Abstract: Fe-based nanocrystalline powders are ideal soft magnetic materials for matching the wide bandgap semiconductors. Previously developed Fe-based nanocrystalline alloys are difficult to produce high-quality precursor powder by gas atomization due to their poor amorphous forming ability, and their following nanocrystallizations also require high temperatures or heating rates. In present work, we invented novel high-performance Fe-based nanocrystalline powders that can be directly manufactured by gas atomization without annealing. The as-atomized Fe_73.3Si₁₂B₁₃Cu_1.7 nanocrystalline powders exhibit fine α-Fe(Si) crystals with an average size of 15.1 nm and high saturation magnetization (M_s) of 156.2 emu/g. The Fe_73.3Si₁₂B₁₃Cu_1.7 soft magnetic powder cores annealed at 480 °C for 60 min process high effective permeability of 35.9 and low core losses (50 mT/100 kHz) of 310.1 mW/cm³. These outstanding magnetic properties and good processability make the developed Fe_73.3Si₁₂B₁₃Cu_1.7 nanocrystalline powders highly promising for high-performance inductors and transformers.

Key words: Fe-based nanocrystalline alloys, High Cu content, Gas atomization, Saturation magnetization, Core loss