title: Atomistic underpinnings for orientation selection in alloy dendritic growth.
abstract: In dendritic solidification, growth morphologies often display a pronounced sensitivity to small changes in composition. To gain insight into the origins of this phenomenon, we undertake an atomistic calculation of the magnitude and anisotropy of the crystal-melt interfacial free energy in a model alloy system featuring no atomic size mismatch and relatively ideal solution thermodynamics. By comparing the results of these calculations with predictions from recent phase-field calculations, we demonstrate that alloying gives rise to changes in free-energy anisotropies that are substantial on the scale required to induce changes in growth orientations.
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Becker
authors.forename: D
authors.initials: D
authors.lastname: Olmsted
authors.forename: M
authors.initials: M
authors.lastname: Asta
authors.forename: J J
authors.initials: JJ
authors.lastname: Hoyt
authors.forename: S M
authors.initials: SM
authors.lastname: Foiles