Study of the zirconia particles incorporation effects on the wear resistance and hardness of polytetrafluoroethylene

Polytetrafluoroethylene (Teflon) is one of the most widely used materials as the matrix in polymer-matrix composites due to its unique properties. In this study, the effect of zirconia particles addition on the wear rate and friction coefficient of pure Teflon has been investigated. For this, composite samples were manufactured by adding of 5 to 30wt.% zirconia into the PTFE matrix containing 10wt% graphite. Production of the samples were done by cold press and sintering method according ASTM D4894 and 4745 standards. To evaluate the wear resistance of the samples, pin on disk test was performed according to ASTM G99 standard. Finally, the hardness of the samples was measured using ASTM D2240 (Shore D) standard. The scanning electron microscope was applied to investigate the distribution of second phase particles and worn surfaces of the samples. The lowest wear rate and friction coefficient and the highest hardness were obtained for the sample containing 20wt.% zirconia. This sample had approximately 3 times lower wear rate and 12% higher hardness with respect to pure PTFE. This improvement is due to the higher load carrying capability of composite samples as a result of zirconia particles incorporation in the polymer matrix.