Disordered dislocation configuration in submicrometer Al crystal subjected to plane strain bending

Bending tests of submicrometer Al pillars were performed in-situ in a transmission electron microscope (TEM). The Al crystal in the bent region experienced substantial lattice distortion, as well as grain refinement resulting in a disordered dislocation configuration arising from a random distribution of low angle grain boundaries (LAGBs). This observed disordered dislocation configuration is in contrast to formation of a low energy dislocation configuration, as predicted on the basis of the theory of strain gradient plasticity, for bulk materials subjected to plane strain bending.