Front tracking approach to modeling binary alloy solidification

Abstract

Purpose – The purpose of this paper is to endorse the idea of using a special post-calculating front tracking (FT) procedure, along with the enthalpy-porosity front tracking (EP-FT) single continuum model, in order to identify zones of different dendritic microstructures developing in the mushy zone during cooling and solidification of a binary alloy. Design/methodology/approach – The 2D and 3D algorithms of the FT approach along with different crystal growth laws were implemented in macroscopic calculations of binary alloy solidification with the identification of different dendrite zones developing during the process. Findings – Direct comparison of results predicted by the FT model with that based on the concept of the critical value of the solid volume fraction shows the sensitivity of the latter on an arbitrary assumed value of the dendrite coherency point (DCP). Moreover, for a carefully chosen DCP value the second model provides results that are close to those given by the FT-based approach. It is also observed that the macro-segregation pattern obtained by the proposed method is hardly influenced by chosen dendrite tip kinetics. Originality/value – To the best authors’ knowledge, for the first time the 3D FT model has been used along with the enthalpy porosity approach to simulate the development of zones of different dendrite morphology during binary alloy solidification. And, a weak influence of assumed different dendrite tip kinetics on the macro-segregation pattern has been proved, what justifies this underlying assumption of the EP-FT method.