Liquid phase separation of Co–Cu alloys in the metastable miscibility gap

Abstract

Liquid phase separation has been investigated in the Cu–Co system using electromagnetic levitation (EML) and processing in drop tube. Owing to the rapid solidification in both methods, properties of the liquid are maintained after solidification. In the Co–84.0 at.% Cu alloy the evolution of droplet dispersions versus cooling rate has been experimentally determined. In drop tube experiments, the experiment duration is short, and ends before collisions of droplets and coagulation become important at a given fluid flow motion. Terrestrial EML processing subjects the liquid to a strong fluid flow, which leads to a bimodal droplet size distribution. Containerless processing in the TEMPUS facility during parabolic flight reduces the fluid flow and, thus, coagulation of droplets.