JP3504735B2 - Method for producing RTMN based anisotropic bonded magnet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention, various motors, relates to a method of manufacturing a RTN based anisotropic bonded magnet which can be used in permanent magnet constituting a magnetic circuit of the actuator such as, hydrogenation, dehydrogenation H ₂ treatment After that, the RTM coarsely pulverized powder containing the element M effective for aligning the orientation of the fine crystals forming the individual powders in a certain direction is added to H ₂ gas alone or an inert gas (excluding N ₂ gas). ) And a de-H ₂ treatment of heating and holding in a predetermined atmosphere, and an average particle size of 0.
An easy-to-handle powder is obtained by forming a crystalline textured powder with a grain size of 5 μm or less and further nitriding it into a bond magnet, which has excellent magnetic properties and high corrosion resistance. The present invention relates to a manufacturing method capable of obtaining a bonded bond magnet.

[0002]

The Sm ₂ Fe ₁₇ compound having BACKGROUND ART Th ₂ Zn ₁₇ structure, by entering the nitrogen between lattices, T _c is increased nearly twice in absolute temperature, Nd-Fe-B based T _c It is reported that an anisotropic magnetic field higher than that of Nd ₂ Fe ₁₄ B by 160 ° C. is obtained (JMDC).
oey and H.A. Sun, J. et al. Magn. Mag
n. Mat 87 (1990) L251).

As a method for producing a permanent magnet using this Sm ₂ Fe ₁₇ N _x , an Sm ₂ Fe ₁₇ alloy powder is heated and held in nitrogen gas and then cooled, and an average particle diameter of 3 μm is obtained by using a ball mill, an attritor or the like. The following is a method for producing a fine powder type anisotropic bonded magnet in which finely pulverized below, a thermosetting resin such as epoxy is mixed, press- molded in a magnetic field, and the resin is further heat-cured, for example, JP-A-2- No. 257603. In this conventional technique, pulverizing Sm ₂ Fe ₁₇ N _x to a particle size of a single magnetic domain or less is an essential condition for obtaining the coercive force of the powder. The rate is low and a high energy product cannot be obtained.

Further, the Sm ₂ Fe ₁₇ alloy powder is heated and held in nitrogen gas, then cooled, finely pulverized to an average particle size of 10 μm or less using a ball mill, an attritor, etc., and a powder of a low melting point metal such as Zn is mixed. After that, press molding in a magnetic field,
Further, a method for producing an anisotropic metal-bonded magnet that is heat-cured at a temperature near the melting point of Zn or the like is disclosed in, for example, Japanese Patent Laid-Open No.
No. 6814. In this conventional technique, Sm
Demagnetization of the surface of the ₂ Fe ₁₇ N _x powder by alloying with Zn or the like is an essential condition for obtaining coercive force, but this lowers the magnetization, and a high energy product cannot be obtained.

Further, an amorphous alloy of Sm ₂ Fe ₁₇ composition is prepared by a mechanical alloying method or a super-quenching method, and then heated and maintained at a predetermined temperature in an inert gas or in a vacuum to form a Th ₂ Zn ₁₇ type alloy. A method for producing a permanent magnet powder having a crystalline texture powder having a grain size of 1 μm or less and having a crystal structure and further heating and holding in nitrogen gas and then cooling is disclosed in, for example, JP-A-4-254304. There is.

In addition, the inventors of the present invention first heat and hold the Sm ₂ Fe ₁₇ alloy powder in H ₂ gas at 600 to 900 ° C.,
It is heated and maintained at 600 to 900 ° C. in an inert gas or in vacuum to form a textured powder of crystals having a particle size of 1 μm or less having a Th ₂ Zn ₁₇ type crystal structure, and further 3 in nitrogen.
A method for producing a permanent magnet powder, which is subjected to a nitriding treatment at 00 to 600 ° C., has been proposed (JP-A-4-343203).

[0007]

In these prior arts, even though the crystal grain size of the obtained magnet powder is equal to or less than the single domain grain size, the grain size of the powder which is an aggregate of the fine crystals is obtained. Since it is large, it is possible to increase the filling rate of the magnet powder when it is molded as a bonded magnet after being mixed with a resin. However, since the crystal orientations of the fine crystals forming the individual powders are different, the resulting magnet powder is magnetically isotropic, and a high energy product cannot be obtained.

