JPH07302725A - Manufacture of r-fe-m-n based bond magnet - Google Patents

Abstract

PURPOSE:To obtain magnetic powder having a fine crystal grain diameter, and realize a bond magnet excellent in magnetic characteristics, by performing a heating diffusion process, after additional elements whose amount is less than or equal to a specified value is added to starting material and mechanical alloying is performed. CONSTITUTION:The following are mixed to obtain composition; 6-8at% of R (which is at least one kind of rare earth element containing Y and contains Sm of 50% or more), 75-92at% of Fe, and 1-15at% of M (one kind or two or more kinds out of Ti, V, Cr, Co, Ni, Nb, Mo, Ta, W, Al, Si, Ga, Zr, In, Sn and Hf). After the mixing, mechanical alloying is performed, and then a heating diffusion process is performed at 600-850 deg.C for l0min-12hr. Thereby powder having a specified average grain diameter whose main phase is the following is obtained; R2Fe17-xMx phase (X=0.2-3.5) having Th2Zn17 type structure or TbCu7 type structure, and Fe-M phase having bcc structure. Alloy powder obtained by nitriding the powder under a specified condition is bonded by using resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an R-Fe-MN series bonded magnet which can be used for a permanent magnet constituting a magnetic circuit such as various motors and actuators, and has a required composition. Mechanically alloying the mixed required metal powder or alloy powder in a specific atmosphere, and diffusing the R ₂ Fe _17-x M _x phase having a Th ₂ Zn ₁₇ type structure or a TbCu ₇ type structure (where x = 0.2-3.
5), and two Fe-M phases having a bcc structure each have a fine crystal grain size and are mixed with each other to form an aggregate powder, which is further subjected to a nitriding treatment and bonded with a resin. The present invention relates to a manufacturing method for obtaining an R-Fe-M-N based bonded magnet having a high coercive force.

[0002]

2. Description of the Related Art Bonded magnets are used in various fields for reasons such as good dimensional accuracy, cost reduction by integral molding with other members, and good yield in thin-walled molded products. -There is a B-based powder. Nd
As the —Fe—B-based permanent magnet powder, a magnet powder having an ultrafine structure obtained by a superquenching method or the like has been used.

The Nd-Fe-B system permanent magnet powder is
The Curie point (Tc) is low at around 300 ° C, and Br, i
Since the temperature coefficient of Hc is large, there is a problem that the temperature coefficient of the magnet characteristics is large when used in a bonded magnet. Therefore, it is possible to raise Tc by adding Co or the like to improve the temperature coefficient of Br, but the temperature coefficient α of Br is limited to about −0.08% / ° C. at most.

Recently, Sm ₂ Fe ₁₇ having a Th ₂ Zn ₁₇ type structure
The compound has a Tc almost twice as high as an absolute temperature by allowing nitrogen to penetrate into the lattice, and the Tc of the Nd-Fe-B system is increased.
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). Further, Nd-Fe-M (M = T having a ThMn ₁₂ type structure)
(i, V, Cr, Mo, etc.)-based compounds also have an increase in Tc due to the intrusion of nitrogen into the interstitial lattice, and Nd ₂ Fe ₁₄ B
It has been reported that an anisotropic magnetic field similar to that of Ying-chang Yang et al., S is obtained.
solid State Commun. 78 (199
1) 317. ).

[0005]

The inventors of the present invention first obtained an alloy having the above-mentioned Nd-Fe-M system composition by a mechanical alloying method, and then heat-diffusion treatment to form fine crystals of a ThMn ₁₂ type structure. A method for producing an RTMN-N-based bonded magnet, in which magnet powder obtained by precipitation and further nitriding treatment is bonded with a resin, has been proposed (JP-A-5-234731). In this manufacturing method, the additional element M needs to be added at 7 at% or more as an essential element for stabilizing the ThMn ₁₂ structure, but there is a problem in magnetic characteristics that the addition of this non-magnetic element lowers the magnetization. It was

