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

Nanometer Zn crystal boundary modified sintered NdFeB magnet with high corrosion resistance and preparation method thereof

A technology of grain boundary modification and high corrosion resistance, applied in the direction of magnetic objects, magnetic materials, inorganic materials, etc., can solve problems such as poor corrosion resistance, and achieve the effects of high magnetic performance, easy operation, and good corrosion resistance.

Inactive Publication Date: 2009-12-30
ZHEJIANG UNIV
View PDF0 Cites 25 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

With the gradual improvement of magnetic properties, the disadvantages of poor corrosion resistance of sintered NdFeB magnets are gradually magnified, which limits the further expansion of its application range.

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

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0018] The preparation method of the highly corrosion-resistant sintered NdFeB magnet modified by the nano-Zn grain boundary comprises the following steps:

[0019] 1) The main phase alloy is made into ingot or quick-setting thin strip by casting process or quick-setting stripping process, and the grain boundary phase alloy is made into quick-quenching strip by quick-quenching process; then coarse crushing is carried out by mechanical crushing or hydrogen explosion crushing respectively After coarse crushing, the main phase alloy powder with an average particle diameter of 2-10 μm and the grain boundary phase alloy powder with an average particle diameter of 1-8 μm are obtained through ball milling or jet milling;

[0020] 2) adding 1%-20% nano-Zn powder and 1%-10% antioxidant to the grain boundary phase alloy powder, and uniformly mixing to obtain nano-Zn modified grain boundary phase alloy powder;

[0021] 3) adding nano-Zn modified grain boundary phase alloy powder with a w...

Embodiment 1

[0026] 1) Prepare the main phase alloy and the grain boundary phase alloy separately. The main phase alloy is prepared by the quick-setting stripping process, the surface speed of the copper roller is 1.6m / s, and the composition is Nd 12.2 Dy 0.2 Fe bal Al 0.4 Zr 0.1 B 5.8 (at%), the grain boundary phase alloy is prepared by rapid quenching process, the rapid quenching speed is 23m / s, and the composition is Nd 20 Dy 2 Fe bal Ga 0.5 Nb 0.5 B 6.5 (at%);

[0027] 2) Powder the main phase alloy and the grain boundary phase alloy respectively. The primary crushing is carried out by the jaw crusher, the secondary crushing is carried out by the secondary crusher, and then the powders with an average particle diameter of 3.6 μm and 2.8 μm are respectively made into powders by means of a jet mill under the protection of nitrogen;

[0028] 3) Adding nano-Zn powder with a weight percentage of 5% and an average particle diameter of 20nm and an antioxidant with a weight ratio o...

Embodiment 2

[0038] 1) Prepare the main phase alloy and the grain boundary phase alloy separately. The main phase alloy is prepared by casting process, and the composition is Nd 13.8 Fe bal B 5.95 (at%), the grain boundary phase alloy is prepared by a rapid quenching process, the rapid quenching speed is 16m / s, and the composition is Nd 17 Dy 3 Tb 0.5 Fe bal Ga 0.1 Cu 0.4 B 6.2 (at%);

[0039] 2) Powder the main phase alloy and the grain boundary phase alloy respectively. Coarse crushing is carried out by hydrogen explosion method, and then powders with average particle diameters of 4.2 μm and 3.5 μm are respectively made by jet milling under the protection of nitrogen;

[0040] 3) adding 20% ​​by weight of nano-Zn powder with an average particle diameter of 40nm and an antioxidant with a weight ratio of 2% to the grain boundary phase alloy powder, and uniformly mixing in a mixer;

[0041] 4) Add the nano-Zn modified grain boundary phase alloy powder to the main phase alloy powd...

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
Average particle diameteraaaaaaaaaa
Average particle diameteraaaaaaaaaa
Login to View More

Abstract

The invention discloses a preparation method of nanometer Zn crystal boundary modified sintered NdFeB magnet with high corrosion resistance, comprising the following steps: 1) main-phase alloy and crystal boundary phase alloy are respectively prepared, wherein, the main-phase alloy adopts casting technology or rapid hardening melt-spun technology to prepare a cast ingot or a rapid hardening thin strip, and the crystal boundary phase alloy adopts rapid quenching technology to prepare a rapid quenching strip; 2) the prepared main-phase alloy and crystal boundary phase alloy are respectively prepared into powder; 3) nanometer Zn powder is mixed with the crystal boundary phase alloy powder to evenly disperse the mixture on the crystal boundary phase alloy powder surface; 4) after nanometer Zn modified crystal phase alloy powder is evenly mixed with the main-phase alloy powder, orientation compression in a magnetic field is prepared into a green body; 5) the green body is sintered in a high vacuum sintering furnace and tempered to prepare the final magnet. The sintered NdFeB magnet prepared by the method of the invention has high performance, favourable corrosion resistance, simple technology and simple operation, and is favourable for batch production on large scale.

Description

technical field [0001] The invention relates to a preparation method of a highly corrosion-resistant sintered NdFeB magnet modified by nano-Zn grain boundaries. Background technique [0002] Sintered NdFeB magnets are a new generation of rare earth permanent magnet materials launched in the early 1980s. They have excellent comprehensive magnetic properties, high cost performance and easy processing. They have been widely used in computers, motors, wind turbines, Electric vehicles, instrumentation, high-fidelity speakers, nuclear magnetic resonance imagers and aerospace navigators and other fields. Because of its high magnetic energy product, it is especially suitable for various replacement products that require miniaturization, light weight, and integration. [0003] Sintered NdFeB magnets are based on Nd 2 Fe 14 The B compound is the matrix, and its magnetic properties are derived from Nd 2 Fe 14 Intrinsic magnetic parameters of B compounds, such as H A 、J s , T c ...

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): H01F1/057H01F1/08B22F9/04B22F3/16
Inventor 严密崔熙贵马天宇罗伟
Owner ZHEJIANG UNIV
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