Microstructure evolution and solidification kinetics of undercooled Co–Ge eutectic alloys

The Co-29.7% Ge eutectic and Co-33% Ge hypereutectic alloys processed in drop tube attain large undercoolings and show “lamellar eutectic to anomalous eutectic” and “dendritic to equiaxed” morphology transitions respectively. The eutectic coupled zone is calculated on the basis of current eutectic and dendritic growth theories, which takes the shape of peanut and leans toward Co-rich side.