On the other hand, since the Sm ₂ Fe ₁₇ system nitride contains a large amount of Sm, which is a small amount of resources, there is a problem that it is relatively expensive, and a permanent magnet powder containing a large amount of abundant elements of resources is required. ing. As a solution, Sm and Fe
The composition ratio of Sm ₂ Fe ₁₇ was mixed so that Fe was larger than the stoichiometric ratio of Sm ₂ Fe ₁₇ , and the mixed raw materials were mechanically alloyed, and the Sm ₂ Fe ₁₇ phase and α-Fe phase were subjected to a heat diffusion treatment. Sm that is nitrided after finely depositing and mixing
_A method of manufacturing a ₂ Fe ₁₇ N _x + α-Fe two-phase magnet has been proposed (for example, J. Ding, PG McCorm).
ican dR. Street, J .; Magn. Mag
n. Mat. 124 (1993), 1). However, according to this method, the crystal grain sizes of the Sm ₂ Fe ₁₇ N _x phase and the α-Fe phase cannot be made sufficiently fine and a high coercive force cannot be obtained.

The present invention relates to R ₂ Fe ₁₇ N _X + α-Fe system 2
Method for producing a phase magnet, particularly a production method using a mechanical alloying method, for producing a bond magnet having high magnetic properties by obtaining magnet powder having a fine crystal grain size, and a method for producing an R-Fe-M-N bond magnet The purpose is to provide.

[0008]

In order to improve the magnetic characteristics in the method of manufacturing an Sm ₂ Fe ₁₇ N _X + α-Fe two-phase magnet using the mechanical alloying method, the inventors have
An ideal structure for this type of magnet, that is, a structure in which Sm ₂ Fe ₁₇ which is a hard phase after nitriding and α-Fe which is a soft phase are extremely finely precipitated and mixed with each other. As a result of earnestly studying the method for realizing the above, the additive element M of 15 at% or less in the starting material was added.
(M: Ti, V, Cr, Co, Ni, Nb, Mo, T
a, W, Al, Si, Ga, Zr, In, Sn, Hf,
One or two or more of them are added, mechanical alloying is performed, and then heat diffusion treatment is performed under appropriate conditions to reveal the above-mentioned ideal structure and improve magnetic properties after nitriding treatment. Based on this finding, the present invention has been completed. Further, in the steps of the heat diffusion treatment and the nitriding treatment, the inventors perform both steps continuously in the same furnace, so that the amount of oxygen in the powder to be treated is higher than that in the case where they are individually performed. It was found that the magnetic properties were reduced and the magnetic properties were improved, and the present invention was completed.

That is, the present invention is: 1) R 6 to 8 at%, Fe 75 to 92 at%, M
1 to 15 at%, (provided that at least one kind of rare earth element including R: Y and containing 50% or more of Sm, M:
Ti, V, Cr, Co, Ni, Nb, Mo, Ta, W,
1 or more of Al, Si, Ga, Zr, In, Sn, Hf), and after mixing and mixing the required metal powder or alloy powder, 2) in vacuum or in Ar gas Mechanically alloying with 3), then 600 ~ 8 in vacuum or Ar gas.
Heat diffusion treatment at 50 ° C for 10 minutes to 12 hours is performed.
R ₂ Fe having a ₂ Zn ₁₇ type structure or a TbCu ₇ type structure
_17-x M _x phase (where x = 0.2 to 3.5), and b
2 phases of Fe-M phase having a cc structure each having an average particle size of 0.05 to 0.5 μm are mixed with each other to obtain a powder having an average particle size of 0.5 to 500 μm, 4) Nitriding treatment is carried out by holding at 300 to 550 ° C. for 10 minutes to 12 hours in 0.5 to 1000 atm of N ₂ gas, R 5 to 7 at% and Fe 75 to 92 at.
%, M 1 to 15 at% and N 3 to 12 at% were obtained, and 5) an R-Fe-M-N based bonded magnet having excellent temperature characteristics, characterized by being bonded with a resin. It is a manufacturing method.

Further, according to the present invention, in the above structure,
R-Fe-M- characterized in that, in the heating diffusion process and the nitriding process, both processes are continuously performed in the same furnace.
We also propose a method for manufacturing N-based bonded magnets.

