Effect of the extrusion conditions on microstructure evolution of the extruded Al–Mg–Si–Cu alloy rods

Hot extrusion experiment was conducted using an Al–Mg–Si–Cu alloy and the effect of the extrusion conditions on microstructure and texture changes through the radial direction was investigated by using SEM/EBSP analysis method. In the surface layer where severe frictional shear deformation is predominant, the recrystallized 〈1 1 0〉//ED grains surrounded by high angle grain boundaries are formed in spite of the existence of some peripheral overcoarse grains. Strong 〈1 0 0〉//ED and 〈1 1 1〉//ED fiber textures evolve in the center where axisymmetric deformation along the extrusion direction is intensive. As the extrusion ratio increases, number of 〈1 1 1〉//ED grains remarkably decreases while the number of 〈1 0 0〉//ED grains apparently increases. It is also found that the 〈1 0 0〉//ED grains surrounded by low angle grain boundaries form orientation colonies in the center of the extruded rods.