Enhanced magnetic properties of Fe-based nanocrystalline composites by addition of carbonyl iron powders

Abstract

Fe-based nanocrystalline/carbonyl iron hybrid soft magnetic composites (N/C HSMCs) with excellent comprehensive magnetic properties were fabricated by cold compaction of gas-atomized FeSiBPNbCu amorphous powder and carbonyl iron powder (CIP). Upon annealing at the optimum temperature, the N/C HSMCs demonstrated excellent magnetic properties including a high permeability range from 104 to 124, high-frequency stability up to 1 MHz, superior DC-bias permeability increase from 58 to 86% at a bias field of 50 Oe, and low core loss that regulated less than 1200 mW/cm3 and reduced to as low as 732 mW/cm3 at 100 kHz for Bm = 0.1 T. The ameliorative magnetic properties of the present N/C HSMCs can be attributed to the addition of CIP, which typically enhances the monolithic saturation magnetic flux density and rebuilds the chain structures in a more integrated formation. Further, the precipitation of an ultrafine α-Fe(Si) phase in the amorphous matrix and a uniform insulation layer covered with the powder were the foundation for numerous other superior performance results.