JP2002299110A - Method of manufacturing rare-earth element permanent magnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which a rare-earth element permanent magnet, that is superior in both coercive force and residual magnetic flux density can be manufactured. SOLUTION: After a mixture of alloy X powder, composed mainly of R<1> 2 T14 B (where R<1> , T, and B respectively denote one or more kinds of rare earth elements including Y (Dy is indispensable), one or more kinds of transition metal elements, and boron) and alloy Y powder, composed mainly of R<2> T (where R<2> and T respectively denote one or more kinds of heavy rare-earth elements and one or more kinds of transition metal elements) is obtained, the mixed powder is sintered. The magnetic characteristics of the rare-earth permanent magnet can be improved, by adjusting the Dy ratio which is the ratio of the content of the heavy rare-earth elements in the alloy X powder to that of the heavy rare-earth elements in the sintered magnet composition to be 0.38-0.99 and R ratio, which is the ratio of the content of the rare-earth elements in the alloy X powder to that of the rare-earth elements, in the sintered magnet composition to be 0.94-1.03.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rare earth permanent magnet having excellent magnetic properties and containing a rare earth element R, a transition metal element T, and boron B as main components.

[0002]

2. Description of the Related Art Among rare earth magnets, the demand for Nd-Fe-B magnets has been increasing year by year because of its excellent magnetic properties, Nd as a main component is abundant in resources and relatively inexpensive. are doing. Research and development for improving the magnetic properties of Nd-Fe-B-based magnets have also been vigorously conducted. In recent years, when manufacturing high-performance Nd-Fe-B-based magnets,
A mixing method of mixing and sintering various metal powders and alloy powders having different compositions has become mainstream.

[0003] Incidentally, the Nd-Fe-B magnet has a problem that the coercive force decreases as the temperature rises because the Curie temperature is low. To solve this problem,
Various attempts have been made. For example, Japanese Patent Publication 5-108
No. 06 proposes increasing the coercive force of an Nd—Fe—B magnet by adding a heavy rare earth element such as Dy or Tb. However, when heavy rare earth elements such as Dy and Tb are added, there arises a problem that the coercive force is improved while the residual magnetic flux density is reduced. JP-A-6-2
No. 83318 and JP-A-7-50205 disclose R ₂ T ₁₄ B-based intermetallic compounds (R is one or more rare earth elements including Y, and T is one or more transition metal elements) ), A method for producing an RTB-based rare earth permanent magnet using a mixing method in which a main phase mainly composed of an R-rich phase is used as a main component phase.
It has been proposed to improve the properties of the magnet by appropriately changing the amount of the system alloy powder. However, JP-A-6-283318 and JP-A-7-5020 disclose
Although the method described in Japanese Patent Application Laid-Open No. 5-205400 is effective in improving the residual magnetic flux density, it has a problem in that the coercive force is reduced.

[0004]

The problem to be solved by the present invention is disclosed in Japanese Patent Application Laid-Open No. 7-57.
No. 913 discloses that an R-T-based alloy powder having an R ₂ T ₁₄ B-based intermetallic compound having an area ratio of 95% or more includes an R-T-based alloy having an R eutectic area ratio of 10% or less. 8-15 powder
It is proposed to add in the range of wt%. JP 7
According to the manufacturing method described in JP-A-57913, a high coercive force can be obtained while suppressing a decrease in residual magnetic flux density. However, there is a need for a method of manufacturing a rare earth permanent magnet having a higher residual magnetic flux density. Therefore, an object of the present invention is to provide a method for manufacturing a rare earth permanent magnet having both excellent coercive force and residual magnetic flux density.

[0005]

