High strength and ductility of nanostructured Al-based alloy, prepared by high-pressure technique

An Al-base alloy 2024 with homogeneous structure and grain size of approximately 70 nm was obtained using a high-pressure torsion process at 6 GPa pressure and five torsional rotations between anvils at room temperature. The resulting structure and mechanical properties of this nanostructured alloy 2024 were investigated in this study. This nanostructured alloy demonstrated a very high ultimate tensile stress (>1 GPa) in testing at room temperature, and superplastic behavior at temperatures >300 °C. After superplastic deformation, the microhardness of the nanostructured alloy was 1.5 GPa, 20% more than the microhardness of the coarse-grained parent material after standard treatment. The ability to achievement both high strength and good ductility in nanostructured metals and alloys makes them attractive for applications in industry, particularly, for micro-systems and for high strength details in components with complex geometry obtained with superplastic deformation.