Slip pattern, microstructure and local crystallography in an aluminium single crystal of copper orientation {112}〈111〉

The evolution of microstructure and local crystallography has been examined in single crystals of {112}〈111〉 orientation of pure Al deformed at room temperature by channel die compression to strains of ϵ=0.5 and ϵ=1.5. Despite the channel die deformation mode used, a sample rotation towards the {4 4 11}〈11 11 8〉 orientation was observed.

Macroscopic shear bands were not seen. Instead, bands of localised glide on crystallographic planes were observed, associated both with shearing of the microstructure and with +TD rotated orientations. Such strain localisation increased with increasing deformation. The complexity of slip within these regions was confirmed by calculation of dislocation boundary characteristics from local TEM orientation measurements.

Dislocation densities calculated using Frank’s formula are consistent with the observed macroscopic slip pattern.