Validation of a Front-Tracking Model of the Columnar to Equiaxed Transition using Solidification Results from the Maxus 7 Microgravity Platform

Abstract

To study the columnar-to-equiaxed transition (CET) in alloy castings, three aluminum-silicon samples were solidified onboard the MAXUS 7 sounding rocket. Temperature measurements were made during the flight and the samples were retrieved and analyzed for their solidified macrostructure. Two of the samples produced a CET while the third sample produced a mixed structure with grains nucleating on the crucible walls. A novel front tracking model of solidification and a model of the MACE test apparatus are presented. Validation of the solidification code is carried out. Cooling curves from the experiments are predicted. A simulation of the solidified macrostructure is also given for each experiment. The CET positions are predicted in agreement with the experimental results.