Engineering heterostructured grains to enhance strength in a single-phase high-entropy alloy with maintained ductility

Abstract

Coarse-grained (CG) single-phase face-centered cubic (fcc) high-entropy alloys (HEAs) normally show insufficient room temperature strength. Here we design and implement a heterogeneous grain structure to strengthen a single-phase fcc Fe29Ni29Co28Cu7Ti7 HEA. Significantly, the heterostructured (HS) fcc HEA shows a dramatic enhancement (increasing from ∼350 to ∼614 MPa) in tensile yield strength as compared to its CG counterpart. As a result of its extraordinary work-hardening ability arising from the heterogeneous grain structure, the novel HS HEA exhibits a very high ultimate strength of ∼1308 MPa, and a good ductility of ∼23.1% which is almost identical to that of its CG counterpart.