The oxidation behavior and corrosion mechanism of SiC matrix ceramics in a high temperature wet air environment

The oxidation behavior and corrosion mechanism of SiC ceramics were investigated at high temperatures ranging from 1000 degrees C to 1200 degrees C in wet environments (75 % water/25 % air). The results demonstrate the formation of protective SiO 2 layers, which effectively inhibit further oxidation at 1000 degrees C and 1100 degrees C. However, simultaneous oxidation and water vapor corrosion occur at 1200 degrees C, leading to substantial weight loss and the development of numerous porous layers that can reach up to 30 mu m after 10 h oxidation. The YAG phases in the SiC ceramics react with SiO 2 to generate Y 2 Si 2 O 7 , Y 2 SiO 5 , and/or Al 2 Si 2 O 7 phases during oxidation process, which exhibit enhanced corrosion resistance under wet environments.