A new strategy for composition design of eutectic high -entropy alloys based on mixing enthalpy

Abstract

Eutectic high - entropy alloys (EHEAs) effectively strike a delicate balance between strength and ductility in metallic materials by creating heterogeneous biphasic layered structures on the micron and nanometer scales. However, designing EHEAs remains a difficult challenging. In this work, a method is proposed to design EHEAs based on the redistribution of mixing enthalpy and binary eutectic compositions. Four new types of non-equal molar ratio EHEAs have been successfully designed. Namely Co 27.6 Cr 7.89 Fe 18.34 Ni 32.5 Nb 13.67 , Co 29.44 Cr 8.1 Fe 18.5 Ni 29.96 Ta 14 , Cr 11.62 Fe 27 Ni 47.38 Nb 14 , and Cr 11.93 Fe 27.2 Ni 47.37 Ta 13.5 . The microstructure of four EHEAs consists of FCC phase and Laves phase . The experimental results show that it is possible to design EHEAs with excellent performance using the new strategy.