High-temperature centrifugation: a tool for finding eutectic compositions in multicomponent alloys

A metallic melt of composition Al52.6Cu13.4Ge28Si6 was processed for 2 h in a centrifuge at a temperature of 530 °C and inertial acceleration of 60 000 g (g=gravitational acceleration), and then slowly cooled to room temperature during continuous centrifugation. Primary phases forming in the melt during cooling were sequentially separated from the remaining liquid, changing the composition of the liquid, until it solidified in a ternary eutectic microstructure of composition Al64Cu3Ge33. Presenting scanning electron microscope images, we demonstrate that this method of high-temperature centrifugation is a efficient tool to isolate and identify multiphase eutectic compositions and the sequence of crystallization in multicomponent alloys. The latter is particularly useful for the discovery of new bulk metallic glasses.