Free Energy Problem for the Simulations of the Growth of Fe₂B Phase Using Phase-Field Method

抄録

The present simulation works develop phase-field method to replicate the growth of Fe₂B boride from austenite phase. The present works also give a major concern on the free energy driving force problem for this transformation. In order to enhance the reliability of this study, free energy driving force is left as the only variable parameter to be optimized while other parameters were taken from experimental data. Several sets of free energy have been established based on the thermo-chemical database and the assumption that there is a parabolic relationship between free energy of boride/austenite and boron concentration. On the other hand, in order to allow the growth of single Fe₂B phase, temperature of 1223 K has been chosen as the evaluated temperature. Based on the comparison of the present numerical results and available experimental data, one set of free energy has been considered to give the appropriate condition that approaching the experimental condition for the growth of Fe₂B from austenite phase.