JPH0521219A - Production of rare-earth permanent magnet - Google Patents

Abstract

PURPOSE:To obtain a well-balanced magnetic property by pressure-molding a mixed alloy powder in the magnetic field, sintering the molded body in a vacuum or atmosphere of inactive gas, and further applying aging heat treatment at such a low temperature as sintering temperature or below. CONSTITUTION:An A alloy is composed of an R<2>T<14>B phase mainly (R: at least one or more kinds of rare-earth elements including Nd, Pr and Dy mainly, T: Fe and Co). A B alloy contains R, Co, Fe and B, and is composed of an R<2>T<114>B phase and/or an R rich phase, and a combined phase with at least one or more kinds of RT<24>B phase, RT<23> phase, RT<22> phase, R<2>T<227> phase and RT<25> phase, and 99-70wt.% A alloy powder is mixed with 1-30wt.% B alloy powder. Thus well-balanced magnetic property can be obtained.

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, which is used in various electric and electronic devices.

[0002]

2. Description of the Related Art Among rare earth magnets, Nd-Fe-B magnets are
Nd, which is the main component, is abundant in resources, low in cost, and excellent in magnetic properties, so that its use is expanding more and more in recent years. Since the invention of the Nd-based magnet, the research and development for improving the magnetic properties has been energetically carried out, and many studies and inventions have been proposed. There are also many methods for manufacturing high-performance Nd magnets by mixing and sintering two kinds of alloy powders with different compositions, which is one of the manufacturing methods for Nd-based sintered magnets. Invention proposals have been proposed.

The two alloy methods proposed so far can be roughly classified into three types. The first method is to prepare an amorphous or fine crystal alloy by liquid quenching one of the raw material alloy powders to be mixed, and mix it with a normal rare earth alloy powder, or to mix both raw material alloy powders together. Method of preparing and mixing by liquid quenching method [Japanese Patent Laid-Open No. 63-9
3841, JP-A-63-115307, JP-A-63-252403, JP-A-663-2
78208, JP-A-1-108707, JP-A-1-146310, JP-A-1-1463
09, refer to Japanese Unexamined Patent Publication No. 1-155603]. Regarding the two-alloy method using the alloy by the liquid quenching method, the
Reported that magnetic characteristics exceeding MGOe were obtained [E. Otuk
i, T. Otuka and T.M. Imai; 11t
h. Int. Workshop on Rare Ea
rth Magnets, Pittsburgh, Pe
nsylvania, USA, October (19
90), p. 328].

In the second method, two kinds of raw material alloy powders to be mixed are mainly used as an R ² Fe ¹⁴ B compound, and an alloy in which the kinds and contents of rare earth elements contained therein are changed is prepared and mixed and sintered. Is the way. That is, a method of mixing two kinds of alloys in which the amount ratio of the contained Nd-rich phase or the kind of rare earth element is changed [JP-A-61-81603, JP-A-61-81604, and JP-A-61-816].
05, JP 61-81606, JP 61-81607, JP 61-119007,
JP-A 61-207546, JP-A 63-245 Sho 3, and JP-A 1-177335].

In the third method, one alloy is mainly used as R ² F.
A method for producing an Nd-based rare earth magnet by forming an alloy powder composed of an e ¹⁴ B compound and mixing and sintering powders of various low melting point elements, low melting point alloys, rare earth alloys, carbides, borides, hydrides, etc. JP-A-60-230959, JP-A-61-263201, JP-A-62-18
1402, JP-A-62-182249, JP-A-62-206802, JP-A-62-2707
46, JP 63-6808, JP 63-104406, JP 63-114939,
See JP-A-63-272006, JP-A-1-111843, and JP-A-1-146308].

[0006]

There are many points that the two-alloy method according to the prior art is not suitable or insufficient for realizing the truly excellent magnetic properties of Nd-based magnet alloys. That is, in the above-mentioned first method, the energy product of the magnet alloy is high, but the coercive force is about 9 kOe, and the coercive force is lowered by the temperature rise. Magnet characteristics. The biggest problem is magnetic field orientation. Even in the first method, an alloy exhibiting magnetism at room temperature can be obtained by appropriately selecting the composition. However, since the alloy obtained by the liquid quenching method becomes an amorphous amorphous phase or fine crystals, it is made into a fine powder and a magnetic field. Even if it is oriented inside, a specific crystal orientation cannot be oriented in the magnetic field direction. Therefore, even if the mixed raw material alloy powder is molded in a magnetic field, the orientation of the molded body obtained is poor,
Sufficient magnet characteristics cannot be obtained after sintering.

