JP3148514B2 - Method for producing R-Fe-M-N bonded magnet - Google Patents

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--M--N bonded magnet which can be used for a permanent magnet constituting a magnetic circuit such as various motors and actuators, and is incorporated into a required composition. The required metal powder or alloy powder mixed is mechanically alloyed in a specific atmosphere, and an R ₂ Fe _17-x M _x phase having a Th ₂ Zn ₁₇ type structure or a TbCu ₇ type structure by diffusion treatment (where x = 0.2-3.
5), and two-phase Fe-M phases having a bcc structure, each having a fine grain size, without a set powder are mixed with each other, further subjected to nitriding, the diffusion process and the denitrification
Process by changing the atmosphere in the same furnace
And bonding the obtained alloy powder with a resin to obtain 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 because of their high dimensional accuracy, cost reduction by integrally molding with other members, and good yield of thin molded products. -B type powder. Nd
As the Fe-B-based permanent magnet powder, a magnet powder having an ultrafine structure obtained by a rapid quenching method or the like has been used.

[0003] The Nd-Fe-B permanent magnet powder is
Curie point (Tc) is as low as about 300 ° C, Br, i
Since the temperature coefficient of Hc is large, there is a problem that the temperature coefficient of the magnet characteristics when used for a bonded magnet is large. Therefore, the temperature coefficient of Br can be improved by increasing Tc by adding Co or the like, 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 increases the Tc almost twice in absolute temperature by injecting nitrogen into the lattice, and the Tc of Nd-Fe-B system
It is reported that an anisotropic magnetic field higher than Nd ₂ Fe ₁₄ B by 160 ° C. can be obtained (JMDC).
oey and H.S. Sun, J .; Magn. Mag
n. Mat. 87 (1990) L251). Nd-Fe-M having a ThMn ₁₂ type structure (M = T
(i, V, Cr, Mo, etc.)-based compounds also increase Tc by allowing nitrogen to penetrate into the interstitial space, and increase Nd ₂ Fe ₁₄ B
It has been reported that an anisotropic magnetic field of the same degree as that obtained by Y-chang Yang et al., S.
olid State Commun. 78 (199
1) 317. ).

[0005]

We [0005] The above, after obtaining the alloy having the above Nd-Fe-M-based composition by a mechanical alloying method, a heat diffusion treatment by fine crystals of ThMn ₁₂ type structure A method for producing an RTMN bonded magnet in which magnet powder obtained by precipitating and further nitriding is bonded with a resin was proposed (Japanese Patent Application Laid-Open No. Hei 5-234731). In this manufacturing method, the additional element M is it is necessary to add more than 7 atomic% as an essential element which stabilizes ThMn ₁₂ structure, there are problems in the magnetic property of magnetization is lowered by the addition of the non-magnetic element Was.

On the other hand, Sm ₂ Fe _17- based nitrides have a problem that they are relatively expensive because they contain a large amount of Sm, which is a small amount of resources, and a permanent magnet powder containing a large number of elements which are abundant in resources is required. ing. As a solution, Sm and Fe
Are mixed so that the composition ratio of Fe is larger than the stoichiometric ratio of Sm ₂ Fe ₁₇ , and the mixed raw materials are mechanically alloyed, and the Sm ₂ Fe ₁₇ phase and the α-Fe phase are heated and diffused. Is finely precipitated and mixed, and then nitrided.
_A method for producing a ₂ Fe ₁₇ N _x + α-Fe-based two-phase magnet has been proposed (for example, J. Ding, PG McCorm).
icandR. Street, J.M. Magn. Mag
n. Mat. 124 (1993), 1). However, according to this method, the crystal grain size of the Sm ₂ Fe ₁₇ N _x phase and the α-Fe phase cannot be made sufficiently small, and a high coercive force cannot be obtained.

The present invention relates to an R ₂ Fe ₁₇ N _X + α-Fe system 2
In a method for producing a phase magnet, in particular, a production method using a mechanical alloying method, a method for producing an R-Fe-M-N-based bonded magnet capable of producing a magnet powder having a fine crystal grain size to produce a bonded magnet having high magnetic properties The purpose is to provide.

