Orientation selection in dendritic evolution

Computational and experimental demonstration of dendritic crystal growth direction and the morphologic diversity of the resulting dendritic structures are discussed. The primary dendrite growth directions can vary continuously between different crystallographic directions as a function of the composition-dependent anisotropy parameters. The dendritic microstructure of chemically etched and electropolished longitudinal sections of solidified alloys was analyzed using scanning electron microscopy and electron back-scattered diffraction (EBSD) orientation measurements. The experimental results shows the change of dendritic growth direction of compositions as a function of anisotropy in the phase-field simulation. The similarities between the computational and the experimental results strongly supports the hypothesis that the change of anisotropy parameters with the composition is the underlying mechanism of the damage of growth direction observed experimentally.