Different influence mechanisms of RE2O3 (RE= La, Y, Er, Lu) on the oxidation behavior of RMI-SiC ceramics in air and O2/H2O atmospheres

The effect of RE 2 O 3 (RE = La, Y, Er, Lu) on the oxidation behavior of RMI-SiC ceramics in air and wet oxygen atmospheres at 1400 °C were studied. The outward migration of RE 3+ cations reduces the oxidation resistance of SiC-RE ceramics in air, but improves the wet-oxidation resistance of SiC-RE ceramics due to the formation of denser RE 2 Si 2 O 7 layer. The outward migration rates of RE 3+ cations may be influenced jointly by the RE 3+ cation radius and the formation rate of RE 2 Si 2 O 7 . The higher mobility of Er 3+ and Y 3+ cations makes Y 2 O 3 and Er 2 O 3 promising modifier for enhancing the wet-oxidation resistance of RMI-SiC f /SiC composites, although the modified components need to be optimized and further analyzed in a more realistic service environment.