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

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.