Investigation of effect of interface energy anisotropy on dendritic growth in unidirectional solidification by front tracking simulation

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 E₄. A modified Fisher dendritic tip solution, which considered the effect of S/L interface energy anisotropy, was obtained as follows: R_IMS = 2.5646 [ΓD_L/Vk₀ ΔT₀]^0.5 E₄^-0.1905, ΔT₀ = mC₀(k₀ - 1)/k₀. 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 the primary dendritic spacing due to its localized effect on the solute diffusion field near the dendritic tip.