Sonication induced amorphisation in Ag nanowires.

It has long been conjectured that pure-element face-centred cubic (fcc) metals can be transformed into a glassy state by deformation at ultra-high strain rates. However, when an impact force is applied at the nanoscale, deformation-induced melting prevents observations of fcc metal amorphisation. Here we propose a sonication treatment of Ag nanowires (fcc) and confirmed amorphisation induced by high strain rates at bent areas of the Ag nanowires. Owing to the mismatch of the deformation modes between the core and the surface, we observed a diameter related increase of the ductility of Ag nanowires under deformation at ultra-high strain rates generated by sonication. The sonication-prepared amorphous Ag was stable at room temperature. Amorphous Ag at the bent areas was highly reactive and was readily recrystallized under light illumination or vulcanised. Our study verifies the occurrence of high strain rate induced amorphisation in pure fcc MGs and provides a powerful tool for mechanical studies on metal nanomaterials under extremely high strain rates and forces.