Effect of rolling reduction on the development of rolling and recrystallization textures in Al-Mg alloys

In order to investigate the effect of Mg content on the development of the rolling textures in Al, pure Al, Al-3 % Mg alloy and Al-5 % Mg alloy were cold rolled by varying rolling reductions up to 97 %. Their rolling textures were investigated by the orientation distribution function analysis. The extent of work hardening introduced by cold rolling was estimated by the hardness measurements. It was found that, at all rolling reductions, the main orientations of the rolling textures depended strongly on the Mg content. In pure Al, {123}<634> was always the main orientation, whereas {112}<111> was most strong in the Al-3 %Mg alloy. In the Al-5 % Mg alloy, the development of both {123}<634> and {112}<111> were strongly suppressed, whereas {110}<112> developed remarkably. In pure Al, most of the texture development occurred at the later half of work hardening, i.e. at rolling reductions above 70 %. With increasing Mg content, rolling texture tended to develop already at lower rolling reductions. Dynamic recovery, which occurred at very high rolling reductions, suppressed the development of the rolling textures. All these results strongly suggested that the formation of dislocation cell structures and shear banding are origins of the formation of these rolling textures. On annealing these specimens at 450 degreesC for 30 min, recrystallization textures developed only in specimens having strong rolling textures, i.e. in the specimens cold rolled more than 70 %. {100}<001> developed only in pure Al and in the Al-3 % Mg ally, in which {123}<634> and {112}<111> were strong in the rolling textures. Recrystallization textures of the Al-5 % Mg alloy was rather random. its main orientation, {103}<321> developed most remarkably at the 90 % rolling reduction.