Effect of transition-elements substitution on mechanical properties and electronic structures of B2-AlCu compounds

Abstract The first-principles calculations have been performed to predict the effect of transition-elements substitution on mechanical properties and electronic structures of B2-AlCu compounds. The results show that Zn, Cd, La and Hg are preferred to replace Al atom, while other transition elements are preferred to replace Cu atom. Among the mechanically stable AlCu-TM compounds, the resistance of axial deformation is greater than that of shear deformation. According to Poisson's ratio and Pugh criteria, all compounds show ductility. The compounds of Al8Cu7Fe, Al8Cu7Tc and Al8Cu7Re exhibit excellent Young's modulus and Vickers hardness in fourth, fifth and sixth periods, respectively. The bulk moduli of all AlCu-TM compounds indicate a low degree of isotropic deviation, while the shear moduli have a large anisotropy. The analysis of the electronic structures of Al8Cu7Fe, Al8Cu7Tc and Al8Cu7Re demonstrates that metal bond and covalent bond are mixed, and the properties of covalent bond between TM and Cu are weak.