Fe3Si/Al2O3 composite magnetic powder core with core-shell structure and preparation method thereof

Abstract

The invention relates to a Fe3Si/Al2O3 composite magnetic powder core with a core-shell structure and a preparation method thereof. The technical scheme is as follows: Fe3O4 powder and FeSiAl powder are taken and mixed according to the mass ratio of (2-15):100, and the mixed powder is ball-milled for 4-12h at 100-300rpm to obtain FeSiAl/Fe3O4 core-shell particles; the FeSiAl/Fe3O4 core-shell particles are placed in a high-temperature sintering furnace, heated to 800-1300 DEG C under vacuum I or protective atmosphere I and sintered for 0.5-5h to obtain a sintered body; and the sintered body isplaced in a heat treatment furnace, heated to 500-1200 DEG C under vacuum II or protective atmosphere II and heat-treated for 0.5-5h to obtain a Fe3Si/Al2O3 composite magnetic powder core with a core-shell structure. The Fe3Si/Al2O3 composite magnetic powder core has the characteristics of less loss of raw materials, environment-friendliness, low production cost and simple preparation process. A product made of the Fe3Si/Al2O3 composite magnetic powder core has the advantages of uniform insulating layer, high resistivity, low magnetic loss, high saturation magnetization and low coercivity.

Description

technical field [0001] The invention belongs to Fe 3 Si / Al 2 o 3 Composite magnetic powder core technology field. Specifically related to a Fe with a core-shell structure 3 Si / Al 2 o 3 Composite magnetic powder core and its preparation method. Background technique [0002] Due to its high saturation magnetization, high resistivity, low magnetostriction and relatively low loss, sendust is widely used in communications, uninterruptible power supply (UPS), solid-state laser power supply, photovoltaic power generation system and LED drive etc. [0003] The electromagnetic properties of sendust are affected by a series of factors, such as the particle size and purity of ferromagnetic particles, the type and content of insulating coating, pressing method, molding pressure, heat treatment atmosphere and temperature, etc. Among them, insulation coating has a significant impact on the density, magnetic permeability, resistivity, eddy current loss and mechanical strength of ma...

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Problems solved by technology

[0006] To this end, scientific and technical personnel have carried out extensive research: such as "an inorganic insulating adhesive for metal soft magnetic powder core and its preparation method" (CN200710099337.2) patent technology, directly mixing magnetic particles with electrically insulating inorganic oxides, Although the preparation method is simple, it is difficult to achieve effective insulation between magnetic particles, the loss reduction is limited, and it will cause the agglomeration of inorganic coating materials and deteriorate the magnetic properties; Wang Jian et al. / SiO 2 Granular and Fe with adjustable insulation thickness 3 Si / Al 2 o 3 Soft Magnetic Composite Core. Materials Science and Engineering B, 2015.08) Although the particle surface is coated with Al 2 o 3 , but the preparation process is complicated, the insulation effect is not good, the loss of raw materials is high, and the cost is high; layer, followed by pickling to remove iron oxides, leaving SiO-containing 2 、Al 2 o 3 and Cr 2 o 3 Wait for the oxide layer, and finally add a binder and a lubricant for compaction to obtain a composite magnetic powder core

Although the insulating layer of the obtained composite magnetic powder core is relatively uniform and the magnetic properties are good, the preparation process is complicated, the operation is not easy, the energy consumption is large and the raw material loss is large, which is not conducive to mass production.

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