Mathematical modelling of macrosegregation formation caused by deformation caused by deformation of the mushy zone

A major cause of unacceptable cast metallic products is macrosegregation, which is encountered in most solidification processes. This defect refers to the uncontrolled redistributon of alloying elements during solidification that leads to large-scale comp osition inhomogeneities. Macrosegregation formation is caused by long-range transport of alloying elements due the relative motion between the liquid and solid phases that co-exist in the solidification interval. There are several mechanisms leading to such relative motion. One o f these is the melt flow induced due to deformation of the solid skeleton, which has received relatively little attention in the scientific literature. The goal og the project is to establish a mathematical model that quantifies the macrosegregation formation caused by deformations of the mushy zone. This also includes the establishment of a material model and associated constitutive equations for the rh eological behaviour of the "sponge-Like" mushy zone. The work will be based on a recent research carried out in a collaboration with Institute National Polytechnique de Grenoble. Besides the fundamental aspects, work will be directed towards studying how different process parameters influence macrosegregati on formation, thus providing new insight for industrial process improvements.