5th International Conference on Advances in Solidification Processes (ICASP-5) 5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining (CSSCR-5)

Macrosegregation refers to the inhomogeneous distribution of alloy elements at the macro scale in solidified castings. It is a common defect in direct chill (DC) casting of aluminium alloys. Since various transport phenomena contribute to the formation of macrosegregation, numerical modelling is a valuable tool to assess their role and study their interplay with process parameters. One such parameter is inlet induced flow and consequently the effect of forced convection on liquid flow and moving solid grains. This complex and coupled flow phenomena cannot be addressed using a 2D simulation of sheet ingots. In this work, we conduct 3D modelling case studies on aluminium sheet ingots to analyze the inlet induced forced convection and its impact on macrosegregation formation. To carry out this investigation, we use a multiphase, multiscale solidification model also accounting for thermal-solutal convection, solidification shrinkage, and equiaxed grain nucleation, growth and transport. We show that forced convection alters significantly grain transport and sedimentation and that macrosegregation formation can be altered by varying the intensity of inlet flow.