Evolution of microstructure and local crystallographic orientations in rolled Al–1%Mn single crystals of {0 0 1}〈1 1 0〉 orientation Original Research Article

Al–1%Mn single crystals of {0 0 1}〈1 1 0〉 orientation, rolled to reductions of between 18% and 90%, were examined using transmission and scanning electron microscope techniques, in order to examine the crystal subdivision pattern over both macroscopic and microscopic length scales. Deformation resulted in a macroscopic subdivision across the specimen thickness into three types of region – matrix regions, transition regions, and a central region consisting of two sharply alternating, highly misoriented, orientations. Significant differences, both in the microstructure and local crystallography, were observed in each of the three types of region. A model linking the location-dependent distortion tensor to the crystal rotation via the slip amplitudes was able to account for the observed pattern of crystal rotations, except for in the central region of each sample. The assumption used in the model of imbalanced slip on two sets of coplanar systems was supported by an analysis, using the Frank formula, of dislocation boundary content.