Morphological diversity in directionally-solidified microstructures with varying anisotropy of solid-liquid interfacial free energy

Abstract

Morphological diversity in directionally-solidified microstructures of fcc-based binary alloys was investigated using quantitative phase-field simulation. The growth morphology for each set of anisotropy parameters was identified from the degree of undercooling of the dendrite tip and a morphology map was constructed. We investigated the effects of solidification conditions and alloy systems on growth morphology and found that the pulling speed has a significant effect, while temperature gradient and partition coefficient have only small effects on the morphology selection. Furthermore, we examined the emergence of doublon and triplet dendrites under conditions of weak interfacial anisotropy.

Keywords

• Directional solidification
• Growth morphology
• Phase-field simulation
• Anisotropy of solid-liquid interfacial free energy
• Multiplet dendrites