The microstructure of melt-spun alloys with liquid miscibility gap

Effect of the melt ejection temperature on the microstructures of (FexCu1-x)(62)Si13B9Al8Ni6Y2 (x=0.48, 0.60 and 0.71) alloys was investigated. Rapid cooling of the examined alloys from the temperature range conventional to single-phase amorphous alloys brought about a non-uniform microstructure due to a liquid/liquid phase separation prior to cooling. The systems with a miscibility gap need to be heated over a critical temperature where homogeneous liquid exists. Microstructures of the ribbons melt spun from the homogeneous melt region are characterized by presence of the spherical precipitates distributed in homogeneous matrix. Both, precipitates and matrix, can constitute either the Fe-rich or the Cu-rich phases depending on the alloy composition. The studies confirmed amorphous nature of the Fe-rich phases, both matrix and precipitates whereas the Cu-rich liquid crystallized due to lower glass forming ability.