JPH07173501A - Permanent magnet alloy powder and production thereof - Google Patents

Abstract

PURPOSE:To obtain the permanent magnet alloy powder excellent in coercive force iHc and residual magnetic flux density Br by specifying the production conditions of a material having a specified composition and controlling the structure and crystal structure. CONSTITUTION:The molten (Fe, M)-Mn-B-R or (Fe, M, Co)-Mn-B-R alloy (R is Nd or Pr, and M is one or >=2 kinds among Al, Si, S, Ni, Cu, Zn, Ga, Ag, Pt, Au and Pb) having a specified composition is super rapidly cooled to form an amorphous structure or the structure wherein crystallites and the amorphous structure coexist, and crystallization heat treatment is applied under specified conditions to obtain a crystallite aggregate wherein a ferromagnetic soft magnetic phase consisting essentially of-iron and iron and a hard magnetic phase having an Nd3Fe14B-type crystal structure coexist in the same granular body and with the average crystal particle diameter of each phase controlled to 1-50nm. A permanent magnet powder having a low content of rare-earth element and having >=5kOe iHc and >=6.5kG Br is obtained in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet alloy powder for bonded magnets, which is most suitable for various motors, actuators, magnetic circuits for magnetic sensors and the like, and a method for producing the same, and has a specific composition with a small content of rare earth elements ( Fe,
M) -Mn-BR or (Fe, M, Co) -Mn-
The B-R alloy melt is made into an amorphous structure or a structure in which fine crystals and amorphous are mixed by a super quenching method using a rotating roll, a splat quenching method, a gas atomizing method or a combination thereof, and α-iron and An alloy powder composed of a fine crystal aggregate of a ferromagnetic soft magnetic phase containing iron as a main component and a hard magnetic phase having an Nd ₂ Fe ₁₄ B type crystal structure was obtained, and by binding this with a resin, hard ferrite was obtained. Residual magnetic flux density Br of 5 kG or more that cannot be obtained with a magnet
The present invention relates to a permanent magnet alloy powder capable of obtaining a Fe-BR system bonded magnet having: and a manufacturing method thereof.

[0002]

2. Description of the Related Art Permanent magnets used in stepping motors, power motors, actuators, etc. used for home appliances and electric components have been mainly limited to hard ferrite magnets, but at low temperatures due to lowering iHc, There are problems such as demagnetization characteristics, low mechanical strength due to the ceramic material, cracks and chips easily occur, and it is difficult to obtain a complicated shape.

Nowadays, automobiles are strongly required to reduce fuel consumption in order to save resources and to improve fuel efficiency, and electric components for automobiles are required to be further reduced in size and weight. Also,
Designs for maximizing the performance-to-weight ratio are also being considered for applications such as home electric motors other than automobile electrical components. In the current motor structure, magnet materials with Br of about 5 to 7 kG are optimal. However, it cannot be obtained with a conventional hard ferrite magnet.

For example, an Nd-Fe-B based bonded magnet satisfies such magnetic characteristics, but contains 10 to 15 at% of Nd, which requires a large number of steps for separating and refining the metal and a reduction reaction and a large-scale facility. Therefore, it is significantly more expensive than a hard ferrite magnet. In addition, since the pitch between the magnetic poles when magnetizing multiple poles is a minimum of about 1.6 mm, it is possible to further improve the unevenness in rotation of the stepping motor and achieve more positioning accuracy comparable to that of a servo motor. At present, no inexpensive permanent magnet material has been found that has a Br of 5 kG or more and can be easily magnetized with multiple poles.

[0005]

On the other hand, Nd-Fe-B
In a magnet system, a magnet material having a Fe ₃ B type compound as a main phase in the vicinity of Nd ₄ Fe ₇₇ B ₁₉ (at%) has recently been proposed (R. Coehorn et al., J. de Phys., C).
8, 1988, pp. 669-670). This magnetic material is a metastable permanent magnet having a crystalline texture of soft magnetic Fe ₃ B and hard magnetic Nd ₂ Fe ₁₄ B by heat-treating an amorphous ribbon.
Is as low as about 2 to 3 kOe, and the heat treatment conditions for obtaining this iHc are narrowly limited, which is not practical in industrial production.

Nd-containing the Fe ₃ B type compound as a main phase
IH by replacing part of Nd of Fe-B magnet with Dy and Tb
A study to improve c to 3-5 kOe has been announced,
In addition to the problem that the price of raw materials rises due to the addition of expensive elements, the added rare earth elements have magnetic moments of Nd and F.
Since it is coupled antiparallel to the magnetic moment of e, there is a problem that the squareness of the magnetization and demagnetization curve deteriorates (R. Coe.
hoorn, J .; Magn, Magn, Mat. , 83
(1990) 228-230).

