Bonding strength of SiC coating on the surface of C/C composite

Abstract

Carbon fiber-reinforced carbon matrix composites (C/Cs) are usually used with anti-oxidation coating applied on their surface, The data about bonding strength between the coating and C/C substrate are indispensable for material design of C/Cs for various high temperature structures. Standardized measuring methods to evaluate the bonding strength, however, have not been established and the scratch method or the indentation method have attempted to be used. The results by these methods do not give quantitative bonding strength and are useful only for relative comparison of specimens with same geometry. In this paper, the bonding strength between SiC coating and C/ C substrate with various coating conditions was attempted to be measured by specially designed shear load method. The experimental results by a this method were discussed in terms of thermal and mechanical loading conditions by using finite element analyses.