Preparation of MoSi2-SiC-Si Coatings for Cf/SiC Composites by in situ Reaction Method

A MoSi2-SiC-Si coating was prepared by in situ reaction method. The phase composition and microstructure of the coating were studied by using XRD,SEM and EDS analysis, and then the anti-oxidation property of the coating was investigated. The results show that the thickness of obtained coating is about 120| , and the main phases are composed of MoSi2, SiC and Si. The MoSi2-SiC-Si coating has excellent anti-oxidation property, which can protect Cf/SiC composites from oxidation at 1500 n air for 96h, the weight loss of the coated samples is only 1.8%. The weight loss of the coated Cf/SiC composites samples is primarily due to the reaction of Cf/SiC composites substrate and oxygen diffusing through the penetration cracks in the coating.