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CN-121983420-A - Method for increasing resistance of permanent magnet

CN121983420ACN 121983420 ACN121983420 ACN 121983420ACN-121983420-A

Abstract

The invention relates to the technical field of permanent magnet materials, in particular to a method for increasing the resistance of a permanent magnet, which comprises the following steps of (1) weighing raw materials, smelting and refining to obtain alloy melt, (2) cooling, pulverizing, forming, sintering, aging, cooling to obtain a samarium cobalt blank, (3) carrying out machining grinding, slicing, end face grinding, cleaning and drying on the samarium cobalt blank to obtain a plurality of sheet magnets, then carrying out argon plasma treatment and nitrogen plasma treatment on each end face of the sheet magnets in sequence, sputtering a boron nitride layer and a silicon dioxide layer on the end face of the sheet magnets by adopting a magnetron sputtering method, and carrying out annealing, bonding and curing to obtain the high-resistance permanent magnet. The method for increasing the resistance of the permanent magnet can effectively increase the resistance of the rotor magnet, thereby reducing the eddy current generated by the motor rotor magnet.

Inventors

  • XIAO TAO
  • XU HAO
  • Fang Xuping
  • FENG YAHUI
  • MAO SHOUDONG

Assignees

  • 杭州磁聚力科技有限公司

Dates

Publication Date
20260505
Application Date
20260130

Claims (10)

  1. 1. A method of increasing the resistance of a permanent magnet comprising the steps of: (1) Weighing Fe, cu, co, zr and Sm raw materials, smelting and refining to obtain alloy melt; (2) Cooling, pulverizing, forming, sintering and aging the alloy melt, and cooling to obtain a samarium cobalt blank; (3) The method comprises the steps of carrying out machining grinding, slicing, end face grinding, cleaning and drying on the samarium cobalt blank to obtain a plurality of sheet magnets, carrying out argon plasma treatment and nitrogen plasma treatment on each end face of the sheet magnets in sequence, sputtering a boron nitride layer on each end face of the sheet magnets by adopting a magnetron sputtering method, sputtering a silicon dioxide layer on the boron nitride layer by adopting the magnetron sputtering method, annealing the sheet magnets after the silicon dioxide layer is sputtered, sequentially bonding the sheet magnets along the direction perpendicular to the cutting face by using an adhesive, and then carrying out curing treatment to obtain the high-resistance permanent magnet.
  2. 2. The method for increasing the resistance of a permanent magnet according to claim 1, wherein in the step (3), the thickness of the boron nitride layer is 2-3 μm, and the corresponding magnetron sputtering method comprises the steps of taking a mixed gas of high-purity argon and high-purity nitrogen as working gases in a high-vacuum magnetron sputtering chamber with the vacuum degree of <5.0 x 10 -5 Pa, wherein the flow ratio of the argon to the nitrogen in the mixed gas is 75-80%, 20-25%, the working pressure is 0.3-0.6 Pa, taking boron-palladium as a boron source, adopting a radio frequency power supply, the sputtering power is 250-300 w, the substrate temperature is 115-125 ℃, and the substrate bias voltage is-50-100V.
  3. 3. The method for increasing the resistance of a permanent magnet according to claim 1, wherein in the step (3), the thickness of the silicon dioxide layer is 1.2-2 μm, and the corresponding magnetron sputtering method comprises the steps of using a mixed gas of high-purity argon and high-purity oxygen as working gas in a high-vacuum magnetron sputtering chamber with the vacuum degree of <5.0 x 10 -5 Pa, wherein the flow ratio of the argon to the oxygen in the mixed gas is 85-90%, 10-15%, the working pressure is 0.5-0.7 Pa, and using a radio frequency power supply to magnetron sputter the silicon dioxide target, the sputtering power is 180-220 w, the substrate temperature is 115-125 ℃, and the substrate bias voltage is-50-100V.
  4. 4. The method of increasing the resistance of a permanent magnet according to claim 1, wherein in the step (3), when each end face of the sheet-shaped magnet is subjected to the argon plasma treatment, the flow rate of the argon gas is 200-400 sccm/min, the treatment power is 200-300W, the treatment time is 15-25 min, and when each end face of the sheet-shaped magnet is subjected to the nitrogen plasma treatment, the flow rate of the nitrogen gas is 100-300 sccm/min, the treatment power is 200-300W, and the treatment time is 10-20 min.
  5. 5. The method for increasing the resistance of a permanent magnet according to claim 1, wherein in the step (3), the thickness of the sheet-shaped magnet is 2-2.8 mm, and the surface roughness Ra of the end surface after grinding is less than 0.2 μm; The cleaning is carried out in acetone, absolute ethyl alcohol and deionized water for 15-20 min each time, and the drying is carried out by adopting high-purity nitrogen for drying.
  6. 6. The method for increasing the resistance of a permanent magnet according to claim 1, wherein in the step (3), the low-temperature annealing is performed under an argon atmosphere, the annealing temperature is 130-145 ℃, and the annealing time is 1-2 hours.
  7. 7. The method for increasing the resistance of a permanent magnet according to any one of claims 1 to 6, wherein the step (1) comprises the steps of weighing 5.0 to 25.0% of Fe, 4.0 to 8.0% of Cu, 36.0 to 65.0% of Co, 2.0 to 4.0% of Zr and 24.0 to 27.0% of Sm in percentage by mass, placing the materials in a vacuum melting furnace, vacuumizing the vacuum melting furnace, charging a protective gas into the vacuum melting furnace, heating and melting, wherein the melting temperature is 1450 to 1550 ℃, and refining to obtain a uniform alloy melt.
  8. 8. The method for increasing the resistance of the permanent magnet according to any one of claims 1 to 6, wherein in the step (2), the cooling comprises the steps of pouring the obtained alloy melt into a condensing die or onto a rapidly rotating copper roller for cooling to obtain a solid material, wherein the solid material is an ingot or a melt-spun tape; the powder preparation comprises the following steps of carrying out coarse breaking on the solid material, and conveying the solid material into an air flow mill for powder preparation to obtain samarium cobalt material powder, wherein the average particle size of the surface area of the samarium cobalt material powder is controlled to be 2.5-6.0 mu m; The molding comprises the following steps of orientation in a magnetic field, protection by filling inert gas in the compression molding process, and pressure maintaining in a cold isostatic press after compression molding to obtain a molded blank.
  9. 9. The method for increasing the resistance of a permanent magnet according to any one of claims 1 to 6, wherein in the step (2), the sintering treatment is performed at 1180 to 1220 ℃ for 2 to 6 hours, and the aging treatment is performed at 720 to 800 ℃ for 2 to 4 hours; the cooling comprises the following steps of cooling to 360-400 ℃ at the speed of 0.5-2 ℃ per minute, and carrying out furnace-following cooling, air cooling or air cooling after heat preservation.
  10. 10. The method of increasing the electrical resistance of a permanent magnet according to any one of claims 1 to 6, wherein in step (3), the adhesive comprises one or more of an epoxy adhesive, a polyimide adhesive, and a polyurethane adhesive.

