Abstract: The composites of polytetrafluoroethylene (PTFE) filled with nano-Si3N4, MoS2, GF, and nano-Al2O3 were prepared by compression molding. The mechanical, friction, and wear properties of the composites were studied. The tensile fracture surface was observed by a scanning electron microscope (SEM) and the reinforcement mechanism was explored. The inclusion of the inorganic fillers increased the surface hardness, tensile strength, and wear resistance, with the optimal loadings of 5 % Si3N4 and 10% Al2O3. However, the fillers had little effect on the friction coefficient. The SEM showed that Si3N4 and Al2O3 have a better combination with the PTFE matrix.

Key words: nano silicon nitride, synergistic effect, polytetrafluoroethylene, mechanical property, tribological property