Study of spatial phase separation during solidification and its impact on the formation of macrosegregations

With the term “spatial phase separation” we have the relative motion between two or more liquid and/or solid phases in mind. This relative motion can be caused by thermo-solutal melt convection, grain sedimentation, sedimentation-induced melt convection, feeding flow through stationary (columnar) or packed (equiaxed) grains, and capillary force driven melt flow (Marangoni). A multiphase solidification model considering the above mentioned phase separation phenomena has been developed by the authors. This paper provides selected modeling results in order to demonstrate the importance of phase separation for the formation of macrosegregations and hence to deepen our understanding of different macrosegregation formation mechanisms.