An object of the present invention is to provide a method for producing an R-T-N type anisotropic bonded magnet, and an R-T of a Th ₂ Zn ₁₇ type crystal structure having a crystal grain size of a single domain grain size or less.
-M-N powder composed of an aggregate of fine crystals, in which the fine crystals forming the individual powders have the same crystallographic orientation, and anisotropic bonded magnet powders having high magnetization and energy products are obtained. It is an object of the present invention to provide a manufacturing method capable of obtaining an anisotropic bonded magnet having excellent magnetic characteristics.

[0009]

SUMMARY OF THE INVENTION Among the prior arts, the inventors of the present invention have proposed a hydrogenation / dehydrogenation method capable of increasing the packing ratio of the magnet powder in a bonded magnet because the powder size of the magnet powder is relatively large. In the method, as a result of diligent examination of the method for obtaining anisotropic magnet powder, 10 at% or less of the additive element M (M: Al,
Ti, V, Cr, Ni, Ga, Zr, Nb, Mo, In, Sn, Hf, Ta, W one or more kinds), the individual powder after hydrogenation and dehydrogenation treatment is added. It was found that the orientation of the fine crystals to be formed is uniform. In addition, the inventors of the present invention, in the above hydrogenation process, when increasing the temperature rising rate when heating to the heating and holding temperature in hydrogen gas, or performing the temperature rising process in vacuum or in an inert gas. After that, when hydrogen gas was introduced into the furnace and heated and held, the orientation degree of crystals in the powder was improved, and it was found that a magnet powder with high magnetization and energy product can be obtained, and the present invention was completed. .

That is, the present invention is 1) R 10-12at%, T 80-90at%, M 10at% or less ( however, 0
(excluding at% ) is subjected to solution treatment at 900 to 1200 ° C for 1 hour or longer, provided that at least 1 of rare earth elements including R: Y is used.
Species and contains 50% or more of Sm, T: Fe or 50% of Fe
Substituted with Co, M; Al, Ti, V, Cr, Ni, Ga, Zr, Nb, Mo, In, S
One, two or more of n, Hf, Ta, W 2) This ingot is at least 9 with an average grain size of 20 μm to 10 mm.
After forming a coarsely pulverized powder consisting of a compound having 5% by volume or more of Th ₂ Zn ₁₇ type structure, 3) the coarsely pulverized powder is 0.1 to 10 atm of H ₂ gas or an inert gas having an H ₂ partial pressure equal to it. (Excluding N ₂ gas, but the total pressure is 10 atm or less), after raising the temperature range of 600 to 750 ℃ at a heating rate of 10 ℃ / min to 200 ℃ / min, 750 ~ 900 ℃ for 30 minutes ~ 8
And heating time held, 4) further in H ₂ partial pressure of 1 × 10 ^-2 Torr or less, 750 to 900 ° C.
The sample is subjected to a H ₂ removal treatment by heating and holding it for 30 minutes to 8 hours, and 5) it is then cooled so that the average crystal grain size is 0.05 to 0.5 μm, and the orientation of the fine crystals forming the individual powder is constant. 6) Next, after pulverizing the powder to 3 to 500 μm and sizing, the powder is 300 to 650 in N ₂ gas at N ₂ pressure of 0.5 to 1000 atm. 30 to ℃
Hold for min-50h, R8-10at%, T65-82at%, M10
At% or less, containing N 8-15 at%, Th ₂ Zn ₁₇ type structure or T
After obtaining an alloy powder having a bCu ₇ type structure, 7) the alloy powder is pulverized to 3 to 500 μm, sized, and then mixed with a resin and molded in a magnetic field.
This is a method for producing a system anisotropic bonded magnet.

Further, the present invention is manufactured by the above configuration .
In production method, 3) the 750 ° C. The crude pulverized powder with or in an inert gas vacuo
After heating to the above temperature range, 0.1 to 10 atm of H ₂ gas or an inert gas having an H ₂ partial pressure equal to it (excluding N ₂ gas, but the total pressure is 10 atm or less) is introduced. , 75 more
RT consisting of a configuration that heats and holds at 0 to 900 ° C for 30 minutes to 8 hours
-We also propose a method for manufacturing MN-based anisotropic bonded magnets.

