Bonding strength of SiC coating on the surfaces of C/C composites

Abstract Carbon fiber-reinforced carbon matrix composites (C/Cs) are usually used with an antioxidation coating. For the prevention of exfoliation, high strength bonding of the coating to the C/C substrate is often required. However, no measures have been established to determine bonding strength for thin and brittle coatings. In the present paper, first, a criterion for interfacial fracture of a SiC coating on a C/C substrate was discussed on the basis of fracture loads measured by a specially designed plunger method. The fracture mechanics approach was shown to be successful to predict the interfacial debonding. Then, a parametric study was carried out to understand the effect of various parameters on the interfacial fracture loads. Keywords: SIC COATINGC/C COMPOSITEINTERFACIAL BONDINGCONVERSIONFRACTURE TOUGHNESS