JPH11329810A - Magnetic alloy and anisotropic magnet using alloy thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic alloy having excellent residual magnetism (Br) or a maximum energy product ((BH) max) by hot plastic working such as hot excrusion. SOLUTION: This alloy is the magnetic alloy, which comprizes R (R is one or more kinds of rare metals) of 28.0-30.0 weight%, B of 0.85-1.10 weight% and the remaining part comprising iron-group transition metal and has the excellent hot plastic working property and the magnetic characteristics. Or Ga of 0.05-0.8 weight% is added into the above described alloy. Or Si or C of 0.03-0.3 weight% is added into the above described alloy. By performing the hot plastic working of these metals at 750 deg.C-850 deg.C, the anisotropic magnet having the more higher magnetic characteristics can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet alloy which can be used as a permanent magnet having an excellent high energy product and good magnetic properties.

[0002]

2. Description of the Related Art In recent years, R (rare earth metal) has been used as a permanent magnet having good residual magnetic flux density (Br) and coercive force (Hc) and excellent magnetic properties having an excellent high energy product ((BH) max). -Fe-B based magnetic alloys have been widely used.

[0003] The R-Fe-B based magnetic alloy has excellent magnetic properties by magnetically giving anisotropy by orienting crystal grains in a specific direction by performing hot plastic working. It becomes a permanent magnet.

[0004] This R-Fe-B-based magnetic alloy is obtained by quenching the alloy melt to obtain amorphous or fine crystalline flakes and then crushing the powder into a powder. It is manufactured by molding and densifying and then hot working plastically, or alternatively, casting the molten alloy and then hot working plastically the cast body.

[0005]

The characteristics of an R-Fe-B based magnet alloy formed by this type of hot plastic working method have a residual magnetic flux density (Br) of about 12.6 kG or less. It has been a problem to provide a magnet alloy having a better maximum energy product ((BH) max) by increasing the residual magnetic flux density (Br).

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and in a R-Fe-B based magnetic alloy, the residual magnetic flux density (Br) is reduced by limiting the composition range of constituent elements. High, maximum energy product ((BH) m
The object of the present invention is to provide an even more excellent magnet alloy of ax).

Also, at the same time, various examinations were made on the forming conditions during plastic working, particularly on the temperature conditions during working, with the aim of providing a magnet alloy having good workability and high Br or high (BH) max. I have.

[0008]

Means for Solving the Problems Regarding magnets obtained by subjecting an R-Fe-B-based magnet alloy to plastic working, there has been little recognition that composition and magnetic properties are strictly correlated in the past. The present inventors have focused on the relationship between the R-Fe-B composition and the magnetic properties, and as the experiments are repeated, the magnetic properties of the present magnet have a strict correlation with the basic composition of R-Fe-B. I found something. Therefore, as a result of further experiments, the present inventors succeeded in producing an anisotropic magnet having high magnetic properties that could not be obtained conventionally by limiting the composition.

[0009] Further, when a high performance anisotropic magnet is manufactured by subjecting an R-Fe-B-based magnet alloy to plastic working, R-Fe-B
Conventionally, plastic working was performed under substantially the same conditions even when the -B composition was different. The present inventors have proposed various compositions of R-Fe
In the course of conducting a number of plastic working experiments on a -B alloy, it was found that the optimum working conditions, especially the heating conditions, differed depending on the R-Fe-B composition. Further, it has been found that, even with an alloy having a composition exhibiting only low properties under conventional molding conditions, excellent magnetic properties can be exhibited by optimizing the temperature conditions. Furthermore, the present inventors finally completed the present invention by earnestly conducting experiments in which the R-Fe-B composition and the processing conditions were changed.

Further, Ga, Si or C is selected as an additive element to R-Fe-B, and the influence of the content on both hot workability and magnetic properties is examined to determine a preferable composition range. Found a magnetic alloy.

That is, the magnet alloy according to the present invention, which is excellent in hot plastic workability and magnetic properties, has an RTB component system, wherein R is a rare earth metal. R: 28.0 to 30.0% by weight, B: 0.85 to 1.10% by weight, and T is one or more of iron group transition metals and substantially the balance It is characterized by having it.

