Strength-ductility synergy of Al0.1CoCrFeNi high-entropy alloys with gradient hierarchical structures

Abstract

A new strategy for strengthening Al0.1CoCrFeNi high-entropy alloys (HEAs) is introduced by architecting the gradient hierarchical structures (GHS). The GHS sheets show a dramatic enhancement in tensile yielding strength and acceptable tensile ductility, outperforming the annealed counterpart, owing to extraordinary strain hardening capacity and nanotwinning activity. The yielding strengths of the GHS sheets are higher than the values calculated by the role of mixture from separate gradient components, suggesting that a synergetic strengthening mechanism of the GHS plays an important role. It may provide a novel guidance to develop HEAs by tailoring and architecting optimized mechanical behaviors from bulk GHS.