Effect of initial grain size on the recrystallization and recrystallization texture of cold-rolled AA 5182 aluminum alloy

AA 5182 aluminum alloy with two different grain sizes was cold rolled to 71.2% reduction and then annealed at different temperatures for 3 h. The effect of initial grain size on the recrystallization and recrystallization texture of AA 5182 aluminum alloy was investigated. The fine-grained alloy recrystallized more rapidly than the coarse-grained alloy since initial grain boundaries were favored nucleation sites. Shear bands and transition bands were more readily formed in the coarse-grained alloy than in the fine-grained alloy. Inhomogeneous distribution of nuclei in the coarse-grained alloy led not only to a slow decrease of yield strength and ultimate tensile strength with increasing annealing temperature, but also to a marked inhomogeneity of recrystallized grains. The recrystallization texture of the fine-grained alloy was characterized by the R component and the cube orientation with some scattering about the rolling direction (RD) towards the Goss orientation, while the recrystallization texture of the coarse-grained alloy exhibited the 22.5° normal direction (ND) rotated cube orientation and the R′ component deviated from the R component. The formation of 22.5° ND rotated cube and R′ textures could be attributed to the inhomogeneous deformed microstructure and unique rolling texture.