Abstract: A SiC coating was derived from a gaseous methyltrichlorosilane (MTS)/H₂ precursor by forced pressure-pulsed CVI (FP-CVI) process at low temperatures and reduced pressure. In the present experiment, the FP-CVI
process was studied, and the correlation between the coating thickness and the depositing conditions, i.e. the deposition temperature, the pressure, the deposition time per pulse and the pulse number was investigated. In 1000--1100℃and (5--25)kPa, the homogeneous β-SiC coating synthesized has (111) orientation. The coating thickness increases as the holding time per pulse and the pulse number increase. It shows a nonlinear behavior between the coating thickness and the pulse number. When the pulse number reaches 300 in all, the mass increment is 36.18% after coating on the carbon fiber.

Key words: carbon fiber, SiC coating, FP-CVI