JP2802546B2 - Manufacturing method of rare earth magnet powder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rare earth element (hereinafter referred to as R) having excellent magnetic anisotropy.
Indicated by The present invention relates to a method for producing a -Fe-B-based alloy magnet powder, a method for producing an R-Fe-B-Co-based alloy magnet powder having excellent magnetic anisotropy and temperature characteristics, and a method for producing the powder. In this case, the present invention relates to a stable manufacturing method with less variation in magnetic characteristics.

Further, the present invention relates to a resin-bonded magnet manufactured by an injection molding method or a compression molding method using the R-Fe-B-Co alloy magnet powder.

BACKGROUND ART With the recent demand for smaller, more efficient, diversified electronic devices and harsh environments such as automobiles exposed to high temperatures, permanent magnets are required to have higher performance. Have been. Rare earth magnets have been actively developed as permanent magnets to meet this demand, and R-Fe-B alloys have recently been attracting attention as permanent magnet materials exhibiting excellent magnetic properties. -Development of Fe-B based alloy magnet powder is being carried out.

In particular, a method for producing an R-Fe-B-based alloy magnet powder by subjecting an R-Fe-B-based alloy to hydrogen absorption and then dehydrogenating is attracting attention as a method for producing a magnet powder having excellent magnetic properties. I have. For example, there is an R-Fe-B-based alloy magnet powder described in JP-A-1-132106.

This R-Fe-B-based alloy magnet powder has a ferromagnetic phase of R ₂
Fe ₁₄ B type intermetallic compound phase (hereinafter referred to as R ₂ Fe ₁₄ B type phase)
An ingot of an R-Fe-B-based alloy or a powder of the ingot having a main phase of hydrogen is held in a hydrogen atmosphere heated to a high temperature to occlude hydrogen. By dehydrogenation below, an R ₂ Fe ₁₄ B type phase, which is a ferromagnetic phase, was generated again. The structure of the resulting R-Fe-B-based alloy magnet powder has a texture mainly composed of a recrystallized structure of an extremely fine R ₂ Fe ₁₄ B type phase having an average particle size of 0.05 to 3 μm. And has high magnetic properties.

However, although the R-Fe-B-based alloy magnet powder produced by the above method has excellent magnetic properties, depending on the alloy composition, crystal structure and grain size of the ingot, homogenization treatment,
Due to minute fluctuations in processing conditions such as hydrogen storage and dehydrogenation, the magnetic anisotropy of the obtained R-Fe-B-based alloy magnet powder is remarkably reduced or the magnetic anisotropy varies. . Such a decrease and variation are not only inconvenient when mass-produced industrially, but also difficult for industrialization.

In order to solve this problem, for example, Japanese Patent Laid-Open No.
The cause of the variation in magnetic anisotropy in Japanese Patent Publication No. 08 and JP-A-4-17604 is that the hydrogen storage treatment causes a temperature drop fluctuation difference due to an endothermic reaction, and the ingot is kept warm. And heating and hydrogen treatment with a heat storage material having However, with respect to the present disclosure, it is difficult to make the entire surface of the ingot come into contact with the heat storage material in Japanese Patent Application Laid-Open No. 5-163510, and the heat treatment furnace must be enlarged to accommodate the heat storage material. The problem is pointed out that the magnetic properties are deteriorated due to the fact that heat storage material fragments adhere to the ingot and are mixed.

On the other hand, the Curie point (Tc) of an R-Fe-B-based alloy magnet is generally about 300 ° C., and the maximum temperature is 370 ° C., and its temperature characteristics are poor.

An alloy containing Co as an element for improving the temperature characteristics is pulverized into a powder of 3 to 10 μm by pulverization, and then molded and sintered. As a result, the rise in the Curie point and the residual magnetic flux that lead to the improvement in the temperature characteristics of the sintered permanent magnet A decrease in density has been found.

However, when Co is contained in the R-Fe-B-based alloy, the coercive force iHc tends to decrease as the Co content increases, and improvement thereof has been desired.

In recent years, resin-bonded magnets have been rapidly increasing in use range of sintered magnets compared to sintered magnets. As the background, resin-bonded magnets are inferior in magnetic properties to sintered magnets of the same type because they are manufactured by bonding organic powder or metal-based resin to magnet powder, It can be said that the range of use is rapidly expanding due to the excellent properties, easy handling and high degree of freedom in shape, and the combination of the development of magnet powder with excellent magnetic properties.

There are a compression molding method, an extrusion molding method, and an injection molding method as a molding method of the resin-bonded magnet. In the compression molding method, it is difficult to integrally mold and the degree of freedom of shape is small, but the filling rate of magnet powder is 80
The magnetic properties can be improved because the volume can be increased up to 90 vol%. In the extrusion method, the filling rate of the magnet powder is 70-75.
Although it has a slightly lower% vol, it has excellent magnetic properties and can be continuously manufactured. On the other hand, the injection molding method can be integrally molded and has excellent dimensional accuracy and shape flexibility, but the amount of magnet powder is limited to 60 to 65% vol in order to enhance productivity.
Therefore, its use has been limited because it is difficult to enhance the magnetic performance.

However, as a resin-bonded magnet using a rare-earth magnet powder having excellent magnetic properties, a Sm-Co-based magnet is disclosed in
No. 3507 has an anisotropic magnet by injection molding, and the magnetic properties are improved by a powder magnetization molding method in which magnet powder is first magnetized with a magnetic field higher than the molding magnetic field.

Among the Nd-Fe-B-based magnets, there is a magnet disclosed in JP-A-3-129702 which is excellent in magnetic anisotropy and corrosion resistance by a compression molding method.

On the other hand, technical disclosures on Nd-Fe-B-based magnets have been made in recent years because of research on improving the magnetic properties of rare-earth magnets and resource issues.

However, it has stable quality with excellent productivity
Regarding Nd-Fe-B-Co-based resin-bonded magnets with excellent magnetic anisotropy and temperature characteristics using Nd-Fe-B-Co-based magnet powder, resin-bonded type manufactured by injection molding or compression molding Nothing is disclosed about magnets.

A first object of the present invention is to provide a stable manufacturing method with a small variation in magnetic properties together with an R-Fe-B-based alloy magnet powder having excellent magnetic anisotropy. A second object is to provide an R-Fe-B-Co-based alloy magnet powder having excellent temperature characteristics in addition to magnetic anisotropy, and a stable manufacturing method with small variations in magnetic characteristics. A third object is to provide an R-Fe-B-Co-based resin-bonded magnet having excellent magnetic anisotropy and temperature characteristics.

DISCLOSURE OF THE INVENTION The present inventors have earnestly studied to achieve the above object, and have obtained the following findings.

