Evolution of the structure and mechanical properties of sheets of the Al–4.7Mg–0.32Mn–0.21Sc–0.09Zr alloy due to deformation accumulated upon rolling

Abstract

The mechanical properties and microstructure of sheets of an Al–4.7Mg–0.32Mn–0.21Sc–0.09Zr alloy deformed and annealed after rolling have been investigated. The total accumulated true strain was ef = 3.33–5.63, and the true strain at room temperature and at 200 °C was eс = 0.25–2.3. The strength properties of the sheets (yield stress σ0.2 = 495 MPa and ultimate tensile strength σu = 525 MPa) in the deformed state were greater than those after equal-channel angular pressing (ECAP) deformation. The mechanical properties of the deformed sheets after annealing depended on the size of subgrains inside the deformed grains bands with high-angle grain boundaries (HABs). With the increase in the annealing temperature from 150 to 300°С, the subgrain size increased from 80 to 300 nm. The relative elongation δ in the as-cast state and after annealing at 200–250°C (δ = 40–50%) was higher than that after annealing at 300–370°C (δ = 24–29%).