Eureka AIR delivers breakthrough ideas for toughest innovation challenges, trusted by R&D personnel around the world.

Preparation method of high-performance sintered Nd-Fe-B magnet with multi-layer grain boundary structure and prepared product

A multi-layer structure, high-performance technology, applied in the direction of magnetic objects, inductor/transformer/magnet manufacturing, magnetic materials, etc., can solve the problems of single grain boundary strengthening effect, failure to realize grain boundary structure, waste of heavy rare earth resources, etc., to achieve The effect of reducing the driving force of electrochemical corrosion, reducing the amount of heavy rare earths, and reducing production costs

Active Publication Date: 2017-05-10
MATERIAL INST OF CHINA ACADEMY OF ENG PHYSICS
View PDF5 Cites 9 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] At present, the grain boundary phase is often used as a whole to study the changes of its melting point, magnetocrystalline anisotropy field, and corrosion potential. It is impossible to achieve fine control of the grain boundary structure, resulting in a single grain boundary strengthening effect and a serious waste of heavy rare earth resources. question

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
  • Preparation method of high-performance sintered Nd-Fe-B magnet with multi-layer grain boundary structure and prepared product
  • Preparation method of high-performance sintered Nd-Fe-B magnet with multi-layer grain boundary structure and prepared product

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] (1) Preparation of NdFeB main phase powder with low rare earth content

[0043] First prepare Nd-Fe-B main phase powder with low rare earth content, the composition is Nd 12.3 Fe bal B 6.1 . NdFeB quick-setting flakes are prepared by smelting and flake rapid cooling. Subsequently, the main phase powder with an average particle size of about 3.8 μm was obtained through hydrogen explosion and jet milling processes.

[0044] (2) Preparation of grain boundary reconstruction alloy

[0045] According to the phase diagram of the alloy and the mixing enthalpy between elements, the alloy composition is designed to reconstruct the grain boundary of heavy rare earth elements with low melting point. It is required that the alloy contains more heavy rare earth elements and has a low melting point, which can be melted and evenly distributed in the main phase grains during heat treatment. around.

[0046] The inventor chooses Dy-Fe binary eutectic point composition Dy 71.5 Fe ...

Embodiment 2

[0051] (1) Preparation of Nd-Fe-B main phase powder with low rare earth content

[0052] First prepare Nd-Fe-B main phase powder with low rare earth content, the composition is Nd 12.3 Fe bal B 6.1 . NdFeB quick-setting flakes are prepared by smelting and flake rapid cooling. Subsequently, the main phase powder with an average particle size of about 3.8 μm was obtained through hydrogen explosion and jet milling processes.

[0053] (2) Preparation of grain boundary reconstruction alloy

[0054] According to the phase diagram of the alloy and the mixing enthalpy between elements, the alloy composition is designed to reconstruct the grain boundary of heavy rare earth elements with low melting point. It is required that the alloy contains more heavy rare earth elements and has a low melting point, which can be melted and evenly distributed in the main phase grains during heat treatment. around.

[0055] The inventor chooses Dy-Fe binary eutectic point composition Tb 71.5 Fe...

Embodiment 3

[0060] (1) Preparation of NdFeB main phase powder with low rare earth content

[0061] First prepare Nd-Fe-B main phase powder with low rare earth content, the composition is Nd 12.3 Fe bal B 6.1 . NdFeB quick-setting flakes are prepared by smelting and flake rapid cooling. Subsequently, the main phase powder with an average particle size of about 3.8 μm was obtained by means of hydrogen explosion and jet milling.

[0062] (2) Preparation of grain boundary reconstruction alloy

[0063] According to the alloy phase diagram and inter-element mixing enthalpy, design the low-melting point heavy rare earth grain boundary to reconstruct the alloy composition. It is required that the alloy contains more heavy rare earth elements and has a low melting point, which can be melted and evenly distributed in the main phase grains during heat treatment. around.

[0064] We chose the Dy-Fe binary eutectic point composition Dy 71.5 Fe 28.5(Atomic percent) As a heavy rare earth grain b...

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

PropertyMeasurementUnit
particle sizeaaaaaaaaaa
melting pointaaaaaaaaaa
particle sizeaaaaaaaaaa
Login to View More

Abstract

The invention discloses a preparation method of a high-performance sintered Nd-Fe-B magnet with a multi-layer grain boundary structure and a prepared product, and aims at solving the problems of a single grain boundary strengthening effect, serious waste of heavy rare-earth resources and the like due to the fact that fine control on the grain boundary structure cannot be achieved in an existing method. According to the multi-layer grain boundary structure of the prepared magnet, a heavy rare-earth thin shell distributed on a grain boundary of a main phase has a relatively high magnetocrystalline anisotropy field, so that magnetic domain inversion of a weak area of the grain boundary in a reverse magnetic field can be inhibited, thereby improving the coercivity and the high-temperature stability of the magnet. Meanwhile, the heavy rare-earth thin shell is only distributed on the grain boundary of the main phase and is rarely diffused to the main phase and a center area of the grain boundary, so that the dosage of heavy rare earth can be greatly reduced and the production cost of the magnet is reduced. In addition, an electrode potential difference between a grain boundary phase and the Nd2Fe14B main phase can be reduced through formation of a high-potential grain boundary center layer in the magnet, the electrochemical corrosion drive force is reduced and the corrosion resistance of the magnet is obviously improved.

Description

technical field [0001] The invention relates to the field of materials, especially the field of permanent magnet materials, and specifically relates to a method for preparing a high-performance sintered Nd-Fe-B magnet with a grain boundary multilayer structure and a product prepared therefrom. Background technique [0002] Nd-Fe-B magnets have excellent magnetic properties and have become the most widely used rare earth functional materials. After more than 30 years of development, sintered Nd-Fe-B magnets have become an indispensable material in social and economic construction and people's daily life, and are widely used in aerospace, generators, electronic computers, automobiles, communications, medical equipment, etc. field. The remanence and maximum energy product of Nd-Fe-B magnets have reached 97% and 93% of the theoretical value respectively, but the coercive force of the magnet is less than half of the theoretical value, and the corrosion resistance of the magnet i...

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
Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/057H01F1/08H01F41/02B22F1/00B22F3/02B22F3/10B22F3/24
CPCH01F1/0576H01F1/0577H01F41/0266B22F3/02B22F3/10B22F3/24B22F2003/248B22F2999/00B22F1/142B22F2202/05
Inventor 张培胡梅娟吴敏张雷张鹏国
Owner MATERIAL INST OF CHINA ACADEMY OF ENG PHYSICS
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
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