The tribological properties of single-layer hybrid PTFE/Nomex fabric/phenolic resin composites underwater

Abstract In this study, the tribological properties of hybrid polytetrafluoroethylene (PTFE)/Nomex fabric/phenolic resin composites were investigated under three operating conditions: dry sliding, dry sliding after soaking in water for 12 h, and water dripping lubrication. The friction coefficient (COF) was measured with a pin-on-disk tribometer. The wear surface was analyzed with a scanning electron microscope. The results show that water weakens the tribological properties of single-layer hybrid PTFE/Nomex fabric/phenolic resin composites. The fabric composites show slight abrasive wear with stable COF under dry sliding conditions, significant abrasive wear with oscillating COF after soaking, and destruction with severely oscillating COF under water dripping lubrication. Generally, water weakens the effect in two ways. The first is weakening the binding force between phenolic resin and Nomex fiber. The second is that Nomex fiber absorbs water and expands, which reduces its strength. Finally, the ideas to improve the tribological properties under water dripping lubrication are presented.