A parametric study of morphology selection in equiaxed dendritic solidification

Morphological change of equiaxed dendritic structure in fcc-based alloys associated with transition in preferred growth direction was investigated by means of three-dimensional quantitative phase-field simulations. The anisotropy parameters of interfacial energy epsilon(1) and epsilon(2) were systematically changed to investigate the growth direction and growth morphology. The growth morphologies can be classified into four types; <1 00> growth, <1 0 0>-like hyperbranched growth, <1 1 0>-like hyperbranched growth and <1 1 0> growth morphologies. An orientation selection map for these morphologies was constructed in a space spanned by epsilon(1) and epsilon(2). Furthermore, dependence of the orientation selection map on solidification condition and alloy system was investigated. When initial supersaturation is large and/or partition coefficient of alloy is small, the region of <1 0 0> growth, typical growth direction of fcc alloy, diminishes in the orientation selection map.