Effect of Various Metal Oxide Insulating Layers on the Magnetic Properties of Fe-Si-Cr Systems

Iron-based soft magnetic composites (SMCs) are the key components of high-frequency electromagnetic systems. Selecting a suitable insulating oxide layer and ensuring the integrity and homogeneity of the heterogeneous core-shell structure of SMCs are essential for optimizing their magnetic properties. In this study, four types of SMCs-Fe-Si-Cr/ZrO2, Fe-Si-Cr/TiO2, Fe-Si-Cr/MgO, and Fe-Si-Cr/CaO-were prepared via ball milling, followed by hot-press sintering. The differences between the microscopic morphologies and magnetic fproperties of the Fe-Si-Cr/AO(x) SMCs prepared using four different metal oxides were investigated. ZrO2, TiO2, MgO, and CaO were successfully coated on the surface of the Fe-Si-Cr alloy powders through ball milling, forming a heterogeneous Fe-Si-Cr/AO(x) core-shell structure with the Fe-Si-Cr alloy powder as the core and the metal oxide as the shell. ZrO2 is relatively hard and less prone to breakage and refinement during ball milling, resulting in a lower degree of agglomeration on the surface of the composites and prevention of peeling and collapse during hot-press sintering. When ZrO2 was used as the insulation layer, the magnetic dilution effect was minimized, resulting in the highest resistivity (4.2 m Omega center dot cm), lowest total loss (580.8 kW/m(3) for P-10mt/100kHz), and lowest eddy current loss (470.0 kW/m(3) for P-ec 10mt/100kHz), while the permeability stabilized earlier at lower frequencies.

Automated summary

In this study, four types of iron-based soft magnetic composites (SMCs) were prepared using different metal oxide substrates. The differences in microscopic morphology and magnetic properties were investigated. The results showed that using ZrO2 as the insulation layer resulted in the highest resistivity, lowest total loss, and lowest eddy current loss, with the permeability stabilizing earlier at lower frequencies.