The Tribological Properties of Polyimide/Polyamide Imide/Epoxy Coating Filled by WS2 and ZnO Under Dry, Water, and Sediment Conditions

Abstract

Three types of polyimide/polyamide imide/epoxy resin (PI/PAI/EP) coating materials filled with different amounts of WS2 and ZnO were designed, and the coatings were prepared on the surface of 1010 steel substrates using liquid spray coating technology. The mechanical and tribological characteristics of these coatings were investigated. The CoFs (coefficients of friction) of these coatings were lower than those of the copper alloy proposed to be replaced under dry sliding wear and water lubrication. The lowest CoF of 0.237 was achieved with 7.35 wt% WS2, and the highest CoF of 0.251 was observed for 4 wt% ZnO. However, the coating with 7.35 wt% WS2 had the lowest hardness and poorest load-bearing capacity under water lubrication. The coating with 4 wt % ZnO had the best load-bearing capacity and the lowest wear rate. The agglomeration of the coating on the substrate was influenced by the content of ZnO. The CoF of the coating was influenced by both the transfer film formed by WS2 and the amount of ZnO floating on the surface of the coating. The embedding of sand into the coating surface during friction increased the surface roughness, which led to an increase in the CoF.