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CN-122025333-A - Iron-silicon-aluminum-based magnetic powder core and preparation method thereof

CN122025333ACN 122025333 ACN122025333 ACN 122025333ACN-122025333-A

Abstract

The invention provides an iron-silicon-aluminum-based magnetic powder core and a preparation method thereof, belonging to the technical fields of soft magnetic materials and powder metallurgy. Adding the Fe-Si-Al alloy powder into a strong alkaline inorganic compound solution, stirring uniformly to obtain Fe-Si-Al alloy powder mixed solution, adding bicarbonate solution, filtering, washing, drying, performing heat treatment to obtain Fe-Si-Al/Al 2 O 3 composite powder, adding magnesium oxide solution, drying and performing heat treatment to obtain Fe-Si-Al/MgAl 2 O 4 composite powder, mixing with a forming agent and a lubricant, and performing heat treatment after die pressing to obtain the Fe-Si-Al-based magnetic powder core. The invention uses MgAl 2 O 4 with high heat conduction and high corrosion resistance as an insulating medium material, thereby improving the high-temperature stability and corrosion resistance of the magnetic powder core and prolonging the service life of the magnetic powder core while ensuring the magnetic performance of the Fe-Si-Al. The preparation method is simple, the cost is low, and the possibility of large-scale production is improved.

Inventors

  • LI CHENGXIN
  • WANG QIANCHENG
  • WU XINGYI
  • FENG BO
  • HUANG HUAQIN
  • WANG RUI
  • WU CHAOYANG
  • DUAN WENJUN

Assignees

  • 安徽工业大学
  • 东北大学

Dates

Publication Date
20260512
Application Date
20260331

Claims (10)

  1. 1. The preparation method of the sendust-based magnetic powder core is characterized by comprising the following steps of: (1) Adding the Fe-Si-Al alloy powder into a strong alkaline inorganic compound solution, and stirring to obtain Fe-Si-Al alloy powder mixed solution; (2) Mixing bicarbonate solution with the Fe-Si-Al alloy powder mixed solution, stirring to obtain an Fe-Si-Al alloy powder mixed solution containing aluminum hydroxide, filtering, washing, drying, and performing heat treatment to obtain Fe-Si-Al/Al 2 O 3 composite powder; (3) Mixing a magnesium oxide solution with the Fe-Si-Al/Al 2 O 3 composite powder, stirring, and then drying and heat-treating to obtain the Fe-Si-Al/MgAl 2 O 4 composite powder; (4) And mixing the sendust/MgAl 2 O 4 composite powder with a forming agent and a lubricant, performing die pressing to obtain a sendust-based magnetic powder core green body, and performing heat treatment to obtain the sendust-based magnetic powder core.
  2. 2. The method for preparing sendust-based magnetic powder core according to claim 1, wherein the strong alkaline inorganic compound solution in step (1) is prepared by dispersing strong alkaline inorganic compound in solvent according to concentration of 1-20 g/L, stirring 5-15 min; the strong alkaline inorganic compound is sodium hydroxide or potassium hydroxide; The solvent is any one of deionized water, ultrapure water, methanol and ethanol.
  3. 3. A method of producing sendust-based magnetic powder cores according to claim 1, wherein the ratio by volume of the sendust powder to the strongly basic inorganic compound solution in step (1) is 300-500 g/L; The Si content of the Fe-Si-Al alloy powder is 4.5-6.5 wt%, the Al content is 6-12 wt%, and the average grain diameter is 100-200 mu m; the stirring temperature is 60-80 ℃, the rotating speed is 300-400 rpm, and the stirring time is 30-60 min.
  4. 4. The method for preparing sendust-based magnetic powder core according to claim 1, wherein the bicarbonate solution in the step (2) is prepared by dispersing bicarbonate in a solvent according to a concentration of 0.5-10 g/L and stirring 5-15 min; The bicarbonate is sodium bicarbonate or potassium bicarbonate; the solvent is any one of deionized water, ultrapure water and methanol.
  5. 5. The method of producing sendust powder cores according to claim 1, wherein the volume ratio of the bicarbonate solution to the sendust powder mixture in step (2) is 1:2; The temperature of the stirring is 60-150 ℃, the rotating speed is 350 rpm, and the time is 30-60 min; The drying is vacuum drying, the vacuum degree is below-0.05 MPa, the drying temperature is 80-90 ℃ and the time is 120-720 min; The heat treatment is carried out at 800-1000 ℃ for 30-120 min, and the heat treatment atmosphere is inert gas.
  6. 6. The method for preparing sendust-based magnetic powder core according to claim 1, wherein the magnesium oxide solution in step (3) is prepared by dispersing magnesium oxide powder into a solvent according to a concentration of 0.1-0.9 g/L, and performing ultrasonic treatment of 8-20 min; The magnesium oxide powder is nanoscale powder, and the average particle size is 500 nm; the solvent is methanol or ethanol; The frequency of the ultrasonic treatment is 20-40 kHz, the time interval of each ultrasonic dispersion treatment is 1-5 min, and the single duration is 4-10 min/time.
  7. 7. A method of producing sendust-based magnetic powder cores according to claim 1, wherein the ratio of the mass of sendust/ai 2 O 3 composite powder to the volume of the magnesium oxide solution in step (3) is 75: 75 g/L; The temperature of the stirring is 70-90 ℃, the rotating speed is 300 rpm, and the time is 60-180 min; the drying is vacuum drying, the vacuum degree is below-0.05 MPa, the drying temperature is 90-100 ℃ and the time is 480-720 min; The heat treatment is carried out at 1050-1350 ℃ under the condition of 120-240 min and inert gas atmosphere.
  8. 8. The method of producing sendust-based magnetic powder core according to claim 1, wherein the sendust/MgAl 2 O 4 composite powder, forming agent and lubricant in step (4) have a mass ratio of 98:1.5:0.5; the molding agent is silicon resin or epoxy resin; the lubricant is zinc stearate or lithium stearate; the pressure of the mould pressing is 900-1600 MPa; The heat treatment is carried out at 500-650 ℃ for 30-180 min, and the heat treatment atmosphere is inert gas.
  9. 9. A sendust-based magnetic powder core prepared by the method for preparing sendust-based magnetic powder core according to any one of claims 1-8.
  10. 10. A sendust-based magnetic powder core according to claim 9, characterized in that the sendust-based magnetic powder core has a resistivity >10.2 Ω -m, a core loss P10/50 of 1.2-1.8W/kg, a P10/400 of 17.4-24.2W/kg and a P1/10k of 10.3-16.2W/kg.

