Yttrium silicate was introduced into the matrix of SiC_f/SiC composites via the slurry impregnation and reactive chemical vapor infiltration (RCVI) methods to improve the water and oxygen corrosion resistance of the modified composite materials. The effects of heat treatment on the modified matrix and strength of the composites were systematically investigated. The results showed that the modified matrix was composed of a mixture of yttrium monosilicate, yttrium disilicate, and silicon carbide. The modified yttrium silicate matrix (named Y-Si-O matrix) and the silicon carbide matrix were laminated and well combined. After heat treatment, the amount of Y-Si-O in the mixed matrix increased. The modified composites with yttrium silicate had a similar flexural strength as SiC_f/SiC composites (∼400 MPa). After treated at 1000 °C – 1300 °C, the strength of the modified composites increased by 17 %–26 %. The highest strength was measured for composites treated at 1200 °C.

通过浆料浸渍和反应化学气相渗透（RCVI）方法将硅酸钇引入SiC _f /SiC复合材料的基体中，以提高改性复合材料的耐水和氧腐蚀能力。系统研究了热处理对复合材料改性基体和强度的影响。结果表明，改性基体由单硅酸钇、二硅酸钇和碳化硅的混合物组成。改性硅酸钇基体（命名为Y-Si-O基体）和碳化硅基体层叠并结合良好。热处理后，混合基体中Y-Si-O的含量增加。含有硅酸钇的改性复合材料具有与 SiC _f相似的弯曲强度/SiC 复合材料（~400 MPa）。在 1000 °C – 1300 °C 处理后，改性复合材料的强度增加了 17%–26%。对于在 1200 °C 下处理的复合材料，测得的强度最高。