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CN-122025331-A - Soft magnetic composite material and preparation method and application thereof

CN122025331ACN 122025331 ACN122025331 ACN 122025331ACN-122025331-A

Abstract

The invention provides a soft magnetic composite material and a preparation method and application thereof, wherein the preparation method comprises the following steps of mixing alloy powder with a chloride salt solution to obtain a mixture; drying the mixture to obtain coated powder, mixing and curing the coated powder with a binder to obtain cured powder, and sequentially carrying out compression molding and annealing treatment on the cured powder to obtain the soft magnetic composite material. According to the preparation method, the insulating coating of the surfaces of the alloy powder particles is realized by utilizing the etching effect of the chloride salt on the alloy powder at high temperature, so that the soft magnetic composite material with high direct current bias performance and high frequency stability is obtained.

Inventors

  • HUANG HAI
  • JING XIAODONG
  • ZHOU DONGQING
  • Guo Lanzhou
  • CHEN KUN
  • GAO XINQIANG

Assignees

  • 中国科学院赣江创新研究院

Dates

Publication Date
20260512
Application Date
20260320

Claims (10)

  1. 1. The preparation method of the soft magnetic composite material is characterized by comprising the following steps: (1) Mixing alloy powder with a chloride salt solution to obtain a mixture; (2) Drying the mixture obtained in the step (1) to obtain coated powder; (3) Mixing and curing the coating powder obtained in the step (2) with a binder to obtain cured powder; (4) And (3) sequentially carrying out compression molding and annealing treatment on the cured powder in the step (3) to obtain the soft magnetic composite material.
  2. 2. The method according to claim 1, wherein the chloride salt in the chloride salt solution of step (1) is 0.075wt% to 1.5wt%, preferably 0.15wt% to 1.5wt%, based on the mass of the alloy powder; preferably, the chloride salt in the chloride salt solution of step (1) comprises stannous chloride dihydrate; Preferably, the solvent in the chloride salt solution of step (1) comprises absolute ethanol; preferably, the mass ratio of the solvent in the chlorine salt solution in the step (1) to the alloy powder is 1 (1.8-2.2).
  3. 3. The method of producing according to claim 1 or 2, wherein the alloy powder of step (1) comprises Fe-Si based alloy powder; Preferably, the silicon content in the Fe-Si based alloy powder is 3wt% to 6.5wt%; Preferably, the mesh number of the alloy powder in the step (1) is 160-700 mesh; Preferably, the temperature of the alloy powder and the chloride salt solution in the step (1) is 20-30 ℃, the time is 0.5-3 h, and the stirring speed is less than or equal to 500rpm.
  4. 4. The method of claim 1 or 2, wherein the drying temperature in step (2) is 80 ℃ to 120 ℃; preferably, the drying time in the step (2) is less than or equal to 12 hours.
  5. 5. The method according to claim 1 or 2, wherein the coated powder of step (2) is further subjected to a pre-oxidation treatment before step (3); Preferably, the temperature of the pre-oxidation treatment is 200-500 ℃ and the time is less than or equal to 2 hours; preferably, the pre-oxidation treatment atmosphere is an oxygen atmosphere or an air atmosphere.
  6. 6. The method of manufacturing according to claim 1 or 2, wherein the binder of step (3) comprises an epoxy resin solution; Preferably, the epoxy resin solution comprises an epoxy resin and an organic solvent; preferably, the epoxy resin accounts for 0.5-3 wt% of the mass of the alloy powder; preferably, the mass ratio of the organic solvent in the epoxy resin solution to the coating powder in the step (2) is 1 (0.8-1.2); preferably, the organic solvent comprises acetone.
  7. 7. The method of claim 1 or 2, wherein the temperature at which the coated powder of step (2) is mixed with the binder is 40 ℃ to 50 ℃; preferably, the coating powder in the step (2) is mixed with the binder and the organic solvent in the binder is evaporated to dryness; Preferably, the temperature of the curing in the step (3) is 90-110 ℃ and the time is less than or equal to 3 hours.
  8. 8. The method according to claim 1 or 2, wherein the pressure of the press molding in the step (4) is 1GPa to 2GPa; preferably, the temperature of the annealing of step (4) is from 400 ℃ to 800 ℃, preferably from 600 ℃ to 800 ℃; preferably, the annealing in the step (4) is carried out for a period of 1-8 hours; preferably, the atmosphere of the annealing of step (4) comprises an inert atmosphere.
  9. 9. A soft magnetic composite material, characterized in that it is produced by the production method according to any one of claims 1 to 8.
  10. 10. Use of a soft magnetic composite material according to claim 9, wherein the use comprises use in an electronic device.