Reasons for limiting composition In the raw material composition used in the present invention, the rare earth element R is Y, La, Pr, Nd, Sm, Gd, Tb, Ho, E.
r, Tm, Lu are included, and at least one of them is included.
It is a seed or more and contains Sm in an amount of 50 at% or more of R. R of 5
The reason why Sm is 0 at% or more is that sufficient coercive force cannot be obtained when Sm is 50 at% or less. Alternatively, the total amount Sm may be used as R. When R is less than 10 at%, the coercive force decreases due to the precipitation of α-Fe.
If it exceeds t%, the RFe ₃ phase will precipitate and the magnetization will decrease, so the range of R of the ingot is set to 10 to 12 at%. A more preferable range of R of the ingot is 10 to 11 at%.
The composition range of Sm when the total amount of Sm is used as R is
For the same reason as above, it is set to 10 to 12 at%.

The R composition after solution treatment, coarse crushing and hydrogenation of the ingot, dehydrogenation H ₂ treatment, and nitriding treatment is reduced as compared with the ingot due to evaporation of the R component during the treatment at high temperature. Tend to do. When R is less than 8 at%, the coercive force decreases due to α-Fe precipitation, and when it exceeds 10 at%, the RFe ₃ phase and the like precipitate and the magnetization decreases, so the range of R after nitriding treatment is 8 ~Ten
At% More preferable range of R after nitriding treatment is 8.5 to
It is 9.5 at%.

T is an iron group element containing Fe and Co. F
It is important that e is contained at 50 at% or more of T. That is, when Fe in T is less than 50%, sufficient magnetization cannot be obtained, which is not preferable. It is preferable to add Co to less than 50% of T because the Curie temperature rises and the magnetization and the anisotropic magnetic field are slightly improved. It is not preferable to add Co in an amount of 50% or more of T, because it causes a decrease in the diffusion rate of nitrogen atoms in the nitriding treatment in the subsequent step. Therefore, T
The substitution rate of Co therein is 50% or less. T is 80 at
If it is less than 10%, the RFe ₃ phase is precipitated and the magnetization is reduced.
If it exceeds 0 at%, the coercive force will decrease due to the precipitation of α-Fe, so it is set to 80 to 90 at%. A more preferable range of T is 85 to 90 at%.

As for the effect of the additional element M, an element effective for stabilizing the mother phase, that is, the R ₂ Fe ₁₇ phase and intentionally remaining, is desired, without completely completing the decomposition reaction of the mother phase during hydrogenation. , Ni, Ga, Zr, and Hf have particularly remarkable effects. Further, among M, Al, Ni, Ga, Zr, In, Sn, and Hf are de-H ₂
It is an element useful for growing recrystallized grains at the time of processing to a size of 0.1 to 1 µm and imparting magnetic anisotropy to the powder. Ti, V, Cr, Nb, Mo, Ta, W have 1 recrystallized grains during H ₂ removal treatment.
It has an effect of preventing coarsening to more than μm, and consequently suppressing a decrease in coercive force. Therefore, as M, it is advisable to use a combination of the above elements according to the purpose. The addition amount, since the second phase is not a ferromagnetic exceeds 10at% lowers the magnetization precipitated, M is set to 10at% or less <br/> under (excluding 0 atomic%). More preferable range of M is 3 at
% Or less.

Further, when N is less than 8 at%, high coercive force cannot be obtained due to weak crystal magnetic anisotropy, and when it exceeds 15 at%, the Th ₂ Zn ₁₇ type structure or the TbCu ₇ type structure becomes unstable. ,
Since the matrix phase is not preferable to decompose the RN and α-Fe, 8 ~ 15 at
%. The more preferable range of N is 13 to 15 at%.

[0017] In reasons for limiting the present invention in the manufacturing conditions, the reason for the average particle size is limited to coarsely pulverized powder in which at least 95 or more vol% consists of compounds having the Th ₂ Zn ₁₇ -type structure of 20μm~10mm, said compound is 95 vol If it is less than%, the magnetic properties deteriorate. More specifically, when the second phase are mixed it is alpha-Fe phase decreases the coercive force, in the case of R-rich phase abundance ratio of Th ₂ Zn ₁₇ type compounds because the magnetization is reduced 9
5 vol% or more. In order to obtain a coarsely pulverized powder having a volume ratio of Th ₂ Zn ₁₇ type compound of 95 % or more, the as-cast 90% ingot is used.
It can be appropriately selected by annealing at a temperature of 0 to 1200 ° C. for 1 hour or more, or controlling the cooling rate of the mold in the ingot making process.

