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Sample records for alloy-kh20n80

  1. Fabrication of welded pipes of the KhN45Yu alloy

    International Nuclear Information System (INIS)

    Lyapunov, A.I.; Krichevskij, E.M.; L'vov, V.N.; Kozlov, N.N.; Kireeva, T.S.

    1977-01-01

    A highly heat-resistant KhN45Yu (EP 747) alloy has been developed; the alloy is designed to withstand prolonged service in the temperature range of 1000-1300 deg C, or short-term service at 1300-1400 deg C. The satisfactory ductility and good weldability of the alloy have made it possible to obtain sheets and pipes (32 x 2.0 mm) by argon arc welding. The ductility of pipes from EP 747 alloy exceeds that of pipes from KhN78T (EI 435) alloy by 5.10%, the strength being approximately equal. In regard to strength the welded joint differs little from the base metal. The ductility characteristics up to 900 deg C are also equal, since failure occurs in the base metal. At higher temperatures the welded joint fails in the metal of the weld, and its ductility drops sharply. The grain size of the base metal corresponds to No. 3-4. The welded joint has a cast structure with a grain size larger than No. 1, but its ductility characteristics are satisfactory. This structure ensures an increased long-term strength of the material at 1000-1200 deg C

  2. Alloy spreading and filling of gaps in brazing of VDU-2 and KhN50VMTYuB heat resistant nickel alloys with VPr3K and VPr10 alloys

    International Nuclear Information System (INIS)

    Shapiro, A.E.; Podol'skij, B.A.; Lepisko, M.R.; Borzyak, A.G.; Moryakov, V.F.; Rostislavskaya, T.T.

    1984-01-01

    A study was made on contact interaction of VDU-2 and KhN50VMTYuB alloys with VPr3K and VPr10 alloys at 1325 and 1220 deg C in argon and industrial vacuum. The contact angles and wettability indexes were determined. The solders fill the vertical gaps of up to 0.25 mm width through 80 mm height. Spreading and filling of gaps proceeds better during soldering in argon with boron trifluoride addition as compared to soldering in industrial vacuum. VPr10 alloy is divided into two phases when wetting KhN50VMTYuB alloy: fusible one on the base of nickel-chromium-manganese solution and infusible one on the base of nickel-niobium eutectics. The square of fusible phase spreading is 2.5...3 times larger as compared to infusible one

  3. Additional materials for welding of the EP99 heat resisting alloy with the EI868 alloy and 12Kh18N9T steel

    International Nuclear Information System (INIS)

    Sorokin, L.I.; Filippova, S.P.; Petrova, L.A.

    1978-01-01

    Presented are the results of the studies aimed at selecting an additive material for argon-arc welding process involving heat-resistant nickel EP99 alloy to be welded to the EI868 alloy and 12Kh18N9T steel. As the additive material use was made of wire made of nickel-chromium alloys and covered electrodes made of the EP367 alloy with additions of tungsten. It has been established that in order to improve the resistance of metal to hot-crack formation during argon arc welding of the EP99 alloy with the EI868 alloy, it is advisable to use an additive material of the EP533 alloy, and while welding the same alloy with the 12Kh18N9T steel, filler wire of the EP367 alloy is recommended

  4. Quality of the KhN73MBTYu alloy after electroslag remelting and vacuum arc remelting

    International Nuclear Information System (INIS)

    Shelgaeva, A.V.; Krichevets, M.I.; Shinkina, N.S.; Komissarov, A.I.

    1978-01-01

    The structure and properties of the heat-resisting KhN73MBTYu alloy are investigated after electroslag remelting (ESR) and vacuum arc (VAR) remelting in commercial furnaces. The complex investigations of the casted metal were carried out by modern methods along with the standard acceptance tests, and a number of service properties were determined. It is established that the ESR metal contains magnesium and has the reduced sulphur concentration; the alloy has more fine-grained structure at high isotropy of the properties at room and operating temperatures; higher endurance is achieved under reversal rotational bending; no laminated fractures are observed. According to the basic quality factors the ESR metal satisfies all requirements for the VAR metal. Due to exclusion of strippling of ESR electrodes and ingots the yield of steel forgings increases by 20-25% and the prime cost decreases in comparison with the industrial production of VAR metal

  5. Composition of the spheroidal objects in KhN77TYuR-VD alloy

    International Nuclear Information System (INIS)

    Kotkis, M.A.; Nabutovskii, L.S.; Ostrov, A.E.; Zil'berman, A.G.

    1986-01-01

    The authors make an element analysis of the spheroidal objects in KhN77TYuR-VD alloy with the use of the energy dispersion microanalyzer with which the Stereoscan S-180 scanning electron microscope is equipped. Examples of the qualitative element analysis are shown. The results of the investigations show that the composition of the spheroidal inclusions includes nickel, chromium, titanium, iron, and also silicon and sulfur. The information obtained makes it possible to make an assumption on the mechanism of origin of these objects

  6. Heat affected zone structure in welded joints of 15Kh1M1FL, 25Kh2NMFA and 20KhN2MFA steels

    International Nuclear Information System (INIS)

    Levenberg, N.E.; German, S.I.; Fomina, O.P.; Netesa, E.M.; Tsaryuk, A.K.; Kornienko, T.A.

    1983-01-01

    Heat affected zone (HAZ) structure of thick-walled, nature joints of 15Kh1M1FL steel for block structure of power reactors and 25Kh2NMFA and 20KhN2MFA steels for rotors - is investigated. Multi-layer arc welding is performed under conditions being created for standard components of turbines. Thermokinetics diagrams of austenite decomposition are built, phase composition and character of the structure forming at HAZ in the process of welding with preheating are studied. It is shown that at HAZ in joints of the steels under consideration in the process of welding with preheating is formed a structure of a grained bainite which is uniform in its structure and phase composition. Small volumes of round and elongated forms consisting of martensite and residual austenite are distributed in α-solid solution of the bainite. The bainite of the HAZ in welded joints possesses high hardness and great stability in the process of tempering

  7. Heat treatment effects on structure and proerties of the alloy type KhN73MBNYu (EhJ 698)

    International Nuclear Information System (INIS)

    Maslenkov, S.B.; Maslenkova, E.A.; Solov'ev, Yu.V.; Zryumov, V.P.

    1994-01-01

    Influence of quenching temperature and various ageing conditions on tensile properties and impact strength of wrought alloy type KhN73MBTYu has been investigated at room temperature and in the range of 500-850 deg C. Two-step quenching followed by ageing at 700-750 deg C. Two-step quenching followed by ageing at 700-750 deg C is shown to assure needed heat resistance of the alloy. Due to the whole complex of structural changes during heat treatments mechanical properties of the alloy preserv high level up to 750 deg C. This temperature is limiting value in the case of long-term operation

  8. Features of argon-arc welding of aluminium alloy AD1 to stainless steel 12Kh18N10T

    International Nuclear Information System (INIS)

    Sadov, I.I.

    1982-01-01

    Welding of pipes made of the 12Kh18N10T stainless steel and the AD1 aluminium alloy is proposed to perform using one-sided aluminizing. It is recommended to use shields in order to protect internal and external surfaces of pipes, aluminizing of which is impossible. It is shown that developed technological process for welded joints made of aluminium and stainless steel for cryogenic apparatus permits to create light-duty cryostat assembly using aluminium alloys instead of copper alloys, to increase reliability of apparatus (usage of welded joints instead of soldered ones), and to improve labour conditions

  9. Magnetostriction of the polycrystalline Fe80Al20 alloy doped with boron

    International Nuclear Information System (INIS)

    Bormio-Nunes, Cristina; Teodoro dos Santos, Claudio; Botani de Souza Dias, Mateus; Doerr, Mathias; Granovsky, Sergey; Loewenhaupt, Michael

    2012-01-01

    Highlights: ► Fe 80 Al 20 polycrystalline alloy magnetostriction 40 ppm increased to 80 ppm due to 2% of B doping. ► B stabilizes α-FeAl phase and a coexistence of α-FeAl + Fe 3 Al improves magnetostriction. ► Presence of Fe 2 B phase causes domain rearrangement revealed by the decrease of the volume magnetostriction. - Abstract: The doping of Fe 80 Al 20 polycrystalline alloy with 2% of boron increased the total magnetostriction twofold compared to a sample without boron. A value close to 80 ppm was achieved at 300 K. The microstructures of the boron-doped alloys show a dendritically solidified matrix with interdendritic α-FeAl and/or Fe 3 Al and Fe 2 B eutectic between the grains. The XRD analysis reveals an increase in the volume fraction of α-FeAl and a correspondent decrease of the Fe 3 Al phase volume fraction as the boron content increases. The increase of the volume fraction of this tetragonal Fe 2 B phase in the samples doped with boron causes the decrease of the strong volume magnetostriction that was observed in the alloy without boron. There is some evidence that the improvement of the magnetostriction magnitude due to the addition of boron to the Fe 80 Al 20 alloy could reach the maximal magnetostriction if the 1:1 optimal ratio of the volume fractions of the α-FeAl and Fe 3 Al phases could be reached.

  10. Beta decomposition of (Hf/sub x/Zr/sub 1-x/)80Nb20 ternary alloys

    International Nuclear Information System (INIS)

    Jones, W.B.; Taggart, R.; Polonis, D.H.

    1978-01-01

    The processes of beta decomposition have been examined in ternary alloys of the form (Hf/sub x/Zr/sub 1-x/) 80 Nb 20 to determine the influence of Hf additions to a basic Zr 80 Nb 20 composition. In the chill cast condition, Hf additions have been found to decrease the temperature coefficient of electrical resistivity from a value of -0.0015%/K for the binary Zr 80 Nb 20 alloy to a value of -0.011%/K for a (Hf 50 Zr 50 ) 80 Nb 20 ternary alloy. This change is explained in terms of the bcc lattice instability typical of Ti, Zr, and Hf alloys. The Hf additions enhance the kinetics of omega-phase precipitation during aging at 648 K. The aging of a (Hf 05 Zr 95 ) 80 Nb 20 alloy for 12 h results in the precipitation of a high volume fraction of cuboidal shaped omega-phase particles. A phase separation which results in the formation of solute lean discs (β/sub l/) occurs together with the precipitation of the omega-phase. These discs formed both randomly within the matrix and heterogeneously along dislocations and at grain boundaries

  11. Study of nitrogen solubility in multicomponent iron alloys at its pressure in gaseous phase up to 1000kPa

    International Nuclear Information System (INIS)

    Pomarin, Yu.M.; Grigorenko, G.M.; Latash, Yu.V.; Kanibolotskij, S.A.

    1983-01-01

    A facility in which metal is melted in a weighed state and nitrogen partical pressure during relting may be charge from 0 to 1000 kPa is developed to investigate nitrogen solubility is liquim metals and alloys. Investigation of nitrogen solubility was performed using samples of 03Kh25N5AM3 steel and Kh20N5, Kh20N10, Kh40N10, Kh40N20 alloys. Positive deflection of [N]=f(√Psub(Nsub(2))) dependence from the Henry law is shown to be observed in the Kh40N10 alloy in the 100-1000 kPa pressure range. In this case the vatue of positive deflection decreases with temperature growth and at T=2273 K nitrogen solubility in the alloy submits to the law of square root. An equation permitting to calculate nitrogen solubility in alloys of Fe-Cr-Ni and Fe-Cr-Mn systems in the 0 to 1000 kPa range of nitrogen partial pressures is obtained

  12. Comparative assessment of filler wires for argon-arc welding of refractory alloys

    International Nuclear Information System (INIS)

    Sorokin, L.I.; Bagdasarov, Yu.S.; Tupikin, V.I.

    1993-01-01

    It is recommended to use wires of similar composition as filler material during argon-arc welding of heat resisting alloys, and Sv-08Kh20N57M8V8T3R wire - for welding of dispersion hardening alloys. Sv-06Kh15N60M15, Sv-KhN64KBMYuVF or Kh11N60M23 wires should be used as filler materials to decrease tendency of welded joints to cracking during welding and heat treatment

  13. Slag inclusions in vacuum-melted ingots of the KhN73MBTYu nickel base alloy

    International Nuclear Information System (INIS)

    Gorin, V.A.; Kleshchev, A.S.; Kazharskaya, L.P.

    1977-01-01

    Three types of slag inclusions in ingots of the vacuum-arc-remelted nickel alloy KhN73MBTYu are considered. Type 1 inclusions are those in the surface zone; type 2 inclusions are agglomerations of nitrides and oxides formed due to the fall of lining slag; type 3 inclusions consist of agglomerations of nitrides and oxides as a result of interaction of dissolved oxygen and nitrogen with melt components. The inclusions are removed by machining of the lateral surface. It should be noted that the presence of a large amount of slag on the surface of the molten pool adversely affects the stability of the electrical regime of melting. Strict adherence to the recommendations on the melting and pouring of the initial metal reduces the pollution of the consumable electrode with nonmetallic inclusions

  14. Magnetostriction of the polycrystalline Fe{sub 80}Al{sub 20} alloy doped with boron

    Energy Technology Data Exchange (ETDEWEB)

    Bormio-Nunes, Cristina, E-mail: cristina@demar.eel.usp.br [Escola de Engenharia de Lorena, Dep. de Eng. de Materiais, Universidade de S.Paulo, Lorena, SP (Brazil); Teodoro dos Santos, Claudio; Botani de Souza Dias, Mateus [Escola de Engenharia de Lorena, Dep. de Eng. de Materiais, Universidade de S.Paulo, Lorena, SP (Brazil); Doerr, Mathias; Granovsky, Sergey; Loewenhaupt, Michael [Institut fuer Festkoerperphysik, TU Dresden, D-01062 Dresden (Germany)

    2012-10-25

    Highlights: Black-Right-Pointing-Pointer Fe{sub 80}Al{sub 20} polycrystalline alloy magnetostriction 40 ppm increased to 80 ppm due to 2% of B doping. Black-Right-Pointing-Pointer B stabilizes {alpha}-FeAl phase and a coexistence of {alpha}-FeAl + Fe{sub 3}Al improves magnetostriction. Black-Right-Pointing-Pointer Presence of Fe{sub 2}B phase causes domain rearrangement revealed by the decrease of the volume magnetostriction. - Abstract: The doping of Fe{sub 80}Al{sub 20} polycrystalline alloy with 2% of boron increased the total magnetostriction twofold compared to a sample without boron. A value close to 80 ppm was achieved at 300 K. The microstructures of the boron-doped alloys show a dendritically solidified matrix with interdendritic {alpha}-FeAl and/or Fe{sub 3}Al and Fe{sub 2}B eutectic between the grains. The XRD analysis reveals an increase in the volume fraction of {alpha}-FeAl and a correspondent decrease of the Fe{sub 3}Al phase volume fraction as the boron content increases. The increase of the volume fraction of this tetragonal Fe{sub 2}B phase in the samples doped with boron causes the decrease of the strong volume magnetostriction that was observed in the alloy without boron. There is some evidence that the improvement of the magnetostriction magnitude due to the addition of boron to the Fe{sub 80}Al{sub 20} alloy could reach the maximal magnetostriction if the 1:1 optimal ratio of the volume fractions of the {alpha}-FeAl and Fe{sub 3}Al phases could be reached.

  15. Nitrogen-containing superlow-carbon austenitic steel 02Kh25N22AM2

    Science.gov (United States)

    Fe'ldgandler, É. G.; Svistunova, T. V.; Savkina, L. Ya.; Lapshina, O. B.

    1996-02-01

    At present the equipment for manufacturing carbamide mineral fertilizers is produced from domestic steel 03Kh17N14M3 having "carbamide quality." Imported equipment also used in the industry is produced from steel of the 25-22-2 (Cr -Ni-Mo) type shipped by various firms, namely, 2RE69 (Sandvik, Sweden), 254SFER (Avesta, Sweden), 2522LCN (VDM, Germany), DM 1.4466 (Germany), and X2CrNiMo 25-22-2 (Dalmine, Italy). The imported steels are used because in some units steel 03Khl7Nl4M3 does not provide the requisite corrosion resistance in an intensified process of carbamide manufacturing. We currently possess domestic high-alloyed steel for producing new and repairing imported equipment operating under the severe conditions of carbamide synthesis. The present paper concerns the structure, mechanical properties, and corrosion resistance of industrially produced steel 02Kh25N22AM2 (ChS-108) and the recommended range of its application.

  16. Corrosion resistance of welded joints in 08Kh22N6T and 08Kh21N6M2T steels made with new electrodes

    International Nuclear Information System (INIS)

    Sidorkina, Y.S.; Leibzon, V.M.; Mankevich, T.V.; Sidlin, E.A.; Zheltova, G.A.

    1986-01-01

    This paper examines the corrosion resistance of 08Kh22N6T and 08Kh21N6M2T steels which would make it possible to ensure equal properties of all the zones of the welded joints. The investigations were carried out on the welded joints in the steels produced with new OZL-40 and OZL-41 electrodes and with standard TsL-11 and EA-400/10u electrodes. The chemical compositions of the steels and deposited metal are presented. The tests of the intercrystalline corrosion resistances of the welded joints in the steels in the as-welded condition and after heat treatment showed that the weld metal is not attacked by intercrystalline corrosion. The tests also showed that the welded joints in 08Kh22N6T steel made with the OZL-40 and TsL-11 electrodes are resistant to corrosion in 55% phosphoric acid at 90 C in 1% sulfuric acid, and in 25% formic acid at 80 C. The investigated steels made with the OZL-40 and OZL-41 electrode respectively show that the welded joints are resistant to intercrystalline and general corrosion, have high mechanical and processing properties and the electrodes, and can be used for welding equipment designed for service in alkaline, neutral, and slightly acid media

  17. Development and industrial mastering hot rolling procedure for low-ductile steels and alloys

    International Nuclear Information System (INIS)

    Degterenko, V.K.; Sokolov, V.A.

    1980-01-01

    The technique for the development of the sheet hot rolling procedure for low-ductile steels and alloys (0Kh17N14M2, 12Kh21N5T, 20Kh25N20C2,40Kh13, 36NKhTYu etc.) is proposed, using plastometer which permits to obtain the data on the deformation resistance in the wide range of temperatures (800-1300 deg C), of deformation degrees (0.1-0.3) and deformation rates (0.001-300 c -1 ). With the help of the plastometric data processed on the computer the calculation of the rolling regimes for the sheet with improved surface quality is carried out at the more uniform loading on the mill stands

  18. Surface crystallization and magnetic properties of amorphous Fe80B20 alloy

    International Nuclear Information System (INIS)

    Vavassori, P.; Ronconi, F.; Puppin, E.

    1997-01-01

    We have studied the effects of surface crystallization on the magnetic properties of Fe 80 B 20 amorphous alloys. The surface magnetic properties have been studied with magneto-optic Kerr measurements, while those of bulk with a vibrating sample magnetometer. This study reveals that surface crystallization is similar to the bulk process but occurs at a lower temperature. At variance with previous results on other iron-based amorphous alloys the surface crystalline layer does not induce bulk magnetic hardening. Furthermore, both the remanence to saturation ratio and the bulk magnetic anisotropy do not show appreciable variations after the formation of the surface crystalline layer. The Curie temperature of the surface layer is lower with respect to the bulk of the sample. These effects can be explained by a lower boron concentration in the surface region of the as-cast amorphous alloy. Measurements of the chemical composition confirm a reduction of boron concentration in the surface region. copyright 1997 American Institute of Physics

  19. Structural changes in heat resisting high nickel alloys during homogenization

    International Nuclear Information System (INIS)

    Kleshchev, A.S.; Korneeva, N.N.; Yurina, O.M.; Guzej, L.S.

    1981-01-01

    Effect of homogenization on the structure and technological plasticity of the KhN73MBTYu and KhN62BMKTYu alloys during treatment with pressure is investigated taking into account peculiarities if the phase composition. It is shown that homogenization of the KhN73MBTYu and KhN62BMKTYu alloys increases the technological plasticity. Homogenization efficiency is conditioned by the change of the grain boundaries and carbide morphology as well as by homogeneous distribution of the large γ'-phase [ru

  20. Fabrication and Characterization of novel W80Ni10Nb10 alloy produced by mechanical alloying

    Science.gov (United States)

    Saxena, R.; Patra, A.; Karak, S. K.; Pattanaik, A.; Mishra, S. C.

    2016-02-01

    Nanostructured tungsten (W) based alloy with nominal composition of W80Ni10Nb10 (in wt. %) was synthesized by mechanical alloying of elemental powders of tungsten (W), nickel (Ni), niobium (Nb) in a high energy planetary ball-mill for 20 h using chrome steel as grinding media and toluene as process control agent followed by compaction at 500 MPa pressure for 5 mins and sintering at 1500°C for 2 h in Ar atmosphere. The phase evolution and the microstructure of the milled powder and consolidated product were investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The crystallite size of W in W80Ni10Nb10 powder was reduced from 100 μm at 0 h to 45.6 nm at 10 h and 34.1 nm at 20 h of milling whereas lattice strain increases to 35% at 20 h of milling. The dislocation density shows sharp increase up to 5 h of milling and the rate of increase drops beyond 5 to 20 h of milling. The lattice parameter of tungsten in W80Ni10Nb10 expanded upto 0.04% at 10 h of milling and contracted upto 0.02% at 20 h of milling. The SEM micrograph revealed the presence of spherical and elongated particles in W80Ni10Nb10 powders at 20 h of milling. The particle size decreases from 100 μm to 2 μm with an increase in the milling time from 0 to 20 hours. The crystallite size of W in milled W80Ni10Nb10 alloy as evident from bright field TEM image was in well agreement with the measured crystallite size from XRD. Structure of W in 20 h milled W80Ni10Nb10 alloy was identified by indexing of selected area diffraction (SAD) pattern. Formation of NbNi intermetallic was evident from XRD pattern and SEM micrograph of sintered alloy. Maximum sinterability of 90.8% was achieved in 20 h milled sintered alloy. Hardness and wear study was also conducted to investigate the mechanical behaviour of the sintered product. Hardness of W80Ni10Nb10 alloy reduces with increasing load whereas wear rate increases with increasing load. The evaluated

  1. Effect of irradiation temperature on crystallization of {alpha}-Fe induced by He irradiations in Fe{sub 80}B{sub 20} amorphous alloy

    Energy Technology Data Exchange (ETDEWEB)

    San-noo, Toshimasa; Toriyama, Tamotsu; Wakabayashi, Hidehiko; Iijima, Hiroshi [Musashi Inst. of Tech., Tokyo (Japan); Hayashi, Nobuyuki; Sakamoto, Isao

    1997-03-01

    Since amorphous alloys are generally highly resistant to irradiation and their critical radiation dose is an order of magnitude higher for Fe-B amorphous alloy than Mo-methods, these alloys are expected to become applicable as for fusion reactor materials. The authors investigated {alpha}-Fe crystallization in an amorphous alloy, Fe{sub 80}B{sub 20} using internal conversion electron Moessbauer spectroscopy. The amount of {alpha}-Fe component was found to increase by raising the He-irradiation dose. The target part was modified to enable He ion radiation at a lower temperature (below 400 K) by cooling with Peltier element. Fe{sub 80}B{sub 20} amorphous alloy was cooled to keep the temperature at 300 K and exposed to 40 keV He ion at 1-3 x 10{sup 8} ions/cm{sup 2}. The amount of {alpha}-Fe crystal in each sample was determined. The crystal formation was not observed for He ion radiation below 2 x 10{sup 18} ions/cm{sup 2}, but that at 3 x 10{sup 8} ions/ cm{sup 2} produced a new phase ({delta} +0.40 mm/sec, {Delta} = 0.89 mm/sec). The decrease in the radiation temperature from 430 to 300 K resulted to extremely repress the production of {alpha}-Fe crystal, suggesting that the crystallization induced by He-radiation cascade is highly depending on the radiation temperature. (M.N.)

  2. Heat treatment effect on ductility of nickel-base alloys

    International Nuclear Information System (INIS)

    Burnakov, K.K.; Khasin, G.A.; Danilov, V.F.; Oshchepkov, B.V.; Listkova, A.I.

    1979-01-01

    Causes of low ductility of the KhN75MBTYu and KhN78T alloys were studied along with the heat treatment effects. Samples were tested at 20, 900, 1100, 1200 deg C. Large amount of inclusions was found in intercrystalline fractures of the above low-ductile alloys. The inclusions of two types took place: (α-Al 2 O 3 , FeO(Cr 2 O 3 xAl 2 O 3 )) dendrite-like ones and large-size laminated SiO 2 , FeO,(CrFe) 2 O 3 inclusions situated as separate colonies. Heat treatment of the alloys does not increase high-temperature impact strength and steel ductility. The heating above 1000 deg C leads to a partial dissolution and coagulation of film inclusions which results in an impact strength increase at room temperature

  3. Temperature dependence of the electrical resistivity of amorphous Co80-xErxB20 alloys

    International Nuclear Information System (INIS)

    Touraghe, O.; Khatami, M.; Menny, A.; Lassri, H.; Nouneh, K.

    2008-01-01

    The temperature dependence of the electrical resistivity of amorphous Co 80-x Er x B 20 alloys with x=0, 3.9, 7.5 and 8.6 prepared by melt spinning in pure argon atmosphere was studied. All amorphous alloys investigated here are found to exhibit a resistivity minimum at low temperature. The electrical resistivity exhibits logarithmic temperature dependence below the temperature of resistivity minimum T min . In addition, the resistivity shows quadratic temperature behavior in the interval T min < T<77 K. At high temperature, the electrical resistivity was discussed by the extended Ziman theory. For the whole series of alloys, the composition dependence of the temperature coefficient of electrical resistivity α shows a change in structural short range occurring in the composition range 8-9 at%

  4. Optimal control of conditions of deformation during rolling the bar alloy from alloy steel

    International Nuclear Information System (INIS)

    Inatovich, Yu.V.; Shilov, V.A.; Shvarts, D.L.; Kudelin, S.P.

    2001-01-01

    A complex of programs for determining the optimal gaps between rollers during rolling of simple merchant sections of alloy steels of a wide brand assortment (12KhN3A, Kh17N2, Kh18N10T) was elaborated. Experience in calculations made according to the programs suggests advisability of their use in the automated design systems for roller calibration and for adjustment of section mills [ru

  5. Magnetic exchange coupling in amorphous Fe80-xDy xB20 alloys

    International Nuclear Information System (INIS)

    Annouar, F.; Lassri, H.; Ayadi, M.; Omri, M.; Lassri, M.; Krishnan, R.

    2005-01-01

    Amorphous Fe 80-x Dy x B 20 alloys have been prepared by melt spinning and their magnetic properties have been studied. The mean field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Co-Co and Dy-Co atom pairs have been evaluated. High-field magnetization studies on samples with stoichiometry close to that of a compensated ferrimagnet show a magnetic behavior that is characteristic of a non-collinear magnetic structure of the Dy and Fe sublattices. The region of the canted moments can be described by a phase diagram in the H-T plane

  6. Electrochemical passivation behaviour of nanocrystalline Fe80Si20 ...

    Indian Academy of Sciences (India)

    Abstract. Passivation behaviour of nanocrystalline coating (Fe80Si20) obtained by in situ mechanical alloying route .... is controlled by the iron oxide film in case of alloys with ..... the surface is covered, thus, producing effective protection of.

  7. Superconductivity, magnetic susceptibility, and electronic properties of amorphous (Mo/sub 1-x/Ru/sub x/)80P20 alloys obtained by liquid quenching

    International Nuclear Information System (INIS)

    Johnson, W.L.; Poon, S.J.; Duwez, P.

    1977-11-01

    Results of x-ray diffraction, transmission electron diffraction, and crystallization studies on amorphous (Mo/sub 1-x/Ru/sub x/) 80 P 20 alloys obtained by liquid quenching are presented and discussed. The alloys are all found to be superconducting with transition temperatures ranging from approximately 3 0 K to approximately 9 0 K. The variation of T/sub c/ with alloy composition is compared to that obtained by Collver and Hammond for vapor quenched transition metal films. Results of magnetic susceptibility measurements are used to estimate the variation of the electronic density of states at the Fermi level, N(0), from the Pauli paramagnetic contribution. The relationship between the variation of T/sub c/ and N(0) is discussed in terms of the microscope theory of superconductivity. Finally, results of measurements of the upper critical field H/sub c2/, and the normal state electronic transport properties are presented and compared with recent theoretical models for amorphous superconductors

  8. Mechanical properties and kinetics of bainite transformation in the 35KhN3MFA and 25KhN3MFA steels

    International Nuclear Information System (INIS)

    Korotushenko, G.V.; Grigorkin, V.I.; Kozlov, V.I.; Sandomirskij, M.M.; Krivonosova, L.F.

    1978-01-01

    The mechanical properties and phase composition of the 25KhN3M A and 25KhN3M A bainitic steels have been investigated under austenization temperature varying from 870 to 1180 deg C and quenching cooling rate varying from 1 to 18x10 3 deg/min. Roentgen and quantitative phase analyses were employed. When bainitic steels are subjected to quenching by cooling with slow rate, their structure reveals b.c.c.-bainite with carbon content below the steel average, tetragonal martensite with a higher carbon content, carbon-rich residual austenite and carbides. Decreasing quenching cooling rates increase the concentration of tetragonal martensite and residual austenite and correspondingly reduce the concentration of b.c.c.-bainite. This tends to degrade the structural strength of bainitic steels in cores of large-size forged products

  9. Ductility increase in difficult to work nickel alloys due to calcium microalloying

    International Nuclear Information System (INIS)

    Shevtsov, V.A.; Grigoryan, R.A.; Aleev, V.P.; Stepanov, V.P.; Bytskij, E.V.

    1995-01-01

    Impact of calcium microadditions on mechanical properties of heat-resisting alloys Kh66VMTYu and KhN33KV is studied. It is established that the calcium additions up to 0.01% essentially increase the alloy plastic characteristics of the alloy without changing its strength characteristics.5 refs., 3 figs

  10. Choice of corrosion-resistant metal for fluotitanic acid

    International Nuclear Information System (INIS)

    Reingeverts, M.D.; Lapchenko, E.P.; Semenyuk, E.Y.

    1986-01-01

    The authors investigate the corrosion and anodic behavior of steels 12Kh18N10T, 08Kh21N6M2T, and 06KhN28MDT, nickel, and molybdenum in 10-40% naturally aerated solutions of H 2 TiF 6 at 20 and 50 degrees C. The authors found that in solutions of fluotitanic acid, as also in tetrafluoroboric and hydrofluoric acids, the most stable alloys are chromium-nickel-molybdenum alloy of type 06KhN28MDT and (for acid concentrations above 20%) copper-nickel-alloys of the monel metal type. Steels 12Kh18N10T and 08Kh21N6M2T can be used in acid concentrations of less than 10% and temperatures up to 20 degrees C with anodic protection

  11. The effect of silicon content on high temperature oxidation of 80Ni-20Cr alloys

    International Nuclear Information System (INIS)

    Takei, Atsushi; Nii, Kazuyoshi

    1981-01-01

    The effect of Si content on the oxidation behavior of 80Ni-20Cr alloys has been studied in the cyclic oxidation in an air stream at 1373K. The addition of 1% and 5%Si to the alloy lowered the mass gain in oxidation, whereas the amount of spalling of oxide scale was increased with the addition of Si. The structure of oxide layers observed by microphotography, X-ray diffraction and electron probe microanalysis (EPMA) were different with the Si content of alloys. The oxide layer of the alloy with 1%Si consists of multi-layers, that is Ni oxide, Cr 2 O 3 and SiO 2 as the external oxide layer. The oxide layer remaining on the alloy with 5%Si, however, was made of a single oxide layer of Cr 2 O 3 containing small amounts of Si and Ni. In spite of the fact that the amount of Si in this alloy is larger than that of the alloy with 1%Si, the SiO 2 oxide layer was not observed at the oxide-alloy interface. It was found by EPMA that the concentration of Si in the oxidized 5%Si alloy substrate was increased in the vicinity of the surface, although Si in the 1%Si alloy was depleted. From the above results the internal oxidation of Si is assumed in the near-surface region of the 5%Si alloy. The internal oxidation of the 5%Si alloy was confirmed by an increase in hardness in the near-surface region. The difference in oxidation behavior between the 1%Si and 5%Si alloys can be understood under the assumption that the oxide layer formed of the 5%Si alloy contained much larger amounts of Ni and Si than that on the 1%Si alloy, and that this oxide layer tends to crack more easily, thus being less protective for the penetration of oxygen. (author)

  12. Submicroscopic structure role in resistance of microplastic deformation of precipitation hardening nickel-chromium base alloys. 2. Softening stage

    International Nuclear Information System (INIS)

    Gitgarts, M.I.; Kukareko, V.A.

    1985-01-01

    Reasons for decrease of elastic limit and hardness of KhN77TYuR, KhN56VMTYu and KhN67VMTYu alloys at early stages of ageing are analyzed. Alloy softening is shown to be conditioned by development of spatial ordering of γ'-particles by the matrix volume. It is concluded that regularity in particle disposition reduces resistance to microplastic shear to a greater extent than to macroplastic strains

  13. Pressure-assisted reaction bonding between W and Si80Ge20 alloy with Ni as the interlayer

    International Nuclear Information System (INIS)

    Xu, Y.; Laabs, F.C.; Beaudry, B.J.; Gschneidner, K.A. Jr.

    1991-01-01

    The conditions and reaction mechanism of W/Ni/Si 80 Ge 20 hot-press bonding have been studied. It was found that a Ni/Si 80 Ge 20 bond can be formed using low pressure, 19.6 MPa, in the temperature range between 780 and 900 degree C in a short time. The kinetics follows a parabolic pattern, suggesting it is a diffusion-controlled process. The activation energy is 2.7 eV and the parabolic rate constant is given by K P = 4.0 x 10 14 exp(-3.2x10 4 /T) (μm 2 /min). The bonding interface has a multilayered structure. A phenomenological mechanism of the bonding formation has been proposed based on scanning electron microscopy observations and energy dispersive spectroscopy. The cracking problem due to thermal stress is discussed based on Oxx's equation. It was found that bonds free from cracks in the Si 80 Ge 20 alloy are formed when the Ni consumption (as measured by the thickness of the nickel layer) is sufficiently small ( 4 . As an interlayer, nickel can join the tungsten sheet and the Si 80 Ge 20 together. It has been also demonstrated that a thin nickel layer formed by vapor deposition on a tungsten sheet may be used as the interlayer in place of nickel sheet

  14. Structural changes IN THE Kh20N45M4B nickel alloys and THE Kh16N15M3B steel due to helium ion bombardment

    International Nuclear Information System (INIS)

    Kalin, B.A.; Chernikov, U.N.; Chernov, I.I.; Kozhevnikov, O.A.; Shishkin, G.N.; Yakushin, V.L.

    1986-01-01

    Using transmission electron microscopy, x-ray structural analysis, and the thermal desorption techniques, the authors carried out a detailed study of the structural and phase changes, defect formation, and helium accumulation in the He + -bombarded 16-15 austenitic steels and 20-45 nickel alloys. Microstructure of the bombarded specimens was studied using the methods of transmission electron microscopy of thin foils in the EVM-100, and EM-301G electron microscopes. Results of x-ray studies on the bombarded specimens are presented. The conducted studies show that bombardment of structural materials with light ions can lead to significant structural damages and changes in the chemical and phase composition of the surface layer. The possible mechanisms of the changes in the chemical and phase composition include selective sputtering and radiation-induced accelerated diffusion of elements in the field of internal lateral stresses developing during the He + implantation process

  15. Estimation of structural strength of 38KhN3MFA steel, melted using different methods

    International Nuclear Information System (INIS)

    Kudrya, A.V.; Mochalov, B.V.; Fadeev, Yu.I.

    1982-01-01

    Quantity of steel melted by different methods using criteria of fracture mechanics is evaluated. Three technological variants of the 38KhN3MFA steel melting: acid Martin steel prepared by the duplex-process (melt 1); the main Martin steel melting with deoxidation and alloying in a ladle by liquid alloy and treatment with synthetic slag with argon purging after production (melt 2) and its electroslag remelt - ESP process (melt 3) are investigated. The analysis of the investigated melts has revealed that crack resistances of the acid Martin steel is higher than that of other melts at practically similar standard mechanical properties with 0.35 probability at 0.05 significance level in the low-tempered state; in the tempered state the best crack resistance is observed in the ESP main Martin steel. Metal of the main Martin melting has lower crack resistance as compared with other meltings at both strength levels. The results of the work point out the necessity of applying the criteria of fracture mechanics for obtaining an objective evaluation of the steel quality

  16. Chromium surface alloying of structural steels during laser treatment

    International Nuclear Information System (INIS)

    Kurov, I.E.; Nagornykh, S.N.; Sivukhin, G.A.; Solenov, S.V.

    1987-01-01

    Results of matrix alloying from the surface layer and creation of considerably increased chromium concentration in the depth which permits to increase the efficiency of laser treatment of steels (12Kh18N10T and 38KhN3M) in the process of their further mechanical polishing, are presented. The treatment was realized by continuous CO 2 -laser at different power densities and scanning rates are presented. A model describing the creation of anomalous distributions of the alloying element in steels is plotted

  17. Effect of heat treatment and plastic deformation on the structure and the mechanical properties of nitrogen-bearing 04N9Kh2A steel

    Science.gov (United States)

    Blinov, V. M.; Bannykh, O. A.; Lukin, E. I.; Kostina, M. V.; Blinov, E. V.

    2014-11-01

    The effect of the conditions of heat treatment and plastic deformation on the structure and the mechanical properties of low-carbon martensitic nickel steel (9 wt % Ni) with an overequilibrium nitrogen content is studied. The limiting strain to failure of 04N9Kh2A steel is found to be 40% at a rolling temperature of 20°C and 80% at a rolling temperature of 900°C. Significant strengthening of the steel (σ0.2 = 1089 MPa) is obtained after rolling at a reduction of 40% at 20°C. The start and final temperatures of the α → γ transformation on heating and those of the γ → α transformation on cooling are determined by dilatometry. The specific features of the formation of the steel structure have been revealed as functions of the annealing and tempering temperatures. Electron-microscopic studies show that, after quenching from 850°C and tempering at 600°C for 1 h, the structure contains packet martensite with thin interlayers of retained austenite between martensite crystals. The strength of the nitrogen-bearing 04N9Kh2A steel after quenching from 850 and 900°C, cooling in water, and subsequent tempering at 500°C for 1 h is significantly higher than that of carboncontaining 0H9 steel used in cryogenic engineering.

  18. Effect of elastic interphase strains on extinction in aging nimonic type alloys

    International Nuclear Information System (INIS)

    Gitgarts, M.I.; Ivashin, V.V.

    1977-01-01

    The effect of νsup(')-phase separation processes on the variation of (3) CuKsub(α) diffraction line integral intensity in KhN67VMTYu alloy ageing has been investigated, the alloy being characterized by various degrees of volumetric inconsistency between the separation phase and matrix. The ageing of KhN67VMTYu alloy, in which the separation of the νsup(')-phase does not cause interphase strains, is not accompanied by abatement of extinction: the diffraction line intensity is practically the same for both aged and tempered specimens

  19. Local corrosion of high alloy steels under biodeposits

    International Nuclear Information System (INIS)

    Korovyakova, M.D.; Nikitin, V.M.; Speshneva, N.V.

    1999-01-01

    Impact of the bacteriozenosis different structural-functional state under biodeposits on corrosion resistance of the 12Kh18N10T and Kh18N10T high-alloy steels in the natural seawater is studied. It is shown that saturation of natural micro communities by separate aerobic and facultative-anaerobic bacterial monocultures increases corrosion resistance of these steels by their overgrow with biodeposits [ru

  20. Inhibitor effect on corrosion of titanium alloys in muriatic solutions of titanium-magnesium production

    International Nuclear Information System (INIS)

    Dobrunov, Yu.V.; Volynskij, V.V.; Kolobov, G.A.; Kuznetsov, S.I.

    1977-01-01

    Corrosion tests of titanium alloys VTI-0, OT4, VT5-1 and steel Kh18N1OT in 10% and 18% HCl with additions of carnallite at 40 deg C have been carried out. It has been established that titanium alloys in 10% and 18% HCl containing 5 and 10% carnallite are sufficiently corrosion resistant in the presence of 0.1-1% FeCl or HNO 3 and can be used for manufacturing the equipment of recirculation gas scrubbers. Steel Kh18N10T is unstable in all the media tested. It is subjected to intensive pitting. Specimens of steel Kh18N10T have also revealed edge cracking

  1. Field-induced non-collinear magnetic structures in amorphous Co80-xDy xB20 alloys

    International Nuclear Information System (INIS)

    Annouar, F.; Roky, K.; Lassri, H.; Elmoussaoui, A.; Driouch, L.; Ayadi, M.; Omri, M.; Krishnan, R.

    2005-01-01

    Amorphous Co 80-x Dy x B 20 alloys have been prepared by melt spinning technique and their magnetic properties have been studied. The mean field theory has been used to explain the temperature dependence of the magnetization. High-field magnetization studies performed at 4.2 K in magnetic fields up to 38 T have revealed, for samples with stoichiometry close to that of a compensated ferrimagnet, a magnetic behavior that is characteristic of a non-collinear magnetic structure of the Dy and Co sublattices. From the non-collinear regime the exchange interactions between the Co and Dy magnetic sublattices and the magnetic anisotropy constants have been evaluated

  2. The effect of thermal treatment on corrosion properties of 0Kh15N16M3B stainless steel tested in the N2O4 boiling medium

    International Nuclear Information System (INIS)

    Kamenev, A.Ya.; Kopets, Z.V.; Mel'nikova, N.N.; Dergaj, A.M.; Fedyushin, E.E.

    1985-01-01

    The experimental data on the effect of thermal treatment on corrosion properties of stainless steel 00Kh16n15m3b tested in the N 2 O 4 boiling medium at 8.0 MPa and 433 K are presented. The electron microscope data on steel microstructure after different heat treatments and phase composition of oxide films emerging at corrosion test are given. It is shown, that the rise of the heat treatment temperature from 823 up to 1023 K increases total corrosion of 00Kh16n15m3b steel under given test conditions and practically does't affect intercrystalline corrosion. Developed oxide layers are of deposited nature and doesn't affect markedly the rate of progress of the corrosive processes. Taking into account high chromium volatility in vacuum one can assume that at the initial stages of the coolant effect, the process of depletion of steel surface by chromium durng heat treatment affects markedly steel corrosion stability

  3. On the corrosion resistance of 01Kh25 ferritic steel

    International Nuclear Information System (INIS)

    Eremeeva, R.A.; Koval', E.K.

    1989-01-01

    Effect of non-ferrous metal ions on corrosion behaviour of 01Kh25 specific low carbon steel as compared to austenitic 12Kh18N10T and 06KhN28MDT steels in boiling solutions of sulfuric and nitric acids and their mixture is studied. Compositions initating commercial ones are chosen the media. It is shown that trough corrosion resistance of 01Kh25 steel in 10% H 2 SO 4 is two order below 06KhN28MDT austenitic steel in presence of Cu 2+ ions as a result of the surface passivation corrosion resistance of ferritic steel is an order higher the austenitic ones. Ferrite steel resistance in the nitric acid and its mixture with sulfuric acid is five timesas much as in 12Kh18N10T austenitic steel

  4. Chemical heat treatment of low alloyed maraging steels

    Energy Technology Data Exchange (ETDEWEB)

    Malinov, L S; Korotich, I K [Zhdanovskij Metallurgicheskij Inst. (Ukrainian SSR)

    1979-09-01

    The investigation concerned the nitriding, cementation, chromizing, borating of economically alloyed maraging grade 04Kh2N5MFYu steel. The investigated methods of chemothermal treatment were found to considerably increase the hardness of the surface layer of the maraging steel. The high tempering of the grade 04Kh2N5MFYu cemented and hardened steel was found to produce secondary hardening. On chromizing, the diffusion layer is an alloyed ferrite which strengthens because of the dispersion hardening on ageing. The formation of the plastic low-carbon martensite at relatively small cooling rates greatly decreases the tendency of the boride layer to cracking.

  5. Magnetic characterization of nanocrystalline Fe80−xCrxCo20 (15≤x≤35) alloys during milling and subsequent annealing

    International Nuclear Information System (INIS)

    Rastabi, Reza Amini; Ghasemi, Ali; Tavoosi, Majid; Sodaee, Tahmineh

    2016-01-01

    Magnetic characterization of nanocrystalline Fe–Cr–Co alloys during milling and annealing process was the goal of this study. To formation of Fe 80−x Cr x Co 20 (15≤x≤35) solid solution, different powder mixtures of Fe, Cr and Co elements were mechanically milled in a planetary ball mill. The annealing process was done in as-milled samples at different temperature in the range of 500–640 °C for 2 h. The produced samples were characterized using X-ray diffraction, scanning electron microscopy, differential scanning calorimetry and vibrating sample magnetometer. Performed mechanical alloying in different powder mixtures lead to the formation of Fe–Cr–Co α-phase solid solution with average crystallite sizes of about 10 nm. The produced nanocrystalline alloys exhibit magnetic properties with the coercivity and saturation of magnetization in the range of 110–200 Oe and 150–220 emu/g, respectively. The coercivity of produced alloys after annealing process decreased and reached to about 40–150 Oe. The highest value of coercivity in as-milled and annealed samples was achieved in alloys with higher Cr contents. - Highlights: • Hc and Ms of produced alloys obtained in the range of 110–200 Oe and 150–220 emu/g. • The highest value of Hc in milled and annealed samples was achieved in Fe 45 Cr 35 Co 20 . • Hc of produced alloys after spinodal decomposition decreased to about 40–150 Oe. • The effect of crystalline defects and residual strain on magnetic fields pinning in milled samples is higher than spinodal decomposition in annealed samples. • The highest value of Hc in as-milled and annealed samples was achieved in Fe 45 Cr 35 Co 20 . The coercivity of produced alloys after annealing process decreased and reach to about 40–150 Oe. • The produced nanocrystalline alloys exhibit magnetic properties with the coercivity and saturation of magnetization in the range of 110–200 Oe and 150–220 emu/g, respectively.

  6. Microstructure and mechanical properties of thermoelectric nanostructured n-type silicon-germanium alloys synthesized employing spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Bathula, Sivaiah [CSIR-Network of Institutes for Solar Energy, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Department of Applied Physics, Delhi Technological University, Delhi (India); Gahtori, Bhasker; Tripathy, S. K.; Tyagi, Kriti; Srivastava, A. K.; Dhar, Ajay, E-mail: adhar@nplindia.org [CSIR-Network of Institutes for Solar Energy, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Jayasimhadri, M. [Department of Applied Physics, Delhi Technological University, Delhi (India)

    2014-08-11

    Owing to their high thermoelectric (TE) figure-of-merit, nanostructured Si{sub 80}Ge{sub 20} alloys are evolving as a potential replacement for their bulk counterparts in designing efficient radio-isotope TE generators. However, as the mechanical properties of these alloys are equally important in order to avoid in-service catastrophic failure of their TE modules, we report the strength, hardness, fracture toughness, and thermal shock resistance of nanostructured n-type Si{sub 80}Ge{sub 20} alloys synthesized employing spark plasma sintering of mechanically alloyed nanopowders of its constituent elements. These mechanical properties show a significant enhancement, which has been correlated with the microstructural features at nano-scale, delineated by transmission electron microscopy.

  7. Welding procedure for 06Kh13N7D2 steel

    International Nuclear Information System (INIS)

    Muromtsev, B.I.; Turkov, I.I.

    1990-01-01

    Based on the results of investigations into the process strength, mechanical and corrosion properties of 08Kh13N7D2 steel welded joints, the optimal method of its welding and a possibility of applying it for high-strength mounting in nuclear power plants are determined

  8. Ultrasound surface treatment of Kh18N10T steel with different structural state. Ul'trazvukovaya poverkhnostnaya obrabotka stali Kh18N10T s razlichnym strukturnym sostoyaniem

    Energy Technology Data Exchange (ETDEWEB)

    Aksenov, V K; Danilov, P A; Mats, A V; Netesov, V M; Yaes, A A [AN Ukrainskoj SSR, Kharkov (Ukrainian SSR). Fiziko-Tekhnicheskij Inst.

    1989-09-01

    Ultrasound surface treatment (USST) is studied for its effect on the structure and mechanical-and-physical properties of Kh18N10T steel with different prehistory. It is shown that surface treatment may both increase and decrease steel microhardness.

  9. KH in Paraffin - KH(P): A Useful Base for Organic Synthesis

    Science.gov (United States)

    Taber, Douglass F.; Nelson, Christopher G.

    2011-01-01

    The preparation of KH as a one:one homogenate with paraffin, termed KH(P), is reported. KH(P), a solid at room temperature, is stable without special handling. On suspension in THF with a phosphonium salt, KH(P) rapidly generates the ylide. Wittig condensation with aromatic, aliphatic and α, β-unsaturated aldehydes proceeds with high Z-selectivity. KH(P) should be a generally useful base for organic synthesis. PMID:17081034

  10. Influence of a preliminary tensile plastic strain on the first stages of oxidation of a Ni80-Cr20 alloy

    International Nuclear Information System (INIS)

    Schmitt, Jean-Francois

    1992-01-01

    This research thesis reports the study of the influence of surface, and maybe also volume, defects created by a uniaxial mechanical strain on the chemical reactivity of metal and alloy surface (adsorption, desorption, segregation, surface chemical reaction), and more particularly on their early stages of oxidation. A tensile micro-machine has been designed and manufactured to study the influence of a mechanical strain on the first stages of oxidation of sample ribbons of Ni80-Cr20 alloy. Tests have been performed under low oxygen pressures. In order to analyze the surface, each reaction is monitored by Auger electron spectrometry, and many samples are transferred to another apparatus to examine the oxide distribution. Results are interpreted in terms of evolution of nickel, chromium and oxygen Auger signals which have been recorded during oxidation experiments. The first layers of the sample alloy are simply modelled and some theoretical calculations are developed which correlate with experimental values [fr

  11. Effect of rolling temperature on 12Kh18N10T steel tube hardening

    International Nuclear Information System (INIS)

    Yushkevich, P.M.; Stepanovich, V.E.; Manankova, L.V.; Usenko, V.N.; Semenov, I.A.

    1984-01-01

    Mechanical properties and substructure of tubes at the constant reduction degree k(the ratio of deformation over wall thickness to deformation over diameter), depending on strain degree during cold and hot tube rolling, have been studied. The investigations are carried out using hot-rolled tubes with the dimensions 88x8 mm of 12Kh1hN10T steel. With the decrease of strain over the wall of the tube, produced of 12Kh18N10T steel as to strain over diameter the values of yield strength and ultimate strength increase with simultaneous decrease in ductility during warm rolling and yield strength and ultimate strength decrease with the increase in ductility-during cold rolling. During warm rolling of the tubes at 250 deg C the hardening of 12Kh18N10T steel is higher, than at the rolling temperature 150 deg C. The optimum temperature range of warm rolling is 120-150 deg C. Grain orientation in the metal of the tubes and degree of texture perfection increase with the temperature increase of the tube warm drolling as compared with col rolli

  12. Antiferromagnetism in a 20% Ho-80% Tb alloy single crystal

    DEFF Research Database (Denmark)

    Lebech, Bente

    1968-01-01

    20% Ho-80% Tb exhibits two magnetic phases, similar to those of Tb. The spiral turn angle varies from 31.1° to 21.4°. A minimum effective spin for the occurrence of stable simple ferromagnetic structure at low temperatures is predicted....

  13. Technical Note: Calibration device for the krypton hygrometer KH20

    Directory of Open Access Journals (Sweden)

    T. Foken

    2012-08-01

    Full Text Available A calibration device for krypton hygrometers (KH20, Campbell Scientific, Inc. with variable path length is presented. This unit allows for in-situ calibrations of the krypton hygrometer, which is typically not very stable over time, during measuring campaigns. It was constructed mainly for application at high altitudes and low temperatures, where further improvements are needed to the IR-hygrometers which are normally used. The changing path length requires that a changing concentration of the absorber be simulated. Because oxygen absorbs more strongly than water vapour, the calibration is made against oxygen and transferred to water vapour. The design of the calibration instrument is made as one unit containing a stepper motor system, PC and humidity sensor. For the calibration, it is necessary to install the krypton hygrometer on this unit.

  14. Welding of high-strength stainless steel 03Kh12N10MT for cryogenic engineering

    International Nuclear Information System (INIS)

    Pustovit, A.I.

    1989-01-01

    Consideration is being given to weld resistance to cold and hot cracking at 93 and 77K and to mechanical properties of welded joints of high-strength stainless steel 03Kh12N10MT, produced under the fluxes AN-17M, AN-18, AN-26, AN-45, ANF-5, 48-OF-6, ANK-45 and ANK-49 in combination with various welding wires. It is shown that welds on 03Kh12N10MT steel meet the requirements only when using 48-OF-6 or ANK-49 flux. It is noted that impact strength of welds at 77K is sufficiently affected by the volume fraction of non-metallic inclusions in weld metal

  15. Nature of negative microplastic deformation in alloys

    International Nuclear Information System (INIS)

    Palatnik, L.S.; Ivantsov, V.I.; Kagan, Ya.I.; Papirov, I.I.; Fat'yanova, N.B.; AN Ukrainskoj SSR, Kharkov. Fiziko-Tekhnicheskij Inst.)

    1985-01-01

    The paper deals with investigation of microplastic deformation of corrosion resistant aging 40KhNYU alloy and the study of physical nature of negative microdeformation in this alloy under tension. Investigation of microplasticity of 40KhNYU alloy was conducted by the method of mechanostatic hysteresis using resistance strain gauge for measuring stresses and deformations. Microplasticity curves for 40KhNYU alloy were obtained. They represent the result of competition between usual (positive) microdeformation and phase (negative) deformation under tensile effect on the alloy. It was established that the negative microdeformation increment occurs during secondary aging of the phase precipitated from initial supersat urated solid solution (primary decomposition product). This phase decomposes under tension with disperse phase precipitation which promotes decreasing its specific volume and specimen volume as a whole

  16. Influence of continuous electron irradiation and different modes of mechanic-thermal treatment on structure-phase composition of alloys 36NKhTYu and 40KhNYu

    International Nuclear Information System (INIS)

    Alontseva, D.L.; Suslov, S.E.; Kupchishin, A.I.; Plotnikov, S.V.; Petrov, V.A.

    2002-01-01

    Principal regularities of structure formation in strongly deformed alloys 36NKhTYu and 40KhNYu under aging in certain temperature range and after electron irradiation are revealed. Morphological features of precipitating phases with purpose of development of methods for getting of optimal structural states providing essential properties rate were determined. Data of electron microscopic examinations of structure-phase composition are compared with data on mechanical properties

  17. Influence of local microplastic strains on stress corrosion of 08Kh18N10T steel

    International Nuclear Information System (INIS)

    Moskvin, L.N.; Efimov, A.A.; Sherman, Ya.I.; Fedorova, T.I.

    1987-01-01

    Study on specific features of microhomogeneous strain in the process of plastic strain development and their role in stress corrosion of 08Kh18N10T steel sheet specimens subject to preliminary strain by 1, 3, 6, 16 and 23% and subsequent tests of stress corrosion in magnesium chloride solution at 150 deg C 140 MPa has been carried out. Analysis of test results has shown that microplastic strain is distributed over a specimen nonuniformly and is accompanied with the slip bands formation which are sources of corrosion crack origination and development. 08Kh18N10T steel manifests the highest trend to stress corrosion under 1% microplastic strain

  18. Development of plastic deformations in 12Kh18N10T steel under cyclic symmetrical bending of specimens of various length

    Energy Technology Data Exchange (ETDEWEB)

    Pisarenko, G.S.; Leonets, V.A.; Bega, N.D. (AN Ukrainskoj SSR, Kiev. Inst. Problem Prochnosti)

    1983-08-01

    Effect of specimen length on intensity of plastic deformation development and cyclic strength is studied for annealed 12Kh18N10T steel under cyclic symmetrical bending. The intensity of microplastic deformations and cyclic strength of annealed 12Kh18N10T steel in the considered case is due to self-heating.

  19. Fouling and biocorrosion of a high-alloy steel in the Golden Horn bay

    International Nuclear Information System (INIS)

    Koryakova, M.D.; Nikitin, V.M.; Suponina, A.P.; Kharchenko, U.V.; Zvyagintsev, A.Yu.

    2002-01-01

    The studies on the effect of contamination of the Golden Horn bay waters (the Peter the Great Bay in the Japanese Sea) on formation of the community of the bacterio- and macrofouling and corrosion resistance of the Kh18N10T high-alloy steel are continued. The dissolved and chemically absorbed oxygen, pH, saprophytes, oil-oxidizing, sulfate-reducing bacteria and heavy metals are among the medium indicators, characterizing the level of pollution of the regions of the samples testing. It is shown, that the obtained experimental data extend our understanding of the dependent effect of three factors: the sea medium → fouling → corrosion resistance of the Kh18N10T high-alloy steel [ru

  20. Magnetic characterization of nanocrystalline Fe{sub 80−x}Cr{sub x}Co{sub 20} (15≤x≤35) alloys during milling and subsequent annealing

    Energy Technology Data Exchange (ETDEWEB)

    Rastabi, Reza Amini; Ghasemi, Ali, E-mail: ali13912001@yahoo.com; Tavoosi, Majid; Sodaee, Tahmineh

    2016-10-15

    Magnetic characterization of nanocrystalline Fe–Cr–Co alloys during milling and annealing process was the goal of this study. To formation of Fe{sub 80−x}Cr{sub x}Co{sub 20} (15≤x≤35) solid solution, different powder mixtures of Fe, Cr and Co elements were mechanically milled in a planetary ball mill. The annealing process was done in as-milled samples at different temperature in the range of 500–640 °C for 2 h. The produced samples were characterized using X-ray diffraction, scanning electron microscopy, differential scanning calorimetry and vibrating sample magnetometer. Performed mechanical alloying in different powder mixtures lead to the formation of Fe–Cr–Co α-phase solid solution with average crystallite sizes of about 10 nm. The produced nanocrystalline alloys exhibit magnetic properties with the coercivity and saturation of magnetization in the range of 110–200 Oe and 150–220 emu/g, respectively. The coercivity of produced alloys after annealing process decreased and reached to about 40–150 Oe. The highest value of coercivity in as-milled and annealed samples was achieved in alloys with higher Cr contents. - Highlights: • Hc and Ms of produced alloys obtained in the range of 110–200 Oe and 150–220 emu/g. • The highest value of Hc in milled and annealed samples was achieved in Fe{sub 45}Cr{sub 35}Co{sub 20}. • Hc of produced alloys after spinodal decomposition decreased to about 40–150 Oe. • The effect of crystalline defects and residual strain on magnetic fields pinning in milled samples is higher than spinodal decomposition in annealed samples. • The highest value of Hc in as-milled and annealed samples was achieved in Fe{sub 45}Cr{sub 35}Co{sub 20}. The coercivity of produced alloys after annealing process decreased and reach to about 40–150 Oe. • The produced nanocrystalline alloys exhibit magnetic properties with the coercivity and saturation of magnetization in the range of 110–200 Oe and 150–220 emu

  1. Low-temperature cyclic cracking resistance of Fe-Cr-Ni and Fe-Cr-Mn steels welded joints

    International Nuclear Information System (INIS)

    Ostash, O.P.; Zhmur-Klimenko, V.T.; Yarema, S.Ya.; Yushchenko, K.A.; Strok, L.P.; Belotserkovets, V.I.

    1983-01-01

    Results of further investigations into regularities of development of low-temperature fatigue fracture of welded oints in 07Kh13G20AN4 steel are presented, they are compared with analogous data traditional cryogenic 0Kh18N10T and 03Kh13AG19 steels. Welded joints have been prepared by means of automatic V-like level arc Welding of plates; 0Kh18N10T and 07Kh13G20AN4 steels have been welded by means of sv-04Kh19N9 wire, 03Kh13AG19 steel-by means of sv-07Kh13AG19 wire. Tests at almost zero (asymmetry coefficient R=0.05) cycle of extension at 15-20 Hz frequency have been conducted on 5 mm thick disk samples at 20 deg C and - 160 deg C according to the given methods. It is shown that by cyclic crack resistance of welded joint zones of 0Kh18N10T steel and chromium-manganese steels at normal temperature the 07Kh13G20AN4 steel exceeds 0Kh18N10T steel, at low temperature it yields to 0Kh18N10T only by fracture toughness of heat affected zones HAZ and weld metal (ne). 07Kh13G20AN4 steel and its welded joints as most hardened and cheap may be a good substituent for 0Kh18N10T steel. Optimization of WM alloying for increase of its cyclic fracture toughness at cryogenic temperatures is necessary

  2. Roentgenoelectronic investigation into oxidation of iron-chromium and iron-chromium-nickel alloys

    International Nuclear Information System (INIS)

    Akimov, A.G.; Rozenfel'd, I.L.; Kazanskij, L.P.; Machavariani, G.V.

    1978-01-01

    Kinetics of iron-chromium and iron-chromium-nickel alloy oxidation (of the Kh13 and Kh18N10T steels) in oxygen was investigated using X-ray electron spectroscopy. It was found that according to X-ray electron spectra chromium oxidation kinetics in the iron-chromium alloy differs significantly from oxidation kinetics of chromium pattern. Layer by layer X-ray electron analysis showed that chromium is subjected to a deeper oxidation as compared to iron, and accordingly, Cr 2 O 3 layer with pure iron impregnations is placed between the layer of mixed oxide (Fe 3 O 4 +Cr 2 O 3 ) and metal. A model of the iron-chromium alloy surface is suggested. The mixed oxide composition on the steel surface is presented as spinel Fesub(2+x)Crsub(1-x)Osub(y)

  3. Microstructural and Mechanical Characterization of Al-0.80Mg-0.85Si-0.3Zr Alloy

    Directory of Open Access Journals (Sweden)

    Kahrıman F.

    2017-12-01

    Full Text Available In this study, Al-0.80Mg-0.85Si alloy was modified with the addition of 0.3 wt.-% zirconium and the variation of microstructural features and mechanical properties were investigated. In order to produce the billets, vertical direct chill casting method was used and billets were homogenized at 580 °C for 6 h. Homogenized billets were subjected to aging practice following three stages: (i solution annealing at 550 °C for 3 h, (ii quenching in water, (iii aging at 180 °C between 0 and 20 h. The hardness measurements were performed for the alloys following the aging process. It was observed that peak hardness value of Al-0.80Mg-0.85Si alloy increased with the addition of zirconium. This finding was very useful to obtain aging parameters for the extruded hollow profiles which are commonly used in automotive industry. Standard tensile tests were applied to aged profiles at room temperature and the results showed that modified alloy had higher mechanical properties compared to the non-modified alloy.

  4. Structural relaxation and embrittlement of Cu/sub 59/Zr/sub 41/ and Fe/sub 80/B/sub 20/ glasses

    International Nuclear Information System (INIS)

    Deng, D.; Argon, A.S.

    1986-01-01

    The effect of physical aging at 0.92 T/sub c/, on phase separation, crystallization, distributed shear relaxations, hardness, and strain to fracture was investigated in Cu/sub 59/Zr/sub 41/ and Fe/sub 80/B/sub 20/ glasses. In Cu/sub 59/Zr/sub 41/ glass, aging resulted in phase separation prior to crystallization, rather than the expected polymorphous crystallization. In Fe/sub 80/B/sub 20/ in the as-quenched alloys a prominent second-order Curie transition was found at 613K, which was recovered by aging. Apart from a nearly four-fold acceleration of the aging process in Fe/sub 80/B/sub 20/ over the Cu/sub 59/Zr/sub 41/ alloy, their mechanical responses to the aging were very similar in alterations of the internal friction spectrum, evolution of hardness, and strain to fracture

  5. On change of vanadium carbide state during 20Kh3MVF steel heat treatment

    International Nuclear Information System (INIS)

    Gitgarts, M.I.; Maksimenko, V.N.

    1975-01-01

    The Xray diffraction study of vanadium carbide MC has been made in the steel-20KH3MVF quenched from 970 and 1040 deg and tempered at 660 deg for 210 hrs. It has been found that the constant of the MC crystal lattice regularly varies with the temperature of isothermal hold-up. In the steel tempered after quenching two vanadium carbides of different content could co-exist simultaneously: carbide formed in the quenching process and carbide formed during tempering. The discovered effect of the temperature dependence of the MC content is, evidently, inherent also to other steels containing vanadium

  6. Thermal oxidation of reactively sputtered amorphous W80N20 films

    International Nuclear Information System (INIS)

    Vu, Q.T.; Pokela, P.J.; Garden, C.L.; Kolawa, E.; Raud, S.; Nicolet, M.

    1990-01-01

    The oxidation behavior of reactively sputtered amorphous tungsten nitride of composition W 80 N 20 was investigated in dry and wet oxidizing ambient in the temperature range of 450 degree C--575 degree C. A single WO 3 oxide phase is observed. The growth of the oxide follows a parabolic time dependence which is attributed to a process controlled by the diffusivity of the oxidant in the oxide. The oxidation process is thermally activated with an activation energy of 2.5±0.05 eV for dry ambient and 2.35±0.05 eV for wet ambient. The pre-exponential factor of the reaction constant for dry ambient is 1.1x10 21 A 2 /min; that for wet ambient is only about 10 times less and is equal to 1.3x10 20 A 2 /min

  7. The effects of alloying elements on microstructures and mechanical properties of tungsten inert gas welded AZ80 magnesium alloys joint

    Science.gov (United States)

    Li, Hui; Zhang, Jiansheng; Ding, Rongrong

    2017-11-01

    The effects of alloying elements on the macrostructures, microstructures and tensile strength of AZ80 Mg alloy weldments were studied in the present study. The results indicate that with the decrease of Al element content of filler wire, the welding defects of seam are gradually eliminated and the β-Mg17Al12 phases at α-Mg boundaries are refined and become discontinuous, which are beneficial to the improvement of tensile strength. With AZ31 Mg alloy filler wire, the maximum tensile strength of AZ80 weldment is 220 MPa and fracture occurs at the welding seam of joint. It is experimentally proved that robust AZ80 Mg alloy joints can be obtained by tungsten inert gas (TIG) welding process with AZ31 Mg alloy filler wire. However, further study is required to improve the microstructures and reduce welding defects of joint in order to further improve the joining strength of AZ80 Mg alloy joint.

  8. Structural changes in surface layer of steel 08Kh18N10T during machining

    International Nuclear Information System (INIS)

    Palenik, J.; Vodarek, V.

    1989-01-01

    The results are reported of a study of the surface layer of steel 08Kh18N10T affected by machining. Structural changes were studied caused by finish turning and by additional roller burnishing. Multiple deformation bands were observed to occur under the given cutting conditions; they mainly consisted of deformation doublets and only in isolated cases of ε-martensite. The presence of α'-martensite was not shown in the specimen surface layer following finish turning. The deformation shear bands in the roller-burnished specimen consisted of both ε-martensite and of deformation doublets. The amount of ε-martensite in the structure was significantly higher than in the specimen worked by turning. Local presence of α'-martensite formations was observed inside the deformation bands. It thus follows that roller burnishing is unsuitable as part of the manufacture of components from steel 08Kh18N10T. (J.B.). 5 figs., 1 tab., 9 refs

  9. Cooling rate and microstructure of surface layers of 5KhNM steel, machined by electroerosion method

    International Nuclear Information System (INIS)

    Foteev, N.K.; Ploshkin, V.V.; Lyakishev, V.A.; Shirokov, S.V.

    1982-01-01

    The cooling rate and microstructure of surface layers of steel 5KhNM machined by electroerosion method have been studied. It is shown that the difference in heating rate of the surface layers with electric discharge over the 5KhNM steel samples depth results in the intensive size reduction of the microstructure. In the surface layer alongside with martensite residual austenite is present, the lattice period of which increases with the increase of pulse duration, carbide phase of complex composition appears, and concentrational heterogeneity in alloying elements (except carbon) is absent

  10. Cooling rate and microstructure of surface layers of 5KhNM steel, machined by electroerosion method

    Energy Technology Data Exchange (ETDEWEB)

    Foteev, N.K.; Ploshkin, V.V.; Lyakishev, V.A.; Shirokov, S.V.

    1982-01-01

    The cooling rate and microstructure of surface layers of steel 5KhNM machined by electroerosion method have been studied. It is shown that the difference in heating rate of the surface layers with electric discharge over the 5KhNM steel samples depth results in the intensive size reduction of the microstructure. In the surface layer alongside with martensite residual austenite is present, the lattice period of which increases with the increase of pulse duration, carbide phase of complex composition appears, and concentrational heterogeneity in alloying elements (except carbon) is absent.

  11. Development of production technology and investigation of quality for forged-welded turbine rotors of steel 25Kh2NVFA

    International Nuclear Information System (INIS)

    Borisov, I.A.; Merinov, G.N.; Slezkina, E.V.

    1997-01-01

    A study was made into mechanical properties and microstructure of turbine rotor components manufactured by forging and heat treated under various conditions. It is revealed that the optimal heat treatment of forgings must include double quenching with subsequent tempering at 630-640 deg C for 10-20 h. Forged and welded rotors should be tempered at 620-630 deg C for 50-100 h. Microscopic examination and mechanical tests showed that low alloy steel 25Kh2NMF can be successfully used for manufacturing rotors of high-, medium-and low-heat turbines

  12. Theoretical study of [Li(H2O)n]+ and [K(H2O)n]+ (n = 1-4) complexes

    International Nuclear Information System (INIS)

    Wojcik, M.J.; Mains, G.J.; Devlin, J.P.

    1995-01-01

    The geometries, successive binding energies, vibrational frequencies, and infrared intensities are calculated for the [Li(H 2 O) n ] + and [K(H 2 O) n ] + (n = 1-4) complexes. The basis sets used are 6-31G * and LANL1DZ (Los Alamos ECP+DZ) at the SCF and MP2 levels. There is an agreement for calculated structures and frequencies between the MP2/6-31G * and MP2/LANL1DZ basis sets, which indicates that the latter can be used for calculations of water complexes with heavier ions. Our results are in a reasonable agreement with available experimental data and facilitate experimental study of these complexes. 19 refs., 4 figs., 6 tabs

  13. The effect of thermoplastic treatment regimes on the microplastic strain of nitrogen-containing steel Kh21G10N7MBF

    International Nuclear Information System (INIS)

    Bannykh, O.A.; Blinov, V.M.; Kostina, M.V.; Grachev, S.V.; Mal'tseva, L.A.

    2005-01-01

    A study is made into the influence of a percentage reduction during cold rolling and subsequent holdings at heat on development of microplastic deformation when bending sheet specimens of stainless austenitic high-nitrogen steel Kh21G10N7MBF. It is revealed that a maximum value of apparent limit of elasticity (∼1800 MPa) is attained due to plastic deformation by rolling at 20 Deg C with a total percentage reduction of 60 % and subsequent aging at 500 Deg C for 1-4 h [ru

  14. REVIVALISME PENDIDIKAN ISLAM AWAL ABAD 20 (STUDI KRITIS PEMBARUAN PENDIDIKAN ISLAM PERSPEKTIF KH. AHMAD DAHLAN

    Directory of Open Access Journals (Sweden)

    Zetty Azizatun Ni'mah

    2016-05-01

    Full Text Available The idea of Islamic educational reform in Indonesia began in the early twentieth century. This was caused by out of concerns Muslim intellectual leaders of the secular education system which implemented the Dutch East Indies and then has a negative impact on the condition of Islamic education in Indonesia. KH. Ahmad Dahlan is pioneer figure of Islamic educational reform in Indonesia. He is of leaders respond to the condition of Islamic education in Indonesia needs to be updated in terms of objectives, materials, methods and management. This article aims to analyze thoughts KH. Ahmad Dahlan. KH. Ahmad Dahlan reform of Islamic education as well as his correlation with the current education system. This issues is examined using research methods “library research” using written materials in the form of books, magazines, journals, articles and other literatures relevant to the discussion. For data analysis the authors use the approach of history, sociology and anthropology. The results of the research that has been conducted by the author suggests that the concept of Islamic education reform in perspective KH. Ahmad: the aim of Islamic education leads to increased economic, politic, social race with modernism education, the Qur’an and Hadits are direct material examined by leaving the classic are often assessed the traditionalists, Islamic education methods abandon traditional methods, the Islamic educational institutions organized under auspices of the Muhammadiyah organization with a model of organizational leadership. Educational issues such as character building, problem solving, integration of scientific and educational innovation are concepts of education offered by KH.Ahmad Dahlan which it is an attempt to anticipate the renewal of the times and the situation in the subsequent periods.

