Method for preparing high-performance neodymium iron boron magnet by pressure impregnation of Dy<3+>/Tb<3+>

A high-performance NdFeB technology, which is applied in the manufacture of inductors/transformers/magnets, magnetic objects, magnetic materials, etc., can solve problems affecting the structure and performance inhomogeneity, Dy/Tb concentration inhomogeneity, etc., to achieve Evenly distributed, the effect of improving the coercive force

Active Publication Date: 2016-09-21
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the existing Dy/Tb technology of grain boundary diffusion is only suitable for thin sheet magnets with a smaller thickness. The Dy/Tb di

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] 1) Change the composition to (NdPr) 30 Fe 68.7 Cu 0.1 Zr 0.2 B 1.0 The oriented compact was pre-sintered in vacuum at 1050°C for 1 h to obtain a pre-sintered compact with a density of 85% (porosity 15%) (the size is ), the surface of the pre-sintered compact is cleaned, and the number is 1#;

[0020] 2) Dy(NO 3 ) 3 ·6H 2 The O salt was dissolved in dimethylformamide to obtain Dy at a concentration of 0.3 mol / l 3+ organic solution;

[0021] 3) Put the calcined billet numbered 1# into the pressure infiltration tank, first vacuumize, and use the negative pressure in the tank to inhale Dy 3+ / Tb 3+ Organic solution, and apply a gas pressure of 0.6MPa to make the organic solution penetrate deep into the NdFeB calcined billet, numbered 2#;

[0022] 4) The 1# and 2# samples were sintered and densified under the same conditions, the sintering temperature was 1000°C, the time was 1h, the argon pressure was 2.0MPa, and the Dy 3+ grain boundary diffusion;

[0023] 5)...

Embodiment 2

[0028] 1) Change the composition to (NdPr) 30 Fe 68.6 Ga 0.2 Al 0.2 B 1.0 The oriented compact was pre-sintered in vacuum at 1050°C for 1.5h to obtain a pre-sintered compact with a density of 92% (porosity 8%) (with a size of ), the surface of the pre-sintered compact is cleaned, and the number is 3#;

[0029] 2) Dy(NO 3 ) 3 ·6H 2 The O salt was dissolved in dimethylformamide to obtain Dy at a concentration of 0.3 mol / l3+ organic solution;

[0030] 3) Put the calcined billet numbered 3# into the pressure infiltration tank, first vacuumize, and use the negative pressure in the tank to inhale Dy 3+ / Tb 3+ Organic solution, and then apply a gas pressure of 0.8MPa to make the organic solution penetrate deep into the NdFeB pre-sintered billet, the number is 4#;

[0031] 4) The samples numbered 3# and 4# were sintered and densified under the same conditions, the sintering temperature was 970°C, the time was 1h, the argon pressure was 4.0MPa, and Dy 3+ grain boundary diff...

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Abstract

The invention discloses a method for preparing a high-performance neodymium iron boron magnet by pressure impregnation of Dy<3+>/Tb<3+>, and belongs to the field of a rare earth permanent magnetic material. The method comprises the specific technological steps of carrying out orientation compacting and vacuum pre-sintering on neodymium iron boron to obtain a partially-compacted pre-sintered blank; then dissolving a Dy/Tb salt into an organic solvent, and filtering the Dy/Tb salt organic solvent in the interior of the neodymium iron boron pre-sintered blank through a pressure impregnation way; keeping a part of the Dy<3+>/Tb<3+> in the interiors of the pre-sintered blank pores, and then further carrying out sintering densification to generate Dy<3+>/Tb<3+> grain boundary diffusion so as to improve the coercivity of the sintered neodymium iron boron magnet. The method has the advantages that the magnet is not limited by the dimensions and shapes; the diffusion path and the diffusion time of the Dy<3+>/Tb<3+> are greatly shortened; and high consistency in improvement of the internal organizational structure of the magnet and the improvement of the performance is realized.

Description

technical field [0001] The invention belongs to the field of rare earth permanent magnet materials, in particular to a pressure impregnated Dy 3+ / Tb 3+ A method for preparing a high-performance NdFeB magnet. Background technique [0002] As the third generation permanent magnet material, sintered NdFeB magnets have excellent magnetic properties and are widely used in new energy vehicles, wind power generation, medical equipment, VCM, permanent magnet high-speed rail and other fields. Since rare earth permanent magnet materials have low profits in the low-end field and cause waste of resources, the application in the high-end field is an important driving force for the development of the sintered NdFeB industry. High-end applications have high requirements on the remanence Br, coercive force Hci, magnetic energy product (BH)max, squareness, heat resistance stability and corrosion resistance of the magnet. In particular, the coercive force of sintered NdFeB magnets is less...

Claims

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Application Information

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IPC IPC(8): H01F41/02H01F1/057
CPCH01F1/0577H01F41/0293
Inventor 包小倩卢克超高学绪李纪恒
Owner UNIV OF SCI & TECH BEIJING
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