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)

Within the framework of the ESA GRADECET project, experiments of directional solidication of cylindrical Ti-Al samples were conducted in hypergravity. The experiments were performed in a centrifuge with the apparent gravity (sum of centrifugal and terrestrial gravity) aligned along the cylinder centerline. 3D numerical simulations of aluminum macrosegregation in these samples are presented. A volume-averaging solidication model is used that accounts for centrifugal and Coriolis accelerations in a non-inertial rotating reference system. We compare the melt ow pattern and the macrosegregation formation under terrestrial gravity and under 20~g centrifugation. The results show that the Coriolis acceleration, although very weak, breaks the symmetry of the thermosolutal convection, having an important impact on the nal macrosegregation pattern. The macrosegregation is entirely modied in comparison with a sample solidied under terrestrial gravity conditions. Besides the aluminum segregation intensity increases with the centrifugation level.