Improved mechanical properties of Co-free high-entropy Cantor alloy: A first-principles study

Abstract

High-entropy alloys (HEAs) have received attention because of their excellent mechanical and thermodynamic properties. A recent study revealed that Co-free face-centered cubic HEAs could improve strength and ductility, which is crucial for nuclear materials. Here we implemented first-principles calculations to explore the fundamental mechanism for enhancing the mechanical properties in Co-free Cr25Fe25Ni25Mn25 alloy. We found that the local lattice distortion of Co-free HEA was more significant than that of the well-known Cantor alloy. Furthermore, the short-range order formation in Co-free HEA caused the highly fluctuated stacking fault energy. Thus, the significant local lattice distortion and the non-uniform solid solution states comprising low- and high-stacking fault regions improve strength and ductility.