Means for Solving the Problems The present inventor has made various studies to obtain higher magnetic characteristics in a method of manufacturing a rare earth permanent magnet using a mixing method. As a result, R-
By changing the ratio of the content of the heavy rare earth element in the TB alloy powder to the content of the heavy rare earth element in the magnet composition after sintering (hereinafter referred to as “Dy ratio” as appropriate), the residual magnetic flux density Br is reduced. It has been found that it can be improved. As another parameter, a ratio of the content of the rare earth element in the RTB-based alloy powder to the content of the rare earth element in the magnet composition after sintering (hereinafter referred to as “R
Ratio. " It has been found that by using (), excellent values can be obtained for both the coercive force Hcj and the residual magnetic flux density Br. Accordingly, the present invention, R ¹ ₂ T ₁₄ B
_{^{(R 1 2 T 14 B:}} R 1 = Y 1 , or two or more rare earth elements including (Dy mandatory), T = transition metal element one or more of, B = boron) as a main component X alloy powder,
A step of obtaining a mixed powder with a Y alloy powder mainly composed of R ² T (R ² T: R ² = one or more heavy rare earth elements, T = one or more transition metal elements); And sintering the mixed powder, wherein Dy is a ratio of the content of the heavy rare earth element in the X alloy powder to the content of the heavy rare earth element in the magnet composition after sintering. The ratio is 0.38 to 0.99, and the R ratio, which is the ratio of the content of the rare earth element in the X alloy powder to the content of the rare earth element in the magnet composition after sintering, is 0.94.
The present invention provides a method for producing a rare earth permanent magnet, wherein As the Dy ratio decreases, the residual magnetic flux density Br tends to increase. However, when the Dy ratio is less than 0.38, the coercive force Hcj decreases. When the Dy ratio exceeds 0.99, a high coercive force Hcj can be obtained, but on the other hand, the residual magnetic flux density Br decreases. In particular, the Dy ratio is 0.6 to 0.8, and the R ratio is 0.94 to 0.8.
When it is set to 99, a rare earth permanent magnet having excellent magnetic properties can be obtained.

In the method for producing a rare earth permanent magnet according to the present invention, the Y alloy powder is an R ² TM alloy, and M is Al,
One or two of Cu, Sn, Ga, Bi and In
More than one species can be selected. In particular, when Ga is selected as M, it is effective in improving the magnetic characteristics of the rare earth permanent magnet. Since Dy has a large anisotropic magnetic field and is effective in improving the coercive force Hcj, the present invention requires that the X alloy powder contain Dy.
In particular, when the magnet after sintering contains 1 to 13 wt% of Dy, a high residual magnetic flux density Br can be obtained. According to the method for manufacturing a rare earth permanent magnet of the present invention, a rare earth permanent magnet having a residual magnetic flux density Br of 1.22 T or more can be obtained. Furthermore, the present inventor has found that the residual magnetic flux density Br increases as the sintering temperature increases. That is,
According to the method for manufacturing a rare earth permanent magnet of the present invention, 1050
By sintering in a temperature range of 1130 ° C., a rare earth permanent magnet having a coercive force Hcj of 1900 kA / m or more and a residual magnetic flux density Br of 1.22 T or more can be obtained.

Although the present invention proposes setting both the R ratio and the Dy ratio to predetermined values, it is effective to use the R ratio or the Dy ratio alone. Therefore, the present invention relates to R
_{^{1 2 T 14 B (R 1}} 2 T 14 B: 1 of rare earth elements including R ¹ = Y
X alloy powder mainly composed of one or more kinds (Dy is essential), T = one or more kinds of transition metal elements, B = boron), and R ² T (R ² T: R ² = heavy rare earth) One or more elements, T = one or more transition metal elements)
A process of obtaining a mixed powder with a Y alloy powder mainly comprising: and a step of sintering the mixed powder, wherein the content of the rare earth element in the X alloy powder and the sintered A method for producing a rare earth permanent magnet, wherein the R ratio, which is the ratio of the content of the rare earth element in the magnet composition, is 0.94 to 0.99. Furthermore, the present _{^{invention, R 1 2 T 14 B (}} R 1 2 T 14 B: 1 or more kinds of rare earth elements including R ¹ = Y (Dy mandatory), T
= Transition metal element one or more, and X alloy powder B = boron) and ^{mainly, R 2 T (R 2 T} : R 2 = 1 , two or more of heavy rare earth elements, T = transition A method for producing a rare earth permanent magnet including a step of obtaining a mixed powder with a Y alloy powder mainly composed of one or more metal elements) and a step of sintering the mixed powder. The Dy ratio, which is the ratio of the rare earth element content to the rare earth element content in the magnet composition after sintering, is 0.65 to 0.99.
A method for producing a rare earth permanent magnet is provided.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
Will be explained. The present invention relates to R¹ _TwoT₁₄X alloy mainly composed of B
Powder and R^TwoMixing with Y alloy powder mainly composed of T,
This is a method of manufacturing rare earth permanent magnets using a so-called mixing method.
You. The method for producing a rare-earth permanent magnet according to the present invention comprises:¹ _TwoT
₁₄B (R¹ _TwoT₁₄B: R¹= One kind of rare earth element containing Y
Or two or more (Dy is essential), T = one of transition metal elements
Or two or more kinds, X = B alloy)
And R^TwoT (R^TwoT: R ^Two= One or two heavy rare earth elements
Or more, T = one or more of transition metal elements)
A step of obtaining a mixed powder with a Y alloy powder to be
Sintering the combined powder. The details will be described below.

