Microtexture tracking in hot-deformed polycrystalline aluminium: Experimental results

A split sample of Al–0.1%Mn has been deformed by a series of compression tests in a channel-die at 400 °C to a final strain of 1.6. The orientations of 176 grains in a 4×4mm2 internal surface were followed by high-resolution electron backscatter diffraction at four different strains to compare with crystal plasticity models. Typically 3000 orientations per grain were used to quantify the average lattice rotations of each grain together with their orientation spreads (termed microtexture tracking). The average orientations tend towards the standard ββ-fibre plane-strain compression texture components, albeit with some variations. The in-grain orientation spreads develop strongly at first, then tend to saturate at high strains. Finally, the influence of grain environment on lattice rotation is examined by means of the rotation “variability at constant orientation”. On average and at the beginning of the deformation, two grains of the same initial orientation, but different neighbours, would rotate by angles that vary by 25% and axes separated by 37°; their orientations at ε=1.2ε=1.2 would vary by 12°.