  15. Peculiarities of welding procedure for the 05Kh12K14N5M5T-VD maraging stainless steel with strength higher 1500 MPa

    International Nuclear Information System (INIS)

    Pustovit, A.I.

    1980-01-01

    The effect of welding procedure of 05Kh12K14N5M5T-VD stainless steel on the properties of its welded joints is investigated. A new procedure of welding for pressure vessels made of this steel using Sv-03Kh15K14N5M3T-EL welding wire is suggested [ru

  16. Tendency of the 18-8 type corrosion-resistant steel to cracking in automatic building-up of copper and copper base alloys in argon

    International Nuclear Information System (INIS)

    Abramovich, V.R.; Andronik, V.A.

    1978-01-01

    Studied was the tendency of the 18-8 type corrosion-resistant steel to cracking during automatic building-up of copper and bronze in argon. The investigation was carried out on the 0kh18n10t steel in argon. It had been established, that the degree of copper penetration into the steel inceases with the increase in the time of the 0Kh18n10t steel contact with liquid copper. Liquid copper and copper base alloys have a detrimental effect on mechanical properties of the steel under external tensile load during intercontant. It is shown that in building-up of copper base alloys on the steel-0Kh18n10t, tendency of the steel to cracking decreases with increase in stiffness of a surfaced weld metal plate and with decrease in building-up energy per unit length. The causes of macrocracking in steel at building-up non-ferrous metals are explained. The technological procedures to avoid cracking are suggested

  17. Study and characterization of the electrical properties of the NiCr(80-20)% in weight alloy, with and without irradiation

    International Nuclear Information System (INIS)

    Otero, M.P.; Lucki, G.

    1979-01-01

    The parameters involved in the order-disorder transition of NiCr(80-20)% in weight alloy were studied by the resistivity method, before and after neutronic irradiation in the IEAR-1 reactor core. In addition to characterizing the electrical properties, obtained in order to fulfill technological application, fundamental studies were made by linear and isothermal annealing during irradiation, studying the variation of rho (resistivity) whit t'(irradiation time) in the isothermal annealing and the variation of rho with T (temperature in 0 C) in the linear annealing. Values obtained were: T sub(c) = (536 +- 4) 0 C T sub(c) = critical temperature of the order-disorder transition and E sub(a) = (1,36 +- 0,14) ev (E sub(a) = activation energy for the vacancies annihilation process). (Author) [pt

  18. Structural features and properties of the laser-deposited nickel alloy layer on a KhV4F tool steel after heat treatment

    Science.gov (United States)

    Shcherbakov, V. S.; Dikova, Ts. D.; Stavrev, D. S.

    2017-07-01

    The study and application of the materials that are stable in the temperature range up to 1000°C are necessary to repair forming dies operating in this range. Nickel-based alloys can be used for this purpose. The structural state of a nickel alloy layer deposited onto a KhV4F tool steel and then heat treated is investigated. KhV4F tool steel (RF GOST) samples are subjected to laser deposition using a pulsed Nd:YAG laser. A nickel-based material (0.02C-73.8Ni-2.5Nb-19.5Cr-1.9Fe-2.8Mn) is employed for laser deposition. After laser deposition, the samples are subjected to heat treatment at 400°C for 5 h, 600°C for 1 h, 800°C for 1 h, and 1000°C for 1 h. The microstructure, the phase composition, and the microhardness of the deposited layer are studied. The structure of the initial deposited layer has relatively large grains (20-40 μm in size). The morphology is characterized by a cellular-dendritic structure in the transition zone. The following two structural constituents with a characteristic dendritic structure are revealed: a supersaturated nickel-based γ solid solution and a chromium-based bcc α solid solution. In the initial state and after heat treatment, the hardness of the deposited material (210-240 HV 0.1) is lower than the hardness of the base material (400-440 HV 0.1). Only after heat treatment at 600°C for 1 h, the hardness increases to 240-250 HV0.1. Structure heredity in the form of a dendritic morphology is observed at temperatures of 400, 600, and 800°C. The following sharp change in the structural state is detected upon heat treatment at 1000°C for 1 h: the dendritic morphology changes into a typical α + γ crystalline structure. The hardness of the base material decreases significantly to 160-180 HV 0.1. The low hardness of the deposited layer implies the use of the layer material in limited volume to repair the forming surfaces of dies and molds for die casting. However, the high ductility of the deposited layer of the nickel

  19. Investigation of fretting corrosion of vacuum-chrome-plated vt3-1 titanium alloy in pair with unprotected vt3-1 alloy and 40khnma steel

    International Nuclear Information System (INIS)

    Rojkh, I.L.; Koltunova, L.N.; Vejtsman, M.G.; Birman, Ya.N.; Skosarev, A.V.; Kogan, I.S.

    1978-01-01

    The character of destruction of contacting surfaces in the process of fretting corrosion of titanium alloy VT3-1 chromized in vacuum in pair with unprotected alloy VT3-1 and steel 40KhNMA has been studied by scanning electron microscopy, electronography, and recording the surface profile. The specific load was 200 kg/cm 2 , vibration amplitude 50 mkm and frequency 500 Hz. It has been established that pairs unprotected with coating are subjected to intensive fretting corrosion especially when they are made of titanium alloy. For the pair chromized alloy VT3-1 - unprotected alloy VT3-1 no destruction of a chromized surface is observed. Vacuum chromium coating in the pair with steel 40KhNMA reveals similar properties as in pair with a titanium alloy. The surface of a steel sample is destroyed because of fretting corrosion, though the intensity of corrosion is lower than in the case of unprotected pairs. Vacuum chromium coating is recommended for protection of titanium alloy VT3-1 from fretting corrosion in pair with steel 40KhNMA or an alloy VT3-1 especially in those cases when various organic coatings are unsuitable

  20. Neutron diffraction study of a nitrogen martensitic steel 0Kh16N4AB under load

    Czech Academy of Sciences Publication Activity Database

    Sumin, V. V.; Papushkin, I.V.; Bannykh, O.A.; Blinov, V.M.; Lukáš, Petr

    2008-01-01

    Roč. 105, č. 1 (2008), s. 88-91 ISSN 0031-918X Institutional research plan: CEZ:AV0Z10480505 Keywords : steel 0Kh16N4AB * neutron diffraction * FSD Subject RIV: BG - Nuclear, Atomic and Molecular Physics , Colliders Impact factor: 0.412, year: 2008

  1. Determination of constant of chemical reaction rate in the process of steel treatment in the endothermal atmosphere

    International Nuclear Information System (INIS)

    Gyulikhandanov, E.L.; Kislenkov, V.V.

    1978-01-01

    The high-temperature method was applied to measuring a relative variation in the electrical resistance of a thin steel foil prepared from the 12KhN3A, 18Kh2N4VA, 20KhGNR, and 20Kh3MVF steels during its carburization and decarburization, and determined was the temperature dependence of the reaction rate of the interaction of the endothermal atmosphere of different compositions with the analloyed γ-Fe. A connection has been established between the reaction rate constant and the thermodynamic activity of carbon in the alloyed austenite at the temperature of about 925 deg C, corresponding to the cementation temperature. This provides the quantitative estimation of the above value for any alloyed steels and with the presence of numerical values of diffusion coefficients; this also enables one to carry out an accurate calculation of the distribution of carbon throughout the depth of a layer when effecting the cementation in the endothermal atmosphere

  2. 50 CFR 80.20 - Land control.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Land control. 80.20 Section 80.20 Wildlife... WILDLIFE RESTORATION AND DINGELL-JOHNSON SPORT FISH RESTORATION ACTS § 80.20 Land control. The State must control lands or waters on which capital improvements are made with Wildlife and Sport Fish Restoration...

  3. Study and characterization of FeNi and NiCr(80-20) % w alloys, during and after neutron irradiation, using the resistivity method

    International Nuclear Information System (INIS)

    Otero, Mauro Pereira

    1978-01-01

    We have used the resistivity method with and without neutron irradiation to study the parameters that appear in the Order-Disorder Transitions of Fe Ni(50-50)% at. and Ni Cr( 80 - 20) % w. alloys. The results obtained with Fe Ni are in agreement with those obtained by Marchand at the University of Grenoble. Several isothermal annealings were made in the range 400 - 302 deg C in which T c (Order-Disorder Transition Critical Temperature) was determined between 327 and 310 deg C. The activation energy obtained was E a = 0,49 eV and is in agreement with works of Marchand, Dienes and Damask. As for Ni Cr(80-20)% the following has been done: a) Electrical Properties characterizations, having in mind the technological applications; b) Linear and isothermal annealings were performed to determine the Order-Disorder Transition Critical Temperature (I ) supported by hypothesis made, taking into account the Yano's and Taylor's marks. The-result is T c = (536 +- 4) deg C; c) determination of activation energy E a = (1,36 +- 0.14) eV. The resistivity measurements mere performed by means of the classical 4-wire method. An anisotropy of electrical resistivity was found to exist depending on the sense of the applied electrical field. (author)

  4. The structural properties of InGaN alloys and the interdependence on the thermoelectric behavior

    Science.gov (United States)

    Kucukgok, Bahadir; Wu, Xuewang; Wang, Xiaojia; Liu, Zhiqiang; Ferguson, Ian T.; Lu, Na

    2016-02-01

    The III-Nitrides are promising candidate for high efficiency thermoelectric (TE) materials and devices due to their unique features which includes high thermal stability. A systematic study of the room temperature TE properties of metalorganic chemical vapor deposition grown InxGa1-xN were investigated for x = 0.07 to 0.24. This paper investigated the role of indium composition on the TE properties of InGaN alloys in particular the structural properties for homogenous material that did not show significant phase separation. The highest Seebeck and power factor values of 507 μV K-1 and 21.84 × 10-4 Wm-1K-1 were observed, respectively for In0.07Ga0.93N at room temperature. The highest value of figure-of-merit (ZT) was calculated to be 0.072 for In0.20Ga0.80N alloy at room temperature.

  5. Effects of carbon nanotubes on the microstructure and mechanical properties of the wrought Mg–2.0Zn alloy

    International Nuclear Information System (INIS)

    Zeng, Xiao-shu; Liu, Yong; Huang, Qiu-yu; Zeng, Gang; Zhou, Guo-hua

    2013-01-01

    The effects of carbon nanotubes (CNTs) on the microstructure and mechanical properties of wrought Mg alloys with of 2.0 wt% of Zn content (Mg–2.0Zn) are investigated by the optical microscope (OM), transmission electron microscope (TEM), scanning electron microscope (SEM) and uniaxial tensile test. Different contents of CNTs are added separately in the as-cast ingots and as-extruded samples. The results showed that CNTs could greatly refine the microstructure of both as-cast alloy and as-extruded alloy. The tensile strength, yield strength, elongation and elasticity modulus of the alloy with CNTs were improved to different extents. Remarkably, the increase of elongation reached approximately 80%. The fracture surface of the alloy with CNTs mainly consisted of dimples with toughness rupture modes. Therefore, it suggests that CNTs could enhance the plasticity of wrought Mg–2.0Zn alloy without the reduction of strength

  6. Measurements of the electrical resistance and the hydrogen depth distribution for Ni 60Nb 20Zr 20 amorphous alloy before and after hydrogen charging

    Science.gov (United States)

    Nakano, Sumiaki; Ohtsu, Naofumi; Nagata, Shinji; Yamaura, Shin-ichi; Uchinashi, Sakae; Kimura, Hisamichi; Shikama, Tatsuo; Inoue, Akihisa

    2005-02-01

    A Ni 60Nb 20Zr 20 amorphous alloy was prepared by the single-roller melt-spinning technique. The change in the electrical resistance of the alloy after electrochemical hydrogen charging in 6 N KOH solution was investigated. The change in the hydrogen depth distribution in the alloy was also investigated by elastic recoil detection. As a result, we found that the electrical resistance of the alloy increases with increasing the hydrogen content in the alloy and that a large number of hydrogen atoms are remained in the surface area of the hydrogen-charged alloy.

  7. Sinter ageing of equiatomic Al20Co20Cu20Zn20Ni20 high entropy alloy via mechanical alloying

    International Nuclear Information System (INIS)

    Mohanty, Sutanuka; Gurao, N.P.; Biswas, Krishanu

    2014-01-01

    The present investigation reports for the first time, the sinter ageing of equiatomic Al 20 Co 20 Cu 20 Ni 20 Zn 20 high entropy alloy (HEA), being synthesized by high energy ball milling of elemental powder blend under protective argon atmosphere, followed by consolidation of the milled powder by spark plasma sintering at different temperatures and applied pressure of 50 MPa. The detailed X-ray diffraction and transmission electron microscopy (TEM) studies indicate the presence of single phase, FCC β supersaturated solid solution in the ball milled powder. However, the sintering of the as-milled powder reveals the formation of α with ordered FCC (L1 2 ) structure within the grains of FCC γ. The microstructural analysis using TEM shows the precipitation of near cuboidal shaped α phase within the grains of γ. The size and shape of the precipitates depend on the sintering temperature. Hardness measurement of the sintered alloys suggests age hardening of the as-milled powder during sintering. The sinter age hardening of HEA is attributed to the fine scale precipitation of α phase. Detailed variation of the hardness and microstructural evolution are reported here to elucidate this novel finding

  8. The structural properties of InGaN alloys and the interdependence on the thermoelectric behavior

    Directory of Open Access Journals (Sweden)

    Bahadir Kucukgok

    2016-02-01

    Full Text Available The III-Nitrides are promising candidate for high efficiency thermoelectric (TE materials and devices due to their unique features which includes high thermal stability. A systematic study of the room temperature TE properties of metalorganic chemical vapor deposition grown InxGa1-xN were investigated for x =  0.07 to 0.24. This paper investigated the role of indium composition on the TE properties of InGaN alloys in particular the structural properties for homogenous material that did not show significant phase separation. The highest Seebeck and power factor values of 507 μV K−1 and 21.84 × 10−4 Wm−1K−1 were observed, respectively for In0.07Ga0.93N at room temperature. The highest value of figure-of-merit (ZT was calculated to be 0.072 for In0.20Ga0.80N alloy at room temperature.

  9. The structural properties of InGaN alloys and the interdependence on the thermoelectric behavior

    Energy Technology Data Exchange (ETDEWEB)

    Kucukgok, Bahadir; Lu, Na, E-mail: Luna@purdue.edu [Lyles School of Civil Engineering, Purdue University, West Lafayette, IN 47907 (United States); Wu, Xuewang; Wang, Xiaojia [Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Liu, Zhiqiang [Institute of Semiconductors, Chinese Academy of Science, Beijing (China); Ferguson, Ian T. [College of Engineering and Computing, Missouri University of Science and Technology, Rolla, MO 65409 (United States)

    2016-02-15

    The III-Nitrides are promising candidate for high efficiency thermoelectric (TE) materials and devices due to their unique features which includes high thermal stability. A systematic study of the room temperature TE properties of metalorganic chemical vapor deposition grown In{sub x}Ga{sub 1-x}N were investigated for x =  0.07 to 0.24. This paper investigated the role of indium composition on the TE properties of InGaN alloys in particular the structural properties for homogenous material that did not show significant phase separation. The highest Seebeck and power factor values of 507 μV K{sup −1} and 21.84 × 10{sup −4} Wm{sup −1}K{sup −1} were observed, respectively for In{sub 0.07}Ga{sub 0.93}N at room temperature. The highest value of figure-of-merit (ZT) was calculated to be 0.072 for In{sub 0.20}Ga{sub 0.80}N alloy at room temperature.

  10. Effect of nonmetallic inclusions on anisotropy of ductility in 35KhN3MFA steel forgings

    International Nuclear Information System (INIS)

    Shtremel', M.A.; Yavojskij, V.I.; Volkov, V.A.; Chursin, G.M.; Chukhlov, V.I.; Fetisov, G.I.; Mochalin, N.K.; Smol'yaninov, L.V.

    1980-01-01

    Characteristics of nonmetaltic inclusions and anizotropy of ductility and of impuct strength of forgings of the 35KhN3MFA steel are compared at different variants of melting and outer-furnace treatment. It is shown that method of melting rugulates anisotropy of ductility primarily through deformability of large inclusions during forging. Deformability of inclusions considerably changes due to introduction of silicocalcium in iron mold [ru

  11. Sulfidation behavior of Fe20Cr alloys

    International Nuclear Information System (INIS)

    Pillis, Marina Fuser

    2001-01-01

    Alloys for use in high temperature environments rely on the formation of an oxide layer for their protection. Normally, these protective oxides are Cr 2 O 3 , Al 2 O 3 and, some times, SiO 2 . Many industrial gaseous environments contain sulfur. Sulfides, formed in the presence of sulfur are thermodynamically less stable, have lower melting points and deviate much more stoichiometrically, compared to the corresponding oxides. The mechanism of sulfidation of various metals is as yet not clear, in spite of the concerted efforts during the last decade. To help address this situation, the sulfidation behavior of Fe20Cr has been studied as a function of compositional modifications and surface state of the alloy. The alloys Fe20Cr, Fe20Cr0.7Y, Fe20Cr5Al and Fe20Cr5Al0.6Y were prepared and three sets of sulfidation tests were carried out. In the first set, the alloys were sulfidized at 700 deg C and 800 deg C for 10h. In the second set, the alloys were pre-oxidized at 1000 deg C and then sulfidized at 800 deg C for up to 45h. In the third set of tests, the initial stages of sulfidation of the alloys was studied. All the tests were carried out in a thermobalance, in flowing H 2 /2%H 2 S, and the sulfidation behavior determined as mass change per unit area. Scanning electron microscopy coupled to energy dispersive spectroscopy and X-ray diffraction analysis were used to characterize the reaction products. The addition of Y and Al increased sulfidation resistance of Fe20Cr. The addition of Y altered the species that diffused predominantly during sulfide growth. It changed from predominant cationic diffusion to predominant anionic diffusion. The addition of Al caused an even greater increase in sulfidation resistance of Fe20Cr, with the parabolic rate constant decreasing by three orders of magnitude. Y addition to the FeCrAl alloy did not cause any appreciable alteration in sulfidation resistance. Pre-oxidation of the FeCrAl and FeCrAlY alloys resulted in an extended

  12. Sàng khôn as A Theorizing Tool in Mobility Education

    Directory of Open Access Journals (Sweden)

    Ngoc Ba Doan

    2017-02-01

    Full Text Available The current virtual and physical mobility of humans, ideas, knowledge and epistemologies has major implications for education, especially in settings where English is seen as the default medium of instruction. While diversity is inherent in mobility, English-only pedagogy is a denial of the richness and potential of diverse resources learners bring with them through their mobility. This paper reports a philosophical stance and pedagogical practices employed by a lecturer in English language education at an Australian university. It argues that students’ full linguistic resources and epistemologies, known as sàng khôn, contribute to their agency and can be used as tools to theorise new knowledge in the context of their mobility education.

  13. Simulation of Microdamage and Evaluation of Remaining Life of Steam Conduit Components from New-Generation Refractory Steel 10Kh9MF-Sh

    Science.gov (United States)

    Gladshtein, V. I.

    2018-03-01

    The effects of microdamage on the remaining life of high-temperature components of steam conduits from high-chromium steel 10Kh9MF-Sh and low-alloy steel 12Kh1M1F are compared. To simulate the microdamage, specimens with a circular notch and different relative diameters are fabricated. Specimens with a notch simulating the highest degree of microdamage and smooth specimens are tested for long-term strength. The coefficient of the remaining life of a conduit is computed for the range of relative damage presenting practical interest.

  14. Effect of method for plastic working procedure on deformability of heat resisting alloys

    International Nuclear Information System (INIS)

    Nikiforov, B.A.

    1979-01-01

    Presented are the results of investigation of deformability of the heat resisting KhN56BMTYUR, KhN67BMTYU alloys at the wire drawing and rolling. The deformability has been evaluated by the results of macro- and micro-analyses, by the change of metal density and mechanical properties in the process of deformation. It is found that by the rolling it is possible to obtain 3-6 mm diameter wire with high surface quality avoiding intermediate heat treatments, cleaning and grinding the wire surface. The production of the wire of the same diameter by drawing is connected with intermediate heat treatments and with the presence of surface and internal defects in the form of longitudinal and transverse cracks, tears, laminations

  15. KH 2PO4 as a novel catalyst for regioselective monobromination of aralkyl ketones using N-bromosuccinimide: a green methodology

    Directory of Open Access Journals (Sweden)

    P. Md. Khaja Mohinuddin

    2015-08-01

    Full Text Available A simple, regioselective and green method has been developed for the preparation of monobrominated ketones from various aralkyl ketones by using N-bromosuccinimide in presence of KH 2PO 4 in EtOH at reflux temperature. The present method is of short reaction time and simple with excellent isolated yields of products. The use of eco-friendly solvent, reuse of organic waste (succinimide and recyclable catalyst used for 4 times without loss of activity are advantageous. This is the first example of the use of KH 2PO 4 as a useful catalyst in organohalogen chemistry and the present method meets reduce-reuse-recycle (RRR principle towards development of green protocol.

  16. Crustal Structure of Khövsgöl, Mongolia

    Science.gov (United States)

    Scott, A. M.; Meltzer, A.; Stachnik, J.; Russo, R.; Munkhuu, U.; Tsagaan, B.

    2017-12-01

    Mongolia is part of the Central Asian Orogenic Belt, an accretionary event that spanned 800 million years from the mid-Proterozoic to mid-Phanerozoic. As a result of the past collisional and rifting events, the modern Khövsgöl rift system of northern Mongolia contains a heterogeneous lithospheric structure. The current rift system has three parallel N-S trending basins that roughly align with terrane boundaries. Structures inherited during the accretionary events may be a factor influencing regional deformation. The forces that drive local deformation are not well understood, but varying processes have been proposed: far-field effects of India-Eurasian plate convergence, westward subduction of the Pacific plate, magmatic underplating at the base of the crust, mantle plume activity, and asthenospheric mantle convection. Determining the nature of crustal features within this poorly understood region may illuminate processes that control rifting within intracontinental settings. A network of 26 broadband seismic stations encompassing 200 square kilometers of the Khövsgöl rift system were deployed from August 2014 to June 2016. More than 2100 events were detected, and most earthquakes were concentrated near rift structures. Events between Busiin-Gol and Darkhad, the westernmost and central basins of the Khövsgöl rift system, are distributed within the crust. An active fault is outlined along the eastern border of the Darkhad basin. Khövsgöl earthquakes bound both sides of the rift. Along the northern border of Lake Khövsgöl, seismic events define a shallow active fault orthogonal to the basin. The largest event recorded within the network was a magnitude ml=5.2 located near the northeastern border of Lake Khövsgöl on 12-05-2014. The focal mechanism of this earthquake is predominantly strike-slip, but also includes an extensional component. This work focuses on earthquake relocation and calculating moment tensors and focal mechanisms of larger regional

  17. Comparative estimation of weld-ability of medium-alloy steels

    International Nuclear Information System (INIS)

    Makarov, Eh.L.; Laz'ko, V.E.

    1977-01-01

    Weldability of various industrial steels has been investigated as affected by mutual presence of carbon and alloying elements in a wide range of concentrations. Mechanical properties and technological strength of medium alloyed steel welded joints have been compared. Technological strength parameters have been found to sharply decrease with increasing carbon content, the decrease depending on the alloying system. Resistance to hot and cold cracking is somewhat decreased by nickel and increased by molibdenum and tungsten. The best mechanical properties are displayed by steels of the Kh2GSNVM type. Industrial evidence on argon arc welding of different constructions made of steels 1.5-20 mm thick is compared to laboratory results. Accordingly, the high strength steels are divided into three groups, i.e. those manifesting good, satisfactory and poor weldability

  18. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nikel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) seamless pipe and tube

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nikel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) seamless pipe and tube

  19. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045 and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) plate, sheet and strip

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045 and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) plate, sheet and strip

  20. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) rod, bar, and wire

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) rod, bar, and wire

  1. Ruderman--Kittel--Kasuya--Yosida interaction in amorphous La80Au20 alloys with dilute Gd impurities

    International Nuclear Information System (INIS)

    Poon, S.J.; Durand, J.

    1976-09-01

    From magnetization measurements on some amorphous dilute La/sub 79-x/Gd/sub x/Au 20 alloys with x less than or equal to 1, it is shown that the magnetic behavior follows the scaling laws of a spin-glass system, characteristic of the 1/r 3 dependence of the pairwise interaction. The strength of the Ruderman-Kittel-Kasuya-Yosida interaction, V(r) = (V/sub o/cos 2k/sub F/r)/r 3 , was determined to be V/sub o/ = 0.20 x 10 -37 erg cm 3 . The corresponding value of the s-f exchange integral is vertical bar J/sub sf/ vertical bar = 0.14 eV, which is compared with values determined from other experiments. 4 figures, 1 table

  2. Bubble formation upon crystallization of high nitrogen iron base alloys

    International Nuclear Information System (INIS)

    Svyazhin, A.G.; Sivka, E.; Skuza, Z.

    2000-01-01

    A study is made into the conditions of nitrogen bubble formation during crystallization of unalloyed iron, alloys of Fe-O, Fe-O-S systems, steels 1Kh13, 0Kh18N9 and a two-phase Fe-11%Cr-1%Mo-0.2%V steel. It is revealed that the amount of bubbles in a high nitrogen steel casting increases with a degree of nitrogen supersaturation and decreases with a cooling rate growth and with a rise of surfactant concentration in the metal. In sound castings a nitrogen content can be increased due to a cooling rate growth, nitrogen dilution with inert gas, an increase of nitrogen pressure during crystallization as well as due to the introduction of such surfactants as sulphur, selenium, tellurium, tin [ru

  3. Positrons in amorphous alloys

    International Nuclear Information System (INIS)

    Moser, Pierre.

    1981-07-01

    Positron annihilation techniques give interesting informations about ''empty spaces'' in amorphous alloys. The results of an extensive research work on the properties of either pre-existing or irradiation induced ''empty spaces'' in four amorphous alloys are presented. The pre-existing empty spaces appear to be small vacancy-like defects. The irradiation induced defects are ''close pairs'' with widely distributed configurations. There is a strong interaction between vacancy like and interstitial like components. A model is proposed, which explains the radiation resistance mechanism of the amorphous alloys. An extensive joint research work to study four amorphous alloys, Fe 80 B 20 ,Fe 40 Ni 40 P 14 B 6 , Cu 50 Ti 50 , Pd 80 Si 20 , is summarized

  4. PENDIDIKAN KARAKTER MENURUT KH. WAHID HASYIM

    Directory of Open Access Journals (Sweden)

    Rangga Sa’adillah S. A. P.

    2015-11-01

    Full Text Available This library research examined two research questions. They are what thoughts of KH. Wahid Hasyim about the character education are and how the concept of character education by KH. Wahid Hasyim is relevant to the current condition of education in Indonesia. This study reveals two findings through an inductive analysis. The chief finding of this study is that there are eight characteristic values taught by KH.Wahid Hasyim including religious, tolerant, independent, democratic, patriotic, nasionalist, communicative, and keen on reading. Second, this study disclosed that the thought of character education by KH. Wahid Hasyim is in line with the goal of character education. He strove to build a multicultural national life, educate an intelligent civilization, build a noble character, encourage people to contribute to the development of human life, and develop the potential of having kind hearts, positive thoughts and good behavior as well as exemplary models. He also sought to generate enthusiasm of citizens to keep the peace, creativity, independence, and to be able to coexist with other nations in a harmony.

  5. Pareto 80/20 Law: Derivation via Random Partitioning

    Science.gov (United States)

    Lipovetsky, Stan

    2009-01-01

    The Pareto 80/20 Rule, also known as the Pareto principle or law, states that a small number of causes (20%) is responsible for a large percentage (80%) of the effect. Although widely recognized as a heuristic rule, this proportion has not been theoretically based. The article considers derivation of this 80/20 rule and some other standard…

  6. Joining of Si3N4 ceramic using PdCo(NiSiB–V system brazing filler alloy and interfacial reactions

    Directory of Open Access Journals (Sweden)

    Huaping Xiong

    2014-02-01

    Full Text Available The wettability of V-active PdCo-based alloys on Si3N4 ceramic was studied with the sessile drop method. And the alloy of Pd50.0–Co33.7–Ni4.0–Si2.0–B0.7–V9.6 (wt%, was developed for Si3N4 ceramic joining in the present investigation. The rapidly-solidified brazing foils were fabricated by the alloy Pd50.0–Co33.7–Ni4.0–Si2.0–B0.7–V9.6. The average room-temperature three-point bend strength of the Si3N4/Si3N4 joints brazed at 1453 K for 10 min was 205.6 MPa, and the newly developed braze gives joint strengths of 210.9 MPa, 206.6 MPa and 80.2 MPa at high temperatures of 973 K, 1073 K and 1173 K respectively. The interfacial reaction products in the Si3N4/Si3N4 joint brazed at 1453 K for 10 min were identified to be VN and Pd2Si by XRD analysis. Based on the XEDS analysis result, the residual brazing alloy existing at the central part of the joint was verified as Co-rich phases, in which the concentration of element Pd was high up to 18.0–19.1 at%. The mechanism of the interfacial reactions was discussed. Pd should be a good choice as useful alloying element in newer high-temperature braze candidates for the joining of Si-based ceramics.

  7. Effect of silicon on the structure, tribological behaviour, and mechanical properties of nitrogen-containing chromium-manganese austenitic steels

    International Nuclear Information System (INIS)

    Korshunov, L.G.; Chernenko, N.L.; Gojkhenberg, Yu.N.

    2003-01-01

    The effect of silicon in quantity of 3.5-4.5 mass. % on tribological behaviour is studied for nitrogen-bearing (0.20-0.52 mass. % of nitrogen) chromium-manganese austenitic steels (10Kh15G23S4A0.20, 10Kh16G17N3S4A0.30, 10Kh19G20NS4A0.50, 12Kh19G19NS2A0.50, 10Kh18G19A0.50, 08Kh16G8N10S4A0.18). Mechanical properties and corrosion resistance of the steels are determined. Using metallographic, x-ray diffraction and electron microscopical methods a study is made into structural transformations running in the steels considered under friction and static tension. It is shown that additional silicon alloying of nitrogen-bearing chromium-manganese austenitic steels results in an essential increase of adhesion wear resistance of the materials on retention of low friction coefficient (f=0.25-0.33). A strong silicon effect on steel tribological behaviour is related with planar slip activation and with an increase of austenite strength and heat resistance [ru

  8. Moessbauer spectroscopy on amorphous Fe/sub x/Ni/sub 80-x/B20 after neutron irradiation

    International Nuclear Information System (INIS)

    Sitek, J.; Miglierini, M.

    1985-01-01

    Amorphous Fe/sub x/Ni/sub 80-x/B 20 glassy alloys (x = 40, 50, 60, and 70) irradiated with fast neutrons in a fluence range of 10 14 to 10 19 cm -2 were investigated by Moessbauer spectroscopy. There were some significant changes in the Moessbauer spectrum parameters of the 10 19 cm -2 irradiated samples except Fe 40 Ni 40 B 20 . This corresponds to a change in the direction of the easy axis of magnetization. The measurements show that the resistance of the Fe-Ni-B system against neutron irradiation improves with increasing Ni content up to a certain point

  9. Improvement of the magnetic property, thermal stability and corrosion resistance of the sintered Nd-Fe-B magnets with Dy{sub 80}Al{sub 20} addition

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Beibei; Li, Xiangbin; Liang, Xiaolin [School of Physics and Technology, Wuhan University, Wuhan, Hubei (China); Yan, Gaolin, E-mail: gaolinyan@whu.edu.cn [School of Physics and Technology, Wuhan University, Wuhan, Hubei (China); Chen, Kan; Yan, Aru [Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang (China)

    2017-05-01

    To improve the coercivity and thermal stability of the Nd-Fe-B sintered magnets simultaneously, the Dy{sub 80}Al{sub 20} (at%) powders with low melting point were introduced into the Nd-Fe-B magnets. Additionally, the magnetic properties, microstructure and thermal stability of the sintered magnets with different amounts of Dy{sub 80}Al{sub 20} were investigated. By adding a small amount of Dy{sub 80}Al{sub 20}, the coercivity was significantly increased from 12.72 to 21.75 kOe. As indicated by the microstructure analysis, a well-developed core-shell structure was formed in the magnets with the addition of Dy{sub 80}Al{sub 20}. The improvement of magnetic properties could be attributed to the refined and uniform matrix phase, continuous grain boundaries and a (Nd, Dy){sub 2}Fe{sub 14}B hardening shell surrounding the matrix phase grains. With the addition of 0–4 wt% Dy{sub 80}Al{sub 20} powder, the reversible temperature coefficients of remanence (α) and coercivity (β) of the magnets could be improved from −0.117 to −0.108%/°C and −0.74 to −0.66%/°C in the range of 20–100 °C, respectively. Additionally, the irreversible loss of magnetic flux (hirr) decreased sharply as Dy{sub 80}Al{sub 20} powder was added. The results of temperature-dependent magnetic properties suggest that, the thermal stability of the magnets was effectively improved with the intergranular addition of Dy{sub 80}Al{sub 20} alloy. Also, the corrosion resistance was found to be improved through small addition of Dy{sub 80}Al{sub 20} powders This was partly due to the stability enhancement of the (Pr, Nd)-rich intergranular phase by Dy{sub 80}Al{sub 20}. - Highlights: • We successfully introduced the Dy{sub 80}Al{sub 20} alloy into the Nd-Fe-B magnets. • The magnetic properties and thermal stability of the Nd-Fe-B magnets were improved. • The corrosion resistance of the Nd-Fe-B magnets were improved.

  10. Effect of hydrostatic pressure on phase transformations in Kh17N8 steel during deformation

    International Nuclear Information System (INIS)

    Eshchenko, R.N.; Teplov, V.A.

    1984-01-01

    The phase composition and structure of Kh17N8 steel strained to different degrees under atmospheric pressure and 1700 MPa are investigated. It has been found that deformation at 1700 MPa causes α and epsilon-martensite formation, the same deformation under atmospheric pressure - only α-martensite formation. The amount of the formed α-martensite is not changed with application of hydrostatic pressure. Electron-microscopic observations have shown that the dispersion of α-martensite formed under pressure is higher than in the absence of pressure; no interconnection in formation of α and epsilon-martensite in samples strained under pressure has been observed

  11. Effect of partial oxygen pressure on physicochemical properties of Kh18N10T steel at isothermal oxidation. Vliyanie partsial'nogo davleniya kisloroda na fiziko-khimicheskie svojstva poverkhnosti stali Kh18N10T pri izotermicheskom okislenii

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, V N; Oshe, E K; Fokin, M N; Bogdanova, S V; Loskutov, A I [AN SSSR, Moscow (USSR). Inst. Fizicheskoj Khimii

    1990-10-01

    Auger-electron spectroscopy, photoelectric polarization, conductometry methods have been used to analyze chemical and defect composition of surface oxide layers, formed on stainless steel Kh18N10T in vacuum (10{sup -9} - 10{sup -2} torr) and at temperatures 593-673 K. The boundary conditions of manifestation of extermal behaviour of the dependence of the surface oxide growth rate at isothermal oxidation of this steel are determined. The relation between passivation properties of the surface oxide and the magnitude of the edge angle of the surface wetting with molten tin is revealed.

  12. Effects of TiN coating on the corrosion of nanostructured Ti-30Ta-xZr alloys for dental implants

    Science.gov (United States)

    Kim, Won-Gi; Choe, Han-Cheol

    2012-01-01

    Electrochemical characteristics of a titanium nitride (TiN)-coated/nanotube-formed Ti-Ta-Zr alloy for biomaterials have been researched by using the magnetic sputter and electrochemical methods. Ti-30Ta-xZr (x = 3, 7 and 15 wt%) alloys were prepared by arc melting and heat treated for 24 h at 1000 °C in an argon atmosphere and then water quenching. The formation of oxide nanotubes was achieved by anodizing a Ti-30Ta-xZr alloy in H3PO4 electrolytes containing small amounts of fluoride ions at room temperature. Anodization was carried out using a scanning potentiostat, and all experiments were conducted at room temperature. The microstructure and morphology of nanotube arrays were characterized by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The TiN coatings were obtained by the radio-frequency (RF) magnetron sputtering technique. The depositions were performed from pure Ti targets on Ti-30Ta-xZr alloys substrates. The corrosion properties of the specimens were examined using potentiodynamic test in a 0.9% NaCl solution by using potentiostat. The microstructures of Ti-30Ta-xZr alloys were changed from an equiaxed to a needle-like structure with increasing Zr content. The interspace between the nanotubes was approximately 20, 80 and 200 nm for Zr contents of 3, 7 and 15 wt%, respectively. The corrosion resistance of the TiN-coated on the anodized Ti-30Ta-xZr alloys was higher than that of the untreated Ti alloys, indicating a better protective effect.

  13. Study of surface layer on 08Kh15N5D2T steel

    International Nuclear Information System (INIS)

    Tyurin, A.G.; Povolotskij, V.D.; Zhivotovskij, Eh.A.; Berg, B.N.

    1986-01-01

    08Kh15N5D2T steel phase composition is investigated. Its surface layer was determined by X-ray diffraction analysis method. It is shown, that a subscale appears to be the reason for corrosion of products, made of EhP410 steel. Under the existing smelling technology the carbon content in it is ≥ 0.05%. Therefore to avoid the metal surface depletion with chromium, one must provide for titanium relation to carbon of not less than 4.5 and carry out the rolled product thermal treatment in a protective atmosphere; otherwise, the technology must include not only the removal of scale from steel but the metal subscale layer as well

  14. Effect of austenitization conditions on kinetics of isothermal transformation of austenite of structural steels

    International Nuclear Information System (INIS)

    Konopleva, E.V.; Bayazitov, V.M.; Abramov, O.V.; Kozlova, A.G.

    1987-01-01

    Effect of austenization of kinetics of pearlite and bainite transformations for steels with different carbon content differing by alloying character and degree has been investigated. Austenization temperature increase is shown to leads to retardation of ferrite-pearlite transformation in low- and medium-carbon alloyed steels. Step-like holding in the region of austenite stable state (850, 950 deg) after high-temperature heating (1100 deg C) increases the rate of transformation partially recovering its kinetics and decomposition velocity after low-temperature heating in steels alloyed advantageously with carbide-forming elements (08Kh2G2F, 30Kh3) and does not affect kinetics in the 35Kh, 30KhGSN2A, 45N5 steels. Increase of heating temperature and growth of an austenite grain cause considerable acceleration of bainite transformation, increase of the temperaure of bainite transformation beginning and increase of the transformation amplitude in the 08Kh2G2F, 30Kh3 steels and affect weakly kinetics in steels with mixed alloying (30KhGSN2A) or low-alloy one (35Kh). The bainite transformation rate in the 45N5 steelite does not depend on austenization. The effect of additional acceleration of bainite transformation as a result holding after high-temperature heating in those steels, where activation of transformation occurs with increase of heating temperature

  15. Special Features of Induction Annealing of Friction Stir Welded Joints of Medium-Alloy Steels

    Science.gov (United States)

    Priymak, E. Yu.; Stepanchukova, A. V.; Bashirova, E. V.; Fot, A. P.; Firsova, N. V.

    2018-01-01

    Welded joints of medium-alloy steels XJY750 and 40KhN2MA are studied in the initial condition and after different variants of annealing. Special features of the phase transformations occurring in the welded steels are determined. Optimum modes of annealing are recommended for the studied welded joints of drill pipes, which provide a high level of mechanical properties including the case of impact loading.

  16. Kankaan tuotekehittäminen erikoisolosuhteisiin K&H Annala Oy:lle

    OpenAIRE

    Koski, Marjo

    2017-01-01

    Opinnäytetyö tehtiin yhteistyössä Suomen ainoan huonekalukankaita valmistavan yrityksen K&H Annala Oy:n kanssa. Työn aiheena oli suunnitella ja tuotteistaa kangasmallisto erikoisolosuhteisiin innovatiivisesta, Italiassa valmistettavasta Flyer-langasta. Projektin lähtökohtana oli opinnäytetyöntekijän kasvava kiinnostuneisuus kudottuja tekstiilejä kohtaan ja kankaan suunnitteluprosessin vieminen teollisen tuotannon puolelle. Projektissa tähdättiin uudentyyppiseen kankaaseen ilmeen ja materiaali...

  17. Effect of agressive medium movement of local corrosion of the steel - 12Kh18N10T

    International Nuclear Information System (INIS)

    Makartsev, V.V.; Pakhomov, V.S.; Abramova, I.M.

    1980-01-01

    The effect of agressive medium movement on the formation of pitting corrosion of the 12Kh18N10T stainless steel in the acidic chloride-nitrate solution at room temperature is studied. It is established that the agressive medium movement hinders the formation of pitting corrosion at potentials more negative than +0.4 V and practically does not affect it at more positive potentials. The investigations have been carried out on a disc electrode rotating at a speed from 0 to 2000 rot./min

  18. Influence of quantity of non-martensite products of transformation on resistance to fracture of improving structural steel

    International Nuclear Information System (INIS)

    Gulyaev, A.P.; Golovanenko, Yu.S.; Zikeev, V.N.

    1978-01-01

    18KhNMFA, low-carbon, alloyed steel and 42KhMFA medium-carbon, alloyed steel have been examined. For the purpose of obtaining different structures in hardening the steel, different cooling rates, different temperatures and isothermal holding times are applied. The following has been shown: on tempering to the same hardness (HV 300), the presence of non-martensite structures in hardened state does not practically influence the standard mechanical properties of steel (sigmasub(B), sigmasub(0.2), delta, PSI). The resistance of steel to the brittle failure is enhanced by the uniform, fine-disperse distribution of the carbide phase in the structure of lower bainite (up to 80 % bainite in martensite for 42KhMF steel to be improved), as well as strongly fragmented packages of rack martensite-bainite (up to 50 % lower bainite in martensite of 18KhNMFA steel). The formation of the upper bainite in the structure of the hardened steels 18KhNMFA and 42KhMF results on tempering in the formation of coarse, non-uniform, branched carbide inclusions, and this, in its turn, leads to raising the cold-shortness threshold and to lowering the amount of work as required for propagation of a crack. The presence of ferritic-pearlitic structures in the structural steels hardened to martensite and bainite results in reducing the resistance of steel to the brittle failure; the presence of every 10 % ferritic-pearlitic component in martensite of the structural steels 18KhNMFA and 42KhMFA to be thermally improved, raises T 50 by 8 deg and 20 deg C, respectively

  19. Radiation stability of chromium low alloys

    International Nuclear Information System (INIS)

    Chakin, V.P.; Kazakov, V.A.

    1990-01-01

    Radiation effect on the behaviour of mechanical properties and structure of chromium low alloys such as VKh-2K, KhP-3, VKhM in the wide range of temperatures and neutron fluences is studied. Radiation stability of the alloys is shown to be limited by low-temperature radiation embrittlement (LTRE), caused by radiation hardening as a result of formation of radiation-induced defects such as dislocation loops and vacancy voids in the structure. The methods for prevention LTRE of chromium alloys are suggested. 8 refs.; 8 figs

  20. Corrosion resistance of metals and alloys in molten alkalies

    International Nuclear Information System (INIS)

    Zarubitskij, O.G.; Dmitruk, B.F.; Minets, L.A.

    1979-01-01

    Literature data on the corrosion of non-ferrous and noble metals, iron and steels in the molten alkalis and mixtures of their base are presented. It is shown that zirconium, niobium and tantalum are characterized by high corrosion stability in the molten NaOH. Additions of NaOH and KOH to the alkali chloride melts result in a 1000 time decrease of zirconium corrosion rate at 850 deg. The data testify to the characteristic passivating properties of OH - ions; Mo and W do not possess an ability to selfpassivation in hydroxide melts. Corrosion resistance of carbon and chromium-nickel steels in hydroxide melts depends considerably on the temperature, electrolyte composition and atmosphere over them. At the temperatures up to 600 deg C chromium-nickel steel is corrosion resistant in the molten alkali only in the inert atmosphere. Corrosion rate of chromium-nickel alloy is the lower the less chromium and the more nickel it contains. For the small installations the 4Kh18N25S2 and Kh23N28M3D3T steels can be recommended

  1. Electrochemical passivation behaviour of nanocrystalline Fe 80 Si ...

    Indian Academy of Sciences (India)

    Passivation behaviour of nanocrystalline coating (Fe80Si20) obtained by in situ mechanical alloying route is studied and compared with that of the commercial pure iron and cast Fe80Si20 in sodium borate buffer solution at two different pH values (7.7 and 8.4). The coating reveals single passivation at a pH of 7.7 and ...

  2. Influence of chemical heterogeneity of solid solutions on brittleness in chromium steels

    International Nuclear Information System (INIS)

    Madyanov, S.A.; Sedov, V.K.; Apaev, B.A.

    1985-01-01

    The role of chemical heterogeneity of solid solutions in formation of mechanical properties of Kh09, Kh15, Kh20, Kh19N2G5T chromium steels has been investigated. It is established that besides the known regioA of chemical heterogeneity in the vicinity of 475 deg C exists a high-temperature region (1000-1050 deg C), where maximum heteroge=- neity of chromium distribution in solid solution, is observed. Both types of chemical heterogeneity cause essential hardening of alloys, which becomes apparent in abrupt change of capability to microplastic deformation The mechanism of occurrence of the given temper brittleness consists in carbon diffusion into microvolunes enriched in carbide-forming elements

  3. Manufacture of rings of 08Kh18N10T sheet for internal structures of WWER type reactors

    International Nuclear Information System (INIS)

    Fojta, A.; Nitka, B.

    1984-01-01

    Technology is presented of the manufacture of rings for the jacket, shaft, core catcher and shaft bottom of WWER-440 reactors produced by Vitkovice Steel Works. The rings are manufactured from sheets of austenitic steel 08Kh18N10T. The materials and technology problems are discussed of sheet production, ring welding technology and annealing following welding. The plastic properties are assessed of the welded joints and problems are outlined of ring production for WWER-1000 reactors. (B.S.)

  4. Cyclic crack resistance of anticorrosion cladding-15Kh2MFA steel joint

    International Nuclear Information System (INIS)

    Zvezdin, Yu.I.; Nikiforchin, G.N.; Timofeev, B.T.; Zima, Yu.V.; Andrusiv, B.N.

    1985-01-01

    Cyclie crack resistance of transition zone in austenitic cladding steel 15Kh2MFA joint is studied, taking into account the geometry of fatigue cracks, fracture micromechanism and crack closure effect. Kinetics of crack development from the cladding to the basic metal and vice versa is considered. Microstructure of transition zone is investigated. The results obtained are considered as applied to WWER. It is emphasized, that the braking of fatigue cracks is observed at low asymmetry of loading cycle. Increased loading asymmetry accelerates sharply the alloy fracture due to the growth of subcladding crack, at that, the direction of crack propagation and the structure of transition zone are not of great importance

  5. Precipitation behavior and effect of new precipitated β phase in AZ80 magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    TANG Wei; HAN En-hou; XU Yong-bo; LIU Lu

    2006-01-01

    Granular precipitate that was a new kind of β-Mg17Al12 phase found in aged AZ80 wrought Mg alloy at all aging temperature was studied. The structure and precipitation behavior of this granular β-Mg17Al12 precipitate were studied by environmental scanning electron microscopy (ESEM) and transmission electron microscopy (TEM). The effect of the granular precipitate on mechanical properties of AZ80 alloy was also studied. The new precipitate that was granular and nucleated both on grain boundaries (GBs) and twin boundaries, has the same crystal structure and lattice parameter as those of the continuous or discontinuous precipitated β-Mg17Al12. And the nucleation and growth of the granular precipitate are faster than those of the other two precipitates at higher temperatures (above 583 K), but are suppressed at lower temperatures (below 423 K). At lower temperatures, the discontinuous β-Mg17Al12 precipitates firstly and the granular β-Mg17Al12 precipitates after aged more than 40 h. The crack is easily nucleated on the phase boundaries of granular phase and matrix because of the weak binding force. As a result, the strength and ductility of AZ80 Mg alloy are decreased by the granular β-Mg17Al12 precipitate.

  6. Phase transformations behavior in a Cu-8.0Ni-1.8Si alloy

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Q. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Li, Z., E-mail: lizhou6931@163.com [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China) and Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Changsha, 410083 (China); Wang, M.P. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Changsha, 410083 (China); Zhang, L.; Gong, S. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Xiao, Z. [Department of Engineering, University of Liverpool, Liverpool, L693 GH (United Kingdom); Pan, Z.Y. [Hunan Nonferrous Metals Holding Group Co., Ltd., Changsha, 410015 (China)

    2011-02-24

    Research highlights: > High solute concentrations Cu-Ni-Si alloy with super high strength and high conductivity has a good prospect for replacing Cu-Be alloys. At least four different kinds of precipitation products (DO{sub 22} ordered structure, {beta}-Ni{sub 3}Si precipitate, {delta}-Ni{sub 2}Si precipitate and {gamma}-Ni{sub 5}Si{sub 2} precipitate) have been observed in previous investigation. Therefore, the overall phase transformation behavior of Cu-Ni-Si alloy appears to be very complex. And most previous studies on the phase transformation usually investigated the precipitation process at only one temperature or at most a few temperatures, which is far away to establish a time-temperature-transformation (TTT) diagram for Cu-Ni-Si alloy. > The phase transformation behavior of Cu-8.0Ni-1.8Si alloy has been studied systematically at wide temperature range in this paper. The results we have gained are that: after solution treatment, followed by different conditions of isothermal treatment, DO{sub 22} ordering, discontinuous precipitation and continuous precipitation were observed in the alloy; discontinuous precipitates of {beta}-Ni{sub 3}Si phase appeared when the alloy isothermal treated at 550 deg. C for short time, which had not been reported by the previous Cu-Ni-Si system alloy's researchers in their papers; two kinds of precipitates of {beta}-Ni{sub 3}Si and {delta}-Ni{sub 2}Si were determined by the TEM characterization; the orientation relationship between the two kinds of precipitates and Cu-matrix is that: (1 1 0){sub Cu}//(1 1 0){sub {beta}}//(211-bar){sub {delta}}, [112-bar]{sub Cu}//[11-bar 2]{sub {beta}}//[3 2 4]{sub {delta}}; during overaging treatment, Cu-matrix, {beta}-Ni{sub 3}Si, {delta}-Ni{sub 2}Si and {delta}'-Ni{sub 2}Si were distinguished in the samples and the orientation relationship between the precipitates and Cu-matrix can be expressed as that: (0 2 2){sub Cu}//(0 2 2){sub {beta}}//(1 0 0){sub {delta}}, (02-bar 2){sub Cu

  7. Advanced Mechanical Properties of a Powder Metallurgy Ti-Al-N Alloy Doped with Ultrahigh Nitrogen Concentration

    Science.gov (United States)

    Shen, J.; Chen, B.; Umeda, J.; Kondoh, K.

    2018-03-01

    Titanium and its alloys are recognized for their attractive properties. However, high-performance Ti alloys are often alloyed with rare or noble-metal elements. In the present study, Ti alloys doped with only ubiquitous elements were produced via powder metallurgy. The experimental results showed that pure Ti with 1.5 wt.% AlN incorporated exhibited excellent tensile properties, superior to similarly extruded Ti-6Al-4V. Further analysis revealed that its remarkably advanced strength could primarily be attributed to nitrogen solid-solution strengthening, accounting for nearly 80% of the strength increase of the material. In addition, despite the ultrahigh nitrogen concentration up to 0.809 wt.%, the Ti-1.5AlN sample showed elongation to failure of 10%. This result exceeds the well-known limitation for nitrogen (over 0.45 wt.%) that causes embrittlement of Ti alloys.

  8. Correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys

    International Nuclear Information System (INIS)

    Feliu, S.; Pardo, A.; Merino, M.C.; Coy, A.E.; Viejo, F.; Arrabal, R.

    2009-01-01

    X-ray photoelectron spectroscopy (XPS) was used in order to investigate the correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys exposed to 98% relative humidity at 50 deg. C. Commercially pure magnesium, used as the reference material, revealed MgO, Mg(OH) 2 and tracers of magnesium carbonate in the air-formed film. For the AZ80 and AZ91D alloys, the amount of magnesium carbonate formed on the surface reached similar values to those of MgO and Mg(OH) 2 . A linear relation between the amount of magnesium carbonate formed on the surface and the subsequent corrosion behaviour in the humid environment was found. The AZ80 alloy revealed the highest amount of magnesium carbonate in the air-formed film and the highest atmospheric corrosion resistance, even higher than the AZ91D alloy, indicating that aluminium distribution in the alloy microstructure influenced the amount of magnesium carbonate formed.

  9. Thermal creep behavior of N36 zirconium alloy cladding tube

    International Nuclear Information System (INIS)

    Wang, P.; Zhao, W.; Dai, X.

    2015-01-01

    N36 is an alloy containing Zr, Sn, Nb and Fe that is developed by China as a superior cladding material to meet the performance of PWR fuel assembly at the maximum fuel rod burn-up. The creep characteristics of N36 zirconium alloy cladding tube were investigated at temperature from 593 K to 723 K with stress ranging from 20 MPa to 160 MPa. Transitions in creep mechanisms were noted, showing the distinct three rate-controlled creep mechanisms for the alloy at test conditions. In the region of low stresses with stress exponent n ∼ 1 and activation energy Q ∼ (104±4) kJ.mol -1 , Coble creep, based on diffusion of materials through grain boundaries, is the dominant rate-controlling mechanism, which contributes to the creep deformation. The formation of slip bands acts as an accommodation mechanism. In the region of middle stress with stress exponent n ∼ 3 and activation energy Q ∼ (195±7) kJ.mol -1 , micro-creep, caused by viscous gliding of dislocations due to the interaction of O atoms with dislocations, controls the deformation. In the high stress region with stress exponent n ∼ 5-6 and activation energy Q ∼ (210±10) kJ.mol -1 , two mechanisms of the climb of edge dislocations (EDC) and the motion of jogged screw dislocation (MJS) contribute to rate controlling process. In test conditions N36 alloy cladding tube behaves a type of creep similar to that noted in class-I (A) alloys

  10. A prominent figure in tatar dryhaeology. A. Kh. Khalikov’S 85th birthday anniversary

    Directory of Open Access Journals (Sweden)

    Khuzin Fayaz Sh.

    2014-06-01

    Full Text Available The article is devoted to scientific activity of Alfred Khasanovich Khalikov (May 30, 1929–July 24, 1994, an outstanding scholar, Dr. habil. (History, Professor, corresponding member of the Academy of Sciences of Tatarstan, a renowned specialist in archaeology and ancient history of the Turkic and Finno-Ugric peoples of the Volga-Ural region. A.Kh. Khalikov was a pioneer discoverer of hundreds of monuments referring to different archaeological periods, from the Paleolithic to modern times. However, the principal sphere of his scientific interests was medieval archaeology and history of the Volga region peoples. As head of major archaeological expeditions, such as the Mari, Tatar, Bilyar, “The Kazan Kremlin”, etc. ones, A.Kh. Khalikov had emerged as organizer of large-scale research in the territory of Tatarstan and other republics and regions of the Middle Volga region for 40 years,. A.Kh. Khalikov created an extensive cultural-chronological scheme of the Stone, the Chalcolithic, the Bronze and Early Iron ages in the Volga region, offered his own concept of ethnogenesis of the Finno-Ugric and Turkic peoples of the region. A.Kh. Khalikov authored over 400 articles and 20 books covering the origin and early history of the peoples of the Middle Volga and Ural regions. On his initiative, a complete list of archaeological monuments of Tatarstan in 6 volumes was created. Preservation of monuments of history and culture was an important direction of his activities. Professor A.Kh. Khalikov was engaged in fruitful teaching process at Kazan State University and created his own scientific school.

  11. Superconductivity, spin-glass properties, and ferromagnetism in amorphous La--Gd--Au alloys

    International Nuclear Information System (INIS)

    Poon, S.J.

    1978-01-01

    The superconducting and magnetic properties of splat cooled amorphous alloys of composition (La/sub 100-x/Gd/sub x/) 80 Au 20 (0 equal to or less than x equal to or less than 100) have been studied. The La 80 Au 20 alloys are ideal type II superconductors (critical temperature T/sub c/ = 3.5 0 K). The concentration range (x 80 Au 20 . The results are compared with recent theories on amorphous magnetism

  12. Effect of operational conditions of electroerosion machining on the surface microgeometry parameters of steels and alloys

    International Nuclear Information System (INIS)

    Foteev, N.K.

    1976-01-01

    Studies the influence of pulse duration and a series of operating conditions of a ShGI-40-440 spark-machining generator on changes in the basic surface microgeometry characteristics of components of stainless steel 1Kh18N10T, steel St 45 and hard alloy T14K8. The microgeometry characteristics of spark-machined surfaces differ significantly from the corresponding characteristics of surfaces machined by cutting and vibro-rolling

  13. Moessbauer spectroscopy on amorphous Fe/sub x/Ni/sub 80-x/B/sub 20/ after neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sitek, J.; Miglierini, M. (Slovenska Vysoka Skola Technicka, Bratislava (Czechoslovakia))

    1985-05-16

    Amorphous Fe/sub x/Ni/sub 80-x/B/sub 20/ glassy alloys (x = 40, 50, 60, and 70) irradiated with fast neutrons in a fluence range of 10/sup 14/ to 10/sup 19/ cm/sup -2/ were investigated by Moessbauer spectroscopy. There were some significant changes in the Moessbauer spectrum parameters of the 10/sup 19/ cm/sup -2/ irradiated samples except Fe/sub 40/Ni/sub 40/B/sub 20/. This corresponds to a change in the direction of the easy axis of magnetization. The measurements show that the resistance of the Fe-Ni-B system against neutron irradiation improves with increasing Ni content up to a certain point.

  14. Effect of partial oxygen pressure on physicochemical properties of Kh18N10T steel at isothermal oxidation

    International Nuclear Information System (INIS)

    Alekseev, V.N.; Oshe, E.K.; Fokin, M.N.; Bogdanova, S.V.; Loskutov, A.I.

    1990-01-01

    Auger-electron spectroscopy, photoelectric polarization, conductometry methods have been used to analyze chemical and defect composition of surface oxide layers, formed on stainless steel Kh18N10T in vacuum (10 -9 - 10 -2 torr) and at temperatures 593-673 K. The boundary conditions of manifestation of extermal behaviour of the dependence of the surface oxide growth rate at isothermal oxidation of this steel are determined. The relation between passivation properties of the surface oxide and the magnitude of the edge angle of the surface wetting with molten tin is revealed

  15. 20 CFR 401.80 - Accounting for disclosures.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Accounting for disclosures. 401.80 Section... AND INFORMATION The Privacy Act § 401.80 Accounting for disclosures. (a) We will maintain an accounting of all disclosures of a record for five years or for the life of the record, whichever is longer...

  16. Wear and Friction Characteristics of AlN/Diamond-Like Carbon Hybrid Coatings on Aluminum Alloy

    Science.gov (United States)

    Nakamura, Masashi; Kubota, Sadayuki; Suzuki, Hideto; Haraguchi, Tadao

    2015-10-01

    The use of diamond-like carbon (DLC) coatings has the potential to greatly improve the wear resistance and friction of aluminum alloys, but practical application has so far been limited by poor adhesion due to large difference in hardness and elasticity between the two materials. This study investigates the deposition of DLC onto an Al-alloy using an intermediate AlN layer with a graded hardness to create a hybrid coating. By controlling the hardness of the AlN film, it was found that the wear life of the DLC film could be improved 80-fold compared to a DLC film deposited directly onto Al-alloy. Furthermore, it was demonstrated through finite element simulation that creating a hardness gradient in the AlN intermediate layer reduces the distribution of stress in the DLC film, while also increasing the force of adhesion between the DLC and AlN layers. Given that both the DLC and AlN films were deposited using the same unbalanced magnetron sputtering method, this process is considered to represent a simple and effective means of improving the wear resistance of Al-alloy components commonly used within the aerospace and automotive industries.

  17. 34 CFR 80.20 - Standards for financial management systems.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Standards for financial management systems. 80.20... Financial Administration § 80.20 Standards for financial management systems. (a) A State must expand and... of applicable statutes. (b) The financial management systems of other grantees and subgrantees must...

  18. Metallographical procedure for detecting carburized layer in the 12Kh18N10T steel tubes

    International Nuclear Information System (INIS)

    Najmark, S.I.; Shmalenyuk, R.P.

    1977-01-01

    The various causes of the tendency to intercrystalline corrosion of stainless steel tubing were studied. 12Kh18N10T steel tube specimens were metallographically investigated to reveal the presence and depth of the carburized layer. Unlubricated specimens and specimens with the graphite-saltpeter lubrication applied on them were austenized in the temperature range from 950 to 1250 deg C and then exposed to a provoking anneal at 650 deg C for 24 h. All the lubricated specimens showed a carbide network along grain boundaries and intercrystalline cracks. The specimens treated without lubrication had no cracks. The method offered can differentiate poor tube cleaning and the undesirable effect of other processing steps on the tubes

  19. Corrosion failure of a bolt made of the 25Kh1MF material

    International Nuclear Information System (INIS)

    Liska, V.; Cechova, D.; Velkoborsky, J.

    1989-01-01

    M36x4 bolts, of which there are 222 at each nuclear power plant unit, are made of the 25Kh1MF or 38KhN3MFA steel. They are located in an environment with elevated temperature, with damp air and with boric acid. Corrosion of these bolts is due to the rather poor metallurgical quality of the steel. No inadmissible inhomogeneities of the type of lines of inclusions occur in the bolt material produced by cold rolling but defects of the type of laps were found on the threads. It is suggested that if the cold rolling technology were obviated, corrosion failure of the bolts might not occur. (M.D.). 7 figs., 3 refs

  20. Spark Plasma Sintering of Co{sub 80}Ni{sub 20} nanopowders synthesized by polyol process and their magnetic and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Ouar, Nassima [Laboratoire des Sciences des Procédés et Matériaux, LSPM, CNRS, UPR 3407, Université Paris XIII, 99 Avenue J.B. Clément, 93430 Villetaneuse (France); Bousnina, Mohamed Ali [Laboratoire des Sciences des Procédés et Matériaux, LSPM, CNRS, UPR 3407, Université Paris XIII, 99 Avenue J.B. Clément, 93430 Villetaneuse (France); Unité de Recherche 99/UR12-30, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Jarzouna (Tunisia); Schoenstein, Frédéric; Mercone, Silvana; Brinza, Ovidiu; Farhat, Samir [Laboratoire des Sciences des Procédés et Matériaux, LSPM, CNRS, UPR 3407, Université Paris XIII, 99 Avenue J.B. Clément, 93430 Villetaneuse (France); Jouini, Noureddine, E-mail: jouini@univ-paris13.fr [Laboratoire des Sciences des Procédés et Matériaux, LSPM, CNRS, UPR 3407, Université Paris XIII, 99 Avenue J.B. Clément, 93430 Villetaneuse (France)

    2014-12-05

    Highlights: • Nanoparticles of Co{sub 80}Ni{sub 20} alloy were prepared by reduction in polyol medium. • SPS consolidation of these nanoparticles led to bulk nanostructured alloy. • Nanowires present hard magnetic behavior contrarily to nanospheres. • Tunable magnetic properties are achieved from hard to soft character. • Tunable mechanical behavior is achieved from ductile material to almost brittle one. - Abstract: A bottom-up process to elaborate nanostructured cobalt materials is here described. We first, synthesized Co{sub 80}Ni{sub 20} nanowires with a mean length L ∼ 270 nm and a mean diameter d ∼ 7 nm and Co{sub 80}Ni{sub 20} nanospheres with a mean diameter D ∼ 200 nm. This was done by a polyol process in presence of Ruthenium (III) chloride hydrate nucleating agent. Then the as-obtained nanopowders were consolidated by spark plasma sintering (SPS) in order to limit the grain size growth. Nanostructures of powders and of the processed bulk samples were studied and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and field emission gun scanning electron microscope (FEGSEM). Standard VSM measurements were processed for magnetic characterizations. Magnetic static measurements were performed at 10 K and 300 K showing that magnetic properties of nanostructured cobalt bulk systems can be tuned from hard to soft just changing the shape of nano-systems used for compaction and/or the sintering conditions. Also the mechanical properties show a strong dependence on the relative bulk densities and on the characteristics of grain inside the consolidated samples. Preliminary results show that nanostructured cobalt obtained from nanowires compaction present higher Vickers Hardness value.

  1. Hardening and stress relaxation during repeated heating of 15Kh2MFA and 15Kh2NMFA steels welded joints

    International Nuclear Information System (INIS)

    Zubchenko, A.S.; Suslova, E.A.

    1986-01-01

    Results of investigation of temperature-time conditions of hardening of welded joints of 15Kh2MFA and 15Kh2NMFA steels and their relaxation resistance, effect of metal structure of imitated heat affected zone (HAZ) on intensity of precipitation hardening at repeated heating are presented as well as the results of the process of relaxation of residual stresses at welded joints samples heating carried out by automatic welding under the flux with the use of adding materials and technology of manufacturing of vessels of WWER-440 and WWER-1000 reactors. Peculiarities of the hardening at repeated heating of the HAZ metal imitated at these steels. Precipitation hardening of overheated 15Kh2MFA steel is connected with precipitations at repeated heating of carbides of the M 7 C 3 , M 3 C and VC type. Stress relaxation in welded joints runs more intensively at the initial stage of repeated heating, i.e. during the same period of the process of dispersed carbide precipitations

  2. Study of 16KhSN high strength steel in different structural states and under working conditions

    International Nuclear Information System (INIS)

    Skudnov, V.A.; Vorob'ev, I.A.; Kutyajkin, V.G.; Bugrov, Yu.V.

    1985-01-01

    A study was made on the effect of deformation degree (up to 60%) during reducing, drawing and heat treatment (annealing at 750 deg C), quenching from 930 deg C and tempering at 350 deg C) on strength, plasticity, hardening degree, notch sensitivity, density and elasticity characteristics of the steel. The effect of test temperature (from-196 up to 1000 deg C) on tensile strength and plasticity was studied as well. It was established that drawing and reducing of 16KhSN steel in annealed state with strain degrees of up to 60% results to increase of strength characteristics 1.7...2.3 times and decrease of plasticity characteristics by 15...23%, strain hardening coefficient - 2.2 times and the maximum strain energy - by 80 MJ/m 3 . Hardening heat treatment (quenching from 930 deg C+temperating at 350 deg C) affects on mechanical properties of 16KhSN steel in much the same way as cold working, but strength characteristics of heat-treated steel increase 2.6...3.6 times and the maximum strain energy grows by 640 MJ/m 3 . Systematic data on the effect of temperature (-196...1000 deg C) and tensile rate (4 mm/min...5m/s) on strength and plasticity of 16KhSN steel in annealed state were obtained

  3. Influence of silicon and atomic order on the magnetic properties of (Fe{sub 80}Al{sub 20}){sub 100}-{sub x}Si{sub x} nanostructured system

    Energy Technology Data Exchange (ETDEWEB)

    Velez, G. Y., E-mail: gyovelca@univalle.edu.co; Perez Alcazar, G. A.; Zamora, Ligia E. [Universidad del Valle, Departamento de Fisica (Colombia); Romero, J. J.; Martinez, A. [Instituto de Magnetismo Aplicado IMA (Spain)

    2010-01-15

    Mechanically alloyed (Fe{sub 80}Al{sub 20}){sub 100-x}Si{sub x} alloys (with x = 0, 10, 15 and 20) were prepared by using a high energy planetary ball mill, with milling times of 12, 24 and 36 h. The structural and magnetic study was conducted by X-rays diffraction and Moessbauer spectrometry. The system is nanostructured and presents only the BCC disordered phase, whose lattice parameter remains constant with milling time, and decreases when the Si content increases. We found that lattice contraction is influenced 39% by the iron substitution and 61% by the aluminum substitution, by silicon atoms. The Moessbauer spectra and their respective hyperfine magnetic field distributions show that for every milling time used here, the ferromagnetism decreases when x increases. For samples with x {>=} 15 a paramagnetic component appears. From the shape of the magnetic field distributions we stated that the larger ferromagnetic phase observed in the samples alloyed during 24 and 36 h is a consequence of the structural disorder induced by mechanical alloying.

  4. Crystallization of the amorphous Fe80Zr12B8 alloy under controlled heating

    International Nuclear Information System (INIS)

    Huang, H.; Shao, G.; Tsakiropoulos, P.

    2008-01-01

    The devitrification process of amorphous Fe 80 Zr 12 B 8 alloy ribbons were studied under controlled thermal conditions. The major crystallization event during continuous heating with differential scanning calorimetory (DSC) is dictated by diffusion controlled growth and the associated atom mobility of the slow diffusing species Zr. The existence of prior nano-crystals formed by pre-annealing below the crystallization temperature had little effect on the major crystallization temperature. The crystallization sequence during heating was: amorphous → amorphous + α-Fe + Fe 3 Zr(B) → amorphous + α-Fe + Fe 3 Zr(B) + Fe 2 Zr. Different from previous findings in alloys of lower Zr and B contents, the peak for the crystallization of the α-Fe phase alone is missing in the DSC traces of this alloy

  5. Thermal transport properties of niobium and some niobium-based alloys from 80 to 1600 K

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J P; Graves, R S; Williams, R K [Oak Ridge National Lab., TN (USA)

    1980-01-01

    The electric resistivity, rho, and Seebeck coefficient, S, of 99.8 at% niobium, and Nb-4.8 at% W, Nb-5 at% Mo, Nb-10 at% Mo, and Nb-2.4 at% Mo-2.4 at% Zr alloys were measured from 80 to 1600 K, and the thermal conductivity, lambda, of the niobium and the Nb-5 at% W alloy was measured from 80 to 1300 K. A technique is described for measuring rho and S of a specimen during radial-heat-flow measurements of lambda. The transport property results, which had uncertainties of +-0.4% for rho and +-1.4% for lambda, showed the influence of tungsten and molybdenum solutes on the transport properties of niobium and were used to obtain the electronic Lorenz function of pure niobium, which was found to approach the Sommerfeld value at high temperatures.

  6. Magnetoresistances in Ni80Fe20-ITO granular film

    International Nuclear Information System (INIS)

    Gao Chunhong; Chen Ke; Yang Yanxia; Xiong Yuanqiang; Chen Peng

    2012-01-01

    Highlights: ► Magnetoresistance (MR) in Ni 80 Fe 20 -ITO granular film are investigated. ► MR is positive at high temperature, and is negative at low temperature. ► MR results from the competition among three mechanisms. - Abstract: The magnetic properties, electrical properties and magnetoresistance are investigated in Ni 80 Fe 20 -ITO granular film with various volume fractions V NF of Ni 80 Fe 20 . The room temperature magnetization hysteresis of sample with V NF = 25% shows superparamagnetic behavior. Current-voltage curve of sample with V NF = 25% at 175 K shows typical tunneling-type behavior. The magnetoresistances of samples with low V NF are positive at high temperature, and are negative at low temperature. The temperature-dependent magnetoresistances result from the competition among ordinary magnetoresistances, the granular-typed tunneling magnetoresistance and the spin-mixing induced magnetoresistances.

