Preparation of Silicon Carbide Refractory Coating by Chemical Vapor Deposition Using Hexamethyldisilylamine Precursor

For the first time, by chemical vapor deposition (CVD) using hexamethyldisilylamine (HMDS, C۶H۱۹NSi۲) as a precursor and N۲ as a carrier gas in the medium temperature range, a silicon carbide (SiC) coating was deposited on a C/C composite substrate. given. Using X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM), the effects of deposition temperature on the phase structure, surface morphology and coating deposition rate were studied. This coating at temperatures of ۱۰۱۰ °C, ۱۰۶۰ °C and ۱۱۰۰ °C β-SiC phase (۳C), at temperatures of ۱۱۳۰ °C and ۱۱۸۰ °C the simultaneous presence of α-SiC (۲H) and β-SiC (۳C) phases, and at the temperature of ۱۲۲۰ °C, it again displays the single phase of β-SiC (۳C) .By changing the deposition temperature, the morphology and microstructure of this coating changes significantly. The change of phase structure and surface morphology is closely related to the nucleation, growth and formation of defects in SiC crystals during the CVD process .

Keywords:

SiC , Coating , CVD , Crystal , Stacking Faults , Twin