LAUSR

Abstract Minor droplets growth and solute segregation have their peculiarities in phase-separating immiscible alloys and can take complex pathways during solidification. The dynamic behaviors of liquid phase separation and surface enrichment in solidifying Al-10 wt% Bi immiscible alloys were revealed by synchrotron X-ray imaging technique. The large-sized Bi droplets would precipitate from Al-matrix melt directly and almost all of the droplets possess different existing states. The distribution of Bi droplets, resulting from the heterogeneous nucleation and repeatedly nucleation, varies with the growth time during cooling. And the growth dynamics of Bi droplets is revealed to be inconsistent with the Gaussian model. We also found that hydrogen bubbles can prevent the occurrence of the liquid phase separation process.