Reason for Limiting Composition The presence of the Fe-M phase is an essential condition in the R-Fe-M-N based bonded magnet according to the manufacturing method of the present invention. This point is related to the conventional R-T-M-N system. It is essentially different from a magnet. In the raw material composition used in the present invention, the rare earth element R is Y, La, Pr, Nd, Sm, Gd, Tb, H.
O, Er, Tm, and Lu are included, and at least one of them contains Sm in an amount of 50 at% or more of R.
The reason why Sm is 50 at% or more of R is that sufficient coercive force cannot be obtained when Sm is 50% or less. Also, R
You may use the whole quantity Sm as. When the R composition before mechanical alloying is less than 6 at%, the volume ratio of the R ₂ Fe _17-x M _x phase to the Fe-M phase is too small, and the coercive force decreases, and when it exceeds 8 at%, Fe- Since the M phase decreases and the magnetization decreases, it is set to 6 to 8 at%. The composition range of Sm when the total amount of Sm is used as R is also set to 6 to 8 at% for the same reason as above. A more preferable range of R before mechanical alloying is 7 to 8 at%.

The R composition after nitriding after heat diffusion after mechanical alloying is because R adheres to the inner wall of the mill or the ball surface during mechanical alloying or evaporates during heat diffusion. It tends to decrease compared to before mechanical alloying. Further, the composition of R relatively decreases due to an increase in the amount of nitrogen due to the nitriding treatment and an increase in the oxygen content due to the oxidation of the powder which is unavoidable in the manufacturing process. When R is less than 5 at%, R for Fe-M phase
The volume ratio of the ₂ Fe _17-x M _x phase is too small, and the coercive force decreases, and when it exceeds 7 at%, R exceeds the stoichiometric composition of R ₂ Fe _17-x M _x. Phase disappears and RFe ₃
Since the phase precipitates and the magnetization decreases, R after nitriding treatment
Is 5 to 7 at%. A more preferable range of R after nitriding treatment is 6 to 7 at%.

R-Fe-M-by the manufacturing method of the present invention
In the N-based bonded magnet, the presence of the Fe-M phase is an essential condition, but in the compound having the ThMn ₁₂ type structure, the stoichiometric composition of R is as low as 7.7 at%, and in the composition range of R of the present invention. The existence of the Fe-M phase becomes difficult.
Therefore, in the present invention, the compound constituting the powder after the heat diffusion treatment is converted into the R ₂ Fe _17-x M _x phase having the Th ₂ Zn ₁₇ type structure or the TbCc ₇ type structure and the Fe-M phase having the bcc structure. limit. Fe is R when less than 75 at%
If the Fe ₃ phase or the like precipitates and the magnetization decreases, and if it exceeds 92 at%, the volume ratio of the R ₂ Fe _17-x M _x phase to the Fe-M phase is too small, and the coercive force decreases, so that it is 75 to 92 at%. And A more preferable range of Fe is 80 to 85 at%.

The additive element M is substituted or solid-solved in the R ₂ Fe ₁₇ phase and the α-Fe phase which are crystallized by the heat diffusion treatment, and the crystal grain size of both phases is coarsened to 0.5 μm or more. Is desired, and as a result the coercive force is prevented from lowering, an element having the effect of suppressing the decrease of coercive force is desired, and Ti, V, Cr, Co, Ni, Nb, Mo, Ta,
There is W. In addition, among M, Al, Si, Ga, Zr,
In, Sn, and Hf are elements useful for stabilizing the crystal structure of the R ₂ Fe _17-x M _x phase and suppressing the in-phase decomposition reaction in the nitriding treatment. Therefore, as M, it is advisable to use a combination of the above elements according to the purpose. When the addition amount exceeds 15 at%, the second phase that is not ferromagnetic precipitates and the magnetization decreases, so M is set to 15 at% or less. A more preferable range of M is 1 to 10 at%.