First, an X alloy and a Y alloy are obtained by blending, melting and solidifying a metal and / or an alloy as raw materials. X alloy powder mainly consists of R ¹ ₂ T ₁₄ B compound phase. Here, R ¹ is a rare earth element containing Y (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb,
Dy, Ho, Er, Yb and Lu), and it is essential to contain Dy. Since Dy has a large anisotropic magnetic field, it is effective in improving the coercive force Hcj. As the transition metal T, Fe, Co, and Ni conventionally used can be used. Among these, Fe and Co are desirable from the viewpoint of sintering properties, and it is particularly desirable to mainly use Fe from the viewpoint of magnetic properties. The Y alloy powder contains R ² and T as main components. Where R ² is
It is one or more of heavy rare earth elements, and particularly preferably contains Dy. In this specification, “R ² T” does not mean that R ² and T are 1: 1 but means that it is an alloy containing R ² and T as main components. Also, “R ² TM” described below does not mean that R ² , T, and M are 1: 1: 1.
It means that the alloy is mainly composed of R ² , T and M. In the present invention, heavy rare earth elements are Gd, T
b, Dy, Ho, Er, Tm, Yb, Lu, Y.
The X alloy powder contains boron B, whereas the Y alloy powder does not contain boron B. Since Y alloy powder need not include essentially boron B configured to work as a grain boundary phase surrounding the R ¹ ₂ T ₁₄ B phase as a main phase after sintering, and Y alloy powder boron B This is because the sinterability is improved by not adding it.

In the present invention, the composition may be selected according to the purpose. However, in order to obtain a rare earth permanent magnet having excellent magnetic properties, a light rare earth element: 17
To 37% by weight, heavy rare earth element: 1 to 13% by weight, boron B: 0.5 to 4.5% by weight, transition metal element T: 51 to 74%
It is desirable that the composition be such that the weight% is obtained. More preferably, the light rare earth element is 20 to 30% by weight, the heavy rare earth element is 3 to 10% by weight, the boron B is 0.9 to 1.2% by weight, and the transition metal element T is 60 to 74% by weight. In addition, when M is added to form R ² TM, the magnet composition after sintering should have M in the range of 0.03 to 1% by weight, more preferably 0.1 to 0.7% by weight. Good. As M, one or more of Al, Cu, Sn, Ga, Bi, and In can be selected. Of these, Ga is particularly preferred. When Ga is selected as M, high coercive force HcJ and residual magnetic flux density Br can be obtained, and sinterability tends to be improved.
The magnetic properties of rare earth permanent magnets are very composition dependent,
In a region outside the above range, it is difficult to obtain excellent magnetic properties even when the present invention is applied.

An X alloy and a Y alloy are obtained by melting and casting a raw metal in a vacuum or an inert gas, preferably an Ar atmosphere. As a raw material metal, a pure rare earth element or a rare earth alloy, pure iron, ferroboron, or an alloy thereof can be used. If there is solidification segregation, the obtained ingot is subjected to a solution treatment if necessary. The conditions are vacuum or Ar atmosphere, 700 to
What is necessary is just to hold at 1500 degreeC area | region for 1 hour or more. There are roughly two methods for obtaining a mixed powder of the X alloy powder and the Y alloy powder. As a first method, there is a method in which the ingot of the X alloy and the ingot of the Y alloy are individually pulverized to obtain an X alloy powder and a Y alloy powder, and then the both are mixed.
As a second method, the ingot of the X alloy and the ingot of the Y alloy are
There is a method in which both alloys are pulverized and mixed while being put in one pulverizer. In the present specification, the following description is given assuming that the first method is used.

The pulverizing step includes a coarse pulverizing step and a fine pulverizing step. First, the ingot of the X alloy and the ingot of the Y alloy are coarsely pulverized to a particle size of about several hundred μm. Coarse grinding is
It is desirable to use a stamp mill, jaw crusher, brown mill or the like in an inert gas atmosphere. In order to improve the coarse pulverizability, it is effective to perform the coarse pulverization after absorbing hydrogen. After the coarse grinding step, the process proceeds to the fine grinding step. The fine pulverization is mainly performed using a jet mill, and the coarse pulverized powder having a particle size of about several hundred μm is performed until the average particle size becomes 3 to 5 μm. The jet mill releases a high-pressure inert gas (for example, nitrogen gas) from a narrow nozzle to generate a high-speed gas flow, accelerates the powder particles by the high-speed gas flow, and collides the powder particles. This is a method of crushing by generating collision with a target or a container wall.

