WorldWideScience

Sample records for beryllium base alloys

  1. Nanostructured Alloys as an Alternative to Copper-Beryllium

    Science.gov (United States)

    2014-11-19

    bushing applications;  2) Nanometal/composite for high specific strength/stiffness components; and  3) Nanometal cobalt / copper enabled...performance of Integran’s Nanovate cobalt -based and nickel- cobalt metals is superior to copper beryllium (peak hardness); Mechanical Property Summary...Nanostructured Cobalt Alloy 285 ksi (1967 MPa) 225 ksi (1550 MPa) 290 ksi (2000 MPa) 18855 ksi (130 GPa) Copper Beryllium (C17200-TH04) 142 ksi

  2. ZIRCONIUM-TITANIUM-BERYLLIUM BRAZING ALLOY

    Science.gov (United States)

    Gilliland, R.G.; Patriarca, P.; Slaughter, G.M.; Williams, L.C.

    1962-06-12

    A new and improved ternary alloy is described which is of particular utility in braze-bonding parts made of a refractory metal selected from Group IV, V, and VI of the periodic table and alloys containing said metal as a predominating alloying ingredient. The brazing alloy contains, by weight, 40 to 50 per cent zirconium, 40 to 50 per cent titanium, and the balance beryllium in amounts ranging from 1 to 20 per cent, said alloy having a melting point in the range 950 to 1400 deg C. (AEC)

  3. THORIUM-BERYLLIUM ALLOYS AND METHOD OF PRODUCING SAME

    Science.gov (United States)

    Spedding, F.H.; Wilhelm, H.A.; Keller, W.H.

    1959-09-01

    >The preparation is described of thorium-berylium alloys from halides of the metals by stmultaneously reducing thorium fluoride and beryllium fluoride with calcium at approximately 650 deg C and maintaining the temperature until the thorium-beryhltum alloy separates from the slag.

  4. Microstructural Characterization of Beryllium Treated Al-Si Alloys

    Directory of Open Access Journals (Sweden)

    M. F. Ibrahim

    2015-01-01

    Full Text Available The present study was carried out on B356 and B357 alloys using the thermal analysis technique. Metallographic samples prepared from these castings were examined using optical microscopy and FESEM. Results revealed that beryllium causes partial modification of the eutectic Si, similar to that reported for magnesium additions. Addition of 0.8 wt.% Mg reduces the eutectic temperature by ~10°C. During solidification of alloys containing high levels of Fe and Mg, but no Sr, formation of a Be-Fe phase was detected at 611°C, close to that of α-Al. The Be-Fe phase precipitates in script-like form at or close to the β-Al5SiFe platelets. A new reaction, composed of fine particles of Si and π-Fe phase, was observed to occur near the end of solidification in high Mg-, high Fe-, and Be-containing alloys. The amount of this reaction decreased with the addition of Sr. Occasionally, Be-containing phase particles were observed as part of the reaction. Addition of Be has a noticeable effect on decreasing the β-Al5FeSi platelet length; this effect may be enhanced by addition of Sr. Beryllium addition also results in precipitation of the β-Al5FeSi phase in nodular form, which lowers its harmful effects on the alloy mechanical properties.

  5. Development of Beryllium-Copper Alloy Ignition Capsules

    Science.gov (United States)

    Cooley, Jason; Alexander, David; Thoma, Daniel; Field, Robert; Day, Robert; Cameron, Bernard; Nobile, Arthur; Rivera, Gerald; Kelly, Ann; Papin, Pallas; Schulze, Roland; Dauelsberg, Lawrence; Alexander, Neil; Galix, Remy

    2004-11-01

    Cu-doped Be capsules are being developed for ignition on the National Ignition Facility (NIF). Our fabrication approach is based on bonding of cylindrical parts containing precision machined hemispherical cavities, followed by machining an external spherical contour to produce a spherical shell. While we have demonstrated this approach, there are several key issues that need to be resolved before a shell meeting NIF specifications can be produced. These issues are synthesis of high purity small grain size Be0.9at%Cu alloy, formation of a strong hemishell bond that will allow the capsule to contain its 400 atm fill gas at room temperature, precision machining and polishing of the capsule to meet stringent specifications for surface finish and spherical quality, and filling with DT. In this paper we report on the progress that has been made in resolving these key issues.

  6. Casting accuracy of a nickel and beryllium-free cobalt-chromium alloy for crown and bridge prostheses and resin-bonded bridges.

    Science.gov (United States)

    Hansson, O

    1985-01-01

    In the 1970's economic factors dictated the development of alternatives to gold alloys in dentistry in the USA and in Europe. A similar development has not occurred in Sweden because of different laws. Alloys that contain nickel and beryllium present a health hazard and are therefore of little interest to the Swedish market. A review of the literature shows that castings of base-metal alloys are less accurate than castings of conventional gold alloys and of low gold alloys. However, in long-span-bridges and in thin resin-bonded cast restorations, their physical and mechanical properties are superior to those of the gold alloys. In this study the casting accuracy of a nickel- and beryllium-free cobalt-chromium alloy, Neobond II Special, is investigated. Neobond II Special was found to be less accurate than Sjödings C-guld. The marginal discrepancies of the castings were small, however, when the castings were oversized. It also proved to be technique sensitive to conventional dental laboratory procedures. Thus, it seems difficult to get castings with an acceptable retention as well as small marginal discrepancies when using the base-metal alloy.

  7. Vacuum hot-pressed beryllium and TiC dispersion strengthened tungsten alloy developments for ITER and future fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiang, E-mail: xliu@swip.ac.cn [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, Sichuan (China); Chen, Jiming; Lian, Youyun; Wu, Jihong; Xu, Zengyu; Zhang, Nianman; Wang, Quanming; Duan, Xuro [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, Sichuan (China); Wang, Zhanhong; Zhong, Jinming [Northwest Rare Metal Material Research Institute, CNMC, Ningxia Orient Group Co. Ltd.,No.119 Yejin Road, Shizuishan City, Ningxia,753000 (China)

    2013-11-15

    Beryllium and tungsten have been selected as the plasma facing materials of the ITER first wall (FW) and divertor chamber, respectively. China, as a participant in ITER, will share the manufacturing tasks of ITER first-wall mockups with the European Union and Russia. Therefore ITER-grade beryllium has been developed in China and a kind of vacuum hot-pressed (VHP) beryllium, CN-G01, was characterized for both physical, and thermo-mechanical properties and high heat flux performance, which indicated an equivalent performance to U.S. grade S-65C beryllium, a reference grade beryllium of ITER. Consequently CN-G01 beryllium has been accepted as the armor material of ITER-FW blankets. In addition, a modification of tungsten by TiC dispersion strengthening was investigated and a W–TiC alloy with TiC content of 0.1 wt.% has been developed. Both surface hardness and recrystallization measurements indicate its re-crystallization temperature approximately at 1773 K. Deuterium retention and thermal desorption behaviors of pure tungsten and the TiC alloy were also measured by deuterium ion irradiation of 1.7 keV energy to the fluence of 0.5–5 × 10{sup 18} D/cm{sup 2}; a main desorption peak at around 573 K was found and no significant difference was observed between pure tungsten and the tungsten alloy. Further characterization of the tungsten alloy is in progress.

  8. Neutron counter based on beryllium activation

    Energy Technology Data Exchange (ETDEWEB)

    Bienkowska, B.; Prokopowicz, R.; Kaczmarczyk, J.; Paducha, M. [Institute of Plasma Physics and Laser Microfusion (IPPLM), Hery 23, 01-497 Warsaw (Poland); Scholz, M.; Igielski, A. [Institute of Nuclear Physics PAS (IFJPAN), Radzikowskiego 152, 31-342 Krakow (Poland); Karpinski, L. [Faculty of Electrical Engineering, Rzeszow University of Technology, Pola 2, 35-959 Rzeszow (Poland); Pytel, K. [National Centre for Nuclear Research (NCBJ), Soltana 7, 05-400 Otwock - Swierk (Poland)

    2014-08-21

    The fusion reaction occurring in DD plasma is followed by emission of 2.45 MeV neutrons, which carry out information about fusion reaction rate and plasma parameters and properties as well. Neutron activation of beryllium has been chosen for detection of DD fusion neutrons. The cross-section for reaction {sup 9}Be(n, α){sup 6}He has a useful threshold near 1 MeV, which means that undesirable multiple-scattered neutrons do not undergo that reaction and therefore are not recorded. The product of the reaction, {sup 6}He, decays with half-life T{sub 1/2} = 0.807 s emitting β{sup −} particles which are easy to detect. Large area gas sealed proportional detector has been chosen as a counter of β–particles leaving activated beryllium plate. The plate with optimized dimensions adjoins the proportional counter entrance window. Such set-up is also equipped with appropriate electronic components and forms beryllium neutron activation counter. The neutron flux density on beryllium plate can be determined from the number of counts. The proper calibration procedure needs to be performed, therefore, to establish such relation. The measurements with the use of known β–source have been done. In order to determine the detector response function such experiment have been modeled by means of MCNP5–the Monte Carlo transport code. It allowed proper application of the results of transport calculations of β{sup −} particles emitted from radioactive {sup 6}He and reaching proportional detector active volume. In order to test the counter system and measuring procedure a number of experiments have been performed on PF devices. The experimental conditions have been simulated by means of MCNP5. The correctness of simulation outcome have been proved by measurements with known radioactive neutron source. The results of the DD fusion neutron measurements have been compared with other neutron diagnostics.

  9. Neutron counter based on beryllium activation

    Science.gov (United States)

    Bienkowska, B.; Prokopowicz, R.; Scholz, M.; Kaczmarczyk, J.; Igielski, A.; Karpinski, L.; Paducha, M.; Pytel, K.

    2014-08-01

    The fusion reaction occurring in DD plasma is followed by emission of 2.45 MeV neutrons, which carry out information about fusion reaction rate and plasma parameters and properties as well. Neutron activation of beryllium has been chosen for detection of DD fusion neutrons. The cross-section for reaction 9Be(n, α)6He has a useful threshold near 1 MeV, which means that undesirable multiple-scattered neutrons do not undergo that reaction and therefore are not recorded. The product of the reaction, 6He, decays with half-life T1/2 = 0.807 s emitting β- particles which are easy to detect. Large area gas sealed proportional detector has been chosen as a counter of β-particles leaving activated beryllium plate. The plate with optimized dimensions adjoins the proportional counter entrance window. Such set-up is also equipped with appropriate electronic components and forms beryllium neutron activation counter. The neutron flux density on beryllium plate can be determined from the number of counts. The proper calibration procedure needs to be performed, therefore, to establish such relation. The measurements with the use of known β-source have been done. In order to determine the detector response function such experiment have been modeled by means of MCNP5-the Monte Carlo transport code. It allowed proper application of the results of transport calculations of β- particles emitted from radioactive 6He and reaching proportional detector active volume. In order to test the counter system and measuring procedure a number of experiments have been performed on PF devices. The experimental conditions have been simulated by means of MCNP5. The correctness of simulation outcome have been proved by measurements with known radioactive neutron source. The results of the DD fusion neutron measurements have been compared with other neutron diagnostics.

  10. Fundamental Studies on the Aluminum-Lithium-Beryllium Alloy System.

    Science.gov (United States)

    1986-08-01

    Rapidly Solidified Crystalline Alloys ," S.K... Solidified Crystalline Alloys ," S.K. Das, B.H. Kear, and C.M. Adam, eds., pp. 157-183, The ,W Metallurgical Society of AIME, Warrendale, PA, (1986). 2.i...Adda, J. Phys. 29, 345(1968) °t. 8. W.C. Oliver and W.D. Nix, Acta Metall. vol. 30,pp. 1335 to - 1347(1982). 9. C.M. Adam and R.E. Lewis, " Rapidly

  11. Beryllium chemistry and processing

    CERN Document Server

    Walsh, Kenneth A

    2009-01-01

    This book introduces beryllium; its history, its chemical, mechanical, and physical properties including nuclear properties. The 29 chapters include the mineralogy of beryllium and the preferred global sources of ore bodies. The identification and specifics of the industrial metallurgical processes used to form oxide from the ore and then metal from the oxide are thoroughly described. The special features of beryllium chemistry are introduced, including analytical chemical practices. Beryllium compounds of industrial interest are identified and discussed. Alloying, casting, powder processing, forming, metal removal, joining and other manufacturing processes are covered. The effect of composition and process on the mechanical and physical properties of beryllium alloys assists the reader in material selection. The physical metallurgy chapter brings conformity between chemical and physical metallurgical processing of beryllium, metal, alloys, and compounds. The environmental degradation of beryllium and its all...

  12. Extremely low-outgassing material: 0.2% beryllium copper alloy

    Science.gov (United States)

    Watanabe, Fumio

    2004-01-01

    Exploration for low-outgassing materials for use in ultrahigh vacuum and extreme high-vacuum systems is one of the most important topics of a vacuum researcher. We have found that a copper alloy containing 0.2% beryllium (0.2% BeCu) can attain an extremely low hydrogen outgassing rate of 10-14 Pa (H2) m/s order. Almost the entire surface of 0.2% BeCu is dominated by a BeO layer, after a 400 °C×72 h prebakeout treatment in an ultrahigh vacuum. This layer functions as a barrier to the processes of oxidization and permeation of hydrogen. In addition, this layer resists carbon contamination. Temperature-programmed desorption spectra show only a single peak for water at 150 °C and small quantities of any other desorption gases. Therefore, an in situ bakeout process in which the temperature simply ramps up to 150 °C and immediately ramps back down is enough for degassing; it does not require an ordinary sustained-temperature bakeout. Using an outgassing sample consisting of 0.2% BeCu disks housed in a 0.2% BeCu nipple chamber, a lowest outgassing rate of the 5.6×10-14 Pa (H2) m/s was measured by the pressure-rise method after pump cutoff. The pressure-rise versus time curve was completely nonlinear. It rises over time to a constant slope of 1/2 in a log-log plot, due to hydrogen diffusion from the bulk, but this requires over a week at room temperature. The hydrogen outgassing from the 0.2% BeCu bulk is completely dominated by a diffusion-limited mechanism. This article will describe why we obtain such low-outgassing rates with 0.2% BeCu. It is based on the observed surface changes with prebakeout treatment seen by x-ray photoelectron spectroscopy, and the improvement of hydrogen outgassing measurements by the pressure-rise method. A comparison is made to ordinary stainless steel. In addition, the concept of an outgassing reduction method will be discussed from a review of the published ultralow-outgassing data and reduction methods. .

  13. Defense programs beryllium good practice guide

    Energy Technology Data Exchange (ETDEWEB)

    Herr, M.

    1997-07-01

    Within the DOE, it has recently become apparent that some contractor employees who have worked (or are currently working) with and around beryllium have developed chronic beryllium disease (CBD), an occupational granulomatous lung disorder. Respiratory exposure to aerosolized beryllium, in susceptible individuals, causes an immunological reaction that can result in granulomatous scarring of the lung parenchyma, shortness of breath, cough, fatigue, weight loss, and, ultimately, respiratory failure. Beryllium disease was originally identified in the 1940s, largely in the fluorescent light industry. In 1950, the Atomic Energy Commission (AEC) introduced strict exposure standards that generally curtailed both the acute and chronic forms of the disease. Beginning in 1984, with the identification of a CBD case in a DOE contractor worker, there was increased scrutiny of both industrial hygiene practices and individuals in this workforce. To date, over 100 additional cases of beryllium-specific sensitization and/or CBD have been identified. Thus, a disease previously thought to be largely eliminated by the adoption of permissible exposure standards 45 years ago is still a health risk in certain workforces. This good practice guide forms the basis of an acceptable program for controlling workplace exposure to beryllium. It provides (1) Guidance for minimizing worker exposure to beryllium in Defense Programs facilities during all phases of beryllium-related work, including the decontamination and decommissioning (D&D) of facilities. (2) Recommended controls to be applied to the handling of metallic beryllium and beryllium alloys, beryllium oxide, and other beryllium compounds. (3) Recommendations for medical monitoring and surveillance of workers exposed (or potentially exposed) to beryllium, based on the best current understanding of beryllium disease and medical diagnostic tests available. (4) Site-specific safety procedures for all processes of beryllium that is likely to

  14. YF-12 Lockalloy ventral fin program, volume 1. [design analysis, fabrication, and manufacturing of aircraft structures using aluminum and beryllium alloys for the lockheed YF-12 aircraft

    Science.gov (United States)

    Duba, R. J.; Haramis, A. C.; Marks, R. F.; Payne, L.; Sessing, R. C.

    1976-01-01

    Results are presented of the YF-12 Lockalloy Ventral Fin Program which was carried out by Lockheed Aircraft Corporation - Advanced Development Projects for the joint NASA/USAF YF-12 Project. The primary purpose of the program was to redesign and fabricate the ventral fin of the YF-12 research airplane (to reduce flutter) using Lockalloy, and alloy of beryllium and aluminum, as a major structural material. A secondary purpose, was to make a material characterization study (thermodynamic properties, corrosion; fatigue tests, mechanical properties) of Lockalloy to validate the design of the ventral fin and expand the existing data base on this material. All significant information pertinent to the design and fabrication of the ventral fin is covered. Emphasis throughout is given to Lockalloy fabrication and machining techniques and attendant personnel safety precautions. Costs are also examined. Photographs of tested alloy specimens are shown along with the test equipment used.

  15. Considerations for the development of health-based surface dust cleanup criteria for beryllium.

    Science.gov (United States)

    Shay, Erin; De Gandiaga, Elise; Madl, Amy K

    2013-03-01

    The exposure-response patterns with beryllium sensitization (BeS), chronic beryllium disease (CBD) and lung cancer are influenced by a number of biological and physicochemical factors. Recent studies have suggested dermal exposure as a pathway for BeS. In light of the current non-health-based DOE Beryllium Rule surface criteria, the feasibility of deriving a human health-based surface dust cleanup criteria (SDCC) for beryllium was assessed based on toxicology and health risk factors via all potential routes of exposure. Beryllium-specific and general exposure factors were evaluated, including (1) beryllium physicochemical characteristics, bioavailability and influence on disease prevalence, and (2) chemical dissipation, resuspension and transfer. SDCC for non-cancer (SDCC) and cancer (SDCC) endpoints were derived from a combination of modern methods applied for occupational, residential and building reentry surface dust criteria. The most conservative SDCC estimates were derived for dermal exposure (5-379 μg/100 cm for 0.1-1% damaged skin and 17-3337 μg/100 cm for intact skin), whereas the SDCC for inhalation exposure ranged from 51 to 485 μg/100 cm. Considering this analysis, the lowest DOE surface criterion of 0.2 μg/100 cm is conservative for minimizing exposure and potential risks associated with beryllium-contaminated surfaces released for non-beryllium industrial or public sector use. Although methodological challenges exist with sampling and analysis procedures, data variability and interpretation of surface dust information in relation to anthropogenic and natural background concentrations, this evaluation should provide useful guidance with regard to cleanup of manufacturing equipment or remediation of property for transfer to the general public or non-beryllium industrial facilities.

  16. CHAPTER 7. BERYLLIUM ANALYSIS BY NON-PLASMA BASED METHODS

    Energy Technology Data Exchange (ETDEWEB)

    Ekechukwu, A

    2009-04-20

    The most common method of analysis for beryllium is inductively coupled plasma atomic emission spectrometry (ICP-AES). This method, along with inductively coupled plasma mass spectrometry (ICP-MS), is discussed in Chapter 6. However, other methods exist and have been used for different applications. These methods include spectroscopic, chromatographic, colorimetric, and electrochemical. This chapter provides an overview of beryllium analysis methods other than plasma spectrometry (inductively coupled plasma atomic emission spectrometry or mass spectrometry). The basic methods, detection limits and interferences are described. Specific applications from the literature are also presented.

  17. Beryllium: genotoxicity and carcinogenicity.

    Science.gov (United States)

    Gordon, Terry; Bowser, Darlene

    2003-12-10

    Beryllium (Be) has physical-chemical properties, including low density and high tensile strength, which make it useful in the manufacture of products ranging from space shuttles to golf clubs. Despite its utility, a number of standard setting agencies have determined that beryllium is a carcinogen. Only a limited number of studies, however, have addressed the underlying mechanisms of the carcinogenicity and mutagenicity of beryllium. Importantly, mutation and chromosomal aberration assays have yielded somewhat contradictory results for beryllium compounds and whereas bacterial tests were largely negative, mammalian test systems showed evidence of beryllium-induced mutations, chromosomal aberrations, and cell transformation. Although inter-laboratory differences may play a role in the variability observed in genotoxicity assays, it is more likely that the different chemical forms of beryllium have a significant effect on mutagenicity and carcinogenicity. Because workers are predominantly exposed to airborne particles which are generated during the machining of beryllium metal, ceramics, or alloys, testing of the mechanisms of the mutagenic and carcinogenic activity of beryllium should be performed with relevant chemical forms of beryllium.

  18. NICKEL-BASE ALLOY

    Science.gov (United States)

    Inouye, H.; Manly, W.D.; Roche, T.K.

    1960-01-19

    A nickel-base alloy was developed which is particularly useful for the containment of molten fluoride salts in reactors. The alloy is resistant to both salt corrosion and oxidation and may be used at temperatures as high as 1800 deg F. Basically, the alloy consists of 15 to 22 wt.% molybdenum, a small amount of carbon, and 6 to 8 wt.% chromium, the balance being nickel. Up to 4 wt.% of tungsten, tantalum, vanadium, or niobium may be added to strengthen the alloy.

  19. Beryllium dimer: a bond based on non-dynamical correlation.

    Science.gov (United States)

    El Khatib, Muammar; Bendazzoli, Gian Luigi; Evangelisti, Stefano; Helal, Wissam; Leininger, Thierry; Tenti, Lorenzo; Angeli, Celestino

    2014-08-21

    The bond nature in beryllium dimer has been theoretically investigated using high-level ab initio methods. A series of ANO basis sets of increasing quality, going from sp to spdf ghi contractions, has been employed, combined with HF, CAS-SCF, CISD, and MRCI calculations with several different active spaces. The quality of these calculations has been checked by comparing the results with valence Full-CI calculations, performed with the same basis sets. It is shown that two quasi-degenerated partly occupied orbitals play a crucial role to give a qualitatively correct description of the bond. Their nature is similar to that of the edge orbitals that give rise to the quasi-degenerated singlet-triplet states in longer beryllium chains.

  20. A diethylhydroxylaminate based mixed lithium/beryllium aggregate

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Raphael J.F. [Paris-Lodron Universitaet Salzburg (Austria). Fachbereich fuer Materialwissenschaften und Physik; Jana, Surajit [Asansol Girls College, West-Bengal (India). Dept. of Chemistry; Froehlich, Roland [Muenster Univ. (Germany). Organisch-Chemisches Inst.; Mitzel, Norbert W. [Bielefeld Univ. (Germany). Anorganische Chemie und Strukturchemie

    2015-07-01

    A mixed lithium/beryllium diethylhydroxylaminate compound containing {sup n}butyl beryllium units of total molecular composition {sup n}Be(ONEt{sub 2}){sub 2} [(LiONEt{sub 2}){sup 2} {sup n}BuBeONEt{sub 2}]{sub 2} (1) was isolated from a reaction mixture of {sup n}butyl lithium, N,N-diethylhydroxylamine and BeCl{sub 2} in diethylether/thf. The crystal structure of 1 has been determined by X-ray diffraction. The aggregate is composed of two ladder-type subunits connected in a beryllium-centered distorted tetrahedron of four oxygen atoms. Only the lithium atoms are engaged in coordination with the nitrogen donor atoms. The DFT calculations support the positional occupation determined for Li and Be in the crystal structure. The DFT and the solid-state structure are in excellent agreement, indicating only weak intermolecular interactions in the solid state. Structural details of metal atom coordination are discussed.

  1. Experimental Investigations on Pulsed Nd:YAG Laser Welding of C17300 Copper-Beryllium and 49Ni-Fe Soft Magnetic Alloys

    Science.gov (United States)

    Mousavi, S. A. A. Akbari; Ebrahimzadeh, H.

    2011-01-01

    Copper-beryllium and soft magnetic alloys must be joined in electrical and electro-mechanical applications. There is a high difference in melting temperatures of these alloys which cause to make the joining process very difficult. In addition, copper-beryllium alloys are of age hardenable alloys and precipitations can brittle the weld. 49Ni-Fe alloy is very hot crack sensitive. Moreover, these alloys have different heat transfer coefficients and reflection of laser beam in laser welding process. Therefore, the control of welding parameters on the formation of adequate weld puddle composition is very difficult. Laser welding is an advanced technique for joining of dissimilar materials since it can precisely control and adjust the welding parameters. In this study, a 100W Nd:YAG pulsed laser machine was used for joining 49Ni-Fe soft magnetic to C17300 copper-beryllium alloys. Welding of samples was carried out autogenously by changing the pulse duration, diameter of beam, welding speed, voltage and frequency. The spacing between samples was set to almost zero. The ample were butt welded. It was required to apply high voltage in this study due to high reflection coefficient of copper alloys. Metallography, SEM analysis, XRD and microhardness measurement was used for survey of results. The results show that the weld strength depends upon the chemical composition of the joints. To change the wells composition and heat input of the welds, it was attempted to deviate the laser focus away from the weld centerline. The best strength was achieved by deviation of the laser beam away about 0.1mm from the weld centerline. The result shows no intermetallic compounds if the laser beam is deviated away from the joint.

  2. TUNGSTEN BASE ALLOYS

    Science.gov (United States)

    Schell, D.H.; Sheinberg, H.

    1959-12-15

    A high-density quaternary tungsten-base alloy having high mechanical strength and good machinability composed of about 2 wt.% Ni, 3 wt.% Cu, 5 wt.% Pb, and 90wt.% W is described. This alloy can be formed by the powder metallurgy technique of hot pressing in a graphite die without causing a reaction between charge and the die and without formation of a carbide case on the final compact, thereby enabling re-use of the graphite die. The alloy is formable at hot- pressing temperatures of from about 1200 to about 1350 deg C. In addition, there is little component shrinkage, thereby eliminating the necessity of subsequent extensive surface machining.

  3. Historical analysis of airborne beryllium concentrations at a copper beryllium machining facility (1964-2000).

    Science.gov (United States)

    McAtee, B L; Donovan, E P; Gaffney, S H; Frede, W; Knutsen, J S; Paustenbach, D J

    2009-06-01

    Copper beryllium alloys are the most commonly used form of beryllium; however, there have been few studies assessing occupational exposure in facilities that worked exclusively with this alloy versus those where pure metal or beryllium oxide may also have been present. In this paper, we evaluated the airborne beryllium concentrations at a machining plant using historical industrial hygiene samples collected between 1964 and 2000. With the exception of a few projects conducted in the 1960s, it is believed that >95% of the operations used copper beryllium alloy exclusively. Long-term (>120 min) and short-term (machining of copper beryllium-containing parts, as well as finishing operations (e.g., deburring and polishing) and decontamination of machinery. A total of 580 beryllium air samples were analyzed (311 personal and 269 area samples). The average concentration based on area samples (1964-2000) was 0.021 microg m(-3) (SD 0.17 microg m(-3); range 0.00012-2.5 microg m(-3)); 68.8% were below the analytical limit of detection (LOD). The average airborne beryllium concentration, based on all personal samples available from 1964 through the end of 2000 (n = 311), was 0.026 microg m(-3) (SD 0.059 microg m(-3); range 0.019-0.8 microg m(-3)); 97.4% were below the LOD. Personal samples collected from machinists (n = 78) had an average airborne concentration of 0.021 microg m(-3) (SD 0.014 microg m(-3); range 0.019-0.14 microg m(-3)); 97.4% were below the LOD. Airborne concentrations were consistently below the Occupational Safety and Health Administration permissible exposure limit for beryllium (2 microg m(-3)). Overall, the data indicate that for machining operations involving copper beryllium, the airborne concentrations for >95% of the samples were below the contemporaneous occupational exposure limits or the 1999 Department of Energy action level of 0.2 microg m(-3) and, in most cases, were below the LOD.

  4. The Effect of Artificial Aging on The Bond Strength of Heat-activated Acrylic Resin to Surface-treated Nickel-chromium-beryllium Alloy

    Science.gov (United States)

    Al Jabbari, Youssef S.; Zinelis, Spiros; Al Taweel, Sara M.; Nagy, William W.

    2016-01-01

    Purpose The debonding load of heat-activated polymethylmethacrylate (PMMA) denture base resin material to a nickel-chromium-beryllium (Ni-Cr-Be) alloy conditioned by three different surface treatments and utilizing two different commercial bonding systems was investigated. Materials and Methods Denture resin (Lucitone-199) was bonded to Ni-Cr-Be alloy specimens treated with Metal Primer II, the Rocatec system with opaquer and the Rocatec system without opaquer. Denture base resin specimens bonded to non-treated sandblasted Ni-Cr-Be alloy were used as controls. Twenty samples for each treatment condition (80 specimens) were tested. The 80 specimens were divided into two categories, thermocycled and non-thermocycled, containing four groups of ten specimens each. The non-thermocycled specimens were tested after 48 hours’ storage in room temperature water. The thermocycled specimens were tested after 2,000 cycles in 4°C and 55°C water baths. The debonding load was calculated in Newtons (N), and collected data were subjected by non parametric test Kruskal-Wallis One Way Analysis of Variance on Ranks and Dunn’s post hoc test at the α = 0.05. Results The Metal Primer II and Rocatec system without opaquer groups produced significantly higher bond strengths (119.9 and 67.6 N), respectively, than did the sandblasted and Rocatec system with opaquer groups, where the bond strengths were 2.6 N and 0 N, respectively. The Metal Primer II was significantly different from all other groups (P<0.05). The bond strengths of all groups were significantly decreased (P<0.05) after thermocycling. Conclusions Although thermocycling had a detrimental effect on the debonding load of all surface treatments tested, the Metal Primer II system provided higher values among all bonding systems tested, before and after thermocycling. PMID:27335613

  5. Effects of beryllium and iron additions on iron-bearing phase in A357 aluminum alloys

    Directory of Open Access Journals (Sweden)

    Chen Zhongwei

    2010-08-01

    Full Text Available Iron is the most deleterious impurity in the Al-Si-Mg casting alloys and can easily form inter-metallic compounds that can significantly affect the subsequent behavior of material properties. Using differential scanning calorimetry (DSC and microstructural analysis, how the Be and Fe additions affect the iron-bearing phase in A357 alloys was investigated. The results show that the iron-bearing phase in A357 alloy comprises mainly the plate-like β-Al5FeSi and a small quantity of the script-type π-Al8FeMg3Si6; and that the plate-like β-Al5FeSi proportion increases with increasing iron content in the alloy. The iron-bearing phase is mostly transformed from the plate-like β-Al5FeSi to the script-type π-Al8FeMg3Si6 with the addition of Be in the alloy. The hardness of alloy samples was also tested. The results show that both the increasing iron content and Be content can increase the hardness of the alloy. This may be contributed to the change of morphology and distribution of the iron-bearing phase in A357 alloy with the addition of iron or Be to the alloy.

  6. Sub-micro level monitoring of beryllium ions with a novel beryllium sensor based on 2,6-diphenyl-4-benzo-9-crown-3-pyridine.

    Science.gov (United States)

    Ganjali, Mohammad Reza; Rahimi-Nasrabadi, Mehdi; Maddah, Bozorgmehr; Moghimi, Abolghasem; Faal-Rastegar, Madjid; Borhany, Shahin; Namazian, Mansour

    2004-07-01

    The 2,6-diphenyl-4-benzo-9-crown-3-pyridine (DPCP) was used as an excellent ionophore in construction of a coated graphite poly(vinyl chloride) (PVC)-based membrane sensor. The best performance was obtained with a membrane composition of 30% poly(vinyl chloride), 60% o-nitrophenyloctyl ether (NPOE), 5% 2,6-diphenyl-4-benzo-9-crown-3-pyridine and 5% sodium tetraphenyl borate (TBP). This sensor shows very good selectivity and sensitivity towards beryllium ion over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The sensor revealed a great enhancement in selectivity coefficients and sensitivity for beryllium, in comparison with the previously reported beryllium electrodes. The electrode exhibits a Nernstian behavior (with slope of 29.6mV per decade) over a very wide concentration range (1.0x10(-7) to 1.0x10(-1)) with a detection limit of 4.0x10(-8)M (360pgml(-1)). It shows relatively fast response time, in whole concentration range (beryllium in mineral ore.

  7. Beryllium 1989

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    The Roskill report on beryllium gives information on the occurrence and reserves, production technology, geographic distribution, consumption and end-uses, stocks, prices and beryllium and health. There is an appendix on international trade statistics. (author).

  8. Status of the Development of Beryllium-Copper Alloy Ignition Capsules by Precision Machining

    Science.gov (United States)

    Nobile, Arthur

    2005-10-01

    Cu-doped Be capsules are being developed for ignition on the National Ignition Facility (NIF). The fabrication approach being pursued at Los Alamos is based on bonding of cylindrical parts containing precision machined hemispherical cavities, followed by machining the external contour to produce a spherical capsule. While we have demonstrated this approach, there are several key issues that need to be resolved before a capsule meeting NIF specifications can be produced. These issues are synthesis of high purity small grain size Be-Cu alloy, formation of a hemishell bond strong enough to allow the capsule to be machined after the hemishells are bonded, precision machining and polishing of the capsule to meet stringent specifications for surface finish and spherical quality, and filling with DT. In this paper we report on the progress that has been made on these issues. This work is performed at Los Alamos National Laboratory and supported by U.S. Department of Energy under contract number W7405-ENG36

  9. Fluorimetric method for determination of Beryllium; Determinazione fluorimetrica del berillio

    Energy Technology Data Exchange (ETDEWEB)

    Sparacino, N.; Sabbioneda, S. [ENEA, Centro Ricerche Saluggia, Vercelli (Italy). Dip. Energia

    1996-10-01

    The old fluorimetric method for the determination of Beryllium, based essentially on the fluorescence of the Beryllium-Morine complex in a strongly alkaline solution, is still competitive and stands the comparison with more modern methods or at least three reasons: in the presence of solid or gaseous samples (powders), the times necessary to finalize an analytic determination are comparable since the stage of the process which lasts the longest is the mineralization of the solid particles containing Beryllium, the cost of a good fluorimeter is by far Inferior to the cost, e. g., of an Emission Spectrophotometer provided with ICP torch and magnets for exploiting the Zeeman effect and of an Atomic absorption Spectrophotometer provided with Graphite furnace; it is possible to determine, fluorimetrically, rather small Beryllium levels (about 30 ng of Beryllium/sample), this potentiality is more than sufficient to guarantee the respect of all the work safety and hygiene rules now in force. The study which is the subject of this publication is designed to the analysis procedure which allows one to reach good results in the determination of Beryllium, chiefly through the control and measurement of the interference effect due to the presence of some metals which might accompany the environmental samples of workshops and laboratories where Beryllium is handled, either at the pure state or in its alloys. The results obtained satisfactorily point out the merits and limits of this analytic procedure.

  10. Machining characteristics and fracture morphologies in a copper-beryllium (Cu-2Be) alloy

    Science.gov (United States)

    Sudhakar, K. V.; Cisneros, J. C.; Cervantes, Hector; Pineda, Cosme Gomez

    2006-02-01

    The technology of materials removal is improved greatly by the introduction of advanced cutting tools like cubic boron nitride, ceramics, polycrystalline diamond and the more recent whisker-reinforced materials. In this paper, the influence of cutting temperature on machinability, mechanical properties, microstructure, and fracture morphology of Cu-2Be alloy using a polycrystalline diamond cutter is investigated. The information on machining, microstructure, and fracture morphology of Cu-2Be alloy are very useful to understand their fabrication characteristics and the basic mechanisms of its deformation and fracture. The machinability (in terms of surface finish) of Cu-2Be alloy is evaluated as a function of cutting temperature, resulting from wet and dry cutting. Machining is carried out on a Hardinge Cobra 42 CNC machine (Hardinge Inc., Elmira, NY), and the machining parameters used—cutting speed, depth of cut, and feed rate—are kept constant during both wet and dry cutting. The machined surface finish on Cu-2Be alloy is measured using a surface finish analyzer (Surftest 401, series 178) technique. The machined specimens are examined for their strength and hardness properties using a standard Universal Testing Machine and Rockwell hardness tester, respectively. Wet cutting (using coolants) produced a smooth surface finish when compared with dry cutting of the Cu-2Be alloy. The machined specimens are examined for their microstructural features using a Nikon optical microscope. The specimens are etched using a suitable etchant solution for revealing such microstructure constituents as grain size, phase proportions, and the possible overheated areas (especially in dry cutting). The fractured surfaces from the tensile and impact toughness tests are investigated for their fracture morphologies (dry and wet cutting) using a microprocessor-controlled scanning electron microscope (Jeol Model JSM 5910 LV). A detailed analysis is also made to understand and interpret

  11. Reactivity test between beryllium and copper

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, H. [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan); Kato, M. [NGK Insulators, Ltd., Aichi-ken (Japan)

    1995-09-01

    Beryllium has been expected for using as plasma facing material on ITER. And, copper alloy has been proposed as heat sink material behind plasma facing components. Therefore, both materials must be joined. However, the elementary process of reaction between beryllium and copper alloy does not clear in detail. For example, other authors reported that beryllium reacted with copper at high temperature, but it was not obvious about the generation of reaction products and increasing of the reaction layer. In the present work, from this point, for clarifying the elementary process of reaction between beryllium and copper, the out-of-pile compatibility tests were conducted with diffusion couples of beryllium and copper which were inserted in the capsule filled with high purity helium gas (6N). Annealing temperatures were 300, 400, 500, 600 and 700{degrees}C, and annealing periods were 100, 300 and 1000h. Beryllium specimens were hot pressed beryllium, and copper specimens were OFC (Oxygen Free Copper).

  12. Use of a Paraffin Based Grout to Stabilize Buried Beryllium and Other Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Gretchen Matthern; Duane Hanson; Neal Yancey; Darrell Knudson

    2005-12-01

    The long term durability of WAXFIXi, a paraffin based grout, was evaluated for in situ grouting of activated beryllium wastes in the Subsurface Disposal Area (SDA), a radioactive landfill at the Radioactive Waste Management Complex, part of the Idaho National Laboratory (INL). The evaluation considered radiological and biological mechanisms that could degrade the grout using data from an extensive literature search and previous tests of in situ grouting at the INL. Conservative radioactive doses for WAXFIX were calculated from the "hottest" (i.e., highest-activity) Advanced Test Reactor beryllium block in the SDA.. These results indicate that WAXFIX would not experience extensive radiation damage for many hundreds of years. Calculation of radiation induced hydrogen generation in WAXFIX indicated that grout physical performance should not be reduced beyond the effects of radiation dose on the molecular structure. Degradation of a paraffin-based grout by microorganisms in the SDA is possible and perhaps likely, but the rate of degradation will be at a slower rate than found in the literature reviewed. The calculations showed the outer 0.46 m (18 in.) layer of each monolith, which represents the minimum expected distance to the beryllium block, was calculated to require 1,000 to 3,600 years to be consumed. The existing data and estimations of biodegradation and radiolysis rates

  13. Structure and Properties of a Beryllium Alloy%一种铍合金材料的结构和性能

    Institute of Scientific and Technical Information of China (English)

    徐五丹; 郭领军; 李贺军; 李晏辉; 王剑锋

    2011-01-01

    The density, structure, chemical element analysis, mechanical, physical and friction properties of a certain type of aircraft brake material -a beryllium alloy were investigated. A comparison of some performances between C/C composites, C/SiC composites and the Be alloy made by powder metallurgy (PM) was made and the results show that beryllium alloy has low density, excellent mechanical and friction properties,and is a potential brake material.%对国外某型号飞机所用的铍合金刹车材料进行了密度测试、结构观察、化学元素分析、力学、物理和摩擦性能表征,并与C/C、C/SiC复合材料和粉末冶金材料的相关性能作了对比,结果表明,粉末冶金铍合金材料密度低,力学和摩擦性能优异,是一种很有发展前途的刹车材料.

  14. Determination of beryllium by using X-ray fluorescence spectrometry.

    Science.gov (United States)

    Zawisza, Beata

    2008-03-01

    X-ray fluorescence spectrometry method is subject to certain difficulties and inconveniences for the elements having the atomic number 9 or less. These difficulties become progressively more severe as the atomic number decreases, and are quite serious for beryllium, which is practically indeterminable directly by XRF. Therefore, an indirect determination of beryllium that is based on the evaluation of cobalt in the precipitate is taken into consideration. In the thesis below, there is a description of a new, simple, and precise method by selective precipitation using hexamminecobalt(III) chloride and ammonium carbonate-EDTA solution as a complexing agent for the determining of a trace amount of beryllium using X-ray fluorescence spectrometry. The optimum conditions for [Co(NH(3))(6)][Be(2)(OH)(3)(CO(3))(2)(H(2)O)(2)].(3)H(2)O complex formation were studied. The complex was collected on the membrane filter, and the Co Kalpha line was measured by XRF. The method presents the advantages of the sample preparation and the elimination of the matrix effects due to the thin film obtained. The detection limit of the proposed method is 0.2 mg of beryllium. The method was successfully applied to beryllium determination in copper/ beryllium/cobalt alloys.

  15. Chronic Beryllium Disease

    Science.gov (United States)

    ... Science Education & Training Home Conditions Chronic Beryllium Disease Chronic Beryllium Disease Make an Appointment Find a Doctor ... MD, MSPH, FCCP (February 01, 2016) What is chronic beryllium disease (CBD)? Chronic beryllium disease (CBD) is ...

  16. Novel potentiometric sensor for monitoring beryllium based on naphto-9-crown-3.

    Science.gov (United States)

    Ganjali, Mohammad Reza; Daftari, Azadeh; Faal-Rastegar, Majid; Moghimi, Abolghasem

    2003-03-01

    A novel poly(vinyl chloride) (PVC) membrane electrode based on naphto-9-crown-3 was prepared and tested for the selective detection of beryllium ions. A suitable lipophilicity of the carrier and appropriate coordination ability were found to be essential for designing an electrode with good response characteristics. A PVC membrane with 9% naphtho-9-crown-3 carrier, 58% o-NPOE plasticizer, 3% tetraphenylborate anionic excluder and 30% poly(vinyl chloride) satisfied these requirements. The proposed sensor displayed a linear response to beryllium over a wide concentration range of 1.0 x 10(-1)-8.0 x 10(-6) M with a Nernstian slope of 29.5 mV per decade. The electrode showed very short response time (<15 s) and could be used in the pH range 3.5-9.0. The selectivity coefficient for alkali, alkaline earth, transition and heavy metal ions was smaller than 4.0 x 10(-4). The sensor was successfully used as an indicator electrode in the potentiometric titration of Be2+ with EDTA. The proposed Be(II) sensor was also used for the determination of Be2+ ions in binary mixtures.

  17. Reliability design and assessment of a micro-probe using the results of a tensile test of a beryllium-copper alloy thin film

    Science.gov (United States)

    Park, Jun-Hyub; Shin, Myung-Soo

    2011-09-01

    This paper describes the results of tensile tests for a beryllium-copper (BeCu) alloy thin film and the application of the results to the design of a probe. The copper alloy films were fabricated by electroplating. To obtain the tensile characteristics of the film, the dog-bone type specimen was fabricated by the etching method. The tensile tests were performed with the specimen using a test machine developed by the authors. The BeCu alloy has an elastic modulus of 119 GPa and the 0.2% offset yield and ultimate tensile strengths of 1078 MPa and 1108 MPa, respectively. The design and manufacture of a smaller probe require higher pad density and smaller pad-pitch chips. It should be effective in high-frequency testing. For the design of a new micro-probe, we investigated several design parameters that may cause problems, such as the contact force and life, using the tensile properties and the design of experiment method in conjunction with finite element analysis. The optimal dimensions of the probe were found using the response surface method. The probe with optimal dimensions was manufactured by a precision press process. It was verified that the manufactured probe satisfied the life, the contact force and the over drive through the compression tests and the life tests of the probes.

  18. 40 CFR 468.20 - Applicability; description of the beryllium copper forming subcategory.

    Science.gov (United States)

    2010-07-01

    ... of pollutants into publicly owned treatment works from the forming of beryllium copper alloys. ... beryllium copper forming subcategory. 468.20 Section 468.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS COPPER FORMING POINT SOURCE...

  19. Mg based alloys obtained by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez, S. [Univ. de Santiago de Chile (Chile). Fac. de Ingenieria; Garcia, G.; Serafini, D.; San Martin, A.

    1999-07-01

    In the present work, we studied the production of magnesium alloys, of stoichiometry 2Mg + Ni, by mechanical alloying (MA) and the behavior of the alloys under hydrogen in a Sievert`s type apparatus. The elemental powders were milled under argon atmosphere in a Spex 8000 high energy ball mill. The milled materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Only minimum amounts of the Mg{sub 2}Ni intermetallic compound was obtained after 22 h of milling time. Most of the material was sticked to the inner surface of the container as well as to the milling balls. Powders milled only for 12 hours transforms to the intermetallic at around 433 K. Effects of the MA on the hydrogen absorption kinetics were also studied. (orig.) 10 refs.

  20. Metallurgical viewpoints on the brittleness of beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Lagerberg, G.

    1960-02-15

    At present the development and use of beryllium metal for structural applications is severely hampered by its brittleness. Reasons for this lack of ductility are reviewed in discussing the deformation behaviour of beryllium in relation to other hexagonal metals. The ease of fracturing in beryllium is assumed to be a consequence of a limited number of deformation modes in combination with high deformation resistance. Models for the nucleation of fracture are suggested. The relation of ductility to elastic constants as well as to grain size, texture and alloying additions is discussed.

  1. A new beryllium ion-selective membrane electrode based on dibenzo(perhydrotriazino)aza-14-crown-4 ether.

    Science.gov (United States)

    Gupta, Vinod Kumar; Singh, Ashok Kumar; Mergu, Naveen

    2012-10-24

    Beryllium(II) selective electrodes have been fabricated based on poly(vinyl chloride) (PVC) matrix membranes containing newly synthesized neutral carrier dibenzo(perhydrotriazino)aza-14-crown-4 ethers as ionophore. Best performance was exhibited by the membrane having a composition ionophore (IIa):PVC:sodium tetraphenylborate (NaTPB):tributyl phosphate (TBP) in the ratio (w/w; mg) of 5:30:3:65. This membrane worked well over a wide concentration range 7.6×10(-6) to 1.0×10(-1) M of Be(2+) with a Nernstian slope of 30.7 mV per decade of beryllium activity. The response time of the sensor is 15s and the membrane can be used over a period of 4 months with good reproducibility. The proposed electrode works well in a wide pH range 3.0-9.0. It was successfully applied to the determination of beryllium in a mineral sample.

  2. Bulk amorphous Mg-based alloys

    DEFF Research Database (Denmark)

    Pryds, Nini

    2004-01-01

    The present paper describes the preparation and properties of bulk amorphous quarternary Mg-based alloys and the influence of additional elements on the ability of the alloy to form bulk amorphous. The main goal is to find a Mg-based alloy system which shows both high strength to weight ratio and...

  3. Fluorometric determination of beryllium with 2-(o-hydroxylphenyl)benzoxazole

    Energy Technology Data Exchange (ETDEWEB)

    Gladilovich, D.B.; Stolyarov, K.P.

    1985-09-01

    According to the authors, of great interest for the fluorometric determination of small quantities of beryllium is 2-(o-hydroxyphenyl)benzthiazole (HPBT). In this work, 2-(o-hydroxyphenyl)benzoaxzole (HPBO), which is an analog of HPBT and differs from it in that the sulfur atom in the heterocyclic portion of the molecule is replaced by an oxygen atom, is proposed as a reagent for the fluorometric determination of beryllium. The fluorescent reaction of HPBO with beryllium is studied in this paper, in addition to the selection of the optimum conditions for the determination and the development of a procedure for the analysis of complex objects on this basis. The reaction proceeds in aqueous ethanol medium at pH 7.2-7.5. The limit of detection is 0.6 ng/ml. Methods have been developed for the determination of 10/sup -2/% beryllium in alloys based on copper and 10/sup -3/-10/sup -4/% in standard samples of silicate rocks.

  4. Properties of laser alloyed surface layers on magnesium base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Galun, R.; Weisheit, A.; Mordike, B.L. (Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Werkstoffkunde und Werkstofftechnik)

    1998-01-01

    The investigations have shown that laser surface alloying is a promising process to improve the wear and corrosion properties of magnesium base alloys without affecting the initial bulk properties like the low density. With an alloying element combination of aluminium and nickel the wear rate in the scratch test was reduced by 90% compared to untreated pure magnesium. Additionally the corrosion resistance was improved by laser alloying with this element combination. Because of distortion or crack formation in the case of large area treatments, the laser alloying should be limited to the treatment of smaller areas. In the near future this process could be an interesting alternative to surface coating or to a partially reinforcement with ceramic fibres or particles. (orig.)

  5. Cobalt-Base Alloy Gun Barrel Study

    Science.gov (United States)

    2014-07-01

    are presented in Section 5. 2. Materials and methods The composition of the cobalt -base alloy (CBA) is presented in Table 1. The production of this... Cobalt -Base Alloy Gun Barrel Study by William S. de Rosset and Jonathan S. Montgomery ARL-RP-0491 July 2014 A reprint...21005-5069 ARL-RP-0491 July 2014 Cobalt -Base Alloy Gun Barrel Study William S. de Rosset and Jonathan S. Montgomery Weapons and Materials

  6. The beryllium production at Ulba metallurgical plant (Ust-Kamenogrsk, Kazakhstan)

    Energy Technology Data Exchange (ETDEWEB)

    Dvinskykh, E.M.; Savchuk, V.V.; Tuzov, Y.V. [Ulba Metallurgical Plant (Zavod), Ust-Kamenogorsk, Abay prospect 102 (Kazakhstan)

    1998-01-01

    The Report includes data on beryllium production of Ulba metallurgical plant, located in Ust-Kamenogorsk (Kazakhstan). Beryllium production is showed to have extended technological opportunities in manufacturing semi-products (beryllium ingots, master alloys, metallic beryllium powders, beryllium oxide) and in production of structural beryllium and its parts. Ulba metallurgical plant owns a unique technology of beryllium vacuum distillation, which allows to produce reactor grades of beryllium with a low content of metallic impurities. At present Ulba plant does not depend on raw materials suppliers. The quantity of stored raw materials and semi-products will allow to provide a 25-years work of beryllium production at a full capacity. The plant has a satisfactory experience in solving ecological problems, which could be useful in ITER program. (author)

  7. High-temperature annealing of proton irradiated beryllium - A dilatometry-based study

    Science.gov (United States)

    Simos, Nikolaos; Elbakhshwan, Mohamed; Zhong, Zhong; Ghose, Sanjit; Savkliyildiz, Ilyas

    2016-08-01

    Ssbnd 200 F grade beryllium has been irradiated with 160 MeV protons up to 1.2 1020 cm-2 peak fluence and irradiation temperatures in the range of 100-200 °C. To address the effect of proton irradiation on dimensional stability, an important parameter in its consideration in fusion reactor applications, and to simulate high temperature irradiation conditions, multi-stage annealing using high precision dilatometry to temperatures up to 740 °C were conducted in air. X-ray diffraction studies were also performed to compliment the macroscopic thermal study and offer a microscopic view of the irradiation effects on the crystal lattice. The primary objective was to qualify the competing dimensional change processes occurring at elevated temperatures namely manufacturing defect annealing, lattice parameter recovery, transmutation 4He and 3H diffusion and swelling and oxidation kinetics. Further, quantification of the effect of irradiation dose and annealing temperature and duration on dimensional changes is sought. The study revealed the presence of manufacturing porosity in the beryllium grade, the oxidation acceleration effect of irradiation including the discontinuous character of oxidation advancement, the effect of annealing duration on the recovery of lattice parameters recovery and the triggering temperature for transmutation gas diffusion leading to swelling.

  8. Iron-based amorphous alloys and methods of synthesizing iron-based amorphous alloys

    Science.gov (United States)

    Saw, Cheng Kiong; Bauer, William A.; Choi, Jor-Shan; Day, Dan; Farmer, Joseph C.

    2016-05-03

    A method according to one embodiment includes combining an amorphous iron-based alloy and at least one metal selected from a group consisting of molybdenum, chromium, tungsten, boron, gadolinium, nickel phosphorous, yttrium, and alloys thereof to form a mixture, wherein the at least one metal is present in the mixture from about 5 atomic percent (at %) to about 55 at %; and ball milling the mixture at least until an amorphous alloy of the iron-based alloy and the at least one metal is formed. Several amorphous iron-based metal alloys are also presented, including corrosion-resistant amorphous iron-based metal alloys and radiation-shielding amorphous iron-based metal alloys.

  9. Shape memory alloy based motor

    Indian Academy of Sciences (India)

    S V Sharma; M M Nayak; N S Dinesh

    2008-10-01

    Design and characterization of a new shape memory alloy wire based Poly Phase Motor has been reported in this paper. The motor can be used either in stepping mode or in servo mode of operation. Each phase of the motor consists of an SMA wire with a spring in series. The principle of operation of the poly phase motor is presented. The motor resembles a stepper motor in its functioning though the actuation principles are different and hence has been characterized similar to a stepper motor. The motor can be actuated in either direction with different phase sequencing methods, which are presented in this work. The motor is modelled and simulated and the results of simulations and experiments are presented. The experimental model of the motor is of dimension 150 mm square, 20 mm thick and uses SMA wire of 0·4 mm diameter and 125 mm of length in each phase.

  10. Investigations of the ternary system beryllium-carbon-tungsten and analyses of beryllium on carbon surfaces; Untersuchung des ternaeren Systems Beryllium-Kohlenstoff-Wolfram und Betrachtungen von Beryllium auf Kohlenstoffoberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Kost, Florian

    2009-05-25

    . Depending on the layer sequence, carbide formation is complete in the temperature range between 570 and 770 K. Be{sub 2}W alloy formation only takes place if further metallic beryllium is available after carbide formation. Be{sub 2}C and Be{sub 2}W dissociate at temperatures T>1170 K. Based on RBS analysis of C/Be/W systems of several 100 nm thickness, the concentration dependent diffusion coefficient for Be in W was determined. Only Be{sub 12}W formation was observed due to the large beryllium reservoir. Carbide formation (Be{sub 2}C) is not observed until the alloy formation is completed. Furthermore, the first successful depth-resolved XPS measurements were performed on ternary layer systems using synchrotron radiation. The reactions in the ternary system are restricted to compounds that are already known from binary system investigations. No further Be, C, W-containing species are detected. Beryllium carbide is dominant in the system as long as it does not dissociate. (orig.)

  11. An industrial risk: Beryllium

    Directory of Open Access Journals (Sweden)

    Emrah Çaylak

    2012-03-01

    Full Text Available Beryllium is a vocational disease factor and berylliumexposure can potentially lead to Chronic Beryllium Disease(CBD in 2-6 % of workers. While acute lymphocyticpneumonia occurred in individuals who were exposedto high doses of beryllium, low dose exposure to berylliumfollowed by a long subclinical period can cause CBDcharacterized with chronic granulomatosis. It has beenobserved that varying amounts of beryllium exposureare necessary to produce symptoms of CBD or berylliumsensitization (BeS. Genetic differences between patientsmay be the underlying cause of these dose-effects andfurther study of the differences in patients exposed to berylliummay lead to earlier diagnosis and the identificationof biomarkers of CBD. In this review, it is summarizedthe general properties of beryllium exposure, the immunopathogenesisand genetic differences of beryllium-induceddiseases, genotoxicity and the carcinogenic effectsof beryllium. J Clin Exp Invest 2012; 3(1: 141-148

  12. F-Alloy: An Alloy Based Model Transformation Language

    OpenAIRE

    Gammaitoni, Loïc; Kelsen, Pierre

    2015-01-01

    Model transformations are one of the core artifacts of a model-driven engineering approach. The relational logic language Alloy has been used in the past to verify properties of model transformations. In this paper we introduce the concept of functional Alloy modules. In essence a functional Alloy module can be viewed as an Alloy module representing a model transformation. We describe a sublanguage of Alloy called F-Alloy that allows the specification of functional Alloy modules. Module...

  13. Cloud-point formation based on mixed micelles for the extraction, preconcentration and spectrophotometric determination of trace amounts of beryllium in water samples.

    Science.gov (United States)

    Beiraghi, Asadollah; Zarei, Ali Reza; Babaee, Saeed

    2007-05-01

    A cloud-point extraction process using a mixed micelle of the cationic surfactant cetyl pyridinium chloride (CPC) and non-ionic surfactant Triton X-114 to extract beryllium from aqueous solutions was investigated. The method is based on the color reaction of beryllium with Chrome Azurol S (CAS) in acetate buffer and the mixed micelle-mediated extraction of the complex. This complex was concentrated in a surfactant-rich phase after separation. The optimal extraction and reaction conditions (e.g. pH, reagent and surfactant concentrations, temperature, incubation and centrifuge times) were evaluated and optimized. Under the optimized conditions, the analytical characteristics of the method (e.g. limit of detection, linear range and preconcentration factor) were obtained. Linearity was obeyed in the range of 0.30 - 18 ng mL(-1) of beryllium and the detection limit of the method was 0.05 ng mL(-1). The interference effect of some cations and anions was also studied. The proposed method was successfully applied to the determination of beryllium in real water samples.

  14. Characteristics of beryllium exposure to small particles at a beryllium production facility.

    Science.gov (United States)

    Virji, M Abbas; Stefaniak, Aleksandr B; Day, Gregory A; Stanton, Marcia L; Kent, Michael S; Kreiss, Kathleen; Schuler, Christine R

    2011-01-01

    Epidemiological studies have reported process-specific elevated prevalence of beryllium sensitization (BeS) and chronic beryllium disease (CBD) among workers. However, exposure-response relationships have been inconsistent, possibly due to incomplete characterization of many biologically relevant aspects of exposure, including particle size. In 1999, two surveys were conducted 3-5 months apart at a beryllium metal, oxide, and alloy production facility during which personal impactor samples (n = 198) and personal 37-mm closed-face cassette (CFC) 'total' samples (n = 4026) were collected. Among process areas, median particle mass median aerodynamic diameter ranged from 5 to 14 μm. A large fraction of the beryllium aerosol was in the nonrespirable size range. Respirable beryllium concentrations were among the highest for oxide production [geometric mean (GM) = 2.02 μg m⁻³, geometric standard deviation (GSD) = 1.3] and pebbles plant (GM = 1.05 μg m⁻³, GSD = 2.9), areas historically associated with high risk of BeS and CBD. The relationship between GM 'CFC total' and GM respirable beryllium for jobs varied by process areas; the rank order of the jobs showed high overall consistency (Spearman r = 0.84), but the overall correlation was moderate (Pearson r = 0.43). Total beryllium concentrations varied greatly within and between workers among process areas; within-worker variance was larger than between-worker variance for most processes. A review of exposure characteristics among process areas revealed variation in chemical forms and solubility. Process areas with high risk of BeS and CBD had exposure to both soluble and insoluble forms of beryllium. Consideration of biologically relevant aspects of exposure such as beryllium particle size distribution, chemical form, and solubility will likely improve exposure assessment.

  15. (Beryllium). Internal Report No. 137, Jan. 15, 1958; Le beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, P.; Rigaud, A

    1959-07-01

    After a brief summary of the physical and chemical properties of beryllium, the various chemical treatments which can be applied to beryllium minerals either directly or after a physical enrichment are discussed. These various treatments give either the hydroxide or beryllium salts, from which either beryllium oxide or metallic beryllium can easily be obtained. The purification, analysis and uses of beryllium are also briefly discussed. (author)

  16. Corrosion of dental copper, nickel, and gold alloys in artificial saliva and saline solutions.

    Science.gov (United States)

    Johansson, B I; Lemons, J E; Hao, S Q

    1989-09-01

    The purpose of this investigation was to study the tarnish and corrosion of three commercial copper alloys, three experimental copper alloys, two nickel alloys, and one high-gold alloy by exposing the specimens for four weeks to artificial saliva and saline solutions. Half of the specimens were brushed, and the solutions were changed regularly. The copper-based and the beryllium-containing nickel alloys exhibited significant surface alterations after exposure to either solution. The potential of elevated release of ions to the oral cavity and to the target organs by some of the investigated alloys should be considered if dental usage of these alloys is to be extended.

  17. Exposure-response analysis for beryllium sensitization and chronic beryllium disease among workers in a beryllium metal machining plant.

    Science.gov (United States)

    Madl, Amy K; Unice, Ken; Brown, Jay L; Kolanz, Marc E; Kent, Michael S

    2007-06-01

    The current occupational exposure limit (OEL) for beryllium has been in place for more than 50 years and was believed to be protective against chronic beryllium disease (CBD) until studies in the 1990s identified beryllium sensitization (BeS) and subclinical CBD in the absence of physical symptoms. Inconsistent sampling and exposure assessment methodologies have often prevented the characterization of a clear exposure-response relationship for BeS and CBD. Industrial hygiene (3831 personal lapel and 616 general area samples) and health surveillance data from a beryllium machining facility provided an opportunity to reconstruct worker exposures prior to the ascertainment of BeS or the diagnosis of CBD. Airborne beryllium concentrations for different job titles were evaluated, historical trends of beryllium levels were compared for pre- and postengineering control measures, and mean and upper bound exposure estimates were developed for workers identified as beryllium sensitized or diagnosed with subclinical or clinical CBD. Five approaches were used to reconstruct historical exposures of each worker: industrial hygiene data were pooled by year, job title, era of engineering controls, and the complete work history (lifetime weighted average) prior to diagnosis. Results showed that exposure metrics based on shorter averaging times (i.e., year vs. complete work history) better represented the upper bound worker exposures that could have contributed to the development of BeS or CBD. Results showed that beryllium-sensitized and CBD workers were exposed to beryllium concentrations greater than 0.2 microg/m3 (95th percentile), and 90% were exposed to concentrations greater than 0.4 microg/m3 (95th percentile) within a given year of their work history. Based on this analysis, BeS and CBD generally occurred as a result of exposures greater than 0.4 microg/m3 and maintaining exposures below 0.2 microg/m3 95% of the time may prevent BeS and CBD in the workplace.

  18. Release of beryllium into artificial airway epithelial lining fluid.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Virji, M Abbas; Day, Gregory A

    2012-01-01

    Inhaled beryllium particles that deposit in the lung airway lining fluid may dissolve and interact with immune-competent cells resulting in sensitization. As such, solubilization of 17 beryllium-containing materials (ore, hydroxide, metal, oxide, alloys, and process intermediates) was investigated using artificial human airway epithelial lining fluid. The maximum beryllium release in 7 days was 11.78% (from a beryl ore melter dust), although release from most materials was beryllium ions may be released in the respiratory tract via dissolution in airway lining fluid. Beryllium-containing particles that deposit in the respiratory tract dissolve in artificial lung epithelial lining fluid, thereby providing ions for absorption in the lung and interaction with immune-competent cells in the respiratory tract.

  19. Beryllium Desorption from Sediments

    Science.gov (United States)

    Boschi, V.; Willenbring, J. K.

    2015-12-01

    Beryllium isotopes have provided a useful tool in the field of geochronology and geomorphology over the last 25 years. The amount of cosmogenic meteoric 10Be and native 9Be absorbed to soils often scales with the residence time and chemical weathering of sediments in a landscape, respectively. Thus, the concentrations in river sediment may be used to quantify the denudation of specific watersheds. When deposited in ocean sediment, these concentrations are thought to record the history of denudation on Earth over the last ~10 Ma. The use of both isotopes often relies on the premise of beryllium retention to sediment surfaces in order to preserve a landscape's erosion and weathering signature. Changes in setting, en route from the soil to fluvial system to the ocean, can cause beryllium desorption and may preclude some applications of the 10Be/9Be system. Four mechanisms were tested to determine the desorption potential of beryllium including a reduction in pH, an increase in ionic strength and complexation with soluble organic and inorganic species. These processes have the potential to mobilize beryllium into solution. For example, by both reducing the pH and increasing the ionic strength, competition for adsorption sites increases, potentially liberating beryllium from the sediment surface. In addition, organic and inorganic ligands can complex beryllium causing it to become mobilized. To determine which of these alterations influence beryllium desorption and to quantify the effect, we prepared separate solutions of beryllium bound to minerals and organic compounds and measured beryllium concentrations in solution before and after adjusting the pH, ionic strength, and changing inorganic and organic ligand concentrations. We conclude from our observations that overall, beryllium sorbed to organic compounds was more resistant to desorption relative to mineral-associated beryllium. Among the methods tested, a reduction in pH resulted in the greatest amount of

  20. Microstructure and property characterization of a modified zinc-base alloy and comparison with bearing alloys

    Science.gov (United States)

    Prasad, B. K.; Patwardhan, A. K.; Yegneswaran, A. H.

    1998-02-01

    The microstructure and physical, mechanical, and tribological properties of a modified zinc-base alloy have been characterized. In order to assess its utility as a bearing alloy, its properties have also been compared with those of a similarly processed conventional zinc-base alloy and a leaded-tin bronze (conforming to ZA27 and SAE 660 specifications, respectively) used for bearing applications. The modified zinc-base alloy shows promise in terms of better elevated-temperature strength and wear response at higher sliding speeds relative to the conventional zinc-base alloy. Interestingly, the wear behavior (especially the seizure pressure) of the modified alloy was also comparable to that of the bronze specimens at the maximum sliding speed, and was superior at the minimum sliding speed. The modified alloy also attained lower density and better hardness. Alloy behavior has been linked to the nature and type of the alloy microconstituents.

  1. 镍铬铍合金烤瓷冠修复中铍离子对口腔常见细菌及牙周组织的影响%Inhibitory Effect of Beryllium Ions on Oral Subgingival Bacterias under Nickel-Chromium-Beryllium Alloy Porcelain Crown Repair and the Effect on Periodontal Tissues

    Institute of Scientific and Technical Information of China (English)

    贺会平; 杨甜甜; 刘欣

    2016-01-01

    Objective] To investigate the inhibitory effect of beryllium ions on the growth of two oral subgingival bacterias under nickel‐chromium‐beryllium alloy porcelain crown repair and the post‐repair effect on periodontal tissues .[Methods] This study was divided into two parts :(1) The in vitro trials were divided into three groups ,the experimental group (containing beryllium ion in artificial saliva 0 .5ml + oral Streptococcus suspension liquid / Porphyromonasgingivalis suspension liquid 0 .5mL) ,the positive group (artificial saliva 0 .5mL + oral streptococci suspension liquid / Porphy‐romonasgingivalis suspension liquid 0 .5mL) and the negative group (artificial saliva 0 .5mL + BHI medium 0 .5 mL) ,and oral streptococci experimentally cultured for 24h ,Porphyromonasgingivalis cultured for 48h .(2) 20 cases of patients un‐dergoing nickel chromium alloy porcelain crowns were selected and measured before restoration ,the levels of gingival sul‐cus fluid (GCF) ,aspartate aminotransferase (GCF‐AST) and alkaline phosphatase (GCF‐ALP) activity were measured respectively 3 months before and after the repair .[Results] In the experimental group ,six beryllium ion concentrations (1 .25 ,2 .5 ,5 ,10 ,20 ,40 ppm) of oral streptococci suspension ,Porphyromonasgingivalis bacteria colony counts were significantly lower than positive group ( P 0 .05) .[Conclusion] In the nickel chromium beryllium alloy ,be‐ryllium ion has a certain inhibitory effect on the growth of Streptococcus mutans suspension and Porphyromonas gingival‐is .Nickel chromium beryllium alloy porcelain crown has little effect on the periodontal tissue .%【目的】探讨镍铬铍合金烤瓷冠修复中铍离子对口腔两种龈下细菌生长的影响及修复后对患者牙周组织的影响。【方法】本研究分为两个部分:①体外实验分为三组,实验组(含有铍离子的人工唾液0.5 mL +口腔链球菌悬液/牙龈卟啉单胞菌悬液0.5 m

  2. Recommended design correlations for S-65 beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Billone, M.C. [Argonne National Lab., IL (United States)

    1995-09-01

    The properties of tritium and helium behavior in irradiated beryllium are reviewed, along with the thermal-mechanical properties needed for ITER design analysis. Correlations are developed to describe the performance of beryllium in a fusion reactor environment. While this paper focuses on the use of beryllium as a plasma-facing component (PFC) material, the correlations presented here can also be used to describe the performance of beryllium as a neutron multiplier for a tritium breeding blanket. The performance properties for beryllium are subdivided into two categories: properties which do not change with irradiation damage to the bulk of the material; and properties which are degraded by neutron irradiation. The irradiation-independent properties described within are: thermal conductivity, specific heat capacity, thermal expansion, and elastic constants. Irradiation-dependent properties include: yield strength, ultimate tensile strength, plastic tangent modulus, uniform and total tensile elongation, thermal and irradiation-induced creep strength, He-induced swelling and tritium retention/release. The approach taken in developing properties correlations is to describe the behavior of dense, pressed S-65 beryllium -- the material chosen for ITER PFC application -- as a function of temperature. As there are essentially no data on the performance of porous and/or irradiated S-65 beryllium, the degradation of properties with as-fabricated porosity and irradiation are determined from the broad data base on S-200F, as well as other types and grades, and applied to S-65 beryllium by scaling factors. The resulting correlations can be used for Be produced by vacuum hot pressing (VHP) and cold-pressing (CP)/sintering(S)/hot-isostatic-pressing (HIP). The performance of plasma-sprayed beryllium is discussed but not quantified.