In the second method, R ² F in the magnet alloy is used.
Phase coexisting with e ¹⁴ B compound is Nd rich phase or Nd ^{1 + X} Fe
⁴ is a B ⁴ phase, exhibits no magnetism at room temperature with the two phases.
Therefore, the mixture of a compound having no magnetism disturbs the orientation, and a magnet having excellent magnetic properties cannot be obtained. Further, even in the third method in which various elements and various compounds are used as the powder to be mixed, since these compounds do not have magnetism, the demagnetizing field becomes large during the orientation in the magnetic field and the effective magnetic field strength decreases, Therefore, the rotation of the magnetic particles in the magnetic field direction is insufficient and the orientation is disturbed.

In the third method, there has been a proposal to improve the magnetic properties by utilizing a low melting point element or alloy in the powder to be mixed. This is because the low melting point phase mixed during sintering is This is based on the idea that the lattice defects existing at the grain boundaries of the R ² Fe ¹⁴ B compound and the nucleation sites such as oxide phases are removed and the grain boundaries are cleaned to improve the coercive force. However, the existence of the low-melting-point phase is actually a disadvantageous condition for improving the magnetic properties, for the following reason. When the low melting point phase becomes a melt from around 660 ° C., the viscosity of the low melting point phase becomes considerably small at the actual sintering temperature of 1,100 ° C. As a result, the compact is contracted by liquid phase sintering, and at the same time, the viscosity of the melt surrounding the grains is small, so that the rotation of the magnetic grains easily occurs, the orientation is disturbed, and the magnetic properties are deteriorated. That is, the desirable liquid phase component in the liquid phase sintering of the Nd magnet is required to maintain an appropriate viscosity so as not to disturb the orientation of the particles, and also to densify the compact and sufficiently clean up the grain boundaries. In the conventional two-alloy method, the magnetic field and the melting point of the liquid-phase alloy component are properly adjusted so that the magnetic field orientation and the coercive force improving roles related to the liquid-phase component are fully considered. I didn't adjust. The present invention is intended to provide a method for manufacturing a rare earth permanent magnet excellent in well-balanced magnetic characteristics by improving the above-mentioned drawbacks in the two-alloy method.

[0009]

The inventors of the present invention have basically reviewed the two-alloy method in order to solve the above problems, and it is sufficient to appropriately select and combine the types and characteristics of the magnetic material constituent phases. The inventors have found that a satisfactory balanced magnetic property can be obtained, and have studied the manufacturing conditions in detail to complete the present invention. The gist of the present invention is that the alloy A is mainly R ² T ¹⁴ B
A phase (wherein R is at least one or more rare earth elements mainly composed of Nd, Pr and Dy, and T is Fe and Co), and a B alloy containing R, Co, Fe and B, In addition, R ² T 1 ¹⁴ B phase and / or R rich phase (where R is the same as above, T ¹ represents a transition metal element mainly composed of Fe and Co) and RT 2 as constituent phases in the alloy. ⁴ B phase, RT ■ 2 ³ phase, RT ^{2 2} phase,
R ² T 2 ⁷ phase and RT 2 ^{5 5} phase (where R is the same as above, T ²
Is an alloy composed of a transition metal element mainly composed of Fe and Co, which represents the same transition metal and B) and a mixed phase with one or more of the five phases, and the alloy powder A is 99 to 70% by weight. 1 to 30% by weight of the B alloy powder, the mixed alloy powder is pressure-molded in a magnetic field, the compact is sintered in a vacuum or an inert gas atmosphere, and the temperature is lower than the sintering temperature. A method for producing a rare earth permanent magnet, characterized in that the aging heat treatment is carried out with, and more specifically, RT ^{2 4} B phase, RT contained in B alloy, RT
^Of the five constituent phases of ^{2 3} phase, RT ^{2 2} phase, R ² T ^{2 7} phase and RT ^{2 5} phase, at least one phase has a melting point of 700 ° C. or higher 1,1
An intermetallic compound having a temperature of 55 ° C. or lower, and a magnetic substance in which at least one phase has a Curie temperature of room temperature or higher,
A method for producing a rare earth magnet, wherein at least one phase is a magnetic material having a Curie temperature of room temperature or higher and a crystalline magnetic anisotropy.

