FeSiBCCr Amorphous Fine Powders with High Saturation Magnetization Based on Particle Size Classification and Its Magnetic Powder Cores with Low Core Loss

FeSiBCCr gas–water combined atomization amorphous powders were divided into five size groups (1#: ≥104 μm; 2#: 74–104 μm; 3#: 48–74 μm; 4#: 38–48 μm; 5#: ≤38 μm) to study the relationship between powder properties and size distribution, and then to prepare high-performance magnetic powder cores (MPCs) through particle size classification. The results of powder characterization show that the circularity of the powder increases with the decrease of the particle size. Due to the finest particle size, the comprehensive properties of 5# powder are better than other powders, with the saturation magnetization of 144.2 emu g^–1 and the coercivity of 0.13 Oe. MPCs prepared by a cold pressing process using 5# powder show excellent soft magnetic properties. The effective permeability is 19.62, and the core losses are 224.10 mW cm^–3 (B_m = 0.05 T, f = 100 kHz) and 1441.5 mW cm^–3 (B_m = 0.02 T, f = 1 MHz), respectively.