Parameters Affecting Thermo-Meohanical Cracking in Coated Media Due to High-Speed Friction Load

This investigation considers the thermo-mechanical effects of an asperity traversing at a high speed over a semi-infinite medium with a thin, hard coated surface. The general analytical solution of the temperature field and the thermal stress state are obtained and expressed in Fourier transform space. The analysis emphasizes the heating effect of the friction force, which leads to the initiation of the thermo-mechanical cracking or “heat-checking,” in the coating layer, the substrate, or their interface. For hard coated layers, the initiation of a crack will occur either in the coating layer, the substrate or the interface depending on the relative properties of the coating and the substrate and their bonding strength.