Oxidation behavior of Al 2 O 3 added reaction-sintered SiC ceramics in wet oxygen environment at 1300°C

Abstract

The oxidation behavior of reaction-bonded SiC ceramics with Al 2 O 3 was investigated at 1300°C for exposure duration up to 100 h under water vapor environment. Results show that Al 2 O 3 is enriched on the oxidation surface, reducing the volatilization of the oxide layer and preventing the reduction of macroscopic size. Raman spectra results further testified that Al 2 O 3 obviously improves the stability of glass structure and reduces the generation of non-bridged oxygen atoms (Si–O–H), which results in a lower reaction activity with steam of the aluminosilicate melt, therefore, significantly improving the oxidation resistance of SiC in O 2 /H 2 O atmosphere.