The anisotropy of three-component medium entropy alloys in AlCoCrFeNi system: First-principle studies

A theoretical investigation of the anisotropy of face-centered-cubic (FCC) and body-centered (BCC) medium entropy alloys (MEAs) based on the first-principle calculations has been implemented. The electronegativity difference Delta(chi), mixing enthalpy Delta H-mix, range of electronegativity R-chi and total charge transfer have been considered. All elastic anisotropies of the selected MEAs change monotonously with the electronegativity difference Delta(chi), more specifically, the anisotropy decreases with decreasing electronegativity difference Delta(chi). A detailed investigation of electronic structure reveals that charges are mainly accumulated around the atom with minimal Pauling electronegativity (chi) and valence electron concentration (VEC), resulting in a high anisotropy of MEAs. For Al-containing MEAs, a substantial number of total charge transfer will lead to a great anisotropy. In addition, the range of electronegativity R-chi can be used to assist in identifying the anisotropy in the localized electron distribution.