Oxidation Behavior and Corrosion Mechanism of Sic Ceramics at High Temperatures in Wet Air Environment

Abstract

The oxidation behavior and corrosion mechanism of SiC ceramics were investigated at high temperatures between 1000 and 1200 ℃ in wet environments (75% water/25% air). Experimental results showed that protective SiO2 layers formed at 1000 and 1100 ℃. Whereas, the oxidation and water vapor corrosion proceed simultaneously at 1200 ℃, resulting in a significant weight loss. Consequently, a porous layer of 30 μm formed after 10 hours oxidation. The calculated activation energy based on the oxide layer thickness data versus time curves was 109 kJ/mol, which was lower than the values reported in dry air environments.

Keywords: SiC ceramics, H2O/Air environment, Oxidation mechanism, High temperature water vapor corrosion