Tribological performance enhanced of PTFE composites by ultra-thin amorphous carbon films: Synergistic mechanism of fillers and films

The enhanced wear resistance of polytetrafluoroethylene (PTFE) composites as sealing components in aerospace hydraulic systems is an important part of advancing aerospace technology. This study was conducted to synergistically strengthen the tribological performance of PTFE composites through filler modification and surface ultrathin amorphous carbon film modification. The results demonstrate that carbon fiber (CF)-filled PTFE composites and ultrathin amorphous carbon films can form a synergistic mechanism, exhibiting effective synergistic deformation and wear resistance effects. The CF and amorphous carbon film combination forms a “hard-lubrication” region, which exhibits an interfacial support–self-lubrication effect. In contrast, the amorphous carbon film on the PTFE surface forms a “soft-protection” region that provides interfacial protection and enables coordinated deformation with the substrate. The two regions collectively form a synergistic mechanism, which ensures the stability of the ultrathin amorphous carbon film and enables the achievement of tribological performance, particularly the enhancement of wear resistance. The deposition of amorphous carbon films on PTFE composites with a CF filler mass ratio of 20 wt% resulted in the most significant improvement in wear resistance, with a 51.09% reduction in the wear rate.