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Surface coating process for neodymium iron boron permanent magnetic material and neodymium iron boron permanent magnetic material

A permanent magnet material, NdFeB technology, applied in metal material coating process, magnetic material, coating and other directions, can solve the problems of high chemical reaction rate of electroless nickel plating, low stability of plating layer, rapid decomposition of plating solution, etc. , to achieve the effect of improving salt spray test indicators, high tensile strength and improving adhesion

Active Publication Date: 2012-07-18
SHENYANG GENERAL MAGNETIC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Through this coating method, the problem of poor bonding between NdFeB electroplating zinc-nickel alloy and the substrate and affecting corrosion resistance is solved. Although direct electroless nickel plating has the advantages of small gaps and high density of the electroless nickel plating layer, however, The chemical reaction rate of electroless nickel plating is high, and the bonding force with the substrate is poor, which causes the coating to fall off easily. In addition, because of the high activity of NdFeB, the plating solution rapidly decomposes as the coating falls off.
Therefore, the coating of the above-mentioned patent is easy to fall off, the stability of the coating is not high, and the service life is not high

Method used

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  • Surface coating process for neodymium iron boron permanent magnetic material and neodymium iron boron permanent magnetic material
  • Surface coating process for neodymium iron boron permanent magnetic material and neodymium iron boron permanent magnetic material
  • Surface coating process for neodymium iron boron permanent magnetic material and neodymium iron boron permanent magnetic material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Select the NdFeB permanent magnet sample with brand 45M and specification Φ30×7mm and proceed as follows:

[0038] (1) First, the sample is chamfered, degreased, pickled, and activated;

[0039] (2) Nickel layer on the bottom surface of electroplating: NiSO is used 4 ·6H 2 O, NiCl 2 , and H 3 BO 3 The nickel plating solution of composition; The mass volume concentration of each component in the nickel plating solution is respectively NiSO 4 ·6H 2 O: 220g / L, NiCl 2 : 35g / L, H 3 BO 3 : 40g / L; the temperature of the nickel plating solution is 48°C, the pH value is 4.2; the current density used in electroplating is 0.8A / dm 2 . Plating time 60min;

[0040] (3) Electroless nickel plating layer: using NiSO 4 ·6H 2 O, NaC 2 h 3 o 2 ·3H 2 O, NaH 2 PO 4 ·H 2 O, Na 3 C 6 h 5 o 7 2H 2 O, and C 4 h 6 o 5 The electroless nickel plating solution of composition; The mass volume concentration of each component in the electroless nickel plating solution is res...

Embodiment 2

[0049] Effect of different electroless nickel layer thicknesses.

[0050] Select 5 samples of NdFeB permanent magnets with grade 45M and specifications Φ30×7mm, respectively marked as C1, C2, C3, C4, and C5, and proceed as follows: the difference from Example 1 is:

[0051] (1) First, chamfer, degrease, pickle, and activate 5 samples.

[0052] (2) The nickel layer on the bottom surface of the electroplating is NiSO 4 ·6H 2 O, NiCl 2 , and H 3 BO 3 The nickel plating solution of composition; The mass volume concentration of each component in the nickel plating solution is respectively NiSO 4 ·6H 2 O: 250g / L, NiCl 2 : 40g / L, H 3 BO 3 : 45g / L; the temperature of the nickel plating solution is 52°C, the pH value is 4.6; the current density used in electroplating is 1A / dm 2 . The electroplating time is 60min.

[0053] (3) The electroless nickel plating layer uses NiSO 4 ·6H 2 O, NaC 2 h 3 o 2 ·3H 2 O, NaH 2 PO 4 ·H 2 O, Na 3 C 6 h 5 o 7 2H 2 O, and C 4 h ...

Embodiment 3

[0076] The grade is 45M, and the size is Φ30×7mm, and the two pieces are marked as D31 and D32 respectively. The order of electroplating nickel layer, electroless nickel plating layer, electroplating copper layer, and electroplating nickel layer is adopted sequentially from the inside to the outside.

[0077] (1) Chamfering, degreasing, pickling, and activation of two samples.

[0078] (2) First, the first nickel layer is electroplated with NiSO 4 ·6H 2 O, NiCl 2 , and H 3 BO 3 The nickel plating solution of composition; The mass volume concentration of each component in the nickel plating solution is respectively NiSO 4 ·6H 2 O: 230g / L, NiCl 2 : 36g / L, H 3 BO 3 : 42g / L; the temperature of nickel plating solution is 50℃, the pH value is 4.4; the current density used in electroplating is 0.8A / dm 2 . The electroplating time is 40min.

[0079] (3) The electroless nickel plating layer uses NiSO 4 ·6H 2 O, NaC 2 h 3 o 2 ·3H 2 O, NaH 2 PO 4 ·H 2 O, Na 3 C 6 h ...

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Abstract

The present invention relates to a surface coating process for neodymium iron boron permanent magnetic material and a neodymium iron boron permanent magnetic material with coating layers. In the process, an electroplated bottom surface nickel layer, a chemically-coated nickel layer, an electroplated copper layer and an electroplated external nickel layer are sequentially coated on the substrate surface of the neodymium iron boron permanent magnetic material from inside to outside, and after coating, the neodymium iron boron permanent magnetic material is subjected to heat treatment in a vacuum furnace. The total thickness of the coating layers on the neodymium iron boron permanent magnetic material prepared with the process is 15-30mum, the thickness of electroplated bottom surface nickel layer is 5-10mum, the thickness of the electroplated copper layer is 5-10mum, the thickness of the electroplated external nickel layer is 5-10mum and the thickness of the chemically-coated nickel layer is 3-10mum. The coating process provided by the invention reduces the bubble formation, looseness and rust stains, enhances the adhesion of the coating layers, reduces the porosity and obtains compact coating layers, thus significantly improving the quality of the electroplated coating layers on the magnet surface, improving the indicates of a salt spray test and increasing the qualification rate of products.

Description

technical field [0001] The invention relates to the field of material surface treatment, in particular to a surface coating process of an NdFeB permanent magnet material and the NdFeB permanent magnet material with the coating. Background technique [0002] NdFeB permanent magnet materials have high magnetic properties, high density and high coercive force, and have been widely used in modern industries, especially electronics industries, such as aviation, aerospace, communications, machinery, power generation, For home appliances, medical equipment, etc., the manufacture of NdFeB permanent magnet materials is manufactured using powder metallurgy technology. The process flow is as follows: [0003] Batching→smelting ingot making→milling→pressing→sintering and tempering→magnetic testing→cutting→electroplating→inspection→finished products. [0004] Electroplating is the last process in the processing of NdFeB permanent magnet materials. If the quality of the electroplating c...

Claims

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Application Information

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IPC IPC(8): C23C28/02C23C18/36C25D5/14H01F1/057
Inventor 孙宝玉崔振华裴文利惠鑫刘振刚
Owner SHENYANG GENERAL MAGNETIC
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