The dislocation behavior in thin metallic crystals was studied using molecular statics simulations. Attention was directed to corroborating the overall film response and the nano-scale defect mechanisms, in particular, the interaction between dislocations and interfaces. The two-dimensional numerical model consisted of atoms of the metallic film having a close-packed crystal structure. The substrate was not explicitly included but special displacement constraints were imposed on the boundary atoms, which were conceived to be the interface layer adjacent to the substrate. A free-sliding interface was shown to be able to cause “reflection” of oncoming dislocations and enhance film plasticity. A rigidly bonded interface, on the other hand, was seen to initially resist approaching dislocations. Partial tangential sliding at the interface resulted in a transitional behavior between the two extremes, as revealed in the parametric analysis. The dislocation–interface reaction occurred more sluggishly as the atomic sliding capability decreased. The sliding capability of interface atoms was also seen to dictate the overall deformation and damage initiation in the film.

Parametric Atomistic Analysis of Dislocation–Interface Interactions in Thin Metallic Films. Y.L.Shen, R.W.Leger: Materials Science and Engineering A, 2006, 423[1-2], 102-6