The effect of defects on the mechanical behavior of silver shape memory nanowires

CJ Ji and HS Park, JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE, 4, 578-587 (2007).

DOI: 10.1166/jctn.2007.2342

We present atomistic simulations of the uniaxial tensile deformation of silver shape memory nanowires to investigate the effects of initial defects on the resulting thermomechanical behavior. In particular, the focus of the work is on investigating the unique atomistic deformation mechanisms that are observed during the tensile loading as a result of the initial defects, while correlating that behavior to the measured mechanical properties of the shape memory nanowires. In particular, wires with initial defects show a non-constant stress state during the < 110 >/111 to < 100 >/100 reorientation due to the presence of multiple propagating twin boundaries, as well as reductions in transformation stresses and strains due to the presence of the initial defects. Under most circumstances, the wires with initial defects still tend to exhibit complete reversibility between the < 110 >/111) and < 100 >/100 orientations, and thus the shape memory effect. Comparisons are made to defect-free shape memory nanowires to illustrate the relative mechanical performance of each structure.