Influence of pore-forming agent on wear resistance of composite coating

In this paper, polystyrene microsphere (PS) is selected as the pore-forming agent to prepare porous phosphate bonded ceramic coating. Then the mixed solution of polytetrafluoroethylene and polyamide-imide (PTFE-PAI) is pressed into the porous coating to prepare the composite coating. Besides, the microstructure and tribological properties of composite coatings were studied. The results show that the hydrophobicity of composite coating is improved because PTFE-PAI is pressed into the coating. Moreover, the coefficient of friction decreases with the increase of PS content due to the self-lubricating ability of polytetrafluoroethylene. Besides, the wear rate also decreases with the increase of PS content, because polytetrafluoroethylene forms a transfer film on the grinding ball, and the original ceramic coating framework can withstand shearing force due to its high hardness, which protects the composite coating and reduces the wear rate. With this self-lubricating capability, the composite coating with 6 wt-% PS showed the smallest wear rate.