Cyclic Plastic Deformation Response of Nanocrystalline BCC Iron

Cyclic plastic deformation behavior of nanocrystalline body-centered cubic (BCC) iron is investigated using molecular dynamics simulation. The formation of X-junction and Y-junction during deformation causes the faster mobility of dislocation, which results in softening behavior of the material. In addition, the generation of vacancy defects behind the moved perfect screw dislocation represents the jerky deformation behavior of nanocrystalline BCC iron. The study also highlights the distribution of atomic strain. The grain boundary sliding may result in local atomic strain distribution at the grain boundary. Whereas the region of maximum defects activity shows a higher distribution of atomic strain. The vivid story of crystalline defects in BCC iron helps to develop a deep understanding of cyclic plastic deformation response in the atomic scale. Graphic Abstract