A quantitative variational phase field framework

The finite solid–liquid interface width in phase field models results non-equilibrium effects, including solute trapping. Prior modeling has shown that this extra degree of freedom, when compared to sharp-interface models, trapping is well captured realistic parameters, such as width, are employed. However, increasing the which desirable for computational reasons, leads artificially enhanced thus making it difficult model departure from equilibrium quantitatively. In present work, we develop a variational guarantees temporal decrease free energy with independent kinetic equations solid and liquid phases. Separate concentrations obviate assumption point wise equality diffusion potentials, done previous works. Non-equilibrium effects trapping, drag kinetics can be introduced controlled manner model. addition, parameters tuned obtain “experimentally-relevant” while using significantly larger widths than prior efforts. A comparison these other suggests about three twenty-five times current best-in-class employed depending upon material system at hand leading speed-up by factor W(d+2), where W d denote spatial dimension, respectively. Finally capacity phenomena demonstrated simulating oscillatory instability formation bands.