The plastic deformation of polycrystalline face-centered cubic metal thin films, with thicknesses of 1μm or less, was investigated by simulating the dynamics of discrete dislocations in a representative columnar grain. The simulations were based upon the assumption that dislocation sources or multiplication sites were rare and that every source had to operate several times in order to generate appreciable plastic deformation. This model was tested by calculating the response of randomly distributed dislocation sources to an applied stress, and by comparing the results with experimental data. Stress-strain curves, dislocation densities, work hardening rates and their dependence upon the film thickness were calculated. The agreement between simulation and experiment was good and many aspects of the thin-film plasticity could be understood by assuming that small-scale plastic deformation was source-controlled rather than being mobility-controlled.

Discrete Dislocation Simulation of Plastic Deformation in Metal Thin Films. B.von Blanckenhagen, E.Arzt, P.Gumbsch: Acta Materialia, 2004, 52[3], 773-84