The evolution of texture in an equal channel pressed aluminum AA1050

Abstract

The aim of this work was to analyze the evolution of texture of an aluminium AA1050 processed by ECAP and further recrystallization in search of optimum processing conditions to improve formability. The initial material was processed by two different routes: the first set of samples came from a hot rolled coil with a mixture of cube, copper and brass textures and the second from roll casting, exhibiting a strong brass texture. The ECAP deformation followed routes A (no sample rotation between passes), Ay (no sample rotation between passes but keeping the normal to rolling direction parallel to the transverse extrusion axis) and Bc (with a 90o sample rotation around the extrusion axis between passes). Texture evaluation was performed by x-ray analysis and results were analyzed by regular texture and orientation distribution function calculations. The normal and planar anisotropy were measured for the deformed and annealed samples. ECAP orientations were generated mostly by rotation around the transverse axis. 〈111〉//ND; orientations can be generated from S, Goss or copper textures but not from brass or cube textures. Therefore route A and starting with the hot rolled or rolled textures should be considered if 〈111〉//ND orientations are desired. Using route Bc, rotating the existing orientations into a favorable position can generate the desired fiber. The strength of a texture after ECAP depends on the orientations of the initial texture, however the correlation starts vanishing after various ECAP steps and the texture finally smoothes out. When 〈111〉//ND was more intense there was an improvement in the planar anisotropy.