Preparation method of grain boundary diffusion heavy rare earth neodymium iron boron magnet and neodymium iron boron magnet

A grain boundary diffusion, NdFeB technology, applied in magnetic objects, inductance/transformer/magnet manufacturing, magnetic materials, etc., can solve the problems of small coercivity improvement of NdFeB magnet materials and poor effect of heavy rare earth elements, etc. To achieve the effect of improving the diffusion efficiency of grain boundaries, improving internal stress and crystal structure arrangement, and improving stability

Active Publication Date: 2019-06-25
宁波雄海稀土速凝技术有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0010] However, this process is the same as the existing grain boundary diffusion heavy rare earth element process, and has the same disadvantages, that is, it is limited to making thinner magnetic parts (thickness generally does not exceed 5mm). When preparing large magnets, the grain boundary The effect of diffusing heavy rare earth elements is poor, and the coercive force improvement of NdFeB magnet materials is small, so it needs to be improved

Method used

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  • Preparation method of grain boundary diffusion heavy rare earth neodymium iron boron magnet and neodymium iron boron magnet
  • Preparation method of grain boundary diffusion heavy rare earth neodymium iron boron magnet and neodymium iron boron magnet
  • Preparation method of grain boundary diffusion heavy rare earth neodymium iron boron magnet and neodymium iron boron magnet

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] A method for preparing a grain boundary diffused heavy rare earth NdFeB magnet, comprising the following steps:

[0050] S1: NdFeB powder with a particle size of 2.0-2.5 μm is obtained by distributing ingredients according to the design, casting and smelting, hydrogen crushing, and jet milling;

[0051] S2: The NdFeB powder is subjected to oriented static pressure molding on the mixture in a 1.5T magnetic field to obtain a rough NdFeB blank with gaps or pores;

[0052] S3: Mix the material containing heavy rare earth elements with NdFeB powder and heat it to the immersion temperature and keep it in a molten state. The immersion temperature is 1100±5°C to obtain a heavy rare earth source melt;

[0053] S4: Put the NdFeB rough blank in a cage or basket and move it above the liquid level of the heavy rare earth source melt, and heat the NdFeB rough blank;

[0054] S5: When the NdFeB rough billet is heated to a temperature lower than the dipping temperature of 85-95°C or 1...

Embodiment 2

[0093] A method for preparing a grain boundary diffused heavy rare earth NdFeB magnet. On the basis of Example 1F, Example 2A-2C is set. The difference between Example 2A-2C and Example 1F is that the immersion time is different, and the immersion time is different. Less than 40min.

Embodiment 3

[0101] A method for preparing a grain boundary diffused heavy rare earth NdFeB magnet, based on the first embodiment, the difference is that the NdFeB powder in S2 is mixed with a binder and then oriented static pressure molding, the binder The mass ratio of NdFeB powder to NdFeB powder is 0.02-0.03:1, and the binder is a low molecular weight carbon chain polymer. At the same time, the oriented static pressure forming and compaction in S2 obtains the NdFeB rough billet;

[0102] The finished NdFeB magnet is a disc with a diameter of 25mm and a thickness of 10mm. The element composition of finished NdFeB magnets is as follows:

[0103] PrNd: 19-20wt%, Ce: 2.2-2.3wt%, Y: 2.4-2.5wt%, Dy: 0.8-0.9wt%, B: 0.80-0.96wt%, Al: 0.3-0.4wt%, Co: 0.8 -1.1wt%, Zr: 0.10-0.12wt%, Cu: 0.10-0.18wt%, the rest is iron and unavoidable impurities.

[0104] The grain boundary diffused heavy rare earth NdFeB magnets with different thicknesses were prepared according to the above preparation method,...

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Abstract

The invention relates to a neodymium iron boron magnet and discloses a preparation method of a grain boundary diffusion heavy rare earth neodymium iron boron magnet and a neodymium iron boron magnet.The neodymium iron boron powders are pressed into a neodymium iron boron rough blank, and then are immersed in a heavy rare earth source molten mass. The heavy rare earth source molten mass proactively permeates the neodymium iron boron rough blank. The solid solution and permeation are generated between the heavy rare earth source molten mass and the neodymium iron boron rough blank so as to fillgaps and defects in the neodymium iron boron rough blank. Further, heavy rare earth elements are subjected to grain boundary diffusion in the neodymium iron boron magnet, to improve the grain boundary diffusion efficiency of the heavy rare earth elements, so that the grain boundary diffusion heavy rare earth element process becomes feasible for strengthening the coercive force of the neodymium iron boron magnet with large thickness, and a neodymium iron boron magnet having a thickness greater than 5 mm and a coercive force enhancement effect higher than that of the existing grain boundary diffusion heavy rare earth element process is obtained.

Description

technical field [0001] The invention relates to a neodymium-iron-boron magnet, in particular to a preparation method of a grain boundary diffused heavy rare earth neodymium-iron-boron magnet and the neodymium-iron-boron magnet. Background technique [0002] NdFeB permanent magnet materials are the most concerned rare earth application industry in my country's rare earth industry. With the development of science and technology and technological progress, the demand for high-performance NdFeB permanent magnet materials is becoming more and more extensive. In order to improve the coercive force and high-temperature usability of NdFeB, the commonly used method is to add a small amount of heavy rare earth elements (such as Dy, Tb, etc.) or optimize the process to refine the magnet grains. [0003] At present, the methods to reduce the usage of heavy rare earth mainly include double alloy process and grain boundary diffusion heavy rare earth element process. [0004] The double a...

Claims

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Application Information

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IPC IPC(8): H01F41/02H01F1/057
Inventor 路河树朱海松曹振宝
Owner 宁波雄海稀土速凝技术有限公司
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