Coating of carbon fibers with amorphous SiC films as diffusion barriers by chemical vapor deposition with triisopropylsilane

Abstract

Carbon fibers 6.5 μm in diameter were coated with amorphous SiC films by chemical vapor deposition at temperatures as low as 800–900 °C, using triisopropylsilane in hydrogen. The morphology of the films was strongly affected by the reaction conditions. The tensile strength of the coated fibers was decreased by the coating, but was little affected by the coating method if smooth and tight films were formed. SiC films formed under optimized conditions effectively protected the fibers from oxidation. When the fibers were enclosed with aluminum at 1000 °C, SiC films effectively retarded the diffusion of aluminum.