Simulation of Dendritic Growth Shape of Isothermal Polycrystalline Binary Alloys in a Forced Flow

Numerical simulation based on phase field method is developed to describe polycrystalline solidification for pure material.The evolution of interface morphology is studied and the effect of flow velocity and anisotropy parameters on the growth morphology of polycrystalline is also investigated for Ni-Cu alloy system. The results indicate that,with increasing time,the growth mode of nuclei transforms from independence to competition.The nucleus grows into an asymmetry dendritic with forced flow.Under the forced flow condition,tip quasi-steady velocity of upstream arm gradually increases,and the nuclei growth in the downstream arm is inhibited and it grows downward inclined,while the nuclei growth in the perpendicular arm is not influenced significantly,in which it grows gradually inclined in the flow direction.As the forced flow velocity is increased,the asymmetry of dendritic shape is intensified.With increase in anisotropic values,the size of each dendrite increases,in which the degree of solute stacking in the upstream arm of a dendrite is gradually weakened.