The impact of misorientation on the grain boundary energy in bi-crystal copper: an atomistic simulation study

Atomistic simulations were performed to investigate the relationships among the misorientation, dislocation density, and grain boundary energy of twist and tilt bi-crystal grain boundaries. In this work, the grain boundary energies were calculated based on the embedded-atom method interatomic potential for Cu. The results show that the dislocation density of the grain boundary changes with the rotation angle, thereby affecting the grain boundary energy. Furthermore, the grain boundary energy of a grain boundary with no dislocations is greater than that of a grain boundary with dislocations, which results from the distribution of the atomic potential energy on the grain boundaries. Additionally, the grain boundary energy increases with the dislocation density of the grain boundary in the case of dislocations on the grain boundary. On this basis, a new relationship is proposed for the misorientation angle and grain boundary energy. We assume that when the driving force of dislocation nucleation breaks through the grain boundary energy barrier, the grain boundary energy declines.