Description

Iron-silicon-aluminum-based magnetic powder core and preparation method thereof Technical Field The invention belongs to the technical field of soft magnetic materials and powder metallurgy, and particularly relates to an iron-silicon-aluminum-based magnetic powder core and a preparation method thereof. Background The iron-based magnetic powder core is a soft magnetic composite material prepared by coating iron-based magnetic powder with an insulating medium material and then pressing and heat treating. The iron-based magnetic powder core is widely applied to magnetic elements such as functional inductance of a medium-high frequency transformer by virtue of good saturation magnetic induction intensity, magnetostriction coefficient close to zero and excellent direct current bias performance. Along with the development of scientific technology, the device has the requirements of high frequency, light weight and miniaturization, and the prior magnetic element needs to be reasonably designed in a small space. However, under the effect of high-density energy, a magnetic element in a small space generates a larger energy loss due to heating, so that improvement of the thermal management capability of the magnetic element is urgent. The high heat conduction material has good application prospect in the aspects of heat release and heat removal in electronic devices. The patent with publication No. CN120977763A discloses a preparation method of a soft magnetic powder core, wherein activated h-BN powder is used for coating metal soft magnetic powder, and then a soft magnetic composite iron core coated with an h-BN insulating layer is obtained through pressing and heat treatment processes, and the soft magnetic composite iron core shows a certain heat conductivity. However, the combination of the layered structure of the h-BN and the metal soft magnetic powder is poor, the h-BN is easy to oxidize in a high-temperature oxidation environment mainly depending on the bonding effect of the coupling agent, and meanwhile, the h-BN is low in hardness, is easy to wear in the processing and using processes, and is not beneficial to subsequent large-scale application. The magnesia-alumina spinel has good erosion resistance and corrosion resistance, and also has the characteristics of strong spalling resistance, good slag resistance, good abrasion resistance and thermal stability, high temperature resistance and the like, and is a novel material for replacing h-BN as an iron-based magnetic powder core insulating medium. The existing bauxite-based sintered magnesia-alumina spinel is formed by sintering high-quality alumina with the Al 2O3 content of more than 76% and high-quality light-burned magnesia powder with the magnesia content of more than 95% at high temperature of more than 1800 ℃ in an ultrahigh-temperature tunnel kiln through a multi-stage homogenization process, and the preparation process is relatively complex. The patent with publication number CN121020627A discloses a high sintering activity and high dispersibility nano magnesia alumina spinel and a preparation method thereof. The preparation method comprises the steps of mixing aluminum chloride, magnesium chloride and deionized water, adding aluminum bicarbonate, performing hydrothermal reaction to enable aluminum hydroxide and magnesium hydroxide to be simultaneously precipitated to obtain a magnesium aluminate spinel precursor, performing first-stage roasting on the magnesium aluminate spinel precursor to enable the magnesium aluminate spinel precursor to be subjected to flash pyrolysis to obtain fine crystal nuclei, obtaining pyrolysis products, and performing second-stage roasting on the pyrolysis products to control crystal nuclei of the pyrolysis products to grow along specific crystal faces, so that nano magnesium aluminate spinel powder is obtained. However, the process has complex preparation flow, is difficult to be effectively applied to the field of magnetic powder cores, and is also unfavorable for mass production. Therefore, research on a preparation method of the sendust-based magnetic powder core, which can meet the requirement of heat management capability and can also solve the technical problem that the preparation process of the magnesia-alumina spinel in the prior art is complex and complicated, is a technical problem to be solved by the technicians in the field. Disclosure of Invention In order to solve the problems in the prior art, the invention provides an iron-silicon-aluminum-based magnetic powder core and a preparation method thereof, wherein the method adopts strong alkali to treat iron-silicon-aluminum alloy powder, then bicarbonate solution is added for neutralization, and (3) generating an aluminum hydroxide precursor, putting the aluminum hydroxide precursor into an atmosphere furnace for heat treatment to obtain Fe-Si-Al 2O3 composite powder, finally adding a magnesium oxide solution, and performing heat treatment to obtain the Fe