Understanding the enhancement of metal plasticity and metallization of ceramics through first-principles studies

The plasticity of materials is a critical issue for saving energy in materials processing. For metals, it is well known that their plasticity increases when subjected to an electric current, a property commonly exploited in metallurgy. However, the physical origin of this phenomenon is not well understood. In addition, recent findings indicate that when electron beams are directed at predominantly brittle ceramic materials, they experience deformation or increased plasticity without fracture. To understand this mechanism, we first focused on the electronic structure primarily at the grain boundaries and dislocations of various metals, where deformation predominantly occurs, and found that the deformation energy barriers decrease as the charge in the slip plane decreases. We extended this approach to ceramic materials and found, intriguingly, that certain ceramics can also acquire metal-like plasticity in the presence of additional charge.