Effects of Sc addition and rolling on the microstructure and mechanical properties of Al-35Zn alloys

Sc addition and rolling were performed to optimize the mechanical properties of Al alloys with high Zn concentrations. The addition of 0.5 Sc reduced the grain size of the Al-35Zn alloys during solidification, heat treatment, and rolling. Nanosized, rod-shaped Zn particles dynamically precipitated from the Al lattice during hot rolling and consequently coarsened during further cold rolling. Following 50% hot rolling and 80% cold rolling, Al-35Zn-0.5Sc alloy demonstrated the highest strength, i.e., an ultimate tensile strength (UTS) of 482 MPa. Moreover, following 90% hot rolling, Al-35Zn-0.5Sc alloy demonstrated balanced mechanical properties including high strength and reasonable ductility (UTS and tensile elongation of 430 MPa and 10%, respectively). This work provided an effective strategy to fabricate Al alloys with high Zn concentrations and excellent mechanical properties.