Growth Characteristics of Chemical Vapor Deposited SiC Coatings

The coatings of β-SiC were prepared from the methyltrichlorosilane (MTS) by lowpressure chemical vapor deposition on graphite substrates. The as deposited coatings were characterized by SEM and XRD. The results of SEM and XRD analyses indicate that the surface morphology of the CVD SiC coating shows pyramid structure with (111) plane preferred orientation. HRTEM was used to investigate the microstructures of the coatings and the interface between the coatings and graphite substrate. The results show that SiC crystal grows according to the preferred orientation of the substrate at the beginning of the deposition, and then the crystal adjusts the growth to (111) plane.