Dendritic solidification in the diffuse regime and under the influence of buoyancy-driven melt convection
M. Apel, I. Steinbach.D. M. Herlach,
Phase Transformations in Multicomponent Melts, Wiley-VCH, Weinheim, 373-385, (2008)
This chapter presents quantitative phase-field simulations of dendritic growth in the diffuse regime and under the influence of melt convection. For this purpose, a general formulation for an interface mobility correction and an antitrapping diffusion flux is proposed and implemented into a general multicomponent multiphase-field model. Simulation results for equiaxed dendritic growth in Ni98Al1Zr1 up to a melt undercooling of 80 K are discussed. The impact of buoyancy-driven melt convection on the dendrite spacing in directional solidification is investigated for a binary alloy. For a ternary alloy, a transition of the orientation of the interdendritic convection rolls with changing alloy composition is demonstrated qualitatively.