Industrialization of a FeSiBNbCu nanocrystalline alloy with high B s of 1.39 T and outstanding soft magnetic properties

High Fe content Fe 76 Si 13 B 8 Nb 2 Cu 1 alloy ribbons with excellent quality and width of 20–55 mm were successfully produced with industrial processes and raw materials, showing the superb manufacturability and impurity tolerance. It is found that impurities and ribbon width have a negligible influence on crystallization behavior, by comparing with samples prepared with high purity materials. The wide annealing time window can be over 50 min in the optimal temperature range of 500–600 °C. Besides, industrialized Fe 76 Si 13 B 8 Nb 2 Cu 1 alloy ribbons exhibit outstanding magnetic properties, including high saturation magnetic flux density ( B s ) of 1.39T, high effect permeability of 28.8 × 10 3 at 1 kHz and low coercivity of 3.5 A/m, which are equivalent to ribbon prepared with pure materials. Extreme low core losses of 0.91 W/kg at 1T and 1 kHz, 5.30 W/kg at 0.5T and 10 kHz were also obtained in ring samples. It is found that fine nanostructure and wide stripe domains are the origins of excellent magnetic properties. This alloy with excellent performance has great potential in applications of high working B and frequency devices and will also be a new reference for industrialization of nanocrystalline alloy.