JP2002155347A - Rare earth alloy, its manufacturing method and method for manufacturing rare earth sintered magnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rare earth alloy to which uniform treatment is possible in a short time in heat treatment for a thin strip ingot and its manufacturing method, and to provide a method for manufacturing a rare earth sintered magnet having excellent magnetic properties. SOLUTION: An alloy essentially consisting of, by weight, 20 to 30% R (wherein, R is Sm or two or more kinds of rare earth elements including Sm by >=50%), 10 to 45% Fe, 1 to 10% Cu and 0.5 to 5% Zr, and the balance Co is melted and is thereafter rapidly cooled by a strip casting method to obtain the rare earth alloy. The alloy contains isometric crystals with a grain size of 1 to 200 μm by >=20 vol.% and has a sheet thickness of 0.05 to 3 mm. In this way, excellent magnetic properties can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rare earth metal, a method for producing the same, and a method for producing an Sm ₂ Co ₁₇ based sintered magnet.

[0002]

2. Description of the Related Art
The method for producing a sintered magnet in a Sm ₂ Co ₁₇ permanent magnet is to finely pulverize a composition-adjusted alloy ingot to 1 to 10 μm,
After pressure molding in a magnetic field, the
At 100-1300 ° C, usually around 1200 ° C, 1
Sinter and solution under conditions of time to 5 hours. Then 70
About 10 at a temperature of about 0 to 900 ° C, usually about 800 ° C.
Hold for about an hour at 400 ° C at a temperature drop rate of -1.0 ° C / min.
It is common to apply an aging treatment of gradually cooling to the following. In a normal process, sintering and solution treatment have an optimum temperature range of ± 3 ° C. with respect to a set temperature, and strict control is required. This is because, during sintering and solution treatment, the presence of various types of constituent phases causes the growth of crystal grains due to portions, and variations due to the heat treatment temperature of the phase change, and
The temperature control of the sintering and solution treatment tends to be stricter as the Sm ₂ Co ₁₇ based sintered magnet has higher characteristics. In order to maintain the optimum temperature range and obtain good magnetic properties, a uniform alloy structure with as little segregation as possible is indispensable.

[0003] As a casting method for obtaining an Sm ₂ Co _17- based magnet alloy having a uniform structure, a method of casting a molten alloy in a box-shaped mold or the like is adopted so that the macro structure becomes a columnar crystal. Have been. Here, in order to obtain columnar crystals, the cooling rate of the molten alloy must be increased to some extent, but in the casting method using a box-shaped mold, in the center of the ingot, the cooling rate is lower than the cooling rate at which the columnar crystals are generated. This tends to cause coarsening of the structure and generation of equiaxed crystals. Although this problem can be solved by a method such as reducing the thickness of the ingot, efficient productivity is reduced. For this reason, an ingot having a certain thickness is produced, and the structure is coarsened and an equiaxed crystal is often generated. The coarsening of the structure and the generation of equiaxed crystals result in segregation in the ingot, which has an adverse effect on the magnet structure after sintering and solution treatment, and causes no good magnetic properties to be obtained.

As a method for solving this problem, a casting method using a single roll (strip casting method) has been proposed (JP-A-8-260083). The ingot produced by this casting method has a fine crystal structure and can obtain a uniform alloy structure without segregation. However, when a sintered magnet was manufactured using an ingot having a fine crystal structure as a raw material, the coercive force was improved as compared with a sintered magnet using an ingot cast in a box mold as a raw material, but the residual magnetic flux was increased. It has been confirmed that the density and the maximum energy product are rather lowered (Japanese Patent Laid-Open No. 9-11138).
No. 3). An ingot having a fine crystal structure has a much smaller average crystal grain size than an ingot cast with a box mold. Therefore, when each ingot is finely pulverized to an average fine powder particle size of 5 μm in the process of manufacturing a sintered magnet, the ingot having a fine crystal structure has a value close to the average crystal particle size and the average fine powder particle size. As a result, the finely pulverized particles are no longer a single crystal, the proportion of the polycrystalline finely pulverized particles increases, and the degree of orientation when molded in a magnetic field also decreases. As a result, it is considered that the degree of orientation of the sintered magnet after the heat treatment decreases, leading to a decrease in the residual magnetic flux density and the maximum energy product. For this reason, in the Sm ₂ Co ₁₇ sintered magnet, the ingot cast by the strip casting method is not used as a raw material ingot.