Similarly, the magnet alloy according to the present invention, which has excellent hot plastic workability and magnetic properties, has an RT-Ga-B component system, wherein R is R: 28.0 to 30.0 with one or more rare earth metals
% By weight, Ga: 0.05 to 0.8% by weight, B: 0.85
-1.10% by weight, and T is one or more of iron-group transition metals and substantially the remainder.

[0013] Similarly, the magnet alloy according to the present invention, which is excellent in hot plastic workability and magnetic properties, has an R-T-X-B component system, wherein R is R is 28.0 to 30.0% by weight of one or more rare earth metals, X is one or two of Si and C, and X is 0.
03 to 0.3% by weight, B: 0.85 to 1.10% by weight,
T is characterized in that one or more of the iron group transition metals are substantially the balance.

Further, in the magnet alloy according to the present invention, which is excellent in hot plastic workability and magnetic properties, R is mainly composed of Nd or Pr and rare earth elements other than Nd and Pr. The metal can be up to 5.0% by weight.

The magnetic alloy according to the present invention, which has excellent hot plastic workability and magnetic properties, is characterized in that T is composed of one or two of Fe and Co. It can be.

Further, the anisotropic magnet according to the present invention, which is excellent in hot plastic workability and magnetic properties, is characterized in that hot plastic working is performed at a temperature of 750 ° C. to 850 ° C. It is characterized by performing.

Similarly, in an embodiment of the anisotropic magnet according to the present invention having excellent hot plastic workability and magnetic properties, the hot plastic working is performed by hot extrusion. May be used.

[0018]

The reasons for limiting the component composition (% by weight) of the magnet alloy excellent in hot plastic workability and magnetic properties according to the present invention are as follows.

R: 28.0-30.0% If the R content is small, the coercive force (iHc) decreases.
It is necessary to be 28.0% or more. On the other hand, when the R content is large, the residual magnetic flux density (Br) is reduced.
It is necessary to make it 0.0% or less.

B: 0.85 to 1.10% B has the effect of improving the coercive force (iHc) and residual magnetic flux density (Br) of this type of magnetic alloy. Since the effect of improving (iHc) and residual magnetic flux density (Br) is small, the content is preferably set to 0.85% or more. However, if it is too large, the residual magnetic flux density (Br) tends to decrease, and the deformation resistance decreases. Since it is required to rapidly increase the processing time for hot extrusion, for example, it is necessary to set it to 1.10% or less.

Ga: 0.05-0.8% Ga has the effect of improving the coercive force (iHc) and residual magnetic flux density (Br) of this type of magnet alloy.
If the content of a is small, the coercive force (iHc) and the residual magnetic flux density (Br) decrease. Therefore, the content is preferably set to 0.05% or more. However, if it is too large, the residual magnetic flux density (Br) decreases. Therefore, it is better to set it to 0.8% or less.

Si or C: 0.03-0.3% Si or C is the residual magnetic flux density (B
It has the effect of improving r), but its effect occurs at 0.03% or more. However, if the content is too large, on the contrary, the residual magnetic flux density (Br) decreases, so it is preferable to set the content to 0.3% or less.

It is desirable that R is mainly composed of Nd or Pr. Since the content of another rare earth metal causes a decrease in the residual magnetic flux density (Br), its content should be 5.0% or less. good.

Further, by setting the temperature at the time of hot plastic working of the magnet alloy having the above-mentioned composition to 750 to 850 ° C., the magnetic properties, particularly the magnetic flux density (Br), can be further increased. Magnetic flux density (Br) is 13.0 kG
A radially anisotropic high energy product magnet alloy having excellent magnetic properties can be obtained.

[0025]

(Example 1) Nd: 29.5% by weight, Co: 6 by ultra-quenching a molten alloy by a single roll method.
After obtaining a ribbon having the composition of wt%, B: 0.95% by weight, and Fe: balance, the ribbon was crushed to obtain a powder.

Next, the powder was cold-pressed, and then hot-pressed at 790 ° C. in an Ar gas atmosphere.

Subsequently, for this hot press molded body,
By performing hot extrusion at a temperature of 820 ° C., a cup-shaped magnet material having a uniform crystal orientation was obtained.