  3. Dissolution of beryllium in artificial lung alveolar macrophage phagolysosomal fluid.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Virji, M Abbas; Day, Gregory A

    2011-05-01

    Dissolution of a lung burden of poorly soluble beryllium particles is hypothesized to be necessary for development of chronic beryllium lung disease (CBD) in humans. As such, particle dissolution rate must be sufficient to activate the lung immune response and dissolution lifetime sufficient to maintain chronic inflammation for months to years to support development of disease. The purpose of this research was to investigate the hypothesis that poorly soluble beryllium compounds release ions via dissolution in lung fluid. Dissolution kinetics of 17 poorly soluble particulate beryllium materials that span extraction through ceramics machining (ores, hydroxide, metal, copper-beryllium [CuBe] fume, oxides) and three CuBe alloy reference materials (chips, solid block) were measured over 31 d using artificial lung alveolar macrophage phagolysosomal fluid (pH 4.5). Differences in beryllium-containing particle physicochemical properties translated into differences in dissolution rates and lifetimes in artificial phagolysosomal fluid. Among all materials, dissolution rate constant values ranged from 10(-5) to 10(-10)gcm(-2)d(-1) and half-times ranged from tens to thousands of days. The presence of magnesium trisilicate in some beryllium oxide materials may have slowed dissolution rates. Materials associated with elevated prevalence of CBD had faster beryllium dissolution rates [10(-7)-10(-8)gcm(-2)d(-1)] than materials not associated with elevated prevalence (p<0.05).

  4. Chronic Beryllium Disease Prevention Program Report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S

    2012-03-29

    This document describes how Lawrence Livermore National Laboratory (LLNL) meets the requirements and management practices of federal regulation 10 CFR 850, 'Chronic Beryllium Disease Prevention Program (CBDPP).' This revision of the LLNL CBDPP incorporates clarification and editorial changes based on lessons learned from employee discussions, observations and reviews of Department of Energy (DOE) Complex and commercial industry beryllium (Be) safety programs. The information is used to strengthen beryllium safety practices at LLNL, particularly in the areas of: (1) Management of small parts and components; and (2) Communication of program status to employees. Future changes to LLNL beryllium activities and on-going operating experience will be incorporated into the program as described in Section S, 'Performance Feedback.'

  5. Characteristics of beryllium bonds; a QTAIM study.

    Science.gov (United States)

    Eskandari, K

    2012-08-01

    The nature of beryllium bonds formed between BeX2 (X is H, F and Cl) and some Lewis bases have been investigated. The distribution of the Laplacian of electron density shows that there is a region of charge depletion around the Be atom, which, according to Laplacian complementary principal, can interact with a region of charge concentration of an atom in the base and form a beryllium bond. The molecular graphs of the investigated complexes indicate that beryllium in BeH2 and BeF2 can form “beryllium bonds” with O, N and P atoms but not with halogens. In addition, eight criteria based on QTAIM properties, including the values of electron density and its Laplacian at the BCP, penetration of beryllium and acceptor atom, charge, energy, volume and first atomic moment of beryllium atom, have been considered and compared with the corresponding ones in conventional hydrogen bonds. These bonds share many common features with very strong hydrogen bonds, however,some differences have also been observed.

  6. 21 CFR 872.3710 - Base metal alloy.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Base metal alloy. 872.3710 Section 872.3710 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3710 Base metal alloy. (a) Identification. A base metal alloy is a device composed primarily of base metals, such as nickel, chromium, or cobalt, that...

  7. Irradiation creep of vanadium-base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, H.; Billone, M.C.; Strain, R.V.; Smith, D.L. [Argonne National Lab., IL (United States); Matsui, H. [Tohoku Univ. (Japan)

    1998-03-01

    A study of irradiation creep in vanadium-base alloys is underway with experiments in the Advanced Test Reactor (ATR) and the High Flux Isotope Reactor (HFIR) in the United States. Test specimens are thin-wall sealed tubes with internal pressure loading. The results from the initial ATR irradiation at low temperature (200--300 C) to a neutron damage level of 4.7 dpa show creep rates ranging from {approx}0 to 1.2 {times} 10{sup {minus}5}/dpa/MPa for a 500-kg heat of V-4Cr-4Ti alloy. These rates were generally lower than reported from a previous experiment in BR-10. Because both the attained neutron damage levels and the creep strains were low in the present study, however, these creep rates should be regarded as only preliminary. Substantially more testing is required before a data base on irradiation creep of vanadium alloys can be developed and used with confidence.

  8. The interaction of beryllium with benzene and graphene: a comparative investigation based on DFT, MP2, CCSD(T), CAS-SCF and CAS-PT2.

    Science.gov (United States)

    Fernandez, Nicolas; Ferro, Yves; Carissan, Yannick; Marchois, Julien; Allouche, Alain

    2014-02-07

    The interaction of beryllium with benzene, graphene and graphitic compounds involves multi-reference electronic states, Jahn-Teller distortion, charge transfer and van der Waals interactions. This is investigated herein using periodic and molecular models at different levels of theory: (i) the second-order Møller-Plesset (MP2) perturbation theory, (ii) the coupled cluster method with inclusion of single double and perturbative triple excitations (CCSD(T)), (iii) the complete active space self-consistent field (CAS-SCF) and (iv) the complete active space with perturbation theory truncated at the 2nd order (CAS-PT2). Molecular and periodic Density Functional Theory (DFT) methods are also used. The two major failures of DFT are addressed with regard to the beryllium benzene and graphene interaction: the degeneracy problem is the source of no specific problem while the delocalization error causes DFT with the Perdew Burke, Ernzerhof functional plus the Grimme correction (DFT/PBE-D2) to be over-binding by about 0.4 eV at a short-range. The agreement between DFT/PBE-D2 and wave-function based methods is nevertheless good; DFT/PBE-D2 provides an accurate description of the electronic structure of the system. By the end of this work, we shall get a better insight into the mechanisms leading beryllium to physisorb on graphene and to chemisorb into the bilayer of graphite.

  9. Cooperativity in beryllium bonds.

    Science.gov (United States)

    Alkorta, Ibon; Elguero, José; Yáñez, Manuel; Mó, Otilia

    2014-03-07

    A theoretical study of the beryllium bonded clusters of the (iminomethyl)beryllium hydride and (iminomethyl)beryllium fluoride [HC(BeX)=NH, X = H, F] molecules has been carried out at the B3LYP/6-311++G(3df,2p) level of theory. Linear and cyclic clusters have been characterized up to the decamer. The geometric, energetic, electronic and NMR properties of the clusters clearly indicate positive cooperativity. The evolution of the molecular properties, as the size of the cluster increases, is similar to those reported in polymers held together by hydrogen bonds.

  10. Beryllium concentration in pharyngeal tonsils in children.

    Science.gov (United States)

    Nogaj, Ewa; Kwapulinski, Jerzy; Misiołek, Maciej; Golusiński, Wojciech; Kowol, Jolanta; Wiechuła, Danuta

    2014-01-01

    Power plant dust is believed to be the main source of the increased presence of the element beryllium in the environment which has been detected in the atmospheric air, surface waters, groundwater, soil, food, and cigarette smoke. In humans, beryllium absorption occurs mainly via the respiratory system. The pharyngeal tonsils are located on the roof of the nasopharynx and are in direct contact with dust particles in inhaled air. As a result, the concentration levels of beryllium in the pharyngeal tonsils are likely to be a good indicator of concentration levels in the air. The presented study had two primary aims: to investigate the beryllium concentration in pharyngeal tonsils in children living in southern Poland, and the appropriate reference range for this element in children's pharyngeal tonsils. Pharyngeal tonsils were extracted from a total of 379 children (age 2-17 years, mean 6.2 ± 2.7 years) living in southern Poland. Tonsil samples were mineralized in a closed cycle in a pressure mineralizer PDS 6, using 65% spectrally pure nitric acid. Beryllium concentration was determined using the ICP-AES method with a Perkin Elmer Optima 5300DVTM. The software Statistica v. 9 was used for the statistical analysis. It was found that girls had a significantly greater beryllium concentration in their pharyngeal tonsils than boys. Beryllium concentration varies greatly, mostly according to the place of residence. Based on the study results, the reference value for beryllium in pharyngeal tonsils of children is recommended to be determined at 0.02-0.04 µg/g.

  11. Beryllium concentration in pharyngeal tonsils in children

    Directory of Open Access Journals (Sweden)

    Ewa Nogaj

    2014-06-01

    Full Text Available Power plant dust is believed to be the main source of the increased presence of the element beryllium in the environment which has been detected in the atmospheric air, surface waters, groundwater, soil, food, and cigarette smoke. In humans, beryllium absorption occurs mainly via the respiratory system. The pharyngeal tonsils are located on the roof of the nasopharynx and are in direct contact with dust particles in inhaled air. As a result, the concentration levels of beryllium in the pharyngeal tonsils are likely to be a good indicator of concentration levels in the air. The presented study had two primary aims: to investigate the beryllium concentration in pharyngeal tonsils in children living in southern Poland, and the appropriate reference range for this element in children’s pharyngeal tonsils. Pharyngeal tonsils were extracted from a total of 379 children (age 2–17 years, mean 6.2 ± 2.7 years living in southern Poland. Tonsil samples were mineralized in a closed cycle in a pressure mineralizer PDS 6, using 65% spectrally pure nitric acid. Beryllium concentration was determined using the ICP-AES method with a Perkin Elmer Optima 5300DVTM. The software Statistica v. 9 was used for the statistical analysis. It was found that girls had a significantly greater beryllium concentration in their pharyngeal tonsils than boys. Beryllium concentration varies greatly, mostly according to the place of residence. Based on the study results, the reference value for beryllium in pharyngeal tonsils of children is recommended to be determined at 0.02–0.04 µg/g.

  12. Mechanisms of hydrogen retention in metallic beryllium and beryllium oxide and properties of ion-induced beryllium nitride; Rueckhaltemechanismen fuer Wasserstoff in metallischem Beryllium und Berylliumoxid sowie Eigenschaften von ioneninduziertem Berylliumnitrid

    Energy Technology Data Exchange (ETDEWEB)

    Oberkofler, Martin

    2011-09-22

    In the framework of this thesis laboratory experiments on atomically clean beryllium surfaces were performed. They aim at a basic understanding of the mechanisms occurring upon interaction of a fusion plasma with a beryllium first wall. The retention and the temperature dependent release of implanted deuterium ions are investigated. An atomistic description is developed through simulations and through the comparison with calculations based on density functional theory. The results of these investigations are compared to the behaviour of hydrogen upon implantation into thermally grown beryllium oxide layers. Furthermore, beryllium nitride is produced by implantation of nitrogen into metallic beryllium and its properties are investigated. The results are interpreted with regard to the use of beryllium in a fusion reactor. (orig.)

  13. Beryllium Manufacturing Processes

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, A

    2006-06-30

    This report is one of a number of reports that will be combined into a handbook on beryllium. Each report covers a specific topic. To-date, the following reports have been published: (1) Consolidation and Grades of Beryllium; (2) Mechanical Properties of Beryllium and the Factors Affecting these Properties; (3) Corrosion and Corrosion Protection of Beryllium; (4) Joining of Beryllium; (5) Atomic, Crystal, Elastic, Thermal, Nuclear, and other Properties of Beryllium; and (6) Beryllium Coating (Deposition) Processes and the Influence of Processing Parameters on Properties and Microstructure. The conventional method of using ingot-cast material is unsuitable for manufacturing a beryllium product. Beryllium is a highly reactive metal with a high melting point, making it susceptible to react with mold-wall materials forming beryllium compounds (BeO, etc.) that become entrapped in the solidified metal. In addition, the grain size is excessively large, being 50 to 100 {micro}m in diameter, while grain sizes of 15 {micro}m or less are required to meet acceptable strength and ductility requirements. Attempts at refining the as-cast-grain size have been unsuccessful. Because of the large grain size and limited slip systems, the casting will invariably crack during a hot-working step, which is an important step in the microstructural-refining process. The high reactivity of beryllium together with its high viscosity (even with substantial superheat) also makes it an unsuitable candidate for precision casting. In order to overcome these problems, alternative methods have been developed for the manufacturing of beryllium. The vast majority of these methods involve the use of beryllium powders. The powders are consolidated under pressure in vacuum at an elevated temperature to produce vacuum hot-pressed (VHP) blocks and vacuum hot-isostatic-pressed (HIP) forms and billets. The blocks (typically cylindrical), which are produced over a wide range of sizes (up to 183 cm dia. by 61

  14. An Alternate to Cobalt-Base Hardfacing Alloys

    Science.gov (United States)

    Hickl, Anthony J.

    1980-03-01

    The price of cobalt has risen dramatically in the last few years, and supply has often been uncertain. The most popular hardfacing alloys contain substantial amounts of cobalt, and have thus been especially affected by these factors. The present study has developed a new hardfacing alloy, HAYNES Alloy No. 716, with lower cobalt content, to replace the most popular alloy, HAYNES STELLITE Alloy No. 6 which is cobalt based. The alloy design which led to the development of the new alloy is discussed, and properties are compared with Alloy No. 6. Hardness at room temperature and elevated temperatures, weldability, and corrosion and abrasion resistance of the new alloy compare favorably with Alloy No. 6.

  15. Functionally Graded Nanophase Beryllium/Carbon Composites

    Science.gov (United States)

    Choi, Michael K.

    2003-01-01

    Beryllium, beryllium alloys, beryllium carbide, and carbon are the ingredients of a class of nanophase Be/Be2C/C composite materials that can be formulated and functionally graded to suit a variety of applications. In a typical case, such a composite consists of a first layer of either pure beryllium or a beryllium alloy, a second layer of B2C, and a third layer of nanophase sintered carbon derived from fullerenes and nanotubes. The three layers are interconnected through interpenetrating spongelike structures. These Be/Be2C/C composite materials are similar to Co/WC/diamond functionally graded composite materials, except that (1) W and Co are replaced by Be and alloys thereof and (2) diamond is replaced by sintered carbon derived from fullerenes and nanotubes. (Optionally, one could form a Be/Be2C/diamond composite.) Because Be is lighter than W and Co, the present Be/Be2C/C composites weigh less than do the corresponding Co/WC/diamond composites. The nanophase carbon is almost as hard as diamond. WC/Co is the toughest material. It is widely used for drilling, digging, and machining. However, the fact that W is a heavy element (that is, has high atomic mass and mass density) makes W unattractive for applications in which weight is a severe disadvantage. Be is the lightest tough element, but its toughness is less than that of WC/Co alloy. Be strengthened by nanophase carbon is much tougher than pure or alloy Be. The nanophase carbon has an unsurpassed strength-to-weight ratio. The Be/Be2C/C composite materials are especially attractive for terrestrial and aerospace applications in which there are requirements for light weight along with the high strength and toughness of the denser Co/WC/diamond materials. These materials could be incorporated into diverse components, including cutting tools, bearings, rocket nozzles, and shields. Moreover, because Be and C are effective as neutron moderators, Be/Be2C/C composites could be attractive for some nuclear applications.

  16. Microstructural evidence of presence of beryllium in Ni-Cr alloys for dental prostheses; Evidencia microestrutural da presenca de berilio em ligas Ni-Cr para proteses dentarias

    Energy Technology Data Exchange (ETDEWEB)

    Alkmin, L.B.; Nunes, C.A., E-mail: lba@ppgem.eel.usp.b [Universidade de Sao Paulo (EEL/USP), Lorena, SP (Brazil). Escola de Engenharia; Coelho, G.C. [Centro Universitario de Volta Redonda (UNIFOA), Volta Redonda, RJ (Brazil); Santos, C. [Protmat Materiais Avancados, Guaratingueta, SP (Brazil)

    2010-07-01

    This study aimed to characterize the microstructure of commercial Ni-Cr alloys for dental prosthesis, with special focus on those containing Be. For this, the materials were characterized in terms of chemical composition, phases and melting point temperature. The following techniques were used: X-ray fluorescence, ICP-OES, scanning electron microscopy, electron probe microanalysis, X-ray diffraction and differential thermal analysis. The results clearly showed the presence of a typical eutectic, formed by the Ni{sub ss} and NiBe phases in those alloys containing Be, which can be considered a 'fingerprint' of the presence of this element in these alloys. (author)

  17. Beryllium contamination and exposure monitoring in an inhalation laboratory setting.

    Science.gov (United States)

    Muller, Caroline; Audusseau, Séverine; Salehi, Fariba; Truchon, Ginette; Chevalier, Gaston; Mazer, Bruce; Kennedy, Greg; Zayed, Joseph

    2010-02-01

    Beryllium (Be) is used in several forms: pure metal, beryllium oxide, and as an alloy with copper, aluminum, or nickel. Beryllium oxide, beryllium metal, and beryllium alloys are the main forms present in the workplace, with inhalation being the primary route of exposure. Cases of workers with sensitization or chronic beryllium disease challenge the scientific community for a better understanding of Be toxicity. Therefore, a toxicological inhalation study using a murine model was performed in our laboratory in order to identify the toxic effects related to different particle sizes and chemical forms of Be. This article attempts to provide information regarding the relative effectiveness of the environmental monitoring and exposure protection program that was enacted to protect staff (students and researchers) in this controlled animal beryllium inhalation exposure experiment. This includes specific attention to particle migration control through intensive housekeeping and systematic airborne and surface monitoring. Results show that the protective measures applied during this research have been effective. The highest airborne Be concentration in the laboratory was less than one-tenth of the Quebec OEL (occupational exposure limit) of 0.15 microg/m(3). Considering the protection factor of 10(3) of the powered air-purifying respirator used in this research, the average exposure level would be 0.03 x 10(- 4) microg/m(3), which is extremely low. Moreover, with the exception of one value, all average Be concentrations on surfaces were below the Quebec Standard guideline level of 3 microg/100 cm(2) for Be contamination. Finally, all beryllium lymphocyte proliferation tests for the staff were not higher than controls.

  18. Hot Corrosion of Cobalt-Base Alloys

    Science.gov (United States)

    1975-06-01

    scale is similar to that which has already been proposed for cobalt . The oxide ions would react with the Al203 to form aluminate ions in the Na2S04...resistance of cobalt -base and nickel-base alloys. The contract was accomplished under the technical direction of Dr. H. C. Graham of the Aerospace Research...Oxidized Specimens RESULTS AND DISCUSSION 1. INTRODUCfiON 2. SODIUM SULFATE INDUCED HOT CORROSION OF COBALT a. Introduction b. Experimental c

  19. Effects of alloying side B on Ti-based AB2 hydrogen storage alloys

    Institute of Scientific and Technical Information of China (English)

    王家淳; 于荣海; 刘庆

    2004-01-01

    Ti-based AB2-type hydrogen storage alloys are a group of promising materials, which will probably replace the prevalent rare earth-based AB5-type alloys and be adopted as the main cathode materials of nickelmetal hydride (Ni-MH) batteries in the near future. Alloying in side B is a major way to improve the performance of Ti-based AB2-type alloys. Based on recent studies, the effects of alloying elements in side B upon the performance of Ti-based AB2 -type hydrogen storage alloys are systematically reviewed here. These performances are divided into two categories, namely PCI characteristics, including hydrogen storage capacity (HSC), plateau pressure (PP), pressure hysteresis (PH) and pressure plateau sloping (PPS) , and electrochemical properties, including discharge capacity (DC), activation property (AP), cycling stability (CS) and high-rate dischargeability (HRD). Furthermore, the existing problems in these investigations and some suggestions for future research are proposed.

  20. Fabric cutting application of FeAl-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Blue, C.A. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Sklad, S.P. [Univ. of Virginia, Charlottesville, VA (United States); Deevi, S.C. [Philip Morris U.S.A., Richmond, VA (United States); Shih, H.R. [Jackson State Univ., MS (United States)

    1998-11-01

    Four intermetallic-based alloys were evaluated for cutting blade applications. These alloys included Fe{sub 3}Al-based (FAS-II and FA-129), FeAl-based (PM-60), and Ni{sub 3}Al-based (IC-50). These alloys were of interest because of their much higher work-hardening rates than the conventionally used carbon and stainless steels. The FeAl-based PM-60 alloy was of further interest because of its hardening possibility through retention of vacancies. The vacancy retention treatment is much simpler than the heat treatments used for hardening of steel blades. Blades of four intermetallic alloys and commercially used M2 tool steel blades were evaluated under identical conditions to cut two-ply heavy paper. Comparative results under identical conditions revealed that the FeAl-based alloy PM-60 outperformed the other intermetallic alloys and was equal to or somewhat better than the commercially used M2 tool steel.

  1. Discontinuous precipitation in copper base alloys

    Indian Academy of Sciences (India)

    K T Kashyap

    2009-08-01

    Discontinuous precipitation (DP) is associated with grain boundary migration in the wake of which alternate plates of the precipitate and the depleted matrix form. Some copper base alloys show DP while others do not. In this paper the misfit strain parameter, , has been calculated and predicted that if 100 > ± 0.1, DP is observed. This criterion points to diffusional coherency strain theory to be the operative mechanism for DP.

  2. Beryllium metal II. a review of the available toxicity data.

    Science.gov (United States)

    Strupp, Christian

    2011-01-01

    Beryllium metal was classified in Europe collectively with beryllium compounds, e.g. soluble salts. Toxicological equivalence was assumed despite greatly differing physicochemical properties. Following introduction of the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) regulation, beryllium metal was classified as individual substance and more investigational efforts to appropriately characterize beryllium metal as a specific substance apart from soluble beryllium compounds was required. A literature search on toxicity of beryllium metal was conducted, and the resulting literature compiled together with the results of a recently performed study package into a comprehensive data set. Testing performed under Organisation for Economic Co-Operation and Development guidelines and Good Laboratory Practice concluded that beryllium metal was neither a skin irritant, an eye irritant, a skin sensitizer nor evoked any clinical signs of acute oral toxicity; discrepancies between the current legal classification of beryllium metal in the European Union (EU) and the experimental results were identified. Furthermore, genotoxicity and carcinogenicity were discussed in the context of the literature data and the new experimental data. It was concluded that beryllium metal is unlikely to be a classical nonthreshold mutagen. Effects on DNA repair and morphological cell transformation were observed but need further investigation to evaluate their relevance in vivo. Animal carcinogenicity studies deliver evidence of carcinogenicity in the rat; however, lung overload may be a species-specific confounding factor in the existing studies, and studies in other species do not give convincing evidence of carcinogenicity. Epidemiology has been intensively discussed over the last years and has the problem that the studies base on the same US beryllium production population and do not distinguish between metal and soluble compounds. It is noted that the correlation

  3. New Developments of Ti-Based Alloys for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Yuhua Li

    2014-03-01

    Full Text Available Ti-based alloys are finding ever-increasing applications in biomaterials due to their excellent mechanical, physical and biological performance. Nowdays, low modulus β-type Ti-based alloys are still being developed. Meanwhile, porous Ti-based alloys are being developed as an alternative orthopedic implant material, as they can provide good biological fixation through bone tissue ingrowth into the porous network. This paper focuses on recent developments of biomedical Ti-based alloys. It can be divided into four main sections. The first section focuses on the fundamental requirements titanium biomaterial should fulfill and its market and application prospects. This section is followed by discussing basic phases, alloying elements and mechanical properties of low modulus β-type Ti-based alloys. Thermal treatment, grain size, texture and properties in Ti-based alloys and their limitations are dicussed in the third section. Finally, the fourth section reviews the influence of microstructural configurations on mechanical properties of porous Ti-based alloys and all known methods for fabricating porous Ti-based alloys. This section also reviews prospects and challenges of porous Ti-based alloys, emphasizing their current status, future opportunities and obstacles for expanded applications. Overall, efforts have been made to reveal the latest scenario of bulk and porous Ti-based materials for biomedical applications.

  4. Estimating occupational beryllium exposure from compliance monitoring data.

    Science.gov (United States)

    Hamm, Michele P; Burstyn, Igor

    2011-01-01

    Occupational exposure to beryllium is widespread and is a health risk. The objectives of this study were to develop plausible models to estimate occupational airborne beryllium exposure. Compliance monitoring data were obtained from the Occupational Safety and Health Administration for 12,148 personal measurements of beryllium exposure from 1979 to 2005. Industry codes were maintained as reported or collapsed based on the number of measurements per cell of a job-exposure matrix (JEM). Probability of exposure was predicted based on year, industry, job, and sampling duration. In these models, probability of exposure decreased over time, was highest in full-shift personal samples, and varied with industry and job. The probability of exposure was calculated using 6 JEMs, each providing similar rankings of the likelihood of non-negligible exposure to beryllium. These statistical models, with expert appraisal, are suitable for the assessment of the probability of elevated occupational exposure to beryllium.

  5. Neutronics Evaluation of Lithium-Based Ternary Alloys in IFE Blankets

    Energy Technology Data Exchange (ETDEWEB)

    Jolodosky, A. [Univ. of California, Berkeley, CA (United States); Fratoni, M. [Univ. of California, Berkeley, CA (United States)

    2015-09-22

    , low electrical conductivity and therefore low MHD pressure drop, low chemical reactivity, and extremely low tritium inventory; the addition of sodium (FLiNaBe) has been considered because it retains the properties of FliBe but also lowers the melting point. Although many of these blanket concepts are promising, challenges still remain. The limited amount of beryllium available poses a problem for ceramic breeders such as the HCPB. FLiBe and FLiNaBe are highly viscous and have a low thermal conductivity. Lithium lead possesses a poor thermal conductivity which can cause problems in both DCLL and LiPb blankets. Additionally, the tritium permeation from these two blankets into plant components can be a problem and must be reduced. Consequently, Lawrence Livermore National Laboratory (LLNL) is attempting to develop a lithium-based alloy—most likely a ternary alloy—which maintains the beneficial properties of lithium (e.g. high tritium breeding and solubility) while reducing overall flammability concerns for use in the blanket of an inertial fusion energy (IFE) power plant. The LLNL concept employs inertial confinement fusion (ICF) through the use of lasers aimed at an indirect-driven target composed of deuterium-tritium fuel. The fusion driver/target design implements the same physics currently experimented at the National Ignition Facility (NIF). The plant uses lithium in both the primary coolant and blanket; therefore, lithium-related hazards are of primary concern. Although reducing chemical reactivity is the primary motivation for the development of new lithium alloys, the successful candidates will have to guarantee acceptable performance in all their functions. The scope of this study is to evaluate the neutronics performance of a large number of lithium-based alloys in the blanket of the IFE engine and assess their properties upon activation. This manuscript is organized as follows: Section 12 presents the models and methodologies used for the analysis; Section

  6. Indentation toughness of Mo5Si3-based alloys

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The indentation toughness of Mo5Si3 -based phases was studied with regard to different alloying elements, amount of alloying addition as well as the presence of secondary phases. Cr, Ti, Nb, Ni and Co were added as alloying elements. The results show that the indentation fracture toughness of Mo5Si3 increases with the alloying additions, from 2.4 Mpa *m1/2 for mon olithic to just over 3 Mpa*m1/2 for highly alloyed Mo5Si3. Small volume fractions of brittle secondary phases may have a positive impact on the inde ntation toughness; while larger fractions seems to lower the toughness.

  7. Fracture toughness of copper-base alloys for ITER applications: A preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, D.J.; Zinkle, S.J.; Rowcliffe, A.F. [Oak Ridge National Lab., TN (United States)

    1997-04-01

    Oxide-dispersion strengthened copper alloys and a precipitation-hardened copper-nickel-beryllium alloy showed a significant reduction in toughness at elevated temperature (250{degrees}C). This decrease in toughness was much larger than would be expected from the relatively modest changes in the tensile properties over the same temperature range. However, a copper-chromium-zirconium alloy strengthened by precipitation showed only a small decrease in toughness at the higher temperatures. The embrittled alloys showed a transition in fracture mode, from transgranular microvoid coalescence at room temperature to intergranular with localized ductility at high temperatures. The Cu-Cr-Zr alloy maintained the ductile microvoid coalescence failure mode at all test temperatures.

  8. Physicochemical characteristics of aerosol particles generated during the milling of beryllium silicate ores: implications for risk assessment.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Chipera, Steve J; Day, Gregory A; Sabey, Phil; Dickerson, Robert M; Sbarra, Deborah C; Duling, Mathew G; Lawrence, Robert B; Stanton, Marcia L; Scripsick, Ronald C

    2008-01-01

    Inhalation of beryllium dusts generated during milling of ores and cutting of beryl-containing gemstones is associated with development of beryllium sensitization and low prevalence of chronic beryllium disease (CBD). Inhalation of beryllium aerosols generated during primary beryllium production and machining of the metal, alloys, and ceramics are associated with sensitization and high rates of CBD, despite similar airborne beryllium mass concentrations among these industries. Understanding the physicochemical properties of exposure aerosols may help to understand the differential immunopathologic mechanisms of sensitization and CBD and lead to more biologically relevant exposure standards. Properties of aerosols generated during the industrial milling of bertrandite and beryl ores were evaluated. Airborne beryllium mass concentrations among work areas ranged from 0.001 microg/m(3) (beryl ore grinding) to 2.1 microg/m(3) (beryl ore crushing). Respirable mass fractions of airborne beryllium-containing particles were 80% in high-energy input areas (beryl melting, beryl grinding). Particle specific surface area decreased with processing from feedstock ores to drumming final product beryllium hydroxide. Among work areas, beryllium was identified in three crystalline forms: beryl, poorly crystalline beryllium oxide, and beryllium hydroxide. In comparison to aerosols generated by high-CBD risk primary production processes, aerosol particles encountered during milling had similar mass concentrations, generally lower number concentrations and surface area, and contained no identifiable highly crystalline beryllium oxide. One possible explanation for the apparent low prevalence of CBD among workers exposed to beryllium mineral dusts may be that characteristics of the exposure material do not contribute to the development of lung burdens sufficient for progression from sensitization to CBD. In comparison to high-CBD risk exposures where the chemical nature of aerosol

  9. Behavior of beryllium pebbles under irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dalle-Donne, M.; Scaffidi-Argentina, F. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reactortechnik; Baldwin, D.L.; Gelles, D.S.; Greenwood, L.R.; Kawamura, H.; Oliver, B.M.

    1998-01-01

    Beryllium pebbles are being considered in fusion reactor blanket designs as neutron multiplier. An example is the European `Helium Cooled Pebble Bed Blanket.` Several forms of beryllium pebbles are commercially available but little is known about these forms in response to fast neutron irradiation. Commercially available beryllium pebbles have been irradiated to approximately 1.3 x 10{sup 22} n/cm{sup 2} (E>1 MeV) at 390degC. Pebbles 1-mm in diameter manufactured by Brush Wellman, USA and by Nippon Gaishi Company, Japan, and 3-mm pebbles manufactured by Brush Wellman were included. All were irradiated in the below-core area of the Experimental Breeder Reactor-II in Idaho Falls, USA, in molybdenum alloy capsules containing helium. Post-irradiation results are presented on density change measurements, tritium release by assay, stepped-temperature anneal, and thermal ramp desorption tests, and helium release by assay and stepped-temperature anneal measurements, for Be pebbles from two manufacturing methods, and with two specimen diameters. The experimental results on density change and tritium and helium release are compared with the predictions of the code ANFIBE. (author)

  10. Corrosion and wear protective composition modulated alloy coatings based on ternary Ni-P-X alloys

    DEFF Research Database (Denmark)

    Leisner, P.; Benzon, M. E.; Christoffersen, Lasse

    1996-01-01

    Scattered reporting in the litterature describes a number of ternary Ni-P-X alloyes (where X can be Co, Cr, Cu, Mo, Pd, Re or W) with promising corrosin and wear protective performance. Based on a systematic study of Ni-P-X alloys it is the intention to produce coatings with improved corrosion...

  11. Conceptual design of the beryllium rotating target for the ESS-Bilbao facility

    Energy Technology Data Exchange (ETDEWEB)

    Terrón, S., E-mail: santiago.terron@essbilbao.org [ESS-Bilbao, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja. 48160 Derio (Spain); Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Sordo, F.; Magán, M.; Ghiglino, A.; Martínez, F.; Vicente, P.J. de; Vivanco, R. [ESS-Bilbao, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja. 48160 Derio (Spain); Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Thomsen, K. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Perlado, J.M. [Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C José Gutiérrez Abascal, 2, 28006 Madrid (Spain); Bermejo, F.J. [Instituto de Estructura de la Materia, IEM-CSIC, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid (Spain); ESS-Bilbao, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja. 48160 Derio (Spain); Abánades, A. [Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C José Gutiérrez Abascal, 2, 28006 Madrid (Spain)

    2013-10-01

    The ESS-Bilbao facility, hosted by the University of the Basque Country (UPV/EHU), envisages the operation of a high-current proton accelerator delivering beams with energies up to 50 MeV. The time-averaged proton current will be 2.25 mA, delivered by 1.5 ms proton pulses with a repetition rate of 20 Hz. This beam will feed a neutron source based upon the Be (p,n) reaction, which will enable the provision of relevant neutron experimentation capabilities. The neutron source baseline concept consists in a rotating beryllium target cooled by water. The target structure will comprise a rotatable disk made of 6061-T6 aluminium alloy holding 20 beryllium plates. Heat dissipation from the target relies upon a distribution of coolant-flow channels. The practical implementation of such a concept is here described with emphasis put on the beryllium plates thermo-mechanical optimization, the chosen coolant distribution system as well as the mechanical behavior of the assembly. -- Highlights: • The conceptual design of ESS-Bilbao neutron production target has been carried out. • This device is a rotating disk holding Be elements cooled by water. • Thermo-mechanical and lifespan behavior of the Be elements have been analyzed. • Disk structure ensures coolability and a proper mechanical behavior of the assembly.

  12. 国内外铍及含铍材料的研究进展%Advances in beryllium and beryllium-containing materials

    Institute of Scientific and Technical Information of China (English)

    许德美; 秦高梧; 李峰; 王战宏; 钟景明; 何季麟; 何力军

    2014-01-01

    The research progress of beryllium and beryllium-containing materials was reviewed in the past two decades in the world, and much effort in this work was focused on beryllium metallurgy, beryllium alloys, beryllium oxide, beryllium matrix composites and intermetallics. The advances of beryllium materials in both research and production techniques in China were summarized, especially in technique gap as compared to that in the developed countries. Finally, the new beryllium materials and their key techniques conforming to the requirements of industry were proposed in the next one decade in China.%综述近20年来国外铍及含铍材料的研究进展,主要包括铍的冶金制备、铍合金、铍和氧化铍金属基复合材料、铍金属间化合物等。概括我国在铍材料方面取得的研究与生产技术进展,以及与国外研发水平的差距。并展望未来10年我国铍及含铍材料需要重点发展的新材料以及突破的关键技术。

  13. Reprocessing technology development for irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, H.; Sakamoto, N. [Oarai Research Establishment, Ibaraki-ken (Japan); Tatenuma, K. [KAKEN Co., Ibaraki-ken (Japan)] [and others

    1995-09-01

    At present, beryllium is under consideration as a main candidate material for neutron multiplier and plasma facing material in a fusion reactor. Therefore, it is necessary to develop the beryllium reprocessing technology for effective resource use. And, we have proposed reprocessing technology development on irradiated beryllium used in a fusion reactor. The preliminary reprocessing tests were performed using un-irradiated and irradiated beryllium. At first, we performed beryllium separation tests using un-irradiated beryllium specimens. Un-irradiated beryllium with beryllium oxide which is a main impurity and some other impurities were heat-treated under chlorine gas flow diluted with Ar gas. As the results high purity beryllium chloride was obtained in high yield. And it appeared that beryllium oxide and some other impurities were removed as the unreactive matter, and the other chloride impurities were separated by the difference of sublimation temperature on beryllium chloride. Next, we performed some kinds of beryllium purification tests from beryllium chloride. And, metallic beryllium could be recovered from beryllium chloride by the reduction with dry process. In addition, as the results of separation and purification tests using irradiated beryllium specimens, it appeared that separation efficiency of Co-60 from beryllium was above 96%. It is considered that about 4% Co-60 was carried from irradiated beryllium specimen in the form of cobalt chloride. And removal efficiency of tritium from irradiated beryllium was above 95%.

  14. Aerosols generated during beryllium machining.

    Science.gov (United States)

    Martyny, J W; Hoover, M D; Mroz, M M; Ellis, K; Maier, L A; Sheff, K L; Newman, L S

    2000-01-01

    Some beryllium processes, especially machining, are associated with an increased risk of beryllium sensitization and disease. Little is known about exposure characteristics contributing to risk, such as particle size. This study examined the characteristics of beryllium machining exposures under actual working conditions. Stationary samples, using eight-stage Lovelace Multijet Cascade Impactors, were taken at the process point of operation and at the closest point that the worker would routinely approach. Paired samples were collected at the operator's breathing zone by using a Marple Personal Cascade Impactor and a 35-mm closed-faced cassette. More than 50% of the beryllium machining particles in the breathing zone were less than 10 microns in aerodynamic diameter. This small particle size may result in beryllium deposition into the deepest portion of the lung and may explain elevated rates of sensitization among beryllium machinists.

  15. T cell recognition of beryllium.

    Science.gov (United States)

    Dai, Shaodong; Falta, Michael T; Bowerman, Natalie A; McKee, Amy S; Fontenot, Andrew P

    2013-12-01

    Chronic beryllium disease (CBD) is a granulomatous lung disorder caused by a hypersensitivity to beryllium and characterized by the accumulation of beryllium-specific CD4(+) T cells in the lung. Genetic susceptibility to beryllium-induced disease is strongly associated with HLA-DP alleles possessing a glutamic acid at the 69th position of the β-chain (βGlu69). The structure of HLA-DP2, the most prevalent βGlu69-containing molecule, revealed a unique solvent-exposed acidic pocket that includes βGlu69 and represents the putative beryllium-binding site. The delineation of mimotopes and endogenous self-peptides that complete the αβTCR ligand for beryllium-specific CD4(+) T cells suggests a unique role of these peptides in metal ion coordination and the generation of altered self-peptides, blurring the distinction between hypersensitivity and autoimmunity.

  16. Investigation on Crystallization Kinetics of Zr-AI-Based Bulk Amorphous Alloys

    Institute of Scientific and Technical Information of China (English)

    王国明; 李维火; 方守狮; 华勤; 肖学山

    2005-01-01

    Zr65Al10Ni10Cu15, Zr52.5Al10Ni10Cu15Be12.5 and Zr52.5Al10Ni14.6 Cu17.9Ti5bulk amorphous alloys were prepared by copper mould casting. The crystallization kinetics was measured by differential scanning calorimeter(DSC) with different heating rates, and the activation energy was calculated using Kissinger equation. The relationship between thermal stability and rate constant of crystallization reaction is discussed on the view of crystallization kinetics, and the effect of small atom Beryllium on thermal stability of bulk amorphous alloys is also studied.

  17. Cast iron-base alloy for cylinder/regenerator housing

    Science.gov (United States)

    Witter, Stewart L.; Simmons, Harold E.; Woulds, Michael J.

    1985-01-01

    NASACC-1 is a castable iron-base alloy designed to replace the costly and strategic cobalt-base X-40 alloy used in the automotive Stirling engine cylinder/generator housing. Over 40 alloy compositions were evaluated using investment cast test bars for stress-rupture testing. Also, hydrogen compatibility and oxygen corrosion resistance tests were used to determine the optimal alloy. NASACC-1 alloy was characterized using elevated and room temperature tensile, creep-rupture, low cycle fatigue, heat capacity, specific heat, and thermal expansion testing. Furthermore, phase analysis was performed on samples with several heat treated conditions. The properties are very encouraging. NASACC-1 alloy shows stress-rupture and low cycle fatigue properties equivalent to X-40. The oxidation resistance surpassed the program goal while maintaining acceptable resistance to hydrogen exposure. The welding, brazing, and casting characteristics are excellent. Finally, the cost of NASACC-1 is significantly lower than that of X-40.

  18. Hydrogen solubility in rare earth based hydrogen storage alloys

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Hirohisa [Tokai Univ., Kanagawa (Japan). School of Engineering; Kuji, Toshiro [Mitsui Mining and Smelting Co. Ltd., Saitama (Japan)

    1999-09-01

    This paper reviews significant results of recent studies on the hydrogen storage properties of rare earth based AB{sub 5} (A: rare earth element, B: transition element) alloys The hydrogen solubility and the hydride formation, typically appeared in pressure-composition isotherms (PCT), are strongly dependent upon alloy composition, structure, morphology and even alloy particle size. Typical experimental results are shown to describe how these factors affect the hydrogen solubility and storage properties.

  19. Characterization of shocked beryllium

    Directory of Open Access Journals (Sweden)

    Papin P.A.

    2012-08-01

    Full Text Available While numerous studies have investigated the low-strain-rate constitutive response of beryllium, the combined influence of high strain rate and temperature on the mechanical behavior and microstructure of beryllium has received limited attention over the last 40 years. In the current work, high strain rate tests were conducted using both explosive drive and a gas gun to accelerate the material. Prior studies have focused on tensile loading behavior, or limited conditions of dynamic strain rate and/or temperature. Two constitutive strength (plasticity models, the Preston-Tonks-Wallace (PTW and Mechanical Threshold Stress (MTS models, were calibrated using common quasi-static and Hopkinson bar data. However, simulations with the two models give noticeably different results when compared with the measured experimental wave profiles. The experimental results indicate that, even if fractured by the initial shock loading, the Be remains sufficiently intact to support a shear stress following partial release and subsequent shock re-loading. Additional “arrested” drive shots were designed and tested to minimize the reflected tensile pulse in the sample. These tests were done to both validate the model and to put large shock induced compressive loads into the beryllium sample.

  20. Non-alloyed Ni3Al based alloys – preparation and evaluation of mechanical properties

    Directory of Open Access Journals (Sweden)

    J. Malcharcziková

    2013-07-01

    Full Text Available The paper reports on the fabrication and mechanical properties of Ni3Al based alloy, which represents the most frequently used basic composition of nickel based intermetallic alloys for high temperature applications. The structure of the alloy was controlled through directional solidification. The samples had a multi-phase microstructure. The directionally solidified specimens were subjected to tensile tests with concurrent measurement of acoustic emission (AE. The specimens exhibited considerable room temperature ductility before fracture. During tensile testing an intensive AE was observed.

  1. Beryllium nitrate inhibits fibroblast migration to disrupt epimorphic regeneration.

    Science.gov (United States)

    Cook, Adam B; Seifert, Ashley W

    2016-10-01

    Epimorphic regeneration proceeds with or without formation of a blastema, as observed for the limb and skin, respectively. Inhibition of epimorphic regeneration provides a means to interrogate the cellular and molecular mechanisms that regulate it. In this study, we show that exposing amputated limbs to beryllium nitrate disrupts blastema formation and causes severe patterning defects in limb regeneration. In contrast, exposing full-thickness skin wounds to beryllium only causes a delay in skin regeneration. By transplanting full-thickness skin from ubiquitous GFP-expressing axolotls to wild-type hosts, we demonstrate that beryllium inhibits fibroblast migration during limb and skin regeneration in vivo Moreover, we show that beryllium also inhibits cell migration in vitro using axolotl and human fibroblasts. Interestingly, beryllium did not act as an immunostimulatory agent as it does in Anurans and mammals, nor did it affect keratinocyte migration, proliferation or re-epithelialization, suggesting that the effect of beryllium is cell type-specific. While we did not detect an increase in cell death during regeneration in response to beryllium, it did disrupt cell proliferation in mesenchymal cells. Taken together, our data show that normal blastema organogenesis cannot occur without timely infiltration of local fibroblasts and highlights the importance of positional information to instruct pattern formation during regeneration. In contrast, non-blastemal-based skin regeneration can occur despite early inhibition of fibroblast migration and cell proliferation.

  2. Quantum molecular dynamics simulations of beryllium at high pressures

    Science.gov (United States)

    Desjarlais, Michael; Knudson, Marcus

    2008-03-01

    The phase boundaries and high pressure melt properties of beryllium have been the subject of several recent experimental and theoretical studies. The interest is motivated in part by the use of beryllium as an ablator material in inertial confinement fusion capsule designs. In this work, the high pressure melt curve, Hugoniot crossings, sound speeds, and phase boundaries of beryllium are explored with DFT based quantum molecular dynamics calculations. The entropy differences between the various phases of beryllium are extracted in the vicinity of the melt curve and agree favorably with earlier theoretical work on normal melting. High velocity flyer plate experiments with beryllium targets on Sandia's Z machine have generated high quality data for the Hugoniot, bulk sound speeds, and longitudinal sound speeds. This data provides a tight constraint on the pressure for the onset of shock melting of beryllium and intriguing information on the solid phase prior to melt. The results of the QMD calculations and the experimental results will be compared, and implications for the HCP and BCC phase boundaries of beryllium will be presented.

  3. Joining of Beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, A

    2006-02-01

    A handbook dealing with the many aspects of beryllium that would be important for the users of this metal is currently being prepared. With an introduction on the applications, advantages and limitations in the use of this metal the following topics will be discussed in this handbook: physical, thermal, and nuclear properties; extraction from the ores; purification and casting of ingots; production and types of beryllium powders; consolidation methods, grades, and properties; mechanical properties with emphasis on the various factors affecting these properties; forming and mechanical working; welding, brazing, bonding, and fastening; machining; powder deposition; corrosion; health aspects; and examples of production of components. This report consists of ''Section X--Joining'' from the handbook. The prefix X is maintained here for the figures, tables and references. In this section the different methods used for joining beryllium and the advantages, disadvantages and limitations of each are presented. The methods discussed are fusion welding, brazing, solid state bonding (diffusion bonding and deformation bonding), soldering, and mechanical fastening. Since beryllium has a high affinity for oxygen and nitrogen with the formation of oxides and nitrides, considerable care must be taken on heating the metal, to protect it from the ambient atmosphere. In addition, mating surfaces must be cleaned and joints must be designed to minimize residual stresses as well as locations for stress concentration (notch effects). In joining any two metals the danger exists of having galvanic corrosion if the part is subjected to moisture or to any type of corroding environment. This becomes a problem if the less noble (anodic) metal has a significantly smaller area than the more noble (cathodic) metal since the ions (positive charges) from the anodic (corroding) metal must correspond to the number of electrons (negative charges) involved at the cathode. Beryllium

  4. HIGH CYCLE FATIGUE PROPERTIES OF NICKEL-BASE ALLOY 718

    Institute of Scientific and Technical Information of China (English)

    K.Kobayashi; K.Yamaguchi; M.Hayakawa; M.Kimura

    2004-01-01

    The fatigue properties of nickel-base Alloy 718 with fine- and grain-coarse grains were investigated. In the fine-grain alloy, the fatigue strength normalized by the tensile strengtn was 0.51 at 107 cycles. In contrast, the fatigue strength of the coarse-grain alloy was 0.32 at the same cycles, although the fatigue strengths in the range from 103to 105 cycles are the same for both alloys. The fracture appearances fatigued at around 106 cycles showed internal fractures originating from the flat facets of austenite grains for both alloys. The difference in fatigue strength at 107 cycles between the fine- and coarse-grain alloys could be explained in terms of the sizes of the facets from which the fractures originated.

  5. Excessively High Vapor Pressure of Al-based Amorphous Alloys

    Directory of Open Access Journals (Sweden)

    Jae Im Jeong

    2015-10-01

    Full Text Available Aluminum-based amorphous alloys exhibited an abnormally high vapor pressure at their approximate glass transition temperatures. The vapor pressure was confirmed by the formation of Al nanocrystallites from condensation, which was attributed to weight loss of the amorphous alloys. The amount of weight loss varied with the amorphous alloy compositions and was inversely proportional to their glass-forming ability. The vapor pressure of the amorphous alloys around 573 K was close to the vapor pressure of crystalline Al near its melting temperature, 873 K. Our results strongly suggest the possibility of fabricating nanocrystallites or thin films by evaporation at low temperatures.

  6. Effects of Be, Sr, Fe and Mg interactions on the microstructure and mechanical properties of aluminum based aeronautical alloys

    Science.gov (United States)

    Ibrahim, Mohamed Fawzy

    The present work was carried out on a series of heat-treatable aluminum-based aeronautical alloys containing various amounts of magnesium (Mg), iron (Fe), strontium (Sr) and beryllium (Be). Tensile test bars (dendrite arm spacing ~ 24mum) were solutionized for either 5 or 12 hours at 540°C, followed by quenching in warm water (60°C). Subsequently, these quenched samples were aged at 160°C for times up to 12 hours. Microstructural assessment was performed. All heat-treated samples were pulled to fracture at room temperature using a servo-hydraulic tensile testing machine. The results show that Be causes partial modification of the eutectic silicon (Si) particles similar to that reported for Mg addition. Addition of 0.8 wt.% Mg reduced the eutectic temperature by ~10°C. During solidification of alloys containing high levels of Fe and Mg, without Sr, a peak corresponding to the formation of a Be-Fe phase (Al8Fe2BeSi) was detected at 611°C. The Be-Fe phase precipitates in a script-like morphology. A new quinary eutectic-like reaction was observed to take place near the end of solidification of high Mg, high Fe, Be-containing alloys. This new reaction is composed mainly of fine particles of Si, Mg2Si, pi-Al 8Mg3FeSi6 and (Be-Fe) phases. The volume fraction of this reaction decreased with the addition of Sr. The addition of Be has a noticeable effect on decreasing the beta-phase length, or volume fraction, this effect may be limited by adding Sr. Beryllium addition also results in the precipitation of the beta-phase in a nodular form, which reduces the harmful effects of these intermetallics on the alloy mechanical properties. Increasing both Mg and Fe levels led to an increase in the amount of the pi-phase; increasing the iron content led to an increase in the volume fraction of the partially soluble beta- and pi-phases, while Mg2Si particles were completely dissolved. The beta-phase platelets were observed to undergo changes in their morphology due to the

  7. Conditions for preparation of ultrapure beryllium by electrolytic refining in molten alkali-metal chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Wohlfarth, Hagen

    1982-02-01

    Electrolytic refining is regarded as the most suitable process for the production of beryllium with impurity contents below 1 at.-ppM. Several parameters are important for electrolytic refining of beryllium in a BeCl/sub 2/-containing LiCl-KCl melt: current density, BeCl/sub 2/ content, electrolyte temperature, composition of the unpurified beryllium and impurity-ion concentrations in the melt, as well as apparatus characteristics such as rotation speed of the cathode and condition of the crucible material. These factors were studied and optimized such that extensive removal of the maximum number of accompanying and alloying elements was achieved.

  8. Suivi médical de salariés exposés au beryllium

    OpenAIRE

    2009-01-01

    International audience; Purpose of the study: determination of a systematised procedure for medical follow-up of beryllium-exposed workers. Method: a medical follow-up of workers from a factory machining beryllium (Be) either plain or as an alloy started in 2001. Be Lymphocyte Proliferation Tests (LPT) were performed for screening Be sensitisation and were calculated again according to 1142-2001 speciation of the American Department Of Energy. A working group included occupational physicians,...

  9. Technical Basis for PNNL Beryllium Inventory

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Michelle Lynn

    2014-07-09

    The Department of Energy (DOE) issued Title 10 of the Code of Federal Regulations Part 850, “Chronic Beryllium Disease Prevention Program” (the Beryllium Rule) in 1999 and required full compliance by no later than January 7, 2002. The Beryllium Rule requires the development of a baseline beryllium inventory of the locations of beryllium operations and other locations of potential beryllium contamination at DOE facilities. The baseline beryllium inventory is also required to identify workers exposed or potentially exposed to beryllium at those locations. Prior to DOE issuing 10 CFR 850, Pacific Northwest Nuclear Laboratory (PNNL) had documented the beryllium characterization and worker exposure potential for multiple facilities in compliance with DOE’s 1997 Notice 440.1, “Interim Chronic Beryllium Disease.” After DOE’s issuance of 10 CFR 850, PNNL developed an implementation plan to be compliant by 2002. In 2014, an internal self-assessment (ITS #E-00748) of PNNL’s Chronic Beryllium Disease Prevention Program (CBDPP) identified several deficiencies. One deficiency is that the technical basis for establishing the baseline beryllium inventory when the Beryllium Rule was implemented was either not documented or not retrievable. In addition, the beryllium inventory itself had not been adequately documented and maintained since PNNL established its own CBDPP, separate from Hanford Site’s program. This document reconstructs PNNL’s baseline beryllium inventory as it would have existed when it achieved compliance with the Beryllium Rule in 2001 and provides the technical basis for the baseline beryllium inventory.

  10. INFLUENCE OF ALLOY COMPOSITION ON WORK HARDENING BEHAVIOR OF ZIRCONIUM-BASED ALLOYS

    Directory of Open Access Journals (Sweden)

    HYUN-GIL KIM

    2013-08-01

    Full Text Available Three types of zirconium base alloy were evaluated to study how their work hardening behavior is affected by alloy composition. Repeated-tensile tests (5% elongation at each test were performed at room temperature at a strain rate of 1.7 × 10−3 s−1 for the alloys, which were initially controlled for their microstructure and texture. After considering the yield strength and work hardening exponent (n variations, it was found that the work hardening behavior of the zirconium base alloys was affected more by the Nb content than the Sn content. The facture mode during the repeated tensile test was followed by the slip deformation of the zirconium structure from the texture and microstructural analysis.

  11. Corrosion resistance improvement of titanium base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Popa, Mihai V.; Vasilescu, Ecaterina; Drob, Paula; Vasilescu, Cora; Drob, Silviu I., E-mail: ec_vasilescu@yahoo.co [Institute of Physical Chemistry ' Ilie Murgulescu' , Bucharest (Romania); Mareci, Daniel [Technical University ' Gh. Asachi' , Iasi (Romania); Rosca, Julia C. Mirza [Las Palmas de Gran Canaria University, Tafira (Spain). Mechanical Engineering Dept.

    2010-07-01

    The corrosion resistance of the new Ti-6Al-4V-1Zr alloy in comparison with ternary Ti-6Al-4V alloy in Ringer-Brown solution and artificial Carter-Brugirard saliva of different pH values was studied. In Ringer-Brown solution, the new alloy presented an improvement of all electrochemical parameters due to the alloying with Zr; also, impedance spectra revealed better protective properties of its passive layer. In Carter-Brugirard artificial saliva, an increase of the passive film thickness was proved. Fluoride ions had a slight negative influence on the corrosion and ion release rates, without to affect the very good stability of the new Ti-6Al-4V-1Zr alloy. (author)

  12. Corrosion resistance improvement of titanium base alloys

    Directory of Open Access Journals (Sweden)

    Mihai V. Popa

    2010-01-01

    Full Text Available The corrosion resistance of the new Ti-6Al-4V-1Zr alloy in comparison with ternary Ti-6Al-4V alloy in Ringer-Brown solution and artificial Carter-Brugirard saliva of different pH values was studied. In Ringer-Brown solution, the new alloy presented an improvement of all electrochemical parameters due to the alloying with Zr; also, impedance spectra revealed better protective properties of its passive layer. In Carter-Brugirard artificial saliva, an increase of the passive film thickness was proved. Fluoride ions had a slight negative influence on the corrosion and ion release rates, without to affect the very good stability of the new Ti-6Al-4V-1Zr alloy.

  13. Fabric cutting application of FeAl-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Blue, C.A. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Sklad, S.P. [University of Virginia, Charlottesville, VA 22905 (United States); Deevi, S.C. [Research, Development, and Engineering Center, Philip Morris USA, Richmond, VA 23234 (United States); Shih, H.-R. [Jackson State University, 1400 J.R. Lynch Street, Jackson, MS 39217 (United States)

    1998-12-31

    Four intermetallic-based alloys were evaluated for cutting blade applications. These alloys included Fe{sub 3}Al-based (FAS-II and FA-129), FeAl-based (PM-60) and Ni{sub 3}Al-based (IC-50). These alloys were of interest because of their much higher work-hardening rates than the conventionally used carbon and stainless steels. The FeAl-based PM-60 alloy was of further interest because of its hardening possibility through retention of vacancies. The vacancy retention treatment is much simpler than the heat treatments used for hardening of steel blades. Blades of four intermetallic alloys and commercially used M2 tool steel blades were evaluated under identical conditions to cut two-ply heavy paper. Comparative results under identical conditions revealed that the FeAl-based alloy PM-60 outperformed the other intermetallic alloys and was equal to or somewhat better than the commercially used M2 tool steel. (orig.) 18 refs.

  14. The uses and adverse effects of beryllium on health

    DEFF Research Database (Denmark)

    Cooper, Ross G.; Harrison, Adrian Paul

    2009-01-01

    Context: This review describes the health effects of beryllium exposure in the workplace and the environment. Aim: To collate information on the consequences of occupational and environmental exposure to beryllium on physiological function and well being. Materials and Methods: The criteria used...... in the current review for selecting articles were adopted from proposed criteria in The International Classification of Functioning, Disability, and Health. Articles were classified based on acute and chronic exposure and toxicity of beryllium. Results: The proportions of utilized and nonutilized articles were...... published in sources unobtainable through requests at the British Library, and some had no impact factor and were excluded. Conclusion: Beryllium has some useful but undoubtedly harmful effects on health and well-being. Measures needed to be taken to prevent hazardous exposure to this element, making its...

  15. Evaluation of historical beryllium abundance in soils, airborne particulates and facilities at Lawrence Livermore National Laboratory.

    Science.gov (United States)

    Sutton, Mark; Bibby, Richard K; Eppich, Gary R; Lee, Steven; Lindvall, Rachel E; Wilson, Kent; Esser, Bradley K

    2012-10-15

    Beryllium has been historically machined, handled and stored in facilities at Lawrence Livermore National Laboratory (LLNL) since the 1950s. Additionally, outdoor testing of beryllium-containing components has been performed at LLNL's Site 300 facility. Beryllium levels in local soils and atmospheric particulates have been measured over three decades and are comparable to those found elsewhere in the natural environment. While localized areas of beryllium contamination have been identified, laboratory operations do not appear to have increased the concentration of beryllium in local air or water. Variation in airborne beryllium correlates to local weather patterns, PM10 levels, normal sources (such as resuspension of soil and emissions from coal power stations) but not to LLNL activities. Regional and national atmospheric beryllium levels have decreased since the implementation of the EPA's 1990 Clean-Air-Act. Multi-element analysis of local soil and air samples allowed for the determination of comparative ratios for beryllium with over 50 other metals to distinguish between natural beryllium and process-induced contamination. Ten comparative elemental markers (Al, Cs, Eu, Gd, La, Nd, Pr, Sm, Th and Tl) that were selected to ensure background variations in other metals did not collectively interfere with the determination of beryllium sources in work-place samples at LLNL. Multi-element analysis and comparative evaluation are recommended for all workplace and environmental samples suspected of beryllium contamination. The multi-element analyses of soils and surface dusts were helpful in differentiating between beryllium of environmental origin and beryllium from laboratory operations. Some surfaces can act as "sinks" for particulate matter, including carpet, which retains entrained insoluble material even after liquid based cleaning. At LLNL, most facility carpets had beryllium concentrations at or below the upper tolerance limit determined by sampling facilities

  16. Genetic determinants of sensitivity to beryllium in mice.

    Science.gov (United States)

    Tarantino-Hutchison, Lauren M; Sorrentino, Claudio; Nadas, Arthur; Zhu, Yiwen; Rubin, Edward M; Tinkle, Sally S; Weston, Ainsley; Gordon, Terry

    2009-06-01

    Chronic beryllium disease (CBD), an irreversible, debilitating granulomatous lung disease is caused by exposure to beryllium. This occupational hazard occurs in primary production and machining of Be-metal, BeO, beryllium - containing alloys, and other beryllium products. CBD begins as an MHC Class II-restricted, T(H)1 hypersensitivity, and the Human Leukocyte Antigen, HLA-DPB1E(69), is associated with risk of developing CBD. Because inbred strains of mice have not provided good models of CBD to date, three strains of HLA-DPB1 transgenic mice in an FVB/N background were developed; each contains a single allele of HLA-DPB1 that confers a different magnitude of risk for chronic beryllium disease: HLA-DPB1*0401 (OR approximately 0.2), HLA-DPB1*0201 (OR approximately 3), and HLA-DPB1*1701 (OR approximately 46). The mouse ear swelling test (MEST) was employed to determine if these different alleles would support a hypersensitivity response to beryllium. Mice were first sensitized on the back and subsequently challenged on the ear. In separate experiments, mice were placed into one of three groups (sensitization/challenge): C/C, C/Be, and Be/Be. In the HLA-DPB1*1701 mice, the strain with the highest risk transgene, the Be/Be group was the only group that displayed significant maximum increased ear thickness of 19.6% +/- 3.0% over the baseline measurement (p beryllium in seven inbred strains were investigated through use of the MEST, these included: FVB/N, AKR, Balb/c, C3H/HeJ, C57/BL6, DBA/2, and SJL/J. The FVB/N strain was least responsive, while the SJL/J and C57/BL6 strains were the highest responders. Our results suggest that the HLA-DPB1*1701 transgene product is an important risk factor for induction of the beryllium-sensitive phenotype. This model should be a useful tool for investigating beryllium sensitization.

  17. Ab initio modeling of decomposition in iron based alloys

    Science.gov (United States)

    Gorbatov, O. I.; Gornostyrev, Yu. N.; Korzhavyi, P. A.; Ruban, A. V.

    2016-12-01

    This paper reviews recent progress in the field of ab initio based simulations of structure and properties of Fe-based alloys. We focus on thermodynamics of these alloys, their decomposition kinetics, and microstructure formation taking into account disorder of magnetic moments with temperature. We review modern theoretical tools which allow a consistent description of the electronic structure and energetics of random alloys with local magnetic moments that become totally or partially disordered when temperature increases. This approach gives a basis for an accurate finite-temperature description of alloys by calculating all the relevant contributions to the Gibbs energy from first-principles, including a configurational part as well as terms due to electronic, vibrational, and magnetic excitations. Applications of these theoretical approaches to the calculations of thermodynamics parameters at elevated temperatures (solution energies and effective interatomic interactions) are discussed including atomistic modeling of decomposition/clustering in Fe-based alloys. It provides a solid basis for understanding experimental data and for developing new steels for modern applications. The precipitation in Fe-Cu based alloys, the decomposition in Fe-Cr, and the short-range order formation in iron alloys with s-p elements are considered as examples.

  18. Thermal fatigue of beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Deksnis, E.; Ciric, D.; Falter, H. [JET Joint undertaking, Abingdon (United Kingdom)] [and others

    1995-09-01

    Thermal fatigue life of S65c beryllium castellated to a geometry 6 x 6 x (8-10)mm deep has been tested for steady heat fluxes of 3 MW/m{sup 2} to 5 MW/m{sup 2} and under pulsed heat fluxes (10-20 MW/m{sup 2}) for which the time averaged heat flux is 5 MW/m{sup 2}. These tests were carried out in the JET neutral beam test facility A test sequence with peak surface temperatures {le} 600{degrees}C produced no visible fatigue cracks. In the second series of tests, with T{sub max} {le} 750{degrees}C evidence for fatigue appeared after a minimum of 1350 stress cycles. These fatigue data are discussed in view of the observed lack of thermal fatigue in JET plasma operations with beryllium PFC. JET experience with S65b and S65c is reviewed; recent operations with {Phi} = 25 MW/m{sup 2} and sustained melting/resolidification are also presented. The need for a failure criterion for finite element analyses of Be PFC lifetimes is discussed.

  19. Cr{sub 2}Nb-based alloy development

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.T.; Tortorelli, P.F.; Horton, J.A. [Oak Ridge National Lab., TN (United States)] [and others

    1996-08-01

    Alloys of Cr-Cr{sub 2}Nb with exceptionally high strength at 1200{degrees}C have been developed. However, these compositions suffer from limited ductility and toughness at room temperature. Despite improvements from processing modifications, as-fabricated defects still limit room temperature mechanical behavior. In contrast, an alloy system with only a small mismatch of the coefficients of thermal expansion of the two phases, Cr-Cr{sub 2}Zr, showed good fabricability. However, these alloys are weaker than Cr-Cr{sub 2}Nb compositions at high temperatures and have poor oxidation resistance. Silicide coatings can provide high-temperature oxidation and sulfidation protection of these alloys. Improvements in room temperature mechanical properties of Laves-phase-strengthened alloys will rely on further development based on increasing the ductility of the matrix phase by impurity control and compositional modifications.

  20. Synthesis of aluminum-based scandium-yttrium master alloys

    Science.gov (United States)

    Bazhin, V. Yu.; Kosov, Ya. I.; Lobacheva, O. L.; Dzhevaga, N. V.

    2015-07-01

    The preparation technology for an Al-2% Sc-0.5% Y master alloy using aluminum-manganese alloys has been developed and tested. The microstructure of the prepared master alloy is studied and the compositions of intermetallics is determined. The efficient technological parameters of the synthesis are determined. It is shown that varying the compositions of starting reagents and alloying additions and optimizing the process conditions (temperature, mixing, etc.) allow us to forecast the manufacturing and operating characteristics of aluminum-based master alloys. Joint additions of scandium and yttrium oxides to a charge favor a substantial decrease in the grain size of the formed intermetallics; this effect appears to the utmost in the case of microallying with yttrium up to 0.5 wt %.