Other studies (Shen Bao-gen et al.,
J. Magn, Magn, Mat. , 89 (199
1) 335 to 340), a part of Fe is replaced with Co to raise the Curie temperature and improve the temperature coefficient of iHc, but there is a problem that Br is lowered with the addition of Co. .

In any case, Fe ₃ B type Nd-Fe-B
A system magnet can be made into a hard magnetic material by heat treatment after it is made amorphous by the ultra-quenching method, but iHc is low and the heat treatment conditions are narrow, stable industrial production cannot be performed, and it is an inexpensive alternative to a hard ferrite magnet. Cannot be provided.

According to the present invention, Fe containing a small amount of rare earth is contained.
-In order to improve iHc of B-R magnets (R is a rare earth element) and enable stable industrial production, it has a coercive force iHc of 5 kOe or more and a residual magnetic flux density Br of 6 kG or more, and is comparable to a hard ferrite magnet. It is an object of the present invention to provide a permanent magnet alloy powder for obtaining an Fe-B-R magnet that has low cost performance and can be provided at low cost, and a manufacturing method thereof.

[0010]

The present invention improves the iHc of a Fe-BR system magnet having a low rare earth concentration in which a soft magnetic phase and a hard magnetic phase coexist, and enables a stable industrial production. As a result of various studies for the purpose of alloy powder, Mn and Al, Si, S, Ni, C were added to an iron-based alloy having a small content of rare earth elements and an iron-based alloy in which a part of iron was replaced by Co.
The alloy melt of a specific composition to which one or more of u, Zn, Ga, Ag, Pt, Au, and Pb are added has an amorphous structure or a structure in which fine crystals and amorphous are mixed by a super-quenching method, etc. The residual magnetic flux density B of 5.5 kG or more, which was not obtained in the hard ferrite magnet, was obtained by obtaining the fine crystal aggregate by the heat treatment at the heating rate of
The inventors have found that an optimum rare earth permanent magnet alloy powder can be obtained for a bonded magnet having r, and completed the present invention.

[0011] This invention is a composition formula (Fe _1-a M a)
_{100-xyz Mn x B y R} z or _{(Fe 1-ab M a Co} )
_{100-xyz Mn x B y R} z ( where R is 1 Pr or Nd
Or two, M is Al, Si, S, Ni, Cu, Z
n, Ga, Ag, Pt, Au, Pb), and symbols x, y, z, a, which limit the composition range.
b satisfies the following values, and α-iron and a ferromagnetic soft magnetic phase containing iron as a main component and a hard magnetic phase having an Nd ₂ Fe ₁₄ B type crystal structure coexist in the same powder particle. The average crystal grain size of the constituent phases is in the range of 1 nm to 50 nm, and the average grain size is 3
μm to 500 μm, magnetic characteristics iHc ≧ 5 kOe, Br
The permanent magnet alloy powder is characterized in that ≧ 6 kG and (BH) max ≧ 7 MGOe. 0.01 ≦ x ≦ 7 at% 10 ≦ y ≦ 30 at% 3 ≦ z ≦ 6 at% 0.005 ≦ a ≦ 0.3 0.005 ≦ b ≦ 0.5

Further, according to the present invention, (1) the composition formula is (Fe
_{1-a M a) 100-} xyz Mn x B y R z or (Fe _{1-ab
M a Co b) 100-xyz} Mn x B y R z ( where R is Pr or one or two Nd, M is Al, Si, S, Ni,
Cu, Zn, Ga, Ag, Pt, Au, Pb), and symbols x, y, which limit the composition range.
The molten alloy having z, a, and b satisfying the above values is rapidly cooled by using a super-cooling method using a rotating roll, a splat quenching method, a gas atomizing method, or a combination thereof, to obtain an amorphous structure or a structure in which fine crystals and amorphous are mixed. , (2) 600 around the temperature at which crystallization starts
C. to 750.degree. C., the heating rate up to 10.degree. C./min.
Crystallization heat treatment at 50 ° C./sec is performed to (3) α-iron and a ferromagnetic soft magnetic phase containing iron as a main component and Nd ₂ Fe ₁₄
A hard magnetic phase having a B-type crystal structure coexists in the same powder particle, and after obtaining a microcrystalline aggregate having an average crystal grain size of each constituent phase in the range of 1 nm to 50 nm, (4) if necessary This is a method for producing a permanent magnet alloy powder, which comprises crushing this to an average particle size of 3 μm to 500 μm to obtain a magnet alloy powder.

