Hot deformation microstructures of Al-1 %Mn single crystals

To determine the basic mechanisms of substructure development within the grains of hot rolled A1 alloys, the influence of processing conditions on the hot channel-die compression structures of Al-l%Mn single crystals has been systematically characterised by automatic EBSD orientation maps. Analysis of the microstructures gives the subgrain sizes and misorien- tation angle distributions, which can be described by physically based mathematical functions. The average subgrain size decreases, as expected, with increasing Zener-Hollomon parameter Z (or increasing flow stress). Most crystals have similar subgrain sizes and distributions. In contrast, the Cube oriented crystals are composed of bands of fine and coarse subgrains. The average adjacent disorientations are also quite similar and are shown to increase with flow stress (or Z). However, the spatially heterogeneous structures of the cube grains are associated with significantly higher average disorientations