The Effect of Fluid-Saturation on Mechanical Behavior of the Coating–Substrate System under Contact Loading

Abstract

The influence of the fluid saturation of a porous coating on the mechanical properties of the coating and the entire coating-substrate system is addressed. An important practical application is targeted as the wear-resistant coatings of endoprostheses of major human joints. Based on the method of movable cellular automata, a 3D-model of the mechanical behavior of a porous fluid-saturated coating on a titanium substrate is constructed. Using this model, the influence of fluid-saturation of the surface-layer of a ceramic coating on the mechanical characteristics of the coating-substrate system is studied numerically. The simulation results demonstrate that the presence of fluid in a thin surface layer of the coating can strongly affect the mechanical response of the entire coating-substrate system under sufficiently high rates of the local contact loading. In particular, the calculations without taking the fluid into account give overestimated values of strength and hardness of the coated materials under the wetting conditions. A simulation of scratching demonstrates that the material with a fluid-saturated surface layer is more stable to wear.