Tribological Behavior of Nano-ZrO2 Reinforced PTFE-PPS Composites

Polytetrafluoroethylene (PTFE) is a commonly used seal material for oil-free engine that is well known for its excellent tribological properties. In this work, the nano-ZrO2 particles were used as the friction modifiers to improve the friction and wear performance of PTFE-PPS composites. The friction and wear characteristics of PTFE/PPS-nano-ZrO2 composites were investigated by a block-on-ring tester under dry friction sliding condition. The worn surfaces, counterpart transfer films and wear debris were studied by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the increase of nano-ZrO2 content could effectively reduce the coefficient of friction and enhance the anti-wear ability of PTFE-PPS composites. Especially, the best tribological properties of the composites were obtained when the particle content of nano-ZrO2 was 10 vol%, the anti-wear performance of composite is 195 times better than that of the unfilled PTFE-PPS composite. Under different conditions, the coefficient of friction of PTFE/PPS-nano-ZrO2 composites was more affected by the applied load while the wear rate was more affected by the sliding velocity.