Analysis on multiple cracking in film/substrate systems with residual stresses

Abstract

The multiple cracks might be initiated in the film on a substrate due to the presence of residual stress. In this paper, the multiple film cracking in the film/substrate systems with residual stress was analyzed. First, a relatively simplified model with the closed solutions considering the edge effect was developed to predict the residual stress within the film segment. Some obvious relationships between the material properties and the dimensions of the film and substrate and the stress distribution in the film could be reflected by using this model. By comparing the analytical results with those from the existing analytical models, finite element analysis, and the existing experimental measurements, it could be concluded that the present analytical model was very rigorous. Then, the energy criterion was adopted to perform the analysis on multiple film cracking on the basis of the knowledge on the residual stress distributions. The closed-form solution for the critical misfit strain for the crack initiation is obtained. When the misfit strain is higher than critical misfit strain, the effects of the thickness and elastic modulus of the film on the crack density in the film and the crack initiation strain were investigated.