Plastic deformation in bi-metal multilayer nanowires

Bi-metal multilayer nanowires attract much more attention in recent years because of potential applications in NEMS. In this work, the tensile loading process is simulated by molecular dynamics method on the Cu-Ni bi-metal multilayer nanowires to investigate their mechanical behaviors. According to the stress-strain curves as well as accompanying microstructural evolution, we focus on analyzing the influence of coherent interfaces on the plastic deformation of the nanowires. These results show that the interfacial stress has considerable effect on the plastic behaviors, which is extraordinarily sensitive to the local regions. Specifically, the interfacial stress may accelerate the destructive lattice distortion in Cu sublayers, while it will retard the plastic deformation in Ni sublayers. In such a case, the plastic deformation takes place in Cu sublayers more easily than in Cu nanowires, and then propagates into Ni sublayers. This should be emphasized in the design of NEMS.