Crystallization of Mg–Al and Al-based metallic liquids under ultra-high gravity

We present results from high-temperature centrifugal processing, which is a new method to detect the sequence of crystallization and to physically isolate eutectic compositions in multi-component alloys. Alloys of composition Mg50Al30Y6Li7Cu7, Mg50Al30Y6Li7Cu7, and Al52.6Cu13.4Ge28Si6 were processed for 2 h in a centrifuge above their melting point at an inertial acceleration of 60,000 g (g=gravitational acceleration) and then slowly cooled to room temperature during continuous centrifugation. This processing leads to a pronounced stratification of crystalline phases in all three alloys, with primary phases sedimented to the sample ends, and binary and ternary eutectic microstructures solidified in the central region of the sample, as resolved by scanning electron microscopy. Thus, this new method yields deep eutectic compositions in a straightforward way, which is very useful information for the discovery of new bulk metallic glasses.