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

Abstract

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−D02=2αMγt, where D0 is the initial average grain size, the geometry factor α=0.96, the average grain boundary mobility M=6.30×10−18e−0.33[eV]kbTm4/(Js) with the Boltzmann constant kb 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.