Predicting mechanical properties of high entropy alloys with face centered cubic structure from first principles calculations

High-entropy alloys (HEAs) are a class of solid-solution alloys with multiple equal or nearly-equal molar constituents and found to exhibit excellent mechanical properties. In this study, we have developed the first-principles density functional theory based computational methods to predict the elastic constants and yield strength of the HEAs with face centered cubic (fcc) crystal structure. Moreover, the developed computational methods were applied to four fcc HEAs including CoFeNi, CoCrFeNi, CoCrFeCuNi, and RhIrPdPtNiCu with equal molar composition. Specifically, we predicted the Young’s modulus to be 204 GPa for CoFeNi, 226 GPa for CoCrFeNi, 217 GPa for CoCrFeCuNi, and 213 GPa for RhIrPdPtNiCu, and the yield strength to be 232 MPa for CoFeNi, 268 MPa for CoCrFeNi, 212 MPa for CoCrFeCuNi, and 520 MPa for RhIrPdPtNiCu. These computational predicted values are found to agree well with available experimental data. Therefore, these first-principles calculation methods can be used for expedite optimization on the mechanical properties of HEAs across vast composition space.