Studies of the Influence of Graphite and MoS2 on the Tribological Behaviors of Hybrid PTFE/Nomex Fabric Composite

Hybrid polytetrafluoroethylene (PTFE)/Nomex (DuPont, USA) composite specimens were prepared with graphite and MoS2 as fillers. The friction and wear tests were conducted under dry sliding conditions at a speed of 0.26 m/s under various loads and environmental temperatures. The results showed that the incorporation of graphite was effective in reducing the wear of the hybrid PTFE/Nomex fabric composite, whereas the MoS2 filler was unfavorable for improving the wear resistance. X-ray photoelectron spectroscopy (XPS) results revealed that MoS2 was oxidized into MoO3 during sliding. The absence of the layered structure of MoO3 resulted in a higher wear rate of fabric composite. Differential scanning calorimetry (DSC) analysis of unfilled and graphite-filled composites and their debris indicated that graphite increased the thermal stability of the unfilled composite and therefore enhanced the wear resistance.