Linlin Guo

This work is a theoretical study aimed to address the lubrication failure of Tom-Pac TP-2557 gel lubricant on the textured high-entropy alloy coatings (THEACs) under wide-temperature-range operating conditions; the rheological lubrication properties of the surface are investigated in this work. Based on lubrication theory and non-Newtonian fluid mechanics, a gel lubrication viscosity model considering temperature dependence and a thermo-mechanical coupled constitutive relationship for the THEACs are established. The results show a significant shear-thinning behavior of the gel within a moderate low-to-medium temperature range, and the onset temperature of thermal degradation is identified. Optimal geometrical and distributional parameters of the surface textures, along with a favorable surface energy range, are determined to achieve desirable interfacial shear strength. Moreover, an anchoring-slip synergistic mode arising from surface energy heterogeneity is found to further enhance lubricating film stability. This research provides a theoretical basis for the gel lubrication design of the THEACs.

This paper presents a cross-scale model for predicting the tribological behavior of textured coatings made of high-entropy alloys. The research methodology includes molecular dynamic modeling, a modified fractal surface model, and the Green’s method with fast Fourier transform. The main results demonstrate the existence of an optimal range of parameters: a fractal dimension of 2.45–2.55 and a texturing density of 15–20%, which reduces the coefficient of friction to 40% compared with untextured surfaces. The practical significance of the work lies in the creation of a theoretical basis for the integrated design and forecasting of the tribological properties of high-entropy coatings.