R-Fe-B rare earth sintered magnet and method for producing same

A technology of sintered magnets and manufacturing methods, which is applied in the direction of inductance/transformer/magnet manufacturing, magnetic materials, magnetic objects, etc., can solve the problems of weakening of magnet characteristics, decrease of magnetic composition ratio of magnet forming body, safety ignition, etc., to achieve suppression reduction, Effect of coercive force improvement and HcJ improvement

Active Publication Date: 2008-12-24
HITACHI METALS LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0018] In addition, in the method of Patent Document 4, a large amount of rare earth metals is also deposited on parts other than the magnets inside the device (for example, the inner wall of the vacuum chamber) during the film formation process, so it is not compatible with the resource saving of heavy rare earth elements, which are precious resources. Contradict
[0019] In addition, in the embodiment targeting low-boiling rare earth metals such as Yb, the coercive force of each R-Fe-B system micro-magnet is surely restored, but during the diffusion heat treatment, the R-Fe-B system magnet and the adsorbed metal Fusion, or difficult to separate from each other after treatment, in fact it is difficult to avoid unreacted adsorbed metal (RH) remaining on the surface of the sintered magnet
This not only reduces the ratio of magnetic components in the formed magnet, resulting in weakened magnetic properties, but also tends to oxidize due to the very strong activity of the rare earth metal itself. preferred
In addition, since rotati...

Method used

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  • R-Fe-B rare earth sintered magnet and method for producing same

Examples

Experimental program
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Embodiment approach 1

[0107] [raw material alloy]

[0108] First, an alloy containing 25% by mass to 40% by mass of the light rare earth element RL, 0.6% to 1.6% by mass of B (boron), and the balance Fe and unavoidable impurities is prepared. A part of B may be replaced with C (carbon), and a part of Fe (less than 50 atomic %) may be replaced with other transition metal elements (such as Co or Ni). According to various purposes, the alloy may also contain about 0.01 to 1.0% by mass of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, In, Sn , Hf, Ta, W, Pb and Bi add at least one element M.

[0109] The above-mentioned alloy is suitably produced by rapidly cooling a molten material alloy by, for example, a strip casting method. Next, the production of the rapidly solidified alloy by the strip continuous casting method will be described.

[0110] First, in an argon atmosphere, a raw material alloy having the above composition is melted by high-frequency melting to form a raw material alloy m...

Embodiment approach 2

[0129] In this embodiment, first, a rare earth element containing 25% by mass to 40% by mass is prepared (heavy rare earth element RH is 0.1% by mass to 5.0% by mass, and the rest is light rare earth element RL). , 0.6% by mass to 1.6% by mass of B (boron), and the balance being Fe and unavoidable impurities. A part of B may be substituted with C (carbon), and a part of Fe (less than 50 atomic %) may be substituted with other transition metal elements (such as Co or Ni). According to various purposes, the alloy may also contain about 0.01 to 1.0% by mass of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, In, Sn , Hf, Ta, W, Pb and Bi add at least one element M.

[0130] Thus, in this embodiment, 0.1 mass % or more and 5.0 mass % or less of the heavy rare earth element RH are added to a raw material alloy in advance. That is, after preparing the known R-Fe- After the B-series rare earth sintered magnet is diffused by vapor deposition, the heavy rare earth element RH d...

Embodiment approach 3

[0136] In the manufacturing method of the R-Fe-B based rare earth sintered magnet of the present embodiment, the sintering step of the R-Fe-B based rare earth sintered magnet powder compact and the step of diffusing the heavy rare earth element RH are performed continuously in the same processing chamber. More specifically, first, a molded body of R-Fe-B rare earth magnet powder containing light rare earth element RL (at least one of Nd and Pr) as the main rare earth element R is mixed with heavy rare earth element The step (A) in which volume bodies of the class element RH (at least one selected from Dy, Ho, and Tb) are arranged oppositely in the processing chamber.

[0137] Then, by performing sintering in the processing chamber, fabricating a 2 Fe 14 Step (B) of R-Fe-B-based rare earth sintered magnet with B-type compound crystal grains as the main phase. Then, the step (C) of supplying the heavy rare earth element RH from the volume body to the R-Fe-B system rare earth s...

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Abstract

In a method for producing an R-Fe-B rare earth sintered magnet, there is firstly prepared an R-Fe-B rare earth sintered magnet body which contains, as the main phase, R2Fe14B compound crystal grains containing a light rare earth element RL (at least one of Nd and Pr) as a main rare earth element R, and then a heavy rare earth element RH is diffused into the rare earth sintered magnet body from the surface thereof by heating the sintered magnet body while supplying the heavy rare earth element RH (at least one substance selected from the group consisting of Dy, Ho and Tb) to the surface of the sintered magnet body.

Description

technical field [0001] The present invention relates to having R 2 Fe 14 R-Fe-B series rare earth sintered magnet with B-type compound grains (R is a rare earth element) as the main phase and its manufacturing method, particularly involving light rare earth element RL (at least one of Nd and Pr) as the main phase. R-Fe-B series rare earth sintered magnet in which main rare earth element R and part of light rare earth element RL are replaced by heavy rare earth element RH (at least one selected from Dy, Ho, and Tb) and its manufacturing method . Background technique [0002] Take Nd 2 Fe 14 R-Fe-B rare earth sintered magnets with B-type compounds as the main phase are known to have the highest performance among permanent magnets, and are used in voice coil motors (VCM) for hard disk drives and electric motors for hybrid vehicles, etc. All kinds of motors and home appliances, etc. When R-Fe-B based rare earth sintered magnets are used in various devices such as motors, e...

Claims

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Application Information

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IPC IPC(8): H01F41/02H01F1/053H01F1/08B22F3/24C22C38/00
CPCH01F41/0293
Inventor 吉村公志森本英幸小高智织
Owner HITACHI METALS LTD
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