The present invention solves the above-mentioned problems, and a rare-earth alloy capable of performing uniform treatment in a short time when heat-treating a ribbon ingot, a method for producing the same, and a rare-earth sintered magnet having excellent magnetic properties. It is intended to provide a manufacturing method.

[0006]

Means for Solving the Problems and Embodiments of the Invention In order to achieve the above object, the present inventor examined the relationship between the alloy structure and the structural change of the Sm ₂ Co _17- based alloy due to heat treatment. 2 equiaxed crystals with a particle size of 1 to 200 μm
Sm containing 0% by volume or more and having a plate thickness of 0.05 to 3 mm
_It has been found that by using a ₂ Co ₁₇ alloy, heat treatment can be performed in a short time and a homogeneous structure can be easily obtained.

[0007] Then, the alloy is heat-treated in a non-oxidizing atmosphere as described above to grow the average crystal grain size,
It has been found that superior magnetic properties can be obtained as compared with a case where a sintered magnet is manufactured using a conventional cast ingot.

Accordingly, the present invention relates to (1) R (where R is Sm or two or more rare earth elements containing 50% by weight or more of Sm) 20 to 30% by weight, Fe 10 to 45% by weight, Cu 1
10 to 10% by weight, Zr 0.5 to 5% by weight, the balance being obtained by melting an alloy containing Co as a main component, followed by quenching by a strip casting method.
Containing 20% by volume or more of equiaxed crystals of
m (2) R (where R is Sm or two or more rare earth elements containing 50% by weight or more of Sm) 20 to 30% by weight, Fe 10 to 45% by weight, Cu 1 to After melting an alloy containing 10% by weight, Zr 0.5 to 5% by weight, and the balance Co as a main component, 1250 to 1600
(3) R (where R is an integer)
Is Sm or two or more rare earth elements containing 50% by weight or more of Sm) 20 to 30% by weight, Fe 10 to 45% by weight, Cu
It is obtained by melting an alloy containing 1 to 10% by weight, Zr 0.5 to 5% by weight, and the balance being Co as a main component, followed by quenching by a strip casting method.
m containing 20% by volume or more of equiaxed crystals and having a thickness of 0.05 to 3
mm in a non-oxidizing atmosphere.
A rare earth element characterized by being subjected to a heat treatment at 000 to 1300 ° C. for 0.5 to 20 hours, finely pulverizing the rare earth magnet alloy, compression molding in a magnetic field, sintering and solution, and then aging. Provided is a method for manufacturing a sintered magnet.

In the Sm ₂ Co ₁₇ alloy, Sm has a very high vapor pressure, evaporates during a high-temperature and long-time heat treatment, and a magnet having a composition deviation causes a magnetic field such as a coercive force variation. On the other hand, if the heat treatment is performed at a low temperature and for a short time in order to avoid the evaporation of Sm, the effect of the heat treatment becomes insufficient, and the residual magnetic flux density,
Although the maximum energy is reduced, the use of the above-mentioned alloy makes it possible to perform an optimal heat treatment in a short time, thereby increasing the crystal grain size without causing a composition deviation, and increasing the Sm ₂ Co This is pulverized using a ₁₇ series magnet alloy, molded in a magnetic field, and sintered, solution-processed and aged to provide Sm with excellent magnetic properties.
_{A 2} Co ₁₇ based sintered magnet can be obtained.

Hereinafter, the present invention will be described in more detail.
The main components of the rare earth alloy (Sm ₂ Co ₁₇ based permanent magnet alloy) composition in the present invention are Sm or two or more rare earth elements containing 50% by weight or more of Sm, 20 to 30% by weight, Fe 10 to 10% by weight.
45% by weight, 1 to 10% by weight of Cu, 0.5 to 5% by weight of Zr, the balance being Co and unavoidable impurities. The rare earth metal other than Sm is not particularly limited, and examples thereof include Nd, Ce, Pr, and Gd. When the content of Sm in the rare earth element is less than 50% by weight, or when the amount of the rare earth element is less than 20% by weight or more than 30% by weight, it is impossible to have effective magnetic properties.

