Tribological behavior of TiCN-based cermets at elevated temperatures

In this paper, TiCN-based cermets, namely TiCN–Ni–Mo and TiCN–Al2O3–Ni–Mo, were fabricated by hot-pressed method. The microstructures, mechanical properties and tribological behaviors at elevated temperatures of TiCN-based cermets were characterized. Compared to TiCN–Ni–Mo, TiCN–Al2O3–Ni–Mo exhibited an increase in the friction and a decrease in the wear. At the lower temperatures, the worn surfaces of TiCN–Ni–Mo were very rough with severe damage as micro-fracture, while the worn surfaces of TiCN–Al2O3–Ni–Mo were relatively smooth. At 600 °C, the tribo-oxidation together with the formation and destruction of tribo-layer were found to be the dominant wear mechanism for TiCN-based cermets. The morphology of transferred lay on the surface of counterbody Si3N4 is related to the specific TiCN-based cermets. A simple model for the tribo-layer at elevated temperatures was proposed.