R-Fe-B alloy magnet powder with magnetic anisotropy has excellent magnetic properties consisting of maximum energy product ((BH) max), coercive force (iHc) and residual magnetic flux density (Br), and is stable with little variation In order to obtain a magnetized alloy magnet powder, the maximum energy product ((BH) max), coercive force (iHc) and residual magnetic flux density (Br) were obtained as an R-Fe-B-Co alloy magnet powder having magnetic anisotropy. In order to obtain a stable alloy magnet powder having excellent magnetic properties and excellent temperature properties and small variations, the R-Fe-B-based alloy or the R-Fe-B-Co-based alloy was hydrogen-absorbed. Then, by performing dehydrogenation treatment, in the hydrogen storage step in producing the R-Fe-B-based alloy magnet powder or the R-Fe-B-Co-based alloy magnet powder, it can be achieved by performing in a pressurized hydrogen atmosphere. I found it .

 Hereinafter, details of the invention will be described.

(A) Manufacturing method of R-Fe-B-based alloy magnet powder (1) R-Fe-B-based alloy The R-Fe-B-based alloy is composed of an R-Fe-B alloy as a base and a part of Fe is Co. , Ni, V, Nb, Ta, Cu, Cr, Mn, T
It may be substituted with one or more of i, Ga, and Zr. Part of B may be replaced with one or more of N, P, S, C, Sn, and Bi.

(2) Homogenization treatment The R-Fe-B alloy as a raw material is an ingot. This ingot is placed in an inert gas atmosphere at a temperature of 800
The temperature is maintained at ~ 1200 ° C to perform the homogenization treatment.

The purpose of this homogenization treatment is to obtain R-Fe-
B-based alloy ingot is often non-equilibrium structure such as alpha-Fe phase is precipitated, this non-equilibrium structure is a cause of lowering the magnetic properties, non-equilibrium prior to the hydrogen storage ~ de H ₂ treatment R ₂ Fe ₁₄ B, which essentially destroys the tissue and destroys the main phase
The purpose of the present invention is to greatly improve magnetic properties by using a homogenized ingot made of a phase as a raw material.

As a homogenization treatment condition, a heat treatment is required in an inert gas atmosphere such as Ar gas in order to prevent oxidation during the homogenization treatment. The pressure of the inert gas atmosphere may be under pressure or under reduced pressure. In the case of under reduced pressure, the pressure should not be reduced until the elements constituting the structure evaporate from the surface of the ingot. This is because the structure fluctuates locally due to the evaporation of the element having a high vapor pressure. When pressurizing, the pressure may be ² to 3 kgf / cm ² from the viewpoint of equipment and processing.

The homogenization treatment temperature is in the range of 800 to 1200 ° C. If the temperature of the homogenization treatment is lower than 800 ° C., a long time is required for the homogenization treatment, so that the industrial productivity is poor. on the other hand,
If the temperature exceeds 1200 ° C., the above-mentioned ingot is undesirably melted.

(3) Coarse pulverization The homogenized ingot is coarsely pulverized into coarse pulverized particles having a size of 5 to 10 mm. The reason for this is that the R-Fe-B-based alloy magnet powder can be manufactured in the final step of reducing contamination such as oxidation of the raw material as much as possible in the process of producing the magnet powder.
The object of the present invention is to improve the magnetic properties of the Fe-B-based alloy magnet powder, to facilitate the handling in industrial production, and to improve the industrial production by shortening the time required for hydrogen storage to dehydrogenation in the subsequent steps.

That is, if the raw material is a powder, the powder itself becomes easily contaminated due to the increased specific surface area of the powder itself as well as the contamination at the time of pulverization. Also, handling with powder is not as easy as coarsely crushed grains.

On the other hand, in the case of an ingot, although handling is easy and no contamination occurs, it takes a long time for hydrogen storage to dehydrogenation treatment in a subsequent process.

(4) Hydrogen storage treatment Next, in order to cause a change in the structure of the above-mentioned homogenized coarsely pulverized particles as a raw material to obtain a recrystallized structure having excellent magnetic properties of the R-Fe-B-based alloy, The temperature is maintained at 750 to 950 ° C. in a pressurized hydrogen atmosphere to absorb hydrogen.

It is necessary to pressurize hydrogen gas in order to store hydrogen uniformly, stably, and quickly in coarsely pulverized particles. As a result, the structural change in the coarsely crushed particles progresses rapidly, and the time during which the coarsely crushed particles are exposed to a high temperature can be shortened. The pressure of the hydrogen gas is preferably 1.2 to 1.6 kgf / cm ² . At less than 1.2 kgf / cm ² , the effect of pressurization does not appear. On the other hand, if it exceeds 1.6 kgf / cm ² , there is a problem of safety in industrial production.
When a mixed gas of hydrogen gas and inert gas is used, a partial pressure of hydrogen gas of 1.2 to 1.6 kgf / cm ² is required.

The temperature is 750 to 950 ° C. If the temperature is lower than 750 ° C., the above-mentioned structural change is not sufficiently performed. If the temperature exceeds 950 ° C., the structural change proceeds excessively, and recrystallization causes grain growth to lower the coercive force.

(5) Dehydrogenation A high coercive force can be obtained by completely dehydrogenating the coarsely pulverized particles that have absorbed hydrogen. As the dehydrogenation conditions, dehydrogenation is performed at a temperature of 500 to 800 ° C. until a vacuum atmosphere with a hydrogen gas pressure of 1 × 10 ⁻⁴ Torr or less is obtained.

Since hydrogen remaining in the magnet powder lowers the magnetic flux density, it is necessary to perform dehydrogenation to a vacuum atmosphere at a hydrogen gas pressure of 1 × 10 ⁻⁴ Torr or less. Further, the hydrogen gas pressure is used to prevent oxidation of the coarsely pulverized particles during the dehydrogenation treatment.

The reason for setting the temperature to 500 to 800 ° C. is that if the temperature is lower than 500 ° C., dehydrogenation becomes insufficient, hydrogen remains in the magnet powder, and the coercive force decreases. On the other hand, if the temperature exceeds 800 ° C., the recrystallized structure becomes coarse and the magnetic properties deteriorate.

The coarsely pulverized particles that have been dehydrogenated are already in a state of being easily contaminated as aggregates of fine powders that have restructured and recrystallized as hydrogen disintegration products, and the hydrogen gas pressure maintained at a temperature of 500 to 800 ° C Immediately cooling from a vacuum atmosphere of 1 × 10 ⁻⁴ Torr or less to room temperature to prevent contamination such as oxidation can improve the residual magnetic flux density.

The cooling rate is increased by using a pressurized inert gas as the atmosphere, and 50 ° C./m to prevent contamination due to condensation of the impurity gas components into the collapsed material during cooling.
It is preferable to cool at a rate of in or more.

