Direct determination of the metastable liquid miscibility gap in undercooled Cu–Co alloys

Abstract

Bulk Cu–Co alloys at compositions ranging from 10 to 80 wt.% Co were highly undercooled using a melt fluxing technique. The metastable liquid separation boundary has been directly determined from the measured temperature-time profiles. It was also calculated using a subregular solution model. The critical point of the miscibility gap was found to be about 80 K below the liquidus. A droplet-shaped microstructure was observed for all solidified specimens (Cu–10 to 80 wt.% Co), when the melts were undercooled into the metastable miscibility boundary.