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The dendritic growth patterns in directional solidification with different amplitudes of solid-liquid interface energy anisotropy were investigated using the two-dimensional cellular automata (CA) model. It is shown that when the preferred growth direction of the crystal was the same as the direction of thermal gradient, the solidification pattern would transform from seaweed to dendrite with the increase of amplitude of interface energy anisotropy. The amplitude of interface energy anisotropy could also influence the morphology of dendritic tips. As the amplitude of interface energy anisotropy increased, the dendritic tip radius, the liquid concentration ahead of the tip and the tip undercooling decreased. A power law relationship evisted between the stability parameter of dendritic tip and the amplitude of interface energy anisotropy in directional solidification. The primary arm spacing changed little with the increase of interface energy anisotropy. When the angle between the preferred growth direction of the crystals and the direction of thermal gradient was-40, and the amplitude of interface energy anisotropy increased, the solidification pattern would transform from seaweed to degenerated dendrite and finally to tilted dendrite.

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The dendritic growth with the different solid/liquid (S/L) interface energy anisotropies in the unidirectional solidification has been investigated using the self-consistent front tracking model. It is found that, for a given solidification condition, there were two kind of interface shape solutions with the different spacing Péclect number ranges. The interface shape with the small spacing Péclect number range was similar with cellular tip, and that with the large spacing Péclect number range referred to dendritic tip. The higher S/L interface energy anisotropy was in favor of the widening of the dendritic growth solution range. There was a certain power exponential relationship between the dendritic tip marginal stability parameter σ * and the S/L interface energy anisotropic parameter E 4 . A modified Fisher dendritic tip solution, which considered the effect of S/L interface energy anisotropy, was obtained as follows: R IMS = 2.5646[ Γ DLV k0ΔT0 ] 0.5 E −0.1905 4 , ΔT 0 = mC 0 (k 0 − 1)/k 0 . The undercooling in front of the S/L interface decreased with increasing the anisotropic parameter. The primary dendritic spacing mainly depended on the interaction of solute diffusion field between the adjacent dendrite, and the S/L interface energy had little influence on