Modeling of Dendritic Growth with Convection Using a Modified Cellular Automaton Model with a Diffuse Interface

A modified cellular automaton model with a diffuse interface has been developed in order to investigate the effects of convection on dendritic growth morphology in an undercooled melt. The present model is based on the coupling of the dendritic growth algorithm generally used in cellular automaton models and the continuum model of phase field models. A diffuse interface is adopted in order to solve the continuum model for species and momentum transfer with convection. The asymmetrical growth of dendrite arms and the deflection behavior have been investigated with various parameters, such as the preferred orientation of crystal growth, the inlet flow velocity, the initial liquid concentration, and the initial supercooling of the melt. It was found that convection induces an asymmetric dendritic growth in the upstream direction, caused by the asymmetry of solute distribution in the liquid ahead of the solid/liquid interface. The asymmetry in dendritic growth is amplified with the increase of both the initial concentration and the flow velocity, and the asymmetry decreases with the increase of the initial supercooling. It can be concluded that the present model can be successfully applied to simulate dendritic growth morphology with convection.