Achieving 2.1 GPa ultrahigh strength in a light-weight eutectic high-entropy alloy with dual heterogeneous structures

Realizing ultrahigh strength near 2 GPa in high-entropy alloys (HEAs) remains a challenge in conventional HEAs. Here, we architected a dual-phase heterogeneous Ni₄₉Fe₂₈Al₁₇V₆ eutectic HEA (EHEA) with bimodal grain size distributions of FCC and B2 phases by cold rolling and subsequent annealing. Partial recrystallization led to hierarchical microstructure characterized by ultrafine recrystallized FCC and B2 grains in both lamellar and non-lamellar eutectic colonies, retained non-recrystallized FCC and B2 eutectic lamellae, as well as non-recrystallized non-lamellar eutectic regions. Our alloy presents an ultra-high yield strength of ∼1.95 GPa, a high tensile strength of ∼2.1 GPa, a good ductility of ∼8.1 %. In particular, the ultra-high yield strength is attributed to the strong hetero-deformation induced (HDI) hardening, which produced by the deformation incompatibility of non-recrystallized grains and the formation of fine recrystallized grains in soft FCC and hard B2 phases. Our study demonstrates a promising pathway for the development of ultra-high strength materials. © 2025 Elsevier Inc.