(B) Manufacturing method of R-Fe-B-Co alloy magnetic powder (1) R-Fe-B-Co alloy An ordinary ingot alloy is used for the R-Fe-B alloy. The composition of this alloy is as follows: R; 12 to 15% B; 5 to 8% Co; 15 to 23% Ga; 0.3 to 2.0%, with the balance being Fe and inevitable impurities.

 Further, the alloy may contain one or more of Mo: 0.70% or less, V; 0.70% or less, Zr; 0.70% or less, Ti; 0.30% or less.

 Hereinafter, the reasons for limitation of each component are shown.

R is one or more of the rare earth elements containing Nd, but Nd alone or a mixture of Nd and Pr or Dy is particularly preferable. If it is less than 12%, the coercive force decreases, and if it exceeds 15%, the residual magnetic flux density decreases.

 In addition, Nd is preferably in the range of 12.1 to 13.0%.

If B is less than 5%, the coercive force decreases, and if it exceeds 8%, the residual magnetic flux density decreases. More preferably, 5.0 to 7.0
% Range.

It is desirable to contain a large amount of Co in order to improve the Curie point, but a small amount is desirable because the coercive force is reduced. Further, it is preferably in the range of 19.5 to 21.5%.

Ga is an element that improves the magnetic anisotropy and coercive force. However, if it is less than 0.3%, the effect cannot be obtained, and if it exceeds 2.0%, the anisotropy and coercive force decrease. Furthermore, preferably
It is in the range of 1.5-1.8%.

Mo, V, and Zr are elements that improve the coercive force and the maximum energy product. However, if the content exceeds 0.70%, the effect of the coercive force is saturated, and the maximum energy product and the residual magnetic flux density are reduced. Was set to 0.70%.

Ti is an element that improves the coercive force, but because it is an element that lowers the residual magnetic flux density, the upper limit of the content is set to 0.30%.

(2) Homogenization treatment and coarse pulverization treatment The homogenization treatment conditions are basically the same as those of the (A) R-Fe-B-based alloy, but the homogenization temperature and hydrogen storage treatment by adding Co are increased. Are different in the size of the coarsely crushed mass.

The homogenization treatment temperature is in the range of 1000 to 1150 ° C. If the temperature of the homogenization treatment is lower than 1000 ° C., a long time is required for the homogenization treatment, so that the industrial productivity is poor. on the other hand,
If the temperature exceeds 1150 ° C., the above ingot melts, which is not preferable.

The homogenized ingot is coarsely crushed into a coarsely crushed lump having a size of 30 mm or less. This is for the purpose of improving magnetic properties by preventing contamination such as oxidation of raw materials in the process of manufacturing the R-Fe-B-Co-based alloy magnet powder, and facilitating handling and improving productivity in industrial production.

(3) Hydrogen storage treatment Pressure was applied in order to cause a structural change of the above-mentioned homogenized coarsely crushed lump as a raw material to obtain a recrystallized structure having excellent magnetic properties of the R-Fe-B-based alloy. In a hydrogen gas atmosphere, the temperature is maintained at 780 to 860 ° C to absorb hydrogen.

It is necessary to pressurize hydrogen gas in order to store hydrogen uniformly, stably and quickly in the coarsely pulverized mass. As a result, the structural change within the coarsely crushed mass can be rapidly progressed, and the time during which the coarsely crushed mass is exposed to a high temperature can be reduced.

The pressure of the hydrogen gas is preferably 1.1 to 1.8 kgf / cm ² . If it is less than 1.1 kgf / cm ² , the effect of pressurization is small. Meanwhile, 1.
If it exceeds 8 kgf / cm ² , the effect will be saturated. Further, there is a problem of safety in industrial production.

When a mixed gas of a hydrogen gas and an inert gas is used, the pressure of the above-mentioned pressurized hydrogen gas atmosphere of 1.1 to 1.8 kgf / cm ² is required as the hydrogen gas partial pressure.

The temperature is 780-860 ° C. If the temperature is lower than 780 ° C., the above structural change is not sufficiently performed, and if the temperature exceeds 840 ° C., the structural change proceeds too much, and recrystallization causes grain growth to lower the coercive force.

The atmosphere during the heating from room temperature to the above-mentioned temperature of 780 to 860 ° C. may be vacuum, an inert gas such as Ar gas, or hydrogen gas.

(4) Dehydrogenation A high coercive force can be obtained by completely dehydrogenating the coarsely pulverized mass that has absorbed hydrogen. As the dehydrogenation conditions, dehydrogenation is performed at a temperature of 500 to 860 ° C. until a vacuum atmosphere with a hydrogen gas pressure of 1 × 10 ⁻⁴ Torr or less is obtained.

Since hydrogen remaining in the magnet powder lowers the residual magnetic flux density, the dehydrogenation treatment is performed up to a vacuum atmosphere at a hydrogen gas pressure of 1 × 10 ⁻⁴ Torr or less. The hydrogen gas pressure is used to prevent oxidation of the coarsely crushed lump during the dehydrogenation treatment.

The reason why the temperature is set to 500 to 860 ° C. is that if the temperature is lower than 500 ° C., dehydrogenation becomes insufficient, hydrogen remains in the magnet powder, and the coercive force decreases. On the other hand, if the temperature exceeds 860 ° C., the recrystallized structure becomes coarse and the magnetic properties deteriorate.

The dehydrogenation treatment may be performed at a predetermined temperature within the range of 500 to 860 ° C, or may be performed while lowering the temperature from 860 ° C or lower.

The dehydrogenated coarse pulverized lump has already changed its structure as a hydrogen disintegration substance, and is in an easily contaminated state as an aggregate of recrystallized fine powder.Hydrogen gas pressure maintained at a temperature of 500 to 860 ° C Immediately cooling from a vacuum atmosphere of 1 × 10 ⁻⁴ Torr or less to room temperature to prevent contamination such as oxidation can improve the residual magnetic flux density.

The cooling rate can be increased by using a pressurized hydrogen gas or an inert gas such as an argon gas as the atmosphere. Further, it is preferable to cool at a rate of 30 ° C./min or more in order to prevent contamination due to the condensation of the impurity gas component into the collapsed product during cooling.

(5) Apparatus for hydrogen storage processing and dehydrogenation processing (hereinafter referred to as the apparatus of the present invention) Heat generation in hydrogen storage processing of R-Fe-B-based alloy and temperature fluctuation due to heat absorption in dehydrogenation processing, hydrogen gas flow rate and It is necessary to control the fluctuation of the hydrogen gas pressure. With these controls, variations in magnetic characteristics are small, and industrial production can be performed.

