Check patentability & draft patents in minutes with Patsnap Eureka AI!

A kind of sintering method of NdFeB magnet

A sintering method, NdFeB technology, applied in the manufacture of magnetic objects, magnetic materials, inductors/transformers/magnets, etc., can solve the problems of limited effect and high micro-cracks, reduce escape velocity, good magnetic properties, and increase pre-heating. The effect of the sintering process

Active Publication Date: 2016-12-21
SANVAC BEIJING MAGNETICS +1
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Filling a certain amount of inert gas can suppress the speed of hydrogen escape, which can reduce the probability of cracks for small-sized blanks, but it has limited effect on large blanks pressed by magnetic powder with high hydrogen content, which occurs during sintering. The proportion of microcracks is still high

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
  • A kind of sintering method of NdFeB magnet

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Example 1: After the hydrogen explosion process, the medium-sized powder with a hydrogen content of 2000-2100 ppm is measured, and after jet milling, 30 square magnets with a weight of 800 g are pressed, and the blanks are stacked in a closed sintering box with a sealed cover , put the material box into the vacuum sintering furnace, and wait until the sintering furnace is vacuumed to 10 -1 After Pa, start to heat up to the first-stage degassing temperature of 300°C, and control the heating rate at 5°C / min. After reaching the degassing temperature of the first stage, keep it warm for 1.5h, then continue to heat up to the degassing temperature of the second stage at 700°C, and control the heating rate at 5°C / min. When the temperature reaches the degassing temperature of the second stage, charge a certain amount Argon gas with a purity of more than 99.9% forms a pressure of 1000Pa in the furnace, heats it for 3 hours, vacuumizes after the heat preservation is over, and con...

Embodiment 2

[0025] Example 2: After the hydrogen explosion process, the medium-sized powder with a hydrogen content of 2000-2100 ppm is measured, and after jet milling, 30 square magnets with a weight of 1000 g are pressed, and the blanks are stacked in a sealed sintering box with a sealed cover , put the material box into the vacuum sintering furnace, and wait until the sintering furnace is vacuumed to 10 -1After Pa, start to heat up to the first-stage degassing temperature of 400°C, and the temperature rise rate is controlled at 3°C / min. After reaching the degassing temperature of the first stage, keep it warm for 1.0h, then continue to heat up to the degassing temperature of the second stage at 800°C, and control the heating rate at 3°C / min. When the temperature reaches the degassing temperature of the second stage, charge a certain amount The argon gas with a purity of more than 99.9% forms a pressure of 2500Pa in the furnace and holds it for 4.5 hours. After the heat preservation is ...

Embodiment 3

[0027] Example 3: After the hydrogen explosion process, the medium-sized powder with a hydrogen content of 2000-2100 ppm is measured, and after jet milling, 30 square magnets with a weight of 1500 g are pressed, and the blanks are stacked in a sealed sintering box with a sealed cover , put the material box into the vacuum sintering furnace, and wait until the sintering furnace is vacuumed to 10 -1 After Pa, start to heat up to the first-stage degassing temperature of 450°C, and the temperature rise rate is controlled at 7°C / min. After reaching the degassing temperature of the first stage, keep it warm for 1.5 hours, then continue to heat up to the degassing temperature of the second stage at 1000°C, and control the heating rate at 7°C / min. When the temperature reaches the degassing temperature of the second stage, charge a certain amount Argon gas with a purity of more than 99.9% forms a pressure of 1500Pa in the furnace, heats it for 5 hours, vacuumizes after the heat preserv...

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

A sintering method of an NdFeB magnet, which includes a material coding process, a first-stage degassing, a second-stage degassing, a sintering process, and a tempering process, and is characterized in that: the method is performed in the second-stage degassing and sintering process A pre-sintering process is also included in between. Since the sintering method of the present invention adopts the closed sintering material box, increases the pre-sintering process, reduces the heating and cooling speed, controls the degassing temperature and other means, reduces the escape speed of hydrogen gas, so that the NdFeB magnetic powder prepared with high hydrogen content The proportion of microcracks in large blanks is greatly reduced, the pass rate of blanks is improved, and the magnetic properties are good.

Description

technical field [0001] The invention relates to a permanent magnet sintering method, in particular to a sintering method of a rare earth permanent magnet material NdFeB magnet. Background technique [0002] As a third-generation rare earth permanent magnet material with excellent comprehensive performance, NdFeB magnets have received considerable attention since their inception. In the course of more than ten years of development, a variety of production processes have been developed successively, and the performance of the magnet has been continuously improved. Using the latest strip casting (Strip Casting) hydrogenation explosion process, supplemented by other means (pulverizing particle size control, molding additives, etc.) can produce high-performance magnets. In addition, the hydrogen explosion process plays an important role in improving the efficiency of powder making and preventing the oxidation of magnetic powder, and has been widely used in the preparation of NdF...

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): C22C1/04C22C38/00B22F3/10H01F1/057H01F41/02
Inventor 王浩颉张瑾赵玉刚刘长庆裴仁鹏
Owner SANVAC BEIJING MAGNETICS
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

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

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com