The Sm ₂ Co ₁₇ based permanent magnet alloy of the present invention comprises:
The raw material having the above composition range is melted by high frequency melting in a non-oxidizing atmosphere, and the molten alloy is further cooled to 1250 to 1250.
It is quenched to 1600 ° C. by a strip casting method. If the temperature of the molten metal before quenching is lower than 1250 ° C., the quenching temperature range becomes narrow, and very large crystals having a crystal grain size of 200 μm or more are formed, leading to uneven composition. In addition, when the temperature of the molten metal is low, the viscosity is low, and a ribbon having a thickness of 3 mm or less is difficult to be formed. Preferably, the temperature is 1300 ° C. or higher. 1
If the temperature is higher than 600 ° C., the evaporation of Sm during melting is so severe that a composition shift occurs and stable production cannot be performed. Preferably, the temperature is 1500 ° C. or lower.

If the crystal grain size of the ribbon thus obtained is small, the grain formation length rate is high during the heat treatment, and the grains smaller in the heat treatment gradually grow into larger grains while being eaten by the larger grains. Therefore, if the particle size is small, the grain growth proceeds quickly. However, if the grains are too fine, the grain growth will vary depending on the location, and the grain size after heat treatment will not be uniform. For these reasons, the crystal grain size is 1 to 200 μm.
Is preferred. More preferably, the thickness is 5 to 100 μm.

The grain size of the alloy system is 1 to 200 μm.
Equiaxed crystal (here, an equiaxed crystal is one in which the difference in length between the major axis and the minor axis is relatively small and the crystal axis direction is random, and solidified in one direction from the roll surface toward the free surface) The columnar crystal is distinguished from the columnar crystal by forming a large number of nuclei, which are buds of the crystal before solidification, and crystallizing all at once when heat is taken away on the roll surface. For this reason, in order to form an equiaxed crystal, it is preferable to perform cooling immediately above the solidification temperature where more nuclei exist. At this time, the equiaxed crystal is easy to obtain a homogeneous structure because many nuclei crystallize at the same time. For this reason, segregation does not occur unlike a large equiaxed crystal having a size of several hundred μm or more which is generated at the time of casting by the book mold method. Furthermore, the equiaxed product has a similar aspect ratio (length ratio of the major axis and the minor axis) to the crystal after the heat treatment, and the heat treatment can be performed in a shorter time than only the columnar crystal having a large difference between the major axis direction and the minor axis direction. it can. When the equiaxed crystal is contained in an amount of 20% by volume or more, the equiaxed product is easily coarsened, and the coarsened grains further grow while taking in small grains, so that heat treatment can be performed in a short time. When the number of equiaxed crystals that induces uniform coarsening of the particle size is large as described above, the treatment can be performed in a shorter time, and the content of the equiaxed crystals is preferably 30% by volume or more, more preferably 40% by volume or more. It is.

If the thickness of the ribbon is too small, it will be excessively cooled on the roll and the crystal grains will be small. Therefore, a thickness of 0.05 mm or more is required to obtain a preferable grain size. It is. On the other hand, if the plate thickness is large, the cooling is slow and the particle size becomes large.

In the case of forming the above-mentioned ribbon thickness, the peripheral speed of the roll during rapid cooling of the roll is preferably 0.5 to 10 m / s. In the strip casting method, the alloy melt can be poured into a single roll or twin rolls and quenched to form an alloy. The temperature of the alloy melt poured into the roll is preferably 1250 to 1600 ° C.

When manufacturing an Sm ₂ Co ₁₇ based sintered magnet using the above Sm ₂ Co ₁₇ based permanent magnet alloy, first, the cast ribbon ingot is placed in a non-oxidizing atmosphere such as argon or helium. 1000-1300 ° C, 0.5
Heat treatment for 20 to 20 hours, whereby the average crystal grain size is 20 to 300 μm, more preferably 30 to 200 μm.
m is preferable. The heat treatment temperature is 1000
If the temperature is lower than 0 ° C, crystal grains of the ingot cannot be sufficiently grown. If the temperature exceeds 1300 ° C, the crystal grains grow sufficiently, but the ingot reaches the melting point, and a uniform structure cannot be obtained. If the heat treatment time is less than 0.5 hour, the growth of the crystal grains varies, and furthermore, it is difficult to sufficiently obtain the growth of the crystal grains. , And good magnetic properties tend not to be obtained due to evaporation of Sm in the ingot. Further, when the average crystal grain size is less than 20 μm, as described above, the average crystal grain size in the ingot and the finely pulverized particle size in the sintered magnet manufacturing process are close to each other. ,
It becomes polycrystalline and disturbs the degree of orientation of the magnet, resulting in deterioration of the residual magnetic flux density and the maximum energy product.In order to obtain an average crystal grain size exceeding 300 μm, a long time or heat treatment at a high temperature is required, Factors such as deterioration of the alloy structure or loss of uniformity of the structure may adversely affect the magnetic properties of the sintered magnet.

