The enhanced magnetic properties of FeSiCr powder cores composited with carbonyl iron powder

Toroid-shaped Fe-based soft magnetic powder cores (SMPCs) were prepared by cold pressing commercial FeSiCr and carbonyl iron powder (CIP) insulated with epoxy resin. The effect of the CIP mass ratio on the magnetic properties of powder cores, which included the dependences of the effective permeability (μe), DC bias characteristic, and core loss (Pcv), was investigated. By optimizing the CIP content, the μe of the magnetic powder cores reaches 31 when the CIP content is 30 wt%, and it exhibits a stable permeability in the frequency range up to 1 MHz. Meanwhile, the DC bias characteristic increases to 78%, and the Pcv is minimized to 1684 mW/cm3, which is reduced by 15% at 50 mT and 250 kHz.