Paralinear oxidation of CVD SiC in water vapor

The oxidation kinetics of CVD SIC mere monitored by thermogravimetric analysis (TGA) in a 50% H2O/50% O-2 gas mixture flowing at 4.4 cm/s for temperatures between 1200 degrees and 1400 degrees C. Paralinear weight change kinetics were observed as the water vapor oxidized the SIC and simultaneously volatilized the silica scale. The long-term degradation rate of SiC is determined by the volatility of the silica scale. Rapid SIC surface recession rates were estimated from these data for actual aircraft engine combustor conditions.