In situ TEM study of pulse-enhanced plasticity of monatomic metallic glasses

The electropulsing process can be used to tailor the microstructure and deformability of metallic glasses (MGs). Here, we report the microstructural origin of enhanced electroplasticity of monatomic Ta MG nanowires. Under electromechanical loading, the Ta MG nanowire exhibits improved ductility and obvious necking behavior. By evaluating the dynamic structural evolution via in situ diffraction, it is found that the atomic mobility in flow units of Ta MG can be improved significantly under the stimulation of pulse current, mainly through the athermal electron-atom interaction, which results in the fast annihilation of flow units and, thereby, fast structural relaxation. These structural evolution processes can help to eliminate the formation of the obvious shear band. These findings provide insight into the origin of electroplasticity in amorphous materials, which is of scientific and technological significance for the design and processing of a variety of MGs.