MDOxidation behavior in wet oxygen environment of Al2O3 modified SiCf/(SiC + B4C) at 1200 °C.

The influence of Al 2 O 3 on the oxidation behavior of SiC f /(SiC + B 4 C) composite materials at 1200 °C in O 2 /H 2 O (40/60) atmosphere was studied employing Scanning Electron Microscope, X-ray Diffraction and Material Universal Testing Machine. Results showed that Al 2 O 3 could impede the crystallization of oxide (cristobalite) during cooling, and lead to a dense and smooth oxidized layer. Furthermore, the strength retention rate increases from 70.44 to 85.94% with Al 2 O 3 after oxidization for 200 h. The above results are attributed to high viscosity and low reaction activity with steam of the aluminosilicates melt. Therefore, Al 2 O 3 can significantly improve the oxidation resistance of SiC f /(SiC + B 4 C) composites in O 2 /H 2 O atmosphere. [ABSTRACT FROM AUTHOR]