The present invention is characterized in that a coarsely pulverized powder having a required particle size can obtain an aggregate of a fine crystal structure without changing its size in appearance, and this point is different from the conventional H ₂ storage pulverization method. It's essentially different. That is, Th
Degassed is reacted with H ₂ gas to R-T-M compounds of ₂ Zn ₁₇ -type structure at high _{temperature, RH 2 ~ 3, α-} Fe, phase separation, etc. T-M alloy phase, a further H ₂ gas When removed by, the recrystallized structure of the R-T-M compound having a Th ₂ Zn ₁₇ type structure or a TbCu ₇ type structure which is a structure containing many stacking faults is obtained again.

The method of the coarsely pulverized starting material, in addition to the conventional mechanical grinding method or a gas atomization method may be coarsely pulverized with H ₂ occlusion pulverization method, the crude by the H ₂ storage in order to simplify the process A method in which the pulverization method and the heat treatment in H ₂ gas for ultrafine crystallization according to the present invention are combined and continuously treated in the same apparatus is also preferable. In the present invention, the reason why the average particle size of the coarsely pulverized powder is limited to 20 μm to 10 mm is that if it is less than 20 μm, there is a risk of magnetic deterioration due to oxidation of the powder, and if it exceeds 10 mm, a hydrogen diffusion path in hydrogenation and dehydrogenation treatments. This is because it is difficult to uniformly process the central portion of the raw material in a short time because of the long time. A more preferable average particle size is 50 to 500 μm.

In the present invention, when H ₂ gas is heated alone or in a mixed gas with an inert gas (excluding N ₂ gas), if the H ₂ partial pressure is less than 0.1 atm, the above-mentioned decomposition and formation are sufficient. The effect cannot be obtained, and if it exceeds 10 atm, the processing equipment becomes too large, which is not preferable in terms of industrial production cost. Therefore, the H ₂ partial pressure is set to 0.1 to 10 atm. A more preferable range is 0.5 to 1.5 atm. Also, N ₂
Even when a mixture of an inert gas excluding gas and H ₂ gas is used at the H ₂ partial pressure, the maximum pressure is 10a for the same reason.
tm or less.

If the heat treatment temperature of H ₂ gas alone or in a mixture with an inert gas (excluding N ₂ gas) is less than 750 ° C., the R-T-M compound only occludes H ₂ and RH
_{2 to 3} , α-Fe, T-M alloy phase, etc. do not undergo phase separation, and if the temperature exceeds 900 ° C, RH _{2 to 3} become unstable and the product undergoes grain growth, and after removing H ₂ , Since it becomes difficult to form an R-T-M compound having an ultrafine structure, 750
It shall be in the range of up to 900 ° C. A more preferable temperature range is 77
5 to 875 ° C. Further, the heating and holding time is required to be 30 minutes to 8 hours in order to sufficiently carry out the above decomposition reaction. More preferable heating holding time is 1 to
4 hours.

The reason why the temperature rising rate in the temperature range of 600 to 750 ° C. is limited to 10 ° C./min to 200 ° C./min in the step of heating and holding the coarsely pulverized powder of the present invention in H ₂ gas is as follows. Is. First, the heating rate is 10 ° C / m
If it is less than in, the time to be converted to H _{2 in} the temperature range of 600 to 750 ° C. becomes long, so that all of the Th ₂ Zn ₁₇ type R-T-M compounds are RH _{2 to 3} , α-Fe, T-M alloy phase, etc. Phase separation into the mother phase, that is, the R ₂ Fe _17-x M _x phase does not remain,
₂ The magnetic and crystal orientation anisotropy after the treatment is lost. Further, when a treatment amount of more than 1 kg is performed at a time, a practical coercive force may not be obtained because the treatment temperature locally exceeds the optimum treatment temperature range due to a large reaction heat. If the temperature rising rate is 10 ° C / min or more,
Since the reaction does not proceed sufficiently in the temperature range of 600 to 750 ° C and reaches the H ₂ conversion temperature range of 750 to 900 ° C with the mother phase remaining, there is a large difference in magnetic and crystal orientation after the H ₂ removal treatment. It is possible to obtain a powder having a directionality. Also, 75
The temperature rise due to the reaction heat of the decomposition reaction in the temperature range of 0 to 900 ° C is small, and it is easy to obtain a practical coercive force even in a large amount of treatment. Therefore, the rate of temperature rise needs to be 10 ° C./min or more in the temperature range of 600 to 750 ° C. Also, 200
A rate of more than ° C / min is not preferable because it is practically difficult to achieve even if an infrared furnace or the like is used, and even if it is possible, the equipment cost becomes excessive. Therefore, the temperature rise rate is 10 ° C / m
in to 200 ° C./min. A more preferable temperature rising rate is 20 ° C / min to 100 ° C / min.

