Ultrahigh Tensile Strength Nanowires with a Ni/Ni–Au Multilayer Nanocrystalline Structure

Superior
mechanical properties of nanolayered structures have attracted great
interest recently. However, previously fabricated multilayer metallic
nanostructures have high strength under compressive load but never
reached such high strength under tensile loads. Here, we report that
our microalloying-based electrodeposition method creates a strong
and stable Ni/Ni–Au multilayer nanocrystalline structure by
incorporating Au atoms that makes nickel nanowires (NWs) strongest
ever under tensile loads even with diameters exceeding 200 nm. When
the layer thickness is reduced to 10 nm, the tensile strength reaches
the unprecedentedly high 7.4 GPa, approximately 10 times that of metal
NWs with similar diameters, and exceeding that of most metal nanostructures
previously reported at any scale.