Simulation of Interdendritic Liquid Permeability for Low and High Solid Fractions During Solidification of Mushy Alloys

A numerical model has been developed for the determination of liquid flow permeability through columnar dendrite during growth and segregation in Al-Si alloys. Therefore, in the present work, two separate computational models of grain growth and interdendritic liquid flow are coupled for modeling of the permeability in partly solid alloy. Grain growth is simulated, using a Cellular Automation Finite Difference (CAFD) for a 2D dendrite and fluid flow by using a Computational Fluid Dynamic (CFD) model for determining permeability. A new model has been presented for calculation and modification of dendrite permeability in high solid fractions. Simulation results show which Si concentration variations, at each time step, could transform the dendrite shape. Also, dendrite morphology could alert the interdendritic permeability factor.