In the present invention, the coarsely pulverized powder is treated with H ₂ alone.
When heating in a gas mixture with a gas or an inert gas (excluding N ₂ gas), instead of raising the temperature in the gas,
After heating to a temperature range of 750 ° C. or higher in a vacuum or an inert gas, a single H ₂ gas or an inert gas (N ₂
The reason for introducing the air-fuel mixture with (excluding gas) is the same as in the case of heating and holding the above-mentioned coarsely pulverized powder in H ₂ gas.
This is to suppress the complete decomposition reaction of the mother phase during temperature rise and prevent overheating due to the heat of reaction to obtain a magnet powder having large anisotropy and high coercive force.

[0024] In the present invention, H ₂ partial pressure at the time of de-H ₂ treatment, 1 × 10 ^-2 for undesirable takes a long time Torr to exceed the handle, and less 1 × 10 ^-2 Torr. H
If the partial pressure of ₂ is within this range, this treatment may be carried out in an inert gas other than N ₂ gas, which eliminates the need for a vacuum vessel equipment that withstands high atmospheric pressure, and simplifies the equipment and is economical. When the temperature of the H ₂ gas removal H ₂ treatment is less than 750 ° C.,
The decomposition of RH _{2 to 3} does not proceed, the target Th ₂ Zn ₁₇ type or TbCu ₇ type compound cannot be obtained, and when the temperature exceeds 900 ° C., the recrystallized structure of the Th ₂ Zn ₁₇ type or TbCu ₇ type compound is generated. Although it can be obtained, it becomes a coarse structure due to grain growth,
Since a high coercive force cannot be obtained, the temperature range is set to 750 to 900 ° C. A more preferable temperature range is 775 to 875 ° C. Further, the heating and holding time is required to be 30 minutes to 8 hours in order to sufficiently carry out the decomposition reaction of RH _{2 to 3} and the recrystallization reaction of the Th ₂ Zn ₁₇ type or TbCu ₇ type compound. A more preferable heating and holding time is 30 minutes to 2 hours.

The average crystal grain size of the powder after the H ₂ removal treatment is 0.05
Reason for limiting the ~ 0.5 [mu] m are difficult to effectively generate less than 0.05 .mu.m, single domain particles the critical size and without any advantage of the characteristics, also more than 0.5 [mu] m as crystals of less than 0.05 .mu.m was obtained This is because it becomes larger and the coercive force of the powder decreases, which is not preferable as a powder for permanent magnets. A more preferable average crystal grain size is 0.1 to 0.5 μm.

In the present invention, the hydrogenation, H ₂ removal treatment and nitriding treatment may be carried out continuously in the same treatment furnace.
In addition, after the H ₂ removal treatment, it may be once taken out of the furnace and subjected to nitriding treatment using another treatment furnace. In the latter case, it is preferable to perform pulverization and sizing to adjust the particle size of the powder as needed before performing the nitriding treatment in order to perform a uniform nitriding treatment. The reason for limiting the N ₂ pressure during the nitriding treatment to 0.5 to 1000 atm is that the nitriding reaction is slow when the pressure is less than 0.5 atm, and the reaction progresses rapidly when the pressure is increased.
This is because if it exceeds 0 atm, the processing equipment becomes too large, which is not preferable in terms of industrial production cost. A more preferable pressure range is 1 to 50 atm. Nitriding temperature is 3
The reason for limiting the temperature to 00 to 650 ° C. is that nitriding does not proceed below 300 ° C., and if it exceeds 650 ° C., the R ₂ Fe _17-x M _x compound decomposes into RN and Fe-M, resulting in deterioration of magnetic properties. This is because A more preferable temperature range is 400 to 50.
It is 0 ° C. If the holding time during the nitriding treatment is less than 30 minutes, sufficient nitriding will not proceed, and if it exceeds 50 hours, decomposition will occur, resulting in deterioration of magnetic properties.
50 hours. A more preferable holding time is 2 to 8 hours.

