From deformation localization to melting and chemical segregation in metallic glass nanoparticles under high strain rate

摘要

Nanoparticles possess many distinguished properties due to their small size and unique internal and surface structures. For metallic glass nanoparticles, the small size combined with disordered atomic structure results in many unexpected results, some of which are superior to crystalline particles. This field, however, remains largely unexplored. Here, we report the mechanical and thermomechanical responses caused by the increasing strain rate in metallic glass nanoparticles under compression. The mechanical properties of nanoparticles resemble those of the bulk when the strain rate is below 10~(10) s~(-1); above this threshold, the nanoparticle exhibits localized deformation and then melting and even chemical segregation at the contact surface area. We reveal that these unique behaviors are the direct results of the lack of effective energy dissipation mechanisms in the disordered materials that are different from crystalline nanoparticles.