  7. Microstructural and mechanical properties of binary Ni–Si eutectic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gogebakan, Musa, E-mail: gogebakan@ksu.edu.tr [Department of Physics, Faculty of Art and Sciences, Kahramanmaras Sutcu Imam University, Kahramanmaras 46100 (Turkey); Kursun, Celal [Department of Physics, Faculty of Art and Sciences, Kahramanmaras Sutcu Imam University, Kahramanmaras 46100 (Turkey); Gunduz, Kerem Ozgur; Tarakci, Mehmet; Gencer, Yucel [Department of Materials Science and Engineering, Gebze Institute of Technology, Gebze, 41400 Kocaeli (Turkey)

    2015-09-15

    Highlights: • Ni{sub 80}Si{sub 20}, Ni{sub 70}Si{sub 30}, Ni{sub 55}Si{sub 45} and Ni{sub 45}Si{sub 55} were prepared by arc melting method. • The maximum microhardness value of 1126 HV obtained for Ni{sub 70}Si{sub 30} alloy. • The microhardness values decreases with increase of Si/Ni ratio. • Ni{sub 80}Si{sub 20} and Ni{sub 55}Si{sub 45} are soft ferromagnetic, Ni{sub 70}Si{sub 30} and Ni{sub 45}Si{sub 55} are paramagnetic. - Abstract: In the present work, Ni–Si eutectic alloys with nominal compositions of Ni{sub 80}Si{sub 20}, Ni{sub 70}Si{sub 30}, Ni{sub 55}Si{sub 45} and Ni{sub 45}Si{sub 55} (Ni and Si with the purity of 99.99%) were prepared by arc melting method under vacuum/argon atmosphere. The effects of Si/Ni ratio on the microstructural properties, thermal transformation behavior, micro-hardness and magnetic properties of the Ni–Si eutectic alloys were investigated. These alloys were characterized by X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), differential thermal analysis (DTA), Vickers microhardness measurement and Vibrating Sample Magnetometer (VSM). The phases expected according to Ni–Si phase diagram for conventional solidified eutectic Ni–Si alloys are considerably consistent with phase detected by XRD in this study. The quantitative results confirm that the chemical composition of the alloys very close to eutectic compositions and the microstructures are in typical lamellar eutectic morphology. The maximum microhardness value of 1126 HV obtained for Ni{sub 70}Si{sub 30} alloy which has highest melting temperature amongst Ni–Si eutectics. The microhardness values decreases with increase of Si/Ni ratio. Ni{sub 80}Si{sub 20} and Ni{sub 55}Si{sub 45} alloys are soft ferromagnetic, Ni{sub 70}Si{sub 30} and Ni{sub 45}Si{sub 55} alloys are paramagnetic with no magnetic saturation.

  8. CENTIMETER CONTINUUM OBSERVATIONS OF THE NORTHERN HEAD OF THE HH 80/81/80N JET: REVISING THE ACTUAL DIMENSIONS OF A PARSEC-SCALE JET

    Energy Technology Data Exchange (ETDEWEB)

    Masque, Josep M.; Estalella, Robert [Departament d' Astronomia i Meteorologia, Universitat de Barcelona, Marti i Franques 1, E-08028 Barcelona, Catalunya (Spain); Girart, Josep M. [Institut de Ciencies de l' Espai, (CSIC-IEEC), Campus UAB, Facultat de Ciencies, Torre C5-parell 2, E-08193 Bellaterra, Catalunya (Spain); Rodriguez, Luis F. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 3-72, 58090 Morelia, Michoacan (Mexico); Beltran, Maria T. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)

    2012-10-10

    We present 6 and 20 cm Jansky Very Large Array/Very Large Array observations of the northern head of the HH 80/81/80N jet, one of the largest collimated jet systems known so far, aimed to look for knots farther than HH 80N, the northern head of the jet. Aligned with the jet and 10' northeast of HH 80N, we found a radio source not reported before, with a negative spectral index similar to that of HH 80, HH 81, and HH 80N. The fit of a precessing jet model to the knots of the HH 80/81/80N jet, including the new source, shows that the position of this source is close to the jet path resulting from the modeling. If the new source belongs to the HH 80/81/80N jet, its derived size and dynamical age are 18.4 pc and >9 Multiplication-Sign 10{sup 3} yr, respectively. If the jet is symmetric, its southern lobe would expand beyond the cloud edge resulting in an asymmetric appearance of the jet. Based on the updated dynamical age, we speculate on the possibility that the HH 80/81/80N jet triggered the star formation observed in a dense core found ahead of HH 80N, which shows signposts of interaction with the jet. These results indicate that parsec-scale radio jets can play a role in the stability of dense clumps and the regulation of star formation in the molecular cloud.

  9. Increased corrosion resistance of the AZ80 magnesium alloy by rapid solidification.

    Science.gov (United States)

    Aghion, E; Jan, L; Meshi, L; Goldman, J

    2015-11-01

    Magnesium (Mg) and Mg-alloys are being considered as implantable biometals. Despite their excellent biocompatibility and good mechanical properties, their rapid corrosion is a major impediment precluding their widespread acceptance as implantable biomaterials. Here, we investigate the potential for rapid solidification to increase the corrosion resistance of Mg alloys. To this end, the effect of rapid solidification on the environmental and stress corrosion behavior of the AZ80 Mg alloy vs. its conventionally cast counterpart was evaluated in simulated physiological electrolytes. The microstructural characteristics were examined by optical microscopy, SEM, TEM, and X-ray diffraction analysis. The corrosion behavior was evaluated by immersion, salt spraying, and potentiodynamic polarization. Stress corrosion resistance was assessed by Slow Strain Rate Testing. The results indicate that the corrosion resistance of rapidly solidified ribbons is significantly improved relative to the conventional cast alloy due to the increased Al content dissolved in the α-Mg matrix and the correspondingly reduced presence of the β-phase (Mg17 Al12 ). Unfortunately, extrusion consolidated solidified ribbons exhibited a substantial reduction in the environmental performance and stress corrosion resistance. This was mainly attributed to the detrimental effect of the extrusion process, which enriched the iron impurities and increased the internal stresses by imposing a higher dislocation density. In terms of immersion tests, the average corrosion rate of the rapidly solidified ribbons was <0.4 mm/year compared with ∼2 mm/year for the conventionally cast alloy and 26 mm/year for the rapidly solidified extruded ribbons. © 2014 Wiley Periodicals, Inc.

  10. Effect of iron content on the structure and mechanical properties of Al25Ti25Ni25Cu25 and (AlTi)60-xNi20Cu20Fex (x=15, 20) high-entropy alloys

    International Nuclear Information System (INIS)

    Fazakas, É.; Zadorozhnyy, V.; Louzguine-Luzgin, D.V.

    2015-01-01

    Highlights: • Three new refractory alloys namely: Al 25 Ti 25 Ni 25 Cu 25 , Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 , were produced by induction-melting and casting. • This kind of alloys exhibits high resistance to annealing softening. • Most the alloys in the annealed state possess even higher Vickers microhardness than the as-cast alloys. • The Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 alloys annealed at 973 K show the highest compressive stress and ductility values. - Abstract: In this work, we investigated the microstructure and mechanical properties of Al 25 Ti 25 Ni 25 C u25 Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 high entropy alloys, produced by arc melting and casting in an inert atmosphere. The structure of these alloys was studied by X-ray diffractometry and scanning electron microscopy. The as-cast alloys were heat treated at 773, 973 and 1173 K for 1800 s to investigate the effects of aging on the plasticity, hardness and elastic properties. Compared to the conventional high-entropy alloys the Al 25 Ti 25 Ni 25 Cu 25 , Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 and Al 20 Ti 20 Ni 20 Cu 20 Fe 20 alloys are relatively hard and ductile. Being heat treated at 973 K the Al 22.5 Ti 22.5 Ni 20 Cu 20 Fe 15 alloy shows considerably high strength and relatively homogeneous deformation under compression. The plasticity, hardness and elastic properties of the studied alloys depend on the fraction and intrinsic properties of the constituent phases. Significant hardening effect by the annealing is found.

  11. A luminary of tatar archaeology. To the 85th anniversary of the birth of A.Kh. Khalikov

    Directory of Open Access Journals (Sweden)

    Khuzin Fayaz Sh.

    2014-06-01

    Full Text Available The article is devoted to scientific activity of Alfred Khasanovich Khalikov (May 30, 1929–July 24, 1994, an outstanding scholar, Dr. habil. (History, Professor, corresponding member of the Academy of Sciences of Tatarstan, a renowned specialist in archaeology and ancient history of the Turkic and Finno-Ugric peoples of the Volga-Ural region. A.Kh. Khalikov was a pioneer discoverer of hundreds of monuments referring to different archaeological periods, from the Paleolithic to modern times. However, the principal sphere of his scientific interests was medieval archaeology and history of the Volga region peoples. As head of major archaeological expeditions, such as the Mari, Tatar, Bilyar, “The Kazan Kremlin”, etc. ones, A.Kh. Khalikov had emerged as organizer of large-scale research in the territory of Tatarstan and other republics and regions of the Middle Volga region for 40 years,. A.Kh. Khalikov created an extensive cultural-chronological scheme of the Stone, the Chalcolithic, the Bronze and Early Iron ages in the Volga region, offered his own concept of ethnogenesis of the Finno-Ugric and Turkic peoples of the region. A.Kh. Khalikov authored over 400 articles and 20 books covering the origin and early history of the peoples of the Middle Volga and Ural regions. On his initiative, a complete list of archaeological monuments of Tatarstan in 6 volumes was created. Preservation of monuments of history and culture was an important direction of his activities. Professor A.Kh. Khalikov was engaged in fruitful teaching process at Kazan State University and created his own scientific school.

  12. Corrosion-electrochemical behavior of metals in alkali solutions

    International Nuclear Information System (INIS)

    Levin, V.A.; Levina, E.Eh.

    1995-01-01

    Results of an investigation into corrosion-electrochemical behaviour of 12Kh18N10T, 10Kh17N13M2T, 08Kh21N6M2T and 15Kh25T steels, 06KhN28MDT and KhN78T alloys as well as NP-2 nickel in sodium, potassium and lithium hydroxide solutions at 95-180 deg C temperatures are considered. It is ascertained, that anode polarization curves of all metals irrespective of hydroxide nature, concentration, temperature, presence of chloride and chlorate additions, are of identic character. The movement of anode polarization curves in the direction of lower current of hydroxide type in NaOH-KOH-LiOH series, temperature and solution concentration reduction at other equal terms. 12 refs.; 6 figs

  13. Heat treatment effect on impact strength of 40Kh steel

    International Nuclear Information System (INIS)

    Golubev, V.K.; Novikov, S.A.; Sobolev, Yu.S.; Yukina, N.A.

    1984-01-01

    The paper presents results of studies on the effect of heat treatment on strength and pattern of 40Kh steel impact failure. Loading levels corresponding to macroscopic spalling microdamage initiation in the material are determined for three initial states. Metallographic study on the spalling failure pattern for 40Kh steel in different initial states and data on microhardness measurement are presented

  14. High temperature aging structures of Ni-20Cr-20W alloys

    International Nuclear Information System (INIS)

    Ohmura, Taizo; Sahira, Kensho; Sakonooka, Akihiko; Yonezawa, Noboru

    1977-01-01

    High temperature aging structures and age hardening of Ni-20Cr-20W alloys developed as the superalloys for the nuclear energy steelmaking, and effects of C and Zr additions to the alloys and the effect of preheat treatment on these properties were studied. M 6 C, α-W and two kinds of M 23 C 6 having different lattice parameters were found as precipitates in the alloys. M 23 C 6 whose lattice parameter was around 10.7A precipitated in the early stage of aging at 700 0 C-1,150 0 C, and the carbide changed to M 6 C at higher temperature than 1,000 0 C, but it remained as a stable carbide at lower temperature than 900 0 C. α-W precipitated at 800 0 C-1,100 0 C after precipitation of M 23 C 6 and it disappeared with increase of M 6 C. M 23 C 6 having the larger lattice parameter (10.9A) precipitated transitionally in aging stage of 26 x 10 3 in Larson Miller parameter at 900 0 C and 1,000 0 C. Age hardening corresponded to the precipitation of M 23 C 6 and it was reduced by the double pre-heat-treatment. Zr addition and amount of C influenced on the aging structure and age hardening. Zr seemed to be a favorable element to stabilize the carbide. (auth.)

  15. Compressibility of Ir-Os alloys under high pressure

    International Nuclear Information System (INIS)

    Yusenko, Kirill V.; Bykova, Elena; Bykov, Maxim; Gromilov, Sergey A.; Kurnosov, Alexander V.; Prescher, Clemens; Prakapenka, Vitali B.; Hanfland, Michael; Smaalen, Sander van; Margadonna, Serena; Dubrovinsky, Leonid S.

    2015-01-01

    Highlights: • fcc- and hcp-Ir-Os alloys were prepared from single-source precursors. • Their atomic volumes measured at ambient conditions using powder X-ray diffraction follow nearly linear dependence. • Compressibility of alloys have been studied up to 30 GPa at room temperature in diamond anvil cells. • Their bulk moduli increase with increasing osmium content. - Abstract: Several fcc- and hcp-structured Ir-Os alloys were prepared from single-source precursors in hydrogen atmosphere at 873 K. Their atomic volumes measured at ambient conditions using powder X-ray diffraction follow nearly linear dependence as a function of composition. Alloys have been studied up to 30 GPa at room temperature by means of synchrotron-based X-ray powder diffraction in diamond anvil cells. Their bulk moduli increase with increasing osmium content and show a deviation from linearity. Bulk modulus of hcp-Ir 0.20 Os 0.80 is identical to that of pure Os (411 GPa) within experimental errors. Peculiarities on fcc-Ir 0.80 Os 0.20 compressibility curve indicate possible changes of its electronic properties at ∼20 GPa

  16. Penetration Enhancing Effect of Polysorbate 20 and 80 on the In ...

    African Journals Online (AJOL)

    Purpose: To investigate the penetration enhancing effect of two polysorbates - polyoxyethylene 20 (POE-20) and polyoxyethylene 80 (POE-80) - on the in vitro percutaneous absorption of ascorbic acid (AA). Methods: For the permeation experiments, Franz diffusion cell covered with aluminum foil providing an effective ...

  17. Stainless austenitic steels strengthened due to reversible phase transformations and by ageing

    International Nuclear Information System (INIS)

    Sagaradze, V.V.; Kositsyna, I.I.; Ozhiganov, A.V.

    1981-01-01

    The effect of the reversible phase transformations, consisting in the conduction of the direct and reverse martensite transformations and aging, during which the intermetallide γ'-phase of the composition Ni 3 Ti is formed, on the streng-thening of alloys in the Fe-Cr-Ni-Ti system is considered. Stainless austenitic steels Kh12N12T3 and Kh12N14T3, which acquire high mechanical properties: σsub(0.2)=685-785 MPa, σsub(B)=1275 MPa, delta >= 20%, as a result of reversible phase transformations and aging, are suggested. After the reversible phase transformations and ageing the steels possess a high resistance to γ-α-transformation during cold treatment [ru

  18. Effect of Zr on the Corrosion Properties of Mg-Li-Al Alloy

    International Nuclear Information System (INIS)

    Kim, Soon Ho; Choi, Sang Hyun; Kim, In Bae; Kim, Kyung Hyun

    1994-01-01

    Effect of Zr on the electrochemical corrosion characteristics of Mg-Li-Al alloy has been investigated by means of potentiodynamic polarization study. The electrochemical behaviors were evaluated in 0.03% NaCl solution and the solution buffered with KH 2 PO 5 · NaOH at room temperature. It was found that the addition of very small quantity of Zr (0.03wt%) in Mg-Li-Al alloy increased corrosion rates and amount of corrosion products and decreased the pitting resistance of the alloy. From the results it was concluded that Zr which is added to increase the strength of Mg-Li-Al alloy is harmful to corrosion properties of the alloy

  19. Evaluation of cast Ti-Fe-O-N alloys for dental applications

    International Nuclear Information System (INIS)

    Koike, Marie; Ohkubo, Chikahiro; Sato, Hideki; Fujii, Hideki; Okabe, Toru

    2005-01-01

    Good mechanical properties, biocompatibility and corrosion resistance make titanium an excellent material for biomedical applications. However, when better mechanical properties than those offered by commercially pure titanium (CPTi) are needed, Ti-6Al-4V is sometimes a good alternative. Some new titanium alloys, developed as industrial structural materials, aim at an intermediate range of strength between that of CP Ti and Ti-6Al-4V. Two of these alloys are Super-TIX800TM (Ti-1% Fe-0.35% O-0.01% N) and Super-TIX800NTM (Ti-1% Fe-0.3% O-0.04% N) (both produced by Nippon Steel Corp., Japan). Besides being stronger than CP Ti, the cost of manufacturing these alloys is reportedly lower than for Ti-6Al-4V since they do not contain any expensive elements. In addition, they are not composed of elements such as aluminum or vanadium, which have caused biocompatibility concerns in medical and dental appliances. To evaluate these alloys as candidates for dental use, it is helpful to compare them to CP Ti (ASTM Grade 2) and Ti-6Al-4V (ASTM Grade 5), which have already been employed in dentistry. We evaluated the tensile properties, mold filling capacity, corrosion characteristics and grindability of these industrial alloys prepared by investment casting. Compared to the strengths of cast CPTi, the yield strength and tensile strength of these cast alloys were more than 20% and approximately 30% higher, respectively. On the other hand, both of these properties were 30% lower than for Ti-6Al-4V. Better grindability and wear resistance were additional benefits of these new alloys for dental applications

  20. Effect of Cr, Ni, and Mo additions on the susceptibility of the 0Kh6n7m7c steel to hot cracking

    International Nuclear Information System (INIS)

    Tolstykh, L.G.; Pryakhin, A.V.; Popov, A.N.; Usynin, V.F.

    1977-01-01

    The effect of chromium, molybdenum, and nickel on the tendency of surfacing materials to form hot cracks (Vsub(kp) was studied using the mathematical statistics method. The St3 steel and 38KhN3MFA steel were used in the study. A device facilitating the hot cracking tendency test procedure was developed. It was found that, in the concentration range involved, Ni and Mo produce no effect on Vsub(kp), and Cr enhances it. A new powder wire, PP-OKh7N8M6S, capable of increasing surface material resistance by 1.5-2 times, has been developed

  1. Coarsening of (Fe, Cr)23C6 carbide phase on the tempering of 14Kh17N2 chromium-nickel steel

    International Nuclear Information System (INIS)

    Psarev, V.I.

    2002-01-01

    Paper lists the results of computer analysis of distribution according to sizes (Fe, Cr) 23 C 6 microparticles resulting from 14Kh17N2 steel tempering under 700 Deg C. Data were obtained at the maximum beneficial magnification of a light microscope. The mentioned curves of distribution densities are characterized by more reliable run from most permissible sizes of dispersed particles. Application of general rules of distributions and of previously elaborated procedure to identify experimental histograms with theoretical distributions enables to derive valuable information on dynamics of coarsening of a disperse phase in this case, as well [ru

  2. Strain-controlled low cycle fatigue properties of a rare-earth containing ME20 magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Mirza, F.A., E-mail: f4mirza@ryerson.ca [Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 (Canada); Wang, K.; Bhole, S.D.; Friedman, J.; Chen, D.L. [Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 (Canada); Ni, D.R.; Xiao, B.L. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Ma, Z.Y., E-mail: zyma@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

    2016-04-20

    The present study was aimed to evaluate the strain-controlled cyclic deformation characteristics and low cycle fatigue (LCF) life of a low (~0.3 wt%) Ce-containing ME20-H112 magnesium alloy. The alloy contained equiaxed grains with ellipsoidal particles containing Mg and Ce (Mg{sub 12}Ce), and exhibited a relatively weak basal texture. Unlike the high rare earth (RE)-containing magnesium alloy, the ME20M-H112 alloy exhibited asymmetrical hysteresis loops somewhat similar to the RE-free extruded Mg alloys due to the presence of twinning-detwinning activities during cyclic deformation. While cyclic stabilization was barely achieved even at the lower strain amplitudes, cyclic softening was the predominant characteristics at most strain amplitudes. The ME20M-H112 alloy showed basically an equivalent fatigue life to that of the RE-free extruded Mg alloys, which could be described by the Coffin-Manson law and Basquin's equation. Fatigue crack was observed to initiate from the near-surface imperfections, and in contrast to the typical fatigue striations, the present alloy showed some shallow dimples along with some fractions of quasi-cleavage features in the crack propagation area.

  3. Development of graded Ni-YSZ composite coating on Alloy 690 by Pulsed Laser Deposition technique to reduce hazardous metallic nuclear waste inventory.

    Science.gov (United States)

    Sengupta, Pranesh; Rogalla, Detlef; Becker, Hans Werner; Dey, Gautam Kumar; Chakraborty, Sumit

    2011-08-15

    Alloy 690 based 'nuclear waste vitrification furnace' components degrade prematurely due to molten glass-alloy interactions at high temperatures and thereby increase the volume of metallic nuclear waste. In order to reduce the waste inventory, compositionally graded Ni-YSZ (Y(2)O(3) stabilized ZrO(2)) composite coating has been developed on Alloy 690 using Pulsed Laser Deposition technique. Five different thin-films starting with Ni80YSZ20 (Ni 80 wt%+YSZ 20 wt%), through Ni60YSZ40 (Ni 60 wt%+YSZ 40 wt%), Ni40YSZ60 (Ni 40 wt%+YSZ 60 wt%), Ni20YSZ80 (Ni 20 wt%+YSZ 80 wt%) and Ni0YSZ100 (Ni 0 wt%+YSZ 100 wt%), were deposited successively on Alloy 690 coupons. Detailed analyses of the thin-films identify them as homogeneous, uniform, pore free and crystalline in nature. A comparative study of coated and uncoated Alloy 690 coupons, exposed to sodium borosilicate melt at 1000°C for 1-6h suggests that the graded composite coating could substantially reduced the chemical interactions between Alloy 690 and borosilicate melt. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Low temperature irradiation effects on iron boron based amorphous metallic alloys

    International Nuclear Information System (INIS)

    Audouard, A.

    1982-09-01

    Three Fe-B amorphous alloys (Fe 80 B 20 , Fe 27 Mo 2 B 20 and Fe 75 B 25 ) and the crystallized Fe 3 B alloy have been irradiated at the temperature of liquid hydrogen. Electron irradiation and irradiation by 10 B fission fragments induce point defects in amorphous alloys. These defects are characterized by an intrinsic resistivity and a formation volume. The threshold energy for the displacement of iron atoms has also been calculated. Irradiation by 235 U fission fragments induces some important structural modifications in the amorphous alloys [fr

  5. Elastic characteristics and microplastic deformation of amorphous alloys on iron base

    International Nuclear Information System (INIS)

    Pol'dyaeva, G.P.; Zakharov, E.K.; Ovcharov, V.P.; Tret'yakov, B.N.

    1983-01-01

    Investigation results of elasticity and microplasticity properties (modulus of normal elasticity E, elasticity limit σsub(0.01) and yield limit σsub(0.2)) of three amorphous alloys on iron base Fe 80 B 20 , Fe 70 Cr 10 B 20 and Fe 70 Cr 5 Ni 5 B 20 are given. Amorphous band of the alloys is obtained using the method of melt hardening. It is shown that amorphous alloys on iron base possess high elasticity and yield limits and hardness and are very perspective for the use as spring materials

  6. Experimental determination of the phase relationships in Zr/2.5 8.0 at% Nb/0 6.7 at% Al alloys with 750 at ppm 0 and 250 at ppm N between 730 900° C

    Science.gov (United States)

    Peruzzi, A.; Bolcich, J.

    1990-11-01

    Zr alloys with 2.5 to 8.0 at% Nb and 0 to 6.7 at% Al were subjected to dynamic and static treatments between 730-900° C and studied by qualitative and quantitative optical metallography, electrical resistance, X-ray diffractometry and electron microanalysis. The experimental data were analyzed by taking into account the effects of oxygen and nitrogen impurities. The main results for Zn-Nb-Al alloys with 750 at ppm O and 250 at ppm N are the following: (i) Equilibrium relationships are established between the α (hcp), β (bcc) and Zr 3Al (Cu 3Au) phases along isothermal sections at 730, 771 and 800°C. (ii) The β/ α + β boundaries are determined along iso-aluminum vertical sections at 6.7, 3.3 and 0 at% Al. (iii) The addition of Al to Zr-Nb alloys increases the solubility of Nb in the α phase, its maximum value at 730° C being about 0.7-0.8 at% for 4 at% Al. (iv) Solubility values for Al in the α-phase of Zr-Al were estimated by extrapolation from ternary alloys. These estimates help to solve an existing discrepancy in the Zr-Al system.

  7. Propriedades estruturais e térmicas de vidros teluretos 20Li2O-80TeO2 Structural and thermal properties of tellurite 20Li2O-80TeO2 glasses

    Directory of Open Access Journals (Sweden)

    E. Idalgo

    2007-09-01

    Full Text Available O presente trabalho reporta estudos sobre a cristalização em vidros teluretos 20Li2O-80TeO2 induzida a partir de tratamentos térmicos realizados sobre vidros com tamanho de partículas entre 38 µm e 75 µm. Estes estudos foram conduzidos em duas matrizes vítreas tratadas e não tratadas termicamente para aliviar as tensões após o quenching, utilizando-se de forma combinada às técnicas de difração de raios X, calorimetria diferencial de varredura e espectroscopia no infravermelho. Os resultados revelaram a presença de três fases cristalinas distintas durante o processo de cristalização e apontaram para uma hierarquia tal que as fases alfa-TeO2 e gama-TeO2 cristalizam-se antecipadamente à fase Li2Te2O5 no vidro 20Li2O-80TeO2 sujeito a tensões mecânicas induzidas durante a síntese. No vidro 20Li2O-80TeO2, livre de tensões mecânicas, não foi possível discriminar esta hierarquia de cristalização.This work report crystallization studies on tellurite 20Li2O-80TeO2 glasses induced from heat thermal annealing on glasses with particle size between 38 µm and 75 µm. These studies were conducted on two glass matrix heat thermal annealed and non-annealed to remove the stress after the quenching, by using the X-Ray diffraction analysis, Fourier transform infrared spectroscopy and differential scanning calorimetry techniques. The results shown the presence of three distinct crystalline alpha-TeO2, gamma-TeO2 and Li2Te2O5 phases during the crystallization process, suggesting a crystallization hierarchy on the glass matrix under stress, since the gamma-TeO2 and alpha-TeO2 phases crystallization occurs before the Li2Te2O5 phase. On the glass stress free, this crystallization hierarchy was not clearly determined.

  8. Temperature-dependent rigidity and magnetism of polyamide 6 nanocomposites based on nanocrystalline Fe-Ni alloy of various geometries

    Directory of Open Access Journals (Sweden)

    M. A. A. Mohamed

    2016-10-01

    Full Text Available The focus of this study is to explore the potential use of Polyamide 6 nanocomposite reinforced with nanocrystalline (nc Fe20Ni80 alloy (Fe20Ni80/PA6 PNC in electromagnetic applications and provide understanding of how the alloy particle geometry is controlling the nanocomposite’s physical properties. Thermomechanical rigidity, room-temperature soft magnetic performance and thermal soft magnetic stability of Fe20Ni80/PA6 PNCs based on spherical-sea urchin alloy particles (UMB2-SU and necklace-like alloy chains (UMB2-NC have been investigated. Both PNCs have considerably superior bulk properties compared to neat PA6 and UMB2-SU exhibits the most remarkable overall performance. Morphological observations disclose two relevant phenomena: i improved dispersion and distribution of the SU alloy particles than the NC ones within PA6 matrix, leading to stronger filler-matrix interfacial interactions within the UMB2-SU as compared to the UMB2-NC and ii presence of constraint polymer regions in between alloy segments within the UMB2-SU that provide secondary reinforcing and soft magnetic mechanisms. Such phenomena along with the lower alloy crystallite size and PA6 γ-crystal type content within the UMB2-SU than in the UMB2-NC, are considered the main responsible factors for the distinctive performance of UMB2-SU. Overall, compared to various ferromagnetic nanocrystalline metallic materials, the research proposes the SU nc Fe20Ni80 alloy as a valuable nanofiller in polymers for electromagnetic applications.

  9. Study of effect of austenite prehistory of 03Ch20N16AG6 steel on it structure and properties

    Energy Technology Data Exchange (ETDEWEB)

    Demchuk, I S; Krakhmalev, V I; Manninen, A I [Leningradskij Politekhnicheskij Inst. (USSR)

    1981-01-01

    Effect of preliminary cold working and different procedures of thermal treatment on structure and mechanical properties of stable austenite of 03Kh20N16AG6 steel is found out. It is shown that the degree of defectability of initial austenite structure predetermines the further deformation behaviour of the steel (level of strength characteristics, plasticity storage, hardening degree etc.) in the wide temperature range. Close connection of structural changes with properties should determine the choice of preliminary treatment of stable austenitic steel as applied to concrete condition of operation.

  10. Particle porosity at plasma are spraying of metals

    International Nuclear Information System (INIS)

    Petrunichev, V.A.; Koroleva, E.B.; Pushilin, N.P.

    1985-01-01

    Quantitative dependences of porosity and character of pore distribution in particles of different materials on particle size and composition of atmosphere in a working chamber are studied experimentally as applied to the process of plasma wire sputtering. Wires 1.2 mm in diameter made of tungsten, molybdenum, Kh20N80 alloy, and zirconium served as sputtering materials. It is shown that pore size and character of their distribution in particles of powders obtained by the method of plasma wire sputtering are dependent on sizes of forming particles and determined by conditions of their cooling. Intensive porosity formation is characteristic of wire sputtering in argon plasma with nitrogen additions, but there are critical values of nitrogen concentration in plasma, above which intensive porosity formation in forming particles stops

  11. Effect of equal channel angular pressing on the strength and ductility of an AZ80 alloy

    International Nuclear Information System (INIS)

    Pereira, T S; Chung, C W; Ding, R; Chiu, Y L

    2009-01-01

    Equal channel angular pressing (ECAP) was applied to an extruded AZ80 Mg alloy in order to refine microstructure and enhance mechanical properties. The results show that the initial grain size of 20 μm of the as-extruded samples has been reduced by 75% after the first pass of ECAP, down to about 5 μm. Also as a result of the severe plastic deformation, the intermetallic compound Mg 17 Al 12 , which was distributed along grain boundaries and forms networks before the ECAP, has been re-arranged into a more homogeneous distribution and with a more spherical shape after the ECAP. Although no strengthening effect has been observed, the grain refinement and precipitate fragmentation caused by the ECAP has resulted in a 28% increase in the elongation to failure in tensile tests. Fractography observation and texture measurement have also been carried out.

  12. Microstructure and corrosion behavior of laser processed NiTi alloy.

    Science.gov (United States)

    Marattukalam, Jithin J; Singh, Amit Kumar; Datta, Susmit; Das, Mitun; Balla, Vamsi Krishna; Bontha, Srikanth; Kalpathy, Sreeram K

    2015-12-01

    Laser Engineered Net Shaping (LENS™), a commercially available additive manufacturing technology, has been used to fabricate dense equiatomic NiTi alloy components. The primary aim of this work is to study the effect of laser power and scan speed on microstructure, phase constituents, hardness and corrosion behavior of laser processed NiTi alloy. The results showed retention of large amount of high-temperature austenite phase at room temperature due to high cooling rates associated with laser processing. The high amount of austenite in these samples increased the hardness. The grain size and corrosion resistance were found to increase with laser power. The surface energy of NiTi alloy, calculated using contact angles, decreased from 61 mN/m to 56 mN/m with increase in laser energy density from 20 J/mm(2) to 80 J/mm(2). The decrease in surface energy shifted the corrosion potentials to nobler direction and decreased the corrosion current. Under present experimental conditions the laser power found to have strong influence on microstructure, phase constituents and corrosion resistance of NiTi alloy. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Amorphous alloys in the U-Cr-V system

    International Nuclear Information System (INIS)

    Ray, R.; Musso, E.

    1979-01-01

    Amorphous uranium-chromium-vanadium alloys and a method of producing them are described. The uranium content of the alloys may vary between 60 and 80 atom percent, and chromium and vanadium between 0 and 40 atom percent, most particularly between 20 and 40 atom percent. A maximum of 10 atom percent of Cr or V may be replaced by other alloying elements, including metalloids and at least one transtion metal element. (LL)

  14. Aging temperature and abrasive wear behaviour of cast Al-(4%, 12%, 20%)Si-0.3% Mg alloys

    International Nuclear Information System (INIS)

    Shah, K.B.; Kumar, Sandeep; Dwivedi, D.K.

    2007-01-01

    In the present paper, influence of aging temperature during artificial age hardening treatment (T 6 ) of cast Al-(4, 12, 20%)Si-0.3% Mg on abrasive wear behaviour has been reported. Alloys were prepared by controlled melting and casting. Cast alloys were given age hardening treatment having sequence of solutionizing, quenching and artificial aging. All the alloys were solutionized at 510 deg. C for 8 h followed by water quenching (30 deg. C) and aging hardening at 150, 170, 190, 210 and 230 deg. C for 12 h. Abrasive wear tests were conducted against of 320 grade SiC abrasive medium at 5 and 10 N normal loads. It was observed that the silicon content and aging temperature significantly affect the wear resistance. Increase in aging temperature improves the wear resistance. Hypereutectic alloy showed better wear resistance than the eutectic alloy under identical conditions. Optical microstructure study of alloys under investigation has shown that cast dendritic structure is destroyed besides the spheroidization of eutectic silicon crystals after the heat treatment. The extent of change in structure depends on aging temperature. Scanning electron microscopy (SEM) of wear surface was carried to analyze the wear mechanism

  15. Magnetic properties of metals and alloys

    International Nuclear Information System (INIS)

    Lyuborskij, F.E.; Livingston, D.D.; Chin, Zh.I.

    1987-01-01

    The nature of magnetic properties of materials and their dependence on the composition and the material structure are described. Properties and application of such materials as the alloys of the Fe-Ni-Co, Fe-Cr-Co, Co-rare earth, Fe-Si, Ni-Se system are considered. Application outlook for amorphous alloys of the (Fe, Ni, Co) 80 (metalloid) 20 type is shown. Methods for magnetic property measurement are pointed out

  16. Influence of milling time on microstructure and magnetic properties of Fe{sub 80}P{sub 11}C{sub 9} alloy produced by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Taghvaei, A.H. [Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Ghajari, F., E-mail: fati.ghajari@gmail.com [Department of Materials Science and Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Markó, D. [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Prashanth, K.G. [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Additive manufacturing Center, Sandvik AB, 81181 Sandviken (Sweden)

    2015-12-01

    Fe{sub 80}P{sub 11}C{sub 9} alloy with amorphous/nanocrytalline microstructure has been synthesized by mechanical alloying of the elemental powders. The microstructure, thermal behavior and morphology of the produced powders have been studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), respectively. The crystallite size, lattice strain and fraction of the amorphous phase have been calculated by Rietveld refinement method. The results indicate that the powders microstructure consists of α-Fe(P,C) nanocrystals with an average diameter of 9 nm±1 nm dispersed in the amorphous matrix after 90 h of milling. Moreover, the fraction of amorphous phase initially increases up to 90 h of milling and then decreases after 120 h of milling, as a result of mechanical crystallization and formation of Fe{sub 2}P phase. The magnetic measurements show that while the saturation magnetization decreases continuously with the milling time, the coercivity exhibits a complicated trend. The correlation between microstructural changes and magnetic properties has been discussed in detail. - Highlights: • Glass formation was investigated in Fe{sub 80}P{sub 11}C{sub 9} by mechanical alloying. • Structural parameters were calculated by Rietveld refinement method. • Milling first increased and then decreased the fraction of amorphous phase. • Magnetic properties were significantly changed upon milling.

  17. 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...

  18. Crystallization of the amorphous Fe{sub 80}Zr{sub 12}B{sub 8} alloy under controlled heating

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H. [School of Engineering (H6), University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Shao, G. [Centre for Materials Research and Innovation, University of Bolton, Bolton BL3 5AB (United Kingdom)], E-mail: G.Shao@bolton.ac.uk; Tsakiropoulos, P. [Department of Engineering Materials, Sir Robert Hadfirld Building, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2008-07-14

    The devitrification process of amorphous Fe{sub 80}Zr{sub 12}B{sub 8} alloy ribbons were studied under controlled thermal conditions. The major crystallization event during continuous heating with differential scanning calorimetory (DSC) is dictated by diffusion controlled growth and the associated atom mobility of the slow diffusing species Zr. The existence of prior nano-crystals formed by pre-annealing below the crystallization temperature had little effect on the major crystallization temperature. The crystallization sequence during heating was: amorphous {yields} amorphous + {alpha}-Fe + Fe{sub 3}Zr(B) {yields} amorphous + {alpha}-Fe + Fe{sub 3}Zr(B) + Fe{sub 2}Zr. Different from previous findings in alloys of lower Zr and B contents, the peak for the crystallization of the {alpha}-Fe phase alone is missing in the DSC traces of this alloy.

  19. Elastic characteristics and microplastic deformation of amorphous alloys on iron base

    Energy Technology Data Exchange (ETDEWEB)

    Pol' dyaeva, G.P.; Zakharov, E.K.; Ovcharov, V.P.; Tret' yakov, B.N. (Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR))

    1983-01-01

    Investigation results of elasticity and microplasticity properties (modulus of normal elasticity E, elasticity limit sigmasub(0.01) and yield limit sigmasub(0.2)) of three amorphous alloys on iron base Fe/sub 80/B/sub 20/, Fe/sub 70/Cr/sub 10/B/sub 20/ and Fe/sub 70/Cr/sub 5/Ni/sub 5/B/sub 20/ are given. Amorphous band of the alloys is obtained using the method of melt hardening. It is shown that amorphous alloys on iron base possess high elasticity and yield limits and hardness and are very perspective for the use as spring materials.

  20. The effect of Sn addition on aging behavior and mechanical properties of wrought AZ80 magnesium alloy

    International Nuclear Information System (INIS)

    Jiang, Luyao; Zhang, Dingfei; Fan, Xiaowei; Guo, Fei; Hu, Guangshan; Xue, Hansong; Pan, Fusheng

    2015-01-01

    Highlights: • Thermodynamic and precipitation kinetics calculation was used to analyze aging hardening after addition of Sn. • Precipitation sequences were determined by the content of Sn element. • The microstructure of Mg 17 Al 12 discontinuous precipitates were influenced by Mg 2 Sn precipitates. - Abstract: The microstructure and mechanical properties of AZ80 wrought magnesium alloys with varying Sn contents (0, 1, 2 and 4 wt.%) have been studied by thermodynamic and precipitation kinetics calculation and examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), hardness test and uniaxial tensile test at room temperature in this paper. The results of thermodynamic and precipitation kinetics calculation showed that the precipitation sequences were determined by the content of Sn element. It was found that in the aging treatment of this work, Mg 17 Al 12 phase precipitated sooner than Mg 2 Sn phase in the alloys with less than 1.72 wt.% Sn and there was a contrary precipitation sequence of these two phases in the alloys with more than 1.72 wt.% Sn. Experimental results were in agreement with those of calculation. According to SEM and TEM observation, Sn promoted precipitation of Mg 17 Al 12 on aging temperature, however the preferential Mg 2 Sn phase suppressed discontinuous Mg 17 Al 12 precipitates by hindering the growth of these in their growth direction. AZ80 with 1–2 wt.% Sn as-aged alloys exhibited outstanding mechanical property that UTS, YS and EL were ∼420 MPa, ∼290 MPa and ∼5%, respectively

  1. Moessbauer study of corrosion products formed on Fe80B20 and Fe40Ni40 (MoB)20 amorphous alloys in an SO2-polluted atmosphere

    International Nuclear Information System (INIS)

    Davalos, J.; Marco, J.F.; Gracia, M.; Gancedo, J.R.; Greneche, J.M.

    1990-01-01

    ICEMS, XPS, XRD, and AES have been used to study the corrosion layers formed on two metallic glasses, Fe 80 B 20 and Fe 40 Ni 40 (MoB) 20 (2605 and 2826 MB, Allied Company), exposed to an SO 2 -polluted humid atmosphere. The iron-containing corrosion products are the same found for pure iron in the same environment, but different relative concentrations were clearly evidenced by ICEMS results. Elemental sulphur, Ni(OH) 2 , and B(OH) 3 , the latter enriched at the surface, were found by XPS, XRD and AES. (orig.)

  2. Nanocrystalline (Fe{sub 60}Al{sub 40}){sub 80}Cu{sub 20} alloy prepared by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Krifa, M.; Mhadhbi, M. [Laboratoire de Chimie Inorganique, 99/UR/12-22, FSS – Université de Sfax, B.P. 1171, Sfax 3018 (Tunisia); Escoda, L.; Güell, J.M. [Dept. de Fisica, Universitat de Girona, Campus Montilivi, 17071 Girona (Spain); Suñol, J.J., E-mail: joanjosep.sunyol@udg.edu [Dept. de Fisica, Universitat de Girona, Campus Montilivi, 17071 Girona (Spain); Llorca-Isern, N.; Artieda-Guzmán, C. [Dept. CMEM, Universitat de Barcelona, Martí Franques 1, 08028 Barcelona (Spain); Khitouni, M. [Laboratoire de Chimie Inorganique, 99/UR/12-22, FSS – Université de Sfax, B.P. 1171, Sfax 3018 (Tunisia)

    2013-03-25

    Highlights: ► Nanocrystalline Fe(Al, Cu) powdered alloy (10 nm) has been synthesized by MA. ► Decreasing the crystallite size increases coercivity and squareness ratio. ► As low crystallites size stronger hard ferromagnetic material results. -- Abstract: A nanostructured disordered Fe(Al, Cu) solid solution was obtained from prealloyed FeAl and elemental Cu powders using a high-energy ball mill. The transformations occurring in the material during milling were studied with the use of X-ray diffraction. The transformation of the phase depends upon the milling time. With the increase of milling time all Cu atoms became dissolved in the bcc Fe and the final product of the MA process was the nanocrystalline Fe(Al, Cu) solid solution with a mean crystallite size of 10 nm. Scanning electron microscopy (SEM) was employed to examine the morphology of the samples as a function of milling times. Magnetic properties were also investigated and were related to the microstructural changes. The system showed hard magnetic behavior.

  3. PROPER MOTIONS OF THE OUTER KNOTS OF THE HH 80/81/80N RADIO-JET

    Energy Technology Data Exchange (ETDEWEB)

    Masqué, Josep M.; Rodriguez, Luis F.; Carrasco-González, Carlos [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia 58089, México (Mexico); Araudo, Anabella [University of Oxford, Astrophysics, Keble Road, Oxford OX1 3RH (United Kingdom); Estalella, Robert [Departament d’Astronomia i Meteorologia and Institut de Ciències del Cosmos (IEEC-UB), Universitat de Barcelona, Martí i Franquès 1, E-08028 Barcelona, Catalunya (Spain); Anglada, Guillem; Osorio, Mayra [Instituto de Astrofísica de Andalucía (CSIC), Apartado 3004, E-18080 Granada (Spain); Girart, Josep M. [Institut de Ciències de l’Espai (CSIC-IEEC), Campus UAB, Carrer de Can Magrans, S/N, E-08193 Cerdanyola del Vallès, Catalunya (Spain)

    2015-11-20

    The radio-knots of the Herbig–Haro (HH) 80/81/80N jet extend from the HH 80 object to the recently discovered Source 34 and has a total projected jet size of 10.3 pc, constituting the largest collimated radio-jet system known so far. It is powered by the bright infrared source IRAS 18162−2048 associated with a massive young stellar object. We report 6 cm JVLA observations that, compared with previous 6 cm VLA observations carried out in 1989, allow us to derive proper motions of the HH 80, HH 81, and HH 80N radio knots located about 2.5 pc away in projection from the powering source. For the first time, we measure proper motions of the optically obscured HH 80N object providing evidence that this knot, along with HH 81 and HH 80 are associated with the same radio-jet. We also confirm the presence of Source 34, located further north of HH 80N, previously proposed to belong to the jet.We derived that the tangential velocity of HH 80N is 260 km s{sup −1} and has a direction in agreement with the expected direction of a ballistic precessing jet. The HH 80 and HH 81 objects have tangential velocities of 350 and 220 km s{sup −1}, respectively, but their directions are somewhat deviated from the expected jet path. The velocities of the HH objects studied in this work are significantly lower than those derived for the radio knots of the jet close to the powering source (600–1400 km s{sup −1}) suggesting that the jet is slowing down due to a strong interaction with the ambient medium. As a result, since HH 80 and HH 81 are located near the edge of the cloud, the inhomogeneous and low density medium may contribute to skew the direction of their determined proper motions. The HH 80 and HH 80N emission at 6 cm is, at least in part, probably synchrotron radiation produced by relativistic electrons in a magnetic field of 1 mG. If these electrons are accelerated in a reverse adiabatic shock, we estimate a jet total density of ≲1000 cm{sup −3}. All of these

  4. Konsep Pendidikan Akhlak dan Dakwah dalam Perspektif Dr. KH. Zakky Mubarak, MA

    Directory of Open Access Journals (Sweden)

    Muchtar Muchtar

    2017-09-01

    Full Text Available Research aims to understand role, and the concept of education and dakwah in perspective Dr. KH. Zakky Mubarak, MA. This research departs from looking at the phenomenon of human life is increasingly complex, entered the modern life and globalization present and the future, wich is characterized by technical and professional paced lives, is forecast to many people ignore the moral and religious in individual and social life. The concept of moral education in the perspective of Dr. KH. Zakky Mubarak, MA that establishes the character of the learners, provide good role models, develop the moral high level, and then apply the knowledge of good character and exemplary in real life so it can become an ingrained habit. The concept of dakwah in perspective Dr. KH. Zakky Mubarak, MA at least two steps that need to be understood by a preacher, first that of bringing the wisdom, it means explaining the wisdoms contained in worship and other Islamic activities without patronizing impression, meaning a preacher should put the words and appropriate sentence appropriate to the circumstances . The second is to mau'idlah hasanah , means giving advice that touch the heart so that the message can be embedded in the memories of audience. Dr. KH. Zakky Mubarak, MA is one of the Nahdlatul Ulama cleric who spend their time preaching, either through a lecture or through scientific papers, scientific papers written contains a lot of moral education that can be used as a reference.  Keywords: Concept of Education and Dakwah, Zakky Mubarak, Nahdlatul Ulama Abstrak Penelitian ini bertujuan untuk mengetahui peran, serta konsep pendidikan akhlak dan dakwah dalam perspektif Dr. KH. Zakky Mubarak, MA. Kesimpulan penelitian ini bahwa Konsep pendidikan akhlak dalam perspektif Dr. KH. Zakky Mubarak, MA yaitu menanamkan pemahaman tentang akhlak terhadap peserta didik, memberikan keteladanan yang baik, mengembangkan pada akhlak tingkat tinggi, dan kemudian mengaplikasikan

  5. Effect of ZnO nano in the blend PET / PC ( 80/20) subjected to UV radiation; Efeito do nano ZnO na mistura PET/PC(80/20) submetida a radiacao UV

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Homero M.; Mendes, Luis C.; Albitres, Gerson A.V.; Cestari, Sibele P.; Mattos, Gabriela C., E-mail: homero@ima.ufrj.br [Universidade Federal do Rio de Janeiro (IMA/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Macromoleculas Professora Eloisa Mano

    2015-07-01

    The aim of this research was to reuse recycled poly(ethylene terephthalate) (PET) in blend with polycarbonate (PC) in order to avoid UV degradation in outdoor application. Nanocomposite based on blend of recycled (PET) and polycarbonate (PC) in the ratio of 80/20 with nano zinc oxide (ZnO) at different concentrations was prepared. The blend was subjected to ultraviolet (UV) radiation for accelerated aging chamber, we evaluated the effect of the presence nZnO filler as a barrier to UV rays. Dynamic-mechanical analysis (DMA) and nuclear magnetic resonance in the solid state (NMR). It is the degradation retardant effect at concentrations starting from 3% nZnO. (author)

  6. Active and passive fire protection system in academic building KH. Mas Mansur, Islamic University of Indonesia

    Directory of Open Access Journals (Sweden)

    Suryoputro M. Ragil

    2018-01-01

    Full Text Available According to the theory of fire triangle, the existence of combustible materials, heat, and oxygen can cause fire disaster. KH. Mas Mansur building, Islamic University of Indonesia has a fire protection, but rarely to be checked regularly and the number of equipment is less standard as well as the lack of an evacuation route map to facilitate the evacuation process. Inside the building also does not provide safety signs such as the evacuation directions, exit, and warning in case of fire. Therefore, researchers analysed the infrastructure of prevention and control in the building KH. Mas Mansur. Researchers used the method of observation, interviews, and checklist to know the condition directly, and compare with the standard regulations. Results concordance rate of existing infrastructure is 67% fire extinguisher, hydrant box 56%, 71% alarms, sprinkler 0%, 40% detectors, emergency doors 71%, 50% emergency stairs, assembly point 0% and directions 0%. The current results were below the standard of at least 80%. As for recommendations, researchers create a new evacuation map then put the existing infrastructure according to standard regulations, and it had consulted with the specialist of Occupational Safety and Health in the field of fire.

  7. Properties of hard alloys on the basis of WC-Co with the additives of nanodisperse TiN

    International Nuclear Information System (INIS)

    Ordanyan, S.S.; Andronova, T.E.; Vladimirova, M.A.; Pantelejev, I.B.; Zalite, I.

    2001-01-01

    The addition of nanodisperse titanium nitride (specific surface area of 20 - 30 m 2 /g, medium diameter of grains of 50 - 100 nm) to the starting hard alloy WC-Co in the stage of wet grinding allows to get some advantages: the growth of WC grains is retarded by the nanoparticles of TiN, being as a barrier for the process of secondary crystallization, and the toughness of hard alloy is being increased due to the formation of finely dispersed structure; the exploitation characteristics of cutting instruments are increased due to the volume alloying by means of titanium nitride having a decreased adhesion to the treated metal and decreased coefficient of friction; the formation of diffusion porosity is being eliminated due to the small size of TiN during the unavoidable dissolution of WC in TiN. (author)

  8. Predicted bond length variation in wurtzite and zinc-blende InGaN and AlGaN alloys

    International Nuclear Information System (INIS)

    Mattila, T.; Zunger, A.

    1999-01-01

    Valence force field simulations utilizing large supercells are used to investigate the bond lengths in wurtzite and zinc-blende In x Ga 1-x N and Al x Ga 1-x N random alloys. We find that (i) while the first-neighbor cation endash anion shell is split into two distinct values in both wurtzite and zinc-blende alloys (R Ga-N 1 ≠R In-N 1 ), the second-neighbor cation endash anion bonds are equal (R Ga-N 2 =R In-N 2 ). (ii) The second-neighbor cation endash anion bonds exhibit a crucial difference between wurtzite and zinc-blende binary structures: in wurtzite we find two bond distances which differ in length by 13% while in the zinc-blende structure there is only one bond length. This splitting is preserved in the alloy, and acts as a fingerprint, distinguishing the wurtzite from the zinc-blende structure. (iii) The small splitting of the first-neighbor cation endash anion bonds in the wurtzite structure due to nonideal c/a ratio is preserved in the alloy, but is obscured by the bond length broadening. (iv) The cation endash cation bond lengths exhibit three distinct values in the alloy (Ga endash Ga, Ga endash In, and In endash In), while the anion endash anion bonds are split into two values corresponding to N endash Ga endash N and N endash In endash N. (v) The cation endash related splitting of the bonds and alloy broadening are considerably larger in InGaN alloy than in AlGaN alloy due to larger mismatch between the binary compounds. (vi) The calculated first-neighbor cation endash anion and cation endash cation bond lengths in In x Ga 1-x N alloy are in good agreement with the available experimental data. The remaining bond lengths are provided as predictions. In particular, the predicted splitting for the second-neighbor cation endash anion bonds in the wurtzite structure awaits experimental testing. copyright 1999 American Institute of Physics

  9. Enhanced Piezoelectric Response of AlN via CrN Alloying

    Energy Technology Data Exchange (ETDEWEB)

    Manna, Sukriti; Talley, Kevin R.; Gorai, Prashun; Mangum, John; Zakutayev, Andriy; Brennecka, Geoff L.; Stevanović, Vladan; Ciobanu, Cristian V.

    2018-03-01

    Since AlN has emerged as an important piezoelectric material for a wide variety of applications, efforts have been made to increase its piezoelectric response via alloying with transition metals that can substitute for Al in the wurtzite lattice. We report on density functional theory calculations of structure and properties of the CrxAl1-xN system for Cr concentrations ranging from zero to beyond the wurtzite-rocksalt transition point. By studying the different contributions to the longitudinal piezoelectric coefficient, we propose that the physical origin of the enhanced piezoelectricity in CrxAl1-xN alloys is the increase of the internal parameter u of the wurtzite structure upon substitution of Al with the larger Cr ions. Among a set of wurtzite-structured materials, we find that CrxAl1-xN has the most sensitive piezoelectric coefficient with respect to alloying concentration. Based on these results, we propose that CrxAl1-xN is a viable piezoelectric material whose properties can be tuned via Cr composition. We support this proposal by combinatorial synthesis experiments, which show that Cr can be incorporated in the AlN lattice up to 30% before a detectable transition to rocksalt occurs. At this Cr content, the piezoelectric modulus d33 is approximately 4 times larger than that of pure AlN. This finding, combined with the relative ease of synthesis under nonequilibrium conditions, may position CrxAl1-xN as a prime piezoelectric material for applications such as resonators and acoustic wave generators.

  10. Enhanced Piezoelectric Response of AlN via CrN Alloying

    Science.gov (United States)

    Manna, Sukriti; Talley, Kevin R.; Gorai, Prashun; Mangum, John; Zakutayev, Andriy; Brennecka, Geoff L.; Stevanović, Vladan; Ciobanu, Cristian V.

    2018-03-01

    Since AlN has emerged as an important piezoelectric material for a wide variety of applications, efforts have been made to increase its piezoelectric response via alloying with transition metals that can substitute for Al in the wurtzite lattice. We report on density functional theory calculations of structure and properties of the Crx Al1 -x N system for Cr concentrations ranging from zero to beyond the wurtzite-rocksalt transition point. By studying the different contributions to the longitudinal piezoelectric coefficient, we propose that the physical origin of the enhanced piezoelectricity in Crx Al1 -x N alloys is the increase of the internal parameter u of the wurtzite structure upon substitution of Al with the larger Cr ions. Among a set of wurtzite-structured materials, we find that Crx Al1 -x N has the most sensitive piezoelectric coefficient with respect to alloying concentration. Based on these results, we propose that Crx Al1 -x N is a viable piezoelectric material whose properties can be tuned via Cr composition. We support this proposal by combinatorial synthesis experiments, which show that Cr can be incorporated in the AlN lattice up to 30% before a detectable transition to rocksalt occurs. At this Cr content, the piezoelectric modulus d33 is approximately 4 times larger than that of pure AlN. This finding, combined with the relative ease of synthesis under nonequilibrium conditions, may position Crx Al1 -x N as a prime piezoelectric material for applications such as resonators and acoustic wave generators.

  11. Effect of Tm substitution on the magnetic properties and local magnetic anisotropy of amorphous Fe80-xTm xB20 ribbons

    International Nuclear Information System (INIS)

    Sayouty, E.H.; Annouar, F.; Lassri, H.; Randrianantoandro, N.; Greneche, J.M.

    2005-01-01

    We have carried out magnetic and Moessbauer studies of amorphous Fe 80-x Tm x B 20 alloys (0 ≤ x ≤ 16). With an increasing Tm content, both the Curie temperature T C and the magnetic moment of Fe atom μ Fe decrease. We have extracted the value of exchange constant A from T C and that of the local magnetic anisotropy constant K L from the coercivity. Moessbauer studies were performed in a transmission geometry and also using the conversion electron spectroscopy. Both Moessbauer spectrometry techniques show that the average hyperfine field decreases linearly with the addition of rare-earth

  12. Metastable structure formation during high velocity grinding

    International Nuclear Information System (INIS)

    Samarin, A.N.; Klyuev, M.M.

    1984-01-01

    Metastable structures in surface layers of samples are; investigated during force high-velocity abrasive grinding. Samples of martensitic (40Kh13), austenitic (12Kh18N10T), ferritic (05Kh23Yu5) steels and some alloys, in particular KhN77TYuR (EhI437B), were grinded for one pass at treatment depth from 0.17 up to 2.6 mm. It is established that processes of homogenizing, recrystallization and coagulation are; developed during force high-velocity grinding along with polymorphic transformations in the zone of thermomechanical effect, that leads to changes of physical and mechanical properties of the surface

  13. Microstructure and Corrosion Behavior of Ni-Alloy/CrN Nanolayered Coatings

    Directory of Open Access Journals (Sweden)

    Hao-Hsiang Huang

    2011-01-01

    Full Text Available The Ni-alloy/CrN nanolayered coatings, Ni-Al/CrN and Ni-P/CrN, were deposited on (100 silicon wafer and AISI 420 stainless steel substrates by dual-gun sputtering technique. The influences of the layer microstructure on corrosion behavior of the nanolayered thin films were investigated. The bilayer thickness was controlled approximately 10 nm with a total coating thickness of 1m. The single-layer Ni-alloy and CrN coatings deposited at 350∘C were also evaluated for comparison. Through phase identification, phases of Ni-P and Ni-Al compounds were observed in the single Ni-alloy layers. On the other hand, the nanolayered Ni-P/CrN and Ni-Al/CrN coatings showed an amorphous/nanocrystalline microstructure. The precipitation of Ni-Al and Ni-P intermetallic compounds was suppressed by the nanolayered configuration of Ni-alloy/CrN coatings. Through Tafel analysis, the corr and corr values ranged from –0.64 to –0.33 V and 1.42×10−5 to 1.14×10−6 A/cm2, respectively, were deduced for various coating assemblies. The corrosion mechanisms and related behaviors of the coatings were compared. The coatings with a nanolayered Ni-alloy/CrN configuration exhibited a superior corrosion resistance to single-layer alloy or nitride coatings.

  14. Study on technology for manufacturing alloy (lead-tin-bismuth-cadmium) having low melting temperature (≤ 80 deg C) used to shield radioactive rays for treating cancer

    International Nuclear Information System (INIS)

    Ngo Xuan Hung; Pham Duc Thai; Nguyen The Khanh; Vu Quang Chat; Nguyen Huu Quyet

    2007-01-01

    Up to now, hospitals in Vietnam have mostly imported radioactive equipments from America, German, France, England to treat cancer. Accompany with those equipments, alloy, namely Cyroben having low melting temperature (≤ 80 o C) is used to cover patients good tissues in order to protect them against harmful rays and help radioactive rays get through the cast hole to kill cancer cells. This project is carried out for determining chemical compositions and melting temperatures of researched alloy to create alloy having low melting temperature (≤ 80 o C) to meet demand for treating cancer in Vietnam. (author)

  15. Positron lifetime measurements on electron irradiated amorphous alloys

    International Nuclear Information System (INIS)

    Moser, P.; Hautojaervi, P.; Chamberod, A.; Yli-Kauppila, J.; Van Zurk, R.

    1981-08-01

    Great advance in understanding the nature of point defects in crystalline metals has been achieved by employing positron annihilation technique. Positrons detect vacancy-type defects and the lifetime value of trapped positrons gives information on the size of submicroscopic vacancy aglomerates and microvoids. In this paper it is shown that low-temperature electron irradiations can result in a considerable increase in the positron lifetimes in various amorphous alloys because of the formation of vacancy-like defects which, in addition of the pre-existing holes, are able to trap positrons. Studied amorphous alloys were Fe 80 B 20 , Pd 80 Si 20 , Cu 50 Ti 50 , and Fe 40 Ni 40 P 14 B 6 . Electron irradiations were performed with 3 MeV electrons at 20 K to doses around 10 19 e - /cm 2 . After annealing positron lifetime spectra were measured at 77 K

  16. TRANSFORMASI KURIKULUM PESANTREN: Telaah Pemikiran KH. MA. Sahal Mahfudh dan Nurcholish Madjid

    OpenAIRE

    Mukhlison Effendi; Suradi Suradi

    2016-01-01

    Abstract; Islamic boarding school is an indigenous Indonesia. Some contribution that given in the Islamization process, create a good community literacy and culture are very large. One reason, because there are Islamic boarding school curriculum transformation. Most influential enticement are KH. MA. Sahal Mahfudh and Nurcholish Madjid enticement. To knowing and determine the transformation both of those figures, the researcher take focus of study as: 1) the speculation of KH. MA. Sahal Mahfu...

  17. Metodologi Fatwa K.H. Muhammad Syaf’i Hadzami

    Directory of Open Access Journals (Sweden)

    Muhammad Ardiansyah

    2018-01-01

    Full Text Available Fatwa is one of the heavy mandates on the shoulders of Moslem scholars. There are some conditions that must be fulflled before the fatwa could be used to solve the problems of the people. Basically, the fatwa replaces the task of the Prophet in conveying the shari’a law, then the scholars did not dare to be reckless in declaring any fatwa. Therefore, being a mufti is not only required by reading the translation of al-Qur’an or Hadith, or by searching on the google, or by copying broadcasts in social media. According to al-Shirazi, the intellectual condition that must be required to be a mufti is deep understanding toward al-Qur’an and Hadith, also understanding sources of speech such as ḥaqîqah-majâz, ‘âmm-khâṣṣ, Arabic language, nâsikh-mansûkh, ijmâ’, ikhtilaf, and tartîb al-adillah. While the moral requirements to be a mufti according to Imam Ahmad bin Hanbal are having pure intention, having broad knowledge, patience, and soul, having strong mentality to fulfl the task, having suffciency of life to avoid being influenced by others, and understanding the condition of society. This paper attempts to examine the fatwas of a mufti from Betawi who had lived in the modern era known as Mu’allim Syaf’i Hadzami. The fatwas were collected in a work entitled Tawḍîḥ al-Adillah. In this article, the author has concluded that Mu’allim uses eight complementary and relevant fatwa methodologies to solve today’s problems

  18. Effect of composition on the structure and properties of Ti-Co-Cr alloys

    Directory of Open Access Journals (Sweden)

    T. Matković

    2010-01-01

    Full Text Available The present work is a study of six as-cast Ti-Co-Cr alloys in the Ti-rich region with the purpose of examining the possibility of obtaining a new β-type Ti-alloys. Two experimental alloys Ti80Co10Cr10 and Ti70Co10Cr20 are nearly single-phases and are identified as bcc β-Ti phase. They also display the lowest hardness values and the best corrosion properties. The present study indicates that the region of biomedically-acceptable ternary Ti-rich alloys is situated within lower concentrations of alloying elements, i.e. about 10 at.% Co and 20 at. % Cr.

  19. Simple models for InGaN alloys

    International Nuclear Information System (INIS)

    Elfituri, Fathi; Hourahine, Ben

    2012-01-01

    The properties of InGaN alloys are important for many applications in optoelectronics, since their fundamental gap spans the visible range. Calculating properties, particularly for InN, is theoretically challenging, especially to obtain accurate values for the band gap. We have developed a semi-empirical parametrisation of (In,Ga) N using the density functional based tight binding method (DFTB), where the band gaps of InN and GaN have been empirically corrected to experiment. We demonstrate the performance of this method by calculating a range of properties for the two materials, including elastic constants and carrier effective masses. There are several methods to model alloys of these material, one of the simplest being the virtual crystal approximation, which we apply to derive electronic properties over the whole composition range for InGaN. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Laser Nitriding of the Newly Developed Ti-20Nb-13Zr at.% Biomaterial Alloy to Enhance Its Mechanical and Corrosion Properties in Simulated Body Fluid

    Science.gov (United States)

    Hussein, M. A.; Kumar, A. Madhan; Yilbas, Bekir S.; Al-Aqeeli, N.

    2017-11-01

    Despite the widespread application of Ti alloy in the biomedical field, surface treatments are typically applied to improve its resistance to corrosion and wear. A newly developed biomedical Ti-20Nb-13Zr at.% alloy (TNZ) was laser-treated in nitrogen environment to improve its surface characteristics with corrosion protection performance. Surface modification of the alloy by laser was performed through a Nd:YAG laser. The structural and surface morphological alterations in the laser nitrided layer were investigated by XRD and a FE-SEM. The mechanical properties have been evaluated using nanoindentation for laser nitride and as-received samples. The corrosion protection behavior was estimated using electrochemical corrosion analysis in a physiological medium (SBF). The obtained results revealed the production of a dense and compact film of TiN fine grains (micro-/nanosize) with 9.1 µm below the surface. The mechanical assessment results indicated an improvement in the modulus of elasticity, hardness, and resistance of the formed TiN layer to plastic deformation. The electrochemical analysis exhibited that the surface protection performance of the laser nitrided TNZ substrates in the SBF could be considerably enhanced compared to that of the as-received alloy due to the presence of fine grains in the TiN layer resulting from laser nitriding. Furthermore, the untreated and treated Ti-20Nb-13Zr alloy exhibited higher corrosion resistance than the CpTi and Ti6Al4V commercial alloys. The improvements in the surface hardness and corrosion properties of Ti alloy in a simulated body obtained using laser nitriding make this approach a suitable candidate for enhancing the properties of biomaterials.

  1. Estimation of the effect of molybdenum on chemical and electrochemical stability of iron-based alloys

    International Nuclear Information System (INIS)

    Tyurin, A.G.

    2003-01-01

    The E-pH diagram for Mo-H 2 O system is made more precise. It is shown that a passivating film on molybdenum in weakly acid, neutral and alkali solutions may constitute MoO 2 only. In strongly acid solutions at anodic polarization the film should transform according to the following scheme: MoO 2 → Mo 4 O 11 → Mo 9 O 26 → MoO 3 . Sections of a Fe-Mo-O system phase diagram and a Fe-Mo-H 2 O system E-pH diagram at 25 deg C are plotted. MoO 2 is found to be a product of iron-molybdenum alloy oxidation in the air and in water. For the system of alloy Kh17N13M2-H 2 O the section of a E-pH diagram is plotted at 25 deg C [ru

  2. Enhanced hardness in epitaxial TiAlScN alloy thin films and rocksalt TiN/(Al,Sc)N superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Bivas [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Lawrence, Samantha K.; Bahr, David F. [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Schroeder, Jeremy L.; Birch, Jens [Thin Film Physics Division, Department of Physics, Chemistry, and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden); Sands, Timothy D. [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2014-10-13

    High hardness TiAlN alloys for wear-resistant coatings exhibit limited lifetimes at elevated temperatures due to a cubic-AlN to hexagonal-AlN phase transformation that leads to decreasing hardness. We enhance the hardness (up to 46 GPa) and maximum operating temperature (up to 1050 °C) of TiAlN-based coatings by alloying with scandium nitride to form both an epitaxial TiAlScN alloy film and epitaxial rocksalt TiN/(Al,Sc)N superlattices on MgO substrates. The superlattice hardness increases with decreasing period thickness, which is understood by the Orowan bowing mechanism of the confined layer slip model. These results make them worthy of additional research for industrial coating applications.

  3. Praktik Pemikiran Inklusif-Sosial KH M Sholeh Bahruddin Ngalah sebagai Manifestasi Pendidikan Multikultural Pesantren

    Directory of Open Access Journals (Sweden)

    M Anang Sholikhudin

    2016-12-01

    Full Text Available Dalam sejarah hidupnya, praktik pemikiran inklusif-sosial Kiai Sholeh sangat dipengaruhi oleh beberapa hal. Pertama, atas perintah ayahanda dengan pesan seperti berikut: “sak temene dek pasar, dek masjid, dek dalan, kabeh iku dulurmu (sesungguhnya baik di pasar, di masjid, maupun di jalanan, di seluruh tempat itu ada saudaramu.” Kedua, penerapan teori Abraham, yakni mencontoh perilaku ayahanda KH M Bahruddin Kalam (almarhum dan juga perilaku kakek KH M Kalam (almarhum. Ketiga, praktik dari rukun Tarekat Naqshabandiyah pada poin kelima dan keenam, yakni “ambugusi kabeh konco, cilik gede, lanang wadon, enom tuo, lan ambagusi kabeh makhluk (bergaul secara baik dengan semua teman, baik kecil maupun besar, laki-laki maupun perempuan, muda maupun tua, dan bergaul secara baik dengan semua makhluk.” Penelitian ini memfokuskan pada praktik pemikiran inklusif-sosial KH M Sholeh Bahruddin dengan model studi kasus, pendekatan yang dipakai adalah expose facto. Data diambil melalui observasi, wawancara serta dokumentasi. Penelitian menyimpulkan bahwa praktik pemikiran inklusif-sosial KH.. M. Sholeh Bahruddin sebenarnya mempertemukan misi perintah masing-masing agama (Islam, Kristen, Katolik, Budha dan Konghucu untuk membangun perdamaian, keamanan dan memelihara kasih sayang bersama-sama dan meminimalisir terjadinya konflik agama. || In the history of his life, the practice of inclusive social thought by Kiai Sholeh greatly influenced by several things. First, on the orders of his father with the following message: “In the markets, in the mosques, as well as on the streets, all over the places there are your brothers.” Secondly, the application of Abraham’s theory, which was practiced by KH M Bahruddin Kalam, the father (deceased of Kiai Sholeh, as well as KH M Kalam, the grandfather (deceased of Kiai Sholeh. Third, the practice of the Naqshabandi pillars that say: “being good with all friends, both small and great, both men and women, young

  4. Out-of-plane coercive field of Ni80Fe20 antidot arrays

    International Nuclear Information System (INIS)

    Gao Chunhong; Chen Ke; Lue Ling; Zhao Jianwei; Chen Peng

    2010-01-01

    The out-of-plane magnetic anisotropy and out-of-plane magnetization reversal process of nanoscale Ni 80 Fe 20 antidot arrays deposited by magnetron sputtering technique on an anodic aluminum oxide (AAO) membrane are investigated. The angular dependence of out-of-plane remanent magnetization of Ni 80 Fe 20 antidot arrays shows that the maximum remanence is in-plane and the squareness of the out-of-plane hysteresis loop follow a |cos θ| dependence. The angular dependence of out-of-plane coercivity of Ni 80 Fe 20 antidot arrays shows that the maximum coercivity lies on the surface of a cone with its symmetric axis normal to the sample plane, which indicates a transition of magnetic reversal from curling to coherent rotation when changing the angle between the applied magnetic field and the sample plane.

  5. Out-of-plane coercive field of Ni 80Fe 20 antidot arrays

    Science.gov (United States)

    Gao, Chunhong; Chen, Ke; Lü, Ling; Zhao, Jianwei; Chen, Peng

    2010-11-01

    The out-of-plane magnetic anisotropy and out-of-plane magnetization reversal process of nanoscale Ni 80Fe 20 antidot arrays deposited by magnetron sputtering technique on an anodic aluminum oxide (AAO) membrane are investigated. The angular dependence of out-of-plane remanent magnetization of Ni 80Fe 20 antidot arrays shows that the maximum remanence is in-plane and the squareness of the out-of-plane hysteresis loop follow a |cos θ| dependence. The angular dependence of out-of-plane coercivity of Ni 80Fe 20 antidot arrays shows that the maximum coercivity lies on the surface of a cone with its symmetric axis normal to the sample plane, which indicates a transition of magnetic reversal from curling to coherent rotation when changing the angle between the applied magnetic field and the sample plane.

  6. Quaternary (liquid + liquid) equilibria of aqueous two-phase polyethylene glycol, poly-N-vinylcaprolactam, and KH{sub 2}PO{sub 4}: Experimental and the generalized Flory-Huggins theory

    Energy Technology Data Exchange (ETDEWEB)

    Foroutan, Masumeh [Department of Physical Chemistry, Faculty of Chemistry, College of Science, University of Tehran, Enghelab Ave., Tehran 14155-6455 (Iran, Islamic Republic of)], E-mail: foroutan@khayam.ut.ac.ir; Zarrabi, Mona [Department of Physical Chemistry, Faculty of Chemistry, College of Science, University of Tehran, Enghelab Ave., Tehran 14155-6455 (Iran, Islamic Republic of)

    2008-06-15

    A quaternary (liquid + liquid) equilibrium study was performed to focus attention on the interaction parameters between poly-N-vinylcaprolactam (PVCL) and poly-ethylene glycol (PEG) as well as between other species. At first, the new experimental data of (liquid + liquid) equilibria for aqueous two-phase systems containing PEG, KH{sub 2}PO{sub 4}, and PVCL at T = 303.15 K have been determined. Then the Flory-Huggins theory with two electrostatic terms (the Debye-Huckel and the Pitzer-Debye-Huckel equations) has been generalized to correlate the phase behavior of the quaternary system. Good agreement has been found between experimental and calculated data from both models especially from the Pitzer-Debye-Huckel equation. Also an effort was done to compare the effect of temperature as well as addition of PVCL on the binodal curves of PEG, KH{sub 2}PO{sub 4}, and water. The effect of the type of salt on the binodals has been also studied, and the salting out power of the salts has been determined.

