Effect of transfer film morphology on the wear rate of SiC/PTFE composite

In our previous work, it was found that there was a good correlation between the transfer film structure and wear rate of polytetrafluorethylene (PTFE) composites, and the transfer film presented a "terrace-like structure" under the influence of fillers. But whether that phenomenon was applicable to different fillers was not verified. In this work, the transfer film formed by silicon carbide (SiC)-filled PTFE was selected to study deeply. The results showed that the "terrace-like structure" was also formed by SiC/PTFE composite, where the number of transfer film layers was 2-3, and the thickness of each layer was about 0.1 mu m. Such phenomenon was different compared with that of silicon dioxide (SiO2)/PTFE composite. By the segmented linear fitting between transfer film thickness and composite wear rate, we found that the effect of changes in transfer film thickness on the wear rate of composite can be divided into two stages: stable stage and promotion stage, and the correlation between maximum thickness and composite wear rate was enhanced. Similar phenomena were also reflected in the relationship between transfer film coverage and the wear rate of the SiC/PTFE composite. The maximum thickness and coverage of the transfer film had different effects on the wear rate of the composite at different stages. When the transfer film coverage was less than 24.8%, the change of the coverage rate of the transfer film showed a great impact on the wear rate of the composite. And when the transfer film maximum thickness was more than 0.342 mu m, the change of the maximum thickness of the transfer film had a great impact on the wear rate of the composite.