Study on the influence of reaction temperature on the preparation of C-Core SiC filaments

Abstract

SiC filaments were widely used as reinforcements in metal-matrix and ceramic-matrix composites. C-core SiC filaments were prepared by CVD process using DC electrically heating for the first time in domestic. The effects of reaction temperature on the morphologies, deposition rate, microstructure, grain size and composition for the C-core SiC filaments coating prepared by CVD process in CH3SiHCl2-H2-Ar system, were explored by means of SEM, XRD, Raman, and AES. The experimental results show that with increasing reaction temperature the deposition rate increases rapidly in an exponential manner, surface kinetic processes become stronger, and Si/C atomic ratio decreases. At low temperatures, Si phase co-deposites with SiC, inhibiting the grain growth, while at high temperatures, the grain growth results in rough surface, and the stress changed from tensile to compressive.