Grain subdivision during deformation of polycrystalline aluminium

High purity aluminium (99.996%) with a grain size of about 200 μm has been deformed by cold-rolling from 5 to 30% reductions. The local crystallographic orientations at three strain levels have been characterized using the electron back scattering pattern (EBSP) technique. The deformation leads to grain subdivision on a scale which is small compared to the grain size and no deformation bands have been found. The observed pattern of crystallographic changes across the grains supplements TEM observations and is in accordance with a general framework for the microstructural evolution.