The raw material holding unit for storing the alloy magnet raw material such as coarsely crushed particles or coarsely crushed mass is composed of a plurality of reaction tubes that divide the raw material and hold the raw materials separated from each other.

For a plurality of reaction tubes, a single heating furnace equipped with a temperature control device for maintaining the same temperature, and a predetermined amount of gas supplied by a single hydrogen gas supply system to maintain a predetermined pressure. And a single vacuum pump system for exhausting hydrogen gas from a plurality of reaction tubes. Further, the outside of the plurality of reaction tubes can be cooled by an inert gas.

The industrial hydrogen storage and dehydrogenation treatments by the apparatus of the present invention can be used for the production of rare earth magnet alloy powder accompanied by an endothermic exothermic reaction, and in particular, control one or more of temperature, hydrogen gas flow rate and hydrogen gas pressure. You will need it when you do.

(6) R-Fe-B-Co-based alloy magnet powder The R-Fe-B-Co-based alloy magnet powder produced by the above process has an extremely fine R ₂ Fe ₁₄ having an average particle size of 0.05 to 3 μm.
It is composed of a texture whose main phase is the recrystallized structure of the B-type ferromagnetic phase, and has a maximum energy product ((BH) max) of 28.5 MGOe or more, preferably 35 MGOe or more, and a residual magnetic flux density (Br) of 10.8 kG.
Above, preferably 12.5 kG or more and coercive force (iHc) 10.0 k
It has excellent magnetic properties over Oe and excellent temperature properties over Curie point (Tc) 480 ° C.

(C) R-Fe-B-Co-based resin-bonded magnet (1) R-Fe-B-Co-based resin-bonded magnet by injection molding R-Fe-Co-B-based alloy magnet powder is 60 to 65 vol% And 35 to 40 vol% of an organic resin or a metal binder. As the resin, nylon 12, nylon 6, or the like is used. When the kneaded material is injection-molded, the magnetic field for molding is 15 because the powder has excellent magnetic properties and the powder is easily oriented.
The injection molding may be performed at kOe or less, preferably about 12 kOe. In addition, the orientation magnetic field can be reduced by improving the degree of shape freedom in order to take advantage of the features of the injection molding method.

(2) R-Fe-B-Co-based resin-bonded magnet by compression molding method 80-90 vol% of R-Fe-Co-B-based alloy magnet powder and 10-20 vol% of thermosetting resin powder are mixed. As the resin, a powder such as an epoxy resin, an acrylic resin, or a phenol resin is used. 120 mixed powder of alloy magnet powder and resin powder
The molding is performed in a magnetic field of 12 kOe or more by heating to a temperature of not less than 0 ° C., preferably to a temperature at which the lowest viscosity of the thermosetting resin is obtained. If the heating temperature is high, the thermosetting reaction proceeds rapidly, so that the orientation of the alloy magnet powder is insufficient and the magnetic properties are degraded.If the heating temperature is low, the thermosetting reaction and the orientation of the alloy magnet powder are poor. Insufficiency results in deterioration of magnetic characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the effects of pressurized hydrogen gas pressure and hydrogen storage temperature during hydrogen storage on the maximum energy product.

FIG. 2 shows the effect of the dehydrogenation treatment temperature on the maximum energy product.

FIG. 3 is a conceptual diagram of the device in the embodiments 3b and 3c.

FIG. 4 shows the variation of the maximum energy product in Example 3b and Comparative Example.

BEST MODE FOR CARRYING OUT THE INVENTION Example 1 Example 1a Nd was used as a rare earth element, melted and cast in a plasma arc furnace, and Nd _12.5 Fe in an atomic% composition of an Nd-Fe-Co-B alloy was used.
A rare earth magnet alloy ingot 1A containing _69.0 Co _11.5 B _6.0 Ga _1.0 as a main component was produced. The above-mentioned ingot is coarsely crushed in an Ar gas atmosphere (hereinafter referred to as a coarse crushing step) to form coarsely crushed particles of about 6 to 8 mm. The coarsely crushed particles are put in a boat and charged in a tube furnace, and the degree of vacuum is 1 × 10 ⁻ After evacuating to a vacuum of ⁴ Torr or less,
8, 1.0, 1.2, 1.4, 1.6 kgf / cm ² of hydrogen gas was introduced into the furnace, and the holding temperature was increased to 60 while maintaining the respective gas pressures.
3 at 0, 700, 750, 800, 850, 900, 950 and 1000 ° C
The treatment was performed for holding the hydrogen gas for a period of time to occlude hydrogen gas.

Next, a dehydrogenation treatment was performed at 800 ° C. for 0.5 hour until a vacuum atmosphere with a hydrogen gas pressure of 5 × 10 ⁻⁵ Torr was obtained. Thereafter, the mixture was cooled down to room temperature in about 10 minutes with 1.2 kgf / cm ² of argon gas. Through the above process, the aggregate (disintegrated material) composed of fine powder is disentangled in a mortar and the average particle size is 25 to 250.
A fine powder of μm was obtained. The magnetic properties of the thus obtained magnet powder were tested and are shown in Tables 1-1 to 1-2. The test was performed using a VSM vibrating magnetometer.

From the above Tables 1-1 to 1-2, the magnetic properties can be improved by absorbing hydrogen in a hydrogen gas atmosphere pressurized to 1.2 kgf / cm ² or more.

Example 1b Using Nd as a rare earth, melting and casting in a plasma arc furnace, the atomic% composition of the Nd-Fe-Co-B system was Nd _12.5 Fe _67.0 Co
_11.5 B _6.0 Rare earth magnet alloy ingot 1B containing Ga _3.0 as a main component was produced. The above ingot is coarsely crushed in an argon gas atmosphere to obtain coarsely crushed particles of about 6 to 8 mm. The coarsely crushed particles are put in a boat and placed in a tubular furnace, and a degree of vacuum of 1 × 10 ^-4
After evacuating to a vacuum of rr or less, hydrogen gas of 1.2 kgf / cm ^{2 was} introduced into the furnace, The pressure was maintained at 800 ° C. for 3 hours while maintaining the pressure to perform a hydrogen storage treatment.

Next, the hydrogen gas pressure was increased to 1.0, 1x10 ^-1 , ^{1x10 -2} , ^1x10
The H ₂ removal treatment was performed at 800 ° C. for 0.5 hour until a vacuum atmosphere with a degree of vacuum of ⁻³ , 1 × 10 ⁻⁴ , and 1 × 10 ⁻⁵ Torr was obtained. afterwards,
It was cooled to room temperature in about 10 minutes with 1.2 kgf / cm ² Ar gas. Through the above treatment, the aggregate (disintegrated material) composed of the fine powder was loosened in a mortar to obtain a fine powder having an average particle size of 25 to 250 μm. The magnetic properties of the thus obtained magnet powder were tested and are shown in Table 1-3.