N diffuses into the R ₂ Fe _17-x M _x phase to form a nitrogen interstitial compound R ₂ Fe _17-x M _x N _y having uniaxial anisotropy, but N is less than 3 at%. In that case, uniaxial anisotropy cannot be obtained, and if it exceeds 12 at%, the Th ₂ Zn ₁₇ type structure or the TbCu ₇ type structure becomes unstable, and R ₂ Fe _17-x M _x N _y
Since the phase decomposes into RN and Fe-M, which is not preferable,
12 at%. More preferable range of N is 7 to 11a.
t%.

Reasons for limiting manufacturing conditions In the present invention, mechanical alloying means mixing and adjusting a metal powder or an alloy powder blended in a required composition, and then forming a fine grinding medium such as steel balls in a vacuum or Ar gas. This is a step of mechanically alloying at room temperature by mixing the metal powder or the alloy powder to the atomic level by the contained fine pulverizer. As a device used for mechanical alloying, a ball mill, a vibration mill, a planetary ball mill, an attritor or the like can be used as long as it can replace the inside of the container with an inert gas. Since it is different, it is necessary to select it appropriately. The product after mechanical alloying is R-Fe-M.
Bcc-F in R-Fe-M system amorphous or R-Fe-M system amorphous
It is desirable that one of e, the element M and Fe-M, or two or more of them be finely dispersed.

The reason for limiting the heat diffusion treatment condition after mechanical alloying to 600 to 850 ° C. for 10 minutes to 12 hours is as follows. Heat diffusion treatment temperature is 600 ℃
If it is less than the above, the diffusion rate of the constituent elements is slow, so that the composition obtained by mechanically alloying and mixing the constituent elements in a microscopic order is a Th ₂ Zn ₁₇ type structure or a structure containing many stacking faults. The rate at which the R ₂ Fe _17-x M _x compound having the TbCu ₇ type structure precipitates becomes extremely slow, and the reaction takes a long time, which is not preferable.
If the temperature exceeds 0 ° C., the R ₂ Fe _17-x M _x compound having the Th ₂ Zn ₁₇ type structure or the TbCu 7 type structure will be rapidly precipitated, but it will become coarse crystals and the coercive force will decrease, which is not preferable. A more preferable temperature range is 650 to 750 ° C. If the heat diffusion treatment time is less than 10 minutes, it will be difficult to make the entire powder into a uniform structure, and if it exceeds 12 hours, the coercive force will decrease due to the growth of coarse particles, and the magnetic properties will deteriorate due to the oxidation of the powder during heat treatment. And the treatment cost rises, which is not preferable. A more preferable heat diffusion treatment time is 30 to 60 minutes.

The reason for limiting the average grain size of the powder after the heat diffusion treatment to 0.05 to 0.5 μm is 0.05 μm.
If it is less than 0.1, it is practically difficult to generate, and even if a crystal having a size of less than 0.05 μm is obtained, there is no advantage in terms of properties, and it is 0.
If it exceeds 5 μm, the grain size of the R ₂ Fe _17-x M _x N _y phase after nitriding treatment becomes larger than the critical domain grain size, and the coercive force of the powder decreases, which is not preferable as a powder for permanent magnets. Is. More preferable average grain size is 0.1 to 0.3 μ
m. R ₂ Fe _17-x M _x constituting the magnet powder of the present invention
It is essential that both the Ny phase and the Fe-M phase maintain the above average grain size range, and that both phases are mixed with each other through the grain boundaries.

In the present invention, the reason for limiting the average particle size of the fine powder having a fine crystal grain size to 0.5 to 500 μm is that if the average particle size is less than 0.5 μm, the magnetic properties may be deteriorated due to the oxidation of the powder and 500 μm. This is because the nitriding treatment takes a long time and is not preferable when it exceeds. The more preferable average particle size of the fine powder is 1 to 10 μm.

