Macroscopic crystal rotation patterns in rolled aluminium single crystals Original Research Article

EBSD crystal orientation measurements are presented for rolled aluminium single crystals initially having Goss, Cube and Rotated Cube orientations; (011)[100], (001)[100] and (001)[110] respectively. The orientation measurements reveal macroscopic-scale crystal rotation patterns having an amplitude that depends on initial crystal orientation. For the set of crystals studied here, the rotation amplitude increases in the order: Goss, Cube, Rotated Cube. Combining a standard model for metal flow through a converging channel with the slip system geometry in each crystal shows that the macroscopic crystal rotation pattern is coupled to the pattern of redundant strains generated during rolling. By simplifying the set of slip systems in each crystal to 2 equivalent slip systems, physical insight into the coupling mechanism between the redundant strain and crystal rotation patterns is gained. From this analysis, it can be understood that the macroscopic crystal rotation pattern reflects the macroscopic redundant strain pattern imposed on the crystal during rolling; orientation stability of a crystal has little influence on the macroscopic rotation pattern. Previously published results for the Cu crystal orientation reveal that Copper-oriented crystals, 112111̄, exhibit a net rotation, but only a small spread of orientations develops during rolling; these results are readily rationalized using the equivalent slip system method. Finally, the transition bands are shown to be bands in which the observed crystal rotations require operation of unpredicted slip systems.