In the fine pulverizing step, the X alloy powder and the Y alloy powder each finely pulverized are mixed in a nitrogen atmosphere. The mixing ratio between the X alloy powder and the Y alloy powder may be about 90:10 to 97: 3 by weight. When pulverizing,
By adding about 0.01 to 0.3 wt% of an additive such as zinc stearate, fine powder having a high degree of orientation can be obtained. Next, a mixed powder composed of the X alloy powder and the Y alloy powder is filled in a mold held by an electromagnet, and is molded in a magnetic field with its crystal axis oriented by applying a magnetic field. This molding in a magnetic field may be performed in a magnetic field of 110 to 130 kA / m at a pressure of about 130 to 160 Mpa.

After compacting in a magnetic field, the compact is sintered in a vacuum or inert gas atmosphere. The sintering temperature needs to be adjusted according to various conditions such as the composition, the pulverization method, the difference between the particle size and the particle size distribution, and the sintering may be performed at 1,050 to 1,130 ° C for about 1 to 5 hours. After sintering, the obtained sintered body can be subjected to an aging treatment. This step is an important step for controlling the coercive force Hcj. When the aging treatment is performed in two stages, heat treatment at around 800 ° C. and around 600 ° C. is effective. If the heat treatment at around 800 ° C. is performed after sintering, the coercive force Hcj increases, which is particularly effective in the mixing method. In addition, since the coercive force Hcj is greatly increased by the heat treatment near 600 ° C., when the aging treatment is performed in one step,
It is preferable to perform aging treatment at around 00 ° C.

[0015]

Next, the present invention will be described in more detail with reference to specific examples. (Example 1) An X alloy and a Y alloy were adjusted by high frequency melting of a raw material metal in an Ar atmosphere, and the X alloy and the Y alloy were pulverized under the following conditions. The particle size after pulverization is 3-5 μm. The obtained fine powder was mixed in a nitrogen atmosphere, and molding and sintering in a magnetic field were performed under the following conditions.
Next, a two-stage aging treatment was performed under the following conditions, and Sample No. 1 was obtained.
And Comparative Examples 1 to 4 were obtained. Composition of X alloy powder and Y alloy powder, mixing ratio of X alloy powder and Y alloy powder,
The composition of the magnet after sintering is as shown in Table 1. In addition,
In Table 1, "Dy ratio" refers to the ratio of the content of heavy rare earth elements in the X alloy powder to the content of heavy rare earth elements in the magnet composition after sintering. In Table 1, “R ratio” means X
The ratio of the rare earth element content in the alloy powder to the rare earth element content in the magnet composition after sintering. Sample No.
With respect to Examples 1 to 4 and Comparative Examples 1 to 4, the coercive force Hcj and the residual magnetic flux density Br were measured using a BH tracer. Table 1 shows the results. Further, regarding the relationship between the Dy ratio and the residual magnetic flux density Br of Sample Nos. 1 to 3 and Comparative Examples 1 and 2,
As shown in FIG. Coarse pulverization: Use of a brown mill (After occlusion of hydrogen, performed in a nitrogen atmosphere.) Fine pulverization: Use of a jet mill (Performed in a high-pressure nitrogen gas atmosphere.) Sintering conditions: Sample Nos. 1, 3, 4 = 1070 ° C × 4 hours Sample No. 2 = 1110 ° C × 4 hours Comparative Examples 1, 3, 4 = 1110 ° C × 4 hours Comparative Example 2 = 1070 ° C × 4 hours Molding conditions in a magnetic field: 147 Mp in a magnetic field of 120 kA / m
Molding at pressure a Two-stage aging treatment: 850 ° C x 1 hour, 540 ° C x 1 hour

[0016]

[Table 1]

