Sonja Steinbach¹, Matthias Kolbe¹, Sebastian Wirth², Laszlo Sturz³, Gerhard Zimmermann³, Florian Kargl¹, Maike Becker⁴; ¹DLR, ²RWTH Aachen, ³ACCESS e.V., ⁴IM2NP

Recent studies with thin Al-Ge samples [M. Becker, 2019] and with Al-Zn alloys [T. Haxhimali, 2006] have shown a transition from the accepted growth direction of fcc-Al to a new direction with increasing solute content, a phenomenon that is called ‘Dendrite Orientation Transition’ (DOT) [F. Gonzales, 2006] and which is explained not only by the effect of composition on the anisotropy of the solid-liquid interfacial energy, but also by the containment of the sample. Therefore observations made on microstructures growing in thin-film samples are not necessarily transferable to 3D conditions. To shed light on this phenomena in 3D and to avoid strong segregation effects occurring in samples with high density differences of the alloy components on ground, Al-46wt%Ge samples were processed in a new furnace set-up for directional solidification experiments in microgravity and are compared to lab experiments.