Enhanced high-frequency electromagnetic properties of Fe-based amorphous soft magnetic composites by adding carbonyl iron powder

In this work, toroid-shaped Fe-based amorphous soft magnetic composites (SMCs) consisting of FeSiBC amorphous powder and carbonyl iron powder (CIP) were prepared by cold pressing. The effects of CIP mass ratio and compaction pressure on the high-frequency electromagnetic properties were systematically investigated. As the CIP content is increased from 0 to 70 wt%, the effective permeability µ_e of the SMCs is significantly improved due to the increase in density, while the core loss P_cv initially declines and then ascends, exhibiting the lowest value at the addition of 50 wt% CIP. In addition, as compaction pressure increases, the µ_e further increases, while the P_cv shows little change. Under the combined effect of optimal CIP addition and compaction pressure, the SMCs exhibit high µ_e of 38.6, high DC-bias performance of 85% (DC magnetic field is 100 Oe), and low P_cv of 691 kW/m³ at 20 mT and 1000 kHz. Compared to the SMCs without CIP, the µ_e is increased by 123.1%, and the P_cv is decreased by 41.2%. These results indicate that the Fe-based amorphous SMCs with excellent soft magnetic properties have a great advantage in the high-power electronics applications.