Oxidation resistant Si–Mo–Al coating for C/SiC coated carbon/carbon composites at high temperature

Abstract

A Si–Mo–Al coating for protecting carbon/carbon (C/C) composites against oxidation at elevated temperature was prepared on the surface of the C/SiC coated C/C composites by slurry method. The phase composition, microstructure and oxidation resistance of the coating at 1773 K in air were investigated. The results show that the as prepared coating was mainly composed of SiC, MoSi₂, Mo(Si,Al)₂ and Si. The coating provided excellent oxidation protective ability at 1773 K in air and can effectively protect the C/C composites from oxidation for 150 h. The failure of the coating at 1873 K in air is attributed to the spalling of the glass layer during the oxidation tests.