First-principle prediction of structural and mechanical properties in NbMoTaWRex refractory high-entropy alloys with experimental validation

In this work, the effect of Re alloying on the phase composition, crystal structure, and mechanical properties of NbMoTaWRe x ( x = 0, 0.27, 0.57, 0.92, 1.33) refractory high-entropy alloys (RHEAs) were systematically investigated by combining the calculation of phase diagram (CALPHAD), first-principle calculations and experiment. The theoretical predictions showed good consistency with the experimental results. As the increase in Re content, the theoretical results showed that all considered alloys have a single body-centered cubic (bcc) structure and the lattice constant and ductility were decreased, while the elastic moduli and hardness were improved. To avoid extreme brittleness, a strategic suggestion was given for the design of Re-containing RHEAs in the future. Graphical abstract