Reasons for limiting the composition The rare earth element R has high magnetic properties only when it contains one or two of Pr or Nd in a specific amount.
For example, in the case of Ce and La, the characteristic that iHc is 2 kOe or more cannot be obtained, and medium rare earth elements and heavy rare earth elements after Sm cause deterioration of magnetic characteristics and make the magnet expensive, which is not preferable. R is 5.0 kO when less than 3 at%
If iHc of e or more cannot be obtained, and if it exceeds 6 at%, it is 6
Since Br of more than kG cannot be obtained, the range is 3 to 6 at%. The preferable range of R is 4 to 5.5 at%.

If B is less than 10 at%, an amorphous structure cannot be obtained even if the ultra-quenching method is used, and even if a heat treatment is applied, it becomes 3
Only iHc less than kOe can be obtained. Further, if it exceeds 30 at%, iHc of 5 kOe or more cannot be obtained, so 10
The range is -30 at%. The preferred range of B is 15 to
It is 20 at%.

Mn is effective in improving iHc,
If it is less than 0.01 at%, such an effect cannot be obtained, and
If it exceeds 7 at%, Br is greatly reduced, and Br of 6 kG or more cannot be obtained. Therefore, the range is 0.01 to 7 at%. The preferable range of Mn is 1 to 5 at%.

Additive element M Al, Si, S, Ni, C
u, Zn, Ga, Ag, Pt, Au, and Pb are substituted with Fe because they have the effect of improving the squareness of the demagnetization curve and increasing Br and (BH) max. Is less than 0.5%, such an effect cannot be obtained, and 3
If it exceeds 0%, since Br of 5.5 kG or more cannot be obtained, the substitution amount with respect to Fe is 0.5% of Fe + Co + M.
30%. The preferred range is 1 to 15%.

Co is effective for improving Br, the squareness of the demagnetization curve, and the temperature characteristics, but the substitution amount of Fe with Co.
If it is less than 5%, such an effect cannot be obtained, and if it exceeds 50%, Br of 6 kG or more cannot be obtained. Therefore, the substitution amount for Fe is in the range of 0.5 to 50% of Fe + Co + M. The preferable range of Co is 2 to 10%.

Fe occupies the remaining content of the above-mentioned elements.

Reasons for limiting manufacturing conditions In the present invention, the molten alloy having the above-mentioned specific composition is formed into an amorphous structure or a structure in which fine crystals and amorphous are mixed by the ultra-quenching method, and the temperature is about 600.degree. The temperature rising rate up to the processing temperature of 750 ° C is 10
By performing a crystallization heat treatment at a temperature of 50 ° C./minute to 50 ° C./second, α-iron and a ferromagnetic soft magnetic phase containing iron as a main component,
A hard magnetic phase having an Nd ₂ Fe ₁₄ B type crystal structure coexists in the same powder particle, and the average crystal grain size of each constituent phase is 1 nm to
It is most important to obtain a microcrystalline aggregate in the range of 50 nm, and a known superquenching method using a rotating roll can be adopted for the superquenching treatment of the molten alloy. If a structure in which amorphous is mixed is obtained, a splat quenching method, a gas atomizing method, or a quenching method combining these methods may be adopted in addition to the super quenching method using a rotating roll. For example, when a Cu roll is used, the roll surface peripheral velocity is 10 to 5
The range of 0 m / sec is preferable because a suitable quenched structure can be obtained. That is, if the peripheral velocity is less than 10 m / sec, it is not preferable if it is amorphous, and if the peripheral velocity of the roll surface exceeds 50 m / sec, it is not preferable because a fine crystal aggregate which can obtain good hard magnetic properties is obtained during crystallization. However, in the structure after ultra-quenching, a small amount of α-Fe phase or metastable Nd-Fe
The presence of the -B compound phase in the quenched ribbon is acceptable as it does not significantly deteriorate the properties.

In the present invention, after the molten alloy having the above-mentioned specific composition is formed into a substantially amorphous structure or a structure in which fine crystals and amorphous are mixed by the ultra-quenching method, the heat treatment that maximizes the magnetic characteristics depends on the composition. However, if the heat treatment temperature is lower than 600 ° C., iHc does not appear because the Nd ₂ Fe ₁₄ B phase does not precipitate, and if it exceeds 750 ° C., grain growth is remarkable, and iHc, Br, and the squareness of the demagnetization curve deteriorate. , The heat treatment temperature is 6 because the above magnetic characteristics cannot be obtained.
It is limited to 00 to 750 ° C. In order to prevent oxidation, the heat treatment atmosphere is preferably an inert gas atmosphere such as Ar or N ₂ gas or a vacuum of 10 ^-2 Torr or more. The magnetic properties of the obtained alloy powder do not depend on the heat treatment time,
If it exceeds the time, Br tends to decrease with the passage of time, so the heat treatment time is preferably less than 6 hours.