From these results, the dehydrogenation gas pressure was 1 × 10 ^-4 Torr
It can be seen that the magnetic properties are improved by the dehydrogenation treatment in a vacuum atmosphere having a degree of vacuum of.

Example 1c Using Nd as a rare earth element, melting and casting in a plasma arc furnace, the atomic% composition of the Nd—Fe—Co—B system was Nd _12.0 Dy _0.5 Fe.
A rare earth magnet alloy ingot containing _70.0 Co _11.5 B _6.0 as a main component was produced.

The homogenization treatment was carried out in an Ar gas atmosphere at a temperature of from 600 to 1300 ° C. for 20 hours. After the coarse pulverization step, the mixture was subjected to a hydrogen storage treatment as coarsely pulverized particles having a size of 5 to 9 mm.

Each was charged in a tube furnace placed in a boat, and the degree of vacuum was 1x10
After evacuating to a vacuum of ^-4 Torr or less, a hydrogen gas of 1.2 kgf / cm ^{2 was} introduced into the furnace, and the gas was maintained at 800 ° C. for 3 hours while maintaining the gas pressure to perform processing. Next, the hydrogen gas pressure was increased to 1 × 10 ⁻⁵
Dehydrogenation at 800 ° C for 0.5 Torr until vacuum
I went over time.

Then, about 10 to room temperature at an argon gas 1.2 kgf / cm ²
Cooled to room temperature in minutes. Through the following treatment, aggregates (disintegrates) made of fine powder are disentangled in a mortar and the average particle size is 25
A fine powder of 250250 μm was obtained. The magnetic properties of the magnet powder thus obtained were tested and are shown in Tables 1-4.

From these results, the homogenization temperature is 800-1200 ° C
As a result, the magnetic properties were improved by homogenization.

Example 1d Using Nd as a rare earth element, melting and casting in a plasma arc furnace, the atomic% composition of the Nd—Fe—Co—B system was Nd _12.5 Fe _69.0 Co
A rare earth magnet alloy ingot 1D containing _11.5 B _6.0 Ga _1.0 as a main component was produced. The ingot was homogenized by keeping it at 1100 ° C. for 20 hours in an argon gas atmosphere, and then coarsely pulverized in an argon gas atmosphere to obtain coarsely pulverized particles of 5 to 7 mm. The coarsely crushed particles were put in a tubular furnace in a boat, evacuated to a vacuum of 1 × 10 ⁻⁴ Torr or less, and then weighed at 1.2 kgf / cm ²
Of hydrogen gas into the furnace and maintain 85
It was kept at 0 ° C. for 3 hours to perform the treatment.

Next, dehydrogenation treatment was performed at 800 ° C. for 0.5 hour until the hydrogen gas pressure reached a vacuum atmosphere of 1 × 10 ⁻⁵ Torr. Thereafter, the cooling rate in an Ar gas atmosphere of 1.2 kgf / cm ² 10 to 10
The test was conducted at five stages of 0 ° C./min.

Aggregates (disintegrates) composed of fine powder through the above processing
Was disentangled in a mortar to obtain a fine powder having an average particle size of 25 to 250 μm. Test the magnetic properties of the magnet powder thus obtained,
The results are shown in Table 1-5.

From the above results, it was found that 50
It can be seen that the magnetic properties are improved by rapid cooling at a temperature of at least ℃ / min.

Example 2 Table 2-1, Table 2-3 and Table 2-6 show the chemical composition, processing conditions (homogenization conditions, hydrogen storage conditions and dehydrogenation conditions) and magnetic properties / temperatures of the present invention. The characteristics are shown in Table 2-2, Table 2-4, Table 2-5 and Table 2.
-7 indicates the chemical composition, processing conditions and magnetic properties of the comparative example.
Shows temperature characteristics.

In Tables 2-1 and 2-3, 2A1 to 2A15 mainly investigated the influence of the chemical composition, and 2B1 to 2B6 mainly investigated the influence of the processing conditions. Table 2 shows the magnetic and temperature characteristics obtained as a result. 6 is shown.

Similarly, for Comparative Examples, in Tables 2-2, 2-4 and 2-5, 2C1 to 2C14 were mainly investigated for the influence of the chemical composition, and 2D1 to 2B10 were mainly investigated for the influence of the processing conditions. Table 2-7 shows the obtained magnetic characteristics and temperature characteristics.

Nd was used as a rare earth element, and it was melted and cast in a plasma arc furnace to produce a rare earth magnet alloy ingot having an Nd-Fe-B-Co-based chemical composition shown in Tables 2-1 and 2-2.

The ingot was rough crushed mass of about 8~15mm was coarsely pulverized in an argon gas atmosphere, the coarsely pulverized mass is are in the boat was charged in a tubular furnace was evacuated to a vacuum below the vacuum degree 1x10 ^-4 Torr .

Then, a predetermined pressurized hydrogen gas shown in Table 2-4 or Table 2-5 was supplied to the furnace. While maintaining the gas pressures in Table 2
4 or at a holding temperature shown in Table 2-5 for 0.5 to 5.0 hours to perform a hydrogen storage treatment.

Next, a dehydrogenation treatment was performed for 0.5 to 1.0 hour until a vacuum atmosphere at a predetermined temperature shown in Table 2-4 or Table 2-5 was obtained. Then, with 1.2 kgf / cm ² of argon gas
Cooled to room temperature for 15-30 minutes.

Aggregates (disintegrates) composed of fine powder through the above processing
Was disentangled with a mortar to obtain a powder having an average particle size of 25 to 420 μm.

Tables 2-6 and 2-7 show the results of testing the magnetic properties and temperature properties of the alloy magnet powder thus obtained. The test method of the magnetic properties is as follows.Put a mixture of the obtained alloy magnet powder and paraffin in a 4.0 mm diameter, 2.5 mm high aluminum pan, orient it in a magnetic field, solidify it, and then use a VSM vibrating magnetometer. It was measured.

The test method of the temperature characteristics was measured by putting the obtained alloy magnet in an alumina container and using a vibrating magnetometer.

From Table 2-6, which is an example of the present invention, it is found that Nd-Fe-B-Co
The maximum energy product ((BH) ma
x), the magnetic properties including the residual magnetic flux density (Br) and the coercive force (iHc) are excellent, and the Curie point (Tc) with high temperature properties is obtained.

As shown in Table 2-6, Co contained 20%, and contained B and Ga.
In the production of the alloy magnet powders of Samples 2A1 to 2A6 to which Co was added in combination, the production was carried out under the processing conditions described above (Table 2-3) to prevent the decrease in the coercive force contradictory to the improvement of the Curie point accompanying the addition of Co And achieved excellent magnetic properties.

