Mechanisms of New Orientation Formation during Recrystallization of Old Deformed Aluminium Bicrystals

Abstract

The crystallography of recrystallization nucleation has been investigated in channel-die deformed pure aluminium bicrystals with {100}<011>/{110}<001> and {100}<001>/{110}<001> orientations. The new grain orientations and misorientations were followed by systematic local orientation measurements using SEM and semi-automatic measurements in a TEM. In particular, orientation mapping combined with in-situ sample heating was used to investigate the formation and growth of new grains and their crystallographic orientation changes at very early stages of recrystallization. Grain boundary migration and ‘consumption’ of the as-deformed areas was always favoured along directions parallel to the traces of the {111} slip planes that had been most active during deformation. The orientations of the first formed nuclei were misoriented with respect to the orientations identified within the neighbouring deformed areas by α(<111>, <112>, or <100>)relations.