  7. Killing Effects of an Isolated Serratia marcescens KH-001 on Diaphorina citri via Lowering the Endosymbiont Numbers

    Directory of Open Access Journals (Sweden)

    Wei Hu

    2018-05-01

    Full Text Available Huanglongbing (HLB is the most devastating citrus disease worldwide, and suppression of the Asian citrus psyllid (Diaphorina citri is regarded as an effective method to inhibit the spread of HLB. In this study, we isolated a strain named as Serratia marcescens KH-001 from D. citri nymphs suffering from disease, and evaluated its killing effect on D. citri via toxicity test and effect on microbial community in D. citri using high-throughput sequencing. Our results indicated that S. marcescens KH-001 could effectively kill 83% of D. citri nymphs, while the fermentation products of S. marcescens KH-001 only killed 40% of the D. citrinymphs. High-throughput sequencing results indicated that the S. marcescens KH-001 increased the OTU numbers from 62.5 (PBS buffer to 81.5, while significantly lowered the Shannon index compared with Escherichia coli DH5α (group E (p < 0.05. OTU analysis showed that the S. marcescens KH-001 had significantly reduced the relative abundance of endosymbionts Wolbachia, Profftella, and Carsonella in group S compared with that in other groups (p < 0.05. Therefore, the direct killing effect of the fermentation products of S. marcescens KH-001 and the indirect effect via reducing the numbers of endosymbionts (Wolbachia, Profftella, and Carsonella of D. citri endow S. marcescens KH-001 a sound killing effect on D. citri. Further work need to do before this strain is used as a sound biological control agents.

  8. Glass formation ability, structure and magnetocaloric effect of a heavy rare-earth bulk metallic glassy Gd{sub 55}Co{sub 20}Fe{sub 5}Al{sub 20} alloy

    Energy Technology Data Exchange (ETDEWEB)

    Jo, C.-L. [Shanghai University, School of Materials Science and Engineering, Yanchang Road 149, Zhabei District, 200072 Shanghai (China)], E-mail: jochollong@163.com; Xia Lei; Ding Ding; Dong Yuanda; Gracien, Ekoko [Shanghai University, School of Materials Science and Engineering, Yanchang Road 149, Zhabei District, 200072 Shanghai (China)

    2008-06-30

    The glass formation ability, the structure and the magnetocaloric effect of the bulk metallic glassy Gd{sub 55}Co{sub 20}Fe{sub 5}Al{sub 20} alloy were investigated. Bulk metallic glassy (BMGs) alloys were prepared by a copper-mold casting method. The glass forming ability and their structure were studied by using X-ray diffraction (XRD) and differential scanning calorimeter (DSC). The XRD analysis revealed that the as-cast cylinder of Gd{sub 55}Co{sub 20}Fe{sub 5}Al{sub 20} alloy showed fully amorphous structure in 2 mm diameter. The DSC revealed that the bulk cylinder of the Gd{sub 55}Co{sub 20}Fe{sub 5}Al{sub 20} alloy showed a distinct glass transition temperature and a relatively wide supercooled liquid region before crystallization. SQUID investigated the magnetic properties and the entropy changes. The Curie temperature of Gd{sub 55}Co{sub 20}Fe{sub 5}Al{sub 20} BMGs alloy was about 130 K, but the maximum magnetic entropy changes(-{delta}S{sub M}) showed at about 125 K, a little lower than the Curie temperature 130 K. The reason could probably be due to the presence of a little amount of nanocrystalline particles between amorphous phases. The BMG alloy has the characteristic of second-order transition (SOT) on Arrott plots. The results showed that the amorphous sample had a relatively improved magnetocaloric effect, indicating that the amorphous alloy could be considered as a candidate for magnetic refrigeration applications in the temperature interval range of 100-200 K.

  9. Surface analysis and electrochemical behavior of Ti–20Zr alloy in simulated physiological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Calderon Moreno, Jose Maria; Vasilescu, Ecaterina; Drob, Paula; Osiceanu, Petre; Vasilescu, Cora; Drob, Silviu Iulian, E-mail: sidrob@chimfiz.icf.ro; Popa, Monica

    2013-11-01

    Highlights: • The advanced Ti–20Zr alloy shows fully lamellar α + β microstructure. • The alloy passive film improves its properties by deposition of HA (XPS, SEM, EDX, Raman, FT-IR). • Alloy revealed lower corrosion rates and higher polarization resistances than Ti. • EIS spectra depicted a more protective passive film on the alloy surface than on Ti. • The passive film is formed by two layers: an inner barrier and an outer porous layer. -- Abstract: An advanced Ti–20Zr alloy was obtained by double vacuum melting in a semi-levitation furnace with cold crucible. The alloy shows fully lamellar α + β microstructure. Cyclic potentiodynamic polarization curves revealed that the alloy passivated easier, more rapid than Ti, having a more stable passive film in Ringer solutions of different pH values, simulating severe functional conditions of an implant. In neutral and alkaline Ringer solutions, the alloy passive film improved its properties in time (1500 h) by the deposition of protective hydroxyapatite, as was demonstrated by XPS, SEM, EDX, Raman and FT-IR measurements. Alloy presented lower corrosion rates and higher polarization resistances (from linear polarization measurements) than those of Ti (tens of times) proving a more resistant passive film. Alloy open circuit potentials had more electropositive values in comparison with Ti and tended to nobler values in time, which denote better passive state and its enhancement in time, due to the new depositions from the physiological solutions. Nyquist and Bode spectra depicted a more protective passive film on the alloy surface than on Ti surface. The passive film is formed by two layers: an inner barrier layer and an outer porous layer. An electric equivalent circuit with two time constants was modeled.

  10. Surface analysis and electrochemical behavior of Ti–20Zr alloy in simulated physiological fluids

    International Nuclear Information System (INIS)

    Calderon Moreno, Jose Maria; Vasilescu, Ecaterina; Drob, Paula; Osiceanu, Petre; Vasilescu, Cora; Drob, Silviu Iulian; Popa, Monica

    2013-01-01

    Highlights: • The advanced Ti–20Zr alloy shows fully lamellar α + β microstructure. • The alloy passive film improves its properties by deposition of HA (XPS, SEM, EDX, Raman, FT-IR). • Alloy revealed lower corrosion rates and higher polarization resistances than Ti. • EIS spectra depicted a more protective passive film on the alloy surface than on Ti. • The passive film is formed by two layers: an inner barrier and an outer porous layer. -- Abstract: An advanced Ti–20Zr alloy was obtained by double vacuum melting in a semi-levitation furnace with cold crucible. The alloy shows fully lamellar α + β microstructure. Cyclic potentiodynamic polarization curves revealed that the alloy passivated easier, more rapid than Ti, having a more stable passive film in Ringer solutions of different pH values, simulating severe functional conditions of an implant. In neutral and alkaline Ringer solutions, the alloy passive film improved its properties in time (1500 h) by the deposition of protective hydroxyapatite, as was demonstrated by XPS, SEM, EDX, Raman and FT-IR measurements. Alloy presented lower corrosion rates and higher polarization resistances (from linear polarization measurements) than those of Ti (tens of times) proving a more resistant passive film. Alloy open circuit potentials had more electropositive values in comparison with Ti and tended to nobler values in time, which denote better passive state and its enhancement in time, due to the new depositions from the physiological solutions. Nyquist and Bode spectra depicted a more protective passive film on the alloy surface than on Ti surface. The passive film is formed by two layers: an inner barrier layer and an outer porous layer. An electric equivalent circuit with two time constants was modeled

  11. Effect of iron content on the structure and mechanical properties of Al{sub 25}Ti{sub 25}Ni{sub 25}Cu{sub 25} and (AlTi){sub 60-x}Ni{sub 20}Cu{sub 20}Fe{sub x} (x=15, 20) high-entropy alloys

    Energy Technology Data Exchange (ETDEWEB)

    Fazakas, É., E-mail: eva.fazakas@bayzoltan.hu [WPI-Advaced Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-Ku, Sendai 980-8577 (Japan); Wigner Research Center for Physics, Hungarian Academy of Sciences, H-1525, P.O.B. 49 (Hungary); Bay Zoltán Nonprofit Ltd., For Applied Research H-1116 Budapest, Fehérvári út 130 (Hungary); Zadorozhnyy, V. [National University of Science and Technology «MISIS», Leninsky prosp., 4, Moscow 119049 (Russian Federation); Louzguine-Luzgin, D.V. [WPI-Advaced Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-Ku, Sendai 980-8577 (Japan)

    2015-12-15

    Highlights: • Three new refractory alloys namely: Al{sub 25}Ti{sub 25}Ni{sub 25}Cu{sub 25}, Al{sub 22.5}Ti{sub 22.5}Ni{sub 20}Cu{sub 20}Fe{sub 15} and Al{sub 20}Ti{sub 20}Ni{sub 20}Cu{sub 20}Fe{sub 20}, were produced by induction-melting and casting. • This kind of alloys exhibits high resistance to annealing softening. • Most the alloys in the annealed state possess even higher Vickers microhardness than the as-cast alloys. • The Al{sub 22.5}Ti{sub 22.5}Ni{sub 20}Cu{sub 20}Fe{sub 15} and Al{sub 20}Ti{sub 20}Ni{sub 20}Cu{sub 20}Fe{sub 20} alloys annealed at 973 K show the highest compressive stress and ductility values. - Abstract: In this work, we investigated the microstructure and mechanical properties of Al{sub 25}Ti{sub 25}Ni{sub 25}C{sub u25} Al{sub 22.5}Ti{sub 22.5}Ni{sub 20}Cu{sub 20}Fe{sub 15} and Al{sub 20}Ti{sub 20}Ni{sub 20}Cu{sub 20}Fe{sub 20} high entropy alloys, produced by arc melting and casting in an inert atmosphere. The structure of these alloys was studied by X-ray diffractometry and scanning electron microscopy. The as-cast alloys were heat treated at 773, 973 and 1173 K for 1800 s to investigate the effects of aging on the plasticity, hardness and elastic properties. Compared to the conventional high-entropy alloys the Al{sub 25}Ti{sub 25}Ni{sub 25}Cu{sub 25}, Al{sub 22.5}Ti{sub 22.5}Ni{sub 20}Cu{sub 20}Fe{sub 15} and Al{sub 20}Ti{sub 20}Ni{sub 20}Cu{sub 20}Fe{sub 20} alloys are relatively hard and ductile. Being heat treated at 973 K the Al{sub 22.5}Ti{sub 22.5}Ni{sub 20}Cu{sub 20}Fe{sub 15} alloy shows considerably high strength and relatively homogeneous deformation under compression. The plasticity, hardness and elastic properties of the studied alloys depend on the fraction and intrinsic properties of the constituent phases. Significant hardening effect by the annealing is found.

  12. Texture and microstructure development during hot deformation of ME20 magnesium alloy: Experiments and simulations

    International Nuclear Information System (INIS)

    Li, X.; Al-Samman, T.; Mu, S.; Gottstein, G.

    2011-01-01

    Highlights: → Second phase precipitates in ME20 hindered activation of tensile twinning at 300 deg. C. → New off-basal sheet texture during c-axis compression at low Z conditions. → Ce amplifies the role of pyramidal -slip over prismatic slip at 0.3T m . → Prismatic slip becomes equally important to deformation at 0.6T m . → Accurate texture predictions using a cluster-type Taylor model with grain interaction. - Abstract: The influence of deformation conditions and starting texture on the microstructure and texture evolution during hot deformation of a commercial rare earth (RE)-containing magnesium alloy sheet ME20 was investigated and compared with a conventional Mg sheet alloy AZ31. For all the investigated conditions, the two alloys revealed obvious distinctions in the flow behavior and the development of texture and microstructure, which was primarily attributed to the different chemistry of the two alloys. The presence of precipitates in the fine microstructure of the ME20 sheet considerably increased the recrystallization temperature and suppressed tensile twinning. This gave rise to an uncommon Mg texture development during deformation. Texture simulation using an advanced cluster-type Taylor approach with consideration of grain interaction was employed to correlate the unique texture development in the ME20 alloy with the activation scenarios of different deformation modes.

  13. Formation of Al70Cu20Fe10 icosahedral quasicrystal by mechanically alloyed method

    International Nuclear Information System (INIS)

    Yin Shilong; Bian Qing; Qian Liying; Zhang Aimei

    2007-01-01

    The structural evolutions of the mechanically alloyed ternary Al 70 Cu 20 Fe 10 powders with the milling time and the annealing treatment have been studied by X-ray diffraction (XRD), transmission electronic microscopy (TEM) and X-ray absorption fine-structure spectroscopy (XAFS) techniques. Results show that an Al 2 Cu compound forms with short-time milling, while a Cu 9 Al 4 compound forms with long-time milling. Fe can react with Al-Cu alloy by annealing treatment. Al 7 Cu 2 Fe compound with tetragonal structure or Al (Cu, Fe) solid solution with cubic structure may form at lower temperature, while a quasicrystal phase of Al 65 Cu 20 Fe 15 alloy may form at higher temperature

  14. Consistent dispersive optical-model analyses for n+209Bi and n+208Pb from -20 to +80 MeV

    International Nuclear Information System (INIS)

    Weisel, G.J.; Tornow, W.; Howell, C.R.

    1993-01-01

    Complementary databases were constructed from published and some new measurements of σ(θ), Ay(θ) and σ T for n+ 208 Pb and n+ 209 Bi covering the energy range 1.0 to 80 MeV. A dispersive optical-model analysis was performed for both scattering systems while constraining many of the parameters to be identical. A good representation of the data is obtained with conventional geometry and spin-orbit parameters. The 208 Pb model predicts quite well measured energies of single-particle and single-hole bound states. Occupation probabilities are calculated. A fully constrained model is presented in which the only differences between the two systems are the Fermi energy and the usual isospin term. This latter model represents all the data well

  15. Synthesis and Characterization of Nanocrystalline Al-20 at. % Cu Powders Produced by Mechanical Alloying

    Directory of Open Access Journals (Sweden)

    Molka Ben Makhlouf

    2016-06-01

    Full Text Available Mechanical alloying is a powder processing technique used to process materials farther from equilibrium state. This technique is mainly used to process difficult-to-alloy materials in which the solid solubility is limited and to process materials where nonequilibrium phases cannot be produced at room temperature through conventional processing techniques. This work deals with the microstructural properties of the Al-20 at. % Cu alloy prepared by high-energy ball milling of elemental aluminum and copper powders. The ball milling of powders was carried out in a planetary mill in order to obtain a nanostructured Al-20 at. % Cu alloy. The obtained powders were characterized using scanning electron microscopy (SEM, differential scanning calorimetry (DSC and X-ray diffraction (XRD. The structural modifications at different stages of the ball milling are investigated with X-ray diffraction. Several microstructure parameters such as the crystallite sizes, microstrains and lattice parameters are determined.

  16. Effect of the isothermal transformation temperature on the fine structure of steel-12Kh1MF

    International Nuclear Information System (INIS)

    Mints, I.I.; Berezina, T.G.; Lanskaya, K.A.

    1976-01-01

    For detailed analysis of bainite and pearlite in steel 12Kh1MF, homogeneous structures were obtained by isothermal annealing at 350, 450, 500, and 650 0 for 1 h. Isothermal transformation of austenite leads to the formation of bainite at 350-500 0 and pearlite at 650 0 . The austenitizing temperature was 980 0 for both types of samples, with holding for 20 min. For comparison, the plates were quenched from 980 0 and 1050 0 in ice-cold brine. The investigation was conducted with use of light and electron microscopes and x-ray analysis. The long-term strength was also determined. Isothermal treatment of steel 12Kh1MF at 350-500 0 C leads to the formation of a structure consisting of upper and lower bainite. At 500 0 the structure consists primarily of upper bainite, and at 350 0 of lower bainite. With tempering of the steel with a structure of upper and lower bainite at 730 0 for 3 h the dislocations undergo redistribution of the polygonization type within ferrite needles, with development of a cellular substructure. The acicular structure of the matrix is retained in this case. The density and evenness of the distribution of carbides is higher in upper bainite than in lower bainite. Steel 12Kh1MF with a structure of upper bainite is more susceptible to recrystallization as compared with a structure of lower bainite, which is responsible for the higher heat resistance of the latter

  17. Effect of preliminary heat treatment on phase transformations and properties of the Kh15N5D2T (VNS-2) steel

    International Nuclear Information System (INIS)

    Madyanov, S.A.; Voronenko, B.I.; Makhnev, E.S.

    1978-01-01

    It is shown that preliminary heat treatment has a significant effect on the α→γ transformation kinetics, the quantity of residual austenite, the grain size and mechanical properties of the Kh15N5D2T steel after final heat treatment. The preliminary heat treatment regimes leading to the increase of the quantity of residual austenite and to grain refining increase the work of crack propagation in the finally strengthened state. The optimum properties were obtained after threefold preliminary tempering for 1h at 650 deg C. An approximately constant relation of α- and γ-phases (approximately 50%) is observed at 625 deg C irrespective of the investigated regimes of preliminary heat treatment

  18. Translation initiation on mRNAs bound by nuclear cap-binding protein complex CBP80/20 requires interaction between CBP80/20-dependent translation initiation factor and eukaryotic translation initiation factor 3g.

    Science.gov (United States)

    Choe, Junho; Oh, Nara; Park, Sungjin; Lee, Ye Kyung; Song, Ok-Kyu; Locker, Nicolas; Chi, Sung-Gil; Kim, Yoon Ki

    2012-05-25

    In the cytoplasm of mammalian cells, either cap-binding proteins 80 and 20 (CBP80/20) or eukaryotic translation initiation factor (eIF) 4E can direct the initiation of translation. Although the recruitment of ribosomes to mRNAs during eIF4E-dependent translation (ET) is well characterized, the molecular mechanism for CBP80/20-dependent translation (CT) remains obscure. Here, we show that CBP80/20-dependent translation initiation factor (CTIF), which has been shown to be preferentially involved in CT but not ET, specifically interacts with eIF3g, a component of the eIF3 complex involved in ribosome recruitment. By interacting with eIF3g, CTIF serves as an adaptor protein to bridge the CBP80/20 and the eIF3 complex, leading to efficient ribosome recruitment during CT. Accordingly, down-regulation of CTIF using a small interfering RNA causes a redistribution of CBP80 from polysome fractions to subpolysome fractions, without significant consequence to eIF4E distribution. In addition, down-regulation of eIF3g inhibits the efficiency of nonsense-mediated mRNA decay, which is tightly coupled to CT but not to ET. Moreover, the artificial tethering of CTIF to an intercistronic region of dicistronic mRNA results in translation of the downstream cistron in an eIF3-dependent manner. These findings support the idea that CT mechanistically differs from ET.

  19. Effect of aluminium on the passivation of zinc–aluminium alloys in artificial seawater at 80 °C

    International Nuclear Information System (INIS)

    Kaewmaneekul, Tanapat; Lothongkum, Gobboon

    2013-01-01

    Highlights: ► Pure Zn and Zn–Al alloys passivate and depassivate in artificial seawater. ► Al retards passivation of Zn–Al alloys. ► Passive film composes of the inner film and the outer charge transfer layers. ► Al increases current density but decreases corrosion resistance of passive films. ► Al increases the electrical conductivity and the capacitance of the films. - Abstract: The effect of Al (0.15, 0.3 and 1.0 wt.%) on the passivation of Zn–Al alloys in artificial seawater at 80 °C is investigated by electrochemical measurements, scanning electron microscopy (SEM) and X-ray diffraction (XRD). It is found that the presence of Al in Zn–Al alloys can retard passivation. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements show that Al increases the current density but decreases the corrosion resistance of passive films, respectively. Mott-Schottky analysis reveals that Al increases the electrical conductivity and the capacitance of the films. Passivation of Zn–Al alloys occurs in artificial seawater when the immersion time is between 120 and 288 h, due to the presence of various Zn and Al protective compounds at the surfaces. Depassivation occurs when the immersion time is between 288 and 720 h, probably due to the decrease of solution pH and the Cl − penetration mechanism.

  20. Extractive-photometric determination of niobium with N-benzoylphenylhydroxylamine and lumogallion in alloyed steels

    International Nuclear Information System (INIS)

    Patratij, Yu.V.; Pilipenko, A.T.

    1978-01-01

    An extractive-photometric method has been developed to determine niobium (5) present as a heteroligand complex with N-benzoylphenylhydroxylamine (BPH) and lumogallion in alloyed steels. The method is based on preliminary extraction of niobium in a complex with BPH from concentrated HCl and subsequent determination of niobium in a 5-n (with respect to HCl) solution with lumogallion added. Sensitivity of the method is 2.0 μg of niobium in 10 ml of extract. The method has been tested on standard steels specimens

  1. Influence of the deposition-induced stress on the magnetic properties of magnetostrictive amorphous (Fe80Co20)80B20 multilayers with orthogonal anisotropy

    International Nuclear Information System (INIS)

    Gonzalez-Guerrero, Miguel; Prieto, Jose Luis; Sanchez, Pedro; Aroca, Claudio

    2007-01-01

    In this work, we experimentally justify that the control of the mechanical stress induced during the deposition of sputtered amorphous magnetostrictive (Fe 80 Co 20 ) 80 B 20 allows a custom design of its magnetic properties. FeCoB multilayers have been sputtered on thermal oxide Si substrates with different buffer materials. The crystalline quality and the thermomechanical properties of the buffer layer influence both the coercive and the anisotropy field. Those buffer layers with both high rigidity and poor thermal conductivity do not allow the dissipation of energy of the incoming sputtered material. Therefore, the mechanical stresses related to the deposition process cannot be released, leading to magnetic layers with high easy-axis coercive field and low anisotropy field. This shows that the mechanical stresses accumulated during deposition are a key parameter for the control of coercivity

  2. Nickel and its alloys as perspective materials for intermediate temperature steam electrolysers operating on proton conducting solid acids as electrolyte

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Petrushina, Irina; Jensen, Jens Oluf

    2012-01-01

    Several stainless steels, nickel-based alloys, Ta-coated stainless steel, niobium, nickel, platinum and gold were evaluated as possible materials for use in the intermediate temperature water electrolysers. The corrosion resistance was measured in molten KH2PO4 as simulated conditions corresponding...

  3. A MULTI-WAVELENGTH STUDY OF THE STAR-FORMING CORE AHEAD OF HH 80N

    International Nuclear Information System (INIS)

    Masque, Josep M.; Estalella, Robert; Osorio, Mayra; Anglada, Guillem; Girart, Josep M.; Garay, Guido; Calvet, Nuria; Beltran, Maria T.

    2011-01-01

    We present observations of continuum emission in the mid-infrared to millimeter wavelength range, complemented with ammonia observations, of the dense core ahead of the radio Herbig-Haro (HH) object HH 80N, found in the GGD 27 region. The continuum emission in all the observed bands peaks at the same position, consistent with the presence of an embedded object, HH 80N-IRS1, within the core. The distribution of the Very Large Array ammonia emission is well correlated with that of the dust, suggesting that photochemical effects caused by the nearby HH object do not play an important role in shaping this particular molecular emission. In order to unveil the nature of HH 80N-IRS1, we analyzed the continuum data of this source, using self-consistent models of protostellar collapse. We find that a young protostar surrounded by a slowly rotating collapsing envelope of radius ∼0.08 pc and 20 M sun plus a circumstellar disk of radius ∼300 AU and 0.6 M sun provide a good fit to the observed spectral energy distribution and to the maps at 350 μm, 1.2 mm, and 3.5 mm of HH 80N-IRS1. Besides, the Atacama Pathfinder Experiment and Plateau de Bure Interferometer continuum maps at 350 μm and 3.5 mm, respectively, reveal additional clumps in the continuum emission. Given the modeling results and the observed morphology of the emission, we propose a scenario consisting of a central embedded Class 0 object, HH 80N-IRS1, with the rest of the material of the HH 80N core possibly undergoing fragmentation that may lead to the formation of several protostars.

  4. Effect of Y2O3 on microstructure and mechanical properties of hypereutectic Al-20% Si alloy

    Institute of Scientific and Technical Information of China (English)

    YANG Ya-feng; XU Chang-lin; WANG Hui-yuan; LIU Chang; JIANG Qi-chuan

    2006-01-01

    The effect of Y2O3 on the microstructure and mechanical properties of the hypereutectic Al-20%Si(mass fraction) alloy was investigated. The results show that, with the addition of Y2O3 into the Al-P-Ti-TiC modifier, the average size of primary silicon in th.e Al-20%Si alloy modified by Al-P-Ti-TiC-Y2O3 modifier (approximately 15μm or less) is significantly reduced, and the morphology of eutectic silicon changes from coarse acicular and plate like to refined fibrous. The Brinell hardness (HB189) and tensile strength (301 MPa) of Al-20%Si alloy modified by the Al-P-Ti-TiC-Y2O3 increase by 11.6% and 10.7%, respectively, for the alloys afrer heat treatment.

  5. Wurtzite BAlN and BGaN alloys for heterointerface polarization engineering

    KAUST Repository

    Liu, Kaikai

    2017-11-30

    The spontaneous polarization (SP) and piezoelectric (PZ) constants of BxAl1-xN and BxGa1-xN (0 ≤ x ≤ 1) ternary alloys were calculated with the hexagonal structure as reference. The SP constants show moderate nonlinearity due to the volume deformation and the dipole moment difference between the hexagonal and wurtzite structures. The PZ constants exhibit significant bowing because of the large lattice difference between binary alloys. Furthermore, the PZ constants of BxAl1-xN and BxGa1-xN become zero at boron compositions of ∼87% and ∼74%, respectively, indicating non-piezoelectricity. The large range of SP and PZ constants of BxAl1-xN (BAlN) and BxGa1-xN (BGaN) can be beneficial for the compound semiconductor device development. For instance, zero heterointerface polarization ΔP can be formed for BAlN and BGaN based heterojunctions with proper B compositions, potentially eliminating the quantum-confined Stark effect for c-plane optical devices and thus removing the need of non-polar layers and substrates. Besides, large heterointerface polarization ΔP is available that is desirable for electronic devices.

  6. Killing Effects of an Isolated Serratia marcescens KH-001 on Diaphorina citri via Lowering the Endosymbiont Numbers.

    Science.gov (United States)

    Hu, Wei; Kuang, Fan; Lu, Zhanjun; Zhang, Ning; Chen, Tingtao

    2018-01-01

    Huanglongbing (HLB) is the most devastating citrus disease worldwide, and suppression of the Asian citrus psyllid ( Diaphorina citri ) is regarded as an effective method to inhibit the spread of HLB. In this study, we isolated a strain named as Serratia marcescens KH-001 from D. citri nymphs suffering from disease, and evaluated its killing effect on D. citri via toxicity test and effect on microbial community in D. citri using high-throughput sequencing. Our results indicated that S. marcescens KH-001 could effectively kill 83% of D. citri nymphs, while the fermentation products of S. marcescens KH-001 only killed 40% of the D. citri nymphs. High-throughput sequencing results indicated that the S. marcescens KH-001 increased the OTU numbers from 62.5 (PBS buffer) to 81.5, while significantly lowered the Shannon index compared with Escherichia coli DH5α (group E) ( p citri endow S. marcescens KH-001 a sound killing effect on D. citri . Further work need to do before this strain is used as a sound biological control agents.

  7. Friction and wear behaviour of hypereutectic Al-Si alloy/steel tribopair under dry and lubricated conditions

    Directory of Open Access Journals (Sweden)

    Parveen Kumar

    2017-12-01

    Full Text Available Dry and lubricated sliding tribological tests on hypereutectic Al-25Si alloy was performed using a ball- on- disk configuration at room temperature. Hypereutectic Al-25Si alloy were prepared by rapid solidification process under T6 condition. Friction coefficient (COF and wear rate of the alloy were measured under different applied loads ranging from 5–100 N. It is found that the friction coefficient varies with load, first declines (from 5-50 N, then increases (from 50-80 N and then again decreases (80-100 N. The wear rate of the samples of hypereutectic Al-25Si alloy, first increases and then decreases with increasing the applied normal load. Hypereutectic Al-25Si alloy presents higher wear rate at 50 N due to the participation of a large amount of needle-like precipitates, but shows low wear rate under high load of 100 N because of the work hardening layer. Worn surface morphologies were analyzed using optical and scanning electron microscope (SEM coupled with an energy dispersive spectrometer (EDS. The improvements in COF and wear rate were mainly attributed to morphology, size and distribution of Si particles due to its fabrication process. The dominant wear mechanism for hypereutectic Al-25Si alloy was adhesive wear, abrasive wear and plastic deformation.

  8. Response of metallic glasses Fe40Ni40P14B6 and Fe80B20 to irradiation with 800-MeV protons

    International Nuclear Information System (INIS)

    Cost, J.R.; Sommer, W.F.

    1981-01-01

    Metallic glasses with compositions of Fe 40 Ni 40 P 14 B 6 and Fe 80 B 20 were irradiated in the 800 MeV proton beam at the Los Alamos Meson Physics Facility while the electrical resistance and length changes were monitored. The resistance and the length of the first alloy were both found to increase and saturate with dose to ΔR/R approx. = 5 x 10 -3 and ΔL/L approx. = 2 x 10 -3 . For the second alloy the total dose of 1.1 x 10 19 p/cm 2 , which was calculated to give roughly 0.12 dpa, was slightly less than that required for saturation. No annealing of these increases was observed for anneals from room temperature to 250 0 C. These results are interpreted in terms of a model in which collision cascades create small regions of increased atomic disorder which fully overlap each other at saturation

  9. Phase transformations in the rapidly solidified Ti{sub 40}Zr{sub 20}Hf{sub 20}Pd{sub 20} alloy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, N. [Division of Engineering Materials, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Yao Kefu [Division of Engineering Materials, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China)], E-mail: kfyao@tsinghua.edu.cn; Louzguine-Luzgin, D.V. [Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-Ku, Sendai 980-8577 (Japan); Qiu Shengbao [Division of Engineering Materials, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Ranganathan, S. [Department of Metallurgy, Indian Institute of Science, Bangalore 560 012 (India); Inoue, A. [Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-Ku, Sendai 980-8577 (Japan)

    2007-10-15

    We report that an approximant phase was initially obtained in amorphous Ti{sub 40}Zr{sub 20}Hf{sub 20}Pd{sub 20} alloy. In the initial stage of the devitrification process, the approximant phase transforms into an icosahedral (I) phase with a high thermal stability while the cF96 Zr{sub 2}Ni-type (space group Fd3-bar m with a=1.25nm and 96 atoms cell{sup -1}) particles precipitate from the amorphous matrix. Eventually the I phase grows to several hundred nanometers when annealed at about 1000K and then transforms into the Zr{sub 2}Ni-type phase with an endothermic reaction.

  10. The Historiography of Islamic Law: The Case of Tārīkh al-Tashrī‘ Literature

    Directory of Open Access Journals (Sweden)

    Arif Maftuhin

    2016-12-01

    Full Text Available Tārīkh al-Tashrī‘ (the history of sharia affairs is a relatively new genre of Islamic historiography and very popular among students of Islamic Law. Despite its popularity, academics of Islamic historiography seem not interested in studying it. There is hardly any academic paper seriously studied the literature. This paper is a first effort to explore the Tārīkhu’t-tashrī‘ literature through a historiographical analysis. As an initial exploration, it argues that Tārīkh al-Tashrī‘ is the latest development of Islamic historiography, developed in the 19th century, but it is a genre of the old Islamic historiography with some new elements. The new elements are influenced by both modern Western historiography and the need to re-open the supposedly closed gate of ijtihād. The paper studied books of Tārīkh al-Tashrī‘ available during the research between 2013-2015. [Tārīkh al-Tashrī‘ adalah genre yang relatif ‘baru’ dalam matarantai perkembangan historiografi Islam­. Literatur ini sangat popular dan menjadi mata kuliah wajib di fakultas-fakultas Syariah di Indonesia maupun Timur Tengah. Hanya saja, meskipun ia sangat populer sebagai mata pelajaran, Tārīkh al-Tashrī‘ belum banyak menarik minat para peneliti historiografi. Makalah in berusaha mengeksplorasi literatur Tārīkh al-Tashrī‘ dengan pendekatan historiografi. Makalah ini berpendapat bahwa Tārīkh al-Tashrī‘, meski terlihat ‘modern’ dari segi kelahirannya, tidak banyak berbeda dengan literatur historiografi klasik. Perbedaan terjadi karena adanya pengaruh historiografi Barat dalam model penulisannya dan karena kebutuhan untuk membuka kembali pintu ijtihad yang tertutup. Kajian dilakukan terhadap kitab-kitab Tārīkh al-Tashrī‘ yang dapat ditemukan selama riset antara 2013-2015 

  11. Fabrication of Si3N4 thin films on phynox alloy substrates for electronic applications

    Science.gov (United States)

    Shankernath, V.; Naidu, K. Lakshun; Krishna, M. Ghanashyam; Padmanabhan, K. A.

    2018-04-01

    Thin films of Si3N4 are deposited on Phynox alloy substrates using radio frequency magnetron sputtering. The thickness of the films was varied between 80-150 nm by increasing the duration of deposition from 1 to 3 h at a fixed power density and working pressure. X-ray diffraction patterns reveal that the Si3N4 films had crystallized inspite of the substrates not being heated during deposition. This was confirmed using selected area electron diffraction and high resolution transmission electron microscopy also. It is postulated that a low lattice misfit between Si3N4 and Phynox provides energetically favourable conditions for ambient temperature crystallization. The hardness of the films is of the order of 6 to 9 GPa.

  12. Wurtzite BAlN and BGaN alloys for heterointerface polarization engineering

    KAUST Repository

    Liu, Kaikai; Sun, Haiding; Alqatari, Feras; Guo, Wenzhe; Liu, Xinwei; Li, Jingtao; Torres Castanedo, Carlos G; Li, Xiaohang

    2017-01-01

    deformation and the dipole moment difference between the hexagonal and wurtzite structures. The PZ constants exhibit significant bowing because of the large lattice difference between binary alloys. Furthermore, the PZ constants of BxAl1-xN and BxGa1-xN become

  13. Study of uranium - 20 Wt per cent plutonium-niobium alloys (1963)

    International Nuclear Information System (INIS)

    Abgrall, J.; Barthelemy, P.; Boucher, R.

    1963-01-01

    U-Pu-Nb alloys containing 20 wt per cent Pu and 10 - 20 - 30 - 40 - 50 or 60 wt per cent Nb have been studied principally to determine the feasibility of their use as fuel element. The fabrication, casting and homogenisation presented certain difficulties due specially to niobium. The transformation temperatures, thermal expansion coefficients and nature of phases have been determined by thermal analysis, dilatometry, micrography and X Rays diffraction. For similar compositions, U-Pu-Mo and U-Pu-Nb alloys have many common points concerning the presence of zeta phase (up to 40 wt per cent Nb), the coefficients of expansion, the good behaviour during thermal cycling and the good resistance to air oxidation in spite of zeta phase. In consequence, irradiation tests in EL 3 reactor (Saclay) will be carried out in the near future. (authors) [fr

  14. Influence of structure and properties of tubular billets of the 12 Kh 18N10T steel on deformability of tubes at cold-rolling mills

    International Nuclear Information System (INIS)

    Vil'yams, O.S.; Bol'shova, N.M.; Olejnik, O.V.; Velikotnaya, E.S.

    1979-01-01

    Metallographic analysis of the defects of the ''oblique cracks'' type on the surface of hot-rolled tubes of the 12Kh18N10T steel has been carried out. Recommended is the complex of mechanical properties and the structure factors (grain size) of conversion hot-rolled tubes, providing the combination of ductility and high rapture strength during rolling at pilger mills. At a grain size not coarser than number 5, a billet must have σsub(T) 5 >=40 %. Hot-rolled coarse-grained billet is not recommended for warm rolng because of high strain hardening

  15. Irradiation and annealing behavior of 15Kh2MFA reactor pressure vessel steel

    International Nuclear Information System (INIS)

    Popp, K.; Bergmann, U.; Bergner, F.; Hampe, E.; Leonhardt, W.D.; Schuetzler, H.P.; Viehrig, H.W.

    1992-01-01

    This work deals with the mechanical properties of RPV steels used WWER-440. The materials under investigation were a forging (base metal 15Kh2MFA) and the corresponding weld. Charpy V-notch specimens and tensile test specimens were irradiated in the WWER-2 Rheinsberg at about 270 C up to the two neutron fluence levels of 4 x 10 18 and 5 x 10 19 n/cm 2 (E>1MeV). Post-irradiation annealing heat treatments were performed, among others a 475 C/152 h treatment of technical interest. (orig.)

  16. Impact of sulfur content on structural and optical properties of Ge20Se80-xSx chalcogenide glasses thin films

    Science.gov (United States)

    Dongol, M.; Elhady, A. F.; Ebied, M. S.; Abuelwafa, A. A.

    2018-04-01

    Chalcogenide system Ge20Se80-xSx (x = 0, 15 and 30%) thin films were prepared by thermal evaporation technique. The amorphous state of the samples was confirmed according to XRD. The structural changes occurring upon replacement Se by S was investigated using Raman spectroscopy. The optical properties of the as-deposited Ge20Se80-xSx thin films have been studied by analysis the transmittance T(λ) measured at room temperature in the wavelength range 200-2500 nm using Swanepoel's method. Urbach energy (Ee) and optical band gap (Eg) were strongly affected by sulfur concentration in the sample. The refractive index evaluated through envelope method was extrapolated by Cauchy dispersion relationship over the whole spectral range. Moreover, the dispersion of refractive index was analyzed in terms of the single-oscillator Wemple-Di Domenico model. The third-order nonlinear susceptibility (χ(3)) and nonlinear refractive index (n2) were calculated and discussed for different Ge20Se80-xSx (x = 0, 15 and 30%).

  17. Effect of Sn additive on the structure and crystallization kinetics in Ge–Se alloy

    Energy Technology Data Exchange (ETDEWEB)

    Abd-Elrahman, M.I., E-mail: mostafaia11@yahoo.com; Hafiz, M.M.; Abdelraheem, A.M.; Abu-Sehly, A.A.

    2016-08-05

    The structure of Ge{sub 20}Se{sub 80−x}Snx glassy alloys and crystallization phases are identified using the X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). The glass transition kinetics and the crystallization mechanism of the system are studied using Differential Scanning Calorimeter (DSC) under non-isothermal condition. The results reveal that glass transition temperature (Tg) increases with increasing Sn content which is attributed to the increase in the coordination number. The increase of the glass transition activation energy (Eg) with increasing Sn content is attributed to the decrease in the internal energy of the system as Sn increases. The compositional dependence of both glass forming ability and thermal stability are studied. From the experimental data, the thermal stability parameter (S) is found to be maximum for Ge{sub 20}Se{sub 78}Sn{sub 2} alloy, which indicates that this alloy is thermally more stable in the composition range under investigation. The effect of composition on the crystallization mechanism is discussed using different kinetic models. The crystallization activation energy (Ec) decreases with increasing Sn. This is attributed to the addition of Sn increases the tendency of crystallization. The calculated values of Avrami exponent (n) indicates the crystallization process occurs in one-and two dimensions for Sn is less than or equals 12 at%, respectively. - Highlights: • Glass and crystallization transitions in Ge{sub 20}Se{sub 80−x}Sn{sub x} candidate for devices. • The addition of Sn increases the tendency of Ge-Se alloy to crystallization. • The glass forming ability and thermal stability increase as Sn decreases. • The dimension of the crystals growth is one or two depending on the Sn content.

  18. Structure and properties of large-sized forged disk of alloy type KhN73MBTYu-VD(EhI 698-VD)

    International Nuclear Information System (INIS)

    Sudakov, V.S.

    1994-01-01

    Investigation results are presented for structure and mechanical properties of serial large-sized forged disk 1100 mm in diameter produced of alloy type EhI 9698-VD hand tested after standard heat treatment and isothermal ageing at operating temperature. Chemical composition studies have revealed no macroheterogeneity. In a central cross-section macrostructure is free of pores, inclusions, delaminating and variation in grain size. The metal of the disk possesses high values of long-term rupture strength and creep resistance at 650-700 deg C

  19. Investigation of processing effects on the corrosion resistance of Ti20Mo alloy in saline solutions

    International Nuclear Information System (INIS)

    Bolat, G.; Izquierdo, J.; Gloriant, T.; Chelariu, R.; Mareci, D.; Souto, R.M.

    2015-01-01

    Graphical abstract: - Highlights: • Alloy fabrication method affects both surface finish and corrosion resistance. • More porous surface finish and higher wettability produced by powder sintering. • Passive layer formed on sintered alloy breaks down in saline solution. • Increase in surface porosity facilitated electron transfer through the oxide film. • More corrosion resistant alloy produced by cold crucible levitation melting. - Abstract: The electrochemical properties of Ti20Mo alloys prepared using different fabrication procedures, namely cold crucible levitation melting (CCLM) and powder sintering, were investigated using linear potentiodynamic polarization and EIS measurements. The surface condition was established using AFM, with the observation of a more porous surface finish in the case of powder sintering. A major effect of surface conditioning on the corrosion resistance of Ti20Mo alloys was observed, where the compact finish exhibits a superior corrosion resistance in chloride-containing saline solutions. Less insulating surfaces towards electron exchange resulted for the more porous finish as revealed by scanning electrochemical microscopy (SECM)

  20. Biomineralisation with Saos-2 bone cells on TiSiN sputtered Ti alloys.

    Science.gov (United States)

    V V, Anusha Thampi; Bendavid, Avi; Martin, P J; Vaithilingam, Vijay; Bean, Penelope A; Evans, Margaret D M; Subramanian, B

    2017-07-01

    Surface modifications of metallic implants are important in order to protect the underlying metals from the harsh corrosive environment inside the human body and to minimize the losses caused by wear. Recently, researches are carried out in developing bioactive surfaces on metallic implants, which supports the growth and proliferation of cells on to these surfaces. Titanium silicon nitride (TiSiN) hard nanocomposites thin films were fabricated on Ti alloys (Ti-6Al-4V) by pulsed direct current (DC) reactive magnetron sputtering. The films were characterized for its microstructural and electrochemical behavior. The higher charge transfer resistance (Rct) and positive shift in Ecorr value of TiSiN/Ti alloys than the bare Ti-alloys indicates a better corrosion resistance offered by the TiSiN thin films to the underlying substrates. The biological response to TiSiN/Ti alloys and control bare Ti-alloys was measured in vitro using cell-based assays with two main outcomes. Firstly, neither the Ti alloy nor the TiSiN thin film was cytotoxic to cells. Secondly, the TiSiN thin film promoted differentiation of human bone cells above the bare control Ti alloy as measured by alkaline phosphatase and calcium production. TiSiN thin films provide better corrosion resistance and protect the underlying metal from the corrosive environment. The thin film surface is both biocompatible and bioactive as indicated from the cytotoxicity and biomineralization studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Corrosion of steels in molten gallium (Ga), tin (Sn) and tin lithium alloy (Sn–20Li)

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Masatoshi, E-mail: kondo.masatoshi@nr.titech.ac.jp [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8550 (Japan); Ishii, Masaomi [Department of Nuclear Engineering, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka-shi, Kanagawa 259-1292 (Japan); Muroga, Takeo [Department of Helical Plasma Research, National Institute for Fusion Science, Toki, Gifu 502-5292 (Japan)

    2015-10-15

    Graphical abstract: Corrosion of RAFM steel, JLF-1, in liquid Sn–20Li was caused by the formation of Fe-Sn alloyed layer. - Highlights: • The corrosion tests were performed for the reduced activation ferritic martensitic steel JLF-1 and the austenitic steel SUS316 in liquid Ga, Sn and Sn-20Li at 873 K up to 750 h. • The weight loss of the specimens exposed to liquid Ga, Sn and Sn-20Li was evaluated. • The corrosion of the steels in liquid Ga was caused by the alloying reaction between Ga and Fe on the steel surface. • The corrosion of the steels in liquid Sn was caused by the alloying reaction between Sn and Fe on the steel surface. • The corrosion of the steels in liquid Sn-20Li was caused by the formation of the Fe-Sn alloyed layer and the diffusion of Sn and Li into the steel matrix. - Abstract: The compatibility of steels in liquid gallium (Ga), tin (Sn) and tin lithium alloy (Sn–20Li) was investigated by means of static corrosion tests. The corrosion tests were performed for reduced activation ferritic martensitic steel JLF-1 (JOYO-HEAT, Fe–9Cr–2W–0.1C) and austenitic steel SUS316 (Fe–18Cr–12Ni–2Mo). The test temperature was 873 K, and the exposure time was 250 and 750 h. The corrosion of these steels in liquid Ga, Sn and Sn–20Li alloy was commonly caused by the formation of a reaction layer and the dissolution of the steel elements into the melts. The reaction layer formed in liquid Ga was identified as Fe{sub 3}Ga from the results of metallurgical analysis and the phase diagram. The growth rate of the reaction layer on the JLF-1 steel showed a parabolic rate law, and this trend indicated that the corrosion could be controlled by the diffusion process through the layer. The reaction layer formed in liquid Sn and Sn–20Li was identified as FeSn. The growth rate had a linear function with exposure time. The corrosion in Sn and Sn–20Li could be controlled by the interface reaction on the layer. The growth rate of the layer formed

  2. Corrosion of steels in molten gallium (Ga), tin (Sn) and tin lithium alloy (Sn–20Li)

    International Nuclear Information System (INIS)

    Kondo, Masatoshi; Ishii, Masaomi; Muroga, Takeo

    2015-01-01

    Graphical abstract: Corrosion of RAFM steel, JLF-1, in liquid Sn–20Li was caused by the formation of Fe-Sn alloyed layer. - Highlights: • The corrosion tests were performed for the reduced activation ferritic martensitic steel JLF-1 and the austenitic steel SUS316 in liquid Ga, Sn and Sn-20Li at 873 K up to 750 h. • The weight loss of the specimens exposed to liquid Ga, Sn and Sn-20Li was evaluated. • The corrosion of the steels in liquid Ga was caused by the alloying reaction between Ga and Fe on the steel surface. • The corrosion of the steels in liquid Sn was caused by the alloying reaction between Sn and Fe on the steel surface. • The corrosion of the steels in liquid Sn-20Li was caused by the formation of the Fe-Sn alloyed layer and the diffusion of Sn and Li into the steel matrix. - Abstract: The compatibility of steels in liquid gallium (Ga), tin (Sn) and tin lithium alloy (Sn–20Li) was investigated by means of static corrosion tests. The corrosion tests were performed for reduced activation ferritic martensitic steel JLF-1 (JOYO-HEAT, Fe–9Cr–2W–0.1C) and austenitic steel SUS316 (Fe–18Cr–12Ni–2Mo). The test temperature was 873 K, and the exposure time was 250 and 750 h. The corrosion of these steels in liquid Ga, Sn and Sn–20Li alloy was commonly caused by the formation of a reaction layer and the dissolution of the steel elements into the melts. The reaction layer formed in liquid Ga was identified as Fe 3 Ga from the results of metallurgical analysis and the phase diagram. The growth rate of the reaction layer on the JLF-1 steel showed a parabolic rate law, and this trend indicated that the corrosion could be controlled by the diffusion process through the layer. The reaction layer formed in liquid Sn and Sn–20Li was identified as FeSn. The growth rate had a linear function with exposure time. The corrosion in Sn and Sn–20Li could be controlled by the interface reaction on the layer. The growth rate of the layer formed in

  3. Specific electrical conductivity in molten potassium dihydrogen phosphate KH2PO4 - An electrolyte for water electrolysis at ∼300°C

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey Valerievich; Berg, Rolf W.; Petrushina, Irina

    2016-01-01

    The conductivity of pure molten KH2PO4 salt and four mixtures with more or less water (KH2PO4-H2O and KH2PO4-KPO3 systems, respectively) were measured at temperatures of 240-320°C and under their own water vapor pressures. Molten KH2PO4 has been proven to be a promising electrolyte for an elevated...

  4. Enhancement of wear and corrosion resistance of low modulus β-type Zr-20Nb-xTi (x=0, 3) dental alloys through thermal oxidation treatment.

    Science.gov (United States)

    Zhang, Jianfeng; Gan, Xiaxia; Tang, Hongqun; Zhan, Yongzhong

    2017-07-01

    In order to obtain material with low elastic modulus, good abrasion resistance and high corrosion stability as screw for dental implant, the biomedical Zr-20Nb and Zr-20Nb-3Ti alloy with low elastic modulus were thermal oxidized respectively at 700°C for 1h and 600°C for 1.25h to obtain the compact oxidized layer to improve its wear resistance and corrosion resistance. The results show that smooth compact oxidized layer (composed of monoclinic ZrO 2 , tetragonal ZrO 2 and 6ZrO 2 -Nb 2 O 5 ) with 22.6μm-43.5μm thickness and 1252-1306HV hardness can be in-situ formed on the surface of the Zr-20Nb-xTi (x=0, 3). The adhesion of oxidized layers to the substrates is determined to be 58.35-66.25N. The oxidized Zr-20Nb-xTi alloys reveal great improvement of the pitting corrosion resistance in comparison with the un-oxidized alloys. In addition, the oxidized Zr-20Nb-3Ti exhibits sharply reduction of the corrosion rates and the oxidized Zr-20Nb shows higher corrosion rates than un-oxidized alloys, which is relevant with the content of the t-ZrO 2 . Wear test in artificial saliva demonstrates that the wear losses of the oxidized Zr-20Nb-xTi (x=0, 3) are superior to pure Ti. All of the un-oxidized Zr-20Nb-xTi (x=0, 3) alloys suffer from serious adhesive wear due to its high plasticity. Because of the protection from compact oxide layer with high adhesion and high hardness, the coefficients of friction and wear losses of the oxidized Zr-20Nb-xTi (x=0, 3) alloys decrease 50% and 95%, respectively. The defects on the oxidized Zr-20Nb have a negative effect on the friction and wear properties. In addition, after the thermal oxidation, compression test show that elastic modulus and strength of Zr-20Nb-xTi (x=0, 3) increase slightly with plastic deformation after 40% of transformation. Furthermore, stripping of the oxidized layer from the alloy matrix did not occur during the whole experiments. As the surface oxidized Zr-20Nb-3Ti alloy has a combination of excellent performance

  5. Correlation between the resistivity and the atomic clusters in liquid Cu-Sn alloys

    Science.gov (United States)

    Jia, Peng; Zhang, Jinyang; Hu, Xun; Li, Cancan; Zhao, Degang; Teng, XinYing; Yang, Cheng

    2018-05-01

    The liquid structure of CuxSn100-x (x = 0, 10, 20, 33, 40, 50, 60, 75, 80 and 100) alloys with atom percentage were investigated with resistivity and viscosity methods. It can be found from the resistivity data that the liquid Cu75Sn25 and Cu80Sn20 alloys had a negative temperature coefficient of resistivity (TCR), and liquid Cu75Sn25 alloy had a minimum value of -9.24 μΩ cm K-1. While the rest of liquid Cu-Sn alloys had a positive TCR. The results indicated that the Cu75Sn25 atomic clusters existed in Cu-Sn alloys. In addition, the method of calculating the percentage of Cu75Sn25 atomic clusters was established on the basis of resistivity theory and the law of conservation of mass. The Cu75Sn25 alloy had a maximum volume of the atomic clusters and a highest activation energy. The results further proved the existence of Cu75Sn25 atomic clusters. Furthermore, the correlation between the liquid structure and the resistivity was established. These results provide a useful reference for the investigation of liquid structure via the sensitive physical properties to the liquid structure.

  6. Structure, mechanical and corrosion properties of powdered stainless steel Kh13

    International Nuclear Information System (INIS)

    Radomysel'skij, I.D.; Napara-Volgina, S.G.; Orlova, L.N.; Apininskaya, L.M.

    1982-01-01

    Structure, mechanical and corrosion properties are studied for compact powdered stainless steel, Grade Kh13, produced from prealloyed powder and a mixture of chromium and iron powders by hot vacuum pressing (HVP) following four schemes: HVP of unsintered billets; HVP of presintered billets; HVP of unsintered billets followed by diffusion annealing; HVP of sintered billets followed by diffusion annealing. Analysis of the structure, mechanical and corrosion properties of Kh13 steel produced according to the four schemes confirmed that production of this steel by the HVP method without presintering of porous billets and diffusion annealing of compact stampings is possible only when prealloyed powder of particular composition is used as a starting material

  7. Pipes out of the chromium-molybdenum 12Kh2M1 steel intended for power units

    International Nuclear Information System (INIS)

    Saf'yanov, A.V.; Plyatskovskij, O.A.; Khokhlov-Nekrasov, O.G.; Palatnikova, E.S.; Karpenko, N.P.

    1977-01-01

    Vanadiumless steel 12Kh2M1 (2.25%Cr, 1%Mo) known to be applied abroad has been used for production of 325x60 mm tubes. The technology involves heating of the blanks to 1270-1300 deg C, their piercing in a double-roller mill, rolling on a pilger mill 8-16'' in thick wall caliber rolls, thermal treatment (normalizing at 930-960 deg C for 1 hour and tempering at 730+-10 deg C for 4 hours and etching (12-22% H 2 SO 4 and up to 143 g/l FeSO 4 ) for 3-4 hours at 55-65 deg C. Good technological properties of the steel and its capacity of working at 540-580 deg C are confirmed. Vanadium alloying of boiler steels does not provide for essential improvement of oxydation resistance and long term strength, but decreases the workability and enhances scatter of working parameters on account of minor variations of chemical composition

  8. 47 CFR 80.205 - Bandwidths.

    Science.gov (United States)

    2010-10-01

    ... frequency deviation for F3E or G3E emission is as follows: (1) 5 kHz in the 72.0-73.0 MHz, 75.4-76.0 MHz and... 12 16K0A2D 20.0 A3E 6K00A3E 8.0 A3N 2 2K66A3N 2.8 A3X 3 3K20A3X 25.0 F1B 4 280HF1B 0.3 F1B 5 300HF1B 0.5 F1B 6 16KOF1B 20.0 F1C 2K80F1C 3.0 F1D 12 16K0F1D 20.0 F2B 6 16KOF2B 20.0 F2C 7 16KOF2C 20.0 F2D...

  9. Welding of heterogeneous 12Kh2MFSR steels with the Mn-Cr-Si-Ni system

    International Nuclear Information System (INIS)

    Smirnov, A.N.; Belogolov, E.I.

    1978-01-01

    The process of welding pipes of the 12Kh2MFSR pearlitic steels and austenitic steels of the Mn-Cr-Si-Ni system was studied. The filler materials were selected, and the working capacity of welded joints was examined in ageing and cyclic heatings. The microhardness of steels was measured, and the ultimate strength of welded joints was determined. The following has been established: the composite joints of steels of the Mn-Cr-Si-Ni system and 12Kh2MFSR steel are advisable to be welded on a coating layer welded by the EhA395/9 electrodes on the surface of a pipe of the 12Kh2MFSR pearlitic steel; this guarantees the sufficient working capacity of welded joints

  10. A graded nano-TiN coating on biomedical Ti alloy: Low friction coefficient, good bonding and biocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Wenfang [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819 (China); Qin, Gaowu, E-mail: qingw@smm.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819 (China); Duan, Jingzhu; Wang, Huan [Spinal surgery, Shengjing Hospital, China Medical University, Shenyang 110004 (China)

    2017-02-01

    In order to solve wear resistance of Ti alloy biomaterials, the concept of a graded nano-TiN coating has been proposed. The coating was prepared on Ti-6Al-4V bio-alloy by DC reactive magnetron sputtering. The wear performance of the coated specimens was measured in Hank's solution under the load of 10 N, and the biocompatibility was evaluated according to ISO-10993-4 standard. The results show that the gradient coating exhibits a gradual change in compositions and microstructures along the direction of film growth. Nano-TiN with the size of several to dozens nanometers and Ti{sub 4}N{sub 3−x} transitional phase with variable composition form a graded composite structure, which significantly improves adhesion strength (L{sub c1} = 80 N, L{sub c2} = 120 N), hardness (21 GPa) and anti-wear performance (6.2 × 10{sup −7} mm{sup 3}/Nm). The excellent bonding and wear resistance result from a good match of mechanical properties at substrate/coating interface and the strengthening and toughening effects of the nanocrystalline composite. The nano-TiN coating has also been proved to have good biocompatibility through in-vitro cytotoxicity, hemocompatibility and general toxicity tests. And thus, the proposed graded nano-TiN coating is a good candidate improving wear resistance of many implant medical devices. - Highlights: • A graded nano-TiN coating was prepared on biomedical Ti alloy by PVD. • The combination of hard and soft phase increases hardness and toughness. • The coating exhibits high bonding, low coefficient of friction and wear rate. • The new coating has good bio-safety and great clinical application prospect.

  11. Effect of Ce addition on microstructure of Al20Cu2Mn3 twin phase in an Al–Cu–Mn casting alloy

    International Nuclear Information System (INIS)

    Chen Zhongwei; Chen Pei; Li Shishun

    2012-01-01

    Highlights: ► Rare earth element Ce can retard the formation of the Al 20 Cu 2 Mn 3 twin phase in an Al–Cu–Mn casting alloy. ► Patterns of the particles of the Al 20 Cu 2 Mn 3 phase in Al–Cu–Mn free Ce alloy are more diverse. ► The symmetry of neighboring components of twins is characterized by glide reflection and reflection. ► The twins of Al 20 Cu 2 Mn 3 phase can enhance the mechanical properties of the Al–Cu–Mn casting alloys. - Abstract: Effects of Ce addition on microstructure of Al 20 Cu 2 Mn 3 twin phase and mechanical properties of an Al–Cu–Mn casting alloy were investigated by transmission electron microscopy, selected area electron diffraction, high resolution transmission electron microscopy and tensile test. The results show that rare earth element Ce can retard the formation of the Al 20 Cu 2 Mn 3 phase in the Al–Cu–Mn alloy. Compared with the Ce containing alloy, patterns of particles of the Al 20 Cu 2 Mn 3 phase in the Al–Cu–Mn free Ce alloy are more diverse. The symmetry of neighboring components of twins is characterized by glide reflection and reflection. In addition, twins of the Al 20 Cu 2 Mn 3 phase can enhance the mechanical properties of the Al–Cu–Mn alloy.

  12. Effect of metal properties of casts of steel-15Kh1M1FL on the crack resistance at 565 deg C

    International Nuclear Information System (INIS)

    Gladshtejn, V.I.; Sheshenev, M.F.

    1976-01-01

    Results are given of prolonged tests of the metal of industrial casts with various fluidity limits. It has been shown experimentally that a quite satisfactory crack resistance is characteristic of a metal with a fluidity limit in the range 30-50 kgf/mm 2 . Metallographic studies have been conducted. Upon variation of the structure and properties of the 15Kh1M1FL steel during operation, the rate of growth of small cracks (up to 2.0 mm) decreases almost by 3 orders of ten (from 1.4x10 -4 to 2.0x10 -7 mm/hour). Subsequent structural changes during prolonged operation (over 50000 hours) result in a gradual increase in the rate of crack growth. At the same time resistance towards appearance of the impermissible high rate of the crack growth, Ksub(10sup(-3)), diminishes monotonically with the operation time. The metal of industrial 15Kh1M1FL steel casts has good crack resistance (Ksub(10sup(-3)) =30-70 kgf/mmsup(3/2) and Vsub(ef) =) kgf/mm 2 ) and a satisfactory local plasticity (critical opening being no more than 0.20 mm for 10 3 hours)

  13. A graded nano-TiN coating on biomedical Ti alloy: Low friction coefficient, good bonding and biocompatibility.

    Science.gov (United States)

    Cui, Wenfang; Qin, Gaowu; Duan, Jingzhu; Wang, Huan

    2017-02-01

    In order to solve wear resistance of Ti alloy biomaterials, the concept of a graded nano-TiN coating has been proposed. The coating was prepared on Ti-6Al-4V bio-alloy by DC reactive magnetron sputtering. The wear performance of the coated specimens was measured in Hank's solution under the load of 10N, and the biocompatibility was evaluated according to ISO-10993-4 standard. The results show that the gradient coating exhibits a gradual change in compositions and microstructures along the direction of film growth. Nano-TiN with the size of several to dozens nanometers and Ti 4 N 3-x transitional phase with variable composition form a graded composite structure, which significantly improves adhesion strength (L c1 =80N, L c2 =120N), hardness (21GPa) and anti-wear performance (6.2×10 -7 mm 3 /Nm). The excellent bonding and wear resistance result from a good match of mechanical properties at substrate/coating interface and the strengthening and toughening effects of the nanocrystalline composite. The nano-TiN coating has also been proved to have good biocompatibility through in-vitro cytotoxicity, hemocompatibility and general toxicity tests. And thus, the proposed graded nano-TiN coating is a good candidate improving wear resistance of many implant medical devices. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Application of experiment planning during investigation of cementation process in solid carburizers

    International Nuclear Information System (INIS)

    Lisenkov, A.N.; Denisov, V.M.; Prigozhina, E.L.

    1981-01-01

    A mathematical model of cementation process in solid carburizirs is obtained, the most effective contents of carburizers are chosen. Specimens are produced out of St20, 12KhN3A, 40Kh13, KhVG steels. It is shown that specimens of St20 and 12KhN3A steels have the higher depth of cementated layer, specimens made of 40Kh13 and KhVG steels-the lower depth. It is shown that the quality of cementated layer structure at recommended regimes improved, cementated layer depth for low-carbon steels changed a little and for tool steels increased infficiently: for KhVG steel in 2-3 times for 40Kh13 steel in 1.5-2.5 times

  15. Experimental evidences for reducing Mg activation energy in high Al-content AlGaN alloy by MgGa δ doping in (AlN)m/(GaN)n superlattice

    OpenAIRE

    Xiao Wang; Wei Wang; Jingli Wang; Hao Wu; Chang Liu

    2017-01-01

    P-type doping in high Al-content AlGaN alloys is a main challenge for realizing AlGaN-based deep ultraviolet optoelectronics devices. According to the first-principles calculations, Mg activation energy may be reduced so that a high hole concentration can be obtained by introducing nanoscale (AlN)5/(GaN)1 superlattice (SL) in Al0.83Ga0.17N disorder alloy. In this work, experimental evidences were achieved by analyzing Mg doped high Al-content AlGaN alloys and Mg doped AlGaN SLs as well as MgG...

  16. On the hypothesis of agressive environment effect evaluation on the cyclic cracking resistance in metals and alloys

    International Nuclear Information System (INIS)

    Romaniv, O.N.; Gladkij, Ya.N.; Nikiforchin, G.N.

    1978-01-01

    Experimental data on studying static and cyclic cracking resistances of steels in water and inert gaseous media are given. Presented are experimental values of threshold coefficients of stress intensities for a series of the systems: metal (the 4340 steel of the 45KhN2MFA type, 12Ni-5Cr-3Mo steel, 9Ni-4Co-0.25C steel and others)-medium. On the base of the above data analysis and representations on the mechanism of crack growth under conditions of permanent and variable load effects the conclusion is drawn on the groundlessness of the hypothesis of contribution superposition resulted from pure fatigue and corrosion-static factors when estimating cracking resistance of metals and alloys

  17. Electrochemical behavior of hydroxyapatite/TiN multi-layer coatings on Ti alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Ju [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University (Korea, Republic of); Jeong, Yong-Hoon [Biomechanics and Tissue Engineering Laboratory, Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University (Korea, Republic of); Brantley, William A. [Division of Restorative Science and Prosthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States)

    2014-12-01

    The electrochemical behavior of hydroxyapatite (HA) and titanium nitride (TiN) multi-layer coatings on Ti–Nb–Zr alloys was investigated by a variety of surface analytical methods. The HA/TiN layers were deposited using a magnetron sputtering system. The HA target was made of human tooth-ash sintered at 1300 °C for 1 h and had an average Ca/P ratio of 1.9. From X-ray diffraction patterns, the Ti–29Nb–5Zr alloy was composed entirely of equiaxed β-phase exhibiting the principal (110) reflection, and the coating exhibited the (111) and (200) reflections for TiN and the (112) and (202) reflections for HA. At the coating surface the HA films consisted of granular particles, and the surface roughness was 4.22 nm. The thickness of the coating layers increased in the order of HA/TiN (lowest), TiN, and HA (highest). Potentiodynamic polarization measurements revealed that the corrosion current density was the lowest, and the corrosion potential and polarization resistance the highest, when the Ti–29Nb–5Zr surface was covered by the HA/TiN film, compared to solely HA or TiN films. - Highlights: • HA/TiN films were deposited by magnetron sputtering on a Ti–29Nb–5Zr biomedical alloy. • The corrosion current density for the HA/TiN films was lower than that of the non-coated alloy. • The polarization resistance of the HA/TiN films was higher than that of the non-coated alloy.

  18. Electrochemical behavior of hydroxyapatite/TiN multi-layer coatings on Ti alloys

    International Nuclear Information System (INIS)

    Kim, Eun-Ju; Jeong, Yong-Hoon; Choe, Han-Cheol; Brantley, William A.

    2014-01-01

    The electrochemical behavior of hydroxyapatite (HA) and titanium nitride (TiN) multi-layer coatings on Ti–Nb–Zr alloys was investigated by a variety of surface analytical methods. The HA/TiN layers were deposited using a magnetron sputtering system. The HA target was made of human tooth-ash sintered at 1300 °C for 1 h and had an average Ca/P ratio of 1.9. From X-ray diffraction patterns, the Ti–29Nb–5Zr alloy was composed entirely of equiaxed β-phase exhibiting the principal (110) reflection, and the coating exhibited the (111) and (200) reflections for TiN and the (112) and (202) reflections for HA. At the coating surface the HA films consisted of granular particles, and the surface roughness was 4.22 nm. The thickness of the coating layers increased in the order of HA/TiN (lowest), TiN, and HA (highest). Potentiodynamic polarization measurements revealed that the corrosion current density was the lowest, and the corrosion potential and polarization resistance the highest, when the Ti–29Nb–5Zr surface was covered by the HA/TiN film, compared to solely HA or TiN films. - Highlights: • HA/TiN films were deposited by magnetron sputtering on a Ti–29Nb–5Zr biomedical alloy. • The corrosion current density for the HA/TiN films was lower than that of the non-coated alloy. • The polarization resistance of the HA/TiN films was higher than that of the non-coated alloy

  19. KOMPARASI PENDIDIKAN ISLAM K.H. AHMAD DAHLAN DAN MUHAMMAD FETHULLAH GÜLEN

    Directory of Open Access Journals (Sweden)

    Mohamad Ali

    2016-05-01

    Full Text Available Islamic education is considered only oriented to the hereafter alone, teach rituals and develop a defensive posture and formisme paradigm. On the other hand, Islamic education is faced with the phenomenon of discontinuity which marked the waning value of respect for the basic values and ethics, such as honesty, discipline, tolerance. This Problem is what ignited K.H. Ahmad Dahlan (1868-1923 and Muhammad Fethullah Gülen (1838 - ... strengthening Islamic education. This study aims to understand the concepts, practices, and comparative Islamic education K.H. Ahmad Dahlan and Muhammad Fethullah Gülen. This type of research is the study of literature  with historical and philosophical approach. The results show: first, the concept of Islamic education K.H. Ahmad Dahlan stressed intregration of religious sciences and the modern sciences, tolerance, open to modernity and perfection of mind (intellect; for Fethullah Gülen education is a manifestation of Allah, which emphasizes ethics, science, and theology. Secondly, the common the sharing concept between the two are at: ideas, foundation, educational goals and teaching methods. Third, while the point of difference lies in the educational materials, dormitory educational models (boarding school and implementing a system of moving class.

  20. Changes in phase composition and stress state of surface layers of VK20 hard alloy after ion bombardment

    International Nuclear Information System (INIS)

    Platonov, G.L.; Leonov, E.Yu.; Anikin, V.N.; Anikeev, A.I.

    1988-01-01

    Titanium ion bombardment of the surface of the hard VK20 alloy is studied for its effect on variations in the phase and chemical composition of its surface layers. It is stated that ion treatment results in the appearance of the η-phase of Co 6 W 6 C composition in the surface layer of the VK20 alloy, in the increase of distortions and decrease of coherent scattering blocks of the hard alloy carbide phase. Such a bombardment is found to provoke a transition of the plane-stressed state of the hard alloy surface into the volume-stressed state. It is established that ion treatment does not cause an allotropic transition of the cobalt phase α-modification, formed during grinding of the hard alloy, into the β-modification

  1. Defect production by fast neutrons and thermal recovery in amorphous Pd80Si20

    International Nuclear Information System (INIS)

    Schumacher, G.; Petry, W.; Klaumuenzer, S.; Wallner, G.; Weck, G.

    1985-01-01

    Defects were introduced into variously pretreated strips of glassy Pd 80 Si 20 by fast neutron irradiation at 4.6 K 2 . The electrical resistivity was measured during irradiation up to 2.10 19 n/cm 2 as well as subsequent isochronal annealing up to 483 K. Most of the results can be understood in terms of the familiar concept of vacancy and interstitial-like defects. However, in addition to the well-known process of mutual annihilation an important mechanism for defect relaxation is the disintegration of localized defects into subatomic ones which are distributed among many atoms

  2. Effect of alloying on elastic properties of ZrN based transition metal nitride alloys

    KAUST Repository

    Kanoun, Mohammed; Goumri-Said, Souraya

    2014-01-01

    We report the effect of composition and metal sublattice substitutional element on the structural, elastic and electronic properties of ternary transition metal nitrides Zr1-xMxN with M=Al, Ti, Hf, V, Nb, W and Mo. The analysis of the elastic constants, bulk modulus, shear modulus, Young's modulus, and Poisson's ratio provides insights regarding the mechanical behavior of Zr1-xMxN. We predict that ternary alloys are more ductile compared to their parent binary compounds. The revealed trend in the mechanical behavior might help for experimentalists on the ability of tuning the mechanical properties during the alloying process by varying the concentration of the transition metal. © 2014 Elsevier B.V.

  3. Effect of alloying on elastic properties of ZrN based transition metal nitride alloys

    KAUST Repository

    Kanoun, Mohammed

    2014-09-01

    We report the effect of composition and metal sublattice substitutional element on the structural, elastic and electronic properties of ternary transition metal nitrides Zr1-xMxN with M=Al, Ti, Hf, V, Nb, W and Mo. The analysis of the elastic constants, bulk modulus, shear modulus, Young\\'s modulus, and Poisson\\'s ratio provides insights regarding the mechanical behavior of Zr1-xMxN. We predict that ternary alloys are more ductile compared to their parent binary compounds. The revealed trend in the mechanical behavior might help for experimentalists on the ability of tuning the mechanical properties during the alloying process by varying the concentration of the transition metal. © 2014 Elsevier B.V.

  4. Experimental evidences for reducing Mg activation energy in high Al-content AlGaN alloy by MgGa δ doping in (AlN)m/(GaN)n superlattice

    Science.gov (United States)

    Wang, Xiao; Wang, Wei; Wang, Jingli; Wu, Hao; Liu, Chang

    2017-03-01

    P-type doping in high Al-content AlGaN alloys is a main challenge for realizing AlGaN-based deep ultraviolet optoelectronics devices. According to the first-principles calculations, Mg activation energy may be reduced so that a high hole concentration can be obtained by introducing nanoscale (AlN)5/(GaN)1 superlattice (SL) in Al0.83Ga0.17N disorder alloy. In this work, experimental evidences were achieved by analyzing Mg doped high Al-content AlGaN alloys and Mg doped AlGaN SLs as well as MgGa δ doped AlGaN SLs. Mg acceptor activation energy was significantly reduced from 0.378 to 0.331 eV by using MgGa δ doping in SLs instead of traditional doping in alloys. This new process was confirmed to be able to realize high p-type doping in high Al-content AlGaN.

