A comparative study of mechanical properties of Ni <001> nanowires from atomistic calculations

We present the fracture behavior of the single-crystal nickel nanowires under uniaxial tension with several Modified embedded-atom method (MEAM) implementations. We compare the structural evolution and deformation mechanism, and contrast the difference between the potential implementations. The stress-strain curves predicted for the strain rates from 10⁹ to 10¹¹ s⁻¹ at 300 K show a mixed behavior. While the increasing ductility of the nanowires is obvious from the increasing flow stress with the underlying crystalline structure preserved as the strain rate is increased, applied strain beyond the critical strain rate induces amorphization, which results in prolonged plastic deformation before necking. We analyze the structural evolution and the origin of strain-dependent material behaviors.