Abstract：
SiC was coated on the surface of carbon fibers substrate by a reaction between thermally evaporated silicon and carbon at 1600℃. SEM and XRD analyses show that the coatings obtained are composed of SiC grains and micro-crystals. The oxidation behavior of coated samples was investigated, and then their oxidation mechanisms were studied. The weight results show that carbon fibers loss weight after oxidation. However, carbon fibers with SiC coating gained weight after oxidation and the weight gain increased with the treatment temperature. The oxidation steps included oxidation of substrate by diffusion of oxygen through coating cracks, the reaction of oxygen and SiC coating and oxidation of coating by diffusion of oxygen through the oxide film. It can be concluded that SiC coatings which were prepared on carbon fibers can improve the oxidation resistance of carbon at elevated temperatures.