Sintered NdFeB magnet having high integral magnetic performance and preparation method thereof

A technology of neodymium iron boron and magnetic properties, which is applied in the direction of magnetic objects, inductors/transformers/magnet manufacturing, magnetic materials, etc. Difficult to control and other problems, to achieve the effect of high internal bonding force, good magnetic properties, and improved adhesion

Inactive Publication Date: 2018-07-24
ZHEJIANG SHEENSEN MAGNETICS TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In order to solve the defects in the prior art that the coating is easily peeled off from the surface of the magnet, resulting in uneven coating amount on the surface of the magnet, difficult to control the production operation, and poor consistency of the magnetic properties of the magnet after heat treatment, the present invention Provide an industrialized preparation method for sintered NdFeB magnets with high comprehensive magnetic properties, improve the coating bonding force and magnet surface adhesion, and realize the industrial application of grain boundary infiltration technology to prepare sintered NdFeB magnets with high comprehensive magnetic properties

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Example 1: Based on No. 52SH magnet

[0023] A preparation method of sintered NdFeB magnet with high comprehensive magnetic properties:

[0024] S1. Magnet surface pretreatment;

[0025] S2, uniformly spraying a layer of homogenized slurry containing heavy rare earth elements, adhesion improver and plasticizer on the surface of the pretreated magnet;

[0026] S3. Place the spray plate with the magnet coded in S2 in a tunnel-type drying tunnel and bake at 40°C for 2 minutes;

[0027] S4. Form a layer of flexible coating with a thickness of 20 μm on the surface of the sintered NdFeB magnet, and then subject the magnet evenly coated with the flexible coating to high-temperature diffusion heat treatment and low-temperature tempering treatment.

[0028] The magnet pretreatment method in the S1 is to use a self-made derusting agent to derust the surface of the magnetic steel, and then use 3% HNO 3 Pickling in alcohol solution for 30S, then ultrasonic cleaning in clean wate...

Embodiment 2

[0035] Embodiment 2: Based on No. 52SHT magnet

[0036] A preparation method of sintered NdFeB magnet with high comprehensive magnetic properties:

[0037] S1. Magnet surface pretreatment;

[0038] S2, uniformly spraying a layer of homogenized slurry containing heavy rare earth elements, adhesion improver and plasticizer on the surface of the pretreated magnet;

[0039] S3. Place the spray plate with the magnet coded in S2 in a tunnel-type drying tunnel and keep warm at 70°C for 3 minutes;

[0040] S4. A layer of flexible coating with a thickness of 510 μm is formed on the surface of the sintered NdFeB magnet, and then the magnet evenly coated with the flexible coating is subjected to high-temperature diffusion heat treatment and low-temperature tempering treatment.

[0041] The magnet pretreatment method in the S1 is to use a self-made derusting agent to derust the surface of the magnetic steel, and then use 3% HNO 3 Pickling in alcohol solution for 45S, then ultrasonicall...

Embodiment 3

[0048] Embodiment 3: Based on No. 50UH magnet

[0049] A preparation method of sintered NdFeB magnet with high comprehensive magnetic properties:

[0050] S1. Magnet surface pretreatment;

[0051] S2, uniformly spraying a layer of homogenized slurry containing heavy rare earth elements, adhesion improver and plasticizer on the surface of the pretreated magnet;

[0052] S3. Place the spray plate with the magnet coded in S2 in a tunnel-type drying tunnel and keep it warm at 100°C for 5 minutes;

[0053] S4. Forming a layer of flexible coating with a thickness of 1000 μm on the surface of the sintered NdFeB magnet, and then subjecting the magnet evenly coated with the flexible coating to high-temperature diffusion heat treatment and low-temperature tempering treatment.

[0054] The magnet pretreatment method in the S1 is to use a self-made derusting agent to derust the surface of the magnetic steel, and then use 3% HNO 3 Pickling in alcohol solution for 60S, then ultrasonic cl...

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Abstract

The invention relates to a preparation method of a sintered NdFeB magnet having high integral magnetic performance. The preparation method comprises the following steps of (1) pre-processing a surfaceof the magnet; (2) uniformly spraying a layer of homogeneous paste containing a heavy rare-earth element, an adhesion force improvement agent and a plasticizer onto the surface of the magnet; and (3)performing drying, wherein a flexible coating layer with high adhesion force is formed on the surface of the sintered NdFeB magnet, and high-temperature permeation diffusion thermal processing and low-temperature tempering are performed on the magnet uniformly coated with the flexible coating layer. By forming the flexible coating layer on the surface of the sintered NdFeB magnet, the problem ofplating layer falling caused by turnover spraying of the magnet during mass production process is solved, and industrial preparation of the sintered NdFeB magnet having high integral magnetic performance can be achieved.

Description

technical field [0001] The invention relates to a magnet and a preparation method thereof, in particular to a sintered NdFeB magnet with high comprehensive magnetic performance and a preparation method thereof. Background technique [0002] The permanent magnetic material industry usually uses the sum (N) of the value of the magnetic energy product (in MGOe) and the value of the intrinsic coercive force (in kOe) in the Gauss unit system to represent the comprehensive hard magnetic performance index of the magnetic material: (BH )max / MGOe+Hcj / kOe=N. Generally, the N of high-performance permanent magnet materials should be equal to (or greater than) 65. The low-carbon economy has put forward higher and higher requirements for the comprehensive magnetic performance index "(BH)max(MGOe)+Hcj(kOe)" of sintered NdFeB magnets. At present, the permanent magnet synchronous transmission system of rail transit and the new The requirements for this indicator in the application fields s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F41/02H01F1/057C23C10/30
Inventor 周晓庆鲍金胜闫向领应耀李旺昌罗阳
Owner ZHEJIANG SHEENSEN MAGNETICS TECH CO LTD
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