Influence of strain rate on microstructures and mechanical properties of 2524Al alloy fabricated by a novel large strain rolling

2524Al alloy sheets with excellent strength-ductility balance were successfully fabricated by large strain rolling in a strain rate range from 5 s⁻¹ to 20 s⁻¹ at 400 °C. The microstructural evolution, mechanical properties and fracture mechanism of the as-rolled sheets were investigated. The results show that there are numerous coarse precipitates of Al₂CuMg and Al₂Cu along the dendrite grain boundaries for as-cast 2524Al alloy. Most of the precipitates disappear after homogenizing annealing treatment. Grain refining plays a key role in the as-rolled microstructural evolution and the mechanical properties. The dendrite grain were broken and become streamline structure after rolled. The sheet fabricated at 10 s⁻¹ exhibits a higher strength and excellent ductility, with the ultimate tensile strength and elongation of 611MPa and 10.5%, respectively. (paper)