Low-cost sintered neodymium iron boron magnet and production method thereof

A NdFeB, low-cost technology, applied in the direction of magnetic objects, inductors/transformers/magnets, magnetic materials, etc., can solve the problems of difficult crushing of ingots, difficulties in powder making process, and influence on the uniform distribution of Nd-rich phase during sintering, etc. , to achieve straight grain boundaries, excellent ingot structure, and improved coercive force

Active Publication Date: 2012-07-18
宁德市星宇科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The thickness of the ingot prepared by the current ingot smelting process is about 20 mm, and α-Fe crystals are easy to exist. Due to the good plasticity of the α-Fe crystal, the ingot is difficult to break, which causes difficulties in the subsequent pulverization process. Prolong the sintering time to obtain uniform Nd2Fe14B crystals; the ingot structure prepared at present is prone to agglomerated Nd-rich phases, which affects the uniform distribution of Nd-rich phases during sintering

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0052] The preparation method of the described low-cost sintered NdFeB magnet comprises the following steps:

[0053] 1) Raw material pretreatment: remove the rust spots and impurities on the surface of each component, and crush or cut the raw material into small pieces below 35mm for batching;

[0054]2) Ingot smelting: Put the pretreated raw materials into the vacuum melting furnace and evacuate the vacuum melting furnace. When the vacuum inside is less than 3Pa, start the heating device, and the heating power is one-third of the maximum power , when the metal Pr and Nd start to melt, stop vacuuming and heating, fill the vacuum melting furnace with argon until the pressure inside it reaches -0.04MPa ~ -0.06MPa, start melting, and adjust the power to the maximum; when all the raw materials After both are melted, adjust the power to three quarters of the maximum value, and smelt for 2-8 minutes; when the surface of the alloy liquid is conjunctival, pour the alloy melt into the...

Embodiment 1

[0070] The preparation method of sintered NdFeB magnet comprises the following steps:

[0071] 1) Weigh raw materials:

[0072] Pr 0.50 kg;

[0073] Nd 2.0 kg;

[0074] Ho 0.5 kg;

[0075] B 0.10 kg;

[0076] Al 0.04 kg;

[0077] Zr 0.01 kg;

[0078] Nb 0.04 kg;

[0079] Cu 0.012 kg;

[0080] Ga 0.003 kg;

[0081] Co 0.04 kg;

[0082] Fe 6.755 kg.

[0083] 2) Raw material pretreatment: remove rust spots and impurities on the surface of the raw material, and crush or cut the raw material into small pieces below 35mm for batching;

[0084] 3) Ingot smelting: Put the pretreated raw materials into the vacuum melting furnace and evacuate the vacuum melting furnace. When the vacuum inside is less than 3Pa, start the heating device, and the heating power is one-third of the maximum power , when the metal Pr and Nd start to melt, stop vacuuming and heating, fill the vacuum melting furnace with argon until the pressure inside it reaches -0.04MPa ~ -0.06MPa, start melting, an...

Embodiment 2

[0095] The preparation method of sintered NdFeB magnet comprises the following steps:

[0096] 1) Weigh raw materials:

[0097] Pr 0.65 kg;

[0098] Nd 2.8 kg;

[0099] Ho 0.3 kg;

[0100] B 0.11 kg;

[0101] Al 0.08 kg;

[0102] Zr 0.02 kg;

[0103] Nb 0.06 kg;

[0104] Cu 0.017 kg;

[0105] Ga 0.008 kg;

[0106] Co 0.10 kg;

[0107] Fe 5.855 kg.

[0108] 2) Raw material pretreatment: remove rust spots and impurities on the surface of the raw material, and crush or cut the raw material into small pieces below 35mm for batching;

[0109] 3) Ingot smelting: Put the pretreated raw materials into the vacuum melting furnace and evacuate the vacuum melting furnace. When the vacuum inside is less than 3Pa, start the heating device, and the heating power is one-third of the maximum power , when the metal Pr and Nd start to melt, stop vacuuming and heating, fill the vacuum melting furnace with argon until the pressure inside it reaches -0.04MPa ~ -0.06MPa, start melting, an...

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Abstract

The invention discloses a low-cost sintered neodymium boron magnet, which comprises components including, by weight percentage, 5.0-6.5% of Pr (praseodymium), 20-28% of Nd (neodymium), 3-5% of Ho (holmium), 1.0-1.1% of boron, 0.4-0.8% of Al (aluminum), 0.1-0.2 % of Zr (zirconium), 0.4-0.6% of Nb (niobium), 0.12-0.17% of Cu (copper), 0.03-0.08% of Ga (gallium), 0.4-1.0% of Co (carbon monoxide) andthe balance iron. The production method includes: pretreatment of raw materials, ingot casting and smelting, hydrogen decrepitation and pulverization, magnetic field orienting and forming, isostatic processing, sintering, ageing and detecting. In the low-cost sintered neodymium boron magnet, high-cost dysprosium of rare metal is substituted by low-cost holmium of rare metal, so that production cost of products is reduced without affecting magnetic performances of the sintered neodymium boron magnet. Furthermore, the production method is simple in operation, excellent ingot casting structure can be obtained by ingot casting and smelting process, and the high-performance sintered neodymium iron boron magnet can be obtained.

Description

technical field [0001] The invention relates to a sintered NdFeB magnet, in particular to a low-cost sintered NdFeB magnet and a preparation method thereof. Background technique [0002] In recent years, with the rapid development of the domestic rare earth permanent magnet industry, the use of sintered NdFeB magnets in the motor industry is also increasing. Due to the rising price of heavy rare earth metal dysprosium (dysprosium iron alloy), the demand for sintered NdFeB motors has greatly increased. The production cost of magnets also restricts the development of the industry, while the holmium (Ho) which is symbiotic with heavy rare earth dysprosium is not well utilized and is left idle. [0003] NdFeB permanent magnet materials are known as the magnet king because of their high magnetic energy product and high coercive force, and are widely used in many fields such as electronics, computers, automobiles, machinery, energy and medical equipment. NdFeB magnets are divided...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F7/02H01F1/057H01F41/02C22C38/16C22C33/04B22F3/16C21D6/00
Inventor 吕竹风徐小卫
Owner 宁德市星宇科技有限公司
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