Slip-induced mechanism of the orientation-dependent deformation banding in cold rolled Al-Mg alloy

The mechanism of deformation banding in cold rolling AlMg alloy is investigated in detail with regards to local lattice rotation and related dislocation slip. The formation of deformation bands (DBs) has a strong orientation dependency where they populate in grains with 〈111〉 and 〈001〉 directions close to the normal direction and 〈101〉 directions close to the rolling direction. On the contrary, DBs are hardly observed in grains close to the {101}〈111〉 orientations. Experimental and numerical analysis indicates that activated secondary slips and their related lattice rotation account for this orientation dependency. The activation of secondary single slip or secondary coplanar slip plays a vital role in the formation of DBs. DBs are formed when the primary and secondary slips lead to sustainable opposite lattice rotations, which gradually split the grain and develop into DBs. Meanwhile, the tendency of the development of Goss texture during the early rolling stage is observed to arise from the generation of DBs.