The importance of microstructural heterogeneities in the work hardening of ultrafine-grained aluminum, studied by in-situ TEM straining and mechanical tests

Technically pure aluminum was deformed by means of hydrostatic extrusion and incremental equal channel angular pressing in order to refine grains to a similar size. Different deformation routes resulted in microstructure varieties in terms of grain boundary characteristics, texture and local defects arrangements. These varieties affected the work hardening abilities measured macroscopically in the tensile test. In-situ TEM straining experiments...