Magnetic Property Improvement and Core-Loss Reduction of Fe-Si-Cr-Based Soft Magnetic Composites with Addition of Fe-50Ni Nanopowder

We studied the effect of change in packing fraction, caused by the addition of nanopowder to micro-sized powders, on the magnetic permeability and core loss of a power inductor core in the high-frequency band. Fe-Si-Cr crystalline alloy was used as the base material of the power inductor core, and Fe-50Ni nanopowder produced by the pulsed wire evaporation method was added to the alloy powder. With the addition of only 10 wt.% Fe-50Ni nanopowder, the core showed the maximum packing fraction and good power inductor characteristics, along with the maximum permeability of 26.598 H/m. Furthermore, the permeability and packing fraction showed the same tendency. In addition, the loss of the core containing 10 wt.% of Fe-50Ni nanopowder was 210.88 mW/cm(3), which is similar to 78.91% lower than that of pure Fe-Si-Cr core. The results obtained in this study reveal that the characteristics of a power inductor can be significantly modified by changing the packing fraction of the core.