Microstructure and growth mechanism of SiC whiskers on carbon/carbon composites prepared by CVD

The SiC whiskers of good quality are expected to act as the reinforcing element in the ceramic coatings for C/C composites. Using CH ₃SiCl₃(MTS) and H₂ as the precursors, SiC whiskers were prepared on the surface of C/C composites by chemical vapor deposition (CVD) at normal atmosphere pressure. XRD, SEM and TEM analyses show that the whiskers are β-SiC structure and their diameters are several-hundred nanometers. With the descending MTS concentration in the depositing room, the purity of the as-prepared whiskers increases and the diameters of the whiskers decrease. The investigation of growth mechanism shows the CVD-SiC whiskers grown up by the vapor-solid (VS) growth process.