Dispersoid Formation and Recrystallization Behavior in an Al-Mg-Si-Mn Alloy

The nucleation and precipitation of Mn-containing dispersoids in an Al-Mg-Si-Mn alloy (6082) have been studied by optical microscopy, EPMA (electron probe microanalysis) and TEM (transmission electron microscopy). The influence of Mn-containing dispersoids on the recrystallization behavior was also investigated. The size and distribution of dispersoids were strongly affected by both the homogenization process and the alloying element distribution formed in the direct chill cast procedure. The Mn-containing dispersoids were observed to nucleate preferentially on the β'-Mg2Si phase and to be aligned along the <100> direction of the matrix. After cold deformation, the morphology of dispersoids greatly influences the recrystallization and grain growth behavior in the annealing process.