  1. On the mechanical properties of TiNb based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Y. [SIMAP-CNRS, Institut Polytechnique de Grenoble, BP 75, St. Martin d’Hères 38402 (France); Georgarakis, K. [WPI Advanced Institute for Materials Research, Tohoku University, Sendai (Japan); SIMAP-CNRS, Institut Polytechnique de Grenoble, BP 75, St. Martin d’Hères 38402 (France); Yokoyama, Y. [WPI Advanced Institute for Materials Research, Tohoku University, Sendai (Japan); Yavari, A.R., E-mail: euronano@minatec.inpg.fr [SIMAP-CNRS, Institut Polytechnique de Grenoble, BP 75, St. Martin d’Hères 38402 (France)

    2013-09-15

    Highlights: •Systematic study of compressive behaviors of TiNb based alloys in different states. •Comparison between X-ray diffraction results in reflection and transmission mode. •High melting temperature TiNb based alloys were fabricated by copper mold casting. •Textures of studied alloys are analyzed through synchrotron radiation data. -- Abstract: A series of TiNb(Sn) alloys were synthesized by copper mold suction casting and subjected to different heat treatments (furnace cooling or water quenching). The microstructure, thermal and mechanical properties of the as-cast and heat treated samples were investigated. For the Ti–8.34 at.% Nb alloy, the as-cast and water quenched samples possess martensitic α′′ phase at room temperature and compression tests of these samples show occurrence of shape memory effect. For β phase Ti–25.57 at.% Nb alloys, stress-induced martensitic transformation was found during compression in the as-cast and water quenched samples. For the ternary Ti–25.05 at.%Nb–2.04 at.%Sn alloy, conventional linear elastic behavior was observed. It is shown that the addition of Sn increases the stability of the β phase. The Young’s moduli of these alloys were also measured by ultrasonic measurements. Water-quenched Ti–25.57 at.%Nb alloy was found to exhibit the lowest Young’s modulus value. Sn addition has small impact on the Young’s moduli of the TiNb alloys.

  2. Effects of surface treatments and storage times on the tensile bond strength of adhesive cements to noble and base metal alloys.

    Science.gov (United States)

    Burmann, Paulo Afonso; Santos, Jose Fortunato Ferreira; May, Liliana Gressler; Pereira, Joao Eduardo da Silva; Cardoso, Paulo Eduardo Capel

    2008-01-01

    This work evaluated two resin cements and a glass-ionomer cement and their bond strength to gold-palladium (Au-Pd), silver-palladium (Ag-Pd), and nickel-chromium-beryllium (Ni-Cr-Be) alloys, utilizing three surface treatments over a period of six months. Eight hundred ten pieces were cast (in a button shape flat surfaces) in one of three alloys. Each alloy group was assigned to three other groups, based on the surface treatment utilized. Specimens were fabricated by bonding similar buttons in using one of three adhesive cements. The 405 pairs were thermocycled and stored in saline solution (0.9% NaCl) at 37 degrees C. The tensile bond strengths were measured in a universal testing machine after storage times of 2, 90, or 180 days. The highest mean bond strength value was obtained with the base metal alloy (10.9 +/- 8.6 MPa). In terms of surface treatment, oxidation resulted in the highest mean bond strength (13.7 +/- 7.3 MPa), followed by sandblasting (10.3 +/- 5.5 MPa) and polishing (3.0 +/- 6.4 MPa). Panavia Ex (13.2 +/- 9.3 MPa) showed significantly higher bond strengths than the other two cements, although the storage time reduced all bond strengths significantly.

  3. Development of Mg-based Hydrogen Storage Alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Mg-based hydrogen storage alloys are considered as a promising candidate for hydrogen system because of its lightweight, high storage capacity, low price and rich mineral resources. In detail,we reviewed the preparation and properties of Mg-Ni-based hydrogen storage alloys. All kinds of attempts have been done to improve the hydriding and dehydriding behaviors. It is found that the partial substitution of foreign elements can decrease the hydrogen absorption temperature,especially the substitution of a more electronegative element, such as Al and Mn. Mechanical alloying (MA) and mechanical grinding (MG) are the most effective methods to improve the hydriding/dehydriding kinetics and electrochemical capacity, and decrease the desorption temperature, but the corrosion resistance is so poor that the 80% of maximum capacity is lost within ten cycles. Microencapsulation is a useful measurement for improving the corrosion resistance and electrocatalytic activity. In order to improve the properties of the alloys for practical application, the alloys should have a large number of defects, which give activated sites, subsequently,MA, MG and electroless plating should be used to improve the hydriding/dehydriding kinetics and protect the surface of alloys, respectively. The new composite Mg-based alloys give a new way for the hydrogen storage material to practical application. Furthermore we put forward several problems which will be discussed in future.

  4. Effects of micro-alloying with Sc and Mn on microstructure and mechanical properties of Al-Mg based alloys

    Institute of Scientific and Technical Information of China (English)

    CHEN Xian-ming; LUO Cheng-ping; PAN Qing-lin; YIN Zhi-ming

    2005-01-01

    An extensive investigation was made on the effects of micro-alloying with small amounts of Sc and Mn on the microstructure and mechanical properties of the Al-Mg based alloys. It is found that the micro-alloying can significantly enhance the tensile strength of the alloys, and eliminate the dendritic cast structure in it. Many fine,spherical and dispersive Al3Sc particles are found in the annealed Al-Mg-Mn-Sc alloys, which can strongly pin up dislocations and subgrain boundaries, thus strongly retarding the recrystallization of the alloys. The strengthening of the micro-alloyed Al-Mg alloys is attributed to the precipitation strengthening by the Al3Sc particles and to the substructure strengthening.

  5. Surface segregations in platinum-based alloy nanoparticles

    Science.gov (United States)

    Yamakawa, Shunsuke; Asahi, Ryoji; Koyama, Toshiyuki

    2014-04-01

    A phase-field model that describes the radial distributions of the ordered-disordered phase and surface segregation in a single-alloy nanoparticle is introduced to clarify the overall behavior of surface segregation of various Pt-based alloy nanoparticles. One of the obstacles to apply a platinum-transition metal alloy as a cathode electro-catalyst of a polymer electrolyte fuel cell is the need to ensure the retention of the designed surface composition in an alloy nanoparticle against the alloy combinations, a particle size, and heat treatment. From the results of calculations for CrPt, FePt, CoPt, NiPt, CuPt, PdPt, IrPt, and AuPt binary nanoparticles with diameters below 10 nm at 973.15 K, the compositional variation within a single particle was found to depend on the balance between the atomic interaction within particles and the surface free energy. In addition, the obtained specific steady-state composition of the surface varied significantly with alloy combination and particle diameter. Based on the general tendencies of a binary system to exhibit segregation, attempts to control the amount of platinum segregation on the surface using a ternary-alloy system were examined.

  6. Microstructures and oxidation behavior of some Molybdenum based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Pratik Kumar [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    The advent of Ni based superalloys revolutionized the high temperature alloy industry. These materials are capable of operating in extremely harsh environments, comprising of temperatures around 1050 C, under oxidative conditions. Demands for increased fuel efficiency, however, has highlighted the need for materials that can be used under oxidative conditions at temperatures in excess of 1200 C. The Ni based superalloys are restricted to lower temperatures due to the presence of a number of low melting phases that melt in the 1250 - 1450 C, resulting in softening of the alloys above 1000 C. Therefore, recent research directions have been skewed towards exploring and developing newer alloy systems. This thesis comprises a part of such an effort. Techniques for rapid thermodynamic assessments were developed and applied to two different systems - Mo-Si alloys with transition metal substitutions (and this forms the first part of the thesis) and Ni-Al alloys with added components for providing high temperature strength and ductility. A hierarchical approach towards alloy design indicated the Mo-Ni-Al system as a prospective candidate for high temperature applications. Investigations on microstructures and oxidation behavior, under both isothermal and cyclic conditions, of these alloys constitute the second part of this thesis. It was seen that refractory metal systems show a marked microstructure dependence of oxidation.

  7. Corrosion evaluation of gold-based dental alloys.

    Science.gov (United States)

    Corso, P P; German, R M; Simmons, H D

    1985-05-01

    Three commercial gold-based dental alloys and three constant-nobility ternary alloys (Au-Ag-Cu) were evaluated for corrosion using a quantitative test battery. Integration of the current density, in a de-aerated solution of 1% NaCl along the approximate potential range found in the mouth (-300 mV to +300 mV vs. SCE), yields a quantitative rank ordering of the test alloys. The results are combined with prior findings on other commercial alloys to demonstrate the interaction of nobility and microstructure. Nobility determines the overall corrosion resistance for gold-based alloys. However, because of mutual insolubility, alloying with copper induces silver segregation, resulting in a higher corrosion rate at a given nobility. Thus, microstructure has an influence on corrosion, but heat treatments are largely ineffective in altering the basic corrosion characteristics. The test techniques, in combination with tarnish evaluations, provide a quantitative battery for alloy evaluation. The results indicate the combinations of nobility, microstructure, and environment most likely to avoid corrosion difficulties.

  8. Can conventional bases and unsaturated hydrocarbons be converted into gas-phase superacids that are stronger than most of the known oxyacids? The role of beryllium bonds.

    Science.gov (United States)

    Yáñez, Manuel; Mó, Otilia; Alkorta, Ibon; Elguero, José

    2013-08-26

    The association of BeX2 (X: H, F, Cl) derivatives with azoles leads to a dramatic increase of their intrinsic acidity. Hence, whereas 1H-tetrazole can be considered as a typical N base in the gas phase, the complex 1H-tetrazole-BeCl2 is predicted to be, through the use of high-level G4 ab initio calculations, a nitrogen acid stronger than perchloric acid. This acidity enhancement is due to a more favorable stabilization of the deprotonated species after the beryllium bond is formed, because the deprotonated anion is a much better electron donor than the neutral species. Consequently, this is a general phenomenon that should be observed for any Lewis base, including those in which the basic site is a hydroxy group, an amino group, a carbonyl group, an aromatic N atom, a second-row atom, or the π system of unsaturated hydrocarbons. The consequence is that typical bases like aniline or formamide lead to BeX2 complexes that are stronger acids than phosphoric or chloric acids. Similarly, water, methanol, and SH2 become stronger acids than sulfuric acid, pyridine becomes a C acid almost as strong as acetic acid, and unsaturated hydrocarbons such as ethylene and acetylene become acids as strong as nitric and sulfuric acids, respectively.

  9. PIGE analysis of magnesium and beryllium

    Science.gov (United States)

    Fonseca, M.; Jesus, A. P.; Luís, H.; Mateus, R.; Cruz, J.; Gasques, L.; Galaviz, D.; Ribeiro, J. P.

    2010-06-01

    In this work, we present an alternative method for PIGE analysis of magnesium and beryllium in thick samples. This method is based on the ERYA - Emitted Radiation Yield Analysis - code, which integrates the nuclear reaction excitation function along the depth of the sample. For this purpose, the excitations functions of the 25Mg(p,p'γ) 25Mg ( Eγ = 585 keV) and 9Be(p,γ) 10B ( Eγ = 718 keV) reactions were employed. Calculated gamma-ray yields were compared, at several proton energy values, with experimental yields for thick samples made of inorganic compounds containing magnesium or beryllium. The agreement is better than 5%. Taking into consideration the experimental uncertainty of the measured yields and the errors related to the stopping power values, this agreement shows that effects as the beam energy straggling, ignored in the calculation, seem to play a minor role.

  10. A Computationally Based Approach to Homogenizing Advanced Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jablonski, P D; Cowen, C J

    2011-02-27

    We have developed a computationally based approach to optimizing the homogenization heat treatment of complex alloys. The Scheil module within the Thermo-Calc software is used to predict the as-cast segregation present within alloys, and DICTRA (Diffusion Controlled TRAnsformations) is used to model the homogenization kinetics as a function of time, temperature and microstructural scale. We will discuss this approach as it is applied to both Ni based superalloys as well as the more complex (computationally) case of alloys that solidify with more than one matrix phase as a result of segregation. Such is the case typically observed in martensitic steels. With these alloys it is doubly important to homogenize them correctly, especially at the laboratory scale, since they are austenitic at high temperature and thus constituent elements will diffuse slowly. The computationally designed heat treatment and the subsequent verification real castings are presented.

  11. Electrochemical properties of TiV-based hydrogen storage alloys

    Institute of Scientific and Technical Information of China (English)

    朱云峰; 李锐; 高明霞; 刘永锋; 潘洪革; 王启东

    2003-01-01

    The electrochemical properties of the super-stoichiometric TiV-based hydrogen storage electrode alloys(Ti0.8Zr0.2)(V0.533Mn0.107Cr0.16Ni0.2)x(x=2, 3, 4, 5, 6) were studied. It is found by XRD analysis that all the al-loys mainly consist of a C14 Laves phase with hexagonal structure and a V-based solid solution phase with BCCstructure. The lattice parameters and the unit cell volumes of the two phases decrease with increasing x. The cyclelife, the linear polarization, the anode polarization and the electrochemical impedance spectra of the alloy electrodeswere investigated systematically. The overall electrochemical properties of the alloy electrode are found improvedgreatly as the result of super-stoichiometry and get to the best when x= 5.

  12. Solvent extraction of beryllium from malonate solutions with liquid anion exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Rao, R.R.; Khopkar, S.M.

    1983-12-01

    Beryllium was quantitatively extracted at pH 5.5-7.0 in microgram amounts with 0.06 M Aliquat 336S in xylene from 5 x 10/sup -3/ M malonic acid solution, stripped with 0.5 M hydrochloric acid, and determined spectrophotometrically at 523 nm as its complex with thorin. Those metals which could not form anionic complexes with malonic acid and were not extracted with beryllium at pH 6.5 were separated from it. Metals forming weak malonato complexes were scrubbed from the organic phase with water. The elements like bismuth, antimony, iron, uranium, gallium, and vanadium which form strong malonato complexes were separated by selective stripping with hydrochloric, sulfuric, or nitric acid. The method was extended for the analysis of beryllium in beryl and beryllium alloys. 1 figure, 6 tables.

  13. Proteomic analysis of beryllium-induced genotoxicity in an Escherichia coli mutant model system.

    Science.gov (United States)

    Taylor-McCabe, Kirsten J; Wang, Zaolin; Sauer, Nancy N; Marrone, Babetta L

    2006-03-01

    Beryllium is the second lightest metal, has a high melting point and high strength-to-weight ratio, and is chemically stable. These unique chemical characteristics make beryllium metal an ideal choice as a component material for a wide variety of applications in aerospace, defense, nuclear weapons, and industry. However, inhalation of beryllium dust or fumes induces significant health effects, including chronic beryllium disease and lung cancer. In this study, the mutagenicity of beryllium sulfate (BeSO(4)) and the comutagenicity of beryllium with a known mutagen 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) were evaluated using a forward mutant detection system developed in Escherichia coli. In this system, BeSO(4) was shown to be weakly mutagenic alone and significantly enhanced the mutagenicity of MNNG up to 3.5-fold over MNNG alone. Based on these results a proteomic study was conducted to identify the proteins regulated by BeSO(4). Using the techniques of 2-DE and oMALDI-TOF MS, we successfully identified 32 proteins being differentially regulated by beryllium and/or MNNG in the E. coli test system. This is the first study to describe the proteins regulated by beryllium in vitro, and the results suggest several potential pathways for the focus of further research into the mechanisms underlying beryllium-induced genotoxicity.

  14. Dose reduction in computed tomography: the effect of eye and testicle shielding on radiation dose measured in patients with beryllium oxide-based optically stimulated luminescence dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Grobe, Henrik; Koch, Arne; Abolmaali, Nasreddin [Dresden University of Technology, OncoRay - Center for Radiation Research in Oncology, Molecular Imaging, Medical Faculty Carl Gustav Carus, Fetscherstrasse 74, P.O. Box 86, Dresden (Germany); Sommer, Marian; Henniger, Juergen [Dresden University of Technology, Radiation Physics Group, Institute of Nuclear and Particle Physics, Dresden (Germany); Hietschold, Volker [University Hospital Carl Gustav Carus, Institute and Policlinic of Radiological Diagnostics, Dresden (Germany)

    2009-05-15

    The aim of this study was to assess the effect of eye and testicle shielding on radiation dose to the lens and the testes of patients undergoing CT examinations. Fifty-one male patients underwent CT twice with identical protocols initially without, the second time with protective garments. Doses to the testes and the lenses were recorded with beryllium oxide-based dosimeters. The dose to the testes and lenses from CT exposure was reduced by 96.2% {+-} 1.7% and 28.2% {+-} 18.5%, when testicle and eye shielding was used, respectively. The effect of the eye shielding on the eye lens dose was found to depend on the x-ray tube position when the eye is primarily exposed during the scan. The maximum eye lens dose reduction achieved was found to be 43.2% {+-} 6.5% corresponding to the anterior position of the tube. A significant correlation between the patient's body mass index and dose exposure could not be found. Eye and testicle shields, apart from being inexpensive and easy to use, were proven to be effective in reducing eye lens and testicle radiation dose burden from CT exposures. (orig.)

  15. Effect of Annealing on Rare Earth Based Hydrogen Storage Alloys

    Institute of Scientific and Technical Information of China (English)

    Li Jinhua

    2004-01-01

    Rare earth-based hydrogen storage alloy used as negative electrode materials for nickel-metal hydride (Ni-MH) batteries are used commercially.The effect of annealing treatment with different annealing temperature and time on the MLNi3.68 Co0.78 Mn0.35 Al0.27 and MMNi3.55 Co0.75 Mn0.40 Al0.30 alloys were investigated.The crystal microstructure,pressure-composition-isotherms (p-C-T) and electrochemical properties of alloys were examined by X-ray diffraction (XRD), automatic PCI monitoring system and electrical performance testing instruments.The optimum annealing treatment conditions of two kinds of alloys were determined.

  16. Laser cladding of Ni-based alloy on stainless steel

    Institute of Scientific and Technical Information of China (English)

    XUE Chun-fang; TIAN Xin-li; TAN Yong-sheng; WU Zhi-yuan

    2004-01-01

    The coatings on a stainless steel substrate were conducted by laser cladding of Ni-based alloy, using a 5 kW continuous wave CO2 flow transverse laser. SEM, EDX and X-ray diffraction were used to analyze the microstructure and constituent phases of the obtained coatings by laser cladding with direct injection of the powder into the melt pool. Solidification planar, cellular and dendrite structures were observed in Ni-based alloy coating. There exists an optimum metallurgical bond between Ni-based laser cladding layer and the base material. The high hardness of the Ni-based alloy coating is attributed to the presence of M7C3-type carbides (essentially chromium-riched carbide) dispersed in the γ(Ni,Fe) phase matrix.

  17. Laser multi-layer cladding of Mg-based alloys

    Institute of Scientific and Technical Information of China (English)

    陈长军; 王东生; 王茂才

    2003-01-01

    By laser multi-layer cladding using a pulsed Nd-YAG irradiation the thickness of the cladding zone Mg-based alloys(ZM2 and ZM5) can reach about 1. 0 mm. The microstructure of the substrate and the cladding zone wasstudied using optical microscope, scanning electron microscopy(SEM), X-ray diffractometry(XRD) and micro hard-ness analysis. It is observed that constituent of ZM5 alloy is δ+Mg17 Al12, that of ZM2 alloy is α+MgZn+Mg9Ce.That of cladding layer ZM2 alloy(L-ZM2) is Mg+ Mg2 Zn11 +MgCe; while that of the cladding layer ZM5 alloy(L-ZM5) is Mg+Mg32 (Al, Zn)49. The hardness of the cladding area can be increased to values above HV127. Veryfine uniform microstructure and the produced new phases of nanometer/sub-micrometer order were obtained. Now,many repaired Mg-based alloy components have been passed by flying test in outside field.

  18. Study on hemocompatibility and corrosion behavior of ion implanted TiNi shape memory alloy and Co-based alloys.

    Science.gov (United States)

    Liang, Chenghao; Huang, Naibao

    2007-10-01

    Biomedical TiNi shape memory alloy and Co-based alloys were ion implanted, and corrosion resistance and hemocompatibility of these had been investigated with electrochemical method, dynamic clotting time, and hemolysis rate tests. The results indicated that the electrochemical stability and anodic polarization behavior of the materials were improved significantly after ion implantation. When TiNi, Co-based alloys were implanted Mo + C and Ti + C, respectively, the corrosion potentials were enhanced more than 200 mV, passive current densities decreased, and passive ranges were broadened. Dynamic clotting time of the ion implanted substances was prolonged and hemolysis rate decreased. All the results pointed out that corrosion resistance and hemocompatibility of the alloys were improved by ion implantation, and effects of dual implantation was better than that of C single implantation. X-ray diffraction analysis of the alloys after dual implantation revealed that TiC, Mo(2)C, Mo(9)Ti(4), and Mo appeared on the surface of TiNi alloy, and CoC(x), Co(3)Ti, TiC, and TiO on the surface of Co-based alloys. These phases dispersing on the alloy surface formed amorphous film, prevented dissolving of alloy elements and improved the corrosion resistance and hemocompatibility of the alloys.

  19. Characterization of the microstructure in Mg based alloy

    KAUST Repository

    Kutbee, Arwa T

    2013-06-01

    The cast products Mg–Sn based alloys are promising candidates for automobile industries, since they provide a cheap yet thermally stable alternative to existing alloys. One drawback of the Mg–Sn based alloys is their insufficient hardness. The hardenability can be improved by engineering the microstructure through additions of Zn to the base alloy and selective aging conditions. Therefore, detailed knowledge about the microstructural characteristics and the role of Zn to promote precipitation hardening is essential for age hardenable Mg-based alloys. In this work, microstructural investigation of the Mg–1.4Sn–1.3Zn–0.1Mn (at.%) precipitation system was performed using TEM. The chemical composition of the precipitates was analyzed using EDS. APT was employed to obtain precise chemical information on the distribution of Zn in the microstructure. It was found from microstructural studies that different precipitates with varying sizes and phases were present; lath-shaped precipitates of the Mg2Sn phase have an incoherent interface with the matrix, unlike the lath-shaped MgZn2 precipitates. Furthermore, nano-sized precipitates dispersed in the microstructure with short-lath morphology can either be enriched with Sn or Zn. On the other hand, APT analysis revealed the strong repulsion between Sn and Zn atoms in a portion of the analysis volume. However, larger reconstruction volume required to identify the role of Zn is still limited to the optimization of specimen preparation.

  20. Beryllium Related Matter

    Energy Technology Data Exchange (ETDEWEB)

    Gaylord, R F

    2008-12-23

    In recent months, LLNL has identified, commenced, and implemented a series of interim controls, compensatory measures, and initiatives to ensure worker safety, and improve safety processes with regards to potential worker exposure to beryllium. Many of these actions have been undertaken in response to the NNSA Independent Review (COR-TS-5/15/2008-8550) received by LLNL in November of 2008. Others are the result of recent discoveries, events or incidents, and lessons learned, or were scheduled corrective actions from earlier commitments. Many of these actions are very recent in nature, or are still in progress, and vary in the formality of implementation. Actions are being reviewed for effectiveness as they progress. The documentation of implementation, and review of effectiveness, when appropriate, of these actions will be addressed as part of the formal Corrective Action Plan addressing the Independent Review. The mitigating actions taken fall into the following categories: (1) Responses to specific events/concerns; (2) Development of interim controls; (3) Review of ongoing activities; and (4) Performance improvement measures.

  1. Mineral resource of the month: beryllium

    Science.gov (United States)

    ,

    2013-01-01

    The article discusses information about Beryllium. It notes that Beryllium is a light metal that has a gray color. The metal is used in the production of parts and devices including bearings, computer-chip heat sinks, and output windows of X-ray tubes. The article mentions Beryllium's discovery in 1798 by French chemist, Louis-Nicolas Vanquelin. It cites that bertrandite and beryl are the principal mineral components for the commercial production of beryllium.

  2. Durable pd-based alloy and hydrogen generation membrane thereof

    Science.gov (United States)

    Benn, Raymond C.; Opalka, Susanne M.; Vanderspurt, Thomas Henry

    2010-02-02

    A durable Pd-based alloy is used for a H.sub.2-selective membrane in a hydrogen generator, as in the fuel processor of a fuel cell plant. The Pd-based alloy includes Cu as a binary element, and further includes "X", where "X" comprises at least one metal from group "M" that is BCC and acts to stabilize the .beta. BCC phase for stability during operating temperatures. The metal from group "M" is selected from the group consisting of Fe, Cr, Nb, Ta, V, Mo, and W, with Nb and Ta being most preferred. "X" may further comprise at least one metal from a group "N" that is non-BCC, preferably FCC, that enhances other properties of the membrane, such as ductility. The metal from group "N" is selected from the group consisting of Ag, Au, Re, Ru, Rh, Y, Ce, Ni, Ir, Pt, Co, La and In. The at. % of Pd in the binary Pd--Cu alloy ranges from about 35 at. % to about 55 at. %, and the at. % of "X" in the higher order alloy, based on said binary alloy, is in the range of about 1 at. % to about 15 at. %. The metals are selected according to a novel process.

  3. Several Issues in the Development of Ti-Nb-Based Shape Memory Alloys

    Science.gov (United States)

    Kim, Hee Young; Miyazaki, Shuichi

    2016-12-01

    Ni-free Ti-based shape memory alloys, particularly Ti-Nb-based alloys, have attracted increasing attraction since the early 2000s due to their wide application potentials in biomedical fields. Recently, there has been significant progress in understanding the martensitic transformation behavior of Ti-Nb-based alloys and many novel superelastic alloys have been developed. The superelastic properties of Ti-Nb-based alloys have been remarkably improved through the optimization of alloying elements and microstructure control. In this paper, in order to explore and establish the alloy design strategy, several important issues in the development of Ti-Nb-based shape memory alloys are reviewed. Particularly, the effects of alloying elements on the martensitic transformation temperature and the transformation strain are analyzed. The effects of omega phase and texture on the superelastic properties are also discussed.

  4. Beryllium--important for national defense

    Science.gov (United States)

    Boland, M.A.

    2012-01-01

    Beryllium is one of the lightest and stiffest metals, but there was little industrial demand for it until the 1930s and 1940s when the aerospace, defense, and nuclear sectors began using beryllium and its compounds. Beryllium is now classified by the U.S. Department of Defense as a strategic and critical material because it is used in products that are vital to national security. The oxide form of beryllium was identified in 1797, and scientists first isolated metallic beryllium in 1828. The United States is the world's leading source of beryllium. A single mine at Spor Mountain, Utah, produced more than 85 percent of the beryllium mined worldwide in 2010. China produced most of the remainder, and less than 2 percent came from Mozambique and other countries. National stockpiles also provide significant amounts of beryllium for processing. To help predict where future beryllium supplies might be located, U.S.Geological Survey (USGS) scientists study how and where beryllium resources are concentrated in Earth's crust and use that knowledge to assess the likelihood that undiscovered beryllium resources may exist. Techniques to assess mineral resources have been developed by the USGS to support the stewardship of Federal lands and to better evaluate mineral resource availability in a global context. The USGS also compiles statistics and information on the worldwide supply of, demand for, and flow of beryllium. These data are used to inform U.S. national policymaking.

  5. 10 CFR 850.33 - Beryllium emergencies.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Beryllium emergencies. 850.33 Section 850.33 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.33 Beryllium emergencies. (a) The responsible employer must comply with 29 CFR 1910.120(l) for...

  6. Beryllium metal I. experimental results on acute oral toxicity, local skin and eye effects, and genotoxicity.

    Science.gov (United States)

    Strupp, Christian

    2011-01-01

    The toxicity of soluble metal compounds is often different from that of the parent metal. Since no reliable data on acute toxicity, local effects, and mutagenicity of beryllium metal have ever been generated, beryllium metal powder was tested according to the respective Organisation for Economical Co-Operation and Development (OECD) guidelines. Acute oral toxicity of beryllium metal was investigated in rats and local effects on skin and eye in rabbits. Skin-sensitizing properties were investigated in guinea pigs (maximization method). Basic knowledge about systemic bioavailability is important for the design of genotoxicity tests on poorly soluble substances. Therefore, it was necessary to experimentally compare the capacities of beryllium chloride and beryllium metal to form ions under simulated human lung conditions. Solubility of beryllium metal in artificial lung fluid was low, while solubility in artificial lysosomal fluid was moderate. Beryllium chloride dissolution kinetics were largely different, and thus, metal extracts were used in the in vitro genotoxicity tests. Genotoxicity was investigated in vitro in a bacterial reverse mutagenicity assay, a mammalian cell gene mutation assay, a mammalian cell chromosome aberration assay, and an unscheduled DNA synthesis (UDS) assay. In addition, cell transformation was tested in a Syrian hamster embryo cell assay, and potential inhibition of DNA repair was tested by modification of the UDS assay. Beryllium metal was found not to be mutagenic or clastogenic based on the experimental in vitro results. Furthermore, treatment with beryllium metal extracts did not induce DNA repair synthesis, indicative of no DNA-damaging potential of beryllium metal. A cell-transforming potential and a tendency to inhibit DNA repair when the cell is severely damaged by an external stimulus were observed. Beryllium metal was also found not to be a skin or eye irritant, not to be a skin sensitizer, and not to have relevant acute oral

  7. A Report on the Validation of Beryllium Strength Models

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Derek Elswick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-05

    This report discusses work on validating beryllium strength models with flyer plate and Taylor rod experimental data. Strength models are calibrated with Hopkinson bar and quasi-static data. The Hopkinson bar data for beryllium provides strain rates up to about 4000 per second. A limitation of the Hopkinson bar data for beryllium is that it only provides information on strain up to about 0.15. The lack of high strain data at high strain rates makes it difficult to distinguish between various strength model settings. The PTW model has been calibrated many different times over the last 12 years. The lack of high strain data for high strain rates has resulted in these calibrated PTW models for beryllium exhibiting significantly different behavior when extrapolated to high strain. For beryllium, the α parameter of PTW has recently been calibrated to high precision shear modulus data. In the past the α value for beryllium was set based on expert judgment. The new α value for beryllium was used in a calibration of the beryllium PTW model by Sky Sjue. The calibration by Sjue used EOS table information to model the temperature dependence of the heat capacity. Also, the calibration by Sjue used EOS table information to model the density changes of the beryllium sample during the Hopkinson bar and quasi-static experiments. In this paper, the calibrated PTW model by Sjue is compared against experimental data and other strength models. The other strength models being considered are a PTW model calibrated by Shuh- Rong Chen and a Steinberg-Guinan type model by John Pedicini. The three strength models are used in a comparison against flyer plate and Taylor rod data. The results show that the Chen PTW model provides better agreement to this data. The Chen PTW model settings have been previously adjusted to provide a better fit to flyer plate data, whereas the Sjue PTW model has not been changed based on flyer plate data. However, the Sjue model provides a reasonable fit to

  8. The effect of selected alloying element additions on properties of Mg-based alloy as bioimplants: A literature review

    Science.gov (United States)

    Zhang, Li-Nan; Hou, Zeng-Tao; Ye, Xin; Xu, Zhao-Bin; Bai, Xue-Ling; Shang, Peng

    2013-09-01

    This review investigates the current application limitations of Mg and Mg alloys. The key issues hindering the application of biodegradable Mg alloys as implants are their fast degradation rate and biological consideration. We have discussed the effect of some selected alloying element additions on the properties of the Mg-based alloy, especially the nutrient elements in human (Zn, Mn, Ca, Sr). Different grain sizes, phase constituents and distributions consequently influence the mechanical properties of the Mg alloys. Solution strengthening and precipitation strengthening are enhanced by the addition of alloying elements, generally improving the mechanical properties. Besides, the hot working process can also improve the mechanical properties. Combination of different processing steps is suggested to be adopted in the fabrication of Mg-based alloys. Corrosion properties of these Mg-based alloys have been measured in vitro and in vivo. The degradation mechanism is also discussed in terms of corrosion types, rates, byproducts and response of the surrounding tissues. Moreover, the clinical response and requirements of degradable implants are presented, especially for the nutrient elements (Ca, Mn, Zn, Sr). This review provides information related to different Mg alloying elements and presents the promising candidates for an ideal implant.

  9. Neutron irradiation of beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S.; Ermi, R.M. [Pacific Northwest National Lab., Richland, WA (United States); Tsai, H. [Argonne National Lab., IL (United States)

    1998-03-01

    Seven subcapsules from the FFTF/MOTA 2B irradiation experiment containing 97 or 100% dense sintered beryllium cylindrical specimens in depleted lithium have been opened and the specimens retrieved for postirradiation examination. Irradiation conditions included 370 C to 1.6 {times} 10{sup 22} n/cm{sup 2}, 425 C to 4.8 {times} 10{sup 22} n/cm{sup 2}, and 550 C to 5.0 {times} 10{sup 22} n/cm{sup 2}. TEM specimens contained in these capsules were also retrieved, but many were broken. Density measurements of the cylindrical specimens showed as much as 1.59% swelling following irradiation at 500 C in 100% dense beryllium. Beryllium at 97% density generally gave slightly lower swelling values.

  10. Beryllium strain under dynamic loading

    Directory of Open Access Journals (Sweden)

    Pushkov Victor

    2015-01-01

    Full Text Available There are some data (not much on dynamic characteristics of beryllium that are important, for example, when estimating construction performance at NPP emergencies. A number of data on stress-strain curves, spall strength, shear strength, fracture and structure responses of shock loaded beryllium have obtained in US and Russian laboratories. For today the model description of this complex metal behavior does not have a reasonable agreement with the experimental data, thus a wider spectrum of experimental data is required. This work presents data on dynamic compression-test diagrams of Russian beryllium. Experiments are performed using Hopkinson bar method (SHPB. Strain rates were ε ∼ 103 s−1.

  11. Recrystallization characteristics of oxide dispersion strengthened nickel-base alloys

    Science.gov (United States)

    Hotzler, R. K.; Glasgow, T. K.

    1980-01-01

    Electron microscopy was employed to study the process of recrystallization in two oxide dispersion strengthened (ODS) mechanically alloyed nickel-base alloys, MA 754 and MA 6000E. MA 754 contained both fine, uniformly dispersed particles and coarser oxides aligned along the working direction. Hot rolled MA 754 had a grain size of 0.5 microns and high dislocation densities. After partial primary recrystallization, the fine grains transformed to large elongated grains via secondary (or abnormal) grain growth. Extruded and rolled MA 6000E contained equiaxed grains of 0.2 micron diameter. Primary recrystallization occurring during working eliminated virtually all dislocations. Conversion from fine to coarse grains was triggered by gamma prime dissolution; this was also a process of secondary or abnormal grain growth. Comparisons were made to conventional and oxide dispersion strengthened nickel-base alloys.

  12. Weldability and Microstructure of Nickel-Silicon Based Alloys

    Institute of Scientific and Technical Information of China (English)

    LIU Qing-cai; LIU Yi; YANG Jian; J.W.Newkirk; ZHANG Shan-hong

    2006-01-01

    The NiSix based alloy typically has poor weldability due to its lower ductility. A limited amount of work has been performed on the weldability of NiSix based alloys. Therefore, the effect of heat treatment and welding parameters on weldability of the alloys, and the relationship between the weldability and microstructure were studied. The results show that the as-cast Ni-Si-Nb-B alloy (Ni 76.5%, Si 20%, Nb 3%, and B 0.5%) could be successfully welded after preheating at 600 ℃. The welding procedure should be performed on the alloys before any heat treatment and a preheating at 600 ℃ should be used. The fusion zone is harder than the matrix due to a large amount of γ phase and a finer microstructure. The cracks are predominantly intergranular in heat affected zone and associated with the needle-like γ phase. The heat treatment before welding increases the tendency of cracking in the fusion zone.

  13. Cr{sub 2}Nb-based alloy development

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.T.; Tortorelli, P.F.; Horton, J.A.; Easton, D.S.; Heatherly, L.

    1996-06-01

    The objective of this work is to develop a new generation of structural materials based on intermetallic alloys for use at high temperatures in advanced fossil energy conversion systems. Target applications of such ultrahigh strength alloys include hot components (for example, air heat exchangers) in advanced energy conversion systems and heat engines. However, these materials may also find use as wear-resistant parts in coal handling systems (for example, nozzles), drill bits for oil/gas wells, and valve guides in diesel engines. One potential class of such alloys is that based on Cr-Cr{sub 2}Nb alloys. The intermetallic phase, Cr{sub 2}Nb, with a complex cubic structure (C-15) has been selected for initial development because of its high melting point (1770{degrees}C), relatively low material density (7.7 g/cm{sup 2}), and excellent high-temperature strength (at 1000 to 1250{degrees}C). This intermetallic phase, like many other Laves phases, has a wide range of compositional homogeneity suggesting the possibility of improving its mechanical and metallurgical properties by alloying additions.

  14. Melting and casting of FeAl-based cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K. [Oak Ridge National Lab., TN (United States); Wilkening, D. [Columbia Falls Aluminum Co., Columbia Falls, MT (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., Anaconda, MT (United States)

    1998-11-01

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{trademark} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast.

  15. Melting and casting of FeAl-based cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Wilkening, D. [Columbia Falls Aluminum Co., 2000 Aluminum Dr., Columbia Falls, MT 59912 (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., P.O. Box 1071, Anaconda, MT 59711 (United States)

    1998-12-31

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{sup TM} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast. (orig.) 18 refs.

  16. Estimation of beryllium ground state energy by Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kabir, K. M. Ariful [Department of Physical Sciences, School of Engineering and Computer Science, Independent University, Bangladesh (IUB) Dhaka (Bangladesh); Halder, Amal [Department of Mathematics, University of Dhaka Dhaka (Bangladesh)

    2015-05-15

    Quantum Monte Carlo method represent a powerful and broadly applicable computational tool for finding very accurate solution of the stationary Schrödinger equation for atoms, molecules, solids and a variety of model systems. Using variational Monte Carlo method we have calculated the ground state energy of the Beryllium atom. Our calculation are based on using a modified four parameters trial wave function which leads to good result comparing with the few parameters trial wave functions presented before. Based on random Numbers we can generate a large sample of electron locations to estimate the ground state energy of Beryllium. Our calculation gives good estimation for the ground state energy of the Beryllium atom comparing with the corresponding exact data.

  17. Thermodynamic and structural properties of Bi-based liquid alloys

    Science.gov (United States)

    Yadav, S. K.; Jha, L. N.; Adhikari, D.

    2015-10-01

    Thermodynamic and microscopic structural properties of two Bi-based liquid alloys, such as In-Bi at 900 K and Tl-Bi at 750 K have been studied employing the regular associated solution model. We have estimated the mole fractions of the complexes and the free monomers assuming the existence of complexes In2 Bi in In-Bi melt and TlBi in Tl-Bi melt. The thermodynamic properties have been studied by computing the Gibbs free energy of mixing, enthalpy of mixing, entropy of mixing and activities of the monomers. The compositional contributions of the heat associated with the formation of complexes and the heat of mixing of the monomers to the net enthalpy change has also been studied. The structural properties of the liquid alloys have been studied by computing concentration fluctuation in the long-wavelength limit, chemical short-range order parameter and the ratio of mutual to intrinsic diffusion coefficients. For both of the alloy systems, the theoretical as well as the experimental values of SCC (0) are found to be lower than the corresponding ideal values over the whole composition range, indicating the hetero-coordinating nature of Bi-In and Bi-Tl alloy melts. All the interaction energy parameters are found to be negative and temperature dependent, and both the alloy systems are found to be weakly interacting.

  18. [Dimensional changes of silver and gallium-based alloy].

    Science.gov (United States)

    Ballester, R Y; Markarian, R A; Loguercio, A D

    2001-01-01

    Gallium-based dental alloys were created with the aim of solving the problem of toxicity of mercury. The material shows mechanical properties similar to those of dental amalgam, but researches point out two unfavorable characteristics: great corrosion and excessive post-setting expansion, and the latter is capable of cracking dental structures. The aim of this study was to evaluate, during 7 days, the in vitro dimensional alteration of a gallium dental alloy (Galloy, SDI, Australia), in comparison with a dental amalgam containing zinc (F400, SDI, Australia), as a function of the contact with saline solution (0.9% NaCl) during the setting period. The storage experimental conditions were: storage in dry environment, immersion in saline solution and contamination during condensation. Additionally, the effects of contamination during the trituration of dental amalgam and the effects of protecting the surface of the gallium alloy with a fluid resin were studied. Specimens were stored at 37 degrees C +/- 1 degree C, and measuring was carried out, sequentially, every 24 h during 7 days. When the gallium alloy was either contaminated or immersed, an expansion significantly greater than that observed in the other experimental conditions was noticed after 7 days. The application of a fluid resin to protect the surface of the cylinders was able to avoid the increase in expansion caused by superficial moisture. The amalgam alloy did not show significant dimensional alterations, except when it was contaminated during trituration.

  19. Improved Mg-based alloys for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Sapru, K.; Ming, L.; Stetson, N.T.; Evans, J. [Energy Conversion Devices, Inc., Troy, MI (United States)

    1998-08-01

    The overall objective of this on-going work is to develop low temperature alloys capable of reversibly storing at least 3 wt.% hydrogen, allowing greater than for 2 wt.% at the system level which is required by most applications. Surface modification of Mg can be used to improve its H-sorption kinetics. The authors show here that the same Mg-transition metal-based multi-component alloy when prepared by melt-spinning results in a more homogeneous materials with a higher plateau pressure as compared to preparing the material by mechanical grinding. They have also shown that mechanically alloyed Mg{sub 50}Al{sub 45}Zn{sub 5} results in a sample having a higher plateau pressure.

  20. Solid state bonding of beryllium-copper for an ITER first wall application

    Energy Technology Data Exchange (ETDEWEB)

    Odegard, B.C. Jr.; Cadden, C.H. [Sandia National Labs., Livermore, CA (United States)

    1998-01-01

    Several different joint assemblies were evaluated in support of a manufacturing technology for diffusion bonding a beryllium armor tile to a copper alloy heat sink for fusion reactor applications. Because beryllium reacts with all but a few elements to form intermetallic compounds, this study considered several different surface treatments as a means of both inhibiting these reactions and promoting a good diffusion bond between the two substrates. All diffusion bonded assemblies used aluminum or an aluminum-beryllium composite (AlBeMet-150) as the interfacial material in contact with beryllium. In most cases, explosive bonding was utilized as a technique for joining the copper alloy heat sink to an aluminum or AlBeMet-150 substrate, which was subsequently diffusion bonded to an aluminum coated beryllium tile. In this approach, a 250 {mu}m thick titanium foil was used as a diffusion barrier between the copper and aluminum to prevent the formation of Cu-Al intermetallic phases. In all cases, a hot isostatic pressing (HIP) furnace was used in conjunction with canned assemblies in order to minimize oxidation and apply sufficient pressure on the assembly for excellent metal-to-metal contact and subsequent bonding. Several different processing schedules were evaluated during the course of this study; bonded assemblies were produced that failed outside the bond area indicating a 100% joint efficiency. (author)

  1. Field-emission spectroscopy of beryllium atoms adsorbed on tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Czyzewski, J.J.; Grzesiak, W.; Krajniak, J. (Politechnika Wroclawska (Poland))

    1981-01-01

    Field emission energy distributions (FEED) have been measured for the beryllium-tungsten (023) adsorption system over the 78-450 K temperature range. A temperature dependence of the normalized half-width, ..delta../d, of FEED peaks changed significantly due to beryllium adsorption; and the curve, ..delta../d vs p, for the Be/W adsorption system was identical in character to the calculated curve based on the free electron model in contrast to the curve for the clean tungsten surface. In the last part of this paper Gadzuk's theory of the resonance-tunneling effect is applied to the beryllium atom on tungsten. Experimental and theoretical curves of the enhancement factor as a function of energy have been discussed.

  2. Monte Carlo uncertainty analyses for integral beryllium experiments

    CERN Document Server

    Fischer, U; Tsige-Tamirat, H

    2000-01-01

    The novel Monte Carlo technique for calculating point detector sensitivities has been applied to two representative beryllium transmission experiments with the objective to investigate the sensitivity of important responses such as the neutron multiplication and to assess the related uncertainties due to the underlying cross-section data uncertainties. As an important result, it has been revealed that the neutron multiplication power of beryllium can be predicted with good accuracy using state-of-the-art nuclear data evaluations. Severe discrepancies do exist for the spectral neutron flux distribution that would transmit into significant uncertainties of the calculated neutron spectra and of the nuclear blanket performance in blanket design calculations. With regard to this, it is suggested to re-analyse the secondary energy and angle distribution data of beryllium by means of Monte Carlo based sensitivity and uncertainty calculations. Related code development work is underway.

  3. Diffusion Bonding between TiAl Based Alloys and Steels

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The joint of 40Cr steel and TiAl based alloy has been studied by means of a high frequency induction diffusion welder. The experimental results show that, the higher the temperature and pressure, the higher the strength of the joints. The optimum parameters are: T=1123~1323 K,t=10~30 min, P=5~20 MPa.

  4. Novel alginate based coatings on Mg alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sangeetha, K.; Roy, Abhijit [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Singh, Satish [Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Lee, Boeun [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Center for Craniofacial Regeneration, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Center for Complex Engineered Multifunctional Materials, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

    2011-12-15

    Coatings on yttrium doped magnesium (Mg4Y) alloy substrates were prepared using alginate hydrogels by dip coating method to improve the surface bioactive properties of the substrate. Furthermore, composite coatings containing nano-sized calcium phosphate corresponding to hydroxyapatite (HA) phase entrapped within alginate hydrogel were also synthesized on the Mg4Y substrates. Surface characteristics of these coated substrates have been investigated using FTIR-ATR, SEM and EDS. The results show that the coatings with alginate alone are not stable in vitro; however, incorporation of NanoCaPs slightly improves the stability of these coatings. In addition, these composite coatings showed cell attachments with fibronectin incorporation. These results indicate that alginate hydrogels have the potential to be used as bioactive coating materials for different biofunctional applications.

  5. Worker Environment Beryllium Characterization Study

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environment, Safety, Health & Quality

    2009-12-28

    This report summarizes the conclusion of regular monitoring of occupied buildings at the Nevada Test Site and North Las Vegas facility to determine the extent of beryllium (Be) contamination in accordance with Judgment of Needs 6 of the August 14, 2003, “Minnema Report.”

  6. Zirconium-based alloys, nuclear fuel rods and nuclear reactors including such alloys, and related methods

    Science.gov (United States)

    Mariani, Robert Dominick

    2014-09-09

    Zirconium-based metal alloy compositions comprise zirconium, a first additive in which the permeability of hydrogen decreases with increasing temperatures at least over a temperature range extending from 350.degree. C. to 750.degree. C., and a second additive having a solubility in zirconium over the temperature range extending from 350.degree. C. to 750.degree. C. At least one of a solubility of the first additive in the second additive over the temperature range extending from 350.degree. C. to 750.degree. C. and a solubility of the second additive in the first additive over the temperature range extending from 350.degree. C. to 750.degree. C. is higher than the solubility of the second additive in zirconium over the temperature range extending from 350.degree. C. to 750.degree. C. Nuclear fuel rods include a cladding material comprising such metal alloy compositions, and nuclear reactors include such fuel rods. Methods are used to fabricate such zirconium-based metal alloy compositions.

  7. Alloy

    Science.gov (United States)

    Cabeza, Sandra; Garcés, Gerardo; Pérez, Pablo; Adeva, Paloma

    2014-07-01

    The Mg98.5Gd1Zn0.5 alloy produced by a powder metallurgy route was studied and compared with the same alloy produced by extrusion of ingots. Atomized powders were cold compacted and extruded at 623 K and 673 K (350 °C and 400 °C). The microstructure of extruded materials was characterized by α-Mg grains, and Mg3Gd and 14H-LPSO particles located at grain boundaries. Grain size decreased from 6.8 μm in the extruded ingot, down to 1.6 μm for powders extruded at 623 K (350 °C). Grain refinement resulted in an increase in mechanical properties at room and high temperatures. Moreover, at high temperatures the PM alloy showed superplasticity at high strain rates, with elongations to failure up to 700 pct.

  8. Replacement of Cobalt base alloys hardfacing by NOREM alloy; EDF experience and development, some metallurgical considerations. Valves application (CLAMA, RAMA)

    Energy Technology Data Exchange (ETDEWEB)

    Carnus, M. [EDF DPN UTO Direction Expertise Technique, Noisy le Grand (France); Confort, X. [VELAN SAS, Lyon (France)

    2011-07-01

    Cobalt base alloys, such as Stellite 6 and 21, are used extensively in applications where superior resistance to wear and corrosion are required. However the use of Cobalt alloys hardfacing materials, especially on valves, is a major contributor to the level of radioactive contamination of nuclear facilities. NOREM alloys, an iron base and cobalt free materials, have been developed through an Electric Power Research Institute (EPRI) long running program during the eighties as an alternative of Stellite. This alloy has relatively good weldability properties, it was developed initially for repairing Stellite hardfacing (deposit over existing hardfacing alloys). This alloy has good corrosion resistance properties associated with elevated hardness (HRC 36-42). Technological properties (such as galling resistance, wear resistance) have been evaluated through different testing programs led by EPRI, AECL(Atomic Energy of Canada Limited), Valves manufacturers, EDF and others during the nineties. More recently EDF (for replacement of globe valves) has carried out testing program focused on weld deposit chemistry and mechanical properties. NOREM is a candidate for replacement of stellite hardfacing on valves. However this alloy is not so versatile as stellite alloys regarding technological properties (such as wear resistance) at elevated temperature and under high contact pressure. As a consequence some limits have to be considered for application on valves operating at elevated temperature and under high contact pressure (> 20 Mpa). Examples of application on valves, from VELAN manufacturer, for EDF PWR equipment are given. The industrial feedback from installed equipment (CLAMA, RAMA) since 2006 on EDF PWR has been good

  9. Melt Protection of Mg-Al Based Alloys

    Directory of Open Access Journals (Sweden)

    María J. Balart

    2016-05-01

    Full Text Available This paper reports the current status of Mg melt protection in view to identify near-future challenges, but also opportunities, for Mg melt protection of Mg-Al based alloys. The goal is to design and manufacture sustainable Mg alloys for resource efficiency, recycling and minimising waste. Among alternative cover gas technologies for Mg melt protection other than SF6: commercially available technologies containing―HFC-134a, fluorinated ketone and dilute SO2―and developed technologies containing solid CO2, BF3 and SO2F2, can potentially produce toxic and/or corrosive by-products. On the other hand, additions of alkaline earth metal oxides to Mg and its alloys have developed a strong comparative advantage in the field of Mg melt protection. The near-future challenges and opportunities for Mg-Al based alloys include optimising and using CO2 gas as feedstock for both melt protection and grain refinement and TiO2 additions for melt protection.

  10. Corrosion resistance of Fe-based amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Botta, W.J., E-mail: wjbotta@ufscar.br [LEPMI, UMR5279 CNRS, Grenoble INP, Université de Savoie, Université Joseph Fourier, 1130, Rue de la piscine, BP 75, 38402 Saint Martin d’Hères (France); Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil); Berger, J.E.; Kiminami, C.S. [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil); Roche, V.; Nogueira, R.P. [LEPMI, UMR5279 CNRS, Grenoble INP, Université de Savoie, Université Joseph Fourier, 1130, Rue de la piscine, BP 75, 38402 Saint Martin d’Hères (France); Bolfarini, C. [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil)

    2014-02-15

    Highlights: ► We report corrosion properties of Fe-based amorphous alloys in different media. ► The Cr-containing alloys had corrosion resistance close to that of Pt in all media. ► The wide range of electrochemical stability is relevant in many industrial domains. -- Abstract: Fe-based amorphous alloys can be designed to present an attractive combination of properties with high corrosion resistance and high mechanical strength. Such properties are clearly adequate for their technological use as coatings, for example, in steel pipes. In this work, we studied the corrosion properties of amorphous ribbons of the following Fe-based compositions: Fe{sub 66}B{sub 30}Nb{sub 4}, [(Fe{sub 0.6}Co{sub 0.4}){sub 0.75}B{sub 0.2}Si{sub 0.05}]{sub 96}Nb{sub 4}, [(Fe{sub 0.7}Co{sub 0.3}){sub 0.75}B{sub 0.2}Si{sub 0.05}]{sub 96}Nb{sub 4}, Fe{sub 56}Cr{sub 23}Ni{sub 5.7}B{sub 16}, Fe{sub 53}Cr{sub 22}Ni{sub 5.6}B{sub 19} and Fe{sub 50}Cr{sub 22}Ni{sub 5.4}B{sub 23}. The ribbons were obtained by rapid solidification using the melt-spinning process, and were characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and optical (OM) and scanning electron microscopy (SEM). The corrosion properties were evaluated by corrosion potential survey and potentiodynamic polarization. The Cr containing alloys, that is the FeCrNiB type of alloys, showed the best corrosion resistance properties with the formation of a stable passive film that ensured a very large passivation plateau.

  11. OVERVIEW OF BERYLLIUM SAMPLING AND ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Brisson, M

    2009-04-01

    Because of its unique properties as a lightweight metal with high tensile strength, beryllium is widely used in applications including cell phones, golf clubs, aerospace, and nuclear weapons. Beryllium is also encountered in industries such as aluminium manufacturing, and in environmental remediation projects. Workplace exposure to beryllium particulates is a growing concern, as exposure to minute quantities of anthropogenic forms of beryllium may lead to sensitization and to chronic beryllium disease, which can be fatal and for which no cure is currently known. Furthermore, there is no known exposure-response relationship with which to establish a 'safe' maximum level of beryllium exposure. As a result, the current trend is toward ever lower occupational exposure limits, which in turn make exposure assessment, both in terms of sampling and analysis, more challenging. The problems are exacerbated by difficulties in sample preparation for refractory forms of beryllium, such as beryllium oxide, and by indications that some beryllium forms may be more toxic than others. This chapter provides an overview of sources and uses of beryllium, health risks, and occupational exposure limits. It also provides a general overview of sampling, analysis, and data evaluation issues that will be explored in greater depth in the remaining chapters. The goal of this book is to provide a comprehensive resource to aid personnel in a wide variety of disciplines in selecting sampling and analysis methods that will facilitate informed decision-making in workplace and environmental settings.

  12. Analysis of thermoelectric properties of high-temperature complex alloys of nickel-base, iron-base and cobalt-base groups

    Science.gov (United States)

    Holanda, R.

    1984-01-01

    The thermoelectric properties alloys of the nickel-base, iron-base, and cobalt-base groups containing from 1% to 25% 106 chromium were compared and correlated with the following material characteristics: atomic percent of the principle alloy constituent; ratio of concentration of two constituents; alloy physical property (electrical resistivity); alloy phase structure (percent precipitate or percent hardener content); alloy electronic structure (electron concentration). For solid-solution-type alloys the most consistent correlation was obtained with electron concentration, for precipitation-hardenable alloys of the nickel-base superalloy group, the thermoelectric potential correlated with hardener content in the alloy structure. For solid-solution-type alloys, no problems were found with thermoelectric stability to 1000; for precipitation-hardenable alloys, thermoelectric stability was dependent on phase stability. The effects of the compositional range of alloy constituents on temperature measurement uncertainty are discussed.

  13. Temperature of phase transformations in heat-resistant nickel-base alloys

    Science.gov (United States)

    Ivanov, A. D.; Ukhlinov, A. G.

    1997-11-01

    The study of phase transformations in heating and cooling of alloys is needed for choosing optimum regimes of their melting, plastic deformation, and heat treatment. In the present paper differential thermal analysis is used to determine the temperature of phase transformations in complexly alloyed nickel-base alloys. Industrial nickel alloys with intermetallic reinforcement manufactured by means of vacuum arc remelting (VAR) and hot deformation (HD) were studied. Alloy KhN56MBYuD was studied after different metallurgical processes, namely, electroslag remelting (ESR), centrifugal casting (CC), powder spraying (PS), and hot isostatic pressing (HIP). All the alloys were studied in the initial state and after heat treatment.

  14. Effect of Impurities and Cerium on Stress Concentration Sensitivity of Al-Li Based Alloys

    Institute of Scientific and Technical Information of China (English)

    孟亮; 田丽

    2002-01-01

    A notch sensitivity factor was derived in order to evaluate the stress concentration sensitivity of Al-Li based alloys. The factor values for the Al-Li alloy sheets containing various contents of impurities and cerium addition were evaluated by determining the mechanical properties. It is found that the impurities Fe, Si, Na and K significantly enhance the stress concentration sensitivity of the alloys 2090 and 8090, whereas cerium addition reduces the stress concentration sensitivity to a certain degree for the high strength alloys. However, an excess amount of cerium addition in the high ductility alloy 1420 can significantly increase the stress concentration sensitivity. As compared with conventional aluminum alloys, the Al-Li based alloys generally show high stress concentration sensitivity. Therefore, a special attention must be paid to this problem in the practical application of Al-Li based alloys.

  15. Nitriding behavior of Ni and Ni-based binary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Fonovic, Matej

    2015-01-15

    Gaseous nitriding is a prominent thermochemical surface treatment process which can improve various properties of metallic materials such as mechanical, tribological and/or corrosion properties. This process is predominantly performed by applying NH{sub 3}+H{sub 2} containing gas atmospheres serving as the nitrogen donating medium at temperatures between 673 K and 873 K (400 C and 600 C). NH{sub 3} decomposes at the surface of the metallic specimen and nitrogen diffuses into the surface adjacent region of the specimen whereas hydrogen remains in the gas atmosphere. One of the most important parameters characterizing a gaseous nitriding process is the so-called nitriding potential (r{sub N}) which determines the chemical potential of nitrogen provided by the gas phase. The nitriding potential is defined as r{sub N} = p{sub NH{sub 3}}/p{sub H{sub 2}{sup 3/2}} where p{sub NH{sub 3}} and p{sub H{sub 2}} are the partial pressures of the NH{sub 3} and H{sub 2} in the nitriding atmosphere. In contrast with nitriding of α-Fe where the nitriding potential is usually in the range between 0.01 and 1 atm{sup -1/2}, nitriding of Ni and Ni-based alloys requires employing nitriding potentials higher than 100 atm{sup -1/2} and even up to ∞ (nitriding in pure NH{sub 3} atmosphere). This behavior is compatible with decreased thermodynamic stability of the 3d-metal nitrides with increasing atomic number. Depending on the nitriding conditions (temperature, nitriding potential and treatment time), different phases are formed at the surface of the Ni-based alloys. By applying very high nitriding potential, formation of hexagonal Ni{sub 3}N at the surface of the specimen (known as external nitriding) leads to the development of a compound layer, which may improve tribological properties. Underneath the Ni{sub 3}N compound layer, two possibilities exist: (i) alloying element precipitation within the nitrided zone (known as internal nitriding) and/or (ii) development of metastable and

  16. Investigation of the Precipitation Behavior in Aluminum Based Alloys

    KAUST Repository

    Khushaim, Muna S.

    2015-11-30

    The transportation industries are constantly striving to achieve minimum weight to cut fuel consumption and improve overall performance. Different innovative design strategies have been placed and directed toward weight saving combined with good mechanical behavior. Among different materials, aluminum-based alloys play a key role in modern engineering and are widely used in construction components because of their light weight and superior mechanical properties. Introduction of different nano-structure features can improve the service and the physical properties of such alloys. For intelligent microstructure design in the complex Al-based alloy, it is important to gain a deep physical understanding of the correlation between the microstructure and macroscopic properties, and thus atom probe tomography with its exceptional capabilities of spatially resolution and quantitative chemical analyses is presented as a sophisticated analytical tool to elucidate the underlying process of precipitation phenomena in aluminum alloys. A complete study examining the influence of common industrial heat treatment on the precipitation kinetics and phase transformations of complex aluminum alloy is performed. The qualitative evaluation results of the precipitation kinetics and phase transformation as functions of the heat treatment conditions are translated to engineer a complex aluminum alloy. The study demonstrates the ability to construct a robust microstructure with an excellent hardness behavior by applying a low-energy-consumption, cost-effective method. The proposed strategy to engineer complex aluminum alloys is based on both mechanical strategy and intelligent microstructural design. An intelligent microstructural design requires an investigation of the different strengthen phases, such as T1 (Al2CuLi), θ′(Al2Cu), β′(Al3Zr) and δ′(Al3Li). Therefore, the early stage of phase decomposition is examined in different binary Al-Li and Al-Cu alloys together with different

  17. Beryllium Lymphocyte Proliferation Test Surveillance Identifies Clinically Significant Beryllium Disease

    Science.gov (United States)

    Mroz, Margaret M.; Maier, Lisa A.; Strand, Matthew; Silviera, Lori; Newman, Lee S.

    2011-01-01

    Background Workplace surveillance identifies chronic beryllium disease (CBD) but it remains unknown over what time frame mild CBD will progress to a more severe form. Methods We examined physiology and treatment in 229 beryllium sensitization (BeS) and 171 CBD surveillance-identified cases diagnosed from 1982 to 2002. Never smoking CBD cases (81) were compared to never smoking BeS patients (83) to assess disease progression. We compared CBD machinists to non-machinists to examine effects of exposure. Results At baseline, CBD and BeS cases did not differ significantly in exposure time or physiology. CBD patients were more likely to have machined beryllium. Of CBD cases, 19.3% went on to require oral immunosuppressive therapy. At 30 years from first exposure, measures of gas exchange were significantly worse and total lung capacity was lower for CBD subjects. Machinists had faster disease progression as measured by pulmonary function testing and gas exchange. Conclusions Medical surveillance for CBD identifies individuals at significant risk of disease progression and impairment with sufficient time since first exposure. PMID:19681064

  18. CuZn Alloy- Based Electrocatalyst for CO2 Reduction

    KAUST Repository

    Alazmi, Amira

    2014-06-01

    ABSTRACT CuZn Alloy- Based Electrocatalyst for CO2 Reduction Amira Alazmi Carbon dioxide (CO2) is one of the major greenhouse gases and its emission is a significant threat to global economy and sustainability. Efficient CO2 conversion leads to utilization of CO2 as a carbon feedstock, but activating the most stable carbon-based molecule, CO2, is a challenging task. Electrochemical conversion of CO2 is considered to be the beneficial approach to generate carbon-containing fuels directly from CO2, especially when the electronic energy is derived from renewable energies, such as solar, wind, geo-thermal and tidal. To achieve this goal, the development of an efficient electrocatalyst for CO2 reduction is essential. In this thesis, studies on CuZn alloys with heat treatments at different temperatures have been evaluated as electrocatalysts for CO2 reduction. It was found that the catalytic activity of these electrodes was strongly dependent on the thermal oxidation temperature before their use for electrochemical measurements. The polycrystalline CuZn electrode without thermal treatment shows the Faradaic efficiency for CO formation of only 30% at applied potential ~−1.0 V vs. RHE with current density of ~−2.55 mA cm−2. In contrast, the reduction of oxide-based CuZn alloy electrode exhibits 65% Faradaic efficiency for CO at lower applied potential about −1.0 V vs. RHE with current density of −2.55 mA cm−2. Furthermore, stable activity was achieved over several hours of the reduction reaction at the modified electrodes. Based on electrokinetic studies, this improvement could be attributed to further stabilization of the CO2•− on the oxide-based Cu-Zn alloy surface.

  19. Mutagenicity, carcinogenicity and teratogenicity of beryllium.

    Science.gov (United States)

    Léonard, A; Lauwerys, R

    1987-07-01

    The carcinogenicity of a number of beryllium compounds has been confirmed in experiments on laboratory animals and this metal has to be treated as a possible carcinogenic threat to man. These carcinogenic properties are associated with mutagenic activity as shown by the results of short-term tests performed in vitro with beryllium chloride and beryllium sulfate. These soluble beryllium compounds can produce some infidelity of in vitro synthesis, forward gene mutations in microorganisms and in mammalian cells. They are also able to induce cell transformation. In addition to the positive results obtained in several short-term assays beryllium compounds have been found to bind to nucleoproteins, to inhibit certain enzymes needed for DNA synthesis, to bind nucleic acids to cell membranes and to inhibit microtubule polymerization. The teratogenicity of beryllium salts is relatively unknown and needs additional investigation.

  20. Advances in identifying beryllium sensitization and disease.

    Science.gov (United States)

    Middleton, Dan; Kowalski, Peter

    2010-01-01

    Beryllium is a lightweight metal with unique qualities related to stiffness, corrosion resistance, and conductivity. While there are many useful applications, researchers in the 1930s and 1940s linked beryllium exposure to a progressive occupational lung disease. Acute beryllium disease is a pulmonary irritant response to high exposure levels, whereas chronic beryllium disease (CBD) typically results from a hypersensitivity response to lower exposure levels. A blood test, the beryllium lymphocyte proliferation test (BeLPT), was an important advance in identifying individuals who are sensitized to beryllium (BeS) and thus at risk for developing CBD. While there is no true "gold standard" for BeS, basic epidemiologic concepts have been used to advance our understanding of the different screening algorithms.

  1. Synthesis and characterization of nanostructured palladium-based alloy electrocatalysts

    Science.gov (United States)

    Sarkar, Arindam

    Low temperature fuel cells like proton exchange membrane fuel cells (PEMFC) are expected to play a crucial role in the future hydrogen economy, especially for transportation applications. These electrochemical devices offer significantly higher efficiency compared to conventional heat engines. However, use of exotic and expensive platinum as the electrocatalyst poses serious problems for commercial viability. In this regard, there is an urgent need to develop low-platinum or non-platinum electrocatalysts with electrocatalytic activity for the oxygen reduction reaction (ORR) superior or comparable to that of platinum. This dissertation first investigates non-platinum, palladium-based alloy electrocatalysts for ORR. Particularly, Pd-M (M = Mo and W) alloys are synthesized by a novel thermal decomposition of organo-metallic precursors. The carbon-supported Pd-M (M = Mo, W) electrocatalyts are then heat treated up to 900°C in H2 atmosphere and investigated for their phase behavior. Cyclic voltammetry (CV) and rotating disk electrode (RDE) measurements reveal that the alloying of Pd with Mo or W significantly enhances the catalytic activity for ORR as well as the stability (durability) of the electrocatalysts. Additionally, both the alloy systems exhibit high tolerance to methanol, which is particularly advantageous for direct methanol fuel cells (DMFC). The dissertation then focuses on one-pot synthesis of carbon-supported multi-metallic Pt-Pd-Co nanoalloys by a rapid microwave-assisted solvothermal (MW-ST) method. The multi-metallic alloy compositions synthesized by the MW-ST method show much higher catalytic activity for ORR compared to their counterparts synthesized by the conventional borohydride reduction method. Additionally, a series of Pt encapsulated Pd-Co nanoparticle electrocatalysts are synthesized by the MW-ST method and characterized to understand their phase behavior, surface composition, and electrocatalytic activity for ORR. Finally, the dissertation

  2. Cr{sub 2}Nb-based alloy development

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.T.; Tortorelli, P.F.; Horton, J.A. [Oak Ridge National Lab., TN (United States)] [and others

    1995-06-01

    The objective of this task is to develop a new generation of structural materials based on intermetallic alloys for use as critical hot components in advanced fossil energy conversion systems. The intermetallic phase, Cr{sub 2}Nb, with a complex cubic structure (C-15) has been selected for this development because of its high melting point (1770{degrees}C), relatively low material density (7.7 g/cm{sup 2}), excellent high-temperature strength (at 1000 to 1250{degrees}C), and potential resistance to oxidation and corrosion. This intermetallic phase, like many other Laves phases, has a wide range of compositional homogeneity suggesting the possibility of improving its mechanical and metallurgical properties by alloying additions. The major engineering concern with Cr{sub 2}Nb and other A{sub 2}B Laves phases is their poor fracture toughness and fracture resistance at ambient temperatures. The single-phase Cr{sub 2}Nb is very hard ({approximately}800 DPH) and brittle at room temperature. Because of this brittleness, the development effort has concentrated on two-phase structures containing the hard intermetallic phase Cr{sub 2}Nb and the softer Cr-rich solid solution phase. Potential applications of Cr-Cr{sub 2}Nb alloys include hot components (for example, air heat exchangers and turbine blades) in advanced energy conversion systems and heat engines, wear-resistant parts in coal handling systems (e.g., nozzles), drill bits for oil/gas wells, and valve guides in diesel engines. Current studies are focuses on enhancement of fracture resistance in tension at ambient temperatures and oxidation resistance above 1000{degrees}C. This report summarizes recent progress on controlling microstructure and improving the mechanical and metallurgical properties and the high-temperature corrosion behavior of Cr-Cr{sub 2}Nb alloys through alloying conditions, material processing, and heat treatment.

  3. Synthesis of metastable aluminum-based intermetallics by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, R.B.; Srinivasan, S.; Desch, P.B.

