Study on the Friction and Wear Behavior of PEEK Composites Filled With Nanometer Compounds and PTFE

The friction and wear behavior of polyetheretherketone (PEEK) composites was investigated, which are reinforced with nanometer Al₂O₃ or nanometer TiO₂ and blended with polytetrafluoroethylene (PTFE) in a fixed weight fraction of 10% and are prepared by heat compression moulding. The studies emphasized particularly on the nanometer Al₂O₃ filled PEEK composites. The tests were performed on a pin-on-disc test apparatus with a PEEK composite pin sliding against AISI 1020 carbon steel disc under dry friction conditions and were all carried out at room temperature. The worn surfaces of the PEEK composites were examined by scanning electron microscopy (SEM). Results indicated that the above PEEK composites exhibited lower friction coefficient and wear rate in comparison with the mixture of PEEK with PTFE. The SEM micrographs of the worn surfaces indicated that the scratched and ploughed marks appeared on the wear scar of PEEK filled with PTFE, while the scuffing on the worn surfaces of nanometer Al₂O₃/PTFE/PEEK was obviously abated. The optimal content of nanometer Al₂O₃ in the filled PEEK composite should be recommended as 6.5 wt %. The friction behavior of the nanometer TiO₂/PTFE/PEEK composites was far better than that of the nanometer Al₂O₃/PTFE/PEEK composites under the same test conditions and with the same content of nanometer compounds, which was perhaps due to much more strong synergistic effect between nanometer TiO2 and PTFE than that between nanometer Al₂O₃ and PTFE.