In the present invention, in order to accurately form a magnet having a complicated shape or a thin wall shape as a bond magnet,
It is necessary to make the particle size of the magnet powder sufficiently small. On the other hand, if the particle size of the powder is too small, it is necessary to use a large amount of resin as a binder as the specific surface area increases. Therefore, the particle size of the powder to be kneaded with the resin is limited to 3 to 500 μm.

The R—Fe—M—N bond magnet according to the present invention may be manufactured by any known manufacturing method such as compression molding, injection molding extrusion molding, roll molding, and resin impregnation method shown below. In the case of compression molding, it is obtained by adding and kneading a thermosetting resin, a coupling agent, a lubricant and the like to magnet powder, and then compression molding and heating in a magnetic field to cure the resin. In the case of injection molding, extrusion molding, or roll molding, after adding thermoplastic resin, coupling agent, lubricant, etc. to the magnet powder and kneading, molding by injection molding, extrusion molding, or roll molding in a magnetic field. Obtained. In the resin impregnation method, the magnet powder may be compression-molded in a magnetic field, and optionally heat-treated, then impregnated with a thermosetting resin and heated to cure the resin. Alternatively, it may be obtained by compression-molding the magnet powder, optionally heat-treating it, and then impregnating it with a thermoplastic resin.

In the present invention, the filling rate of the magnet powder in the bonded magnet depends on the manufacturing method, but is 70-9.
It is 9.5 wt% and the balance 0.5 to 30 wt% is resin or the like. In the case of compression molding, the filling rate of magnet powder is 9
5-99.5 wt%, 90-95w in the case of injection molding method
t%, in the case of the resin impregnation method, 96 to 99.5 wt% is preferable. In the present invention, the synthetic resin used as the binder may be either thermosetting or thermoplastic,
A thermally stable resin is preferable, for example, polyamide, polyimide, polyester, phenol resin, fluorine resin,
Silicon resin, epoxy resin, etc. are appropriately selected.

[0030]

According to the present invention, in the method for producing an RTN-based bonded magnet by the hydrogen treatment method, by adding the element M having the effect of suppressing the decomposition of the mother phase during the hydrogenation treatment, A part thereof was finely dispersed, and then the recombination of the mother phase at the time of the H ₂ removal treatment was caused by the remaining mother phase as a nucleus, and the nitriding treatment was performed to make the crystal orientation uniform. A powder for anisotropic bonded magnets can be manufactured. In addition, the present invention provides an RT method by a hydrogen treatment method.
In the method for producing an MN-based anisotropic bonded magnet,
When hydrogenating, it passes through a specific temperature range sufficiently quickly.
Alternatively, by raising the temperature in a specific temperature range in a vacuum or in an inert gas, it is possible to ensure that the above mother phase remains, and to obtain an R-T-M-N anisotropic bonded magnet powder having excellent magnetic properties. It can be manufactured with good reproducibility regardless of the amount of treatment, and by bonding this with a resin, an R—Fe—M—N anisotropic bonded magnet can be easily manufactured.

