Magnet fabrication method for reducing dysprosium content

A technology of magnets and content, applied in magnetic objects, inductance/transformer/magnet manufacturing, magnetic materials, etc., can solve problems such as cost reduction, high price, and low reserves

Inactive Publication Date: 2016-11-09
LONGYAN ZIJIN INNOVATION RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, Dy and Tb elements are heavy rare earth elements with low reserves a...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0017] The first step is to prepare NdFeB cast pieces through a vacuum induction melting furnace. The ingredients in the raw materials are: Nd30.3%, Pr0.1%, Co4%, Ga0.46%, B0.92%, and the balance is Fe. The melting furnace Internal vacuum reaches 10 -3 Pa filled with argon gas to 2000Pa, after smelting, cast in copper rollers and throw the strips to obtain cast pieces, the strip speed is 30m / s; then prepare micron-sized NdFeB powders by jet milling, and the air pressure of jet mill nozzles 0.5MP, the speed of classifying wheel is 3000rpm, and the particle size of NdFeB powder is 20-60µm after jet milling;

[0018] In the second step, the obtained powder is put into the cavity of a magnetic field press, oriented and pressed in a magnetic field, and the compact density reaches 4.5g / cm 3 , put the green compact after oriented pressing into the isostatic press and continue pressing to increase the density of the green compact to 6.5 / cm 3 ;

[0019] The third step is to use ther...

example 2

[0022] The first step is to prepare NdFeB cast pieces through a vacuum induction melting furnace. The ingredients in the raw materials are: Nd30.3%, Pr0.1%, Co4%, Ga0.46%, B0.92%, and the balance is Fe. The melting furnace Internal vacuum reaches 10 -3 Pa filled with argon gas to 2000Pa, after smelting, cast in copper rollers and throw the strips to obtain cast pieces, the strip speed is 30m / s; then prepare micron-sized NdFeB powders by jet milling, and the air pressure of jet mill nozzles 0.5MP, the speed of classifying wheel is 3000rpm, and the particle size of NdFeB powder is 20-60µm after jet milling;

[0023] In the second step, the obtained powder is put into the cavity of a magnetic field press, oriented and pressed in a magnetic field, and the compact density reaches 4.5g / cm 3 , put the green compact after oriented pressing into the isostatic press and continue pressing to increase the density of the green compact to 6.5 / cm 3 ;

[0024] The third step is to use ther...

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Abstract

The invention discloses a magnet fabrication method for reducing dysprosium content. The magnet fabrication method comprises the following steps of firstly, fabricating an Nd-Fe-B casting piece, and then fabricating micro-scale Nd-Fe-B powder; secondly, performing compression moulding on the obtained powder; thirdly, spraying a layer of metal dysprosium on the surface of a press blank by a thermal spraying device after compression, wherein the dysprosium dosage accounts for 2-3%; fourthly, adjusting nozzle pressure of thermal spraying, spraying distance and spraying travelling speed so that the coating thickness reaches 50-150 micrometers; and finally, placing the press blank subjected to thermal spraying coating in a tubular sintering furnace for sintering, cooling the press blank, and taking out the press blank when a temperature reaches a room temperature. By the magnet fabrication method, the coercivity is ensured, and meanwhile, the addition amount of Dy element is reduced; compared with the current process, the magnet fabrication method has the advantages that the dysprosium content is reduced by 2%; and a magnet can be applied to fields such as small and special electrical machines and sensors.

Description

technical field [0001] The invention relates to a rare earth permanent magnet alloy, in particular to a sintered magnet of neodymium-iron-boron, in particular to a method for preparing a magnet with reduced dysprosium content. Background technique [0002] The sintered NdFeB permanent magnet material, known as the king of magnetism, has a very broad application range and market prospects, and is gradually shifting to high-tech fields, such as being used in the manufacture of generators and motors for electric vehicles with hundreds of kw, and the manufacture of MW-level magnets. permanent magnet motor for wind power generation. In recent years, my country's NdFeB manufacturing technology has made significant progress, permanent magnet equipment has been continuously developed and improved, new technologies have been adopted, and product grades have rapidly improved. Some domestic enterprises have been able to manufacture UH, EH, VH and AH high-coercivity sintered NdFeB, but...

Claims

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Application Information

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IPC IPC(8): H01F1/057H01F41/02
CPCH01F1/0576H01F1/0577H01F41/0266H01F41/0293
Inventor 肖震韩珩钟炳文解伟
Owner LONGYAN ZIJIN INNOVATION RES INST
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