An adaptive, fully implicit multigrid phase-field model for the quantitative simulation of non-isothermal binary alloy solidification

Using state-of-the-art numerical techniques, such as mesh adaptivity, implicit time-stepping and a non-linear multi-grid solver, the phase-field equations for the non-isothermal solidification of a dilute binary alloy have been solved. Using the quantitative, thin-interface formulation of the problem we have found that at high Lewis number a minimum in the dendrite tip radius is predicted with increasing undercooling, as predicted by marginal stability theory. Over the dimensionless undercooling range 0.2-0.8 the radius selection parameter, sigma*, was observed to vary by over a factor of 2 and in a non-monotonic fashion, despite the anisotropy strength being constant. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.