Preparation of ZrC-SiC composite coatings by chemical vapor deposition and study of co-deposition mechanism

In this work, the ZrC-SiC composite coatings were co-deposited by chemical vapor deposition (CVD) using ZrCl4, MTS, CH4 and H-2 as raw materials. The morphologies, compositions and phases of the composite coatings were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results indicated that the morphologies, compositions and phases of the composite coatings were related to the deposition temperature, the flow rate of the carrier H-2 gas, and the ratio of C/Zr. Moreover, the co-deposition mechanism of the composite coatings was also studied. It was found that different deposition temperatures resulted in different deposition mechanisms. At temperatures in the range of 1150-1250 degrees C, the ZrC-SiC co-deposition was controlled by the surface kinetic process. At temperatures in the range of 1250-1400 degrees C, the ZrC-SiC co-deposition was controlled by the mass transport process. (C) 2019 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.