Advertisement

Journal of Materials Science

, Volume 30, Issue 13, pp 3421–3428 | Cite as

Coarsening of hafnium carbide particles in tungsten

  • Y. Ozaki
  • R. H. Zee
Article

Abstract

The coarsening behaviour of finely dispersed HfC particles in a W-HfC alloy was investigated by monitoring the growth rate of the particles. An activation energy of 480 kJ mol−1 was obtained for the process. Diffusion experiments of hafnium in tungsten were conducted at temperatures between 1773 and 2573 K using a secondary ion mass spectroscopy technique to determine the diffusion contribution to the coarsening process. The diffusion process at high temperature is controlled by lattice diffusion with an activation energy of 335 kJ mol−1 whereas that at low temperature is governed by grain-boundary diffusion with an activation energy of 170 kJ mol−1. It appears that the coarsening process is controlled by two energy barriers: one dictated by the diffusivity of hafnium and the other by the solubility limit as a function of temperature. The strain energy required to dissociate the carbide particles into individual species was also considered. The effects of the coarsening of HfC particles in a dispersion-strengthened W-0.4 mol% HfC alloy on recrystallization and creep deformation were illustrated using a concerted experimental modelling analysis. Results show that the strengthening effect of the HfC particles is significantly reduced at temperatures above 1800 K, due to particle coarsening.

Keywords

Carbide Activation Energy Tungsten Hafnium Creep Deformation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Y. OZAKI, P. GAO, and R. H. ZEE, in “Proceedings of the 10th Symposium on Space Nuclear Power and Propulsion”, Part I, Albuquerque, January 1992, edited by M. EL-GENK, (American Institute of Physics, Woodbury, NY, 1993) 63.Google Scholar
  2. 2.
    Y. OZAKI and R. H. ZEE, Scripta Metall. 30 (10) (1994) 1263.CrossRefGoogle Scholar
  3. 3.
    W. D. KLOPP, P. L. RAFFO and W. R. WITZKE, J. Metals 6 (1971) 27.Google Scholar
  4. 4.
    R. H. TITRAN, J. R. STEPHENS and D. W. PETRASEK, NASA TM-101364, DOE/NASA/16310-8 (1988).Google Scholar
  5. 5.
    B. L. CHEN, PhD dissertation, Arizona State University (1990).Google Scholar
  6. 6.
    K. S. SHIN, A. LUO, B. L. CHEN and D. L. JACOBSON, J. Metals 8 (1990) 12.Google Scholar
  7. 7.
    A. J. ARDELL, Acta Metall 15 (1967) 1772.CrossRefGoogle Scholar
  8. 8.
    A. SHEPELA, J. Less-Common Metals 26 (1972) 33.CrossRefGoogle Scholar
  9. 9.
    K. B. POVAROVA, Russ. Metall. 2 (1981) 134.Google Scholar
  10. 10.
    A. A. KOROLEV, L. V. PAVLINOV and M. I. GAVRILYUK, Fiz. Metal. Metalloved. 33 (1972) 295.Google Scholar
  11. 11.
    R. E. PAWEL and T. S. LUNDY, Acta Metall. 17 (1969) 979.CrossRefGoogle Scholar
  12. 12.
    P. J. GOODHEW, “Specimen Preparation for Transmission Electron Microscopy of Materials (Microscopy Handbooks 03)” (Oxford University Press, Oxford, 1984).Google Scholar
  13. 13.
    S. K. BHATTACHARYYA and K. C. RUSSELL, Metall. Trans. 3 (1972) 2195.CrossRefGoogle Scholar
  14. 14.
    A. J. ARDELL, in “Proceedings of Phase Transformations '87”, University of Cambridge, July 1987, edited by G. W. LORIMER (Institute of Metals, London, 1988). p. 485.Google Scholar
  15. 15.
    H. BRAUN and E. RUDY, Z. Metallkde 51 (1960) 360.Google Scholar
  16. 16.
    R. P. ELLIOT, “Constitution of Binary Alloys: First Supplement” (McGraw-Hill, New York, 1965) p. 514.Google Scholar
  17. 17.
    V. N. YEREMENKO, T. Y. VELIKANOVA, L. V. ARTYUKH and A. S. VISHNEVSKY, Rev. Int. Haut. Temp. Refract. 12 (1975) 209.Google Scholar
  18. 18.
    E. GEBHARDT, E. FROMM and U. ROY, Z. Metallkde 57 (1966) 732.Google Scholar
  19. 19.
    E. K. STORMS, “The Refractory Carbides” (Academic Press, New York, 1967).Google Scholar
  20. 20.
    R. A. ORIANI, Acta Metall. 14 (1966) 84.CrossRefGoogle Scholar
  21. 21.
    E. O. HALL, Proc. Phys. Soc. 747 (1951) 1364.Google Scholar
  22. 22.
    N. J. PETCH, J. Iron Steel Inst. 25 (1953) 174.Google Scholar
  23. 23.
    C. S. SMITH, Trans Met. Soc. AIME 175 (1948) 345.Google Scholar
  24. 24.
    H. M. YUM, NASA TM-101446, DOE/NASA/16310-7 (1988).Google Scholar
  25. 25.
    B. L. CHEN, A. LUO, K. S. SHIN and D. L. JACOBSON, in “Refractory Metals: State-of-the Art 1988”, edited by P. KUMAR and R. L. AMMON (Minerals, Metals and Materials Society, Warrendale, PA, 1989) p. 65.Google Scholar
  26. 26.
    A. LUO, D. L. JACOBSON and K. S. SHIN, in “Proceedings of the 26th Intersociety Energy Conversion Engineering Conference”, Vol. 3, Boston, August 1991 (American Nuclear Society, 1991) p. 142.Google Scholar
  27. 27.
    R. LAGNEBORG, Scripta Metall. 7 (1973) 605.CrossRefGoogle Scholar

Copyright information

© Chapman & Hall 1995

Authors and Affiliations

  • Y. Ozaki
    • 1
  • R. H. Zee
    • 1
  1. 1.Materials Engineering ProgramAuburn UniversityUSA

Personalised recommendations