Activation of plastic deformation mechanisms in nanocrystalline iron

The molecular dynamics method is used to study the features of nucleation and development of plasticity in nanocrystalline iron under shear loading in constrained conditions. The behavior of the material under loading is divided into several stages. On each of them the mechanisms of plastic deformation are revealed, which play the main role in the development of structural rearrangements in the loaded sample. It is shown that the nucleation and slip of dislocations plays a significant role in the development of plasticity at all stages of deformation. Subsequently, along with intragranular slip, grain boundary sliding is activated. Twinning leads to the localization of plastic deformation and changes grain shapes. At a further shear, the process of grain boundary migration is activated, which results in recrystallization of the deformed sample.