Atomistic Simulation of Nano-Rolling Process for Nanocrystalline Tungsten

Abstract

Nanocrystalline tungsten (NC W) sheets and foils have significant high-temperature applications in various technological sectors and hence their economical large-scale production is highly necessary. However, research to help understand the underlying nanoscale deformation mechanisms is limited. Here, we have developed an atomistic model to study the temperature effect on the structural and grain orientation evolution in NC W during nano-rolling. Structural analysis shows that the contribution of dislocation mechanisms decreases and twin mechanisms increases with an increase in temperature. Moreover, atomic strain analysis revealed that cryo-rolling causes formation of a smoother surface, whereas hot-rolling leads to uneven surfaces. A bimodal grain structure is obtained during the cryo-rolling, whereas equiaxed grains are formed at high temperature due to dynamic recrystallization. This work provides insights into comprehending the deformation mechanisms at atomic level, and the compendium of this research will help in studying nano-rolling in other metallic systems.