Phase-field simulation of the effect of interactions between ordered domains on transformation kinetics in precipitation

A two-dimensional phase-field simulation is performed to investigate the effect of interactions between ordered domains on transformation kinetics in Ni-Al binary alloys. By comparing the simulated results of the one-domain system with those of the four-domain system, it is concluded that the transformation of the one-domain system is faster than that of the four-domain one due to the coalescence of the 'in-phase' particles (same kinds of domains) and the mutual blocking effect of the 'out-of-phase' particles (different kinds of domains). Simulated results are also compared with the Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory, and it is found that the JMAK model can describe the transformation kinetics at the initial stage well; however, in the subsequent evolution process, the JMAK model will overestimate the transformation due to the neglecting of the soft impingement.