Deposition kinetics and boundary layer theory in the chemical vapor deposition of β-SiC on the surface of C/C composite


In this study, SiC was deposited on carbon/carbon (C/C) composite substrate using chemical vapor deposition (CVD) method to investigate the kinetics of the deposition process. Therefore, the time, temperature, precursor composition (SiCl4:N2:CH4) and substrate position in the reactor were varied to evaluate the deposition rate. X-ray diffraction (XRD) method was used to characterize the phase composition and calculate the grain size and the texture coefficient of the coatings. Field emission scanning electron microscopy (FESEM) was utilized to observe the coating morphology, microstructure and thickness. As observed β-SiC was the dominant phase of the coating with varied preferred growth crystalline planes of (111), (220) or (311). The coating thickness was 2 µm and 5 µm for the samples treated at 1000 and 1100°C, respectively.