Wear transitions of aluminium oxides at elevated temperatures

The wear behaviour of two aluminium oxides of different purities was investigated on a pin-on-disc tribometer working at ambient or elevated temperatures in dry conditions. Three successive periods of sliding have been identified and correlated with transitions in friction and wear regimes. The first period corresponds basically to a mechanism of interfacial adaptation with no generation of wear particles. The two following periods are relevant to the degradation of the surfaces which lead to different wear rates resulting in different states of equilibrium in the contact zone with regard to production, recycling and loss of particles. The main effect of the temperature environment is to increase extensively the adhesion forces between the detached particles.