Analysis and evaluation of interface mechanics for thin films using the method of image

The evaluation of interface mechanics was very useful for the design of thin solid film. According to the method of image, interface stresses and deformations of coating-substrate system were gained. Using this mathematical calculation model, the indentation test data was carried out and the results were analysed. Based on the mechanical model and test, the critical state of interface stresses from elastic deformation to plastic yield was evaluated. From experimental and calculating results, interface shear stress and normal stress had different affecting level for the coating failure under the same surface load. And a fitting relationship equation for the two stresses was also gained to determining the failure value in designing. The method of this paper could be used for thin film interface mechanics design and evaluation.