The N ₂ pressure during the nitriding treatment is 0.5 to 1000.
The reason for limiting to atm is that if it is less than 0.5 atm, the nitriding reaction is slow, and if the pressure is increased, the reaction proceeds rapidly,
If it exceeds 1000 atm, the processing equipment becomes too large,
This is because it is not preferable in terms of industrial production cost. A more preferable pressure range is 1 to 50 atm. The reason for limiting the temperature during the nitriding treatment to 300 to 550 ° C. is that nitriding does not proceed below 300 ° C. and R ₂ Fe _17-x exceeds 550 ° C.
This is because the M _x compound decomposes into RN and Fe-M, which causes deterioration of magnetic properties. A more preferable temperature range is 400
~ 450 ° C. The holding time during nitriding is 1
If it is less than 0 minutes, sufficient nitriding does not proceed, and if it exceeds 12 hours, decomposition occurs and deterioration of magnetic properties is caused, so that it is set to 10 minutes to 12 hours. A more preferable holding time is 1 to 5 hours.

In the present invention, as a method for continuously performing both the heat diffusion treatment and the nitriding treatment in the same furnace,
Either a batch type or a continuous type furnace may be used. In the latter case, at least two chambers of a heating diffusion treatment chamber and a nitriding treatment chamber are provided, and a container containing a processing raw material is provided between both chambers in the furnace. It is preferable that the structure be moved.

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 the magnet powder, followed by compression molding and heating to cure the resin. In the case of injection molding, extrusion molding, and roll molding, it can be obtained by adding thermoplastic resin, coupling agent, lubricant, etc. to the magnet powder and kneading it, and then molding by injection molding, extrusion molding, or roll molding. . In the resin impregnation method, the magnet powder is compression-molded, optionally heat-treated, then impregnated with a thermosetting resin, and heated to cure the resin. Alternatively, the magnet powder may be obtained by compression molding, heat treatment if necessary, and impregnation 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%, and 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, and for example, polyamide, polyimide, polyester, phenol resin, fluorine resin, silicon resin, epoxy resin or the like is appropriately selected.

[0024]

The present invention is based on the Th ₂ Zn ₁₇ type structure or TbC.
to replace the Fe in the R ₂ Fe ₁₇ of u ₇ type structure with additive element M, R ₂ Fe ₁₇ having a Th ₂ Zn ₁₇ type crystal structure or the TbCu ₇ structure crystallizes in heat diffusion treatment performed after mechanical alloying _-x M _x compound particle size to be able to 0.5μm below, so that the crystal grain size of crystallized out becomes equal to or less than the single magnetic domain particle size, after the nitriding treatment, for obtaining magnet alloy powder Exhibits excellent coercive force. In addition, the present invention provides a specific composition of R-Fe-M mixed in atomic order.
After the alloy alloy powder is produced by mechanical alloying, it is further heat-diffused at 600 to 850 ° C.
R ₂ Fe of Th ₂ Zn ₁₇ type structure or TbCu ₇ type structure
It is possible to obtain a powder having a specific average crystal grain size with two main phases being the _17-x M _x phase and the Fe-M phase of the bcc structure, and subjecting this to nitriding treatment in N ₂ gas under specific conditions. The required R-Fe having a coercive force of 3 kOe or more.
An -MN alloy powder can be produced, and by bonding this with a resin, an R-Fe-MN bonded magnet having excellent temperature characteristics can be easily produced.

[0025]

【Example】

Example As a raw material metal powder, R powder having a particle size of 250 μm or less, Fe powder having a particle size of 150 μm or less, and powder of the additional element M were mixed in the composition shown in Table 1, and 36 g of this compounded raw material was measured with a diameter of 128 mm × height of 132 mm Charge into the ball mill, and further charge 500 g of stainless steel balls with a diameter of 9.8 mm as a fine grinding medium. After replacing the inside of this ball mill with Ar gas, mechanically under the conditions of rotation speed of 95 rpm and rotation time of 200 hours. Alloyed. As a result of mechanical alloying, Example No. The raw materials 1 to 9 were fine powders having an average particle size of 1.5 μm. This powder was a mixture of an amorphous phase and a Fe-M phase having a crystalline bcc structure according to X-ray diffraction.

