Place: ONERA, Paris, France
Glide of dislocations and their mutual interactions govern the intrinsic plastic behavior of most metals. In the case of bcc metals like alpha-Fe, dislocations exhibit large differences in their mobilities. While pure screw dislocations experience high lattice resistance due to their non-planar cores, all non-screw dislocations are expected to glide easily at low applied stresses. However, details about their core structures and glide mechanisms are largely unknown. In this work, we carried out atomistic simulations for a number of dislocations and other extended defects in alpha-Fe using the magnetic bond-order potential (BOP), which is able to provide a correct description of both directional covalent bonds and magnetic interactions in iron. We will present an analysis of both static (structural, magnetic) and dynamic (behavior under applied stress) properties of these dislocations and discuss the implications on the plastic behavior.