THE EDGE CRACKING AND DECOHESION OF THIN-FILMS

The cracking and decohesion processes that may accompany a residually stressed thin film on a substrate have been investigated. Attention is focused on an interfacial edge crack, loaded by a linear variation of residual stress across the thickness of the film. The interfacial stress intensity factor and the non-singular T-stresses at the interfacial crack tip are evaluated using the finite element method, and the role of the T-stresses and the interfacial phase angle in influencing the selection of crack path is discussed. The results ate used to predict the distributions of residual stress for which kinking switches from the substrate to the film.