A Cosserat crystal plasticity and phase field approach to grain boundary migration and recrystallization
Anna Ask, Samuel Forest, Kais Ammar Centre des Matériaux, Mines ParisTech CNRS UMR 7633, PSL University
Benoît Appolaire, Institut Jean Lamour, Université de Lorraine, CNRS UMR 7198
Formulating appropriate simulation models that capture the microstructure evolution at the mesoscale in metals undergoing thermomechanical treatments is a formidable challenge. In this work, an approach combining higher-order dislocation density based crystal plasticity with a phasefield model is used to predict microstructure evolution in deformed polycrystals [1,2]. This approach allows to model the heterogeneous reorientation of the crystal lattice due to viscoplastic deformation inside the grains and the reorientation due to migrating grain boundaries. The Cosserat effects arise from the development of lattice rotation and curvature inside the grains and at the grain boundaries. The model is used to study the effect of strain localization in subgrain boundary formation and grain boundary migration due to stored dislocation densities. It is demonstrated that both phenomena are inherently captured by the coupled approach [3].
Grain boundary migration after straining in a few grains: 1 slip system per grain (left), four slip systems per grain (right); lattice orientation field (top), cristallinity phase field (bottom)
Grain boundary migration after straining in a few grains: 1 slip system per grain (left), four slip systems per grain (right); lattice orientation field (top), cristallinity phase field (bottom)
