Tribological Properties of Ti₃SiC₂-Inconel 718 Couple at Elevated Temperatures

The tribological properties of Ti₃SiC₂ sliding against Ni-based alloy Inconel 718 from ambient temperature to 800 ℃ were investigated. The experiment results indicated that the tribological behaviors of the couple were improved with the increase of temperatures. The Ti₃SiC₂-Inconel 718 couple presented excellent tribological properties at 800 ℃. The friction coefficient was 0.81 at ambient temperature and wear rate of Ti₃SiC₂ was 4×10^-3 mm³/(N·m). In contrast, the friction coefficient was 0.37 at 800 ℃ and the wear rate of Ti₃SiC₂ reduced to 10^-5 mm³/(N·m). The deformation at elevated temperature and the tribo-oxidation led to the decrease of friction coefficient. The high wear rate of Ti₃SiC₂ was determined by the fracture and pullout of Ti₃SiC₂ grains and material transfer to the counterbody alloy during the sliding process below 300 ℃,while at 400~800 ℃,the fracture and pull-out of Ti₃SiC₂ grains were inhibited which resulted in the very low wear rate.