Grain Growth: From modeling to measurements
Scalable Grain Growth Models
Grain boundary properties are a function of five crystallographic degrees of freedom, which include the misorientation between grains and the normal of the grain boundary plane. Fully capturing the dependence of the grain boundary energy and mobility on crystallography poses a challenge in phase field models. We approach the problem by developing orientation-field phase field models for grain growth, which use a single vector field to track the local orientation of the grains. These models allows the grain boundary energy and mobility to be functions of all five crystallographic degrees of freedom, without adding additional order parameters to track individual grains.
4D Tomography Experiments
Measuring the energy and mobility of individual grain boundaries is difficult and time-consuming, traditionally requiring the synthesis of precise bicrystals containing the boundary of interest. Instead, our approach is to couple phase field simulations of grain boundary motion to time-resolved tomography experiments which measure the evolution of grains and their orientations in a sample. By fitting the parameters of a phase field simulation to reproduce the experimental data, we can deduce the properties of nearly every boundary in the system simultaneously, eliminating the need for precise measurements of single grain boundaries.
Participants
