Effect of strain on generalized stacking fault energies and plastic deformation modes in fcc-hcp polymorphic high-entropy alloys: A first-principles investigation

The generalized stacking fault energy (GSFE) is a material property that can provide invaluable insights into describing nanoscale plasticity phenomena in crystalline materials. Lattice strains have been suggested to influence such phenomena. Here, the GSFE curves for sequential faulting pathways dual phase [face-centered cubic (fcc) and hexagonal close-packed (hcp)] ${\mathrm{Cr}}_{20}{\mathrm{Mn}}_{20}{\mathrm{Fe}}_{20}{\mathrm{Co}}_{20}{\mathrm{Ni}}_{20}, {\mathrm{Cr}}_{25}{\mathrm{Fe}}_{25}{\mathrm{Co}}_{25}{\mathrm{Ni}}_{25}, {\mathrm{Cr}}_{20}{\mathrm{Mn}}_{20}{\mathrm{Fe}}_{34}{\mathrm{Co}}_{20}{\mathrm{Ni}}_{6}, {\mathrm{Cr}}_{20}{\mathrm{Mn}}_{20}{\mathrm{Fe}}_{30}{\mathrm{Co}}_{20}{\mathrm{Ni}}_{10}$, ${\mathrm{Cr}}_{10}{\mathrm{Mn}}_{30}{\mathrm{Fe}}_{50}{\mathrm{Co}}_{10}$ high-entropy alloys are investigated on ${{111}}_{\text{fcc}}$ ${(0002)}_{\text{hcp}}$ planes using density-functional calculations. dependence of GSFEs imposed volumetric longitudinal lattice studied detail ${\mathrm{Cr}}_{20}{\mathrm{Mn}}_{20}{\mathrm{Fe}}_{20}{\mathrm{Co}}_{20}{\mathrm{Ni}}_{20}$ ${\mathrm{Cr}}_{10}{\mathrm{Mn}}_{30}{\mathrm{Fe}}_{50}{\mathrm{Co}}_{10}$. competition between various plastic deformation modes discussed both phases based effective barriers determined from calculated compared with experimentally observed mechanisms. intrinsic energy, unstable twinning found be closely related how they affected by applied strain. ratio two these planar energies thus serve as characteristic property. An inverse relationship hcp axial ${(c/a)}_{\text{hcp}}$ revealed explained via band theory.