Self-Lubricant Effect of Tri-Oxidizing Layer in Surface of Bulk Ti_3SiC_2 Materials

摘要

In this paper, tribological tests for Ti_3SiC_2sliding against low carbon steel were made on a block-on-disc type friction tester, with the normal pressures from 0.1 to 0.8 MPa and the sliding speed of 30 to 50 m/s. The surface state was observed and analyzed by SEM and XRD. A definite tribo-glazing layer was found over the worn surface of the Ti_3SiC_2 block, which seems to be primary reason for Ti_3SiC_2 to have comparatively lower friction coefficient and wear rate, because the tribo-glazing layer would be fusible under high frictional temperature. The tribo-glazing layer was the results of tribo-chemical oxidation reaction and the cause forming it could be the high frictional temperature and the mechanical catabolism in the surface of Ti_3SiC_2 during sliding friction. Due to the tribo-oxidation reaction is un-reversible and self-adaptive, the tribo-glazing layer in area and thickness are function of normal pressures and sliding speed.