Effects of growth rate and temperature gradient on the microstructure parameters in the directionally solidified succinonitrile-7.5 wt.% carbon tetrabromide alloy

Abstract

Succinonitrile (SCN)-7.5 wt.% carbon tetrabromide (CTB) alloy was unidirectionally solidified with a constant growth rate (V = 33 mu m/s) at five different temperature gradients (G = 4.1-7.6 K/mm) and with a constant temperature gradient (G = 7.6 K/mm) at five different growth rates (V = 7.2-116.7 mu m/s). The primary dendrite arm spacings, secondary dendrite arm spacings, dendrite tip radius and mushy zone depths were measured. Theoretical models for the microstructure parameters 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. (C) 2007 Elsevier B.V. All rights reserved.