Development of a grain growth model for U₃Si₂ using experimental data, phase field simulation and molecular dynamics

The purpose of this work is to develop a model for normal grain growth in U₃Si₂. The average grain boundary energy was determined from previously published molecular dynamics simulations. The grain growth kinetics were quantified at various temperatures by annealing nanocrystalline samples. The mobility was determined by comparing phase field grain growth simulations to the experimental data. From these various methods, we found that the average grain size D in U₃Si₂ can be estimated over time t using the equation D²−D₀ ²=2αMγt, where D₀ is the initial average grain size, the geometry factor α=0.96, the average grain boundary mobility [Formula presented] with the Boltzmann constant k_b and temperature T, and the average grain boundary energy has been found as a function of temperature, e.g. γ¯=0.83 J/m² at 673 K.