High-coercivity Nd-Fe-B rare-earth permanent magnet and fabrication process thereof

A rare earth permanent magnet and preparation process technology, applied in the manufacture of permanent magnets, magnetic objects, inductors/transformers/magnets, etc., can solve the problems of difficulty in industrialization, low magnetization, affecting the microstructure of magnets, etc.

Inactive Publication Date: 2018-05-04
GRIREM ADVANCED MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] However, the addition of Tb and Dy brings two serious problems: (1) Most of Tb and Dy enter the grain, and form Tb with Fe and B elements 2 Fe 14 B or Dy 2 Fe 14 B compound, the magnetization of this type of compound is much lower than the main phase Nd of NdFeB permanent magnet 2 Fe 14 B, thereby greatly reducing the remanence and energy product of the material; (2) Heavy rare earth elements such as Tb and Dy are expensive and are scarce resources, and their reserves are only 1/10 to 1/100 of Nd, and the ore veins are limited to several productio

Method used

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  • High-coercivity Nd-Fe-B rare-earth permanent magnet and fabrication process thereof
  • High-coercivity Nd-Fe-B rare-earth permanent magnet and fabrication process thereof
  • High-coercivity Nd-Fe-B rare-earth permanent magnet and fabrication process thereof

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Embodiment 1

[0057] The preparation method of this embodiment is: the invention is to prepare R by the steps of alloy melting, powder making, molding and sintering a FeMB magnets, processed into 10×10×7 (7 is c-axis direction, unit mm) magnets by wire cutting, R b Plated onto the magnet surface by the present invention, wherein the specific parameters adopted by the electrodeposition method (preparation of rare earth film by ionic liquid) are: the ionic liquid is: 1-ethyl-3-methylimidazolium tetrafluoroborate, the main salt TbCl 3 The concentration is 0.2mol / L, the electrodeposition temperature is 20°C, and the current density at constant potential is 6000A m -2 , after coating for 2000s, stop the coating, the film thickness is 3.0μm, and then carry out two-stage heat treatment on the sample, the first-stage heat treatment process is 800°C, keep warm for 1h and then cool, the cooling rate is 50°C / h, and the second-stage heat treatment process is 400°C Keep warm at ℃ for 1 hour, and the co...

Embodiment 2

[0063] The preparation method of this embodiment is: the invention is to prepare R by the steps of alloy melting, powder making, molding and sintering a FeMB magnets, processed by wire cutting into 10×10×8 (8 is the c-axis direction, unit mm) magnets, R b Plated onto the magnet surface by the present invention, wherein the specific parameters adopted by the electrodeposition method (preparation of rare earth film by ionic liquid) are: the ionic liquid is: 1-ethyl-3-methylimidazolium tetrafluoroborate, the main salt TbCl 3 The concentration is 0.2mol / L, the electrodeposition temperature is 70°C, and the current density at constant potential is 6000A m -2 , after coating for 2000s, stop the coating, the film thickness is 3.0μm, and then carry out two-stage heat treatment on the sample, in which the first-stage heat treatment process is 800°C, keep warm for 100h and then cool, the cooling rate is 300°C / h, and the second-stage heat treatment process is 655 Keep warm at ℃ for 10 h...

Embodiment 3

[0069] The preparation method of this embodiment is: the invention is to prepare R by the steps of alloy melting, powder making, molding and sintering a FeMB magnets, processed by wire cutting into 10×10×1 (1 is c-axis direction, unit mm) magnets, R b Plated onto the magnet surface by the present invention, wherein the specific parameters adopted by the electrodeposition method (preparation of rare earth film by ionic liquid) are: the ionic liquid is: 1-butyl-1-methylpyrrole bistrifluoromethylsulfonimide salt, Main salt TbCl 3 The concentration is 0.2mol / L, the electrodeposition temperature is 40°C, and the current density at constant potential is 3000A m -2 , after coating for 1800s, stop the coating, the film thickness is 5.0μm, and then carry out two-stage heat treatment on the sample, in which the first-stage heat treatment process is 700°C, keep warm for 10h and then cool, the cooling rate is 150°C / h, and the second-stage heat treatment process is 480°C Keep warm at ℃ f...

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Abstract

The invention provides a fabrication process of a high-coercivity Nd-Fe-B rare-earth permanent magnet. A technology of preparing a rare-earth thin film from an ion liquid is applied to fabricate a high-performance magnet, a Rb thin film is grown on a surface of the magnet by the technology, a Rb element plated on the surface of the magnet is diffused to the interior of the magnet by primary high-temperature thermal processing, a rare-earth rich phase is uniformly distributed around the magnet by secondary low-temperature tempering, and meanwhile, unbalanced tissue and internal stress brought by high-temperature processing are eliminated. The intrinsic coercivity of the magnet after being processed by the process can be obviously improved, so that the high-coercivity Nd-Fe-B rare-earth permanent magnet is fabricated. By the process, the production efficiency can be improved, the heavy rare-earth dosage during the fabrication process is reduced, and meanwhile, high coercivity is obtainedunder the condition that residual magnetism and magnetic energy product of the magnet are not reduced.

Description

technical field [0001] The invention belongs to the technical field of magnetic functional materials, and relates to a permanent magnet and a preparation process thereof, more specifically, to a high-coercivity Nd-Fe-B rare earth permanent magnet, a preparation process thereof and a device containing the same. Background technique [0002] Nd-Fe-B permanent magnet is the most magnetic permanent magnet material so far. It is widely used in electromechanical, electronic and medical fields. It is the fastest growing permanent magnet material with the best market prospect in the world. However, Nd-Fe-B permanent magnets have an obvious disadvantage, that is, poor temperature stability, and it is difficult to apply in a working environment above 150°C, so they are greatly limited in high-temperature applications. In particular, the rapid development of energy-saving gasoline-electric hybrid vehicles in recent years puts forward higher requirements for Nd-Fe-B permanent magnets in...

Claims

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Application Information

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IPC IPC(8): H01F1/057H01F1/08H01F41/02C25D3/54
CPCC25D3/54H01F1/0577H01F41/026
Inventor 闫文龙王祥生罗阳于敦波胡州谢佳君彭海军卢硕
Owner GRIREM ADVANCED MATERIALS CO LTD
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