Atomic-scale homogenization in an fcc-based high-entropy alloy via severe plastic deformation

The atomic-scale homogenization of a face-centered-cubic-based high-entropy alloy (HEA), Al0.3Cu0.5-CoCrFeNi, using severe plastic deformation (SPD) is reported. Atom probe tomography revealed that water quenching from high temperature cannot produce a homogeneous single phase, and clustering of Cu, Al and Ni still exists. Subsequent processing by high-pressure torsion produced nanostructured non-equilibrium single phase with homogeneous elemental distribution at atomic scale. Importantly, such a non-equilibrium single phase is stable at room temperature due to the sluggish diffusion kinetics. These observations suggest that SPD is an effective approach for producing single-phase HEAs for fundamental studies and applications. (C) 2016 Elsevier B.V. All rights reserved.