Discrete dislocation dynamics simulations, and stereo in situ straining transmission electron microscopy, were used to study dislocation motion in thin foils. Stereo imaging, before and after in situ tensile straining, was used to describe the 3-dimensional evolution of dislocation structures with incremental straining. The initial 3-dimensional configuration was used as the input for 3-dimensional discrete dislocation dynamics simulations, and the final 3-dimensional configuration was used to perfect and check the dislocation dynamics simulation. Complex 3-dimensional structures of dislocations were observed; with appreciable out-of-plane motion. Computer simulations, which incorporated the Friedel-Escaig cross-slip mechanism, indicated that the surface image-forces were sufficiently strong to activate out-of-plane motions of screw dislocation segments near to the surface. The cross-slip of screw segments, and the dislocation climb of edge components, were shown to be necessary mechanisms when explaining the observed 3-dimensional dislocation motion.

Dislocation Motion in Thin Cu Foils - a Comparison between Computer Simulations and Experiment. Z.Wang, R.J.McCabe, N.M.Ghoniem, R.LeSar, A.Misra, T.E.Mitchell: Acta Materialia, 2004, 52[6], 1535-42