    1991-01-01

    We have used mechanical alloying (MA) to prepare fine-grained powders of Al 25 at. % X (X = Ti, Zr, Hf) having the metastable cubic L1{sub 2} structure. Hexane (C{sub 6}H{sub 14}) is added to the milling media to avoid the agglomeration of the aluminum powder. Carbon from the decomposition of the hexane incorporates into the powder to form a fine dispersion of carbides. These carbides are beneficial because they limit grain growth during consolidation and add strength to the alloy. We have consolidated the mechanically alloyed powders using conventional hot-pressing and non-conventional dynamic pressing. We used hot pressing to consolidate mechanically alloyed L1{sub 2}-Al{sub 3}Ti powder in the presence of excess of Al. The compact has the DO{sub 22} structure. Its room-temperature compressive strength is 1.2 GPa (exceeding that of cast Al{sub 3}Ti by a factor of 10). At 400{degrees}C, the compressive strength decreases to 1 GPa. The ductility, which is negligible at room temperature, increases to 6% at 400{degrees}C. We used dynamic pressing to consolidate L1{sub 2}-Al{sub 5}CuZr{sub 2} powder. The compact, having the L1{sub 2} structure, has fine grains (44 nm) and a fine dispersion of ZrC precipitates (7 nm). Its hardness is in the range of 1030 kg mm{sup {minus}2}. Current efforts are to investigate ternary alloys based on fine-grained trialuminides which include a ductile second phase. 26 refs., 8 figs.

  4. SOURCE AND PATHWAY DETERMINATION FOR BERYLLIUM FOUND IN BECHTEL NEVADA NORTH LAS VEGAS FACILITIES

    Energy Technology Data Exchange (ETDEWEB)

    BECHTEL NEVADA

    2004-07-01

    In response to the report ''Investigation of Beryllium Exposure Cases Discovered at the North Las Vegas Facility of the National Nuclear Security Administration'', published by the U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA) in August 2003, Bechtel Nevada (BN) President and General Manager Dr. F. A. Tarantino appointed the Beryllium Investigation & Assessment Team (BIAT) to identify both the source and pathway for the beryllium found in the North Las Vegas (NLV) B-Complex. From September 8 to December 18, 2003, the BIAT investigated the pathway for beryllium and determined that a number of locations existed at the Nevada Test Site (NTS) which could have contained sufficient quantities of beryllium to result in contamination if transported. Operations performed in the B-1 Building as a result of characterization activities at the Engine Maintenance, Assembly, and Disassembly (EMAD); Reactor Maintenance, Assembly, and Disassembly (RMAD); Test Cells A and C; and the Central Support Facility in Area 25 had the greatest opportunity for transport of beryllium. Investigative monitoring and sampling was performed at these sites with subsequent transport of sample materials, equipment, and personnel from the NTS to the B-1 Building. The timeline established by the BIAT for potential transport of the beryllium contamination into the B-1 Building was from September 1997 through November 2002. Based on results of recently completed swipe sampling, no evidence of transport of beryllium from test areas has been confirmed. Results less than the DOE beryllium action level of 0.2 ???g/100 cm2 were noted for work support facilities located in Area 25. All of the identified sites in Area 25 worked within the B-1 tenant's residency timeline have been remediated. Legacy contaminants have either been disposed of or capped with clean borrow material. As such, no current opportunity exists for release or spread of beryllium

  5. Preparation and research on poisoning resistant Zr-Co based hydrogen storage alloys

    Institute of Scientific and Technical Information of China (English)

    LI Hualing; WANG Shumao; JIANG Lijun; ZHANG Lidong; LIU Xiaopeng; LI Zhinian

    2008-01-01

    At present,all hydrogen storage alloys are poisoned by hydrogen mixed with CO,CO2,etc,which decreases the hydrogen storage property sharply.Zr-Co based hydrogen storage alloys with good poisoning resistance were prepared by alloying,fluorinating,and electroless plating.The experiment results show that the poisoning resistance of the Zr-Co based alloy was improved remarkably after the treatments.The poisoning resistance mechanism of the Zr-Co based hydrogen storage alloys was analyzed.

  6. Microscopic study of the structure of the Steel Ni-based Alloy: Hastelloy G35 Alloy

    Science.gov (United States)

    Sabir, F.; Ben Lenda, O.; Saissi, S.; Marbouh, K.; Tyouke, B.; Zerrouk, L.; Ibnlfassi, A.; Ouzaouit, K.; Elmadani, S.

    2017-03-01

    The study of the influence of heat treatment on changes of mechanical and structural properties of Steel Ni-based Alloy is a highly interdisciplinary topic at the interface of the physical chemistry of metallic materials, which also helps in environmental and economic protection.After heat treatment, the structural and micro-structural studies for the different transformation temperature led to identify phases formed and the morphology. This work has been carried out using different techniques: X-ray diffraction, optical microscopy and scanning electron microscopy.

  7. Perspectives on radiation effects in nickel-base alloys for applications in advanced reactors

    Science.gov (United States)

    Rowcliffe, A. F.; Mansur, L. K.; Hoelzer, D. T.; Nanstad, R. K.

    2009-07-01

    Because of their superior high temperature strength and corrosion properties, a set of Ni-base alloys has been proposed for various in-core applications in Gen IV reactor systems. However, irradiation-performance data for these alloys is either limited or non-existent. A review is presented of the irradiation-performance of a group of Ni-base alloys based upon data from fast breeder reactor programs conducted in the 1975-1985 timeframe with emphasis on the mechanisms involved in the loss of high temperature ductility and the breakdown in swelling resistance with increasing neutron dose. The implications of these data for the performance of the Gen IV Ni-base alloys are discussed and possible pathways to mitigate the effects of irradiation on alloy performance are outlined. A radical approach to designing radiation damage-resistant Ni alloys based upon recent advances in mechanical alloying is also described.

  8. Polarization-corrosion behavior of commercial gold- and silver-base casting alloys in Fusayama solution.

    Science.gov (United States)

    Johnson, D L; Rinne, V W; Bleich, L L

    1983-12-01

    Based on polarization measurements, high Au alloys are highly corrosion-resistant and exhibit the lowest corrosion rates; intermediate Au, Ag, and Pd alloys with Cu are passive but exhibit higher corrosion rates. Twenty weight percent (w/o) In-Ag alloys exhibit active corrosion behavior at potentials only 100 mV noble to the corrosion potential.

  9. Inhibited solid propellant composition containing beryllium hydride

    Science.gov (United States)

    Thompson, W. W. (Inventor)

    1978-01-01

    An object of this invention is to provide a composition of beryllium hydride and carboxy-terminated polybutadiene which is stable. Another object of this invention is to provide a method for inhibiting the reactivity of beryllium hydride toward carboxy-terminated polybutadiene. It was found that a small amount of lecithin inhibits the reaction of beryllium hydride with the acid groups in carboxy terminated polybutadiene.

  10. MEASUREMENTS OF THE PROPERTIES OF BERYLLIUM FOIL

    Energy Technology Data Exchange (ETDEWEB)

    ZHAO,Y.; WANG,H.

    2000-03-31

    The electrical conductivity of beryllium at radio frequency (800 MHz) and liquid nitrogen temperature were investigated and measured. This summary addresses a collection of beryllium properties in the literature, an analysis of the anomalous skin effect, the test model, the experimental setup and improvements, MAFIA simulations, the measurement results and data analyses. The final results show that the conductivity of beryllium is not as good as indicated by the handbook, yet very close to copper at liquid nitrogen temperature.

  11. Effect of beryllium nitrate on early and late pregnancy in rats

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, R.; Sharma, S.; Mathur, S.; Prakash, A.O.

    1987-01-01

    Beryllium is widely used in fatigue-resistant alloys, nuclear reactors, space device, missiles parts, electronics and other specialized purposes. Workers both in industries and mines are constantly exposed through inhalation or direct skin contact. A number of investigations have been made in different laboratories in relation to its toxicological effects in laboratory animals and humans. The lethal dose (LD/sub 50/) of beryllium nitrate through intravenous route in rats has been reported from our laboratory to be 3.16 mg/kg body weight. But not much is known about its effects on reproductive physiology. The present communication deals with the effect of beryllium nitrate on early and late pregnancy in the albino rats.

  12. The prospects of biodegradable magnesium-based alloys in osteosynthesis

    Directory of Open Access Journals (Sweden)

    V. N. Chorny

    2013-12-01

    various types of implants for osteosynthesis in traumatology and orthopedics. As the analysis of scientific papers over the past decade, the number of scientific articles devoted to the study of the properties of magnesium alloys and their effect on bone formation, as well as their use in osteosynthesis has grown significantly. Implants which are based on magnesium, may have several advantages over bioinert metal alloys, polymers, and bioceramics. They are not toxic, not carcinogenic, the mechanical properties of a structure close to the cortical bone, and may have osteoinductive and anti-bacterial action. Also, there is no need for a second surgical intervention. The main problems to be addressed, in our view, are as follows. 1. Need to examine the nature of -bone formation in the fracture in the presence of the implant based on magnesium alloy. 2. To examine the impact of products of magnesium degradation on the surrounding tissue and the body as a whole. 3. Loss of rigidity of the implant magnesium based alloy in the process of biodegradation.

  13. Resistance of a directionally solidified gamma/gamma prime-delta eutectic alloy to recrystallization. [Ni-base alloy

    Science.gov (United States)

    Tewari, S. N.; Scheuermann, C. M.; Andrews, C. W.

    1976-01-01

    A lamellar nickel-base directionally-solidified eutectic gamma/gamma prime-delta alloy has potential as an advanced gas turbine blade material. The microstructural stability of this alloy was investigated. Specimens were plastically deformed by uniform compression or Brinell indentation, then annealed between 750 and 1120 C. Microstructural changes observed after annealing included gamma prime coarsening, pinch-off and spheroidization of delta lamellae, and appearance of an unidentified blocky phase in surface layers. All but the first of these was localized in severely deformed regions, suggesting that microstructural instability may not be a serious problem in the use of this alloy.

  14. Estimations of neutron yield from beryllium target irradiated by SPring-8 hard synchrotron radiation

    CERN Document Server

    Gryaznykh, D A; Plokhoi, V V

    2000-01-01

    The possibility of creating a neutron source based on ''SPring-8'' synchrotron radiation interaction with beryllium targets is discussed. The possible neutron yield is estimated to be of order 10 sup 1 sup 2 s sup - sup 1 .

  15. Development of Fe-based nanocrystalline materials by mechanical alloying

    Directory of Open Access Journals (Sweden)

    Suñol, J. J.

    2008-06-01

    Full Text Available Two alloys, Fe80NbB10 and Fe70Ni14Zr6B10, were produced by mechanical alloying. The formation of the nanocrystallites (about 7-8 nm at 80h MA was detected by X-ray diffraction. After milling for 80 h, differential scanning calorimetry scans show low-temperature recovery processes and several crystallization processes related with crystal growth and reordering of crystalline phases. The apparent activation energy values are 315 ± 40 kJ mol–1 for alloy A, and 295 ± 20 kJ mol–1 and 320 ± 25 kJ mol–1 for alloy B. Furthermore, a melt-spun Fe-based ribbon was mechanically alloyed to obtain a powdered-like alloy. The increase of the rotation speed and the ball-to-powder weight ratio reduces the necessary time to obtain the powdered form.

    Dos aleaciones, Fe80Nb10B10 (A y Fe70Ni14Zr6B10 (B, han sido producidas por aleado mecánico. Mediante difracción de rayos X se ha detectado la formación de nanocristales (7-8 nm a las 80 h de aleado. Tras molturar 80 h, las curvas calorimétricas muestran procesos exotérmicos asociados a la relajación estructural y al crecimiento cristalino y reordenación de la fase cristalina. Los valores de la energía aparente de activación de las cristalizaciones son 315 ± 40 kJ mol–1 para la aleación A, y 295 ± 20 kJ mol–1 y 320 ± 25 kJ mol–1 para la aleación B. Por otra parte, se ha procedido a la molturación de una cinta de una aleación de base hierro hasta obtener un material en forma de polvo. El incremento de la velocidad de rotación y de la relación en peso bolas polvo reduce el tiempo necesario para obtener este material.

  16. Wear resistant zirconium base alloy article for water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Gillett, J.E.; Shockling, L.A.; Sherwood, D.G.

    1988-03-01

    In a water reactor operating environment, the combination having improved fretting wear resistance is described comprising: an elongated tubular water displacer rod; having a low neutron absorption cross section guide support plates distributed along the length of the water displacer rod; the water displacer rod intersecting the guide support plates through apertures in the guide support plates; the water displacer rod having a plurality of spaced apart annular electrospark deposited coatings, each coating facing the wall of a respective aperture, the electrospark deposited coatings comprising Cr/sub 2/C/sub 3/; wherein the water displacer rod has a tube wall composed of a zirconium base alloy; and wherein the guide support plates are composed of a stainless steel alloy.

  17. Age-hardening in a commercial Mg-based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Macchi, C.E. [IFIMAT, UNCentro and CONICET, Pinto 399, B7000GHG Tandil (Argentina); Somoza, A. [IFIMAT, UNCentro and CICPBA, Pinto 399, B7000GHG Tandil (Argentina); Nie, J.F. [School of Physics and Materials Engineering, PO Box 69M, Monash University, Victoria 3800 (Australia)

    2007-07-01

    Age-hardening phenomena induced by thermal and thermo-mechanical treatments in the commercial Mg-based alloy WE54 were studied by positron annihilation lifetime spectroscopy and Vickers microhardness. To this aim, samples were plastically deformed and subsequently aged at 250 C for times ranging from 0 to 1000 hours. The results obtained are discussed in terms of the role of vacancies in the solute transport and therefore they contribute to the discussion on the vacancy-solute clusters (and/or intermediate precipitates) interactions during the precipitation sequence of the WE54. Besides, we show that cold work previous aging not only accelerates but increases the hardening response of the alloy. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Corrosion-resistant nickel-base alloys for gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, J.W.; Hulsizer, W.R.

    1976-08-01

    Laboratory corrosion screening procedures used during the past ten years in developing nickel-base superalloys for gas turbine applications are described. Hot salt corrosion tests have included crucible and salt shower exposures. Reproducible techniques were established and alloy composition effects defined, leading to development of M313, IN-587, a IN-792. Correlations have been made with corrosion results in burner rigs, and engine experience confirming anticipated behavior is now becoming available. During this work a number of limitations of these accelerated laboratory tests were uncovered; these are discussed. Finally, brief descriptions of the states of development of alloy MA 755E (an oxide dispersion-strengthened superalloy) and IN-939 (a cast 23 percent chromium superalloy) are outlined as examples of advanced corrosion resistant, high strength materials of the future.

  19. TEM study of impurity segregations in beryllium pebbles

    Science.gov (United States)

    Klimenkov, M.; Chakin, V.; Moeslang, A.; Rolli, R.

    2014-12-01

    Beryllium is planned to be used as a neutron multiplier in the Helium-cooled Pebble Bed European concept of a breeding blanket of demonstration power reactor DEMO. In order to evaluate the irradiation performance, individual pebbles and constrained pebble beds were neutron-irradiated at temperatures typical of fusion blankets. Beryllium pebbles 1 mm in diameter produced by the rotating electrode method were subjected to a TEM study before and after irradiation at High Flux Reactor, Petten, Netherlands at 861 K. The grain size varied in a wide range from sub-micron size up to several tens of micrometers, which indicated formation bimodal grain size distribution. Based on the application of combined electron energy loss spectroscopy and energy dispersive X-ray spectroscopy methods, we suggest that impurity precipitates play an important role in controlling the mechanical properties of beryllium. The impurity elements were present in beryllium at a sub-percent concentration form beryllide particles of a complex (Fe/Al/Mn/Cr)B composition. These particles are often ordered along dislocations lines, forming several micron-long chains. It can be suggested that fracture surfaces often extended along these chains in irradiated material.

  20. TEM study of impurity segregations in beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Klimenkov, M., E-mail: michael.klimenkov@kit.edu [Institute for Applied Materials – Applied Materials Physics, Karlsruhe Institute of Technology, Hermann-von-Helmholz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Chakin, V.; Moeslang, A. [Institute for Applied Materials – Applied Materials Physics, Karlsruhe Institute of Technology, Hermann-von-Helmholz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Rolli, R. [Institute for Applied Materials – Materials and Biomechanics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-12-15

    Beryllium is planned to be used as a neutron multiplier in the Helium-cooled Pebble Bed European concept of a breeding blanket of demonstration power reactor DEMO. In order to evaluate the irradiation performance, individual pebbles and constrained pebble beds were neutron-irradiated at temperatures typical of fusion blankets. Beryllium pebbles 1 mm in diameter produced by the rotating electrode method were subjected to a TEM study before and after irradiation at High Flux Reactor, Petten, Netherlands at 861 K. The grain size varied in a wide range from sub-micron size up to several tens of micrometers, which indicated formation bimodal grain size distribution. Based on the application of combined electron energy loss spectroscopy and energy dispersive X-ray spectroscopy methods, we suggest that impurity precipitates play an important role in controlling the mechanical properties of beryllium. The impurity elements were present in beryllium at a sub-percent concentration form beryllide particles of a complex (Fe/Al/Mn/Cr)B composition. These particles are often ordered along dislocations lines, forming several micron-long chains. It can be suggested that fracture surfaces often extended along these chains in irradiated material.

  1. The uses and adverse effects of beryllium on health

    Directory of Open Access Journals (Sweden)

    Cooper Ross

    2009-01-01

    Full Text Available Context: This review describes the health effects of beryllium exposure in the workplace and the environment. Aim: To collate information on the consequences of occupational and environmental exposure to beryllium on physiological function and well being. Materials and Methods: The criteria used in the current review for selecting articles were adopted from proposed criteria in The International Classification of Functioning, Disability, and Health. Articles were classified based on acute and chronic exposure and toxicity of beryllium. Results: The proportions of utilized and nonutilized articles were tabulated. Years 2001-10 gave the greatest match (45.9% for methodological parameters, followed by 27.71% for 1991-2000. Years 1971-80 and 1981-90 were not significantly different in the information published and available whereas years 1951-1960 showed a lack of suitable articles. Some articles were published in sources unobtainable through requests at the British Library, and some had no impact factor and were excluded. Conclusion: Beryllium has some useful but undoubtedly harmful effects on health and well-being. Measures need to be taken to prevent hazardous exposure to this element, making its biological monitoring in the workplace essential.

  2. Alloy 690 in PWR type reactors; Aleaciones base niquel en condiciones de primario de los reactores tipo PWR

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Briceno, D.; Serrano, M.

    2005-07-01

    Alloy 690, used as replacement of Alloy 600 for vessel head penetration (VHP) nozzles in PWR, coexists in the primary loop with other components of Alloy 600. Alloy 690 shows an excellent resistance to primary water stress corrosion cracking, while Alloy 600 is very susceptible to this degradation mechanisms. This article analyse comparatively the PWSCC behaviour of both Ni-based alloys and associated weld metals 52/152 and 82/182. (Author)

  3. Manufacturing and thermomechanical testing of actively cooled all beryllium high heat flux test pieces

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, N.N.; Sokolov, Yu.A.; Shatalov, G.E. [and others

    1995-09-01

    One of the problems affiliated to ITER high heat flux elements development is a problem of interface of beryllium protection with heat sink routinely made of copper alloys. To get rid of this problem all beryllium elements could be used as heat receivers in places of enhanced thermal loads. In accordance with this objectives four beryllium test pieces of two types have been manufactured in {open_quotes}Institute of Beryllium{close_quotes} for succeeding thermomechanical testing. Two of them were manufactured in accordance with JET team design; they are round {open_quotes}hypervapotron type{close_quotes} test pieces. Another two ones are rectangular test sections with a twisted tape installed inside of the circular channel. Preliminary stress-strain analysis have been performed for both type of the test pieces. Hypervapotrons have been shipped to JET where they were tested on JET test bed. Thermomechanical testing of pieces of the type of {open_quotes}swirl tape inside of tube{close_quotes} have been performed on Kurchatov Institute test bed. Chosen beryllium grade properties, some details of manufacturing, results of preliminary stress-strain analysis and thermomechanical testing of the test pieces {open_quotes}swirl tape inside of tube{close_quotes} type are given in this report.

  4. A selective optical sensor for beryllium determination based on incorporating of 1,8-dihydroxyanthrone in a poly (vinyl chloride) membrane

    Energy Technology Data Exchange (ETDEWEB)

    Beiraghi, Assadollah [Faculty of Chemistry, Tarbiat Moallem University, Mofatteh Ave., No.49, P. O. Box 15614, Tehran (Iran, Islamic Republic of); Babaee, Saeed, E-mail: Safnba@Gmail.com [Faculty of Chemistry, Tarbiat Moallem University, Mofatteh Ave., No.49, P. O. Box 15614, Tehran (Iran, Islamic Republic of); Roshdi, Mina [Faculty of Chemistry, Tarbiat Moallem University, Mofatteh Ave., No.49, P. O. Box 15614, Tehran (Iran, Islamic Republic of)

    2011-06-15

    A new optical sensor was fabricated for determination of beryllium ions. The optode membrane was prepared by incorporation of 1,8-dihydroxyanthrone and sodium tetraphenylborate (NaTPB) in a plasticized poly (vinyl chloride) membrane containing ortho-nitrophenyl octyl ether (o-NPOE) as a plasticizer. Color of the sensing membrane in contact with Be{sup 2+} ions at pH 10.5, was changed from orange to red. The different variables affecting uptake efficiency were evaluated and optimized. Under the optimum conditions (i.e. 28.0% PVC, 60.0% o-NPOE, 8.0% 1,8-dihydroxyanthrone, 4.0% NaTPB and response time of 6 min), the proposed sensor displayed a linear range of 0.1-5 {mu}g mL{sup -1} with a detection limit of 0.03 {mu}g mL{sup -1}. Also the precision (RSD%) was better than 2.9% for 7 replicate determinations of 1 {mu}g mL{sup -1} Be in various membranes. The selectivity of the probe was studied for some cations and anions. Experimental results showed that the sensor was high selective in the presence of ethylenediaminetetraacetic acid (EDTA) as a masking agent and could be used as an effective tool in analyzing the beryllium content of water samples.

  5. A selective optical sensor for beryllium determination based on incorporating of 1,8-dihydroxyanthrone in a poly (vinyl chloride) membrane.

    Science.gov (United States)

    Beiraghi, Assadollah; Babaee, Saeed; Roshdi, Mina

    2011-06-15

    A new optical sensor was fabricated for determination of beryllium ions. The optode membrane was prepared by incorporation of 1,8-dihydroxyanthrone and sodium tetraphenylborate (NaTPB) in a plasticized poly (vinyl chloride) membrane containing ortho-nitrophenyl octyl ether (o-NPOE) as a plasticizer. Color of the sensing membrane in contact with Be(2+) ions at pH 10.5, was changed from orange to red. The different variables affecting uptake efficiency were evaluated and optimized. Under the optimum conditions (i.e. 28.0% PVC, 60.0% o-NPOE, 8.0% 1,8-dihydroxyanthrone, 4.0% NaTPB and response time of 6 min), the proposed sensor displayed a linear range of 0.1-5 μg mL(-1) with a detection limit of 0.03 μg mL(-1). Also the precision (RSD%) was better than 2.9% for 7 replicate determinations of 1 μg mL(-1) Be in various membranes. The selectivity of the probe was studied for some cations and anions. Experimental results showed that the sensor was high selective in the presence of ethylenediaminetetraacetic acid (EDTA) as a masking agent and could be used as an effective tool in analyzing the beryllium content of water samples.

  6. Beryllium particulate exposure and disease relations in a beryllium machining plant.

    Science.gov (United States)

    Kelleher, P C; Martyny, J W; Mroz, M M; Maier, L A; Ruttenber, A J; Young, D A; Newman, L S

    2001-03-01

    We examined the relationship between exposure to beryllium and the presence of beryllium sensitization (BeS) and chronic beryllium disease (CBD) in a cohort of workers in a beryllium precision machining facility. Twenty workers with BeS or CBD (cases) were compared with 206 worker-controls in a case-control study. Exposure for each job title was measured using cascade impactors placed in the workers' breathing zone to measure total beryllium exposure and exposure to particles 0.20. In conclusion, increased cumulative and LTW exposure to total and respirable beryllium was observed in workers with CBD or BeS compared with the controls. These results support efforts to control beryllium exposure in the workplace.

  7. Investigation of solidification dynamics of Zr-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kobold, Raphael; Herlach, Dieter [Institut fuer Materialphysik im Weltraum, Deutsches Zentrum fuer Luft- und Raumfahrt, 51170 Koeln (Germany); Ruhr-Universitaet Bochum, 44780 Bochum (Germany)

    2013-07-01

    In contrast to experiments with most undercooled binary alloys the velocity of dendritic growth of a Cu50Zr50 alloy does not increase monotonically with undercooling but passes through a maximum and then decreases. To study this behaviour we investigate Zr-based alloys such as CuZr, NiZr and NiZrAl with Zirconium concentrations ranging from 36 to 64 at.% including eutectic and intermetallic phases. We use electrostatic levitation technique to melt and undercool samples with a diameter of 2-3 mm under ultra-high-vacuum conditions. Containerless processing is an effective tool for undercooling metallic melts far below their equilibrium melting temperatures since heterogeneous nucleation on container walls is completely avoided. During crystallisation of the undercooled melt the heat of crystallisation is released. The rapid increase of the temperature at the solid-liquid interface makes the solidification front visible. The velocities of the solidification front are recorded by using a high-speed camera with a maximum rate of 50.000 frames per second and are analyzed with a software for optical ray tracing. Furthermore, we try to model the growth velocity vs. the undercooling temperature and perform sample EBSD analysis with a scanning electron microscope.

  8. Metallic ion release from biocompatible cobalt-based alloy

    Directory of Open Access Journals (Sweden)

    Dimić Ivana D.

    2014-01-01

    Full Text Available Metallic biomaterials, which are mainly used for the damaged hard tissue replacements, are materials with high strength, excellent toughness and good wear resistance. The disadvantages of metals as implant materials are their susceptibility to corrosion, the elastic modulus mismatch between metals and human hard tissues, relatively high density and metallic ion release which can cause serious health problems. The aim of this study was to examine metallic ion release from Co-Cr-Mo alloy in artificial saliva. In that purpose, alloy samples were immersed into artificial saliva with different pH values (4.0, 5.5 and 7.5. After a certain immersion period (1, 3 and 6 weeks the concentrations of released ions were determined using Inductively Coupled Plasma - Mass Spectrophotometer (ICP-MS. The research findings were used in order to define the dependence between the concentration of released metallic ions, artificial saliva pH values and immersion time. The determined released metallic ions concentrations were compared with literature data in order to describe and better understand the phenomenon of metallic ion release from the biocompatible cobalt-based alloy. [Projekat Ministarstva nauke Republike Srbije, br. III 46010 i br. ON 174004

  9. Modeling of hydrogen interactions with beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Longhurst, G.R. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States)

    1998-01-01

    In this paper, improved mathematical models are developed for hydrogen interactions with beryllium. This includes the saturation effect observed for high-flux implantation of ions from plasmas and retention of tritium produced from neutronic transmutations in beryllium. Use of the models developed is justified by showing how they can replicated experimental data using the TMAP4 tritium transport code. (author)

  10. Investigation of beryllium/steam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chekhonadskikh, A.M.; Vurim, A.D.; Vasilyev, Yu.S.; Pivovarov, O.S. [Inst. of Atomic Energy National Nuclear Center of the Republic of Kazakstan Semipalatinsk (Kazakhstan); Shestakov, V.P.; Tazhibayeva, I.L.

    1998-01-01

    In this report program on investigations of beryllium emissivity and transient processes on overheated beryllium surface attacked by water steam to be carried out in IAE NNC RK within Task S81 TT 2096-07-16 FR. The experimental facility design is elaborated in this Report. (author)

  11. Benchmark Experiment for Beryllium Slab Samples

    Institute of Scientific and Technical Information of China (English)

    NIE; Yang-bo; BAO; Jie; HAN; Rui; RUAN; Xi-chao; REN; Jie; HUANG; Han-xiong; ZHOU; Zu-ying

    2015-01-01

    In order to validate the evaluated nuclear data on beryllium,a benchmark experiment has been performed at China Institution of Atomic Energy(CIAE).Neutron leakage spectra from pure beryllium slab samples(10cm×10cm×11cm)were measured at 61°and 121°using timeof-

  12. Diffusion-bonded beryllium aluminum optical structures

    Science.gov (United States)

    Grapes, Thomas F.

    2003-12-01

    Beryllium aluminum material can present significant advantages for optical support structures. A likely advantage of beryllium aluminum compared to aluminum or titanium for such structures is its higher specific stiffness. However, beryllium aluminum material is significantly more expensive than most competing materials. The cost problem with beryllium aluminum is exacerbated if fabrication methods that result in near net shape parts are not used. Near net shape methods result in the least amount of material "thrown away" in the fabrication process. Casting is a primary example of near net shape manufacturing that is appropriate for some optical support structures. Casting aluminum, and other materials as well, is common. Casting of beryllium aluminum is very difficult, however, and has not had significant success. Diffusion bonding - a different approach for achieving near net shape beryllium aluminum optical support structures, was pursued and accomplished. Diffusion bonding is a term used to describe the joining of solid metal pieces under high temperature and pressure, but without melting. Three different optical support structures were designed and built of beryllium aluminum using diffusion bonding. Relatively small solid beryllium aluminum pieces were arranged together and then joined under hot isostatic pressure conditions. The resulting relatively large pressure bonded part was then machined to achieve the final product. Significant cost savings as compared to machining the part from a solid block were realized. Difficulties achieving diffusion bonds in complex joints were experienced and addressed.

  13. Structural characteristics of Ni3Al based alloys depending on the preparation conditions

    Directory of Open Access Journals (Sweden)

    J. Malcharcziková

    2015-10-01

    Full Text Available The paper presents an evaluation of the influence of the composition of alloys based on Ni3Al on their mechanical characteristics. The structure of the alloy was controlled through directional solidification. The achieved values of mechanical characteristics are in good agreement with the material structure. The alloys with sub-stoichiometric contents of aluminium have a multiphase structure. These alloys contain network with high values of tensile strain. The microstructure of the samples was investigated and behaviour of dislocations in the alloys was analysed by Transmission electron microscopy methods (TEM.

  14. Influence of S. mutans on base-metal dental casting alloy toxicity.

    Science.gov (United States)

    McGinley, E L; Dowling, A H; Moran, G P; Fleming, G J P

    2013-01-01

    We have highlighted that exposure of base-metal dental casting alloys to the acidogenic bacterium Streptococcus mutans significantly increases cellular toxicity following exposure to immortalized human TR146 oral keratinocytes. With Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), S. mutans-treated nickel-based (Ni-based) and cobalt-chromium-based (Co-Cr-based) dental casting alloys were shown to leach elevated levels of metal ions compared with untreated dental casting alloys. We targeted several biological parameters: cell morphology, viable cell counts, cell metabolic activity, cell toxicity, and inflammatory cytokine expression. S. mutans-treated dental casting alloys disrupted cell morphology, elicited significantly decreased viable cell counts (p S. mutans-treated Ni-based dental casting alloys induced elevated levels of cellular toxicity compared with S. mutans-treated Co-Cr-based dental casting alloys. While our findings indicated that the exacerbated release of metal ions from S. mutans-treated base-metal dental casting alloys was the likely result of the pH reduction during S. mutans growth, the exact nature of mechanisms leading to accelerated dissolution of alloy-discs is not yet fully understood. Given the predominance of S. mutans oral carriage and the exacerbated cytotoxicity observed in TR146 cells following exposure to S. mutans-treated base-metal dental casting alloys, the implications for the long-term stability of base-metal dental restorations in the oral cavity are a cause for concern.

  15. BERYLLIUM MEASUREMENT IN COMMERCIALLY AVAILABLE WET WIPES

    Energy Technology Data Exchange (ETDEWEB)

    Youmans-Mcdonald, L.

    2011-02-18

    Analysis for beryllium by fluorescence is now an established method which is used in many government-run laboratories and commercial facilities. This study investigates the use of this technique using commercially available wet wipes. The fluorescence method is widely documented and has been approved as a standard test method by ASTM International and the National Institute for Occupational Safety and Health (NIOSH). The procedure involves dissolution of samples in aqueous ammonium bifluoride solution and then adding a small aliquot to a basic hydroxybenzoquinoline sulfonate fluorescent dye (Berylliant{trademark} Inc. Detection Solution Part No. CH-2) , and measuring the fluorescence. This method is specific to beryllium. This work explores the use of three different commercial wipes spiked with beryllium, as beryllium acetate or as beryllium oxide and subsequent analysis by optical fluorescence. The effect of possible interfering metals such as Fe, Ti and Pu in the wipe medium is also examined.

  16. Some characteristics of fine beryllium particle combustion

    Science.gov (United States)

    Davydov, D. A.; Kholopova, O. V.; Kolbasov, B. N.

    2007-08-01

    Beryllium dust will be produced under plasma interaction with beryllium armor of the first wall in ITER. Exothermal reaction of this dust with water steam or air, which can leak into the reactor vacuum chamber in some accidents, gives concern in respect to reactor safety. Results of studies devoted to combustion of fine beryllium particles are reviewed in the paper. A chemically active medium and elevated temperature are prerequisite to the combustion of beryllium particles. Their ignition is hampered by oxide films, which form a diffusion barrier on the particle surface as a result of pre-flame oxidation. The temperature to initiate combustion of particles depends on flame temperature, particle size, composition of combustible mixture, heating rate and other factors. In mixtures enriched with combustible, the flame temperature necessary to ignite individual particles approaches the beryllium boiling temperature.

  17. Performance of a base isolator with shape memory alloy bars

    Institute of Scientific and Technical Information of China (English)

    Fabio Casciati; Lucia Faravelli; Karim Hamdaoui

    2007-01-01

    A new and innovative base isolation device is introduced in this paper based on extensive research carried out by the authors and their co-workers.A prototype of the device was built and experimentally tested on the shaking table.The new base isolation device consists of two disks,one vertical cylinder with an upper enlargement sustained by three horizontal cantilevers,and at least three inclined shape memory alloy(SMA) bars.The role of the SMA bars is to limit the relative motion between the base and the superstructure,to dissipate energy by their super-elastic constitutive law and to guarantee the re-centring of the device.To verify the expected performance,a prototype was built and tested under sinusoidal waves of displacement of increasing frequency with different amplitudes.It is shown that the main feature of the proposed base isolation device is that for cyclic loading,the super-elastic behavior of the alloy results in wide load-displacement loops,where a large amount of energy is dissipated.

  18. Characteristics on Bi-Pb Based Alloys Quenched from Melt

    Institute of Scientific and Technical Information of China (English)

    Rizk Mostafa Shalaby

    2009-01-01

    Three different bismuth-lead systems namely, Wood's alloy (Bi50Pb25Sn12.5Cd12.5), Newton's alloy (Bi50Pb31.2Sn18.8) and Rose's alloy (Bi50Pb28Sn22), with one used as fusible alloys were quenched from melt by melt spinning technique. Thermal analysis, structure and mechanical properties of all alloys have been studied and analyzed. From X-ray diffraction analysis, an intermetallic compound phase, designated Pb7Bi3 is detected. The formation of an intermetallic compound phase causes a pronounced increase in the electrical resistivity. The Wood's alloy containing-cadmium exhibits mechanical properties superior to both the Newton's and Rose's alloys. The presence of cadmium in Wood's alloy decreases its melting point. Wood's alloy has better properties, which make it useful in various applications such as in protection shields for radiotherapy, locking of mechanical devices and welding at low temperature.

  19. On the corrosion behavior and biocompatibility of palladium-based dental alloys

    Science.gov (United States)

    Sun, Desheng

    Palladium-based alloys have been used as dental restorative materials for about two decades with good clinical history. But there have been clinical case reports showing possible allergy effects from these alloys. The aim of this study was to characterize the corrosion behavior and mechanisms of several palladium-based dental alloys by potentiodynamic polarization methods, electrochemical impedance spectroscopy (EIS), and scanning Kelvin probe force microscopy/atomic force microscopy (SKPFM/AFM), and to evaluate their biocompatibility by a cell culture technique and an animal model. Using SKPFM/AFM and scanning electron microscopy, the Ru-enriched phase from the use of ruthenium as a grain-refining element was identified as being slightly more noble than the palladium solid solution matrix in a high-palladium alloy. Other secondary precipitates that exist in the microstructures of these high-palladium alloys have minimal differences in Volta potential compared to the matrix. For high-palladium alloys, corrosion is generally uniform due to the predominant palladium content in the different phases. Potentiodynamic polarization and EIS have shown that representative palladium-silver alloys have low corrosion tendency and high corrosion resistance, which are equivalent to a well-known high-noble gold-palladium alloy in simulated body fluid and oral environments. The palladium-silver alloys tested are resistant to chloride ion corrosion. Passivation and dealloying have been identified for all of the tested palladium-silver alloys. The great similarity in corrosion behavior among the palladium-silver alloys is attributed to their similar chemical compositions. The variation in microstructures of palladium-silver alloys tested does not cause significant difference in corrosion behavior. The corrosion resistance of these palladium-silver alloys at elevated potentials relevant to oral environment is still satisfactory. The release of elements from representative dental

  20. Design of Zr-based AB2 type hydrogen storage alloys

    Institute of Scientific and Technical Information of China (English)

    文明芬; 王秋萍; 王兴海; 翟玉春; 陈廉

    2003-01-01

    The influences of the ratio of the radius of atom A(rA)to radius of atom B(rB),electronegativity and electron number were discussed on the Laves phase formation and the characteristics of Zr-based AB2 type hydrogen storage alloy.An enthalpy model of Zr-based AB2 alloy was obtained from known data and twelve Zr-based alloys were designed to test the model.The results show that the predicted values are in good agreement with the experimental values.The model can be used for predicting enthalpy values of Zr-based hydrogen storage alloys and settles a foundation for experiments.

  1. Beryllium coating on Inconel tiles

    Energy Technology Data Exchange (ETDEWEB)

    Bailescu, V.; Burcea, G.; Lungu, C.P.; Mustata, I.; Lungu, A.M. [Association EURATOM-MEC Romania, National Institute of Laser, Plasma and Radiation Physics, Bucharest (Romania); Rubel, M. [Alfven Laboratory, Royal Institute of Technology, Stockholm (Sweden); Coad, J.P. [Culham Science Centre, EURATOM-UKAEA Fusion Association, Abingdon, OX, Oxon (United Kingdom); Matthews, G.; Pedrick, L.; Handley, R. [UKAEA Fusion, Association Euratom-UKAEA, Culham Science and Engineering Centre, OX 3DB ABINGDON, Oxon (United Kingdom)

    2007-07-01

    Full text of publication follows: The Joint European Torus (JET) is a large experimental nuclear fusion device. Its aim is to confine and study the behaviour of plasma in conditions and dimensions approaching those required for a fusion reactor. The plasma is created in the toroidal shaped vacuum vessel of the machine in which it is confined by magnetic fields. In preparation for ITER a new ITER-like Wall (ILW) will be installed on Joint European Torus (JET), a wall not having any carbon facing the plasma [1]. In places Inconel tiles are to be installed, these tiles shall be coated with Beryllium. MEdC represented by the National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest and in direct cooperation with Nuclear Fuel Plant Pitesti started to coat Inconel tiles with 8 {mu}m of Beryllium in accordance with the requirements of technical specification and fit for installation in the JET machine. This contribution provides an overview of the principles of manufacturing processes using thermal evaporation method in vacuum and the properties of the prepared coatings. The optimization of the manufacturing process (layer thickness, structure and purity) has been carried out on Inconel substrates (polished and sand blasted) The results of the optimization process and analysis (SEM, TEM, XRD, Auger, RBS, AFM) of the coatings will be presented. Reference [1] Takeshi Hirai, H. Maier, M. Rubel, Ph. Mertens, R. Neu, O. Neubauer, E. Gauthier, J. Likonen, C. Lungu, G. Maddaluno, G. F. Matthews, R. Mitteau, G. Piazza, V. Philipps, B. Riccardi, C. Ruset, I. Uytdenhouwen, R and D on full tungsten divertor and beryllium wall for JET TIER-like Wall Project, 24. Symposium on Fusion Technology - 11-15 September 2006 -Warsaw, Poland. (authors)

  2. Development of environmentally friendly cast alloys and composites. High zinc Al-base cast alloys

    Directory of Open Access Journals (Sweden)

    W.K. Krajewski

    2010-01-01

    Full Text Available This work is devoted to grain refinement of the foundry Al-20 wt% Zn (AlZn20 alloy, aiming at improving ductility of the sand-cast alloy The melted alloy was inoculated using traditional AlTi5B1 (TiBAl and AlTi3C0.15 (TiCAl master alloys and newly introduced (Zn,Al-Ti3 one. The performed structural examinations showed out significant increasing of the grain population of the inoculated alloy and plas-ticity increase represented by elongation. The high damping properties of the initial alloy, measured using an ultrasonic Olympus Epoch XT device, are basicly preserved after inoculation. Also tensile strength preserves its good values, while elongation shows an increase – which are beneficials of the employed grain-refining process.

  3. Postirradiation examination of beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)

    1998-03-01

    Postirradiation examinations of COBRA-1A beryllium pebbles irradiated in the EBR-II fast reactor at neutron fluences which generated 2700--3700 appm helium have been performed. Measurements included density change, optical microscopy, scanning electron microscopy, and transmission electron microscopy. The major change in microstructure is development of unusually shaped helium bubbles forming as highly non-equiaxed thin platelet-like cavities on the basal plane. Measurement of the swelling due to cavity formation was in good agreement with density change measurements.

  4. 40 CFR 421.150 - Applicability: Description of the primary beryllium subcategory.

    Science.gov (United States)

    2010-07-01

    ... primary beryllium subcategory. 421.150 Section 421.150 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Primary Beryllium Subcategory § 421.150 Applicability: Description of the primary beryllium... beryllium by primary beryllium facilities processing beryllium ore concentrates or beryllium hydroxide...

  5. The surface spin polarization of Co-based Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Fetzer, Roman; Wuestenberg, Jan-Peter; Neuschwander, Sabine; Aeschlimann, Martin; Cinchetti, Mirko [University of Kaiserslautern (Germany). Department of Physics and Research Center OPTIMAS; Jourdan, Martin; Herbort, Christian; Vilanova Vidal, Enrique; Jakob, Gerhard [University of Mainz (Germany). Institute of Physics

    2010-07-01

    Co-based Heusler alloys belong mainly to the family of half-metallic ferromagnets (HMFs). The predicted full spin polarization at the Fermi level due to the minority spin band gap makes this class of materials highly interesting for application in the field of spintronics. Thus, the characterization of the surface of Co-based Heusler compounds is extremely relevant for understanding and improving the performance of Heusler-based spintronics devices, like tunnel-magnetoresistance (TMR) junctions. Using Auger electron spectroscopy (AES) and low energy spin polarized electron photoemission, we systematically studied the correlation between chemical composition and spin polarisation of the surface. For various Co-based Heusler alloys, e.g. Co{sub 2}CrAl, Co{sub 2}MnAl and Co{sub 2}FeGa{sub 0.5}Ge{sub 0.5}, we found different degrees of spin-polarization at the very surface region. Reasons for the distinct deviation from the predicted 100% spin polarization and the dependence on the specific surface preparation procedure are discussed.

  6. Replacement of Co-base alloy for radiation exposure reduction in the primary system of PWR

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jeong Ho; Nyo, Kye Ho; Lee, Deok Hyun; Lim, Deok Jae; Ahn, Jin Keun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kim, Sun Jin [Hanyang Univ., Seoul (Korea, Republic of)

    1996-01-01

    Of numerous Co-free alloys developed to replace Co-base stellite used in valve hardfacing material, two iron-base alloys of Armacor M and Tristelle 5183 and one nickel-base alloy of Nucalloy 488 were selected as candidate Co-free alloys, and Stellite 6 was also selected as a standard hardfacing material. These four alloys were welded on 316SS substrate using TIG welding method. The first corrosion test loop of KAERI simulating the water chemistry and operation condition of the primary system of PWR was designed and fabricated. Corrosion behaviors of the above four kinds of alloys were evaluated using this test loop under the condition of 300 deg C, 1500 psi. Microstructures of weldment of these alloys were observed to identify both matrix and secondary phase in each weldment. Hardnesses of weld deposit layer including HAZ and substrate were measured using micro-Vickers hardness tester. The status on the technology of Co-base alloy replacement in valve components was reviewed with respect to the classification of valves to be replaced, the development of Co-free alloys, the application of Co-free alloys and its experiences in foreign NPPs, and the Co reduction program in domestic NPPs and industries. 18 tabs., 20 figs., 22 refs. (Author).

  7. Technical issues for beryllium use in fusion blanket applications

    Energy Technology Data Exchange (ETDEWEB)

    McCarville, T.J.; Berwald, D.H.; Wolfer, W.; Fulton, F.J.; Lee, J.D.; Maninger, R.C.; Moir, R.W.; Beeston, J.M.; Miller, L.G.

    1985-01-01

    Beryllium is an excellent non-fissioning neutron multiplier for fusion breeder and fusion electric blanket applications. This report is a compilation of information related to the use of beryllium with primary emphasis on the fusion breeder application. Beryllium resources, production, fabrication, properties, radiation damage and activation are discussed. A new theoretical model for beryllium swelling is presented.

  8. Materials Properties of Modifeied Ni-Based Alloy

    Directory of Open Access Journals (Sweden)

    Kraus, L.

    2007-01-01

    Full Text Available The thermomechanical processing of NiMoCr solid solution nickel base superalloy is the way to considerably influence the grain size. As uniform coarse grain size increases the creep strength and crack growth resistance. In the work, the processing to achieve uniform recrystallized grain structure with variation of thermomechanical parameters is investigated. The creep behavior of the alloy after various hot working conditions is determined. The results of creep tests showed that creep characteristics such as strain rate and lifetime were greatly dependent on the initial hot working conditions and annealing parameters.

  9. Palladium-based dental alloys are associated with oral disease and palladium-induced immune responses

    NARCIS (Netherlands)

    Muris, J.; Scheper, R.J.; Kleverlaan, C.J.; Rustemeyer, T.; van Hoogstraten, I.M.W.; von Blomberg, M.E.; Feilzer, A.J.

    2014-01-01

    Background Palladium (Pd) and gold (Au) based dental alloys have been associated with oral disease. Objectives This study was designed to explore possible associations between the presence of Au-based and Pd-based dental alloys, and oral lesions, systemic complaints, and specific in vivo and in vitr

  10. Migration of Beryllium via Multiple Exposure Pathways among Work Processes in Four Different Facilities.

    Science.gov (United States)

    Armstrong, Jenna L; Day, Gregory A; Park, Ji Young; Stefaniak, Aleksandr B; Stanton, Marcia L; Deubner, David C; Kent, Michael S; Schuler, Christine R; Virji, M Abbas

    2014-01-01

    Inhalation of beryllium is associated with the development of sensitization; however, dermal exposure may also be important. The primary aim of this study was to elucidate relationships among exposure pathways in four different manufacturing and finishing facilities. Secondary aims were to identify jobs with increased levels of beryllium in air, on skin, and on surfaces; identify potential discrepancies in exposure pathways, and determine if these are related to jobs with previously identified risk. Beryllium was measured in air, on cotton gloves, and on work surfaces. Summary statistics were calculated and correlations among all three measurement types were examined at the facility and job level. Exposure ranking strategies were used to identify jobs with higher exposures. The highest air, glove, and surface measurements were observed in beryllium metal production and beryllium oxide ceramics manufacturing jobs that involved hot processes and handling powders. Two finishing and distribution facilities that handle solid alloy products had lower exposures than the primary production facilities, and there were differences observed among jobs. For all facilities combined, strong correlations were found between air-surface (rp ≥ 0.77), glove-surface (rp ≥ 0.76), and air-glove measurements (rp ≥ 0.69). In jobs where higher risk of beryllium sensitization or disease has been reported, exposure levels for all three measurement types were higher than in jobs with lower risk, though they were not the highest. Some jobs with low air concentrations had higher levels of beryllium on glove and surface wipe samples, suggesting a need to further evaluate the causes of the discrepant levels. Although such correlations provide insight on where beryllium is located throughout the workplace, they cannot identify the direction of the pathways between air, surface, or skin. Ranking strategies helped to identify jobs with the highest combined air, glove, and/or surface exposures

  11. Mechanochemical method for producing iron-based nitrogen-containing nanocrystalline alloys

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Iron-based products account the main volume of powder metallurgy production. Nevertheless its strength and reliability are not enough in comparison with classical cast materials. So that is why making nanostructural powder materials allows to increase strength and extend the range of products. A principally new way of nanostructure production is possible by means of iron mechanical alloying with nitride-forming and nitrogen both at the same time.Unlike classical technology of internal nitrogenation, nitrogen saturation, in our case, occurs by whole volume at plastic deformation conditions. A review of experimental results of phase forming alloys in the Fe-Ni, Fe-Ni-Cr, Fe-Ni-N, Fe-Ni-Cr-N, Fe-Cr-Ni systems prepared by mechanical alloying are given. The influence of the technological parameters of mechanical alloying, atmosphere of mechanical activation on nitrogen content and phase composition of examined alloys has been studied. Experimental results of the influence of mechanical alloying technological parameters on degree of ammonia dissociation and nitrogen content in examined alloys are presented. Heat treatment influence of mechanically alloyed, nitrogen-containing alloys on theirphase composition and structure are investigated.It was shown that using mechanical alloying, it's possible to prepare high-alloyed iron-based alloys containing more than 1% of nitrogen. It was established that technology of mechanical alloying in ammonia atmosphere allows to prepare austenitic steels with nanocrystalline structure, which affords high value of yield stress. Physico-chemical patterns of interaction between the nitrogen-containing atmosphere and nitride-forming elements under their mutual mechanical activation conditions were established in consequence of theoretical and experimental researches. Some scientific principles of nanocrystalline materials were gained by quantitative description of correlation between the mechanical dose, nitrogen potertial, nitrogen content

  12. Method for improve x-ray diffraction determinations of residual stress in nickel-base alloys

    Science.gov (United States)

    Berman, Robert M.; Cohen, Isadore

    1990-01-01

    A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys which comprises covering part of a predetermined area of the surface of a nickel-base alloy with a dispersion, exposing the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample.

  13. Method for improving x-ray diffraction determinations of residual stress in nickel-base alloys

    Science.gov (United States)

    Berman, R.M.; Cohen, I.

    1988-04-26

    A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys is discussed. Part of a predetermined area of the surface of a nickel-base alloy is covered with a dispersion. This exposes the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose, since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample. 2 figs.

  14. Method for producing La/Ce/MM/Y base alloys, resulting alloys and battery electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Gschneidner, Jr., Karl A.; Schmidt, Frederick A.

    2016-12-20

    A carbothermic reduction method is provided for reducing a La-, Ce-, MM-, and/or Y-containing oxide in the presence of carbon and a source of a reactant element comprising Si, Ge, Sn, Pb, As, Sb, Bi, and/or P to form an intermediate alloy material including a majority of La, Ce, MM, and/or Y and a minor amount of the reactant element. The intermediate material is useful as a master alloy for in making negative electrode materials for a metal hydride battery, as hydrogen storage alloys, as master alloy additive for addition to a melt of commercial Mg and Al alloys, steels, cast irons, and superalloys; or in reducing Sm.sub.2O.sub.3 to Sm metal for use in Sm--Co permanent magnets.

  15. DEGRADATION BEHAVIORS OF NEW TYPE TiV-BASED HYDROGEN STORAGE ELECTRODE ALLOYS

    Institute of Scientific and Technical Information of China (English)

    X.Z. Sun; Y.F. Zhu; Y. Lin; R. Li; M.X. Gao; H.G. Pan

    2006-01-01

    The degradation behaviors of the TiV-based multiphase hydrogen storage alloy Ti0.8Zr0.2V3.2Mn0.64-Cr0.96Ni1.2 during electrochemical cycling in alkaline electrolyte have been studied by XRD, SEM,EIS and AES measurements. XRD analysis indicates that the alloy consists of a C14-type Laves phase and a V-based solid solution. The lattice parameters of both phases are increased after discharged with cycling, which indicates that more irreversible hydrogen remains not discharged in the alloy. It should be responsible for the decrease of discharge capacity. SEM micrographs show that after 10 electrochemical cycles, a large number of cracks can be observed in the alloy, existing mainly in the V-based solid solution phase. Moreover, after 30 cycles, the alloy particles are obviously pulverized due to the larger expansion and shrinkage of cell volumes during hydrogen absorption and desorption, which induces the fast degradation of the TiV-based hydrogen storage alloys. EIS and AES measurements indicate that some passive oxide film has been formed on the surface of alloy electrode, which has higher charge-transfer resistance, lower hydrogen diffusivity, and less electro-catalytic activity. Therefore it can be concluded that the pulverization and oxidation of the alloy are the main factors responsible for the fast degradation of the TiV-based hydrogen storage alloys.

  16. Assessment of irradiation effects on beryllium reflector and heavy water tank of JRR-3M

    Energy Technology Data Exchange (ETDEWEB)

    Murayama, Yoji; Kakehuda, Kazuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-10-01

    The JRR-3M, a swimming pool type research reactor with beryllium and heavy water reflectors, has been operated since 1990. Since the beryllium reflectors are close to fuel and receive high fast neutron fluence in a relatively short time, they may be subject to change their dimensions by swelling due mostly to entrapped helium gaseous. This may bend the reflectors to the outside and narrow gaps between the reflectors and the fuel elements. The gaps have been measured with an ultrasonic thickness gage in an annual inspection. The results in 1996 show that the maximum of expansion in the diametral directions was 0.6 mm against 1.6 mm of a managed value for replacement of the reflector. A heavy water tank of the JRR-3M is made of aluminum alloy A5052. Surveillance tests of the alloy have been conducted to evaluate irradiation effects of the heavy water tank. Five sets of specimens of the alloy have been irradiated in the beryllium reflectors where fast neutron flux is higher than that in the heavy water tank. In 1994, one set of specimens had been unloaded and carried out the post-irradiation tests. The results show that the heavy water tank preserved satisfactory mechanical properties. (author)

  17. A theoretical framework for evaluating analytical digestion methods for poorly soluble particulate beryllium.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Brink, Christopher A; Dickerson, Robert M; Day, Gregory A; Brisson, Michael J; Hoover, Mark D; Scripsick, Ronald C

    2007-04-01

    Complete digestion of all chemical forms and sizes of particulate analytes in environmental samples is usually necessary to obtain accurate results with atomic spectroscopy. In the current study, we investigate the physicochemical properties of beryllium particles likely to be encountered in samples collected from different occupational environments and present a hypothesis that a dissolution theory can be used as a conceptual framework to guide development of strategies for digestion procedures. For monodisperse single-chemical constituent primary particles, such as those encountered when handling some types of beryllium oxide (BeO) powder, theory predicts that a digestion procedure is sufficient when it completely dissolves all primary particles, independent of cluster size. For polydisperse single-chemical constituent particles, such as those encountered during the handling of some types of beryllium metal powder, theory predicts that a digestion procedure is sufficient only when it completely dissolves the largest particle in the sample. For samples with unknown or multi-chemical constituent particles and with particles having undefined sizes, e.g., fume emissions from a copper-beryllium alloy furnace operation or dust from a beryl ore crushing operation, a surface area-limited and single-constituent-dependent dissolution theory may not predict complete dissolution, thereby requiring non-routine robust treatment procedures with post-digestion filtration, followed by examination of residual particulate material. Additionally, for beryllium, and likely other poorly soluble materials, particulate reference materials of various chemical forms and size distributions are needed to better evaluate and harmonize analytical digestion procedures. Figure Generation of aerosol particles during machining of beryllium oxide.

  18. Combinatorial Density Functional Theory-Based Screening of Surface Alloys for the Oxygen Reduction Reaction

    DEFF Research Database (Denmark)

    Greeley, Jeffrey Philip; Nørskov, Jens Kehlet

    2009-01-01

    A density functional theory (DFT)-based, combinatorial search for improved oxygen reduction reaction (ORR) catalysts is presented. A descriptor-based approach to estimate the ORR activity of binary surface alloys, wherein alloying occurs only in the surface layer, is described, and rigorous...... for the ORR but, with few exceptions, they are found to be thermodynamically unstable in the acidic environments typical of low-temperature fuel cells. The results suggest that, absent other thermodynamic or kinetic mechanisms to stabilize the alloys, surface alloys are unlikely to serve as useful ORR...

  19. THE IDAHO NATIONAL LABORATORY BERYLLIUM TECHNOLOGY UPDATE

    Energy Technology Data Exchange (ETDEWEB)

    Glen R. Longhurst

    2007-12-01

    A Beryllium Technology Update meeting was held at the Idaho National Laboratory on July 18, 2007. Participants came from the U.S., Japan, and Russia. There were two main objectives of this meeting. One was a discussion of current technologies for beryllium in fission reactors, particularly the Advanced Test Reactor and the Japan Materials Test Reactor, and prospects for material availability in the coming years. The second objective of the meeting was a discussion of a project of the International Science and Technology Center regarding treatment of irradiated beryllium for disposal. This paper highlights discussions held during that meeting and major conclusions reached

  20. Co-based alloys design based on first-principles calculations: Influence of transition metal and rare-earth alloying element on stacking fault energy

    Science.gov (United States)

    Achmad, Tria Laksana; Fu, Wenxiang; Chen, Hao; Zhang, Chi; Yang, Zhi-Gang

    2017-01-01

    The main idea of alloy design is to reduce costs and time required by the traditional (trial and error) method, then finding a new way to develop the efficiency of the alloy design is necessary. In this study, we proposed a new approach to the design of Co-based alloys. It is based on the concept that lowering the ratio of stable and unstable stacking fault energy (SFE) could bring a significant increase in the tendency of partial dislocation accumulation and FCC to HCP phase transformation then enhance mechanical properties. Through the advance development of the computing techniques, first-principles density-functional-theory (DFT) calculations are capable of providing highly accurate structural modeling at the atomic scale without any experimental data. The first-principles calculated results show that the addition of some transition metal (Cr, Mo, W, Re, Os, Ir) and rare-earth (Sc, Y, La, Sm) alloying elements would decrease both stable and unstable SFE of pure Co. The dominant deformation mechanism of binary Co-4.5 at.% X (X = alloying element) is extended partial dislocation. Our study reveals Re, W, Mo and La as the most promising alloying additions for the Co-based alloys design with superior performances. Furthermore, the underlying mechanisms for the SFE reduction can be explained regarding the electronic structure.

  1. Effect of composition on antiphase boundary energy in Ni3Al based alloys: Ab initio calculations

    Science.gov (United States)

    Gorbatov, O. I.; Lomaev, I. L.; Gornostyrev, Yu. N.; Ruban, A. V.; Furrer, D.; Venkatesh, V.; Novikov, D. L.; Burlatsky, S. F.

    2016-06-01

    The effect of composition on the antiphase boundary (APB) energy of Ni-based L 12-ordered alloys is investigated by ab initio calculations employing the coherent potential approximation. The calculated APB energies for the {111} and {001} planes reproduce experimental values of the APB energy. The APB energies for the nonstoichiometric γ' phase increase with Al concentration and are in line with the experiment. The magnitude of the alloying effect on the APB energy correlates with the variation of the ordering energy of the alloy according to the alloying element's position in the 3 d row. The elements from the left side of the 3 d row increase the APB energy of the Ni-based L 12-ordered alloys, while the elements from the right side slightly affect it except Ni. The way to predict the effect of an addition on the {111} APB energy in a multicomponent alloy is discussed.

  2. Relationship between phase composition and corrosion resistanceof Ni-Ti-Nb based shape memory alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The stability and microstructure of Ni-Ti-Nb based shape memory alloys were investigated after alloyed with elements Zr, Cr and V. In artificial seawater (3.5%NaCl) and physiological solution (5%NaCl+0.1%H2O2), the results show that the alloying elements influence the corrosion behavior of Ni-Ti-Nb alloys. Generally, Zr improves the corrosion resistance of Ni-Ti-Nb alloy, Cr reduces its corrosion resistance and V does not change the property. In order to investigate the reason of the difference,the relation of the phase components and corrosion resistance of Ni-Ti-Nb based shape memory alloys were studied by element analysis and SEM.

  3. High temperature oxidation behavior of ODS iron-base alloys for nuclear energy application

    Energy Technology Data Exchange (ETDEWEB)

    Li, M.; Zhou, Z.; Liao, L.; Chen, W.; Ge, C. [Univ. of Science and Technology Beijing, School of Materials Science and Engineering, Beijing (China)

    2010-07-01

    Oxide dispersion strengthened (ODS) iron based alloys are considered as promising high temperature structural material for advanced nuclear energy systems due to its higher creep strength and radiation damage resistance than conventional commercial steels. In this study, the oxidation behavior of ODS iron based alloys with different Cr content (12-18%) was investigated by exposing samples at high temperature of 700℃ and 1000℃ in atmosphere environment, the exposure time is up to 500 h. Results showed that 14Cr and 18Cr ODS alloys exhibited better oxidation resistance than 12Cr ODS alloys. For the same chromium content, the oxidation resistance of ODS alloys are better than that of non-ODS alloys. (author)

  4. Efficacy of serial medical surveillance for chronic beryllium disease in a beryllium machining plant.

    Science.gov (United States)

    Newman, L S; Mroz, M M; Maier, L A; Daniloff, E M; Balkissoon, R

    2001-03-01

    There is limited information on the use of the blood beryllium lymphocyte proliferation test (BeLPT) at regular intervals in medical surveillance. Employees of a beryllium machining plant were screened with the BeLPT biennially, and new employees were screened within 3 months of hire. Of 235 employees screened from 1995 to 1997, a total of 15 (6.4%) had confirmed abnormal BeLPT results indicating beryllium sensitization; nine of these employees were diagnosed with chronic beryllium disease. Four of the 15 cases were diagnosed within 3 months of first exposure. When 187 of the 235 employees participated in biennial screening in 1997 to 1999, seven more had developed beryllium sensitization or chronic beryllium disease, increasing the overall rate to 9.4% (22 of 235). The blood BeLPT should be used serially in beryllium disease surveillance to capture new or missed cases of sensitization and disease. Beryllium sensitization and chronic beryllium disease can occur within 50 days of first exposure in modern industry.

  5. Evaluation of different finish line designs in base metal alloys

    Directory of Open Access Journals (Sweden)

    Aghandeh R

    1999-06-01

    Full Text Available This investigation was performed according to the widespread application of base metal alloys"nand few articles published about the marginal integrity of restorations fabricated by these metals."nThree standard dies of a maxillary first premolar were prepared with a flat shoulder finish line in buccal"naspect and chamfer in palatal. One of them left with no change. On the buccal aspect of the second and"nthird dies 135?and 1607 bevel were added respectively"nUsing dual wax technique, nine wax patterns were formed on each die and casting procedure of selected"nnon precious alloy was performed by centrifugal method. Marginal gaps of each copping seated on dies"nwere measured by scanning electron microscope (SEM with X500 magnification. Measurements were"ndone on three areas of marked dies on buccal aspect. Measurement son palatal aspect was done on"nmarked midpalatal point as control."nResults and statistical analysis showed no significant difference among marginal gaps in lingual aspect."nBut on the buccal aspect there were statistically significant differences among the groups (P<0.001. Flat"nshoulder had the best marginal integrity (mean 4 micron. Shoulder with 160' bevel had the most marginal"ngap (mean 26.5 micron and shoulder with 1357 bevel was between two other groups (mean 15.7 micron.

  6. The wettability of Fe based alloy on TiO

    Institute of Scientific and Technical Information of China (English)

    李庆奎; 钟海云; 钟晖; 戴艳阳

    2002-01-01

    For developing TiO based imitated gold materials, the wettabilities of Fe and Fe-Cr-Ni-Ti on TiO were studied. The results indicated that the wettabilities of Fe and Fe-Cr on TiO were poor, and their wetting angles were about 90° at melting point. The wetting angles reduced with the increase of wetting temperature, but the influence of temperature was small. Fe and Fe-Cr containing Cr 50% or less could react with TiO on the interface to form Fe2Ti and Ti2O3, but this did not improve the wettability effectively. When Ni-Ti was added into Fe-Cr alloy, Ni3Ti was formed on the interface, which can reduce the interface energy, improve the wettability, and prevent the formation of Fe2Ti and Ti2O3. The wetting angles could go down to about 40° when 3% Ni-Ti was added to Fe-Cr alloy.

  7. Laser cladding of Ni-based alloy on copper substrate

    Institute of Scientific and Technical Information of China (English)

    Fang Liu; Changsheng Liu; Xingqi Tao; Suiyuan Chen

    2006-01-01

    The laser cladding of Ni1015 alloy on Cu substrate was prepared by a high power continuous wave CO2 laser. Its microstructure was analyzed by optical microscope (OM), scanning electron microscope (SEM), and X-Ray diffraction (XRD). The average microhardness of the cladding coating was Hv 280, which was almost three times of that of the Cu substrate (Hv 85). OM and SEM observations showed that the obtained coating had a smooth and uniform surface, as well as a metallurgical combination with the Cu substrate without cracks and pores at the interface. With the addition of copper into the nickel-based alloy, the differences of thermal expansion coefficient and melting point between the interlayer and cladding were reduced, which resulted in low stresses during rapid cooling. Moreover, large amount of (Cu, Ni) solid solution formed a metallurgical bonding between the cladding coating and the substrate, which also relaxed the stresses, leading to the reduction of interfacial cracks and pores after laser cladding.

  8. A Shape Memory Alloy Based Cryogenic Thermal Conduction Switch

    Science.gov (United States)

    Notardonato, W. U.; Krishnan, V. B.; Singh, J. D.; Woodruff, T. R.; Vaidyanathan, R.

    2005-01-01

    Shape memory alloys (SMAs) can produce large strains when deformed (e.g., up to 8%). Heating results in a phase transformation and associated recovery of all the accumulated strain. This strain recovery can occur against large forces, resulting in their use as actuators. Thus an SMA element can integrate both sensory and actuation functions, by inherently sensing a change in temperature and actuating by undergoing a shape change as a result of a temperature-induced phase transformation. Two aspects of our work on cryogenic SMAs are addressed here. First - a shape memory alloy based cryogenic thermal conduction switch for operation between dewars of liquid methane and liquid oxygen in a common bulkhead arrangement is discussed. Such a switch integrates the sensor element and the actuator element and can be used to create a variable thermal sink to other cryogenic tanks for liquefaction, densification, and zero boil-off systems for advanced spaceport applications. Second - fabrication via arc-melting and subsequent materials testing of SMAs with cryogenic transformation temperatures for use in the aforementioned switch is discussed.

  9. Corrosion Mechanisms in Brazed Al-Base Alloy Sandwich Structures as a Function of Braze Alloy and Process Variables

    Science.gov (United States)

    2013-02-01

    produce results on precipitation hardened Al alloys which provide a good indicator of long term field exposure performance in natural environments [15...I \\ I I i i I i i i I 750 ZOO AI-0.15Cu-0.9Mg-0.6Si (wt%) J50 m 100 10000 1000 10000 100000 1000000 i 10o Time, min Time...for good corrosion resistance and simultaneous weld penetration to achieve bonding vi. Designed New Braze alloy based on combined metallurgical

  10. Ultrasonic evaluation of beryllium-copper diffusion bonds

    Energy Technology Data Exchange (ETDEWEB)

    Jamieson, E.E.

    2000-06-08

    A study was performed to compare the effectiveness of several advanced ultrasonic techniques when used to determine the strength of diffusion bonded beryllium-copper, which heretofore have each been applied to only a few material systems. The use of integrated backscatter calculations, frequency domain reflection coefficients, and time-of-flight variance was compared in their ability to characterize the bond strength in a series of beryllium-copper diffusion bond samples having a wide variation in bond quality. Correlation of integrated backscatter calculations and time-of-flight variance with bond strength was good. Some correlation of the slope of the frequency based reflection coefficient was shown for medium and high strength bonds, while its Y-intercept showed moderate correlation for all bond strengths.

