Further investigation on the tribological behavior of Al2O3-20Ag20CaF2 composite at 650 °C

The friction and wear behaviors of the self-lubricating Al2O3-20Ag20CaF(2) disk against an Al2O3 pin pair have been investigated over a broad load range from 1 to 30 N and sliding velocities from 0.084 to 1 m/s at 650(degrees)C. Four typical wear modes have been identified and the wear mode map was constructed to illustrate the influence of load and speed on the friction coefficient and wear rate. The results showed the effective self-lubricating region (II) (continuous lubricating film) is almost independent of sliding speed, and mainly dependent on the load. It is suggested that the plastic deformation and plastic flow during sliding play an important role in the formation of the self-lubricating film on the sliding surface. Furthermore, the worn surface in the region (II) (continuous lubricating film) was found to be much softer than the original surface and the distribution of Vickers hardness became more uniform due to the presence of the lubricating film on the worn surface.