SUBSTRUCTURE EVOLUTION DURING DIFFERENT HOT DEFORMATION PROCESSES OF COMMERCIAL NON-HEAT TREATABLE ALUMINUM-ALLOYS

The objective of the present work was to examine to what extent differ ent laboratory resting equipment, such as plane strain compression (PS C), torsion, rolling and extrusion reveal the same substructure evolut ion juring hot deformation of aluminium. The investigation included th ree non-heat treatable aluminium alloys; commercial purity aluminium ( cp Al), cp Al + 1 wt.%Mn and cp Al + 1 wt.%Mg. The substructure was ch aracterized by the subgrain size and the misorientation between neares t neighbour subgrains using a scanning electron microscope equipped wi th the SINTEF EBSP-system. The results showed that the subgrain size o f the PSC-materials was significantly smaller as compared with the oth er deformation modes. The larger subgrain sizes in the hot rolled and extruded specimens were attributed to recovery effects owing to a dela y in quenching time. In the case of the hot torsion specimens, the lar ger subgrain size as compared with the PSC-results was ascribed to tex ture effects by means of differences in the Taylor factor when deformi ng in shear and plane strain deformation conditions. The misorientatio n results for the different deformation conditions were inside the sam e scatter band.