Novel FePBNbCr glassy alloys “SENNTIX” with good soft-magnetic properties for high efficiency commercial inductor cores

According to a recent study, Fe-based glassy alloys are expected good soft-magnetic properties such as high saturation magnetization and lower coercive force. We focused on Fe-based glassy alloys and have succeeded in developing novel glassy Fe97−x−yPxByNb2Cr1 (x = 5–13, y = 7–15) alloys for an inductor material. The glassy alloy series of Fe97−x−yPxByNb2Cr1 (x = 5–13, y = 7–15) have high glass-forming ability with the large critical thickness of 110–150 μm and high Bs of 1.25–1.35 T. The glassy alloy powder with chemical composition Fe77P10.5B9.5Nb2Cr1 exhibits an excellent spherical particle shape related to the lower melting point and liquid phase point. In addition, Fe–P–B–Nb–Cr powder/resin composite core has much lower core loss of 653–881 kW/m3, which is approximately 1/3 lower than the conventional amorphous Fe–Si–B–Cr powder/resin composite core and 1/4 lower than the conventional crystalline Fe–Si–Cr powder/resin composite core due to the lower coercive force of 2.5–3.1 A/m. Based on above results, the glassy Fe77P10.5B9.5Nb2Cr1 alloy powder enable to achieve ultra-high efficient and high quality products in a commercial inductor. In fact, the surface mounted inductor using Fe–P–B–Nb–Cr powder/resin exhibits the high efficiency of approximately 2.0% compared with the conventional inductors made of the crystalline Fe–Si–Cr powder/resin composite core.

► We have succeeded in developing novel glassy Fe97−x−yPxByNb2Cr1 (x = 5–13, y = 7–15) alloys for an inductor material.
► The glassy Fe97−x−yPxByNb2Cr1 (x = 5–13, y = 7–15) alloys have the large critical thickness of 110–150 μm and high Bs of 1.25-1.35 T.
► The glassy Fe77P10.5B9.5Nb2Cr1 alloy powder/resin composite core has much lower core loss of 653–881 kW/m3, which is approximately 1/3 lower than the conventional amorphous Fe–Si–B–Cr powder/resin composite core due to the lower coercive force of 2.5–3.1 A/m.