  5. Intergranular tellurium cracking of nickel-based alloys in molten Li, Be, Th, U/F salt mixture

    Science.gov (United States)

    Ignatiev, Victor; Surenkov, Alexander; Gnidoy, Ivan; Kulakov, Alexander; Uglov, Vadim; Vasiliev, Alexander; Presniakov, Mikhail

    2013-09-01

    In Russia, R&D on Molten Salt Reactor (MSR) are concentrated now on fast/intermediate spectrum concepts which were recognized as long term alternative to solid fueled fast reactors due to their attractive features: strong negative feedback coefficients, easy in-service inspection, and simplified fuel cycle. For high-temperature MSR corrosion of the metallic container alloy in primary circuit is the primary concern. Key problem receiving current attention include surface fissures in Ni-based alloys probably arising from fission product tellurium attack. This paper summarizes results of corrosion tests conducted recently to study effect of oxidation state in selected fuel salt on tellurium attack and to develop means of controlling tellurium cracking in the special Ni-based alloys recently developed for molten salt actinide recycler and tranforming (MOSART) system. Tellurium corrosion of Ni-based alloys was tested at temperatures up to 750 °C in stressed and unloaded conditions in molten LiF-BeF2 salt mixture fueled by about 20 mol% of ThF4 and 2 mol% of UF4 at different [U(IV)]/[U(III)] ratios: 0.7, 4, 20, 100 and 500. Following Ni-based alloys (in mass%): HN80М-VI (Mo—12, Cr—7.6, Nb—1.5), HN80МТY (Mo—13, Cr—6.8, Al—1.1, Ti—0.9), HN80МТW (Mo—9.4, Cr—7.0, Ti—1.7, W—5.5) and ЕМ-721 (W—25.2, Cr—5.7, Ti—0.17) were used for the study in the corrosion facility. If the redox state the fuel salt is characterized by uranium ratio [U(IV)]/[U(III)] uranium intermetallic compounds and alloys with nickel and molybdenum. This leads to spontaneous behavior of alloy formation processes on the specimens' surface and further diffusion of uranium deep into the metallic phase. As consequence of this films of intermetallic compounds and alloys of nickel, molybdenum, tungsten with uranium are formed on the alloys specimens' surface, and intergranular corrosion does not take place. In the fuel salt with [U(IV)]/[U(III)] = 4-20 the potentials of uranium

  6. Peculiarities of austenitic state in premartensitic temperature range

    International Nuclear Information System (INIS)

    Sarrak, V.I.; Suvorova, S.O.

    1982-01-01

    A review of works on the study of austenite behaviour in premartensitic temperature range carried out using the investigation methods of resistance to microplastic deformation, mechanical properties and internal friction, is presented. The investigation is carried out using carbon-free iron-nickel alloy N31, alloy 40N24 and alloy 50Kh20N10. It is established that in premartensitic temperature range at a certain temperature Msub(elast.) exceeding by approximately 35 deg C the starting temperature of martensitic transformation, austenite state changes sharply: mechanical instability as to microplastic deformation appears. It manifests itself in an anomalous decrease of resistance to microplastic deformation at the temperature approaching the beginning of martensitic transformation. Martensitic transformation develops under tension in an elastic region. At the temperature above Msub(elast.) martensitic transformation develops only under the effect of plastic deformation. Decrease of temperature of martensitic transformation start as a result of microplastic deformation and subsequent ageing is connected with blocking of possible places of martensite initiation

  7. Peculiarities of austenitic state in premartensitic temperature range

    Energy Technology Data Exchange (ETDEWEB)

    Sarrak, V.I.; Suvorova, S.O.

    A review of works on the study of austenite behaviour in premartensitic temperature range carried out using the investigation methods of resistance to microplastic deformation, mechanical properties and internal friction, is presented. The investigation is carried out using carbon-free iron-nickel alloy N31, alloy 40N24 and alloy 50Kh20N10. It is established that in premartensitic temperature range at a certain temperature Msub(elast.) exceeding by approximately 35 deg C the starting temperature of martensitic transformation austenite state changes sharply: mechanical instability as to microplastic deformation appears. It manifests itself in an anomalous decrease of resistance to microplastic deformation at the temperature approaching the beginning of martensitic transformation. Martensitic transformation develops under tension in an elastic region. At the temperature above Msub(elast.) martensitic transformation develops only under the effect of plastic deformation. Decrease of temperature of martensitic transformation start as a result of microplastic deformation and subsequent ageing is connected with blocking of possible places of martensite initiation.

  8. Effect of ZnO nano in the blend PET / PC ( 80/20) subjected to UV radiation

    International Nuclear Information System (INIS)

    Pires, Homero M.; Mendes, Luis C.; Albitres, Gerson A.V.; Cestari, Sibele P.; Mattos, Gabriela C.

    2015-01-01

    The aim of this research was to reuse recycled poly(ethylene terephthalate) (PET) in blend with polycarbonate (PC) in order to avoid UV degradation in outdoor application. Nanocomposite based on blend of recycled (PET) and polycarbonate (PC) in the ratio of 80/20 with nano zinc oxide (ZnO) at different concentrations was prepared. The blend was subjected to ultraviolet (UV) radiation for accelerated aging chamber, we evaluated the effect of the presence nZnO filler as a barrier to UV rays. Dynamic-mechanical analysis (DMA) and nuclear magnetic resonance in the solid state (NMR). It is the degradation retardant effect at concentrations starting from 3% nZnO. (author)

  9. A stochastic analysis of the effect of hydrostatic pressure on the pit corrosion of Fe-20Cr alloy

    International Nuclear Information System (INIS)

    Zhang Tao; Yang Yange; Shao Yawei; Meng, Guozhe; Wang, Fuhui

    2009-01-01

    The effect of hydrostatic pressure on the pit corrosion behavior of Fe-20Cr alloy was investigated in 3.5% NaCl solution by means of potentiodynamic polarization and potentiostatic technology, and the experiment data was analyzed based on stochastic theory. With the increase of hydrostatic pressure, the pit corrosion resistance of Fe-20Cr alloy was deteriorated, which was distinguished by the decrease of critical pit potential (E cirt ) and the increase of passive current density. The results also demonstrated that there exist two effects of hydrostatic pressure on the corrosion behavior of Fe-20Cr alloy: (1) the pit generation rate was evidently increased compared to that under lower hydrostatic pressure, and the metastable pits become faster and larger. However, it seemed that pit generation mechanism shows no hydrostatic pressure dependence; (2) the probability of pit growth increased with the increase of hydrostatic pressure, which implied that the metastable pit on Fe-20Cr alloy exhibited higher probability to become larger pit cavity during shorter time interval than that under lower hydrostatic pressure.

  10. Study of cast and thermo-mechanically strengthened chromium-nickel nitrogen-containing steel

    International Nuclear Information System (INIS)

    Prokoshkina, V.G.; Kaputkina, L.M.; Svyazhin, A.G.

    2000-01-01

    The effect of nitrogen on the structure and strength of corrosion-resistant chromium-nickel steels after thermal and thermomechanical treatment is studied. The 06Kh15N7AD and 07Kh15N7DAMB steels alloying by nitrogen was accomplished through the basic composition steels remelting in the molecular nitrogen atmosphere under the pressure of 0.1-2.5 MPa. The 02Kh15N5DAF and 05Kh15N5DAM steels ingots were obtained through melting in a plasma furnace under the nitrogen pressure of 0.4MPA. The high-temperature thermomechanical treatment (HTMT) was performed by rolling with preliminary blanks heating up to 1050 deg C and the rolling end temperature not below 950 deg C. It is shown, that the HTMT of the nitrogen-containing steels makes it possible to obtain strength characteristics by 1.5 times exceeding the properties of traditionally applicable corrosion-resistant steels, whereby sufficiently high plasticity of the nitrogen-containing steel is retained [ru

  11. A theory of piezoelectric, elastic, and dielectric properties of the KH2PO4 family crystals under the strain u6. Phase transition and the piezoelectric effect in the KH2PO4 crystal

    International Nuclear Information System (INIS)

    Levits'kij, R.R.; Lyisnij, B.M.

    2003-01-01

    In order to study the dielectric, piezoelectric and elastic properties of ferroelectrics and antiferroelectrics of the KH 2 PO 4 family, we consider an extended proton tunneling model that takes into account the shear strain u 6 . In the four-particle cluster approximation for the short-range interactions and the mean field approximation for the long-range interaction we calculate the transverse components of the dielectric susceptibility tensor of the KH 2 PO 4 family ferroelectrics

  12. Water vapor pressure over molten KH_2PO_4 and demonstration of water electrolysis at ∼300 °C

    International Nuclear Information System (INIS)

    Berg, R.W.; Nikiforov, A.V.; Petrushina, I.M.; Bjerrum, N.J.

    2016-01-01

    Highlights: • The vapor pressure over molten KH_2PO_4 was measured by Raman spectroscopy to be about 8 bars at ∼300 °C. • Raman spectroscopy shows that molten KH_2PO_4 under its own vapor pressure contains much dissolved water. • It is demonstrated spectroscopically that water electrolysis is possible in KH_2PO_4 electrolyte forming H_2 and O_2 at 300 °C. • Molten KH_2PO_4 is a possible electrolyte for water electrolysis. - Abstract: A new potentially high-efficiency electrolyte for water electrolysis: molten monobasic potassium phosphate, KH_2PO_4 or KDP has been investigated at temperatures ∼275–325 °C. At these temperatures, KH_2PO_4 was found to dissociate into H_2O gas in equilibrium with a melt mixture of KH_2PO_4−K_2H_2P_2O_7−KPO_3−H_2O. The water vapor pressure above the melt, when contained in a closed ampoule, was determined quantitatively vs. temperature by use of Raman spectroscopy with methane or hydrogen gas as an internal calibration standard, using newly established relative ratios of Raman scattering cross sections of water and methane or hydrogen to be 0.40 ± 0.02 or 1.2 ± 0.03. At equilibrium the vapor pressure was much lower than the vapor pressure above liquid water at the same temperature. Electrolysis was realized by passing current through closed ampoules (vacuum sealed quartz glass electrolysis cells with platinum electrodes and the electrolyte melt). The formation of mixtures of hydrogen and oxygen gases as well as the water vapor was detected by Raman spectroscopy. In this way it was demonstrated that water is present in the new electrolyte: molten KH_2PO_4 can be split by electrolysis via the reaction 2H_2O → 2H_2 + O_2 at temperatures ∼275–325 °C. At these temperatures, before the start of the electrolysis, the KH_2PO_4 melt gives off H_2O gas that pressurizes the cell according to the following dissociations: 2KH_2PO_4 ↔ K_2H_2P_2O_7 + H_2O ↔ 2KPO_3 + 2H_2O. The spectra show however that the water by

  13. Crystallization of amorphous pseudobinary alloys of the type (Fe1-x Nix)80 B20

    International Nuclear Information System (INIS)

    Vasconcellos, M.A.Z.; Baibich, M.N.

    1984-01-01

    It was studied the crystallization of amorphous metallic ribbons of Fe 1-x Ni x 80 B 2 0 using the method of isochronous heating at variable slopes. The crystallization temperatures were determined from the transition observed in the electrical resistivity. (M.W.O.) [pt

  14. Out-of-plane coercive field of Ni{sub 80}Fe{sub 20} antidot arrays

    Energy Technology Data Exchange (ETDEWEB)

    Chunhong, Gao [School of Physical Science and Technology, Southwest University, Chongqing 400715 (China); Ke, Chen [Chongqing Electric Power College, Chongqing (China); Ling, Lue; Jianwei, Zhao [School of Physical Science and Technology, Southwest University, Chongqing 400715 (China); Chen Peng, E-mail: pchen@swu.edu.c [School of Physical Science and Technology, Southwest University, Chongqing 400715 (China)

    2010-11-15

    The out-of-plane magnetic anisotropy and out-of-plane magnetization reversal process of nanoscale Ni{sub 80}Fe{sub 20} antidot arrays deposited by magnetron sputtering technique on an anodic aluminum oxide (AAO) membrane are investigated. The angular dependence of out-of-plane remanent magnetization of Ni{sub 80}Fe{sub 20} antidot arrays shows that the maximum remanence is in-plane and the squareness of the out-of-plane hysteresis loop follow a |cos {theta}| dependence. The angular dependence of out-of-plane coercivity of Ni{sub 80}Fe{sub 20} antidot arrays shows that the maximum coercivity lies on the surface of a cone with its symmetric axis normal to the sample plane, which indicates a transition of magnetic reversal from curling to coherent rotation when changing the angle between the applied magnetic field and the sample plane.

  15. Effect of technological procedures on the crack resistance of nickel alloy welded joints under heat treatment

    International Nuclear Information System (INIS)

    Bagdasarov, Yu.S.; Sorokin, L.I.; Yakushin, B.F.; Moryashchev, S.F.

    1983-01-01

    Comparison of the efficiency of some technological procedures directed to the increase of crack resistance of KhN50MBKTYUR (EhP99) alloy welded joints under heat treatment was conducted. Welded joints were manufactured by the methods of electron beam welding, laser welding, automatic argon-arc welding. The latter was conducted by conventional technology as well as with electromagnetic mixing of liquid metal of welding bath, with compulsory cooling of weld matal, with pulse arc. It is shown that the high fracture resistance of welded joints, manufactured by electron beam and laser welding is achieved by combination of high mechanical properties of heat affected zone metal and reduced elastic potential energy margin of residual welding stresses (as compared to argon-arc welding)

  16. Microstructure evolution of the Si{sub 3}N{sub 4}/Si{sub 3}N{sub 4} joints brazed using Au-Ni-V filler alloys with different V content

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zhang, J., E-mail: hitzhangjie@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zhang, H.W.; Fan, G.H.; He, Y.M. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-08-18

    Highlights: > Si{sub 3}N{sub 4} ceramic was brazed using Au-Ni-V filler alloy with different V content. > The microstructure evolution of the joint was study in detail in the paper. > The polygonal Ni{sub 2}SiV{sub 3} and Ni{sub 3}V phase in the joint were investigated by TEM. > The formation of different compounds and alloys in joint was detailed discussed. - Abstract: Au-Ni-V filler alloys with different vanadium contents were designed to braze Si{sub 3}N{sub 4} ceramic at 1373 K for 30 min, and the microstructures of brazing seams were investigated by SEM and TEM. When the Au-Ni-V filler alloy contains 5 at.% V, round-like Ni[Si, V, Au] precipitates form in the Au[Ni] solid solution matrix and a VN reaction layer with 0.5 {mu}m thickness appears on Si{sub 3}N{sub 4} interface. When the V content increases to 10 at.%, a new polygonal Ni{sub 2}SiV{sub 3} phase occurs in the seam, and the Ni[Si, V, Au] precipitate coarsens and VN layer thickens. With increase of V contents to 15 and 20 at.%, laminar Ni[Au] and polygonal Ni{sub 3}V precipitates form. With 25 at.% V content in the filler alloy, the Ni{sub 2}SiV{sub 3} and Ni{sub 3}V precipitates distribute homogenously in the brazing seam. These microstructure evolutions were attributed to the reaction between Si{sub 3}N{sub 4} and vanadium, which forms VN reaction layer and releases Si into the molten alloy.

  17. First-principle natural band alignment of GaN / dilute-As GaNAs alloy

    Directory of Open Access Journals (Sweden)

    Chee-Keong Tan

    2015-01-01

    Full Text Available Density functional theory (DFT calculations with the local density approximation (LDA functional are employed to investigate the band alignment of dilute-As GaNAs alloys with respect to the GaN alloy. Conduction and valence band positions of dilute-As GaNAs alloy with respect to the GaN alloy on an absolute energy scale are determined from the combination of bulk and surface DFT calculations. The resulting GaN / GaNAs conduction to valence band offset ratio is found as approximately 5:95. Our theoretical finding is in good agreement with experimental observation, indicating the upward movements of valence band at low-As content dilute-As GaNAs are mainly responsible for the drastic reduction of the GaN energy band gap. In addition, type-I band alignment of GaN / GaNAs is suggested as a reasonable approach for future device implementation with dilute-As GaNAs quantum well, and possible type-II quantum well active region can be formed by using InGaN / dilute-As GaNAs heterostructure.

  18. High-performance Ag0.8Pb18+xSbTe20 thermoelectric bulk materials fabricated by mechanical alloying and spark plasma sintering

    International Nuclear Information System (INIS)

    Wang Heng; Li Jingfeng; Nan Cewen; Zhou Min; Liu Weishu; Zhang Boping; Kita, Takuji

    2006-01-01

    Polycrystalline Ag n Pb m SbTe m+2n thermoelectric materials, whose compositions can be described as Ag 0.8 Pb 18+x SbTe 20 were prepared using a combined process of mechanical alloying and spark plasma sintering. Electric properties of the sintered samples with different Pb contents were measured from room temperature to 700 K. The maximum power factor of 1.766 mW/mK 2 was obtained at 673 K for the Ag 0.8 Pb 22 SbTe 20 sample, which corresponds to a high dimensionless figure of merit, ZT=1.37. This best composition is different from that reported before

  19. Protective effect of KhOSP-10 inhibitor during corrosion, hydrogenadsorption and corrosion cracking of a steel in sulfuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Mindyuk, A K; Svist, E I; Savitskaya, O P; Goyan, E B; Gopanenko, A N [AN Ukrainskoj SSR, Lvov. Fiziko-Mekhanicheskij Inst.

    1975-01-01

    The protective propeties of inhibitor KhOSP-10 in the time of corrosion and corrosive cracking of steel 40Kh are higher then those of inhibitors KPI-1, KI-1, I-I-V etc. Its ability to reduce steel hydrogenation is the same as in the case of KPI-1 inhibitor i.e. below that of KI-1. HCl additives enhance the efficiency of inhibitors KPI-1, KI-1, I-1-V etc. up to the protective ability of KhOSP-10. Kinetics of the electrode processes was estimated from polarization curves.

  20. Effect of smelt aluminium on mechanical properties of steels

    International Nuclear Information System (INIS)

    Ryabov, V.R.; Dykhno, I.S.; Deev, G.F.; Karikh, V.V.

    1987-01-01

    Effect of smelt aluminium on mechanical properties of armco-iron and 12 Kh18N10T steel is studied. It is stated that in smelt aluminium and aluminium alloy contact with armco-iron the sample ductility is decreased. Corrosion effect of smelt alluminium on (18Kh15N5AM3) steel in the form of reinforced wire in aluminium-steel KAS-1A composite material is investigted. It is stated in experiment that during smelt alluminium-steel contact interaction of heterogeneous phases takes place

  1. Close toleranoe forging of chromium steel blades for powerful steam turbines

    International Nuclear Information System (INIS)

    Shastin, Eh.G.; Kositskij, Yu.N.; Lyubchits, G.A.

    1989-01-01

    Work on simulating technological process on die-forging hammer was performed in order to reduce the preparation period bringing technology of close tolerance forging of turbine blades to a commercial level. A special attention was paid to development of accurate forming of forgings of 20Kh13Sh, 12Kh13 and 15Kh11MFSh steels on screw presses with nominal effort equal to 80 and 144 MN

  2. Collective effects of interface roughness and alloy disorder in InxGa1-xN/GaN multiple quantum wells

    International Nuclear Information System (INIS)

    Zeng, K.C.; Smith, M.; Lin, J.Y.; Jiang, H.X.

    1998-01-01

    The collective effects of alloy disorder and interface roughness on optical properties of In x Ga 1-x N/GaN multiple quantum wells (MQWs) have been studied. The results are compared with those of GaN/AlGaN MQWs and InGaN epilayers. In x Ga 1-x N/GaN MQWs emit a broad and asymmetrical photoluminescence (PL) band, while GaN/AlGaN MQWs and InGaN epilayers emit narrower and Gaussian-shaped PL bands. Furthermore, the decay of excitons at low temperatures in In x Ga 1-x N/GaN MQWs follows a nonexponential function even at the lower-energy side of the PL spectral peak, while those in GaN/AlGaN MQWs and in InGaN epilayers follow a single exponential function. Both alloy disorder and interface roughness have to be included in order to interpret the PL emission spectrum and the decay dynamics in In x Ga 1-x N/GaN MQWs. Important parameters of the In x Ga 1-x N/GaN MQWs, σ x ,σ L , and dτ/dL, denoting the alloy disorder, the interface roughness, and the rate of changing of the exciton decay lifetime with well width, respectively, have been deduced. The method developed here can be used to determine σ x ,σ L , and dτ/dL in any MQW systems with wells being alloy materials. copyright 1998 American Institute of Physics

  3. Quasicrystalline phase formation in the mechanically alloyed Al{sub 70}Cu{sub 20}Fe{sub 10}

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, S. N. de, E-mail: snm@dfi.uem.br; Cadore, S.; Pereira, H. A.; Santos, I. A.; Colucci, C. C.; Paesano, A. [Universidade Estadual de Maringa, Departamento de Fisica (Brazil)

    2010-01-15

    In the present work, the formation of the Al{sub 70}Cu{sub 20}Fe{sub 10} icosahedral phase by mechanical alloying the elemental powders in a high-energy planetary mill was investigated by X-ray diffraction and Moessbauer spectroscopy. It was verified that the sample milled for 80 h produces an icosahedral phase besides Al(Cu, Fe) solid solution ({beta}-phase) and Al{sub 2}Cu intermetallic phase. The Moessbauer spectrum for this sample was fitted with a distribution of quadrupole splitting, a doublet and a sextet, revealing the presence of the icosahedral phase, {beta}-phase and {alpha}-Fe, respectively. This compound is not a good hydrogen storage. The results of the X-ray diffraction and Moessbauer spectroscopy of the sample milled for 40 h and annealed at 623 deg. C for 16 h shows essentially single i-phase and tetragonal Al{sub 7}Cu{sub 2} Fe phase.

  4. Long-term behaviour of heat-resistant steels and high-temperature materials

    International Nuclear Information System (INIS)

    1987-01-01

    This book contains 10 lectures with the following subjects: On the effect of thermal pretreatment on the structure and creep behaviour of the alloy 800 H (V. Guttmann, J. Timm); Material properties of heat resistant ferritic and austenitic steels after cold forming (W. Bendick, H. Weber); Investigations for judging the working behaviour of components made of alloy 800 and alloy 617 under creep stress (H.J. Penkalla, F. Schubert); Creep behaviour of gas turbine materials in hot gas (K.H. Kloos et al.); Effect of small cold forming on the creep beahviour of gas turbine blades made of Nimonic 90 (K.H. Keienburg et al.); Investigations on creep fatigue alternating load strength of nickel alloys (G. Raule); Change of structure, creep fatigue behaviour and life of X20 Cr Mo V 12 1 (by G. Eggeler et al.); Investigations on thermal fatigue behaviour (K.H. Mayer et al.); Creep behaviour of similar welds of the steels 13 Cr Mo 4 4, 14 MoV 6 3, 10 Cr Mo 910 and GS-17 Cr Mo V 5 11 (K. Niel et al.); Determining the creep crack behaviour of heat resistant steels with samples of different geometry (K. Maile, R. Tscheuschner). (orig.,/MM) [de

  5. Etching of anode wire deposits with CF4/isobutane (80:20) avalanches

    International Nuclear Information System (INIS)

    Openshaw, R.; Henderson, R.S.; Faszer, W.; Salomon, M.

    1991-01-01

    An ionization exposure of 0.5 C per cm of wire in a gas mixture of CF 4 /isobutane (80:20) is shown to reverse anode wire damage in single-wire chambers. Several chambers aged in argon/ethane (50:50) and argon/ethane/ethanol (50:50:0.2) and having pulse height reduction of 25-30% have recovered pulse heights and currents to greater than 98% of their initial values. Inspection of the anode wires indicates that the thick deposits caused by the exposure in argon/ethane have been removed. Auger electron spectroscopy reveals only a thin residual layer containing primarily carbon and oxygen. This etching ability of CF 4 /isobutane (80:20) avalanches may explain the extremely good ageing characteristics previously reported for this mixture. (orig.)

  6. [Effect of KH2PO4 on the odonto- and osteogenic differentiation potential of human stem cells from apical papillae].

    Science.gov (United States)

    Wang, Yan-ping; Wu, Jin-tao; Wang, Zi-lu; Zheng, Yang-yu; Zhang, Guang-dong; Yu, Jin-hua

    2013-01-01

    To determine the effects of KH2PO4 on the odonto- and osteogenic differentiation potential of human stem cells from apical papillae (SCAP) in vitro. SCAP were isolated and cultured respectively in alpha minimum essential medium (α-MEM) or α-MEM containing 1.8 mmol/L KH2PO4. Alkaline phosphatase (ALP) activity, alizarin red staining, real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were used to examine the odonto and osteogenic potential of SCAP in the two media. SCAP cultured in α-MEM containing 1.8 mmol/L KH2PO4 exhibited a higher ALP activity [(0.370 ± 0.013) Sigma unit×min(-1)×mg(-1)] at day 3 than control group [(0.285 ± 0.008) Sigma unit×min(-1)×mg(-1)] and KH2PO4-treated SCAP formed more calcified nodules at day 5 [(0.539 ± 0.007) µg/g] and day 7 [(1.617 ± 0.042) µg/g] than those in normal medium [(0.138 ± 0.037) µg/g, P odonto- and osteogenic markers were significantly up-regulated after the stimulation of KH2PO4 at day 3 and 7 respectively, as compared with control group. 1.8 mmol/L KH2PO4 can promote the odonto and osteogenic differentiation potential of human SCAP.

  7. Structural and thermal properties of tellurite 20Li2O-80TeO2 glasses

    OpenAIRE

    Idalgo, E. [UNESP; Araújo, E. B. [UNESP

    2007-01-01

    O presente trabalho reporta estudos sobre a cristalização em vidros teluretos 20Li2O-80TeO2 induzida a partir de tratamentos térmicos realizados sobre vidros com tamanho de partículas entre 38 µm e 75 µm. Estes estudos foram conduzidos em duas matrizes vítreas tratadas e não tratadas termicamente para aliviar as tensões após o quenching, utilizando-se de forma combinada às técnicas de difração de raios X, calorimetria diferencial de varredura e espectroscopia no infravermelho. Os resultados r...

  8. Mutation and crystallization of the first KH domain of human polycytosine-binding protein 1 (PCBP1) in complex with DNA

    International Nuclear Information System (INIS)

    Yoga, Yano M. K.; Traore, Daouda A. K.; Wilce, Jacqueline A.; Wilce, Matthew C. J.

    2011-01-01

    The successful preparation of a mutant KH domain representing the first KH domain of PCBP1 and its crystallization in complex with a C-rich DNA are reported. This structure is anticipated to provide high-resolution information that will allow better understanding of the basis of cytosine specificity by PCBPs. Polycytosine-binding proteins (PCBPs) are triple KH-domain proteins that play an important role in the regulation of translation of eukaryotic mRNA. They are also utilized by viral RNA and have been shown to interact with ssDNA. Underlying their function is the specific recognition of C-rich nucleotides by their KH domains. However, the structural basis of this recognition is only partially understood. Here, the preparation of a His-tagged KH domain is described, representing the first domain of PCBP1 that incorporates a C54S mutation as well as the addition of a C-terminal tryptophan. This construct has facilitated the preparation of highly diffracting crystals in complex with C-rich DNA (sequence ACCCCA). Crystals of the KH1–DNA complex were grown using the hanging-drop vapour-diffusion method in 0.1 M phosphate–citrate pH 4.2, 40%(v/v) PEG 300. X-ray diffraction data were collected to 1.77 Å resolution and the diffraction was consistent with space group P2 1 , with unit-cell parameters a = 38.59, b = 111.88, c = 43.42 Å, α = γ = 90.0, β = 93.37°. The structure of the KH1–DNA complex will further our insight into the basis of cytosine specificity by PCBPs

  9. Polysorbates 20 and 80 used in the formulation of protein biotherapeutics: structure and degradation pathways.

    Science.gov (United States)

    Kerwin, Bruce A

    2008-08-01

    Polysorbates 20 and 80 (Tween 20 and Tween 80) are used in the formulation of biotherapeutic products for both preventing surface adsorption and as stabilizers against protein aggregation. The polysorbates are amphipathic, nonionic surfactants composed of fatty acid esters of polyoxyethylene sorbitan being polyoxyethylene sorbitan monolaurate for polysorbate 20 and polyoxyethylene sorbitan monooleate for polysorbate 80. The polysorbates used in the formulation of biopharmaceuticals are mixtures of different fatty acid esters with the monolaurate fraction of polysorbate 20 making up only 40-60% of the mixture and the monooleate fraction of polysorbate 80 making up >58% of the mixture. The polysorbates undergo autooxidation, cleavage at the ethylene oxide subunits and hydrolysis of the fatty acid ester bond. Autooxidation results in hydroperoxide formation, side-chain cleavage and eventually formation of short chain acids such as formic acid all of which could influence the stability of a biopharmaceutical product. Oxidation of the fatty acid moiety while well described in the literature has not been specifically investigated for polysorbate. This review focuses on the chemical structure of the polysorbates, factors influencing micelle formation and factors and excipients influencing stability and degradation of the polyoxyethylene and fatty acid ester linkages.

  10. Influence of time presetting procedure for rapid local heat;.ng on brazing temperature conditions

    International Nuclear Information System (INIS)

    Lezhnin, G.P.; Tul'skikh, V.E.

    1985-01-01

    Correlation of known and suggested presetting procedures for heating period during induction brazing was conducted. It is shown that brazing time must be established considering heat propagation during heating in order to obtain the assigned joint temperature regardless of heating rate change. Methods for temperature calculation in assigned zones of the joint are suggested. The suggested presetting procedure for heating time was applied for induction vacuum brazing of a tube of 12Kh18N10T steel to a pipe connection of VT20 alloy

  11. Thermal stability of amorphous structure and magnetic properties Fe{sub 80-x}Co{sub x}P{sub 14}B {sub 6} (x=20-40) ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Kostyrya, S.A.; Idzikowski, B. [Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznan (Poland); Tkatch, V.I.; Popov, V.V.; Rassolov, S.G. [Donetsk Physics and Engineering Institute of National Academy of Sciences of Ukraine, R. Luxemburg 72, 83114 Donetsk (Ukraine)

    2006-01-01

    Amorphous structure and its thermal stability as well as magnetic properties of Fe{sub 80-x}Co{sub x}P{sub 14}B{sub 6} (20{<=}x{<=}40) glasses have been studied by X-ray diffraction, non-isothermal differential scanning calorimetry (DSC) and thermomagnetic (TMG) measurements. The Curie temperature increases with Co content, while the glass transition and crystallization onset temperatures decrease. As a result, for alloys x=30, 32 and 35 at%, the transition into paramagnetic state take place close to glass transition temperature. However, for x=40 at% the TMG curve, in the vicinity of magnetic transition temperature, is overlapped by ferromagnetic crystallization products. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. A pseudoatom in a cage: trimetallofullerene Y(3)@C(80) mimics y(3)n@c(80) with nitrogen substituted by a pseudoatom.

    Science.gov (United States)

    Popov, Alexey A; Zhang, Lin; Dunsch, Lothar

    2010-02-23

    Y(3)C(80) obtained in the synthesis of nitride clusterfullerenes Y(3)N@C(2n) (2n = 80-88) by the reactive atmosphere method is found to be a genuine trimetallofullerene, Y(3)@C(80), with low ionization potential and divalent state of yttrium atoms. DFT studies of the electronic structure of Y(3)@C(80) show that this molecule mimics Y(3)N@C(80) with the pseudoatom (PA) instead of the nitrogen atom. Topology analysis of the electron density and electron localization function show that yttrium atoms form Y-PA bonds rather than direct Y-Y bonds. Molecular dynamics simulations show that the Y(3)PA cluster is as rigid as Y(3)N and rotates inside the fullerene cage as a single entity.

  13. The System 80+ Standard Plant design control document. Volume 20

    International Nuclear Information System (INIS)

    1997-01-01

    This Design Control Document (DCD) is a repository of information comprising the System 80+trademark Standard Plant Design. The DCD also provides that design-related information to be incorporated by reference in the design certification rule for the System 80+ Standard Plant Design. Applicants for a combined license pursuant to 10 CFR 52 must ensure that the final Design Certification Rule and the associated Statements of Consideration are used when making all licensing decisions relevant to the System 80+ Standard Plant Design. The Design Control Document contains the DCD introduction, The Certified Design Material (CDM) [i.e., ''Tier 1''] and the Approved Design Material (ADM) [i.e., ''Tier 2''] for the System 80+ Standard Plant Design. The CDM includes the following sections: (1) Introductory material; (2) Certified Design Material for System 80+ systems and structures; (3) Certified Design Material for non-system-based aspects of the System 80+ Certified design; (4) Interface requirements; and (5) Site parameters. The ADM, to the extent applicable for the System 80+ Standard Plant Design, includes: (1) the information required for the final safety analysis report under 20 CFR 50.34; (2) other relevant information required by 10 CFR 52.47; and (3) emergency operations guidelines. This volume contains 2 technical specifications bases as part of Appendix 16 A Tech Spec Bases. They are TS B3.8 Electrical Power Technical Systems Bases and TS B3.9 Refueling Operations Bases. All 3 parts of section 17 (QA) and all 10 parts of section 18 (Human Factors) of the ADM Design and Analysis are contained in this volume. Topics covered in section 17 are: design phase QA; operations phase QA; and design phase reliability assurance. Topics covered by section 18 are: design team organization; design goals; design process; functional task analysis; control room configuration; information presentation; control and monitoring; verification and validation; and review documents

  14. Effect of cooling rate and Mg addition on the structural evaluation of rapidly solidified Al-20wt%Cu-12wt%Fe alloy

    Energy Technology Data Exchange (ETDEWEB)

    Karaköse, Ercan, E-mail: ekarakose@karatekin.edu.tr [Çankırı Karatekin University, Faculty of Sciences, Department of Physics, 18100 Çankırı (Turkey); Çolak, Hakan [Çankırı Karatekin University, Faculty of Sciences, Department of Chemistry, 18100 Çankırı (Turkey)

    2016-11-15

    The present work examines the effect of Mg contents and cooling rate on the morphology and mechanical properties of Al{sub 20}Cu{sub 12}Fe quasicrystalline alloy. The microstructure of the alloys was analyzed by scanning electron microscopy and the phase composition was identified by X-ray diffractometry. The melting characteristics were studied by differential thermal analysis under an Ar atmosphere. The mechanical features of the melt-spun and conventionally solidified alloys were tested by tensile-strength test and Vickers micro-hardness test. It was found that the final microstructure of the Al{sub 20}Cu{sub 12}Fe samples mainly depends on the cooling rate and Mg contents, which suggests that different cooling rates and Mg contents produce different microstructures and properties. The average grain sizes of the melt spun samples were about 100–300 nm at 35 m/s. The nanosize, dispersed, different shaped quasicrystal particles possessed a remarkable effect to the mechanical characteristics of the rapidly solidified ribbons. The microhardness values of the melt spun samples were approximately 18% higher than those of the conventionally counterparts. - Highlights: •Quasicrystal-creating materials have high potential for applications. •Different shaped nanosize quasicrystal particles were observed. •The addition of Mg has an important impact on the mechanical properties. •H{sub V} values of the MS0, MS3 and MS5 samples at 35 m/s were 8.56, 8.66 and 8.80 GPa. •The volume fraction of IQC increases with increasing cooling rates.

  15. Layered growth model and epitaxial growth structures for SiCAlN alloys

    International Nuclear Information System (INIS)

    Liu Zhaoqing; Ni Jun; Su Xiaoao; Dai Zhenhong

    2009-01-01

    Epitaxial growth structures for (SiC) 1-x (AlN) x alloys are studied using a layered growth model. First-principle calculations are used to determine the parameters in the layered growth model. The phase diagrams of epitaxial growth are given. There is a rich variety of the new metastable polytype structures at x=1/6 ,1/5 ,1/4 ,1/3 , and 1/2 in the layered growth phase diagrams. We have also calculated the electronic properties of the short periodical SiCAlN alloys predicted by our layered growth model. The results show that various ordered structures of (SiC) 1-x (AlN) x alloys with the band gaps over a wide range are possible to be synthesized by epitaxial growth.

  16. Reflection of K.H. Ahmad Dahlan’s educational ideas for school development

    Directory of Open Access Journals (Sweden)

    S. Suripto

    2017-09-01

    Full Text Available This research was aimed to reflect the form of K.H. Ahmad Dahlan’s educational ideas in schools. The kind of this research was qualitative with multi sites approach.  The research was conducted at MTs Muhammadiyah 2 and Muhammadiyah 1 Vocational School – Trenggalek.The object of this research was the form of K.H. Ahmad Dahlan’s educational ideas whereas the subject was all the school's administrators. Data were collected through deep interview, documentation and observation techniques. Data validity was tested with; credibility, transferability, and confirmability. Data analysis model was interractionally each other; data reduction, data presentation, conclusion withdrawal, and verification. The research result were; first, at MTs Muhammadiyah 2, the form of K.H. Ahmad Dahlan’s educational ideas covered: Muhammadiyah values, such as a. TBC eradication, worry attitude towards the improvement of fundamentalist religious culture in the society (LDII, b. Willingness to sacrifice attitude grown by the school founders’ core team, organizers, and administrators; c. The spirit of dakwah and dedication for the nation and the religion. Second, at Muhammadiyah 1 Vocational School, it covered a. Charity effort movement for all (rahmatan lilalamin; b. Amar maruf nahy munkar was formed in the construction of all field of life, c. Working was the spirit of movement organization. Keywords: educational ideas, school development

  17. Comparing magnetostructural transitions in Ni{sub 50}Mn{sub 18.75}Cu{sub 6.25}Ga{sub 25} and Ni{sub 49.80}Mn{sub 34.66}In{sub 15.54} Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dubenko, Igor [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Granovsky, Alexander [Faculty of Physics, Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Lahderanta, Erkki [Lappeenranta University of Technology, 53851 (Finland); Kashirin, Maxim; Makagonov, Vladimir [Voronezh State Technical University, Voronezh 394026 (Russian Federation); Aryal, Anil; Quetz, Abdiel; Pandey, Sudip [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Rodionov, Igor [Faculty of Physics, Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Samanta, Tapas; Stadler, Shane [Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Mazumdar, Dipanjan, E-mail: dmazumdar@siu.edu [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Ali, Naushad [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States)

    2016-03-01

    The crystal structure, magnetic and transport properties, including resistivity and thermopower, of Ni{sub 50}Mn{sub 18.75}Cu{sub 6.25}Ga{sub 25} and Ni{sub 49.80}Mn{sub 34.66}In{sub 15.54} Heusler alloys were studied in the (10–400) K temperature interval. We show that their physical properties are remarkably different, thereby pointing to different origin of their magnetostructural transition (MST). A Seebeck coefficient (S) was found to pass minimum of about −20 µV/K in respect of temperature for both compounds. It was shown that MST observed for both compounds results in jump-like changes in S for Ga-based compound and jump in resistivity of about 20 and 200 µΩ cm for Ga and In –based compounds, respectively. The combined analyzes of the present results with that from literature show that the density of states at the Fermi level does not change strongly at the MST in the case of Ni–Mn–In alloys as compared to that of Ni–Mn–Ga. - Graphical abstract: Temperature dependencies of resistivity for Ni{sub 50}Mn{sub 18.75}Cu{sub 6.25}Ga{sub 25} and Ni{sub 49.80}Mn{sub 34.66}In{sub 15.54} obtained on heating (open symbols) and cooling (closed symbols). Arrows indicate the temperature of direct (T{sub M}) and inverse (T{sub A}) martensitic transitions and ferromagnetic ordering of the austenitic (T{sub C}) and martensitic (T{sub CM}) phases. The T{sub CM}=T{sub A}/T{sub M} in the case of Ga-based alloy. - Highlights: • Magnetostructural transitions (MST) in two compounds with same parent material. • The figure exemplifies how sensitive MST properties are to the density of states. • Proper understanding is required for utilizing these multifunctional materials.

  18. Etching of anode wire deposits with CF4/isobutane (80:20) avalanches

    International Nuclear Information System (INIS)

    Openshaw, R.; Henderson, R.S.; Faszer, W.; Salomon, M.

    1990-11-01

    An ionization exposure of 0.5 coulombs per cm of wire in a gas mixture of CF 4 /isobutane (80:20) is shown to reverse anode wire damage in single-wire chambers. Several chambers aged in argon/ethane (50:50) and argon/ethane/ethanol (50:50:0.2) and having pulse height reductions of 25-30% have recovered pulse heights and currents to greater than 98% of their initial values. Inspection of the anode wires indicates that the thick deposits caused by the exposure in argon/ethane have been removed. Auger electron spectroscopy reveals only a thin residual layer containing primarily carbon and oxygen. This etching ability of CF 4 /isobutane (80:20) avalanches may explain the extremely good ageing characteristics previously reported for this mixture. (Author) (13 refs., 3 tabs., 11 figs.)

  19. Investigation of localization effect in GaN-rich InGaN alloys and ...

    Indian Academy of Sciences (India)

    Abstract. The temperature-dependent PL properties of GaN-rich InxGa1−xN alloys is investigated and S-shaped temperature dependence is observed in all InGaN samples. It is found that the origin of localization effect in samples. A and B are different from that in sample C. For samples A and B, In content fluctuations ...

  20. BInGaN alloys nearly lattice-matched to GaN for high-power high-efficiency visible LEDs

    Science.gov (United States)

    Williams, Logan; Kioupakis, Emmanouil

    2017-11-01

    InGaN-based visible light-emitting diodes (LEDs) find commercial applications for solid-state lighting and displays, but lattice mismatch limits the thickness of InGaN quantum wells that can be grown on GaN with high crystalline quality. Since narrower wells operate at a higher carrier density for a given current density, they increase the fraction of carriers lost to Auger recombination and lower the efficiency. The incorporation of boron, a smaller group-III element, into InGaN alloys is a promising method to eliminate the lattice mismatch and realize high-power, high-efficiency visible LEDs with thick active regions. In this work, we apply predictive calculations based on hybrid density functional theory to investigate the thermodynamic, structural, and electronic properties of BInGaN alloys. Our results show that BInGaN alloys with a B:In ratio of 2:3 are better lattice matched to GaN compared to InGaN and, for indium fractions less than 0.2, nearly lattice matched. Deviations from Vegard's law appear as bowing of the in-plane lattice constant with respect to composition. Our thermodynamics calculations demonstrate that the solubility of boron is higher in InGaN than in pure GaN. Varying the Ga mole fraction while keeping the B:In ratio constant enables the adjustment of the (direct) gap in the 1.75-3.39 eV range, which covers the entire visible spectrum. Holes are strongly localized in non-bonded N 2p states caused by local bond planarization near boron atoms. Our results indicate that BInGaN alloys are promising for fabricating nitride heterostructures with thick active regions for high-power, high-efficiency LEDs.

  1. Long-term strength and allowable stresses of grade 10Kh9MFB and X10CrMoVNb9-1 (T91/P91) chromium heat-resistant steels

    Science.gov (United States)

    Skorobogatykh, V. N.; Danyushevskiy, I. A.; Schenkova, I. A.; Prudnikov, D. A.

    2015-04-01

    Currently, grade X10CrMoVNb9-1 (T91, P91) and 10Kh9MFB (10Kh9MFB-Sh) chromium steels are widely applied in equipment manufacturing for thermal power plants in Russia and abroad. Compilation and comparison of tensile, impact, and long-term strength tests results accumulated for many years of investigations of foreign grade X10CrMoVNb9-1, T91, P91, and domestic grade 10Kh9MFB (10Kh9MFB-Sh) steels is carried out. The property identity of metals investigated is established. High strength and plastic properties of steels, from which pipes and other products are made, for operation under creep conditions are confirmed. Design characteristics of long-term strength on the basis of tests with more than one million of hour-samples are determined ( and at temperatures of 500-650°C). The table of recommended allowable stresses for grade 10Kh9MFB, 10Kh9MFB-SH, X10CrMoVNb9-1, T91, and P91 steels is developed. The long-time properties of pipe welded joints of grade 10Kh9MFB+10Kh9MFB, 10Kh9MFB-Sh+10Kh9MFB-Sh, X10CrMoVNb9-1+X10CrMoVNb9-1, P91+P91, T91+T91, 10Kh9MFB (10Kh9MFB-Sh)+X10CrMoVNb9-1(T/P91) steels is researched. The welded joint reduction factor is experimentally determined.

  2. Evolution of secondary-phase precipitates during annealing of the 12Kh18N9T steel irradiated with neutrons to a dose of 5 DPA

    Science.gov (United States)

    Tsai, K. V.; Maksimkin, O. P.; Turubarova, L. G.

    2007-03-01

    The formation and evolution of thermally-induced secondary precipitates in an austenitic stainless steel 12Kh18N9T irradiated in the core of a laboratory reactor VVR-K to a dose of 5 dpa and subjected to post-radiation isochronous annealings for 1 h in a temperature range from 450 to 1050°C have been studied using transmission electron microscopy (TEM) and microhardness measurements. It has been shown that the formation of stitch (secondary) titanium carbides and M 23C6 carbides at grain and twin boundaries after annealing at 1050°C is preceded by a complex evolution of fineparticles of secondary phases (titanium carbides and nitrides) precipitated at dislocation loops and dislocations during annealing at temperatures above 750°C.

  3. Preparation and Properties of Ti-TiN-Zr-ZrN Multilayer Films on Titanium Alloy Surface

    Directory of Open Access Journals (Sweden)

    LIN Song-sheng

    2017-06-01

    Full Text Available 24 cycles Ti-TiN-Zr-ZrN soft-hard alternating multilayer film was deposited on TC11 titanium alloy by vacuum cathodic arc deposition method. The structure and performance of the multilayer film, especially wear and sand erosion resistance were investigated by various analytical methods including pin on disc wear tester, sand erosion tester, 3D surface topography instrument, scanning electron microscopy (SEM, X-ray diffraction(XRD, micro-hardness tester and scratch adhesion tester. The results indicate that the Vickers-hardness of the multilayer film with thickness of 5.8μm can reach up to 28.10GPa. The adhesive strength of these coatings can be as high as 56N. Wear rate of the multilayer coated alloy is one order of magnitude smaller than bare one, which decreased from 7.06×10-13 m3·N-1·m-1 to 3.03×10-14m3·N-1·m-1. Multilayer films can play the role in hindering the extension of cracks, and thus sand erosion properties of the TC11 titanium alloy substrates are improved.

  4. Laser surface alloying of aluminium-transition metal alloys

    Directory of Open Access Journals (Sweden)

    Almeida, A.

    1998-04-01

    Full Text Available Laser surface alloying has been used as a tool to produce hard and corrosion resistant Al-transition metal (TM alloys. Cr and Mo are particularly interesting alloying elements to produce stable highstrength alloys because they present low diffusion coefficients and solid solubility in Al. To produce Al-TM surface alloys a two-step laser process was developed: firstly, the material is alloyed using low scanning speed and secondly, the microstructure is modified by a refinement step. This process was used in the production of Al-Cr, Al-Mo and Al-Nb surface alloys by alloying Cr, Mo or Nb powder into an Al and 7175 Al alloy substrate using a CO2 laser. This paper presents a review of the work that has been developed at Instituto Superior Tecnico on laser alloying of Al-TM alloys, over the last years.

    En el presente trabajo se estudia la aleación superficial mediante láser de aluminio con metales de transición. El cromo y el molibdeno son particularmente interesantes porque producen aleaciones de alta resistencia y por el bajo coeficiente de difusión y solución sólida en aluminio. Para producir estas aleaciones se ha seguido un procedimiento desarrollado en dos partes. En primer lugar, el material se alea usando una baja velocidad de procesado y en segundo lugar la estructura se modifica mediante un refinamiento posterior. Este procedimiento se ha empleado en la producción de aleaciones Al-Cr, Al-Mo y Al-Nb mediante aleación con láser de CO2 de polvos de Cr, Mo o Nb en aluminio y la aleación 7175. Este trabajo es una revisión del desarrollado en el Instituto Superior Técnico de Lisboa en los últimos años.

  5. Abrupt symmetry decrease in the ThT2Al20 alloys (T = 3d transition metal)

    International Nuclear Information System (INIS)

    Uziel, A.; Bram, A.I.; Venkert, A.; Kiv, A.E.; Fuks, D.; Meshi, L.

    2015-01-01

    Th-T-Al system, where T-3d transition metals, was studied at ThT 2 Al 20 stoichiometry to establish the influence of T on the structural stability of ternary aluminide formed. Different alloys were prepared, varying T in the row from Ti to Fe. Using electron microscopy and X-ray diffraction methods it was found that ThT 2 Al 20 phase adopts CeCr 2 Al 20 structure type when T = Ti, V, and Cr. Starting from Mn, the symmetry of the stable Al-rich phase, which forms in the alloys with the same composition, decreases from cubic to orthorhombic. The results of Density Functional Theory (DFT) calculations coincide with experiments. Concepts of the Theory of Coordination Compounds and Jahn–Teller effect were used to explain the observed abrupt change of the symmetry. These considerations were supported by DFT calculations. - Highlights: • Type of transition metal influences symmetry change in the ThT 2 Al 20 alloys. • It was found that cubic ThT 2 Al 20 phase is stable for T = Ti, V and Cr. • When T = Mn, Fe–Al + orthorhombic ThT 2 Al 10 are formed, lowering the symmetry. • Experimental results and DFT calculations were in full agreement. • TCC and of Jahn–Teller effect were used for explanation of the results

  6. Defect accumulation in welded joints of 12Kh1MF steel steam pipelines during creep

    International Nuclear Information System (INIS)

    Anokhov, A.E.; Alekhova, I.A.

    1982-01-01

    Technique for investigation of micropore accumulation in 12Kh1MF steel welded joints is proposed. The micropore density in different zones of welded joints in non-uniform. It is shown that failure localization in welded joint in the softening zone during the creep takes place due to the micropore priority accumulation in this zone. It is found out that accumulation of residual deformations in different zones of 12Kh1MF welded joints under creep runs more uniformly as the level of working stresses decreases and test duration increases

  7. Specific electrical conductivity in molten potassium dihydrogen phosphate KH2PO4 - An electrolyte for water electrolysis at ∼300°C

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey Valerievich; Berg, Rolf W.; Petrushina, Irina

    2016-01-01

    The conductivity of pure molten KH2PO4 salt and four mixtures with more or less water (KH2PO4-H2O and KH2PO4-KPO3 systems, respectively) were measured at temperatures of 240-320°C and under their own water vapor pressures. Molten KH2PO4 has been proven to be a promising electrolyte for an elevated...... temperature pressurized water electrolyzer demonstrating high conductivity of ∼0.30Scm-1 at 300°C. The conductivity data are given as polynomial functions of temperature and composition. The melting point of the pure salt under its own water vapor pressure was determined to be ∼272°C....

  8. ABSORCIÓN DE NUTRIMENTOS EN EL CULTIVAR DE PAPA MNF-80

    Directory of Open Access Journals (Sweden)

    Gilberto Cabalceta

    2005-01-01

    Full Text Available Se determinaron las curvas de crecimien- to y absorción de nutrimentos de la variedad de papa MNF-80 en 2 zonas en las laderas del volcán Irazú, una situada a 3000 msnm (Irazú y otra a 1500 msnm (Juan Viñas, en Andisoles de fertilidad moderada. Cada 15 días después de la siembra (DDS se tomaron muestras, las cuale se dividieron en parte aérea, tubérculo y raíz, para medir su peso fresco y seco y la concentración de nutrimentos. La tasa de crecimiento fue mayor en Juan Viñas (80-90 días a madurez que en Irazú (135 días, debido a que a mayor altitud, la temperatura, la luminosidad y la velocidad de desarrollo disminuyen. Los nutrimentos absorbidos en mayor cantidad en ambas fincas fueron K y N (>100 kg ha-1, seguidos por P, Ca, Mg y S (8-20 kg ha-1. En la finca Irazú, para un rendimiento de 36 t ha-1, se absorbió 110, 15, 166, 12, 10, y 11 kg ha-1 de N, P, K, Ca, Mg y S, respectivamente. También, 904, 68, 162, 317, y 42 g ha-1 de Fe, Cu, Zn, Mn y B, respectivamente. En la finca Juan Viñas, para un rendimiento de 28 t ha-1, se absorbió 133, 8, 173, 22, 10, y 10 kg ha-1 de N, P, K, Ca, Mg y S, respectivamente. N, P, K, Ca, Mg y S ocurrió hasta los 60 DDS, y a excepción del Ca, los demás nutrimentos presentan otro momento de absorción al final del ciclo.En la finca Juan Viñas la mayor absorción total de N, P, K, Ca, Mg y S ocurrió hasta los 45 DDS. También, 1097,68, 181, 651, y 84 g ha-1 de Fe, Cu, Zn, Mn, y B, respectivamente. En Irazú la mayor absorción de

  9. Study of optical properties of vacuum evaporated carbon nanotube containing Se80Te16Cu4 thin films

    Science.gov (United States)

    Upadhyay, A. N.; Tiwari, R. S.; Singh, Kedar

    2016-08-01

    Thin films of Se80Te16Cu4 glassy alloy and 3 wt.% of carbon nanotubes (CNTs) containing Se80Te16Cu4 glassy composite were deposited on clean glass substrate by thermal evaporation technique. The scanning electron microscope and energy dispersive x-ray analysis were performed to investigate the surface morphology and elemental composition of as synthesised samples. The reflectance and transmittance spectra of as-deposited thin films were recorded (200-1100 nm) by using UV/VIS/NIR spectrophotometer. The optical band gap and optical constants such as absorption coefficient (α), refractive index (n) and extinction coefficient (k) of Se80Te16Cu4 and 3 wt.% CNTs-Se80Te16Cu4 glassy composite thin films were calculated. It is observed that optical properties alter due to CNTs incorporation in Se80Te16Cu4 glassy alloy. Effect on optical properties due to CNTs incorporation can be explained in terms of concentration of unsaturated bonds/defects in the localised states.

  10. Corrosion characteristics of Hastelloy N alloy after He+ ion irradiation

    International Nuclear Information System (INIS)

    Lin Jianbo; Yu Xiaohan; Li Aiguo; He Shangming; Cao Xingzhong; Wang Baoyi; Li Zhuoxin

    2014-01-01

    With the goal of understanding the invalidation problem of irradiated Hastelloy N alloy under the condition of intense irradiation and severe corrosion, the corrosion behavior of the alloy after He + ion irradiation was investigated in molten fluoride salt at 700 °C for 500 h. The virgin samples were irradiated by 4.5 MeV He + ions at room temperature. First, the virgin and irradiated samples were studied using positron annihilation lifetime spectroscopy (PALS) to analyze the influence of irradiation dose on the vacancies. The PALS results showed that He + ion irradiation changed the size and concentration of the vacancies which seriously affected the corrosion resistance of the alloy. Second, the corroded samples were analyzed using synchrotron radiation micro-focused X-ray fluorescence, which indicated that the corrosion was mainly due to the dealloying of alloying element Cr in the matrix. Results from weight-loss measurement showed that the corrosion generally correlated with the irradiation dose of the alloy. (author)

  11. AERODYNAMIC IMPROVEMENT OF KhADI 33 RACING CAR RADIATOR COMPARTMENT

    Directory of Open Access Journals (Sweden)

    A. Avershyn

    2011-01-01

    Full Text Available Aerodynamic characteristics of radiator compartment of KhADI 33 racing car on the basis of the decision of the interfaced problem of internal and external aerodynamics are numerically investigated. The rational variant of radiator compartment which is characterized by high throughput and low level of non-uniformity of speed field at the input is offered.

  12. Ureteral in situ biocompatibility of L-lactide-glycolic acid copolymer 80:20 stent

    International Nuclear Information System (INIS)

    Hou Yuchuan; Wang Chunxi; Zhang Baogang; Chen Xuesi

    2006-01-01

    Objective: To evaluate the in situ biocompatibility of a new biodegradable ureteral stent made of L-lactide-glycolic acid copolymer 80:20 (PLGA 80:20). Methods: 16 dogs served as experimental animals. Ureteral stents of PLGA 80:20 were inserted in situ into the left ureter after transection at the mid level, then the ureters were routinely anastomosed. Ureters surrounding the stent were taken out 2, 4, 8 and 12 weeks postoperatively. The ureters were dissected to find changes of stents and local ureters. Histological analysis was performed to investigate tissue reactions to the stent and evaluate the biocompatibility. Rods of UROVISION stent served as controls. Results: The PLGA stent was degraded completely within 12 weeks post implantation. In the early stage (2-4 weeks), both stents induced epithelial hyperplasia and inflammatory cell reaction at local ureter (P>0.05). In the later stage (8-12 weeks), the tissue reaction nearly subsided in PLGA stented ureters after degradation of the device. Whereas, the tissue reaction induced by UROVISION stent had lasted throughout the observation period, even deteriorated with time going (P<0.05). Conclusion: The tissue reaction induced by PLGA stent is retrievable. PLGA is regarded highly compatible and can serve as an ideal material for biodegradable ureteral stent. (authors)

  13. Influence of anisotropic hardening on longitudinal welding strains and stresses

    International Nuclear Information System (INIS)

    Gatovskij, K.M.; Revutskij, M.N.

    1981-01-01

    The algorithm and program for estimation of longitudinal welding strains and stresses with account of hardening and Bauschinger effect, which expand the possibilities of more complete description of stress change during thermodeformation welding cycles at bead surfacing on plate made of the 06Kh18N9T steel and AMg61 alloy. It is shown that for metals, deformation curves which are characterized by considerable yield moduli (Esub(T)/E>=0.05) hardening effect is considerable and its account leads to the decrease of stress level in the heataffected zone (down to 20%) [ru

  14. Ductile long range ordered alloys with high critical ordering temperature and wrought articles fabricated therefrom

    Science.gov (United States)

    Liu, Chain T.; Inouye, Henry

    1979-01-01

    Malleable long range ordered alloys having high critical ordering temperatures exist in the V(Fe, Co).sub.3 and V(Fe, Co, Ni).sub.3 systems. These alloys have the following compositions comprising by weight: 22-23% V, 14-30% Fe, and the remainder Co or Co and Ni with an electron density no more than 7.85. The maximum combination of high temperature strength, ductility and creep resistance are manifested in the alloy comprising by weight 22-23% V, 14-20% Fe and the remainder Co and having an atomic composition of V(Fe .sub.0.20-0.26 C Co.sub.0.74-0.80).sub.3. The alloy comprising by weight 22-23% V, 16-17% Fe and 60-62% Co has excellent high temperature properties. The alloys are fabricable into wrought articles by casting, deforming, and annealing for sufficient time to provide ordered structure.

  15. Thermodynamic investigations of the Mn-Ni-C-N quarternary alloys by solid-state galvanic cell technique

    International Nuclear Information System (INIS)

    Teng Lidong; Aune, Ragnhild; Seetharaman, Seshadri

    2005-01-01

    In view of the important applications of carbides and nitrides of transition metals in the hard materials industries, the thermodynamic activities of manganese in Mn-Ni-C-N alloys have been studied by solid-state galvanic cell technique with CaF 2 as the solid electrolyte. The phase compositions and microstructure of various alloys have been analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Nitrogen was introduced into the alloy by equilibrating with N 2 gas. It was established during the experiments that the solubility of nitrogen in the alloys was affected by the carbon content. A (Mn,Ni) 4 (N,C) nitride was formed during the nitriding procedure in the alloys. The electromotive force (EMF) measurements were carried out in the temperature range 940-1127 K in order to determine the activities of Mn in the alloys. The activities of manganese were calculated and compared with those of the corresponding Mn-Ni-C ternary alloys

  16. Influence of sulphur and phosphorus impurities on ductility of 25Kh2NMFA steel during forging

    International Nuclear Information System (INIS)

    Onishchenko, A.K.

    1989-01-01

    Using cylindrical samples of the 25Kh2NMFA steel with sulfur and phosphorus content in the range of 0.001-0.030%, tensile test with the rate of deformation 10 -3 s -1 at the temperatures of 800-1200 deg C has been conducted. Analysis of fracture foci and plasticity diagrams has shown, that to ensure ductility during forging and high mechanical properties, the content of sulfur and phosphorus impurities in the 25Kh2NMFA steel must not exceed 0.015%

  17. Oxidation of U-20 at% Zr alloy in air at 423-1063 K

    International Nuclear Information System (INIS)

    Matsui, Tsuneo; Yamada, Takanobu; Ikai, Yasushi; Naito, Keiji

    1993-01-01

    The oxidation behavior of U 0.80 Zr 0.20 alloy (two-phase mixture of U and UZr 2 below 878 K and single solid solution above 1008 K) was studied by thermogravimetry in the temperature range from 423 to 1063 K in air. During oxidation in the low temperature region (423-503 K), the sample kept its initial shape (a rectangular rod) and the surface of the sample was covered by a black thin adherent UO 2+x oxide layer. On the other hand, by oxidation in the middle temperature region, the sample broke to several pieces of thin plates and blocks, and fine powder at 643-723 K and entirely to fine powder at 775-878 K, all of which were analyzed to be a mixture of U 3 O 8 and ZrO 2 . By oxidation in the high temperature region (1008-1063 K) the sample broke to very fine powder, which consisted of U 3 O 8 and ZrO 2 . Based on the sample shape, the oxide phase identified after oxidation and the slope value of the bilogarithmic plots of the weight gain against time, the oxidation kinetics was analyzed with a paralinear equation in the low temperature region below 503 K and a linear equation in the middle and high temperature regions above 643 K. Oxidation rates of U 0.80 Zr 0.20 (two-phase mixture) in the low and middle temperature regions were smaller than those of uranium metal. A discontinuity in the plot of the linear oxidation rate constant versus reciprocal temperature was found to be present between 723 and 838 K, similarly to the case of uranium metal previously reported. The linear rate constants of single-phase solid solution in the high temperature region above 1008 K seemed to be a little smaller than those estimated by the extrapolation of the values in the middle temperature region. (orig.)

  18. Oxidation of U-20 at% Zr alloy in air at 423 1063 K

    Science.gov (United States)

    Matsui, Tsuneo; Yamada, Takanobu; Ikai, Yasushi; Naito, Keiji

    1993-01-01

    The oxidation behavior of U 0.80Zr 0.20 alloy (two-phase mixture of U and UZr 2 below 878 K and single solid solution above 1008 K) was studied by thermogravimetry in the temperature range from 423 to 1063 K in air. During oxidation in the low temperature region (423-503 K), the sample kept its initial shape (a rectangular rod) and the surface of the sample was covered by a black thin adherent UO2 + x oxide layer. On the other hand, by oxidation in the middle temperature region, the sample broke to several pieces of thin plates and blocks, and fine powder at 643-723 K and entirely to fine powder at 775-878 K, all of which were analyzed to be a mixture of U 3O 8 and ZrO 2. By oxidation in the high temperature region (1008-1063 K) the sample broke to very fine powder, which consisted of U 3O 8 and ZrO 2. Based on the sample shape, the oxide phase identified after oxidation and the slope value of the bilogarithmic plots of the weight gain against time, the oxidation kinetics was analyzed with a paralinear equation in the low temperature region below 503 K and a linear equation in the middle and high temperature regions above 643 K. Oxidation rates of U 0.80Zr 0.20 (two-phase mixture) in the low and middle temperature regions were smaller than those of uranium metal. A discontinuity in the plot of the linear oxidation rate constant versus reciprocal temperature was found to be present between 723 and 838 K, similarly to the case of uranium metal previously reported. The linear rate constants of single-phase solid solution in the high temperature region above 1008 K seemed to be a little smaller than those estimated by the extrapolation of the values in the middle temperature region.

  19. Corrosion resistance of chromium-nickel steel containing rare earths

    International Nuclear Information System (INIS)

    Asatiani, G.N.; Mandzhgaladze, S.N.; Tavadze, L.F.; Chuvatina, S.N.; Saginadze, D.I.

    1983-01-01

    Effect of additional out-of-furnace treatment with complex alloy (foundry alloy) calcite-silicon-magnesium-rare earth metal on corrosion resistance of the 03Kh18N20M3D3C3B steel has been studied. It is shown that introduction of low additions of rare earths improves its corrosion resistance improves its corrosion resistance in agressive media (in 70% - sulfuric acid) in the range of transition from active to passive state. Effect of additional introduction of rare earth metals is not considerable, if potential of steel corrosion is in the range of stable passive state (32% - sulfuric acid). Additional out-of-furnace treatment with complex foundry alloy, containing rare earth metals, provides a possibility to use a steel with a lower content of Cr, Ni, Mo, than in conventional acid-resistant steels in highly agressive media

  20. Correlation of magnetic and mechanical properties of hydrogenated, compositionally modulated, amorphous Fe80Zr20 films (abstract)

    International Nuclear Information System (INIS)

    Rengarajan, S.; Yun, E.J.; Lee, B.H.; Cho, B.I.; Walser, R.M.

    1996-01-01

    Recent research has demonstrated that large amounts of hydrogen can be electrolytically incorporated in amorphous, compositionally modulated (CM) FeZr films. The first irreversible changes in the magnetic state of an electrolytically hydrogenated iron-rich amorphous alloy were observed. The hydrogen-induced changes in the magnetization were interpreted in terms of specific structural rearrangements. In this work, simultaneous measurements of the variations in the magnetization and mechanical properties of these films were measured as a function of hydrogen charging to further clarify the hydrogen-induced structure changes. The Young close-quote s moduli E and internal friction d of as-deposited, and as-hydrogenated CM Fe 80 Zr 20 thin films were calculated from the displacements of a vibrating composite cantilever, measured using a laser heterodyne interferometer (LHI) having a displacement sensitivity of ∼0.01 A. E and d were measured using the resonant frequency method. CM films with thickness 1390 A and modulation wavelength ∼10 A were deposited on glass cantilevers (5 mm long, 2 mm wide, and 150 μm thick) by sequentially sputtering (rf diode) elemental Fe and Zr targets. The samples were electrolytically hydrogenated for various times in 2 N phosphoric acid with a current density of 26.3 mA/cm 2 . The maximum change in magnetization of the film (from 71.5 to 551 emu/cm 3 ) was observed after 5 min. During this time, E increased 18-fold from 535 GPa to 9.63 TPa. The unusually high Young close-quote s modulus of the as-deposited CM film is comparable to those previously observed in other CM films. The change is three times larger than the change in the E of carbon steel at the martensitic transformation, and nine times larger than the hydrogen induced increase in E of pure single crystals of iron. (Abstract Truncated)

  1. Irradiation effects in magnesium and aluminium alloys

    International Nuclear Information System (INIS)

    Sturcken, E.F.

    1979-01-01

    Effects of neutron irradiation on microstructure, mechanical properties and swelling of several magnesium and aluminium alloys were studied. The neutron fluences of 2-3 X 10 22 n/cm 2 , >0.2 MeV produced displacement doses of 20 to 45 displacements per atom (dpa). Ductility of the magnesium alloys was severely reduced by irradiation induced recrystallization and precipitation of various forms. Precipitation of transmuted silicon occurred in the aluminium alloys. However, the effect on ductility was much less than for the magnesium alloys. The magnesium and aluminium alloys had excellent resistance to swelling: The best magnesium alloy was Mg/3.0 wt% Al/0.19 wt% Ca; its density decreased by only 0.13%. The best aluminium alloy was 6063, with a density decrease of 0.22%. (Auth.)

  2. Amorphous Alloy Membranes Prepared by Melt-Spin methods for Long-Term use in Hydrogen Separation Applications

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, Dhanesh; Kim, Sang-Mun; Adibhatla, Anasuya; Dolan, Michael; Paglieri, Steve; Flanagan, Ted; Chien, Wen-Ming; Talekar, Anjali; Wermer, Joseph

    2013-02-28

    Amorphous Ni-based alloy membranes show great promise as inexpensive, hydrogenselective membrane materials. In this study, we developed membranes based on nonprecious Ni-Nb-Zr alloys by adjusting the alloying content and using additives. Several studies on crystallization of the amorphous ribbons, in-situ x-ray diffraction, SEM and TEM, hydrogen permeation, hydrogen solubility, hydrogen deuterium exchange, and electrochemical studies were conducted. An important part of the study was to completely eliminate Palladium coatings of the NiNbZr alloys by hydrogen heattreatment. The amorphous alloy (Ni0.6Nb0.4)80Zr20 membrane appears to be the best with high hydrogen permeability and good thermal stability.

  3. Research for magnetocaloric effect of Gd{sub 1-x}Dy{sub x} alloy

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Xueling; Shitao, Li; An, Zhang; Hui, Xu; Ni, Jiansen; Zhou, Bangxin [Institute of Materials, Shanghai University, Shanghai 20007 (China)

    2007-12-15

    The magnetocaloric effect (MEC) in Gd{sub 1-x}Dy{sub x} (x=0.13,0.20,0.27,0.34,0.40) alloys is investigated using commercial elements with purity of up to 99.80% for Gd and Dy. These alloys are prepared by arc melting in stoichiometric proportions on a water-cooled copper crucible under high pure argon atmosphere. As a result, when x was changed from 0 to 40at%, the adiabatic temperature change ({delta}T) increases from 1.6 K to 3.1 K, the Curie temperature decreased from 288 K to 245.5 K. Gd{sub 73}Dy{sub 27} exhibits the largest {delta}T{sub max} value of 3.1 K at the T{sub C} value of 260 K among the alloys investigated up to 1.2 T (tesla) applied field, it is almost same as the {delta}T of high pure unitary Gd (99.99%) and is clearly superior to commercial unitary Gd (99.80%). The T{sub C} of Gd{sub 73}Dy{sub 27} alloy is minor to high pure unitary Gd (99.99%) and commercially unitary Gd (99.80%). But this alloy prepared by commercial elements with low cost has better MEC to be a promising candidate for magnetic working substances for room temperature magnetic refrigeration. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Water vapor pressure over molten KH2PO4 and demonstration of water electrolysis at ∼300ºC

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Nikiforov, Aleksey Valerievich; Petrushina, Irina

    2016-01-01

    A new potentially high-efficiency electrolyte for water electrolysis: molten monobasic potassium phosphate, KH2PO4 or KDP has been investigated at temperatures ∼275–325 °C. At these temperatures, KH2PO4 was found to dissociate into H2O gas in equilibrium with a melt mixture of KH2PO4—K2H2P2O7—KPO3...... of water and methane or hydrogen to be 0.40 ± 0.02 or 1.2 ± 0.03. At equilibrium the vapor pressure was much lower than the vapor pressure above liquid water at the same temperature. Electrolysis was realized by passing current through closed ampoules (vacuum sealed quartz glass electrolysis cells...... with platinum electrodes and the electrolyte melt). The formation of mixtures of hydrogen and oxygen gases as well as the water vapor was detected by Raman spectroscopy. In this way it was demonstrated that water is present in the new electrolyte: molten KH2PO4 can be split by electrolysis via the reaction 2H2O...

  5. Novel Amorphous Fe-Zr-Si(Cu) Boron-free Alloys

    Science.gov (United States)

    Kopcewicz, M.; Grabias, A.; Latuch, J.; Kowalczyk, M.

    2010-07-01

    Novel amorphous Fe80(ZrxSi20-x-y)Cuy boron-free alloys, in which boron was completely replaced by silicon as a glass forming element, have been prepared in the form of ribbons by a melt quenching technique. The X-ray diffraction and Mössbauer spectroscopy measurements revealed that the as-quenched ribbons with the composition of x = 6-10 at. % and y = 0, 1 at. % are predominantly amorphous. DSC measurements allowed the estimation of the crystallization temperatures of the amorphous alloys. The soft magnetic properties have been studied by the specialized rf-Mössbauer technique in which the spectra were recorded during an exposure of the samples to the rf field of 0 to 20 Oe at 61.8 MHz. Since the rf-collapse effect observed is very sensitive to the local anisotropy fields it was possible to evaluate the soft magnetic properties of amorphous alloys studied. The rf-Mössbauer studies were accompanied by the conventional measurements of the quasi-static hysteresis loops from which the magnetization and coercive fields were estimated. It was found that amorphous Fe-Zr-Si(Cu) alloys are magnetically very soft, comparable with those of the conventional amorphous B-containing Fe-based alloys.

  6. On the protective effect of KhOSP-10 inhibitor during corrosion, hydrogenadsorption and corrosion cracking of a steel in sulfuric acid

    International Nuclear Information System (INIS)

    Mindyuk, A.K.; Svist, E.I.; Savitskaya, O.P.; Goyan, E.B.; Gopanenko, A.N.

    1975-01-01

    The protective propeties of inhibitor KhOSP-10 in the time of corrosion and corrosive cracking of steel 40Kh are higher then those of inhibitors KPI-1, KI-1, I-I-V etc. Its ability to reduce steel hydrogenation is the same as in the case of KPI-1 inhibitor i.e. below that of KI-1. HCl additives enhance the efficiency of inhibitors KPI-1, KI-1, I-1-V etc. up to the protective ability of KhOSP-10. Kinetics of the electrode processes was estimated from polarization curves

  7. Hydrogen effect on mechanical properties and flake formation in the 10KhSND steel rolled plates

    Energy Technology Data Exchange (ETDEWEB)

    Muradova, R G; Zakharov, V A; Kuzin, A P; Gol' tsov, V A; Podgajskij, M S [Donetskij Politekhnicheskij Inst. (Ukrainian SSR); Donetskij Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii (Ukrainian SSR))

    1982-01-01

    The effect of hydrogen on mechanical properties of the 10KhSND steel rolled plates during natural aging is studied. Optimum period of metal acceptance tests, which are advisable to conduct after 5-7 day natural aging of finished products, are found out. The technique is worked out and a safe hydrogen content to prevent flake formation in the 10KhSND steel is determined. It is shown that a safe hydrogen content is dependent on the experiment conditions (sample dimensions, conditions of cooling, and prehistory).

