Thermodynamically consistent modelling of recrystallization and grain coarsening in precipitation-hardened alloys

The strength of technically relevant alloys is mainly determined by the grain size distribution, the amount and size of precipitates, solid-solution hardening and work hardening. A reliable material model to capture these effects should be formulated within a comprehensive thermodynamic framework. The strategy of Rational Extended Thermodynamics is applied to derive a thermodynamically consistent model representing the coupling between elastoplastic deformation, the evolution of the grain structure and recrystallization. In addition, the model takes the dragging effect of precipitates on grain boundaries and dislocations into account, which leads to significant strengthening. For the microstructure description, a mean-field approach is used. Due to the thermodynamic framework, the model is able to consistently predict the interplay between deformation, microstructure evolution, dynamic hardening and softening and the related temperature change. The strength of technically relevant alloys is mainly determined by the grain size distribution, the amount and size of precipitates, solid-solution hardening and work hardening. A reliable material model to capture these effects should be formulated within a comprehensive thermodynamic framework. The strategy of Rational Extended Thermodynamics is applied to derive a thermodynamically consistent model representing the coupling between elastoplastic deformation, the evolution of the grain structure and recrystallization. In addition, the model takes the dragging effect of precipitates on grain boundaries and dislocations into account, which leads to significant strengthening. For the microstructure description, a mean-field approach is used. Due to the thermodynamic framework, the model is able to consistently predict the interplay between deformation, microstructure evolution, dynamic hardening and softening and the related temperature change.