Technique for treating surface of permanent magnet material

A technology of surface treatment and permanent magnet materials, applied in the direction of magnetic materials, metal material coating technology, magnetic objects, etc., can solve problems such as easy rust and corrosion, lower product stability and reliability, magnetic performance decline or damage, etc. Achieve high corrosion resistance, good anti-corrosion effect, uniform surface effect

Active Publication Date: 2010-06-09
BEIJING ZHONG KE SAN HUAN HI TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The rare earth element neodymium in the NdFeB powder alloy is active in nature, which makes the corrosion resistance of the entire NdFeB alloy very poor. It is easy to rust and corrode in a hot and humid environment, and the magnetic properties will be reduced or damaged due to corrosion failure. , which seriously affects the service life of NdFeB permanent magnets and reduces the stability and reliability of the product

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Will twenty four* 2.3 kg of 15*18mm sintered NdFeB permanent magnet material is polished in a vibration mill for 2 hours. After degreasing and degreasing with sodium phosphate 20g / liter, sodium carbonate 10g / liter and sodium hydroxide 10g / liter, pickle in 1% nitric acid to remove surface oxides, wash 3 times with water, and then activate with 5% sulfuric acid before galvanizing . The composition of the galvanizing solution is: potassium chloride 180 grams / liter, zinc chloride 50 grams / liter, boric acid 50 grams / liter, the thickness of the galvanized layer is 2 microns, and the grain size is 5 nanometers. The above-mentioned pretreated NdFeB permanent magnet material is put into neutral nickel plating solution, the composition of nickel plating solution is nickel sulfate heptahydrate 80 grams per liter, sodium citrate 104 grams per liter, sodium chloride 15 grams per liter liter, boric acid 55 g / l; pH is 7.2. React at 45°C for 25 minutes in a tumbler, and the R val...

Embodiment 2

[0026] Will twenty four* 2.5 kg of 15*18mm bonded NdFeB permanent magnet materials were polished according to the method in Example 1, degreased and degreased, and activated by pickling. For galvanizing, the composition of the galvanizing solution is: zinc oxide 15 g / l, sodium hydroxide 150 g / l, the thickness of the galvanized layer is 5 microns, and the grain size is 15 nanometers. Carry out nickel plating again, the composition of neutral nickel is nickel sulfate heptahydrate 120 grams / liter, sodium citrate 160 grams / liter, sodium chloride 45 grams / liter, boric acid 55 grams / liter. The pH is 7.0. At a temperature of 45°C, the reaction was carried out in a tumbler for 65 minutes, and the R value was 1.33. A coating is formed on the surface of the NdFeB permanent magnet material. The thickness of the nickel plating layer is 15 micrometers, and the lattice size is 100 nanometers. After the cross file test, the plating layer does not peel off, does not peel off, and has go...

Embodiment 3

[0028] Will twenty four* 2.5 kg of sintered NdFeB permanent magnet material of 15*18 mm is polished according to the method of Example 1, degreased and degreased, and activated by pickling. Galvanizing, the composition of the galvanizing solution is: ammonium chloride 280 g / L, zinc chloride 32 g / L. The thickness of the galvanized layer is 6 microns, and the lattice size is 15 nanometers. Carry out nickel plating again, the composition of neutral nickel plating solution is nickel sulfate heptahydrate 70 grams / liter, 105 grams / liter of sodium citrate, 15 grams / liter of sodium chloride, 25 grams / liter of boric acid. The pH is 6.5. React at 45°C for 80 minutes in a tumbler, with an R value of 1.5. A coating is formed on the surface of the NdFeB permanent magnet material. The thickness of the nickel plating layer is 5 microns, and the lattice size is 50 nanometers. After the cross file test, the coating has no peeling, no peeling, and the bonding force is very good, see Tab...

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Abstract

The invention relates to a method for treating the surface of a permanent magnet material. A surface treatment method comprises the steps of chamfer angle burnishing, degreasing and oil removing, acid cleaning for rust cleaning, acid liquor activation, galvanizing rendering, and nickel plating for film forming. The method solves the problem of magnetic flux loss of the material under a hot and humid condition through multilayer plating, and can effectively reduce the magnetic flux loss of the material. Compared with a nickel plated product, the high temperature demagnetizing loss of the method is lower than 1 percent, and compared with a galvanized product, the moist heat of the method is over 500 hours, and the PCT of the method is over 96 hours.

Description

technical field [0001] The invention relates to the field of surface treatment of materials, in particular to the surface treatment technology of NdFeB permanent magnet materials. Specifically, the invention relates to a surface treatment method for permanent magnet materials. Background technique [0002] In recent years, the application and development of neodymium iron boron (NdFeB) permanent magnet materials is very rapid, and the success of the protection of NdFeB permanent magnet materials is related to one of the key technologies whether the material can be popularized and applied. The material is mainly made of rare earth metals such as neodymium Nd, iron and boron through powder metallurgy process. As the strongest magnetic material at present, it has been widely used in electroplating devices, machinery, medical treatment, automobiles and other fields, and its application prospects are very broad. [0003] The premise of the application of NdFeB permanent magnet m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/057C23G1/14C23G1/02C23C28/02
Inventor 白晓刚潘广麾
Owner BEIJING ZHONG KE SAN HUAN HI TECH
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