Dependency of the dendritic arm spacings and tip radius on the growth rate and composition in the directionally solidified succinonitrile-carbon tetrabromide alloys

Succinonitrile (SCN)-carbon tetrabromide (CTB) alloys for different concentrations of CTB (C0) were unidirectionally solidified with a constant temperature gradient (G=7.5 K/mm) at different growth rates (V=6.5-103.5 μm/s). The primary dendrite arm spacings, secondary dendrite arm spacings and dendrite tip radius were measured as a function of growth rates and compositions. Theoretical models for the dendrite arm spacings and tip radius have been compared with the experimental observations, and a comparison of our results with the current theoretical models and previous experimental results have also been made.