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

Abstract

The invention relates to a Fe3Si / Al2O3 composite powder with core-shell structure and a preparation method thereof. According to the technical scheme, the method includes the steps of mixing Fe3O4 powder and FeSiAl powder according to the mass ratio, being 2-15 to 100, of the Fe3O4 powder to the FeSiAl powder, at 100 rpm to 300 rpm, carrying out ball milling on the mixed powder for 4 hours to 12 hours to obtain FeSiAl / Fe3O4 core-shell particles, putting the FeSiAl / Fe3O4 core-shell particles in a high-temperature tubular furnace, heating to 800 DEG C to 1300 DEG C under a vacuum condition or aprotective atmosphere condition, and carrying out heat treatment for 0.5 hour to 2 hours to obtain the Fe3Si / AL2O3 composite powder with the core-shell structure. The composite powder and the method have the advantages of less raw material loss, environmental friendliness, low preparation cost and simple process, and the prepared Fe3Si / Al2O3 composite powder with the core-shell structure is uniform in insulating layer, high in saturation magnetization intensity and low in coercive force.

Description

technical field [0001] The invention belongs to Fe 3 Si / Al 2 o 3 Composite powder technology field. Specifically related to a Fe with a core-shell structure 3 Si / Al 2 o 3 Composite powder and method for its preparation. Background technique [0002] Because of its low cost, high magnetic permeability, low loss and excellent thermal stability, FeSiAl alloy is widely used in technologies such as radar, television, power supply, inductive filter and FM choke coil as an indispensable magnetic component of power supply circuit. in the field. [0003] The electromagnetic properties of FeSiAl 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 magnet...

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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; Method" (CN201310351622.4) patented technology, though the surface of iron particles is coated with Al by sol-gel method 2 o 3 , but the preparation process is complicated, the single output is small, the production cannot be expanded, the loss of raw materials is large, and the cost is high; "A method for coating iron-based soft magnetic alloy and preparation method for composite magnetic powder core" (CN201510602786.9) patented technology , the oxide layer is obtained by high-temperature oxidation, and then pickled 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.