Shear Localization and Damage in AA5754 Aluminum Alloy Sheets

In this article, we study the Portevin-Le Chatelier (PLC) bands and their influences on strain localization and fracture in continuous cast (CC) AA5754 aluminum sheets. Three types of tensile tests are conducted: (1) tensile samples are pulled directly to fracture at 223 K, (2) tensile samples are pulled at 223 K to initiate diffuse necking followed by unloading and reloading to fracture at room temperature, and (3) tensile samples are pulled at 223 K to localized necking and unloaded followed by reloading to fracture at room temperature. Furthermore, in situ V-bending test coupled with deformation mapping using digital image correlation is used to study damage at large strains. The results show that PLC bands detect favorable geometrical sites for shear band initiation. The formation of shear bands precedes damage and damage is a consequence of shear band formation.