聚四氟乙烯和石墨对聚醚酰亚胺摩擦学性能的影响

摘要

The tribological performances of polyetherimide( PEI) composite materials filled with polytetraflu-oroethylene( PTFE) and graphite were evaluated on UMT-2 friction and wear tester, respectively. The micro-structures of worn surfaces, cross-sections of the PEI composite were examined with scanning electron micro-scope( SEM) , and wear mechanism was analyzed. The result showed that PEI composite filled with PTFE and graphite were improved significantly on friction and wear properties. The friction coefficient is reduced to below 0. 3(the friction coefficient of pure PEI is 0. 41), the wear rate is reduced by 3 orders of magnitude. When filled with 10%PTFE in composites PTFE system, the friction coefficient of the composites is lowest, and the friction coefficient of the graphite counterpart is lowest in 15% graphite content. The lowest friction coefficient is 0. 23 and 0. 27. For the wear rate, PEI composite materials filled with PTFE and graphite are both de-creased with the content increasing respectively. Consequently, compared with the PEI composite materials filled with graphite, the PEI composite materials filled with PTFE has more excellent tribological performance and mechanical behavior. The mechanical behavior of two kinds of the PEI composites was also measured, such as tensile strength, bending strength, impact strength and Rockwell hardness. The results show that, when the mass fraction of 5%—15%, which is the best tribological performance improvement in addition, comprehensive mechanical properties of blends of materials is still good.%将聚四氟乙烯( PTFE)和石墨两类减摩耐磨填料填充到聚醚酰亚胺( PEI)中，表征其摩擦性能，利用扫描电子显微镜分析了磨损表面的显微结构，并分析了磨损机制.研究结果表明， PTFE和石墨的填充明显改善了PEI的摩擦磨损性，摩擦系数降低到0.3以下(纯PEI的摩擦系数为0.41)，磨损率降低了3个数量级.在PTFE体系中， PTFE质量分数为10%时， PEI基共混材料的摩擦系数最低为0.23；而在质量分数为15%的石墨体系中， PEI基共混材料摩擦系数最低为0.27.磨损率随着填料含量的增加而逐渐下降，在填料质量分数为20%之后，摩损率下降平缓.因此PTFE和石墨的填充对PEI的摩擦学性能起到了很好的改善作用，而且PTFE比石墨的改善效果更优益.共混物的机械性能测试结果表明，在填料质量分数为5%~15%时，共混物具有良好的机械性能.