The present invention will be described in detail below. The present invention is a so-called two-alloy method, which is a rare earth permanent magnet (hereinafter referred to as magnet alloy C).
That is, the raw material A alloy is mainly composed of R ² T ¹⁴ B compound phase, and R is Y containing La, Ce, Pr,
It is at least one kind of rare earth element mainly composed of Nd, Pr and Dy selected from Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. Further, T represents Fe and Co, and the Co content is 0.1 to 40% by weight. The addition of Co raises the Curie temperature of the alloy A and also improves the corrosion resistance of the alloy. Alloy A is cast by melting the raw material metal in a vacuum or an inert gas, preferably Ar atmosphere. As the raw material metal, pure rare earth elements or rare earth alloys, pure iron, ferroboron, and alloys thereof are used, but trace impurities that are inevitable in general industrial production are included. In the obtained ingot, the R ² Fe ¹⁴ B phase is formed by the peritectic reaction between αFe and the rare earth-rich phase, and therefore the αFe phase, the R-rich phase, the B-rich phase, and the Nd3C phase due to solidification segregation even after casting.
o phase etc. may remain. In the present invention, it is desirable that the A alloy has a large amount of R ² Fe ¹⁴ B phases, and therefore, solution treatment is performed if necessary. The condition is that the heat treatment is performed in a temperature range of 700 to 1,200 ° C. for 1 hour or more under vacuum or Ar atmosphere.

The B alloy is an alloy mainly composed of R, Co, Fe, B and Ga, and has the composition formula RaFebCocBdGae (where R is
La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb including Y
And at least one rare earth element mainly composed of Nd, Pr and Dy selected from Lu, 15 ≦ a ≦ 40, 0 ≦ b ≦ 80, 5 ≦ c
≦ 85, 0 ≦ d ≦ 20, 0.1 ≦ e ≦ 20, a + b + c + d + e = 100 (each atom%)), and the raw material metal is vacuum or inert gas like the A alloy. Preferably, it is melted and cast in an Ar atmosphere. As the raw material metal, pure rare earth elements or rare earth alloys, pure iron, pure cobalt, ferroboron, and alloys thereof are used, but trace impurities that are inevitable in general industrial production are included. If the amount a of the rare earth element R is less than 15 atomic%, the amount R is too small to obtain a sufficient amount of liquid phase in the sintering process and the density of the sintered body cannot be increased. The melting point becomes too low, and the effect of improving magnetic properties is lost. The amount c of Co is 5
If it is less than atomic%, RT 2 ⁴ B phase, RT ² 3 phase, RT ² 2 phase, R ²
Each phase of T ^{2 7} phase and RT ^{2 5} equality is no longer appear, not the effect of improving magnetic characteristics. Further, the B alloy can be produced by heat-treating the ribbon obtained by the liquid quenching method. That is, in the liquid quenching method, the B alloy after quenching has an amorphous phase or a fine crystalline phase, and is heated at a temperature not lower than the crystallization temperature for a certain period of time to cause crystallization or recrystallization growth. Thus, the predetermined constituent phase of the present invention can be precipitated.

In this composition range, the phases mainly appearing in the B alloy are R ² T ^{1 14} B phase (mainly R ² Fe ¹⁴ B phase) and R
Rich phase (where R is the same as above, T ¹ represents a transition metal element mainly composed of Fe and Co), RT ² 4 ^B phase, RT 2
³ phase, RT 2 2 ² phase, R ² T 2 ⁷ phase and RT ^{2 5} phase (where R is the same as above, T ² is a transition metal element mainly composed of Fe and Co, the same transition metal and B) The present invention is characterized by using a B alloy containing at least one or two or more phases of the front two phases and the rear five phases. The phase described as the R-rich phase represents all the various R-rich phases in which the R component is 35 atomic% or more. Of these seven types of phases, the _two phases, R ₂ Fe ₁₄ B phase and R rich phase, are phases that have also appeared in the conventionally known two-alloy method and the ordinary manufacturing method of rare earth iron boron magnet alloy. is there. Remaining RT ² 4B
Phase, RT ² 3-phase, RT 2 ^2-phase, R ^{2 T} ■ ^{2 7} phase, five phase RT ² 5 phase emerges by adding 5 atomic% or more Co in B alloy, the present invention It is peculiar to the two alloy method. These five phases first appeared as equilibrium phases in the B alloy by adding Co in an amount of 5 atomic% or more.
FIG. 1 is an example of the composition of the B alloy of the present invention taken by scanning electron microscope and the composition was determined by EPMA (electron probe X-ray microanalyzer) and X-ray analysis.
T ^{2 4} B-phase, 2.RT ^{2 3-phase,} 3.RT ^{2 2} phase, the presence of 4.R rich phase is represented clearly. The two-alloy method according to the invention is
The alloy is characterized by containing at least one or more of these five phases, and the presence of these phases made it possible to realize high magnetic properties in the magnet alloy produced by the two-alloy method.