[0008]

Means for Solving the Problems The inventors of the present invention have proposed a method for manufacturing a Sm ₂ Fe ₁₇ N _X + α-Fe-based two-phase magnet using a mechanical alloying method, in order to improve magnetic characteristics.
An ideal structure for this type of magnet, that is, a structure in which Sm ₂ Fe ₁₇ , which becomes 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 intensive studies on the method of realizing
(M: Ti, V, Cr, Co, Ni, Nb, Mo, T
a, W, Al, Si, Ga, Zr, In, Sn, Hf,
One or more of them), and after performing mechanical alloying, performing heat diffusion treatment under appropriate conditions, whereby the above-described ideal structure appears and the magnetic properties after nitriding treatment are improved. With this in mind, the present invention has been completed. In addition, the inventors of the present invention performed the heating diffusion process and the nitriding process in the same furnace continuously in the same furnace, so that the amount of oxygen in the powder to be processed is smaller than in the case where the processes are performed individually. 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 provides: 1) R 6 to 8 at%, Fe 75 to 92 at%, M
1 to 15 at%, (where R is at least one kind of rare earth element including Y and contains 50% or more of Sm; M: Ti, V, Cr, Co, Ni, Nb, Mo, Ta,
(W, Al, Si, Ga, Zr, In, Sn, Hf), after mixing and mixing the required metal powder or alloy powder so that the composition becomes 2) in vacuum or Ar Mechanical alloying in gas, 3) 600-8 in vacuum or Ar gas
Perform a heat diffusion treatment at 50 ° C. for 10 minutes to 12 hours,
R ₂ Fe having a ₂ Zn ₁₇ type structure or a TbCu ₇ type structure
_17-x M _x phase (where x = 0.2-3.5), and b
2) Fe-M phase having a cc structure is mixed with each other having an average particle size of 0.05 to 0.5 μm to obtain a powder having an average particle size of 0.5 to 500 μm. perform nitriding treatment of holding N 10 minutes to 12 hours 300 to 550 ° C. in ₂ gas of 0.5～1000Atm, cut the heat diffusion treatment and the nitriding treatment in the same furnace
It is performed continuously by changing the atmosphere , R 5-7at%, Fe
75 to 92 at%, M 1 to 15 at%, N3 to 12
5) An R-Fe-M-N-based bonded magnet having excellent temperature characteristics, characterized in that an alloy powder containing at.

[0010]

Reasons for Restricting Composition The R-Fe-MN-based bonded magnet according to the production method of the present invention requires the presence of the Fe-M phase, which is a problem with the conventional R-T-M-N-based magnet. 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 at 50 at% or more of R.
The reason why 50 at% or more of R is Sm is that if Sm is 50% or less, a sufficient coercive force cannot be obtained. Also, R
May be used as the total amount Sm. If 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 is reduced. Since the M phase is reduced and the magnetization is reduced, the content is set to 6 to 8 at%. When the total amount of Sm is used as R, the composition range of Sm is also set to 6 to 8 at% for the same reason as described above. A more preferable range of R before mechanical alloying is 7 to 8 at%.

R composition after nitriding treatment after heat diffusion treatment after mechanical alloying, R adheres to the inner wall of a mill or a ball surface during mechanical alloying or evaporates during heat diffusion treatment. It tends to decrease compared to before mechanical alloying. In addition, the composition of R relatively decreases due to an increase in the amount of nitrogen due to nitriding treatment and an increase in oxygen charge due to oxidation of powder which is inevitable in the manufacturing process. If R is less than 5 at%, R with respect to the Fe-M phase
_When the volume ratio of the ₂ Fe _17-x M _x phase is too small, the coercive force is reduced, and when it exceeds 7 at%, R exceeds the stoichiometric composition of R ₂ Fe _17-x M _x , so that Fe-M Phase disappears, RFe ₃
Phase and the like are precipitated and the magnetization is reduced.
Is 5 to 7 at%. The more preferable range of R after the nitriding treatment is 6 to 7 at%.

