Journal of Materials Science

, Volume 18, Issue 5, pp 1374–1380 | Cite as

Effect of vacuum-treatment on mechanical properties of W-Ni-Fe heavy alloy

  • H. K. Yoon
  • S. H. Lee
  • S. -J. L. Kang
  • D. N. Yoon


The effect of heat-treatment in vacuum and hydrogen on the ductility and UTS of the sintered 96W-2.8Ni-1.2Fe (by wt%) heavy alloy has been studied. The elongation of the as-sintered alloy is about 8%, but after a few minutes of heat treatment in vacuum at 800° C it increases markedly to about 19%. When the sintered specimen is heat-treated in vacuum at 600° C, the elongation increases rapidly with time, reaching 20% after about 10 min. The values of UTS also increase after vacuum treatment. Heat treatment in hydrogen, however, shows no change in mechanical properties from the as-sintered state. The effect of vacuum treatment is thus attributed to the removal of hydrogen embrittlement. Based on the hydrogen diffusion model, a practical guide line is suggested for determining the optimum vacuum treatment conditions. The scanning electron micrographs of the fracture surfaces show that hydrogen weakens mainly the interface between tungsten grains and matrix.


Heat Treatment Tungsten Ductility Fracture Surface Electron Micrographs 
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  1. 1.
    T. D. Watts, Technical Report Number Doc. Y-1675, AEC, Oak Ridge, Tennessee (1969).Google Scholar
  2. 2.
    L. Ekbom,Scand. J. Met. 5 (1976) 179.Google Scholar
  3. 3.
    F. E. Sczerzenie andH. E. Rogers, in “Hydrogen in Metals”, edited by I. M. Bernstein and A. W. Thompson (ASM, Metals Park, Ohio, 1974) p. 645.Google Scholar
  4. 4.
    H. Sheinberg, J. T. Frakes andR. E. Riley, Technical Report Number LA-4685-Ms, Scientific Laboratories, University of California, New Mexico (1971).Google Scholar
  5. 5.
    J. M. Googin, W. L. Harper, A. C. Neeley andL. R. Phillips, Technical Report Number Y-1364, Union Carbide Nuclear Co., Y-12 Plant (1961).Google Scholar
  6. 6.
    J. M. Sakai andC. Grabarek, in “Powder Metallurgy in Defense Technology” Vol. 4 (MPIF, Princeton, 1978) p. 85.Google Scholar
  7. 7.
    D. V. Edmonds andP. N. Jones,Metall. Trans. 10A (1979) 289.Google Scholar
  8. 8.
    R. V. Minakova, A. N. Pilyankevich, O. K. Teodorovich andI. N. Frantsevich,Poroshk. Mettall. No. 5 (65) (1968) 73.Google Scholar
  9. 9.
    K. S. Churn andD. N. Yoon,Power Met. 4 (1979) 175.Google Scholar
  10. 10.
    K. Seto, T. Seto andS. Iwasaki,J. Jpn. Soc. Power Met. 7 (1960) 149.Google Scholar
  11. 11.
    R. H. Krock andL. Shepard,Trans. AIME 227 (1963) 1127.Google Scholar
  12. 12.
    J. Crank, “The Mathematics of Diffusion”, 2nd edn. (Clarendon Press, Oxford, 1975) p. 73.Google Scholar
  13. 13.
    G. L. Powell,Anal. Chem. 44 (1972) 2357.Google Scholar
  14. 14.
    S. C. Smith, in “Hydrogen in Metals”, edited by I. M. Bernstein and A. W. Thompson (ASM, Metals Park, Ohio, 1974) p. 485.Google Scholar

Copyright information

© Chapman and Hall Ltd. 1983

Authors and Affiliations

  • H. K. Yoon
    • 1
  • S. H. Lee
    • 1
  • S. -J. L. Kang
    • 1
  • D. N. Yoon
    • 1
  1. 1.Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologySeoulKorea

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