Atomistically Informed Phase Field Modeling of Solid-Solid Phase Transformations

The quantification of the role of alloying elements on interface migration during phase transformations in steels and selected non-ferrous alloys (e.g., Ti-based) remains an active area of research that was inspired by seminal contributions of Mats Hillert. In previous studies we had introduced atomistically informed solute drag models for simulation of grain growth and recrystallization. In the present study this approach is extended to diffusional phase transformations where a fast-diffusing species (e.g., C in Fe) redistributes between the parent and daughter phases. The proposed methodology is demonstrated with a conceptional analysis of nano- and mesoscale phase field simulations for model binary and ternary alloys. The approach is shown to be consistent with the formulations of the Hillert–Sundman solute drag model. The challenges in applying this simulation approach to experimental data are critically discussed.