As shown in Table 1, the comparison between Sample No. 2 (Dy amount 6.207) and Comparative Example 1 (Dy amount 6.18) in which the magnets after sintering had almost the same Dy amount showed that Sample No. .
No. 2 has a coercive force Hcj of 1984 kA / m and a residual magnetic flux density B
r is 1.227T, which is a good value. In Comparative Example 1, the coercive force Hcj is 1740 kA / m,
The residual magnetic flux density Br is 1.2T, and especially the coercive force Hcj is a low value. Next, the sample N having almost the same Dy amount was used.
o.3 (Dy amount 7.030) and Comparative Example 2 (Dy amount 7.04)
4), sample No. 3 has a coercive force Hcj of 2
086 kA / m and a residual magnetic flux density Br of 1.21 T, both showing good values, whereas in Comparative Example 2, the coercive force Hcj was 2101 kA / m and the residual magnetic flux density Br was 1.0.
15T, the residual magnetic flux density Br decreases. Here, the Dy ratio of Comparative Example 1 is 0.324, and the Dy ratio of Comparative Example 2 is 1.022. Next, Sample No. 1 (Dy amount 4.6)
65) and Comparative Example 1 (Dy amount 6.18),
The coercive force Hcj of Comparative Example 1 was 1740 kA / m, whereas the sample No. 1 obtained a good coercive force Hcj of 1843 kA / m despite the Dy amount being much smaller than that of Comparative Example 1. I have. The residual magnetic flux density Br of Comparative Example 1 was 1.2 T, whereas the residual magnetic flux density Br of Sample No. 1 was 1.29 T, and the residual magnetic flux density Br of Comparative Example 1 was 1.2 T.
Greatly exceeds. That is, the sample No. 1 having the Dy ratio of 0.517 has a higher coercive force Hcj and the residual magnetic flux density Br than the comparative example 1 having the Dy ratio of 0.324. Therefore, the Dy ratio affects the residual magnetic flux density Br and the coercive force Hcj, and when the Dy ratio is out of the predetermined range, the residual magnetic flux density Br or the coercive force Hcj.
Can be said to decrease. From the above results, the Dy ratio was 0.3.
It has been found that by setting the ratio to 8 to 0.99, a good coercive force Hcj and a residual magnetic flux density Br can be obtained. Specifically, Sample Nos. 1 to 4 having a Dy ratio in the range of 0.38 to 0.9 each have a coercive force Hcj of 1800 kA / m or more and a residual magnetic flux density Br of 1.21 T or more.
Have gained.

Next, attention is paid to the column of R ratio in Table 1. Comparing Sample No. 2 and Comparative Examples 1 and 4 in which the Dy amount in the magnet after sintering is almost equal, when the R ratio is 0.888 (Comparative Example 1), the residual magnetic flux density Br is 1.2T. However, the coercive force Hcj shows a low value of 1740 kA / m. When the R ratio is 1.051 (Comparative Example 4), the coercive force Hcj shows a high value of 1930 kA / m, while the residual magnetic flux density Br is 1.16.
It shows a low value of 9T. In contrast, the R ratio is 0.9.
When it is 71 (sample No. 2), it is 1800 kA / m
The coercive force Hcj and the residual magnetic flux density Br of not less than 1.21 T are obtained.
It is noted that both r show good values. Sample No. 4 (Dy amount of 3.2) having an R ratio of 0.979
70) and Comparative Example 3 having an R ratio of 1.052 (Dy amount of 3.0)
00), sample N having an R ratio of 0.979
No. 0.4 shows better coercive force Hcj and residual magnetic flux density Br than Comparative Example 3 in which the R ratio is 1.052. Therefore, good coercive force Hcj and residual magnetic flux density B
In order to obtain r, the R ratio is also a parameter. From the above results, it was found that by setting the R ratio to 0.94 to 1.03, and more preferably 0.94 to 0.99, good coercive force Hcj and residual magnetic flux density Br can be obtained. In the present invention, the X alloy powder is Dy
It is an essential requirement that Dy be contained, but a desirable amount of Dy is that the magnet composition after sintering contains Dy in an amount of about 1 to 13 wt%, and more preferably about 3 to 10 wt%.

