Texture, microstructure and formability of SC and DC cast Al–Mg alloys

Abstract

Texture, microstructure and formability were studied in direct chill (DC) cast and strip cast (SC) Al–Mg alloys (AA5754 and AA5182) and were found to largely depend on the production processes (DC versus SC) and chemical compositions. DC hot bands are usually fully recrystallized and thus have strong recrystallization textures while SC hot bands have deformation structures and thus strong deformation textures. It is difficult to obtain strong recrystallization textures in SC hot band materials with elevated temperature annealing. However, annealed SC5754 hot bands have stronger recrystallization texture components than annealed SC5182 hot bands. This is due to the fact that a stronger dynamic precipitation occurs in SC5182 hot bands during annealing. As a result, annealed SC5754 hot bands have small 90° earing while SC5182 hot bands have both 90° earing and 45° earing after annealing. Cross rolling of materials with a deformation structure causes a significant texture change in the final cold rolled samples while it causes no texture change in materials with a recrystallized structure. Compared to samples after straight rolling, cross rolling reduces the volume fraction of the deformation texture components (especially the copper component) with little change in recrystallization texture components. Al–Mg alloys are strong and difficult to work. However, the workability can be significantly improved after annealing at an elevated temperature.