Modeling of solutal dendritic growth with melt convection

The effect of fluid flow on two-dimensional (2D) dendritic growth has been studied using a modified cellular automaton (MCA)-transport model. The model adopts a CA approach for the simulation of dendritic growth and a transport model for the numerical solution of flow dynamics and mass transport by both diffusion and convection. The physics of complete time-dependent interaction of melt convection, mass transfer and dendritic growth during solidification is directly embedded in the present model. The model is applied to simulate single and multi-dendritic growth of Al–Cu alloys in a forced flow. The effect of alloy composition on the convective dendritic morphology is investigated. The simulation results show that the dendritic morphology is strongly influenced by the presence of melt convection. The deflection of primary dendrite arms occurs in the upstream direction of fluid flow. Side branching is largely favored in the upstream region and suppressed in the downstream region. It is also found that the asymmetric growth features of convective dendrites are increasingly noticeable with the increase of solute composition.