[0013] R-Fe-M- by the production method of the present invention
In an N-based bonded magnet, the presence of an Fe-M phase is an essential condition. However, in a compound having a ThMn ₁₂ type structure, the stoichiometric composition of R is as low as 7.7 at%, and in the R composition range of the present invention. It is difficult to make the Fe-M phase exist.
Therefore, in the present invention, the compound constituting the powder after the heat diffusion treatment is converted into an R ₂ Fe _17-x M _x phase having a Th ₂ Zn ₁₇ type structure or a TbCc ₇ type structure, and an Fe-M phase having a bcc structure. limit. Fe is less than 75 at% when R
If the Fe ₃ phase or the like precipitates and the magnetization decreases, and 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. And A more preferable range of Fe is 80 to 85 at%.

The additive element M substitutes or forms a solid solution in the R ₂ Fe ₁₇ phase and the α-Fe phase crystallized by the heat diffusion treatment, and the crystal grain size of both phases is increased to 0.5 μm or more. Are desired to have an effect of preventing the occurrence of a coercive force as a result, and Ti, V, Cr, Co, Ni, Nb, Mo, Ta,
There is W. Further, 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 decomposition reaction of the same phase in the nitriding treatment. Therefore, as M, it is advisable to use a combination of the above elements according to the purpose. If the amount of addition exceeds 15 at%, the non-ferromagnetic second phase precipitates and lowers the magnetization, 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, where N is less than 3 at%. If this is not the case, uniaxial anisotropy cannot be obtained, and if it exceeds 12 at%, the Th ₂ Zn ₁₇ type structure or TbCu ₇ type structure becomes unstable, and R ₂ Fe _17-x M _x N _y
The phase is decomposed into RN and Fe-M, which is not preferable.
12 at%. A more preferable range of N is 7 to 11a.
t%.

Reasons for Limiting Manufacturing Conditions In the present invention, mechanical alloying refers to mixing and adjusting a metal powder or an alloy powder blended to a required composition, and then milling a fine pulverizing medium such as a steel ball 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 grinding device. 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 the inside of the container can be replaced 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 amorphous amorphous or R-Fe-M amorphous
e, one of the elements M and Fe-M, or two or more of them are desirably in a finely dispersed state.

The reasons for limiting the heat diffusion treatment conditions after the mechanical alloying to 600 to 850 ° C. for 10 minutes to 12 hours are as follows. If the temperature of the heat-diffusion treatment is lower than 600 ° C, the diffusion rate of the constituent elements is low, so that a composition in which the constituent elements obtained after mechanical alloying are mixed in a microscopic order may have a Th ₂ Zn _17- type structure or a large number of layers. R ₂ Fe _17-x M _x compound rate becomes extremely slow to precipitate with the TbCu ₇ structure is a structure including the defect is not preferable because it takes a long time to reaction, and when it exceeds 850 ° C. Th ₂ Zn _Although an R ₂ Fe _17-x M _x compound having a _17- type structure or a TbCu _7- type structure is quickly precipitated, it is not preferable because it becomes a large crystal and the coercive force decreases. A more preferred temperature range is 650-750 ° C. If the heat diffusion treatment time is less than 10 minutes, it is difficult to form a uniform structure of the entire powder, and if it exceeds 12 hours, the coercive force decreases due to coarse grain growth, and the magnetic properties decrease due to oxidation of the powder during heat treatment. And the processing cost rises undesirably. More preferred heat diffusion treatment time is 30
~ 60 minutes.

The reason why the average crystal grain size of the powder after the heat diffusion treatment is limited to 0.05 to 0.5 μm is that 0.05 μm
If it is less than 0.05 μm, it is practically difficult to produce a crystal.
If it exceeds 5 μm, the particle size of the R ₂ Fe _17-x M _x N _y phase after nitriding becomes larger than the critical diameter of the single magnetic domain particles, and the coercive force of the powder decreases, which is not preferable as a powder for permanent magnets. It is. More preferred average grain size is 0.1 to 0.3 μm
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 crystal grain size range, and that both phases are mixed with each other via a grain boundary.

In the present invention, the reason why the average particle size of the fine powder having a fine crystal grain size is limited 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 oxidation of the powder. This is because, if it exceeds 3, it takes a long time for the nitriding treatment, which is not preferable. The more preferable average particle size of the fine powder is 1 to 10 μm.

