Achieving enhanced mechanical performance in a duplex eutectic Ni49Fe20Al17Cr8V6 high-entropy alloy with heterogeneous structure

Abstract

Here, we prepared a Ni₄₉Fe₂₀Al₁₇Cr₈V₆ eutectic high-entropy alloy (EHEA) with dual phases by direct cast method. The as-cast EHEA exhibits dual-phase lamellar structure with soft FCC/L1₂ and hard B2 phases. Specifically, the as-cast EHEA shows an excellent mechanical performance, i.e., a high yield strength of ∼795 MPa, a high tensile strength of ∼1232 MPa and a large uniform elongation of ∼16.3 %. The optimized thermo-mechanical process, i.e., cold-rolling with a thickness reduction of ∼90 % and annealing at 775 °C for 2 h, was applied to the as-cast EHEA, architecting a heterogeneous structure in the studied EHEA. Distinctly, the yield strength increases significantly from ∼795 MPa to ∼1314 MPa, while the total elongation slightly decreases from ∼16.3 % to ∼15.5 %. Such excellent mechanical performance was mainly attributed to HDI strengthening, dislocation strengthening and interface strengthening. The strengthening strategy in this work indicates a promising potential for developing high-performance alloys in the future.