Some computational results on dendritic growth in binary alloy are obtained by using a phase-field model coupled the solute gradient term. The effect of crystalline anisotropy on the morphological formation, tip steady state and the solute partition is investigated for different dendrites. The interface formation and tip steady state are affected evidently with increase in anisotropy for ͗100͘ dendrite growth, but the solute partition coefficient is not significantly influenced. For ͗110͘ preferred growth directions, when the anisotropy strength is lower than the critical value, the tip velocity of [ 1 10]

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The evolution of interface morphology for a single-phase Nickel-Copper binary alloy in directional solidification is studied by using a phase-field model cooperated solute concentration gradient corrections. The effect of pulling velocity V and strength of the crystalline anisotropy γ on interface morphology and the solute segregation is formulated. The results indicate that, the transition from plane to cells/fine cellular structures, then to planar structures(plane-cell-plane) will happen with the increment of V, and the level of solute trapping becomes stronger. When the crystal grows with cellular structures, γ crucially influences the interface pattern formation at the lower growth velocity, but the solute partition ratio is not significantly affected by the anisotropy strength. Then, the operating behavior for planar growth is hardly any affected by the crystalline anisotropy.

Phase field model coupled with flow field is solved by the adaptive finite element method. The simulation results show that the forced flow can induce side-branches though there is no thermal noise. When the flow velocity is low, the symmetry of dendrite morphology is slightly influenced by forced flow. With the increase of flow velocity, the symmetry of dendrite morphology is collapsed completely.

Coupling the force flow field with the phase field model for the isothermal growth of dendrite multiple grains, Sola algorithm is used to calculate the flow speed and pressure of liquid metal, double grid numerical method was used to reduce the calculation amount of computer simulation, the space factor and time factor were introduced to improve the accuracy of double grid numerical calculation, Taking Al-2%-Cu alloy for example, the dendrite growth process of the binary alloy was simulated under forced convection environment; Simulation results can capture the real dendrite growth and interactions of the liquid metal flow in the process of dendrite growth under forced convection environment: The flow of metal liquid affects the growth morphology of dendrite multi-grain. The flow of liquid metal changes the growth speed of dendrite tip in different directions for each dendrite, the greater of the liquid metal initial flow speed, the worse of dendrite morphology symmetry; different initial flow speeds result in the different distance between each dendrite. The metal liquid forced flow causes the instability of dendrite growth interface, it changes the degree of undercooling, composition, dendrite tip growth rate and the curvature radius of dendrite tip in the dendrite growth forefront interface. For the forefront dendrite growth interface free energy system, the dendrite tip growth speed and curvature radius were adjusted by the competitive growth of dendrite tips, thus reached a new stable state for the interface, which resulted in the emergence of bifurcation in dendrite tips. The liquid metal flow speed between different grains was affected by the relative position and morphology between different grains, and also affected by the initial inflow speed of the liquid metal.