Abstract:High-speed friction and wear behaviors of bulk Ti₃SiC₂ sliding drily against low carbon steel were investigated. Tests were carried out using a block-on-disk type tester with normal pressures ranging from 0.1 to 0.8MPa and several sliding speeds from 20 to 60m/s. The results show that, in the case of sliding speeds of 20-40m/s, the friction coefficient exhibits a decreasing tendency with increasing the normal pressure after an increment in the smaller pressure range, and the worn quantity of Ti₃SiC₂ exhibits a nearly linear increase with increasing the normal pressure. However, when the sliding speed is up to 60m/s, the friction coefficient exhibits a monotonous increase and the worn quantity exhibits a quadric increase with increasing the normal pressure. These speed-dependent and pressure-dependent behaviors are attributed to the antifriction effects of a frictionally generated oxide film covering the friction surface of Ti₃SiC₂, and a balance between the generating rate and the removing (wearing) rate of the film. 

Key words: Ti₃SiC₂; tribological behavior; oxide film; antifriction effect; sliding speed; normal pressure