Relating nanoscale plasticity to bulk ductility in aluminum alloys

In situ transmission electron microscopy nanocompression tests of aluminum alloy pillars revealed higher yield stress and greater ductility post-annealing, analogous to what is seen in bulk testing. The annealed pillars showed a complex three-dimensional deformation behavior, whereas the as-extruded sample showed a simpler two-dimensional plasticity. This difference in behavior is consistent with the hypothesis that increasing the Cr content in solution results in stronger obstacles to dislocation motion, leading to a more three-dimensional plasticity at the nanoscale and an increase in bulk ductility.