Dry wear behaviors of graphite/cermet self-lubricating composite under different sliding conditions and simulation of temperature field

In this paper, the dry sliding wear tests of graphite/cermet self-lubricating material at different velocities and loads were conducted to further understand the wear failure mechanism of the composite. The worn morphologies under varying conditions and chemical compositions on worn surfaces were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. Additionally, the transient temperature field of the self-mated cermets composite pairs during sliding was simulated by finite element method (FEM). Results indicates that the volume wear rate of graphite/cermet composite will increase with the elevation of sliding speed or load, but the fluctuation of increase in wear rate with load is not significant at lower speed. The main wear mechanism of graphite/cermet composite is a mixture of oxidation and adhesion, and the delamination of oxides film will be aggravated with rising load. Furthermore, finite element simulation shows that the maximum temperature caused by friction locates near the exit zone of contact surface between two rubbing pairs, which has a pronounced effect on the worn scars of the two ends in the worn area of specimen. Moreover, some “flash temperature islands” are observed on the surface of counter-ring in the simulation of transient temperature filed owing to the nonlinearity of friction process.