The influence of solid–liquid interfacial energy anisotropy on equilibrium shapes, nucleation, triple lines and growth morphologies

Abstract„ The anisotropy of the solid liquid interfacial energy plays a key role during the formation of as-solidi“ed microstruc-tures. Using then-vector formalism of Cahn and Homan, this contribution presents the eect that anisotropy has on the equilib-rium shapes of crystals and on surface tension equilibrium at triple lines. Consequences for heterogeneous nucleation of anisotropiccrystals and for dendritic growth morphologies are detailed with speci“c examples related to Al Zn and Zn Al alloys. 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. Keywords:Solid liquid interfacial energy anisotropy; Heterogeneous nucleation; Equilibrium shape; Dendrite morphology 1. IntroductionThe formation of primary phase microstructures inmetallic alloys at speeds of typically less than0.01 m s 1 is primarily controlled by diusion of soluteelements in the liquid phase and capillarity eects[1].As diusion in the liquid phase is isotropic, the growthdirections of dendrites, as well as their growth kinetics,are dictated by the anisotropy of the solid liquid (s ) interfacial energyc