An intrinsic correlation between driving force and energy barrier upon grain boundary migration

The migration of grain boundary (GB), which plays a key role in the microstructural evolution of polycrystalline materials, remains mysterious due to the unknown relationship between GB mobility associated with specific geometry and external conditions (e.g. temperature, stress, etc., hence the thermodynamic driving force). Combining the rate equation of GB migration with molecular dynamics simulations, an intrinsic correlation between driving force and energy barrier for the migration of various types of GBs (i.e. twist, symmetric tilt, asymmetric tilt, and mixed twist-tilt) is herein explored, showing the decrease of energy barrier with increasing thermodynamic driving force.