Tribological behavior of PTFE film with nanodiamond

The effect of nanodiamond addition on the tribological behavior of polytetrafluoroethylene (PTFE) film was investigated. Nanodiamond particles produced by detonation method were added up to 4 wt.% to PTFE film to improve the wear resistance and thermal stability. Tribological tests of nanodiamond-reinforced PTFE coatings were performed by using a ball-on-plate reciprocating wear tester at room temperature and 150 °C. The wear resistance of PTFE composite coating was increased with increasing content of nanodiamond up to 2 wt.% but decreased slightly with further addition of nanodiamond at tested temperature ranges. The coefficient of friction and width of wear track changed from 0.21 to 0.16 and 0.85 to 0.44 mm, respectively, when 2 wt.% of nanodiamond was added to PTFE. Possible mechanisms for enhancement of tribological properties by nanodiamond additions were discussed based on SEM and TEM observation. This study showed that nanodiamond was well dispersed and enhanced the tribological properties of PTFE by hardening PTFE composite with nanodiamond and by the self-lubricating effect between PTFE composite film and sliding ball.