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

Rare earth-iron-boron based magnet and method for production thereof

一种磁铁、稀土的技术，应用在高性能磁铁领域，能够解决磁铁表面层富Nd相受损、磁铁表面部分磁性降低等问题

Inactive Publication Date: 2009-03-18
JAPAN SCI & TECH CORP +1
View PDF12 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] In addition, when sintered magnets are used in actual motors, the final size and coaxiality must be obtained by grinding. At this time, the Nd-rich phase on the surface of the magnet will be damaged due to tiny grinding cracks and oxidation. , the result is that the magnetism of the surface portion of the magnet is reduced to a fraction of that of the interior of the magnet

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
  • Rare earth-iron-boron based magnet and method for production thereof
  • Rare earth-iron-boron based magnet and method for production thereof
  • Rare earth-iron-boron based magnet and method for production thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0071] From Nd 12.5 Fe 78.5 co 1 B 8 The formed alloy ingot is manufactured into an alloy flake with a thickness of about 0.3mm according to the single-roll rapid cooling solidification method. Then, the flakes were filled in a container and released after absorbing 500 kPa of hydrogen at room temperature to obtain an amorphous powder with a size of 0.1 to 0.2 mm, which was then pulverized by a jet mill to produce a fine powder of about 3 μm.

[0072] After adding and mixing 0.05% by mass of calcium stearate to the fine powder, fill it into a mold, extrude it in a magnetic field, fill it into a vacuum furnace, and sinter it at 1080°C for 1 hour, then cut, open holes, Cylindrical grinding and other mechanical processing to manufacture a volume of 11.2mm with an outer diameter of 2.4mm, an inner diameter of 1mm, and a length of 3mm 3 cylindrical magnets. Let this be a comparative example sample (1).

[0073] Next, use Figure 4 In the three-dimensional sputtering apparatu...

Embodiment 2

[0082] Same as Example 1, with Nd 12.5 Fe 78.5 co 1 B 8 The composed alloy is used as the starting material to manufacture a sintered magnet block with a side length of 24mm, which is cut and ground with a grindstone and subjected to electrical discharge machining, thereby manufacturing an outer diameter of 4mm, a thickness of 1mm, and a volume of 12.6mm 3 disc magnet. After mounting the metal targets of Dy and Tb in the three-dimensional sputtering device, the magnet was placed inside the coiled tungsten electrode wire, and the targets were sequentially exchanged to form a film for each metal. The film forming operation is to remove the oxide film on the surface of the magnet by reverse sputtering in the same manner as in Example 1, then apply 60W of RF output and 200W of DC output, and perform normal sputtering for 5 to 50 minutes to form a film of 2 to 18 μm.

[0083] Then, one of the two magnets was packed into an electric furnace in a closed operation box, and heat-tr...

Embodiment 3

[0089] From Nd 12 Dy 0.5 Fe 80 B 7.5 Composition of raw material alloys, disk-shaped magnets having an outer diameter of 4 mm and a thickness of 0.2 mm, 0.4 mm, 1 mm, 2 mm, or 4 mm were produced by the same procedure as in Example 2. Next, put these magnets into a three-dimensional sputtering device, perform reverse sputtering, remove the oxide film on the surface of the magnet, apply 100W of RF output and 120W of DC output, and perform ordinary sputtering for 15 minutes to form 2μm on the surface of the magnet. Dy metal film. Next, the film-formed magnets were loaded into an electric furnace in a sealed operating box, and heat-treated at 800° C. for 30 minutes to obtain samples (16) to (20) of the present invention. In addition, a sintered magnet having an outer diameter of 4 mm and a thickness of 1 mm without sputtering was used as a comparative sample (8).

[0090] The magnetic properties of each sample were measured by a vibrating sample type magnetometer, and the tot...

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 diameteraaaaaaaaaa
diffusion lengthaaaaaaaaaa
particle diameteraaaaaaaaaa
Login to View More

Abstract

[Object] To provide a high-performance rare earth-based magnet exhibiting a high coercive force or a high residual magnetic flux density even when the content of a rare earth element such as Dy or the like which is scarce is reduced. [Construction] A rare earth-iron-boron based magnet includes a crystal grain boundary layer enriched in element M (M is at least one rare earth element selected from Pr, Dy, Tb, and Ho) by diffusion of the element M from the surface of the magnet, wherein the relation between the coercive force H cj and the content of the element M in the whole of the magnet is represented by the following expression: H cj ‰¥ 1 + 0.2 × M (wherein 0.05 ‰¤ M ‰¤ 10) wherein H cj is the coercive force (unit: MA / m), and M is the content of the element M in the whole of the magnet (% by mass). Furthermore, the magnet satisfies the following expression: Br ‰¥ 1.68.- 0.17 × H cj wherein Br is the residual magnetic flux density (unit: T) .

Description

technical field [0001] The present invention relates to a high-performance magnet capable of effectively using rare metals such as Dy in Nd-Fe-B-based or Pr-Fe-B-based rare earth-iron-boron magnets and a method for producing the same. Background technique [0002] It is known that rare earth-iron-boron magnets, especially Nd-Fe-B sintered magnets, are the magnets with the highest performance among permanent magnets, and can be widely used in audio coil motors (VCM) and magnetic resonance imaging (MRI) of hard disk drives. ) of the magnetic circuit, etc. Among the magnets suitable for the above purposes, it is suitable that the magnetic characteristics have a high residual magnetic flux density Br and a high maximum energy product (BH) max Characteristic of the magnet, the coercive force Hcj does not need to be so high. [0003] On the other hand, in recent years, heat resistance is required in electric vehicle applications, and magnets having high coercive force are requir...

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 Patents(China)
IPC IPC(8): H01F1/04H01F1/08H01F1/053H01F1/057H01F41/02
CPCH01F1/0575H01F41/0293H01F41/026H01F1/032H01F1/057H01F1/053
Inventor 町田宪一铃木俊治
Owner JAPAN SCI & TECH CORP
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