The deformation mechanisms in Cu-Ni-Cu composite nanowires subjected to uniaxial tensile loading are investigated using molecular-dynamics simulations. We particularly explore the coupled effects of geometry and coherent interface on the tendency of nanowires to deform via twins and show pseudoelastic behavior. It is found that the critical size to exhibit pseudoelasticity in composite nanowires is $5.6\times 5.6{\text{nm}}^2$, which is 6.5 times greater than single-crystalline Cu nanowires. Our results also show that the composite nanowires offer stiffness enhancement compared to the corresponding single-crystal Cu nanowires.

• Received 30 November 2009

DOI:https://doi.org/10.1103/PhysRevB.81.054117