Durability of Ceramic Matrix Composites in Combustion EnvironmentsSiO2 scale volatility and the resulting recession of SiC has been previously identified for CVD, as well as sintered, SiC and Si3N4 materials. Linear weight loss and surface recession of SiC was observed as a result of SiO2 volatility for both fuel-lean and fuel-rich gas mixtures. A strong Arrhenius temperature dependence exist and parametric studies using multiple linear regression were used to develop recession relationships as a function of e(sup -Q/RT) central dot P(sup X)V(sup y) for both lean and rich combustion conditions. Recession of 0.2 - 2.0 micron/hr is predicted for typical combustion conditions at 1200 - 1400 C, with a somewhat higher absolute recession rate and activation energy for rich combustion versus lean.
Document ID
20000021273
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Robinson, Raymond C. (DYNACS Engineering Co., Inc. Brook Park, OH, United States)
Smialek, James L. (NASA Glenn Research Center Cleveland, OH, United States)