Designing hierarchical eutectic high-entropy alloys via partial similar substitution in the Ni-Fe-Ti-Hf-Nb alloys

Abstract

Hierarchical eutectic high entropy alloys show distinguished mobility and castability, the fine lamella structure, and the excellent compression property, but their development still faces challenges. Here, the partial similar substitution method is to design hierarchical eutectic high-entropy alloys. This concept successfully developed a hierarchical eutectic Ni3FeTi3HfNb2 high-entropy alloy composed of B2 intermetallic compounds and disordered body-centered cubic (BCC) phases. It displays an outstanding compression property, with the yield strength (σs) as high as 1407 MPa, the large fracture strain of 22.1% and the large elastic strain of 3.0%. The combination of high strength and good ductility exhibits a promising application in industry. Moreover, the anisotropy and the relationships among microstructure evolution, mechanical property and Nb concentration are systematically discussed.