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Preparation method of sintered neodymium-iron-boron permanent-magnet surface ceramic coating

A ceramic coating and NdFeB technology, which is applied in the field of preparation of ceramic coatings on the surface of sintered NdFeB permanent magnets, to achieve the effects of prolonging service life, simple and easy industrial application, and low production cost

Inactive Publication Date: 2014-04-09
NANCHANG HANGKONG UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But so far, there is no report on the preparation of ceramic coatings on sintered NdFeB permanent magnets by micro-arc oxidation treatment at home and abroad.

Method used

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  • Preparation method of sintered neodymium-iron-boron permanent-magnet surface ceramic coating
  • Preparation method of sintered neodymium-iron-boron permanent-magnet surface ceramic coating

Examples

Experimental program
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Effect test

Embodiment 1

[0009] The preparation method of the ceramic coating on the surface of the sintered NdFeB permanent magnet in this embodiment is carried out according to the following steps:

[0010] (1) Chamfering and polishing: use mechanical vibrating and rolling chamfering methods to perform surface polishing on 38SH sintered NdFeB permanent magnets, and the final size is 30×15×4mm;

[0011] (2) Degreasing and degreasing: put the chamfered magnet into a 60°C alkaline degreasing agent (the main components are sodium carbonate, sodium phosphate, sodium silicate and emulsifier, etc.) for 10 minutes to degrease and degrease;

[0012] (3) Pickling and derusting: add 5% HNO 3 The solution is pickled and derusted for 30s;

[0013] (4) Micro-arc oxidation: Put the permanent magnet after pickling and derusting into the electrolyte for micro-arc oxidation treatment. The electrolyte is a sodium aluminate system, that is, sodium aluminate and potassium dihydrogen phosphate with deionized water as th...

Embodiment 2

[0017] The preparation method of the ceramic coating on the surface of the sintered NdFeB permanent magnet in this embodiment is carried out according to the following steps:

[0018] (1) Chamfering and polishing: use mechanical vibrating and rolling chamfering methods to perform surface polishing on 38SH sintered NdFeB permanent magnets, and the final size is 30×15×4mm;

[0019] (2) Degreasing and degreasing: put the chamfered magnet into a 60°C alkaline degreasing agent (the main components are sodium carbonate, sodium phosphate, sodium silicate and emulsifier, etc.) for 10 minutes to degrease and degrease;

[0020] (3) Pickling and derusting: add 10% HNO 3 The solution is pickled and derusted for 20s;

[0021] (4) Micro-arc oxidation: Put the permanent magnet after pickling and rust removal into the electrolyte for micro-arc oxidation treatment. The electrolyte is potassium fluozirconate system, that is, potassium fluozirconate and phosphoric acid are prepared with deioniz...

Embodiment 3

[0025] The preparation method of the ceramic coating on the surface of the sintered NdFeB permanent magnet in this embodiment is carried out according to the following steps:

[0026] (1) Chamfering and polishing: use mechanical vibrating and rolling chamfering methods to perform surface polishing on 38SH sintered NdFeB permanent magnets, and the final size is 30×15×4mm;

[0027] (2) Degreasing and degreasing: put the chamfered magnet into a 60°C alkaline degreasing agent (the main components are sodium carbonate, sodium phosphate, sodium silicate and emulsifier, etc.) for 10 minutes to degrease and degrease;

[0028] (3) Pickling and derusting: add 10% HNO 3 The solution is pickled and derusted for 20s;

[0029] (4) Micro-arc oxidation: Put the permanent magnet after pickling and rust removal into the electrolyte for micro-arc oxidation treatment. The electrolyte is potassium fluorotitanate system, that is, potassium fluorotitanate and dipotassium hydrogen phosphate are deio...

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Abstract

The invention relates to a preparation method of a sintered neodymium-iron-boron permanent-magnet surface ceramic coating. The preparation method comprises steps of: (1) chamfering and polishing, namely, subjecting a sintered neodymium-iron-boron permanent-magnet material to surface polishing processing by utilization of a mechanical vibration grinding and barreling chamfering method; (2) degreasing and removing oil, namely, adding the chamfered and polished magnet into an alkaline oil removing agent to remove oil and degrease; (3) removing rust by acid-washing namely, adding the magnet into an acid solution to remove rust by acid-washing; (4) performing micro-arc oxidation, namely, adding the permanent magnet rust of which is removed by acid-washing into an electrolyte and performing micro-arc oxidation; and (5) washing and drying, namely, washing the permanent magnet processed by micro-arc oxidation with distilled water and naturally drying, thus finally forming an oxidized ceramic coating on the surface of the neodymium-iron-boron permanent magnet. The preparation method achieves simple and feasible industrial application and is low in production cost, is free from influence of appearance structures of the magnet material and is free from pollution to the environment. The preparation method can effectively improve the corrosion resistance and wear resistance of the neodymium-iron-boron permanent magnet and prolong the service lifetime of the magnet.

Description

technical field [0001] The invention relates to the field of surface modification of metal materials, in particular to a method for preparing a ceramic coating on the surface of a sintered NdFeB permanent magnet. Background technique [0002] NdFeB permanent magnets are widely used in microwave communication, audio-visual technology, high-energy micro-motor, instrumentation, computer, magnetic separation technology, wind power generation, automobile industry and medical equipment because of their high saturation magnetization, coercive force and magnetic energy product. field has been widely used. However, due to the limitation of the production process of sintered NdFeB permanent magnets, there are a large number of pores on the surface, and NdFeB itself has a multiphase structure (NdFeB 2 Fe 14 B hard magnetic phase, Nd-rich phase and B-rich phase), there is a large chemical potential difference between each phase, and it is easy to form a corrosion battery in a humid en...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25D11/34
Inventor 徐吉林罗军明钟震晨
Owner NANCHANG HANGKONG UNIVERSITY
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