Theoretics-directed effect of copper or aluminum content on the ductility characteristics of Al-based (Al₃Ti, AlTi, AlCu, AlTiCu₂) intermetallic compounds

First-principle simulations have been applied to investigate the effect of copper (Cu) or aluminum (Al) content on the ductility of Al₃Ti, AlTi, AlCu, and AlTiCu₂ alloys. The mechanical stable and elastic properties of Al-based intermetallic compounds are researched by density functional theory with the generalized gradient approximation (DFT-GGA). The calculated lattice constants are in conformity with the previous experimental and theoretical data. The deduced elastic constants show that the investigated Al₃Ti, AlTi, AlCu, and AlTiCu₂ structures are mechanically stable. Shear modulus, Young's modulus, Poisson's ratio, and the ratio B/G have also been figured out by using reckoned elastic constants. A further analysis of Young's modulus and Poisson's ratio reveals that the third added element copper content has significant effects on the Al-Ti-based ICs ductile character.