First-principles study of the effect of V, Co, Ca, Sr, Ga, As doping on the mechanical properties of Al2Cu

Strengthening phase and element doping are two important methods to improve the mechanical properties of Al-Cu alloys. In this work, first-principles calculations based on the density functional theory were used to investigate the influence of doping elements (V, Co, Ca, Sr, Ga, As) on mechanical properties of θ phase (Al2Cu) in Al-Cu alloy. The results showed the additions of As and Ga can increase the strength of θ compound with decrement on ductility. But V and Co doping exhibited the opposite effect that they can enhance ductility and reduce some amounts of strength. And the strengths of Ca and Sr doped structures were increased in a few quantities. By analyzing on electronic structure, it is implied that there exists an apparent relation between orbital hybridization and the charge transfer of mechanical properties. This work provides a theoretical basis for understanding the doping mechanism in Al2Cu and a possible way to improve the performances of Al-Cu alloy.