Method for improving performance of sintered neodymium-iron-boron magnet

A neodymium-iron-boron and magnet technology, used in the manufacture of magnetic materials, magnetic objects, inductors/transformers/magnets, etc., can solve the problems of ineffective coercive force improvement and narrow application range, and achieve high coercivity, Wide range of applications, reducing the effect of loss

Active Publication Date: 2013-10-23
NINGBO YUNSHENG +5
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the distribution concentration of the Dy element gradually decreases from the outside to the inside of the sintered NdFeB thin-film magnet, and the diffusion depth of the Dy element reaches tens of microns at most.

Method used

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  • Method for improving performance of sintered neodymium-iron-boron magnet
  • Method for improving performance of sintered neodymium-iron-boron magnet

Examples

Experimental program
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Example Embodiment

[0025] Embodiment one: a kind of method improving the performance of sintered NdFeB magnet, comprises the following steps:

[0026] ① Preparation of sintered NdFeB magnet green body 1; Sintered NdFeB magnet green body 1 is prepared by casting, hydrogen crushing, jet milling, orientation and molding. The orientation magnetic field is 1.6T, and the isostatic pressure is 200MPa. Press for 10 seconds, the density of sintered NdFeB magnet green body 1 is 3.6g / cm 3 , the thickness is 10mm;

[0027] ②Preparing two massive heavy rare earth 2, the heavy rare earth 2 is massive heavy rare earth Dy;

[0028] ③Under the protection of an inert gas, first place a separation plate 3 on the bottom of the evaporation diffusion box 4, and then place two pieces of heavy rare earth 2, sintered NdFeB magnet green body 1 and two isolation nets 5 up and down on the separation plate 3, wherein the sintered NdFeB magnet green body 1 is located between two pieces of heavy rare earth 2, and the two pi...

Example Embodiment

[0036] Embodiment two: a kind of method that improves the performance of sintered NdFeB magnet, comprises the following steps:

[0037] ① Preparation of sintered NdFeB magnet green body 1; Sintered NdFeB magnet green body 1 is prepared by casting, hydrogen crushing, jet milling, orientation and molding. The orientation magnetic field is 1.4T, and the isostatic pressure is 140MPa. Press for 10 seconds, the density of sintered NdFeB magnet green body 1 is 4g / cm 3 , the thickness is 40mm;

[0038] ②Preparing two massive heavy rare earth 2, the heavy rare earth 2 is massive heavy rare earth Dy;

[0039] ③Under the protection of an inert gas, first place a separation plate 3 on the bottom of the evaporation diffusion box 4, and then place two pieces of heavy rare earth 2, sintered NdFeB magnet green body 1 and two isolation nets 5 up and down on the separation plate 3, wherein the sintered NdFeB magnet green body 1 is located between two pieces of heavy rare earth 2, and the two ...

Example Embodiment

[0047] Embodiment three: a method for improving the performance of sintered NdFeB magnets, comprising the following steps:

[0048] ① Preparation of sintered NdFeB magnet green body 1; Sintered NdFeB magnet green body 1 is prepared by casting, hydrogen crushing, jet milling, orientation and molding. The orientation magnetic field is 1.6T, and the isostatic pressure is 200MPa. Press for 10 seconds, the density of sintered NdFeB magnet green body 1 is 3.8g / cm 3 , the thickness is 10mm;

[0049] ② Prepare two massive heavy rare earths 2, and the heavy rare earth 2 is massive heavy rare earth Tb;

[0050] ③Under the protection of an inert gas, first place a separation plate 3 on the bottom of the evaporation diffusion box 4, and then place two pieces of heavy rare earth 2, sintered NdFeB magnet green body 1 and two isolation nets 5 up and down on the separation plate 3, wherein the sintered NdFeB magnet green body 1 is located between two pieces of heavy rare earth 2, and the tw...

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Abstract

The invention discloses a method for improving the performance of a sintered neodymium-iron-boron magnet. Two pieces of heavy rare earth, a sintered neodymium-iron-boron magnet green body and two separation nets are arranged on a separation board in an evaporation diffusion box one above another; the sintered neodymium-iron-boron magnet green body is positioned between the two pieces of heavy rare earth; the two pieces of heavy rare earth cover the upper surface and the lower surface of the sintered neodymium-iron-boron magnet green body; and when the sintered neodymium-iron-boron magnet green body is subjected to vacuum sintering under the condition that the vacuum degree is less than 1*10<-2>Pa, the two pieces of heavy rare earth are evaporated and diffused in an enclosed space, and heavy rare earth elements are diffused into the sintered neodymium-iron-boron magnet green body and are better distributed in the grain boundary and on the crystalline grain edge of the sintered neodymium-iron-boron magnet green body. The method has the advantages that specific to the sintered neodymium-iron-boron magnet of which the thickness surpasses 3 millimeters, the coercive force can be increased on the basis of ensuring that the residual magnetism does not fall basically; and the method is suitable for sintered neodymium-iron-boron magnets of which the thicknesses do not surpass 3 millimeters as well as sintered neodymium-iron-boron magnets of which the thicknesses surpass 3 millimeters, and has a wide application range.

Description

technical field [0001] The invention relates to a method for improving the performance of an NdFeB magnet, in particular to a method for improving the performance of a sintered NdFeB magnet. Background technique [0002] Sintered neodymium-iron-boron (NdFeB) magnets have high remanence, coercive force and maximum energy product. Since their inception, they have been widely used in the fields of national defense, household appliances, electronic information and automobile industries. Sintered NdFeB magnets are mainly composed of Nd 2 Fe 14 B. Composition of Nd-rich phase and B-rich phase, where Nd 2 Fe 14 B is the magnetic phase, and the excellent magnetic properties of sintered NdFeB magnets are mainly attributed to Nd 2 Fe 14 The high saturation magnetization of phase B (μ 0 m s =1.6T) and anisotropy field (7.3T), the Nd-rich phase and the microstructure of the sintered NdFeB magnet determine the coercive force of the sintered NdFeB magnet. The theoretical limit of ...

Claims

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Application Information

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IPC IPC(8): H01F41/02H01F1/057
Inventor 蒋小察丁勇吕向科李海晞张民
Owner NINGBO YUNSHENG
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