Processing of metallic glass-forming liquids under ultra-high gravity

A high-temperature centrifugation experiment is presented where a metallic liquid of composition Mg56Al30Li7Cu7 is processed at an inertial acceleration of 60,000 g and temperature of up to 530 °C. Slow cooling across the melting temperature during continuous centrifugation results in a pronounced stratification of crystalline phases. Primary crystals, which form first upon cooling, sediment to the sample ends until finally eutectic microstructures solidify from the remaining liquid in the central region of the sample. The stratification sequence of the primary crystals and the isolation of multi-phase eutectic compositions provide valuable information towards the development of new bulk metallic glasses. Theoretical considerations for the sedimentation of crystals in viscous metallic liquids are outlined and the setup of the high-temperature centrifugation experiment is presented.