Dry friction and wear of self-mated sliding couples of SiC-TiC and Si 3N 4-TiN

Abstract

Dry friction and wear tests were performed with self-mated couples of SiC with 50% TiC and of Si 3N 4 with 30% TiN at room temperature and 400 °C or 800 °C. The friction coefficient of the couple SiC-TiC/SiC-TiC is only half of that of the couple SiC/SiC under room temperature conditions. At 400 °C it exceeds the friction coefficient of SiC/SiC except at the highest sliding velocity of 3 m s −1, where the wear coefficient of SiC/SiC is high. With the other test conditions the wear coefficient of SiC-TiC/ SiC-TiC is lower than that of SiC/SiC. The couple Si 3N 4-TiN/Si 3N 4-TiN exhibits high friction coefficients under all test conditions. The friction coefficients are partially higher than that of the couple Si 3N 4/Si 3N 4. The wear behaviour of the self-mated couples of Si 3N 4 and Si 3N 4-TiN is similar at room temperature, but at 800 °C the wear coefficient of Si 3N 4-TiN/Si 3N 4-TiN is approximately two orders of magnitude smaller than that of Si 3N 4/Si 3N 4. Small spot electron spectroscopy for chemical analysis (ESCA) revealed that TiO 2, and SiC xO y, and SiN xO y, were present on the surfaces.