The effect of deformation on texture, microstructure and recrystallizationof a cross-rolled Cu-5 wt% Al alloy

Polycrystalline Cu-5 wt %Al alloy was rolled initially to 30% deformation a nd 60% deformation and then additionally rolled after switching the rolling direction with the transverse direction to deformations: 10-80%. Examinati ons of the textures and microstructures after deformation and subsequent re crystallization were performed. It was found that the change in the direction of plastic flow alone is not sufficient for localization of the plastic deformation in the form of shear bands; also, the application of a large amount of deformation is required. The shear bands constitute the basic feature of microstructure in samples subjected to cross-rolling with the total true deformation greater then 0.9 . Shear bands are the places where recrystallization commences and proceeds relatively fast. Regions between shear bands recrystallized at higher temp eratures, however, the recrystallization proceeds slower and progress by th e growth of grains from the former shear bands. The grain size after recrys tallization is not uniform. Finer grains appear within former shear bands. The deformations imposed after change in the rolling direction slowly chang es the alloy-type texture formed during initial rolling. After the 80% redu ction in thickness by the secondary rolling the texture being formed during the initial rolling is rotated around the normal direction by 90 degrees. The recrystallization texture for that material (with a high density of she ar bands) contain components which can be derived from the components of th e deformation texture by their rotation around the common [111] poles by an gles about 40-50 degrees.