2016 Volume 57 Issue 9 Pages 1462-1470
In this study, bulk nanostructured 2024 Al alloy sheets with optimized strength and ductility were successfully prepared through an effective thermo-mechanical process including solution treatment, heavy deformation by accumulative roll bonding (ARB) and cold rolling (CR), and subsequent low temperature aging. A lamellar boundary structure with mean grain thickness of 40 nm could be clearly observed after 3-cycle ARB and 50% CR with total equivalent strain of 3.2. The ultimate tensile strength and elongation to failure of the ARB+CR processed sample were 599 MPa and 1.7%, respectively. After subsequent low temperature aging at 100℃ for 20 h, the ultimate tensile strength and elongation to failure became 635 MPa and 7%, respectively, showing simultaneously increased strength and ductility compared to the cold-worked state. The reasons for the superior mechanical properties were discussed.