Preparation method of sintered neodymium iron boron magnet

A technology of sintered magnets and NdFeB, applied in the direction of magnetic objects, inductors/transformers/magnets manufacturing, magnetic materials, etc., can solve the problems of low output, etc., and achieve the effects of inhibiting grain growth, promoting shrinkage, and improving performance

Active Publication Date: 2017-08-08
YANTAI ZHENGHAI MAGNETIC MATERIAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the problem that still remains is the low throughput associated with depositing metal coatings by sputtering etc.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] 1) Preparation of sintered magnets: Nd-23.8%, Pr-5%, Dy-0.6%, Tb -0.4%, Co-0.5%, Cu-0.13%, Ga-0.1%, Al-0.1%, Zr-0.12%, B-1%, the balance is iron and unavoidable impurities, in an inert gas environment The pouring is completed in the vacuum melting furnace under the furnace, the pouring temperature is 1450°C, the speed of the quenching roll is 60r / min, the cooling water is passed through the quenching roll, and the thickness of the obtained scales is about 0.3mm; then, the scales are made into a uniform Magnetic powder with a particle size of 3.4 μm; Orientation pressing at room temperature and an environment with a magnetic field strength of 2T orientation field to make a compact; put the compact into a sintering furnace under an Ar atmosphere, and sinter at 1100°C for 5 hours to obtain a green compact. The blank was aged at 500°C for 5 hours to obtain a sintered blank. The sintered blank is machined into a magnet with a size of 40mm*20mm*4mm. After degreasing, picklin...

Embodiment 2

[0033] 1) The weight ratio of neodymium, dysprosium, terbium, cobalt, copper, aluminum, boron: Nd-30.1%, Dy-0.5%, Co-0.8%, Cu-0.13%, Al-0.2%, B-1% Ratio, the balance is Fe and unavoidable impurities. The casting is completed in a vacuum melting furnace under an inert gas environment. The pouring temperature is 1450°C, the speed of the quenching roll is 60r / min, and cooling water is passed through the quenching roll. The thickness of the obtained scales is about 0.32 mm; Then, the scales were powdered by HD and jet milled to produce magnetic powder with an average particle size of 3.6 μm; orientation pressing was carried out at room temperature and in an environment with a magnetic field strength of 2T orientation field to make compacts; the compacts were placed in Ar In a sintering furnace under atmosphere, sinter at 1060° C. for 6 hours to obtain a green compact, and age the green compact at 510° C. for 4 hours to obtain a sintered blank. The sintered blank is processed into ...

Embodiment 3

[0041] 1) The weight ratio of neodymium, dysprosium, terbium, cobalt, copper, aluminum, boron: Nd-30.5%, Tb-0.5%, Co-1.1%, Cu-0.16%, Al-0.4%, B-1.02% Ratio, the balance is Fe and unavoidable impurities. The casting is completed in a vacuum melting furnace under an inert gas environment. The pouring temperature is 1460°C, the speed of the quenching roll is 65r / min, and cooling water is passed through the quenching roll. The thickness of the obtained scales is about 0.36 mm; then, the flakes are powdered by HD and jet milled to make magnetic powder with an average particle size of 3.0 μm; orientation pressing is carried out at room temperature and the magnetic field strength is 2T orientation field to make compacts; then the compacts are put into Sintering at 910°C for 1.5h in a vacuum hot-press furnace under Ar atmosphere. After the sintering is completed, the system starts to apply pressure for hot-pressing sintering. The hot-pressing temperature is 920° C., the pressure is 11...

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Abstract

The invention relates to a preparation method of a sintered neodymium iron boron magnet. The preparation method comprises the following steps: pretreating a sintered magnet R1-Fe-B-M; mixing heavy rare earth power with metal Ga, and then mixing with an organic solvent to prepare a sizing agent, wherein the content of the Ga in the mixed power is 0.5 wt% to 20 wt%, wherein the heavy rare earth is one or a compound of more of Dy, Tb, alloy of Dy and Tb and hydride of Dy or Tb; enabling the surface of the sintered magnet to be covered with the obtained sizing agent, and then carrying out grain boundary diffusion treatment after drying, wherein the thickness of the sizing agent on the surface of the magnet is 20 to 200 microns. According to the method disclosed by the invention, by using a self-bonding effect of the Ga in the sizing agent of the mixed powder, the problems that fluorides are directly coated and hydride powder is easy to fall off are solved, and the defect that the magnetic property is reduced caused by the fact that excess C and N, together with heavy rear earth, are permeated into the magnet due to an added adhesive is also overcome.

Description

technical field [0001] The invention relates to a method for preparing an NdFeB magnet, belonging to the technical field of magnet preparation technology. Background technique [0002] Since its discovery, NdFeB permanent magnet materials have been widely used in communications, medical, automotive, electronics, aviation and other fields due to their excellent magnetic properties and high cost performance; however, their low coercive force and poor temperature Stability and corrosion resistance seriously limit the expansion of its application range. With the development of science and technology, the requirements for the comprehensive performance of NdFeB magnets in various fields are getting higher and higher. Therefore, the development of high comprehensive performance NdFeB magnets has become a The inevitable trend. [0003] Typical indicators of magnet performance are remanence and coercive force. Coercive force is an important index to measure the magnetic properties ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F41/02H01F1/057H01F1/08
CPCH01F1/0571H01F1/0577H01F41/0293
Inventor 史丙强魏蕊杜伟
Owner YANTAI ZHENGHAI MAGNETIC MATERIAL CO LTD
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