Wear performance of SiC/G coating at elevated temperatures

To improve the wear performance of SiC Materials, a SiC/graphite (SiC/G) coating was prepared by CVD. Wear tests were conducted at elevated temperatures, and related microstructure and mechanical characteristics were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and micro-hardness tester. The results show that the SiC/G coating has excellent anti-wear performance with low friction coefficient at RT owing to the lubrication of graphite. Moreover, the friction coefficient of the SiC/G coating is lower than that of the uncoated SiC samples at all tested temperatures. As the temperature rose to 250 degrees C, the wear mechanism of SiC/G coating was shifted to severe adhesive wear, which resulted in an increase in friction coefficient. However, fracture and oxidation dominated the friction process of SiC/G at 500 degrees C, which caused an increase in wear volume. In addition, the formation of silica debris was conductive to the decrease of friction coefficient. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.