Tribo-oxide Competition and Oxide Layer Formation of Ti(3)SiC(2)/CaF(2) Self-Lubricating Composites during the Friction Process in a Wide Temperature Range

Ti(3)SiC(2)/CaF(2) composites were prepared by the spark plasma sintering (SPS) process. Both the microstructure of Ti(3)SiC(2)/CaF(2) and the influence of test temperature on the tribological behavior of the Ti(3)SiC(2)/CaF(2) composites were investigated. The synergistic effect of friction and oxidation was evaluated by analyzing the worn surface morphology. The results showed that Ti(3)SiC(2)/CaF(2) were still brittle materials after adding CaF(2), which was in agreement with Ti(3)SiC(2). The hardness, relative density, flexural strength and compressive strength of the Ti(3)SiC(2)/CaF(2) composites were slightly lower than those of Ti(3)SiC(2), and the addition of CaF(2) decreased the decomposition temperature of Ti(3)SiC(2) from 1350 to 1300 °C. Simultaneously, as the temperature of the test increased, the friction coefficient of Ti(3)SiC(2)/CaF(2) showed a downward trend (from 0.81 to 0.34), and its the wear rate was insensitive.