  8. Hydrogen effect on mechanical properties and flake formation in the 10KhSND steel rolled plates

    International Nuclear Information System (INIS)

    Muradova, R.G.; Zakharov, V.A.; Kuzin, A.P.; Gol'tsov, V.A.; Podgajskij, M.S.

    1982-01-01

    The effect of hydrogen on mechanical properties of the 10KhSND steel rolled plates during natural aging is studied. Optimum period of metal acceptance tests, which are advisable to conduct after 5-7 day natural aging of finished products, are found out. The technique is worked out and a safe hydrogen content to prevent flake formation in the 10KhSND steel is determined. It is shown that a safe hydrogen content is dependent on the experiment conditions (sample dimensions, conditions of cooling, and prehistory)

  9. Meat quality attributes of the Longissimus lumborum muscle of the Kh'ara genotype of llama (Lama glama) reared extensively in northern Chile.

    Science.gov (United States)

    Mamani-Linares, L W; Gallo, C B

    2013-05-01

    Twenty male llama of the Kh'ara genotype, reared extensively in the north of Chile, were slaughtered at ages between 2 and 4 permanent teeth (2 to 3.5years) and analyses were carried out on the Longissimus lumborum muscle, including composition (moisture, fat, protein, ash, cholesterol, amino acids, fatty acid profile and collagen content) and meat quality parameters (pH, color, water holding capacity and Warner-Bratzler shear-force). Llama meat was characterized by a low cholesterol (39.04mg/100g) and intramuscular fat (1.56%) content, a total collagen content of 6.28mg/g, of which 20.28% was soluble collagen. Amino acid composition and fatty acid profile were similar to those found for beef finished on forage. Llama meat showed a low n-6/n-3 (4.69) and hypocholesterolemic/hypercholesterolemic (1.55) ratio and acceptable values of DFA (65.78%). Quality parameters in llama Longissimus muscle were within the ranges reported for more traditional meats such as beef and lamb. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Nontoxic corrosion inhibitors for N80 steel in hydrochloric acid

    OpenAIRE

    M. Yadav; Debasis Behera; Usha Sharma

    2016-01-01

    The purpose of this paper is to evaluate the protective ability of 1-(2-aminoethyl)-2-oleylimidazoline (AEOI) and 1-(2-oleylamidoethyl)-2-oleylimidazoline (OAEOI) as corrosion inhibitors for N80 steel in 15% hydrochloric acid, which may find application as eco-friendly corrosion inhibitors in acidizing processes in petroleum industry. Different concentrations of synthesized inhibitors AEOI and OAEOI were added to the test solution (15% HCl) and the corrosion inhibition of N80 steel in hydroch...

  11. The tensile properties of alloys 800H and 617 in the range 20 to 950deg C

    International Nuclear Information System (INIS)

    Abd El-Azim, M.E.; Ennis, P.J.; Schuster, H.; Nickel, H.

    1990-01-01

    The tensile properties of Alloy 800H and Alloy 617 in the solution treated condition and after ageing or carburization have been determined for the temperature range 20 to 950deg C. It was found that ageing at 900deg C prior to testing led to an increase in strength and a decrease in ductility at test temperatures up to 700deg C. Above 700deg C, there was no significant difference between the tensile properties of solution treated and aged material. Carburization caused a severe loss of ductility in both alloys at temperatures of 20 to around 800deg C, but the ductility increased sharply at test temperatures above 800deg C, accompanied by a change in the fracture mode from fracture of the carbide particles themselves to void formation and separation at the carbide/matrix interface. The correlation between tensile properties and creep data was investigated in tests carried out at different strain rates. Reasonable agreement was found at 800 to 950deg C for Alloy 617 and at 800 to 900deg C for Alloy 800H. Strain ageing effects were observed in both alloys at some temperatures and strain rates; these effects were serrated flow, negative strain rate sensitivity, peaks in the normalized UTS-temperature curves and plateaus in the elongation-temperature curves. The experimental results were interpreted in the light of two current models for strain ageing, the dislocation-dislocation interaction model and the dislocation-solute interaction model. (orig.) [de

  12. Porphyrins as Corrosion Inhibitors for N80 Steel in 3.5% NaCl Solution: Electrochemical, Quantum Chemical, QSAR and Monte Carlo Simulations Studies

    Directory of Open Access Journals (Sweden)

    Ambrish Singh

    2015-08-01

    Full Text Available The inhibition of the corrosion of N80 steel in 3.5 wt. % NaCl solution saturated with CO2 by four porphyrins, namely 5,10,15,20-tetrakis(4-hydroxyphenyl-21H,23H-porphyrin (HPTB, 5,10,15,20-tetra(4-pyridyl-21H,23H-porphyrin (T4PP, 4,4′,4″,4‴-(porphyrin-5,10,15,20-tetrayltetrakis(benzoic acid (THP and 5,10,15,20-tetraphenyl-21H,23H-porphyrin (TPP was studied using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization, scanning electrochemical microscopy (SECM and scanning electron microscopy (SEM techniques. The results showed that the inhibition efficiency, η% increases with increasing concentration of the inhibitors. The EIS results revealed that the N80 steel surface with adsorbed porphyrins exhibited non-ideal capacitive behaviour with reduced charge transfer activity. Potentiodynamic polarization measurements indicated that the studied porphyrins acted as mixed type inhibitors. The SECM results confirmed the adsorption of the porphyrins on N80 steel thereby forming a relatively insulated surface. The SEM also confirmed the formation of protective films of the porphyrins on N80 steel surface thereby protecting the surface from direct acid attack. Quantum chemical calculations, quantitative structure activity relationship (QSAR were also carried out on the studied porphyrins and the results showed that the corrosion inhibition performances of the porphyrins could be related to their EHOMO, ELUMO, ω, and μ values. Monte Carlo simulation studies showed that THP has the highest adsorption energy, while T4PP has the least adsorption energy in agreement with the values of σ from quantum chemical calculations.

  13. Coulomb dissociation of N-20,N-21

    NARCIS (Netherlands)

    Roeder, Marko; Adachi, Tatsuya; Aksyutina, Yulia; Alcantara, Juan; Altstadt, Sebastian; Alvarez-Pol, Hector; Ashwood, Nicholas; Atar, Leyla; Aumann, Thomas; Avdeichikov, Vladimir; Barr, M.; Beceiro, Saul; Bemmerer, Daniel; Benlliure, Jose; Bertulani, Carlos; Boretzky, Konstanze; Borge, Maria J. G.; Burgunder, G.; Caamano, Manuel; Caesar, Christoph; Casarejos, Enrique; Catford, Wilton; Cederkall, Joakim; Chakraborty, S.; Chartier, Marielle; Chulkov, Leonid; Cortina-Gil, Dolores; Crespo, Raquel; Pramanik, Ushasi Datta; Diaz-Fernandez, Paloma; Dillmann, Iris; Elekes, Zoltan; Enders, Joachim; Ershova, Olga; Estrade, A.; Farinon, F.; Fraile, Luis M.; Freer, Martin; Freudenberger, M.; Fynbo, Hans; Galaviz, Daniel; Geissel, Hans; Gernhaeuser, Roman; Goebel, Kathrin; Kalantar-Nayestanaki, Nasser; Najafi, Mohammad Ali; Rigollet, Catherine; Stoica, V.; Streicher, Branislav; Van de Walle, J.

    2016-01-01

    Neutron-rich light nuclei and their reactions play an important role in the creation of chemical elements. Here, data from a Coulomb dissociation experiment on N-20,N-21 are reported. Relativistic N-20,N-21 ions impinged on a lead target and the Coulomb dissociation cross section was determined in a

  14. Effect of Solution Treatment on Precipitation Behaviors, Age Hardening Response and Creep Properties of Elektron21 Alloy Reinforced by AlN Nanoparticles.

    Science.gov (United States)

    Saboori, Abdollah; Padovano, Elisa; Pavese, Matteo; Dieringa, Hajo; Badini, Claudio

    2017-12-02

    In the present study, the solution and ageing treatments behavior of Mg-RE-Zr-Zn alloy (Elektron21) and its nano-AlN reinforced nanocomposites have been evaluated. The properties of the thermal-treated materials were investigated in terms of Vickers hardness, the area fraction of precipitates, microstructure and phase composition. The solution treatments were performed by treating at 520 °C, 550 °C and 580 °C in argon atmosphere. The outcomes show that the hardness of the solutionized alloys was slightly affected by the solution temperature. X-ray diffraction and image analysis revealed that the complete dissolution of precipitates was not possible, neither for Elektron21 (El21) nor for its AlN containing nanocomposites. The ageing treatment of El21 led to a significant improvement in hardness after 20 h, while for longer times, it progressively decreased. The effect of ageing on the hardness of El21-AlN composites was found to be much less than this effect on the hardness of the host alloy. Electron backscatter diffraction (EBSD) analysis of El21 and El21-1%AlN after solution treatment confirm the random orientation of grains with a typical texture of random distribution. The as-cast creep results showed that the incorporation of nanoparticles could effectively improve the creep properties, while the results after solution treatment at 520 °C for 12 h followed by ageing treatment at 200 °C for 20 h confirmed that the minimum creep rate of T6-El21 was almost equal to the as-cast El21-AlN.

  15. Early stages of the mechanical alloying of TiC–TiN powder mixtures

    International Nuclear Information System (INIS)

    Mura, Giovanna; Musu, Elodia; Delogu, Francesco

    2013-01-01

    The present work focuses on the alloying behavior of TiC–TiN powder mixtures submitted to mechanical processing by ball milling. Accurate X-ray diffraction analyses indicate a progressive modification of the unit cell parameters of the TiC and TiN phases, suggesting the formation of TiC- and TiN-rich solid solutions with an increasingly larger content of solutes. Once the discrete character of the mechanical treatment is taken into due account, the smooth change of the unit cell parameters can be explained by a sequence of mutual dissolution stages related to individual collisions. At each collision, the average chemical composition of small amounts of TiC- and TiN-rich phases changes discontinuously. The discontinuous changes can be tentatively ascribed to local mass transport processes activated by the mechanical deformation of powders at collisions. -- Highlights: ► Mechanically processed TiC–TiN powder mixtures form two solid solutions. ► An analytical model was developed to describe the mechanical alloying kinetics. ► The amount of powder alloyed at collision was indirectly estimated. ► A few nanomoles of material participate in the alloying process at each collision. ► The chemical composition of the solid solutions was shown to change discontinuously.

  16. Transmission electron microscopy of aged Ti-10Mo-20Nb alloy after hot swaging; Microscopia eletronica de transmissao da liga Ti-10Mo-20Nb envelhecida apos forjamento a quente

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Sinara Borborema, E-mail: sinarab@msn.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Baldan, Renato, E-mail: renatobaldan@gmail.com [Universidade de Sao Paulo (EEL/USP), Lorena, SP (Brazil). Escola de Engenharia; Torres, Juliana; Oliveira, Nathalia Rodrigues, E-mail: juliana_torres_5@hotmail.com, E-mail: nathalia_roliveira@yahoo.com.br [Centro Universitario de Volta Redonda (UNIFOA), Volta Redonda, RJ (Brazil); Nunes, Carlos Angelo; Mei, Paulo Roberto, E-mail: cnunes@demar.eel.usp.br, E-mail: pmei@fem.unicamp.br [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil)

    2014-08-15

    Ti alloys are widely used in biomedical applications. Within this class, metastable β -Ti alloys stand, because through thermomechanical processing it is possible to obtain mechanical properties and in particular one suitable Young's modulus for biomedical applications. These alloys require high mechanical strength and a low Young's modulus to avoid stress shielding. Preliminary studies showed that the microstructure of the Ti-10Mo- 20Nb alloy after cold forging and aging 500 °C/24 h consisted in bimodal distribution of α phase in the β matrix. The aim of this study was to characterize the microstructure of Ti-10Mo-20Nb alloy after hot forging and aging at 500 °C for 24 hours. Microstructural characterization consisted of analyzes by X-ray diffraction and transmission electron microscopy. According to the results, while the cold forging resulted in a bimodal α distribution in the β matrix, hot forging resulted in a thin and homogeneous α precipitation in the β matrix. (author)

  17. TEM microstructural characterization of melt-spun aged Al-6Si-3Cu-xMg alloys

    International Nuclear Information System (INIS)

    Lopez, Ismeli Alfonso; Zepeda, Cuauhtemoc Maldonado; Gonzalez Reyes, Jose Gonzalo; Flores, Ariosto Medina; Rodriguez, Juan Serrato; Gomez, Luis Bejar

    2007-01-01

    Three Al-6Si-3Cu-xMg alloys (x = 0.59, 3.80 and 6.78 wt.%) were produced using melt-spinning. As-melt-spun ribbons were aged at 150, 180 and 210 deg. C for times between 0.05 and 100 h. Microstructural changes were examined using transmission electron microscopy (TEM) and microhardness was measured. TEM analysis of the as-melt-spun alloys revealed 5 nm nanoparticles and larger particles (50 nm) composed of Al 2 Cu (θ) for the 0.59% Mg alloy and Al 5 Cu 2 Mg 8 Si 6 (Q) for 3.80% and 6.78% Mg alloys. Silicon solid solubility was extended to 9.0 at.% and Mg in solid solution reached 6.7 at.%. After aging treatments the 6.78% Mg alloy exhibited the most significant increase in microhardness, reaching 260 kg/mm 2 . TEM analysis of aged specimens also showed θ and Q phase (5-20 nm nanoparticles and 35-40 nm particles). The combination of the volume fraction and size of the particles plays an important role in microhardness variation

  18. Facile directing agent-free synthesis and magnetism of nanocrystalline Fe–Ni alloy with tunable shape

    International Nuclear Information System (INIS)

    Mohamed, Marwa A.A.

    2014-01-01

    Highlights: • Simple directing agent-free wet chemical method for high-yield synthesis of nc Fe-Ni particles with tunable shape. • The alloy morphology is controlled by varying synthesis conditions; concentration of metal ions and pH of reaction. • Synthesis conditions control the final shape of alloy particles via controlling their growth rate and capping with OH − ions. • The alloy magnetic behavior is driven away from soft magnetic toward hard one, by particles anisotropy and size reduction. • The branched wires morphology can be considered a new morphology of distinctive magnetic behavior, for nc Fe-Ni alloy. - Abstract: This article reports the synthesis of nanocrystalline (nc) Fe 20 Ni 80 particles with tunable shape, using a heterogeneous directing agent-free aqueous wet chemical method of mild synthesis conditions. The particle morphology has been controlled by varying synthesis conditions. The results demonstrate that the morphology of alloy particles changes from quasi-isotropic to anisotropic architecture by decreasing concentration of metal ions or increasing pH of reaction solution. Deep interpretations of such phenomena are reported. Magnetic behavior of the alloy is driven away from soft magnetic and toward hard magnetic behavior, by anisotropy and size reduction of alloy particles. This broadens practical applications of nc Fe 20 Ni 80 alloy. Overall, the study provides an effective economical way for high-yield synthesis of nc Fe–Ni particles with tailored shape and subsequently magnetic properties for a specific technological application. Additionally, it adds a new morphology, highly branched wires, of distinctive magnetic behavior to the known morphologies of nc Fe–Ni particles

  19. MINGAU SEMI-INSTANTÂNEO DE CANJIQUINHA-SOJA (80:20 OBTIDO PELO PROCESSO DE EXTRUSÃO

    Directory of Open Access Journals (Sweden)

    SIN-HUEI WANG

    2009-07-01

    Full Text Available

    Com o objetivo de obter um mingau semi-instantâneo para nutrição infantil, foi extrusada uma mistura de canjiquinha e soja (80:20 usando-se extrusor Brabender de dupla rosca com velocidade de alimentação constante de 20,8 kg/h, velocidade da rotação de parafuso de 100 rpm e diâmetro de matriz de 5 mm. Os perfis da temperatura de barril (TB foram: zona 1, 60°C (constante, zona 2, 90°C (constante, zona 3, 90, 110, 130 ou 150°C, e zona 4 (matriz 110, 130 ou 150°C. Os resultados mostraram que o aumento da TB na zona 3 causou um aumento na viscosidade inicial (VI, solubilidade de nitrogênio (SN e dispersibilidade de proteína (DP, porém uma diminuição na temperatura de viscosidade máxima (tºVmáx, viscosidade máxima (Vmáx , viscosidade mínima (Vmín e viscosidade final (VF das farinhas extrusadas de canjiquinha-soja (80:20. O aumento da TB na zona 4 resultou num aumento na VI, Vmáx, Vmín, SN e DP, porém numa diminuição na tºVmáx e VF. Os mingaus submetidos anteriormente às TBs em 130-130 e 130-150ºC nas zonas 3 e 4, respectivamente, apresentaram melhor aparência, consistência e sabor, sendo igualmente preferidos pelos consumidores. Não houve atividade do inibidor de tripsina nas farinhas extrusadas estudadas.

  20. Electrochemical Impedance Spectroscopy Of Metal Alloys

    Science.gov (United States)

    Macdowell, L. G.; Calle, L. M.

    1993-01-01

    Report describes use of electrochemical impedance spectroscopy (EIS) to investigate resistances of 19 alloys to corrosion under conditions similar to those of corrosive, chloride-laden seaside environment of Space Transportation System launch site. Alloys investigated: Hastelloy C-4, C-22, C-276, and B-2; Inconel(R) 600, 625, and 825; Inco(R) G-3; Monel 400; Zirconium 702; Stainless Steel 304L, 304LN, 316L, 317L, and 904L; 20Cb-3; 7Mo+N; ES2205; and Ferralium 255. Results suggest electrochemical impedance spectroscopy used to predict corrosion performances of metal alloys.

  1. Coulomb dissociation of N 20,21

    OpenAIRE

    Röder, Marko; Adachi, Tatsuya; Aksyutina, Yulia; Alcantara, Juan; Altstadt, Sebastian; Alvarez-Pol, Hector; Ashwood, Nicholas; Atar, Leyla; Aumann, Thomas; Avdeichikov, Vladimir; Barr, M.; Beceiro, Saul; Bemmerer, Daniel; Benlliure, Jose; Bertulani, Carlos

    2016-01-01

    Neutron-rich light nuclei and their reactions play an important role in the creation of chemical elements. Here, data from a Coulomb dissociation experiment on N20,21 are reported. Relativistic N20,21 ions impinged on a lead target and the Coulomb dissociation cross section was determined in a kinematically complete experiment. Using the detailed balance theorem, the N19(n,γ)N20 and N20(n,γ)N21 excitation functions and thermonuclear reaction rates have been determined. The N19(n,γ)N20 rate is...

  2. Successive carbon- and boron saturation of KhVG steel in powder mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Alimov, Yu A; Gordienko, S I

    1975-01-01

    Method of successive saturation of KhVG steel with carbon and boron in powder mixtures is described. After carbonization of steel in a charcoal carburator at 930 deg C during 3 hrs a domain of equiaxial large grains is formed there the latter representing carbides of Fe/sub 3/C and (Fe, M)/sub 3/C. The increase of duration of carbonization up to 5 hrs and above results in formation of a cement grid greatly impairing the mechanical properties of the metal. Carbonization is followed by borating in powdered technical boron carbide at 900 deg C for 4 hrs which ensures formation on the sample surface of a borated layer with depth up to 65 mkm covering the carbonized zone. As followed from metallographic and x-ray structural analysis, the borated layer consists of boride needles with complex composition (Fe, Cr, Mn)B. Oil hardening of carbonized KhVG steel from 850 deg C and low-temperature tempering at 180 deg C for 1 hr results in formation in the main metal of martensite-carbide structure and, respectively, in the decrease of the microhardness gradient between the diffusion layers, as compared with borated KhVG steel. Operation tests of strengthened matrices of preforming machines under the conditions of application of dynamic pressing forces up to 1500 kg Fce/cm/sup 2/ demonstrated that the cyclical strength of carboborated coverings is 2.0-3.0 times higher than that of borated ones. The method of carboborating is recommended for strengthening the details of stamp and press tools.

  3. Vaporization study on lanthanum-neodymium alloys by mass-spectrometry

    International Nuclear Information System (INIS)

    Shoji, Y.; Matsui, T.

    1999-01-01

    Partial vapor pressure of Nd(g) over La x Nd 1-x alloys (x = 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80 and 0.90) was measured with a time-of-flight mass-spectrometer equipped with a tungsten Knudsen cell over the temperature range of 1474-1767 K. Thermodynamic activity of neodymium in the liquid alloys was determined by comparing the partial vapor pressure of Nd(g) over the alloys with that over the pure metal. The thermodynamic activity of lanthanum in the alloys was calculated from that of neodymium obtained experimentally in this study by graphic integration using the Gibbs-Duhem equation. Both activities for each element, thus obtained, showed positive deviations from Raoult's law over the entire compositional range. Thermodynamic quantities such as Gibbs free energy of formation, excess enthalpy etc. were also calculated from the thermodynamic activities. (orig.)

  4. Investigation of secondary hardening in Co–35Ni–20Cr–10Mo alloy using analytical scanning transmission electron microscopy

    International Nuclear Information System (INIS)

    Sorensen, D.; Li, B.Q.; Gerberich, W.W.; Mkhoyan, K.A.

    2014-01-01

    The mechanism of secondary hardening in MP35N (Co–35Ni–20Cr–10Mo) alloy due to exposures at elevated temperatures has been studied. It was observed that short exposure to elevated temperatures increased the ultimate tensile strength and yield stress while decreasing the elongation of MP35N wires. Upon aging at temperatures from 300 to 900 °C the elastic modulus increased although no changes in crystallographic orientation or microstructure were observed. The grain size and major texture components were unchanged following aging. Analytical scanning transmission electron microscope investigation showed that MP35N is hardened by preferential segregation of molybdenum to stacking faults and deformation twins. It also revealed that the concentration of molybdenum segregation was proportional to the amount of initial cold work before aging

  5. About Moral Ideals of Turkic Philosopher M.Kh. Dulaty

    Directory of Open Access Journals (Sweden)

    Botagoz S.Asankulova

    2015-04-01

    Full Text Available The ideas of moral upbringing during the period of Kazakh kingdom on the example of M.Kh.Dulaty ҆s work «Tarikh-i-Rashidi» are given in the article. The main idea is historical-pedagogical aspect of investigation of moral upbringing problems. Genesis of progressive ideas in this direction is the basis of historical experience, which allows to define the dynamics of upbringing process contributing to the moral perfection of personality.

  6. Thermodynamics of complex structures formed between single-stranded DNA oligomers and the KH domains of the far upstream element binding protein

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Kaushik; Sinha, Sudipta Kumar; Bandyopadhyay, Sanjoy, E-mail: sanjoy@chem.iitkgp.ernet.in [Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur 721302 (India)

    2016-05-28

    The noncovalent interaction between protein and DNA is responsible for regulating the genetic activities in living organisms. The most critical issue in this problem is to understand the underlying driving force for the formation and stability of the complex. To address this issue, we have performed atomistic molecular dynamics simulations of two DNA binding K homology (KH) domains (KH3 and KH4) of the far upstream element binding protein (FBP) complexed with two single-stranded DNA (ss-DNA) oligomers in aqueous media. Attempts have been made to calculate the individual components of the net entropy change for the complexation process by adopting suitable statistical mechanical approaches. Our calculations reveal that translational, rotational, and configurational entropy changes of the protein and the DNA components have unfavourable contributions for this protein-DNA association process and such entropy lost is compensated by the entropy gained due to the release of hydration layer water molecules. The free energy change corresponding to the association process has also been calculated using the Free Energy Perturbation (FEP) method. The free energy gain associated with the KH4–DNA complex formation has been found to be noticeably higher than that involving the formation of the KH3–DNA complex.

  7. Quasicrystalline and crystalline phases in Al65Cu20(Fe, Cr)15 alloys

    International Nuclear Information System (INIS)

    Liu, W.; Koester, U.; Mueller, F.; Rosenberg, M.

    1992-01-01

    Two types of icosahedral quasicrystals are observed in Al 65 Cu 20 Fe 15-x Cr x (0 ≤ x ≤ 15) alloys, the face-centred AlCuFe-type icosahedral phase with dissoluted Cr and the primitive AlCuCr-type icosahedral phase with dissoluted Fe. In the vicinity of Al 65 Cu 20 Fe 8 Cr 7 a stable decagonal phase (a=0.45 nm and c=1.23 nm) forms competitively with the icosahedral quasicrystals. All these three quasicrystalline phases can be regarded as Hume-Rothery phases stabilized by the energy band factor. The density is measured to be 4.57, 4.44, and 4.11 g/cm 3 for the icosahedral Al 65 Cu 20 Fe 15 , the decagonal Al 65 Cu 20 Fe 8 Cr 7 , and the icosahedral Al 65 Cu 20 Cr 15 alloys, respectively. Depending on the composition in the range between Al 65 Cu 20 Fe 8 Cr 7 and Al 65 Cu 20 Cr 15 , several crystalline phases are observed during the transormation of the AlCuCr-type icosahedral phase: the 1/1-3/2-type orthorhombic (o) and the 1/0-3/2-type tetragonal (t) approximants of the decagonal phase, a hexagonal (h) phase, as well as a long-range vacancy ordered τ 3 -phase derived from a CsCl-type structure with a=0.2923 nm. The structures of all the crystalline phases are closely related to those of the icosahedral (i) and decagonal (d) quasicrystals, which leads to a definite orientation relationship as follows: i5 parallel d10 parallel o[100] parallel t[100] parallel h[001] parallel τ 3 [110]. (orig.)

  8. El método de Newton para la optimización de una nueva ecuación constitutiva para la fluencia plástica dependiente de la deformación. Aplicación a las aleaciones de magnesio AZ80 y AZ61

    Directory of Open Access Journals (Sweden)

    Gutiérrez, V.

    2013-10-01

    Full Text Available A new numerical algorithm has been developed, based on Newton's method, for optimizing the parameters of a new strain dependent constitutive equation, based on the Garofalo equation. The adjustment is direct, with second order algorithms, for an equation derived from that of Garofalo with a nonlinear objective function. This new optimization algorithm has been applied to creep data of two magnesium alloys AZ80 and AZ61, having an unusual plastic behavior. A certain pseudo-stationary exists in the curves studied, in the sense that the usual deformation states are not manifested in an obvious way. The parameters of the new constitutive equation, dependent on strain, have been determined for these alloys. For analyzing the precision of the parameters and the accuracy of modeling of the stress-strain curves, a statistical treatment has been applied which allows assessing the quality of the constitutive equation proposed and the consistency of these parameters. Stress-strain curves have been compared with the modeling results, reaching a good agreement between the experimental data and the resulting modeling.Se ha desarrollado un nuevo algoritmo numérico, basado en el método de Newton, para la optimización de los parámetros de una nueva ecuación constitutiva, dependiente de la deformación, derivada de la ecuación de Garofalo. El ajuste es directo, con algoritmos de segundo orden, de una ecuación derivada de la de Garofalo con una función objetivo no lineal. Este nuevo algoritmo de optimización ha sido aplicado a los datos de fluencia de dos aleaciones de magnesio, AZ80 y AZ61, con un comportamiento plástico inusual, existiendo una pseudo-estacionariedad en algunas de las curvas estudiadas, en el sentido de que no se manifiestan de forma evidente los estados usuales de deformación. Se han obtenido los parámetros de la nueva ecuación constitutiva, dependiente de la deformación, para estas aleaciones. Para el análisis de la precisión de

  9. Preliminary heat treatment of 4KhM2Fch die steel

    International Nuclear Information System (INIS)

    Leonidov, V.M.; Berezkin, Y.A.; Nikitenko, E.V.

    1986-01-01

    To improve the machinability and preparation of the structure for hardening, die steels are given a preliminary treatment which provides a reduction in hardness as a result of separation in the structure of the carbide and ferrite phases, coagulation of the carbides, and acquisition by them of a granular form and also the obtaining of fine grains and a uniform distribution of the structural constituents. The microstructure was evaluated after etching in 4% nital on an MIM-8M microscope. The 4KhM2Fch steel was given a preliminary heat treatment of normalize and anneal. It was concluded that for 4KhM2Fch steel a preliminary heat treatment of normalizing from 950 0 C with a hold of 1.5-2 h, annealing at 750-760 0 C with a hold of 2-3 h, cooling to the isothermal temperature of 670-680 0 C with a hold of 3-4 h, and further air cooling is recommended. The structure after such a heat is granular pearlite with a rating 1-2 and a hardness of 220-250 HB

  10. Effects of fabrication practices and techniques on the corrosion and mechanical properties of Ni-Cr-Mo nickel based alloys UNS N10276, N06022, N06686, and N06625

    International Nuclear Information System (INIS)

    Hinshaw, E.B.; Crum, J.R.

    1996-01-01

    Ni-Cr-Mo alloys have excellent resistance to both oxidizing and reducing type environments; however, heat treating, surface condition, welding, and type of welding consumable can have a significant affect on the corrosion resistance and mechanical properties of these alloys. It is also important when performing standard ASTM intergranular corrosion tests on welded test coupons to make an accurate comparison of alloys being tested. A standard weld procedure and consistent post-weld sample conditioning method should be incorporated into the comparison test program. An evaluation of the effect of various fabrication practices on the corrosion resistance of the alloy was performed using accelerated corrosion tests ASTM G28B. The fabrication conditions examined were as-welded, welded-pickled, welded-annealed-pickled, welded annealed ground, welded-ground, using over matching filler metals, and various levels of heat input. In addition to fabrication techniques, the effect of ASTM G28B test duration on corrosion rates of UNS N10276, N06022, N06686, and N06625 was evaluated. ASTM G28A intergranular corrosion and mechanical testing using welded coupons of UNS N06625 were also performed to determine the affect of post-weld annealing and aging heat treatments on the corrosion resistance and mechanical properties of UNS N06625

  11. Early stages of the mechanical alloying of TiC-TiN powder mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Mura, Giovanna [Dipartimento di Ingegneria Elettrica ed Elettronica, Universita degli Studi di Cagliari, via Marengo 2, 09123 Cagliari (Italy); Musu, Elodia [Industrial Telemicroscopy Laboratory, Sardegna Ricerche, Polaris, Technology Park of Sardinia, Edificio 3, Loc. Piscinamanna, 09010 Pula (Italy); Delogu, Francesco, E-mail: francesco.delogu@dimcm.unica.it [Dipartimento di Ingegneria Meccanica, Chimica, e dei Materiali, Universita degli Studi di Cagliari, via Marengo 2, I-09123 Cagliari (Italy)

    2013-01-15

    The present work focuses on the alloying behavior of TiC-TiN powder mixtures submitted to mechanical processing by ball milling. Accurate X-ray diffraction analyses indicate a progressive modification of the unit cell parameters of the TiC and TiN phases, suggesting the formation of TiC- and TiN-rich solid solutions with an increasingly larger content of solutes. Once the discrete character of the mechanical treatment is taken into due account, the smooth change of the unit cell parameters can be explained by a sequence of mutual dissolution stages related to individual collisions. At each collision, the average chemical composition of small amounts of TiC- and TiN-rich phases changes discontinuously. The discontinuous changes can be tentatively ascribed to local mass transport processes activated by the mechanical deformation of powders at collisions. -- Highlights: Black-Right-Pointing-Pointer Mechanically processed TiC-TiN powder mixtures form two solid solutions. Black-Right-Pointing-Pointer An analytical model was developed to describe the mechanical alloying kinetics. Black-Right-Pointing-Pointer The amount of powder alloyed at collision was indirectly estimated. Black-Right-Pointing-Pointer A few nanomoles of material participate in the alloying process at each collision. Black-Right-Pointing-Pointer The chemical composition of the solid solutions was shown to change discontinuously.

  12. Innovative Education and Science in Information Technologies: Experience of M.Ye. Zhukovsky National Aerospace University «KhAI»

    Directory of Open Access Journals (Sweden)

    Kryvtsov, V.S.

    2015-05-01

    Full Text Available Information technologies are among the most promising and fastest growing sectors in the world and Ukrainian industry. In the paper the authors share the experience of National Aerospace University «KhAI» in personnel education and training for the IT industry and the results of successful cooperation with IT companies. Innovative education programs, scientific and practical researches in information technologies, which are implementing in KhAI are also discussed.

  13. Structural evolutions of the mechanically alloyed Al70Cu20Fe10 ...

    Indian Academy of Sciences (India)

    The i-phase was observed only for short-time milled powders after heat treatment above 600°C. The -phase was one of the major phases in the Al70Cu20Fe10 alloy. The w-Al7Cu2Fe1 phase (w-phase) was obtained only after heat treatment of the short-time milled and unmilled samples. The present investigation ...

  14. Double stage crystallization of bulk Ge20Te80 glass

    International Nuclear Information System (INIS)

    Parthasarathy, G.; Bandyopadhyay, A.K.; Gopal, E.S.R.; Subbanna, G.N.

    1984-01-01

    The growing interest of the semiconducting glasses is partly because of their interesting electrical and optical properties. These properties are usually connected with their crystallization. In many glasses, the glass-supercooled liquid transition precedes crystallization. The glass transition temperature (Tsub(g)) is found to exhibit multistage processes for a few systems. In this communication, we report the observation of a double Tsub(g) effect in bulk Ge 20 Te 80 glass and also explain the structural changes taking place in the two stages. (author)

  15. Influence of heat treatment on the strength and fracture toughness of 7N01 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bo [School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan (China); Wang, Xiaomin, E-mail: xmwang991011@163.com [School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan (China); Chen, Hui; Hu, Jie [School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan (China); Huang, Cui [School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan (China); Gou, Guoqing [School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan (China)

    2016-09-05

    7N01 aluminum (Al) alloys are treated by five heat treatment methods as peak aging (T6), over aging (T74), high temperature and subsequently low temperature aging (HLA), retrogression and reaging (RRA) and double retrogression and reaging (DRRA). The strength and fracture toughness of the five samples are tested, and the microstructures are investigated by optical microscopy (OM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results show that 7N01 Al-alloy treated at T6 condition has high strength but low fracture toughness. Compared with T6 treatment, T74 and HLA treatments increase the fracture toughness by 67% and 90% respectively, while the strength decrease by 9% and 17%. RRA process is a proper treatment method for 7N01 which improves the fracture toughness without sacrificing strength. The fracture toughness of DRRA treated alloy is much lower than that of RRA. Quantitative analysis through TEM images shows that the heat treatment affects the mechanical properties of 7N01 Al-alloy highly through changing the precipitates in grains and on grain boundaries, which can be explained by the coherency strengthening mechanism and Orowan mechanism. - Highlights: • Five heat treatments which can change the properties of 7N01 Al alloy were designed. • Quantitative analysis of precipitates was employed to study the mechanism. • RRA treatment can make proper strength/toughness property balances for 7N01 Al alloy.

  16. Influence of heat treatment on the strength and fracture toughness of 7N01 aluminum alloy

    International Nuclear Information System (INIS)

    Li, Bo; Wang, Xiaomin; Chen, Hui; Hu, Jie; Huang, Cui; Gou, Guoqing

    2016-01-01

    7N01 aluminum (Al) alloys are treated by five heat treatment methods as peak aging (T6), over aging (T74), high temperature and subsequently low temperature aging (HLA), retrogression and reaging (RRA) and double retrogression and reaging (DRRA). The strength and fracture toughness of the five samples are tested, and the microstructures are investigated by optical microscopy (OM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results show that 7N01 Al-alloy treated at T6 condition has high strength but low fracture toughness. Compared with T6 treatment, T74 and HLA treatments increase the fracture toughness by 67% and 90% respectively, while the strength decrease by 9% and 17%. RRA process is a proper treatment method for 7N01 which improves the fracture toughness without sacrificing strength. The fracture toughness of DRRA treated alloy is much lower than that of RRA. Quantitative analysis through TEM images shows that the heat treatment affects the mechanical properties of 7N01 Al-alloy highly through changing the precipitates in grains and on grain boundaries, which can be explained by the coherency strengthening mechanism and Orowan mechanism. - Highlights: • Five heat treatments which can change the properties of 7N01 Al alloy were designed. • Quantitative analysis of precipitates was employed to study the mechanism. • RRA treatment can make proper strength/toughness property balances for 7N01 Al alloy.

  17. Influence of corrosive media on the mechanical resistance of the uranium-vanadium alloy containing 0.20% by weight. Hydrogen embrittlement

    International Nuclear Information System (INIS)

    Arnould-Laurent, Robert; Fidelle, J.-P.

    1976-10-01

    Tests were carried out on the alloy UV 0.2% in order to determine its limits of utilization. The alloy was shown to be sensitive to the following phenomena: intrinsic brittleness (FI) due to dissolved residual hydrogen from fabrication; cracking by stress corrosion (FCSC), possible in certain conditions owing to a passive but imperfect behavior of the metal surface (appearance of microcracks at the surface or corrosion pitting due to inadequate protection by the surface oxide layer); generalized stress accelerated corrosion (CGAC), of microscopic aspect similar to that observed for corrosion under H 2 gas. In practice these effects are obtained, singly or in combination, as follows: maintenance under dry argon - Fi; deformation tests to rupture in aqueous solutions (pH:2 to 14) or after exposure to a chlorinated solvent: FI + FCSC predominating. Below pH2 no stress corrosion; delayed fracture under damp air - at 80 deg and 100 deg C - FI + FCSC under high stresses, giving rise to short failure times (tr) - FI + CSC + CGAC with CGAC predominating under lower stresses, giving long failure times; at 20 and 60 deg C - FCSC + FI predominating. Under high stresses (leading to short failure times) the FCSC contribution increases with temperature [fr

  18. Coulomb Excitation of the N = 50 nucleus 80Zn

    International Nuclear Information System (INIS)

    Van de Walle, J.; Cocolios, T. E.; Huyse, M.; Ivanov, O.; Mayet, P.; Raabe, R.; Sawicka, M.; Stefanescu, I.; Duppen, P. van; Aksouh, F.; Ames, F.; Habs, D.; Lutter, R.; Behrens, T.; Gernhauser, R.; Kroell, T.; Kruecken, R.; Bildstein, V.; Blazhev, A.; Eberth, J.

    2008-01-01

    Neutron rich Zinc isotopes, including the N = 50 nucleus 80 Zn, were produced and post-accelerated at the Radioactive Ion Beam (RIB) facility REX-ISOLDE (CERN). Low-energy Coulomb excitation was induced on these isotopes after post-acceleration, yielding B(E2) strengths to the first excited 2 + states. For the first time, an excited state in 80 Zn was observed and the 2 1 + state in 78 Zn was established. The measured B(E2,2 1 + →0 1 + ) values are compared to two sets of large scale shell model calculations. Both calculations reproduce the observed B(E2) systematics for the full Zinc isotopic chain. The results for N = 50 isotones indicate a good N = 50 shell closure and a strong Z = 28 proton core polarization. The new results serve as benchmarks to establish theoretical models, predicting the nuclear properties of the doubly magic nucleus 78 Ni

  19. Alloy scattering dependence of electron transport in AlGaN

    International Nuclear Information System (INIS)

    Yarar, Z.; Ozdemir, M.

    2010-01-01

    The electron transport and velocity characteristics in AlGaN are examined using an ensemble Monte Carlo simulation method. A three valley band structure model where nonparabolicity effects are considered in all valleys is used for Monte Carlo calculations. All of the major electron scattering interactions like acoustic and optical phonon, intervaley, ionized impurity and alloy disorder scatterings are included in the calculations. The velocity-applied electric field characteristics are analyzed as a function of Al molar fraction and temperature in the ranges of x=0.1 to x=0.5 and 77 K to 500 K, respectively. The velocity overshoot is clearly observed and the population of valleys seems well-matched with the occupancy of valleys in AlGaN. The results of electron steady state velocity-field curves are found that the alloy disorder scattering has important effects on the electron transport characteristics of AlGaN.

  20. Growth and properties of Al-rich InxAl1-xN ternary alloy grown on GaN template by metalorganic chemical vapour deposition

    International Nuclear Information System (INIS)

    Oh, Tae Su; Suh, Eun-Kyung; Kim, Jong Ock; Jeong, Hyun; Lee, Yong Seok; Nagarajan, S; Lim, Kee Young; Hong, Chang-Hee

    2008-01-01

    An Al-rich In x Al 1-x N ternary alloy was grown on a GaN template by metal-organic chemical vapour deposition (MOCVD). The GaN template was fabricated on a c-plane sapphire with a low temperature GaN nucleation layer. The growth of the 300 nm thick In x Al 1-x N layer was carried out under various growth temperatures and pressures. The surface morphology and the InN molar fraction of the In x Al 1-x N layer were assessed by using atomic force microscopy (AFM) and high resolution x-ray diffraction, respectively. The AFM surface images of the In x Al 1-x N ternary alloy exhibited quantum dot-like grains caused by the 3D island growth mode. The grains, however, disappeared rapidly by increasing diffusion length and mobility of the Al adatoms with increasing growth temperature and the full width at half maximum value of ternary peaks in HR-XRD decreased with decreasing growth pressure. The MOCVD growth condition with the increased growth temperature and decreased growth pressure would be effective to grow the In x Al 1-x N ternary alloy with a smooth surface and improved quality. The optical band edge of In x Al 1-x N ternary alloys was estimated by optical absorbance and, based on the results of HR-XRD and optical absorbance measurements, we obtained the bowing parameter of the In x Al 1-x N ternary alloy at b = 5.3 eV, which was slightly larger than that of previous reports

  1. Nontoxic corrosion inhibitors for N80 steel in hydrochloric acid

    Directory of Open Access Journals (Sweden)

    M. Yadav

    2016-11-01

    Full Text Available The purpose of this paper is to evaluate the protective ability of 1-(2-aminoethyl-2-oleylimidazoline (AEOI and 1-(2-oleylamidoethyl-2-oleylimidazoline (OAEOI as corrosion inhibitors for N80 steel in 15% hydrochloric acid, which may find application as eco-friendly corrosion inhibitors in acidizing processes in petroleum industry. Different concentrations of synthesized inhibitors AEOI and OAEOI were added to the test solution (15% HCl and the corrosion inhibition of N80 steel in hydrochloric acid medium containing inhibitors was tested by weight loss, potentiodynamic polarization and AC impedance measurements. Influence of temperature (298–323 K on the inhibition behavior was studied. Surface studies were performed by using FTIR spectra and SEM. Both the inhibitors, AEOI and OAEOI at 150 ppm concentration show maximum efficiency 90.26% and 96.23%, respectively at 298 K in 15% HCl solution. Both the inhibitors act as mixed corrosion inhibitors. The adsorption of the corrosion inhibitors at the surface of N80 steel is the root cause of corrosion inhibition.

  2. High pressure stability analysis and chemical bonding of Ti1-xZrxN alloy: A first principle study

    International Nuclear Information System (INIS)

    Chauhan, Mamta; Gupta, Dinesh C.

    2016-01-01

    First-principles pseudo-potential calculations have been performed to analyze the stability of Ti 1-x Zr x N alloy under high pressures. The first order phase transition from B1 to B2 phase has been observed in this alloy at high pressure. The variation of lattice parameter with the change in concentration of Zr atom in Ti 1-x Zr x N is also reported in both the phases. The calculations for density of states have been performed to understand the alloying effects on chemical bonding of Ti-Zr-N alloy.

  3. Investigation of strain effects on phase diagrams in the ternary nitride alloys (InAlN, AlGaN, InGaN)

    Energy Technology Data Exchange (ETDEWEB)

    Mohamad, Ranim; Chen, Jun; Ruterana, Pierre [CIMAP, UMR 6252, CNRS-ENSICAEN-CEA-UNICAEN, Caen (France); Bere, Antoine [Laboratoire de Physique et de Chimie de l' Environnement, Universite Ouaga I Pr Joseph KI-ZERBO, Ouagadougou (Burkina Faso)

    2017-09-15

    In this work, we used a modified Stillinger-Weber potential and a methodology of free energy calculation based on numerical computation of the configuration partition function of an alloy, to make a comprehensive study of the properties of group-III nitride ternary compounds (In{sub x}Ga{sub 1-x}N; In{sub x}Al{sub 1-x}N; Al{sub x}Ga{sub 1-x}N). The wurtzite structure was used; and the critical temperatures for the random ternary alloys are determined as 2717 K for In{sub x}Al{sub 1-x}N, 1718 K for In{sub x}Ga{sub 1-x}N, and 177 K for Al{sub x}Ga{sub 1-x}N, respectively. Therefore, Al{sub x}Ga{sub 1-x}N has no unstable mixing region at typical growth temperatures around 1100 C. In contrast, In{sub x}Al{sub 1-x}N and In{sub x}Ga{sub 1-x}N exhibit a wide unstable region, which means that being thick layers, their stability as homogeneous alloys is probably limited. In agreement with other reports, it is also pointed out that the critical temperature T{sub c} may be decreased when the layers are grown under strain. Although the compression and extension have the same effect below 1.5% strain, it is shown, for the first time, that when the compressive strain goes beyond, T{sub c} abruptly increases in contrast to the case of tensile strain where it continues to decrease. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Phonon structures of GaN-based random semiconductor alloys

    Science.gov (United States)

    Zhou, Mei; Chen, Xiaobin; Li, Gang; Zheng, Fawei; Zhang, Ping

    2017-12-01

    Accurate modeling of thermal properties is strikingly important for developing next-generation electronics with high performance. Many thermal properties are closely related to phonon dispersions, such as sound velocity. However, random substituted semiconductor alloys AxB1-x usually lack translational symmetry, and simulation with periodic boundary conditions often requires large supercells, which makes phonon dispersion highly folded and hardly comparable with experimental results. Here, we adopt a large supercell with randomly distributed A and B atoms to investigate substitution effect on the phonon dispersions of semiconductor alloys systematically by using phonon unfolding method [F. Zheng, P. Zhang, Comput. Mater. Sci. 125, 218 (2016)]. The results reveal the extent to which phonon band characteristics in (In,Ga)N and Ga(N,P) are preserved or lost at different compositions and q points. Generally, most characteristics of phonon dispersions can be preserved with indium substitution of gallium in GaN, while substitution of nitrogen with phosphorus strongly perturbs the phonon dispersion of GaN, showing a rapid disintegration of the Bloch characteristics of optical modes and introducing localized impurity modes. In addition, the sound velocities of both (In,Ga)N and Ga(N,P) display a nearly linear behavior as a function of substitution compositions. Supplementary material in the form of one pdf file available from the Journal web page at http://https://doi.org/10.1140/epjb/e2017-80481-0.

  5. Effect of nickel and MnS inclusions in the metal on the pitting corrosion of low-carbon stainless steels

    International Nuclear Information System (INIS)

    Frejman, L.I.; Nguen, The Dong; Volkov, D.E.; Konnov, Yu.P.

    1986-01-01

    The resistance to pitting corrosion of steels on the 03Kh17-03Kh18 base containing up to 20 % Ni at different levels of S and Mn impurities contamination is investigated. It is shown that up to 50 % of nickel introduced into ordinary steels with 5-6 % Ni is spent to compensate the resistance decrease caused by MnS inclusions. Full compensation is not attained even in the 10-20 %. Ni range in which nickel practically does not affect the resistance of neither ordinary, nor pure (without MnS) steels. Titanium introduction into ordinary steel on the Kh22N6 base permits to surpass the level of 03Kh17N3 pure steel resistance and attain the level of 03Kh17N6 pure steel almost by all characteristics (including passivated characteristics in sulfuric acid) besides pitting repassivity. In this property pure steels with Ni >or approx. 3 % surpass even the molybdenum containing 03Kh21NbM2T ordinary steel though they by far concede by passivation in sulfuric acid

  6. The investigation of Fe-Mn-based alloys with shape memory effect by small-angle scattering of polarized neutrons

    International Nuclear Information System (INIS)

    Kopitsa, G.P.; Runov, V.V.; Grigoriev, S.V.; Bliznuk, V.V.; Gavriljuk, V.G.; Glavatska, N.I.

    2003-01-01

    The small-angle polarized neutron scattering (SAPNS) technique has been used to study a nuclear and magnetic homogeneity in the distribution of both substituent (Si, Cr, Ni) and interstitial (C, N) alloying elements on the mesoscopic range in Fe-Mn-based alloys with shape memory effect (SME). The four groups of alloys with various basic compositions: FeMn 18 (wt%), FeMn 20 Si 6 , FeMn 20 Cr 9 N 0.2 and FeMn 17 Cr 9 Ni 4 Si 6 were investigated. It was found that the small-angle scattering of neutrons and depolarization on these alloys are very small altogether. The scattering did not exceed 1.5% from the incident beam and depolarization ∼2% for all samples. It means that these alloys are well nuclear and magnetically homogeneous on the scale of 10-1000 A. However, the difference in the homogeneity depending on the compositions still takes place. Thus, the adding of Si in FeMn 18 and FeMn 20 Cr 9 N 0.2 alloys improves the homogeneity pronouncedly. At once, the effect of the doping by C or N atoms on the homogeneity in FeMn 20 Si 6 and FeMn 17 Cr 9 Ni 4 Si 6 alloys is multivalued and depend on the presence of substitutional atoms (Ni and Cr). The capability of SAPNS as a method for the study of mesoscopic homogeneity in materials with SME and testing of the quality of their preparation is discussed

  7. Electrochemical Corrosion and In Vitro Bioactivity of Nano-Grained Biomedical Ti-20Nb-13Zr Alloy in a Simulated Body Fluid

    Directory of Open Access Journals (Sweden)

    Mohamed A. Hussein

    2017-12-01

    Full Text Available The bioactivity and the corrosion protection for a novel nano-grained Ti-20Nb-13Zr at % alloy were examined in a simulated body fluid (SBF. The effect of the SPS’s temperature on the corrosion performance was investigated. The phases and microstructural details of the developed alloy were analyzed by XRD (X-ray Diffraction, SEM (Scanning Electron Microscopy, and TEM (Transmission Electron Microscope. The electrochemical study was investigated using linear potentiodynamic polarization and electrochemical impedance spectroscopy in a SBF, and the bioactivity was examined by immersing the developed alloy in a SBF for 3, 7, and 14 days. The morphology of the depositions after immersion was examined using SEM. Alloy surface analysis after immersion in the SBF was characterized by XPS (X-ray Photoelectron Spectroscopy. The results of the bioactivity test in SBF revealed the growth of a hydroxyapatite layer on the surface of the alloy. The analysis of XPS showed the formation of protective oxides of TiO2, Ti2O3, ZrO2, Nb2O5, and a Ca3(PO42 compound (precursor of hydroxyapatite deposited on the alloy surface, indicating that the presented alloy can stimulate bone formation. The corrosion resistance increased by increasing the sintering temperature and the highest corrosion resistance was obtained at 1200 °C. The improved corrosion protection was found to be related to the alloy densification. The bioactivity and the corrosion resistance of the developed nanostructured alloy in a SBF renders the nanostructured Ti-20Nb-13Zr alloy a promising candidate as an implant material.

  8. Nitrogen effect on the tendency of Cr-Ni-MN steels to delayed fracture under stress and hydrogen effects

    International Nuclear Information System (INIS)

    Suvorova, S.O.; Fillipov, G.A.

    1996-01-01

    Austenitic steels types 03Kh17N16G10AM5, 03Kh6N12G10AM5 and 07Kh13AG20 with various nitrogen contents were studied for their tendency to delayed fracture using mechanical tests, fractography and X ray diffraction analysis. The steel type 07Kh13G20 exhibited the highest strength in the initial state but showed an increase tendency to delayed fracture after hydrogenation. It is underlined that nitrogen additions essentially intensify the tendency of cold worked steels to delayed fracture. This fact should be taken into account when using nitrogen-containing Cr-Ni-Mn steels under severe operational conditions. 4 refs., 2 tabs

  9. Effect of molybdenum on structure, microstructure and mechanical properties of biomedical Ti-20Zr-Mo alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, Pedro Akira Bazaglia [UNESP - Univ Estadual Paulista, Laboratório de Anelasticidade e Biomateriais, 17.033-360, Bauru, SP (Brazil); IBTN/Br – Institute of Biomaterials, Tribocorrosion and Nanomedicine, Brazilian Branch, 17.033-360 Bauru, SP (Brazil); Buzalaf, Marília Afonso Rabelo [USP – Universidade de São Paulo, Departamento de Ciências Biológicas, 17.012-901, Bauru, SP (Brazil); Grandini, Carlos Roberto, E-mail: betog@fc.unesp.br [UNESP - Univ Estadual Paulista, Laboratório de Anelasticidade e Biomateriais, 17.033-360, Bauru, SP (Brazil); IBTN/Br – Institute of Biomaterials, Tribocorrosion and Nanomedicine, Brazilian Branch, 17.033-360 Bauru, SP (Brazil)

    2016-10-01

    Titanium has an allotropic transformation around 883 °C. Below this temperature, the crystalline structure is hexagonal close-packed (α phase), changing to body-centered cubic (β phase). Zirconium has the same allotropic transformation around 862 °C. Molybdenum has body-centered cubic structure, being a strong β-stabilizer for the formation of titanium alloys. In this paper, the effect of substitutional molybdenum was analyzed on the structure, microstructure and selected mechanical properties of Ti-20 Zr-Mo (wt%) alloys to be used in biomedical applications. The samples were prepared by arc-melting and characterized by x-ray diffraction with subsequent refinement by the Rietveld method, optical and scanning electron microscopy. The mechanical properties were analyzed by Vickers microhardness and dynamic elasticity modulus. X-ray measurements and Rietveld analysis revealed the presence of α′ phase without molybdenum, α′ + α″ phases with 2.5 wt% of molybdenum, α″ + β phases with 5 and 7.5 wt% of molybdenum, and only β phase with 10 wt% of molybdenum. These results were corroborated by microscopy results, with a microstructure composed of grains of β phase and lamellae and needles of α′ and α″ phase in intra-grain the region. The hardness of the alloy was higher than the commercially pure titanium, due to the action of zirconium and molybdenum as hardening agents. The samples have a smaller elasticity modulus than the commercially pure titanium. - Highlights: • Ti-20Zr-Mo system alloys were developed. • β-Stabilizer effect of Zr in the presence of another β-stabilizer element • Alloys with low elastic modulus.

  10. 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.

  11. 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.

  12. KCl-induced high temperature corrosion of selected commercial alloys. Part II: alumina and silica-formers

    DEFF Research Database (Denmark)

    Kiamehr, Saeed; Dahl, Kristian Vinter; Montgomery, Melanie

    2016-01-01

    for 168 h in flowing N2(g)+5%O2(g)+15%H2O(g) (vol.%) with samples covered under KCl powder. A KCl-free exposure was also performed for comparison.Corrosion morphology and products were studied with scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffractometry (XRD......Laboratory testing on selected alumina and silica-forming alloys was performed to evaluate their performance against high temperature corrosion induced by potassium chloride (KCl). The alloys studied were FeCrAlY, Kanthal APM, Nimonic 80A, 214, 153MA and HR160. Exposure was conducted at 600 °C......-chromium-silicon-oxygen containing layer forms as the innermost corrosion product. The layer was uniformly distributed over the surface and appears to render some protection as this alloy exhibited the best performance among the investigated alloys. To reveal further aspects of the corrosion mechanism, Nimonic 80A was exposed...

  13. Corrosion behaviour of Mg/Al alloys in high humidity atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Arrabal, R.; Pardo, A.; Merino, M.C.; Mohedano, M.; Casajus, P. [Facultad de Quimicas, Departamento de Ciencia de Materiales, Universidad Complutense, 28040 Madrid (Spain); Merino, S. [Departamento de Tecnologia Industrial, Universidad Alfonso X El Sabio, Villanueva de la Canada, 28691 Madrid (Spain)

    2011-04-15

    The influence of relative humidity (80-90-98% RH) and temperature (25 and 50 C) on the corrosion behaviour of AZ31, AZ80 and AZ91D magnesium alloys was evaluated using gravimetric measurements. The results were compared with the data obtained for the same alloys immersed in Madrid tap water. The corrosion rates of AZ alloys increased with the RH and temperature and were influenced by the aluminium content and alloy microstructure for RH values above 90%. The initiation of corrosion was localised around the Al-Mn inclusions in the AZ31 alloy and at the centre of the {alpha}-Mg phase in the AZ80 and AZ91D alloys. The {beta}-Mg{sub 17}Al{sub 12} phase acted as a barrier against corrosion. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. External electric field effects on Schottky barrier at Gd3N@C80/Au interface

    Science.gov (United States)

    Onishi, Koichi; Nakashima, Fumihiro; Jin, Ge; Eto, Daichi; Hattori, Hayami; Miyoshi, Noriko; Kirimoto, Kenta; Sun, Yong

    2017-08-01

    The effects of the external electric field on the height of the Schottky barrier at the Gd3N@C80/Au interface were studied by measuring current-voltage characteristics at various temperatures from 200 K to 450 K. The Gd3N@C80 sample with the conduction/forbidden/valence energy band structure had a face-centered cubic crystal structure with the average grain size of several nanometers. The height of the Gd3N@C80/Au Schottky barrier was confirmed to be 400 meV at a low electric field at room temperature. Moreover, the height decreases with the increasing external electric field through a change of permittivity in the Gd3N@C80 sample due to a polarization of the [Gd3] 9 +-[N3 -+("separators="|C80 ) 6 -] dipoles in the Gd3N@C80 molecule. The field-dependence of the barrier height can be described using a power math function of the electric field strength. The results of the field-dependent barrier height indicate that the reduction in the Schottky barrier is due to an image force effect of the transport charge carrier at the Gd3N@C80/Au interface.

  15. Unified model studies of N = 84 and N = 80 nuclei

    International Nuclear Information System (INIS)

    Corrigan, T.M.

    1977-12-01

    The unified model which couples two valence nucleons to collective quadrupole surface vibrations is applied to the N = 84 and N = 80 nuclei which have respectively two neutrons and two neutron holes outside the closed N = 82 core. Two different interactions between these valence nucleons are considered. The first is a simple pairing interaction, and the second used matrix elements determined in a bare G matrix calculation. The simple pairing force gives much better results. A two step diagonalization is employed to treat the core and valence nucleons consistently. Up to four phonons are retained in the collective basis and the diagonalized (coupled) valence nucleon space is truncated at approximately the same energy. The experimental spectra and electromagnetic properties are well reproduced for both types of nuclei, and in the N = 84 nuclei the four phonon contribution was found to be nonnegligible. In addition, a closed form, multiplicity resolved expression for matrix elements of α (the collective surface coordinate) is presented, and a table of these values for N less than or equal to 6 is given

  16. Indirect improvement of high temperature mechanical properties of a Mg-based alloy Elektron21 by addition of AlN nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Daudin, R. [Univ. Grenoble Alpes, CNRS, SIMaP, F-38000 Grenoble (France); Terzi, S. [European Space Agency, ESTEC, TEC-TS, EPN Campus, CS20156, 38042 Grenoble Cedex 9 (France); Mallmann, C. [Univ. Grenoble Alpes, CNRS, SIMaP, F-38000 Grenoble (France); Martín, R. Sánchez [IMDEA Materials Institute, Tecnogetafe C/ Eric Kandel, 2, 28906 Getafe, Madrid (Spain); Lhuissier, P. [Univ. Grenoble Alpes, CNRS, SIMaP, F-38000 Grenoble (France); Boller, E.; Pacureanu, A. [European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble (France); Katsarou, L.; Dieringa, H. [Helmholtz-Zentrum Geesthacht, Magnesium Innovation Centre – MagIC, Max-Planck-Str. 1, 21502 Geesthacht (Germany); Salvo, L. [Univ. Grenoble Alpes, CNRS, SIMaP, F-38000 Grenoble (France)

    2017-03-14

    Magnesium being the lightest metal on earth used as a structural material, the design of the chemistry and the microstructures of Mg-based alloys has been developed over the years to always further ameliorate their mechanical properties. A supplementary option consists in adding ceramic nanoparticles to such alloys to design Mg-based metal matrix nanocomposites (MMNCs) displaying improvement of both strength and ductility. In practice however, careful attention is required to understand the fundamental mechanisms at the heart of the enhancement of these properties as they still remain quite uncertain and subjected to misleading interpretations. Here, high temperature (350 °C) strain rate jump tests in compression reveal an enhancement of 20–60% of the mechanical properties when AlN nano-particles are added to the Elektron21 alloy (Mg-2.8Nd-1.2Gd-0.4Zr-0.3Zn, in wt%). At the same time, nano-indentation investigations suppose that forest or Orowan strengthening, due to particles-dislocations interactions, is unlikely to occur. Instead, using complementary microstructural characterization techniques (scanning electron macroscopy, energy dispersive spectroscopy as well as micro- and nano-tomography), we show that AlN nano-particles physically and chemically interact with the alloy and modify the overall microstructure, in particular the intermetallic phase, at the origin of the improvement of the mechanical properties.

  17. Development of Al-Mg-Li alloys for fusion reactor

    International Nuclear Information System (INIS)

    Shoji, Yoshifusa; Yoshida, Hideo; Uno, Teruo; Baba, Yoshio; Kamada, Koji.

    1985-01-01

    Aluminum-magnesium-lithium alloys featuring low residual induced radioactivity and high electrical resistivity have been developed for fusion reactor structural materials. The addition of lithium in aluminum and Al-Mg alloys markedly increases electrical resistivity and tensile strength of them. However the elongation of Al-Mg-Li alloys containing more than 2 mass% lithium are less than 10 %. The Al-4--5 mass%Mg-1 mass%Li alloys are optimum for fusion reactor materials, and exhibit high resistivity (86 nΩm: 20 %IACS), medium strength (300 MPa) and good formability (22 % elongation). The variation of electrical resistivity of Al-Li and Al-Mg-Li alloys in solid solution can be approximated by the Matthiessen's rule. (author)

  18. MTS-MD of Biomolecules Steered with 3D-RISM-KH Mean Solvation Forces Accelerated with Generalized Solvation Force Extrapolation.

    Science.gov (United States)

    Omelyan, Igor; Kovalenko, Andriy

    2015-04-14

    We developed a generalized solvation force extrapolation (GSFE) approach to speed up multiple time step molecular dynamics (MTS-MD) of biomolecules steered with mean solvation forces obtained from the 3D-RISM-KH molecular theory of solvation (three-dimensional reference interaction site model with the Kovalenko-Hirata closure). GSFE is based on a set of techniques including the non-Eckart-like transformation of coordinate space separately for each solute atom, extension of the force-coordinate pair basis set followed by selection of the best subset, balancing the normal equations by modified least-squares minimization of deviations, and incremental increase of outer time step in motion integration. Mean solvation forces acting on the biomolecule atoms in conformations at successive inner time steps are extrapolated using a relatively small number of best (closest) solute atomic coordinates and corresponding mean solvation forces obtained at previous outer time steps by converging the 3D-RISM-KH integral equations. The MTS-MD evolution steered with GSFE of 3D-RISM-KH mean solvation forces is efficiently stabilized with our optimized isokinetic Nosé-Hoover chain (OIN) thermostat. We validated the hybrid MTS-MD/OIN/GSFE/3D-RISM-KH integrator on solvated organic and biomolecules of different stiffness and complexity: asphaltene dimer in toluene solvent, hydrated alanine dipeptide, miniprotein 1L2Y, and protein G. The GSFE accuracy and the OIN efficiency allowed us to enlarge outer time steps up to huge values of 1-4 ps while accurately reproducing conformational properties. Quasidynamics steered with 3D-RISM-KH mean solvation forces achieves time scale compression of conformational changes coupled with solvent exchange, resulting in further significant acceleration of protein conformational sampling with respect to real time dynamics. Overall, this provided a 50- to 1000-fold effective speedup of conformational sampling for these systems, compared to conventional MD

  19. Nanotube formation and morphology change of Ti alloys containing Hf for dental materials use

    International Nuclear Information System (INIS)

    Jeong, Yong-Hoon; Lee, Kang; Choe, Han-Cheol; Ko, Yeong-Mu; Brantley, William A.

    2009-01-01

    In this paper, Ti-Hf (10, 20, 30 and 40 wt.%) alloys were prepared by arc melting, and subjected to heat treatment for 24 h at 1000 o C in an argon atmosphere. Formation of surface nanotubes was achieved by anodizing a Ti-Hf alloy in 1.0 M H 3 PO 4 electrolytes with small amounts of NaF at room temperature. Microstructures of the alloys and nanotube morphology were examined by field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The homogenized Ti-Hf alloys had a needle-like microstructure of α phase, and nanotubes formed on Ti-xHf alloys had the anatase phase after treatment that promoted crystallization. Uniform nanotubes formed for Hf contents up to 20 wt.%. Irregular nanotubes formed on the Ti-30Hf and Ti-40Hf alloys. The structure of the irregular layers on the Ti-30Hf and Ti-40Hf alloys had nanotubes of two sizes. Increasing the Hf content in Ti led to the formation of nanotubes with more narrow size. The pores in the nanotubes typically had a diameter ranging from 80-120 nm and a length of approximately 1.7 μm. It is concluded that nanotube morphology on Ti-Hf alloys can controlled by varying the amount of Hf.

  20. Ductile fracture of two-phase welds under 77K. [Steel-EhP810, steel-EhP666, steel-08Kh18N10T, steel-EhP659-VI, steel-chP810

    Energy Technology Data Exchange (ETDEWEB)

    Yushchenko, K.A.; Voronin, S.A.; Pustovit, A.I.; Shavel' , A.V.

    The effect of the type of welding and fillers on crack resistance of welded joints high-strength steel EhP810 and its various compounds with steels EhP666, 08Kh18N10T has been studied. For the welding of steel EhP810 with steels EhP810, EhP666, 08Kh18N10T electron-beam, automatic, argon tungsten arc with non-consumable electrode with various fillers, as well as argon metal-arc welding with consumable electrode, were used. It is shown, that for a joint, made by electron-beam welding, parameters sigmasub(u), Ksub(IcJ), KCV are higher than for a joint of a similar phase structure made using filler wire EhP659-VI. It is explained by the fact, that during electron-beam welding joint metal refining takes place, which removes gases. In welded joints of chP810 steel, having joints with austenitic structure, characteristic of crack resistance Ssub(c) increases by more than 0.2 mm in contrast to two-phase joints, which conventional yield strength at 77 K exceeds 1000 MPa. It is worth mentioning, that for other classes of steels formation of two-phase structure of joint increases welded joint resistance to brittle fracture. It is possible to obtain the required structure of joint with assigned level of resistance to brittle fracture by means of the use of different fillers, optimum and welding procedure, regulating the part of the basic metal in joint content.

  1. High Temperature Life Testing of 80Ni-20Cr Wire in a Simulated Mars Atmosphere for the Sample Analysis at Mars (SAM) Instrument Suite Gas Processing System (GPS) Carbon Dioxide Scrubber

    Science.gov (United States)

    Hoffman, Christopher; Munoz, Bruno; Gundersen, Cynthia; Thomas, Walter, III; Stephenson, Timothy

    2008-01-01

    In support of the GPS for the SAM instrument suite built by NASA/GSFC, a life test facility was developed to test the suitability of 80Ni-20Cr alloy wire, 0.0142 cm diameter, for use as a heater element for the carbon dioxide scrubber. The element would be required to operate at 1000 C in order to attain the 800 C required for regeneration of the getter. The element also would need to operate in the Mars atmosphere, which consists mostly of CO2 at pressures between 4 and 12 torr. Data on the high temperature degradation mechanism of 80Ni- 20Cr in low pressure CO2, coupled with the effects of thermal cycling, were unknown. In addition, the influence of work hardening of the wire during assembly and the potential for catastrophic grain growth also were unknown. Verification of the element reliability as defined by the mission goals required the construction of a test facility that would accurately simulate the duty cycles in a simulated Mars atmosphere. The experimental set-up, along with the test protocol and results will be described.

  2. Moessbauer spectra studied of spin-wave excitation for amorphous alloys

    International Nuclear Information System (INIS)

    Huang Zhigao

    1992-01-01

    The average hyperfine fields of amorphous Fe 70 Co 20 Zr 10 , Fe 80 Co 10 Zr 10 and Fe 86 Co 4 -Zr 10 alloys at different temperature were measured by the Moessbauer technique. According to Bloch's T 3/2 relation, spin-wave excitations of above amorphous alloys were studied and their B 3/2 values were found to be 0.40 +- 0.02, 0.45 +- 0.02 and 0.88 +- 0.04, respectively. Comparing the B 3/2 values of crystals, a-Fe-(Co, Ni)-ME, a-Fe-(Cr, Mn, W)-ME and a-Fe-B or TM-Zr invar alloys, the obvious difference among them was observed. Above results can be explained well by the exchange coupling fluctuation and the disorder of spatial arrangement. In this work, the difference between the stiffness coefficients obtained from the inelastic neutron scattering and the magnetization measurements for amorphous Invar alloys was also explained

  3. Octanol-Water Partition Coefficient from 3D-RISM-KH Molecular Theory of Solvation with Partial Molar Volume Correction.

    Science.gov (United States)

    Huang, WenJuan; Blinov, Nikolay; Kovalenko, Andriy

    2015-04-30

    The octanol-water partition coefficient is an important physical-chemical characteristic widely used to describe hydrophobic/hydrophilic properties of chemical compounds. The partition coefficient is related to the transfer free energy of a compound from water to octanol. Here, we introduce a new protocol for prediction of the partition coefficient based on the statistical-mechanical, 3D-RISM-KH molecular theory of solvation. It was shown recently that with the compound-solvent correlation functions obtained from the 3D-RISM-KH molecular theory of solvation, the free energy functional supplemented with the correction linearly related to the partial molar volume obtained from the Kirkwood-Buff/3D-RISM theory, also called the "universal correction" (UC), provides accurate prediction of the hydration free energy of small compounds, compared to explicit solvent molecular dynamics [ Palmer , D. S. ; J. Phys.: Condens. Matter 2010 , 22 , 492101 ]. Here we report that with the UC reparametrized accordingly this theory also provides an excellent agreement with the experimental data for the solvation free energy in nonpolar solvent (1-octanol) and so accurately predicts the octanol-water partition coefficient. The performance of the Kovalenko-Hirata (KH) and Gaussian fluctuation (GF) functionals of the solvation free energy, with and without UC, is tested on a large library of small compounds with diverse functional groups. The best agreement with the experimental data for octanol-water partition coefficients is obtained with the KH-UC solvation free energy functional.

  4. Hydrogen release from irradiated vanadium alloy V-4Cr-4Ti

    Energy Technology Data Exchange (ETDEWEB)

    Klepikov, A.Kh. E-mail: klepikov@ietp.alma-ata.su; Romanenko, O.G.; Chikhray, Y.V.; Tazhibaeva, I.L.; Shestakov, V.P.; Longhurst, G.R. E-mail: gxl@inel.gov

    2000-11-01

    The present work is an attempt to obtain data concerning the influence of neutron and {gamma} irradiation upon hydrogen retention in V-4Cr-4Ti vanadium alloy. The experiments on in-pile loading of vanadium alloy specimens at the neutron flux density 10{sup 14} n/cm{sup 2} s, hydrogen pressure of 80 Pa, and temperatures of 563, 613 and 773 K were carried out using the IVG.1M reactor of the Kazakhstan National Nuclear Center. A preliminary set of loading/degassing experiments with non-irradiated material has been carried out to obtain data on hydrogen interaction with vanadium alloy. The, data presented in this work are related both to non-irradiated and irradiated samples.

  5. Hydrogen release from irradiated vanadium alloy V-4Cr-4Ti

    International Nuclear Information System (INIS)

    Klepikov, A.Kh.; Romanenko, O.G.; Chikhray, Y.V.; Tazhibaeva, I.L.; Shestakov, V.P.; Longhurst, G.R.