In the present invention, the above-mentioned alloy A and alloy B were mixed in a specific ratio, and the magnet alloy C was produced by the so-called two-alloy method, whereby high magnetic properties could be exhibited. Less than,
The reason why the presence of these mixed phases in the B alloy leads to the high magnetic properties of the magnet alloy will be described. The first reason is that these mixed phases have a Curie temperature above room temperature, which was achieved by the additive element Co. Further, these phases have magnetocrystalline anisotropy in a particular crystallographic direction. Therefore, when B alloy powder containing at least one of these phases as a main constituent phase is mixed with A alloy powder mainly composed of R2Fe14B phase and oriented in a magnetic field, B alloy is also a ferromagnetic substance and is magnetically anisotropic. As a result, almost all particles are oriented with their crystal directions aligned in the applied magnetic field direction, and high magnetic properties can be obtained.

The second reason is that the melting points of these phases are in a temperature range suitable for liquid phase sintering of Nd rare earth magnets, that is, 700.
It is to be in the range of ℃ to 1,155 ℃. This temperature range is higher than the melting point of the Nd-rich phase (500 to 650 ° C.) and lower than the melting point of the R ² Fe ¹⁴ B phase (1,155 ° C.).
Therefore, at the normal sintering temperature, only the Nd-rich phase is present and the viscosity of the melt is too low, and as a result, the orientation of the particles is not disturbed, and the liquid phase is formed again. The density will be increased while cleaning the grain boundaries, and high magnet characteristics will be realized after sintering. Another effect of the addition of Co is improvement in corrosion resistance. B
Since the alloy contains more rare earth elements than the A alloy, it is prone to oxidative deterioration, but by adding Co, oxidative deterioration can be prevented and stable magnetic characteristics can be obtained. Further, addition of Co to the A alloy also improves the corrosion resistance of the alloy, reduces oxidative deterioration, and provides stable magnetic properties. A large amount of Dy added to the B alloy exists near the grain boundaries even after both are sintered, and has an effect of improving the coercive force of the magnet alloy C.

Next, a method for producing the magnet alloy C by the two-alloy method will be described. The A alloy and the B alloy obtained as described above are separately crushed and then mixed in a predetermined ratio. The crushing is performed by wet or dry crushing. Rare earth alloys are very active, in order to prevent oxidation during grinding, in an atmosphere such as Ar or nitrogen for dry grinding, in a non-reactive organic solvent such as CFC for wet grinding. Done. The mixing step is also performed in an inert atmosphere or a solvent as needed. Grinding is generally carried out in stages such as coarse grinding and fine grinding, but mixing may be carried out at any stage.
That is, a predetermined amount may be mixed after coarse pulverization and then fine pulverization may be performed, or a predetermined ratio may be mixed after all pulverization is completed. Both A and B alloys need to be mixed uniformly with almost the same average particle size, and the average particle size is preferably in the range of 0.5 to 20 μm. If the average particle size is less than 0.5 μm, it is easily oxidized and deteriorated.
If it exceeds, the sinterability will deteriorate.

The mixing ratio of the A alloy powder and the B alloy powder is A
It is preferable to mix the B alloy powder in the range of 1 to 30% by weight with respect to the alloy powder 99 to 70% by weight. If the B alloy powder is less than 1% by weight, the sintered density cannot be increased and coercive force cannot be obtained. If it exceeds 30% by weight, the proportion of the non-magnetic phase after sintering becomes too large and the residual magnetic flux density becomes small. The obtained mixed fine powder of A alloy and B alloy is then molded into a desired size by a molding press in a magnetic field, and further sintered and heat treated. Sintering is performed in a temperature range of 900 to 1,200 ° C. in a vacuum or an argon atmosphere for 30 minutes or more, and then, an aging heat treatment is performed at a temperature lower than the sintering temperature for 30 minutes or more. After the sintering, the density of the molded body of the magnet alloy C is densified to 95% or more in terms of the true density ratio, and a high residual magnetic flux density can be obtained.

