纳米SiO2填充改性聚四氟乙烯复合材料的摩擦磨损性能研究

摘要

The modified nano-SiO2 doped polytetrafluroethylene (PTFE) composites were prepared by cold-pressing and sintering process,and the friction and wear behavior of nano-SiO2/PTFE composites with different nano-SiO2 contents were investigated at different rotational speeds.Moreover,the depth of wear scar of the as-prepared samples were observed by 3D video microscope,and the surface microstructure of the composite were characterized by scanning electron microscope,meanwhile,the wear mechanism of the composite were discussed.The results indicate that the friction coefficient of PTFE composites increases to a certain extent with the filling of nano-SiO2,but the volume wear rate reduces significantly.Besides,the volume wear rate of the as-prepared samples decreases by 89.5％ than pure PTFE at the rotational speed of 80 r/min when the doping ratio of nano-SiO2 is 5％.Meanwhile,the observation results show that the wear mechanism of the composites gradually changes from plough wear and adhesive wear to abrasive wear,and the slight fatigue wear occurs when the doping ratio of nano-SiO2 is 10％.%通过冷压烧结成型工艺制备了纳米二氧化硅(SiO2)填充改性聚四氟乙烯(PTFE)复合材料,探究了不同添加比例的纳米SiO2/PTFE复合材料在不同转速下摩擦磨损情况.采用三维视频显微镜观察了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理.结果表明,填充纳米SiO2后的PTFE复合材料其摩擦因数虽有一定程度的升高,但其体积磨损率却大幅降低.且当纳米SiO2填充质量分数为5％时,复合材料的体积磨损率降到最低,并在转速为80 r/min时较纯PTFE降低了89.5％.观察分析微观形貌发现,随着纳米SiO2含量的增大,复合材料的磨损机理逐渐由犁耕磨损和黏着磨损向磨粒磨损转变,且当纳米SiO2填充含量为10％时,出现轻微的疲劳磨损.