Next, heat treatment is performed in Ar gas under the heat diffusion treatment conditions shown in Table 2 to form R ₂ Fe having a Th ₂ Zn ₁₇ type structure.
The two phases of the _17-x M _x phase and the bcc structure Fe-M phase to obtain a powder as a main phase. The average crystal grain size and the average grain size of the powder were 0.1 μm and 1.5 μm, respectively. S
As a result of EM observation, the powder particle size distribution was large, and it appeared that each powder was agglomerated with fine particles. The powder after mechanical alloying was newly heat-treated in Ar gas under the heat diffusion treatment conditions shown in Table 2, and the atmosphere in the treatment furnace was replaced with N ₂ gas at a pressure of 1 atm, and the nitridation shown in Table 2 was performed. After nitriding under the conditions, it was cooled. The composition of the obtained alloy powder is shown in Table 1, and the composition of Example No. The X-ray diffraction patterns of 1-3 are shown in FIG. As is clear from FIG. 1, the sample No. The X-ray diffraction patterns of the magnet powders 1, 2, and 3 are Sm ₂ Fe _17-x M _x N _y phase and bc, respectively.
It consists of the diffraction peak of the Fe-M phase of the c structure, indicating that the magnet powder of the present invention consists of these two phases.

Further, 2.0 wt% of an epoxy resin was mixed with the obtained alloy powder, the mixture was compression-molded at a pressure of 3.0 ton / cm ² , and the resin was cured at a temperature of 150 ° C. for 1 hour. A bond magnet was produced. The properties of the bonded magnet were measured and are shown in Table 2. 1 (Example N
o. The demagnetization curve of 1) is shown in FIG. As is clear from FIG. 2, since the demagnetization curve has a large inclination of the minor loop shown by the dotted line, the Sm ₂ Fe ₁₇ -xMxNy phase and the F
It can be seen that the e-Co phase mixes with each other at a distance short enough to cause magnetic exchange interactions with each other. Further, the sample No. When the rate of temperature change of the residual magnetic flux density and the coercive force of the bonded magnet of Example 1 (Example No. 1) at 20 to 140 ° C. was measured, α = −
It was 0.02% / ° C and β = -0.28 / ° C.

Example No. After blending in the same composition as in Example 1, the above mechanical alloying treatment was performed, and the obtained powder was subjected to a heat diffusion treatment in which it was kept in Ar gas at 650 ° C. for 30 minutes. After cooling this powder, it was once taken out into the atmosphere, charged into a nitriding furnace, and subjected to a nitriding treatment at 400 ° C. for 2 hours in N ₂ gas at a pressure of 1 atm for magnet powder (Example No. 10). Got The composition of the obtained alloy powder is shown in Table 1.
In the above example No. Table 2 shows the magnetic characteristics of the bonded magnet after resin bonding in the same manner as in No. 1.

Comparative Example 1 Using the same raw material powder as in Example, the composition shown in Table 1 was added, and then the same mechanical alloying treatment as in Example was applied, and the obtained powder Ar gas is shown in Table 2. Heat treatment was performed under heat diffusion treatment conditions, the atmosphere in the treatment furnace was replaced with N ₂ gas at a pressure of 1 atm, and nitriding treatment was performed under the nitriding conditions shown in Table 2 to obtain magnet powder (Comparative Example No. 1). Obtained. The composition of the obtained alloy powder is shown in Table 1, and the magnetic characteristics of the bonded magnet after resin bonding in the same manner as in the examples are shown in Table 2.

Comparative Example 2 Example No. After blending in the same composition as 1 and subjected to the same mechanical alloying treatment as in the example, the obtained powder was Ar.
A heat diffusion treatment was carried out in which the gas was kept at 300 ° C. for 15 minutes, and the atmosphere in the treatment furnace was replaced with N ₂ gas at a pressure of 1 atm. No. 2) was obtained. The composition of the obtained alloy powder is shown in Table 1, and the magnetic characteristics of the bonded magnet after resin bonding in the same manner as in the examples are shown in Table 2.