  11. Multiscale modelling of hydrogen behaviour on beryllium (0001 surface

    Directory of Open Access Journals (Sweden)

    Ch. Stihl

    2016-12-01

    Full Text Available Beryllium is proposed to be a neutron multiplier and plasma facing material in future fusion devices. Therefore, it is crucial to acquire an understanding of the microscopic mechanisms of tritium accumulation and release as a result of transmutation processes that Be undergoes under neutron irradiation. A multiscale simulation of ad- and desorption of hydrogen isotopes on the beryllium (0001 surface is developed. It consists of ab initio calculations of certain H adsorption configurations, a suitable cluster expansion approximating the energies of arbitrary configurations, and a kinetic Monte Carlo method for dynamic simulations of adsorption and desorption. The processes implemented in the kinetic Monte Carlo simulation are deduced from further ab initio calculations comprising both, static relaxation as well as molecular dynamics runs. The simulation is used to reproduce experimental data and the results are compared and discussed. Based on the observed results, proposals for a refined model are made.

  12. Effects of Ti and Co on the Electrochemical Characteristics of MgNi-Based Alloy Electrodes

    Institute of Scientific and Technical Information of China (English)

    FENG,Yan; JIAO,Li-Fang; YUAN,Hua-Tang; ZHAO,Ming

    2007-01-01

    Mg-based hydrogen storage alloys MgNi, Mg0.9Ti0.1Ni and Mg0.9Ti0.1Ni0.9Co0.1 were successfully prepared by means of mechanical alloying (MA). The structure and the electrochemical characteristics of these Mg-based materials were also studied. The results of X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that the main phases of the alloys exhibit amorphous structures, and trace of Ni co-exists. The charge-discharge cycle tests indicate these alloys have good electrochemical active characteristics. And the cycle stability of Ti and Co doped alloy was better than that of MgNi alloy. After 50 cycle charge-discharge, the discharge capacity of the Mg0.9Ti0.1Ni0.9Co0.1 alloy was much better than that of MgNi and Mg0.9Ti0.1Ni alloys. The discharge capacity of Mg0.9Ti0.1Ni0.9Co0.1 was 102.8% higher than that of MgNi alloy, and 45.49% higher than that of the Mg0.9Ti0.1Ni alloy. During the process of charge-discharge cycle test, the main reason for the electrode capacity fading is the corrosion of Mg to Mg(OH)2 on the surface of alloys. The Tafel polarization test indicates Ti and Co improve the anticorrosion in an alkaline solution. The EIS results suggest that proper amount of Ti and Co doping improve the electrochemical catalytical activity on the Mg-based alloy surface significantly.

  13. Hydrogen release from reactor-irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Klepikov, A.Kh. [Kazakh State Univ., Alma-Ata (Kazakstan); Tazhibaeva, I.L. [Kazakh State Univ., Alma-Ata (Kazakstan); Shestakov, V.P. [Kazakh State Univ., Alma-Ata (Kazakstan); Romanenko, O.G. [Kazakh State Univ., Alma-Ata (Kazakstan); Chikhray, Y.V. [Kazakh State Univ., Alma-Ata (Kazakstan); Kenzhin, E.A. [IAE NNC RK, Semipalatinsk-21 (Russian Federation); Cherepnin, Yu.S. [IAE NNC RK, Semipalatinsk-21 (Russian Federation); Tikhomirov, L.N. [IAE NNC RK, Semipalatinsk-21 (Russian Federation)

    1996-10-01

    Experiments on gas release of reactor-irradiated beryllium samples were carried out and compared to control samples. The simultaneous influence of reactor irradiation and exposure to hydrogen results in more hydrogen retention in beryllium, than if beryllium is initially irradiated and then exposed to hydrogen. Appearance of low temperature peaks at 460 K and 540 K with 0.71 eV/atom and 0.84 eV/atom desorption activation energies, respectively, assessed in a frame of a second order desorption model, is mainly responsible for the increase in hydrogen content. These peaks can be attributed to chemical hydrogen bonds with surface oxide. The simultaneous influence of hydrogen and nuclear reactor irradiation at a temperature of 1150 K was assumed to increase significantly microcrack formation near the surface of beryllium samples, resulting in an increase in low temperature peak intensities. (orig.).

  14. Synthesis and ceramization of polycarbosilane containing beryllium

    Institute of Scientific and Technical Information of China (English)

    黄小忠; 周珊; 程勇; 杜作娟; 段曦东; 王超英

    2014-01-01

    Polycarbosilane containing beryllium (BPCS) precursors was prepared by the reaction of polycarbosilane (PCS) with beryllium acetylacetone (Be (acac)2). The analysis of structures and components of BPCS demonstrates that their main structures are basically the same as PCS. Ceramization of BPCS precursors shows that BPCS precursors are organic below 600 °C and inorganic at 800 °C. At 1400 °C, BPCS precursors convert into silicon carbide ceramics. The ceramization of different beryllium content precursors were studied, which show that beryllium plays an important role in the inhibition of crystalline grain growth ofβ-SiC at high temperature and it can adjust the dielectric constant of silicon carbide ceramics.

  15. Evaluation of Nb-base alloys for the divertor structure in fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Purdy, I.M. [Argonne National Laboratory, Upton, IL (United States)

    1996-04-01

    Niobium-base alloys are candidate materials for the divertor structure in fusion reactors. For this application, an alloy should resist aqueous corrosion, hydrogen embrittlement, and radiation damage and should have high thermal conductivity and low thermal expansion. Results of corrosion and embrittlement screening tests of several binary and ternary Nb alloys in high-temperature water indicated the Mb-1Zr, Nb-5MO-1Zr, and Nb-5V-1Z4 (wt %) showed sufficient promise for further investigation. These alloys, together with pure Nb and Zircaloy-4 have been exposed to high purity water containing a low concentration of dissolved oxygen (<12 ppb) at 170, 230, and 300{degrees}C for up to {approx}3200 h. Weight-change data, microstructural observations, and qualitative mechanical-property evaluation reveal that Nb-5V-1Zr is the most promising alloy at higher temperatures. Below {approx}200{degrees}C, the alloys exhibit similiar corrosion behavior.

  16. Thermodynamics-Based Computational Design of Al-Mg-Sc-Zr Alloys

    Science.gov (United States)

    Haidemenopoulos, G. N.; Katsamas, A. I.; Kamoutsi, H.

    2010-04-01

    Alloying additions of Sc and Zr raise the yield strength of Al-Mg alloys significantly. We have studied the effects of Sc and Zr on the grain refinement and recrystallization resistance of Al-Mg alloys with the aid of computational alloy thermodynamics. The grain refinement potential has been assessed by Scheil-Gulliver simulations of solidification paths, while the recrystallization resistance (Zener drag) has been assessed by calculation of the precipitation driving forces of the Al3Sc and Al3Zr intermetallics. Microstructural performance indices have been derived, used to rank several alloy composition variants, and finally select the variant with the best combination of grain refinement and recrystallization resistance. The method can be used, with certain limitations, for a thermodynamics-based design of Al-Mg and other alloy compositions.

  17. Development and Making of New Jewellery Palladium Based Alloys at JSC "Krastsvetmet"

    Institute of Scientific and Technical Information of China (English)

    YEFIMOV V. N.; MAMONOV S. N.; SHULGIN D. R.; YELTSIN S. I.

    2012-01-01

    Complex of research and development work aimed at implementation of jewellery palladium based alloys technology has been carried out at JSC Krastsvetmet.A range of palladium alloys jewellery fabrication has been organized.Compositions of a number of jewellery palladium alloys grade 850,900,950 and 990 have been proposed,their production and application in jewellery manufacture has been organized.To produce palladium alloys induction melting in inert atmosphere and melt pouring into a copper mould has been used.The ingots heat treatment conditions,as well as semi-finished jewelry plastic deformation parameters have been determined.

  18. A Palladium-Based Alloy for Prosthetic Dentistry:Structure and Properties

    Institute of Scientific and Technical Information of China (English)

    STEPANOVA Galina; PARUNOV Vitaly; VASEKIN Vasily; KAREVA Maria; SINAGEJKINA Julia

    2012-01-01

    Abstract.Using the results of physical and chemical researches and mechanical tests of the Pd-Au-Cu-Sn system alloys,a new palladium-based alloy has been chosen and studied in detail.It has a higher plasticity and a lower hardness than the Palladent alloy,widely used in prosthetic dentistry:its hardness is lower than 300 MPa,and its specific elongation is 10%~14 %.At the same time,such important practical characteristics of the alloys as the strength of adhesion to ceramics and thermal expansion coefficient are almost similar.

  19. Characteristics of multi-component MI-based hydrogen storage alloys and their hydride electrodes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A series of multi-component MI-based hydrogen storage alloys with a cobalt atomic ratio of 0.40-0.75 w ere prepared. The electrochemical properties under different charge-discharge conditions and PCT characteristics measured by electrochemical method were investigated. The addition of other alloying elements for partial substitution of Co lowers the hydrogen equilibrium pressure and discharge capacity, but improves the cycling stability and makes the alloys keep nearly the same rate discharge capability and high-temperature discharge capability as those of the compared alloy.The reasons were discussed.

  20. Thermodynamic properties of gadolinium in Ga-Sn and Ga-Zn eutectic based alloys

    Science.gov (United States)

    Maltsev, Dmitry S.; Volkovich, Vladimir A.; Yamshchikov, Leonid F.; Chukin, Andrey V.

    2016-09-01

    Thermodynamic properties of gadolinium in Ga-Sn and Ga-Zn eutectic based alloys were studied. Temperature dependences of gadolinium activity in the studied alloys were determined at 573-1073 K employing the EMF method. Solubility of gadolinium in the Ga-Sn and Ga-Zn alloys was measured at 462-1073 K using IMCs sedimentation method. Activity coefficients as well as partial and excess thermodynamic functions of gadolinium in the studied alloys were calculated on the basis of the obtained experimental data.

  1. Benchmark Experiment for Beryllium Slab Samples

    Institute of Scientific and Technical Information of China (English)

    NIE; Yang-bo; BAO; Jie; HAN; Rui; RUAN; Xi-chao; REN; Jie; HUANG; Han-xiong; ZHOU; Zu-ying

    2013-01-01

    The neutron leakage spectra were measured at 60°from pure beryllium slab samples(10 cm×10 cm×5 cm and 10 cm×10 cm×11 cm)by TOF method.The experimental results were compared with the calculated ones by MCNP5 simulation,using the evaluated data of beryllium from CENDL3.1,

  2. Nanocrystalline Al-based alloys - lightweight materials with attractive mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Latuch, J; Cieslak, G; Dimitrov, H; Krasnowski, M; Kulik, T, E-mail: takulik@rekt.pw.edu.p [Warsaw University of Technology, Faculty of Materials Science and Engineering, Woloska 141, 02-507 Warsaw (Poland)

    2009-01-01

    In this study, several ways of bulk nanocrystalline Al-based alloys' production by high-pressure compaction of powders were explored. The effect of chemical composition and compaction parameters on the structure, quality and mechanical properties of the bulk samples was studied. Bulk nanocrystalline Al-Mm-Ni-(Fe,Co) alloys were prepared by ball-milling of amorphous ribbons followed by consolidation. The maximum microhardness (540 HV0.1) was achieved for the samples compacted at 275 deg. C under 7.7 GPa (which resulted in an amorphous bulk) and nanocrystallised at 235 deg. C for 20 min. Another group of the produced materials were bulk nanocrystalline Al-Si-(Ni,Fe)-Mm alloys obtained by ball-milling of nanocrystalline ribbons and consolidation. The hardness of these samples achieved the value five times higher (350HV) than that of commercial 4xxx series Al alloys. Nanocrystalline Al-based alloys were also prepared by mechanical alloying followed by hot-pressing. In this group of materials, there were Al-Fe alloys containing 50-85 at.% of Al and ternary or quaternary Al-Fe-(Ti, Si, Ni, Mg, B) alloys. Microhardness of these alloys was in the range of 613 - 1235 HV0.2, depending on the composition.

  3. Hydrogen release from deposited beryllium layers

    Energy Technology Data Exchange (ETDEWEB)

    Shestakov, V.P.; Klepikov, A.Kh.; Chikhray, Y.V.; Tazhibaeva, I.L. [NIIETF of Al Farabi Kazakh State Univ., Almaty (Kazakhstan)

    2000-04-01

    The analysis of hydrogen retained in deposited beryllium layers deposited by magnetron sputtering was carried out by means of thermodesorption (TDS) technique. Two hydrogen release peaks were clearly seen on the thermodesorption curves at the temperatures 760-800 K and 920-970 K. Hydrogen concentrations in the deposited beryllium layers were calculated from the gas release curves corresponding to the number of Be atoms in the beryllium layer of 100% theoretical density. Average hydrogen concentration in the beryllium samples loaded in the process of magnetron sputtering was equal to 3800{+-}200 appm. The experiments with beryllium layers, enriched with carbon, revealed the increase of retained hydrogen concentration up to 9600{+-}200 appm. Assuming that gas release can be described within the framework of model of diffusion from layer system BeO-Be-BeO, hydrogen diffusion coefficient in BeO and the trapping and detrapping constants for the traps appearing in beryllium in the process of deposition were evaluated. (orig.)

  4. Tritium release from neutron irradiated beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Scaffidi-Argentina, F.; Werle, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reactortechnik

    1998-01-01

    One of the most important open issues related to beryllium for fusion applications refers to the kinetics of the tritium release as a function of neutron fluence and temperature. The EXOTIC-7 as well as the `Beryllium` experiments carried out in the HFR reactor in Petten are considered as the most detailed and significant tests for investigating the beryllium response under neutron irradiation. This paper reviews the present status of beryllium post-irradiation examinations performed at the Forschungszentrum Karlsruhe with samples from the above mentioned irradiation experiments, trying to elucidate the tritium release controlling processes. In agreement with previous studies it has been found that release starts at about 500-550degC and achieves a maximum at about 700-750degC. The observed release at about 500-550degC is probably due to tritium escaping from chemical traps, while the maximum release at about 700-750degC is due to tritium escaping from physical traps. The consequences of a direct contact between beryllium and ceramics during irradiation, causing tritium implanting in a surface layer of beryllium up to a depth of about 40 mm and leading to an additional inventory which is usually several times larger than the neutron-produced one, are also presented and the effects on the tritium release are discussed. (author)

  5. Occupational Exposure to Beryllium. Final rule.

    Science.gov (United States)

    2017-01-09

    The Occupational Safety and Health Administration (OSHA) is amending its existing standards for occupational exposure to beryllium and beryllium compounds. OSHA has determined that employees exposed to beryllium at the previous permissible exposure limits face a significant risk of material impairment to their health. The evidence in the record for this rulemaking indicates that workers exposed to beryllium are at increased risk of developing chronic beryllium disease and lung cancer. This final rule establishes new permissible exposure limits of 0.2 micrograms of beryllium per cubic meter of air (0.2 [mu]g/m\\3\\) as an 8-hour time-weighted average and 2.0 [mu]g/m\\3\\ as a short-term exposure limit determined over a sampling period of 15 minutes. It also includes other provisions to protect employees, such as requirements for exposure assessment, methods for controlling exposure, respiratory protection, personal protective clothing and equipment, housekeeping, medical surveillance, hazard communication, and recordkeeping. OSHA is issuing three separate standards--for general industry, for shipyards, and for construction--in order to tailor requirements to the circumstances found in these sectors.

  6. Corrosion resistance and electrochemical potentiokinetic reactivation testing of some iron-base hardfacing alloys

    Energy Technology Data Exchange (ETDEWEB)

    Cockeram, B.V.

    1999-11-01

    Hardfacing alloys are weld deposited on a base material to provide a wear resistant surface. Commercially available iron-base hardfacing alloys are being evaluated for replacement of cobalt-base alloys to reduce nuclear plant activation levels. Corrosion testing was used to evaluate the corrosion resistance of several iron-base hardfacing alloys in highly oxygenated environments. The corrosion test results indicate that iron-base hardfacing alloys in the as-deposited condition have acceptable corrosion resistance when the chromium to carbon ratio is greater than 4. Tristelle 5183, with a high niobium (stabilizer) content, did not follow this trend due to precipitation of niobium-rich carbides instead of chromium-rich carbides. This result indicates that iron-base hardfacing alloys containing high stabilizer contents may possess good corrosion resistance with Cr:C < 4. NOREM 02, NOREM 01, and NoCo-M2 hardfacing alloys had acceptable corrosion resistance in the as-deposited and 885 C/4 hour heat treated condition, but rusting from sensitization was observed in the 621 C/6 hour heat treated condition. The feasibility of using an Electrochemical Potentiokinetic Reactivation (EPR) test method, such as used for stainless steel, to detect sensitization in iron-base hardfacing alloys was evaluated. A single loop-EPR method was found to provide a more consistent measurement of sensitization than a double loop-EPR method. The high carbon content that is needed for a wear resistant hardfacing alloy produces a high volume fraction of chromium-rich carbides that are attacked during EPR testing. This results in inherently lower sensitivity for detection of a sensitized iron-base hardfacing alloy than stainless steel using conventional EPR test methods.

  7. Thermophysical Properties of Liquid AlTi-Based Alloys

    Science.gov (United States)

    Egry, I.; Holland-Moritz, D.; Novakovic, R.; Ricci, E.; Wunderlich, R.; Sobczak, N.

    2010-05-01

    The surface tension and density of three liquid AlTi-based alloys (AlTiV, AlTiNb, and AlTiTa) have been measured using electromagnetic levitation as a tool for containerless processing. Surface tension has been determined by the oscillating-drop method, while the density was measured using a shadowgraph technique. Both quantities were determined over a wide temperature range, including the undercooled regime. In addition, sessile-drop and pendant-drop experiments to determine the surface tension were performed in a recently built high-temperature furnace. The measured data were compared to thermodynamic calculations using phenomenological models and the Butler equation. Generally, good agreement was found.

  8. Laser vision sensing based on adaptive welding for aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhixiang; SONG Yonglun; ZHANG Jun; ZHANG Wanchun; JIANG Li; XIA Xuxin

    2007-01-01

    A laser vision sensing based on the adaptive tungsten inert gas(TIG)welding system for large-scale aluminum alloy components was established to fit various weld groove conditions.A new type of laser vision sensor was used to precisely measure the weld groove.The joint geometry data,such as the bevel angle,the gap,the area,and the mismatch,etc.,aided in assembling large-scale aerospace components before welding.They were also applied for automatic seam tracking,such as automatic torch transverse alignment and torch height adjustment in welding.An adaptive welding process was realized by automatically adjusting the wire feeding speed and the welding current according to the groove conditions.The process results in a good weld formation and high welding quality,which meet the requirements of related standards.

  9. Laser welding of AZ61 magnesium-based alloys

    Institute of Scientific and Technical Information of China (English)

    Wang Hongying; Li Zhijun; Zhang Yihui

    2006-01-01

    Laser welding of AZ61 magnesium alloys was carried out asing a CO2 laser weldingexperimental system.The welding properties of AZ61 sheets with different thickness were investigated.The effect of processing parameters including laser power, welding speed and protection gas flow was researched.The results show that laser power and welding speed have large effect on the weld width and joint dimensions.Protection gas flow has relatively slight effect on the weld width.The property test of three typical joints indicates that microhardness and tensile strength in weld zone are higher than that of AZ61 base metal.Joints with good appearance and excellent mechanical properties can be produced using CO2 laser welding method.The microstructure with small grains in weld zone is believed to be responsible for the excellent mechanical properties of AZ61 joints.

  10. Shape Memory Alloy-Based Periodic Cellular Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I effort will develop and demonstrate an innovative shape memory alloy (SMA) periodic cellular structural technology. Periodic cellular structures...

  11. Electron-ion plasma modification of Al-based alloys

    Science.gov (United States)

    Ivanov, Yurii; Rygina, Mariya; Petrikova, Elizaveta; Krysina, Olga; Teresov, Anton; Ivanova, Olga; Ikonnikova, Irina

    2016-01-01

    The paper reports on the study where we analyzed the surface structure and strength properties of coated Al alloys modified by electron-ion plasma treatment. The Al alloys were deposited with a thin (≈0.5 μm) TiCu film coating (TiCu-Al system) and with a hard TiCuN coating (TiCuN-AlSi system) on a TRIO vacuum setup in the plasma of low-pressure arc discharges. The temperature fields and phase transformations in the film-substrate system were estimated by numerical simulation in a wide range of electron energy densities (5-30 J/cm2) and pulse durations (50-200 μs). The calculations allowed us to determine the threshold energy density and pulse duration at which the surface structure of the irradiated Al-based systems is transformed in a single-phase state (solid or liquid) and in a two-phase state (solid plus liquid). The elemental composition, defect structure, phase state, and lattice state in the modified surface layers were examined by optical, scanning, and transmission electron microscopy, and by X-ray diffraction analysis. The mechanical characteristics of the modified layers were studied by measuring the hardness and Young's modulus. The tribological properties of the modified layers were analyzed by measuring the wear resistance and friction coefficient. It is shown that melting and subsequent high-rate crystallization of the TiCu-Al system makes possible a multiphase Al-based surface structure with the following characteristics: crystallite size ranging within micrometer, microhardness of more than 3 times that in the specimen bulk, and wear resistance ≈1.8 times higher compared to the initial material. Electron beam irradiation of the TiCuN-AlSi system allows fusion of the coating into the substrate, thus increasing the wear resistance of the material ≈2.2 times at a surface hardness of ˜14 GPa.

  12. Precipitation hardening in Fe--Ni base austenitic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chang, K.M.

    1979-05-01

    The precipitation of metastable Ni/sub 3/X phases in the austenitic Fe--Ni-base alloys has been investigated by using various combinations of hardening elements, including Ti, Ta, Al, and Nb. The theoretical background on the formation of transition precipitates has been summarized based on: atomic size, compressibility, and electron/atom ratio. A model is proposed from an analysis of static concentration waves ordering the fcc lattice. Ordered structure of metastable precipitates will change from the triangularly ordered ..gamma..', to the rectangularly ordered ..gamma..'', as the atomic ratio (Ti + Al)/(Ta + Nb) decreases. The concurrent precipitation of ..gamma..' and ..gamma..'' occurs at 750/sup 0/C when the ratio is between 1.5 and 1.9. Aging behavior was studied over the temperature range of 500/sup 0/C to 900/sup 0/C. Typical hardness curves show a substantial hardening effect due to precipitation. A combination of strength and fracture toughness can be developed by employing double aging techniques. The growth of these coherent intermediate precipitates follows the power law with the aging time t : t/sup 1/3/ for the spherical ..gamma..' particles; and t/sup 1/2/ for the disc-shaped ..gamma..''. The equilibrium ..beta.. phase is observed to be able to nucleate on the surface of imbedded carbides. The addition of 5 wt % Cr to the age-hardened alloys provides a non-magnetic austenite which is stable against the formation of mechanically induced martensite.Cr addition retards aging kinetics of the precipitation reactions, and suppresses intergranular embrittlement caused by the high temperature solution anneal. The aging kinetics are also found to be influenced by solution annealing treatments.

  13. Processing of New Materials by Additive Manufacturing: Iron-Based Alloys Containing Silver for Biomedical Applications

    Science.gov (United States)

    Niendorf, Thomas; Brenne, Florian; Hoyer, Peter; Schwarze, Dieter; Schaper, Mirko; Grothe, Richard; Wiesener, Markus; Grundmeier, Guido; Maier, Hans Jürgen

    2015-07-01

    In the biomedical sector, production of bioresorbable implants remains challenging due to improper dissolution rates or deficient strength of many candidate alloys. Promising materials for overcoming the prevalent drawbacks are iron-based alloys containing silver. However, due to immiscibility of iron and silver these alloys cannot be manufactured based on conventional processing routes. In this study, iron-manganese-silver alloys were for the first time synthesized by means of additive manufacturing. Based on combined mechanical, microscopic, and electrochemical studies, it is shown that silver particles well distributed in the matrix can be obtained, leading to cathodic sites in the composite material. Eventually, this results in an increased dissolution rate of the alloy. Stress-strain curves showed that the incorporation of silver barely affects the mechanical properties.

  14. Microstructure and nano-mechanical property of cold spray Co-base refractory alloy coating

    Institute of Scientific and Technical Information of China (English)

    Yongli LIANG; Bi SHI; Xiaoping YANG; Junbao ZHANG; Xianming MENG

    2011-01-01

    Co-base refractory alloy coating was prepared on carbon steel substrate by cold spray technology; microstructure and nano-mechenical property were examined by scanning electron microscope (SEM) and nano indenter individually. The results showed that about 250 μm Co-base refractory alloy coating could be deposited on steel substrate by cold spray technique, interface between coating and substrate was combined well, and the refractory alloy particle had a significant plastic deformation during deposition process; mixing Ni powders into Co-base refractory alloy powders could increase the density and decrease the nano-hardness of coating, the nano-hardness and elastic modulus of refractory alloy coating was higher than 6 GPa and 160 GPa, respectively.

  15. Sanitary-hygienic and ecological aspects of beryllium production

    Energy Technology Data Exchange (ETDEWEB)

    Dvinskykh, E.M.; Savchuk, V.V.; Sidorov, V.L.; Slobodin, D.B.; Tuzov, Y.V. [Ulba Metallurgical Plant, Ust-Kamenogorsk (Kazakhstan)

    1998-01-01

    The Report describes An organization of sanitary-hygienic and ecological control of beryllium production at Ulba metallurgical plant. It involves: (1) the consideration of main methods for protection of beryllium production personnel from unhealthy effect of beryllium, (2) main kinds of filters, used in gas purification systems at different process areas, (3) data on beryllium monitoring in water, soil, on equipment. This Report also outlines problems connected with designing devices for a rapid analysis of beryllium in air as well as problems of beryllium production on ecological situation in the town. (author)

  16. Calculations for electron-impact excitation and ionization of beryllium

    Science.gov (United States)

    Zatsarinny, Oleg; Bartschat, Klaus; Fursa, Dmitry V.; Bray, Igor

    2016-12-01

    The B-spline R-matrix and the convergent close-coupling methods are used to study electron collisions with neutral beryllium over an energy range from threshold to 100 eV. Coupling to the target continuum significantly affects the results for transitions from the ground state, but to a lesser extent the strong transitions between excited states. Cross sections are presented for selected transitions between low-lying physical bound states of beryllium, as well as for elastic scattering, momentum transfer, and ionization. The present cross sections for transitions from the ground state from the two methods are in excellent agreement with each other, and also with other available results based on nonperturbative convergent pseudostate and time-dependent close-coupling models. The elastic cross section at low energies is dominated by a prominent shape resonance. The ionization from the {(2s2p)}3P and {(2s2p)}1P states strongly depends on the respective term. The current predictions represent an extensive set of electron scattering data for neutral beryllium, which should be sufficient for most modeling applications.

  17. Infection free titanium alloys by stabile thiol based nanocoating.

    Science.gov (United States)

    Cökeliler, Dilek; Göktaş, Hilal; Tosun, Pinar Deniz; Mutlu, Selma

    2010-04-01

    As biomedical materials, titanium and titanium alloys (Ti-6Al-4V) are superior to many materials in terms of mechanical properties and biocompatibility. However, they are still not sufficient for prolonged clinical use because the biocompatibility of these materials must be improved. In this study, the prevention of the attachment of test microorganism on the Ti alloy surfaces by thiol (-SH) and hydroxyl (-OH) functional group containing monomer in plasma based electron beam generator was reported in order to prepare anti-fouling surfaces. The precursor, 11-mercaptoundecanoic acid is used as plasma source to create nano-film with 30-60 nm approximately. The surface chemistry and topology of uncoated and coated samples are characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Atomic Force Microscopy (AFM). Static contact angle measurements are performed to state the change of surface hydrophilicity. All coated samples are tested in-vitro environment with Staphylococcus epidermidis that is chosen as the test bacteria strain in view of its significance for the pathogenesis of medical-device-related infections. This test is repeated after certain period of times and samples are waited in dynamic fluid media in order to investigate the stability of nano-coating. Plasma polymerized 11-mercaptoundecanoic acid film (PP MUA) with 42 +/- 4 nm is found alternative, stabile and simple method to create bacterial anti-fouling surfaces. The static contact angle of the coated surface is 34 +/- 80 whereas the uncoated surface is 57 +/- 50. For the coated surface, the presence of C-OH and C==O groups in infrared spectra defining the PP MUA is achieved by the plasma polymerization. The attachment of the model microorganism on the biomaterial surface prepared by PP MUA is reduced 85.3% if compared to unmodified control surface.

  18. Cerium-based conversion coatings on magnesium alloys

    Science.gov (United States)

    Castano Londono, Carlos Eduardo

    This research is primarily focused on gaining a better understanding of the deposition and corrosion behavior of cerium-based conversion coatings (CeCCs) on AZ31B and AZ91D Mg alloys. Deposition of homogenous and protective CeCCs was highly dependent on the surface preparation steps. The best results were obtained when Mg samples underwent grinding, acid cleaning, and alkaline cleaning processes. This reduced the number of active cathodic sites and promoted the formation of a protective Al-rich Mg oxide/hydroxide layer. Electrochemical properties of the CeCCs were also strongly correlated with morphological, microstructural, and chemical characteristics. Protective CeCCs were deposited on both AZ31 and AZ91 Mg alloys using a range of deposition times (5 to 180 s) and temperatures (10 to 80 °C). However, shorter deposition times (5 s) and lower deposition temperatures (~10 °C) showed higher impedance and longer bath stability than other deposition conditions. The increase in impedance was related with fewer cracks and smaller nodule sizes. Additional investigations of post-treated CeCCs exposed to NaCl environments showed an increased in the total impedance. The increase in corrosion protection of the CeCCs was associated with an overall increase in coating thickness from 400 to 800 nm. A microstructural evolution from ~3 nm nodular nanocrystals of CeO2/CePO4*H2O embedded in an amorphous matrix to >50 nm CePO4*H2O nanocrystals was responsible for the electrochemically active corrosion protection. Exposure of CeCCs to sunlight in humid environments promoted the reduction of Ce(IV) into Ce(III) species compared to unexposed coatings. This reduction process was related with photocatalytic water oxidation reaction.

  19. Electronic-Structure-Based Design of Ordered Alloys

    DEFF Research Database (Denmark)

    Bligaard, Thomas; Andersson, M.P.; Jacobsen, Karsten Wedel

    2006-01-01

    We describe some recent advances in the methodology of using electronic structure calculations for materials design. The methods have been developed for the design of ordered metallic alloys and metal alloy catalysts, but the considerations we present are relevant for the atomic-scale computation...

  20. Thermal analysis of selected tin-based lead-free solder alloys

    DEFF Research Database (Denmark)

    Palcut, Marián; Sopoušek, J.; Trnková, L.

    2009-01-01

    The Sn-Ag-Cu alloys have favourable solderability and wetting properties and are, therefore, being considered as potential lead-free solder materials. In the present study, tin-based Sn-Ag-Cu and Sn-Ag-Cu-Bi alloys were studied in detail by a differential scanning calorimetry (DSC) and thermodyna......The Sn-Ag-Cu alloys have favourable solderability and wetting properties and are, therefore, being considered as potential lead-free solder materials. In the present study, tin-based Sn-Ag-Cu and Sn-Ag-Cu-Bi alloys were studied in detail by a differential scanning calorimetry (DSC...... was simulated using the Thermo-Calc software package. This approach enabled us to obtain the enthalpy of cooling for each alloy and to compare its temperature derivative with the experimental DSC curves....

  1. Microstructure and tensile properties of magnesium alloy modified by Si/Ca based refiner

    Institute of Scientific and Technical Information of China (English)

    DUAN Zhi-chao; SUN Yang-shan; WEI Yu; DU Wen-wen; XUE Feng; ZHU Tian-bai

    2005-01-01

    Microstructure and mechanical properties of pure magnesium and AZ31 alloy with Ca/Si based refiner addition were investigated. The results indicate that addition of Ca/Si based refiners to pure magnesium and AZ31 alloy results in remarkable microstructure refinement. With proper amount of refiner addition, the grain size in as cast ingots can be one order of magnitude lower than that without refiner addition. Small amount of refiner addition to AZ31 alloy increases both ultimate strength and yield strength significantly, while the ductility of the alloy with refiner addition is similar to that without refiner addition. Addition of refiner improves the deformability of AZ31 alloy and extruded or hot rolled specimens (rods or sheets) with refiner addition exhibit higher surface quality and mechanical properties than those without refiner addition.

  2. Scale formation on Ni-based alloys in simulated solid oxide fuel cell interconnect environments

    Energy Technology Data Exchange (ETDEWEB)

    Ziomek-Moroz, Margaret; Cramer, Stephen D.; Holcomb, Gordon R.; Covino, Bernard S., Jr.; Bullard, Sophie J.; Singh, P. (PNNL); Windisch, C.F. (PNNL); Johnson, C.D. (NETL); Schaeffer, C. (National Energy Research Laboratory, Morgantown, WV)

    2004-11-01

    Recent publications suggest that the environment on the fuel side of the bi-polar stainless steel SOFC interconnects changes the oxidation behavior and morphology of the scale formed on the air side. The U.S. Department of Energy Albany Research Center (ARC), has examined the role of such exposure conditions on advanced nickel base alloys. Alloy formulations developed at ARC and commercial alloys were studied using X-ray diffraction (XRD) and Raman spectroscopy. The electrical property of oxide scales formed on selected alloys was determined in terms of areaspecific resistance (ASR). The corrosion behavior of ARC nickel-based alloys exposed to a dual environment of air/ H2 were compared to those of Crofer 22APU and Haynes 230.

  3. Strengthening mechanisms of indirect-extruded Mg–Sn based alloys at room temperature

    Directory of Open Access Journals (Sweden)

    Wei Li Cheng

    2014-12-01

    Full Text Available The strength of a material is dependent on how dislocations in its crystal lattice can be easily propagated. These dislocations create stress fields within the material depending on their intrinsic character. Generally, the following strengthening mechanisms are relevant in wrought magnesium materials tested at room temperature: fine-grain strengthening, precipitate strengthening and solid solution strengthening as well as texture strengthening. The indirect-extruded Mg–8Sn (T8 and Mg–8Sn–1Al–1Zn (TAZ811 alloys present superior tensile properties compared to the commercial AZ31 alloy extruded in the same condition. The contributions to the strengthen of Mg–Sn based alloys made by four strengthening mechanisms were calculated quantitatively based on the microstructure characteristics, physical characteristics, thermomechanical analysis and interactions of alloying elements using AZ31 alloy as benchmark.

  4. Properties and Application of Iron-based Shape Memory Alloy

    Institute of Scientific and Technical Information of China (English)

    Li Jian-chen; Jiang Qing; Dai Jun

    2005-01-01

    The properties of FeMnSiCrNi shape memory alloy were investigated. The results show that the best shape memory effect of Fel4Mn6Si9Cr5Ni alloy is 85%. The transformation amount of the ε→γ transformation is not complete after heating the alloy to 1000 K, As and Af points drop with increased transformation enthalpy ( △Hγ→ε) by thermal cycling and increased prestrain. The alloy shows also good creep and stress relaxation resistance. In addition, the alloy having a tensile force of 20 kN and a sealing pressure of 6 MPa can satisfy requirements for possible industrial application on pipe joints.

  5. Perpendicular Magnetic Anisotropy in Co-Based Full Heusler Alloy Thin Films

    Science.gov (United States)

    Wu, Y.; Xu, X. G.; Miao, J.; Jiang, Y.

    2015-12-01

    Half-metallic Co-based full Heusler alloys have been qualified as promising functional materials in spintronic devices due to their high spin polarization. The lack of perpendicular magnetic anisotropy (PMA) is one of the biggest obstacles restricting their application in next generation ultrahigh density storage such as magnetic random access memory (MARM). How to induce the PMA in Co-based full Heusler alloy thin films has attracted much research interest of scientists. This paper presents an overview of recent progress in this research area. We hope that this paper would provide some guidance and ideas to develop highly spin-polarized Co-based Heusler alloy thin films with PMA.

  6. Influences of Alloying Elements W, Mo, Cr and Nb on Retained Beta Phase in 47Al Based near γ-TiAl Alloys

    Institute of Scientific and Technical Information of China (English)

    Limin DONG; Rui YANG

    2003-01-01

    The influences of alloying elements W, Mo, Cr, and Nb on retainedβ phase in 47Al based near γ-TiAl alloys have been studied.The results reveal that the amount of retained β phase is increased by the addition of Cr, Mo, W in rising rank, although the distribution of β phase in Cr-bearing alloys is different from that of Mo- or W-bearing alloys. For Nb-doped alloys, no retained β was found even when 5 at. pct Nb was added. The as-cast microstructural features and the distribution of theβ phase in the different alloy families were compared and interpreted in terms of the different segregation behaviour of these elements in Ti.

  7. Recent progress in high B{sub s} Fe-based nanocrystalline soft magnetic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, M; Yoshizawa, Y, E-mail: motoki_ohta@hitachi-metals.co.jp [Hitachi Metals Ltd., 2-15-17 Egawa, Shimamoto Osaka, 961-0013 (Japan)

    2011-02-16

    High saturation magnetic flux density (high-B{sub s}) alloy has been developed in an Fe-based nanocrystalline alloy system. A nanocrystalline phase with an average grain size of about 20 nm is obtained by annealing Cu-substituted and/or Cu-and-Si-complex-substituted Fe-B amorphous alloys. The alloy exhibits low coercivity of less than 7 A m{sup -1} and a high B{sub s} of more than 1.8 T. The iron loss at 50 Hz and 1.6 T for a toroidal core made of Fe{sub 80.5}Cu{sub 1.5}Si{sub 4}B{sub 14} nanocrystalline alloy is 0.46 W kg{sup -1}, which is about 2/3 of that of grain-oriented Si steel. Moreover, the iron loss at 10 kHz and 0.2 T for a wound core made of this alloy is 7.5 W kg{sup -1}, which is about 25% of that of non-grain-oriented Si steel and about 60% of that of an Fe-based amorphous alloy. In addition, the cut cores made of the alloy show good superimposed dc-current characteristics and appear promising in applications such as power choke coils (at the high-frequency region).

  8. Imprecise knowledge based design and development of titanium alloys for prosthetic applications.

    Science.gov (United States)

    Datta, S; Mahfouf, M; Zhang, Q; Chattopadhyay, P P; Sultana, N

    2016-01-01

    Imprecise knowledge on the composition-processing-microstructure-property correlation of titanium alloys combined with experimental data are used for developing rule based models for predicting the strength and elastic modulus of titanium alloys. The developed models are used for designing alloys suitable for orthopedic and dental applications. Reduced Space Searching Algorithm is employed for the multi-objective optimization to find composition, processing and microstructure of titanium alloys suitable for orthopedic applications. The conflicting requirements attributes of the alloys for this particular purpose are high strength with low elastic modulus, along with adequate biocompatibility and low costs. The 'Pareto' solutions developed through multi-objective optimization show that the preferred compositions for the fulfilling the above objectives lead to β or near β-alloys. The concept of decision making employed on the solutions leads to some compositions, which should provide better combination of the required attributes. The experimental development of some of the alloys has been carried out as guided by the model-based design methodology presented in this research. Primary characterizations of the alloys show encouraging results in terms of the mechanical properties.

  9. Mechanical performance of irradiated beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Scaffidi-Argentina, F.; Dalle-Donne, M.; Werle, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reaktortechnik

    1998-01-01

    For the Helium Cooled Pebble Bed (HCPB) Blanket, which is one of the two reference concepts studied within the European Fusion Technology Programme, the neutron multiplier consists of a mixed bed of about 2 and 0.1-0.2 mm diameter beryllium pebbles. Beryllium has no structural function in the blanket, however microstructural and mechanical properties are important, as they might influence the material behavior under neutron irradiation. The EXOTIC-7 as well as the `Beryllium` experiments carried out in the HFR reactor in Petten are considered as the most detailed and significant tests for investigating it. This paper reviews the present status of beryllium post-irradiation examinations performed at the Forschungszentrum Karlsruhe with samples from these irradiation experiments, emphasizing the effects of irradiation of essential material properties and trying to elucidate the processes controlling the property changes. The microstructure, the porosity distribution, the impurity content, the behavior under compression loads and the compatibility of the beryllium pebbles with lithium orthosilicate (Li{sub 4}SiO{sub 4}) during the in-pile irradiation are presented and critically discussed. Qualitative information on ductility and creep obtained by hardness-type measurements are also supplied. (author)

  10. Illness Absences Among Beryllium Sensitized Workers

    Science.gov (United States)

    Watkins, Janice P.; Ellis, Elizabeth D.; Girardi, David J.; Cragle, Donna L.

    2014-01-01

    Objectives. This study examined absence rates among US Department of Energy workers who had beryllium sensitization (BeS) or were diagnosed with chronic beryllium disease (CBD) compared with those of other workers. Methods. We used the lymphocyte proliferation test to determine beryllium sensitivity. In addition, we applied multivariable logistic regression to compare absences from 2002 to 2011 between workers with BeS or CBD to those without, and survival analysis to compare time to first absence by beryllium sensitization status. Finally, we examined beryllium status by occupational group. Results. Fewer than 3% of the 19 305 workers were BeS, and workers with BeS or CBD had more total absences (odds ratio [OR] = 1.31; 95% confidence interval [CI] = 1.18, 1.46) and respiratory absences (OR = 1.51; 95% CI = 1.24, 1.84) than did other workers. Time to first absence for all causes and for respiratory conditions occurred earlier for workers with BeS or CBD than for other workers. Line operators and crafts personnel were at increased risk for BeS or CBD. Conclusions. Although not considered “diseased,” workers with BeS have higher absenteeism compared with nonsensitized workers. PMID:25211750

  11. Perfect cubic texture, structure, and mechanical properties of nonmagnetic copper-based alloy ribbon substrates

    Science.gov (United States)

    Khlebnikova, Yu. V.; Rodionov, D. P.; Gervas'eva, I. V.; Egorova, L. Yu.; Suaridze, T. R.

    2015-03-01

    A sharp cubic texture is formed in a number of copper alloys subjected to cold deformation by rolling by 98.6-99% followed by recrystallization annealing, which opens up fresh opportunities for long thin ribbons made of these alloys to be used as substrates in the production of second-generation high- T c superconductor (2G HTSC) cables. The possibility of creating ternary alloys based on a binary Cu-30 at % Ni alloy with additional elements that harden its fcc matrix (iron, chromium) is shown. The measurements of the mechanical properties of textured ribbons made of these alloys demonstrate that their yield strength is higher than that of a textured ribbon made of pure copper by a factor of 2.5-4.5.

  12. Phase Transformations and Microstructural Evolution in Aged Mn-Cu-Based Alloys

    Science.gov (United States)

    1990-06-01

    Sakhno, V. M. and Udovenko, V. A., "Fine Crystal Structure of MnCuGe Alloys", Physical Metalurgy and Metallography, Vol. 51, No. 4, pp. 93-97, 1981. 36...93 vi I. INTRODUCTION The physical metallurgy of alloys based on the Cu-Mn system has been a subject of research for more than 40 years [Ref. 1-4...separation within it [Ref. 24-30]. The most thorough and revealing body of research on the metal physics of Cu-Mn-based alloys has been reported in the

  13. Experimental Study on Machining Shape Hole of Ni-based Super-heat-resistant Alloy

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Inconel 718 and Waspaloy, Nickel-based super-heat-resistant alloy, are high-strength, thermal-resistant and corrosion-resistant alloy that are widely used in parts of gas turbines and airplane engines. Due to their extremely tough and thermal-resistant nature, they are well known as materials that are difficult to cut. Shape holes on a disc of an aircraft engine, made of Ni-based super-heat-resistant alloy, are required with good surface integrity and geometric accuracy. This kind of shape hole is produced ...

  14. Martensitic transformation and related magnetic effects in Ni-Mn-based ferromagnetic shape memory alloys

    Institute of Scientific and Technical Information of China (English)

    Wang Dun-Hui; Han Zhi-Da; Xuan Hai-Cheng; Ma Sheng-Can; Chen Shui-Yuan; Zhang Cheng-Liang; Du You-Wei

    2013-01-01

    Ferromagnetic shape memory alloys,which undergo the martensitic transformation,are famous multifunctional materials.They exhibit many interesting magnetic properties around the martensitic transformation temperature due to the strong coupling between magnetism and structure.Tuning magnetic phase transition and optimizing the magnetic effects in these alloys are of great importance.In this paper,the regulation of martensitic transformation and the investigation of some related magnetic effects in Ni-Mn-based alloys are reviewed based on our recent research results.

  15. Study on DC welding parameters of Al-alloy shaping based on arc-welding robot

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Al-alloy arc-welding shaping system based on arc-welding robot is established, and the Al-alloy shaping manufacture is realized with the DC (direct current) gas metal arc welding (GMAW). The research indicates that the metal transfer type of DC GMAW, heat input and the initial temperature of the workpiece greatly affect the Al-alloy shaping based on arc welding robot. On the penetration, the weld width and the reinforcement, the influence of welding parameters is analyzed by generalized regression neural network (GRNN) fitting.

  16. The Importance of Rare-Earth Additions in Zr-Based AB2 Metal Hydride Alloys

    Directory of Open Access Journals (Sweden)

    Kwo-Hsiung Young

    2016-07-01

    Full Text Available Effects of substitutions of rare earth (RE elements (Y, La, Ce, and Nd to the Zr-based AB2 multi-phase metal hydride (MH alloys on the structure, gaseous phase hydrogen storage (H-storage, and electrochemical properties were studied and compared. Solubilities of the RE atoms in the main Laves phases (C14 and C15 are very low, and therefore the main contributions of the RE additives are through the formation of the RENi phase and change in TiNi phase abundance. Both the RENi and TiNi phases are found to facilitate the bulk diffusion of hydrogen but impede the surface reaction. The former is very effective in improving the activation behaviors. −40 °C performances of the Ce-doped alloys are slightly better than the Nd-doped alloys but not as good as those of the La-doped alloys, which gained the improvement through a different mechanism. While the improvement in ultra-low-temperature performance of the Ce-containing alloys can be associated with a larger amount of metallic Ni-clusters embedded in the surface oxide, the improvement in the La-containing alloys originates from the clean alloy/oxide interface as shown in an earlier transmission electron microscopy study. Overall, the substitution of 1 at% Ce to partially replace Zr gives the best electrochemical performances (capacity, rate, and activation and is recommended for all the AB2 MH alloys for electrochemical applications.

  17. Welding and mechanical properties of cast FAPY (Fe-16 at. % Al-based) alloy slabs

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Goodwin, G.M.; Alexander, D.J.; Howell, C.R.

    1995-08-01

    The low-aluminum-content iron-aluminum program deals with the development of a Fe-Al alloy with aluminum content such as a produce the minimum environmental effect at room temperature. The FAPY is an Fe-16 at. % Al-based alloy developed at the Oak Ridge National Laboratory as the highest aluminum-containing alloy with essentially no environmental effect. The chemical composition for FAPY in weight percent is: aluminum = 8.46, chromium = 5.50, zirconium = 0.20, carbon = 0.03, molybdenum = 2.00, yttrium = 0.10, and iron = 83.71. The cast ingots of the alloy can be hot worked by extrusion, forging, and rolling processes. The hot- worked cast structure can be cold worked with intermediate anneals at 800{degrees}C. Typical room-temperature ductility of the fine-grained wrought structure is 20 to 25% for this alloy. In contrast to the wrought structure, the cast ductility at room temperature is approximately 1% with a transition temperature of approximately 100 to 150{degrees}C, above which ductility values exceed 20%. The alloy has been melted and processed into bar, sheet, and foil. The alloy has also been cast into slabs, step-blocks of varying thicknesses, and shapes. The purpose of this section is to describe the welding response of cast slabs of three different thicknesses of FAPY alloy. Tensile, creep, and Charpy-impact data of the welded plates are also presented.

  18. Oxidation behaviour of experimental Co-Re-base alloys in laboratory air at 1000 C

    Energy Technology Data Exchange (ETDEWEB)

    Klauke, Michael; Mukherji, Debashis; Roesler, Joachim [Technische Universitaet Braunschweig, Institut fuer Werkstoffe (Germany); Gorr, Bronislava; Christ, Hans-Juergen [Universitaet Siegen, Institut fuer Werkstofftechnik (Germany); Braz da Trindade Filho, Vicente [Vallourec und Mannesmann Tubes, Duesseldorf (Germany)

    2009-01-15

    The oxidation behaviour of experimental Co-Re-based alloy at 1000 C was studied. A set of binary, ternary and quaternary alloys from the Co-Re-Cr-C system was used as model alloys to understand the role each alloying element plays on oxidation. The morphology and composition of the oxide scale that formed was analysed by X-ray diffraction, energy dispersive spectroscopy and scanning electron microscopy. It was found that the present Co-Re alloys with 23 at.% and 30 at.% Cr additions behaved very similarly to Co-Cr binary alloys with equivalent Cr content. The oxide scale was multilayered, consisting of a dense CoO outer layer, a porous mixed oxide layer containing Co-oxide and Co-Cr spinel, and a discontinuous and non-protective Cr{sub 3}O{sub 2} layer. The binary Co-Re alloy behaved differently in oxidation, and it formed only a monolithic CoO scale. However, Re in combination with Cr promotes Cr-Re-rich {sigma} phase formation, which oxidises preferentially compared to the Co matrix. Carbon ties up part of the Cr to form Cr{sub 23}C{sub 6} type carbides. However, these carbides are not stable at 1000 C and dissolved with time, therefore C had only a minor role in the oxidation behaviour. In general, increasing Cr content in the alloy improved oxidation resistance. (orig.)

  19. Electron-ion plasma modification of Al-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Yurii, E-mail: yufi55@mail.ru [Institute of High-Current Electronics of the Siberian Branch of the Russian Academy of Sciences, 634055, Russia, Tomsk, 2/3 Akademicheskiy Ave (Russian Federation); National Research Tomsk State University, 634050, Russia, Tomsk, 36 Lenina Str (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050, Russia, Tomsk, 30 Lenina Str (Russian Federation); Rygina, Mariya, E-mail: l-7755me@mail.ru [National Research Tomsk Polytechnic University, Tomsk, 634050, Russia, Tomsk, 30 Lenina Str (Russian Federation); Petrikova, Elizaveta, E-mail: elizmarkova@yahoo.com; Krysina, Olga, E-mail: krysina-82@mail.ru; Teresov, Anton, E-mail: tad514@sibmail.com [Institute of High-Current Electronics of the Siberian Branch of the Russian Academy of Sciences, 634055, Russia, Tomsk, 2/3 Akademicheskiy Ave (Russian Federation); National Research Tomsk State University, 634050, Russia, Tomsk, 36 Lenina Str (Russian Federation); Ivanova, Olga, E-mail: ivaov@mail.ru; Ikonnikova, Irina, E-mail: irina-ikonnikova@yandex.ru [Tomsk State University of Architecture and Building, Tomsk, 634002, Russia, Tomsk, 2 Solyanaya Sq (Russian Federation)

    2016-01-15

    The paper reports on the study where we analyzed the surface structure and strength properties of coated Al alloys modified by electron-ion plasma treatment. The Al alloys were deposited with a thin (≈0.5 μm) TiCu film coating (TiCu-Al system) and with a hard TiCuN coating (TiCuN–AlSi system) on a TRIO vacuum setup in the plasma of low-pressure arc discharges. The temperature fields and phase transformations in the film–substrate system were estimated by numerical simulation in a wide range of electron energy densities (5–30 J/cm{sup 2}) and pulse durations (50–200 μs). The calculations allowed us to determine the threshold energy density and pulse duration at which the surface structure of the irradiated Al-based systems is transformed in a single-phase state (solid or liquid) and in a two-phase state (solid plus liquid). The elemental composition, defect structure, phase state, and lattice state in the modified surface layers were examined by optical, scanning, and transmission electron microscopy, and by X-ray diffraction analysis. The mechanical characteristics of the modified layers were studied by measuring the hardness and Young’s modulus. The tribological properties of the modified layers were analyzed by measuring the wear resistance and friction coefficient. It is shown that melting and subsequent high-rate crystallization of the TiCu–Al system makes possible a multiphase Al-based surface structure with the following characteristics: crystallite size ranging within micrometer, microhardness of more than 3 times that in the specimen bulk, and wear resistance ≈1.8 times higher compared to the initial material. Electron beam irradiation of the TiCuN–AlSi system allows fusion of the coating into the substrate, thus increasing the wear resistance of the material ≈2.2 times at a surface hardness of ∼14 GPa.

  20. 75 FR 80734 - Chronic Beryllium Disease Prevention Program

    Science.gov (United States)

    2010-12-23

    ... CFR Part 850 RIN 1992-AA39 Chronic Beryllium Disease Prevention Program AGENCY: Office of Health... beryllium disease prevention program. The Department solicits comment and information on the permissible... course of action regarding its chronic beryllium disease prevention program. DATES: All comments on...

  1. Occupational and non-occupational allergic contact dermatitis from beryllium.

    Science.gov (United States)

    Vilaplana, J; Romaguera, C; Grimalt, F

    1992-05-01

    There are various references to sensitization to beryllium in the literature. Since introducing a patch testing series for patients with suspected sensitization to metals, we have found 3 cases of sensitization to beryllium. Of these 3 cases, we regard the first 2 as having relevant sensitization. Beryllium chloride (1% pet.) was positive in 3 patients and negative in 150 controls.

  2. 20 CFR 30.508 - What is beryllium sensitivity monitoring?

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false What is beryllium sensitivity monitoring? 30... and Offsets; Overpayments Payment of Claims and Offset for Certain Payments § 30.508 What is beryllium sensitivity monitoring? Beryllium sensitivity monitoring shall consist of medical examinations to confirm...

  3. Rapid iodometric determination of copper in some copper-base alloys

    NARCIS (Netherlands)

    Agterdenbos, J.; Eelberse, P.A.

    1966-01-01

    Copper-base alloys, especially those containing tin, are readily dissolved in a mixture of hydrofluoric and nitric acids. In the resulting solution copper can be titrated iodometrically in the conventional manner.

  4. Investigation on low activated materials on the base of V-Ti-Cr alloys

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Low activated materials on the base of vanadium are among the key materials for future fusion reactors. In the Russian Federation the long term National Program on the development of such vanadium alloys is under the way.

  5. Investigation on low activated materials on the base of V-Ti-Cr alloys

    Institute of Scientific and Technical Information of China (English)

    Potapenko; M.; Shikov; A.; Chernov; V.; Drobishev; V.; Gubkin; I.

    2005-01-01

    Low activated materials on the base of vanadium are among the key materials for future fusion reactors. In the Russian Federation the long term National Program on the development of such vanadium alloys is under the way.……

  6. Shape Memory Alloy-Based Periodic Cellular Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase II effort will continue to develop and demonstrate an innovative shape memory alloy (SMA) periodic cellular structural technology. Periodic cellular...

  7. Beryllium ignition target design for indirect drive NIF experiments

    Science.gov (United States)

    Simakov, A. N.; Wilson, D. C.; Yi, S. A.; Kline, J. L.; Salmonson, J. D.; Clark, D. S.; Milovich, J. L.; Marinak, M. M.

    2016-03-01

    Beryllium (Be) ablator offers multiple advantages over carbon based ablators for indirectly driven NIF ICF ignition targets. These are higher mass ablation rate, ablation pressure and ablation velocity, lower capsule albedo, and higher thermal conductivity at cryogenic temperatures. Such advantages can be used to improve the target robustness and performance. While previous NIF Be target designs exist, they were obtained a long time ago and do not incorporate the latest improved physical understanding and models based upon NIF experiments. Herein, we propose a new NIF Be ignition target design at 1.45 MJ, 430 TW that takes all this knowledge into account.

  8. Synthesis and evaluation of ageing effect on Cu–Al–Be–Mn quaternary Shape Memory Alloys

    Directory of Open Access Journals (Sweden)

    A.G. Shivasiddaramiah

    2016-09-01

    Full Text Available Copper based shape memory alloy exhibits high transformation temperature and ability to differ the achieved properties through alloying additions. A quaternary Cu–Al–Be–Mn shape memory alloys of 0.2–0.4 wt% of manganese, 0.4–0.5 wt% of Beryllium and 10–14 wt% of aluminium with remaining copper, showing β-phase at higher temperature and show shape memory effect when quenching to lower temperatures, SMA's were prepared by induction melting. The objective is to study the effect of thermal ageing at different temperatures Af (above austenitic phase finish temperature and at different time on shape memory effect and transformation temperatures. The aged specimens or SMA's were studied by DSC, OM and hardness measurements. The results from this study help to find the applications in different thermal conditions.

  9. Study the effect of beryllium reflector poisoning on the Syrian MNSR.

    Science.gov (United States)

    Omar, H; Ghazi, N; Haddad, Kh; Ezzuddin, H

    2012-06-01

    Neutron interactions with beryllium lead to formation of (3)H and strong neutron absorbers (3)He and (6)Li in the reflector (so called beryllium poisoning). After the reactor shutdown, the concentration of (3)He increases in time due to tritium decay. This paper illustrates the impact of poisoning accumulation in the beryllium reflectors on reactivity for the Syrian MNSR research reactor. The prediction of (6)Li and (3)He poison concentrations, initiated by the 9Be(n,α) reaction, in the beryllium reflectors of the MNSR was also presented. The results were based on MCNP Monte Carlo calculations and solutions to the differential equations which describe the time dependent poison concentrations as a function of reactor operation time and shutdown periods. The whole reactor history was taken into account to predict reliable values of parasitic isotope concentrations. It was found that the (3)He and (6)Li accumulations in the beryllium reflectors during the actual working history decreased the excess reactivity by about 28%. While, the effect became more significant at the reactor life's end and the reactor became subcritical after 25,000 h operation. The results contained in this paper could be used in assess the safety analysis of the MNSR reactor.

  10. [Effects of beryllium chloride on cultured cells].

    Science.gov (United States)

    Sakaguchi, T; Sakaguchi, S; Nakamura, I; Kagami, M

    1984-05-01

    The effects of beryllium on cultured cells were investigated. Three cell-lines (HeLa-S3, Vero, HEL-R66) were used in these experiments and they were cultured in Eagle's MEM plus 5 or 10% FBS (Fetal Bovine Serum) containing beryllium in various concentrations. HeLa cells or Vero cells were able to grow in the medium with 10 micrograms Be/ml (1.1 mM). On the other hand, the growth of HEL cells were strongly inhibited, even when cultured in the medium with 1 microgram Be/ml (1.1 X 10(-1) mM) and the number of living cells showed markedly low level as compared to that of the control samples cultured in the medium without beryllium. The cytotoxic effects of beryllium on these cells, which were cultured for three days in the medium with beryllium, were observed. None of cytotoxic effects were found on HeLa cells cultured with 0.5 micrograms/ml (5.5 X 10(-2) mM) and on Vero cells cultured with 0.05 micrograms Be/ml (5.5 X 10(-3) mM), while HEL cells received cytotoxic effects even when cultured in the medium containing 0.05 micrograms Be/ml (5.5 X 10(-3) mM), and these effects on the cells appeared strong when cultured in the medium without FBS. It was revealed from these experiments that HEL cells are very sensitive in terms of toxic effects of beryllium. Therefore, there cells can be used for the toxicological study on low level concentrations of the metal.

  11. Thermal Fatigue Behaviour of Co-Based Alloy Coating Obtained by Laser Surface Melt-Casting on High Temperature Alloy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A thermal fatigue behaviour of C o-based alloy coating obtained by laser surface melt-casting on the high tempe rature alloy GH33 was studied. The results show that after each time of thermal cycling, the final residual stress was formed in the melt-casting layer which is attributed to the thermal stress and structural stress. Through the first 50 times of thermal cycling, the morphology of coating still inherits the laser casting one, but the dendrites get bigger; After the second 50 times of thermal cycling, corrosion pits emerge from coating, and mostly in the places where coating and substrate meet. The fatigue damage type of coating belongs to stress corrosi on.

  12. MACHINING OF NICKEL BASED ALLOYS USING DIFFERENT CEMENTED CARBIDE TOOLS

    Directory of Open Access Journals (Sweden)

    BASIM A. KHIDHIR

    2010-09-01

    Full Text Available This paper presents the results of experimental work in dry turning of nickel based alloys (Haynes – 276 using Deferent tool geometer of cemented carbide tools. The turning tests were conducted at three different cutting speeds (112, 152, 201and 269 m/min while feed rate and depth of cut were kept constant at 0.2 mm/rev and 1.5 mm, respectively. The tool holders used were SCLCR with insert CCMT-12 and CCLNR – M12-4 with insert CNGN-12. The influence of cutting speed, tool inserts type and workpiece material was investigated on the machined surface roughness. The worn parts of the cutting tools were also examined under scanning electron microscope (SEM. The results showed that cutting speed significantly affected the machined surface finish values in related with the tool insert geometry. Insert type CCMT-12 showed better surface finish for cutting speed to 201 m/min, while insert type CNGN-12 surface roughness increased dramatically with increasing of speed to a limit completely damage of insert geometer beyond 152 m/min.

  13. Shape Memory Alloy (SMA)-Based Launch Lock

    Science.gov (United States)

    Badescu, Mircea; Bao, Xiaoqi; Bar-Cohen, Yoseph

    2014-01-01

    Most NASA missions require the use of a launch lock for securing moving components during the launch or securing the payload before release. A launch lock is a device used to prevent unwanted motion and secure the controlled components. The current launch locks are based on pyrotechnic, electro mechanically or NiTi driven pin pullers and they are mostly one time use mechanisms that are usually bulky and involve a relatively high mass. Generally, the use of piezoelectric actuation provides high precession nanometer accuracy but it relies on friction to generate displacement. During launch, the generated vibrations can release the normal force between the actuator components allowing shaft's free motion which could result in damage to the actuated structures or instruments. This problem is common to other linear actuators that consist of a ball screw mechanism. The authors are exploring the development of a novel launch lock mechanism that is activated by a shape memory alloy (SMA) material ring, a rigid element and an SMA ring holding flexure. The proposed design and analytical model will be described and discussed in this paper.

  14. Shape-Memory-Alloy-Based Deicing System Developed

    Science.gov (United States)

    1996-01-01

    Ice buildup on aircraft leading edge surfaces has historically been a problem. Most conventional deicing systems rely either on surface heating to melt the accreted ice or pneumatic surface inflation to mechanically debond the ice. Deicers that rely solely on surface heating require large amounts of power. Pneumatic deicers usually cannot remove thin layers of ice and lack durability. Thus, there is a need for an advanced, low-power ice protection system. As part of the NASA Small Business and Innovation Research (SBIR) program, Innovative Dynamics, Inc., developed an aircraft deicing system that utilizes the properties of Shape Memory Alloys (SMA). The SMA-based system has achieved promising improvements in energy efficiency and durability over more conventional deicers. When they are thermally activated, SMA materials change shape; this is analogous to a conventional thermal expansion. The thermal input is currently applied via conventional technology, but there are plans to implement a passive thermal input that is supplied from the energy transfer due to the formation of the ice itself. The actively powered deicer was tested in the NASA Lewis Icing Research Tunnel on a powered rotating rig in early 1995. The system showed promise, deicing both rime and glaze ice shapes as thin as 1/8 in. The first prototype SMA deicer reduced power usage by 45 percent over existing electrothermal systems. This prototype system was targeted for rotorcraft system development. However, there are current plans underway to develop a fixed-wing version of the deicer.

  15. 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.

  16. Survey of BGFA Criteria for the Cu-Based Bulk Amorphous Alloys

    Directory of Open Access Journals (Sweden)

    D. Janovszky

    2011-01-01

    Full Text Available To verify the effect of composition on the bulk glass forming ability (BGFA of Cu-based alloys, properties have been collected from the literature (~100 papers, more than 200 alloys. Surveying the BGFA criteria published so far, it has been found that the atomic mismatch condition of Egami-Waseda is fulfilled for all the Cu-based BGFAs, the value being above 0,3. The Zhang Bangwei criterion could be applied for the binary Cu-based alloys. The Miracle and Senkov criteria do not necessarily apply for Cu based bulk amorphous alloys. The critical thickness versus =/(+ plot of Lu and Liu extrapolates to =0.36, somewhat higher than the 0.33 value found in other BGFA alloys. The Park and Kim parameter correlates rather poorly with the critical thickness for Cu based alloys. The Cheney and Vecchino parameter is a good indicator to find the best glass former if it is possible to calculate the exact liquids projection. In 2009 Xiu-lin and Pan defined a new parameter which correlates a bit better with the critical thickness. Based on this survey it is still very difficult to find one parameter in order to characterize the real GFA without an unrealized mechanism of crystallization.

  17. Ternary Magnesium-Lithium Base Constitution Diagrams and Magnesium Alloys of Low Alloy Additions

    Science.gov (United States)

    1951-03-01

    testing machine using Templin Grips. Strain was measured with a Peters Ex- tensometer in conjunction with a Southwark-Emery stress- strain recorder. The...press. Originally, the equipment was mounted in a South- wark-Emery testing machine having a maximum available force of 50 tons. The equipment was...this development was described in the last Summary Report(l). Experimental work on the original holder machined from a block of aluminum alloy 20 was

  18. Rational design of Nb-based alloys for hydrogen separation: A first principles study

    Directory of Open Access Journals (Sweden)

    Byungki Ryu

    2013-02-01

    Full Text Available We have investigated the effect of alloying metal elements on hydrogen solubility and mechanical integrity of Nb-based alloys, Nb15M1 (where M = Ca–Zn, Ge, using first principles-based calculations. In general, the chemical interaction between the interstitial H and metal is weakened as the alloying element is changed from an early to a late transition metal, leading to lower H solubility and higher resistance to H embrittlement. This effect becomes more pronounced when a smaller alloying element is used due to stronger elastic interaction between interstitial H and metal atoms. These finding may provide scientific basis for rational design of Nb-based hydrogen separation membranes with tailored H solubility to effectively suppress H embrittlement while maintaining excellent hydrogen permeation rate.

  19. Ductile Bulk Aluminum-Based Alloy with Good Glass-Forming Ability and High Strength

    Institute of Scientific and Technical Information of China (English)

    ZHUO Long-Chao; PANG Shu-Jie; WANG Hui; ZHANG Tao

    2009-01-01

    Based on a new approach for designing glassy alloy compositions,bulk Al-based alloys with good glass-forming ability (GFA) are synthesized.The cast Al86Si0.5Ni4.06Co2.94 Y6Sc0.5 rod with a diameter of 1 mm shows almost fully amorphous structure besides about 5% fcc-Al nucleated in the center of the rod.The bulk alloy with high Al concentration exhibits an ultrahigh yield strength of 1.18 Gpa and maximum strength of 1.27 Gpa as well as an obvious plastic strain of about 2.4% during compressive deformation.This light Al-based alloy with good GFA and mechanical properties is promising as a new high specific strength material with good deformability.

  20. Commercialization status of Ni{sub 3}Al-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1997-12-31

    The Ni{sub 3}Al-based alloys have been under development at the Oak Ridge National Laboratory (ORNL) and other research institutions in the United States and around the world for the last ten years. The incremental developments of composition, melting process, casting methods, property data, corrosion data, weldability development, and prototype component testing under production-like operating conditions have pushed the ORNL-developed Ni{sub 3}Al-based alloys closer to commercialization. This paper will present the highlights of incremental technical developments along with the approach and current status of commercialization. It is concluded that cast components are the primary applications of Ni{sub 3}Al-based alloys, and applications range from heat-treating fixtures of forging dies. It is also concluded that the commercialization process is accelerated when technology is licensed to an organization that can produce the alloy, has component manufacturing capability, and is also a user.