    2000-01-01

    The present work is an attempt to obtain data concerning the influence of neutron and γ irradiation upon hydrogen retention in V-4Cr-4Ti vanadium alloy. The experiments on in-pile loading of vanadium alloy specimens at the neutron flux density 10 14 n/cm 2 s, hydrogen pressure of 80 Pa, and temperatures of 563, 613 and 773 K were carried out using the IVG.1M reactor of the Kazakhstan National Nuclear Center. A preliminary set of loading/degassing experiments with non-irradiated material has been carried out to obtain data on hydrogen interaction with vanadium alloy. The, data presented in this work are related both to non-irradiated and irradiated samples

  6. Abrupt symmetry decrease in the ThT{sub 2}Al{sub 20} alloys (T = 3d transition metal)

    Energy Technology Data Exchange (ETDEWEB)

    Uziel, A.; Bram, A.I. [Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva, 8410501 (Israel); Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, 8410501 (Israel); Venkert, A. [Nuclear Research Center-Negev, POB 9001, Beer-Sheva (Israel); Kiv, A.E.; Fuks, D. [Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva, 8410501 (Israel); Meshi, L., E-mail: louisa@bgu.ac.il [Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva, 8410501 (Israel); Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, 8410501 (Israel)

    2015-11-05

    Th-T-Al system, where T-3d transition metals, was studied at ThT{sub 2}Al{sub 20} stoichiometry to establish the influence of T on the structural stability of ternary aluminide formed. Different alloys were prepared, varying T in the row from Ti to Fe. Using electron microscopy and X-ray diffraction methods it was found that ThT{sub 2}Al{sub 20} phase adopts CeCr{sub 2}Al{sub 20} structure type when T = Ti, V, and Cr. Starting from Mn, the symmetry of the stable Al-rich phase, which forms in the alloys with the same composition, decreases from cubic to orthorhombic. The results of Density Functional Theory (DFT) calculations coincide with experiments. Concepts of the Theory of Coordination Compounds and Jahn–Teller effect were used to explain the observed abrupt change of the symmetry. These considerations were supported by DFT calculations. - Highlights: • Type of transition metal influences symmetry change in the ThT{sub 2}Al{sub 20} alloys. • It was found that cubic ThT{sub 2}Al{sub 20} phase is stable for T = Ti, V and Cr. • When T = Mn, Fe–Al + orthorhombic ThT{sub 2}Al{sub 10} are formed, lowering the symmetry. • Experimental results and DFT calculations were in full agreement. • TCC and of Jahn–Teller effect were used for explanation of the results.

  7. Study of wurtzite and zincblende GaN/InN based solar cells alloys: First-principles investigation within the improved modified Becke-Johnson potential

    KAUST Repository

    Ul Haq, Bakhtiar

    2014-09-01

    Wurtzite GaInN alloys with flexible energy gaps are pronounced for their potential applications in optoelectronics and solar cell technology. Recently the unwanted built-in fields caused by spontaneous polarization and piezoelectric effects in wurtzite (WZ) GaInN, has turned the focus towards zinc-blende (ZB) GaInN alloys. To comprehend merits and demerits of GaInN alloys in WZ and ZB structures, we performed a comparative study of the structural, electronic and optical properties of Ga1-xInxN alloys with different In concentration using first-principles methodology with density function theory with generalized gradient approximations (GGA) and modified Becke-Johnson (mBJ) potential. Investigations pertaining to total energy of GaInN for the both phases, demonstrate a marginal difference, reflecting nearly equivalent stability of the ZB-GaInN to WZ-GaInN. The larger ionic radii of indium (In), result in larger values of lattice parameters of Ga1-xInxN with higher In concentration. For In deficient Ga1-xInxN, at first, the formation enthalpies increase rapidly as the In content approaches to 45% in WZ and 47% in ZB, and then decreases with the further increase in In concentration. ZB-Ga1-xInxN alloys exhibit comparatively narrower energy gaps than WZ, and get smaller with increase in In contents. The smaller values of effective masses of free carriers, in WZ phase, than ZB phase, reflect higher carrier mobility and electrical conductivity of WZ-Ga1-xInxN. Moreover wide energy gap of WZ-Ga1-xInxN results in large values of the absorption coefficients comparatively and smaller static refractive indices compared to ZB-Ga1-xInxN. Comparable electronic and optical characteristics of the ZB-Ga1-xInxN to WZ-Ga1-xInxN endorses it a material of choice for optoelectronics and solar cell applications besides the WZ-Ga1-xInxN. © 2014 Elsevier Ltd.

  8. Study of wurtzite and zincblende GaN/InN based solar cells alloys: First-principles investigation within the improved modified Becke-Johnson potential

    KAUST Repository

    Ul Haq, Bakhtiar; Ahmed, Rashid; Shaari, Amiruddin; El Haj Hassan, Fouad; Kanoun, Mohammed; Goumri-Said, Souraya

    2014-01-01

    Wurtzite GaInN alloys with flexible energy gaps are pronounced for their potential applications in optoelectronics and solar cell technology. Recently the unwanted built-in fields caused by spontaneous polarization and piezoelectric effects in wurtzite (WZ) GaInN, has turned the focus towards zinc-blende (ZB) GaInN alloys. To comprehend merits and demerits of GaInN alloys in WZ and ZB structures, we performed a comparative study of the structural, electronic and optical properties of Ga1-xInxN alloys with different In concentration using first-principles methodology with density function theory with generalized gradient approximations (GGA) and modified Becke-Johnson (mBJ) potential. Investigations pertaining to total energy of GaInN for the both phases, demonstrate a marginal difference, reflecting nearly equivalent stability of the ZB-GaInN to WZ-GaInN. The larger ionic radii of indium (In), result in larger values of lattice parameters of Ga1-xInxN with higher In concentration. For In deficient Ga1-xInxN, at first, the formation enthalpies increase rapidly as the In content approaches to 45% in WZ and 47% in ZB, and then decreases with the further increase in In concentration. ZB-Ga1-xInxN alloys exhibit comparatively narrower energy gaps than WZ, and get smaller with increase in In contents. The smaller values of effective masses of free carriers, in WZ phase, than ZB phase, reflect higher carrier mobility and electrical conductivity of WZ-Ga1-xInxN. Moreover wide energy gap of WZ-Ga1-xInxN results in large values of the absorption coefficients comparatively and smaller static refractive indices compared to ZB-Ga1-xInxN. Comparable electronic and optical characteristics of the ZB-Ga1-xInxN to WZ-Ga1-xInxN endorses it a material of choice for optoelectronics and solar cell applications besides the WZ-Ga1-xInxN. © 2014 Elsevier Ltd.

  9. Neutron resistant irradiation alloy and usage thereof

    International Nuclear Information System (INIS)

    Okada, Osamu; Nakata, Kiyotomo; Kato, Takahiko.

    1997-01-01

    A neutron irradiation embrittlement-resistant alloy comprising a Ti alloy having an average grain size of 2μm or smaller and containing from 30 to 40wt% of Al is subjected to powder solidification and then to isothermal forging at a forging rate of from 50 to 80% at a temperature range of from 1150 to 1500K. Namely, since the Ti-Al type alloy comprises from 30 to 30wt% of Al, optionally, from 1 to 6% of Mn, from 0.1 to 0.5% of Si, from 4 to 16% of V and the balance of Ti, it has excellent specific strength, high durable temperature and excellent neutron irradiation resistance, and has ductility required as structural materials. Accordingly, if the Ti-Al type alloy excellent in embrittlement resistance to neutron irradiation dimensional stability of materials is applied to constitutional parts of a reactor core of a nuclear reactor and a thermonuclear reactor to be exposed under neutron irradiation, high reliability is provided and the amount of activated materials is reduced by improving the working life of the materials. (N.H.)

  10. Magnetoimpedance effect of the Ni80Fe20/Cu composite wires: The influence of DC current imposed on the Cu base

    Directory of Open Access Journals (Sweden)

    Delu Chen

    2014-06-01

    Full Text Available In this paper, the copper composite wires of 75 μm in diameter with a sputtered layer of Ni80Fe20 permalloy were prepared, with a DC current applied to the basal Cu terminals during the fabrication process. The influence of the DC current on the magnetic configuration and Magneto-Impedance (MI effect was studied. The results indicate that both the current amplitude and actuation duration have significant effect on the magnetic properties of the Ni80Fe20 layer. With appropriate current applied, the induced magnetic field leads to a circumferential magnetic domain structure and reduces significantly the equivalent anisotropy field of Ni80Fe20 layer. Then, the GMI ratio of the composite wires was significantly increased. A maximum GMI of 194.8% can be reached when the current was fixed at 100 mA and the Ni80Fe20 thickness is 780 nm. If the Ni80Fe20 thickness is above 780 nm, the coercivity of the coating layer increases while the GMI ratio of the composite wire reduces, since the magnetic anisotropy of the Ni80Fe20 layer varies from circumferential to longitudinal. The results were explained combining the thermal and magnetic effects of current.

  11. Increasing the brittle fracture resistance in manual arc welding and heat treatment of type 12KhM steels

    International Nuclear Information System (INIS)

    Tikhonov, V.P.; Bychenkova, G.A.; Gordeev, Y.V.; Ilyuhov, C.V.

    1984-01-01

    The extensive application of heat-resisting steels is delayed by their poor weldability. Optimum technology has been developed for manual arc welding and heat treatment of structures of type 12KhM steels resulting in high cracking resistance. Trials were conducted to evaluate the efficiency of removing the structural stresses in tempering the structures. On the basis of the experimental results, it may be assumed that the toughness properties of the welded joints produced by manual arc welding can be improved by optimizing the alloying system of the weld metal, with the parent metal treated in the optimum heat treatment conditions. The aim of subsequent investigations was to assess the properties of the weld metal made with vanadium-free electrodes. It was found that the impact toughness increased two to three times; the mean hardness and the maximum hardness were both less than 220. The reduction in hardness and increase of the toughness properties of the metal are caused by the lower degree of hardening of the bulk of the grain and, consequently, by the lower concentration of plastic strain at the grain boundaries

  12. Cyclic deformation and fatigue of rolled AZ80 magnesium alloy along different material orientations

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Ying, E-mail: yxiong@zjut.edu.cn [Key Laboratory of Special Purpose Equipment and Advanced Processing Technology, Ministry of Education, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Jiang, Yanyao, E-mail: yjiang@unr.edu [University of Nevada, Reno, Department of Mechanical Engineering, Reno, NV 89557 (United States)

    2016-11-20

    The effect of material orientation on cyclic deformation and fatigue behavior of rolled AZ80 magnesium (Mg) alloy was experimentally investigated under fully reversed strain-controlled loading in ambient. The testing specimens were taken from a rolled AZ80 Mg plate at four orientations with respect to rolled plane: 0°(ND, normal direction), 30°(ND30), 60°(ND60), and 90°(RD, rolled direction). Fatigue fracture morphologies of specimens along different orientation were analyzed by scanning electron microscopy (SEM). Overall cyclic hardening was observed for the material loaded in different directions. For a given strain amplitude, the ND specimens had the lowest fatigue resistance among the specimens of all material orientations. The fatigue life of an ND30 specimens is similar to that of an ND60 specimen at a given strain amplitude and both are higher than that of an RD specimen when the strain amplitude is higher than 0.4%, whereas an RD specimen exhibits a better fatigue resistance when the strain amplitude is lower than 0.4%. A mixed fracture mode with transgranular and intergranular cracking related to lamellar-like features occurred during stable crack growth, and an intergranular fracture mode related to dimple-like features exhibited in the fast fracture region. A multiaxial fatigue model based on the strain energy density can correlate all the fatigue experiments of the material at different material orientations.

  13. Stress Corrosion Cracking Behavior of LD10 Aluminum Alloy in UDMH and N2O4 propellant

    Science.gov (United States)

    Zhang, Youhong; Chang, Xinlong; Liu, Wanlei

    2018-03-01

    The LD10 aluminum alloy double cantilever beam specimens were corroded under the conditions of Unsymmetric Uimethyl Hydrazine (UDMH), Dinitrogen Tetroxide (N2O4), and 3.5% NaCl environment. The crack propagation behavior of the aluminum alloy in different corrosion environment was analyzed. The stress corrosion cracking behavior of aluminum alloy in N2O4 is relatively slight and there are not evident stress corrosion phenomenons founded in UDMH.

  14. Interfacial microstructure of Si{sub 3}N{sub 4}/Si{sub 3}N{sub 4} brazing joint with Cu-Zn-Ti filler alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)], E-mail: hitzhangjie@hit.edu.cn; Zhang, X.M.; Zhou, Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Naka, M. [Joining and Welding Research Institute, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Svetlana, Atroshenko [Faculty of Mathematics and Mechanics, Saint-Petersburg State University (Russian Federation)

    2008-11-15

    In this study, Si{sub 3}N{sub 4} ceramic was jointed by a brazing technique with a Cu-Zn-Ti filler alloy. The interfacial microstructure between Si{sub 3}N{sub 4} ceramic and filler alloy in the Si{sub 3}N{sub 4}/Si{sub 3}N{sub 4} joint was observed and analyzed by using electron-probe microanalysis, X-ray diffraction and transmission electron microscopy. The results indicate that there are two reaction layers at the ceramic/filler interface in the joint, which was obtained by brazing at a temperature and holding time of 1223 K and 15 min, respectively. The layer nearby the Si{sub 3}N{sub 4} ceramic is a TiN layer with an average grain size of 100 nm, and the layer nearby the filler alloy is a Ti{sub 5}Si{sub 3}N{sub x} layer with an average grain size of 1-2 {mu}m. Thickness of the TiN and Ti{sub 5}Si{sub 3}N{sub x} layers is about 1 {mu}m and 10 {mu}m, respectively. The formation mechanism of the reaction layers was discussed. A model showing the microstructure from Si{sub 3}N{sub 4} ceramic to filler alloy in the Si{sub 3}N{sub 4}/Si{sub 3}N{sub 4} joint was provided as: Si{sub 3}N{sub 4} ceramic/TiN reaction layer/Ti{sub 5}Si{sub 3}N{sub x} reaction layer/Cu-Zn solution.

  15. H-Phase Precipitation and Martensitic Transformation in Ni-rich Ni-Ti-Hf and Ni-Ti-Zr High-Temperature Shape Memory Alloys

    Science.gov (United States)

    Evirgen, A.; Pons, J.; Karaman, I.; Santamarta, R.; Noebe, R. D.

    2018-03-01

    The distributions of H-phase precipitates in Ni50.3Ti29.7Hf20 and Ni50.3Ti29.7Zr20 alloys formed by aging treatments at 500 and 550 °C or slow furnace cooling and their effects on the thermal martensitic transformation have been investigated by TEM and calorimetry. The comparative study clearly reveals faster precipitate-coarsening kinetics in the NiTiZr alloy than in NiTiHf. For precipitates of a similar size of 10-20 nm in both alloys, the martensite plates in Ni50.3Ti29.7Zr20 have larger widths and span a higher number of precipitates compared with the Ni50.3Ti29.7Hf20 alloy. However, for large H-phase particles with hundreds of nm in length, no significant differences in the martensitic microstructures of both alloy systems have been observed. The martensitic transformation temperatures of Ni50.3Ti29.7Hf20 are 80-90 °C higher than those of Ni50.3Ti29.7Zr20 in the precipitate-free state and in the presence of large particles of hundreds on nm in length, but this difference is reduced to only 10-20 °C in samples with small H-phase precipitates. The changes in the transformation temperatures are consistent with the differences in the precipitate distributions between the two alloy systems observed by TEM.

  16. Microstructure and Mechanical Properties Evolution of the Al, C-Containing CoCrFeNiMn-Type High-Entropy Alloy during Cold Rolling.

    Science.gov (United States)

    Klimova, Margarita; Stepanov, Nikita; Shaysultanov, Dmitry; Chernichenko, Ruslan; Yurchenko, Nikita; Sanin, Vladimir; Zherebtsov, Sergey

    2017-12-29

    The effect of cold rolling on the microstructure and mechanical properties of an Al- and C-containing CoCrFeNiMn-type high-entropy alloy was reported. The alloy with a chemical composition (at %) of (20-23) Co, Cr, Fe, and Ni; 8.82 Mn; 3.37 Al; and 0.69 C was produced by self-propagating high-temperature synthesis with subsequent induction. In the initial as-cast condition the alloy had an face centered cubic single-phase coarse-grained structure. Microstructure evolution was mostly associated with either planar dislocation glide at relatively low deformation during rolling (up to 20%) or deformation twinning and shear banding at higher strain. After 80% reduction, a heavily deformed twinned/subgrained structure was observed. A comparison with the equiatomic CoCrFeNiMn alloy revealed higher dislocation density at all stages of cold rolling and later onset of deformation twinning that was attributed to a stacking fault energy increase in the program alloy; this assumption was confirmed by calculations. In the initial as-cast condition the alloy had low yield strength of 210 MPa with yet very high uniform elongation of 74%. After 80% rolling, yield strength approached 1310 MPa while uniform elongation decreased to 1.3%. Substructure strengthening was found to be dominated at low rolling reductions (<40%), while grain (twin) boundary strengthening prevailed at higher strains.

  17. Factors Affecting Adolescents' Involvement in Cyberbullying: What Divides the 20% from the 80%?

    Science.gov (United States)

    Shin, Namin; Ahn, Hwasil

    2015-07-01

    Despite some variations among cyberbullying studies, about 20% of the youth population surveyed appears to be involved in cyberbullying. Coincidentally, the current study found that exactly 20% of the students surveyed were involved in cyberbullying as bullies (7.8%), victims (7.5%), and bully/victims (4.7%). What divides those 20% from the 80% of noninvolved students? This study aimed to produce a parsimonious and accurate model that can predict the occurrence of involvement in cyberbullying among youth. Data were collected from a questionnaire survey administered to 1,036 students enrolled in secondary schools in South Korea. Stepwise logistic regression (SLR) was carried out to predict the dichotomous dependent variable (involved/noninvolved) with 10 independent variables grouped into three categories: (a) demographic, (b) media-related, and (c) school and psychology factors. The result of the SLR analysis yielded a four-step model including the variables of cyber-confidence, weekday game time, mobile activities, and age as being significant in explaining the 20/80 division (model χ(2)=34.306, df=4, pcyberbullying than other students. In particular, the construct of cyber-confidence calls for further elaboration and research, given its controversial function with respect to adolescents' involvement in cyberbullying. Also, this study may bring about insights into practical considerations needed for concerned researchers, teachers, and parents to identify who is inside the group involved in cyberbullying so as to help the participating adolescents escape from the circle of cyberbullying.

  18. Regularities in eliminating the porosity in some crystalline and amorphous materials

    International Nuclear Information System (INIS)

    Betekhtin, V.I.; Kadomtsev, A.G.; Amosova, O.V.

    2003-01-01

    The results of the number of studies on eliminating the porosity under the effect of increased temperatures and pressures performed on the cast alloys (VT5L; AL2), steels (30KhG5N2A) and amorphous alloys (Co 59 Fe 5 Si 11 Ni 10 B 15 , Fe 61 Co 20 Si 5 B 14 , Fe 77 Ni 1 Si 9 B 13 ) are considered. The change in the porosity parameters was controlled through the small-angle X-ray scattering electron microscopy. It is shown that the effect of the hydrostatic pressure leads to decrease in the excessive free volume in the amorphous alloys, related to the availability of the micropores of about 10 nm dimensions and consequently to the increase in the strength, microhardness and temperature of the viscous-brittle transition. It is noted that the acting forces of the microporosity elimination may be related both to the internal stress and the Laplace pressure conditioned by the pores surface curvature [ru

  19. Corrosion resistance of amorphous and crystalline Pd40Ni40P20 alloys in aqueous solutions

    DEFF Research Database (Denmark)

    Wu, Y.F.; Chiang, Wen-Chi; Chu, J.

    2006-01-01

    The corrosion behaviors of amorphous and crystalline Pd40Ni40P20 alloys in various aqueous solutions are reported in this paper. The corrosion resistance of crystalline (annealed) Pd40Ni40P20 is better than that of amorphous Pd40Ni40P20 in various corrosive solutions, due to crystalline Pd40Ni40P20...... and mainly consists of inert Pd5P2, NI3P, Ni2Pd2P and noble Pd phases. These inert and noble properties result in a higher corrosion resistance in crystalline Pd40Ni40P20....

  20. Využití Paretova pravidla 8020 při zefektivnění prodejního sortimentu

    Directory of Open Access Journals (Sweden)

    Vladimíra Kučerová

    2014-04-01

    Full Text Available Purpose of the article: The article is focused on the use of Pareto’s rule “8020” in streamlining of sales range. It is based on the assumption that 80% of the impact is due to 20% of the causes. The application of this rule on the chosen problem can be expressed as a question: “Which products from an assortment of shop bring the highest share of the sales?” Scientific aim: The primary aim is to develop a methodology for evaluating of assortment effectiveness in retail stores with food, based on analysis of contribution of individual items range on margins and sales volumes. Methodology: The general procedure of analysis using Pareto’s rule is based on secondary data which come from scientific works done by other researchers in the area. The universal procedure was further modified for the investigated problem. The outcome is a methodology for evaluating of the range saleability. The method of case study was applied to verify the practical application of the methodology. Findings: The proposed methodology is practically useful as a tool for evaluation of the shop assortment in an effort to achieve higher sales efficiency and customer value. The principles, the application and the evaluation of the methodology are demonstrated by the case study called “The analysis of the sales range in a retail food shop”. Conclusions: The research focuses on the food retail. Therefore the proposed methodology suited to condition in this field. For other retail or wholesale areas would be the methodology applicable only after proper changes in segmentation of assortment and the calculation formula.

  1. Microstructure, mechanical behavior and biocompatibility of powder metallurgy Nb-Ti-Ta alloys as biomedical material.

    Science.gov (United States)

    Liu, Jue; Chang, Lin; Liu, Hairong; Li, Yongsheng; Yang, Hailin; Ruan, Jianming

    2017-02-01

    Microstructures, mechanical properties, apatite-forming ability and in vitro experiments were studied for Nb-25Ti-xTa (x=10, 15, 20, 25, 35at.%) alloys fabricated by powder metallurgy. It is confirmed that the alloys could achieve a relative density over 80%. Meanwhile, the increase in Ta content enhances the tensile strength, elastic modulus and hardness of the as-sintered alloys. When increasing the sintering temperatures, the microstructure became more homogeneous for β phase, resulting in a decrease in the modulus and strength. Moreover, the alloys showed a good biocompatibility due to the absence of cytotoxic elements, and were suitable for apatite formation and cell adhesion. In conclusion, Nb-25Ti-xTa alloys are potentially useful in biomedical applications with their mechanical and biological properties being evaluated in this work. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Effect of N+Cr alloying on the microstructures and tensile properties of Hadfield steel

    International Nuclear Information System (INIS)

    Chen, C.; Zhang, F.C.; Wang, F.; Liu, H.; Yu, B.D.

    2017-01-01

    The microstructures and tensile behaviors of traditional Hadfield steel, named Mn12 steel, and Hadfield steel alloyed with N+Cr, named Mn12CrN steel were studied through optical microscopy, transmission electron microscopy, and scanning electron microscopy, among others. Three different tensile strain rates of 5×10 −4 , 5×10 −3 , and 5×10 −2 s −1 were selected in the tensile test. The deformation microstructures and fracture morphologies of the two steels after fracture in the tensile test were observed to analyze the tensile deformation response to different tensile strain rates. Results showed that the grain size of Mn12CrN steel was evidently refined after alloying with N+Cr. The grain would not become abnormally coarse even with increasing austenitizing temperature. During tensile deformation, the strength and plasticity of Mn12CrN steel were superior to those of Mn12 steel at the same strain rate. With increasing the strain rate, the changes in strength and plasticity of Mn12CrN steel were less sensitive to tensile strain rate compared with Mn12 steel. The effects of grain refinement and N+Cr alloying on dynamic strain aging and deformation twining behaviors were responsible for this lack of sensitivity to strain rate.

  3. Development of the advanced nuclear materials -Development of Inconel alloys-

    International Nuclear Information System (INIS)

    Kuk, Il Hyun; Chang, Jin Sung; Lee, Chang Kyu; Park, Soon Dong; Kim, Woo Kon; Jeong, Man Kyo; Woo, Yoon Myung; Han, Chang Hee

    1995-07-01

    The performance and the integrity of the steam generator U-tubes directly affects the efficiency and economics of nuclear power plant because they are closely interrelated with the maintenance and repair. Also the steam generator U-tubes have been one of world-wide hot issues in nuclear power plants for long time because of their continuing corrosion-related degradation. Right after stress corrosion cracking of Alloy 600 tubes are reported at primary side, in which the environment is believed to be tightly controlled all the time, in mid 80's, alloy 690 has started to replace alloy 600. Alloy 690 is basically same with alloy 600 except more Cr content. Firstly minor elements in alloy 690 (C, B, N, Y, Mo) were added or controlled to improve hot workability and corrosion resistance. It would be much more desirable if the mechanism or basic understanding of the degradation phenomena of steam generator U-tubes in operation conditions can be illuminated through the alloy modification research. Alloy 600 tubes which were preproduced in cooperation with Sammi Special Steel were evaluated, being compared with imported one. Also alloy 600 and alloy 690 tubes were produced from Inconel 600 and 690 INCO- forged bar. These will be closely evaluated with purely Korean-made alloy 600 and 690 tubes. 22 tabs., 93 figs., 14 refs. (Author)

  4. Cooling intensification during quenching of power plant components - the way to increase reliability

    International Nuclear Information System (INIS)

    Borisov, I.A.

    1989-01-01

    To enchance the complex of mechanical properties and to increase operation time of large components of power facilities, regimes of accelerated cooling are developed. Results of heat treatment with accelerated cooling of turbine rotor of steel 26KhN3M2FAA, disks of turbine welded rotor of steel 20KhN2MFAA, components of steel 35KhN3MFA, are given. Special steels with carbon content less than 0.30% for details of power machine-building are developed

  5. Structural inheritance in cast 30KhGNM-type steel

    International Nuclear Information System (INIS)

    Sadovskij, V.D.; Bershtejn, L.I.; Mel'nikova, A.A.; Polyakova, A.M.; Schastlivtsev, V.M.

    1980-01-01

    Structural inheritance in the cast 30KhGNM-type steel depending on the heating rate and the temperature of preliminary tempering is investigated. When eating the cast steel with a beinite structure at the rate of 1-150 deg/min, the restoration of austenite grain and the following recrystallization due to the phase cold work, are observed. Slow heating from room temperature or preliminary tempering hinder grain restoration during heating. A non-monotonous effect of tempering temperature on the structural inheritance is established which can be connected with the kinetics of decomposition of residual austenite in steel

  6. Effect of Ni Addition on the Wear and Corrosion Resistance of Fe-20Cr-1.7C-1Si Hardfacing Alloy

    International Nuclear Information System (INIS)

    Lee, Sung Hoon; Kim, Ki Nam; Kim, Seon Jin

    2011-01-01

    In order to improve the corrosion resistance of Fe-20Cr-1.7C-1Si hardfacing alloy without a loss of wear resistance, the effect of Ni addition was investigated. As expected, the corrosion resistance of the alloy increased with increasing Ni concentration. The wear resistance of the alloy did not decrease, even though the hardness decreased, up to Ni concentration of 5 wt.%. This was attributed to the fact that the decrease in hardness was counterbalanced by the strain-induced martensitic transformation. The wear resistance of the alloy, however, decreased abruptly with increases of the Ni concentration over 5 wt.%.

  7. Role of Ag-alloy in the thermal stability of Ag-based ohmic contact to GaN(0 0 0 1) surface

    International Nuclear Information System (INIS)

    Xiong, Zhihua; Qin, Zhenzhen; Zhao, Qian; Chen, Lanli

    2015-01-01

    First-principles calculations are performed to study Ag and Ag-alloy adsorption stability on GaN(0 0 0 1) surface. We find Ag only contact to GaN surface is unstable under high temperature. While Ag-alloy adsorption exhibits better adsorption stability and electronic properties than that of the Ag only contact,due to the enhanced interaction between Ag-alloy and GaN(0 0 0 1) surface. The Ag-alloy, particularly AgNi, is proposed to be used as very promising ohmic contact to GaN for practical applications

  8. Influence of aggressive media on the mechanical behavior of the uranium--0.20 wt % vanadium alloy the role of hydrogen embrittlement

    International Nuclear Information System (INIS)

    Arnould-Laurent, R.

    The tests comprised tensile tests under constant load or up to the fracture point using cylindrical or flat, trapezoidal test pieces, tests in which disks were ruptured under gaseous pressure, and tenacity tests. The alloy was found to be sensitive to: (1) intrinsic brittleness (I.B.) due to dissolved residual hydrogen from the preparation stage. This manifested itself mainly by cracking at an elongation threshold of about 3 percent. (2) Cracking due to stress corrosion (S.C.C.) in the true sense, which is made possible under certain conditions by an imperfect passivation of the metal surface. The process is initiated either by the appearance of microcracks which appear at the surface, or by corrosion pits. (3) Generalized corrosion accelerated by the stress (S.A.C.), whose microscopic appearance is similar to that observed with corrosion under gaseous hydrogen. Below pH 2 there is no stress corrosion. Stress rupture tests in moist air at 80 and 100 0 C measure I.B. + S.C.C. under high stress, giving rise to short lifetimes. I.B. + S.C.C. + S.A.C., with S.A.C. predominant, occurs under lower stresses that give long lifetimes. Stress rupture tests measure at 20 and 60 0 C I.B. + S.C.C. with I.B. predominant. Under high stresses (short lifetimes) the magnitude of the S.C.C. component increases as the temperature increases. The most serious effects are those of S.A.C. at 80 and 100 0 C, and of I.B. at all temperatures. The way this alloy behaves can only be changed by an effective reduction in the quantity of residual hydrogen present, or by coatings that will in no case allow the ingress of hydrogen. 62 fig, 82 references, 15 tables

  9. LOCATING THE TRAILING EDGE OF THE CIRCUMBINARY RING IN THE KH 15D SYSTEM

    International Nuclear Information System (INIS)

    Capelo, Holly L.; Herbst, William; Leggett, S. K.; Hamilton, Catrina M.; Johnson, John A.

    2012-01-01

    Following two years of complete occultation of both stars in the binary T Tauri star KH 15D by its opaque circumbinary ring, KH 15D has abruptly brightened again during apastron phases, reaching I = 15 mag. Here, we show that the brightening is accompanied by a change in spectral class from K6/K7 (the spectral class of star A) to ∼K1, and a bluing of the system in V – I by about 0.3 mag. A radial velocity measurement confirms that, at apastron, we are now seeing direct light from star B, which is more luminous and of earlier spectral class than star A. Evidently, the trailing edge of the occulting screen has just become tangent to one anse of star B's projected orbit. This confirms a prediction of the precession models, supports the view that the tilted ring is self-gravitating, and ushers in a new era of the system's evolution that should be accompanied by the same kind of dramatic phenomena observed from 1995 to 2009. It also promotes KH 15D from a single-lined to a double-lined eclipsing binary, greatly enhancing its value for testing pre-main-sequence models. The results of our study strengthen the case for truncation of the outer ring at around 4 AU by a sub-stellar object such as an extremely young giant planet. The system is currently at an optimal configuration for detecting the putative planet and we urge expedient follow-up observations.

  10. Die forging of the alloys Az80 and Zk60

    NARCIS (Netherlands)

    Kurz, G.; Clauw, B.; Sillekens, W.H.; Letzig, D.

    2009-01-01

    Overall goal of the MagForge project is to provide tailored and cost-effective technologies for the industrial manufacturing of magnesium forged components. Scientific and technological aspects are new alloys/feedstock materials with improved performance, forging process modeling and design tools

  11. Comparative study of Ce0.80Sm0.20 Ba0.80Y0.20O3-δ (YB-SDC) electrolyte by various chemical synthesis routes

    Science.gov (United States)

    Tariq, Sana; Marium, Aniqa; Raza, Rizwan; Ashfaq Ahmad, M.; Ajmal Khan, M.; Abbas, Ghazanfar; Waseem Boota, M.; Khalid Imran, S.; Arshad, Sarfraz; Ikram, Muhammad

    2018-03-01

    Solid Oxide Fuel Cells is received a significant attention in recent years due to higher efficiency and fuel flexibility. The one of the main challenge for SOFC is to lower the operating temperature of SOFCs. Therefore, different strategies are used in order to enhance the ionic conduction of electrolyte, which can lower the overall SOFC operating temperature. The present work is focused on this strategy to enhance the electrolytic conductivity. Therefore, the ceria based composite electrolytes Ce0.80Sm0.20B0.80Y0.20O3-δ (YBSDC) are synthesized using three different approaches i.e. co-precipitation (YBSDC-1), sol-gel (YBSDC-2) and ball milling (YBSDC-3). Their crystal structures and surface morphologies are characterized through X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques, respectively. The four-probe technique is employed to measure their dc conductivities in the temperature range (300-700) °C under air atmosphere. The open circuit voltage (OCV) and current are recorded with natural gas as fuel {flow rate kept at 100 ml min-1 at 1 atm pressure} over the temperature range (300-600) °C. The electrolyte (YBSDC-1) prepared by co-precipitation technique is shown better results as compare to other two electrolytes (YBSDC-2 and YBSDC-3). The electrolyte (YBSDC-1) having maximum dc conductivity (0.096 S/cm), peak power density 224 mW cm-2 and OCV 0.94 V at 600 °C. These results show that YBSDC-1electrolyte is potential candidate for low temperature SOFCs.

  12. Reliability and durability of the 12Kh1MF steel tubes of electroslag remelting and their welded joints

    International Nuclear Information System (INIS)

    Lanskaya, K.A.; Kulikova, L.V.; Mazel', R.E.; Khromchenko, F.A.; Strizhenova, V.F.

    1978-01-01

    Results of investigating the positive effect of electrolag remelting (ESR) on the properties of the base metal and welded joint of the 12Kh1MF steel steam pipes with the aim of increasing their durability up to 20,000 hrs, are presented. To estimate the quality and properties of tube billet metal, microstructure, content and nature of nonmetallic inclusions, content of gases, austenite grain size, austenite transformations during continuous cooling, metal ductility, mechanical properties at different temperatures and heat resisting properties, have been investigated. It is established, that the base metal in tubes of electroslag remelting possess higher heat resistance, while welded joints besides, have high deformability and resistance to brittle fracture

  13. Positron lifetime and Moessbauer study of Fe80-xNixB20 metallic glasses

    International Nuclear Information System (INIS)

    Baluch, S.; Miglierini, M.; Groene, R.; Sitek, J.

    1989-01-01

    In order to investigate the short-range order (SRO) of iron-rich Fe 80-x Ni x B 20 (x = 10, 20, 30, 40) metallic glasses positron lifetime and Moessbauer measurements were carried out. Positron lifetimes of samples and Moessbauer hyperfine structure data of neutron-irradiated samples as functions of nickel content are shown and discussed. Results give evidence that high Ni content stabilizes the structure and can be connected with a higher degree of SRO in metallic glasses

  14. Specific features of corrosion processes in a crack tip in chloride solution

    International Nuclear Information System (INIS)

    Kurov, O.V.; Vasilenko, I.I.

    1981-01-01

    Electrode potentials of metal and pH solution are measured by means of microelectrodes on structural materials-45 and 12Kh18N10T steels, AT3 titanium alloy and D16 aluminium alloy in the vertex of corrosion crack formed during corrosion cracking in 3% NaCl solution. Metal corrosion is shown to be followed by hydrogen liberation on all the investigated materials at corrosion potentials. The effects of chemical composition of alloys as well as external polarization on the solution pH in the crack vertex are determined

  15. Corrosión por depósitos salinos de los aceros SA213-T22 y SA213-TP347H en presencia de una mezcla 80%V2O5-20%Na2SO4-20%Na2SO4

    Directory of Open Access Journals (Sweden)

    Romero, M. A.

    1998-02-01

    Full Text Available Many hot corrosion problems in industrial and utility boilers are caused by molten salts. The corrosion processes which occur in salts are of an electrochemical nature, and so they can be studied using electrochemical test methods. In this research, electrochemical techniques in molten salt systems have been used for the measurements of molten corrosion processes. Electrochemical test methods are described here for a salt mixture of 80%V2O5-20%Na2SO4 at 540-680°C. To establish better the electrochemical corrosion rate mearurements for molten salt systems, information from electrochemical potentiodynamic polarization curves, such as polarization resistance and Tafel slopes were used in this study to generate corrosion rate data. The salt was contained in a quartz crucible inside a stainless steel retort. The atmosphere used was air. A thermocouple sheathed with quartz glass was introduced into the molten salt for temperature monitoring and control. Two materials were tested in the molten mixture: SA213-T22 and SA213-TP347H steels. The corrosion rates values obtained using electrochemical methods were around 0.58-7.14 mm/yr (22.9-281 mpy. The corrosion rate increase with time.Muchos problemas de corrosión por depósitos salinos en la industria eléctrica, especialmente en los generadores de vapor, se deben al ataque por sales fundidas. El proceso de corrosión en sales fundidas es de naturaleza electroquímica; así, puede estudiarse empleando técnicas electroquímicas. Este proceso de corrosión en un sistema de sales fundidas, mezcla de 80%V2O5 y 20%Na2SO4 a temperaturas comprendidas entre 540 y 680°C, se evaluó en esta investigación por medio de técnicas electroquímicas. Para medir la velocidad de corrosión por depósitos salinos se parte de curvas de polarización potenciodinámicas determinando la resistencia de polarización por extrapolación de las pendientes de Tafel. Las sales se fundieron en un crisol de cuarzo dentro de un

  16. Microstructure and magnetic properties of nanostructured (Fe{sub 0.8}Al{sub 0.2}){sub 100–x}Si{sub x} alloy produced by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Boukherroub, N. [UR-MPE, M' hamed Bougara University, Boumerdes 35000 (Algeria); Guittoum, A., E-mail: aguittoum@gmail.com [Nuclear Research Centre of Algiers, 02 Bd Frantz Fanon, BP 399 Alger-Gare, Algiers (Algeria); Laggoun, A. [UR-MPE, M' hamed Bougara University, Boumerdes 35000 (Algeria); Hemmous, M. [Nuclear Research Centre of Algiers, 02 Bd Frantz Fanon, BP 399 Alger-Gare, Algiers (Algeria); Martínez-Blanco, D. [SCTs, University of Oviedo, EPM, 33600 Mieres (Spain); Blanco, J.A. [Department of Physics, University of Oviedo, Calvo Sotelo St., 33007 Oviedo (Spain); Souami, N. [Nuclear Research Centre of Algiers, 02 Bd Frantz Fanon, BP 399 Alger-Gare, Algiers (Algeria); Gorria, P. [Department of Physics and IUTA, EPI, University of Oviedo, 33203 Gijón (Spain); Bourzami, A. [Laboratoire d' Etudes des Surfaces et Interfaces des Matériaux Solides (LESIMS), Université Sétif1, 19000 Sétif (Algeria); Lenoble, O. [Institut Jean Lamour, CNRS-Université de Lorraine, Boulevard des aiguillettes, BP 70239, F-54506 Vandoeuvre lès Nancy (France)

    2015-07-01

    We report on how the microstructure and the silicon content of nanocrystalline ternary (Fe{sub 0.8}Al{sub 0.2}){sub 100–x}Si{sub x} powders (x=0, 5, 10, 15 and 20 at%) elaborated by high energy ball milling affect the magnetic properties of these alloys. The formation of a single-phase alloy with body centred cubic (bcc) crystal structure is completed after 72 h of milling time for all the compositions. This bcc phase is in fact a disordered Fe(Al,Si) solid solution with a lattice parameter that reduces its value almost linearly as the Si content is increased, from about 2.9 Å in the binary Fe{sub 80}Al{sub 20} alloy to 2.85 Å in the powder with x=20. The average nanocrystalline grain size also decreases linearly down to 10 nm for x=20, being roughly half of the value for the binary alloy, while the microstrain is somewhat enlarged. Mössbauer spectra show a sextet thus suggesting that the disordered Fe(Al,Si) solid solution is ferromagnetic at room temperature. However, the average hyperfine field diminishes from 27 T (x=0) to 16 T (x=20), and a paramagnetic doublet is observed for the powders with higher Si content. These results together with the evolution of both the saturation magnetization and the coercive field are discussed in terms of intrinsic and extrinsic properties. - Highlights: • Single-phase nanocrystalline (Fe{sub 0.8}Al{sub 0.2}){sub 100–x}Si{sub x} (x=0, 5, 10, 15 and 20 at%) powders were successfully fabricated by mechanical alloying for a milling time of 72 h. • The insertion of Si atoms leads to a unit-cell contraction and a decrease in the average crystallite size. • The hyperfine and magnetic properties of (Fe{sub 0.8}Al{sub 0.2}){sub 100–x}Si{sub x} were influenced by the Si content.

  17. First-Principle Study of the Optical Properties of Dilute-P GaN1-xPx Alloys.

    Science.gov (United States)

    Borovac, Damir; Tan, Chee-Keong; Tansu, Nelson

    2018-04-16

    An investigation on the optical properties of dilute-P GaN 1-x P x alloys by First-Principle Density Functional Theory (DFT) methods is presented, for phosphorus (P) content varying from 0% up to 12.5%. Findings on the imaginary and real part of the dielectric function are analyzed and the results are compared with previously reported theoretical works on GaN. The complex refractive index, normal-incidence reflectivity and birefringence are presented and a difference in the refractive index in the visible regime between GaN and GaNP alloys of ~0.3 can be engineered by adding minute amounts of phosphorus, indicating strong potential for refractive index tunability. The optical properties of the GaN 1-x P x alloys indicate their strong potential for implementation in various III-nitride-based photonic waveguide applications and Distributed Bragg Reflectors (DBR).

  18. [Effects of different amounts of phosphate fertilizers on copper, zinc transfer in red soil under the application of KH2PO4].

    Science.gov (United States)

    Guo, Liang; Li, Zhong-wu; Huang, Bin; Wang, Yan; Zhang, Yan

    2014-09-01

    In order to study the effects of different phosphate addition amounts on migration and transformation of heavy metals (Cu, Zn) in soil, an indoor leaching experiment using soil columns was carry out to study the leaching behavior of Cu and Zn. The KH2PO4 was chosen as the fertilizer application at the doses of 5 mg.kg-1, 15 mg.kg-1 and 25 mg.kg-1. The results showed that KH2PO4, could reduce the leachate pH, but different phosphate amounts had little effect on leachate pH, pH in leachate kept rising in the whole leaching process. With the application of KH2PO4, Cu migration was mainly in the surface layer while Zn migrated into deeper soil. Concentrations of Cu, Zn in deep soil leachate were low indicating that it was harmless to the shallow groundwater. After leaching, heavy metals mainly existed in the residual form in soil, the proportion of residual form of Cu was around 60% and the proportion of residual form of Zn was around 40%. High concentration of KH2PO4 helps the transformation of Zn from residual organic combination state to exchange state.

  19. Effect of KH2PO4 on gene expression, morphological and biochemical characteristics of stevia rebaudiana Bertoni under in vitro conditions.

    Science.gov (United States)

    Kahrizi, D; Ghari, S M; Ghaheri, M; Fallah, F; Ghorbani, T; Beheshti Ale Agha, A; Kazemi, E; Ansarypour, Z

    2017-08-15

    Stevia rebaudiana is one of the most important biologically sourced and low-calorie sweeteners Bertoni that has a lot of steviol glycosides. Tissue culture is the best for propagation of stevia and micro nutrients can affect both morphological traits and steviol glycosides production. Therefore, the effect of different concentrations of KH2PO4on stevia growth factors and gene expression had been studied by tissue culture methods, RT-PCR and HPLC. According the results, bud numbers had increased significantly in MS + 0.034 mMKH2PO4 media and the highest measured length was seen in plants grown under MS + 0.034 mM KH2PO4 treatment. Also, the highest growth rate (1.396 mm/d) was observed in MS + 0.034 mMKH2PO4.The best concentration of KH2PO4 for expression of UGT74G1 was 0.00425mMand the best one for UGT76G1 expression was 0.017mM. Interestingly, the best media for both stevioside and rebaudioside A accumulation was 0.017mM KH2PO4containing media. There was positive correlation between the best media for gene expression and the best one for steviol glycosides production.

  20. Computational study of GaAs1-xNx and GaN1-yAsy alloys and arsenic impurities in GaN

    International Nuclear Information System (INIS)

    Laaksonen, K; Komsa, H-P; Arola, E; Rantala, T T; Nieminen, R M

    2006-01-01

    We have studied the structural and electronic properties of As-rich GaAs 1-x N x and N-rich GaN 1-y As y alloys in a large composition range using first-principles methods. We have systematically investigated the effect of the impurity atom configuration near both GaAs and GaN sides of the concentration range on the total energies, lattice constants and bandgaps. The N (As) atoms, replacing substitutionally As (N) atoms in GaAs (GaN), cause the surrounding Ga atoms to relax inwards (outwards), making the Ga-N (Ga-As) bond length about 15% shorter (longer) than the corresponding Ga-As (Ga-N) bond length in GaAs (GaN). The total energies of the relaxed alloy supercells and the bandgaps experience large fluctuations within different configurations and these fluctuations grow stronger if the impurity concentration is increased. Substituting As atoms with N in GaAs induces modifications near the conduction band minimum, while substituting N atoms with As in GaN modifies the states near the valence band maximum. Both lead to bandgap reduction, which is at first rapid but later slows down. The relative size of the fluctuations is much larger in the case of GaAs 1-x N x alloys. We have also looked into the question of which substitutional site (Ga or N) As occupies in GaN. We find that under Ga-rich conditions arsenic prefers the substitutional N site over the Ga site within a large range of Fermi level values

  1. The Kinetics of Bainitic Transformation of Roll Steel 75Kh3MF

    Science.gov (United States)

    Kletsova, O. A.; Krylova, S. E.; Priymak, E. Yu.; Gryzunov, V. I.; Kamantsev, S. V.

    2018-01-01

    The critical points of steel 75Kh3MF and the temperature of the start of martensitic transformation are determined by a dilatometric method. The thermokinetic and isothermal diagrams of decomposition of supercooled austenite are plotted. The microstructure and microhardness of steel specimens cooled at different rates are studied. The kinetics of the occurrence of bainitic transformation in the steel is calculated using the Austin-Ricket equation.

  2. Ex situ n+ doping of GeSn alloys via non-equilibrium processing

    Science.gov (United States)

    Prucnal, S.; Berencén, Y.; Wang, M.; Rebohle, L.; Böttger, R.; Fischer, I. A.; Augel, L.; Oehme, M.; Schulze, J.; Voelskow, M.; Helm, M.; Skorupa, W.; Zhou, S.

    2018-06-01

    Full integration of Ge-based alloys like GeSn with complementary-metal-oxide-semiconductor technology would require the fabrication of p- and n-type doped regions for both planar and tri-dimensional device architectures which is challenging using in situ doping techniques. In this work, we report on the influence of ex situ doping on the structural, electrical and optical properties of GeSn alloys. n-type doping is realized by P implantation into GeSn alloy layers grown by molecular beam epitaxy (MBE) followed by flash lamp annealing. We show that effective carrier concentration of up to 1 × 1019 cm‑3 can be achieved without affecting the Sn distribution. Sn segregation at the surface accompanied with an Sn diffusion towards the crystalline/amorphous GeSn interface is found at P fluences higher than 3 × 1015 cm‑2 and electron concentration of about 4 × 1019 cm‑3. The optical and structural properties of ion-implanted GeSn layers are comparable with the in situ doped MBE grown layers.

  3. Bulgarian ethnos according to A.Kh. Khalikov’ works: scientific concept and its theoretical bases

    Directory of Open Access Journals (Sweden)

    Izmaylov Iskander L.

    2017-02-01

    Full Text Available The article is devoted to the problems of Bulgar and Tatar ethnogenesis studied in the works of the prominent Kazan archaeologist A.Kh. Khalikov. His concept was based on the fact that a number of ethnic groups (Turkic, Finno-Ugric, and East Slavic participated in the formation of these peoples and that the key role in these processes was played by their mutual cultural influence. The concept of ethnogenesis and ethnic history of the Tatar people offered by A.Kh. Khalikov was a serious theoretical breakthrough against the background of both ideology-biased historical schemes of the Soviet era and the various nationalist ideas, differing from them by a comprehensive, integral scientific analysis of predominantly archaeological data. At present, however, when theoretical and factual bases of historical and ethnological research have considerably expanded, a number of conflicting issues have arisen in the framework of this concept, which, therefore, require new approaches to their solution.

  4. Effect of N+Cr alloying on the microstructures and tensile properties of Hadfield steel

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Zhang, F.C., E-mail: zfc@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); National Engineering Research Center for Equipment and Technology of Cold Strip Rolling, Yanshan University, Qinhuangdao 066004 (China); Wang, F. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Liu, H.; Yu, B.D. [China Railway Shanhaiguan Bridge Group Co. LTD, Qinhuangdao 066205 (China)

    2017-01-02

    The microstructures and tensile behaviors of traditional Hadfield steel, named Mn12 steel, and Hadfield steel alloyed with N+Cr, named Mn12CrN steel were studied through optical microscopy, transmission electron microscopy, and scanning electron microscopy, among others. Three different tensile strain rates of 5×10{sup −4}, 5×10{sup −3}, and 5×10{sup −2} s{sup −1} were selected in the tensile test. The deformation microstructures and fracture morphologies of the two steels after fracture in the tensile test were observed to analyze the tensile deformation response to different tensile strain rates. Results showed that the grain size of Mn12CrN steel was evidently refined after alloying with N+Cr. The grain would not become abnormally coarse even with increasing austenitizing temperature. During tensile deformation, the strength and plasticity of Mn12CrN steel were superior to those of Mn12 steel at the same strain rate. With increasing the strain rate, the changes in strength and plasticity of Mn12CrN steel were less sensitive to tensile strain rate compared with Mn12 steel. The effects of grain refinement and N+Cr alloying on dynamic strain aging and deformation twining behaviors were responsible for this lack of sensitivity to strain rate.

  5. Role of Chloride in the Corrosion and Fracture Behavior of Micro-Alloyed Steel in E80 Simulated Fuel Grade Ethanol Environment

    Directory of Open Access Journals (Sweden)

    Olufunmilayo O. Joseph

    2016-06-01

    Full Text Available In this study, micro-alloyed steel (MAS material normally used in the production of auto parts has been immersed in an E80 simulated fuel grade ethanol (SFGE environment and its degradation mechanism in the presence of sodium chloride (NaCl was evaluated. Corrosion behavior was determined through mass loss tests and electrochemical measurements with respect to a reference test in the absence of NaCl. Fracture behavior was determined via J-integral tests with three-point bend specimens at an ambient temperature of 27 °C. The mass loss of MAS increased in E80 with NaCl up to a concentration of 32 mg/L; beyond that threshold, the effect of increasing chloride was insignificant. MAS did not demonstrate distinct passivation behavior, as well as pitting potential with anodic polarization, in the range of the ethanol-chloride ratio. Chloride caused pitting in MAS. The fracture resistance of MAS reduced in E80 with increasing chloride. Crack tip blunting decreased with increasing chloride, thus accounting for the reduction in fracture toughness.

  6. Density changes in amorphous Pd80Si20 during low temperature ion irradiation

    International Nuclear Information System (INIS)

    Schumacher, G.; Birtcher, R.C.; Rehn, L.E.

    1994-11-01

    Density changes in amorphous Pd 80 Si 20 during ion irradiation below 100K were detected by in situ HVEM measurements of the changes in specimen length as a function of ion fluence. A decrease in mass density as a function of the ion fluence was observed. The saturation value of the change in mass density was determined to be approximately -1.2%

  7. Removing hydrochloric acid exhaust products from high performance solid rocket propellant using aluminum-lithium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Terry, Brandon C., E-mail: terry13@purdue.edu [School of Aeronautics and Astronautics, Purdue University, Zucrow Laboratories, 500 Allison Rd, West Lafayette, IN 47907 (United States); Sippel, Travis R. [Department of Mechanical Engineering, Iowa State University, 2025 Black Engineering, Ames, IA 50011 (United States); Pfeil, Mark A. [School of Aeronautics and Astronautics, Purdue University, Zucrow Laboratories, 500 Allison Rd, West Lafayette, IN 47907 (United States); Gunduz, I.Emre; Son, Steven F. [School of Mechanical Engineering, Purdue University, Zucrow Laboratories, 500 Allison Rd, West Lafayette, IN 47907 (United States)

    2016-11-05

    Highlights: • Al-Li alloy propellant has increased ideal specific impulse over neat aluminum. • Al-Li alloy propellant has a near complete reduction in HCl acid formation. • Reduction in HCl was verified with wet bomb experiments and DSC/TGA-MS/FTIR. - Abstract: Hydrochloric acid (HCl) pollution from perchlorate based propellants is well known for both launch site contamination, as well as the possible ozone layer depletion effects. Past efforts in developing environmentally cleaner solid propellants by scavenging the chlorine ion have focused on replacing a portion of the chorine-containing oxidant (i.e., ammonium perchlorate) with an alkali metal nitrate. The alkali metal (e.g., Li or Na) in the nitrate reacts with the chlorine ion to form an alkali metal chloride (i.e., a salt instead of HCl). While this technique can potentially reduce HCl formation, it also results in reduced ideal specific impulse (I{sub SP}). Here, we show using thermochemical calculations that using aluminum-lithium (Al-Li) alloy can reduce HCl formation by more than 95% (with lithium contents ≥15 mass%) and increase the ideal I{sub SP} by ∼7 s compared to neat aluminum (using 80/20 mass% Al-Li alloy). Two solid propellants were formulated using 80/20 Al-Li alloy or neat aluminum as fuel additives. The halide scavenging effect of Al-Li propellants was verified using wet bomb combustion experiments (75.5 ± 4.8% reduction in pH, ∝ [HCl], when compared to neat aluminum). Additionally, no measurable HCl evolution was detected using differential scanning calorimetry coupled with thermogravimetric analysis, mass spectrometry, and Fourier transform infrared absorption.

  8. Removing hydrochloric acid exhaust products from high performance solid rocket propellant using aluminum-lithium alloy

    International Nuclear Information System (INIS)

    Terry, Brandon C.; Sippel, Travis R.; Pfeil, Mark A.; Gunduz, I.Emre; Son, Steven F.

    2016-01-01

    Highlights: • Al-Li alloy propellant has increased ideal specific impulse over neat aluminum. • Al-Li alloy propellant has a near complete reduction in HCl acid formation. • Reduction in HCl was verified with wet bomb experiments and DSC/TGA-MS/FTIR. - Abstract: Hydrochloric acid (HCl) pollution from perchlorate based propellants is well known for both launch site contamination, as well as the possible ozone layer depletion effects. Past efforts in developing environmentally cleaner solid propellants by scavenging the chlorine ion have focused on replacing a portion of the chorine-containing oxidant (i.e., ammonium perchlorate) with an alkali metal nitrate. The alkali metal (e.g., Li or Na) in the nitrate reacts with the chlorine ion to form an alkali metal chloride (i.e., a salt instead of HCl). While this technique can potentially reduce HCl formation, it also results in reduced ideal specific impulse (I_S_P). Here, we show using thermochemical calculations that using aluminum-lithium (Al-Li) alloy can reduce HCl formation by more than 95% (with lithium contents ≥15 mass%) and increase the ideal I_S_P by ∼7 s compared to neat aluminum (using 80/20 mass% Al-Li alloy). Two solid propellants were formulated using 80/20 Al-Li alloy or neat aluminum as fuel additives. The halide scavenging effect of Al-Li propellants was verified using wet bomb combustion experiments (75.5 ± 4.8% reduction in pH, ∝ [HCl], when compared to neat aluminum). Additionally, no measurable HCl evolution was detected using differential scanning calorimetry coupled with thermogravimetric analysis, mass spectrometry, and Fourier transform infrared absorption.

  9. 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

  10. Effect of nitrogen addition and annealing temperature on superelastic properties of Ti-Nb-Zr-Ta alloys

    Energy Technology Data Exchange (ETDEWEB)

    Tahara, Masaki [Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Kim, Hee Young, E-mail: heeykim@ims.tsukuba.ac.jp [Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Hosoda, Hideki [Precision and Intelligence Laboratory, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); Nam, Tae-hyun [School of Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processingnd ERI, Gyeongsang National University, 900 Gazwadong, Jinju, Gyeongnam 660-701 (Korea, Republic of); Miyazaki, Shuichi, E-mail: miyazaki@ims.tsukuba.ac.jp [Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); School of Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processingnd ERI, Gyeongsang National University, 900 Gazwadong, Jinju, Gyeongnam 660-701 (Korea, Republic of)

    2010-10-15

    Research highlights: In this study, the effects of composition and annealing temperature on microstructure, shape memory effect and superelastic properties were investigated in Ti-Nb-4Zr-2Ta-N alloys by measuring stress-strain curves at various temperatures and using transmission electron microscopy. Dissolution of {alpha} phase increases M{sub s} and decreases the critical stress for slip for the Ti-22Nb-4Zr-2Ta alloy while it causes the decrease of M{sub s} and the increase of the critical stress for slip for the Ti-20Nb-4Zr-2Ta-0.6N alloy. The different effect of dissolution of {alpha} phase can be attributed to the fact that N is absorbed in {alpha} phase. - Abstract: The composition dependence of the mechanical properties and martensitic transformation behavior of Ti-Nb-4Zr-2Ta-N alloys is investigated. The effect of annealing temperature on the microstructural evolution and superelastic properties in the N-added and N-free alloys is compared. The addition of N decreases M{sub s} of Ti-Nb-4Zr-2Ta alloys by about 200 K per 1 at.%N and improves the superelastic properties of Ti-Nb-4Zr-2Ta alloys. The dissolution of {alpha} phase increases the martensitic transformation start temperature and decreases the superelastic recovery strain for the N-free alloy, whereas it causes opposite effects for the N-added alloy. The different annealing temperature dependences of superelastic properties are discussed on the basis of microstructure observation.

  11. Effect of nitrogen addition and annealing temperature on superelastic properties of Ti-Nb-Zr-Ta alloys

    International Nuclear Information System (INIS)

    Tahara, Masaki; Kim, Hee Young; Hosoda, Hideki; Nam, Tae-hyun; Miyazaki, Shuichi

    2010-01-01

    Research highlights: In this study, the effects of composition and annealing temperature on microstructure, shape memory effect and superelastic properties were investigated in Ti-Nb-4Zr-2Ta-N alloys by measuring stress-strain curves at various temperatures and using transmission electron microscopy. Dissolution of α phase increases M s and decreases the critical stress for slip for the Ti-22Nb-4Zr-2Ta alloy while it causes the decrease of M s and the increase of the critical stress for slip for the Ti-20Nb-4Zr-2Ta-0.6N alloy. The different effect of dissolution of α phase can be attributed to the fact that N is absorbed in α phase. - Abstract: The composition dependence of the mechanical properties and martensitic transformation behavior of Ti-Nb-4Zr-2Ta-N alloys is investigated. The effect of annealing temperature on the microstructural evolution and superelastic properties in the N-added and N-free alloys is compared. The addition of N decreases M s of Ti-Nb-4Zr-2Ta alloys by about 200 K per 1 at.%N and improves the superelastic properties of Ti-Nb-4Zr-2Ta alloys. The dissolution of α phase increases the martensitic transformation start temperature and decreases the superelastic recovery strain for the N-free alloy, whereas it causes opposite effects for the N-added alloy. The different annealing temperature dependences of superelastic properties are discussed on the basis of microstructure observation.

  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. Organizational and technological compatibility of the technological processes of second and third line maintenance of KhTZ-3522 tractors

    Directory of Open Access Journals (Sweden)

    Kyzminskyj Roman

    2018-01-01

    Full Text Available The work is devoted to systematic substantiation of productivity, production structure and specialization of service stations of KhTZ-3522 tractors. Based on the technical and economic comparative analysis of the results of the technological processes modeling of the second and third line maintenance of KhTZ-3522 tractors, the parametrical series of production structures of service stations both mono- and polytechnological specialization, which can work effectively in a wide range of the general annual program of orders, and in the conditions of seasonal fluctuations of orders for the maintenance of these tractors, are found. The results of calculations of the indicators system for organizational and technological compatibility of technological processes of the second and third line maintenance of KhTZ-3522 tractors in the joint technological flow are presented. The dependencies of these indicators on the total annual program of orders for service stations of different productivity are analyzed. According to the results of the analysis, the polytechnological specialization of such service stations is substantiated.

  14. Two stage S-N curve in corrosion fatigue of extruded magnesium alloy AZ31

    Directory of Open Access Journals (Sweden)

    Yoshiharu Mutoh

    2009-11-01

    Full Text Available Tension-compression fatigue tests of extruded AZ31 magnesium alloys were carried out under corrosive environments:(a high humidity environment (80 %RH and (b 5 wt. %NaCl environment. It was found that the reduction rate of fatiguestrength due to corrosive environment was 0.12 under a high humidity and 0.53 under a NaCl environment. It was alsoobserved that under corrosive environments, the S-N curve was not a single curve but a two-stage curve. Above the fatiguelimit under low humidity, the crack nucleation mechanism was due to a localized slip band formation mechanism. Below thefatigue limit under low humidity, the reduction in fatigue strength was attributed to the corrosion pit formation and growth to the critical size for fatigue crack nucleation under the combined effect of cyclic load and the corrosive environment. The critical size was attained when the stress intensity factor range reached the threshold value for crack growth.

  15. On Ni/Au Alloyed Contacts to Mg-Doped GaN

    Science.gov (United States)

    Sarkar, Biplab; Reddy, Pramod; Klump, Andrew; Kaess, Felix; Rounds, Robert; Kirste, Ronny; Mita, Seiji; Kohn, Erhard; Collazo, Ramon; Sitar, Zlatko

    2018-01-01

    Ni/Au contacts to p-GaN were studied as a function of free hole concentration in GaN using planar transmission line measurement structures. All contacts showed a nonlinear behavior, which became stronger for lower doping concentrations. Electrical and structural analysis indicated that the current conduction between the contact and the p-GaN was through localized nano-sized clusters. Thus, the non-linear contact behavior can be well explained using the alloyed contact model. Two contributions to the contact resistance were identified: the spreading resistance in the semiconductor developed by the current crowding around the electrically active clusters, and diode-type behavior at the interface of the electrically active clusters with the semiconductor. Hence, the equivalent Ni/Au contact model consists of a diode and a resistor in series for each active cluster. The reduced barrier height observed in the measurements is thought to be generated by the extraction of Ga from the crystalline surface and localized formation of the Au:Ga phase. The alloyed contact analyses presented in this work are in good agreement with some of the commonly observed behavior of similar contacts described in the literature.

  16. New results on long term aging tests for rad-waste container alloy selection

    Energy Technology Data Exchange (ETDEWEB)

    Alves, H.; Wahl, V.; Ibas, O.; Stenner, F. [ThyssenKrupp VDM GmbH, Altena (Germany)

    2004-07-01

    The current design of containers for high level nuclear waste proceeds on using an outer barrier of corrosion resistant Ni-based super alloy. The current alloy of choice is alloy 22 (UNS N06022). It is a quaternary Ni-Cr- Mo-W alloy system. The new but well established alloy 59 (UNS N06059) is an excellent equal or even a superior alternative to alloy 22 for the 10,000 years reliability being sought. Alloy 59 is a pure ternary alloy in the Ni-Cr-Mo alloy system. Objective of this paper is to present data comparing these two alloys. Therefore the behaviour of alloy 59 and alloy 22 was characterised after aging in air for 10,000 h and 20,000 h at different temperatures (200, 300 and 427 deg. C). Since the performance of weldments is of great concern, both welded and unwelded specimens were studied. Mechanical properties of the air aged alloys were measured at room temperature by tensile and notch impact-bending test. Thermal stability and aqueous corrosion are considered to be the key issues in the long-term performance of container materials proposed for the geological disposal of high level nuclear waste. The long-term thermal stability and corrosion resistance of the alloy 59 compared to alloy 22 is discussed. Corrosion resistance was evaluated in ASTM G28 A and 'green death' solution laboratory tests; hereby corrosion rates and depth of attack were determined. Metallo-graphical studies were performed in mill annealed and air aged conditions. The results of the aging tests at 10,000 h and 20,000 h show that alloy 59 is an equal or better candidate material due to its superior localised corrosion resistance behaviour (pitting and crevice corrosion resistance) and better thermal stability needed especially in multi-pass welding of thick sections. Therefore alloy 59 seems to be the most promising alternative to alloy 22. (authors)

  17. New results on long term aging tests for rad-waste container alloy selection

    International Nuclear Information System (INIS)

    Alves, H.; Wahl, V.; Ibas, O.; Stenner, F.

    2004-01-01

    The current design of containers for high level nuclear waste proceeds on using an outer barrier of corrosion resistant Ni-based super alloy. The current alloy of choice is alloy 22 (UNS N06022). It is a quaternary Ni-Cr- Mo-W alloy system. The new but well established alloy 59 (UNS N06059) is an excellent equal or even a superior alternative to alloy 22 for the 10,000 years reliability being sought. Alloy 59 is a pure ternary alloy in the Ni-Cr-Mo alloy system. Objective of this paper is to present data comparing these two alloys. Therefore the behaviour of alloy 59 and alloy 22 was characterised after aging in air for 10,000 h and 20,000 h at different temperatures (200, 300 and 427 deg. C). Since the performance of weldments is of great concern, both welded and unwelded specimens were studied. Mechanical properties of the air aged alloys were measured at room temperature by tensile and notch impact-bending test. Thermal stability and aqueous corrosion are considered to be the key issues in the long-term performance of container materials proposed for the geological disposal of high level nuclear waste. The long-term thermal stability and corrosion resistance of the alloy 59 compared to alloy 22 is discussed. Corrosion resistance was evaluated in ASTM G28 A and 'green death' solution laboratory tests; hereby corrosion rates and depth of attack were determined. Metallo-graphical studies were performed in mill annealed and air aged conditions. The results of the aging tests at 10,000 h and 20,000 h show that alloy 59 is an equal or better candidate material due to its superior localised corrosion resistance behaviour (pitting and crevice corrosion resistance) and better thermal stability needed especially in multi-pass welding of thick sections. Therefore alloy 59 seems to be the most promising alternative to alloy 22. (authors)

  18. Effect of composition and heat treatment on the phase formation of mechanically alloyed Cr-B and Mo-B powders

    International Nuclear Information System (INIS)

    Wu, H M; Hu, C J; Pai, K Y

    2009-01-01

    Blended elemental Cr-B and Mo-B powders in atomic ratio of 67:33, 50:50, and 20:80 were subjected to mechanical alloying up to 60 h and subsequent heat treatment to investigate effect of composition and heat treatment on the phase formation of Cr-B and Mo-B powders. It was studied by X-ray diffraction and differential thermal analysis. Mechanical alloying these powder mixtures for 60 h leads essentially to a amorphous structure except for the Mo 20 B 80 powder, which creates a partially amorphous MoB 4 structure. Annealing at lower temperatures relieves the strains cumulative in the milled powders and creates no new phase. The structures obtained after annealing the milled powders at higher temperature vary and depend on the overall composition of the powder mixtures. Annealing the milled Mo-B powders having greater Mo content ends up with a dissociation reaction at higher temperature.

  19. Semiquantitative activation analysis in metallic alloys submitted to irregular irradiation

    International Nuclear Information System (INIS)

    Veissid, N.; Lucki, G.

    1979-01-01

    An analytic semiquantitative method using neutron activation was developed to determine the impurities and verify the composition of metallic alloys. By the radioactive transformation law, the number of atoms of each element present in the sample is determined measuring the activity in a multichannel. Two samples were analysed: a) Sample of nominal compositions FeNiCr (49,95-49,95 - 0,1% at). b) Sample of nominal composition NiCr (80,20% at). (Author) [pt

  20. Comparative study of Ce0.80Sm0.20 Ba0.80Y0.20O3-δ (YB-SDC electrolyte by various chemical synthesis routes

    Directory of Open Access Journals (Sweden)

    Sana Tariq

    2018-03-01

    Full Text Available Solid Oxide Fuel Cells is received a significant attention in recent years due to higher efficiency and fuel flexibility. The one of the main challenge for SOFC is to lower the operating temperature of SOFCs. Therefore, different strategies are used in order to enhance the ionic conduction of electrolyte, which can lower the overall SOFC operating temperature. The present work is focused on this strategy to enhance the electrolytic conductivity. Therefore, the ceria based composite electrolytes Ce0.80Sm0.20B0.80Y0.20O3-δ (YBSDC are synthesized using three different approaches i.e. co-precipitation (YBSDC-1, sol-gel (YBSDC-2 and ball milling (YBSDC-3. Their crystal structures and surface morphologies are characterized through X-ray Diffraction (XRD and Scanning Electron Microscopy (SEM techniques, respectively. The four-probe technique is employed to measure their dc conductivities in the temperature range (300–700 °C under air atmosphere. The open circuit voltage (OCV and current are recorded with natural gas as fuel {flow rate kept at 100 ml min−1 at 1 atm pressure} over the temperature range (300–600 °C.The electrolyte (YBSDC-1 prepared by co-precipitation technique is shown better results as compare to other two electrolytes (YBSDC-2 and YBSDC-3. The electrolyte (YBSDC-1 having maximum dc conductivity (0.096 S/cm, peak power density 224 mW cm−2 and OCV 0.94 V at 600 °C. These results show that YBSDC-1electrolyte is potential candidate for low temperature SOFCs. Keywords: Hydrogen, Energy, Ball milling, Composite, Conductor

  1. PENDIDIKAN KARAKTER MENURUT K.H. HASYIM ASY’ARI DALAM KITAB ADÂB AL-‘ÂLIM WA AL-MUTA‘ALLIM

    OpenAIRE

    Sholikah Sholikah

    2015-01-01

    The article deals with K.H. Hasyim Asy’ari’s thought of character education. The result of the study indicates that according to K.H. Hasyim Asy’ari the characters of teachers and students in his work Adab al-‘Âlim wa al-Muta’allim can be classified into three parts, are mentality or character, which should be possessed by teachers and learners: attempts to be done in order to become characterized teachers and learners, and: teaching strategies employed by educators and learning strategies us...

  2. Evaluation of mechanically alloyed Cu-based powders as filler alloy for brazing tungsten to a reduced activation ferritic-martensitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Prado, J. de, E-mail: javier.deprado@urjc.es; Sánchez, M.; Ureña, A.

    2017-07-15

    80Cu-20Ti powders were evaluated for their use as filler alloy for high temperature brazing of tungsten to a reduced activation ferritic/martensitic steel (Eurofer), and its application for the first wall of the DEMO fusion reactor. The use of alloyed powders has not been widely considered for brazing purposes and could improve the operational brazeability of the studied system due to its narrower melting range, determined by DTA analysis, which enhances the spreading capabilities of the filler. Ti contained in the filler composition acts as an activator element, reacting and forming several interfacial layers at the Eurofer-braze, which enhances the wettability properties and chemical interaction at the brazing interface. Brazing thermal cycle also activated the diffusion phenomena, which mainly affected to the Eurofer alloying elements causing in it a softening band of approximately 400 μm of thickness. However, this softening effect did not degrade the shear strength of the brazed joints (94 ± 23 MPa), because failure during testing was always located at the tungsten-braze interface. - Highlights: •W-Eurofer brazed joints, manufactured using Cu-based mechanically alloyed powders as filler is proposed. •The benefits derivate from the alloyed composition could improve the operational brazeability of the studied system. •Tested pre-alloyed fillers have a more homogeneous melting stage which enhances its spreading and flowing capabilities. •This behaviour could lead to work with higher heating rates and lower brazing temperatures.

  3. Hydrogen and deuterium permeation in copper alloys, copper--gold brazing alloys, gold, and the in situ growth of stable oxide permeation barriers

    International Nuclear Information System (INIS)

    Begeal, D.R.

