J. Phys. IV France
Volume 11, Numéro PR3, Août 2001
Thirteenth European Conference on Chemical Vapor Deposition
Page(s) Pr3-861 - Pr3-867
Thirteenth European Conference on Chemical Vapor Deposition

J. Phys. IV France 11 (2001) Pr3-861-Pr3-867

DOI: 10.1051/jp4:20013107

CVD mullite and mullite-alumina corrosion protection coatings for silicon based ceramics

S. M. Zemskova, J. A. Haynes and K. M. Cooley

Oak Ridge National Laboratory, P.O. Box 2008, 1 Bethel Valley Road, Oak Ridge, TN 37831-6063, U.S.A.

Application of silicon-based ceramics (SiC, Si3N4) and SiC/SiC composites as high-temperature structural materials requires the development of environmentally resistant coatings due to rapid degradation of the protective silica scale in high temperature water vapor. The CVD method of fabricating dense, high-purity, crystalline mullite (3Al2O3x2SiO2) and mullite-alumina coatings was utilized in this study. The textured mullite coatings were generally comprised of crystalline grains (0.3-0.5 µm) with a columnar structure. Coatings with thickness of less than 2µm, provided excellent corrosion protection for Si3N4 and SiC/SiC exposed to lowvelocity, high pressure (1 MPa) steam at 1200°C.

© EDP Sciences 2001