Improvement of tensile ductility of heavily rolled and recovery annealed aluminum alloy sheet

摘要

For non-heat treatable aluminum alloys, strength can be achieved by heavy cold working, but poor ductility is often accompanied. In order to restore some ductility, a low temperature recovery annealing may be applied, in which the annealing is carried out at a temperature below the onset of recrystallization. The recovery annealing often produces yield drop, which is followed by flow localization, early onset of necking, and poor ductility. In this work, Al-Fe-Mn alloy sheets produced by heavy cold rolling (98%) followed by recovery annealing were investigated. Anisotropic tensile tests were carried out with stress axis along the directions of 0°, 45°, and 90° from rolling direction. It was observed that the presence of Mn in solid solution could improve both the tensile strength and ductility of the recovery annealed aluminum alloy sheet. Microscopic observations were also performed and related to the tensile properties.