Effect of anti-oxidative filler on the interfacial mechanical properties of carbon-carbon composites measured at high temperature

PAN-based carbon fibers impregnated with phenolic resin used as the precursor of carbonized matrix was modified by addition the anti-oxidative filler: molybdenum disilicide (MoSi₂) in different contents, i.e., 0, 4, 12 and 20% by weight. These composites were unidirectionally fabricated by the prepreg method, and were submitted to carbonization (heat treated to 1100 °C) and graphitization (to 2300 °C), via a one step manufacturing process. In this work, the influence of MoSi₂ content on the interlaminar shear strength (ILSS) of the composites was measured at room temperatures and 1000 °C. The presence of MoSi₂ in the C-C composites was found to significantly increase the toughness and degree of adhesion at interfaces between carbon fibers and resin matrix.