Effect of crystallinity of PAN-based carbon fiber surfaces on the formation characteristics of silicon carbide coating

Silicon carbide (SiC) coating was synthesized on PAN-based carbon fiber surfaces by reaction of silicon monoxide (SiO) with carbon fibers. The effect of the crystallinity of carbon fiber surfaces on the formation characteristics of SiC coating was discussed. As the crystallinity of carbon fiber surfaces increases, the thickness of SiC coatings decreases from 341 nm to 128 nm and the surface of SiC coating becomes dense. The microstructure of coated fibers shows that the growth orientation of SiC crystallites is consistent with the orientation of graphite crystallites. It is proposed that amorphous carbon and graphite crystallites in carbon fibers would transform into amorphous SiC and continuous SiC crystallites, respectively.