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High temperature reactions within SiC–Al2O3 composites

Published online by Cambridge University Press:  31 January 2011

Ahmed Gadalla*
Affiliation:
Chemical Engineering Department, Texas A&M University, College Station, Texas 77843-3122
Mohamed Elmasry*
Affiliation:
Chemical Engineering Department, Texas A&M University, College Station, Texas 77843-3122
Paisan Kongkachuichay
Affiliation:
Chemical Engineering Department, Texas A&M University, College Station, Texas 77843-3122
*
a)Author to whom correspondence should be addressed.
b)Now with Nuclear Energy Organization, Cairo, Egypt.
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Abstract

Composites of SiC–Al2O3 and SiC–mullite are unstable at high temperatures. The reactions occurring within the composites between 1700 and 1850 °C in stagnant inert atmospheres were characterized. Gaseous products cause excessive weight losses which cannot be attributed to passive oxidation. These losses can be successfully retarded by processing under high pressures. Compatible phases were determined by x-ray analysis for mixtures lying in the section SiC–Al4C3−Al2O3−SiO2. The reactions produced condensed phases of Al2OC and Al4O4C as well as gaseous SiO and CO. The condensed phases have high vapor pressures above 1700 °C. The effect of these reactions on densification of composites by firing at different temperatures for various periods under different pressures was studied. Dense materials prepared under high pressures at 1825 °C were tested at 1700 °C under normal pressure in argon, where active oxidation is expected, and weight losses were insignificant.

Type
Articles
Copyright
Copyright © Materials Research Society 1992

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References

1.Larsen, D. C., Adams, J.W, Johnson, L.R, Teotia, A.P.S., and Hill, L. G., in Ceramic Materials for Advanced Heat Engines, Technical And Economic Evaluation (Noyes Publications, Park Ridge, NJ, 1985), pp. 47.Google Scholar
2.Sheppard, L. M., Am. Ceram. Soc. Bull. 69, 1012 (1990).Google Scholar
3.Dobson, M. M., Silicon Carbide Alloys (Parthenon Press, Carnfoarth, Lancashire, England, 1986), pp. 15.Google Scholar
4.Lacky, W. J., Stinton, D.P., Cerny, G.A., Schaffauser, A.C., and Fehrenbacher, L. L., Adv. Ceram. Mater. 2, 24 (1987).CrossRefGoogle Scholar
5.Helms, H. E., Heitman, P.W., Lindgren, L.C, and Thrasher, S.R., Ceramic Applications in Turbine Engines (Noyes Publications, Park Ridge, NJ, 1986), pp. 143–237.Google Scholar
6.Ostertag, C. P., in Sintering of Advanced Ceramics, edited by Handwerker, C. A., Blendell, J. E., and Kaysser, W. A (The American Ceramic Society, Inc., Westerville, OH, 1990), pp. 745752.Google Scholar
7.Sacks, M. D., Lee, H-W., and Rojas, O. E., J. Am. Ceram. Soc. 71, 370 (1988).CrossRefGoogle Scholar
8.Tiegs, T. N. and Becher, P. F., Am. Ceram. Soc. Bull. 67, C267 (1984).Google Scholar
9.Porter, J. R., Lange, F. F., and Chokshi, A. H., Am. Ceram. Soc. Bull. 66, 343 (1987).Google Scholar
10.Lundberg, R., Kahlman, L., Pompe, R., Carlson, R., and Warren, R., Am. Ceram. Soc. Bull. 66, 330 (1987).Google Scholar
11.Gadkaree, K. P. and Chyung, K., Am. Ceram. Soc. Bull. 65, 370 (1986).Google Scholar
12.Panda, P. C. and Seydel, E.R., Am. Ceram. Soc. Bull. 65, 338 (1986).Google Scholar
13.Shalek, P. D., Petrovic, J.J., Hurley, G.F., and Gac, F.D., Am. Ceram. Soc. Bull. 65, 351 (1986).Google Scholar
14.Becher, P. F. and Wei, G. C., J. Am. Ceram. Soc. 67, C267 (1984).CrossRefGoogle Scholar
15.Samanta, S. C. and Musikant, S., Ceram. Eng. Sci. Proc. 6, 663 (1985).CrossRefGoogle Scholar
16.Gac, F. D. and Petrovic, J. J., J. Am. Ceram. Soc. 68, C200 (1985).CrossRefGoogle Scholar
17.Kingery, W. D., Bowen, H. K., and Uhlmann, D. R., Introduction to Ceramics (John Wiley & Sons, Inc., New York, 1976), 2nd ed., p. 240.Google Scholar
18.Federer, J. C., presented at The 1st Int. Ceramics Science & Technology Congress, Anaheim, CA, October 31-November 3, 1989, paper no. 27-SXV-89C.Google Scholar
19.Jackson, T. B., Hurford, A.C., Bruner, S.L., and Cutler, R.A., in Silicon Carbide ‘87, edited by Cawley, J. C. and Semler, C.E. (The American Ceramic Society, Inc., Westerville, OH, 1989), pp. 227240.Google Scholar
20.Cutler, R. A. and Jackson, T.B., in 3rd Int. Symp. on Ceramic Materials and Components for Engines, edited by Tennery, V. J. (Las Vegas, NV, November 27–30, 1988), pp. 309318A.Google Scholar
21.Chase, M. W., Jr., Davies, C. A., Downey, J.R., Jr., Frurip, D.J., McDonald, R. A., and Syverud, A. N., JANAF Thermochemical Tables (The American Chemical Society and the American Institute of Physics, New York, 1986), 3rd ed.Google Scholar
22.Kubo, H., Endo, H., and Sugita, K., Proceedings of the 1986 International Powder Metallurgy, Diisseldorf, West Germany, July 7–11, 1986, pp. 11511154.Google Scholar
23.Okada, K. and Otsuka, N., J. Am. Ceram. Soc. 69, 652 (1986).CrossRefGoogle Scholar
24.Winnacker, K. and Kiichler, L, Chemische Technologie (Carl Hanser Verley, Miinchen, Germany), Vols. 1 and 2.Google Scholar