Bonding Strength and Fracture Properties of Al (021)/Al2CuMg (001) Interface and Ag-Doped Modification: A First-Principles Study

The Al (021)/Al2CuMg (001) interface models based on experimental orientation relationship are constructed, the structure, work of adhesion, tensile strength, stacking fault energy (GSFE), doping modification, and electronic structure are investigated by first-principles calculations. The CuMg-terminated interface evolves into Al-2-terminated interface, which is consistent with experimental observations. Due to stronger bond strength, the M1-type interface has higher work of adhesion (2.023 J m(-2)) and tensile strength (6.78 GPa) than these of M2-type interface. Meanwhile, Ag doping can enhance the tensile strength of M2-type interface to 6.63 GPa. By calculating the 2 d plot of GSFE, it is found that most slip directions for all interfaces are 1 2 [110], [010], and [100] directions in Al2CuMg, respectively. Doping Ag atom improves the antislip ability of the M2-type interface and further influences the tensile and slip properties of the Al/Al2CuMg interface. The charge density difference, electron localization function, and partial density of states demonstrate that the metallic and covalent bonds are mainly formed by Al-2p orbitals at the interface, so the charge distribution of atoms in the vicinity of the interface is affected by the extranuclear electron of doping Ag atom.