Importance of microstructural evolution on prediction accuracy of microsegregation in Al-Cu and Fe-Mn alloys

Microsegregation in Al-Cu and Fe-Mn alloys is analyzed by conducting solidification experiments, two-dimensional (2D) and three-dimensional (3D) quantitative phase-field simulations for two-sided asymmetric diffusion, and using the one-dimensional (1D) finite difference method (FDM). Comparisons of these results substantiate that the 3D quantitative phase-field simulation can predict microsegregation behaviors with a high degree of accuracy. The disagreement between the results of the 1D-FDM simulation and the experiment, which is similar to that often observed in early works, can be ascribed to the fact that 1D-FDM simulation does not consider the details of microstructural evolution. The main factor causing disagreements in microsegregation among the results of 1D, 2D and 3D simulations is discussed in terms of the solid-liquid interfacial area density and its relationship with overlapping of the solute diffusion layer. (C) 2018 Elsevier Ltd. All rights reserved.