Next, the Sm ₂ Co ₁₇ permanent magnet alloy is coarsely pulverized and finely pulverized to an average particle size of 1 to 10 μm, preferably about 5 μm. This coarse pulverization can be performed, for example, in an inert gas atmosphere by a jaw crusher, a brown mill, a pin mill, hydrogen storage, or the like. Also,
The pulverization can be performed by a wet ball mill using an alcohol, hexane or the like as a solvent, a dry ball mill in an inert gas atmosphere such as nitrogen or argon, a jet mill using an inert gas stream, or the like.

Further, the above-mentioned pulverization is preferably carried out by 10 k
A pressing machine in a magnetic field capable of applying a magnetic field of Oe or more is preferably 500 kg / cm ² or more and 200 kg / cm ² or more.
Compression molding is performed under a pressure of less than 0 kg / cm ² . Subsequently, the obtained compression-molded product is subjected to heat treatment in a non-oxidizing atmosphere gas such as argon in a gas atmosphere of 1100 to 1300.
° C, preferably 0.5 to 1150 ° C to 1250 ° C.
After sintering and solution treatment for ~ 5 hours, quenching is performed after completion. Subsequently, an aging treatment is performed at a temperature of 700 to 900 ° C., preferably 750 to 850 ° C., for 5 to 40 hours, and gradually cooling to 400 ° C. or less at a temperature lowering rate of −1.0 ° C./min. Thereby, the Sm ₂ Co ₁₇ based sintered magnet of the present invention can be obtained.

[0019]

Next, the present invention will be described in detail with reference to examples of the present invention and comparative examples. However, the present invention is not limited to these examples.

[Example 1] A Sm ₂ Co ₁₇ magnet ingot was composed of 25.5% by weight of Sm, 16.0% by weight of Fe,
Cu: 5.0% by weight, Zr: 3.0% by weight, the balance being Co, and melting in a high-frequency melting furnace using an alumina crucible in an argon gas atmosphere, followed by strip casting (water cooling). 1m / s using single roll
An alloy having a thickness of 0.3 mm was produced by casting at a melt temperature of 1350 ° C. at a roll peripheral speed of 1 mm. FIG. 1 shows a polarizing microscope structure photograph at this time. This alloy has an average crystal grain size of 10 μm and an equiaxed crystal 9 having a crystal grain size of 1 to 200 μm.
5% by volume, with the balance being columnar crystals. Here, the average crystal grain size indicates the grain size when the volume is converted into a sphere. (Hereinafter, the average crystal grain size is assumed to be obtained by this method.) Next, the Sm ₂ Co _17- based magnet ingot was placed in an argon atmosphere using a heat treatment furnace in an argon atmosphere.
Heat treatment was performed at 200 ° C. for 1 hour, and after the completion, it was rapidly cooled.
The Sm content of the Sm ₂ Co _17- based magnet alloy obtained here was quantified by an ion exchange separation method, and the average crystal grain size was measured.

Further, the Sm ₂ Co _17- based magnet alloy was roughly pulverized to about 500 μm or less by a jaw crusher, and then finely pulverized to an average particle size of about 5 μm by a jet mill using a nitrogen stream. The obtained finely pulverized product is pressed by a press machine in a magnetic field for 15 minutes.
It was molded at a pressure of 1.5 t / cm ^{2 in} a magnetic field of kOe. The obtained compact was sintered in an argon atmosphere at 1210 ° C. for 2 hours using a heat treatment furnace, and then subjected to a solution treatment at 1190 ° C. for 1 hour in an argon atmosphere. After the solution treatment, the mixture was rapidly cooled, and each of the obtained sintered bodies was kept in an argon atmosphere at 800 ° C. for 10 hours, and gradually cooled to 400 ° C. at a temperature lowering rate of −1.0 ° C./min. A sintered magnet was produced. For each of the obtained sintered magnets, BH
The magnetic properties were measured with a tracer.