[0017]

EXAMPLES Hereinafter, specific embodiments of the present invention will be described with reference to examples, but the present invention is not limited to these. (Example 1, Comparative Example 1) Composition formula 12.5Nd-6B-1.5Co-80Fe using Nd, Fe metal and ferroboron having a purity of 99.9% by weight.
After alloy casting (at each atomic%) was melted and cast in an Ar atmosphere of a high frequency melting furnace, the ingot was solution-treated at 1,070 ° C. in an Ar atmosphere for 20 hours. This is an A1 alloy. Next, an alloy of composition formula 20Nd-10Dy-20Fe-6B-44Co was similarly melt-cast in an Ar atmosphere using a high-frequency melting furnace using Nd, Dy, Fe, Co metals and ferroboron with a purity of 99.9% by weight. B1
It was an alloy. The A1 alloy ingot and the B1 alloy ingot were separately coarsely crushed in a nitrogen atmosphere to 30 mesh or less, and then 90% by weight of the A1 alloy coarse powder and 10% by weight of the B1 alloy coarse powder were replaced with nitrogen. 30 in V blender
Mix for minutes. This mixed coarse powder was finely pulverized with a jet mill using high-pressure nitrogen gas to an average particle size of about 5 μm. The obtained mixed fine powder was press-molded at a pressure of about 1 Ton / cm ² while orienting in a magnetic field of 15 kOe. Next, this compact was sintered in an Ar atmosphere sintering furnace at 1,070 ° C for 1 hour,
Further, the alloy was subjected to an aging heat treatment at 530 ° C. for 1 hour and rapidly cooled to prepare a magnet alloy C1.

For comparison, an alloy having the same composition as that of Example 1 was manufactured by the conventional one-alloy method to obtain Comparative Example 1. That is,
The same composition (magnet alloy C1) after mixing both A1 and B1 alloys is weighed from the beginning, melted, crushed, sintered, and aged heat treated to 2
The magnetic characteristics were compared with the magnet by the alloy method (magnet composition C1 of Example 1). The composition of this magnet alloy C1 is 13.1 Nd-in both Example 1 by the two-alloy method and Comparative Example 1 by the one-alloy method.
It is 0.8Dy-4.5Co-6.0B-75.6Fe. Table 1 shows the magnetic property values and the sintered body densities obtained for both the sintered body magnets of Example 1 and Comparative Example 1. The magnetic properties of Example 1 are almost the same as those of Comparative Example 1 in terms of the density of the sintered body, but the values of Example 1, such as residual magnetic flux density, coercive force, and maximum energy product, are much higher than those of Comparative Example 1. There is. Thus, even if the composition of the magnet alloy C is exactly the same, there is a considerable difference in the magnetic properties, indicating that the two-alloy method is an extremely effective method for improving the magnetic properties of the Nd magnet. The metal structure of the B1 alloy in the cast state is shown in FIG. 1 by a backscattered electron image photograph of a scanning electron microscope. As can be seen from the lightness and darkness of the photograph, there are four main constituent phases in the B1 alloy. Each phase is analyzed by EPMA (electron probe X-ray microanalyzer) and X-ray analysis.
RT ^{2 4} B-phase as shown in FIG, RT ^{2 3-phase,} RT ^{2 2} phase,
It was found to be the R-rich phase.

(Examples 2-12, Comparative Examples 2-12) As shown in Table 1, corresponding to the alloy compositions of Examples 2-12, A1, A3, A5, A7-A10, A12 as A alloys. Of the composition alloy B2, B3, B5, B6, B7, B9, B10, B12 as an alloy B, and then pulverized by the same method as in Example 1 and mixed in a predetermined ratio in a magnetic field. Molding, sintering (1,050 to 1,120 ° C x 1 hour), aging treatment (500 to 600 ° C x 1 to 10 hours) were carried out to produce a two-alloy method magnetic alloy C2 to C12, and its magnetic characteristics were measured to obtain Table 1 2 is also described. For comparison, Examples 2 to 2 except that alloys having the same compositions as those of Examples 2 to 12 were produced by the one alloy method.
Magnetic alloys C2 to C12 were manufactured under the same conditions as in Example 12, and the magnetic properties were measured to give Comparative Examples 2 to 12, which are also shown in Tables 1 and 2.

