High-coercivity and high-stability neodymium iron boron magnet and preparation method based on crystal boundary reconstruction

A high-coercivity, high-stability technology, applied in the direction of magnetic objects, inductors/transformers/magnets, magnetic materials, etc., can solve problems that are difficult to control, achieve improved physical and chemical properties, high reactivity, and reduce driving force Effect

Active Publication Date: 2013-05-15
ZHEJIANG UNIV
View PDF3 Cites 57 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Under the traditional process, the Nd-rich grain boundary phase is n

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

[0026] The specific steps of the preparation method of high coercive force and high stability NdFeB magnet based on grain boundary reconstruction are as follows:

[0027] 1) Prepare the main alloy powder with an average particle diameter of 3-10 μm by adopting three processes of rapid solidification casting, hydrogen explosion and jet milling. The main alloy is expressed in atomic percentage, and its composition is (Nd a RE 1-a ) x Fe 100-x-y-z m y B z ;

[0028] 2) The grain boundary phase alloy is made into ingot by casting process or quick-solidified flake by quick-setting casting process or quick-quenched strip by quick-quenching process, and the average particle diameter is prepared by jet mill or mechanical ball milling process. 1~10μm grain boundary phase alloy powder, the grain boundary phase alloy is expressed in atomic percentage, and its composition is R 100-u M' u , R is one or more of Gd, Tb, Dy, Ho, Er;

[0029] 3) Mix the grain boundary phase alloy powde...

Embodiment 1

[0035] 1) The main alloy powder is prepared by three processes of rapid solidification casting, hydrogen explosion and jet milling. The main alloy is expressed in atomic percentage, and its composition is Nd 12.6 Fe 81.3 B 6.1 ;

[0036] 2) The grain boundary phase alloy is made into ingot by casting process, and the grain boundary phase alloy powder is prepared by mechanical ball milling process. The grain boundary phase alloy is expressed in atomic percentage, and its composition is Dy 71.5 Fe 28.5 ;

[0037] 3) Mix the grain boundary phase alloy powder and the added nano oxide CuO powder in the mixer under the protection medium of aviation gasoline to obtain the grain boundary phase alloy powder modified by nano powder, in which the added nano oxide The average particle diameter of CuO powder is about 55nm, accounting for 0.05% of the total powder weight;

[0038] 4) Mix the main alloy powder and the grain boundary phase alloy powder modified by nano-powder in a blende...

Embodiment 2

[0043] 1) The main alloy powder is prepared by three processes of rapid solidification casting, hydrogen explosion and jet milling. The main alloy is expressed in atomic percentage, and its composition is Nd 13.18 Fe 80.81 Al 0.24 Nb 0.07 B 5.70 ;

[0044] 2) The grain boundary phase alloy is made into quick-setting flakes by the quick-setting casting process, and the grain boundary phase alloy powder is prepared by using the mechanical ball milling process. The grain boundary phase alloy is expressed in atomic percentage, and its composition is Dy 32.50 Fe 62.00 Cu 5.50 ;

[0045] 3) Combine the grain boundary phase alloy powder with the added nano-oxide SiO 2 The powder is mixed uniformly in a mixer under the protective medium of petroleum ether to obtain a grain boundary phase alloy powder modified by nano powder, wherein the added nano oxide SiO 2 The average particle diameter of the powder is about 20nm, accounting for 0.001% of the total powder weight;

[0046] ...

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
Diameteraaaaaaaaaa
Average particle diameteraaaaaaaaaa
Login to view more

Abstract

The invention discloses a high-coercivity and high-stability neodymium iron boron magnet and a preparation method based on crystal boundary reconstruction. The preparation method comprises the steps of separating design and preparation of main alloy and crystal boundary phase alloy powder, nano-modification of crystal boundary phase, powder mixing, magnetic field profiling, isostatic pressing, sintering and thermal treatment. According to the high-coercivity and high-stability neodymium iron boron magnet and the preparation method is based on crystal boundary reconstruction and combines with a rich heavy rear earth novel crystal boundary phase and nano-modification technology, namely the rich heavy rare earth novel crystal boundary phase is redesigned and synthesized, in the process of magnetic sintering and tempering, magnetic hardening is achieved through spread of the heavy rare earth element to the boundary layers of the principle phase crystal grain, and thus a high-coercivity magnetic is prepared under the condition that no or less heavy rear earth is added in the principle phase. Meanwhile the distribution of the crystal boundary and the form of the crystal grain boundary are optimized through a nano-modification method, a pinning domain wall restrains counter magnetic field nucleation and crystal grain growth, and thus high coercivity and high stability of the neodymium iron boron is achieved. The high-coercivity and high-stability neodymium iron boron magnet and preparation method based on crystal boundary reconstruction is simple in process, low in cost and suitable for large-scale volume production.

Description

technical field [0001] The invention relates to a NdFeB magnet with high coercive force and high stability based on grain boundary reconstruction and a preparation method. Background technique [0002] Nd-Fe-B has the incomparable advantages of other types of permanent magnet materials such as high magnetic energy product and high cost performance, and is currently the most widely used rare earth permanent magnet material. By 2015, the world demand for NdFeB products will be as high as 200,000 tons. It can be seen that NdFeB materials will still play an important role in the modern information technology industry for a long time in the future. [0003] The main technical indicators to measure the performance of NdFeB permanent magnets include remanence B r , the maximum energy product ( BH ) max ,Coercivity H c and Curie temperature T c . After years of hard work, based on relatively mature alloy composition design theory and preparation process optimization, B r...

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): H01F1/057H01F7/02H01F41/02B22F9/04B22F3/16
Inventor 严密金佳莹马天宇梁丽萍张培
Owner ZHEJIANG UNIV
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
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap