Improvement of electromagnetic properties of FeSiAl soft magnetic composites

Currently, soft magnetic composites (SMCs) are usually used for high-current power devices. As a kind of SMCs, the FeSiAl magnetic powder core exhibits excellent magnetic properties, but it is difficult to improve its permeability and DC-bias characteristics. Thus, developing SMC s with high permeability and lower power loss remains a challenge. Here, the FeSiAl powder was mixed with carbonyl iron powder (CIP) which coated with nano-SiO 2 and pressed into toroidal magnetic core with silicon resin as adhesive. For MHz frequency, the SMCs with excellent power loss, saturation magnetization and permeability were obtained. Saturation magnetization of the mixed powder increased markedly with the CIP content increasing. For magnetic powder cores, the SEM and the mappings show that the large deformation CIP was helpful to improve core density. With the addition of CIP, the permeability and DC-bias properties were improved. In addition, the power loss was greatly reduced by the optimized annealing temperature.