  1. Mineral resource of the month: beryllium

    Science.gov (United States)

    Shedd, Kim B.

    2006-01-01

    Beryllium metal is lighter than aluminum and stiffer than steel. These and other properties, including its strength, dimensional stability, thermal properties and reflectivity, make it useful for aerospace and defense applications, such as satellite and space-vehicle structural components. Beryllium’s nuclear properties, combined with its low density, make it useful as a neutron reflector and moderator in nuclear reactors. Because it is transparent to most X rays, beryllium is used as X-ray windows in medical, industrial and analytical equipment.

  2. Effect of Repeated Firings of Porcelain on Bond Strength of Two Base Metal Alloys

    Directory of Open Access Journals (Sweden)

    Gerami Panah F

    2001-05-01

    Full Text Available The formation of oxides on the surface of the metal are proven to contribute to the formation of strong bonding. However, The base metal alloys are expected to exhibit more oxidation than high gold alloys, increase in oxide layer thickness due to repeated firing in them can reduce the bond strength. The aim of this study was to compare the effect of repeated porcelain firing on the bond strength of two base metal alloys (Minalux and Verabond II. Sixteen metal plates (20x5x0.5 from each alloy were cast and prepared according to the manufacturers' instruction. Porcelain with uniform thickness (Imm was applied on the middle one third of metal plates. After this stage, each alloy group divided to three subgroups. Group I was fired for the second time to form the final glaze, group II and III were fired two and four more times respectively. Specimens were subjected to 3-point flexural test in a digital tritest machine. Results showed no significant differences between bond strength of two alloys. Also results showed repeated firing had no significant effect on bond strength. Due to these findings, this study support similarity of two alloys (Minalux and Verabond II in their bond strength with porcelain.

  3. X-ray elastic constant determination and residual stress of two phase TiAl-based intermetallic alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To evaluate the residual stress in TiAl-based alloys by X-ray diffraction, X-ray elastic constants (REC) of a γ-TiAl alloy were determined. From these results, the stress state of a given phase in a duplex TiAl-based alloy under a uniaxial tensile loading has been characterized by X-ray diffraction. The results show that the X-ray elastic constants and the microscopic stresses of the given phase are different from the apparent elastic constants and the macroscopic stresses of the alloy. The reason of the different distribution of the alloy was also discussed.

  4. Reproducibility and correctness of the procedure of photometric determination of beryllium with 2-(o-hydroxyphenyl)benzoxazole

    Energy Technology Data Exchange (ETDEWEB)

    Tikhonova, N.B.; Charykov, A.K.; Gladilovich, D.B.

    1985-09-01

    This paper discusses two methods of evaluation of correctness on the example of the fluorometric determination of beryllium by 2-(o-hydroxyphenyl) benzoxazole (HPBO), as well as an evaluation of the reproducibility of this procedure for the level of beryllium concentration 10-36 ng/ml. The traditional method of detection and evaluation of systematic errors in chemical analysis is comparison of the average result of repeated analysis of a standard sample with specified content of the component to be determined. The second method discussed is based on an experimental estimation of the constant and proportional components of the systematic error by a combination of the methods of doubling and additives. It is shown that the fluorometric method of determining beryllium with HPBO at an absolute beryllium content of 0.25-1.0 micrograms is satisfactorily reproducible and does not contain systematic errors at the level of significance beta=0.05.

  5. Preliminary results for explosion bonding of beryllium to copper

    Energy Technology Data Exchange (ETDEWEB)

    Butler, D.J. [Northwest Technical Industries, Inc., Sequim, WA (United States); Dombrowski, D.E. [Brush Wellman, Inc., Cleveland, OH (United States)

    1995-09-01

    This program was undertaken to determine if explosive bonding is a viable technique for joining beryllium to copper substrates. The effort was a cursory attempt at trying to solve some of the problems associated with explosive bonding beryllium and should not be considered a comprehensive research effort. There are two issues that this program addressed. Can beryllium be explosive bonded to copper substrates and can the bonding take place without shattering the beryllium? Thirteen different explosive bonding iterations were completed using various thicknesses of beryllium that were manufactured with three different techniques.

  6. Choice of copper-based alloys for ribbon substrates with a sharp cube texture

    Science.gov (United States)

    Khlebnikova, Yu. V.; Rodionov, D. P.; Gervas'eva, I. V.; Suaridze, T. R.; Akshentsev, Yu. N.; Kazantsev, V. A.

    2014-12-01

    It has been shown that, in some copper-based alloys subjected to cold deformation by rolling to 98.6-99% followed by recrystallization annealing, a sharp cube texture can be produced. Optimum conditions of annealing have been determined, which make it possible to produce a sharp biaxial texture in Cu-Ni, Cu-Fe, and Cu-Cr alloys with the fraction of cube grains of more than 95%; this opens a possibility of using thin ribbons made of these alloys as substrates for multilayer film compositions, in particular when developing second-generation high-temperature superconductors.

  7. Photoluminescence enhancement from GaN by beryllium doping

    Science.gov (United States)

    García-Gutiérrez, R.; Ramos-Carrazco, A.; Berman-Mendoza, D.; Hirata, G. A.; Contreras, O. E.; Barboza-Flores, M.

    2016-10-01

    High quality Be-doped (Be = 0.19 at.%) GaN powder has been grown by reacting high purity Ga diluted alloys (Be-Ga) with ultra high purity ammonia in a horizontal quartz tube reactor at 1200 °C. An initial low-temperature treatment to dissolve ammonia into the Ga melt produced GaN powders with 100% reaction efficiency. Doping was achieved by dissolving beryllium into the gallium metal. The powders synthesized by this method regularly consist of two particle size distributions: large hollow columns with lengths between 5 and 10 μm and small platelets in a range of diameters among 1 and 3 μm. The GaN:Be powders present a high quality polycrystalline profile with preferential growth on the [10 1 bar 1] plane, observed by means of X-ray diffraction. The three characteristics growth planes of the GaN crystalline phase were found by using high resolution TEM microscopy. The optical enhancing of the emission in the GaN powder is attributed to defects created with the beryllium doping. The room temperature photoluminescence emission spectra of GaN:Be powders, revealed the presence of beryllium on a shoulder peak at 3.39 eV and an unusual Y6 emission at 3.32eV related to surface donor-acceptor pairs. Also, a donor-acceptor-pair transition at 3.17 eV and a phonon replica transition at 3.1 eV were observed at low temperature (10 K). The well-known yellow luminescence band coming from defects was observed in both spectra at room and low temperature. Cathodoluminescence emission from GaN:Be powders presents two main peaks associated with an ultraviolet band emission and the yellow emission known from defects. To study the trapping levels related with the defects formed in the GaN:Be, thermoluminescence glow curves were obtained using UV and β radiation in the range of 50 and 150 °C.

  8. Cost effective aluminum beryllium mirrors for critical optics applications

    Science.gov (United States)

    Say, Carissa; Duich, Jack; Huskamp, Chris; White, Ray

    2013-09-01

    The unique performance of aluminum-beryllium frequently makes it an ideal material for manufacturing precision optical-grade metal mirrors. Traditional methods of manufacture utilize hot-pressed powder block in billet form which is subsequently machined to final dimensions. Complex component geometries such as lightweighted, non-plano mirrors require extensive tool path programming, fixturing, and CNC machining time and result in a high buy-to-fly ratio (the ratio of the mass of raw material purchased to the mass of the finished part). This increases the cost of the mirror structure as a significant percentage of the procurement cost is consumed in the form of machining, tooling, and scrap material that do not add value to the final part. Inrad Optics, Inc. and IBC Advanced Alloys Corp. undertook a joint study to evaluate the suitability of investment-cast Beralcast® 191 and 363 aluminum-beryllium as a precision mirror substrate material. Net shape investment castings of the desired geometry minimizes machining to just cleanup stock, thereby reducing the recurring procurement cost while still maintaining performance. The thermal stability of two mirrors, (one each of Beralcast® 191 and Beralcast® 363), was characterized from -40°F to +150°F. A representative pocketed mirror was developed, including the creation of a relevant geometry and production of a cast component to validate the approach. Information from the demonstration unit was used as a basis for a comparative cost study of the representative mirror produced in Beralcast® and one machined from a billet of AlBeMet® 162 (AlBeMet® is a registered trademark of Materion Corporation). The technical and financial results of these studies will be discussed in detail.

  9. Biocompatibility of new Ti-Nb-Ta base alloys.

    Science.gov (United States)

    Hussein, Abdelrahman H; Gepreel, Mohamed A-H; Gouda, Mohamed K; Hefnawy, Ahmad M; Kandil, Sherif H

    2016-04-01

    β-type titanium alloys are promising materials in the field of medical implants. The effect of β-phase stability on the mechanical properties, corrosion resistance and cytotoxicity of a newly designed β-type (Ti77Nb17Ta6) biocompatible alloys are studied. The β-phase stability was controlled by the addition of small quantities of Fe and O. X-ray diffraction and microstructural analysis showed that the addition of O and Fe stabilized the β-phase in the treated solution condition. The strength and hardness have increased with the increase in β-phase stability while ductility and Young's modulus have decreased. The potentio-dynamic polarization tests showed that the corrosion resistance of the new alloys is better than Ti-6Al-4V alloy by at least ten times. Neutral red uptake assay cytotoxicity test showed cell viability of at least 95%. The new alloys are promising candidates for biomedical applications due to their high mechanical properties, corrosion resistance, and reduced cytotoxicity.

  10. Iron-based alloy and nitridation treatment for PEM fuel cell bipolar plates

    Science.gov (United States)

    Brady, Michael P [Oak Ridge, TN; Yang, Bing [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN

    2010-11-09

    A corrosion resistant electrically conductive component that can be used as a bipolar plate in a PEM fuel cell application is composed of an alloy substrate which has 10-30 wt. % Cr, 0.5 to 7 wt. % V, and base metal being Fe, and a continuous surface layer of chromium nitride and vanadium nitride essentially free of base metal. A oxide layer of chromium vanadium oxide can be disposed between the alloy substrate and the continuous surface nitride layer. A method to prepare the corrosion resistant electrically conductive component involves a two-step nitridization sequence by exposing the alloy to a oxygen containing gas at an elevated temperature, and subsequently exposing the alloy to an oxygen free nitrogen containing gas at an elevated temperature to yield a component where a continuous chromium nitride layer free of iron has formed at the surface.

  11. Characterization of the wear response of a modified zinc-based alloy vis-à-vis a conventional zinc-based alloy and a bearing bronze at a high sliding speed

    Science.gov (United States)

    Prasad, B. K.; Yegneswaran, A. H.; Patwardhan, A. K.

    1996-11-01

    In this investigation, an attempt has been made to examine the wear response of a modified zinc-based alloy at a high speed (4.60 m/s) of sliding over a range of applied pressures. A conventional zinc-based alloy and a bearing bronze have also been subjected to identical tests with a view to assess the working capability of the modified alloy with respect to the existing ones. The wear characteristics of the alloys have been correlated with their microstructural features, while operating wear mechanisms have been studied through analyses of wear surfaces, subsurfaces, and debris particles. The conventional zinc-based alloy attained most inferior wear behavior when compared with that of the modified (zinc-based) alloy and the bronze. Interestingly, the modified alloy exhibited its wear response to be much better than that of the conventional zinc-based alloy due to the presence of nickel/silicon containing (hard and thermally stable) microconstituents. Moreover, the modified alloy also seized at a pressure similar to that of the bronze, although its wear rate prior to seizure was more than that of the latter. The study clearly indicates that it is possible to develop modified versions of zinc-based alloys having much improved wear characteristics over the conventional variety; the information gains special attention in view of the high speed of sliding selected in this study.

  12. Burner Rig Hot Corrosion of Five Ni-Base Alloys Including Mar-M247

    Science.gov (United States)

    Nesbitt, James A.; Helmink, R.; Harris, K.; Erickson, G.

    2000-01-01

    The hot corrosion resistance of four new Ni-base superalloys was compared to that of Mar-M247 by testing in a Mach 0.3 burner rig at 900 C for 300 1-hr cycles. While the Al content was held the same as in the Mar-M247, the Cr and Co levels in the four new alloys were decreased while other strengthening elements (Re, Ta) were increased. Surprisingly, despite their lower Cr and Co contents, the hot corrosion behavior of all four new alloys was superior to that of the Mar-M247 alloy. The Mar-M247 alloy began to lose weight almost immediately whereas the other four alloys appeared to undergo an incubation period of 50-150 1-hr cycles. Examination of the cross-sectional microstructures showed regions of rampant corrosion attack (propagation stage) in all five alloys after 300 1-hr cycles . This rampant corrosion morphology was similar for each of the alloys with Ni and Cr sulfides located in an inner subscale region. The morphology of the attack suggests a classic "Type I", or high temperature, hot corrosion attack.

  13. Positron lifetimes in Cu-based {beta}-phase alloys

    Energy Technology Data Exchange (ETDEWEB)

    Plazaola, F. [Bilbo, Euskal Herrilo Unibertsitatea (Spain). Elektrika eta Elektronika Saila; Romero, R.; Somoza, A. [Tandil, Universidad Nacional del Centro de la Provincia de Buenos Aires (Argentina). IFIMAT

    1997-05-01

    Experimental and theoretical characterization of the positron lifetimes for bulk and vacancy-type defects are considered in the ordered {beta}-phase Cu-Zn-Al alloys. The general trend exhibits the same behaviour in both cases, in which the bulk positron lifetimes vary very little with alloy`s composition. The ordered structure can be described as two interpenetrating sublattices: however, within the theoretical approach, there is no preferential positron trapping at the mono vacancies of one of the two sublattices. The calculated lifetimes of positrons trapped at mono vacancies depend mainly on the Al content in the next near-neighbourhood. The lifetimes of positrons trapped at divacancies are 10-25 ps larger than the ones at mono vacancies. The experimental vacancy-type defect lifetimes are in good agreement with the ones calculated for mono vacancies.

  14. Microstructure of Ni-Based Self-Fluxing Alloy Coating (PartⅠ)

    Institute of Scientific and Technical Information of China (English)

    WANG Jin-hua; Milan Friesel; Magnus Willander; Richard Warren

    2005-01-01

    The microstructure of a Ni-based self-fluxing alloy coating produced by an oxygen-acetylene flame spraying Ni-16.5Cr-3.3B-4.7Si-4. 4Fe-0. 8C system alloy powder onto a common steel substrate was investigated by microanalysis methods. The phases in the coating were observed by SEM and determined by XEDS X-Ray energy spectrum and X-Ray diffraction patterns. Meanwhile, some molecular formulas were calculated.

  15. Formation Mechanism of Curved Martensite Structures in Cu-based Shape Memory Alloys

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The curved martensite structures have been observed in CuZnAl-based shape memory alloys by both transmission electron microscope and optical microscope. It was found that the curved martensite structures observed in as-solution treated, as-aged and as-trained alloys usually occurred around dislocation tangles or precipitate, at the plate boundary or grain boundary, and when the growing plates collided with each other or alternate mutually.

  16. Basic research for alloy design of Nb-base alloys as ultra high temperature structural materials; Chokoon kozoyo niobuki gokin no gokin sekkei no tame no kisoteki kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Miura, E. [Tohoku University, Sendai (Japan); Yoshimi, K.; Hanada, S. [Tohoku Univ., Sendai (Japan). Research Inst. for Iron, Steel and Other Metals

    1997-02-01

    This paper describes an influence of additional elements on the high temperature deformation behavior of Nb-base solid solution alloys. Highly concentrated solid solution single crystals of Nb-Ta and Nb-Mo alloys were prepared. Compression test and strain rate sudden change test were conducted in the vacuum at temperatures ranging from 77 to 1773 K, to determine the strain rate sensitivity index. Yield stress of the Nb-Ta alloy was similar to that of Nb alloy at temperatures over 0.3{times}T{sub M}, where T{sub M} is fusing point of Nb. While, the yield stress increased with increasing the impurity oxygen concentration at temperatures below 0.3{times}T{sub M}. The yield stress became much higher than that of Nb alloy. The strain rate sensitivity index showed positive values in the whole temperature range. On the other hand, the yield stress of Nb-Mo alloy was higher than that of Nb alloy in the whole temperature range, and increased with increasing the Mo concentration. The strain rate sensitivity index showed negative values at the temperature range from 0.3{times}T{sub M} to 0.4{times}T{sub M}. It was found that serration occurred often for Nb-40Mo alloys. 1 ref., 4 figs., 1 tab.

  17. Measurement of neutron yield by 62 MeV proton beam on a thick Beryllium target

    CERN Document Server

    Alba, R; Boccaccio, P; Celentano, A; Colonna, N; Cosentino, G; Del Zoppo, A; Di Pietro, A; Esposito, J; Figuera, P; Finocchiaro, P; Kostyukov, A; Maiolino, C; Osipenko, M; Ricco, G; Ripani, M; Viberti, C M; Santonocito, D; Schillaci, M

    2012-01-01

    In the framework of research on IVth generation reactors and high intensity neutron sources a low-power prototype neutron amplifier was recently proposed by INFN. It is based on a low-energy, high current proton cyclotron, whose beam, impinging on a thick Beryllium converter, produces a fast neutron spectrum. The world database on the neutron yield from thick Beryllium target in the 70 MeV proton energy domain is rather scarce. The new measurement was performed at LNS, covering a wide angular range from 0 to 150 degrees and an almost complete neutron energy interval. In this contribution the preliminary data are discussed together with the proposed ADS facility.

  18. Status of beryllium development for fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Billone, M.C. [Argonne National Lab., IL (United States); Donne, M.D. [Kernforschungszentrum Karlsruhe GmbH (Germany). Institut fuer Neutronphysik and Reaktortechnik; Macaulay-Newcombe, R.G. [McMaster Univ., Ontario, CA (United States). Dept. of Engineering Physics

    1994-05-01

    Beryllium is a leading candidate material for the neutron multiplier of tritium breeding blankets and the plasma facing component of first wall and divertor systems. Depending on the application, the fabrication methods proposed include hot-pressing, hot-isostatic-pressing, cold isostatic pressing/sintering, rotary electrode processing and plasma spraying. Product forms include blocks, tubes, pebbles, tiles and coatings. While, in general, beryllium is not a leading structural material candidate, its mechanical performance, as well its performance with regard to sputtering, heat transport, tritium retention/release, helium-induced swelling and chemical compatibility, is an important consideration in first-wall/blanket design. Differential expansion within the beryllium causes internal stresses which may result in cracking, thereby affecting the heat transport and barrier performance of the material. Overall deformation can result in loading of neighboring structural material. Thus, in assessing the performance of beryllium for fusion applications, it is important to have a good database in all of these performance areas, as well as a set of properties correlations and models for the purpose of interpolation/extrapolation.

  19. Preparation of Ti-based amorphous brazing alloy

    Institute of Scientific and Technical Information of China (English)

    ZOU Jia-sheng; JIANG Zhi-guo; XU Zhi-rong; CHEN Guang

    2006-01-01

    A new kind of amorphous active brazing alloy foil with the composition of Ti40Zr25Ni15Cu20 was successfully synthesized using melt spinning in roll forging machine in argon atmosphere. The amorphous structure and composition were examined by X-ray diffraction, differential thermal analysis and energy dispersive X-ray detector. The results show that the Ti40Zr25Ni15Cu20 amorphous alloy foil has excellent wettability on Si3N4 ceramic and demonstrate a strong glass forming ability. The reduced glass transition temperature (Trg) and the temperature interval of supercooled liquid region before crystallization are 0.76 and 78 K, respectively.

  20. Subtask 12D5: Thermal creep properties of vanadium-base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.; Loomis, B.A.; Smith, D.L. [Argonne National Lab., IL (United States)

    1995-03-01

    The objective of this work is to provide baseline data on the thermal creep properties of candidate vanadium base alloys. Vanadium-base alloys are promising candidate materials for application in fusion reactor structural components because of several important advantages. V-4Cr-4Ti has been identified as one of the most promising candidate alloys and was selected for comprehensive tests and examination. In the present investigation, thermal creep rates and stress-rupture life of V-4Cr-4Ti and V-10Cr-5Ti alloys were determined at 600{degrees}C. The impurity composition and microstructural characteristics of creep-tested specimens were analyzed and correlated with the measured creep properties. The results of these tests show that V-4Cr-4Ti, which contains impurity compositions typical of a commercially fabricated vanadium-based alloy, exhibits creep strength substantially superior to that of V-20Ti, HT-9, or Type 316 stainless steel. The V-10Cr-5Ti alloy exhibits creep strength somewhat higher than that of V-4Cr-4Ti. 9 refs., 7 figs., 2 tabs.

  1. Microstructure and mechanical properties of Ni and Fe-base boride-dispersion-strengthened microcrystalline alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wade, C.S.; Park, H.G.; Hoagland, R.G. (Ohio State Univ., Columbus (USA))

    This paper considers the relation between microstructure and mechanical properties of two Ni-base and two Fe-base Boride-Dispersion-Strengthened Microcrystalline (BDSM) alloys. In these very fine grained materials the borides were primarily Cr, Mo, and MoFe in a fcc matrix in three of the alloys, and a bcc in one of the Fe-base alloys. Strength data and resistance to stress corrosion cracking are reported and, in the latter case, extraordinary resistance to SCC in NaCl, Na{sub 2}S{sub 2}O{sub 3} and boiling MgCl{sub 2} environments was observed in every case. The fcc BDSM alloys also demonstrated excellent thermal stability in terms of strength and fracture roughness up to 1000 C. The bcc alloy suffered severe loss of toughness. The fracture mode involved ductile rupture in all alloys and they display a reasonably linear correlation between K{sub Ic} and the square root of particle spacing.

  2. Elastic anharmonicity of bcc Fe and Fe-based random alloys from first-principles calculations

    Science.gov (United States)

    Li, Xiaoqing; Schönecker, Stephan; Zhao, Jijun; Vitos, Levente; Johansson, Börje

    2017-01-01

    We systematically investigate elastic anharmonic behavior in ferromagnetic body-centered cubic (bcc) Fe and Fe1 -xMx (M =Al , V, Cr, Co, or Ni) random alloys by means of density-functional simulations. To benchmark computational accuracy, three ab initio codes are used to obtain the complete set of second- and third-order elastic constants (TOECs) for bcc Fe. The TOECs of Fe1 -xMx alloys are studied employing the first-principles alloy theory formulated within the exact muffin-tin orbital method in combination with the coherent-potential approximation. It is found that the alloying effects on C111,C112 , and C123, which are governed by normal strains only, are more pronounced than those on C144,C166 , and C456, which involve shear strains. Remarkably, the magnitudes of all TOECs but C123 decrease upon alloying with Al, V, Cr, Co, or Ni. Using the computed TOECs, we study compositional effects on the pressure derivatives of the effective elastic constants (d Bi j/d P ), bulk (d K /d P ), and shear moduli (d G /d P ) and derive longitudinal acoustic nonlinearity parameters (β ). Our predictions show that the pressure derivatives of K and G decrease with x for all solute elements and reveal a strong correlation between the compositional trends on d K /d P and d G /d P arising from the fact that alloying predominantly alters d B11/d P . The sensitivity of d B11/d P to composition is attributed to intrinsic alloying effects as opposed to lattice parameter changes accompanying solute addition. For Fe and the considered Fe-based alloys, β along high-symmetry directions orders as β [111 ]>β [100 ]>β [110 ] , and alloying increases the directional anisotropy of β but reduces its magnitude.

  3. Assessment of Personal Airborne Exposures and Surface Contamination from X-ray Vaporization of Beryllium Targets at the National Ignition Facility.

    Science.gov (United States)

    Paik, Samuel Y; Epperson, Patrick M; Kasper, Kenneth M

    2017-02-28

    This study presents air and surface sampling data collected over the first two years since beryllium was introduced as a target material at the National Ignition Facility. Over this time, 101 experiments with beryllium-containing targets were executed. The data provides an assessment of current conditions in the facility and a baseline for future impacts as new, reduced regulatory limits for beryllium are being proposed by both the Occupational Safety and Health Administration and Department of Energy. This study also investigates how beryllium deposits onto exposed surfaces as a result of x-ray vaporization and the effectiveness of simple decontamination measures in reducing the amount of removable beryllium from a surface. Based on 1,961 surface wipe samples collected from entrant components (equipment directly exposed to target debris) and their surrounding work areas during routine reconfiguration activities, only one result was above the beryllium release limit of 0.2 μg/100 cm(2) and 27 results were above the analytical reporting limit of 0.01 μg/100 cm(2), for a beryllium detection rate of 1.4%. Surface wipe samples collected from the internal walls of the NIF target chamber, however, showed higher levels of beryllium, with beryllium detected on 73% and 87% of the samples during the first and second target chamber entries (performed annually), respectively, with 23% of the samples above the beryllium release limit during the second target chamber entry. The analysis of a target chamber wall panel exposed during the first 30 beryllium-containing experiments (cumulatively) indicated that 87% of the beryllium contamination remains fixed onto the surface after wet wiping the surface and 92% of the non-fixed contamination was removed by decontaminating the surface using a dry wipe followed by a wet wipe. Personal airborne exposures assessed during access to entrant components and during target chamber entry indicated that airborne beryllium was not present

  4. Detection of beryllium treatment of natural sapphires by NRA

    Science.gov (United States)

    Gutiérrez, P. C.; Ynsa, M.-D.; Climent-Font, A.; Calligaro, T.

    2010-06-01

    Since the 1990's, artificial treatment of natural sapphires (Al 2O 3 crystals coloured by impurities) by diffusion of beryllium at high temperature has become a growing practice. This process permits to enhance the colour of these gemstones, and thus to increase their value. Detection of such a treatment - diffusion of tens of μg/g of beryllium in Al 2O 3 crystals - is usually achieved using high sensitivity techniques like laser-ablation inductively coupled plasma mass spectrometry (LA-ICP/MS) or laser-induced breakdown spectrometry (LIBS) which are unfortunately micro-destructive (leaving 50-100-μm diameter craters on the gems). The simple and non-destructive alternative method proposed in this work is based on the nuclear reaction 9Be(α, nγ) 12C with an external helium ion beam impinging on the gem directly placed in air. The 4439 keV prompt γ-ray tagging Be atoms are detected with a high efficiency bismuth germanate scintillator. Beam dose is monitored using the 2235 keV prompt γ-ray produced during irradiation by the aluminium of the sapphire matrix through the 27Al(α, pγ) 30Si nuclear reaction. The method is tested on a series of Be-treated sapphires previously analyzed by LA-ICP/MS to determine the optimal conditions to obtain a peak to background appropriate to reach the required μg/g sensitivity. Using a 2.8-MeV external He beam and a beam dose of 200 μC, beryllium concentrations from 5 to 16 μg/g have been measured in the samples, with a detection limit of 1 μg/g.

  5. Detection of beryllium treatment of natural sapphires by NRA

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, P.C., E-mail: carolina.gutierrez@uam.e [Centro de Micro-Analisis de Materiales (CMAM), Universidad Autonoma de Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Ynsa, M.-D.; Climent-Font, A. [Centro de Micro-Analisis de Materiales (CMAM), Universidad Autonoma de Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Dpto. Fisica Aplicada C-12, Universidad Autonoma de Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Calligaro, T. [Centre de Recherche et de Restauration des musees de France C2RMF, CNRS-UMR171, 14 quai Francois Mitterrand, 75001 Paris (France)

    2010-06-15

    Since the 1990's, artificial treatment of natural sapphires (Al{sub 2}O{sub 3} crystals coloured by impurities) by diffusion of beryllium at high temperature has become a growing practice. This process permits to enhance the colour of these gemstones, and thus to increase their value. Detection of such a treatment - diffusion of tens of {mu}g/g of beryllium in Al{sub 2}O{sub 3} crystals - is usually achieved using high sensitivity techniques like laser-ablation inductively coupled plasma mass spectrometry (LA-ICP/MS) or laser-induced breakdown spectrometry (LIBS) which are unfortunately micro-destructive (leaving 50-100-{mu}m diameter craters on the gems). The simple and non-destructive alternative method proposed in this work is based on the nuclear reaction {sup 9}Be({alpha}, n{gamma}){sup 12}C with an external helium ion beam impinging on the gem directly placed in air. The 4439 keV prompt {gamma}-ray tagging Be atoms are detected with a high efficiency bismuth germanate scintillator. Beam dose is monitored using the 2235 keV prompt {gamma}-ray produced during irradiation by the aluminium of the sapphire matrix through the {sup 27}Al({alpha}, p{gamma}){sup 30}Si nuclear reaction. The method is tested on a series of Be-treated sapphires previously analyzed by LA-ICP/MS to determine the optimal conditions to obtain a peak to background appropriate to reach the required {mu}g/g sensitivity. Using a 2.8-MeV external He beam and a beam dose of 200 {mu}C, beryllium concentrations from 5 to 16 {mu}g/g have been measured in the samples, with a detection limit of 1 {mu}g/g.

  6. Microstructure evolution model based on deformation mechanism of titanium alloy in hot forming

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-li; LI Miao-quan

    2005-01-01

    The microstructure evolution in hot forming will affect the mechanical properties of the formed product.However, the microstructure is sensitive to the process variables in deformation process of metals and alloys. A microstructure evolution model of a titanium alloy in hot forming, which included dislocation density rate and primary α phase grain size, was presented according to the deformation mechanism and driving forces, in which the effect of the dislocation density rate on the grain growth was studied firstly. Applying the model to the high temperature deformation process of a TC6 alloy with deformation temperature of 1 133 - 1 223 K, strain rate of 0.01 -50 s-1 and height reduction of 30%, 40% and 50%, the material constants in the present model were calculated by the genetic algorithm(GA) based objective optimization techniques. The calculated results of a TC6 alloy are in good agreement with the experimental ones.

  7. Structural transformations in wear resistance of iron- and cobalt-based amorphous alloys during abrasive wear

    Science.gov (United States)

    Korshunov, L. G.; Shabashov, V. A.; Chernenko, N. L.

    2010-04-01

    The wear resistance and structural changes in a number of amorphous alloys based on iron and cobalt and in high-carbon tool steels are studied during wear by a fixed abrasive (crondum, Carborundum) at room temperature and -196°C. The abrasive wear resistance of the amorphous alloys is shown to be 1.6-3.1 lower than that of the high-carbon tool steels having a similar hardness. The relatively low level of the abrasive wear resistance of the amorphous alloys is assumed to be caused by strain softening of their surface during wear. A nanocrystalline structure is found to form in local microvolumes in a thin deformed surface layer of the alloys.

  8. Improvement on Hot Workability of γ-TiAl Base Alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    γ-TiAl base alloys have potential usage in aerospace engine fortheir high specific strength. In order to improve their poor hot workability, a new approach of hot deformation processing was investigated. The starting microstructure of Ti-46.5Al-2.5V-1.0Cr (atom percent, %) alloy is fully lamellar (FL) microstructure. The near gamma (NG) microstructure can be obtained through Nickel microalloying and heat treatment at 1 150 ℃. The isothermal compression tests were conducted on both materials using MTS machine at temperatures of 950 ℃, 1 000 ℃, and 1 050 ℃, and the strain rates of 0.01, 0.1 and 1 s-1. Compared with the γ-TiAl alloy with FL microstructure, the Ni-bearing alloy with NG microstructure has better hot workability, such as enlarged hot workable region, decreased flow stresses, more uniform and finer deformed microstructure.

  9. Research on fabricating Fe base amorphous alloy by bar plasma spraying

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Since amorphous alloys have wider application, they can not be fabricated using the conventional cooling velocity. The bar material plasma spraying is adopted to fabricate Fe base amorphous alloy in this investigation. The crystallization degree, microstructure, micro-hardness, composition, crystallization temperature of the amorphous alloy and the flying rules of the atomized particles in the process of the plasma spray are tested. The results show that the alloy prepared has the high amorphous degree and homogeneous microstructure, micro-hardness and the crystallization temperature can reach 1187HV and 531℃ respectively. The atomization is very well during the process of plasma spraying; and there is high thermal gradient, the cooling velocity reaches 6.07×107K/s.

  10. Undercooling and demixing of copper-based alloys

    DEFF Research Database (Denmark)

    Kolbe, M.; Brillo, J.; Egry, I.

    2006-01-01

    Since the beginning of materials science research under microgravity conditions immiscible alloys have been an interesting subject. New possibilities to investigate such systems are offered by containerless processing techniques. Of particular interest is the ternary system Cu-Fe-Co, and its limi...

  11. Injectable liquid alkali alloy based-tumor thermal ablation therapy.

    Science.gov (United States)

    Rao, Wei; Liu, Jing

    2009-01-01

    The alkali metal was recently found to be a very useful agent for inducing minimally invasive tumor hyperthermia therapy. However, the solid-like metal makes it somewhat inconvenient to perform the surgery. Here, to overcome this drawback, the NaK alloy in liquid state at room temperature was proposed as a highly efficient thermal ablative agent for tumor treatment. For illustration purposes, the functionalized liquid NaK alloy at a mass ratio 1:1 was obtained and an amount of 0.35 ml was injected into in vitro pork. The sizes of the damage region and temperature response were measured. It was found that significant temperature increase by a magnitude of > 80 degrees C can easily be obtained. This produced a large coagulation and necrotic area within selected areas for in vitro tests and the necrotic region volume is three times that of the NaK injection quantity. Furthermore, for the in vivo experiment, breast EMT6 tumor in mouse was subjected to treatment by NaK alloy. Tumor was harvested after the experiment to assess its viability. Histological section showed complete necrosis at the target site. These conceptual results demonstrate that using injectable liquid alkali alloy to ablate tumor is rather promising. This study also raised interesting issues waiting for clarification in future technical and animal studies aiming to assess efficacy, side effects and safety of the new therapy.

  12. Corrosion Performance of Fe-Based Alloys in Simulated Oxy-Fuel Environment

    Science.gov (United States)

    Zeng, Zuotao; Natesan, Ken; Cai, Zhonghou; Rink, David L.

    2017-02-01

    The long-term corrosion of Fe-based alloys in simulated oxy-fuel environment at 1023 K (750 °C) was studied. Detailed results are presented on weight change, scale thickness, internal penetration, microstructural characteristics of the corrosion products, and the cracking of scales for the alloys after exposure at 1023 K (750 °C) for up to 3600 hours. An incubation period during which the corrosion rate was low was observed for the alloys. After the incubation period, the corrosion accelerated, and the corrosion process followed linear kinetics. Effects of alloy, CaO-containing ash, and gas composition on the corrosion rate were also studied. In addition, synchrotron nanobeam X-ray analysis was employed to determine the phase and chemical composition of the oxide layers on the alloy surface. Results from these studies are being used to address the long-term corrosion performance of Fe-based alloys in various coal-ash combustion environments and to develop methods to mitigate high-temperature ash corrosion.

  13. MRI compatibility of several early transition metal based alloys and its influencing factors.

    Science.gov (United States)

    Zhou, Da-Bo; Wang, Shao-Gang; Wang, Shao-Ping; Ai, Hong-Jun; Xu, Jian

    2017-02-03

    Magnetic resonance imaging (MRI) compatibility of three early transition metal (ETM) based alloys was assessed in vitro with agarose gel as a phantom, including Zr-20Nb, near-equiatomic (TiZrNbTa)90 Mo10 and Nb-60Ta-2Zr, together with pure tantalum and L605 Co-Cr alloy for comparison. The artifact extent in the MR image was quantitatively characterized according to the maximum area of 2D images and the total volume in reconstructed 3D images with a series of slices under acquisition by fast spin echo (FSE) sequence and gradient echo (GRE) sequence. It was indicated that the artifacts extent of L605 Co-Cr alloy with a higher magnetic susceptibility (χv ) was approximately 3-fold greater than that of the ETM-based alloys with χv in the range of 160-250 ppm. In the ETM group, the MRI compatibility of the materials can be ranked in a sequence of Zr-20Nb, pure tantalum, (TiZrNbTa)90 Mo10 and Nb-60Ta-2Zr. In addition, using a rabbit cadaver with the implanted tube specimens as a model for ex vivo assessment, it was confirmed that the artifact severity of Nb-60Ta-2Zr alloy is significantly reduced in comparison with the L605 alloy. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017.

  14. Physical Simulation of Friction Stir Welding and Processing of Nickel-Base Alloys Using Hot Torsion

    Science.gov (United States)

    Rule, James R.; Lippold, John C.

    2013-08-01

    The Gleeble hot torsion test was utilized in an attempt to simulate the friction stir-processed microstructure of three Ni-base alloys: Hastelloy X, Alloy 625, and Alloy 718. The simulation temperatures were based on actual thermal cycles measured by embedded thermocouples during friction stir processing of these alloys. Peak process temperatures were determined to be approximately 1423 K (1150 °C) for Hastelloy X and Alloy 625 K and 1373 K (352 °C and 1100 °C) for Alloy 718. The peak temperature and cooling rates were programed into the Gleeble™ 3800 thermo-mechanical simulator to reproduce the stir zone and thermo-mechanically affected zone (TMAZ) microstructures. The TMAZ was successfully simulated using this technique, but the stir zone microstructure could not be accurately reproduced, with hot torsion samples exhibiting larger grain size than actual friction stir processing trials. Shear stress and strain rates as a function of temperature were determined for each material using hot torsion simulation.

  15. Potentiality of the “Gum Metal” titanium-based alloy for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Gordin, D.M. [Institut des Sciences Chimiques de Rennes (UMR CNRS 6226), INSA Rennes, 20 Avenue des Buttes de Coësmes, F-35043 Rennes Cedex (France); Ion, R. [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Vasilescu, C.; Drob, S.I. [Institute of Physical Chemistry “Ilie Murgulescu” of Romanian Academy, Spl. Independentei 202, 060021 Bucharest (Romania); Cimpean, A. [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095 Bucharest (Romania); Gloriant, T., E-mail: Thierry.Gloriant@insa-rennes.fr [Institut des Sciences Chimiques de Rennes (UMR CNRS 6226), INSA Rennes, 20 Avenue des Buttes de Coësmes, F-35043 Rennes Cedex (France)

    2014-11-01

    In this study, the “Gum Metal” titanium-based alloy (Ti–23Nb–0.7Ta–2Zr–1.2O) was synthesized by melting and then characterized in order to evaluate its potential for biomedical applications. Thus, the mechanical properties, the corrosion resistance in simulated body fluid and the in vitro cell response were investigated. It was shown that this alloy presents a very high strength, a low Young's modulus and a high recoverable strain by comparison with the titanium alloys currently used in medicine. On the other hand, all electrochemical and corrosion parameters exhibited more favorable values showing a nobler behavior and negligible toxicity in comparison with the commercially pure Ti taken as reference. Furthermore, the biocompatibility tests showed that this alloy induced an excellent response of MC3T3-E1 pre-osteoblasts in terms of attachment, spreading, viability, proliferation and differentiation. Consequently, the “Gum Metal” titanium-based alloy processes useful characteristics for the manufacturing of highly biocompatible medical devices. - Highlights: • The Gum Metal alloy composition was synthesized by melting in this study. • Appropriate mechanical properties for biomedical applications were obtained. • High corrosion resistance in simulated body fluids was observed. • Excellent in-vitro cell response was evidenced.

  16. Effect of solution hardening on the shape memory effect of Fe-Mn based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Tsuzaki, K.; Natsume, Y.; Maki, T. [Kyoto Univ. (Japan). Dept. of Materials Science and Engineering; Tomota, Y. [Ibaraki Univ., Hitachi (Japan)

    1995-10-01

    Fe-high Mn-Si alloys, which undergo {gamma} (fcc) to {var_epsilon} (hcp) martensitic transformation, exhibit a pronounced shape memory effect. The origin of shape memory effect of these alloys is the reversion of stress-induced {var_epsilon} martensite. A shape change must hence be accomplish3ed by stress-induced martensitic transformation without permanent slip in austenite ({gamma}) in order to obtain a good shape memory effect. It is clear that the intrusion of permanent slip can be suppressed by increasing the strength of austenite and by decreasing the applied stress required for a shape change due to stress-induced martensitic transformation. It has been reported that the addition of the interstitial elements of C and N as well as the substitutional elements of Mo and V increases the 0.2% proof stress of austenite in Fe-high Mn alloys. However, there have been few studies on the effect of these alloying elements on the shape memory effect of Fe-high Mn based alloys. In the present study, it was aimed to improve the shape memory effect of Fe-high Mn based alloys by the strengthening of austenite through solution hardening due to C and Mo.

  17. Correlation Between Superheated Liquid Fragility And Onset Temperature Of Crystallization For Al-Based Amorphous Alloys

    Directory of Open Access Journals (Sweden)

    Guo J.

    2015-06-01

    Full Text Available Amorphous alloys or metallic glasses have attracted significant interest in the materials science and engineering communities due to their unique physical, mechanical, and chemical properties. The viscous flow of amorphous alloys exhibiting high strain rate sensitivity and homogeneous deformation is considered to be an important characteristic in thermoplastic forming processes performed within the supercooled liquid region because it allows superplastic-like deformation behavior. Here, the correlation between the superheated liquid fragility, and the onset temperature of crystallization for Al-based alloys, is investigated. The activation energy for viscous flow of the liquid is also investigated. There is a negative correlation between the parameter of superheated liquid fragility and the onset temperature of crystallization in the same Al-based alloy system. The activation energy decreases as the onset temperature of crystallization increases. This indicates that the stability of a superheated liquid can affect the thermal stability of the amorphous alloy. It also means that a liquid with a large superheated liquid fragility, when rapidly solidified, forms an amorphous alloy with a low thermal stability.

  18. Pack cementation diffusion coatings for Fe-base and refractory alloys. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, R.A. [Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

    1998-03-10

    With the aid of computer-assisted calculations of the equilibrium vapor pressures in halide-activated cementation packs, processing conditions have been identified and experimentally verified for the codeposition of two or more alloying elements in a diffusion coating on a variety of steels and refractory metal alloys. A new comprehensive theory to treat the multi-component thermodynamic equilibria in the gas phase for several coexisting solid phases was developed and used. Many different processes to deposit various types of coatings on several types of steels were developed: Cr-Si codeposition for low- or medium-carbon steels, Cr-Al codeposition on low-carbon steels to yield either a Kanthal-type composition (Fe-25Cr-4Al in wt.%) or else a (Fe, Cr){sub 3}Al surface composition. An Fe{sub 3}Al substrate was aluminized to achieve an FeAl surface composition, and boron was also added to ductilize the coating. The developmental Cr-lean ORNL alloys with exceptional creep resistance were Cr-Al coated to achieve excellent oxidation resistance. Alloy wires of Ni-base were aluminized to provide an average composition of Ni{sub 3}Al for use as welding rods. Several different refractory metal alloys based on Cr-Cr{sub 2}Nb have been silicided, also with germanium additions, to provide excellent oxidation resistance. A couple of developmental Cr-Zr alloys were similarly coated and tested.

  19. Control of equiaxed grains in a complicated Cu-Ni based alloy prepared by centrifugal casting

    Directory of Open Access Journals (Sweden)

    Luo Zongqiang

    2011-02-01

    Full Text Available A complicated Cu-Ni based alloy was developed to fabricate wear-resisting bush for high temperature application. The concern focuses on the control of equiaxed grains in the developed alloy ingot prepared by centrifugal casting. The results show that the equiaxed grains are determined by the pouring temperature of the melt, the cooling rate and the rotation speed of the mold. With the decrease in pouring temperature, the fraction of the equiaxed grains in the transverse section of the ingot increases and the average length of columnar grain decreases. When the pouring temperature is confined below 1,250℃, complete equiaxed grains can be obtained. Based on the optimal centrifugal casting processing, the tensile strength of the developed alloy ingot with complete equiaxed grains reaches to 810 MPa and 435 MPa at room temperature and 500℃, respectively, which is 14% and 110% higher than that of common commercial QAl10-4-4 alloy. The wear rate of the developed alloy is 7.0 × 10-8 and 3.8 × 10-7 mm3•N-1•mm-1 at room temperature and 500℃, respectively, which is 5 times and 39 times lower than that of QAl10-4-4 alloy.

  20. Subtask 12F1: Effect of neutron irradiation on swelling of vanadium-base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.; Loomis, B.A.; Smith, D.L. [Argonne National Lab., IL (United States)

    1995-03-01

    The objective of this work is to determine the effects of neutron irradiation on the density change, void distribution, and microstructural evolution of vanadium-base alloys. Swelling behavior and microstructural evolution of V-Ti, V-Cr-Ti, and V-Ti-Si alloys were investigated after irradiation at 420-600{degrees}C up to 114 dpa. The alloys exhibited swelling maxima between 30 and 80 dpa and swelling decreased on irradiation to higher dpa. This is in contrast to the monotonically increasing swelling of binary alloys that contain Fe, Ni, Cr, Mo, W, and Si. Precipitation of dense Ti{sub 5}Si{sub 3} promotes good resistance to swelling of the Ti-containing alloys, and it was concluded that Ti of >3 wt.% and 400-1000 wppm Si are necessary to effectively suppress swelling. Swelling was minimal in V-4Cr-4Ti, identified as the most promising alloy based on good mechanical properties and superior resistance to irradiation embrittlement. 18 refs., 6 figs., 1 tab.

  1. Subtask 12F3: Effects of neutron irradiation on tensile properties of vanadium-base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, B.A.; Chung, H.M.; Smith, D.L. [Argonne National Lab., IL (United States)

    1995-03-01

    The objective of this work is to determine the effects of neutron irradiation on the tensile properties of candidate vanadium-base alloys. Vanadium-base alloys of the V-Cr-Ti system are attractive candidates for use as structural materials in fusion reactors. The current focus of the U.S. program of research on these alloys is on the V-(4-6)Cr-(3-6)Ti-(0.05-0.1)Si (in wt.%) alloys. In this paper, we present experimental results on the effects of neutron irradiation on tensile properties of selected candidate alloys after irradiation at 400{degrees}C-600{degrees}C in lithium in fast fission reactors to displacement damages of up to {approx}120 displacement per atom (dpa). Effects of irradiation temperature and dose on yield and ultimate tensile strengths and uniform and total elongations are given for tensile test temperatures of 25{degrees}C, 420{degrees}C, 500{degrees}, and 600{degrees}C. Effects of neutron damage on tensile properties of the U.S. reference alloy V-4Cr-4Ti are examined in detail. 7 refs., 10 figs., 1 tab.

  2. Corrosion Performance of Fe-Based Alloys in Simulated Oxy-Fuel Environment

    Science.gov (United States)

    Zeng, Zuotao; Natesan, Ken; Cai, Zhonghou; Rink, David L.

    2016-09-01

    The long-term corrosion of Fe-based alloys in simulated oxy-fuel environment at 1023 K (750 °C) was studied. Detailed results are presented on weight change, scale thickness, internal penetration, microstructural characteristics of the corrosion products, and the cracking of scales for the alloys after exposure at 1023 K (750 °C) for up to 3600 hours. An incubation period during which the corrosion rate was low was observed for the alloys. After the incubation period, the corrosion accelerated, and the corrosion process followed linear kinetics. Effects of alloy, CaO-containing ash, and gas composition on the corrosion rate were also studied. In addition, synchrotron nanobeam X-ray analysis was employed to determine the phase and chemical composition of the oxide layers on the alloy surface. Results from these studies are being used to address the long-term corrosion performance of Fe-based alloys in various coal-ash combustion environments and to develop methods to mitigate high-temperature ash corrosion.

  3. Quantification and micron-scale imaging of spatial distribution of trace beryllium in shrapnel fragments and metallurgic samples with correlative fluorescence detection method and secondary ion mass spectrometry (SIMS).

    Science.gov (United States)

    Abraham, J L; Chandra, S; Agrawal, A

    2014-11-01

    Recently, a report raised the possibility of shrapnel-induced chronic beryllium disease from long-term exposure to the surface of retained aluminum shrapnel fragments in the body. Since the shrapnel fragments contained trace beryllium, methodological developments were needed for beryllium quantification and to study its spatial distribution in relation to other matrix elements, such as aluminum and iron, in metallurgic samples. In this work, we developed methodology for quantification of trace beryllium in samples of shrapnel fragments and other metallurgic sample-types with main matrix of aluminum (aluminum cans from soda, beer, carbonated water and aluminum foil). Sample preparation procedures were developed for dissolving beryllium for its quantification with the fluorescence detection method for homogenized measurements. The spatial distribution of trace beryllium on the sample surface and in 3D was imaged with a dynamic secondary ion mass spectrometry instrument, CAMECA IMS 3f secondary ion mass spectrometry ion microscope. The beryllium content of shrapnel (∼100 ppb) was the same as the trace quantities of beryllium found in aluminum cans. The beryllium content of aluminum foil (∼25 ppb) was significantly lower than cans. SIMS imaging analysis revealed beryllium to be distributed in the form of low micron-sized particles and clusters distributed randomly in X-Y- and Z dimensions, and often in association with iron, in the main aluminum matrix of cans. These observations indicate a plausible formation of Be-Fe or Al-Be alloy in the matrix of cans. Further observations were made on fluids (carbonated water) for understanding if trace beryllium in cans leached out and contaminated the food product. A direct comparison of carbonated water in aluminum cans and plastic bottles revealed that beryllium was below the detection limits of the fluorescence detection method (∼0.01 ppb). These observations indicate that beryllium present in aluminum matrix was either

  4. Properties of thermally stable PM Al-Cr based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Vojtech, D. [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic)], E-mail: Dalibor.Vojtech@vscht.cz; Verner, J. [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Serak, J. [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Simancik, F. [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 831 02 Bratislava 3 (Slovakia); Balog, M. [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 831 02 Bratislava 3 (Slovakia); Nagy, J. [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 831 02 Bratislava 3 (Slovakia)

    2007-06-15

    The presented paper describes properties of Al-6.0 wt.%Cr-2.3 wt.%Fe-0.4 wt.%Ti-0.7 wt.%Si alloy produced by powder metallurgy (PM). The powder alloy was prepared by the pressure nitrogen melt atomization. The granulometric powder fraction of less than 45 {mu}m was then hot-extruded at 450 deg. C to produce a rod of 6 mm in diameter. Microstructure of the as-extruded material was composed of recrystallized {alpha}(Al) grains (the average grain size of 640 nm) and Al{sub 13}Cr{sub 2} spheroids (the average particle diameter of 130 nm and interparticle spacing of 290 nm). Metastable phases were not observed due to their decomposition on the hot extrusion. Hardness of the as-extruded material was 108 HV1, ultimate tensile strength, 327 MPa, yield strength, 258 MPa and elongation, 14%. Mechanical properties resulted mainly from Hall-Petch strengthening. The room-temperature mechanical properties were also measured after a long-term annealing at 400 deg. C. The investigated PM material was compared with the commercial Al-11.8 wt.%Si-0.9 wt.%Ni-1.2 wt.%Cu-1.2 wt.%Mg casting alloy generally applied at elevated temperatures. The PM alloy showed much higher thermal stability, since its room temperature hardness and tensile properties did not degradate significantly even after annealing at 400 deg. C/200 h. In contrast, the hardness and strength of the casting alloy reduced rapidly already after a 30 min annealing. The excellent thermal stability of the investigated PM material was a consequence of very slow diffusivities and low equilibrium solubilities of chromium and iron in solid aluminium.

  5. Coating of 6028 Aluminum Alloy Using Aluminum Piston Alloy and Al-Si Alloy-Based Nanocomposites Produced by the Addition of Al-Ti5-B1 to the Matrix Melt

    Science.gov (United States)

    El-Labban, Hashem F.; Abdelaziz, M.; Mahmoud, Essam R. I.

    2014-10-01

    The Al-12 pctSi alloy and aluminum-based composites reinforced with TiB2 and Al3Ti intermetallics exhibit good wear resistance, strength-to-weight ratio, and strength-to-cost ratio when compared to equivalent other commercial Al alloys, which make them good candidates as coating materials. In this study, structural AA 6028 alloy is used as the base material. Four different coating materials were used. The first one is Al-Si alloy that has Si content near eutectic composition. The second, third, and fourth ones are Al-6 pctSi-based reinforced with TiB2 and Al3Ti nano-particles produced by addition of Al-Ti5-B1 master alloy with different weight percentages (1, 2, and 3 pct). The coating treatment was carried out with the aid of GTAW process. The microstructures of the base and coated materials were investigated using optical microscope and scanning electron microscope equipped with EDX analyzer. Microhardness of the base material and the coated layer were evaluated using a microhardness tester. GTAW process results in almost sound coated layer on 6028 aluminum alloy with the used four coating materials. The coating materials of Al-12 pct Si alloy resulted in very fine dendritic Al-Si eutectic structure. The interface between the coated layer and the base metal was very clean. The coated layer was almost free from porosities or other defects. The coating materials of Al-6 pct Si-based mixed with Al-Ti5-B1 master alloy with different percentages (1, 2, and 3 pct), results in coated layer consisted of matrix of fine dendrite eutectic morphology structure inside α-Al grains. Many fine in situ TiAl3 and TiB2 intermetallics were precipitated almost at the grain boundary of α-Al grains. The amounts of these precipitates are increased by increasing the addition of Al-Ti5-B1 master alloy. The surface hardness of the 6028 aluminum alloy base metal was improved with the entire four used surface coating materials. The improvement reached to about 85 pct by the first type of

  6. Computer-Aided Design of Manufacturing Chain Based on Closed Die Forging for Hardly Deformable Cu-Based Alloys

    Science.gov (United States)

    Pietrzyk, Maciej; Kuziak, Roman; Pidvysots'kyy, Valeriy; Nowak, Jarosław; Węglarczyk, Stanisław; Drozdowski, Krzysztof

    2013-07-01

    Two copper-based alloys were considered, Cu-1 pct Cr and Cu-0.7 pct Cr-1 pct Si-2 pct Ni. The thermal, electrical, and mechanical properties of these alloys are given in the paper and compared to pure copper and steel. The role of aging and precipitation kinetics in hardening of the alloys is discussed based upon the developed model. Results of plastometric tests performed at various temperatures and various strain rates are presented. The effect of the initial microstructure on the flow stress was investigated. Rheologic models for the alloys were developed. A finite element (FE) model based on the Norton-Hoff visco-plastic flow rule was applied to the simulation of forging of the alloys. Analysis of the die wear for various processes of hot and cold forging is presented as well. A microstructure evolution model was implemented into the FE code, and the microstructure and mechanical properties of final products were predicted. Various variants of the manufacturing cycles were considered. These include different preheating schedules, hot forging, cold forging, and aging. All variants were simulated using the FE method and loads, die filling, tool wear, and mechanical properties of products were predicted. Three variants giving the best combination of forging parameters were selected and industrial trials were performed. The best manufacturing technology for the copper-based alloys is proposed.

  7. Neutronics and activation analysis of lithium-based ternary alloys in IFE blankets

    Energy Technology Data Exchange (ETDEWEB)

    Jolodosky, Alejandra, E-mail: aleja311@berkeley.edu [University of California Berkeley, Berkeley, CA 94706 (United States); Kramer, Kevin [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA (United States); Meier, Wayne; DeMuth, James; Reyes, Susana [TerraPower, Bellevue, WA 98005 (United States); Fratoni, Massimiliano [University of California Berkeley, Berkeley, CA 94706 (United States)

    2016-06-15

    Highlights: • Monte Carlo calculations were performed on numerous lithium ternary alloys. • Elements with high neutron multiplication performed well with low absorbers. • Enriching lithium decreases minimum lithium concentration of alloys by 60% or more. • Alloys that performed well neutronically were selected for activation calculations. • Alloys activated, except LiBaBi, do not pose major environmental or safety concerns. - Abstract: An attractive feature of using liquid lithium as the breeder and coolant in fusion blankets is that it has very high tritium solubility and results in very low levels of tritium permeation throughout the facility infrastructure. However, lithium metal vigorously reacts with air and water and presents plant safety concerns. The Lawrence Livermore National Laboratory is carrying an effort to develop a lithium-based ternary alloy that maintains the beneficial properties of lithium (e.g. high tritium breeding and solubility) and at the same time reduces overall flammability concerns. This study evaluates the neutronics performance of lithium-based alloys in the blanket of an inertial fusion energy chamber in order to inform such development. 3-D Monte Carlo calculations were performed to evaluate two main neutronics performance parameters for the blanket: tritium breeding ratio (TBR), and the fusion energy multiplication factor (EMF). It was found that elements that exhibit low absorption cross sections and higher q-values such as Pb, Sn, and Sr, perform well with those that have high neutron multiplication such as Pb and Bi. These elements meet TBR constrains ranging from 1.02 to 1.1. However, most alloys do not reach EMFs greater than 1.15. Additionally, it was found that enriching lithium with {sup 6}Li significantly increases the TBR and decreases the minimum lithium concentration by more than 60%. The amount of enrichment depends on how much total lithium is in the alloy to begin with. Alloys that performed well in the TBR

  8. Thermodynamic Tuning of Mg-Based Hydrogen Storage Alloys: A Review

    Directory of Open Access Journals (Sweden)

    Min Zhu

    2013-10-01

    Full Text Available Mg-based hydrides are one of the most promising hydrogen storage materials because of their relatively high storage capacity, abundance, and low cost. However, slow kinetics and stable thermodynamics hinder their practical application. In contrast to the substantial progress in the enhancement of the hydrogenation/dehydrogenation kinetics, thermodynamic tuning is still a great challenge for Mg-based alloys. At present, the main strategies to alter the thermodynamics of Mg/MgH2 are alloying, nanostructuring, and changing the reaction pathway. Using these approaches, thermodynamic tuning has been achieved to some extent, but it is still far from that required for practical application. In this article, we summarize the advantages and disadvantages of these strategies. Based on the current progress, finding reversible systems with high hydrogen capacity and effectively tailored reaction enthalpy offers a promising route for tuning the thermodynamics of Mg-based hydrogen storage alloys.

  9. Atomic scale properties of magnetic Mn-based alloys probed by emission Mössbauer spectroscopy

    CERN Multimedia

    Mn-based alloys are characterized by a wealth of properties, which are of interest both from fundamental physics point of view and particularly attractive for different applications in modern technology: from magnetic storage to sensing and spin-based electronics. The possibility to tune their magnetic properties through post-growth thermal processes and/or stoichiometry engineering is highly important in order to target different applications (i.e. Mn$_{x}$Ga) or to increase their Curie temperature above room temperature (i.e. off-stoichiometric MnSi). In this project, the Mössbauer effect will be applied at $^{57}$Fe sites following implantation of radioactive $^{57}$Mn, to probe the micro-structure and magnetism of Mn-based alloys on the atomic-scale. The proposed experimental plan is devoted to establish a direct correlation between the local structure and bulk magnetism (and other physical properties) of Mn-based alloys.

  10. Computational studies of physical properties of Nb-Si based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang, Lizhi [Middle Tennessee State Univ., Murfreesboro, TN (United States)

    2015-04-16

    The overall goal is to provide physical properties data supplementing experiments for thermodynamic modeling and other simulations such as phase filed simulation for microstructure and continuum simulations for mechanical properties. These predictive computational modeling and simulations may yield insights that can be used to guide materials design, processing, and manufacture. Ultimately, they may lead to usable Nb-Si based alloy which could play an important role in current plight towards greener energy. The main objectives of the proposed projects are: (1) developing a first principles method based supercell approach for calculating thermodynamic and mechanic properties of ordered crystals and disordered lattices including solid solution; (2) application of the supercell approach to Nb-Si base alloy to compute physical properties data that can be used for thermodynamic modeling and other simulations to guide the optimal design of Nb-Si based alloy.

  11. Influence of neutron irradiation on the tritium retention in beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Rolli, R.; Ruebel, S.; Werle, H. [Forschungszentrum Karlsruhe, Inst. fuer Neutronenphysik und Reaktortechnik, Karlsruhe (Germany); Wu, C.H.

    1998-01-01

    Carbon-based materials and beryllium are the candidates for protective layers on the components of fusion reactors facing plasma. In contact with D-T plasma, these materials absorb tritium, and it is anticipated that tritium retention increases with the neutron damage due to neutron-induced traps. Because of the poor data base for beryllium, the work was concentrated on it. Tritium was loaded into the samples from stagnant T{sub 2}/H{sub 2} atmosphere, and afterwards, the quantity of the loaded tritium was determined by purged thermal annealing. The specification of the samples is shown. The samples were analyzed by SEM before and after irradiation. The loading and the annealing equipments are contained in two different glove boxes with N{sub 2} inert atmosphere. The methods of loading and annealing are explained. The separation of neutron-produced and loaded tritium and the determination of loaded tritium in irradiated samples are reported. Also the determination of loaded tritium in unirradiated samples is reported. It is evident that irradiated samples contained much more loaded tritium than unirradiated samples. The main results of this investigation are summarized in the table. (K.I.)

  12. Ballistic Impact Properties of Zr-Based Amorphous Alloy Composites Reinforced with Woven Continuous Fibers

    Science.gov (United States)

    Kim, Gyeong Su; Son, Chang-Young; Lee, Sang-Bok; Lee, Sang-Kwan; Song, Young Buem; Lee, Sunghak

    2012-03-01

    This study aims at investigating ballistic impact properties of Zr-based amorphous alloy (LM1 alloy) matrix composites reinforced with woven stainless steel or glass continuous fibers. The fiber-reinforced composites with excellent fiber/matrix interfaces were fabricated without pores and misinfiltration by liquid pressing process, and contained 35 to 41 vol pct of woven continuous fibers homogeneously distributed in the amorphous matrix. The woven-STS-continuous-fiber-reinforced composite consisted of the LM1 alloy layer of 1.0 mm in thickness in the upper region and the fiber-reinforced composite layer in the lower region. The hard LM1 alloy layer absorbed the ballistic impact energy by forming many cracks, and the fiber-reinforced composite layer interrupted the crack propagation and blocked the impact and traveling of the projectile, thereby resulting in the improvement of ballistic performance by about 20 pct over the LM1 alloy. According to the ballistic impact test data of the woven-glass-continuous-fiber-reinforced composite, glass fibers were preferentially fragmented to form a number of cracks, and the amorphous matrix accelerated the fragmentation of glass fibers and the initiation of cracks. Because of the absorption process of ballistic impact energy by forming very large amounts of cracks, fragments, and debris, the glass-fiber-reinforced composite showed better ballistic performance than the LM1 alloy.

  13. Nanostructure Characterization of Bismuth Telluride-Based Powders and Extruded Alloys by Various Experimental Methods

    Science.gov (United States)

    Vasilevskiy, D.; Bourbia, O.; Gosselin, S.; Turenne, S.; Masut, R. A.

    2011-05-01

    High-resolution transmission electron microscopy (HRTEM) observations of mechanically alloyed powders and bulk extruded alloys give experimental evidence of nanosized grains in bismuth telluride-based materials. In this study we combine HRTEM observations and x-ray diffraction (XRD) measurements, of both mechanically alloyed powders and extruded samples, with mechanical spectroscopy (MS) of extruded rods. Both HRTEM and XRD show that nanostructures with an average grain size near 25 nm can be achieved within 2 h of mechanical alloying from pure elements in an attritor-type milling machine. Residual strain orthogonal to the c-axis of powder nanoparticles has been evaluated at about 1.2% by XRD peak broadening. In contrast, XRD has been found unreliable for evaluation of grain size in highly textured extruded materials for which diffraction conditions are similar to those of single crystals, while MS appears promising for study of bulk extruded samples. Nanostructured extruded alloys at room temperature exhibit an internal friction (IF) background that is one order of magnitude higher than that of conventional zone-melted material with a grain size of several millimeters. IF as a function of sample temperature gives activation energies that are also different between bulk materials having nano- and millimeter-size grains, a result that is attributed to different creep mechanisms. Nanograin size, as well as orientation and volumetric proportion, provide valuable information for optimization of technological parameters of thermoelectric alloys and should be carefully cross-examined by various independent methods.

  14. Structure and mechanical properties of Ti-5Cr based alloy with Mo addition

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Wen-Fu [Department of Materials Science and Engineering, Da-Yeh University, Taiwan (China); Wu, Shih-Ching [Department of Dental Laboratory Technology, Central Taiwan University of Science and Technology, Taiwan (China); Institute of Biomedical Engineering and Material Science, Central Taiwan University of Science and Technology, Taiwan (China); Chang, Hsiang-Hao [Department of Materials Science and Engineering, Da-Yeh University, Taiwan (China); Hsu, Hsueh-Chuan, E-mail: hchsu@ctust.edu.tw [Department of Dental Laboratory Technology, Central Taiwan University of Science and Technology, Taiwan (China); Institute of Biomedical Engineering and Material Science, Central Taiwan University of Science and Technology, Taiwan (China)

    2010-07-20

    The effects of molybdenum (Mo) on the structure and mechanical properties of a Ti-5Cr-based alloy were studied with an emphasis on improving its strength/modulus ratio. Commercially pure titanium (c.p. Ti) was used as a control. As-cast Ti-5Cr and a series of Ti-5Cr-xMo (x = 1, 3, 5, 7, 9 and 11 wt.%) alloys were prepared by using a commercial arc-melting vacuum-pressure casting system, and investigated with X-ray diffraction (XRD) for phase analysis. Three-point bending tests were performed to evaluate the mechanical properties of all specimens and their fractured surfaces were observed by using scanning electron microscopy (SEM). The experimental results indicated that Ti-5Cr-7Mo, Ti-5Cr-9Mo and Ti-5Cr-11Mo alloys exhibited ductile properties, and the {beta}-phase Ti-5Cr-9Mo alloy exhibited the lowest bending modulus. However, the Ti-5Cr-3Mo and Ti-5Cr-5Mo alloys had much higher bending moduli due to the formation of the {omega} phase during quenching. It is noteworthy that the Ti-5Cr-9Mo alloy exhibited the highest bending strength/modulus ratios at 26.0, which is significantly higher than those of c.p. Ti (8.5) and Ti-5Cr (13.3). Furthermore, the elastically recoverable angle of the Ti-5Cr-9Mo alloy (30{sup o}) was greater than that of c.p. Ti (2.7{sup o}). The reasonably high strength (or high strength/modulus ratio) {beta}-phase Ti-5Cr-9Mo alloy exhibited a low modulus, ductile property, and excellent elastic recovery capability, which qualifies it as a novel implant materials.

  15. Thin-walled aluminum alloy tube NC precision bending based on finite element simulation

    Institute of Scientific and Technical Information of China (English)

    GU Rui-jie; YANG He; ZHAN Mei; LI Heng

    2006-01-01

    Elongation and springback are the bottleneck problems of thin-walled aluminum alloy tube NC precision bending. So thin-walled aluminum alloy tube NC precision bending based on finite element simulation is put forward. The finite element model of thin-walled aluminum alloy tube NC bending is established based on the DYNAFORM platform. The process of thin-walled aluminum alloy tube NC precision bending is simulated with the model and the elongation and springback of tube bending can be is put forward and the computing equations of bending angle, bending radius, blanking length and initial bending section based on elongation and springback angle are derived. The bending angle, bending radius, blanking length and initial bending section of tube bending can be gained with these equations based on the elongation and springback angle from the simulation. The study can be used to control the quality of thin-walled aluminum alloy tube NC bending so that precision bending without redundance can be realized.

  16. Interface structure and formation mechanism of diffusion-bonded joints of TiAl-based alloy to titanium alloy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Vacuum diffusion bonding of a TiAl-based alloy (TAD) to a titanium alloy (TC2) was carried out at 1 273 K for 15~120 min under a pressure of 25 MPa. The kinds of the reaction products and the interface structures of the joints were investigated by SEM, EPMA and XRD. Based on this, a formation mechanism of the interface structure was elucidated. Experimental and analytical results show that two reaction layers have formed during the diffusion bonding of TAD to TC2. One is Al-rich α(Ti)layer adjacent to TC2,and the other is (Ti3Al+TiAl)layer adjacent to TAD,thus the interface structure of the TAD/TC2 joints is TAD/(Ti3Al+TiAl)/α(Ti)/TC2.This interface structure forms according to a three-stage mechanism,namely(a)the occurrence of a single-phase α(Ti)layer;(b)the occurrence of a duplex-phase(Ti3Al+TiAl)layer;and(c)the growth of the α(Ti)and (Ti3Al+TiAl)layers.

