填料粒径对Cu/PTFE复合材料摩擦学性能影响的数值模拟

Numerical Simulation of Influence of Filler Size on Tribological Properties of Cu/PTFE Composites

利用离散元方法对Cu/PTFE复合材料与45钢摩擦副建立滑动摩擦模型,重点探讨了填充质量一定时,Cu颗粒粒径对Cu/PTFE复合材料摩擦磨损性能的影响.模拟结果表明:Cu/PTFE复合材料与45钢滑动摩擦过程中,在45钢表面形成一层转移颗粒层,转移颗粒层的形成可以降低PTFE基复合材料的磨损;随着Cu粒径的增大,摩擦转移量呈增加趋势,说明一定范围内,较大粒径的Cu填充PTFE基复合材料更加有利于转移颗粒层的形成;滑动摩擦系数随着Cu粒径的增大呈减小趋势;PTFE基复合材料的磨损量、磨损率均随Cu粒径的增大先增加后减小.

The sliding friction model of Cu/PTFE composite sliding against 45 steel was set up based on discrete element method to investigated the influence of Cu particle size on the friction and wear of the Cu/PTFE composites in the same filler content. The simulation results show that a transferred particle layer was formed on the surface of 45 steel during friction. The formation of the transferred particle layer reduced the wear of the Cu/PTFE composites effectively. The transferred amount increased simultaneous with the increment of Cu particle size, which suggested that in a certain range, the larger size of the Cu particles in the PTFE matrix composites, the more conducive to the formation of the transferred particle layer. The coefficient of friction showed a decreasing trend with the increase of Cu particle size. The wear loss and wear rate of the PTFE composites were all firstly increased then decreased with the increase of Cu particle size.