Hydrogen-affected cross-slip process in fcc nickel

Abstract

The effects of H on the cross-slip process of a dissociated screw dislocation in nickel are studied by atomistic simulations using a configuration-space-path technique. We find that H binding in the stacking fault exerts no effect on the activation energy of cross-slip. H that is bound to the cores of the partial dislocations and moves with the dislocations during cross-slip leads to an increase of the activation energy and thus induces slip planarity. Slip planarity is due only to a net decrease of the H-binding energy in the cross-slip process.