Investigation on tribological behaviour of copper-free composite friction material under dry sliding at high-temperature

This research uses a rotary pin-on-disc tribometer to explore the friction and wear behaviour of a copper-free semi-metallic friction composite over various operating temperatures, 25 °C, 150 °C, 250 °C, 350 °C, and 450 °C. The tribological performance of copper-free semi-metallic specimens is significantly affected by heat degradation. It was found that at 450 °C, severe wear of the pin specimen occurred. The friction layer coverage gradually decreased at ≥ 250 °C. The composite pin's wear rate was found to increase 13.26 times from 450 °C to 25 °C, whereas the disc wear rate at 450 °C was 0.86 times the wear rate at 25 °C for the loading condition of 60 N load, 2.09 m/s sliding velocity and 6283 m sliding distance. Micro-ploughing was the primary wear process below and at 150 °C, whereas groove development, delamination, and severe adhesion dominated above 150 °C.