Further, Samples 2A7 to 2A15 were prepared by adding Md to Nd-Fe-B-Co alloy.
It is an investigation of the effects of the addition of o, V, Ti and Zr. The coercive force was further improved by these additions, and 10.8
~ 12.8 kOe has been obtained.

Samples 2B1 to 2B6 were obtained by investigating the effects of the holding temperature in the homogenization process, the holding temperature, the time and the gas pressure in the hydrogen storage process, and the holding temperature, the time and the gas pressure in the dehydrogenation process. Under any of the conditions, excellent magnetic characteristics and temperature characteristics are achieved.

 Next, a comparative example of the present invention will be described.

Samples 2C1-2C13 shown in Table 2-2 were processed under the processing conditions (Table 2-
Samples 2C1 to 2C13) in No. 4 were examined for the influence of the chemical composition under the conditions of the present invention. As a result, the obtained magnetic characteristics and temperature characteristics are shown in Table 2-7 (Samples 2C1 to 2C1).
See 3).

Sample 2C1 had a low coercive force of 3.0 kOe due to low Nd, and sample 2C2 had a Curie point of 400 due to low Co.
° C and low.

In Sample 2C3, the Curie point was improved to 560 ° C. due to the large amount of Co, but the coercive force was lowered to 4.0 kOe. Sample 2C4
Means that Co and B are small and Ga is large,
At 8.0 kOe, the Curie point has dropped to 420 ° C. Sample 2C5
Has a low residual magnetic flux density of 9.0 kG due to the large amount of B.

Sample 2C7 had a coercive force of 6.7 because Ga was not added.
kOe and not improved. Sample 2C8 has a low coercive force of 3.8 kOe due to a small amount of B, and sample C8 has a low coercive force of 5.0 kOe due to a large amount of Ga. Sample 2C10 contains Nd and
Due to the large amount of Ga, the residual magnetic flux density is reduced to 9.5 kG, and the coercive force is reduced to 7.5 kOe.

Sample 2C11 has a large amount of Mo, sample 2C12 has a large amount of V, sample 2C13 has a large amount of Zr, and sample C13 has a large amount of Ti, so that the coercive force is improved to 11.0 to 14.0 kOe.
Is obtained, but the residual magnetic flux density is lowered to 8.0 to 10.5 kG.

Regarding the processing conditions, samples 2D1 to 2D10 shown in Table 2-2 (samples 2D1 to 2D10 in Table 2-2) were investigated as the chemical compositions of the present invention under the processing conditions shown in Table 2-5. As a result, the obtained magnetic characteristics and temperature characteristics are shown in Table 2-7 (samples 2D1 to 2D10).

Sample 2D1 had a coercive force of 2.0 due to the high homogenization temperature.
kOe and the residual magnetic flux density decreased to 8.0 kG.

Sample 2D2 has a high holding temperature in the hydrogen storage process,
On the other hand, sample 2D3 has a low coercive force of 7.0 and 4.0 kOe due to a low holding temperature in the hydrogen gas occlusion treatment. Sample 2D4 has a low holding temperature in the hydrogen storage process and a high gas pressure in the dehydrogenation process,
The coercive force is as low as 5.0 kOe and the residual magnetic flux density is as low as 11.0 kG.

Sample 2D5 has a coercive force of 3.0 due to the low homogenization temperature.
It is as low as kOe and the residual magnetic flux density is as low as 8.5 kG. Sample 2D6 is
High coercive force (2.0 kOe) and high residual magnetic flux density of 7.8 k due to high holding temperature in hydrogen storage and dehydrogenation
G and low.

Sample 2D7 has a low coercive force of 4.8 kOe and a low residual magnetic flux density of 9.3 kG because of the low gas pressure in the hydrogen storage treatment. Sample 2D8 has a higher coercive force of 3.5 kOe because the gas pressure in the hydrogen storage process is increased and the holding temperature in the hydrogen storage process and the dehydrogenation process is higher than that of sample D6.
And the residual magnetic flux density is as low as 8.5 kG.

Sample 2D9 has a low coercive force of 8.0 kOe due to a low holding temperature in the dehydrogenation treatment. Sample 2D10 has a low coercive force of 7.0 kOe and a residual magnetic flux density of 9.8 kG due to the high gas pressure in the dehydrogenation process, that is, the poor vacuum atmosphere.
And low.

Example 3 In order to specify test conditions using the apparatus of the present invention, an example
3a shows a preliminary test, and Example 3b shows this test.

Example 3a A rare earth magnet alloy ingot containing Nd _12.3 Fe _60.1 Co _19.8 B _6.0 Ga _1.8 as a main component in the atomic% composition of a Nd-Fe-Co-B alloy was produced by melting and casting in a plasma arc furnace. The ingot was kept in an argon gas atmosphere at 1100 ° C. for 40 hours to perform a homogenization treatment, and then coarsely pulverized in an argon gas atmosphere to obtain a coarsely crushed mass of 5 to 18 mm. This coarsely pulverized lump was charged into a tubular furnace placed in a boat, evacuated to a vacuum of 1 × 10 ⁻⁵ Torr or less, and then hydrogen gas of 1.2 to 2.6 kgf / cm ² was introduced into the furnace, and each gas pressure was changed. While maintaining the temperature at 700 to 900 ° C. for 3 hours to perform a hydrogen storage treatment. Next, dehydrogenation treatment was performed at 700 to 900 ° C. for 0.5 hour until a vacuum atmosphere with a hydrogen gas pressure of 5 × 10 ⁻⁵ Torr was obtained. Then, with 1.2 kgf / cm ² of argon gas to room temperature,
It was cooled to room temperature in 10 minutes. Through the above process, the aggregate (disintegrated material) composed of powder is disentangled with a mortar and the average particle size is 74.
A powder of 105105 μm was obtained. The maximum energy product ((BH) max) of the magnet powder thus obtained was measured, and the results are shown in FIGS. For the measurement, a vibration type magnetometer was used as in Example 2.

From FIG. 1, the maximum energy product ((BH) max) greatly depends on the hydrogen storage processing temperature and the hydrogen gas pressure in the hydrogen storage processing, and the region having excellent magnetic properties is narrow. Also,
From FIG. 2, the maximum energy product ((BH) max) is also sensitive to the dehydrogenation treatment temperature. Therefore, it is important to control the temperature and the hydrogen gas pressure during the hydrogen storage process and the temperature during the dehydrogenation process in mass production.

