Possible debonding mode of coated film under thermal loading

Deformation modes in thin films are discussed in order to evaluate the possible debonding mechanism. A combined simulation technique is employed in order to evaluate the thermo-mechanical response of a thin film layer attached to a substrate. A thermo-elasto-plastic finite element analysis is carried out on a jointed system, while only the film layer is picked up and both the deformation and eigen-mode analyses are implemented with reference to the data obtained in the former analysis. This approach enables us to capture the mechanical stiffness of the thin film layer. The effects of crystal morphology of substrate are discussed in terms of the interfacial force and the out-of-plane deformation of the thin film.