Regulation Of Interface Diffusion And Oxidation Of Iron-based Microcellular Soft Magnetic Composites

China in the layout of"Industry 4.0"plan pointed out:to accelerate the transformation from Chinese manufacturing to Chinese creation,and to enter the ranks of manufacturing power in 2025.With the rapid development of electronic information,5G communication and new energy vehicles.In recent years,AI technology and mechanical automation technology have been continuously optimized and improved.Transformers,sensors and inductors as the main components have been concerned and studied by many scholars at home and abroad.Transformers,sensors and inductors as the main components have been concerned and studied by many scholars at home and abroad.Insulation coating of magnetic powder with high resistivity is mainly realized by physical and chemical methods.In the sintering process of soft magnetic composites?SMCs?,due to the impurity diffusion caused by the action of stress and current,it is easy to narrow the gap width of the material,so as to reduce the resistivity.Therefore,it is necessary to eliminate the impurity diffusion,effectively control the diffusion and realize the controllable diffusion sintering.Therefore,the research direction of this paper is to improve the resistivity of composite materials.It is proposed to improve the comprehensive performance of soft magnetic composite materials by constructing a layer of metal oxide diffusion barrier layer on the surface of the alloy,and then sintering it with nanoscale zinc-ni ferrite to form a double-shell structure.This paper selects the Fe-Si_6.5alloy powder as substrate material,the combination of creative vacuum evaporation deposition coating technology and the discharge plasma sintering?SPS?technology,through evaporation coating and high temperature oxidation on the surface of iron and silicon alloy plating uniform magnesium oxide thin layer,and then by physical grinding method and nano nickel zinc ferrite powder insulation coating,finally through the SPS sintering block preparation of soft magnetic composites.By means of SEM,XRD,VSM and other advanced equipment,the samples were characterized and analyzed,and the morphology and performance differences of sintered samples under different element content,sintering temperature and pressure were compared to obtain the ideal preparation process.In addition,soft magnetic composite materials?SMCs?have a tendency to design insulation layers that take into account their soft magnetic properties and resistivity.In this paper,the composite system of Fe@Ni_0.5Zn_0.5Fe₂O₄ is taken as an example to study the effect of MnO₂ oxidant on the soft magnetic properties and resistivity of the sample.The SMCs interface discharge plasma sintering?SPS?oxidation that simultaneously improves the soft magnetic properties and resistivity Reduction mechanism.Fe@Ni_0.5Zn_0.5Fe₂O₄?MnO₂?composite powders with different content of MnO₂ were prepared by ball milling.Fe/Ni_0.5Zn_0.5Fe₂O₄?MnO₂?bulk SMCs samples were prepared by SPS sintering.The results show that the addition of MnO2 oxidant under the condition of SPS can promote the local redox reaction of the SMCs interface,reduce the Fe²⁺concentration at the B-site of ferrite,increase the Fe³⁺,reduce the frequency of electron transition at the B-site,and increase the zinc-nickel ferrite layer.Effective number of Bohr magnetons and B-B magnetic superexchange.Compared with the sample without MnO₂,the resistivity was increased by 25.2%,and the saturation magnetic induction intensity was increased by 6.4%.It shows multiple effects of simultaneously improving the soft magnetic properties and resistivity of SMCs.It provides a theoretical basis for the research and development of new high-performance soft magnetic composite materials.