Description

Soft magnetic composite material and preparation method and application thereof Technical Field The invention belongs to the technical field of soft magnetic materials, and relates to a soft magnetic composite material, a preparation method and application thereof. Background With the rapid development of new energy fields, electronic devices are continuously evolving toward miniaturization, high frequency and low loss. The soft magnetic material is used as a common component material and mainly bears important functions such as energy conversion, filtering and the like. In order to meet the increasingly higher performance requirements of electronic devices, soft magnetic materials are required to have the comprehensive properties of high magnetic flux density, low high frequency loss, good direct current bias performance and the like. Compared with the traditional soft magnetic alloy material, the soft magnetic composite material has the advantages of three-dimensional isotropy, high magnetic permeability, low loss and the like, and is one of the soft magnetic materials with the most development prospect at present. The soft magnetic composite material effectively inhibits large eddy current among alloy particles by insulating and coating the surface of the soft magnetic alloy, thereby maintaining excellent high-frequency performance and low power loss. At present, research and development of soft magnetic composite materials mainly focuses on regulation and control of high magnetic permeability and low loss, and research focuses on type selection of a coating layer and optimization of a coating process. Common soft magnetic composite materials have the advantages of high magnetic permeability, low loss and the like, but have poor direct current bias performance. The key point is that the direct current bias performance of the soft magnetic material is the capability of measuring the material in the direct current bias field resistance, and mainly depends on the saturation magnetization intensity of the magnetic powder, the magnetic anisotropy field and the air gap distribution of the magnetic powder core. The coating layer of the conventional soft magnetic composite material mainly plays a role of electric insulation, and has limited regulation and control on magnetic domain structures among magnetic powder particles. Therefore, the soft magnetic composite material is obviously restricted in the application field requiring high DC bias performance. The development of the soft magnetic composite material capable of effectively improving the DC bias characteristic while maintaining good high-frequency soft magnetic performance and the preparation method thereof have important significance. For example, CN113560570a discloses a preparation method of iron-silicon-aluminum-nickel powder core, which prepares alloy magnetic powder with high saturation magnetization through mechanical ball milling and high temperature solution treatment, then performs insulating coating of nano silicon oxide on the surface of the alloy magnetic powder, and finally realizes cooperative promotion of high saturation magnetic polarization and high direct current bias performance. And as CN118248450A discloses a low-loss high-DC bias FeSi soft magnetic composite material and a preparation method thereof, the method carries out ball milling treatment on FeSi powder and FeSiAl powder to obtain core-shell FeSi@FeSiAl composite powder, and then carries out insulation treatment on the composite powder to successfully prepare the soft magnetic composite material with high magnetic conductivity and low loss. In addition, CN115116689a discloses a low-loss and high-dc bias magnetic powder core and a preparation method thereof, the process comprises the steps of carrying out phosphoric acid and organic silicon resin pretreatment on magnetic powder to obtain intermediate powder, then carrying out chromic acid treatment on the intermediate powder, finally adding water glass and a binder for compression molding, and ensuring the stability and uniformity of an insulating layer through the inorganic-organic multilayer cladding structure, wherein the finally prepared magnetic core has higher magnetic permeability, good dc superposition performance and lower loss. Although the method disclosed by the prior art can improve the DC bias performance to a certain extent, the problems of limited bias performance improvement range, complex preparation process, high stability of a multilayer coating structure, high uniformity control difficulty and the like still exist, and aiming at the defects, a simple preparation method capable of remarkably improving the DC bias characteristic of a soft magnetic composite material and keeping excellent high-frequency magnetic performance is required to be developed. Disclosure of Invention The invention aims to provide a soft magnetic composite material, a preparation method and application thereof, wherein the preparati