Effect of Ti3SiC2 Content on Tribological Behavior of Ni3Al Matrix Self-Lubricating Composites from 25 to 800 °C

The self-lubricating composites of Ni3Al-Ti3SiC2-TiC-C (NMC) with varying Ti3SiC2 contents were fabricated by spark plasma sintering technique. Dry sliding pin-on-disc friction and wear tests of NMC against Si3N4 ceramic ball were undertaken at 25, 200, 400, 600, and 800 A degrees C in air, respectively. The results showed that NMC with 15 wt.% Ti3SiC2 lubricant owned the excellent tribological properties over a wide temperature range from 25 to 800 A degrees C, whose friction coefficients and wear rates were about 0.17-0.58 and 0.31-4.2 x 10(-5) mm(3)/N/m, respectively. A possible explanation for these results was that the subsurface microstructure self-refinement and the special stratification morphology of the tribo-layer were beneficial to the reduction of friction coefficient. Meanwhile, the protective action of the tribo-layer for the frictional surface could also decrease the wear rate.