Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for simultaneously improving coercive force and corrosion resistance of sintered NdFeB

A technology of coercive force and corrosion resistance, which is applied in the field of surface engineering of sintered NdFeB magnetic materials, can solve the problem that the coercive force and corrosion resistance of sintered NdFeB cannot be improved at the same time, so as to improve corrosion resistance, avoid failure, Effect of improving coercive force and corrosion resistance

Active Publication Date: 2021-04-20
INST OF MECHANICS - CHINESE ACAD OF SCI
View PDF8 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method uses magnetron sputtering to prepare a new type of multilayer coating on the surface of sintered NdFeB magnetic materials. The multilayer coating composed of three kinds of coatings can solve the problem of coercive force and corrosion resistance of sintered NdFeB after vacuum heat treatment. The problem of not being able to improve at the same time

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for simultaneously improving coercive force and corrosion resistance of sintered NdFeB
  • Method for simultaneously improving coercive force and corrosion resistance of sintered NdFeB
  • Method for simultaneously improving coercive force and corrosion resistance of sintered NdFeB

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] A method for simultaneously improving the coercivity and corrosion resistance of sintered NdFeB, comprising the following steps:

[0048] (1) pre-coating treatment;

[0049] (2) Glow plasma cleaning;

[0050] (3) grain boundary diffusion layer - heavy rare earth coating deposition;

[0051] (4) Barrier layer - high entropy alloy nitride coating deposition;

[0052] (5) Corrosion-resistant layer - high-entropy alloy coating deposition;

[0053] (6) Vacuum heat treatment;

[0054] (7) Wait for the sample to cool down to room temperature.

[0055] The method uses magnetron sputtering to prepare a new type of multilayer coating on the surface of sintered NdFeB magnetic materials, such as figure 1 As shown, the overall structure of the prepared multilayer coating is as follows figure 1 As shown, the bottom layer: use heavy rare earth coating (Dy or Tb or its alloy) as grain boundary diffusion coating; outermost layer: use high entropy alloy coating (AlCrTiVZr) as corro...

Embodiment 2

[0057] In this embodiment, a sintered NdFeB magnet with a size of 25mm*25mm*3mm and a grade of 52N is selected. Dy coating, (AlCrTiVZr)N coating and AlCrTiVZr coating were deposited on the surface sequentially by magnetron sputtering technology, followed by vacuum heat treatment. The specific process is as follows:

[0058] (1) Pre-coating treatment. The sintered NdFeB magnetic material is derusted, polished and ultrasonically cleaned in sequence, and then dried;

[0059] (2) Glow plasma cleaning. Fix the NdFeB magnetic material on the workpiece frame of the vacuum chamber and vacuumize the cavity to 5×10 -3 Pa; Introduce Ar into the vacuum cavity and adjust the flow rate so that the vacuum chamber pressure is 1.5Pa; load the negative bias voltage on the workpiece holder, and set the predetermined voltage value, frequency and duty cycle. The specific parameters are: voltage value -600V, frequency 40Khz, duty cycle 90%, glow cleaning time 10min;

[0060] (3) Heavy rare ear...

Embodiment 3

[0071] In this embodiment, the substrate is exactly the same as that in Embodiment 2, and the Dy coating, (AlCrTiVZr)N coating, and AlCrTiVZr coating are sequentially deposited on its surface by magnetron sputtering technology, followed by vacuum heat treatment. The specific process is as follows:

[0072] (1) complete the same as step 1 in embodiment 2;

[0073] (2) exactly the same as step 2 in embodiment 2;

[0074] (3) Heavy rare earth coating deposition. After glow plasma cleaning, adjust the Ar flow rate so that the vacuum chamber pressure is 0.5 Pa, and turn the workpiece until the magnetic material faces the Dy target. Turn on the magnetron sputtering power supply, and sputter the heavy rare earth Dy target. The setting parameters of the magnetron sputtering power supply are: sputtering current 1A, frequency 40Khz, duty cycle 50%. The specific parameters of its negative bias voltage: voltage value -700V, frequency 40Khz, duty cycle 90%. The temperature parameter o...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention belongs to the field of sintered NdFeB magnetic material surface engineering, and discloses a method for simultaneously improving coercive force and corrosion resistance of sintered NdFeB. The method specifically comprises the following steps of: (1) conducting coating pretreatment; (2) cleaning a glow plasma; (3) depositing a grain boundary diffusion layer-heavy rare earth coating; (4) depositing a barrier layer-high-entropy alloy nitride coating; (5) depositing a corrosion-resistant layer-high-entropy alloy coating; (6) conducting vacuum heat treatment; and (7) after a sample is cooled to room temperature, taking out the sample to finish the treatment of the sintered NdFeB magnetic material. According to the method, a novel multi-layer coating is prepared on the surface of the sintered NdFeB magnetic material through magnetron sputtering, wherein in the bottommost layer, a heavy rare earth coating is adopted as a grain boundary diffusion coating; in the outermost layer, a high-entropy alloy coating is adopted as a corrosion-resistant coating; and in the middle layer, a high-entropy alloy nitride coating is adopted as a barrier coating. After the multi-layer coating composed of the three coatings is subjected to vacuum heat treatment, the problem that the coercive force and the corrosion resistance of sintered NdFeB cannot be improved at the same time can be solved.

Description

technical field [0001] The invention belongs to the field of surface engineering of sintered NdFeB magnetic materials, and in particular relates to a method for simultaneously improving the coercive force and corrosion resistance of sintered NdFeB magnets. Background technique [0002] As the third generation of rare earth permanent magnet materials, sintered neodymium iron boron (NdFeB) magnetic materials are widely used in electronic communications, transportation energy, computers and other fields. In particular, the development trend of global new energy electric vehicles replacing traditional fuel vehicles has greatly promoted the demand for NdFeB magnets for rare earth permanent magnet motors. However, the application of NdFeB magnets in rare earth permanent magnet motors still faces two urgent problems: corrosion and thermal stability. First, the sintered NdFeB magnetic material has a multi-phase structure, and the active neodymium phase is prone to corrosion, and th...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C23C14/16C23C14/06C23C14/18C23C14/35C23C14/58C23C10/08H01F41/02
Inventor 夏原许亿李光
Owner INST OF MECHANICS - CHINESE ACAD OF SCI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com