Iron-silicon-aluminum soft magnetic powder core with high direct-current bias performance and preparation method of iron-silicon-aluminum soft magnetic powder core

Abstract

The invention belongs to the technical field of soft magnetic materials, and relates to an iron-silicon-aluminum soft magnetic powder core with high direct-current bias performance and a preparation method of the magnetic powder core. The method comprises the following steps: selecting crushing-method iron-silicon-aluminum magnetic powder with the particle size of less than 200 meshes, andcarryingout insulation coating treatment on the iron-silicon-aluminum powder particles by using organic silicon modified epoxy resin to preparethe iron-silicon-aluminum soft magnetic powder core with the effective magnetic conductivity of 75.The soft magnetic powder core has excellent soft magnetic performance, especially the direct current bias performance of the soft magnetic powder core is greatly improved, the direct current bias performance of the powder core under the condition of 100Oe is higher than 40%, and the volume loss Pcv under the conditions of 50kHz and 100mT is lower than 250mW / cm <3 >.

Description

Technical field [0001] The invention belongs to the technical field of soft magnetic materials, and particularly relates to a sendust soft magnetic powder core with high DC bias performance and a preparation method thereof. Background technique [0002] The metal soft magnetic powder core represented by sendust has the advantages of high resistivity, high magnetic flux density, low coercivity, and low loss. The magnetocrystalline anisotropy constant and magnetostriction coefficient are both close to 0, and it has an excellent synthesis. Soft magnetic properties are widely used in electronic components such as filters, boost inductors and differential mode inductors. With the development of power electronic devices in the direction of high power, metal soft magnetic powder cores are required to have low loss and excellent DC saturation resistance. Especially in an AC-DC converter, when the anti-DC saturation performance cannot meet the requirements of the device, it is easy to ca...

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Problems solved by technology

Especially in AC-DC converters, when the anti-DC saturation performance cannot meet the requirements of the device, it is easy to cause a sharp attenuation of the inductance, resulting in excessive loss and excessive circuit ripple

[0003] Patent CN104795195A discloses a preparation method of sendust core, at 1000°C, H 2 The metal magnetic powder is pretreated for 1-1.5 hours under certain conditions, and then sieved at 147 μm, 104 μm, 61 μm, and 45 μm to obtain sieved powder. The sieved powder is subjected to surface insulation passivation, compression molding, and heat treatment through chromic anhydride to prepare magnetic powder. A powder core with a conductivity of 138μ has a volume loss of 68mW / cm at 50kHz and 50mT 3 , the method published in this patent requires high-temperature pretreatment of the magnetic powder, and the process flow is complicated; in the patent CN108777205A, a composite powder core composed of sendust magnetic powder and iron-based amorphous magnetic powder is prepared, and its 140 μ magnetic permeability is stitched. Volume loss at 50kHz, 50mT is 68mW / cm 3 ; The method published in this patent uses iron-based amorphous materials, which increases the material cost, and the loss performance has not been significantly improved; the patent CN107675074B has prepared a 180-mesh crushing method through alloy melting, ball milling, and heat treatment. Metal magnetic powder; the anti-DC performance of the 60μ sendust powder core prepared by using the metal magnetic powder published in this patent is about 70% under the condition of a DC field strength of 50Oe

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