Example 3b Nd _12.3 Fe _60.1 Co in atomic% composition of Nd-Fe-Co-B alloy
Using a vacuum induction melting furnace, four 5 kg rare earth magnet alloy ingots containing _19.8 B _6.0 Ga _1.8 as a main component were produced. The above ingot is placed in an argon gas atmosphere at 1100 ° C
And then homogenized by holding for 40 hours, and then coarsely pulverized in an argon gas atmosphere to obtain a coarsely pulverized lump of 10 to 30 mm. About 1 kg of this coarsely pulverized mass is added to each reaction tube of the apparatus of the present invention shown in FIG.
Each was charged into a heating furnace. After evacuating to a vacuum of 1x10 ^-4 Torr or less, a hydrogen gas of 1.3 kgf / cm ² flows into the tube,
The gas pressure was maintained at 800 ° C. for 5 hours to perform a hydrogen storage treatment.

Next, dehydrogenation treatment was performed at 800 ° C. for 1.0 hour until the hydrogen gas pressure reached a vacuum atmosphere of 1 × 10 ⁻⁵ Torr. Thereafter, cooling was performed at 80 ° C./min in an Ar gas atmosphere of 1.2 kgf / cm ² .

Five samples were sampled from each reaction tube, and the aggregate (disintegrated material) composed of the powder was disentangled with a mortar to obtain a powder having an average particle size of 25 to 250 μm. The maximum energy product was measured and is shown in FIG. The test was performed under the same conditions as in Example 3a.

The comparative example used a coarse powder mass having the same composition as tested in the present invention. About 7 kg of the same amount was placed in a tube furnace made of a single heat-resistant stainless steel, and hydrogen absorption and dehydrogenation were performed.
These processing conditions were the same as in the present invention.

35 samples were sampled at random from a tube furnace, and the aggregate (disintegrated material) composed of powder was disentangled in a mortar to obtain powder having an average particle size of 25 to 250 μm. The maximum energy product was measured and is shown in FIG. 4 for comparison with the results of the present invention.
The test was performed under the same conditions as in Example 3a.

From FIG. 2, the average value of the maximum energy product ((BH) max) of the alloy magnet powder obtained in the present invention reaches 38.2 MGOe, and the range of the variation is as narrow as 36 to 40 MGOe. On the other hand, in the comparative example, the average value is only 32.7 MGOe, and the range of the variation is as wide as 27 to 40.

Example 3c Table 3-1 shows the chemical composition of the present invention, and Table 3-2 shows its magnetic properties and temperature properties. 10 using a vacuum induction melting furnace
Melt and cast in kilograms, rare earth magnet alloy ingot 3A ~ 3E
Was prepared. Place the above ingot in an argon gas atmosphere
Homogenization treatment was performed by maintaining the temperature at 1100 ° C. for 40 hours, and then coarsely pulverized in an argon gas atmosphere to obtain a coarsely pulverized lump of 10 to 30 mm. About 1 kg of this coarsely pulverized lump was put into each reaction tube of the apparatus of the present invention shown in FIG. 1 and charged into a heating furnace. Vacuum 1x10 ^-4 Torr
After evacuating to the following vacuum, 1.3 kgf / cm ² of hydrogen gas was introduced into the tube, and the gas pressure was maintained at 800 ° C. for 5 hours to perform a hydrogen storage treatment.

Next, dehydrogenation treatment was performed at 800 ° C. for 1.0 hour until the hydrogen gas pressure reached a vacuum atmosphere of 1 × 10 ⁻⁵ Torr. Thereafter, cooling was performed at 80 ° C./min in an argon gas atmosphere of 1.2 kgf / cm ² .

From Table 3-2, the maximum energy product ((BH) max) is 35M
GOe or more, residual magnetic flux density (Br) 12.5kG or more, coercive force (i
Hc) is 10kOe or more excellent magnetic properties and Curie point (Tc)
Shows excellent temperature characteristics of 480 ° C. or higher.

Example 4 An example of a resin-bonded magnet was first described in Example 4a.
Describes the injection molding method, and 4b describes the compression molding method. The manufacture of the alloy magnet powder used for the molding of both is collectively described in Example 4a.

Example 4a Invention Examples (Samples 4A to 4E) and Comparative Examples (Samples 4F to 4H)
Table 4-1 shows the chemical composition of the rare earth alloy magnet powder of
The processing conditions (homogenization conditions, hydrogen storage conditions and dehydrogenation conditions are collectively referred to) when manufacturing rare earth alloy magnet powder from alloy ingots having chemical compositions 4A to 4H are described below. It is shown in Table 4-2. Therefore, regarding the results of the magnetic characteristics and the temperature characteristics of the resin-bonded magnets manufactured by the injection molding method shown in Table 4-3, the samples 4A1 to 4A3, 4B1, 4C1, 4D1, and 4E1 are the results of the present invention, Sample 4A4, 4C2, 4E2, 4F1, 4G1
And 4H1 are the results for the comparative example.

A rare earth magnet alloy having a chemical composition of Nd-Fe-B-Co was melted and cast in a plasma arc furnace to produce an ingot shown in Table 4-1. This ingot was homogenized at 1080 ° C. for 40 hours in an Ar gas atmosphere.

Next, the ingot was coarsely pulverized in an argon gas atmosphere to form a coarsely pulverized lump having a size of about 8 to 15 mm. The coarsely pulverized lump was charged into the apparatus of the present invention and evacuated to a vacuum of 1 × 10 ⁻⁴ Torr or less.

After that, a predetermined pressurized hydrogen gas shown in Table 4-2 is flown into the furnace, and is maintained at the holding temperature shown in Table 2 for 3.0 to 5.0 hours while maintaining the respective gas pressures to absorb hydrogen. Was done.

Next, a dehydrogenation treatment was performed for 0.5 to 1.5 hours until a vacuum atmosphere at a predetermined temperature shown in Table 4-2 was obtained.
Thereafter, the mixture was cooled to room temperature with Ar gas of 1.2 kgf / cm ² for 15 to 30 minutes.

Through the above treatment, the aggregate (disintegrated material) made of the powder was loosened in a mortar to obtain a powder having an average particle size of 44 to 300 μm.

The thus obtained 13 types of alloy magnet powders of Samples 4A1 to H1 shown in Table 4-2 were each subjected to a compounding process by a kneading machine, and were molded by an injection molding machine.

First, the compound was made by kneading the alloy magnet powder with 60 vol%, using a binder of nylon 12, a coupling agent of silane, and a lubricant of zinc stearate.

Next, injection molding was performed. The molding temperature was 265 ° C., the mold temperature was 85 ° C., and the molding pressure was 85 kgf / cm ² . The strength of the orientation magnetic field during molding was 11 kOe. The shape of the molded body is a rectangular parallelepiped of 10 × 10 × 8 mm.

The compact was magnetized in an air-core coil with a magnetizing magnetic field of 45 kOe.

