Deformation of cube-oriented grains and formation of recrystallized cube grains in a hot deformed commercial AlMgMn aluminium alloy

Abstract

The cube orientation is usually found to be the strongest recrystallization texture component in annealed aluminium. The purpose of the present work was to obtain a better understanding of the cube orientation, both with respect to the behaviour of cube-oriented grains during deformation and the formation of recrystallized cube grains. Extensive use was made of the EBSP technique to characterize samples of a hot deformed AlMgMn alloy and plane strain compression tests were used to simulate hot rolling under a wide range of conditions of strain, strain rate and temperature. The investigations included: (i) the stability of cube-oriented grains during deformation, (ii) characterization of cube-oriented regions in the as-deformed state and (iii) nucleation of recrystallized cube grains. The work has demonstrated that cube-oriented grains present in the material prior to deformation remain orientation metastable during deformation and are deformed to bands. These cube bands have a unique subgrain size distribution with a long tail of large subgrains, making them very potent as nucleation sites for recrystallized grains. Nucleation of recrystallized cube grains takes place preferentially from those bands which are surrounded by the S deformation texture component.