The reason why the N ₂ pressure during nitriding is limited 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 proceeds rapidly when the pressure is increased, but when the pressure exceeds 1000 atm, the processing equipment becomes large. This is because it is not preferable in terms of industrial production cost. A more preferred 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 exceeds 550 ° C.
This is because the Fe _17-x M _x compound is decomposed into RN and Fe-M, leading to deterioration of magnetic properties. More preferred temperature range is 400-450
° C. The holding time of nitriding treatment, sufficient nitride does not proceed in less than 10 minutes, also occur decompose above 12 hours, because that causes invited the deterioration of the magnetic properties, and 10 minutes to 12 hours . A more preferred retention time is 1 to 5 hours.

In the present invention, as a method of continuously performing both the heat diffusion process and the nitriding process by switching the atmosphere in the same furnace, either a batch type or a continuous type furnace may be used. In such a case, it is preferable to provide at least two chambers of a heat diffusion processing chamber and a nitriding processing chamber, and to move the container containing the processing raw material between the two chambers in the furnace.

The R-Fe-MN-based bonded magnet in the present invention may be manufactured by any known method such as compression molding, injection molding, extrusion molding, rolling molding, and resin impregnation described below. In the case of compression molding, a thermosetting resin, a coupling agent, a lubricant, and the like are added and kneaded to the magnet powder, and the mixture is heated after compression molding to cure the resin. In the case of injection molding, extrusion molding, and rolling molding, a thermoplastic resin, a coupling agent, a lubricant, etc. are added and kneaded to the magnet powder, and then molded by any of injection molding, extrusion molding, and rolling molding. . In the resin impregnation method, magnet powder is compression-molded, heat-treated as necessary, then impregnated with a thermosetting resin, and heated to cure the resin. Alternatively, the magnet powder is obtained by compression molding, heat-treating as necessary, and then impregnating with a thermoplastic resin.

In the present invention, the filling rate of the magnet powder in the bonded magnet varies depending on the above-mentioned manufacturing method.
9.5 wt%, and the remaining 0.5 to 30 wt% is resin and others. In the case of the compression molding method, the filling rate of the magnet powder is 9
5 to 99.5 wt%, 90 to 95 w in the case of the injection molding method
In the case of the resin impregnation method, the content is preferably 96 to 99.5 wt%. In the present invention, the synthetic resin used as the binder can be used in both thermosetting and thermoplastic.
A thermally stable resin is preferable, and for example, polyamide, polyimide, polyester, phenol resin, fluorine resin, silicon resin, epoxy resin and the like are appropriately selected.

[0024]

The present invention provides a 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 The particle size of the compound can be reduced to 0.5 μm or less. As a result, the crystallized crystal particle size becomes equal to or smaller than the single magnetic domain particle size, and after the nitriding treatment, the obtained alloy powder for magnet is obtained. Express excellent coercive force. Further, the present invention relates to a specific composition of R-Fe-M
After producing a system alloy powder by mechanical alloying, it is further subjected to heat diffusion treatment at 600 to 850 ° C,
R ₂ Fe having a Th ₂ Zn ₁₇ type structure or a TbCu ₇ type structure
_17-x M _x phase and two-phase Fe-M phase of the bcc structure can be obtained a powder having a specific average grain size of the main phase, N ₂ gas at a particular condition this same furnace , A required R-Fe-M-N-based alloy powder having a coercive force of 3 kOe or more can be produced, and by combining this with a resin, R-Fe-M having excellent temperature characteristics can be obtained.
-An N-based bonded magnet can be easily manufactured.

[0025]

【Example】

Example After mixing 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 an additive element M into the composition shown in Table 1, 36 g of the compounded raw material having a size of 128 mm in diameter × 132 mm in height was used as the raw metal powder. 500 g of stainless steel balls having a diameter of 9.8 mm were charged as a pulverizing medium in a ball mill, and the inside of the ball mill was purged with Ar gas, and then mechanically rotated at 95 rpm for 200 hours. Alloying treatment was performed. As a result of mechanical alloying, Example No. The raw materials Nos. 1 to 9 became fine powder having an average particle size of 1.5 μm. According to X-ray diffraction, this powder was a mixture of an amorphous phase and a Fe-M phase having a crystalline bcc structure.