[Comparative Example 1] An alloy having the same composition as in Example 1 was melted in a high-frequency melting furnace using an alumina crucible in an argon gas atmosphere, and strip casting was performed (using a water-cooled single roll, 1 m / m2). at a molten metal temperature of 1650 ° C. at a roll temperature of 1650 ° C.).
A 3 mm alloy was made. FIG. 2 shows a micrograph of the polarizing microscope structure at this time. This alloy had an average crystal grain size of 20 μm, a crystal structure having a crystal grain size of 1 to 200 μm, 5% by volume of equiaxed crystals, and a balance of columnar crystals.

The Sm ₂ Co _17- based magnet alloy obtained here was subjected to heat treatment in the same manner as in Example 1, and the Sm ₂ Co ₁₇
The Sm content of the m ₂ Co _17- based magnet alloy was quantified by an ion exchange separation method, and the average crystal grain size was measured.

The obtained Sm ₂ Co _17- based magnet alloy was
In the same production method as in Example 1, coarse pulverization, fine pulverization, molding in a magnetic field, sintering, solution treatment, and then aging treatment were performed to produce a sintered magnet. The magnetic properties of the obtained sintered magnet were measured in the same manner as in Example 1.

Table 1 shows Sm in Example 1 and Comparative Example 1.
Sm amount of ₂ Co ₁₇ magnet alloy, the average grain size, and show the magnetic properties of the sintered magnets obtained from the magnet alloy. From this, the example has a higher residual magnetic flux density,
It is clear that the coercive force and the maximum energy product are excellent.

[0026]

[Table 1]

Example 2 A Sm ₂ Co ₁₇ based magnet ingot was composed of Sm: 20.0% by weight, Ce: 5.5% by weight, F:
e: 14.0% by weight, Cu: 5.0% by weight, Zr: 3.
0% by weight, the balance being Co, melted in an argon crucible using an alumina crucible in a high-frequency melting furnace, and strip-casting (using a water-cooled single roll, 2.5 m / s roll peripheral speed) at 14
Casting at a melting temperature of 00 ° C makes the plate thickness 0.2m
m were prepared. The average crystal grain size of this alloy is 30μ
The crystal was composed of 80% by volume of equiaxed crystals having a crystal grain size of 1 to 200 μm and the remainder being columnar crystals. Next, the Sm ₂ Co
_{The 17} system magnet ingot was heat-treated at 1100 ° C. for 2 hours in an argon atmosphere using a heat treatment furnace.
Quenched. The crystal grain size of the Sm ₂ Co _17- based magnet alloy obtained here was measured, and the distribution was examined. This is shown in FIG.

Next, the Sm ₂ Co _17- based magnet alloy was roughly pulverized to about 500 μm or less with a jaw crusher, and then finely pulverized to a mean particle size of about 5 μm by a jet mill using a nitrogen stream. The obtained pulverized product was molded by a press in a magnetic field at a pressure of 1.5 t / cm ^{2 in} a magnetic field of 15 kOe. The obtained compact was sintered in an argon atmosphere at 1190 ° C. for 2 hours using a heat treatment furnace, and then subjected to a solution treatment in an argon atmosphere at 1170 ° C. for 1 hour. After the solution treatment was completed, the mixture was quenched and each of the obtained sintered bodies was kept at 800 ° C. for 10 hours in an argon atmosphere.
Until the temperature was lowered at a rate of -1.0 ° C./min to produce a sintered magnet. For each of the obtained sintered magnets, B-
Magnetic properties were measured with an H tracer.

Comparative Example 2 An alloy having the same composition as in Example 2 was melted in an argon gas atmosphere using an alumina crucible in a high-frequency melting furnace, and strip casting was performed (using a water-cooled single roll, 50 m / m2). s roll peripheral speed)
Casting at a temperature of 1240 ° C with a thickness of 0.1
mm alloy was produced. The average crystal grain size of this alloy is 0.1.
5% by volume of equiaxed crystals having a crystal grain size of 1 to 200 μm at 5 μm, 90% by volume of equiaxed crystals having a crystal grain size of less than 1 μm, and the remainder being columnar crystals. The Sm ₂ Co _17- based magnet alloy obtained here was subjected to a heat treatment in the same manner as in Example 2, and the crystal grain size of the Sm ₂ Co _17- based magnet alloy obtained here was measured.
The distribution was examined. This is shown in FIG.

The obtained Sm ₂ Co _17- based magnet alloy was
By the same manufacturing method as in Example 2, coarse grinding, fine grinding, molding in a magnetic field, sintering, solution treatment, and then aging treatment were performed to produce a sintered magnet. Magnetic properties of the obtained sintered magnet were measured in the same manner as in Example 2.

