Effect of Copper Segregation at Low-Angle Grain Boundaries on the Mechanisms of Plastic Relaxation in Nanocrystalline Aluminum: An Atomistic Study

The paper studies the mechanisms of plastic relaxation and mechanical response depending on the concentration of Cu atoms at grain boundaries (GBs) in nanocrystalline aluminum with molecular dynamics simulations. A nonmonotonic dependence of the critical resolved shear stress on the Cu content at GBs is shown. This nonmonotonic dependence is related to the change in plastic relaxation mechanisms at GBs. At a low Cu content, GBs slip as dislocation walls, whereas an increase in Cu content involves a dislocation emission from GBs and grain rotation with GB sliding.

Automated summary

This paper investigates the impact of Cu atom concentration at grain boundaries (GBs) on plastic relaxation mechanisms and mechanical response in nanocrystalline aluminum using molecular dynamics simulations. The study reveals a nonmonotonic relationship between the critical resolved shear stress and Cu content at GBs, which is attributed to changes in plastic relaxation mechanisms. At low Cu content, GBs slip via dislocation walls, whereas an increase in Cu content leads to dislocation emission from GBs and grain rotation with GB sliding.