Next, a heat treatment is performed in Ar gas under the heat diffusion treatment conditions shown in Table 2 to obtain an 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 average grain size of the powder were 0.1 μm and 1.5 μm, respectively. S
Upon EM observation, the powder particle size distribution was large, and each powder appeared to be agglomerated with fine particles. The powder after the mechanical alloying was newly heat-treated in Ar gas under the heat diffusion treatment conditions shown in Table 2, and the atmosphere in the processing furnace was replaced with N ₂ gas at a pressure of 1 atm. After nitriding under the conditions, it was cooled. Table 1 shows the composition of the obtained alloy powder. The X-ray diffraction patterns of Nos. 1 to 3 are shown in FIG. As is clear from FIG. The X-ray diffraction patterns of the magnetic powders of 1, 2, and 3 show that the Sm ₂ Fe _17-x M _x N _y phase and the bc
It consists of the diffraction peak of the Fe-M phase having the c structure, which indicates that the magnet powder of the present invention consists of these two phases.

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

[0028]

Comparative Example 1 Using the same raw material powder as in the example, after blending into the composition shown in Table 1, the same mechanical alloying treatment as in the example was performed. Heat treatment was performed under the 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 a magnet powder (Comparative Example No. 1). Obtained. Table 1 shows the composition of the obtained alloy powder, and Table 2 shows the magnetic properties of the bonded magnet after resin bonding in the same manner as in the example.

Comparative Example 2 After blending into the same composition as in Example 1, the same mechanical alloying treatment as in the example was performed.
A heat diffusion treatment was performed for 15 minutes at 300 ° C. in a gas, 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. No. 2) was obtained. Table 1 shows the composition of the obtained alloy powder, and Table 2 shows the magnetic properties of the bonded magnet after resin bonding in the same manner as in the example.

Comparative Example 3 After blending into the same composition as in Example 2, the same mechanical alloying treatment as in Example was performed.
Heat treatment was performed in a gas under the thermal 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 nitriding treatment was performed at 900 ° C. for 2 hours. Example No. 3) was obtained. Table 1 shows the composition of the obtained alloy powder, and Table 2 shows the magnetic properties of the bonded magnet after resin bonding in the same manner as in the example.

Comparative Example 4 Using the same raw material powder as in the example, after blending into the composition shown in Table 1, the same mechanical alloying treatment as in the example was performed. A heat treatment is performed under the heat diffusion processing conditions, the atmosphere in the processing furnace is replaced with a N ₂ gas at a pressure of 1 atm, and a nitriding treatment is performed under the nitriding conditions shown in Table 2 to obtain an NdFe _12-x V having a ThMn ₁₂ type structure.
_x N _y phase to obtain a powder for a magnet of a main phase (Comparative Example No.4). Table 1 shows the composition of the obtained alloy powder, and Table 2 shows the magnetic properties of the bonded magnet after resin bonding in the same manner as in the example.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

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

[Brief description of the drawings]

FIG. 1 shows sample Nos. X of 1, 2, 3 magnet powder
It is a graph which shows a line diffraction pattern.

FIG. 2 shows sample Nos. 3 is a graph showing a demagnetization curve of a bonded magnet of No. 1;

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI H01F 1/08 H01F 1/06 A (56) References JP-A-6-69010 (JP, A) JP-A-6-330252 ( JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01F 41/02 B22F 1/00 B22F 9/04 C22C 38/00 H01F 1/06 H01F 1/08

Claims (1)

(57) [Claims] 1. 6 to 8 at% of R (at least one kind of rare earth element including 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 blending and mixing the required metal powder or alloy powder so as to have a composition of １５15 at%, mechanical alloying is performed in vacuum or Ar gas, and then 600 to 850 ° C. in vacuum or Ar gas. Heat diffusion treatment 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.
2 phase M-phase, to give an average particle size 0.5~500μm powder are mixed with one another each have an average particle size 0.05 to 0.5 [mu] m, the powder of 0.5～1000Atm N ₂ A nitriding treatment is performed in a gas at 300 to 550 ° C. for 10 minutes to 12 hours, and the heat diffusion treatment is performed in the same furnace as the nitriding treatment.
Atmosphere is switched from vacuum or Ar to nitrogen gas inside
Continuously carried out by obtaining, R 5~7at%, Fe
75 to 92 at%, M 1 to 15 at%, N 3-1
R-Fe-M- having excellent temperature characteristics characterized in that an alloy powder containing 2 at% was obtained and bonded with a resin.
A method for producing an N-based bonded magnet.