NUMERICAL SIMULATION OF DENDRITIC GROWTH IN UNDERCOOLED MELT USING PHASE-FIELD APPROACH

Abstract

Using the phase-field approach, the dendritic growth in the undercooled pure metal melt is simulated, and the dependence of dendritic growth upon the anisotropy,interfacial kinetics,thermal diffusivity and surface energy is investigated.The calculated results indicate that the heat noise can trigger the growth of side-branches;however this dose not influence the selection of the tip operating state.The dimensionless tip velocity increases and the tip radius decreases with the increase of anisotropy. Correspondently,the dimensionless tip velocity decreases and tip radius increases when the interfacial kinetics or thermal diffusivity (when the interface kinetic coeffiecient is less than 1) inreases. The surface energy tends to increase the size of dendrite and keeps the stability of interface under the disturbance of heat noise.The greater the surface energy,the weaker the tendency to form side-branches.