Different Foamed Metal–Reinforced Composites: Tribological Behavior and Temperature Field Simulation

Abstract

Four kinds of foamed metals (foamed Ni, FeNi, CuNi, and Cu) filled with polytetrafluoroethylene (PTFE) and graphite were developed as rubbing materials. These open-cell foamed metals had the same interconnected three-dimensional (3D) metallic skeletons. The friction and wear properties of the new composites were investigated on an M-2000 friction and wear tester. To study the influence of the metallic skeleton on the contact between the sample and the rotating ring, an electric field was imposed to monitor the formation of transfer film by means of contact resistance. A thermocouple was embedded into the sample to measure the temperature variation caused by friction. Optical and scanning electron microscopes were used to study the worn surface morphologies. The temperature field of the sample and the effect of the metallic skeleton on temperature were calculated using finite element analysis (FEA). It was found that the foamed metal–reinforced composites possessed better thermal conductivity and wear resistance than homologous polymers, which was attributed to the following two main reasons: first, the metallic skeletons are beneficial for restraining the plastic flow of polymeric matrix and second, the heat can be conducted along the 3D supporting skeletons effectively.