Polydimensional modelling of dendritic growth and microsegregation in multicomponent alloys

Various models for simulating dendritic solidification have been proposed in the past. However, those models based on cellular automata (adopting the virtual front-tracking (VFT) concept) are often only suitable for the consideration of one alloying element. As typical industrial alloys are constituted of numerous alloying elements, the application of these models to practical alloys is therefore rather limited. In order to overcome this drawback, a new, modified VFT model, which allows for the treatment of several alloying elements in the low Peclet number regime, is presented. By a new and effective approach, based on a functional extrapolation of the concentration gradient, we are able to study dendritic growth in multicomponent Fe-C-Si-Mn-P-S alloys. Comparisons with well-established analytical models confirm the correctness of the model; results for free and constrained dendritic growth effectively demonstrate the capabilities of this new model. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.