Formation of dual-layer melt-spun ribbon through liquid phase separation

A dual-layer ribbon of Co-Si-B-Cu alloy was prepared by the single-roller melt-spinning method. The substrate surface comprised Co-Si-B-based amorphous phase with Cu crystalline nanoscale globules, while the free surface showed a thin crystalline Cu layer. A macroscopically separated unique structure was obtained by the simultaneous occurrence of liquid phase separation of the Co-Cu-based alloy system and amorphous phase formation in the Co-Si-B alloy layer.