; Crichton, W.; Inoue, A.

    2001-01-01

    The phase evolution with the temperature and time in the process of crystallization of Al 89 La 6 Ni 5 amorphous alloy has been investigated by in situ high-temperature and high-pressure x-ray powder diffraction using synchrotron radiation. Two crystalline phases, fcc-Al and a metastable bcc-(AlNi) 11 La 3 -like phase, were identified after the first crystallization reaction, revealing a eutectic reaction instead of a primary reaction suggested in the literature. Time-dependent nucleation in the amorphous alloy is detected and the experimental data can be fitted by both the Zeldovich's and Kashchiev's transient nucleation models with transient nucleation times of 220 and 120 min, respectively. Copyright 2001 American Institute of Physics

  15. Squeeze Casting Method Of AI-Si Alloy For Piston Material

    International Nuclear Information System (INIS)

    Wagiyo, H.; Dani, Muhammad; Sulistioso, G.S.; Pardede, Elman; Handayani, Ari; Teguh, Yulius S.P.P.

    2001-01-01

    The AI-Si alloy is an alloy used as piston material. This alloys could be as AI-Si hypereutectic alloy (Si content more than 12.5 % wt.), as AI-Si eutectic alloy (Si cuntent 12.5 % wt, and as AI-Si hypoeutectic alloy (Si content less than 12.5 % wt.). The synthesize of AI-Si alloy piston generally using the technique of gravity casting in a dies. This method is causing high porousity. By using the squeeze technique, amount ofporousity in AI-Si alloy is possibly reduced and the density of this alloy should be higher. The other factors such as alloying elements of AI-Si alloy (Mg. Cu, Zn) would increase the mechanical properties especially the hardness. The focuses of this research are the microstructure and the maximum hardness during the heat treatment of AI-Si alloy which was added by alloying elments. The result of hardness at test shows the maximum hardness at 94.7 kg/mm 2 obtained at aging temperature of 210 o C for hours with homogenous dendritic microstructure

  16. La grossesse chez l'adolescente à l'hôpital de Tsévié (Togo ...

    African Journals Online (AJOL)

    Objectif : Décrire le profil des grossesses chez l'adolescente à l'hôpital de Tsévié (Togo). Matériel et méthode : Il s'agissait d'une étude descriptive analytique portant sur les dossiers des parturientes âgées de 10 à 19 ans reçues à l'hôpital de Tsévié entre janvier 2011 et juin 2012. Résultats : Au cours de cette période, 180 ...

  17. Metallurgical and Mechanical Characterization of High Temperature Titanium Alloys Joined by Friction Stir Welding

    Science.gov (United States)

    Gangwar, Kapil Dev

    In the world of joining, riveting and additive manufacturing, weight reduction, and omission of defects (at both macro and micro level) remain of paramount. Therefore, in the wake of ubiquitous fusion welding (FW) and widely accepted approach of riveting using Inconel bolts to resist corrosion at higher temperature, friction stir welding (FSW) has emerged as a novice jewel in friction based additive manufacturing industry. With advancements in automation of welding process and tool material, FSW of materials with higher work hardening such as steel and titanium has also become probable. Process and property relations associated with FSW are inevitable in case of dissimilar titanium alloys, due to presence of heterogeneity (whether atrocious or advantageous) in and around the weld nugget. These process property relationships are needed to be studied and addressed properly in order to optimize the processing window for improved mechanical and metallurgical properties. In this study FSWed similar and dissimilar butt joints of α+β, and near α titanium, alloys have been produced for varying processing conditions in order to study the effect of rotation speed (rpm) and traverse speed (TS; mm-min-1). The aim of this study is to assess the effect of tool geometry, tool rpm, TS on microstructure and mechanical properties of most widely used α+β titanium alloy, Ti-6Al-4V (Ti-64), standard grain and fine grain in addition to α+β,Ti-5Al-4V (T-54M), standard grain, and near α, Ti-6Al-2Mo-4Zr-2Sn (Ti-6242), standard grain (SG) and fine grain (FG). During FSW, a unique α+β fine-grained microstructure has been formed depending on whether or not the peak temperature in the weld nugget (WN) reached above or below β transus temperature. The resulting microstructure consists of acicular α+β, emanating from the prior β grain boundary as the weld cools off. The changes in the microstructure are observed by optical microscopy (OM). Later, a detailed analysis of material

  18. Effectiveness of Ti-micro alloying in relation to cooling rate on corrosion of AZ91 Mg alloy

    International Nuclear Information System (INIS)

    Candan, S.; Celik, M.; Candan, E.

