The Tribological and Mechanical Properties of Polyimide/Polyamide Imide/Epoxy Resin, Polytetrafluoroethylene-ZrO2 Coating on an Engine Bearing

Abstract

To improve the poor tribological performances of the copper alloy used in engine bearings under boundary lubrication and dry sliding wear, a new polymer coating consisting of polyimide/polyamide imide/epoxy resin (PI/PAI/EP), polytetrafluoroethylene (PTFE) and ZrO2 has been designed. The tribological and mechanical characteristics of the coatings at various thicknesses were studied by friction and wear experiments, nanoindentation experiments, simulation experiments of the stress and deformation and fluid-structure coupling simulation tests. The results showed that when the thickness of the coating was 20 μm, the deformation of the coating was the lowest and the friction coefficient of the coating was 0.167. As the thickness of the coating was increased, the support effect of the substrate on the coating decreased, and the thickness of the coating increased under positive pressure. Compared with the substrate, the friction coefficient of the coating under boundary oil lubrication conditions was reduced by 53.85%. The fluid-structure coupling calculation showed that the boundary lubrication and dry sliding wear of the copper alloy were improved by the designed coating. The fluid-structure coupling calculation showed that the peak variation rates of the coating bearing pressure was 0.02%. The coating on the surface of the bearing had little influence on the oil pressure, but at the same time, improved the tribological properties of the engine bearing.