Author(s)

M. Conti & A. Giuliani

Abstract

The growth of a free dendrite from a supercooled alloy melt is studied with the Phase-field model in the isothermal approximation; the surface tension is assumed asymmetric with four- fold anisotropy. The solute diffusion across the solid-liquid interface reflects the non- equilibrium conditions of the growth process: the concentration jump deviates from the static value and decreases with increasing the interface velocity. We also explored the effect of different difrusivities in the solid and in the liquid phases; previous studies based on the equilibrium formulation of the free boundary equations predicted a monotonic increase of P^Vtip with the solute diffusivity of the solid phase; due to non-equilibrium effects this result is not recovered in the present investigation. 1

Keywords