TANG Huidong ¹ ,TAN Shouhong ²

（1. Department of Materials Engineering Technology, Changzhou Institute of Engineering Technology, Changzhou 213164;2. Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050）

Abstract: In order to improve the low reflectance of polished RB SiC, the dense structure PVD SiC coating was coated on the surface of RB SiC substrate by RF magnetron sputtering. The crystal phase of PVD SiC coating was characterized by XRD. The surface morphology and the surface roughness of RB SiC substrate and PVD SiC coating were measured by AFM and surface profilometer. The reflectance was determined in the visible and IR range. The results show that: when the surface of RB SiC substrate is coated with PVD SiC coating, the surface defects decrease obviously after polished. The surface roughness yields to 0.809nm. The reflectance increases about 2%. The highest reaches 99.2%. The effect of improvement upgrades significantly. It demonstrates that PVD SiC coating is hoped to be used in visible and IR region.

Keywords: RB SiC, PVD SiC coating, the surface roughness, scattering loss, reflectance