  17. Room temperature synthesis of Ni-based alloy nanoparticles by radiolysis.

    Energy Technology Data Exchange (ETDEWEB)

    Nenoff, Tina Maria; Berry, Donald T.; Lu, Ping; Leung, Kevin; Provencio, Paula Polyak; Stumpf, Roland Rudolph; Huang, Jian Yu; Zhang, Zhenyuan

    2009-09-01

    Room temperature radiolysis, density functional theory, and various nanoscale characterization methods were used to synthesize and fully describe Ni-based alloy nanoparticles (NPs) that were synthesized at room temperature. These complementary methods provide a strong basis in understanding and describing metastable phase regimes of alloy NPs whose reaction formation is determined by kinetic rather than thermodynamic reaction processes. Four series of NPs, (Ag-Ni, Pd-Ni, Co-Ni, and W-Ni) were analyzed and characterized by a variety of methods, including UV-vis, TEM/HRTEM, HAADF-STEM and EFTEM mapping. In the first focus of research, AgNi and PdNi were studied. Different ratios of Ag{sub x}- Ni{sub 1-x} alloy NPs and Pd{sub 0.5}- Ni{sub 0.5} alloy NP were prepared using a high dose rate from gamma irradiation. Images from high-angle annular dark-field (HAADF) show that the Ag-Ni NPs are not core-shell structure but are homogeneous alloys in composition. Energy filtered transmission electron microscopy (EFTEM) maps show the homogeneity of the metals in each alloy NP. Of particular interest are the normally immiscible Ag-Ni NPs. All evidence confirmed that homogeneous Ag-Ni and Pd-Ni alloy NPs presented here were successfully synthesized by high dose rate radiolytic methodology. A mechanism is provided to explain the homogeneous formation of the alloy NPs. Furthermore, studies of Pd-Ni NPs by in situ TEM (with heated stage) shows the ability to sinter these NPs at temperatures below 800 C. In the second set of work, CoNi and WNi superalloy NPs were attempted at 50/50 concentration ratios using high dose rates from gamma irradiation. Preliminary results on synthesis and characterization have been completed and are presented. As with the earlier alloy NPs, no evidence of core-shell NP formation occurs. Microscopy results seem to indicate alloying occurred with the CoNi alloys. However, there appears to be incomplete reduction of the Na{sub 2}WO{sub 4} to form the W

  18. Guinier-Preston Zone, Quasicrystal and Long-period Stacking Ordered Structure in Mg-based Alloys, A Review

    Institute of Scientific and Technical Information of China (English)

    Yongbo XU; Daokui XU; Xiaohong SHAO; En-hou HAN

    2013-01-01

    Both the solid solution and precipitation are mainly strengthening mechanism for the magnesium-based alloys.A great number of alloying elements can be dissolved into the Mg matrix to form the solutes and precipitates.Moreover,the type of precipitates varies with different alloying elements and heat treatments,which makes it quite difficult to understand the formation mechanism of the precipitates in Mg-based alloys in depth.Thus,it is very hard to give a systematical regularity in precipitation process for the Mg-based alloys.This review is mainly focused on the formation and microstructural evolution of the precipitates,as a hot topic for the past few years,including Guinier-Preston Zones,quasicrystals and long-period stacking ordered phases formed in a number of Mg-TM-RE alloy systems,where TM =AI,Zn,Zr and RE =Y,Gd,Hd,Ce and La.

  19. Crystallization in Fe- and Co-Based Amorphous Alloys Studied by In-Situ X-Ray Diffraction

    Science.gov (United States)

    Zhang, L. J.; Yu, P. F.; Cheng, H.; Zhang, M. D.; Liu, D. J.; Zhou, Z.; Jin, Q.; Liaw, P. K.; Li, G.; Liu, R. P.

    2016-12-01

    The amorphous alloys, Fe80Si20, Fe78Si9B13, and Fe4Co67Mo1.5Si16.5B11, were prepared by the spinning method in pure argon. The crystallization behaviors of the three amorphous alloys were researched by in-situ X-ray diffraction (XRD), and the crystallization activation energy was calculated, based on the results of differential scanning calorimetry. The crystallization mechanism of the Fe- and Co-based alloys was analyzed, based on the experimental data. The transformation kinetics was described in terms of Johnson-Mehl-Avrami kinetics, except that the Avrami exponent of the Fe78Si9B13 amorphous alloy annealed at 753 K (480 °C) was 4.12; the obtained values for the overall Avrami exponents of the other three amorphous alloys were below 1, as usually found for the Fe-Si amorphous alloys.

  20. Effects of can parameters on canned-forging process of TiAl base alloy(Ⅰ)--Microstructural analyses

    Institute of Scientific and Technical Information of China (English)

    刘咏; 韦伟峰; 黄伯云; 何双珍; 周科朝; 贺跃辉

    2002-01-01

    By using thermal simulation technique, the conventional canned-forging process of TiAl based alloy was studied. The effect of can parameters on the microstruct ures of TiAl alloy was analyzed in this process. The results show that, the defo rmation microstructure of TiAl based alloy without canning is inhomogeneous. In lateral area, crack and shearing lines can be found; while in central area, fine -grained shearing zone can be found. The effect of can is to reduce the seconda ry tensile stress. However, only when the deformation of the steel can is coinci dental with that of TiAl alloy ingot, can this effect be effective. Moreover, a thick can would enhance the microstructural homogeneity in TiAl based alloy. With the H/D ratio of the ingot increasing, the deformation of TiAl alloy would be more unsteady, therefore, a thicker can should be needed.

  1. Oxygen Behavior in Bulk Amorphous Zr-base Alloy

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Bulk Zr55Al10Ni5Cu30 metallic glass plates with a dimension of 85 mm×35mm×4 mm and a complicated plate werefabricated by injecting casting method using spongy zirconium and industrial purity aluminum, nickel and copper asraw materials. It was shown that the holding time of liquid metals at elevated temperatures had a great influence onthe oxygen content of the plates due to the contamination resulting from the atmosphere. Increasing holding timeresulted in the increase of oxygen content in the injected alloy. The glass transition temperatures of the bulk metallicglass plates are higher than that reported in the literature and crystallization temperature is lower for the one withhigher oxygen content at the same heating rate. The extension of the undercooled liquid region △Tx reaching about87 K is 3 K higher than that previously reported and 26 K higher than that with oxygen content of 0.076 wt pct forthe one with oxygen content as high as 0.065 wt pct. Therefore the oxygen content of the alloy has a significantinfluence on the glass forming ability and thermal stability of bulk metal glass. It is suggested that direct correlationbetween high glass forming ability and large △Tx is only valid for a well-defined Iow oxygen concentration or has tobe reconsidered by incorporating oxygen as an additional alloying element.

  2. Tetragonal Heusler-Like Mn-Ga Alloys Based Perpendicular Magnetic Tunnel Junctions

    Science.gov (United States)

    Ma, Qinli; Sugihara, Atsushi; Suzuki, Kazuya; Zhang, Xianmin; Miyazaki, Terunobu; Mizukami, Shigemi

    2014-10-01

    Films of the Mn-based tetragonal Heusler-like alloys, such as Mn-Ga, exhibit a large perpendicular magnetic anisotropy (PMA), small damping constant, small saturation magnetization and large spin polarizations. These properties are attractive for the application to the next generation high density spin-transfer-torque (STT) magnetic random access memory (STT-MRAM). We reviewed the structure, magnetic properties and Gilbert damping of the alloy films with large PMA, and the current status of research on tunnel magnetoresistance (TMR) in perpendicular magnetic tunnel junctions (p-MTJs) based on Mn-based tetragonal Heusler-like alloy electrode, and also discuss the issues for the application of those to STT-MRAM.

  3. Characterization of plasma sprayed beryllium ITER first wall mockups

    Energy Technology Data Exchange (ETDEWEB)

    Castro, R.G.; Vaidya, R.U.; Hollis, K.J. [Los Alamos National Lab., NM (United States). Material Science and Technology Div.

    1998-01-01

    ITER first wall beryllium mockups, which were fabricated by vacuum plasma spraying the beryllium armor, have survived 3000 thermal fatigue cycles at 1 MW/m{sup 2} without damage during high heat flux testing at the Plasma Materials Test Facility at Sandia National Laboratory in New Mexico. The thermal and mechanical properties of the plasma sprayed beryllium armor have been characterized. Results are reported on the chemical composition of the beryllium armor in the as-deposited condition, the through thickness and normal to the through thickness thermal conductivity and thermal expansion, the four-point bend flexure strength and edge-notch fracture toughness of the beryllium armor, the bond strength between the beryllium armor and the underlying heat sink material, and ultrasonic C-scans of the Be/heat sink interface. (author)

  4. Influence of Cumulative Plastic Deformation on Microstructure of the Fe-Al Intermetallic Phase Base Alloy

    Directory of Open Access Journals (Sweden)

    Bednarczyk I.

    2014-10-01

    Full Text Available This article is part of the research on the microstructural phenomena that take place during hot deformation of intermetallic phase-based alloy. The research aims at design an effective thermo - mechanical processing technology for the investigated intermetallic alloy. The iron aluminides FeAl have been among the most widely studied intermetallics because their low cost, low density, good wear resistance, easy of fabrication and resistance to oxidation and corrosion. There advantages create wide prospects for their industrial applications for components of machines working at a high temperature and in corrosive environment. The problem restricting their application is their low plasticity and their brittle cracking susceptibility, hampers their development as construction materials. Consequently, the research of intermetallic-phase-based alloys focuses on improvement their plasticity by hot working proceses. The study addresses the influence of deformation parameters on the structure of an Fe-38% at. Al alloy with Zr, B Mo and C microadditions, using multi – axis deformation simulator. The influence of deformation parameters on microstructure and substructure was determined. It was revealed that application of cumulative plastic deformation method causes intensive reduction of grain size in FeAl phase base alloy.

  5. The strengthening mechanism of a nickel-based alloy after laser shock processing at high temperatures

    Directory of Open Access Journals (Sweden)

    Yinghong Li, Liucheng Zhou, Weifeng He, Guangyu He, Xuede Wang, Xiangfan Nie, Bo Wang, Sihai Luo and Yuqin Li

    2013-01-01

    Full Text Available We investigated the strengthening mechanism of laser shock processing (LSP at high temperatures in the K417 nickel-based alloy. Using a laser-induced shock wave, residual compressive stresses and nanocrystals with a length of 30–200 nm and a thickness of 1 μm are produced on the surface of the nickel-based alloy K417. When the K417 alloy is subjected to heat treatment at 900 °C after LSP, most of the residual compressive stress relaxes while the microhardness retains good thermal stability; the nanocrystalline surface has not obviously grown after the 900 °C per 10 h heat treatment, which shows a comparatively good thermal stability. There are several reasons for the good thermal stability of the nanocrystalline surface, such as the low value of cold hardening of LSP, extreme high-density defects and the grain boundary pinning of an impure element. The results of the vibration fatigue experiments show that the fatigue strength of K417 alloy is enhanced and improved from 110 to 285 MPa after LSP. After the 900 °C per 10 h heat treatment, the fatigue strength is 225 MPa; the heat treatment has not significantly reduced the reinforcement effect. The feature of the LSP strengthening mechanism of nickel-based alloy at a high temperature is the co-working effect of the nanocrystalline surface and the residual compressive stress after thermal relaxation.

  6. Effects of AI Addition on the Thermoelectric Properties of Zn-Sb Based Alloys

    Institute of Scientific and Technical Information of China (English)

    CUI Jiaolin; LIU Xianglian; YANG Wei; CHEN Dongyong; MAO Liding; QIAN Xin

    2009-01-01

    The β-Zn4Sb3, emerged as a compelling p-type thermoelectric material, is widely used in heat-electricity conversion in the 400-650 K range. In order to probe the effects of slight doping on the crystal structure and physical properties, we prepared the samples of Al-added Zn-Sb based alloys by spark plasma sintering and evaluated their microstructures and thermoelectric properties. After a limited Al addition into the Zn-Sb based alloys we observed many phases in the alloys, which include a major phase β-Zn4Sb3,intermetallic phases ZnSb and AISb. The major β-Zn4Sb3 phase plays a fundamental role in controlling the thermoelectric performance, the precipitated phases ZnSb and AISb are of great importance to tailor the transport properties, such as the gradual enhancement of lattice thermal conductivity, in spite of an increased phonon scattering in additional grain boundaries. The highest thermoelectric figure of merit of 0.55 is obtained for the alloy with a limited AI addition at 653 K, which is 0.08 higher than that of un-doped β-Zn4Sb3 at the corresponding temperature. Physical property experiments indicate that there is a potentiality for the improvement of thermoelectric properties if a proper elemental doping is carried out into the Zn-Sb based alloys, which was confirmed by AI addition in the present work.

  7. Plasma cleaning of beryllium coated mirrors

    Science.gov (United States)

    Moser, L.; Marot, L.; Steiner, R.; Newman, M.; Widdowson, A.; Ivanova, D.; Likonen, J.; Petersson, P.; Pintsuk, G.; Rubel, M.; Meyer, E.; Contributors, JET

    2016-02-01

    Cleaning systems of metallic first mirrors are needed in more than 20 optical diagnostic systems from ITER to avoid reflectivity losses. Currently, plasma sputtering is considered as one of the most promising techniques to remove deposits coming from the main wall (mainly beryllium and tungsten). This work presents the results of plasma cleaning of rhodium and molybdenum mirrors exposed in JET-ILW and contaminated with typical tokamak elements (including beryllium and tungsten). Using radio frequency (13.56 MHz) argon or helium plasma, the removal of mixed layers was demonstrated and mirror reflectivity improved towards initial values. The cleaning was evaluated by performing reflectivity measurements, scanning electron microscopy, x-ray photoelectron spectroscopy and ion beam analysis.

  8. Electronic bistability in linear beryllium chains.

    Science.gov (United States)

    Helal, Wissam; Monari, Antonio; Evangelisti, Stefano; Leininger, Thierry

    2009-04-30

    A theoretical investigation on the mixed-valence behavior (bistability) of a series of cationic linear chains composed of beryllium atoms, Be(N)(+) (with N = 6,..., 12), is presented. The calculations were performed at CAS-SCF and MR-CI levels by using an ANO basis set containing 6s4p3d2f orbitals for each atom. Our results show a consistent gradual shift between different classes of mixed-valence compounds as the number of beryllium atoms increases, from class III strong coupling toward class II valence trapped. Indeed, in the largest cases (N > 10), the cationic chains were found to be closer to class I, where the coupling vanishes. The intramolecular electron transfer parameters V(ab), E(a), and E(opt) were calculated for each atomic chain. It is shown that the decrease of V(ab) with increasing N follows an exponential pattern.

  9. Calculations for electron-impact excitation and ionization of beryllium

    CERN Document Server

    Zatsarinny, Oleg; Fursa, Dmitry V; Bray, Igor

    2016-01-01

    The B-spline R-matrix and the convergent close-coupling methods are used to study electron collisions with neutral beryllium over an energy range from threshold to 100 eV. Coupling to the target continuum significantly affects the results for transitions from the ground state, but to a lesser extent the strong transitions between excited states. Cross sections are presented for selected transitions between low-lying physical bound states of beryllium, as well as for elastic scattering, momentum transfer, and ionization. The present cross sections for transitions from the ground state from the two methods are in excellent agreement with each other, and also with other available results based on nonperturbative convergent pseudo-state and time-dependent close-coupling models. The elastic cross section at low energies is dominated by a prominent shape resonance. The ionization from the $(2s2p)^3P$ and $(2s2p)^1P$ states strongly depends on the respective term. The current predictions represent an extensive set o...

  10. Influence of aluminium content on the physical, mechanical and sliding wear properties of zinc-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, B.K. [CSIR, Bhopal (India). Regional Res. Lab.; Patwardhan, A.K. [Roorkee Univ. (India). Dept. of Metallurgical Engineering; Yegneswaran, A.H. [CSIR, Bhopal (India). Regional Res. Lab.

    1997-04-01

    Attention has been focussed on the influence of Al content on the physical, mechanical and sliding wear properties of Zn-based alloys. Aspects studied include microstructure, density, electrical conductivity, hardness, tensile strength and elongation as well as sliding wear response of the alloys. Microstructural features of the alloys showed the presence of primary {alpha}, eutectic/eutectoid {alpha} + {eta} (depending on whether the alloy was hypereutectic/hypereutectoid with regard to the concentration of Al) along with the meta stable {epsilon} phase. The study suggests that it is possible to design and develop Zn-based alloys with a wide range of concentration of Al. The alloys in turn attain different combinations of physical, mechanical and wear properties which could suit a variety of engineering applications. Increasing the Al content in the alloy system proves beneficial within limits. In other words, there exists an optimum quantity of Al which could reap its advantage to the maximum extent. This of course varies with reference to a specific property of the alloy(s). The changing response of the alloys has been explained in terms of their microstructural features and the effects produced as a result of the test conditions maintained while characterizing the specimens. (orig.)

  11. Novel Zn-based alloys for biodegradable stent applications: Design, development and in vitro degradation.

    Science.gov (United States)

    Mostaed, E; Sikora-Jasinska, M; Mostaed, A; Loffredo, S; Demir, A G; Previtali, B; Mantovani, D; Beanland, R; Vedani, M

    2016-07-01

    The search for a degradable metal simultaneously showing mechanical properties equal or higher to that of stainless steel and uniform degradation is still an open challenge. Several magnesium-based alloys have been studied, but their degradation rate has proved to be too fast and rarely homogeneous. Fe-based alloys show appropriate mechanical properties but very low degradation rate. In the present work, four novel Zn-Mg and two Zn-Al binary alloys were investigated as potential biodegradable materials for stent applications. The alloys were developed by casting process and homogenized at 350°C for 48h followed by hot extrusion at 250°C. Tube extrusion was performed at 300°C to produce tubes with outer/inner diameter of 4/1.5mm as precursors for biodegradable stents. Corrosion tests were performed using Hanks׳ modified solution. Extruded alloys exhibited slightly superior corrosion resistance and slower degradation rate than those of their cast counterparts, but all had corrosion rates roughly half that of a standard purity Mg control. Hot extrusion of Zn-Mg alloys shifted the corrosion regime from localized pitting to more uniform erosion, mainly due to the refinement of second phase particles. Zn-0.5Mg is the most promising material for stent applications with a good combination of strength, ductility, strain hardening exponent and an appropriate rate of loss of mechanical integrity during degradation. An EBSD analysis in the vicinity of the laser cut Zn-0.5Mg tube found no grain coarsening or texture modification confirming that, after laser cutting, the grain size and texture orientation of the final stent remains unchanged. This work shows the potential for Zn alloys to be considered for stent applications.

  12. Quantitative method of determining beryllium or a compound thereof in a sample

    Energy Technology Data Exchange (ETDEWEB)

    McCleskey, T. Mark (Los Alamos, NM); Ehler, Deborah S. (Los Alamos, NM); John, Kevin D. (Santa Fe, NM); Burrell, Anthony K. (Los Alamos, NM); Collis, Gavin E. (Los Alamos, NM); Minogue, Edel M. (Los Alamos, NM); Warner, Benjamin P. (Los Alamos, NM)

    2010-08-24

    A method of determining beryllium or a beryllium compound thereof in a sample, includes providing a sample suspected of comprising beryllium or a compound thereof, extracting beryllium or a compound thereof from the sample by dissolving in a solution, adding a fluorescent indicator to the solution to thereby bind any beryllium or a compound thereof to the fluorescent indicator, and determining the presence or amount of any beryllium or a compound thereof in the sample by measuring fluorescence.

  13. Quantitative method of determining beryllium or a compound thereof in a sample

    Energy Technology Data Exchange (ETDEWEB)

    McCleskey, T. Mark; Ehler, Deborah S.; John, Kevin D.; Burrell, Anthony K.; Collis, Gavin E.; Minogue, Edel M.; Warner, Benjamin P.

    2006-10-31

    A method of determining beryllium or a beryllium compound thereof in a sample, includes providing a sample suspected of comprising beryllium or a compound thereof, extracting beryllium or a compound thereof from the sample by dissolving in a solution, adding a fluorescent indicator to the solution to thereby bind any beryllium or a compound thereof to the fluorescent indicator, and determining the presence or amount of any beryllium or a compound thereof in the sample by measuring fluorescence.

  14. Beryllium induces premature senescence in human fibroblasts.

    Science.gov (United States)

    Coates, Shannon S A; Lehnert, Bruce E; Sharma, Sunil; Kindell, Susan M; Gary, Ronald K

    2007-07-01

    After cells have completed a sufficient number of cell divisions, they exit the cell cycle and enter replicative senescence. Here, we report that beryllium causes proliferation arrest with premature expression of the principal markers of senescence. After young presenescent human fibroblasts were treated with 3 microM BeSO(4) for 24 h, p21 cyclin-dependent kinase inhibitor mRNA increased by >200%. Longer periods of exposure caused mRNA and protein levels to increase for both p21 and p16(Ink4a), a senescence regulator that prevents pRb-mediated cell cycle progression. BeSO(4) also caused dose-dependent induction of senescence-associated beta-galactosidase activity (SA-beta-gal). Untreated cells had 48 relative fluorescence units (RFU)/microg/h of SA-beta-gal, whereas 3 microM BeSO(4) caused activity to increase to 84 RFU/microg/h. In chromatin immunoprecipitation experiments, BeSO(4) caused p53 protein to associate with its DNA binding site in the promoter region of the p21 gene, indicating that p53 transcriptional activity is responsible for the large increase in p21 mRNA elicited by beryllium. Forced expression of human telomerase reverse transcriptase (hTERT) rendered HFL-1 cells incapable of normal replicative senescence. However, there was no difference in the responsiveness of normal HFL-1 fibroblasts (IC(50) = 1.9 microM) and hTERT-immortalized cells (IC(50) = 1.7 microM) to BeSO(4) in a 9-day proliferation assay. The effects of beryllium resemble those of histone deacetylase-inhibiting drugs, which also cause large increases in p21. However, beryllium produced no changes in histone acetylation, suggesting that Be(2+) acts as a novel and potent pharmacological inducer of premature senescence.

  15. Computer simulation of electronic excitations in beryllium

    CERN Document Server

    Popov, A V

    2016-01-01

    An effective method for the quantitative description of the electronic excited states of polyatomic systems is developed by using computer technology. The proposed method allows calculating various properties of matter at the atomic level within the uniform scheme. A special attention is paid to the description of beryllium atoms interactions with the external fields, comparable by power to the fields in atoms, molecules and clusters.

  16. Effect of rhenium on short term oxidation of niobium based alloys for high temperature applications

    Science.gov (United States)

    Sierra, Ruth M.

    The effect of adding Re to Nb-based alloys and is intended to analyze in depth the microstructures of Nb based alloys with Re, Si and Cr additions, in atomic percentages. The binary alloys (Nb-5Re, Nb-5Si and Nb-5Cr) reveal the formation of a single phase, NbSS, NbSS + Nb3Si and NbSS+NbCr2 respectively. The formation of the single phase was confirmed by TEM studies for the Nb-5Re alloy. Addition of Re to form ternary alloys, has helped in the formation of Nb5Si 3 and (Nb, Re) Cr2, in Nb-5Re- 5Si and Nb-5Re-5Cr respectively. Quaternary alloy Nb-5Re-5Si-5Cr has Nb5Si3, NbCr2 and NbSS. The oxidation behavior has been studied and the formation of the oxides has been characterized using XRD, SEM, EDS. Nb-Re-Si-Cr-X (Al, B, W) alloy system has been examined at temperatures between 700 and 1400°C in air. The continued work was to develop and discover a new materials system capable of replacing nickel based super alloys. Additions of aluminum were found to provide limited oxidation resistance. A discontinuous layer of Al2O3 and SiO2 was observed to form at all temperatures adapted for this study. Alloy containing aluminum additions were observed to suffer from pest oxidation at intermediate temperatures due to the development of Nb2O5. Poor oxidation resistance at intermediate temperatures for alloys with aluminum additions was attributed to a transformation in the structure of Nb2O5 formed. Pesting was observed at 900°C, consuming the metal completely. Additions of chromium were observed to increase oxidation resistance through the development of a layered oxide structure containing SiO2 and CrNbO4. Internal oxidation layer was observed to develop oxides in the midst of the phases formed. Boron addition has helped in the formation of the 3, 5 silicides, NbSS, and Laves phase. The combination of oxides of Nb2O5, CrNbO4 and SiO2 has helped improve the oxidation resistance of the alloy. Rhenium in this alloy has been a major element in terms of forming Re-oxides which has

  17. A corrosion resistant cerium oxide based coating on aluminum alloy 2024 prepared by brush plating

    Energy Technology Data Exchange (ETDEWEB)

    Tang Junlei; Han Zhongzhi [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zuo Yu, E-mail: zuoy@mail.buct.edu.cn [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Tang Yuming [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2011-01-15

    Cerium oxide based coatings were prepared on AA2024 Al alloy by brush plating. The characteristic of this technology is that hydrogen peroxide, which usually causes the plating solution to be unstable, is not necessary in the plating electrolyte. The coating showed laminated structures and good adhesive strength with the substrate. X-ray diffraction and X-ray photoelectron spectroscopy analysis showed that the coatings were composed of Ce(III) and Ce(IV) oxides. The brush plated coatings on Al alloys improved corrosion resistance. The influence of plating parameters on structure and corrosion resistance of the cerium oxide based coating was studied.

  18. The fluidity and molding ability of glass-forming Zr-based alloy melt

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The fluidity and filling ability of glass-forming Zr-based alloy melt in copper mould were investigated both theoretically and experimentally. The major factors which affected the flowing behavior of the metallic melt in the mold were determined,which provides the foundation for overcoming the contradiction between the filling and formation of amorphous alloy during the rapid cooling process of the metallic melts. The casting factors to prepare a metallic ring were discussed and selected. As a result,a Zr-based bulk metallic glass ring was prepared successfully.

  19. Ultrahigh performance of Ti-based glassy alloy tube sensor for Coriolis mass flowmeter

    Institute of Scientific and Technical Information of China (English)

    MA Chao-li; A. INOUE; ZHANG Tao

    2006-01-01

    Bulk metallic glasses (BMGs) have potential applications for both structural and functional components owing to their good mechanical properties. With the aim of demonstrating great engineering value of BMGs, a direct melt-forming technique based on suction casting for the production of glassy alloy tubes was developed. The fabrication, structure, geometry, properties and sensor performance of the tubes were examined. The results show that the Coriolis mass flowmeters using the Ti-based glassy alloy sensor tube exhibit excellent measurement sensitivity, viz. 28.5 times higher than that of the conventional flowmeter manufactured using stainless steel (SUS316) tube.

  20. AFM research on the mechanism of Fe-based alloy stress annealed inducing magnetic anisotropy

    Institute of Scientific and Technical Information of China (English)

    FANG YunZhang; ZHENG JinJu; SHI FangYe; WU FengMin; SUN HuaiJun; LIN GenJin; YANG XiaoHong; MAN QiKui; YE FangMin

    2008-01-01

    The cross-section of the Fe-based alloy (Fe73.5Cu1Nb3Si13.5B9) ribbon annealed at 540℃ under various tensile stress was investigated with atomic force microscope (AFM). The stress effect mechanism in Fe-based alloy ribbon tensile stress an- nealed inducing transverse magnetic anisotropy field was studied using the X-ray diffraction spectra and longitudinal drive giant magneto-impedance effect curves, and the model of direction dominant in encapsulated grain agglomeration was es- tablished. The relationship between the direction dominant in encapsulated grain agglomeration and magnetic anisotropy field was disclosed.

  1. Irradiation effects in oxide dispersion strengthened (ODS) Ni-base alloys for Gen. IV nuclear reactors

    Science.gov (United States)

    Oono, Naoko; Ukai, Shigeharu; Kondo, Sosuke; Hashitomi, Okinobu; Kimura, Akihiko

    2015-10-01

    Oxide particle dispersion strengthened (ODS) Ni-base alloys are irradiated by using simulation technique (Fe/He dual-ion irradiation) to investigate the reliability to Gen. IV high-temperature reactors. The fine oxide particles with less than 10 nm in average size and approximately 8.0 × 1022 m-3 in number density remained after 101 dpa irradiation. The tiny helium bubbles were inside grains, not at grain-boundaries; it is advantageous effect of oxide particles which trap the helium atoms at the particle-matrix interface. Ni-base ODS alloys demonstrated their great ability to overcome He embrittlement.

  2. Morphology and Magnetic Properties of Electrodeposited Iron and Nickel Based Alloy Foils

    Institute of Scientific and Technical Information of China (English)

    GUO Zhan-cheng; LIU Mei-feng; SUN Chun-wen; LIU Yu-xing; LU Wei-chang

    2004-01-01

    An alternative to conventional process for the preparation of soft magnetic metal foils of Fe, Fe-Ni, Fe-Co and Fe-Ni-Co by electroforming was described. The microstructure and magnetic properties were observed. The results showed that the crystal size of the iron-based alloy foil is less than 10 μm, while that of nickel-based alloy foil is about 2 μm. Moreover, the electroformed Fe-Ni foil has better magnetic properties than the conventional milled permalloy 1J79 foil.

  3. AFM research on the mechanism of Fe-based alloy stress annealed inducing magnetic anisotropy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The cross-section of the Fe-based alloy (Fe73.5Cu1Nb3Si13.5B9) ribbon annealed at 540℃ under various tensile stress was investigated with atomic force microscope (AFM). The stress effect mechanism in Fe-based alloy ribbon tensile stress an-nealed inducing transverse magnetic anisotropy field was studied using the X-ray diffraction spectra and longitudinal drive giant magneto-impedance effect curves, and the model of direction dominant in encapsulated grain agglomeration was es-tablished. The relationship between the direction dominant in encapsulated grain agglomeration and magnetic anisotropy field was disclosed.

  4. Assessment Of Usability Of Molten Salt Mixtures In Metallurgy Of Aluminum Alloys And Recycling Of Composite Materials Based On The Matrix Of Al Alloys

    Directory of Open Access Journals (Sweden)

    Jackowski J.

    2015-09-01

    Full Text Available Effectiveness of the slags used in metallurgy of aluminum alloys and in recycling of composite materials containing these alloys depends on their surface properties at the phase boundaries they are in contact with. An index of surface properties of molten mixtures of slag-forming salts has been formulated. Its calculated values are compared with measured results of surface tension (liquid – atmosphere and interfacial tension (liquid – liquid in the considered systems. It was found that the index can be helpful for purposes of proper choice of the mixtures of slag-forming salts used both in Al alloys metallurgy and in recycling of composite materials based on the matrix of Al alloys.

  5. A NEAR REAL-TIME BERYLLIUM MONITOR WITH CAM AND WIPE ANALYSIS CAPABILITIES

    Energy Technology Data Exchange (ETDEWEB)

    D.T. Kendrick; Steven Saggese

    2002-12-01

    Science & Engineering Associates, Inc. (SEA), under contract No. DE-AC26-00NT40768, was tasked by the US Department of Energy--National Energy Technology Laboratory to develop and test a near real-time beryllium monitor for airborne and surface measurements. Recent public awareness of the health risks associated with exposure to beryllium has underscored the need for better, faster beryllium monitoring capabilities within the DOE. A near real-time beryllium monitor will offer significant improvements over the baseline monitoring technology currently in use. Whereas the baseline technology relies upon collecting an air sample on a filter and the subsequent analysis of the filter by an analytical laboratory, this effort developed a monitor that offers near real-time measurement results while work is in progress. Since the baseline typically only offers after-the-fact documentation of exposure levels, the near real-time capability provides a significant increase in worker protection. The beryllium monitor developed utilizes laser induced breakdown spectroscopy, or LIBS as the fundamental measurement technology. LIBS has been used in a variety of laboratory and field based instrumentation to provide real-time, and near-real-time elemental analysis capabilities. LIBS is an analytical technique where a pulsed high energy laser beam is focused to a point on the sample to be interrogated. The high energy density produces a small high temperature plasma plume, sometimes called a spark. The conditions within this plasma plume result in the constituent atoms becoming excited and emitting their characteristic optical emissions. The emission light is collected and routed to an optical spectrometer for quantitative spectral analysis. Each element has optical emissions, or lines, of a specific wavelength that can be used to uniquely identify that element. In this application, the intensity of the beryllium emission is used to provide a quantitative measure of the abundance of the

  6. Effects of Er:YAG laser treatments on surface roughness of base metal alloys.

    Science.gov (United States)

    Kunt, Göknil Ergün; Güler, Ahmet Umut; Ceylan, Gözlem; Duran, Ibrahim; Ozkan, Pelin; Kirtiloğlu, Tuğrul

    2012-01-01

    We investigated the effects of different Er:YAG laser treatments on the surface roughness of base metal alloys. A total of 36 specimens were prepared of two base metal alloys (Wiron 99, Bellabond plus). The surfaces of the specimens were standardized by gradual wet grinding with 320-, 600-, 800- and 1,000-grit silicon carbide paper for 10 s each on a grinding machine at 300 rpm. Specimens of each alloy were randomly divided into six groups (n = 6) comprising a control group (group C), a group sandblasted with Al(2)O(3) powder at 60 psi for 10 s through a nozzle at a distance of 10 mm (group S), and four Er:YAG laser (Fotona AT) treatment groups. The laser treatment groups were as follows: 500 mJ, 10 Hz, 100 μs (group 500MSP); 500 mJ, 10 Hz, 300 μs (group 500SP); 400 mJ, 10 Hz, 100 μs (group 400MSP); and 400 mJ, 10 Hz, 300 μs (group 400SP). Surface roughness measurements (Ra) were performed using a profilometer. The data were analysed by two-way ANOVA, and mean values were compared using Tukey's HSD test (α = 0.05). According to the two-way ANOVA results, the base metal alloys and interaction between base metal alloy and surface treatment were not statistically significant different (p > 0.05), the surface treatments were significantly different (p Er:YAG laser treatment at 400 and 500 mJ/10 Hz is not an alternative method for surface roughening of base metal alloys.

  7. Possible health risks from low level exposure to beryllium.

    Science.gov (United States)

    Stange, A W; Hilmas, D E; Furman, F J

    1996-07-17

    The first case of chronic beryllium disease (CBD) at the Rocky Flats Environmental Technology Site (Rocky Flats) was diagnosed in a machinist in 1984. Rocky Flats, located 16 miles northwest of Denver, Colorado, is part of the United States Department of Energy (DOE) nuclear weapons complex. Research and development operations using beryllium began at Rocky Flats in 1953, and beryllium production operations began in 1957. Exposures could have occurred during foundry operations, casting, shearing, rolling, cutting, welding, machining, sanding, polishing, assembly, and chemical analysis operations. The Beryllium Health Surveillance Program (BHSP) was established in June 1991 at Rocky Flats to provide health surveillance for beryllium exposed employees using the Lymphocyte Proliferation Test (LPT) to identify sensitized individuals. Of the 29 cases of CBD and 76 cases of beryllium sensitization identified since 1991, several cases appear to have had only minimal opportunistic exposures to beryllium, since they were employed in administrative functions rather than primary beryllium operations. In conjunction with other health surveillance programs, a questionnaire and interview are administered to obtain detailed work and health histories. These histories, along with other data, are utilized to estimate the extent of an individual's exposure. Additional surveillance is in progress to attempt to characterize the possible risks from intermittent or brief exposures to beryllium in the workplace.

  8. Disposal of beryllium and cadmium from research reactors; Entsorgung von Beryllium und Cadmium aus Forschungsreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Lierse von Gostomski, C.; Remmert, A.; Stoewer, W. [Inst. fuer Radiochemie, Technische Univ. Muenchen, Garching (Germany); Bach, F.W.; Wilk, P.; Kutlu, I. [Inst. fuer Werkstoffkunde, Univ. Hannover, Hannover (Germany); Blenski, H.J.; Berthold, M. [Gesellschaft fuer Nuklear-Service mbH, Essen (Germany); Nerlich, K.D.; Plank, W. [TUeV Sueddeutschland Bau und Betrieb GmbH, Muenchen (Germany)

    2003-07-01

    Beryllium and cadmium mostly occur in metal form as radioactive special materials during the deconstruction of research reactors. Beryllium is usually used in these reactors as a neutron reflector and moderator, while cadmium is used above all as a neutron absorber. Both metals together have a high chemotoxicity as well as an inventory of radionuclides which has not been more closely characterised up to now. A high tritium content is to be expected, particularly in the case of beryllium; this tritium is due to the reaction of the metal with thermal reactor neutrons in particular. However, other nuclides which may be formed by neutron capture from impurities also contribute to the activity inventory. Up to now there is no qualified process for proper treatment, conditioning and intermediate and final repository in Germany. (orig.)

  9. Experimental research of optical fiber hydrogen gas sensing system based on palladium-silver alloy

    Science.gov (United States)

    Cui, Lu-jun; Zhou, Gao-feng; Li, Zheng-feng; Cao, Yan-long

    2016-11-01

    A novel optical fiber hydrogen sensing system based on palladium (Pd) and sliver (Ag) is proposed. By direct current (DC) magnetron process, Pd/Ag alloy ultra-thin films were deposited on the substrate to eliminate the hydrogen embrittlement of sensor based on pure Pd. Several samples with different thin film thicknesses were fabricated at different substrate temperatures and tested in the optical fiber hydrogen sensor setup. We do a series of experiments for obtaining optimum sputtering parameters, such as optimum sputtering temperature and thickness of Pd/Ag alloy film. The humidity effect and reliability experiment for the optical fiber hydrogen gas sensor are reported in detail. The testing results demonstrate the Pd/Ag alloy is a promising material for optical fiber hydrogen gas sensor.

  10. Tensile properties of a nickel-base alloy subjected to surface severe plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Tian, J.W. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN (United States); Dai, K. [Quality Engineering and Software Technology, East Hartford, CT 06108 (United States); Villegas, J.C. [Intel Corporation, Chandler, AZ (United States); Shaw, L. [Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, Storrs, CT (United States)], E-mail: leon.shaw@uconn.edu; Liaw, P.K. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN (United States); Klarstrom, D.L. [Haynes International, Inc., Kokomo, IN (United States); Ortiz, A.L. [Departamento de Ingenieria Mecanica, Energetica y de los Materiales, Universidad de Extremadura, 06071 Badajoz (Spain)

    2008-10-15

    A surface severe plastic deformation (S{sup 2}PD) method has been applied to bulk specimens of HASTELLOY C-2000 alloy, a nickel-base alloy. The mechanical properties of the processed C-2000 alloy were determined via tensile tests and Vickers hardness measurements, whereas the microstructure was characterized using scanning electron microscopy, transmission electron microscopy, and X-ray diffractometry. The improved tensile strength was related to the nanostructure at the surface region, the residual compressive stresses, and the work-hardened surface layer, all of which resulted from the S{sup 2}PD process. To understand the contributions of these three factors, finite element modeling was performed. It was found that the improved tensile strength could be interpreted based on the contributions of nano-grains, residual stresses, and work hardening.

  11. Hydrogen absorption in uranium-based alloys with cubic γ -U structure

    Science.gov (United States)

    Havela, L.; Kim-Ngan, N.-T. H.

    2017-03-01

    UH3-type hydrides were formed by hydrogenation of splat-cooled U-based alloys upon applying high H2 pressures (>2.5 bar). Hydrogenation of U1‑x Mo x alloys (with x  ⩾  0.12 (12 at.% Mo) containing the cubic γ-U phase leads to a formation of nanocrystalline β-UH3, why those of U1‑x Zr x alloys (with x  ⩾15 at.% Zr) implies a pure α-UH3. The Curie temperature of hydride (UH3)0.85Mo0.15 reaches 200 K it may be the first U-based ferromagnet with such high T C. The results reflect the dominant U–H interaction. Invited talk at 8th International Workshop on Advanced Materials Science and Nanotechnology (IWAMSN2016), 8–12 November 2016, Ha Long City, Vietnam.

  12. Hydrogen gas sensor based on palladium and yttrium alloy ultrathin film

    Science.gov (United States)

    Yi, Liu; You-ping, Chen; Han, Song; Gang, Zhang

    2012-12-01

    Compared with the other hydrogen sensors, optical fiber hydrogen sensors based on thin films exhibits inherent safety, small volume, immunity to electromagnetic interference, and distributed remote sensing capability, but slower response characteristics. To improve response and recovery rate of the sensors, a novel reflection-type optical fiber hydrogen gas sensor with a 10 nm palladium and yttrium alloy thin film is fabricated. The alloy thin film shows a good hydrogen sensing property for hydrogen-containing atmosphere and a complete restorability for dry air at room temperature. The variation in response value of the sensor linearly increases with increased natural logarithm of hydrogen concentration (ln[H2]). The shortest response time and recovery response time to 4% hydrogen are 6 and 8 s, respectively. The hydrogen sensors based on Pd0.91Y0.09 alloy ultrathin film have potential applications in hydrogen detection and measurement.

  13. Evaluation of shape memory effect and damping characteristics of Cu–Al–Be–Mn shape memory alloys

    Directory of Open Access Journals (Sweden)

    A.G. Shivasiddaramaiah

    2016-09-01

    Full Text Available Among different shape memory alloys, copper (Cu based alloys were the most favourable alloys, because of their attaining price and good characteristic properties. In this present work different weight compositions of Cu–Al–Be–Mn shape memory alloys are considered and are in the range of 10–14 wt% of aluminium (Al, 0.4–0.5 wt% of beryllium (Be and 0.3–0.4 wt% of manganese (Mn and these alloys were synthesized by ingot metallurgy, which exhibits β-phase at higher temperatures, also demonstrates a shape memory effect (SME after quenching to room temperature. The Be, Mn and Al content was varied in different sets to study the shape memory effect and damping behaviour of the alloys by using differential scanning calorimetry and dynamic mechanical analyzer respectively. These alloys exhibit higher damping or internal friction in the martensitic condition and internal friction or damping peak in the transition zone.

  14. Progress in research on cold crucible directional solidification of titanium based alloys

    Directory of Open Access Journals (Sweden)

    Chen Ruirun

    2014-07-01

    Full Text Available Cold crucible directional solidification (CCDS is a newly developed technique, which combines the advantages of the cold crucible and continuous melting. It can be applied to directionally solidify reactive, high purity and refractory materials. This paper describes the principle of CCDS and its characteristics; development of the measurement and numerical calculation of the magnetic field, flow field and temperature field in CCDS; and the CCDS of Ti based alloys. The paper also reviews original data obtained by some scholars, including the present authors, reported in separate publications in recent years. In Ti based alloys, Ti6Al4V, TiAl alloys and high Nb-containing TiAl alloys, have been directionally solidified in different cold crucibles. The crosssections of the cold crucibles include round, near rectangular and square with different sizes. Tensile testing results show that the elongation of directionally solidified Ti6Al4V can be improved to 12.7% from as cast 5.4%. The strength and the elongation of the directionally solidified Ti47Al2Cr2Nb and Ti44Al6Nb1.0Cr2.0V are 650 MPa/3% and 602.5 MPa/1.20%, respectively. The ingots after CCDS can be used to prepare turbine or engine blades, and are candidates to replace Ni super-alloy at temperatures of 700 to 900 °C.

  15. Fabrication methods and applications of microstructured gallium based liquid metal alloys

    Science.gov (United States)

    Khondoker, M. A. H.; Sameoto, D.

    2016-09-01

    This review contains a comparative study of reported fabrication techniques of gallium based liquid metal alloys embedded in elastomers such as polydimethylsiloxane or other rubbers as well as the primary challenges associated with their use. The eutectic gallium-indium binary alloy (EGaIn) and gallium-indium-tin ternary alloy (galinstan) are the most common non-toxic liquid metals in use today. Due to their deformability, non-toxicity and superior electrical conductivity, these alloys have become very popular among researchers for flexible and reconfigurable electronics applications. All the available manufacturing techniques have been grouped into four major classes. Among them, casting by needle injection is the most widely used technique as it is capable of producing features as small as 150 nm width by high-pressure infiltration. One particular fabrication challenge with gallium based liquid metals is that an oxide skin is rapidly formed on the entire exposed surface. This oxide skin increases wettability on many surfaces, which is excellent for keeping patterned metal in position, but is a drawback in applications like reconfigurable circuits, where the position of liquid metal needs to be altered and controlled accurately. The major challenges involved in many applications of liquid metal alloys have also been discussed thoroughly in this article.

  16. Potentiality of the "Gum Metal" titanium-based alloy for biomedical applications.

    Science.gov (United States)

    Gordin, D M; Ion, R; Vasilescu, C; Drob, S I; Cimpean, A; Gloriant, T

    2014-11-01

    In this study, the "Gum Metal" titanium-based alloy (Ti-23Nb-0.7Ta-2Zr-1.2O) was synthesized by melting and then characterized in order to evaluate its potential for biomedical applications. Thus, the mechanical properties, the corrosion resistance in simulated body fluid and the in vitro cell response were investigated. It was shown that this alloy presents a very high strength, a low Young's modulus and a high recoverable strain by comparison with the titanium alloys currently used in medicine. On the other hand, all electrochemical and corrosion parameters exhibited more favorable values showing a nobler behavior and negligible toxicity in comparison with the commercially pure Ti taken as reference. Furthermore, the biocompatibility tests showed that this alloy induced an excellent response of MC3T3-E1 pre-osteoblasts in terms of attachment, spreading, viability, proliferation and differentiation. Consequently, the "Gum Metal" titanium-based alloy processes useful characteristics for the manufacturing of highly biocompatible medical devices.

  17. Neutronics Evaluation of Lithium-Based Ternary Alloys in IFE Blankets

    Energy Technology Data Exchange (ETDEWEB)

    Jolodosky, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fratoni, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-11-20

    Pre-conceptual fusion blanket designs require research and development to reflect important proposed changes in the design of essential systems, and the new challenges they impose on related fuel cycle systems. One attractive feature of using liquid lithium as the breeder and coolant is that it has very high tritium solubility and results in very low levels of tritium permeation throughout the facility infrastructure. However, lithium metal vigorously reacts with air and water and presents plant safety concerns. If the chemical reactivity of lithium could be overcome, the result would have a profound impact on fusion energy and associated safety basis. The overriding goal of this project is to develop a lithium-based alloy that maintains beneficial properties of lithium (e.g. high tritium breeding and solubility) while reducing overall flammability concerns. To minimize the number of alloy combinations that must be explored, only those alloys that meet certain nuclear performance metrics will be considered for subsequent thermodynamic study. The specific scope of this study is to evaluate the neutronics performance of lithium-based alloys in the blanket of an inertial confinement fusion (ICF) engine. The results of this study will inform the development of lithium alloys that would guarantee acceptable neutronics performance while mitigating the chemical reactivity issues of pure lithium.

  18. Cerium-Based, Intermetallic-Strengthened Aluminum Casting Alloy: High-Volume Co-product Development

    Science.gov (United States)

    Sims, Zachary C.; Weiss, D.; McCall, S. K.; McGuire, M. A.; Ott, R. T.; Geer, Tom; Rios, Orlando; Turchi, P. A. E.

    2016-07-01

    Several rare earth elements are considered by-products to rare earth mining efforts. By using one of these by-product elements in a high-volume application such as aluminum casting alloys, the supply of more valuable rare earths can be globally stabilized. Stabilizing the global rare earth market will decrease the long-term criticality of other rare earth elements. The low demand for Ce, the most abundant rare earth, contributes to the instability of rare earth extraction. In this article, we discuss a series of intermetallic-strengthened Al alloys that exhibit the potential for new high-volume use of Ce. The castability, structure, and mechanical properties of binary, ternary, and quaternary Al-Ce based alloys are discussed. We have determined Al-Ce based alloys to be highly castable across a broad range of compositions. Nanoscale intermetallics dominate the microstructure and are the theorized source of the high ductility. In addition, room-temperature physical properties appear to be competitive with existing aluminum alloys with extended high-temperature stability of the nanostructured intermetallic.

  19. Indoor environmental corrosion of Ag-based alloys in the Egyptian Museum (Cairo, Egypt)

    Science.gov (United States)

    Ingo, G. M.; Angelini, E.; Riccucci, C.; de Caro, T.; Mezzi, A.; Faraldi, F.; Caschera, D.; Giuliani, C.; Di Carlo, G.

    2015-01-01

    In this study, we have investigated the indoor environmental corrosion of Ag-based alloys after long-term exposure in a showcase of an exhibition room and in the open atmosphere at the Egyptian Museum of Cairo (Egypt). In order to simulate the corrosion processes that occur at the surface of archaeological artefacts, Ag-based alloys with chemical composition, metallurgical features and micro-chemical structure similar to those of ancient alloys have been purposely produced as sacrificial reference samples. Our findings show that corrosion phenomena on alloy surface are mainly caused by environmental sulphur and chlorine containing species that react in different ways depending on the exhibition conditions and on the alloy composition. This approach allows to identify the degradation agents and mechanisms that really take place at the surface of objects similar to ancient artefacts without the necessity of sampling them. Moreover, it is possible to get useful indications for the safe storage or exhibition of silver archaeological artefacts, their cleaning and conservation.

  20. A new approach to the hazard classification of alloys based on transformation/dissolution.

    Science.gov (United States)

    Skeaff, James M; Hardy, David J; King, Pierrette

    2008-01-01

    . For the other alloys, we developed a new critical surface area-toxic units (CSA-TU) approach to derive their GHS classification proposals. The CSA-TU approach can be readily applied to other multicomponent alloy systems, without the need to arbitrarily select a particular component among several as the determinant of toxicity. This paper shows how regulatory obligations, such as those mandated by REACH, can be met with a laboratory-based CSA-TU method for deriving hazard classification proposals for alloys, linking to attendant environmental protection management decisions. Drawing on T/D data derived from laboratory testing of the alloy itself, the CSA-TU approach can be applied to establish scientifically defensible decisions on hazard classification proposals for an alloy of interest. The resulting decisions can then be incorporated into environmental management measures in such jurisdictions as the European Union. Based on an approach developed specifically for alloys, the hazard classification decisions can be regarded as relevant, credible, and protective of the environment. Since alloys are usually more resistant to chemical attack than their components, this approach is a considerable improvement over the possibility provided for in the GHS of calculating a hazard classification level for an alloy from the classification levels of its components.

  1. Semi-solid metal processing of aluminum alloy A356 and magnesium alloy AZ91: Comparison based on metallurgical consideration

    Energy Technology Data Exchange (ETDEWEB)

    Kleiner, S.; Beffort, O. [Swiss Federal Laboratories for Materials Testing and Research, EMPA Thun, CH-3602 Thun (Switzerland); Ogris, E.; Uggowitzer, P.J. [Institute of Metallurgy, ETH Swiss Federal Institute of Technology, CH-8092 Zuerich (Switzerland)

    2003-09-01

    Thixocasting or rheocasting of AZ and AM magnesium alloys continues to be a problematic case in semi-solid processing. The comparison with the aluminum thixo alloy A356 shows that the metallurgical and physical properties of the Mg alloy AZ91 are little compatible with this technology: The conclusions from this study are of fundamental importance for future developments in this field of research. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  2. Boundary Engineering for the Thermoelectric Performance of Bulk Alloys Based on Bismuth Telluride.

    Science.gov (United States)

    Mun, Hyeona; Choi, Soon-Mok; Lee, Kyu Hyoung; Kim, Sung Wng

    2015-07-20

    Thermoelectrics, which transports heat for refrigeration or converts heat into electricity directly, is a key technology for renewable energy harvesting and solid-state refrigeration. Despite its importance, the widespread use of thermoelectric devices is constrained because of the low efficiency of thermoelectric bulk alloys. However, boundary engineering has been demonstrated as one of the most effective ways to enhance the thermoelectric performance of conventional thermoelectric materials such as Bi2 Te3 , PbTe, and SiGe alloys because their thermal and electronic transport properties can be manipulated separately by this approach. We review our recent progress on the enhancement of the thermoelectric figure of merit through boundary engineering together with the processing technologies for boundary engineering developed most recently using Bi2 Te3 -based bulk alloys. A brief discussion of the principles and current status of boundary-engineered bulk alloys for the enhancement of the thermoelectric figure of merit is presented. We focus mainly on (1) the reduction of the thermal conductivity by grain boundary engineering and (2) the reduction of thermal conductivity without deterioration of the electrical conductivity by phase boundary engineering. We also discuss the next potential approach using two boundary engineering strategies for a breakthrough in the area of bulk thermoelectric alloys.

  3. Experimental and Theoretical Investigation of Three Alloy 690 Mockup Components: Base Metal and Welding Induced Changes

    Directory of Open Access Journals (Sweden)

    Rickard R. Shen

    2014-01-01

    Full Text Available The stress corrosion cracking (SCC resistance of cold deformed thermally treated (TT Alloy 690 has been questioned in recent years. As a step towards understanding its relevancy for weld deformed Alloy 690 in operating plants, Alloy 690 base metal and heat affected zone (HAZ microstructures of three mockup components have been studied. All mockups were manufactured using commercial heats and welding procedures in order to attain results relevant to the materials in the field. Thermodynamic calculations were performed to add confidence in phase identification as well as understanding of the evolution of the microstructure with temperature. Ti(C,N banding was found in all materials. Bands with few large Ti(C,N precipitates had negligible effect on the microstructure, whereas bands consisting of numerous small precipitates were associated with locally finer grains and coarser M23C6 grain boundary carbides. The Ti(C,N remained unaffected in the HAZ while the M23C6 carbides were fully dissolved close to the fusion line. Cold deformed solution annealed Alloy 690 is believed to be a better representation of this region than cold deformed TT Alloy 690.

  4. Electrochemical characterisation of nickel-based alloys in sulphate solutions at 320 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Le Canut, J.-M.; Maximovitch, S. E-mail: suzanne.maximovitch@lepmi.inpg.fr; Dalard, F

    2004-08-15

    Nickel alloy steam generator tubes of pressurized water reactors (PWR) are sensitive to stress corrosion cracking (SCC) and the possibility of predicting SCC from electrochemical measurements is of considerable interest for nuclear industry. The electrochemical properties of several nickel-based alloys were studied at 320 deg. C in sulphate solutions at neutral or slightly alkaline pH from corrosion potential measurements, polarisation curves and polarisation resistance (R{sub p}) measurements by linear voltammetry and electrochemical impedance spectroscopy (EIS). The passive layers were much more stable in neutral conditions, due to the presence of chromium oxide, and alloys 600TT and 690 showed the best passivity. R{sub p} measurements confirmed that alloys 600TT and 690 have the lowest corrosion rates. At alkaline pH, the passivation currents were higher than those obtained at neutral pH, and the alloys showed a close behaviour. Reduction of sulphates to sulphides seemed to be possible. Results are in agreement with thermodynamic and surface analysis data of literature. The electrochemical stability did not appear to be directly related to SCC susceptibility since it varied inversely with the pH dependance of SCC in sulphate medium.

  5. The Microstructure and Capacitance Characterizations of Anodic Titanium Based Alloy Oxide Nanotube

    Directory of Open Access Journals (Sweden)

    Po Chun Chen

    2013-01-01

    Full Text Available This paper presents a simple anodization process to fabricate ordered nanotubes (NTs of titanium and its alloys (Ti-Mo and Ti-Ta. TiO2, MoO3, and Ta2O5 are high dielectric constant materials for ultracapacitor application. The anodic titanium oxide contains a compact layer on the NT film and a barrier layer under the NT film. However, the microstructure of oxide films formed by anodic Ti-Mo and Ti-Ta alloys contains six layers, including a continuous compact layer, a continuous partial porous layer, a porous layer, a net layer, an ordering NT film, and an ordering compact barrier layer. There are extra layers, which are a partial porous layer and a porous layer, not presented on the TiO2 NT film. In this paper, we fabricated very high surface area ordered nanotubes from Ti and its alloys. Based on the differences of alloys elements and compositions, we investigated and calculated the specific capacitance of these alloys oxide nanotubes.

  6. High-strength Zr-based bulk amorphous alloys containing nanocrystalline and nanoquasicrystalline particles

    Directory of Open Access Journals (Sweden)

    A Inoue, C Fan, J Saida and T Zhang

    2000-01-01

    Full Text Available It was recently found that the addition of special elements leading to the deviation from the three empirical rules for the achievement of high glass-forming ability causes new mixed structures consisting of the amorphous phase containing nanoscale compound or quasicrystal particles in Zr–Al–Ni–Cu–M (M=Ag, Pd, Au, Pt or Nb bulk alloys prepared by the copper mold casting and squeeze casting methods. In addition, the mechanical strength and ductility of the nonequilibrium phase bulk alloys are significantly improved by the formation of the nanostructures as compared with the corresponding amorphous single phase alloys. The composition ranges, formation factors, preparation processes, unique microstructures and improved mechanical properties of the nanocrystalline and nanoquasicrystalline Zr-based bulk alloys are reviewed on the basis of our recent results reported over the last two years. The success of synthesizing the novel nonequilibrium, high-strength bulk alloys with good mechanical properties is significant for the future progress of basic science and engineering.

  7. Creep-rupture behavior of a developmental cast-iron-base alloy for use up to 800 deg C

    Science.gov (United States)

    Titran, Robert H.; Scheuermann, Coulson M.

    1987-01-01

    A promising iron-base cast alloy is being developed as part of the DOE/NASA Stirling Engine Systems Project under contract DEN 3-282 with the United Technologies Research Center. This report presents the results of a study at the Lewis Research Center of the alloy's creep-rupture properties. The alloy was tested under a variety of conditions and was found to exhibit the normal 3-stage creep response. The alloy compared favorably with others being used or under consideration for the automotive Stirling engine cylinder/regenerator housing.

  8. Fundamentals of Manufacturing Technologies for Aircraft Engine Parts Made of TiAl Based Alloys

    Directory of Open Access Journals (Sweden)

    Szkliniarz W.

    2016-09-01

    Full Text Available The study presents fundamentals of manufacturing technologies for aircraft engine construction elements, made of light, intermetallic TiAl based alloy, which is characterized by high relative strength and good creep and oxidation resistance. For smelting of alloy, the vacuum metallurgy methods were used, including application of induction furnace equipped with special crucibles made of isostatic-pressed, high-density graphite. To produce good quality construction element for aircraft engine, such as low-pressure turbine blade, there were methods of gravity casting from a very high temperature to the preheated shell moulds applied.

  9. Chemical durability and degradation mechanisms of HT9 based alloy waste forms with variable Zr content

    Energy Technology Data Exchange (ETDEWEB)

    Olson, L. N. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-30

    In Corrosion studies were undertaken on alloy waste forms that can result from advanced electrometallurgical processing techniques to better classify their durability and degradation mechanisms. The waste forms were based on the RAW3-(URe) composition, consisting primarily of HT9 steel and other elemental additions to simulate nuclear fuel reprocessing byproducts. The solution conditions of the corrosion studies were taken from an electrochemical testing protocol, and meant to simulate conditions in a repository. The alloys durability was examined in alkaline and acidic brines.

  10. Evolution of precipitate in nickel-base alloy 718 irradiated with argon ions at elevated temperature

    Science.gov (United States)

    Jin, Shuoxue; Luo, Fengfeng; Ma, Shuli; Chen, Jihong; Li, Tiecheng; Tang, Rui; Guo, Liping

    2013-07-01

    Alloy 718 is a nickel-base superalloy whose strength derives from γ'(Ni3(Al,Ti)) and γ″(Ni3Nb) precipitates. The evolution of the precipitates in alloy 718 irradiated with argon ions at elevated temperature were examined via transmission electron microscopy. Selected-area electron diffraction indicated superlattice spots disappeared after argon ion irradiation, which showing that the ordered structure of the γ' and γ″ precipitates became disordered. The size of the precipitates became smaller with the irradiation dose increasing at 290 °C.

  11. An X-ray diffraction study of defect parameters in a Ti-base alloy

    Indian Academy of Sciences (India)

    G Karmaker; P Mukherjee; A K Meikap; S K Chattopadhyay; S K Chatterjee

    2001-12-01

    Detailed studies based on the well established method of Fourier line shape analysis have been made on the X-ray diffraction profile of hexagonal titanium alloy of nominal composition Ti–6.58% Al–3.16% Mo–1.81% Zr–0.08% Fe–0.012% N–0.0078% C. While deformation fault probability, , has been found to be quite high compared to that of pure titanium, the deformation growth fault parameter, , shows a negative value ruling out the presence of growth fault in this alloy in the deformed state.

  12. Emeraldine base as corrosion protective layer on aluminium alloy AA5182, effect of the surface microstructure

    DEFF Research Database (Denmark)

    Cecchetto, L; Ambat, Rajan; Davenport, A.J.

    2007-01-01

    AA5182 aluminium alloy cold rolled samples were coated by thin Wlms of emeraldine base (EB) obtained from a 5% solution in N-methylpyrrolidinone. Accelerated corrosion tests prove this coating very eVective for corrosion protection of aluminium alloys in neutral environment. This study underlines......: • a weak redox activity of the polymer which passivate the metal, • a proton involving self-healing process taking place at the polymer–metal interface, which contributes to delay local acidiWcation in Wrst steps of corrosion on EB coated aluminium surfaces....

  13. Urinary levels of nickel and chromium associated with dental restoration by nickel-chromium based alloys.

    Science.gov (United States)

    Chen, Bo; Xia, Gang; Cao, Xin-Ming; Wang, Jue; Xu, Bi-Yao; Huang, Pu; Chen, Yue; Jiang, Qing-Wu

    2013-03-01

    This paper aims to investigate if the dental restoration of nickel-chromium based alloy (Ni-Cr) leads to the enhanced excretions of Ni and Cr in urine. Seven hundred and ninety-five patients in a dental hospital had single or multiple Ni-Cr alloy restoration recently and 198 controls were recruited to collect information on dental restoration by questionnaire and clinical examination. Urinary concentrations of Ni and Cr from each subject were measure by graphite furnace atomic absorption spectrometry. Compared to the control group, the urinary level of Ni was significantly higher in the patient group of dental restoration. Potential short- and long-term effects of Ni-Cr alloy restoration need to be investigated.

  14. Study on Nanocrystalline Rare Earth Mg-Based System Hydrogen Storage Alloys with AB3-Type

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A sort of rare earth Mg-based system hydrogen storage alloys with AB3-type was prepared by double-roller rapid quenching method. The alloys were nanocrystalline multi-phase structures composed of LaNi3 phase and LaNi5 phase by X-ray diffraction and scanning electron microscopy analyses, and the suitable absorption/desorption plateau was revealed by the measurement of P-C-I curve. Electrochemical studies indicate that the alloys exhibit good electrochemical properties such as high capacity and stable cycle life, and the discharge capacity is 369 mAh·g-1 at 0.2 C (72 mA·g-1), after 460 cycles, the capacity decay was only 19.4% at 2 C (720 mA·g-1).

  15. Nitridation of Ni-based alloys: thermodynamics, kinetics, and deformation phenomena accompanying internal precipitation

    Institute of Scientific and Technical Information of China (English)

    Alexander A. Kodentsov; Jorma K. Kivilahti; Frans J.J. van Loo

    2006-01-01

    When a moderately stable phase is precipitated out during an internal reaction, the behaviour of the penetrating atoms within the diffusion zone can be interpreted based on thermodynamic considerations. Evidence for "up-hill" diffusion of the penetrating species through the matrix towards the precipitation front during the internal nitridation of Ni-Cr alloys at 1125℃ and 6000 bar of N2-pressure was predicted. Such behaviour of nitrogen is opposite to the boundary conditions in Wagner's description of internal reactions. A volume change associated with the precipitation reaction resulted in a stress gradient between the alloys surface and the internal nitridation front. Stress relief occurred mainly by transport of nickel to the gas/metal interface. Pipe diffusion-controlled creep is the dominant stress accommodation mechanism during nitriding of dilute Ni-Cr alloys at 700℃ under a flowing NH3 + H2 gas mixture.

  16. EFFECT OF TESTING ENVIRONMENT ON FRACTURING BEHAVIOR OF Fe3Si BASED ALLOY

    Institute of Scientific and Technical Information of China (English)

    J.H. Peng; G.L. Chen

    2003-01-01

    The mechanical behavior of Fe3Si based alloy with B2 structure was studied by tensionand fracture toughness test in various testing media. The fracture strength σb ofFe3Si alloy decreased in the following order: oxygen, air and hydrogen respectively.The fracture toughness in different testing environment showed that KiC in oxygenis 11.5±0.3MPa. m1/2, and is 8.6±0.4MPa. m1/2 in distilled water. The reductionof fracture toughness is contributed to the environmental reaction of Si with water.Addition of Al element in Fe3Si is not beneficial to improve the intrinsic ductility ofFe-14Si-3Al alloy. The scattering phenomenon of fracture strength was found, andexplained by fracture mechanics. It was found by means of SEM that the fracture modechanged from transgranular in oxygen to intergranular in hydrogen gas and distilledwater.

  17. Void growth in high strength aluminium alloy single crystals: a CPFEM based study

    Science.gov (United States)

    Asim, Umair; Siddiq, M. Amir; Demiral, Murat

    2017-04-01

    High strength aluminium alloys that are produced through forming and joining processes are widely used in aerospace components. The ductile failure in these metals occurs due to the evolution and accumulation of microscopic defects, such as microvoids and shear bands. The present work investigates the underlying physical mechanisms during ductile failure by performing a rigorous, fully-validated, three-dimensional crystal plasticity, finite element study with aluminium alloy single crystals. Representative volume element (RVE) based simulations of single crystalline aluminium alloys (AA-5xxx) with different void geometries and orientations have been performed. Both local and nonlocal crystal plasticity constitutive models have been implemented in a finite element framework and are used to seek new insights into the interrelationships among void growth, initial porosity, initial void size, plastic anisotropy, and local/nonlocal size effects.

  18. INTERFACIAL INTERACTION IN CASTING ALUMINA MATRIX COMPOSITE ALLOYS BASED ON THE SYSTEM AL-SIO2

    Directory of Open Access Journals (Sweden)

    A. V. Arabey

    2012-01-01

    Full Text Available The results of the analysis of the processes of interfacial interaction in casting alloys, based on the system Al- SiO2, obtained using heterophase (liquid-solid mixing technology components-silica sand and aluminum are presented.

  19. Moessbauer study of the orientation of the magnetic moments in Fe—based nanocrystalline alloys

    Institute of Scientific and Technical Information of China (English)

    HuBing-Yuan; ZhangGui-Lin; 等

    1997-01-01

    Magneto-impedance(MI) effect in Fe-based nanocrystalline Fe73 Cu1Nb1.5Mo2Si13.5B alloys has been observed by Moessbauer spectroscopy.The results show that the field dependence of the MI ratio is strongly influenced by the transverse magnetic structure in samples.

  20. ZnO-based semiconductors studied by Raman spectroscopy. Semimagnetic alloying, doping, and nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Schumm, Marcel

    2009-07-01

    ZnO-based semiconductors were studied by Raman spectroscopy and complementary methods (e.g. XRD, EPS) with focus on semimagnetic alloying with transition metal ions, doping (especially p-type doping with nitrogen as acceptor), and nanostructures (especially wet-chemically synthesized nanoparticles). (orig.)

  1. Au-Ge based Candidate Alloys for High-Temperature Lead-Free Solder Alternatives

    DEFF Research Database (Denmark)

    Chidambaram, Vivek; Hald, John; Hattel, Jesper Henri

    2009-01-01

    Au-Ge based candidate alloys have been proposed as an alternative to high-lead content solders that are currently being used for high-temperature applications. The influence of the low melting point metals namely In, Sb and Sn to the Au-Ge eutectic with respect to the microstructure and microhard...

