Influences of interface properties and coating thickness on fracture behaviors of coating/substrate systems

Interface delamination plays an important role on the failure of multi-layer parts, influences of interface properties and coating thickness on interface fracture of coating/substrate systems attract great attention. In this paper, interface fracture behaviors of ceramic coating/substrate systems u nder three-point bending were modelled based on finite element simulations with interface cohesive elements. Influences of coating thickness, interfacial strength and interfacial fracture toughness on interface crack evolution were studied. The simulations indicate that interface crack initiates earlier for the thicker coating systems or the systems with the smaller interface fracture toughness, and the influence of interface strength is more complicated. The simulation results are in agreement with the experimental results and instructive to understand interface failure behaviors of coating/substrate systems deeply.