1 research outputs found
Strain Hardening and Size Effect in Five-fold Twinned Ag Nanowires
Metallic
nanowires usually exhibit ultrahigh strength but low tensile ductility
owing to their limited strain hardening capability. Here we study
the unique strain hardening behavior of the five-fold twinned Ag nanowires
by nanomechanical testing and atomistic modeling. In situ tensile
tests within a scanning electron microscope revealed strong strain
hardening behavior of the five-fold twinned Ag nanowires. Molecular
dynamics simulations showed that such strain hardening was critically
controlled by twin boundaries and pre-existing defects. Strain hardening
was size dependent; thinner nanowires achieved more hardening and
higher ductility. The size-dependent strain hardening was found to
be caused by the obstruction of surface-nucleated dislocations by
twin boundaries. Our work provides mechanistic insights into enhancing
the tensile ductility of metallic nanostructures by engineering the
internal interfaces and defects