Evaluation on tribological characteristics of (TiC+TiB)/Ti-6Al-4V composite in the range from 25 °C to 600 °C

The tribological characteristics of 6%(TiC + TiB)/Ti-6Al-4V composite against Cr12MoV steel were systematically investigated using a pin-on-disc wear machine in a static temperature range of 25-600 degrees C. At 25 degrees C, the wear rate variation was proportional to the load and inverse to sliding speed. Meanwhile, the wear mechanism underwent a transition from delamination and slight oxidative wear at 0.11 m/s to delamination and abrasive wear at 0.22 m/s and then became mainly oxidation wear at 0.33 m/s. At elevated temperatures, the critical temperatures can be found, 300 degrees C under 300 N and 400 degrees C under 100 N, respectively. Above critical temperatures, the effect of load on the wear rate was weakened due to the appearance of massive tribo-layers, and the specific wear rates were reduced by roughly an order of magnitude compared with room temperature, furthermore, the coefficients of friction still remained high value without heat attenuation, the main mechanism was mild oxidation wear. The composite exhibited excellent wear resistance due to high strength and the formation of dense and continuous tribo-layer with tribo-oxides, particularly the presence of Fe2O3.