Oxidation behaviour of reaction-bonded alumina compacts using an Al88Si12 alloy precursor
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The oxidation behaviour of attrition-milled Al88Si12/Al2O3 powder mixtures was investigated for the formation of mullite/Al2O3 composites by the reaction bonded alumina (RBAO) process. Cylindrical powder compacts were heated at 5°C min−1 to temperatures between 450 and 1400°C. Oxidation occurred rapidly between ca. 400 and 750°C. Dense, outer reaction layers which formed at the lower temperatures inhibited complete oxidation and led to fracture of the body during continued heating to higher temperatures (above ca. 850°C) While the incorporation of ZrO2 improved the oxidation of the samples, X-ray analysis indicated that the Si in the alloy reacted with the ZrO2 to form phases which prevented the formation of mullite at the temperatures used in the experiments.
KeywordsOxidation Polymer Alumina Powder Compact Powder Mixture
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- 1.G. Maczura, K. J. Moody and E. M. Anderson, Ceram. Bull. 71 (1992) 780.Google Scholar
- 2.W. D. Kingery, H. K. Bowen and D. R. Uhlmann, in “Introduction to ceramics”, 2nd Edn (John Wiley & Sons, New York, 1976) p. 508.Google Scholar
- 3.M. E. Washburn and W. S. Coblenz, Ceram. Bull. 67 (1988) 356.Google Scholar
- 12.J. Szekely, J. W. Evans and H. Y. Sohn, in “Gas-solid reactions” (Academic Press, New York, 1976) p. 130.Google Scholar