Table 4-3 shows the results of measuring the magnetic characteristics and the temperature characteristics of the resin-bonded magnet obtained by magnetization.

Regarding the temperature characteristics, α is the temperature coefficient of Br and β is iHc
Are measured and shown.

From the present invention examples and comparative examples in Table 4-3, it is understood that the resin-bonded magnet according to the present invention has excellent magnetic properties and temperature properties.

Here, the samples 4F1, 4G1, and 4H1 shown in Table 4-2 were obtained by investigating the influence of the chemical composition using the processing conditions as the conditions of the present invention. As a result, the obtained magnetic characteristics and temperature characteristics are shown in Table 4-3 (Samples 4F1 and 4F4). G1 and 4H1).

Sample 4F1 has a low residual magnetic flux density of 6.6 kG due to a large amount of Nd, and G1 has a residual magnetic flux density of 6.0 kG due to a large amount of B.
And low. Sample 4H1 has a low maximum energy product, residual magnetic flux density, and coercive force bHc because Ga is small.

Sample 4A4 has a low maximum energy product because the hydrogen gas pressure for the hydrogen storage treatment is low. Sample 4C2 has a low maximum energy product and a low coercive force because the holding temperature for the hydrogen storage treatment is high. Sample 4E2 has a low maximum energy product and a low coercive force due to the high gas pressure of the dehydrogenation treatment.

 Table 4-2 shows a conventional example.

First, an Sm-Co-based anisotropic resin-bonded magnet was manufactured by an injection molding method. A compound was prepared by kneading 60 vol% of Sm ₂ Co ₁₇ powder with nylon 12 as a binder, a silane-based coupling agent, and zinc stearate as a lubricant. This compound was injection molded with a molding magnetic field of 15 kOe. A sample 4K1 was prepared under the conditions of a molding temperature of 260 ° C., a mold temperature of 80 ° C., and a molding pressure of 65 kgf / cm ² . The shape of the molded body is a rectangular parallelepiped of 10 × 10 × 8 mm.

Next, an Nd-Fe-B based isotropic resin-bonded magnet was produced by an injection molding method. The powder having the composition of Nd ₁₄ Fe ₈₀ B ₆ was formed into a flake-like magnet by a melt spinning method and pulverized to 32 mesh or less. 60 vol% of the magnetic powder thus obtained
Nylon 12 was used as a binder, silane was used as a coupling agent, and zinc stearate was used as a lubricant to prepare a compound. This compound was injection molded with a molding magnetic field of 15 kOe. Molding temperature is 280 ℃, mold temperature is
Sample 4K2 was produced under the conditions of 85 ° C. and a molding pressure of 65 kgf / cm ² . The shape of the molded body is a rectangular parallelepiped of 10 × 10 × 8 mm.

These compacts were magnetized in an air-core coil with a magnetic field of 45 kOe.

Table 4-4 shows the measurement results of the magnetic characteristics and the temperature characteristics of the resin-bonded magnet thus obtained.

Samples 4K1 and 4K2 both have lower maximum energies ((BH) max) than the present invention.

Example 4b Thirteen kinds of alloy magnet powders and resin powders of samples 4A1 to 4H1 shown in Table 4-2 were mixed and heated and compression-molded.

First, the alloy magnet powder was 83 vol%, and as a binder, 17 vol% of epoxy resin Epicoat 1004 (manufactured by Yuka Shell Epoxy), a curing agent, a curing accelerator and a silane coupling agent were mixed.

Next, compression molding was performed. The molding temperature was 160 ° C. and the molding pressure was 7.5 ton / cm ² . The strength of the orientation magnetic field during molding was 15 kOe. The shape of the molded body is 10 × 10 × 8 mm
Is a rectangular parallelepiped.

The compact was magnetized in an air-core coil with a magnetizing magnetic field of 45 kOe.

Table 4-5 shows the results of measuring the magnetic characteristics and temperature characteristics of the resin-bonded magnet obtained by magnetization.

Regarding the temperature characteristics, α is the temperature coefficient of Br and β is iHc
Are measured and shown.

From the present invention examples and comparative examples in Table 4-5, it is understood that the resin-bonded magnet according to the present invention has excellent magnetic properties and temperature properties.

 Next, a comparative example of the present invention will be described.

Samples 4F1, 4G1 and 4H1 shown in Table 4-2 were obtained by investigating the influence of the chemical composition under the processing conditions of the present invention. As a result, the obtained magnetic characteristics and temperature characteristics are shown in Table 4-5.

Sample 4F11 has a low residual magnetic flux density of 7.3 kG due to a large amount of Nd, and sample 4G11 has a low residual magnetic flux density of 6.7 kG due to a large amount of B. Sample 4H11 has low maximum energy product, residual magnetic flux density, and coercive force (bHc) because Ga is small.

Sample 4A41 has a low maximum energy product because the hydrogen gas pressure for the hydrogen storage treatment is low. Sample 4C21 has a low maximum energy product and a low coercive force because the holding temperature for the hydrogen storage treatment is high. Sample 4E21 has a low maximum energy product and a low coercive force because the gas pressure for the dehydrogenation treatment is high.

Continued on the front page Application for accelerated examination (72) Inventor Yoshinobu Sugiura 2-115, Karasu-cho, Handa-shi, Aichi 8 (56) References JP-A-3-146608 (JP, A)

Claims (2)

(57) [Claims] (1) Atomic percentage of Nd: 12.1 to 13.0%, B: 5.0 to 7.
0%, Co; 19.0-21.5%, Ga; 1.5-1.8%, the remainder is Fe and an ingot of a Nd-Fe-B-Co-based alloy consisting of unavoidable impurities, in an inert gas atmosphere, Temperature 1000
After homogenizing by holding at ~ 1150 ° C, the coarsely crushed mass obtained by coarsely crushing the homogenized ingot is distributed and put into a plurality of reaction tubes, respectively. 1.2 to 1.6 kgf /
In a hydrogen gas atmosphere pressurized to cm ² , the plurality of reaction tubes are simultaneously held at a temperature of 780 to 860 ° C., and hydrogen gas is absorbed in the coarsely pulverized particles. Excellent magnetic anisotropy and temperature characteristics, characterized by dehydrogenating at a temperature of 500 to 860 ° C until a vacuum atmosphere of hydrogen gas pressure 1x10 ^-4 Torr or less, and then rapidly cooling these multiple reaction tubes simultaneously And a method for producing an Nd-Fe-B-Co alloy magnetic powder. 2. The Nd-Fe-B-Co according to claim 1, wherein the plurality of reaction tubes are arranged in a single heating furnace, and the hydrogen gas pressure is controlled by a single hydrogen gas supply system. Method for producing system alloy magnet powder.