Influences of preparation techniques on glass-forming ability of Fe-P-B-Si-C amorphous alloys

It has been widely accepted that the ultrafast cooling rate is required for the glass formation of amorphous alloys. Here, the larger glass-forming ability (GFA) of Fe76P5(B0.5Si0.3C0.2)(19) amorphous alloy was achieved by water quenching at lower cooling rate under argon atmosphere. Cylindrical rods with diameters of 1-2 mm were prepared by water quenching without flux treatment, Cu-mold injection casting, and Cu-mold suction casting, respectively. The influences of the preparation techniques with different cooling rates on GFA, thermal property, and nucleation/growth behavior were examined. The critical diameter of the Fe76P5(B0.5Si0.3C0.2)(19) amorphous alloys is 1.7 mm for water quenching while smaller than 1.0 mm for injection casting. Microstructure analysis indicates that the crystallization and solidification processes are quite different between the water-quenched and the injection-cast rods. These findings could deepen fundamental understanding on the relationship between the cooling rate, techniques, and GFA of Fe-based amorphous alloys.