    2016-01-01

    In this study, micro Ti-alloyed AZ91 Mg alloys (AZ91 + 0.5wt.%Ti) have been investigated in order to clarify effectiveness of micro alloying and/or cooling rate on their corrosion properties. Molten alloys were solidified under various cooling rates by using four stage step mold. The microstructural investigations were carried out by using scanning electron microscopy (SEM). Corrosion behaviors of the alloys were evaluated by means of immersion and electrochemical polarization tests in 3.5% NaCl solution. Results showed that the Mg 17 Al 12 (β) intermetallic phase in the microstructure of AZ91 Mg alloy formed as a net-like structure. The Ti addition has reduced the distribution and continuity of β intermetallic phase and its morphology has emerged as fully divorced eutectic. Compared to AZ91 alloy, the effect of the cooling rate in Ti-added alloy on the grain size was less pronounced. When AZ91 and its Ti-added alloys were compared under the same cooling conditions, the Ti addition showed notably high corrosion resistance. Electrochemical test results showed that while I corr values of AZ91 decrease with the increase in the cooling rate, the effect of the cooling rate on I corr values was much lower in the Ti-added alloy. The corrosion resistance of AZ91 Mg alloy was sensitive towards the cooling rates while Ti-added alloy was not affected much from the cooling conditions. - Highlights: • Effect the cooling rate on grain size was less pronounced in the Ti-added alloy. • The morphology of the β phase transformed into fully divorced eutectics. • Ti addition exhibited significantly higher corrosion resistance. • Ti micro alloying is more effective than faster cooling of the alloy on corrosion.

  19. The modification of some properties of Al-2%Mg alloy by Ti &Li alloying elements

    Directory of Open Access Journals (Sweden)

    Talib Abdulameer Jasim

    2017-11-01

    Full Text Available Aluminium-Magnisium alloys are light, high strength with resistance to corrosion and good weldability. When the content of magnesium  exceeds 3% there is a tendency to stress corrosion . This work is an attempt is to prepare low density alloy with up to approximately 2.54 g / cm3 by adding different contents of Ti, and lithium to aluminum-2%Magnisium alloy. The lithium is added in two aspects, lithium chloride and pure metal. The casting performed using conventional casting method. Moreover, solution heat treatment (SHT at 520 ºC for 4 hrs, quenching in cold water, and aging at 50ºC for 4 days were done to get better mechanical properties of all samples. Microstructure was inspected by light optical microscope before and after SHT. Alloy3 which contains 1.5%Ti was tested by SEM and EDS spectrometer to exhibit the shape and micro chemical analysis of Al3Ti phase. Hardness, ultimate tensile strength, and modulus of elasticity were tested for all alloys. The results indicated that Al3Ti phase precipitates in alloys contain 0.5%T, 1%Ti, And 1.5%Ti.  The phases Al3Li as well as Al3Ti were precipitated in alloy4 which contains 2%Ti, and 2.24%Li. Mechanical properties test results also showed that the alloy4 has achieved good results, the modulus of elasticity chanced from 310.65GPa before SHT to 521.672GPa, after SHT and aging, the ultimate tensile strength was changed from 365MPa before SHT to 469MPa, after SHT and aging,  and hardness was increased from 128 to 220HV.

  20. Magnetisation processes and magnetic viscosity of mechanically alloyed SmCo5

    International Nuclear Information System (INIS)

    Ding, J.; Smith, P.A.I.; McCormick, P.G.; Street, R.

    1996-01-01

    Mechanically alloyed SmCo 5 materials with coercivities in the range of 50-75 kOe were studied in this work. Irreversible magnetisation processes were investigated by measuring remanences after initial magnetisation and after demagnetisation. A large deviation of the demagnetisation remanence from the Wohlfarth relationship indicated that interactions between grains play an important role in the irreversible magnetisation process. Viscosity tests showed nearly linear relationship between the magnetic field and the viscosity parameter for the initial magnetisation, while the viscosity was not strongly dependent on the field for the demagnetisation. High values of the viscosity parameter, Λ, between 120 to 220 Oe were measured at fields near coercivity. (orig.)