A Novel Hexagonal Close-Packed High-Entropy Alloy with Outstanding Strength-Ductility Synergy

Abstract

Refractory high-entropy alloys (HEAs) are new potential candidates in high temperature applications. However, most present refractory HEAs are single-phase body-centered cubic (BCC) structure, which is brittle at room temperature. Then strategies to ductile the refractory HEAs and maintain their good high temperature strength at the same time should be under consideration. In the present study, a novel WReOsIr HEA with hexagonal close-packed (HCP) structure was developed. This alloy not only has excellent high-temperature strength (416.7 MPa at 1473 K), but also exhibits good ductility (30.7%) at room temperature. The better room temperature plasticity is found to originate from the deformation twins formed inside the grains.