Nano-network mediated high strength and large plasticity in an Al-based alloy

A novel Al-based Al–La–Ni–Co–Y composites consisting of the soft α-Al grains surrounded by a rigid frame of nanosized Al3Y/Al3Ni intermetallic phases was developed, and such nano-network structured composite not only showed a high fracture strength of ∼1.1 GPa but also a large plasticity of ∼11%. It was found that the nanosized rigid frame can arrest and suppress propagation of slip bands. In addition, after the severe plastic deformation, splitting of the α-Al grains occurred as a result of the large applied stress, leading to the formation of subgrains. Consequently, plastic deformation of the α-Al grains is confined, giving rise to the unique macroscopic properties.

► We developed a novel nano-network frame composites in Al–La–Ni–Co–Y alloy. ► The composites show high fracture strength of 1.1 GPa and large plasticity of 11%. ► The nanosized hard frame can suppress intergranular propagation of slip bands.