High performance of Fe-based soft magnetic composites coated with novel nano-CaCO3/epoxy nanocomposites insulating layer

In this paper, a novel type of nano-CaCO 3 /epoxy nanocomposites insulating layer for the FeSiCr/carbonyl-iron soft magnetic composites (SMCs) has been successfully developed. The novel inorganic/resin nanocomposites can greatly reduce the core loss of the SMCs while maintain other excellent magnetic properties . By optimizing the content of insulating layer, the FeSiCr/carbonyl-iron SMCs exhibits the lowest core loss of 466.5 ​mW/cm 3 at a maximum magnetic induction of 50 ​mT and frequency of 100 ​kHz, which is greatly reduced by 24.2%, compared with the sample only coated by epoxy resin . Meanwhile, the effective permeability and quality factor remains high. In addition, the production process of the novel nano-CaCO 3 /epoxy nanocomposites insulating layer exhibits the advantages of simplicity, convenience and low cost compared with other ceramic coatings (Al 2 O 3 , MgO , SiO 2 , etc.) and surface nitride coatings, which is more suitable for the industrialization of molded inductors, and therefore has a variety of industrial application prospects.