Research on composition customization strategy and magnetic properties optimization of soft magnetic composite cores based on interfacial solid reaction
Soft magnetic composite cores(SMCs)are considered the most promising electromagnetic conversion device due to their excellent properties,including high saturation magnetisation,high permeability,and relatively low core loss.However,core loss and permeability,as the key performance parameters for the effective operation of electromagnetic devices,are often restricted.Therefore,by adjusting the distribution characteristics of the powder matrix,the insulating layer,and increasing the ferromagnetic filling factor within the soft magnetic composite core,in-situ coating of the insulating layer can be realised,which helps to simultaneously reduce core loss and improve magnetic permeability.In this work,a novel interface solid-phase reaction strategy was designed.Firstly,calcium acetate was uniformly coated on the surface of Fe-Si-Al soft magnetic alloy powder using hydrothermal method.Subsequently,Fe-Si-Al based soft magnetic composite cores were prepared by hot pressing sintering.The effects of sintering temperature and insulation layer phase transition on the morphology,microstructure,and magnetic properties of the prepared soft magnetic composite cores were studied.The results showed that calcium acetate was successfully coated onto Fe-Si-Al alloy powder surface by hydrothermal method,forming a core-shell heterostructure with the Fe-Si-Al alloy powder as the core and calcium acetate as the shell.This provided powder materials for subsequent preparation of soft magnetic composite cores.Raising sintering temperature eliminated internal pores within soft magnetic composite cores while promoting transition from calcium acetate to calcium carbonate to Al2O3·SiO2·CaSiO3,ultimately providing high-quality insulation.The insulating layer of the soft magnetic composite core prepared by high temperature sintering at 850 ℃ was dense and uniform,and the magnetic dilution effect was minimised.At 10 mT and 100 kHz,the soft magnetic composite core had the highest permeability(67.2),the lowest core loss(9.24× 10-5 kW/cm3),and a relatively higher saturation magnetisation(129.0 emu/g),which had the best comprehensive performance,and provided a solution to restrict the reverse relationship between permeability and loss in traditional soft magnetic materials.Therefore,insulation methods based on thermal decomposition and oxidation of organic salt compounds are expected to be an important supplement to the magnetic property optimisation strategy of soft magnetic composite cores based on interfacial solid phase reaction engineering.
soft magnetic composite coresinsulating layerinterfacial solid phase reactionmagnetic propertiesoptimisation strategy
万方数据
维普
