[SIS10] Amorphous/Nanocrystalline Soft Magnetic Materials

[14E-SIS10-01] Special Invited: Novel FeCo-based Amorphous Alloy and Powder with High Saturation Magnetic Flux Density and Corrosion Resistance for Inductive Devices

*H. Matsumoto¹ (1.TDK Corporation, Japan)

Keywords:Soft magnetic materials, FeCo-based amorphous alloys, Amorphous alloy powders, Corrosion resistance, Inductors

High saturation magnetic flux density (B_s) and corrosion resistance are required in soft magnetic materials for suppressing the magnetic saturation and supporting usage environments in power supplies of information and communication technology (ICT) devices with large current driving. This study investigated the magnetic characteristics, amorphous stability, and corrosion behavior of novel FeCo-based (Fe_0.7Co_0.3)_88−x−yB₁₁P_xSi_yCr₁ amorphous alloys relative to a conventional FeSiB type amorphous alloy. The metallic ribbon of (Fe_0.7Co_0.3)₈₂B₁₁P₄Si₂Cr₁ alloy exhibited high Bs of 1.71 T and high corrosion potential of −520 mV as well as high amorphous forming ability of 87 μm, sufficient to obtain a single amorphous phase even in powder morphology. The (Fe_0.7Co_0.3)₈₂B₁₁P₄Si₂Cr₁ amorphous alloy powder consisted of a single amorphous phase and also exhibited high B_s of 1.61 T. Moreover, an inductor using the (Fe_0.7Co_0.3)₈₂B₁₁P₄Si₂Cr₁ amorphous alloy powder exhibited high DC-bias characteristics and excellent corrosion resistance compared to that using the conventional FeSiB amorphous alloy powder.