Thermal stability of carbon-MoSi2-carbon composites by thermogravimetric analysis

A thermal stability of carbon-carbon composites with increase of oxidation resistant filler, MoSi2, have been studied by thermogravimetric analysis du ring the graphitization process. In this work, the initial decomposition te mperature, temperature of maximum rate of weight loss, integral procedure d ecomposition temperature, and decomposition temperature range for the degra dation temperatures, and the activation energy based on Horowitz-Metzger ca lculating method were characterized in a thermal stability study. It has be en found that 12-20 wt% filler on the basis of the resin matrix leads to an improvement of degradation temperature and to an effectively increase of a ctivation energy of the composites. This is probably due to the effect of t he inherent MoSi2 properties, resulted from a brittle-to-ductile transition for increasing the interfacial adhesion between fiber and matrix, and a mo bile diffusion barrier formation against oxygen attack, in the vicinity of 900-1000 degrees C. (C) 2000 Kluwer Academic Publishers.