Lightweight Co-free eutectic high-entropy alloy with high strength and ductility by casting

Abstract

We report a cast light-weight dual-phase eutectic high-entropy alloy (EHEA) of Ni49Fe28Al17V6 that comprises of alternating FCC and ordered B2 lamellae. Such lamellar EHEA exhibits a superior tensile strength of ∼ 1.3 GPa in combination with a large uniform elongation of ∼ 26%, well surpassing those of other state-of-the-art cast EHEAs. The high strength-ductility synergy originates largely from the extensive dislocation activities in both FCC and B2 lamellae. In addition, the martensitic transformation of the B2 lamellae during deformation further promotes the work hardening capability to enhance the tensile strength and ductility.

Keywords

• Eutectic high-entropy alloy
• Lamellar structure
• mechanical properties
• strengthening mechanism
• martensitic transformation