Abstract
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Grain boundary (GB) is the interface between different oriented crystals of the same material, and it
can have a significant effect on the many properties of materials. When the average or entire range of
grain size is reduced to less than 100 nm, the conventional plastic deformation mechanisms
dominated by dislocation processes become difficult and GBmediated deformation mechanisms
become increasingly important. One of the mechanisms that can play a profound role in the strength
and plasticity of metallic polycrystalline materials is the heterogeneous nucleation and emission of
dislocations from GB. In this study, we conducted molecular dynamics simulations to study the
dislocation nucleation from copper bicrystal with a number of 〈1 10〉 tilt GBs that covered a wide
range of misorientation angles (θ).Wewill show from this analysis that the mechanic behavior of GBs
and the energy barrier of dislocation nucleation from GBs are closely related to the lattice
crystallographic orientation, GBenergy, and the intrinsic GBstructures. An atomistic analysis of the
nucleation mechanisms provided details of this nucleation and emission process that can help us to
better understand the dislocation source in GB.