Description

Method for increasing resistance of permanent magnet Technical Field The invention relates to the technical field of permanent magnet materials, in particular to a method for increasing the resistance of a permanent magnet. Background Along with the rapid development of modern industry, the magnetic material is widely applied to various important fields such as medical treatment, computer technology, micro-communication technology, automobiles, aviation, new energy, instrument technology, deep sea equipment, energy conservation and emission reduction industry and the like. In the future, with the development of quantum communication technology, innovation of energy modes and improvement of automation, the demand for magnetic materials is higher and higher. In particular, in the field of energy, magnetic materials play an indispensable role in energy conservation and emission reduction and in energy consumption reduction. In recent years, the demand for magnetic materials has increased even more as the motor has increased in speed and weight, but the effective utilization rate of the motor has been low due to heat generated by the motor itself during use. In addition, due to the eddy current effect of the motor, the temperature of the motor is increased, the temperature of the magnet is increased, the magnetic energy product of the magnet is reduced, and the working efficiency of the motor is reduced. The eddy current of the motor mainly comes from a rotor magnet and a rotor sheath, and the rotor sheath adopts carbon fiber materials in recent years, so that the eddy current can be greatly reduced, but the eddy current of the rotor magnet of the high-speed motor has no reliable reduction method due to low resistance. Disclosure of Invention In view of this, the invention provides a method for increasing the resistance of a permanent magnet, which can effectively increase the resistance of a rotor magnet and further reduce the eddy current generated by the rotor magnet of a motor. In order to achieve the above purpose, the invention is realized by the following technical scheme: a method of increasing the resistance of a permanent magnet comprising the steps of: (1) Weighing Fe, cu, co, zr and Sm raw materials, smelting and refining to obtain alloy melt; (2) Cooling, pulverizing, forming, sintering and aging the alloy melt, and cooling to obtain a samarium cobalt blank; (3) The method comprises the steps of carrying out machining grinding, slicing, end face grinding, cleaning and drying on the samarium cobalt blank to obtain a plurality of sheet magnets, carrying out argon plasma treatment and nitrogen plasma treatment on each end face of the sheet magnets in sequence, sputtering a boron nitride layer on each end face of the sheet magnets by adopting a magnetron sputtering method, sputtering a silicon dioxide layer on the boron nitride layer by adopting the magnetron sputtering method, annealing the sheet magnets after the silicon dioxide layer is sputtered, sequentially bonding the sheet magnets along the direction perpendicular to the cutting face by using an adhesive, and then carrying out curing treatment to obtain the high-resistance permanent magnet. Preferably, in the step (3), the thickness of the boron nitride layer is 2-3 mu m, and the corresponding magnetron sputtering method comprises the steps of taking mixed gas of high-purity argon and high-purity nitrogen as working gas in a high-vacuum magnetron sputtering chamber with the vacuum degree of less than 5.0X10 -5 Pa, wherein the flow ratio of the argon to the nitrogen in the mixed gas is 75-80%, 20-25%, the working pressure is 0.3-0.6 Pa, the boron palladium is taken as a boron source, the sputtering power is 250-300 w, the substrate temperature is 115-125 ℃, and the substrate bias voltage is-50-100V. Preferably, in the step (3), the thickness of the silicon dioxide layer is 1.2-2 mu m, and the corresponding magnetron sputtering method comprises the steps of taking mixed gas of high-purity argon and high-purity oxygen as working gas in a high-vacuum magnetron sputtering chamber with the vacuum degree of less than 5.0X10 -5 Pa, wherein the flow ratio of the argon to the oxygen in the mixed gas is 85-90%, 10-15%, the working pressure is 0.5-0.7 Pa, using a radio frequency power supply to magnetically sputter the silicon dioxide target, the sputtering power is 180-220 w, the substrate temperature is 115-125 ℃, and the substrate bias voltage is-50-100V. Preferably, in the step (3), when each end face of the sheet-shaped magnet is subjected to argon plasma treatment, the flow rate of argon is 200-400 sccm/min, the treatment power is 200-300W, the treatment time is 15-25 min, and when each end face of the sheet-shaped magnet is subjected to nitrogen plasma treatment, the flow rate of nitrogen is 100-300 sccm/min, the treatment power is 200-300W, and the treatment time is 10-20 min. Preferably, in the step (3), the thickness of the sheet-shaped magnet is