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r-t-b permanent magnet

A R-T-B, permanent magnet technology, applied in the field of permanent magnets, can solve the problems of difficulty in obtaining high coercive force magnets, low characteristics of Nd-Fe-B magnets, etc., and achieve the effect of reducing magnetic characteristics and high bonding strength

Active Publication Date: 2019-03-26
TDK CORPARATION
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the Br of the Y-T-B magnet disclosed in Patent Document 4 is about 0.5 to 0.6 T, and its HcJ is about 250 to 350 kA / m, which are significantly lower than those of the Nd-Fe-B magnet.
As described above, in the R-T-B system permanent magnet, in the case where Ce or Y is contained as the rare earth element R, it is difficult to obtain a magnet having a high coercive force

Method used

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Experimental program
Comparison scheme
Effect test

Embodiment 1～3、 comparative example 1～3

[0061] In order tetragonal crystal R 2 T 14 In the composition where R of the B structure is Nd and only Ce is substituted (x=0.0~0.7, z=0.0), although the residual magnetic flux density B r and coercive force H cJ gradually decreased, but the bond strength increased. However, while x ≥ 0.6 it is found that the residual magnetic flux density B r and coercive force H cJ Decreases gradually, but the improvement of bond strength saturates. That is, it can be seen that when only Ce is substituted for Nd (z=0.0), the decrease in magnetic properties can be slightly suppressed compared with the conventional Nd-Fe-B-based magnet in the range of 0.04f ) and Ce occupying 4g crystal sites (ie Ce 4g ) the existence ratio Ce 4f / (Ce 4f +Ce 4g ) is 0.86 to 0.91, most of the Ce substituted for Nd selectively occupy the 4f crystal site.

Embodiment 4～6、 comparative example 5～6

[0065] In order tetragonal crystal R 2 T 14 In structure B, in which R is Nd and is half-substituted by Ce and Y (x=0.2-0.7, z=0.5), the bonding strength increases with the increase of the amount x of Ce and Y for Nd. However, the improvement of the bonding strength saturates when x≥0.6. In addition, the residual magnetic flux density B r and coercive force H cJ dropped sharply. That is, it can be seen that in the composition (z=0.5) in which Nd is half-substituted with Ce and Y each, within the range of 0.04f ) and Ce occupying 4g crystal sites (ie Ce 4g ) the existence ratio Ce 4f / (Ce 4f +Ce 4g ) is 0.87-0.88, most of the Ce substituted for Nd selectively occupy the 4f crystal site.

Embodiment 3、 Embodiment 6～8、 comparative example 7～8

[0066] [Example 3, Examples 6-8, Comparative Examples 7-8, Comparative Example 11]

[0067] In order tetragonal crystal R 2 T 14 In structure B, R is Nd, and half of Nd is replaced by Y or Ce or both (x=0.5, z=0.0~1.0), although the residual magnetism increases with the relative amount z of Y relative to Ce Flux density B r and coercive force H cJ gradually increased, but the bond strength decreased.

[0068] In addition, if the relative amount of Y relative to Ce exceeds half (z≥0.6), the adhesive strength will decrease significantly, but the residual magnetic flux density B r and coercive force H cJThe improvement tends to be roughly saturated. That is, it can be seen that within the range of 0.0≤z≤0.5, a permanent magnet having magnetic properties not inferior to conventional Nd-Fe-B-based magnets and higher adhesive strength can be obtained.

[0069] In addition, it can be seen that in the above range, Ce occupying the 4f crystal site (that is, Ce 4f ) and Ce occup...

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Abstract

The invention provides an R-T-B permanent magnet which has the same magnetic properties as the existing Nd-Fe-B permanent magnet and has high bonding strength, and is suitable as an excitation magnet for a permanent magnet synchronous rotating machine. magnet. By the composition of the compound forming the main phase as (R 1‑x (Ce 1‑z Y z ) x ) 2 T 14 B (R is a rare earth element composed of one or more selected from La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and T is Fe or Fe and Co is one or more transition metal elements that are essential elements, 0.0<x≤0.5, 0.0≤z≤0.5), in the case of occupying the tetragonal crystal R 2 T 14 The Ce of the 4f crystal site in the B structure is Ce 4f And the Ce occupying 4g crystal sites is Ce 4g , there exists a ratio Ce 4f / (Ce 4f +Ce 4g ) is 0.8≤Ce 4f / (Ce 4f +Ce 4g )≤1.0, so as to obtain a magnet with the same magnetic properties as the existing Nd-Fe-B permanent magnet and high bonding strength.

Description

technical field [0001] The present invention relates to an R-T-B permanent magnet, in particular to a permanent magnet with high adhesiveness obtained by selectively substituting a part of R in the R-T-B permanent magnet with Ce and Y. Background technique [0002] known as tetragonal R 2 T 14 The R-T-B permanent magnet with B compound as the main phase (R is a rare earth element, T is Fe or a part of it replaced by Co, B is boron) has excellent magnetic properties, which is an invention since 1982 (Patent Document 1: A representative high-performance permanent magnet since Japanese Patent Application Laid-Open No. 59-46008). [0003] The R-T-B system magnet composed of Nd, Pr, Dy, Ho, and Tb as the rare earth element R has a large anisotropic magnetic field Ha, and is preferably used as a permanent magnet material. Among them, the Nd-Fe-B-based magnets in which the rare earth element R is Nd have a good balance of saturation magnetization Is, Curie temperature Tc, and an...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01F1/057
CPCH01F1/0577C22C38/002C22C38/005H01F1/057
Inventor 铃木健一崔京九桥本龙司
Owner TDK CORPARATION