A cost-effective eutectic high entropy alloy with an excellent strength–ductility combination designed by VEC criterion

Abstract

Due to the excellent combination of strength and ductility, eutectic high entropy alloys (EHEAs) are of great interests to the researchers. Here, a cobalt free cost-effective eutectic high entropy alloy was designed by VEC criterion. The cobalt element in AlCoCrFeNi2.1 alloy is replaced by Fe and Ni in equal proportions to maintain VEC value unchanged. The designed AlCrFe1.5Ni2.6 alloy exhibited a eutectic microstructure composed of FCC (L12) phase and BCC (B2) phase. The room temperature mechanical properties of the designed alloy were comparable to those of AlCoCrFeNi2.1 EHEA and better than those of a majority of as-cast high entropy alloys. An excellent combination of strength and ductility originates from the hetero-interface strengthening and slip continuity across the Kurdjumov-Sachs (K–S) interface. The present work proves the VEC criterion could successfully be used to design the cost-effective eutectic high entropy alloy and the designed alloy has a great potential in engineering applications.

Keywords

• Eutectic high entropy alloy
• Microstructure
• Kurdjumov-sachs (K–S)
• Mechanical properties
• Deformation mechanism