In order to improve the shortcomings of high wear of polytetrafluoroethylene,four low content flake-graphite filled PTFE modified composites were prepared by cold-pressing and sintering process,.and their friction and wear properties were investigated at higher load(0.8 MPa) and at different rotational speeds.The depth of wear scar of the as-prepared samples was observed by 3D video microscope,the surface microstructure of the composite was characterized by scanning electron microscope,and the wear mechanism of the composite was discussed.The results indicate that the friction coefficient and the volume wear rate of the PTFE composites after graphite filling are reduced to some extent at higher load.When the mass fraction of graphite is 5％,the composite has the lowest friction coefficient and volume wear rate,and compared with pure PTFE,the friction coefficient and the volume wear rate are reduced by 19.7％ and 84.25％ at the speed of 80 r/min separately.The wear mechanism of the composites is gradually changed from plowing to adhesive wear with the increase of the graphite content at higher load,and when the mass fraction of graphite is 10％,the slight fatigue wear occurs.%为了改善聚四氟乙烯高磨耗的缺点,通过冷压烧结成型工艺制备4种低含量鳞片石墨填充改性聚四氟乙烯(PTFE)复合材料,探究其在较高载荷(0.8 MPa)及不同转速下的摩擦磨损情况.采用三维视频显微镜观察样品的表面磨痕深度,借助扫描电镜观察摩擦表面形貌并分析磨损机制.结果表明:在较高载荷下石墨填充PTFE复合材料的摩擦因数和体积磨损率都较纯PTFE有一定程度的降低;且当石墨填充质量分数为5％时,复合材料的摩擦因数和体积磨损率降到最低,在载荷为0.8 MPa、转速为80 r/min时较纯PTFE分别降低了19.7％和84.25％;在较高载荷下,随着石墨含量的增大,复合材料的磨损机制逐渐由犁耕磨损向黏着磨损转变,且当石墨质量分数为10％时,出现轻微的疲劳磨损.
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