Controlling thermal noise in phase-field simulation for nucleation during isothermal solidification of a pure metal

Abstract

It is currently challenging to quantitatively describe the nucleation behavior using the phase-field model because it depends on the computational grid size. In this study, the grid size dependence of nucleation behavior during isothermal solidification in pure Fe was investigated by changing the magnitude of thermal noise inducing the nucleation. To remove such dependence, a neural network was utilized to compute the magnitude of thermal noise needed to describe the desired nucleation rate for a given grid size and degree of undercooling. It was found that the nucleation rate can be controlled using the present approach, and the nucleation rates in pure Fe obtained by molecular dynamics simulations and experiments could be accurately reproduced.