A Deterministic Stress-Activated Model for Tribo-Film Growth and Wear Simulation

A new model was developed for the simulation of growth and wear of tribo-chemical films by combining a boundary element method-based contact model and a stress-activated Arrhenius tribo-film growth equation. Using this methodology, it is possible to predict the evolution and steady-state thickness of the tribo-film (self-limitation) at various operating conditions. The model was validated using two cases for which experimental data were available in the literature. The first case is a single microscopic contact consisting of a DLC-coated AFM tip and an iron-coated substrate. The second case is a macroscale contact between a bearing steel ball and disk. Subsequently, mild wear (wear after running-in) was modeled by assuming diffusion of the substrate atoms into the tribofilm.