Influence of LSEG Content on Tribological Behaviors of PTFE/LSEG Composites under Dry Sliding Condition

This paper provides a PTFE/LSEG solid self-lubricating composite that exhibits very low friction coefficient and wear rate. In present study, the influences of the content of expanded graphite with nanoscale lamellar-structure (LSEG) in PTFE/LSEG composite on tribological properties were carried out. Six compounds of PTFE with LSEG (0–30 wt. %) were evaluated on MMU-5G friction and wear tester. The wear tests were conducted at a nominal contact pressure of 2.85MPa and a sliding speed of 0.48m/s. The transfer film formed on the mating surface and worn surface of PTFE/LSEG composite were observed using a scanning electron microscope (SEM) and a confocal laser scanning microscope (CLSM). The results show that the friction coefficient and wear rate could be obviously reduced because of the addition of LSEG into PTFE matrix. Compared with that of neat PTFE, wear resistance of PTFE/LSEG composite increased by 31.6 times. The images of CLSM and SEM indicate that the transfer film generated on the surface of mating pair is likely responsible for the low wear rate observed in these experiments.