Liquid-phase Separation in Rapid Solidification of Undercooled Fe-Co-Cu Melts

The homogeneous liquid was separated into two phases,(Fe,Co)-rich L1 and Cu-rich L2,once the melt was undercooled below a liquid-phase separation temperature T sep.If the duration from T sep to T s1(solidification temperature of L1 phase),termed the liquid-phase separation interval t,exceeded a critical value,an egg-type structure was observed.By utilizing differential thermal analyses(DTA),the solidification process of the undercooled Fe-Co-Cu alloys was studied.Additionally,an immiscible boundary was obtained,which was a convex parabola with a symmetrical axis of x Cu =0.52.Depending on the relative amounts of L1 and L2,the minor phase was nucleated firstly to form liquid droplets and separated from the original liquids at the beginning of liquid-phase separation.