Dynamic recovery and its orientation dependence in face-centered cubic crystals

The orientation dependence of dynamic recovery in face-centered cubic crystals is investigated in relation to the critical annihilation distance of screw dislocations. The critical conditions for the onset of state III are discussed in terms of a cross-slip mechanism that is locally modified by the interaction with a neighboring attractive screw dislocation. Two orientation domains are defined. From [111] to the central region of the standard stereographic triangle, the attractive interaction stress enforces obtuse cross-slip, which inhibits dynamic recovery. The critical parameters for dynamic recovery are then derived using simple scaling laws. For other orientations, the interaction stress enhances cross-slip, which is treated using Escaig's model. Numerical results are obtained using a single adjustable parameter. They are fully consistent with experimental data in copper and silver at 300 K. The discussion emphasizes the need for more precise information from atomic-scale modeling of the dynamic recovery process. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.