Measurement of anisotropy of crystal-melt interfacial energy for a binary Al-Cu alloy

The anisotropy of solid-liquid interfacial energy for an Al-4.0 wt% Cu alloy is determined through measurement of equilibrium shape. Measurements are performed using a fine dispersion of liquid particles entrained within a single-crystal single-phase solid. Specimens are sectioned normal to the (100) direction in the continuous phase, and the droplets are observed to exhibit four-fold symmetry on this plane. The radial variation on this plane is measured using optical and chemical techniques, and the normalized anisotropy parameter is determined to be 0.98%. Equilibrium conditions are validated, and quench effects are investigated using microchemical analysis techniques. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd, All rights reserved.