Next, a sample was cut out from the outer wall of the cup-shaped magnet material and the magnetic properties in the radial direction were examined. As a result, the residual magnetic flux density (Br) was 13.5 kG, and the coercive force (i
Hc) was found to have high magnetic properties of 13.8 kOe and a maximum energy product ((BH) max) of 42.1 MGOe.

(Example 2) Nd: 29.2% by weight, Co:
6% by weight, B: 0.92% by weight, Ga: 0.6% by weight,
Fe: After obtaining a ribbon having the remaining composition, the ribbon was crushed to obtain a powder.

Using this powder, a cup-shaped magnet material was obtained in the same manner as in Example 1. Next, as a result of examining the magnetic characteristics in the same manner as in Example 1, the residual magnetic flux density (Br) was 1
3.7 kG, coercive force (iHc) 15.3 kOe, and maximum energy product ((BH) max) 44.3 MG
Oe was found to have high magnetic properties.

Example 3 A powder having the composition shown in Table 1 was obtained in the same manner as in Example 1. Using each powder, a cup-shaped magnet material was produced in the same manner as in Example 1, and the magnetic properties were examined. The results are shown in Table 1. Sample numbers 1, 5, 6, 12, 21, 25, and 29 in Table 1 show comparative examples. Sample Nos. 1 and 5 in Table 1 have Nd outside the range and have low coercive force and maximum energy product. Sample numbers 6 and 12 in which B is out of the range have a low maximum energy product. Further, Ga,
Sample numbers 21, 25, and 29 with large amounts of Si and C added also have low maximum energy products.

[0032]

[Table 1]

Example 4 A cup-shaped magnet material having the alloy composition used in Examples 1 and 2 was produced in the same manner as in Example 1. However, at this time, the temperature of the hot extrusion was varied as shown in Table 2. Table 2 shows the results of examining the magnetic properties of each magnet material. From Table 2,
It can be seen that when the temperature of the extrusion processing is 750 to 850 ° C., a high characteristic of Br of 13.0 kG or more can be obtained.

[0034]

[Table 2]

[0035]

According to the present invention, there is provided a magnet alloy having a high residual magnetic flux density (Br) and an excellent maximum energy product ((BH) max) by using a magnet alloy having a composition limited by the present invention. Is possible.

Further, the temperature of the hot plastic working is set to 750 to 8
By limiting the temperature to 50 ° C., the magnetic properties, particularly the residual magnetic flux density (Br), of the alloy having the composition shown in claims 1 to 5 are obtained.
Can be further increased.

Claims (7)

[Claims] An R-T-B component system wherein R is one or more rare earth metals, R: 28.0 to 30.0% by weight, B: 0.85 to 1.10 A magnetic alloy having excellent hot plastic workability and magnetic properties, wherein T is one or more of iron group transition metals and substantially the balance. 2. It has an RT-Ga-B component system, wherein R is one or more rare earth metals and R: 28.0-3.
0.0% by weight, Ga: 0.05 to 0.8% by weight, B:
0.85 to 1.10% by weight, T is one or more of iron group transition metals, and the balance is substantially the balance, and the magnet alloy is excellent in hot plastic workability and magnetic properties. 3. It has an RTXB component system, wherein R is one or more rare earth metals and R: 28.0-30.
0% by weight, X is one or two of Si and C, and X:
0.03 to 0.3% by weight, B: 0.85 to 1.10% by weight, T is one or more of iron group transition metals and substantially the balance is hot plasticity. Magnet alloy with excellent workability and magnetic properties. 4. R is mainly composed of Nd or Pr.
4. The magnet alloy according to claim 1, wherein the rare earth metal other than Pr and Pr is 5.0% by weight or less. 5. The magnet alloy according to claim 1, wherein T comprises one or two of Fe and Co. 6. The magnetic alloy according to claim 1, wherein said magnetic alloy is 750 ° C.
Anisotropic magnets with excellent magnetic properties that have been subjected to hot plastic working at -850 ° C. 7. The anisotropic magnet having excellent magnetic properties according to claim 6, wherein the hot plastic working is hot extrusion.