(Example 2) An experiment conducted to confirm a change in magnetic characteristics due to a change in sintering temperature will be described as Example 2. The X alloy powder and the Y alloy powder were adjusted under the same conditions as in Example 1, and pulverized, mixed, and molded in a magnetic field. The molded body after molding in a magnetic field is 1070 ° C, 1090 ° C,
After sintering at 1110 ° C. for 4 hours each, a two-stage aging treatment was performed under the same conditions as in Example 1 to obtain Sample Nos. 5 to 13 and Comparative Examples 5 to 7. The composition of the X alloy powder and the Y alloy powder, the mixing ratio of the X alloy powder and the Y alloy powder, and the composition of the magnet after sintering are as shown in Table 2. Here, samples Nos. 5 to 7 have a Dy ratio of 0.396 and an R ratio of 0.971, samples Nos. 8 to 10 have a Dy ratio of 0.641, an R ratio of 0.973, and samples Nos. 11 to 13 have a Dy ratio of 0.738, R ratio 0.97
4, Comparative Examples 5 to 7 have a Dy ratio of 1.0 and an R ratio of 1.0. With respect to Sample Nos. 5 to 13 and Comparative Examples 5 to 7, the coercive force Hcj and the residual magnetic flux density Br were measured with a BH tracer. Table 3 shows the results. Sample Nos. 5 to 5
13 and Comparative Examples 5 to 7 and the Residual Magnetic Flux Density Br
2 is shown in FIG. In FIG. 2, the curve (a) shows the case where the Dy ratio is 0.396 and the R ratio is 0.971 (sample No. 5).
7) shows the relationship between the sintering temperature and the residual magnetic flux density Br. Similarly, curve (b) shows a Dy ratio of 0.641 and an R ratio of 0.4.
973 (Sample Nos. 8 to 10), the curve (c) is D
When the y ratio is 0.738 and the R ratio is 0.974 (Sample No. 11
13) and curve (d) show the relationship between the sintering temperature and the residual magnetic flux density Br when the Dy ratio is 1.0 and the R ratio is 1.0 (Comparative Examples 5 to 7).

[0020]

[Table 2]

[0021]

[Table 3]

As shown in Table 3, as the sintering temperature increases, the coercive force Hcj tends to decrease. Sample No.5
7 are the same Dy ratio and R ratio, but the sintering temperature is 1
070 ° C (Sample No. 5), 1090 ° C (Sample No. 5)
6) As the temperature rises to 1110 ° C. (Sample No. 7), the coercive force Hcj becomes 2062 kA / m (Sample No. 7).
5), 2013 kA / m (Sample No. 6), 1984 k
A / m (Sample No. 7). This tendency is the same for Sample Nos. 8 to 10, Sample Nos. 11 to 13, and Comparative Examples 5 to 7. On the other hand, as shown in Table 3 and FIG. 2, the residual magnetic flux density Br tends to increase as the sintering temperature increases. That is, Sample Nos. 11 to 13 having a Dy ratio of 0.738 and an R ratio of 0.974 (FIG. 2)
In the curve (c)), the sintering temperature was 1070 ° C. (sample N
o.11) to 1110 ° C. (Sample No. 13)
The residual magnetic flux density Br increases from 1.233T to 1.242T.

Next, Sample Nos. 5 to 7 (Dy ratio 0.39)
6, R ratio 0.971) and Comparative Examples 5 to 7 (Dy ratio 1.0,
(R ratio 1.0). As shown in FIG. 2, when the sintering temperature is 1070 ° C., the comparative example 5 (curve (d)) shows a higher residual magnetic flux density Br than the sample No. 5 (curve (a)). . However, the sintering temperature was 1110 ° C
, The residual magnetic flux density Br of Comparative Example 7 (curve (d))
Is 1.216 T, whereas the residual magnetic flux density Br of sample No. 7 (curve (a)) is improved to 1.227 T. That is, as is apparent from FIG. 2, the Dy ratio is 1.0.
In this case, it can be said that it is difficult to obtain a residual magnetic flux density Br of 1.22 T or more even when the sintering temperature is increased.

The Dy ratio is 0.641 and the R ratio is 0.97.
Sample Nos. 8 to 10 (curve (b)), and D
Sample No. 1 having a y ratio of 0.738 and an R ratio of 0.974
All of the curves 1 to 13 (curve (c)) were 1.23.
It is noted that it shows an excellent residual magnetic flux density Br of T or more. Here, the R ratio of Sample Nos. 8 to 10 was 0.97.
3, and the R ratios of Sample Nos. 11 to 13 are 0.974, so that the R ratios of both are almost equal. However, when looking at FIG. 2, Sample Nos. 8 to 10 (Dy ratio of 0.
Sample Nos. 11 to 13 show the curve No. 641) as the curve (c).
Since the residual magnetic flux density Br is higher and more stable than (Dy ratio 0.738), the influence of the Dy ratio on the residual magnetic flux density Br is greater than the R ratio. From the above results, it can be seen that the residual magnetic flux density Br tends to increase with the sintering temperature, and that the Dy ratio is set to about 0.38 to 0.99, whereby a good residual magnetic flux of 1.22 T or more is obtained. Density B
It was found that r could be obtained.

