Significant Improvement of Resistance to Dry/water Oxygen Corrosion at Medium and High Temperatures of SiC/SiC Composites Upon Matrix Modification by Ca-Y-Al-Si-O Microcrystalline Glass

Matrix modification is of great significance for the densification of CVI-SiC/SiC, as well as the improvement of self-healing and oxidation resistance. A eutectic component of Y2O3-Al2O3-SiO2 system modified with CaO (CYAS) was used in this study to modify SiC/SiC at 1400 degrees C. The oxidation behaviour of the composites was investigated under dry/water oxygen atmosphere at 900 degrees C and 1300 celcius. Compared to the relatively dense SiC/ SiC, the modified SiC/SiC showed a slight increase in flexural strength and fracture toughness at room tem-perature, as well as a significant increase in oxidation resistance and densification. Our work provides a low-cost, simple-to-operate, short-cycle densification method for CVI-SiC/SiC composites that increases their oxidation resistance without compromising their mechanical properties at room temperature.