  2. Corrosion behaviour, microstructure and phase transitions of Zn-based alloys

    Indian Academy of Sciences (India)

    A K Yildiz; M Kaplan

    2004-08-01

    This paper is aimed at investigating the corrosion behaviour, microstructure and phase transitions of Zn-based alloys with different compositions. The corrosion tests are carried out both in acidic medium using 1 N HCl solution and in temperature dependence of thermogravimetric analysis (TGA). In the two different media, in particular, the corrosion behaviour of Zn-based alloys with respect to Al and Si contents is examined, and microstructure in acidic and TGA and phase transformations in TGA are also studied. Corrosion mechanism in TGA is also examined in terms of oxidation parameters and activation energies. The study reveals that corrosion behaviour of Zn-based alloys in acidic medium shows sometimes an increase and sometimes a decrease with time due to Al content which assists in delaying the corrosion by forming a oxide layer on the surface of Zn-based alloys. This property does not appear in temperature dependence of TGA. Further, Si content appears to remain in main matrix without being affected by acidic solution. On the other hand, it is observed that in microstructure, AlO(Al2O3), ZnO oxides and Zn–Cu phase precipitations are formed in main matrix, grain boundaries and partially inside the grains.

  3. Bonding Be to Cu alloys using a proprietary Brush Wellman process and new results for bonding Be to AlBeMet

    Energy Technology Data Exchange (ETDEWEB)

    Dombrowski, D.E. [Brush Wellman Inc., Cleveland, OH (United States)

    1998-01-01

    A novel process has been investigated for bonding of beryllium to copper alloys. The process is compatible with current manufacturing capabilities and can be readily scaled up from laboratory to production scale. The effect of process variations on the bond are shown. Also shown are several new approaches for direct bonding of beryllium to an AlBeMet interlayer. Bond strengths of Be/AlBeMet 162/Cu alloy couples are presented. (author)

  4. Ambient-temperature high damping capacity in TiPd-based martensitic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Dezhen [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Zhou, Yumei, E-mail: zhouyumei@mail.xjtu.edu.cn [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Ding, Xiangdong [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Otsuka, Kazuhiro [Ferroic Physics Group, National Institute for Materials Science, Tsukuba 305-0047, Ibaraki (Japan); Lookman, Turab [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Sun, Jun [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Ren, Xiaobing [Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Ferroic Physics Group, National Institute for Materials Science, Tsukuba 305-0047, Ibaraki (Japan)

    2015-04-24

    Shape memory alloys (SMAs) have attracted considerable attention for their high damping capacities. Here we investigate the damping behavior of Ti{sub 50}(Pd{sub 50−x}D{sub x}) SMAs (D=Fe, Co, Mn, V) by dynamic mechanical analysis. We find that these alloys show remarkably similar damping behavior. There exists a sharp damping peak associated with the B2–B19 martensitic transformation and a high damping plateau (Q{sup −1}~0.02–0.05) over a wide ambient-temperature range (220–420 K) due to the hysteretic twin boundary motion. After doping hydrogen into the above alloys, a new relaxation-type damping peak appears in the martensite phase over 270–360 K. Such a peak is considered to originate from the interaction of hydrogen atoms with twin boundaries and the corresponding damping capacity (Q{sup −1}~0.05–0.09) is enhanced by roughly twice that of the damping plateau for each alloy. Moreover, the relaxation peaks are at higher temperatures for the TiPd-based alloys (270–370 K) than for the TiNi-based alloys (190–260 K). We discuss the influence of hydrogen diffusion, mobility of twin boundaries and hydrogen–twin boundary interaction on the temperature range of the relaxation peak. Our results suggest that a martensite, with appropriate values for twinning shear and hydrogen doping level, provides a route towards developing high damping SMAs for applications in desired temperature ranges.

  5. Tritium release from neutron irradiated beryllium: Kinetics, long-time annealing and effect or crack formation

    Energy Technology Data Exchange (ETDEWEB)

    Scaffidi-Argentina, F.; Werle, H. [Forschungszentrum Karlsruhe, (Germany)

    1995-09-01

    Since beryllium is considered as one of the best neutron multiplier materials in the blanket of the next generation fusion reactors, several studies have been started to evaluate its behaviour under irradiation during both operating and accidental conditions. Based on safety considerations, tritium produced in beryllium during neutron irradiation represents one important issue, therefore it is necessary to investigate tritium transport processes by using a comprehensive mathematical model and comparing its predictions with well characterized experimental tests. Because of the difficulties in extrapolating the short-time tritium release tests to a longer time scale, also long-time annealing experiments with beryllium samples from the SIBELIUS irradiation. have been carried out at the Forschungszentrum Karlsruhe. Samples were annealed up to 12 months at temperatures up to 650{degrees}C. The inventory after annealing was determined by heating the samples up to 1050{degrees}C with a He+0.1 vo1% H{sub 2} purge gas. Furthermore, in order to investigate the likely effects of cracks formation eventually causing a faster tritium release from beryllium, the behaviour of samples irradiated at low temperature (40-50{degrees}C) but up to very high fast neutron fluences (0.8-3.9{center_dot}10{sup 22} cm{sup -2}, E{sub n}{ge}1 MeV) in the BR2 reactor has been investigated. Tritium was released by heating the beryllium samples up to 1050{degrees}C and purging them with He+0.1 vo1% H{sub 2}. Tritium release from high-irradiated beryllium samples showed a much faster kinetics than from the low-irradiated ones, probably because of crack formation caused by thermal stresses in the brittle material and/or by helium bubbles migration. The obtained experimental data have been compared with predictions of the code ANFIBE with the goal to better understand the physical mechanisms governing tritium behaviour in beryllium and to assess the prediction capabilities of the code.

  6. Differences in estimates of size distribution of beryllium powder materials using phase contrast microscopy, scanning electron microscopy, and liquid suspension counter techniques

    Directory of Open Access Journals (Sweden)

    Day Gregory A

    2007-02-01

    Full Text Available Abstract Accurate characterization of the physicochemical properties of aerosols generated for inhalation toxicology studies is essential for obtaining meaningful results. Great emphasis must also be placed on characterizing particle properties of materials as administered in inhalation studies. Thus, research is needed to identify a suite of techniques capable of characterizing the multiple particle properties (i.e., size, mass, surface area, number of a material that may influence toxicity. The purpose of this study was to characterize the morphology and investigate the size distribution of a model toxicant, beryllium. Beryllium metal, oxides, and alloy particles were aerodynamically size-separated using an aerosol cyclone, imaged dry using scanning electron microscopy (SEM, then characterized using phase contrast microscopy (PCM, a liquid suspension particle counter (LPC, and computer-controlled SEM (CCSEM. Beryllium metal powder was compact with smaller sub-micrometer size particles attached to the surface of larger particles, whereas the beryllium oxides and alloy particles were clusters of primary particles. As expected, the geometric mean (GM diameter of metal powder determined using PCM decreased with aerodynamic size, but when suspended in liquid for LPC or CCSEM analysis, the GM diameter decreased by a factor of two (p

  7. Rapid dendrite growth in quaternary Ni-based alloys

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The high undercooling and rapid solidification of Ni-10%Cu-10%Fe-10%Co quaternary alloy were achieved by electromagnetic levitation and glass fluxing techniques. The maximum undercooling of 276 K (0.16TL) was obtained in the experiments. All the solidified samples are determined to be α-Ni single-phase solid solutions by DSC thermal analysis and X-ray diffraction analysis. The microstructure of the α-Ni solid solution phase transfers from dendrite to equiaxed grain with an increase in undercooling, accompanied by the grain refinement effect. When the undercooling is very large, the solute trapping effect becomes quite significant and the microsegregation is suppressed. The experimental measurement of α-Ni dendrite growth velocity indicates that it increases with undercooling according to the relation, V=8×10-2×△T1.2.

  8. Superconducting state parameters of indium-based binary alloys

    Indian Academy of Sciences (India)

    A M Vora; Minal H Patel; P N Gajjar; A R Jani

    2002-05-01

    Our well-recognized pseudopotential is used to investigate the superconducting state parameters viz; electron–phonon coupling strength , Coulomb pseudopotentialµ *, transition temperature c, isotope effective exponent and interaction strength 0 for the In1-Zn and In1-Sn binary alloys. We have incorporated six different types of local field correction functions, proposed by Hartree, Taylor, Vashistha–Singwi, Ichimaru–Utsumi, Farid et al and Sarkar et al to show the effect of exchange and correlation on the aforesaid properties. Very strong influence of the various exchange and correlation functions is concluded from the present study. The comparison with other such theoretical values is encouraging, which confirms the applicability of our model potential in explaining the superconducting state parameters of binary mixture.

  9. Exploring Half Metals in Li-based Half Heusler Alloys

    Science.gov (United States)

    Busemeyer, B.; Shaughnessy, M.; Fong, C. Y.

    2011-11-01

    We examine the electronic and magnetic properties of three Li-related half Heusler alloys, namely LiMnN, LiMnP, and LiMnSi in a structure close to the well-known zinc-blende structure in the attempt to search for new half metallic materials. If they do demonstrate half metallic properties, this will open new grounds for finding half metallic spintronic materials. Our results will furnish guidelines for future exploration of alkali-related half metals. Using the primitive cell LiMnSi is a half metal, while the pnictides are not. However when the conventional cell is used, we find that Li3Mn4P4 and Li3Mn4N4 are half metals. The physical reason for these two pnictides to be half metallic and for their magnetic moment per unit cell will be presented.

  10. Ternary alloys based on II-VI semiconductor compounds

    CERN Document Server

    Tomashyk, Vasyl; Shcherbak, Larysa

    2013-01-01

    Phase Equilibria in the Systems Based on ZnSSystems Based on ZnSeSystems Based on ZnTeSystems Based on CdSSystem Based on CdSeSystem Based on CdTeSystems Based on HgSSystems Based on HgSeSystems Based on HgTeIndexReferences appear at the end of each chapter.

  11. Quaternary alloys based on II-VI semiconductors

    CERN Document Server

    Tomashyk, Vasyl

    2014-01-01

    Systems Based on ZnSSystems Based on ZnSeSystems Based on ZnTeSystems Based on CdSSystems Based on CdSeSystems Based on CdTeSystems Based on HgSSystems Based on HgSeSystems Based on HgTeIndexReferences appear at the end of each chapter.

  12. 10 CFR 850.20 - Baseline beryllium inventory.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Baseline beryllium inventory. 850.20 Section 850.20 Energy... Baseline beryllium inventory. (a) The responsible employer must develop a baseline inventory of the... inventory, the responsible employer must: (1) Review current and historical records; (2) Interview...

  13. Joining of beryllium by braze welding technique: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Banaim, P.; Abramov, E. [Ben-Gurion Univ. of the Negev, Beersheba (Israel); Zalkind, S.; Eden, S.

    1998-01-01

    Within the framework of some applications, there is a need to join beryllium parts to each other. Gas Tungsten Arc Braze Welds were made in beryllium using 0.3 mm commercially Aluminum (1100) shim preplaced at the joint. The welds exhibited a tendency to form microcracks in the Fusion Zone and Heat Affected Zone. All the microcracks were backfilled with Aluminum. (author)

  14. Ionization energies of beryllium in strong magnetic fields

    Institute of Scientific and Technical Information of China (English)

    GUANXiao-xu; ZHANGYue-xia

    2004-01-01

    We have develop an effective frozen core approximation to calculate energy levels and ionization enegies of the beryllium atom in magnetic field strengths up to 2.35 × 105T. Systematic improvement over the Hartree-Fock results for the beryllium low-lying states has been accomplished.

  15. Ionization energies of beryllium in strong magnetic fields

    Institute of Scientific and Technical Information of China (English)

    GUAN Xiao-xu; ZHANG Yue-xia

    2004-01-01

    We have develop an effective frozen core approximation to calculate energy levels and ionization enegies of the beryllium atom in magnetic field strengths up to 2.35×105T. Systematic improvement over the Hartree-Fock results for the beryllium low-lying states has been accomplished.

  16. Beryllium toxicity testing in the suspension culture of mouse fibroblasts.

    Science.gov (United States)

    Rössner, P; Bencko, V

    1980-01-01

    Suspension culture of mouse fibroblast cell line L-A 115 was used to test beryllium toxicity in the presence of magnesium ions. Beryllium added to the MEM cultivation medium was bound in a complex with sulphosalicylic acid BeSSA complex, because the use of beryllium chloride turned out to yield ineffective beryllium phosphate that formed macroscopically detectable insoluble opacities. The BeSSA complex was used in the concentration range: 10(-3)--10(-9)M, magnesium was used in 3 concentrations: 10(-1)M, 5 x 10(-2)M and 10(-2)M. Growth curve analysis revealed pronounced beryllium toxicity at the concentration of 10(-3)M, magnesium-produced toxic changes were observed only at the concentration of 10(-1)M. No competition between the beryllium and magnesium ions was recorded. It is assumed that the possible beryllium-magnesium competition was significantly modified by the use of BeSSA complex-bound beryllium.

  17. IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR BERYLLIUM AND COMPOUNDS

    Science.gov (United States)

    EPA's assessment of the noncancer health effects and carcinogenic potential of Beryllium was added to the IRIS database in 1998. The IRIS program is updating the IRIS assessment for Beryllium. This update will incorporate health effects information published since the last assess...

  18. Computational evaluation of unsaturated carbonitriles as neutral receptor model for beryllium(II) recognition.

    Science.gov (United States)

    Rosli, Ahmad Nazmi; Ahmad, Mohd Rais; Alias, Yatimah; Zain, Sharifuddin Md; Lee, Vannajan Sanghiran; Woi, Pei Meng

    2014-12-01

    Design of neutral receptor molecules (ionophores) for beryllium(II) using unsaturated carbonitrile models has been carried out via density functional theory, G3, and G4 calculations. The first part of this work focuses on gas phase binding energies between beryllium(II) and 2-cyano butadiene (2-CN BD), 3-cyano propene (3-CN P), and simpler models with two separate fragments; acrylonitrile and ethylene. Interactions between beryllium(II) and cyano nitrogen and terminal olefin in the models have been examined in terms of geometrical changes, distribution of charge over the entire π-system, and rehybridization of vinyl carbon orbitals. NMR shieldings and vibrational frequencies probed charge centers and strength of interactions. The six-membered cyclic complexes have planar structures with the rehybridized carbon slightly out of plane (16° in 2-CN BD). G3 results show that in 2-CN BD complex participation of vinyl carbon further stabilizes the cyclic adduct by 16.3 kcal mol(-1), whereas, in simpler models, interaction between beryllium(II) and acetonitrile is favorable by 46.4 kcal mol(-1) compared with that of ethylene. The terminal vinyl carbon in 2-CN BD rehybridizes to sp (3) with an increase of 7 % of s character to allow interaction with beryllium(II). G4 calculations show that the Be(II) and 2-CN BD complex is more strongly bound than those with Mg(II) and Ca(II) by 98.5 and 139.2 kcal mol(-1) (-1), respectively. QST2 method shows that the cyclic and acyclic forms of Be(II)-2-CN BD complexes are separated by 12.3 kcal mol(-1) barrier height. Overlap population analysis reveals that Ca(II) can be discriminated based on its tendency to form ionic interaction with the receptor models.

  19. Microstructures and mechanical properties of Al-Mg and Al-Zn-Mg based alloys containing minor scandium and zirconium

    Institute of Scientific and Technical Information of China (English)

    尹志民; 姜锋; 潘青林; 郭飞跃; 朱大鹏; 宋练鹏; 曾渝; 王涛

    2003-01-01

    A series of Al-Mg and Al-Zn-Mg based alloys with and without Sc, Zr were prepared by ingot metallurgy. The mechanical properties and microstructures of the studied alloys under different treatment conditions were studied. In addition, the existing form and acting mechanism of minor Sc and Zr in Al-Mg and Al-Zn-Mg based alloys were analyzed and discussed. The following conclusions can be drawn. First, adding of minor Sc and Zr to those alloys can increase the strength of Al-Mg and Al-Zn-Mg based alloys by 25%, while the ductility can remain in 15% and 8%, respectively. Second, in Al-Mg and Al-Zn-Mg based alloys, minor Sc and Zr mainly exist in two forms of aluminides containing Sc and Zr, one is Al3(Sc,Zr)I precipitated from the melt during solidification, the other is Al3(Sc,Zr)Ⅱ precipitated during homogenization. The former is the most effective grain refiner for α(Al) solid solution matrix, and the latter is coherent with the matrix and can strongly pin dislocations and subboundaries, which can effectively restrain recrystallization of the alloys during hot deformation, annealing and solid solution. Third, strengthening caused by adding minor Sc and Zr to the studied alloys is mainly due to fine-grain strengthening, precipitation strengthening and substructure strengthening of Al3(Sc, Zr) caused by restraining recrystallization.

  20. 4-d magnetism: Electronic structure and magnetism of some Mo-based alloys

    Science.gov (United States)

    Liu, Yong; Bose, S. K.; Kudrnovský, J.

    2017-02-01

    We report results of a first-principles density-functional study of alloys of the 4 d -element Mo with group IV elements Si, Ge and Sn in zinc blende (ZB) and rock salt (RS) structures. The study was motivated by a similar study of ours based on the 4 d -element Tc, which showed the presence of half-metallic states with integer magnetic moment (1μB) per formula unit in TcX (X=C, Si, Ge) alloys. The calculated Curie temperatures for the ferromagnetic (FM) phases were low, around or less than 300 K. Searching for the possibility of 4 d -based alloys with higher Curie temperatures we have carried out the study involving the elements Mo, Ru and Rh. Among these the most promising case appears to be that involving the element Mo. Among the MoX (X=Si, Ge, Sn) alloys in ZB and RS structures, both MoGe and MoSn in ZB structures are found to possess an integer magnetic moment of 2μB per formula unit. ZB MoSn can be classified as a marginal/weak half-metal or a spin gapless semiconductor, while ZB MoGe would be best described as a gapless magnetic semiconductor. The calculated Curie temperatures are in the range 300-700 K. Considering the theoretical uncertainty in the band gaps due not only to the treatment of exchange and correlation effects, but density functional theory itself, these classifications may change somewhat, but both merit investigation from the viewpoint of potential spintronic application. Based on their higher Curie temperatures, Mo-based alloys would serve such purpose better than the previously reported Tc-based ones.

  1. Phonon dispersion in alkali metals and their equiatomic sodium-based binary alloys

    Institute of Scientific and Technical Information of China (English)

    Aditya M. VORA

    2008-01-01

    In the present article, the theoretical calcula-tions of the phonon dispersion curves (PDCs) of five alkali metals viz. Li, Na, K, Rb, Cs and their four equia-tomic sodium-based binary alloys viz. Na0.5Li0.5,Na0.5K0.5, Na0.5Rb0.5 and Na0.5Cs0.5 to second order in a local model potential is discussed in terms of the real-space sum of the Born yon Karman central force con-stants. Instead of the concentration average of the force constants of pure alkali metals, the pseudo-alloy-atom (PAA) is adopted to directly compute the force constants of the four equiatomic sodium based binary alloys and was successfully applied. The exchange and correlation functions due to the Hartree (H) and Ichimaru-Utsumi (IU) are used to investigate the influence of the screening effects. The phonon frequencies of alkali metals and their four equiatomic sodium-based binary alloys in the longit-udinal branch are more sensitive to the exchange and cor-relation effects in comparison with the transverse branches. The PDCs of pure alkali metals are found in qualitative agreement with the available experimental data. The frequencies in the longitudinal branch are sup-pressed rather due to IU-screening function than those due to static H-screening function.

  2. High-frequency magnetic characteristics of Fe-Co-based nanocrystalline alloy films

    Institute of Scientific and Technical Information of China (English)

    HIHARA; Takehiko; SUMIYAMA; Kenji

    2010-01-01

    Magnetically soft Fe-Co-based nanocrystalline alloy films were produced by two preparation methods:One using a new energetic cluster deposition technique and another using a conventional magnetron sputtering technique.Their structural,static magnetic properties and high-frequency magnetic characteristics were investigated.In the energetic cluster deposition method,by applying a high-bias voltage to a substrate,positively charged clusters in a cluster beam were accelerated electrically and deposited onto a negatively biased substrate together with neutral clusters from the same cluster source,to form a high-density Fe-Co alloy cluster-assembled film with good high-frequency magnetic characteristics.In the conventional magnetron sputtering method,only by rotating substrate holder and without applying a static inducing magnetic field on the substrates,we produced Fe-Co-based nanocrystalline alloy films with a remarkable in-plane uniaxial magnetic anisotropy and a good soft magnetic property.The obtained Fe-Co-O,Fe-Co-Ti-N,and Fe-Co-Cr-N films all revealed a high real permeability exceeding 500 at a frequency up to 1.2 GHz.This makes Fe-Co-based nanocrystalline alloy films potential candidates as soft magnetic thin film materials for the high-frequency applications.

  3. Room temperature deformation of in-situ grown quasicrystals embedded in Al-based cast alloy

    Directory of Open Access Journals (Sweden)

    Boštjan Markoli

    2013-12-01

    Full Text Available An Al-based cast alloy containing Mn, Be and Cu has been chosen to investigate the room temperature deformation behavior of QC particles embedded in Al-matrix. Using LOM, SEM (equipped with EDS, conventional TEM with SAED and controlled tensile and compression tests, the deformation response of AlMn2Be2Cu2 cast alloy at room temperature has been examined. Alloy consisted of Al-based matrix, primary particles and eutectic icosahedral quasicrystalline (QC i-phase and traces of Θ-Al2Cu and Al10Mn3. Tensile and compression specimens were used for evaluation of mechanical response and behavior of QC i-phase articles embedded in Al-cast alloy. It has been established that embedded QC i-phase particles undergo plastic deformation along with the Al-based matrix even under severe deformation and have the response resembling that of the metallic materials by formation of typical cup-and-cone feature prior to failure. So, we can conclude that QC i-phase has the ability to undergo plastic deformation along with the Al-matrix to greater extent contrary to e.g. intermetallics such as Θ-Al2Cu for instance.

  4. Ni-Cr based dental alloys; Ni release, corrosion and biological evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Reclaru, L., E-mail: lucien.reclaru@pxgroup.com [PX Holding S.A., Dep R and D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds (Switzerland); Unger, R.E.; Kirkpatrick, C.J. [Institute for Pathology, REPAIR Lab, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstr.1, D-55101 Mainz (Germany); Susz, C.; Eschler, P.-Y.; Zuercher, M.-H. [PX Holding S.A., Dep R and D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds (Switzerland); Antoniac, I. [Materials Science and Engineering Faculty, Politehnica of Bucharest, 060042 Bucharest (Romania); Luethy, H. [Institute of Dental Materials Science and Technology, University of Basel, Hebelstrasse 3, CH-4056 Basel (Switzerland)

    2012-08-01

    In the last years the dental alloy market has undergone dramatic changes for reasons of economy and biocompatibility. Nickel based alloys have become widely used substitute for the much more expensive precious metal alloys. In Europe the prevalence of nickel allergy is 10-15% for female adults and 1-3% for male adults. Despite the restrictions imposed by the EU for the protection of the general population in contact dermatitis, the use of Ni-Cr dental alloys is on the increase. Some questions have to be faced regarding the safety risk of nickel contained in dental alloys. We have collected based on many EU markets, 8 Ni-Cr dental alloys. Microstructure characterization, corrosion resistance (generalized, crevice and pitting) in saliva and the quantities of cations released in particular nickel and CrVI have been evaluated. We have applied non parametric classification tests (Kendall rank correlation) for all chemical results. Also cytotoxicity tests and an evaluation specific to TNF-alpha have been conducted. According to the obtained results, it was found that their behavior to corrosion was weak but that nickel release was high. The quantities of nickel released are higher than the limits imposed in the EU concerning contact with the skin or piercing. Surprisingly the biological tests did not show any cytotoxic effect on Hela and L929 cells or any change in TNF-alpha expression in monocytic cells. The alloys did not show any proinflammatory response in endothelial cells as demonstrated by the absence of ICAM-1 induction. We note therefore that there is really no direct relationship between the in vitro biological evaluation tests and the physico-chemical characterization of these dental alloys. Clinical and epidemiological studies are required to clarify these aspects. - Highlights: Black-Right-Pointing-Pointer Nickel released was higher than the limits imposed in EU in contact with the skin. Black-Right-Pointing-Pointer No direct relationship between the

  5. Protection of air in premises and environment against beryllium aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Bitkolov, N.Z.; Vishnevsky, E.P.; Krupkin, A.V. [Research Inst. of Industrial and Marine Medicine, St. Petersburg (Russian Federation)

    1998-01-01

    First and foremost, the danger of beryllium aerosols concerns a possibility of their inhalation. The situation is aggravated with high biological activity of the beryllium in a human lung. The small allowable beryllium aerosols` concentration in air poses a rather complex and expensive problem of the pollution prevention and clearing up of air. The delivery and transportation of beryllium aerosols from sites of their formation are defined by the circuit of ventilation, that forms aerodynamics of air flows in premises, and aerodynamic links between premises. The causes of aerosols release in air of premises from hoods, isolated and hermetically sealed vessels can be vibrations, as well as pulses of temperature and pressure. Furthermore, it is possible the redispersion of aerosols from dirty surfaces. The effective protection of air against beryllium aerosols at industrial plants is provided by a complex of hygienic measures: from individual means of breath protection up to collective means of the prevention of air pollution. (J.P.N.)

  6. Toxicological effects of beryllium on platelets and vascular endothelium.

    Science.gov (United States)

    Togna, G; Togna, A R; Russo, P; Caprino, L

    1997-06-01

    Although ample research has described the toxic effects of the metal beryllium on the respiratory apparatus, less is known about its effects on the vascular apparatus, including pulmonary blood vessels. We investigated the in vitro effects of beryllium on endothelial vascular adenosine diphosphatase activity and prostacyclin production in bovine aortic endothelium, and on nitric oxide release in isolated rabbit arteries. Rabbit and human platelet responsiveness was also evaluated. Beryllium inhibited vascular endothelial adenosine diphosphatase activity, prostacyclin production, and nitric oxide release, thus inducing functional alterations in vascular endothelial cells. It also induced platelet hyperreactivity to arachidonic acid, as shown by a lowering of the threshold of aggregating concentration and by concurrently increasing thromboxane production. In contrast, beryllium left the response to aggregating and nonaggregating concentrations of ADP and collagen unchanged. These findings show that beryllium may impair some vascular endothelial functions and alter the interaction between platelet and endothelial mediators.

  7. Results of the radiological and beryllium verification survey at the Peek Street Site, Schenectady, New York (SY001V)

    Energy Technology Data Exchange (ETDEWEB)

    Foley, R.D.; Johnson, C.A.; Carrier, R.F.; Allred, J.F.

    1994-10-01

    At the request of the U.S. Department of Energy (DOE), a team from Oak Ridge National Laboratory conducted an independent verification radiological and non-radioactive beryllium survey at the Peek Street site, located at 425 Peek Street, Schenectady, New York. The purpose of the survey, conducted during 1993 and continuing through January 1994, was to confirm the success of the remedial actions performed to remove any beryllium concentrations or radioactive materials in excess of the identified guidelines. The verification survey included surface gamma scans and gamma readings at one meter indoors and outdoors, alpha and beta scans inside the structure, and the collection of soil, dust and debris samples and smears for radionuclide and beryllium analyses. Results of the survey demonstrated that all radiological and beryllium measurements on the property were within applicable DOE guidelines. Based on all data collected, the industrial property at 425 Peek Street and the adjacent state-owned bike path in Schenectady, New York, conforms to all applicable radiological and non-radioactive beryllium guidelines established for this site by DOE and approved by the State of New York.

  8. Trace level determination of beryllium in natural and flavored mineral waters after pre-concentration using activated carbon.

    Science.gov (United States)

    Kılınç, Ersin; Bakırdere, Sezgin; Yaman, Mehmet

    2011-04-01

    The concentrations of beryllium (Be) in natural and flavored mineral water samples were determined by flame atomic absorption spectrophotometer (FAAS) after pre-concentration based on the complexation of Be(+2) with a mixture of acetylacetone (pentane-2,4-dione) plus morin (3,5,7,2',4'-pentaoxyflavone) and adsorption on activated carbon. The adsorbed complex was eluted with 1.5 ml of 2.0 M HNO(3) and evaporated to dryness. After adding 1.5 ml of 2 M HNO(3) and centrifuging, Be in acid solution was determined by FAAS. To remove a number of metals present in water, EDTA was used as a chelating agent. Beryllium in mineral water samples was pre-concentrated by 500-fold, taking 750 ml as initial sample and 1.5 ml as the final volume. The relative standard deviations were sufficiently low for practical purposes and recoveries were up to 85%. Spiking experiments were performed in real samples to establish accuracy and recoveries. The limits of detection and quantification were 0.01 and 0.03 ng ml(-1), respectively. Twenty samples were analyzed for their beryllium content using optimum parameters. The highest concentration of beryllium was found to be 0.94 ± 0.15 ng ml(-1) in a natural mineral water, while beryllium was not detected in five samples.

  9. Breaking through the strength-ductility trade-off dilemma in an Al-Si-based casting alloy

    Science.gov (United States)

    Dang, B.; Zhang, X.; Chen, Y. Z.; Chen, C. X.; Wang, H. T.; Liu, F.

    2016-08-01

    Al-Si-based casting alloys have a great potential in various industrial applications. Common strengthening strategies on these alloys are accompanied inevitably by sacrifice of ductility, known as strength-ductility trade-off dilemma. Here, we report a simple route by combining rapid solidification (RS) with a post-solidification heat treatment (PHT), i.e. a RS + PHT route, to break through this dilemma using a commercial Al-Si-based casting alloy (A356 alloy) as an example. It is shown that yield strength and elongation to failure of the RS + PHT processed alloy are elevated simultaneously by increasing the cooling rate upon RS, which are not influenced by subsequent T6 heat treatment. Breaking through the dilemma is attributed to the hierarchical microstructure formed by the RS + PHT route, i.e. highly dispersed nanoscale Si particles in Al dendrites and nanoscale Al particles decorated in eutectic Si. Simplicity of the RS + PHT route makes it being suitable for industrial scaling production. The strategy of engineering microstructures offers a general pathway in tailoring mechanical properties of other Al-Si-based alloys. Moreover, the remarkably enhanced ductility of A356 alloy not only permits strengthening further the material by work hardening but also enables possibly conventional solid-state forming of the material, thus extending the applications of such an alloy.

  10. Advancement of Compositional and Microstructural Design of Intermetallic γ-TiAl Based Alloys Determined by Atom Probe Tomography

    Directory of Open Access Journals (Sweden)

    Thomas Klein

    2016-09-01

    Full Text Available Advanced intermetallic alloys based on the γ-TiAl phase have become widely regarded as most promising candidates to replace heavier Ni-base superalloys as materials for high-temperature structural components, due to their facilitating properties of high creep and oxidation resistance in combination with a low density. Particularly, recently developed alloying concepts based on a β-solidification pathway, such as the so-called TNM alloy, which are already incorporated in aircraft engines, have emerged offering the advantage of being processible using near-conventional methods and the option to attain balanced mechanical properties via subsequent heat-treatment. Development trends for the improvement of alloying concepts, especially dealing with issues regarding alloying element distribution, nano-scale phase characterization, phase stability, and phase formation mechanisms demand the utilization of high-resolution techniques, mainly due to the multi-phase nature of advanced TiAl alloys. Atom probe tomography (APT offers unique possibilities of characterizing chemical compositions with a high spatial resolution and has, therefore, been widely used in recent years with the aim of understanding the materials constitution and appearing basic phenomena on the atomic scale and applying these findings to alloy development. This review, thus, aims at summarizing scientific works regarding the application of atom probe tomography towards the understanding and further development of intermetallic TiAl alloys.

  11. Neutron beams from protons on beryllium.

    Science.gov (United States)

    Bewley, D K; Meulders, J P; Octave-Prignot, M; Page, B C

    1980-09-01

    Measurements of dose rate and penetration in water have been made for neutron beams produced by 30--75 MeV protons on beryllium. The effects of Polythene filters added on the target side of the collimator have also been studied. A neutron beam comparable with a photon beam from a 4--8 MeV linear accelerator can be produced with p/Be neutrons plus 5 cm Polythene filtrations, with protons in the range 50--75 MeV. This is a more economical method than use of the d/Be reaction.

  12. Thermal cooling effects in the microstructure and properties of cast cobalt-base biomedical alloys

    Science.gov (United States)

    Vega Valer, Vladimir

    Joint replacement prosthesis is widely used in the biomedical field to provide a solution for dysfunctional human body joints. The demand for orthopedic knee and hip implants motivate scientists and manufacturers to develop novel materials or to increase the life of service and efficiency of current materials. Cobalt-base alloys have been investigated by various researchers for biomedical implantations. When these alloys contain Chromium, Molybdenum, and Carbon, they exhibit good tribological and mechanical properties, as well as excellent biocompatibility and corrosion resistance. In this study, the microstructure of cast Co-Cr-Mo-C alloy is purposely modified by inducing rapid solidification through fusion welding processes and solution annealing heat treatment (quenched in water at room temperature. In particular the effect of high cooling rates on the athermal phase transformation FCC(gamma)↔HCP(epsilon) on the alloy hardness and corrosion resistance is investigated. The Co-alloy microstructures were characterized using metallography and microscopy techniques. It was found that the as cast sample typically dendritic with dendritic grain sizes of approximately 150 microm and containing Cr-rich coarse carbide precipitates along the interdendritic boundaries. Solution annealing gives rise to a refined microstructure with grain size of 30 microm, common among Co-Cr-Mo alloys after heat treating. Alternatively, an ultrafine grain structure (between 2 and 10 microm) was developed in the fusion zone for specimens melted using Laser and TIG welding methods. When laser surface modification treatments were implemented, the developed solidification microstructure shifted from dendritic to a fine cellular morphology, with possible nanoscale carbide precipitates along the cellular boundaries. In turn, the solidified regions exhibited high hardness values (461.5HV), which exceeds by almost 110 points from the alloy in the as-cast condition. The amount of developed athermal

  13. Biocorrosion behavior and cell viability of adhesive polymer coated magnesium based alloys for medical implants

    Science.gov (United States)

    Abdal-hay, Abdalla; Dewidar, Montasser; Lim, Jae Kyoo

    2012-11-01

    The present study was ultimately aimed to design novel adhesive biodegradable polymer, poly(vinyl acetate) (PVAc), coatings onto Mg based alloys by the dip-coating technique in order to control the degradation rate and enhance the biocompatibility of magnesium alloys. The influence of various solvents on PVAc surface topography and their protection of Mg alloys were dramatically studied in vitro. Electrochemical polarization, degradation, and PVAc film cytocompatibility were also tested. Our results showed that the solvent had a significant effect on coating quality. PVAc/dichloromethane solution showed a porous structure and solution concentration could control the porous size. The coatings prepared using tetrahydrofuran and dimethylformamide solvents are exceptional in their ability to generate porous morphology even at low polymer concentration. In general, the corrosion performance appears to be different on different PVAc-solvent system. Immersion tests illustrated that the porous morphology on PVAc stabilized corrosion rates. A uniform corrosion attack in artificial simulation body fluid was also exhibited. The cytocompatibility of osteoblast cells (MC3T3) revealed high adherence, proliferation, and survival on the porous structure of PVAc coated Mg alloy, which was not observed for the uncoated samples. This novel PVAc coating is a promising candidate for biodegradable implant materials, which might widen the use of Mg based implants.

  14. Shape-Memory Effect and Pseudoelasticity in Fe-Mn-Based Alloys

    Science.gov (United States)

    La Roca, P.; Baruj, A.; Sade, M.

    2017-03-01

    Several Fe-based alloys are being considered as potential candidates for applications which require shape-memory behavior or superelastic properties. The possibility of using fabrication methods which are well known in the steel industry is very attractive and encourages a large amount of research in the field. In the present article, Fe-Mn-based alloys are mainly addressed. On the one hand, attention is paid to the shape-memory effect where the alloys contain (a) a maximum amount of Mn up to around 30 wt%, (b) several possible substitutional elements like Si, Cr, Ni, Co, and Nb and (c) some possible interstitial elements like C. On the other hand, superelastic alloys are analyzed, mainly the Fe-Mn-Al-Ni system discovered a few years ago. The most noticeable properties resulting from the martensitic transformations which are responsible for the mentioned properties, i.e., the fcc-hcp in the first case and the bcc-fcc in the latter are discussed. Selected potential applications are also analyzed.

  15. Shape-Memory Effect and Pseudoelasticity in Fe-Mn-Based Alloys

    Science.gov (United States)

    La Roca, P.; Baruj, A.; Sade, M.

    2016-12-01

    Several Fe-based alloys are being considered as potential candidates for applications which require shape-memory behavior or superelastic properties. The possibility of using fabrication methods which are well known in the steel industry is very attractive and encourages a large amount of research in the field. In the present article, Fe-Mn-based alloys are mainly addressed. On the one hand, attention is paid to the shape-memory effect where the alloys contain (a) a maximum amount of Mn up to around 30 wt%, (b) several possible substitutional elements like Si, Cr, Ni, Co, and Nb and (c) some possible interstitial elements like C. On the other hand, superelastic alloys are analyzed, mainly the Fe-Mn-Al-Ni system discovered a few years ago. The most noticeable properties resulting from the martensitic transformations which are responsible for the mentioned properties, i.e., the fcc-hcp in the first case and the bcc-fcc in the latter are discussed. Selected potential applications are also analyzed.

  16. Optical modeling of nickel-base alloys oxidized in pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Clair, A. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Universite de Bourgogne, 9 avenue Alain Savary, BP 47870, 21078 Dijon cedex (France); Foucault, M.; Calonne, O. [Areva ANP, Centre Technique Departement Corrosion-Chimie, 30 Bd de l' industrie, BP 181, 71205 Le Creusot (France); Finot, E., E-mail: Eric.Finot@u-bourgogne.fr [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Universite de Bourgogne, 9 avenue Alain Savary, BP 47870, 21078 Dijon cedex (France)

    2012-10-01

    The knowledge of the aging process involved in the primary water of pressurized water reactor entails investigating a mixed growth mechanism in the corrosion of nickel-base alloys. A mixed growth induces an anionic inner oxide and a cationic diffusion parallel to a dissolution-precipitation process forms the outer zone. The in situ monitoring of the oxidation kinetics requires the modeling of the oxide layer stratification with the full knowledge of the optical constants related to each component. Here, we report the dielectric constants of the alloys 600 and 690 measured by spectroscopic ellipsometry and fitted to a Drude-Lorentz model. A robust optical stratification model was determined using focused ion beam cross-section of thin foils examined by transmission electron microscopy. Dielectric constants of the inner oxide layer depleted in chromium were assimilated to those of the nickel thin film. The optical constants of both the spinels and extern layer were determined. - Highlights: Black-Right-Pointing-Pointer Spectroscopic ellipsometry of Ni-base alloy oxidation in pressurized water reactor Black-Right-Pointing-Pointer Measurements of the dielectric constants of the alloys Black-Right-Pointing-Pointer Optical simulation of the mixed oxidation process using a three stack model Black-Right-Pointing-Pointer Scattered crystallites cationic outer layer; linear Ni-gradient bottom layer Black-Right-Pointing-Pointer Determination of the refractive index of the spinel and the Cr{sub 2}O{sub 3} layers.

  17. Solid particle erosion of steels and nickel based alloys candidates for USC steam turbine blading

    Energy Technology Data Exchange (ETDEWEB)

    Cernuschi, Federico; Guardamagna, Cristina; Lorenzoni, Lorenzo [ERSE SpA, Milan (Italy); Robba, Davide [CESI, Milan (Italy)

    2010-07-01

    The main objective of COST536 Action is to develop highly efficient steam power plant with low emissions, from innovative alloy development to validation of component integrity. In this perspective, to improve the operating efficiency, materials capable of withstanding higher operating temperatures are required. For the manufacturing of components for steam power plants with higher efficiency steels and nickel-based alloys with improved oxidation resistance and creep strength at temperature as high as 650 C - 700 C have to be developed. Candidate alloys for manufacturing high pressure steam turbine diaphragms, buckets, radial seals and control valves should exhibit, among other properties, a good resistance at the erosion phenomena induced by hard solid particles. Ferric oxide (magnetite) scales cause SPE by exfoliating from boiler tubes and steam pipes (mainly super-heaters and re-heaters) and being transported within the steam flow to the turbine. In order to comparatively study the erosion behaviour of different materials in relatively short times, an accelerated experimental simulation of the erosion phenomena must be carried out. Among different techniques to induce erosion on material targets, the use of an air jet tester is well recognised to be one of the most valid and reliable. In this work the results of SPE comparative tests performed at high temperatures (550 C, 600 C and 650 C) at different impaction angles on some steels and nickel based alloys samples are reported. (orig.)

  18. Fatigue Strength Estimation Based on Local Mechanical Properties for Aluminum Alloy FSW Joints

    Directory of Open Access Journals (Sweden)

    Kittima Sillapasa

    2017-02-01

    Full Text Available Overall fatigue strengths and hardness distributions of the aluminum alloy similar and dissimilar friction stir welding (FSW joints were determined. The local fatigue strengths as well as local tensile strengths were also obtained by using small round bar specimens extracted from specific locations, such as the stir zone, heat affected zone, and base metal. It was found from the results that fatigue fracture of the FSW joint plate specimen occurred at the location of the lowest local fatigue strength as well as the lowest hardness, regardless of microstructural evolution. To estimate the fatigue strengths of aluminum alloy FSW joints from the hardness measurements, the relationship between fatigue strength and hardness for aluminum alloys was investigated based on the present experimental results and the available wide range of data from the references. It was found as: σa (R = −1 = 1.68 HV (σa is in MPa and HV has no unit. It was also confirmed that the estimated fatigue strengths were in good agreement with the experimental results for aluminum alloy FSW joints.

  19. The electronic mechanism of the gamma/gamma' interface strength of Ir-based alloys

    CERN Document Server

    Chen, K; Tse, J S

    2002-01-01

    The electronic structures of the gamma/gamma' interface for two-phase Ir-based alloys (Ir/Ir sub 3 Ta and Ir/Ir sub 3 Ti) have been investigated by performing first-principles quantum mechanics DMol3 (a type of density functional theory for molecules) calculations. The Mayer bond order (MBO) is used to represent the shear and cohesion strengths of the interface by a local sum of the horizontal and vertical MBOs. By comparison with those for single-crystal Ir, the results show that both the cohesive and shear strengths of the gamma/gamma' interface for the Ir/Ir sub 3 Ta alloy increase. The cohesive strength of the interface for the Ir/Ir sub 3 Ti alloy increases, whereas the shear strength of the interface for Ir/Ir sub 3 Ti decreases. The electron charge density, the Hirshfeld charge, and orbital charge transfers are also calculated and analysed. An electronic mechanism for the gamma/gamma' interface strength of Ir-based alloys is then suggested.

  20. Glass forming ability of Zr-and Fe-based alloys at quenching from melts

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The master alloy ingots(MAI)with the nominal composition Zr52.5 Ti5Cu17.9 Ni14.6Al10 and Fe61Co7Zr10Mo5W2B15(at%)were prepared by arc-melting in Ti-gettered Ar atmosphere.The Zr-based buttons of 6 mm and 9 mm in diameter were fully amorphous,but those of 13 mm in diameter experienced crystallization.The glass forming ability(GFA)of Fe-based alloys was relatively lower,and the buttons obtained were fully crystallized.The microhardness of the Zr-based buttons was about 500(Hv),and the Fe-based rod obtained by injection technique exhibited a high Vickers hardness of 1329.In addition,an amorphous-crystalline transition layers were observed in both the buttons and the rods.

  1. Alloying effects of refractory elements in the dislocation of Ni-based single crystal superalloys

    Directory of Open Access Journals (Sweden)

    Shiyu Ma

    2016-12-01

    Full Text Available The alloying effects of W, Cr and Re in the [100] (010 edge dislocation cores (EDC of Ni-based single crystal superalloys are investigated using first-principles based on the density functional theory (DFT. The binding energy, Mulliken orbital population, density of states, charge density and radial distribution functions are discussed, respectively. It is clearly demonstrated that the addition of refractory elements improves the stability of the EDC systems. In addition, they can form tougher bonds with their nearest neighbour (NN Ni atoms, which enhance the mechanical properties of the Ni-based single crystal superalloys. Through comparative analysis, Cr-doped system has lower binding energy, and Cr atom has evident effect to improve the systemic stability. However, Re atom has the stronger alloying effect in Ni-based single crystal superalloys, much more effectively hindering dislocation motion than W and Cr atoms.

  2. Research on CMT welding of nickel-based alloy with stainless steel

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Cold Metal Transfer (CMT) welding technique is a new welding technique introduced by Fronius company. CMT welding of nickel-based alloy with stainless steel was carried out using CuSi3 filler wire in this paper. Effects of welding parameters, including welding current, welding speed, etc, on weld surface appearance were tested. Microstructure and mechanical properties of CMT weld were studied. The results show that the thickness of interface reaction layer of the nickel-based alloy is 14.3μm, which is only 4.33% of base material. The weld is made up of two phases,α-copper and iron-based solid solution. Rupture occurs initially at the welded seam near the edge of stainless steel in shear test. The maximum shear strength of the CuSi3 welded joint is 184.9MPa.

  3. What is a Beryllium Measurement? A Critical Look at Beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Charles Davis; Dan Field; John Hess; Dan Jensen

    2006-03-01

    DOE workplaces strive to comply with the 10 CFR 850.31(b)(1) surface concentration release criterion. The usual planning considerations for demonstrating compliance are these: how many swipes, and where; which sample preparation and analytical methods; what reporting limits; and what sample statistic to compare with the criterion. We have reviewed swipe samples from hundreds of Nevada Test Site workplaces: office buildings; experimental facilities; forward area field units; shops; and tunnels. Our experiences have led us to a critical examination of the inner workings of the measurement process itself, involving details generally taken for granted when those usual questions are asked. In this presentation we dissect the ICP-AES Be measurement process. We discuss calibration options and how they impact the distributions of analytical results. We look at distributions of blank results obtained from different labs, and discuss their relevance to determining reporting limits. We examine the way measurements are made from spectra, how that process impacts our understanding of the actual statistical distributions of Be measurements, and how interferences can affect Be measurements. Our objective is to gain sufficient confidence in the measurement process so that the usual questions will make sense and the survey results will be credible. Based on our observations, we offer these recommendations: prepare calibration samples in digested blank swipes; force the calibration line through (0,0); base reporting limits on field blank measurement distributions rather than 40 CFR 236 calculations; use, but do not believe, the usual lognormal distribution assumption; and avoid the 234.861 nm emission line.

  4. 40 CFR 63.11166 - What General Provisions apply to primary beryllium production facilities?

    Science.gov (United States)

    2010-07-01

    ... primary beryllium production facilities? 63.11166 Section 63.11166 Protection of Environment ENVIRONMENTAL... Primary Nonferrous Metals Area Sources-Zinc, Cadmium, and Beryllium Primary Beryllium Production Facilities § 63.11166 What General Provisions apply to primary beryllium production facilities? (a) You...

  5. Application of sintered titanium alloys to metal denture bases: a study of titanium powder sheets for complete denture base.

    Science.gov (United States)

    Doi, H; Harrori, M; Hasegawa, K; Yoshinari, M; Kawada, E; Oda, Y

    2001-02-01

    The purpose of this study was the fabrication of titanium powder sheets to enable the application of sintered titanium alloys as metal denture bases. The effects of titanium particle shape and size, binder content, and plasticizer content on the surface smoothness, tensile strength and elongation of titanium powder sheets was investigated. To select a suitable ratio of powdered metal contents for application as a metal denture base, the effects of aluminum content in Ti sheets and various other powder metal contents in Ti-Al sheets on the density, sintering shrinkage, and bending strength were evaluated. Based on the results of the above experiments, we developed a mixed powder sheet composed of 83Ti-7Al-10Cr with TA45 titanium powder (atomized, -45 microm), and 8 mass% binder content. This titanium alloy sheet had good formability and ductility. Its sintered titanium alloy had a density of 3.2 g/cm3, sintering shrinkage of 3.8%, and bending strength of 403 MPa. The titanium alloy sheet is clinically acceptable for fabricating denture bases.

  6. Vacuum Brazing of TiAl Based Alloy with 40Cr Steel

    Institute of Scientific and Technical Information of China (English)

    周昀; 薛小怀; 吴鲁海; 楼松年

    2004-01-01

    The vacuum brazing of TiAl based alloy with 40Cr steel was investigated using Ag-Cu-Ti filler metal.The experimental results show that the Ag, Cu, Ti atoms in the filler metal and the base metal inter-diffuse toward each other during brazing and react at the interface to form an inter-metallic AlCu2Ti compound which joins two parts to produce a brazing joint with higher strength.

  7. Effects of Ti and Zr Substituted on the Electrochemical Characteristics of MgNi-Based Alloy Electrodes

    Institute of Scientific and Technical Information of China (English)

    FENG Yan; JIAO Li-Fang; YUAN Hua-Tang; ZHAO Ming

    2007-01-01

    Mg-based hydrogen storage alloys MgNi, Mg0.9Ti0.1Ni, and Mg0.9Ti0.06Zr0.04Ni were successfully prepared by means of mechanical alloying (MA). The structure and the electrochemical characteristics of these Mg-based materials were studied. The X-ray diffraction (XRD) result shows that the main phases of the alloys exhibit amorphous structure. The scanning electron microscopy (SEM) photograph shows that the particle size of Ti and Zr substituted alloys was about 2-4 μm in diameter. The cycle lives of the alloys were prolonged by adding Ti and Zr. After 50charge-discharge cycles, the discharge capacity of Mg0.9Ti0.06Zr0.04Ni was 91.74% higher than that of MgNi alloy and 37.96% higher than that of Mg0.9Ti0.1Ni alloy. The main reason for the electrode capacity decay is the formation of Mg(OH)2 (product of Mg corrosion) at the surface of alloy. The potentiodynamic polarization result indicates that Ti and Zr doping improves the anticorrosion in an alkaline solution. The electrochemical impedance spectroscopy (EIS) results suggest that proper amount of Ti and Zr doping improves the electrochemical catalytic activity significantly.

  8. Comparison of Crevice Corrosion of Fe-Based Amorphous Metal and Crystalline Ni-Cr-Mo Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Shan, X; Ha, H; Payer, J H

    2008-07-24

    The crevice corrosion behaviors of an Fe-based bulk metallic glass alloy (SAM1651) and a Ni-Cr-Mo crystalline alloy (C-22) were studied in 4M NaCl at 100 C with cyclic potentiodynamic polarization and constant potential tests. The corrosion damage morphologies, corrosion products and the compositions of corroded surfaces of these two alloys were studied with optical 3D reconstruction, Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Auger Electron Spectroscopy (AES). It was found that the Fe-based bulk metallic glass (amorphous alloy) SAM1651 had a more positive breakdown potential and repassivation potential than crystalline alloy C-22 in cyclic potentiodynamic polarization tests and required a more positive oxidizing potential to initiate crevice corrosion in constant potential test. Once crevice corrosion initiated, the corrosion propagation of C-22 was more localized near the crevice border compared to SAM1651, and SAM1651 repassivated more readily than C-22. The EDS results indicated that the corrosion products of both alloys contained high amount of O and were enriched in Mo and Cr. The AES results indicated that a Cr-rich oxide passive film was formed on the surfaces of both alloys, and both alloys were corroded congruently.

  9. Influence of the pulsed plasma treatment on the corrosion resistance of the low-alloy steel plated by Ni-based alloy

    Science.gov (United States)

    Dzhumaev, P.; Yakushin, V.; Kalin, B.; Polsky, V.; Yurlova, M.

    2016-04-01

    This paper presents investigation results of the influence of high temperature pulsed plasma flows (HTPPF) treatment on the corrosion resistance of low-alloy steel 0.2C-Cr-Mn- Ni-Mo cladded by the rapidly quenched nickel-based alloy. A technique that allows obtaining a defect-free clad layer with a good adhesion to the substrate was developed. It is shown that the preliminary treatment of steel samples by nitrogen plasma flows significantly increases their corrosion resistance in the conditions of intergranular corrosion test in a water solution of sulfuric acid. A change of the corrosion mechanism of the clad layer from intergranular to uniform corrosion was observed as a result of sub-microcrystalline structure formation and homogeneous distribution of alloying elements in the plasma treated surface layer thus leading to the significant increase of the corrosion resistance.

  10. Microstructural Evolution During Friction Stir Welding of Mild Steel and Ni-Based Alloy 625

    Science.gov (United States)

    Fernandez, Johnnatan Rodriguez; Ramirez, Antonio J.

    2017-01-01

    Microstructure evolution during friction stir welding (FSW) of mild steel and Ni-based alloy 625 was studied. Regarding the Ni-based alloy, the welding process led to grain refinement caused by discontinuous and continuous dynamic recrystallization, where bulging of the pre-existing grains and subgrain rotation were the primary mechanisms of recrystallization. In the steel, discontinuous dynamic recrystallization was identified as the recovery process experienced by the austenite. Simple shear textures were observed in the regions affected by the deformation of both materials. Although the allotropic transformation obscured the deformation history, the thermo-mechanically affected zone was identified in the steel by simple shear texture components. A new methodology for the study of texture evolution based on rotations of the slip systems using pole figures is presented as an approximation to describe the texture evolution in FSW.

  11. Microstructural Evolution During Friction Stir Welding of Mild Steel and Ni-Based Alloy 625

    Science.gov (United States)

    Fernandez, Johnnatan Rodriguez; Ramirez, Antonio J.

    2017-03-01

    Microstructure evolution during friction stir welding (FSW) of mild steel and Ni-based alloy 625 was studied. Regarding the Ni-based alloy, the welding process led to grain refinement caused by discontinuous and continuous dynamic recrystallization, where bulging of the pre-existing grains and subgrain rotation were the primary mechanisms of recrystallization. In the steel, discontinuous dynamic recrystallization was identified as the recovery process experienced by the austenite. Simple shear textures were observed in the regions affected by the deformation of both materials. Although the allotropic transformation obscured the deformation history, the thermo-mechanically affected zone was identified in the steel by simple shear texture components. A new methodology for the study of texture evolution based on rotations of the slip systems using pole figures is presented as an approximation to describe the texture evolution in FSW.

  12. Sn-Sb-Se based binary and ternary alloys for phase change memory applications

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Kyung-Min

    2008-10-28

    In this work, the effect of replacing Ge by Sn and Te by Se was studied for a systematic understanding and prediction of new potential candidates for phase change random access memories applications. The temperature dependence of the electrical/structural properties and crystallization kinetics of the Sn-Se based binary and Sn-Sb-Se based ternary alloys were determined and compared with those of the GeTe and Ge-Sb-Te system. The temperature dependence of electrical and structural properties were investigated by van der Pauw measurements, X-ray diffraction, X-ray reflectometry. By varying the heating rate, the Kissinger analysis has been used to determine the combined activation barrier for crystallization. To screen the kinetics of crystallization, a static laser tester was employed. In case of binary alloys of the type Sn{sub x}Se{sub 1-x}, the most interesting candidate is SnSe{sub 2} since it crystallizes into a single crystalline phase and has high electrical contrast and reasonably high activation energy for crystallization. In addition, the SnSe{sub 2}-Sb{sub 2}Se{sub 3} pseudobinary alloy system also might be sufficient for data retention due to their higher transition temperature and activation energy for crystallization in comparison to GeTe-Sb{sub 2}Te{sub 3} system. Furthermore, SnSe{sub 2}-Sb{sub 2}Se{sub 3} pseudobinary alloys have a higher crystalline resistivity. The desired rapid crystallization speed can be obtained for Sn{sub 1}Sb{sub 2}Se{sub 5} and Sn{sub 2}Sb{sub 2}Se{sub 7} alloys. (orig.)

  13. Novel bioactive Co-based alloy/FA nanocomposite for dental applications

    Directory of Open Access Journals (Sweden)

    Mohammadhossein Fathi

    2012-01-01

    Full Text Available Background: Dental cobalt base alloys are biocompatible dental materials and have been widely used in dentistry. However, metals are bioinert and may not present bioactivity in human body. Bioactivity is the especial ability to interact with human body and make a bonding to soft and hard tissues. The aim of the present research was fabrication and bioactivity evaluation of novel cobalt alloy/Fluorapatite nanocomposite (CoA/FaNC with different amounts of Fluorapatite (FA nanopowder. Materials and Methods: Co-Cr-Mo alloy (ASTM F75 powder was prepared and mixed in a planetary ball mill with different amounts of FA nanopowders (10, 15, 20% wt. Prepared composite powders were cold pressed and sintered at 1100°C for 4 h. X-ray diffraction (XRD, scanning electron microscopy and transition electron microscopy techniques were used for phase analysis, crystallite size determination of FA and also for phase analysis and evaluation of particle distribution of composites. Bioactivity behavior of prepared nanocomposites was evaluated in simulated body fluid (SBF for 1 up to 28 days. Results: Results showed that nucleus of apatite were formed on the surface of the prepared CoA/FaNC during 1 up to 28 days immersion in the SBF solution. On the other hand, CoA/FaNC unlike Co-base alloy possessed bone-like apatite-formation ability. Conclusion: It was concluded that bioinert Co-Cr-Mo alloy could be successfully converted into bioactive nanocomposite by adding 10, 15, 20 wt% of FA nano particles.

  14. Biocorrosion behavior and cell viability of adhesive polymer coated magnesium based alloys for medical implants

    Energy Technology Data Exchange (ETDEWEB)

    Abdal-hay, Abdalla [Departmentt of Bionano System Engineering, College of Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Mechanical Design Engineering, Advanced wind power system research institute, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Dewidar, Montasser [Department of Materials and Mechanical Design, Faculty of Energy Engineering, South Valley University, Aswan (Egypt); Lim, Jae Kyoo, E-mail: jklim@jbnu.ac.kr [Department of Mechanical Design Engineering, Advanced wind power system research institute, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer The corrosion behavior of magnesium for orthopedic applications is extremely poor. Black-Right-Pointing-Pointer The solvent (DCM, THF and DMF) had a strong effect on the coatings performance. Black-Right-Pointing-Pointer Mg bar alloy coated with PVAc/DCM layers provided an excellent bonding strength. Black-Right-Pointing-Pointer Treated samples indicated significant damping for the degradation rate. Black-Right-Pointing-Pointer Cytocompatibility on MC3T3 cells of the PVAc/DCM samples revealed a good behavior. - Abstract: The present study was ultimately aimed to design novel adhesive biodegradable polymer, poly(vinyl acetate) (PVAc), coatings onto Mg based alloys by the dip-coating technique in order to control the degradation rate and enhance the biocompatibility of magnesium alloys. The influence of various solvents on PVAc surface topography and their protection of Mg alloys were dramatically studied in vitro. Electrochemical polarization, degradation, and PVAc film cytocompatibility were also tested. Our results showed that the solvent had a significant effect on coating quality. PVAc/dichloromethane solution showed a porous structure and solution concentration could control the porous size. The coatings prepared using tetrahydrofuran and dimethylformamide solvents are exceptional in their ability to generate porous morphology even at low polymer concentration. In general, the corrosion performance appears to be different on different PVAc-solvent system. Immersion tests illustrated that the porous morphology on PVAc stabilized corrosion rates. A uniform corrosion attack in artificial simulation body fluid was also exhibited. The cytocompatibility of osteoblast cells (MC3T3) revealed high adherence, proliferation, and survival on the porous structure of PVAc coated Mg alloy, which was not observed for the uncoated samples. This novel PVAc coating is a promising candidate for biodegradable implant materials, which might

  15. Urinary levels of nickel and chromium associated with dental restoration by nickel-chromium based alloys

    Institute of Scientific and Technical Information of China (English)

    Bo Chen; Gang Xia; Xin-Ming Cao; Jue Wang; Bi-Yao Xu; Pu Huang; Yue Chen; Qing-Wu Jiang

    2013-01-01

    This paper aims to investigate if the dental restoration of nickel-chromium based alloy (Ni-Cr) leads to the enhanced excretions of Ni and Cr in urine. Seven hundred and ninety-five patients in a dental hospital had single or multiple Ni-Cr alloy restoration recently and 198 controls were recruited to collect information on dental restoration by questionnaire and clinical examination. Urinary concentrations of Ni and Cr from each subject were measure by graphite furnace atomic absorption spectrometry. Compared to the control group, the urinary level of Ni was significantly higher in the patient group of 〈 1 month of the restoration duration, among which higher Ni excretions were found in those with either a higher number of teeth replaced by dental alloys or a higher index of metal crown not covered with the porcelain. Urinary levels of Cr were significantly higher in the three patient groups of 〈1, 1 to 〈3 and 3 to 〈6 months, especially in those with a higher metal crown exposure index. Linear curve estimations showed better relationships between urinary Ni and Cr in patients within 6-month groups. Our data suggested significant increased excretions of urinary Ni and Cr after dental restoration. Potential short- and long-term effects of Ni-Cr alloy restoration need to be investigated.

  16. Characterization of constitutional liquid film migration in nickel-base alloy 718

    Science.gov (United States)

    Acoff, V. L.; Thompson, R. G.

    1996-09-01

    When multiphase alloys are rapidly heated, it is possible to cause melting of the interface between phases. This is called constitutional liquation if, during melting, the bulk composition is in a nonliquid region of the phase diagram but the tie-line between the liquating phases passes through a liquid region. The liquid produced during constitutional liquation can spread along grain boundaries and promote liquid film migration (LFM). This is known as constitutional liquid film migration (CLFM), which is thermodynamically similar to liquid film migration; however, mechanistically there are significant differences. Nickel-base alloy 718 has been studied to show the features of migration that are unique to CLFM. Experimentation consisted of heat-treating rods of alloy 718 to promote the trapping of niobium carbide particles on the grain boundaries. These samples were then subjected to isothermal treatments above their constitutional-liquation temperature, which produced CLFM of the grain boundaries. The movement of the liquid films away from their centers of curvature, the formation of a new solid solution behind the migrated liquid films, and the reversals of curvature of the migrated liquid films confirmed that CLFM was the phenomenon observed. The concentration of niobium behind the migrated liquid films for isothermal treatments below the solidus temperature was shown to be greater than the niobium concentration in the matrix. Above the solidus temperature, there was no increase in niobium concentration. The validity of the coherency strain hypothesis as the driving force for CLFM in alloy 718 is discussed.

  17. High temperature stability of Cr-carbides in an experimental Co-Re-based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Mukherji, Debashis; Klauke, Michael; Roesler, Joachim [Technische Universitaet Braunschweig (Germany). Institut fuer Werkstoffe; Strunz, Pavel [Nuclear Physics Institute and Research Center Rez (Czech Republic); Zizak, Ivo [Berliner Elektronenspeicherring-Gesellschaft fuer Synchrotronstrahlung, Berlin (Germany); Schumacher, Gerhard; Wiedenmann, Albrecht [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Berlin (Germany)

    2010-03-15

    The stability of the microstructure at high temperatures was studied in an experimental Co-Re-based alloy. The experimental alloy is mainly strengthened by Cr-carbides, particularly by those in the form of thin lamellar plates. Electron microscopic investigation on samples exposed for up to 1000 h to temperatures of 1000 and 1200 C showed that Cr{sub 23}C{sub 6} type carbides present in the alloy in different morphologies are unstable at these temperatures. It was also observed that the alloy hardness dropped after exposing the samples to elevated temperatures and much of this loss occurred within the first 100 h. In-situ diffraction measurements with synchrotron radiation showed that carbide dissolution started as early as 3 h of holding at 1000 C. Moreover, in-situ small angle neutron scattering results indicated that the carbides at the grain boundaries and the blocky carbides dissolve first and then the thin lamellar carbides. Further, the enrichment of Cr in the Co-matrix phase, which took place due to the dissolution of Cr-carbides, stabilized a Cr-Re-rich {sigma} phase. Although the dissolution of lamellar carbides results in a significant loss of strength, the formation of {sigma} phase with extremely high hardness partly compensated the for loss. The {sigma} phase is stable even at 1200 C. (orig.)

  18. Atom probe tomography of Ni-base superalloys Allvac 718Plus and Alloy 718.

    Science.gov (United States)

    Viskari, L; Stiller, K

    2011-05-01

    Atom probe tomography (APT) allows near atomic scale compositional- and morphological studies of, e.g. matrix, precipitates and interfaces in a wide range of materials. In this work two Ni-base superalloys with similar compositions, Alloy 718 and its derivative Allvac 718Plus, are subject for investigation with special emphasis on the latter alloy. The structural and chemical nuances of these alloys are important for their properties. Of special interest are grain boundaries as their structure and chemistry are important for the materials' ability to resist rapid environmentally induced crack propagation. APT has proved to be suitable for analyses of these types of alloys using voltage pulsed APT. However, for investigations of specimens containing grain boundaries and other interfaces the risk for early specimen fracture is high. Analyses using laser pulsing impose lower electrical field on the specimen thereby significantly increasing the success rate of investigations. Here, the effect of laser pulsing was studied and the derived appropriate acquisition parameters were then applied for microstructural studies, from which initial results are shown. Furthermore, the influence of the higher evaporation field experienced by the hardening γ' Ni(3)(Al,Nb) precipitates on the obtained results is discussed.

  19. Failure analysis of AZ31 magnesium alloy sheets based on the extended GTN damage model

    Science.gov (United States)

    Wang, Rui-ze; Chen, Zhang-hua; Li, Yu-jie; Dong, Chao-fang

    2013-12-01

    Based on the Gurson-Tvergaard-Needleman (GTN) model and Hill's quadratic anisotropic yield criterion, a combined experimental-numerical study on fracture initiation in the process of thermal stamping of Mg alloy AZ31 sheets was carried out. The aim is to predict the formability of thermal stamping of the Mg alloy sheets at different temperatures. The presented theoretical framework was implemented into a VUMAT subroutine for ABAQUS/EXPLICIT. Internal damage evolution due to void growth and coalescence developed at different temperatures in the Mg alloy sheets was observed by scanning electron microscopy (SEM). Moreover, the thermal effects on the void growth, coalescence, and fracture behavior of the Mg alloy sheets were analyzed by the extended GTN model and forming limit diagrams (FLD). Parameters employed in the GTN model were determined from tensile tests and numerical iterative computation. The distribution of major and minor principal strains in the specimens was determined from the numerical results. Therefore, the corresponding forming limit diagrams at different stress levels and temperatures were drawn. The comparison between the predicted forming limits and the experimental data shows a good agreement.

  20. Failure analysis of AZ31 magnesium alloy sheets based on the extended GTN damage model

    Institute of Scientific and Technical Information of China (English)

    Rui-ze Wang; Zhang-hua Chen; Yu-jie Li; Chao-fang Dong

    2013-01-01

    Based on the Gurson-Tvergaard-Needleman (GTN) model and Hill’s quadratic anisotropic yield criterion, a combined experimental-numerical study on fracture initiation in the process of thermal stamping of Mg alloy AZ31 sheets was carried out. The aim is to predict the formability of thermal stamping of the Mg alloy sheets at diff erent temperatures. The presented theoretical framework was implemented into a VUMAT subroutine for ABAQUS/EXPLICIT. Internal damage evolution due to void growth and coalescence developed at diff erent temperatures in the Mg alloy sheets was observed by scanning electron microscopy (SEM). Moreover, the thermal eff ects on the void growth, coalescence, and fracture behavior of the Mg alloy sheets were analyzed by the extended GTN model and forming limit diagrams (FLD). Parameters employed in the GTN model were determined from tensile tests and numerical iterative computation. The distribution of major and minor principal strains in the specimens was determined from the numerical results. Therefore, the corresponding forming limit diagrams at diff erent stress levels and temperatures were drawn. The comparison between the predicted forming limits and the experimental data shows a good agreement.