Biaxial Stressing of Sheets of Friction Stir Processed Aluminum Alloy A319

Cast Aluminum alloy A319 was multiple friction stir processed (5 single passes) to obtain a somewhat refined, equi-axed microstructure in which the size of the second phase particles had also decreased. The processed sheets, which had greater formability than the as-cast material, were subjected to different gas pressures and forming temperatures in an attempt to form a hemispherical dome. But the sheets failed before the hemispherical shape could be attained. The results of the forming experiments, which indicate extended plasticity, and the corresponding microstructures are discussed.