Rare earth magnet and production process thereof

一种稀土磁体、磁体的技术,应用在磁体、电感/变压器/磁铁制造、磁性物体等方向,能够解决高矫顽磁力、剩磁降低的程度增大、不利于获得等问题,达到提高矫顽磁力、优异批量生产率的效果

Inactive Publication Date: 2010-02-03
DAIDO STEEL CO LTD
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

Therefore, the size of the crystal grains is 5 μm to 10 μm, which is not conducive to obtaining high coercive force from the point of view of monodomain theory, so this method is fundamentally not preferred
In addition, since most of the element Dy diffuses into the interior of the main grain during high-temperature sintering, there is a defect that the degree of reduction in remanence will increase despite the increase in coercive force

Method used

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  • Rare earth magnet and production process thereof
  • Rare earth magnet and production process thereof
  • Rare earth magnet and production process thereof

Examples

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preparation example Construction

[0090] Other examples of the production method of the R-X-B series alloy powder include a method of melting-casting the R-X-B series alloy having the above predetermined composition to obtain an ingot, storing the ingot at a high temperature of about 800° C. and releasing hydrogen gas, thereby Obtain R-X-B alloy powder. According to this method, an ingot is stored at a high temperature and hydrogen gas is released, thereby pulverizing the ingot to an extent of about several hundreds of micrometers, and at the same time obtaining a powder having a crystal structure of fine recrystallized grains, wherein the recrystallized grains The grain size is several hundred nanometers, and the recrystallized grains are deposited by their azimuthal alignment. The R-X-B-based alloy powder (so-called HDDR powder) thus obtained is a powder having magnetic anisotropy.

[0091] Next, the RH metal and / or RH alloy is prepared. Examples of methods for producing such powders include the above-ment...

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Abstract

The present invention provides a rare earth magnet, which is formed through at least hot molding, the rare earth magnet containing grains including an R 2 X 14 B phase as a main phase, and a grain boundary phase surrounding peripheries of the grains, in which R is at least one element selected from the group consisting of Nd, Pr, Dy, Tb and Ho, and X is Fe or Fe with a part being substituted by Co; in which an element RH is more concentrated in the grain boundary phase than in the grains, in which the element RH is at least one element selected from the group consisting of Dy, Tb and Ho; and the element RH is present with a substantially constant concentration distribution from the surface part of the magnet to the central part of the magnet.

Description

technical field [0001] The present invention relates to a rare earth magnet and its manufacturing method. Background technique [0002] In general, rare earth magnets such as the Nd-Fe-B type are used at room temperature, for example, in voice coil motors (VCMs) in hard disk drives, or in magnetic resonance imaging (MRI) Such rare earth magnets are required to have heat resistance. [0003] In recent years, the application range of this type of rare earth magnet is expanding, for example, it is used in EPS motors of general automobiles, driving motors of hybrid electric vehicles (HEV), or motors for FA (robots or machine tools). As the range of applications expands, rare earth magnets are required to be heat resistant and able to withstand applications in relatively high temperature environments. This trend is especially evident when rare earth magnets are used in automobiles. [0004] The most common way to improve the heat resistance of rare earth magnets is to increase...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/053H01F7/00H01F41/02B22F1/17
CPCC22C38/002H01F41/0266B22F2998/00C22C38/005C22C28/00C22C33/0278B22F2998/10H01F1/0576H01F41/0293C22C2202/02C22C38/10B22F3/12B22F1/025B22F1/17B22F2207/01B22F3/02B22F3/14B22F3/24
Inventor 铃木俊治桥野早人平冈将宏薮见崇生
Owner DAIDO STEEL CO LTD
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