Method for preparing Al coating on surface of sintered NdFeB by adopting detonation spraying

A technology of explosive spraying and coating, applied in the direction of coating, metal material coating process, molten spraying, etc., can solve the problems of complex process, high cost, unfavorable ecological environment, etc., achieve low surface porosity and improve corrosion resistance sex, combined with good results

Inactive Publication Date: 2014-10-29
BEIHANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are still some shortcomings in the existing Al coating technology: poor uniformity, low bonding force, and high cracks; and the process is complicated and the cost is high; Waste liquid contains a lot of toxic substances, and it is difficult to purify, and its discharge is very harmful to the ecological environment

Method used

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  • Method for preparing Al coating on surface of sintered NdFeB by adopting detonation spraying
  • Method for preparing Al coating on surface of sintered NdFeB by adopting detonation spraying
  • Method for preparing Al coating on surface of sintered NdFeB by adopting detonation spraying

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] The first step: substrate pretreatment

[0038] (A) A sintered NdFeB sample whose brand name is N35 is not magnetized is used as the base material, the hardness Hv=6.20, and the density D is 7.6;

[0039] Place the substrate in alcohol with a mass fraction of 99.7% for degreasing treatment by ultrasonic cleaning. Under the condition of a frequency of 30KHz, after ultrasonic cleaning for 5 minutes, naturally dry to obtain the first substrate;

[0040] (B) Install the first substrate on a DB-1 sandblasting machine, adjust the pressure to 0.7 MPa, select 60 mesh corundum sand for sandblasting, and obtain a second substrate with a roughness of Ra=3;

[0041] Step 2: Preparation of Al coating by detonation spraying process

[0042] Explosion spraying material selects industrial pure aluminum (mass percentage purity is 99.99%) powder, and average particle diameter is 38 microns; The XRD photograph of aluminum powder is as follows image 3 As shown, the abscissa is the angle...

Embodiment 2

[0053] The first step: substrate pretreatment

[0054] (A) A sintered NdFeB sample whose brand name is N35 is not magnetized is used as the base material, the hardness Hv=6.20, and the density D is 7.6;

[0055] Place the substrate in alcohol with a mass fraction of 99.7% for degreasing treatment by ultrasonic cleaning. Under the condition of frequency of 40KHz, after ultrasonic cleaning for 5 minutes, naturally dry to obtain the first substrate;

[0056] (B) Install the first substrate on a DB-1 sandblasting machine, adjust the pressure to 0.7 MPa, select 60 mesh corundum sand for sandblasting, and obtain a second substrate with a roughness of Ra=3.5);

[0057] Step 2: Preparation of Al coating by detonation spraying

[0058] The explosive spraying material is made of industrial pure aluminum (mass percentage purity is 99.99%) powder, and the average particle size is 38 microns;

[0059] Loading detonation spray material into gas detonation spray equipment;

[0060] mounti...

Embodiment 3

[0067] The first step: substrate pretreatment

[0068] (A) A sintered NdFeB sample whose brand name is N35 is not magnetized is used as the base material, the hardness Hv=6.20, and the density D is 7.6;

[0069] Place the substrate in alcohol with a mass fraction of 99.7% for degreasing treatment by ultrasonic cleaning. Under the condition of frequency of 30KHz, after ultrasonic cleaning for 15 minutes, naturally dry to obtain the first substrate;

[0070] (B) Install the first substrate on a DB-1 sandblasting machine, adjust the pressure to 0.7 MPa, select 60 mesh corundum sand for sandblasting, and obtain a second substrate with a roughness of Ra=3.3;

[0071] Step 2: Preparation of Al coating by detonation spraying

[0072] The explosive spraying material is made of industrial pure aluminum (mass percentage purity is 99.99%) powder, and the average particle size is 38 microns;

[0073] Loading detonation spray material into gas detonation spray equipment;

[0074] mounti...

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Abstract

The invention discloses a method for preparing an Al coating on the surface of sintered NdFeB by adopting detonation spraying. The micron-sized Al coating obtained by virtue of the method disclosed by the invention is closely combined with an NdFeB substrate material, is in a pure aluminum phase and has the advantages of high uniformity and compactness and low porosity. The corrosion current density of the sintered NdFeB with the Al coating in a saline solution is only one fifth of that of the sintered NdFeB; an Al2O3 oxidation film layer is formed on the surface of the Al coating, so that the sintered NdFeB substrate can be effectively protected.

Description

technical field [0001] The invention relates to a method for preparing a micron-sized Al coating on the surface of sintered NdFeB by using an explosive spraying process. Background technique [0002] Sintered NdFeB is the most magnetic permanent magnet material so far. It is widely used in many fields such as electronics, electromechanical, instrumentation and medical treatment. It is the fastest growing permanent magnet material with the best market prospect in the world today. However, one of the most obvious disadvantages of sintered NdFeB materials is poor corrosion resistance, which greatly limits the application of such magnets in high temperature and humid environments. [0003] Detonation flame spraying (detonation flame spraying) is a thermal spraying process in which the thermal energy formed by the instantaneous release of high energy (explosion energy) heats and melts the sprayed material, accelerates it and deposits it on the surface of the workpiece to form a c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23C4/08C23C4/12C23C4/126
Inventor 周春根马吉昭刘晓芳
Owner BEIHANG UNIV
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