Comparative Example 3 Thickness of Sm ₂ Co _17- based magnet alloy obtained by melting in a high-frequency melting furnace using an alumina crucible in an argon gas atmosphere so as to have the same composition as in Example 2. Was cast to a copper box-type mold so that the diameter was 15 mm. The obtained Sm ₂ Co _17- based magnet alloy was measured for crystal grain size in the same manner as in Example 2, and the distribution was examined. This is shown in FIG.

The obtained Sm ₂ Co _17- based magnet alloy was
By the same manufacturing method as in Example 2, coarse grinding, fine grinding, molding in a magnetic field, sintering, solution treatment, and then aging treatment were performed to produce a sintered magnet. Magnetic properties of the obtained sintered magnet were measured in the same manner as in Example 2.

Table 2 shows the magnetic properties of the Sm ₂ Co _17- based magnet alloy in Example 2 and Comparative Examples 2 and 3. Comparing FIG. 3, FIG. 4, and FIG. 5, Example 2 has a uniform distribution around 50 μm, whereas Comparative Example 2 has a large distribution width and many small grains. Comparative Example 3 has a very large particle size. Reflecting this, Example 2 is compared with Comparative Examples 2 and 3,
It can be seen that the residual magnetic flux density, coercive force, and maximum energy product are excellent.

[0034]

[Table 2]

[0035]

According to the present invention, excellent magnetic characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a polarization image photograph of an alloy ribbon in Example 1 taken by a polarization microscope.

FIG. 2 is a polarization image photograph of an alloy ribbon in Comparative Example 1 taken by a polarization microscope.

FIG. 3 is a particle size distribution diagram after heat treatment of an alloy ribbon in Example 2.

FIG. 4 is a particle size distribution diagram after heat treatment of an alloy ribbon in Comparative Example 2.

FIG. 5 is a particle size distribution chart of a thin alloy ribbon after heat treatment in Comparative Example 3.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 1/053 H01F 41/02 G 41/02 1/04 B (72) Inventor Takahiro Hashimoto Takefu City, Fukui Prefecture 2-1-5 Hokufu Shin-Etsu Chemical Co., Ltd. Magnetic Materials Research Laboratory (72) Inventor Takehisa Minowa 2-1-5 Kitafu, Takeo-shi, Fukui Prefecture Shin-Etsu Chemical Co., Ltd. Magnetic Materials Research Laboratory F-term (reference) 4K018 AA27 BA05 BA18 BA19 BB05 BC01 BC08 BD01 CA04 DA11 FA08 KA45 5E040 AA08 AA19 BD01 CA01 HB03 HB06 HB11 NN01 NN18 5E062 CD04 CE04 CG05

Claims (3)

[Claims] 1. 20 to 30% by weight of R (where R is Sm or two or more rare earth elements containing 50% by weight or more of Sm)
Fe10 to 45% by weight, Cu1 to 10% by weight, Zr0.
After melting the alloy containing 5 to 5% by weight and the balance Co as a main component,
A rare earth alloy obtained by quenching by a strip casting method, containing 20% by volume or more of equiaxed crystals having a particle size of 1 to 200 μm and having a thickness of 0.05 to 3 mm. 2. 20 to 30% by weight of R (where R is Sm or two or more rare earth elements containing 50% by weight or more of Sm)
Fe10 to 45% by weight, Cu1 to 10% by weight, Zr0.
After melting the alloy containing 5 to 5% by weight and the balance Co as a main component,
The method for producing a rare earth alloy according to claim 1, wherein the strip casting is performed at a hot water temperature of 1250 to 1600 ° C. 3. 20 to 30% by weight of R (where R is Sm or two or more rare earth elements containing 50% by weight or more of Sm)
Fe10 to 45% by weight, Cu1 to 10% by weight, Zr0.
After melting the alloy containing 5 to 5% by weight and the balance Co as a main component,
A rare earth alloy obtained by quenching by a strip casting method and containing 20% by volume or more of equiaxed crystals having a particle size of 1 to 200 μm and a plate thickness of 0.05 to 3 mm,
1000 ° C. to 1300 ° C. in a non-oxidizing atmosphere,
After performing a heat treatment for 0.5 to 20 hours, finely pulverizing the rare earth magnet alloy, compression molding in a magnetic field, sintering, solutionizing,
Next, a method for producing a rare earth sintered magnet, which is subjected to aging treatment.