Oxidation of Metals

, Volume 26, Issue 5–6, pp 363–384 | Cite as

High-temperature oxidation of a rapidly solidified amorphous Ta-Ir alloy

  • Catherine M. Cotell
  • Gregory J. Yurek


The oxidation products formed at 500 and 700°C on an amorphous Ta-44.5 at% Ir alloy in an Ar-0.1% O2 gas mixture were characterized using SEM, XRD, EPMA, TEM, STEM, AES, and XPS. Initially, a thin (3–4 nm) layer of Ta2O5 formed at the surface of the alloy. Continued growth of the Ta2O5, which occurred very rapidly, involved diffusion of oxygen anions from the Ta2O5/gas interface to the alloy/Ta2O5 interface, where tantalum was selectively oxidized. Because the oxide grew more quickly than iridium could diffuse back into the alloy, the iridium coalesced into platelets of crystalline iridium-rich alloy that were oriented approximately parallel to the oxide/alloy interface, and which became embedded in a matrix of Ta2O5. The unoxidized core remained in the glassy state. The oxidation process and/or the dissolution of oxygen into the unoxidized alloy caused the alloy to become embrittled.

Key words

high-temperature oxidation metallic glasses amorphous alloys tantalum iridium 


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  1. 1.
    U. Gonser, M. Ackermann, and H.-G. Wagner,J. Mag. Mat. 31-34, 1605 (1983).Google Scholar
  2. 2.
    L. Leonardsson and B. Andersson,Proceeding of the 4th International Conference on Rapidly Quenched Metals (Metals Society, London, 1981), p. 579.Google Scholar
  3. 3.
    O. Hunderi and R. Bergerson,Corr. Sci. 22, 135 (1982).Google Scholar
  4. 4.
    J. Bigot, Y. Calvayrac, M. Harmelin, J-P. Chevalier, and A. Quivy,Proceedings of the 4th International Conference on Rapidly Quenched Metals (Metals Society, London, 1981), p. 1463.Google Scholar
  5. 5.
    L. Ley and J. D. Riley,Proceedings of the 7th International Vacuum Congress and 3rd International Conference on Solid Surfaces (Berger and Sohne, Vienna), p. 2031, 1977.Google Scholar
  6. 6.
    M. Fisher, D. E. Polk, and B. C. Giessen inRapid Solidification Processing—Principles and Technologies II, R. Mehrabian, B. Kear, and M. Cohen, eds. (Claitors Publishing Division, Baton Rouge, LA, 1978), p. 140.Google Scholar
  7. 7.
    S. Davis, M. Fischer, B. C. Giessen, and D. E. Polk, inRapidly Quenched Metals III, B. Cantor, ed. (The Metals Society, London, 1978), Vol. 2, p. 245.Google Scholar
  8. 8.
    O. Kubaschewski and C. B. Alcock,Metallurgical Thermochemistry, 5th ed (Pergamon Press, New York, 1979), pp. 380, 383.Google Scholar
  9. 9.
    C. D. Wagner, W. Davis, W. M. Riggs, L. E. Davis, J. F. Moulder, and G. E. Muilenberg,Physical Electronics Handbook of X-Ray Photoelectron Spectroscopy (Perkin-Elmer publication, Eden Prairie, Minnesota 1979).Google Scholar
  10. 10.
    A. E. McHale and H. L. Tuller,J. Am. Cer. Soc.,68, 651 (1985).Google Scholar
  11. 11.
    V. P. Elyutin, T. G. Lenskaya, Yu. A. Pavlov, and V. P. Polyakov,Dokl. Akad. Nank. SSSR (Tech. Phys.) 199, 62 (1971).Google Scholar
  12. 12.
    C. Wagner,J. Electrochem. Soc. 99, 369 (1952).Google Scholar
  13. 13.
    B. Cantor and R. W. Cahn, inAmorphous Metallic Alloys, F. E. Luborsky, ed. (Butterworths, London, 1983), p. 487.Google Scholar
  14. 14.
    M. Kijek, M. Ahmadzadeh, B. Cantor, and R. W. Cahn,Scripta Met. 14, 1337 (1980).Google Scholar
  15. 15.
    C. Wagner,J. Electrochem. Soc. 103, 571 (1956).Google Scholar
  16. 16.
    G. Yurek, ORNL Report No. ORNL-5116 (Oak Ridge National Laboratory, Oak Ridge, TN, 1979).Google Scholar
  17. 17.
    R. Wong and M. D. Merz, Battelle Pacific Northwest Division, Richland, Washington, private communication.Google Scholar
  18. 18.
    S. Mrowec and K. Przybylski,High Temp. Mat. Proc. 6, 1 (1984).Google Scholar

Copyright information

© Plenum Publishing Corporation 1986

Authors and Affiliations

  • Catherine M. Cotell
    • 1
  • Gregory J. Yurek
    • 1
  1. 1.H. H. Uhlig Corrosion LaboratoryMassachusetts Institute of TechnologyCambridge

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