Atomistic simulation on the transformation behaviour of structural units at Σ27 tilt grain boundary

Molecular dynamics simulations have been employed to investigate the transformation of structural units at the grain boundary under tensile conditions. A series of symmetric tilt-[110]-Σ27 bi-crystal Cu models are considered in this research. The findings indicate that atomic potential energy significantly influences the transformation of structural units. The potential energy of the common atom from two neighbouring structural units breaks through the threshold due to external loading, leading to its migration to adjacent atomic layers. This migration triggers the transformation of the structural unit and results in the nucleation of dislocations on the grain boundaries, which further leads to a precipitous decline in the potential energy of the grain boundaries.