Example 3 According to Examples 1 and 2, D
It became clear that good coercive force Hcj and residual magnetic flux density Br can be obtained by setting the y ratio to 0.38 to 0.99 and the R ratio to 0.94 to 0.99. An experiment conducted to confirm a preferable combination of the Dy ratio and the R ratio, that is, how to combine the Dy ratio and the R ratio in order to obtain a good coercive force Hcj and a residual magnetic flux density Br was performed in Example 3. It will be described as.
X alloy and Y alloy were adjusted under the same conditions as in Example 1,
Pulverization, mixing and molding in a magnetic field were performed. After sintering each of the compacts after being molded in a magnetic field at 1090 ° C. and 1110 ° C. for 4 hours, respectively, a two-stage aging treatment was performed under the same conditions as in Example 1, and Sample Nos. Obtained. The composition of the X alloy powder and the Y alloy powder, the mixing ratio of the X alloy powder and the Y alloy powder, and the composition of the magnet after sintering are as shown in Table 4. With respect to Sample Nos. 14 to 18 and Comparative Examples 8 and 9, the coercive force Hcj and the residual magnetic flux density Br were measured using a BH tracer under the same conditions as in Example 1. Table 5 shows the results. In addition, for convenience of comparison, Table 5 shows samples Nos. 1 to 13 obtained in Examples 1 and 2 and Comparative Examples 1 to 3.
7, the Dy ratio, the R ratio, the coercive force Hcj, and the residual magnetic flux density Br are also shown. Hereinafter, a preferable combination of the Dy ratio and the R ratio will be examined using Sample Nos. 1 to 18 and Comparative Examples 1 to 9. Sample No. 1
To 18 and Comparative Examples 1 to 9, the coercive force Hcj was 1800
Those having a kA / m or more and a residual magnetic flux density Br of 1.16 T or more (all except Sample No. 5 and Comparative Examples 1 to 3) are shown in FIG.

[0026]

[Table 4]

[0027]

[Table 5]

Referring to FIG. 3, the coercive force Hcj is 1900 k.
It can be seen that there is no comparative example with A / m or more and residual magnetic flux density Br of 1.22 T or more. On the other hand, sample N
o.2 and 7 to 18 each have a coercive force Hcj of 1900 kA / m or more and a residual magnetic flux density Br of 1.22 T or more.
Is shown. In particular, sample Nos. 8 to 13, 16 to
18, a coercive force Hcj of 1950 kA / m or more,
And a residual magnetic flux density Br of not less than 1.23T. Here, sample Nos. 8 to 13 and 16
Focusing on the Dy ratio and the R ratio of Sample Nos.
-10 are Dy ratio 0.641, R ratio 0.973, sample No.
11 to 13 have a Dy ratio of 0.738, an R ratio of 0.974, and a sample N
Sample Nos. 18 and 17 have a Dy ratio of 0.733 and an R ratio of 0.973, and Sample No. 18 has a Dy ratio of 0.638 and an R ratio of 0.973. From this tendency, the Dy ratio is set to 0.5 to 0.99, more preferably 0.6 to 0.9, more preferably 0.6 to 0.8,
And the R ratio is 0.8 to 0.99, further 0.94 to 0.99.
Thus, it can be said that excellent coercive force Hcj and residual magnetic flux density Br can be obtained.

Next, sample N having a sintering temperature of 1090 ° C.
FIG. 4 shows the coercive force Hcj and the residual magnetic flux density Br of o, 6, 9, 12, 14, 16, 18 and Comparative Examples 6 and 8. As shown in FIG. 4, Sample Nos. 9, 12, 16, and 18 show particularly excellent coercive force Hcj and residual magnetic flux density Br, and a value of about 2000 kA / m or more was obtained for coercive force Hcj. I have. Moreover, it is noted that all of the samples Nos. 9, 12, 16, and 18 exhibit a residual magnetic flux density Br of 1.23 T or more while maintaining this good coercive force Hcj. Next, sample No. 18 and sample No. 9 are compared. 4, sample No. 18 is located at the upper right of sample No. 9, and sample No. 18 has higher coercive force Hcj and residual magnetic flux density Br than sample No. 9. However, as shown in Table 5, the Dy ratio of Sample No. 18 was 0.638, the R ratio was 0.973, the Dy ratio of Sample No. 9 was 0.641, and the R ratio was 0.973. Are approximately equal. Here, looking at Tables 2 and 4, while Sample No. 18 contains Ga, Sample No. 9
Contains Sn without Ga. Sample No. 18 and Sample N
Since other compositions of o.9 are almost equal, Ga
Is effective in improving coercive force Hcj and residual magnetic flux density Br.

[0030]

As described in detail above, according to the present invention,
A method for manufacturing a rare earth permanent magnet having both excellent coercive force and residual magnetic flux density can be provided.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the Dy ratio and the residual magnetic flux density Br of Sample Nos. 1 to 3 and Comparative Examples 1 and 2.

