Plastic deformation on the microscale showed a significant size effect in the sense that plastic response was stronger than that of macroscopic bulk materials. This effect was often ascribed to the deposition of misfit dislocations, to the presence of geometrically necessary dislocations or to bowing-out of discrete dislocations. The models based upon these assumptions did predict the size effect, but they were not completely satisfactory. This paper discusses an alternative model, based upon the continuum-theory of dislocations, which ascribes size effects to the bowing of continuously distributed dislocations, treated within a rigorous continuum mechanics framework. Results were compared to those of tensile tests on thin Cu-films, presented in the literature. A quantitative agreement was found concerning the size effect and the influence of grain orientation.

Application of a Continuum Dislocation-Based Model to a Tensile Test on a Thin Film. C.Schwarz, R.Sedláček, E.Werner: Materials Science and Engineering A, 2005, 400-401, 443-7