Example 1 No. 1 shown in Table 1 obtained by the high frequency melting method. 1-1
The ingot of composition 0 was subjected to solution treatment at 1100 ° C. for 24 hours to make the Th ₂ Zn ₁₇ type compound in the ingot 95 vol% or more, and then the average particle size was 100 μm in a stamp mill in an Ar gas atmosphere. After coarsely pulverizing into powder, the coarsely pulverized powder was heated in vacuum to the hydrotreating temperature shown in Table 2 and maintained at that temperature.
H ₂ gas with H ₂ partial pressure of 1.0 atm was introduced into the furnace, and
After hydrogenation under the hydrogenation conditions shown in, the H ₂ partial pressure is 1
A H ₂ removal treatment was performed under an H ₂ removal condition shown in Table 2 in an atmosphere of × 10 ^-4 Torr to obtain a powder having a texture with an average crystal grain size of 0.3 μm. Then, the powder was pulverized to a size of 45 μm or less by a disc mill, further subjected to nitriding treatment at 475 ° C. for 4 hours in N ₂ gas at a pressure of 3 atm, and then cooled. The composition of the obtained alloy powder is shown in Table 1. 2.0 wt% of an epoxy resin was mixed with the powder, the mixture was compression-molded in a magnetic field of 10 kOe at a pressure of 3.0 ton / cm ² , and the resin was cured at a temperature of 150 ° C. for 1 hour to form a bond magnet. Created. Table 2 shows the magnetic properties of the obtained bonded magnet.

No. 1 shown in Table 1 obtained by the high frequency melting method. The ingots having the compositions of 11 to 12 were subjected to solution treatment at 1100 ° C. for 24 hours to remove the Th ₂ Zn ₁₇ type compound in the ingot by 9
After adjusting the content to 5 vol% or more, coarse pulverization was performed in an Ar gas atmosphere with a stamp mill to an average particle size of 100 μm, and the temperature rising rate from room temperature to the holding temperature was 5 ° C./in H ₂ gas with an H ₂ partial pressure of 1.0 atm. The temperature was raised at min, and the H ₂ removal treatment was performed under the H ₂ removal conditions shown in Table 2 to obtain a powder having a texture with an average crystal grain size of 0.3 μm. Then, this powder was pulverized to a size of 45 μm or less by a disk mill, further subjected to nitriding treatment at 475 ° C. for 4 hours in N ₂ gas at a pressure of 3 atm and then cooled. The composition of the obtained alloy powder is shown in Table 1. 2.0 wt% of epoxy resin was mixed with the powder to obtain 10 kOe.
Compression molding at a pressure of 3.0 ton / cm ² in a magnetic field of
Further, the resin was cured at a temperature of 150 ° C. for 1 hour to prepare a bonded magnet. Table 2 shows the magnetic properties of the obtained bonded magnet.

Comparative Example 1 No. 1 shown in Table 1 obtained by the high frequency melting method. 13-
The ingot having the composition of 14 was subjected to solution treatment at 1100 ° C. for 24 hours to make the Th ₂ Zn ₁₇ type compound in the ingot 95 vol% or more, and then coarse pulverization, hydrogen treatment and de-soldering similar to those in the example. H
_Two treatments were performed to obtain a powder having a texture with an average crystal grain size of 0.3 μm. Then, this powder was pulverized to a size of 45 μm or less by a disk mill, and the same nitriding treatment as in the example was carried out to prepare a bonded magnet. The obtained bonded magnet was magnetically isotropic.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

According to the present invention, R-
In the method for producing a TN-based bonded magnet, by adding an element M that has an effect of suppressing the decomposition of the mother phase during the hydrogenation treatment, a part of the mother phase remains in a finely dispersed state, and then the demagnetization is performed. It is possible to produce a powder for anisotropic bonded magnets in which crystal orientations are uniform, by causing recombination of the mother phase at the time of H ₂ treatment to occur with the remaining mother phase as a nucleus and further performing a nitriding treatment. Further, according to the present invention, R-
In the method for producing a TMN-based anisotropic bonded magnet, a specific temperature range is sufficiently and quickly passed during hydrogenation, or a specific temperature range is raised in a vacuum or an inert gas. certainty if tighten the remaining matrix can be reproducibly manufactured irrespective of excellent RTMN based anisotropic bonded powder throughput magnet magnetic properties, by this binding with a resin, easily R- T -Manufacture MN-based anisotropic bonded magnets.

