Novel Fe-based amorphous magnetic powder cores with ultra-low core losses

Abstract

Amorphous magnetic alloy powders were prepared from bulk metallic glasses Fe₇₄Cr₂Mo₂Sn₂P₁₀Si₄B₄C₂ with supercooled liquid region of 32 K by water atomization. Amorphous magnetic powder core precursor was produced from a mixture of the amorphous alloy powder with addition of insulation and bonding materials by mold compacting at room temperature. After annealing the core precursor, the amorphous magnetic core exhibits superior magnetic properties as compared with molypermalloy powder core. The initial permeability up to 1 MHz was about 80, the flux density at 300 Oe was 1.06 T and the core loss at 100 kHz for B _m =0.1 T was only 329 kW/m³. The ultra-low core loss is attributed to the combination of relatively high resistivity and the amorphous structure of the Fe-based amorphous powder. Besides the outstanding magnetic properties, the Fe-based amorphous magnetic powder core had a much lower cost which renders the powder cores a potential candidate for a variety of industrial applications.