Influence of the anisotropy in lattice friction on the macroscopic behavior of magnesium single crystal: A study by discrete dislocation dynamics

It is known that the lattice friction in hexagonal close-packed (hcp) Mg crystals is anisotropic and depends on the family of slip systems. In this study, the relation between the lattice friction and the single mechanism involving the reaction between dislocations from different families of slip systems, as well as the relation between the lattice friction and the macroscopic behavior are analyzed using discrete dislocation dynamics simulations. In this work, it is demonstrated that for small values of the friction stress, the recombination stress is controlled by the line tension of dislocations, while for large values of the friction stress, the recombination stress is controlled by the lattice friction. Further, for low values of the lattice friction, the macroscopic behavior is controlled by the well known forest mechanism, while when increasing the lattice friction (which can be viewed as a decrease in the temperature), the macroscopic behavior is controlled by the lattice friction itself. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.