Structural stability and mechanical properties of B2 ordered refractory AlNbTiVZr high entropy alloys

Highlights: • Al-Zr bond dominates chemical ordering in ordered AlNbVTiZr alloy. • Ordered configurations with lower total energies significantly increase elastic constant of C₁₁. • (AlV)-(NbZrTi) configuration with lower total energy has a larger tensile strength than disordered configuration. • Chemical ordering mediates thermodynamic properties of AlNbVTiZr, but has little effects at high pressure. -- Abstract: Local chemical ordering influences significantly the mechanical properties of refractory high entropy alloys. In this work, the effects of local chemical ordering on the structural stability and mechanical properties of AlNbVTiZr are investigated by using first-principles simulations. It is shown that the AlZr bond dominates the chemical ordering for ordered configurations. The local ordering enhances the structural stability, elastic property and ideal strength. By taking into account the effects of temperature and pressure, we found that chemical ordering mediates the thermodynamic properties of the AlNbVTiZr alloy, but it has little effect at high pressure.