Equiaxed dendritic solidification with convection .2. Numerical simulations for an Al-4 wt pct Cu alloy

The multiphase model developed in part I for equiaxed dendritic solidification with melt convection and solid-phase transport is applied to numerically predict structural and compositional development in an Al-4 wt pet Cu alloy solidifying in a rectangular cavity. A numerical technique combining a fully implicit control-volume-based finite difference method with a multiple time-step scheme is developed for accurate and efficient simulations of both micro- and macroscale phenomena. Quantitative results for the dendritic microstructure evolution in the presence of melt convection and solid movement are obtained. The remarkable effects of the solid-liquid multiphase flow pattern on macrosegregation as well as the grain size distribution are illustrated.