The influence of deformation texture on nucleation and growth of cube grains during primary recrystallization of AA1050 alloy

The influences of microstructure and texture on the early stages of recrystallization of a commercial AA1050 alloy have been characterized with particular attention to cube grain formation. Samples were deformed along two deformation modes to form different as-deformed texture components and then lightly annealed: one group was plane strain compressed (PSC) in a channel-die, whereas the second group was deformed by equal channel angular extrusion (ECAE). The textures were measured by X-ray diffraction and SEM/EBSD. After both deformation modes a very weak residual cube texture component was observed in the samples. Cube-oriented grains were not formed during annealing of the ECAE samples whose main as-deformed texture components were close to {124}<651>. During recrystallization these transformed to two components of ∼{100}<011> and ∼{221}<114>-type essentially by <110> rotations. Cube grains were extensively formed only during annealing of PSC samples. They were situated preferentially inside or in between the S-oriented deformed areas with local misorientations about <111> axes.

An example of a near-cube band which grows out as a cube grain into near S-oriented neighbours. This clearly requires some form of cube grain re-orientation during initial growth, probably by the coordinated movement of dislocations. (a) Microstructure of the layer and the corresponding {111} pole figure showing (b) the orientations measured inside the S1-cube layer and neighbouring S3- oriented layers. Dotted lines mark the S1-cube layer (cube band).263