Dependence of rate on complex GB migration by ramped-ECO

Abstract

GB migration plays a central role in microstructural evolution. Many experiments and simulations have been conducted to clarify the relationships between GB velocity and various parameters to tailor GB networks. However, the complexity of GB migration has surpassed initial expectations. In this study, the ramped Energy Conserving Orientational (r-ECO) Driving Force (DF) in Molecular Dynamics (MD) simulations was utilized to investigate grain boundary (GB) motion for $\Sigma$3(110), $\Sigma$15(211), and $\Sigma$11(311). My findings indicate that the rate of the driving force determines the velocity of GB migration. Furthermore, a reverse shear coupling behavior during GB migration was observed when the rate was decreased in $\Sigma$15(211). In addition to the change in the direction of shear coupling, a linear relationship between the rate and the transition point during shear coupling migration was discovered. Specifically, a larger rate leads to a forward shift in the transition point. Moreover, GB transition from coupled to only normal migration states in the presence of dislocations nucleated in the GB was observed. These findings contribute to a deeper understanding of microstructural evolution and have implications for designing materials with enhanced properties.