[0020]

[Table 1]

[Table 2]

[0021]

EFFECTS OF THE INVENTION The rare earth permanent magnet manufactured according to the present invention effectively utilizes expensive additive elements and has several magnetic properties superior to those of the conventional rare earth magnets having the same composition. It has become possible to provide a high-performance magnet with a well-balanced residual magnetic flux density and high energy product. Therefore, it is expected to be widely used in the future as a high-performance magnet for various electric and electronic devices.

[Brief description of drawings]

FIG. 1 is a metallographic diagram in a cast state of a B1 alloy of Example 1 by a scanning electron microscope photograph.

[Explanation of symbols]

1 RT ^{2 4} B phase 2 RT ^{2 3} phase 3 RT ^{2 2} phase 4 R rich phase

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[Procedure amendment]

[Submission date] July 10, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

The two alloy methods proposed so far can be roughly classified into three types. The first method is to prepare an amorphous or fine crystal alloy by liquid quenching one of the raw material alloy powders to be mixed, and mix it with a normal rare earth alloy powder, or to mix both raw material alloy powders together. Method of preparing and mixing by liquid quenching method [Japanese Patent Laid-Open No. 63-9
3841, JP 63-115307, JP 63-252403, JP Akira 63 -278
208, JP-A-1-108707, JP-A-1-146310, JP-A-1-146309,
See Japanese Patent Laid-Open No. 1-155603]. Regarding the two-alloy method using the alloy by this liquid quenching method, recently, 50MG
Reported that magnetic properties exceeding Oe were obtained [E.Otuki, T.Otuka
and T.Imai; 11th.Int.Workshopon Rare Earth Magnet
s, Pittsburgh, Pennsylvania, USA, October (1990), p.328
Has been referred to].

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

In the second method, two kinds of raw material alloy powders to be mixed are mainly used as R ₂ Fe ₁₄ B compound, and an alloy in which the kind and content of the rare earth element contained are changed is prepared and mixed and sintered. Is the way. That is, a method of mixing two kinds of alloys in which the amount ratio of the contained Nd-rich phase or the kind of rare earth element is changed [JP-A-61-81603, JP-A-61-81604, and JP-A-61-816].
05, JP 61-81606, JP 61-81607, JP 61-11900
7, JP 61-207546, JP 63-245 90 3, Hei 1-177335 is the JP reference.

Claims (5)

[Claims] 1. An A alloy is mainly used as an R ₂ T ₁₄ B phase (here, R
Is an alloy of at least one or more rare earth elements mainly composed of Nd, Pr and Dy, and T represents Fe and Co), and the B alloy contains R, Co, Fe and B, and R ₂ T ^{1 14} B phase and / or R rich phase (where R is the same as above, T ¹ is a transition metal element mainly composed of Fe and Co), RT ^{2 4} B phase and RT ² as constituent phases ³ phase, RT ^{2 2} phase, R ² T
^{2 7} phase and RT ^{2 5} phase (wherein R is as defined above, T ² is F
Transition metal elements mainly composed of e and Co, transition metals and B
The alloy consisting of one or two or more phases out of the five phases of A) and 99 to 70% by weight of alloy powder B
The alloy powder is mixed in an amount of 1 to 30% by weight, the mixed alloy powder is pressure-molded in a magnetic field, the molded body is sintered in a vacuum or an inert gas atmosphere, and further subjected to an aging heat treatment at a temperature lower than the sintering temperature. A method of manufacturing a rare earth permanent magnet, characterized in that 2. RT ^{2 4} contained in the B alloy according to claim 1.
B phase, RT ^{2 3-phase,} RT ^{2 2} phase, a melting point of at least one or more phases of the five constituent phases of R ² T ^{2 7} phase and RT ^{2 5} phase 70
A method for producing a rare earth permanent magnet, which is an intermetallic compound having a temperature of 0 ° C to 1,155 ° C. 3. A rare earth magnet, wherein at least one of the five constituent phases contained in the B alloy according to claim 1 or 2 is a magnetic material having a Curie temperature of room temperature or higher. Manufacturing method. 4. Among the five constituent phases contained in the B alloy according to claim 1, 2 or 3, at least one phase is a magnetic material having a Curie temperature of room temperature or higher and a crystalline magnetic anisotropy. A method for manufacturing a rare earth magnet, characterized by being present. 5. The A alloy, B alloy and A according to claim 1.
A method for producing a rare earth magnet, wherein the B mixed alloy powder has an average particle size within a range of 0.5 to 20 μm.