NdFeB magnet sintering method

A technology of NdFeB and magnets, applied in the direction of magnetic objects, magnetic materials, inorganic materials, etc., can solve the problems of increased rare earth loss and low pulverization efficiency, and achieve the goal of improving particle size distribution, improving utilization rate, and uniform particles Effect

Inactive Publication Date: 2015-04-29
NINGBO HONGLEI MAGNETICS
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] With the continuous advancement of sintered NdFeB technology, the powder particle size of sintered NdFeB is continuously refined. In principle, when the main phase grain is single crystal and has a good grain boundary phase, the coercivity of the magnet The power will be greatly improved, so in the process of jet milling, the finer the average particle size of the fine powder, the better, and the particle size distribution requirements are getting higher and higher, but the efficiency of milling becomes lower and lower, and The loss of rare earths is also gradually increasing

Method used

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Embodiment 1

[0026] A method for sintering NdFeB magnets, said method comprising the steps of:

[0027] According to the composition (PrNd) 29 Gd 3 co 0.5 Al 1.0 Cu 0.2 B 0.98 Fe bal (percentage by weight) Weigh the NdFeB compound material and melt it in a vacuum quick-setting furnace with a vacuum degree of 0.3-0.8Pa to make the NdFeB compound material flake, and the melting temperature is 1500 ° C; recycle the NdFeB waste Clean the NdFeB recovery waste, and then hydrogen crush the NdFeB preparation flakes and NdFeB recovery waste respectively to obtain NdFeB preparation coarse powder and NdFeB recovery waste coarse powder. The dehydrogenation temperature during hydrogen crushing is The temperature is 540°C, and the dehydrogenation time is 4.5h;

[0028] The coarse powder of recycled NdFeB waste is subjected to jet milling to make fine powder of recycled NdFeB waste with an average particle size of 60 μm, and the fine powder of recycled NdFeB waste and the coarse powder of NdFeB co...

Embodiment 2

[0033] A method for sintering NdFeB magnets, said method comprising the steps of:

[0034] According to the composition (PrNd) 29.5 Gd 3 co 0.5 Al 1.0 Cu 0.2 B 0.98 Fe bal (weight percentage) Weigh the NdFeB compound material and melt it in a vacuum quick-setting furnace with a vacuum degree of 0.3Pa to make the NdFeB compound material flake, and the melting temperature is 1550 ° C; the NdFeB recycled waste is cleaned to obtain NdFeB recovery waste, and then the NdFeB preparation flakes and the NdFeB recovery waste are subjected to hydrogen crushing to obtain NdFeB preparation coarse powder and NdFeB recovery waste coarse powder, and the dehydrogenation temperature is 530 during hydrogen crushing ℃, the dehydrogenation time is 5h;

[0035] The coarse powder of recycled NdFeB waste is subjected to jet milling to make fine powder of recycled NdFeB waste with an average particle size of 20 μm, and the fine powder of recycled NdFeB waste and the coarse powder of NdFeB compo...

Embodiment 3

[0040] A method for sintering NdFeB magnets, said method comprising the steps of:

[0041] According to the composition (PrNd) 30 Gd 3 co 0.5 Al 1.0 Cu 0.2 B 0.98 Fe bal (percentage by weight) Weigh the NdFeB compound material and melt it in a vacuum quick-setting furnace with a vacuum degree of 0.8Pa to make the NdFeB compound material flake, and the melting temperature is 1450 ° C; the NdFeB recycled waste is cleaned to obtain NdFeB recovery waste, and then the NdFeB preparation flakes and the NdFeB recovery waste are subjected to hydrogen crushing respectively to obtain NdFeB preparation coarse powder and NdFeB recovery waste coarse powder, and the dehydrogenation temperature is 550 during hydrogen crushing ℃, dehydrogenation time is 4h;

[0042] The NdFeB recycling waste coarse powder is air-milled to make NdFeB recycling waste fine powder with an average particle size of 100 μm, and the NdFeB recycling waste fine powder and NdFeB preparation material coarse powder ...

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Abstract

The invention relates to an NdFeB magnet sintering method, and belongs to the technical field of rare earth magnetic materials. The method comprises the following steps that NdFeB preparing materials are weighed and are subjected to vacuum melting to obtain throwing sheets; cleaning is carried out, NdFeB recovery waste materials are obtained, the throwing sheets and the recovery waste materials are respectively subjected to hydrogen crushing to obtain preparing material coarse powder and recovery waste material coarse powder; the recovery waste material coarse powder is subjected to airflow milling powder preparation to be made into recovery waste material fine powder with the average granularity being 20 to 100mum, and the recovery waste material fine powder is mixed with the preparing material coarse powder according to a ratio being (2 percent to 50 percent) and (50 percent to 98 percent); the mixed materials are subjected to secondary airflow milling to be made into NdFeB micro powder with the average granularity being 2 to 4mum; the micro powder is pressed, formed and pressurized to obtain a blank; the sintering aging processing is carried out, and a NdFeB magnet is obtained. The NdFeB magnet sintering method has the advantages that the powder preparing efficiency is high, the rare earth loss is little, the time of the preparing method is short, and the production cost is low.

Description

technical field [0001] The invention relates to a method for sintering an NdFeB magnet, belonging to the technical field of rare earth magnetic materials. technical background [0002] In recent years, with the rapid expansion of the application field of NdFeB magnets, the demand for raw materials has become larger and larger. However, due to the high cost of rare earth mining and the strengthening of national regulation, the cost of materials has gradually increased. increase. Under the current situation of excessive price increase, the price tolerance of the downstream market is relatively limited. Some downstream enterprises have chosen to use cheaper ferrite or AlNiCo, SmCo and other materials to replace the rare earth in the raw materials of NdFeB magnets. This brings greater instability to the NdFeB magnet market. In addition, NdFeB magnet materials are highly brittle and have complex specifications, which are prone to problems such as missing corners and poor dimens...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F41/02H01F1/057H01F1/08B22F1/00B22F3/16
Inventor 张宏芳
Owner NINGBO HONGLEI MAGNETICS
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