Hierarchical ultrafine-grained/nanocystalline Al-based bulk alloy with high strength and large plasticity

► An in-situ ultrafine/nanocrystalline Al-based bulk alloy was produced by copper mold casting. ► Hierarchical ultrafine-grained/nanocrystalline eutectic colonies were observed. ► It exhibits ultrahigh strength of ∼1.24 GPa and large ductility of ∼26%. ► The combined deformation mechanisms were studied.