纳米ZrO2和聚醚醚酮填充聚四氟乙烯的摩擦学性能基于环-块摩擦模型的演变过程

Evolution of Tribological Behavior of Polytetrafluoroethylene Filled with Nano-ZrO2 and Polyetheretherketone Based on Block-on-Ring Friction Model

用不同体积分数的纳米ZrO2和聚醚醚酮(PEEK)颗粒填充改性聚四氟乙烯(PTFE)复合材料。使用环-块摩擦磨损试验机测试PTFE复合材料在滑动速度为2 m/s、载荷为200 N的试验条件下的摩擦学性能。获取不同阶段摩擦学性能的数据,计算出在整个试验过程中样品的瞬时磨损率。利用扫描电镜观察不同试验阶段对偶钢环表面形貌的变化图像并进行分析。利用仿真模拟软件(ABAQUS)对摩擦过程中PTFE复合材料的接触应力变化进行分析。结果表明,纳米ZrO2和PEEK颗粒可以协同改善PTFE复合材料的摩擦学性能。特别是添加8%的纳米ZrO2和20%的PEEK能使PTFE复合材料同时获得最佳的耐磨性(1.29×10-6 mm3/Nm)和较低的摩擦系数。在摩擦试验的后期PTFE复合材料的瞬时磨损率突然急剧上升。根据瞬时磨损率、磨损表面、转移膜形貌和磨屑形态特征的变化规律,将整个磨损过程分为3个阶段(低磨损阶段、过渡磨损阶段和严重磨损阶段)。

The PTFE composites filled with different volume concentrations of nano-ZrO2 and polyetheretherketone(PEEK)particles.The tribological properties of the PTFE composites were tested through a ring-block friction and wear tester under the sliding speed of 2 m/s,with the load of 200 N.Data on the tribological properties at different stages were obtained and the instantaneous wear rate of the samples throughout the test was calculated.SEM was used to observe and analyze the changes of the surface morphology of the counterpart steel rings at different test stages.The simulation of the contact stress of the PTFE composites during the friction process was analyzed by the simulation software.The results show that Nano-ZrO2 and PEEK particles can synergistically improve the tribological properties of PTFE composites.In particular,the addition of 8%nano-ZrO2 and 20%PEEK enables PTFE composite to get the best wear resistance(1.29×10-6 mm3/Nm)and low friction coefficient simultaneously.The instantaneous wear rate of 5%nano-ZrO2/10%PEEK/PTFE suddenly rises sharply at the late stage of the friction test.The entire wear process of 5%nano-ZrO2/10%PEEK/PTFE is divided into three stages(the low wear stage,transition wear stage and severe wear stage),according to the evolution of the instantaneous wear rate,worn surface,transfer film and wear debris morphology.