Crystallographic aspects of the early stages of recrystallisation in brass-type shear bands Original Research Article

The orientations of recrystallisation nuclei and their adjacent, as-deformed regions have been characterised in deformed single crystals of different metals (Cu, Ag and Cu–2%Al) in which twinning and/or shear banding occur. The {112}〈111〉 oriented crystals of these metals have been plane strain compressed to different strains then lightly annealed and the crystallographic aspects of the recrystallisation process along shear bands (SB) examined by TEM/CBED and SEM/EBSD. The results clearly show the existence of a well-defined crystallographic relation between the local deformation substructure and the first recrystallised areas of uniform orientation. The first-formed nuclei always exhibit near 30∘〈111〉 type misorientations, in the direction of highest growth with respect to one of the two main groups of the deformation texture components. The 〈111〉 rotation axis can be correlated with one of the slip plane normals of high activity within the SB. As recrystallisation proceeds, recrystallisation twinning develops strongly and facilitates rapid growth; the first and higher generations of twins then tend to obscure the initial primary crystallographic relation between the SB and recrystallisation nuclei.