Comparative Example 3 Example No. After blending in the same composition as 2 and subjected to the same mechanical alloying treatment as in the example, the obtained powder is Ar.
Heat treatment was performed in a gas under the thermal diffusion treatment conditions shown in Table 2, the atmosphere in the treatment furnace was replaced with N ₂ gas at a pressure of 1 atm, and nitriding treatment was performed at 900 ° C. for 2 hours to obtain magnet powder (comparative). Example No. 3) was obtained. The composition of the obtained alloy powder is shown in Table 1, and the magnetic characteristics of the bonded magnet after resin bonding in the same manner as in the examples are shown in Table 2.

Comparative Example 4 Using the same raw material powder as in Example, the composition shown in Table 1 was added, and then the same mechanical alloying treatment as in Example was applied, and in the obtained powder Ar gas, shown in Table 2. NdFe _12-x V having a ThMn ₁₂ type structure is obtained by performing heat treatment under heat diffusion treatment conditions, further replacing the atmosphere in the treatment furnace with N ₂ gas at a pressure of 1 atm, and nitriding treatment under the nitriding conditions shown in Table 2.
_x N _y phase to obtain a powder for a magnet of a main phase (Comparative Example No.4). The composition of the obtained alloy powder is shown in Table 1, and the magnetic characteristics of the bonded magnet after resin bonding in the same manner as in the examples are shown in Table 2.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

According to the present invention, as the stabilizing element M of the Th ₂ Zn ₁₇ type structure or the TbCu ₇ type structure, Ti,
V, Cr, Co, Ni, Nb, Mo, Ta, W, Al,
By producing an R-Fe-M alloy powder having a specific composition containing at least one kind of Si, Ga, Zr, In, Sn, and Hf at 15 at% or less, the heat diffusion treatment temperature after mechanical alloying is 600 to The temperature can be set to a relatively low temperature of 850 ° C., and this heat diffusion treatment facilitates T
R ₂ Fe _17-x having h ₂ Zn ₁₇ type structure or TbCu ₇ type structure
It is possible to obtain a powder having a specific average crystal grain size having two phases of the M _x phase and the Fe-M phase of the bcc structure as main phases, and subjecting this to nitriding treatment in N ₂ gas under specific conditions,
Required R-Fe-MN having coercive force of 3 kOe or more
A system alloy powder can be produced, and by bonding this with a resin, an R—Fe—M—N system bonded magnet having excellent temperature characteristics can be easily produced.

[Brief description of drawings]

1 is a sample No. of an example. X of 1,2,3 magnet powder
It is a graph which shows a line diffraction pattern.

2 is a sample No. of the example. It is a graph which shows the demagnetization curve of the bonded magnet of No. 1.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area H01F 1/06

Claims (2)

[Claims] 1. R (6: 8 at% of at least one kind of rare earth element containing R: Y and containing 50% or more of Sm)
Fe 75 to 92 at%, M (M: Ti, V, Cr, C
o, Ni, Nb, Mo, Ta, W, Al, Si, Ga,
One or more of Zr, In, Sn and Hf) 1
After mixing and mixing the required metal powder or alloy powder so as to obtain a blend composition of ˜15 at%, mechanical alloying is performed in vacuum or in Ar gas, and further 600 to 850 ° C. in vacuum or in Ar gas. The heat diffusion treatment is performed for 10 minutes to 12 hours to obtain a Th ₂ Zn ₁₇ type structure or Tb.
R ₂ Fe _17-x M _x phase having a Cu ₇ type structure (where x =
0.2-3.5), and Fe- having a bcc structure
Two phases, M phase, each having an average particle size of 0.05 to 0.5 μm are mixed with each other to obtain a powder having an average particle size of 0.5 to 500 μm, and the powder is mixed with 0.5 to 1000 atm of N ₂ Nitriding treatment is carried out by holding in gas at 300 to 550 ° C. for 10 minutes to 12 hours, R 5 to 7 at%, Fe 75 to 92 a
An alloy powder containing t%, M 1 to 15 at% and N 3 to 12 at% was obtained, and this was bonded with a resin to produce an R-Fe-M-N bond magnet having excellent temperature characteristics. Method. 2. The process of heating diffusion process and nitriding process, both steps are continuously performed in the same furnace, and the production of the R—Fe—M—N based bonded magnet according to claim 1. Method.