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采用机械混匀、带温预压、烧结等工艺制备了莫来石填充的聚四氟乙烯(PTFE)复合材料,通过万能材料试验机、X射线衍射仪(XRD)、静态热机械分析仪(TMA)分别表征了复合材料的力学性能、物相和热学性质;研究使用MRH-3型高速环块磨损试验机来测试复合材料的耐摩擦磨损性能,借助场发射扫描电子显微镜研究了复合材料摩擦面形貌并分析摩擦磨损机理。结果表明:莫来石在PTFE体系中起填充增强作用,改性聚四氟乙烯复合材料的弹性模量显著增加;莫来石的填充提高了聚四氟乙烯的玻璃化转变温度,其平均线膨胀系数也呈下降趋势;当莫来石的质量分数由0增加至50%时,复合材料的摩擦系数呈先降低、后升高的趋势,复合材料的耐磨损性能显著改善;当莫来石的质量分数为40%时,其磨损率降低至纯聚四氟乙烯的1/530。
The polytetrafluoroethylene (PTFE) composites filled with mullite were prepared by mechanical mixing, pre-pressing with temperature, sintering and so on. Through the universal material testing machine, X-ray diffractometer (XRD) and static thermomechanical analyzer TMA) were used to characterize the mechanical properties, phase and thermal properties of the composites respectively. The MRH-3 high-speed ring block wear tester was used to test the tribological properties of the composites. The field emission scanning electron microscopy Surface morphology and analysis of friction and wear mechanism. The results show that mullite plays a role of filling and strengthening in the PTFE system, the elastic modulus of the modified polytetrafluoroethylene composites increases significantly, and the filling of mullite increases the glass transition temperature of polytetrafluoroethylene. The average line When the mass fraction of mullite increased from 0 to 50%, the friction coefficient of the composite decreased first and then increased, and the wear resistance of the composite material significantly improved. When the content of mullite increased from 0 to 50% Stone mass fraction of 40%, the wear rate reduced to 1/530 of pure PTFE.