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A preparation method of composite NdFeB magnet with coercive force gradient distribution characteristics

A gradient distribution, NdFeB technology, applied in the manufacture of inductors/transformers/magnets, electrical components, circuits, etc., can solve the problem that the gradient distribution of the coercive force of the magnet cannot be controlled more accurately

Active Publication Date: 2022-04-26
JIANGSU UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the grain boundary diffusion technology can prepare NdFeB magnets with coercivity gradient distribution characteristics, due to the complexity of thermodynamics and kinetics in the diffusion process of sintered NdFeB magnets, the current grain boundary diffusion technology cannot be more accurately controlled. Gradient distribution of magnet coercive force after diffusion

Method used

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  • A preparation method of composite NdFeB magnet with coercive force gradient distribution characteristics
  • A preparation method of composite NdFeB magnet with coercive force gradient distribution characteristics
  • A preparation method of composite NdFeB magnet with coercive force gradient distribution characteristics

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Embodiment 1

[0026] A method for preparing a composite NdFeB magnet with coercive force gradient distribution characteristics, comprising the following steps:

[0027] Select sintered NdFeB magnets: 40H magnets with a dysprosium (Dy) content of 4wt%, N52 magnets without dysprosium, and an average grain size of 1-10 μm. Cut 40H magnet into 10×10×1(c-axis)mm 3 The component magnet thin slices, take 2 pieces, cut the N52 magnet into 10×10×2(c-axis)mm 3 Take one piece of component magnet thin slices, polish off the surface oxide layer with sandpaper, and clean it with acetone ultrasonically.

[0028] as attached figure 1 As shown, one N52 component magnet sheet after treatment was placed between two 40H component magnet sheets, and stacked together to obtain a sample.

[0029] Put the sample into the hot-press furnace for hot-press welding. The process is: vacuumize the hot-press furnace to 1×10 -2 Pa, then raise the temperature of the hot-press furnace to 700°C, apply a pressure of 30MPa ...

Embodiment 2

[0035] A method for preparing a composite NdFeB magnet with coercive force gradient distribution characteristics, comprising the following steps:

[0036] Select sintered NdFeB magnets: 38EH magnet with Dy content of 10wt%, 40H magnet with Dy content of 4wt%, and the average grain size is 1-10μm. Cut 38EH magnet into 10×10×1(c-axis)mm 3 Component magnet thin slices, take 2 pieces, cut the 40H magnet into 10×10×4(c-axis)mm 3 Take one piece of component magnet thin slices, polish off the surface oxide layer with sandpaper, and clean it with acetone ultrasonically.

[0037] as attached figure 2 As shown, one 40H component magnet sheet after treatment was placed between two 38EH component magnet sheets, and stacked together to obtain a sample.

[0038] Put the sample into the hot-press furnace for hot-press welding. The process is: vacuumize the hot-press furnace to 5×10 -2 Pa, then raise the temperature of the hot-press furnace to 900°C, apply a pressure of 5 MPa and keep th...

Embodiment 3

[0044] A method for preparing a composite NdFeB magnet with coercive force gradient distribution characteristics, comprising the following steps:

[0045] Select sintered NdFeB magnets: 40SH magnet with 5wt% dysprosium (Dy), 48H magnet with 3wt% dysprosium content, and N52 magnet without dysprosium, with an average grain size of 1-10 μm. Cut 40SH magnet into 10×10×1(c-axis)mm 3 The component magnet thin slices, take 2 pieces, cut the 48H magnet into 10×10×1(c-axis)mm 3 The component magnet thin slices, take 2 pieces, cut the N52 magnet into 10×10×2(c-axis)mm 3Take one piece of component magnet thin slices, polish off the surface oxide layer with sandpaper, and clean it with acetone ultrasonically.

[0046] as attached image 3 As shown, put two pieces of 40SH component magnet slices on the two pole faces after treatment, one piece of N52 component magnet slices is placed between two pieces of 40SH component magnet slices, one piece of 40SH component magnet slices and one P...

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Abstract

The invention discloses a method for preparing a composite NdFeB magnet with coercivity gradient distribution characteristics. According to the designed coercive force gradient distribution of the composite NdFeB magnet and the size of the composite NdFeB magnet, different Sintered NdFeB magnets with large coercivity are cut and polished into component magnet sheets, then selected and combined by adjusting the volume fraction, stacked together to obtain samples, and the samples are subjected to hot-press furnace hot-press welding, Low-temperature annealing in a vacuum tube annealing furnace to produce a composite NdFeB magnet. In the present invention, component magnet sheets with different coercive forces are stacked together, and a composite NdFeB magnet with coercive force gradient distribution characteristics is prepared by using hot-pressing diffusion welding technology, and the coercive force of the composite NdFeB magnet is The size of the gradient distribution can be quantitatively regulated according to the application needs, so as to achieve the effect and purpose of precise regulation, and provide a method for efficiently utilizing heavy rare earth elements to prepare high-coercivity NdFeB magnets.

Description

technical field [0001] The invention relates to a method for preparing an NdFeB magnet, in particular to a method for preparing a composite NdFeB magnet with coercive force gradient distribution characteristics. Background technique [0002] NdFeB permanent magnet material is a type of permanent magnet material with the highest magnetic energy product at present, and has been widely used in aerospace, power electronics, medical equipment, transportation and other fields. In recent years, with the vigorous development of the high-efficiency permanent magnet motor industry, the demand for NdFeB magnets that can be used at higher temperatures continues to increase. The coercive force of NdFeB magnets decreases with the increase of temperature. At present, the preparation of high coercive force NdFeB magnets that meet the application at higher temperatures is usually partially replaced by the heavy rare earth element dysprosium for the light rare earth element neodymium. to ach...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01F41/02C21D1/26C21D1/773
CPCH01F41/0253C21D1/26C21D1/773
Inventor 陈夫刚陈洪美刘宁王晓丽赵勇
Owner JIANGSU UNIV OF SCI & TECH