Discrete Dislocation Dynamics simulations of dislocation transport during sliding

Plastic deformation largely determines the properties of tribological contacts. To modify such contacts, it is thus necessary to understand the underlying mechanisms of dislocation motion and multiplication. In a sliding contact, dislocations do not only multiply, but also follow the moving tip - and are therefore "transported" by the tip. Three dimensional Discrete Dislocation Dynamics simulations of sliding with a spherical tip are conducted to analyse dislocation transport in an fcc crystal, at stresses below those typically required to nucleate dislocations at a free surface. Sliding direction, glide plane orientation and Burgers vector orientation determine whether a dislocation can be transported or not, and how far the transport leads. A model is proposed to identify the glide systems, on which dislocations are transported. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.