Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-27T05:34:19.571Z Has data issue: false hasContentIssue false
  • English
  • Français

Mechanism of MoSi2 pest during low temperature oxidation

Published online by Cambridge University Press:  18 February 2016

T.C. Chou  and
T.G. Nieh
T.C. Chou
Affiliation:
Lockheed Research and Development Division, O/93-10, B/204, 3251 Hanover Street, Palo Alto, California 94304
T.G. Nieh
Affiliation:
Lockheed Research and Development Division, O/93-10, B/204, 3251 Hanover Street, Palo Alto, California 94304
Get access

Extract

The pest of monolithic poly- and single-crystalline molybdenum disilicide, as well as its composites, has been investigated by low temperature oxidation in air at temperatures ranging from 350 to 700 °C. Pest phenomenon (i.e., disintegration from bulk into powders) was consistently observed from samples oxidized at temperatures between 375 and 500 °C. In contrast, samples oxidized at 550 °C exhibited only severe cracking, and samples oxidized at 350 °C or at/above 600 °C were intact. The pested samples resulted in powdery products consisting of MoO3 whiskers, SiO2 clusters, and residual MoSi2. The MoO3 whiskers exhibited protruding characteristics, and were highly concentrated at microstructural heterogeneous sites, such as interparticle boundaries, grain boundaries, and cracks. Blisters were observed and found to be formed predominantly on the grain boundary and interparticle boundary interfaces of tested samples. These blisters were often found to be erupted, indicating that significant vapor pressure was built up underneath the sample surface. Interrupted oxidation tests at 500 °C revealed that a substantial volume change also occurred. The development of the pest of MoSi2 was found, macroscopically, to consist of nucleation and growth. In most cases, it initiated from some local microstructural inhomogeneities, and propagated throughout the samples. Based on the morphologies of disintegrated powders, two different kinetic processes were identified to be responsible for the pest reaction. According to the results from single crystals, the pest of MoSi2 appeared to be kinetically controlled by the formation and volatilization of MoO3. The mechanism of MoSi2 pest is proposed and discussed. Thermodynamic analyses are also presented to substantiate the experimental observations.

Type
Research Article
Information
Journal of Materials Research , Volume 8 , Issue 1 , January 1993 , pp. 214 - 226
Copyright
Copyright © Materials Research Society 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Fitzer, Von E., “Molybdenum Disilicide as High-Temperature Material,” Plansee Proa, 2nd Seminar, Reutte/Tyrol, 1955, pp. 56–79.Google Scholar
2. Rausch, J. J., ARF 2981-4, Armour Research Foundation, August 31, 1961, NSA 15-31171.Google Scholar
3. Aitken, E. A., in Intermetallic Compounds, edited by Westbrook, J. H. (John Wiley & Sons, Inc., New York, 1967), pp. 491–516.Google Scholar
4. Schilichting, J., High Temp.–High Press. 10, 241 (1978).Google Scholar
5. Searcy, A.W., J. Am. Ceram. Soc. 40, 431 (1957).CrossRefGoogle Scholar
6. Berkowitz-Mattuck, J. B. and Dils, R. R., Electrochem, J.. Soc. 112, 583 (1965).Google Scholar
7. Wirkus, C.D. and Wilder, D.R., J. Am. Ceram. Soc. 49, 173 (1966).Google Scholar
8. Lavrenko, V. A., Shemet, V. Z., and Goncharuk, A. V., Thermochim. Acta 93, 501 (1985).CrossRefGoogle Scholar
9. Coatings of High Temperature Materials, edited by Hausner, H. H. (Plenum, New York, 1966).CrossRefGoogle Scholar
10. Samsonov, G. V., Silicides and Their Uses in Engineering (Akad. Nauk. Ukr. SSR, Kiev, 1959).Google Scholar
11. Guivarc'h, A., Auvray, P., Le Cun, L., Boulet, J. P., Pelous, G., and Martinez, A., J. Appl. Phys. 49, 233 (1978).CrossRefGoogle Scholar
12. Perio, A. and Torres, J., J. Appl. Phys. 59, 2760 (1986).Google Scholar
13. Perio, A., Torres, J., Bomchil, G., Arnaud d'Avitaya, F., and Pantel, R., Appl. Phys. Lett. 45, 857 (1984).Google Scholar
14. Murarka, S. P., Silicides for VLSI Applications (Academic Press, New York, 1983).Google Scholar
15. Fitzer, E. and Remmele, W., 5th Int. Conf. on Composite Materials (TMS, Warrendale, PA, 1985), pp. 515–530.Google Scholar
16. Fitzer, E. and Schmidt, F. K., High Temp.-High Press. 3, 445 (1971).Google Scholar
17. Lu, T. C., Evans, A. G., Hecht, R. J., and Mehrabian, R., Acta Metall. 39, 1853 (1991).Google Scholar
18. Meschter, P.J., Scripta Met. et Mat. 25, 521 (1991).Google Scholar
19. Carter, D.H., “SiC Whisker-Reinforced MoSi2,” LA-11411-T (Los Alamos National Laboratory, NM, 1988).Google Scholar
20. Meschter, P.J., Scripta Met. et Mat. 25, 1065 (1991).Google Scholar
21. Bhattacharya, A. K. and Petrovic, J.J., J. Am. Ceram. Soc. 75, 23 (1992).Google Scholar
22. Meschter, P.J., Metall. Trans. A23 1763 (1992).Google Scholar
23. Chou, T. C. and Nieh, T. G., Scripta Met. et Mat. 26, 1637 (1992).CrossRefGoogle Scholar
24. Chou, T. C. and Nieh, T. G., Scripta Met. et Mat. 27, 19 (1992).Google Scholar
25. Nakamura, M., Matsumoto, S., and Hirano, T., J. Mater. Sci. 25, 3309 (1990).CrossRefGoogle Scholar
26. Joint Committee on Powder Diffraction Standards (JCPDS) #5- 508.Google Scholar
27. Gokhale, A. B. and Abbaschian, G. J., in Binary Alloy Phase Diagrams, edited by Massalski, T. B., Murray, J. L., Bennett, L. H., and Baker, H. (ASM, Metals Park, OH, 1986), Vol. I, p. 1632.Google Scholar
28. Ho, C.H., Prakash, S., Doerr, H.J., Deshpandey, C.V., and Bunshah, R.F., Thin Solid Films 207, 294 (1992).Google Scholar
29. Kubaschewski, O. and Alcock, C. B., Metallurgical Thermochemistry, 5th ed. (Pergamon Press, New York, 1979), pp. 336–384.Google Scholar
30. Barin, I., Knacke, O., and Kubaschewski, O., Thermochemical Properties of Inorganic Substances (Springer, New York, 1977), pp. 422–489.Google Scholar
31. Westbrook, J.H. and Wood, D.L., J. Nucl. Mater. 12, 208 (1964).Google Scholar
32. Kubaschewski, O. and Alcock, C. B., Metallurgical Thermochemistry, 5th ed. (Pergamon Press, New York, 1979), pp. 115–117.Google Scholar
33. Brewer, L., Lamoreaux, R. H., Ferro, R., Marazza, R., and Girgis, K., Molybdenum: Physico-Chemical Properties of Its Compounds and Alloys, edited by Brewer, L. (International Atomic Energy Agency, Vienna, 1980), p. 38.Google Scholar
34. Belton, G. R. and Jordan, A. S., J. Phys. Chem. 69, 2065 (1965).Google Scholar
35. Millner, T. and Neugebauer, J., Nature 163, 601 (1949).CrossRefGoogle Scholar
36. McKamey, C. G. (private communications, 1992).Google Scholar