Influence of Feeding Flow and Shrinkage Pipe Formation on Macrosegregation of Investment Cast-TiAl Alloys

A single-domain multi-phase model is developed to predict macrosegregation of investment tilt cast gamma -TiAl, considering the effect of both buoyancy and shrinkage induced flow. The model combines the volume of fluid method for tracking the gas/liquid and gas/solid interfaces during the formation of shrinkage pipe with continuum transport equations for velocity, temperature and composition. This model is used to investigate the influence of riser shapes and volume on the composition distribution and the shrinkage pipe shape in the final cast part. The influence of cooling conditions on fluid flow and shrinkage pipe formation during solidification is also studied.