Development of novel FeCo based amorphous FeCoBPSiCr alloy with high Bs of 1.71 T and high corrosion resistance

Metallic ribbons of different compositions were prepared using a single-roller melt-spinning method. The (Fe0.8Co0.2)83B11P4Si2 alloy without Cr showed both high saturation magnetic flux (Bs) of 1.78 T and high corrosion resistance, with a corrosion potential of −607 mV and a corrosion current density of 29 μA/cm2 compared to those of a conventional high-Bs Fe79B13.5Si5.5C2 amorphous alloy. The (Fe0.7Co0.3)82B11P4Si2Cr1 alloy with Cr also exhibited a high Bs of 1.71 T and high corrosion resistance at the same level as that of a conventional Fe73B11Si11C3Cr2 amorphous alloy. The (Fe0.7Co0.3)82B11P4Si2Cr1 alloy showed a corrosion potential of −509 mV and a corrosion current density of 18 μA/cm2. Furthermore, the (Fe0.7Co0.3)82B11P4Si2Cr1 alloys exhibited a high amorphous forming ability because of a single amorphous phase in the metallic ribbon at a thickness of >60 μm. Based on these results, the (Fe0.7Co0.3)82B11P4Si2Cr1 amorphous alloy with the possibility of powderization was confirmed to be a suitable material for the magnetic core that is widely used in metallic inductive components.