    1978-01-01

    The deuterium permeation through several copper alloys has been measured over a temperature range of 550 to 830 K using the membrane technique. In some cases, the hydrogen permeability was also measured. The results were divided into three categories: common alloys, gold alloys, and stable oxide forming alloys. Common alloys which showed typical bulk metallic diffusion with litle change in the permeation activation energy as compared to copper (77 kJ/mol for D 2 ) were: (additions are in weight percent) 5% Sn, 2.3% U, 0.15% Zr, 4% Sn+4% Pb+4% Zn, 3% Si, and 7% Al+2% Fe. Compared to copper, the D 2 permeability at 573 K was reduced by factors of 2.0, 2.7, 4.5, 5.3, 5.9, and 7.0, respectively. A series of gold--copper alloys including pure gold, 80% Au, 50% Au, 49% Au, and 35% Au also showed typical bulk metallic diffusion with a trend of decreasing permeability (increasing activation energies for permeation) with increasing gold content. There were also pronounced inflections or shifts in the permeability at approx.370 0 C, or about the order--disorder transition for Cu 3 Au and CuAu, for the 80% and 50% alloys. Two alloys did not exhibit bulk metallic permeation behavior and the permeabiltiy was in fact controlled by surface oxide layers. It was found that a layer of beryllium oxide could be formed on Cu+2% Be and a layer of aluminum oxide could be formed on Cu+7% Al+2% Si. As compared to 0.25 mm-thick copper, the deuterium permeability at 500 0 C was reduced by a factor of approx.250 for Cu--Be and approx.1000 for Cu--Al--Si. The activation energies for deuterium permeation were 98 kJ/mol and 132 kJ/mol, respectively. The mechanism for the oxide growth is the high-temperature hydrogen reduction of nearby less stable oxides, simultaneous with oxidation of the active metal, Be or Al, by trace amounts of water in the hydrogen. Ion microprobe mass analysis identified the oxide layers as containing beryllium or aluminum but not containing copper

  4. Evaluation of mechanically alloyed Cu-based powders as filler alloy for brazing tungsten to a reduced activation ferritic-martensitic steel

    Science.gov (United States)

    de Prado, J.; Sánchez, M.; Ureña, A.

    2017-07-01

    80Cu-20Ti powders were evaluated for their use as filler alloy for high temperature brazing of tungsten to a reduced activation ferritic/martensitic steel (Eurofer), and its application for the first wall of the DEMO fusion reactor. The use of alloyed powders has not been widely considered for brazing purposes and could improve the operational brazeability of the studied system due to its narrower melting range, determined by DTA analysis, which enhances the spreading capabilities of the filler. Ti contained in the filler composition acts as an activator element, reacting and forming several interfacial layers at the Eurofer-braze, which enhances the wettability properties and chemical interaction at the brazing interface. Brazing thermal cycle also activated the diffusion phenomena, which mainly affected to the Eurofer alloying elements causing in it a softening band of approximately 400 μm of thickness. However, this softening effect did not degrade the shear strength of the brazed joints (94 ± 23 MPa), because failure during testing was always located at the tungsten-braze interface.

  5. Structural evolution of Ni-20Cr alloy during ball milling of elemental powders

    International Nuclear Information System (INIS)

    Lopez B, I.; Trapaga M, L. G.; Martinez F, E.; Zoz, H.

    2011-01-01

    The ball milling (B M) of blended Ni and Cr elemental powders was carried out in a Simoloyer performing on high-energy scale mode at maximum production to obtain a nano structured Ni-20Cr alloy. The phase transformations and structural changes occurring during mechanical alloying were investigated by X-ray diffraction (XRD) and optical microscopy (Om). A gradual solid solubility of Cr and the subsequent formation of crystalline metastable solid solutions described in terms of the Avrami-Ero fe ev kinetics model were calculated. The XRD analysis of the structure indicates that cumulative lattice strain contributes to the driving force for solid solution between Ni and Cr during B M. Microstructure evolution has shown, additionally to the lamellar length refinement commonly observed, the folding of lamellae in the final processing stage. Om observations revealed that the lamellar spacing of Ni rich zones reaches a steady value near 500 nm and almost disappears after 30 h of milling. (Author)

  6. Structural evolution of Ni-20Cr alloy during ball milling of elemental powders

    Energy Technology Data Exchange (ETDEWEB)

    Lopez B, I.; Trapaga M, L. G. [IPN, Centro de Investigacion y de Estudios Avanzados, Unidad Queretaro, Libramiento Norponiente No. 2000, Juriquilla, 76230 Queretaro (Mexico); Martinez F, E. [Centro de Investigacion e Innovacion Tecnologica, Cerrada de Cecati s/n, Col. Santa Catarina Azcapotzalco, 02250 Mexico D. F. (Mexico); Zoz, H., E-mail: israelbaez@gmail.co [Zoz GmbH, D-57482, Wenden (Germany)

    2011-07-01

    The ball milling (B M) of blended Ni and Cr elemental powders was carried out in a Simoloyer performing on high-energy scale mode at maximum production to obtain a nano structured Ni-20Cr alloy. The phase transformations and structural changes occurring during mechanical alloying were investigated by X-ray diffraction (XRD) and optical microscopy (Om). A gradual solid solubility of Cr and the subsequent formation of crystalline metastable solid solutions described in terms of the Avrami-Ero fe ev kinetics model were calculated. The XRD analysis of the structure indicates that cumulative lattice strain contributes to the driving force for solid solution between Ni and Cr during B M. Microstructure evolution has shown, additionally to the lamellar length refinement commonly observed, the folding of lamellae in the final processing stage. Om observations revealed that the lamellar spacing of Ni rich zones reaches a steady value near 500 nm and almost disappears after 30 h of milling. (Author)

  7. Energy investigations on the mechanical properties of magnesium alloyed by X = C, B, N, O and vacancy

    KAUST Repository

    Wu, Xiaozhi

    2013-10-25

    The generalized stacking fault (GSF) energies and surface energies of magnesium and its alloys with alloying atoms X = C, B, N, O and vacancy have been investigated using the first-principles methods. It is found that the predominant reducing effects of the alloying atoms and vacancy on the stacking fault energy are resulted from the position of them in the 1st layer near the slip plane. The stacking fault energies are nearly the same as the pure magnesium while the alloying atoms and vacancy are placed in the 2nd, 3rd, 4th, 5th and 6th layers. It has been shown that O strongly reduces the GSF energy of Mg. The alloying atoms C, B and N increase the surface energy, but O and vacancy reduce the surface energy of Mg. The ductilities of Mg and Mg alloys have been discussed based on the Rice criterion by using the ratio between surface energy and unstable stacking fault energy. © 2013 Higher Education Press and Springer-Verlag Berlin Heidelberg.

  8. Creep rupture properties of oxidised 20%Cr austenitic stainless steels

    International Nuclear Information System (INIS)

    Lobb, R.C.; Ecob, R.C.

    1989-02-01

    Sheet specimens of stabilised 20%Cr/25%Ni/Nb and nitrided 20%Cr/25%Ni/Ti stainless steels, both used as fuel cladding materials in CAGRs, have been oxidised in simulated reactor gas (Co 2 /1-2%CO) for up to l.9kh at 850 0 C, including intermediate thermal cycles to room temperature. The oxidised specimens have been creep tested subsequently at 750 0 C, under conditions of constant stress. The creep rupture properties are affected differently for the two materials. For 20%Cr/25%Ni/Nb stainless steel, there was no effect of oxidation on the intrinsic microstructure, when compared with thermally aged, non-oxidised material. Any differences in creep ductility were ascribed to geometric effects in specimens of this alloy. Lower ductilities were associated with an increased incidence of pitting attack (higher oxide spallation) and it was concluded that the extent of local, rather than general, loss of section controlled the ductility. For nitrided 20%Cr/25%Ni/Ti stainless steel, the intrinsic microstructure was affected by oxidation, such that increased grain boundary precipitation of M 23 C 6 occurred. The resultant effect was for a greater tendency for intergranular failure at lower ductility than for the thermally aged material. The magnitude of this reduction could not be quantified because the specimen geometry was also changed by oxidation. In this instance, the oxidation mode that produced the most severe loss of section was grain boundary, rather than pitting, attack. This mode of attack was not linked directly to oxide fracture/spallation, but to the period of oxidation. (author)

  9. Analysis of tellurium-silicon alloys. Part 1. Determination of tellurium by the reduction from perchloric acid solution

    International Nuclear Information System (INIS)

    Teperek, J.

    1977-01-01

    When 100-150 mg of tellurium is dissolved in the solution containing 20 cm 3 72 wt.% of perchloric acid, the reduction of tellurium to elementary form is possible only after adding 60-100 milimoles of HCl. The reduction is performed by adding 1 cm 3 of saturated sodium pyrosulphite solution (Na 2 S 2 O 5 ) and 10 cm 3 of 10 wt.% hydrazine hydrochloride solution (N 2 H 4 .2HCl) to 80-90 cm 3 of cold solution of Te in HClO 4 -HCl mixture. The reduction is completed after 3-5 min. of boiling. When 150-200 mg sample of Te-Si alloy is dissolved in 20 cm 3 of hot 72% per chloric acid, the separation of components is reached. Tellurium can be determinated in filtrate by proposed procedure with high accuracy and precision. (author)

  10. Issues associated with the metalorganic chemical vapor deposition of ScGaN and YGaN alloys.

    Energy Technology Data Exchange (ETDEWEB)

    Koleske, Daniel David; Knapp, James Arthur; Lee, Stephen Roger; Crawford, Mary Hagerott; Creighton, James Randall; Cross, Karen Charlene; Thaler, Gerald

    2009-07-01

    The most energy efficient solid state white light source will likely be a combination of individually efficient red, green, and blue LED. For any multi-color approach to be successful the efficiency of deep green LEDs must be significantly improved. While traditional approaches to improve InGaN materials have yielded incremental success, we proposed a novel approach using group IIIA and IIIB nitride semiconductors to produce efficient green and high wavelength LEDs. To obtain longer wavelength LEDs in the nitrides, we attempted to combine scandium (Sc) and yttrium (Y) with gallium (Ga) to produce ScGaN and YGaN for the quantum well (QW) active regions. Based on linear extrapolation of the proposed bandgaps of ScN (2.15 eV), YN (0.8 eV) and GaN (3.4 eV), we expected that LEDs could be fabricated from the UV (410 nm) to the IR (1600 nm), and therefore cover all visible wavelengths. The growth of these novel alloys potentially provided several advantages over the more traditional InGaN QW regions including: higher growth temperatures more compatible with GaN growth, closer lattice matching to GaN, and reduced phase separation than is commonly observed in InGaN growth. One drawback to using ScGaN and YGaN films as the active regions in LEDs is that little research has been conducted on their growth, specifically, are there metalorganic precursors that are suitable for growth, are the bandgaps direct or indirect, can the materials be grown directly on GaN with a minimal defect formation, as well as other issues related to growth. The major impediment to the growth of ScGaN and YGaN alloys was the low volatility of metalorganic precursors. Despite this impediment some progress was made in incorporation of Sc and Y into GaN which is detailed in this report. Primarily, we were able to incorporate up to 5 x 10{sup 18} cm{sup -3} Y atoms into a GaN film, which are far below the alloy concentrations needed to evaluate the YGaN optical properties. After a no-cost extension was

  11. Strengthening of metallic alloys with nanometer-size oxide dispersions

    Science.gov (United States)

    Flinn, J.E.; Kelly, T.F.

    1999-06-01

    Austenitic stainless steels and nickel-base alloys containing, by wt. %, 0.1 to 3.0% V, 0.01 to 0.08% C, 0.01 to 0.5% N, 0.05% max. each of Al and Ti, and 0.005 to 0.10% O, are strengthened and ductility retained by atomization of a metal melt under cover of an inert gas with added oxygen to form approximately 8 nanometer-size hollow oxides within the alloy grains and, when the alloy is aged, strengthened by precipitation of carbides and nitrides nucleated by the hollow oxides. Added strengthening is achieved by nitrogen solid solution strengthening and by the effect of solid oxides precipitated along and pinning grain boundaries to provide temperature-stabilization and refinement of the alloy grains. 20 figs.

  12. First-principle study of the structural, electronic, and optical properties of cubic InN{sub x}P{sub 1-x} ternary alloys under hydrostatic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Hattabi, I. [Ibn Khaldoun Univ. de Tiaret (Algeria). Lab. Synthese et Catalyse; Abdiche, A.; Riane, R. [Sidi-bel-Abbes Univ. (Algeria). Applied Materials Lab.; Moussa, R. [Sidi-bel-Abbes Univ. (Algeria). Physic Dept.; Hadji, K. [Ibn Khaldoun Univ. de Tiaret (Algeria). Science and Technology Dept.; Soyalp, F. [Yuezuencue Yil Univ., Van (Turkey). Dept. of Physics; Varshney, Dinesh [Devi Ahilya Univ., Indore (India). Materials Science Lab.; Syrotyuk, S.V. [National Univ. ' Lviv Polytechnic' , Lviv (Ukraine). Semiconductor Electronics Dept.; Khenata, R. [Mascara Univ. (Algeria). Lab. de Physique Quantique et de Modelisation Mathematique (LPQ3M)

    2016-07-01

    In this article, we present results of the first-principle study of the structural, electronic, and optical properties of the InN, InP binary compounds and their related ternary alloy InN{sub x}P{sub 1-x} in the zinc-blend (ZB) phase within a nonrelativistic full potential linearised augmented plan wave (FP-LAPW) method using Wien2k code based on the density functional theory (DFT). Different approximations of exchange-correlation energy were used for the calculation of the lattice constant, bulk modulus, and first-order pressure derivative of the bulk modulus. Whereas the lattice constant decreases with increasing nitride composition x. Our results present a good agreement with theoretical and experimental data. The electronic band structures calculated using Tran-Blaha-modified Becke-Johnson (TB-mBJ) approach present a direct band gap semiconductor character for InN{sub x}P{sub 1-x} compounds at different x values. The electronic properties were also calculated under hydrostatic pressure for (P=0.00, 5.00, 10.0, 15.0, 20.0, 25.0 GPa) where it is found that the InP compound change from direct to indirect band gap at the pressure P≥7.80 GPa. Furthermore, the pressure effect on the dielectric function and the refractive index was carried out. Results obtained in our calculations present a good agreement with available theoretical reports and experimental data.

  13. Structural and magnetic characterization of Nd-based Nd-Fe and Nd-Fe-Co-Al metastable alloys

    International Nuclear Information System (INIS)

    Kumar, G.

    2005-01-01

    The aim of the present work is to characterize a metastable hard magnetic phase referred to as ''A1'' in Nd-Fe alloys, which forms as a part of the fine eutectic depending on the composition and cooling rate. In order to define the range of composition for the formation of A1, Nd 100-x Fe x (x=20,25,40) alloys are cooled at about 150 K/s. The effect of cooling rate on the formation of hard magnetic A1 is studied by investigating the Nd 80 Fe 20 alloys cooled at different rates. The Nd-richer regions are identified as dhcp Nd and fcc Nd-Fe solid solution. However, the Fe-richer regions also referred to as A1, are diffuse and give an average composition of Nd 56 Fe 44 . HRTEM images of the Fe-richer regions reveal the presence of 5-10 nm crystallites embedded in an amorphous phase. The demagnetization curves the hard magnetic Nd80Fe20 measured at temperatures above 30 K are typical of a hard magnetic material. The measurements of initial magnetization, field dependence of coercivity, and temperature dependence of coercivity suggest the Stoner-Wohlfarth type magnetization reversal process for the hard magnetic A1. The values of anisotropy constant are estimated by fitting the magnetization data to the law-of-approach to saturation. The temperature dependence of anisotropy constant and the coercivity indicate that the origin of coercivity is magnetic anisotropy

  14. Effects of surface treatments on bond strength of dental Ti-20Cr and Ti-10Zr alloys to porcelain

    International Nuclear Information System (INIS)

    Lin, Hsi-Chen; Wu, Shih-Ching; Ho, Wen-Fu; Huang, Ling-Hsiu; Hsu, Hsueh-Chuan

    2010-01-01

    The purpose of this study was to investigate the effect of surface treatments, including sandblasting and grinding, on the bond strength between a low-fusing porcelain and c.p. Ti, Ti-20Cr and Ti-10Zr alloys. The surface treatments were divided into 2 groups. Grinding surface treatment was applied to the first group, which served as the control, and sandblasting was applied to the second group. After treatment, low-fusing porcelain (Titankeramik) was fired onto the surface of the specimens. A universal testing machine was used to perform a 3-point bending test. The metal-ceramic interfaces were subjected to scanning electron microscopic analysis. Of the sandblasted samples, the debonding test showed that Ti-20Cr alloy had the strongest (31.50 MPa) titanium-ceramic bond (p < 005), followed by c.p. Ti (29.4 MPa) and Ti-10Zr (24.3 MPa). Of the grinded samples, Ti-20Cr alloy showed 27.3 MPa titanium-ceramic bond (p < 005), followed by c.p. Ti (14.3 MPa) and Ti-10Zr (failure). The SEM micrographs of the metal surface after debonding showed residual porcelain retained on all samples. On the whole, sandblasting surface treatment appears to have had a more beneficial effect on the Ti-ceramic bond strength than grinding surface treatment. Furthermore, surface treatment of Ti-20Cr with either grinding or sandblasting resulted in adequate bond strength, which exceeded the lower limit value in the ISO 9693 standard (25 MPa).

  15. On the problem of soldering refractory metals with silver-containing solders

    International Nuclear Information System (INIS)

    Anikeev, E.F.; Andryushchenko, V.I.; Chepelenko, V.N.; Batov, V.M.

    1981-01-01

    The processes of wetting, spreading and interphase interactions of copper-silver liquid alloys alloyed with Ni and Si, with niobium, tantalum, molybdenum, tungsten, 12Kh18N10T steel and nickel are studied. It has been determined that Ni or Si additions into the copper-silver solder improve the wetting and adhesion. When soldering with the alloy containing Ni additions, the strength of a soldered Joint grows with the increase of soldering duration while soldering with the alloy containing Si additions, the strength decreases. That is why Ni-containing solders are preferable for soldering thick-walled structures, and Si-containing solders - for thin-walled structures [ru

  16. Alloys of nickel-iron and nickel-silicon do not swell under fast neutron irradiation

    International Nuclear Information System (INIS)

    Silvestre, G.; Silvent, A.; Regnard, C.; Sainfort, G.

    1975-01-01

    This research is concerned with the effect of fast-neutron irradiation on the swelling of nickel and nickel alloys. Ni-Fe (0-60at%Fe) and Ni-Si (0-8at%Si) were studied, and the fluences were in the range 10 20 -4.3x10 22 n/cm 2 . In dilute alloys, the added elements are dissolved and reduce swelling, silicon being particularly effective. In more concentrated alloys, irradiation of Ni-Fe and Ni-Si alloys brings about the formation of plate-shaped precipitates of Ni 3 X and these alloys do not swell. (Auth.)

  17. Synthesis and thermoelectric properties of Sb{sub 0.20}CoSb{sub 2.80} skutterudite

    Energy Technology Data Exchange (ETDEWEB)

    Figueirêdo, C.A., E-mail: camila_fig@hotmail.com [Universidade Federal do Rio Grande do Sul, PGCIMAT, Instituto de Física, 91501-970 Porto Alegre, RS (Brazil); Gallas, M.R. [Universidade Federal do Rio Grande do Sul, PGCIMAT, Instituto de Física, 91501-970 Porto Alegre, RS (Brazil); Institute for Multiscale Simulations, Friedrich-Alexander-Universität, Nägelsbachstrasse 49b, 91052 Erlangen (Germany); Zorzi, J.E. [Universidade de Caxias do Sul, Instituto de Materiais Cerâmicos, 95765-000 Bom Princípio, RS (Brazil); Perottoni, C.A. [Universidade Federal do Rio Grande do Sul, PGCIMAT, Instituto de Física, 91501-970 Porto Alegre, RS (Brazil); Universidade de Caxias do Sul, Instituto de Materiais Cerâmicos, 95765-000 Bom Princípio, RS (Brazil)

    2014-06-15

    Highlights: • A HP-HT Sb{sub 0.20}CoSb{sub 2.80} phase was prepared by processing cobalt antimonide at 7.7 GPa and 550 °C, for (at least) 5 min. • The mechanism of formation of this phase involves (i) decomposition of cobalt antimonide into CoSb{sub 2} and Sb, and (ii) insertion of Sb into the remaining cobalt antimonide. • The mechanism of formation is qualitatively different from that responsible for the formation of the high pressure (greater than 20 GPa) phase. - Abstract: Polycrystalline samples of cobalt antimonide (CoSb{sub 2.79}) were submitted to different conditions of pressure, temperature and processing time, in a high-pressure toroidal-type chamber, aiming to maximize the production of the high pressure phase previously observed in experiments with a diamond anvil cell. Rietveld refinements of X-ray powder diffraction data were performed to determine the phase composition and structural parameters. The maximum yield, 89(2) wt.% of Sb{sub x}CoSb{sub 3−x} phase, was obtained at 7.7 GPa, 550 °C and (at least) 5 min of processing time. The mechanism behind the formation of Sb{sub x}CoSb{sub 3−x} at high pressure and high temperature is actually not the same as that previously inferred from experiments at higher pressures (20 GPa) and room temperature with the diamond anvil cell. Indeed, evidences suggest that, at high pressure and high temperature, Sb{sub x}CoSb{sub 3−x} is formed by insertion of Sb resulting from decomposition of cobalt antimonide. Thermal conductivity, Seebeck coefficient and electrical conductivity were estimated for CoSb{sub 2.79} and Sb{sub 0.20}CoSb{sub 2.80}. The thermoelectric figure of merit at room temperature for Sb{sub 0.20}CoSb{sub 2.80} resulted 33% greater than that for CoSb{sub 2.79}.

  18. Low-temperature nitriding of austenitic steel in a vibrofluidized bed

    Science.gov (United States)

    Baraz, V. R.; Grachev, S. V.

    1999-11-01

    The prospects for use of a vibrofluidized bed (VFB) for low-temperature nitrogen saturation of high-strength austenitic steel based on Cr-Ni-Mn (12Kh17N8G2S2MF) are considered. The positive effect of preliminary plastic deformation on the intensity of nitriding is described. The temperature and time parameters of nitriding in a VFB for strain-aging austenitic steel 12Kh17N8G2S2MF are shown to be adequate for the regimes of the final heat-treatment operation of aging. This creates the possibility of combining the operations of surface alloying and strain aging into a single cycle. This combined treatment increases substantially the resistance of the steel to cyclic loads while preserving the strength parameters. It is shown that the presented method of low-temperature nitriding in a VFB is expedient for improving the service characteristics of austenitic steel 12Kh17N8G2S2MF used for production of force springs of automobile brake systems.

  19. High pressure stability analysis and chemical bonding of Ti{sub 1-x}Zr{sub x}N alloy: A first principle study

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, Mamta; Gupta, Dinesh C., E-mail: sosfizix@gmail.com, E-mail: mamta-physics@yahoo.co.in [Condensed Matter Theory Group, School of Studies in Physics, Jiwaji University, Gwalior – 474 011 (India)

    2016-05-23

    First-principles pseudo-potential calculations have been performed to analyze the stability of Ti{sub 1-x}Zr{sub x}N alloy under high pressures. The first order phase transition from B1 to B2 phase has been observed in this alloy at high pressure. The variation of lattice parameter with the change in concentration of Zr atom in Ti{sub 1-x}Zr{sub x}N is also reported in both the phases. The calculations for density of states have been performed to understand the alloying effects on chemical bonding of Ti-Zr-N alloy.

  20. Analyzing power measurements for 209Bi(n,n) at 6 and 9 MeV and consistent dispersive optical-model analyses for n+209Bi and n+208Pb from -20 to +80 MeV

    International Nuclear Information System (INIS)

    Weisel, G.J.; Tornow, W.; Howell, C.R.; Felsher, P.D.; AlOhali, M.; Roberts, M.L.; Das, R.K.; Walter, R.L.; Mertens, G.

    1996-01-01

    High-accuracy measurements of A y (θ) data for elastic scattering for n+ 209 Bi have been performed at 6 and 9 MeV. The data are incorporated into a large database of σ(θ), A y (θ), and σ T for n+ 209 Bi covering the energy range 1.0 endash 80 MeV. A complementary database is constructed for n+ 208 Pb and a dispersive optical-model analysis is performed for both scattering systems while constraining many of the parameters to be identical for both systems. A good representation of both databases is obtained with conventional geometry and spin-orbit parameters. The 208 Pb model predicts quite well the measured energies of valence single-particle and single-hole bound states. Occupation probabilities and spectroscopic factors for the same bound states are also calculated. Finally, a fully constrained model is presented in which the only differences between the n+ 208 Pb and the n+ 209 Bi systems are the Fermi energy and the isospin dependence in the real volume potential. copyright 1996 The American Physical Society

  1. Effect of filler metals and heat treatment on mechanical properties of welded joints of the VT20L and VT6L titanium cast alloys

    International Nuclear Information System (INIS)

    Abramova, V.N.; Polyakov, D.A.; Vas'kin, Yu.V.; Kulikov, F.R.; Prostov, I.A.; Yasinskij, K.K.

    1979-01-01

    Developed is a technology of welding and heat treatment of the VT20L and VT6L alloys, providing the mechanical properties of welds on the base metal level. It is found, that for residual stress relieving it is quite enough to anneal the alloys at 650 deg C. Welding of the investigated alloys up to 20 mm thick using SPT-2 additional wire provides the welded joint strength on a level of 0.8 σsub(u) of base metal. Usage of additional wire of base metal provides equal strength of welds and base metal

  2. Investigation of self-organized quantum dots in InGaN alloys for photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Jinshe; Wang, Mingyue [Chongqing Normal Univ. (China). Dept. of Physics

    2008-07-01

    The self-organized quantum dots in InGaN alloys grown by metal organic chemical vapor deposition for photovoltaic devices were investigated using photoluminescence spectra, x-ray diffraction and atomic force microscopy measurements. The AFM view of the alloy shows the island-like microstructure appearing to be composed of granular-crystalline in nanometer scale. By analysis of the PL, it has been found that the narrow 493nm emission peak with 490nm and 487nm shoulder peaks was originated from InGaN self-organized quantum dots, which provide a candidate for realizing high efficiencies photovoltaic devices. (orig.)

  3. The effect of alloying and treatment on martensite transformation during deformation in Fe-Cr-Mn steels with unstable austenite

    International Nuclear Information System (INIS)

    Malinov, L.S.; Konop, V.I.; Sokolov, K.N.

    1977-01-01

    The effect is studied of alloying with chromium (6-10%), silicon (1-2%), molybdenum (1-3%), and copper (2%), the heat treatment conditions, and the deformation conditions, or the martensitic transformation and mechanical properties of Fe-Cr-Mn steels of the transitional class based on 0G8AM2S. It is shown that appropriate alloying and treatment, taking into account the degree of stability of the austenite, can ensure a complex of high mechanical properties of the steels investigated. For instance, the treatment of steel 0Kh10AG8MD2S by the technique: hardening+ 40% deformation at 400 deg C + 10% deformation at room temperature has yielded the following mechanical properties: sigmasub(B)=150 kgf/mm 2 , sigmasub(T)=110 kgf/mm 2 , sigma=18%, psi=32%

  4. Evaluation of candidate Stirling engine heater tube alloys after 3500 hours exposure to high pressure doped hydrogen or helium

    Science.gov (United States)

    Misencik, J. A.; Titran, R. H.

    1984-01-01

    The heater head tubes of current prototype automotive Stirling engines are fabricated from alloy N-155, an alloy which contains 20 percent cobalt. Because the United States imports over 90 percent of the cobalt used in this country and resource supplies could not meet the demand imposed by automotive applications of cobalt in the heater head (tubes plus cylinders and regenerator housings), it is imperative that substitute alloys free of cobalt be identified. The research described herein focused on the heater head tubes. Sixteen alloys (15 potential substitutes plus the 20 percent Co N-155 alloy) were evaluated in the form of thin wall tubing in the NASA Lewis Research Center Stirling simulator materials diesel fuel fired test rigs. Tubes filled with either hydrogen doped with 1 percent CO2 or with helium at a gas pressure of 15 MPa and a temperature of 820 C were cyclic endurance tested for times up to 3500 hr. Results showed that two iron-nickel base superalloys, CG-27 and Pyromet 901 survived the 3500 hr endurance test. The remaining alloys failed by creep-rupture at times less than 3000 hr, however, several other alloys had superior lives to N-155. Results further showed that doping the hydrogen working fluid with 1 vol % CO2 is an effective means of reducing hydrogen permeability through all the alloy tubes investigated.

  5. Removing hydrochloric acid exhaust products from high performance solid rocket propellant using aluminum-lithium alloy.

    Science.gov (United States)

    Terry, Brandon C; Sippel, Travis R; Pfeil, Mark A; Gunduz, I Emre; Son, Steven F

    2016-11-05

    Hydrochloric acid (HCl) pollution from perchlorate based propellants is well known for both launch site contamination, as well as the possible ozone layer depletion effects. Past efforts in developing environmentally cleaner solid propellants by scavenging the chlorine ion have focused on replacing a portion of the chorine-containing oxidant (i.e., ammonium perchlorate) with an alkali metal nitrate. The alkali metal (e.g., Li or Na) in the nitrate reacts with the chlorine ion to form an alkali metal chloride (i.e., a salt instead of HCl). While this technique can potentially reduce HCl formation, it also results in reduced ideal specific impulse (ISP). Here, we show using thermochemical calculations that using aluminum-lithium (Al-Li) alloy can reduce HCl formation by more than 95% (with lithium contents ≥15 mass%) and increase the ideal ISP by ∼7s compared to neat aluminum (using 80/20 mass% Al-Li alloy). Two solid propellants were formulated using 80/20 Al-Li alloy or neat aluminum as fuel additives. The halide scavenging effect of Al-Li propellants was verified using wet bomb combustion experiments (75.5±4.8% reduction in pH, ∝ [HCl], when compared to neat aluminum). Additionally, no measurable HCl evolution was detected using differential scanning calorimetry coupled with thermogravimetric analysis, mass spectrometry, and Fourier transform infrared absorption. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Nuclear data sheets update for A = 80

    International Nuclear Information System (INIS)

    Singh, B.

    1992-01-01

    Nuclear spectroscopic information for known nuclides of mass number 80 (Zn, Ga, Ge, As, Se, Br, Kr, Rb, Sr, Y, Zr) have been evaluated and presented together with adopted energies and Jπ of levels in these nuclei. No data are yet available for excited states in 80 Zn and 80 Y. This evaluation represents a revision of earlier ones (82Si20,75Gr19). No data are available for 80 Ni, but calculations of %β - n and T 1/2 (g.s.) using RPA method have been reported by 89Kr02. A severe disagreement is noted in the systematics (85Wa02) and measured (82De36,81LKi12) Q(ε) of 80 Y decay. A remeasurement of this value is required to clarify the difference of about 2 Mev

  7. Effect of La2O3 Nanoparticles on the Brazeability, Microstructure, and Mechanical Properties of Al-11Si-20Cu Alloy

    Science.gov (United States)

    Sharma, Ashutosh; Roh, Myung Hwan; Jung, Jae Pil

    2016-08-01

    The Al-11Si-20Cu brazing alloy and its ex situ composite with the content ranging from 0.01 to 0.05 wt.% of La2O3 are produced by electromagnetic induction-cum-casting route. The brazeability of the alloy and composite samples are tested using the spreading technique according to JIS Z-3197 standard. The mechanical properties such as filler microhardness, tensile shear strength, and elongation of the brazed joints are evaluated in the as-brazed condition. It is reported that incorporation of an optimal amount of 0.05 wt.% of hard La2O3 nanoparticles in the Al-Si-Cu matrix inhibits the growth of the large CuAl2 intermetallic compounds (IMCs) and Si particles. As a consequence, the composite filler brazeability, microhardness, joint tensile shear strength, and elongation are improved significantly compared to those of monolithic Al-11Si-20Cu alloy.

  8. Effects of oxygen pressure on the oxidation behavior of Ni-20FCr alloy

    International Nuclear Information System (INIS)

    Takei, Atsushi; Nii, Kazuyoshi

    1982-01-01

    The Ni-20Cr alloy was oxidized at 1373 K at various oxygen partial pressures, ranging from 10 -7 to 10 4 Pa, which were controlled by Ar-O 2 mixtures. A large difference was observed between the oxidation behavior in a high Po 2 (>= 10 2 Pa) range and that in a low Po 2 ( 2 of 10 4 and 1 Pa, the former being typical in high Po 2 and the latter in low Po 2 . The mass gain-time curves showed that the growth rate of scale in the low Po 2 lie between the parabolic and linear law, while that in the high Po 2 obeys the parabolic law, which indicates that the scale formed in the low Po 2 is less protective than that in the high Po 2 . It was found, on the other hand, that the oxide scales formed in the low Po 2 were more adherent to the alloy than those formed in the high Po 2 . In the high Po 2 a large amount of spalling was observed on cooling even in short time oxidation. The oxide scales formed in the low Po 2 were uniform in thickness and rather porous, while those formed in the high Po 2 were dense and non-uniform in thickness. In the low Po 2 a number of small voids were found at the oxide-alloy interface. In the high Po 2 , however, large voids were found; this suggests the occurrence of plastic deformation of the oxide and the alloy by the stress induced in the growing scale. The above difference in oxidation behavior can be ascribed to the difference between growth mechanisms of the oxide scale in the high and low Po 2 . (author)

  9. Elastic and thermo-physical properties of TiC, TiN, and their intermediate composition alloys using ab initio calculations

    International Nuclear Information System (INIS)

    Kim, Jiwoong; Kang, Shinhoo

    2012-01-01

    Highlights: ► Elastic properties of TiC, TiN and their alloys were calculated by ab initio calculations. ► Debye temperature and Gruneisen constant of TiC, TiN and their alloys were calculated as a function of nitrogen content. ► Thermo-physical properties were calculated as a function of nitrogen content. ► Thermal expansion of the alloys was fitted in different temperature range. - Abstract: The equilibrium lattice parameters, elastic properties, material brittleness, heat capacities, and thermal expansion coefficients of TiC, TiN, and their intermediate composition alloys (Ti(C 1−x N x ), x = 0.25, 0.5, and 0.75) were calculated using ab initio density functional theory (DFT) methods. We employed the Debye–Gruneisen model to calculate a finite temperature heat capacity and thermal expansion coefficient. The calculated elastic moduli and thermal expansion coefficients agreed well with the experimental data and with other DFT calculations. Accurate heat capacities of TiC, TiN, and their intermediate composition alloys were obtained by calculating not only the phonon contributions but also the electron contributions to the heat capacity. Our calculations indicated that the heat capacity differences between each composition originated mainly from the electronic contributions.

  10. Spin-dependent Seebeck coefficients of Ni80Fe20 and Co in nanopillar spin valves

    NARCIS (Netherlands)

    Dejene, F. K.; Flipse, J.; van Wees, B. J.

    2012-01-01

    We have experimentally determined the spin-dependent Seebeck coefficient of permalloy (Ni80Fe20) and cobalt (Co) using nanopillar spin valve devices, a stack of two ferromagnetic layers separated by a nonmagnetic layer. The devices were specifically designed to separate heat-related effects from

  11. Effect of zirconium on the structure and phase composition of steel 03Kh8SYu

    International Nuclear Information System (INIS)

    Tarzhumanova, V.A.; Ryabchenkov, A.V.; Shatunova, A.V.; Yoganova, S.A.

    1986-01-01

    Previously, the authors determined the optimum zirconium content providing retention of a fine-grained structure for steel 03Kh8SYu during high-temperature heating. It was suggested that this was caused by separation in the steel of intermetallic phase Fe 3 Zr. This paper presents results of further studies in this direction. X-ray analysis results for the anodic residues of the steels are presented. It can be seen that in steel without zirconium, carbides of the type M 23 C 6 and M 7 C 3 and aluminum nitride are present. On adding 0.05% Zr, zirconium nitride forms in addition to the existing aluminum nitride and carbides of the type M 7 C 3 . The authors also investigated the effect of zirconium on the tendency of the steel toward grain growth at higher temperature; they studied the structure of steel 03Kh8SYu with 0.61% Zr after soaking specimens for 100 h at 950-1100 C. Results are presented

  12. Short-range order of amorphous FeNiB alloy after neutron irradiation

    International Nuclear Information System (INIS)

    Miglierini, M.; Sitek, J.; Baluch, S.; Cirak, J.; Lipka, J.

    1990-01-01

    Transmission Moessbauer spectroscopy was used to study irradiation-induced changes in the short-range order of an amorphous Fe 80-x Ni x B 20 alloy. Neutron irradiation led to an increase of the width of a hyperfine field distribution implying atomic rearrangement towards disordering. Changes in a mean value of a HFD and Moessbauer line areas can be associated with a reorientation of spins due to radiation damage. (orig.)

  13. Manufacturing and characterization of Ni-free N-containing ODS austenitic alloy

    Science.gov (United States)

    Mori, A.; Mamiya, H.; Ohnuma, M.; Ilavsky, J.; Ohishi, K.; Woźniak, Jarosław; Olszyna, A.; Watanabe, N.; Suzuki, J.; Kitazawa, H.; Lewandowska, M.

    2018-04-01

    Ni-free N-containing oxide dispersion strengthened (ODS) austenitic alloys were manufactured by mechanical alloying (MA) followed by spark plasma sintering (SPS). The phase evolutions during milling under a nitrogen atmosphere and after sintering were studied by X-ray diffraction (XRD). Transmission electron microcopy (TEM) and alloy contrast variation analysis (ACV), including small-angle neutron scattering (SANS) and ultra-small-angle X-ray scattering (USAXS), revealed the existence of nanoparticles with a diameter of 3-51 nm for the samples sintered at 950 °C. Sintering at 1000 °C for 5 and 15 min caused slight growth and a significant coarsening of the nanoparticles, up to 70 nm and 128 nm, respectively. The ACV analysis indicated the existence of two populations of Y2O3, ε-martensite and MnO. The dispersive X-ray spectrometry (EDS) confirmed two kinds of nanoparticles, Y2O3 and MnO. The material was characterized by superior micro-hardness, of above 500 HV0.1.

  14. Pendidikan Karakter Menurut K.H. Hasyim Asy'ari Dalam Kitab Adâb Al-‘Âlim Wa Al-Muta‘Allim

    OpenAIRE

    Sholikah, Sholikah

    2015-01-01

    The article deals with K.H. Hasyim Asy'ari's thought of character education. The result of the study indicates that according to K.H. Hasyim Asy'ari the characters of teachers and students in his work Adab al-‘Âlim wa al-Muta'allim can be classified into three parts, are mentality or character, which should be possessed by teachers and learners: attempts to be done in order to become characterized teachers and learners, and: teaching strategies employed by educators and learning strategies us...

  15. The inhibitory effect of different concentrations of KH902 eye drops on corneal neovascularization induced by alkali burn

    Directory of Open Access Journals (Sweden)

    Yan Wu

    2017-01-01

    Full Text Available Purpose: The aim of this study was to evaluate the inhibitory effect of different concentrations of KH902 eye drops on rabbit corneal neovascularization (CNV induced by alkali burn. Methods: Forty-eight adult rabbits were randomized into four groups after alkali burning: Group A (2.5 mg/ml, Group B (5 mg/ml, and Group C (10 mg/ml by different concentrations of KH902 eye drops and Group D by saline solution as control with three times a day for 2 weeks. At days 7, 14, and 28, the anterior segment photographs, confocal microscopy, and histopathology were performed to evaluate corneal opacity, neovascularization, inflammatory cell density, vessel size, and edema. Immunohistochemistry was applied to analyze the vascular endothelial growth factor (VEGF level. Results: (1 The CNV in the medicine-treated groups showed a reduction without obvious corneal side effects histologically. (2 Compared to the control group, the three medicine-treated groups showed a reduction in the VEGF levels and CNV areas on days 7, 14, and 28 and in the inflammatory cell density on days 14 and 28 (P 0.05. Conclusion: KH902 eye drops in lower concentration showed an obvious reduction of the CNV growing for rabbit corneal alkali burn without side effects.

  16. Characterization of defects and nanostructural alterations in the Nimonic 80A superalloy by using Transmission Electron Microscopy

    International Nuclear Information System (INIS)

    Guillen Giron, Teodolito; Leon Salazar, Jose Luis

    2015-01-01

    TEM (Transmission Electron Microscopy) probes are analyzed in aeronautical applications. Intercrystalline defects present in the Nimonic 80A superalloy are studied after being thermally treated and then subjecting the specimens to cyclic stresses. The TEM test specimens are pre-tested under high frequency (1 000 Hz and 20 000 Hz) fatigue at the University of Siegen in Germany simulating the working conditions of this alloy in aircraft turbines or other types of aeronautical applications. The mechanical stress has generated many deformations and nanometric defects in this material, evidenced in the dislocations. Defects are observed using very powerful microscopy techniques such as TEM. The results are obtained from the TEM analysis and have revealed characteristic precipitates in the Nimonic 80A sample when subjected to thermal treatments. The alloy has evidenced the formation of dislocations resulting from the mechanical stresses of the specimens. The influence of rainfall is evidenced in the mechanism of formation, grouping and movement of the dislocations in the microstructure of the samples used. (author) [es

  17. Magnetic properties of Fe20 Ni80 antidots: Pore size and array disorder

    International Nuclear Information System (INIS)

    Palma, J.L.; Gallardo, C.; Spinu, L.; Vargas, J.M.; Dorneles, L.S.; Denardin, J.C.; Escrig, J.

    2013-01-01

    Magnetic properties of nanoscale Fe 20 Ni 80 antidot arrays with different hole sizes prepared on top of nanoporous alumina membranes have been studied by means of magnetometry and micromagnetic simulations. The results show a significant increase of the coercivity as well as a reduction of the remanence of the antidot arrays, as compared with their parent continuous film, which depends on the hole size introduced in the Fe 20 Ni 80 thin film. When the external field is applied parallel to the antidots, the reversal of magnetization is achieved by free-core vortex propagation, whereas when the external field is applied perpendicular to the antidots, the reversal occurs through a process other than the coherent rotation (a maze-like pattern). Besides, in-plane hysteresis loops varying the angle show that the degree of disorder in the sample breaks the expected hexagonal symmetry. - Highlights: • Magnetic properties are strongly influenced by the pore diameter of the samples. • Coercive fields for antidots are higher than the values for the continuous film. • Disorder breaks the hexagonal symmetry of the sample. • Each hole acts as a vortex nucleation point. • Antidots have unique properties that allow them to be used in applications

  18. Low-emissivity coating of amorphous diamond-like carbon/Ag-alloy multilayer on glass

    International Nuclear Information System (INIS)

    Chiba, Kiyoshi; Takahashi, Toshiyuki; Kageyama, Takashi; Oda, Hironori

    2005-01-01

    Transparent low-emissivity (low-e) coatings comprising dielectrics of amorphous diamond-like carbon (DLC) and Ag-alloy films are investigated. All films have been prepared by dc magnetron sputtering. An index of refraction of the DLC film deposited in a gas mixture of Ar/H 2 (4%) shows n = 1.80 + 0.047i at 500 nm wavelength. A multilayer stack of DLC (70 nm thick)/Ag 87.5 Cu 12.5 -alloy (10 nm)/DLC (140 nm)/Ag 87.5 Cu 12.5 -alloy (10 nm)/DLC (70 nm) has revealed clear interference spectra with spectra selectivity. This coating performs low emittance less than 0.1 for black body radiation at 297 K, exhibiting a transparent heat mirror property embedded in DLC films

  19. Mechanically alloyed PrFeB nanocrystalline magnets

    International Nuclear Information System (INIS)

    Kaszuwara, W.; Leonowicz, M.

    1998-01-01

    Mechanically alloyed PrFeB nanocrystalline magnets were prepared by extensive ball milling of Pr, Fe and Fe 80 B 20 powders, followed by diffusion annealing. After milling, the material consisted of nanocrystalline α-Fe crystallites embedded in amorphous Pr-rich matrix. Thermomagnetic and calorimetric investigations of the transformations which occurred during annealing showed that the amorphous phase crystallised at 240 C, leading to the formation of crystalline Pr having lattice constants 10% greater than those shown in the ASTM data. This fact indicated that mechanical alloying and low temperature annealing led to the formation of a solid solution of either Fe or B in Pr, which does not exist in the equilibrium state. The Pr 2 Fe 14 B phase was subsequently formed within a temperature range of 420-620 C. The magnetic properties of magnets depend on the phase structure and grain size. Milling time appears to be a decisive processing parameter for the tailoring of the magnetic properties. Depending on the phase structure, the coercivities varied from 100 to 1200 kA/m and, respectively, the remanences from 0.98 T to 0.6 T. The highest maximum energy product was 80 kJ/m 3 . (orig.)

  20. On the electrodeposition of /sup 80m/Br, /sup 80/Br and /sup 82/Br species from (eta, gamma) activated dibromoethane - N,N-dimethyl aniline mixture

    International Nuclear Information System (INIS)

    Zaman, M.R.

    1997-01-01

    Thermal neutron activation have been carried out in dibromomethane (DBM)-n,n-dimethyl aniline (N,N-DMA) system and the /sup 80m/Br, /sup 82/Br species have been electrodeposited on Ag/AgBr electrodes under a constant electric field of 175 volts cm/sup -1/. With the addition of N,N-DMA, anodic deposition has been severely decreased for all the radiobromines and cathode plate shows zero activities. Results are critically discussed by explaining the chemical reactivity of the amine. Electrode deposition pattern and the chemical stabilization mode of the nucleogenic bromine species in this system are deduced to some extents. (author)

  1. The Influence of Heat Treatment and Quencing Media at Bronze 80% Cu–20% Sn toward Fatique Life

    Directory of Open Access Journals (Sweden)

    Anak Agung Istri Agung Sri Komaladewi

    2012-11-01

    Full Text Available Production of the Balinese gamelan product rest on molding process which then continued with forging process, adjustment,and finally the finishing process. But still often to make the failure from this material like. The material become brokebecause heavy thing with the user processing (playing gambelan with continuity in the long time. The broke that happenfrom the heavy thing by the continuety that is called fatigue. At this examination the things that will be up is how much theheat treatment influence and the cooler thing with the fatigue life through the Reversed Bending process. By to variated theheat treatment and cooler thing to Bronze mixture 80%Cu and 20%Sn. This examination to aim at knowing the heattreatment influence and cooler thing at the composition of Bronze 80%Cu and 20%Sn about the fatigue life.The makingprocess of this things made by copper solution and the white Tin with the composition are 80%Cu and 20%Sn by variatedheat treatment and cooler media. The produce of this solution will print with the Reversed Bending speciment. Then thespeciment gift the heat treatment about 6500 C, 7000 C till 7500 C, and then the speciment keep cold by the water, oil and theair. The thing will be analize from the breach counture, Macro Structure and Micro Structure.The examination produceshowing the growing up at the fatigue life in the Bronze mixture 80%Cu - 20%Sn, From the heat treatment 6500 C, 7000 Cand 7500 C and become the drop age fatigue with the water cooler media with the age fatigue abaut 36621 cycle, and thefatigue by oil about 44975 cycle and the air cooler age fatigue about 55191 cycle. The inspection makro structure thebreach face colouring litle bit dark and the inspection mikro structure, the metal structure lool more bright.

  2. Investigations into the corrosion resistance of copper aluminium alloys. Effect of phosphorus as corrosion resistant third alloying element in the ternary system CuAl20P1

    International Nuclear Information System (INIS)

    Allwardt, A.

    1997-01-01

    The effect of phosphorus on the corrosion resistance of Al-bronzes is studied in detail in this work. A literature review showed that there are a lot of things known about the microstructure and the mechanical properties of Al-bronzes. In spite of their corrosion resistance the corrosion properties and the structure of the protective oxide films of Al-bronzes were seldom a matter of interest. Systematic studies of the influence of different alloying elements on the oxide film and the corrosion properties are rare. Therefore, it is not possible to predict the corrosion resistance of Al-bronzes, made by alloying particular elements. The high corrosion resistance of the new alloy CuAl 20 P 1 was the reason to investigate the influence of phosphorus on the corrosion properties of Al-bronzes in more detail. A systematic study of the microstructure and the corrosion properties of Cu, CuP x , CuAl 20 and CuAl 20 P x offers an insight into the effect of aluminium and phosphorus on the formation of the oxide film on Al-bronzes. It was found that there exists a critical amount of 1 at.-% of phosphorus. Above and below this amount the corrosion resistance becomes worse. This behaviour could be explained by XPS-and electrochemical measurements. Although there are still some questions about the influence of phosphorus on the corrosion resistance of Al-bronzes, this work has produced some important results, which in the future may be helpful to develop new high corrosion resistant Al-bronzes more efficiently: - on clean surface Al-bronze, the oxidation of Al and Cu takes place simultaneously, - Al promotes the formation of Cu 2 O but impedes the formation of Cu(II)-oxide/-hydride in neutral solutions, - P impedes the formation of Cu 2 O and as a consequence promotes the formation of aluminium oxide. This results in a higher amount of Al in the oxide film on the surface of the alloy, which leads to a better corrosion resistance. (author) figs., tabs., 106 refs

  3. Study on the process of calibration and deep centring of blanks

    International Nuclear Information System (INIS)

    Potapov, I.N.; Romantsev, B.A.; Popov, V.A.; Volodin, V.V.; Goncharuk, A.V.

    1985-01-01

    Process of calibration and deep centring of blanks before broaching is developed and studied. Investigations are performed at a semi-industrial screw rolling mill MISiS-100 T. Blanks made of 40Kh, 60, 50, 45KhN2MFA, 30KhGSNA steels 80, 85, and 90 mm in diameter and 300 mm long were calibrated and centered after heating in a furnace to a depth of 200 mm at shafts and faces with different calibration. 30KhN2MFA steel is chosen for face material; heat treatment is conducted under the following conditions: heating up to 950-1000 deg C and hold-up during 30-35 min with the following cooling in the air. The above experimental investigations reveal that the process of calibration and deep centring accomplished at a three-shaft screw rolling mill is rather stable and provides a high accuracy of centering hollow marking

  4. Epithelial Fluid Transport is Due to Electro-osmosis (80%), Plus Osmosis (20%).

    Science.gov (United States)

    Fischbarg, Jorge; Hernandez, Julio A; Rubashkin, Andrey A; Iserovich, Pavel; Cacace, Veronica I; Kusnier, Carlos F

    2017-06-01

    Epithelial fluid transport, an important physiological process shrouded in a long-standing enigma, may finally be moving closer to a solution. We propose that, for the corneal endothelium, relative proportions for the driving forces for fluid transport are 80% of paracellular electro-osmosis, and 20% classical transcellular osmosis. These operate in a cyclical process with a period of 9.2 s, which is dictated by the decrease and exhaustion of cellular Na + . Paracellular electro-osmosis is sketched here, and partially discussed as much as the subject still allows; transcellular osmosis is presented at length.

  5. Electron mobility of two-dimensional electron gas in InGaN heterostructures: Effects of alloy disorder and random dipole scatterings

    Science.gov (United States)

    Hoshino, Tomoki; Mori, Nobuya

    2018-04-01

    InGaN has a smaller electron effective mass and is expected to be used as a channel material for high-electron-mobility transistors. However, it is an alloy semiconductor with a random distribution of atoms, which introduces additional scattering mechanisms: alloy disorder and random dipole scatterings. In this work, we calculate the electron mobility in InGaN- and GaN-channel high-electron-mobility transistors (HEMTs) while taking into account acoustic deformation potential, polar optical phonon, alloy disorder, and random dipole scatterings. For InGaN-channel HEMTs, we find that not only alloy disorder but also random dipole scattering has a strong impact on the electron mobility and it significantly decreases as the In mole fraction of the channel increases. Our calculation also shows that the channel thickness w dependence of the mobility is rather weak when w > 1 nm for In0.1Ga0.9N-channel HEMTs.

  6. KevlarTM Fiber-Reinforced Polybenzoxazine Alloys for Ballistic Impact Application

    Directory of Open Access Journals (Sweden)

    Chanchira Jubsilp

    2011-10-01

    Full Text Available A light weight ballistic composites from KevlarTM-reinforcing fiber having polybenzoxazine (BA/urethane prepolymer (PU alloys as a matrix were investigated in this work. The effect of alloy compositions on the ballistic composite properties was determined. The results revealed that the enhancement in the glass transition temperature (Tg of the KevlarTM-reinforced BA/PU composites compared to that of the KevlarTM-reinforced polybenzoxazine composite was observed. The increase of the elastomeric PU content in the BA/PU alloy resulted in samples with tougher characteristics. The storage modulus of the KevlarTM-reinforced BA/PU composites increased with increasing the mass fraction of polybenzoxazine. A ballistic impact test was also performed on the KevlarTM-reinforced BA/PU composites using a 9 mm handgun. It was found that the optimal contents of PU in the BA/PU alloys should be approximately 20wt%. The extent of the delaminated area and interfacial fracture were observed to change with the varied compositions of the matrix alloys. The appropriate thickness of KevlarTM-reinforced 80/20 BA/PU composite panel was 30 plies and 50 plies to resist the penetration from the ballistic impact equivalent to levels II-A and III-A of NIJ standard. The arrangement of composite panels with the higher stiffness panel at the front side also showed the best efficiency of ballistic penetration resistance.

  7. Crevice corrosion propagation on alloy 625 and alloy C276 in natural seawater

    International Nuclear Information System (INIS)

    McCafferty, E.; Bogar, F.D.; Thomas, E.D. II; Creegan, C.A.; Lucas, K.E.; Kaznoff, A.I.

    1997-01-01

    Chemical composition of the aqueous solution within crevices on two different Ni-Cr-Mo-Fe alloys immersed in natural seawater was determined using a semiquantitative thin-layer chromatographic method. Active crevices were found to contain concentrated amounts of dissolved Ni 2+ , Cr 3+ , Mo 3+ , and Fe 2+ ions. Propagation of crevice corrosion for the two alloys was determined from anodic polarization curves in model crevice solutions based upon stoichiometric dissolution or selective dissolution of alloy components. Both alloys 625 (UNS N06625) and C276 (UNS N10276) underwent crevice corrosion in the model crevice electrolytes. For the model crevice solution based upon selective dissolution of alloy constituents, the anodic dissolution rate for alloy 625 was higher than that for alloy C276. This trend was reversed for the model crevice solution based upon uniform dissolution of alloy constituents

  8. Energy investigations on the mechanical properties of magnesium alloyed by X = C, B, N, O and vacancy

    KAUST Repository

    Wu, Xiaozhi; Liu, Lili; Wang, Rui; Gan, Liyong; Liu, Qing

    2013-01-01

    The generalized stacking fault (GSF) energies and surface energies of magnesium and its alloys with alloying atoms X = C, B, N, O and vacancy have been investigated using the first-principles methods. It is found that the predominant reducing

  9. Ignition characteristics of the nickel-based alloy UNS N07001 in pressurized oxygen

    Science.gov (United States)

    Bransford, J. W.; Billiard, P. A.

    1990-01-01

    The development of ignition and combustion in pressurized oxygen atmospheres was studied for the nickel-based alloy UNS N07001. Ignition of the alloy was achieved by heating the top surface of a cylindrical specimen with a continuous-wave CO2 laser. Two heating procedures were used. In the first, laser power was adjusted to maintain an approximately linear increase in surface temperature. In the second, laser power was periodically increased until autoheating (self-heating) was established. It was found that the alloy would autoheat to combustion from temperatures below the solidus temperature. In addition, the alloy had a tendency to develop combustion zones (hot spots) at high oxygen pressures when the incremental (step) heating test mode was used. Unique points on the temperature-time curves that describe certain events are defined and the temperatures at which these events occur are given for the oxygen pressure range of 1.72 to 13.8 MPa (250 to 2000 psia).

  10. An investigation on the hydrogen storage characteristics of the melt-spun nanocrystalline and amorphous Mg20-xLaxNi10 (x = 0, 2) hydrogen storage alloys

    International Nuclear Information System (INIS)

    Zhang Yanghuan; Li Baowei; Ren Huiping; Guo Shihai; Wu Zhongwang; Wang Xinlin

    2009-01-01

    Mg 2 Ni-type hydrogen storage alloys Mg 20-x La x Ni 10 (x = 0, 2) were prepared by casting and rapid quenching. The structures and morphologies of the as-cast and quenched alloys were studied by X-ray diffraction (XRD), scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM). Thermal stability of the as-quenched alloys was researched by differential scanning calorimetry (DSC). The hydrogen absorption and desorption kinetics of the alloys were measured using an automatically controlled Sieverts apparatus, and their electrochemical properties were measured by a tri-electrode open cell. The results showed that the no amorphous phase formed in the as-quenched La-free alloy, but the as-quenched alloys containing La held a major amorphous phase. The quenching rate induced a light influence on the crystallization temperature of the amorphous phase, and it significantly improved the initial hydrogenation rate and the hydrogen absorption capacity of the alloys. The discharge capacity and the cycle stability of the alloys grew with the increase of the quenching rate. When the quenching rate increased from 0 (as-cast was defined at a quenching rate of 0 m s -1 ) to 30 m s -1 , the hydrogen absorption capacity of the alloys for x = 0 and 2 at 200 deg. C and 1.5 MPa in 10 min changed from 1.21 to 3.10 wt.% and from 1.26 to 2.60 wt.%, the maximum discharge capacity from 30.26 to 135.51 mAh g -1 and from 197.23 to 406.51 mAh g -1 at a current density of 20 mA g -1 , and the capacity retaining rate at 20th cycle from 36.71 to 27.06% and from 37.26 to 78.33%, respectively

  11. InN/GaN short-period superlattices as ordered InGaN ternary alloys

    International Nuclear Information System (INIS)

    Kusakabe, Kazuhide; Imai, Daichi; Wang, Ke; Yoshikawa, Akihiko

    2016-01-01

    Coherent (InN) 1 /(GaN) n short-period superlattices (SPSs) were successfully grown through dynamic atomic layer epitaxy (D-ALEp) mode by RF-plasma molecular beam epitaxy (MBE), where GaN layer thicknesses n were thinned down to 4 monolayer (ML). After this achievement, we demonstrated quasi-ternary InGaN behavior in their photoluminescence (PL) spectra for the first time. It was found interestingly that GaN layer thickness of n = 4 ML was the criterion both for structural control and continuum-band formation. Although highly lattice-mismatched InN/GaN interfaces easily introduce relaxation in (InN) 1 /(GaN) 4 SPSs during growth depending on the dynamic surface stoichiometry condition, this problem was overcome by precise control/removal of fluid-like residual In/Ga metals on the growth front with in-situ monitoring method. The (InN) 1 /(GaN) n SPSs with n ≥ 7 ML showed a constant PL peak energy around 3.2 eV at 12 K, reflecting discrete electron/hole wavefunctions. On the other hand, the (InN) 1 /(GaN) 4 SPSs indicated the red-shifted PL peak at 2.93 eV at 12 K, which was attributed to the continuum-band state with increasing in the overlap of electrons/hole wavefunctions. This result is concluded that the (InN) 1 /(GaN) 4 SPSs can be considered as ordered InGaN alloys. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Viscoplastic behavior of zirconium alloys in the temperatures range 20 deg C - 400 deg C: characterization and modeling of strain ageing phenomena

    International Nuclear Information System (INIS)

    Graff, St.

    2006-10-01

    The anomalous strain rate sensitivity of zirconium alloys over the temperatures range 20-600 C has been widely reported in the literature. This unconventional behavior is related to the existence of strain ageing phenomenon which results from the combined action of thermally activated diffusion of foreign atoms to and along dislocation cores and the long range of dislocations interactions. The important role of interstitial and substitutional atoms in zirconium alloys, responsible for strain ageing and the lack of information about the domain where strain ageing is active have not been yet adequately characterized because of the multiplicity of alloying elements and chemical impurities. The aim of this work is to characterize experimentally the range of temperatures and strain rates where strain ageing is active on the macroscopic and mesoscopic scales. We propose also a predictive approach of the strain ageing effects, using the macroscopic strain ageing model suggested by McCormick (McCormick, 1988; Zhang et al., 2000). Specific zirconium alloys were elaborated starting from a crystal bar of zirconium with 2.2 wt% hafnium and very low oxygen content (80 wt ppm), called ZrHf. Another substitutional atom was added to the solid solution under the form of 1 wt% niobium. Some zirconium alloys were doped with oxygen, others were not. All of them were characterized by various mechanical tests (standard tensile tests, tensile tests with strain rate changes, relaxation tests with unloading). The experimental results were compared with those for the standard oxygen doped zirconium alloy (1300 wt ppm) studied by Pujol (Pujol, 1994) and called Zr702. The following experimental evidences of the age-hardening phenomena were collected and then modeled: 1) low and/or negative strain rate sensitivity around 200-300 C, 2) creep arrest at 200 C, 3) relaxation arrest at 200 C and 300 C, 4) plastic strain heterogeneities observed in laser extensometry on the millimeter scale

  13. Viscoplastic behavior of zirconium alloys in the temperatures range 20 deg C - 400 deg C: characterization and modeling of strain ageing phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Graff, St

    2006-10-15

    The anomalous strain rate sensitivity of zirconium alloys over the temperatures range 20-600 C has been widely reported in the literature. This unconventional behavior is related to the existence of strain ageing phenomenon which results from the combined action of thermally activated diffusion of foreign atoms to and along dislocation cores and the long range of dislocations interactions. The important role of interstitial and substitutional atoms in zirconium alloys, responsible for strain ageing and the lack of information about the domain where strain ageing is active have not been yet adequately characterized because of the multiplicity of alloying elements and chemical impurities. The aim of this work is to characterize experimentally the range of temperatures and strain rates where strain ageing is active on the macroscopic and mesoscopic scales. We propose also a predictive approach of the strain ageing effects, using the macroscopic strain ageing model suggested by McCormick (McCormick, 1988; Zhang et al., 2000). Specific zirconium alloys were elaborated starting from a crystal bar of zirconium with 2.2 wt% hafnium and very low oxygen content (80 wt ppm), called ZrHf. Another substitutional atom was added to the solid solution under the form of 1 wt% niobium. Some zirconium alloys were doped with oxygen, others were not. All of them were characterized by various mechanical tests (standard tensile tests, tensile tests with strain rate changes, relaxation tests with unloading). The experimental results were compared with those for the standard oxygen doped zirconium alloy (1300 wt ppm) studied by Pujol (Pujol, 1994) and called Zr702. The following experimental evidences of the age-hardening phenomena were collected and then modeled: 1) low and/or negative strain rate sensitivity around 200-300 C, 2) creep arrest at 200 C, 3) relaxation arrest at 200 C and 300 C, 4) plastic strain heterogeneities observed in laser extensometry on the millimeter scale

  14. Vortex distribution in amorphous Mo{sub 80}Ge{sub 20} plates with artificial pinning center

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hitoshi [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Huy, Ho Thanh [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Department of Physics and Electronics, University of Sciences, Vietnam National University HCMC, 227 Nguyen Van Cu, District 5, HoChiMinh City (Viet Nam); Miyoshi, Hiroki; Okamoto, Takuto; Dang, Vu The [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Kato, Masaru [Institute for Nanofabrication Research, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Department of Mathematical Science, Osaka Prefecture University1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Ishida, Takekazu, E-mail: ishida@center.osakafu-u.ac.jp [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Institute for Nanofabrication Research, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan)

    2016-11-15

    Highlights: • We reveal that the vortex distribution in small amorphous Mo{sub 80}Ge{sub 20} superconducting starshaped plate by using a scanning SQUID microscope. • We find that vortex configuration evolves systematically when the applied magnetic field is changed at the several different fields. • We fabricate an artificial dip by Ar ion milling in a mesoscopic plate, and find this works as a pinning center by comparing the vortex behavior in a sample without pins. - Abstract: Vortices in superconductor give rise to a rich variety of phenomena because they interact with shielding currents, temperature gradients, sample defects, boundaries, and other neighboring vortices. It would be very important to understand particular features of vortex states in a downsized system. Our study focuses on vortex states in small star-shaped Mo{sub 80}Ge{sub 20} plates with and without an artificial pin at the plate center. Vortex states are greatly influenced by the sample geometry, the temperature and the magnetic field, and they can be occasionally exotic compared to the bulk case. We use the amorphous Mo{sub 80}Ge{sub 20} films due to the nature of weak pinning in studying vortex configurations. We applied scanning superconducting quantum interference device (SQUID) microscopy because it enables us to see vortex states directly and it is the most sensitive instrument for mapping tiny local current flows or magnetic moments without damaging the sample. We interpreted that vortex configurations had essentially the nature of mirror reflection symmetry in both cases with an artificial pin and without an artificial pin and pinned cases while the influence of disorder was seen in our observation on the specimen without an artificial pin.

  15. Structural and magnetic properties of Mn{sub 50}Fe{sub 50−x}Sn{sub x} (x=10, 15 and 20) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Tanmoy [LCMP, S.N. Bose National Centre for Basic Sciences, Kolkata 700106 (India); Agarwal, Sandeep [Haldia Institute of Technology, Haldia 721657 (India); Mukhopadhyay, P.K., E-mail: pkm@bose.res.in [LCMP, S.N. Bose National Centre for Basic Sciences, Kolkata 700106 (India)

    2016-11-15

    In this work we report measurements and comparisons of the structural, magnetic and transport properties of a series of Mn{sub 50}Fe{sub 50−x}Sn{sub x} alloys (x=10, 15 and 20). We found that while the lower Sn composition sample stabilized in β-Mn-type crystallographic phase, the higher Sn composition alloys contained both β-Mn-type as well as Mn{sub 3}Sn-type hexagonal DO{sub 19} phases. Through d.c. and a.c. magnetic property measurements we have established the existence of a ferromagnetic transition near room temperature followed by a spin reorientation at lower temperature in the Mn{sub 3}Sn-type crystallographic phase of the alloys. Our resistivity study also revealed an interesting behavior with negative temperature coefficient (TCR) in these alloys. - Highlights: • Mn{sub 50}Fe{sub 50-x}Sn{sub x} alloys were studied over a limited concentration range. • Lower Sn alloys behaved similar to ß-Mn alloys both structurally and magnetically. • Higher Sn alloys showed magnetic transitions similar to Mn{sub 3}Sn and Fe{sub 3}Sn. • Resistivity showed bad metallic behavior with negetive temperature coefficient.

  16. Advanced nickel base alloys for high strength, corrosion applications

    Science.gov (United States)

    Flinn, J.E.

    1998-11-03

    Improved nickel-base alloys of enhanced strength and corrosion resistance, produced by atomization of an alloy melt under an inert gas atmosphere and of composition 0--20Fe, 10--30Cr, 2--12Mo, 6 max. Nb, 0.05--3 V, 0.08 max. Mn, 0.5 max. Si, less than 0.01 each of Al and Ti, less than 0.05 each of P and S, 0.01--0.08C, less than 0.2N, 0.1 max. 0, bal. Ni. 3 figs.

  17. Niobium alloys production with elements of high steam pressure and high ductilidate Nb46,5%Ti, Nb 1%Zr, Nb 1%Ti and Nb20% Ta

    International Nuclear Information System (INIS)

    Pinatti, D.G.; Baldan, C.A.; Dainesi, C.R.; Sandim, H.R.Z.

    1988-01-01

    The melting technology of niobium alloys with high ductilidade and high steam pressure, having the Ti, Zr and Ta as alloying elements is described. The electron beam technique for production of Nb 46,5%Ti, Nb 1%Zr and Nb 20%Ta alloys is analysed, aiming a product with high grade and low cost. (C.G.C.) [pt

  18. Proposición de dos aleaciones fundidas para su estudio en la construcción de martillos de molinos desmeduladores de bagazo. // Proposition of two casted alloys for their study in the construction of bagasse crush mills hammers.

    Directory of Open Access Journals (Sweden)

    F. Diez Torres

    2005-05-01

    Full Text Available El presente trabajo constituye un análisis teórico que tiene como objetivo la determinación de cuáles serían las aleaciones autilizar y la tecnología de colada adecuada para la fabricación de los martillos de los desmeduladores de bagazo a partir dealeaciones fundidas resistentes al desgaste.Se analizan los resultados de las experiencias realizadas con recubrimientos por soldadura de recargue duro, con los cualesse corroboraron las hipótesis sobre los mecanismos de desgaste ocurrentes y las estructuras metalográficas adecuadas paracada perfil del martillo.Se propone la realización de ensayos de campo con martillos construidos con hierros al cromo debido a que se caracterizanpor poseer carburos de cromo con la posibilidad de obtener diferentes contenidos y distribución de los mismos en matricesque van desde la austenítica a martensítica. Se propone realizar los ensayos con las aleaciones 15-3 y 20-3 con y sintratamiento térmico y con colada en coquilla, con diferentes velocidades de enfriamiento en cada perfil de trabajo con el finde obtener la estructura metalográfica adecuada.Palabras claves: Aleaciones, martillos desmenuzadores de bagazo, recubrimiento por soldadura.____________________________________________________________________________Abstract.The present paper constitutes a theoretical analysis for the determination of an appropriate cast technology determinationfor the production of bagasse crush hammers with wear cast iron alloys.The results of welding hard facing coatings with the wear mechanisms hypothesis and appropriate metallographic structureswere corroborated.Field tests with chromium cast iron hammers are proposed due that this alloys is characterized to posses chromiumcarbides, with the possibility to obtain different contents and distribution in austenitic, martensitic or intermediate metalmatrices. Tests with 15-3 and 20-3 alloys with or without thermal treatment and metal mold casting with different

  19. Electrochemistry of Zn(II)/Zn on Mg alloy from the N-butyl-N-methylpyrrolidinium dicyanamide ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Ming-Jay, E-mail: martinez730523@yahoo.com.tw [National Synchrotron Radiation Research Center, Hsinchu, Taiwan (China); Lin, Pei-Chiung [Department of Chemistry, National Cheng Kung University, Tainan, Taiwan (China); Chang, Jeng-Kuei, E-mail: jkchang@ncu.edu.tw [Institute of Materials Science and Engineering, National Central University, Taoyuan, Taiwan (China); Chen, Jin-Ming; Lu, Kueih-Tzu [National Synchrotron Radiation Research Center, Hsinchu, Taiwan (China)

    2011-07-01

    Highlights: > Electrodeposition of Zn was successfully demonstrnated in the water- and air-stable BMP-DCA ionic liquid. While ZnCl{sub 2} is insoluble in the BMP-TFSI ionic liquid, it dissolves easily in the BMP-DCA. > Amperometric titration experiments indicated that Zn(II) probably complexed as [Zn(DCA){sub 3}]- with DCA- anion. > Chronoamperometric experiments showed that the electrodeposition of Zn on GC and Mg alloy substrates involved 3D-instantaneous nucleation/growth process. > A lower deposition rate would bring out a more uniform and compact Zn coating layer (which is also thicker) and, consequently, this coating revealed a protection capability for the Mg substrate against corrosion. - Abstract: Electrochemical reaction of Zn(II)/Zn on glassy carbon electrode(GC) and Mg alloy substrates was investigated in the room-temperature ionic liquid, N-butyl-N-methyl-pyrrolidinium dicyanamide (BMP-DCA) containing ZnCl{sub 2} at 323 K. Amperometric titration experiments suggest that Zn(II) reacted with DCA anions forming [Zn(DCA){sub 3}]{sup -} complex anion, which also could be reduced to Zn metal via a single-step electron transfer process. By chronoamperometric measurements, the electrodeposition of Zn on GC and Mg alloy substrates involved three-dimensional instantaneous nucleation under diffusion control at 323 K. The Zn deposits are also systematically characterized by the techniques of powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Zn layer deposited at a lower current density on Mg alloy substrates was more compact and uniform when compared to that deposited at a higher current density; consequently, this coating revealed a protection capability for the Mg substrate against corrosion.

  20. Hasan Basri Çantay’ın “On Kere Kırk Hadis” Adlı Eserinde Ahkâm Hadislerine Getirdiği Fıkhî Yorumlar

    Directory of Open Access Journals (Sweden)

    Mehmet Özkan

    2015-06-01

    Full Text Available Milli mücadele yıllarının öne çıkan isimlerinden biri olan Hasan Basri Çantay yazarlık, gazetecilik, öğretmenlik ve milletvekilliği gibi birçok alanda faaliyet göstermiş, çeşitli konularda yazılar yazmış, eserler kaleme almıştır. İslami ilimler alanında da kendini yetiştiren Çantay’ın bu alandaki en önemli eseri “Kur’an-ı Hakîm ve Meal-i Kerîm” adlı Kur’an mealidir. İkinci önemli eseri, “On Kere Kırk Hadis” adlı kitabıdır. 1955-1962 yılları arasında üç cilt halinde basılan bu kitap iman, ibâdet, temizlik, ahlak, muâmelat, evlenme, boşanma, suç ve cezalar, şûra, askerlik ve cihat, savaş hukuku,  helal,  haram gibi birçok konuyla ilgili bin iki yüz hadisten oluşmaktadır. Bunların yaklaşık dört yüz yirmisi ahkâm hadisidir. Çantay, hadisleri tercüme etmekle kalmamış yeri geldikçe izahlarda da bulunmuştur. Bu çalışmada Çantay’ın yaklaşık yüz otuz ahkâm hadisine yaptığı izah ve fıkhî değerlendirmelerden örneklere yer verilecektir.