Abstract and subjects
A new constitutive plasticity model for prismatic slip in hexagonal alpha-titanium is developed. In the concept pure edge and screw dislocation densities evolve on the {1 0 (1) over bar 0} (1 (2) over bar 1 0) slip systems. The model considers that the screw dislocation segments have a spread out core, leading to a much higher velocity of edge compared with screw dislocations. This enables the model to describe the observed transition in strain hardening from stage I to stage II in single crystals oriented for prismatic slip. Good agreement is found between the experimentally observed and simulated stress strain behavior. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.