Microstructure evolution and strain localization during shear deformation of an aluminium alloy

Strain localization by shear banding during shear tests of a commercial aluminium alloy is described at different scales using optical microscopy, SEM and TEM. The evolution of the dislocation microstructure is correlated to the global mechanical behaviour. Two initial states of the material-heavily cold-rolled and recovered after cold-rolling-having the same crystallographical texture are compared. The localization occurs only for the as-rolled samples, and its consequence on damage and fracture depends on the angle between the initial rolling direction and the shearing direction. The discussion focuses on the predominant role of the microstructure, rather than the crystallographic texture, in the localization phenomena. Macroscopic arguments for localization are also evoked. Copyright (C) 1996 Acta Metallurgica Inc.