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-6-20817 (JP, A) JP-A-8-316018 (JP, A) JP-A-6-172936 (JP, A) JP-A-6- 279915 (JP, A) JP-A-5-166615 (JP, A) Hiroshi Yamamoto et al., Magnetic properties of Sm-Fe-Co-V based nitride compounds and their bonded magnets, Institute of Electrical Engineers of Japan Material Magnetics Research Group, Japan Electrotechnical Society, December 2, 1993, MAG-93-244 to 253, 11-19 (58) Fields investigated (Int.Cl. ⁷ , DB name) H01F 41/02 B22F 1/00 H01F 1/04 H01F 1/08

Claims (2)

(57) [Claims] 1. R (at least one of rare earth elements including R: Y and containing 50% or more of Sm) 10 to 12 at%, T (T: Fe or Fe)
(A part of Co is replaced by 50% or less of Co) 80 to 90 at%, M (M; Al, Ti, V, C
r, Ni, Ga, Zr, Nb, Mo, In, Sn, Hf, Ta, and one or more) ingot made of 10at% or less (excluding 0 atomic%) of W, from 900 to 1
After solution heat treatment at 200 ℃ for 1 hour or more, the average particle size is 20μm-1
At least 95 vol% of 0 mm was made into a coarsely pulverized powder consisting of a compound having a Th ₂ Zn ₁₇ type structure, and then the coarsely pulverized powder was mixed with 0.1
~ 10 atm H ₂ gas or an inert gas with H ₂ partial pressure equal to it (excluding N ₂ gas, but the total pressure is 10 atm or less) in the temperature range of 600 ~ 750 ℃ heating rate 10 ℃ / min ~ 200 ℃ / mi
After heating at n, then held heated for 30 minutes to 8 hours 750 to 900 ° C., further H ₂ partial pressure of 1 × 10 ^-2 Torr de H ₂ for 30 minutes to 8 hours heating held at 750 to 900 ° C. Below The powder is treated and then cooled to have an average crystal grain size of 0.05 to 0.5 μm, and fine powder forming individual powder has a texture having a uniform orientation in a certain direction to obtain a powder having the following texture. After pulverizing the powder to 3 to 500 μm and sizing, the powder is squeezed to 300 in N ₂ gas at N ₂ pressure of 0.5 to 1000 atm.
Hold at ~ 650 ° C for 30 minutes ~ 50 hours, R8 ~ 10at%, T65 ~ 8
2at%, M 10at% or less, containing N 8-15at%, after obtaining an alloy powder having a Th ₂ Zn ₁₇ type structure or a TbCu ₇ type structure, the alloy powder was pulverized to 3 to 500 μm and sized. Then, a method for producing an RTMN-based anisotropic bonded magnet, which comprises mixing a resin and molding in a magnetic field. 2. R (at least one of rare earth elements including R: Y and containing 50% or more of Sm) 10 to 12 at%, T (T: Fe or Fe)
(A part of Co is replaced by 50% or less of Co) 80 to 90 at%, M (M; Al, Ti, V, C
r, Ni, Ga, Zr, Nb, Mo, In, Sn, Hf, Ta, and one or more) ingot made of 10at% or less (excluding 0 atomic%) of W, from 900 to 1
After solution heat treatment at 200 ℃ for 1 hour or more, the average particle size is 20μm-1
After forming a coarsely pulverized powder of 0 mm at least 95 vol% or more of a compound having a Th ₂ Zn ₁₇ type structure, after heating the coarsely pulverized powder to a temperature range of 750 ° C. or higher in a vacuum or an inert gas, , 0.1 to 10 atm of H ₂ gas or an inert gas having H ₂ partial pressure equal to it (excluding N ₂ gas, but the total pressure is 1
(0 atm or less), and further heat and hold at 750 to 900 ° C for 30 minutes to 8 hours, and 750 to 900 at H ₂ partial pressure of 1 × 10 ^-2 Torr or less.
℃ to perform de H ₂ process of heating for 30 minutes to 8 hours, then the average grain size and cooling is 0.05 to 0.5 [mu] m, and the orientation of microcrystals to form individual powder aligned in a predetermined direction Powder with a texture
After pulverizing and sizing to m, the powder is N ₂ pressure 0.5 ~ 1000atm
In N ₂ gas for 30 minutes to 50 hours at 300 to 650 ℃, R 8 to
10at%, T65~82at%, M 10at % or less, containing N 8~15at%, after obtaining an alloy powder having a Th ₂ Zn ₁₇ type structure or the TbCu ₇ structure, the alloy powder 3~500μm Characterized by crushing and sizing, then mixing the resin and molding in a magnetic field
Manufacturing method of RTMN type anisotropic bonded magnet.