Journal of Materials Research and Technology (Sep 2024)
Effect of hygrothermal aging on the friction behavior and wear mechanism of the multi-filler reinforced epoxy composites for coated steel
Abstract
Polymer-based composites for steel structure coating are an effective strategy to improve tribological properties and service durability under hygrothermal aging conditions. In the present paper, epoxy resin was improved by mechanical reinforcement and frictional lubrication fillers, and a kind of multi-filler reinforced epoxy composite (MFREC) was successfully prepared. Water uptake behavior, mechanical and thermal property evolution, friction behavior and wear mechanism as well as micro-topography analysis of MFREC under hygrothermal aging were conducted and discussed in detail. The research results showed that the water uptake curve of MFREC after distilled water and 5 wt% NaCl water solution immersions confirmed the two-stage diffusion model, where the quasi-equilibrium water uptakes were 4.23% and 3.67%, respectively. Additionally, the fundamental reason for the degradation of the mechanical and thermal properties of MFREC was the hydrolysis of the resin and the de-bonding of the fillers/matrix interface. The interface shear strength of MFREC adhesive and steel gradually decreased with the hygrothermal aging, but did not lose the bonding property, because the uniformly dispersed multi-fillers can fill the internal defects of the matrix and prolong the crack propagation path to block the effect. Before hygrothermal aging, MFREC had excellent friction and wear resistance compared to resin matrix, especially under water lubrication conditions. The anti-wear rate of MFREC increased by up to 59.6% compared to the room temperature dry test environment due to the coupling effects of the water lubrication and anti-friction characteristics of modified fillers. Hygrothermal aging had little effect (＜12%) on the friction coefficient of MFREC, but the anti-wear properties decreased significantly, especially the Ws increased by 255.1% under the 60 °C immersion condition. Because the degradation of thermal/mechanical properties was not enough to resist the high shear stress of the steel ball, leading to severe fatigue wear.
