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Method for preparing rare earth permanent magnet by hot pressing

A rare-earth permanent magnet and hot-press forming technology, which is applied in the manufacture of inductors/transformers/magnets, magnetic objects, magnetic materials, etc., can solve the problems of small grains, difficulty in forming and anti-oxidation

Active Publication Date: 2021-08-13
太原盛开源永磁设备有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method is difficult to shape and prevent oxidation because the crystal grains are too small.

Method used

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  • Method for preparing rare earth permanent magnet by hot pressing
  • Method for preparing rare earth permanent magnet by hot pressing

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0051] The material ratio of RFeB master alloy is as follows:

[0052]

[0053] Vacuum smelting according to the above formula, quick-setting flakes to obtain 0.20-0.45mm thick RFeB master alloy - quick-setting flakes.

[0054] The quick-setting flakes were processed according to the method described in this application, wherein the R T M alloy is NdCu alloy powder, in which Nd90% and Cu10%.

[0055] In order to ensure the performance, it is required that the surface of the quick-setting sheet has no oxide layer, and the discharge of the quick-setting furnace is required to be in a sealed barrel. When adding the hydrogen crushing furnace, it should also be strictly protected from contact with air.

[0056] Put the quick-setting flakes and NdCu alloy powder accounting for 1% of the total mass of the quick-setting flakes into the HDDR treatment furnace. After the vacuum reaches 0.1Pa, the temperature is raised at a rate of 10 degrees / min to 820 degrees, and hydrogen is fil...

Embodiment 2

[0059] The material ratio of RFeB master alloy is as follows:

[0060]

[0061] Vacuum smelting according to the above formula, quick-setting flakes to obtain 0.20-0.45mm thick RFeB master alloy - quick-setting flakes.

[0062] Equipped with TbCuAl alloy and its powder, Tb80%, Cu10%, Al10% (mass percentage).

[0063] The quick-setting flakes and the TbCuAl alloy powder with 1.5% mass of the quick-setting flakes are put into the HDDR treatment furnace together. After the vacuum reaches 0.1Pa, the temperature is raised at a rate of 20 degrees / min to 700 degrees. At the same time, fill with hydrogen gas at 70KPa. Hold at 750°C for 30 minutes, and increase the hydrogen pressure to 80KPa. Then the hydrogen pressure was reduced to 8KPa and kept for 50 minutes; then the vacuum pump was turned on fully, and the vacuum degree reached 100Pa and kept for 100 minutes. Then stop heating, keep the vacuum state, and cool down with the furnace. After cooling, seal it out of the oven. ...

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Abstract

The invention relates to a method for preparing a NdFeB rare earth permanent magnet material, in particular to a method for preparing a rare earth permanent magnet by hot pressing. The problem that the remanence and coercivity of the rare earth permanent magnet prepared in the prior art cannot be high at the same time is solved. The present invention penetrates R during HDDR processing T M alloy, R T M enters and coats the grains along the new grain boundaries generated by the HDDR process. The hot pressing temperature is low, and the grains hardly grow. In the absence of Dy and Tb, high coercivity is obtained. If the infiltrated alloy contains Dy and Tb, these atoms diffuse into the surface layer of the main phase during preheating and heat treatment to achieve grain boundary hardening. On the premise that the remanence decreases very little, the coercivity is greatly improved.

Description

technical field [0001] The invention relates to a preparation method of NdFeB rare earth permanent magnet materials, in particular to a method for preparing rare earth permanent magnets by hot pressing. Background technique [0002] Chinese Patent No. 201410094229 .6 discloses a method of using hot pressing to manufacture magnetic materials for permanent magnets, which incorporates a first material in the form of a nuclear powder containing Nd, Fe, and B, and a metal alloy containing A second material in the form of Dy, Tb, or a surface powder of both is combined such that a coated, composite-like material is formed having a non-uniform distribution of Dy or Tb constituting the second material, and then Perform thermoforming. For particles of 1-5 microns, it is impossible to coat the surface with a film of 1-10 nm, or industrial production. The given coating schemes such as mechanical grinding, vortex coating, ion sputtering, and high-voltage particle sputtering are diffic...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01F1/057H01F41/02
CPCH01F1/0576H01F41/0266
Inventor 董元
Owner 太原盛开源永磁设备有限公司