Preparation method of neodymium-iron-boron magnet

A neodymium-iron-boron and magnet technology, applied in the direction of magnetic objects, magnetic materials, inorganic materials, etc., can solve the problems of the decline of the magnetic performance of the magnet and the high oxygen content of the magnet, and achieve the effect of mass production.

Inactive Publication Date: 2017-05-31
ZHEJIANG ZHONGKE MAGNETIC IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, in the production of high-performance sintered NdFeB, such as N54, 52M, 50H and other high-remanence and high-energy product grades, in order to increase the Br of the magnet, it is necessary to increase the volume fraction of the main p

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0018] Specific embodiment one:

[0019] The invention relates to the field of the production of neodymium iron boron magnets, and more specifically to a method for preparing neodymium iron boron magnets, including the following steps:

[0020] (1) Weigh 30.0%-31.5% neodymium praseodymium, 0.9%-1.05% boron, 0-2.0% terbium, 0.03%-0.60% aluminum, 0.05%-0.25% copper, and 0.3%-1.5% cobalt according to the weight percentage of the elements. , Zirconium 0-0.2%, niobium 0-0.3%, gallium 0.05-0.3% and iron 62.35%-68.67%;

[0021] (2) Load the material weighed in step (1) into a crucible, vacuum the crucible to below 10 Pa, and oven with a power of 50 kw until the vacuum is lower than 5 Pa, fill with argon to 26.8 kPa, and then increase the power to 550kw smelting, after the iron is melted, refining for 7-12 minutes until the temperature is 1440-1500℃, and then start casting, obtain cast pieces and cool;

[0022] (3) Put the cast piece obtained in step (2) into a rotary hydrogen crushing furna...

Example

[0029] Specific case 1: A N54 sintered NdFeB magnet.

[0030] ① Ingredients. The formula is as follows: weigh 30.1% neodymium praseodymium, 0.94% boron, 0.05% aluminum, 0.09% copper, 0.7% cobalt, 0.06% zirconium, 0.1% niobium, 0.1% gallium, and 67.86% of iron according to element weight percentages.

[0031] ②Smelting. Put the above ingredients into the crucible, pump the furnace vacuum to below 10Pa, and oven with 50kw power until the vacuum is lower than 5Pa, fill with argon gas to 26.8kPa, then increase the power to 550kw for smelting, and refining after the iron is melted 7 When the temperature reaches 1440°C within minutes, the casting starts, and the cast slab is obtained and cooled. After the cast slab is cooled, the furnace is turned on and the material is discharged.

[0032] ③Hydrogen crushed. Put the cast piece into a rotary hydrogen crushing furnace, evacuated to less than 1 Pa, pass in 0.066 MPa hydrogen, after saturated hydrogen absorption, heated to 540°C for dehydr...

Example

[0038] Specific case 2: A 52M sintered NdFeB magnet.

[0039] ① Ingredients. The formula is as follows: 30.08% neodymium praseodymium, 0.94% boron, 0.12% terbium, 0.09% aluminum, 0.11% copper, 0.9% cobalt, 0.06% zirconium, 0.1% niobium, 0.18% gallium, and the rest are iron.

[0040] ②Smelting. Put the above ingredients into the crucible, pump the furnace vacuum to below 10Pa, and oven with 50kw power until the vacuum is lower than 5Pa, fill with argon to 26.8kPa, then increase the power to 550kw for smelting, and refining after melting the iron. When the temperature reaches 1445°C within minutes, the casting starts, and the cast slab is obtained and cooled. After the cast slab is cooled, the furnace is turned on and discharged.

[0041] ③Hydrogen crushed. Put the cast piece into a rotary hydrogen crushing furnace, evacuated to below 1 Pa, pass in hydrogen gas of 0.07 MPa, after saturated hydrogen absorption, heat to 570°C for dehydrogenation for 5 hours, cool to normal temperature...

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Abstract

The invention provides a preparation method of a neodymium-iron-boron magnet, relating to the field of production of the neodymium-iron-boron magnet. By virtue of processes of formula optimization, oriented molding, magnet oxygen content control and the like, the invention provides a preparation method of a high-performance sintering neodymium-iron-boron magnet, which solves the problem of batch production of high-performance sintering neodymium-iron-boron products. The preparation method comprises the following steps: weighing 30.0-31.5% of praseodymium and neodymium, 0.9-1.0% of boron, 0-2.0% of terbium, 0.03-0.60% of aluminum, 0.05-0.25% of copper, 0.3-1.5% of cobalt, 0-0.2% of zirconium, 0-0.3% of niobium, 0.05-0.3% of gallium and 62.35-68.67% of iron, and melting and casting to obtain a cast sheet; putting the cast sheet into a rotary hydrogen smashing furnace for processing to obtain coarse powder; adding a lubricating agent into the coarse powder for grinding to obtain fine powder; adding a lubricating agent and an antioxidant into the fine powder, and mixing the powder with a double-cone powder mixer to obtain powder; and making a mold to obtain a billet product, and sintering and cooling to obtain a finished product.

Description

technical field [0001] The invention relates to the field of NdFeB magnet production, in particular to a preparation method of NdFeB magnets. Background technique [0002] NdFeB magnets have excellent magnetic properties. Usually, their production processes include batching, smelting, hydrogen crushing, powder making, orientation pressing, isostatic pressing, sintering, tempering, post-processing, surface treatment, etc. [0003] The theoretical magnetic energy product of sintered NdFeB magnet is 64MGOe, but limited by the main phase ratio, relative density, orientation degree and other factors of the actual magnet, the positive limit of magnetic energy in the test is about 59MGOe. In a sense, high magnetic energy product NdFeB The development potential of permanent magnet materials is very limited. However, from the perspective of production and application, there are not many companies that can stably mass-produce high-energy-product NdFeB permanent magnet materials N54, ...

Claims

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Application Information

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IPC IPC(8): H01F1/057H01F1/08C22C38/32C22C38/06C22C38/16C22C38/10C22C38/14C22C38/12
CPCH01F1/0571C22C38/002C22C38/005C22C38/06C22C38/10C22C38/12C22C38/14C22C38/16C22C38/32H01F1/0576H01F1/0577
Inventor 吴中平梁海斌
Owner ZHEJIANG ZHONGKE MAGNETIC IND
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