A discrete dislocation dynamics study was made, of plastic deformation in a thin film, which was caused by thermal mismatch with a substrate. A unit-cell analysis was carried out, with dislocations in the film being represented by line singularities in an isotropic linear elastic medium. Their mutual interactions, as well as interactions with the interface and the free surface, were accounted for by using a coupled dislocation-dynamics plus finite-element technique. The formulation included a set of constitutive rules for modelling the generation, glide, annihilation and pinning of dislocations by point obstacles. The simulation monitored the evolution of the dislocation structure as thermal stresses built up, as well as during relaxation at constant temperature. This led to dense dislocation distributions near to the interface, and a dislocation-free zone along the stress-free surface of the film.

2D Dislocation Dynamics in Thin Metal Layers. L.Nicola, E.Van der Giessen, A.Needleman: Materials Science and Engineering A, 2001, 309-310, 274-7