Debonding between coating and substrate due to rolling–sliding contact

Rolling–sliding contact of layered elastic solid is an important technical issue, since surfaces are often subjected to contact stresses. Generally, elastic surfaces are coated to increase wear resistance of the materials. However, coating materials sometimes debonds from substrate due to tangential and normal forces acting on the surface. Because of these forces, or existing bonding faults, cracks form between coating and substrate. If these forces are applied continuously, the crack propagates resulting in debonding. In this study, a numerical solution is applied to interface cracking. The variations of the stress intensity factors (KI, KII) with load position are obtained for various cases such as different combinations material of coating layer and substrate and changes in the coefficient of friction on the surface. Effects of the combination of the materials and the coefficient of friction on the stress intensity factors are discussed. The direction of the propagation of interface crack is also examined.