A cold-welding map incorporating various competing mechanisms and size effects

Abstract

It has been found that nano-objects can spontaneously bond together, followed by a continuous growth of the welded area, even at low homologous temperatures. This so-named “cold welding” phenomenon can be utilized in advanced small-scale manufacturing, thus offering a promising solution to the challenges in tuning functionality, durability, and performance of nano-materials and nano-devices. This study develops a kinetic model that incorporates various competing driving-forces, and delineates their dominant parametric regimes on a cold-welding map with respect to bonding fraction, temperature, and absolute feature sizes. Cold welding can now be understood as governed either by curvature driven or as Coble creep, thus solving contradictions in the explanations of many recent experiments.