Effect of Different Kinds of Fillers on the Terrace-Like Structure of the Transfer Film and the Wear Behavior of the PTFE-Based Composites

It was found that the transfer film of SiO 2 /Polytetrafluoroethylene (PTFE) composite had terrace-like structure that affected the tribological properties in our previous work. Interestingly, the thickness of the different layers in this morphology was approximately equal, and the coverage rate of the different layers decreased with the increase of the number of layers. It is unknown whether this morphology exists in PTFE composites filled with other types of fillers. Especially, little is known about the influence of the different kinds of fillers on the morphology of the transfer film. In this paper, the effects of three different kinds of fillers, Polyetheretherketone (PEEK), WS 2 , and Si 3 N 4 , on the morphology of the transfer film were studied. The results showed that the transfer films of all the PTFE composites had terrace-like structure with a single layer of approximately the same thickness independent of the filler type. The effect of filler type on the number of layers was significant. The number of layers of the transfer film of PEEK/PTFE composite was the largest (4 layers) and that of WS 2 /PTFE composite was the smallest (1 layers). The wear resistance of the PTFE composites was independent of the monolayer thickness but increased with the number of layers.