Cube{100}<001> Grains Nucleation during Annealing of S-Oriented Aluminum Single Crystal

Abstract

The crystallographic aspects of nucleation of cube grains during annealing have been analyzed in (234)[20-28 11] - oriented aluminum single crystal. The samples were plane strain compressed in a channel-die up to logarithmic strains of 0.5 (40%) and then annealed to develop initial and final stages of primary recrystallization. The deformed and annealed samples were analyzed using scanning electron microscopy equipped with EBSD facility. Local orientation measurements reveled that significant part of the sample deforms homogeneously with only small deviation from the initial crystal orientation. The heterogeneities were thin bands of localized strain in which the crystal lattice rotate towards another variant of S orientation. After annealing the orientations identified inside deformed/recovered areas were similar to that observed in the sample just after deformation. The crystal lattice of recrystallized grains exhibit a well-defined clockwise and anticlockwise rotations around the axes grouped near all normals of the {111} planes of the deformed/recovered state. The cube grains were observed in both homogeneously and heterogeneously deformed areas despite the cube-oriented nuclei surrounded by high angle boundary were not present in the as-deformed structure.