Modulation of demagnetization field and DC bias performance of carbonyl iron molded inductors by mixing submicron FeSi particles

In the modern era of advanced electronic equipment, the capacity of electronic components to function effectively in high-current environments, i.e. DC bias performance, has become a subject of increasing interest. The use of magnetic powder composite technology has been shown to enhance the DC bias performance of electronic components. In this paper, the submicron spherical FeSi powders, which were prepared by DC arc plasma method, mixed with micron-sized carbonyl iron powders (CIPs) to prepare CIP/FeSi soft magnetic composites (SMCs) and molded inductors. It is shown that the mixing of FeSi powders inevitably reduces the permeability of the SMCs, but provides modulatable DC bias performance. The study found that the SMCs’ magnetic permeability was 32.46, which is a 8.7% decrease. The saturation current was 2.86 A, which is a 28.8% increase, and the DC bias performance was significantly improved. In this paper, the mechanism of the mixed FeSi magnetic powder to improve the DC bias performance of SMCs is elucidated by combining the periodic modeling of mixed magnetic powders and the analysis of FeSi powder structure and properties. This study provides a theoretical basis for the composition and structure design of soft magnetic composites, and the prepared SMCs can be used in high-current operating environments, which have a good application prospect.