Tribological properties of phenyl-silicone rubber composites with nano-CeO2 and graphene under thermal-oxidative aging

Phenyl-silicone rubber composite components have been used in the sealing field under various working conditions. However, research on friction behavior during service is somewhat lacking. Thermal-oxidative aging’s effects on the tribological properties of phenyl-silicone rubber composites are investigated in this work. With the addition of nano-CeO2 and graphene, the coefficient of friction (COF) gradually decreases between the GCr15 steel ball and phenyl-silicone rubber composites, which can be attributed to nano-CeO2’s and graphene’s protection of surface matrices during aging and friction-heat generating processes. The results of this study indicate that the COF gradually decreases as the load increases because frictional heat generation increases with loads, resulting in softening the matrix and decreasing friction resistance. When the graphene content increases (0.8–1.5 phr), the wear rate (Ws) of phenyl-silicone rubber composites increases due to the destruction of graphene transfer films and severe fatigue wear. This study provides new ideas for improving the friction and wear properties of phenyl-silicone rubber composites before and after thermal-oxidative aging.