FIG. 2 is a graph showing the relationship between the sintering temperature and the residual magnetic flux density Br of Sample Nos. 5 to 13 and Comparative Examples 5 to 7.

FIG. 3 Samples Nos. 1-4, 6-18, Comparative Examples 4-9
4 is a graph showing the coercive force Hcj and the residual magnetic flux density Br of the present invention.

FIG. 4 shows a sample No. 6 having a sintering temperature of 1090 ° C.
Coercive force H of 9, 12, 14, 16, 18 and Comparative Examples 6, 8
It is a graph which shows cj and residual magnetic flux density Br.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Makoto Nakane 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDC Corporation F-term (reference) 4K018 AA08 AA11 AA27 BA04 BA05 BA18 BC12 CA04 KA45 5E040 AA04 AA19 BD01 CA01 NN01 NN12 NN13

Claims (8)

[Claims] 1. A ^{_{R 1 2 T 14 B (R}} 1 2 T 14 B: 1 or more kinds of rare earth elements including R ¹ = Y (Dy mandatory), T
= Transition metal element one or more, and X alloy powder B = boron) and ^{mainly, R 2 T (R 2 T} : R 2 = 1 , two or more of heavy rare earth elements, T = transition A method for producing a rare earth permanent magnet, comprising: a step of obtaining a mixed powder with a Y alloy powder mainly containing one or more metal elements) and a step of sintering the mixed powder. D, which is the ratio of the content of heavy rare earth elements to the content of heavy rare earth elements in the magnet composition after sintering
The y ratio is 0.38 to 0.99, and the R ratio, which is the ratio of the content of the rare earth element in the X alloy powder to the content of the rare earth element in the magnet composition after sintering, is 0.94 to 1.94. 03
A method for producing a rare earth permanent magnet. 2. A Dy ratio, which is a ratio of a content of a heavy rare earth element in the X alloy powder to a content of a heavy rare earth element in a magnet composition after sintering, is 0.6 to 0.8, and
The R ratio, which is the ratio of the content of the rare earth element in the alloy powder to the content of the rare earth element in the magnet composition after sintering, is 0.9.
The method for producing a rare earth permanent magnet according to claim 1, wherein the number is from 4 to 0.99. 3. The method according to claim 1, wherein the Y alloy powder is M (M = Al, C
and at least one of u, Sn, Ga, Bi, and In).
3. The method for producing a rare earth permanent magnet according to item 1. 4. Dy is added to the magnet composition after sintering in an amount of 1 to 13 wt.
%. The method for producing a rare earth permanent magnet according to claim 1, wherein 5. The sintered magnet composition having a residual magnetic flux density of 1.
The method for producing a rare earth permanent magnet according to any one of claims 1 to 4, wherein the permanent magnet is at least 22T. 6. The sintered magnet composition has a residual magnetic flux density of 1.
The method for producing a rare-earth permanent magnet according to any one of claims 1 to 5, wherein the permanent magnet has a coercive force of 22 T or more and a coercive force of 1900 kA / m or more. 7. ^{_{R 1 2 T 14 B (R}} 1 2 T 14 B: 1 or more kinds of rare earth elements including R ¹ = Y (Dy mandatory), T
= Transition metal element one or more, and X alloy powder B = boron) and ^{mainly, R 2 T (R 2 T} : R 2 = 1 , two or more of heavy rare earth elements, T = transition A method for producing a rare earth permanent magnet, comprising: a step of obtaining a mixed powder with a Y alloy powder mainly containing one or more metal elements) and a step of sintering the mixed powder. A method for producing a rare earth permanent magnet, wherein the R ratio, which is the ratio of the content of the rare earth element to the content of the rare earth element in the magnet composition after sintering, is 0.94 to 0.99. 8. ^{_{R 1 2 T 14 B (R}} 1 2 T 14 B: 1 or more kinds of rare earth elements including R ¹ = Y (Dy mandatory), T
= Transition metal element one or more, and X alloy powder B = boron) and ^{mainly, R 2 T (R 2 T} : R 2 = 1 , two or more of heavy rare earth elements, T = transition A method for producing a rare earth permanent magnet, comprising: a step of obtaining a mixed powder with a Y alloy powder mainly containing one or more metal elements) and a step of sintering the mixed powder. A method for producing a rare earth permanent magnet, wherein the Dy ratio, which is the ratio of the content of the rare earth element to the content of the rare earth element in the magnet composition after sintering, is 0.65 to 0.99.