An important feature of the present invention is the rate of temperature rise from around the temperature at which crystallization starts during heat treatment. At a rate of temperature rise of less than 10 ° C./minute, grain growth occurs during temperature rise, and good results are obtained. It is not preferable because it does not form a fine crystal aggregate that provides hard magnetic characteristics and iHc of 5 kOe or more cannot be obtained. In addition, at a heating rate exceeding 50 ° C / sec, 600 ° C
The Nd ₂ Fe ₁₄ B phase generated after passing through the alloy is not sufficiently precipitated, iHc not only decreases, but also a demagnetization curve with a decrease in magnetization near the Br point in the second quadrant of the magnetization curve, (BH) max is deteriorated, which is not preferable. The rate of temperature increase up to the temperature at which crystallization starts during heat treatment is arbitrary, and rapid heating or the like can be applied to increase the treatment efficiency.

Crystal Structure The crystal phase of the rare earth permanent magnet alloy powder according to the present invention is α
-Iron and a ferromagnetic soft magnetic phase containing iron as a main component, and Nd ₂
The hard magnetic phase having the Fe ₁₄ B type crystal structure coexists in the same powder particle, and the average crystal grain size of each constituent phase is 1 nm to 50 n.
It is characterized by comprising a fine crystal aggregate of m. A more preferable average crystal grain size is 1 nm to 20 nm.
In the present invention, the average crystal grain size of the permanent magnet alloy is 50
When the thickness exceeds nm, the squareness of the demagnetization curve is significantly deteriorated, and B
Magnetic properties of r ≧ 6 kG and (BH) max ≧ 7 MGOe cannot be obtained. Further, the smaller the average crystal grain size is, the more preferable, but it is difficult to obtain the average crystal grain size of less than 1 nm in industrial production. Therefore, the lower limit is set to 1 nm.

Magnetization Method A molten alloy having a specific composition is formed into an amorphous structure or a structure in which fine crystals and amorphous are mixed by the above-mentioned ultra-quenching method, and 600 ° C. to 750 ° C. near the temperature at which crystallization starts.
The permanent magnet according to the present invention obtained as a fine crystal aggregate having an average crystal grain size of 1 nm to 50 nm by performing a crystallization heat treatment at a temperature rising rate up to a treatment temperature of 10 ° C. of 10 ° C./min to 50 ° C./sec. To magnetize with alloy powder, 75
Any of the known sintered magnetizing method and bond magnetizing method that can be solidified and consolidated at 0 ° C. or less can be adopted, and if necessary, the alloy has an average particle diameter of 3 μm to 500 μm.
After being pulverized into the alloy powder (1) and mixed with a known binder to form a required bonded magnet, a bonded magnet having a residual magnetic flux density Br of 5 kG or more can be obtained.

[0024]

According to the present invention, the (Fe, M) -Mn-BR alloy melt or the (Fe, M, Co) -Mn-BR alloy melt (R is Nd) having a specific composition containing a small amount of rare earth elements is used.
Alternatively, Pr) is formed into a substantially amorphous structure or a structure in which fine crystals and amorphous are mixed by the above-mentioned rapid quenching method, and the obtained ribbons, flakes, and spherical powders are heated to about 600 ° C. to 750 ° C. from a temperature near the start of crystallization. By performing a crystallization heat treatment with a temperature rising rate up to a processing temperature of 10 ° C / min to 50 ° C / sec, α-iron and a ferromagnetic soft magnetic phase containing iron as a main component and Nd ₂ Fe A hard magnetic phase having a ₁₄ B-type crystal structure coexists in the same powder particle, and a fine crystal aggregate having an average crystal grain size of each structural phase in the range of 1 nm to 50 nm is obtained. At this time, by adding Mn, the structure is refined to about 1/2 to 1/3 as compared with the composition not containing Mn, and a part of Mn is Fe of the R ₂ Fe ₁₄ B phase which is a hard magnetic phase.
Substitution of atoms improves the anisotropy constant of the R ₂ Fe ₁₄ B phase, thereby improving iHc.
Causes a large decrease in magnetization because the magnetic coupling with Fe is antiferromagnetic. However, the additional element M (A
l, Si, S, Ni, Cu, Zn, Ga, Ag, Pt,
Fe, by adding one or more of Au and Pb)
Since an intermetallic compound having a ferromagnetism of -M, Mn-M, and Fe-Mn-M is produced, iHc can be improved without causing a significant decrease in magnetization. Further, by substituting a part of Fe with a part of Co, the decrease of the magnetization is further suppressed, and iH is obtained without impairing the squareness of Br and the demagnetization curve.
c can be improved. Also, the F of the R ₂ Fe ₁₄ B phase
By replacing a part of e with Co, the Curie temperature rises, the temperature coefficient of iHc is improved, and iHc ≧ 5k
Oe, Br ≧ 6.5 kG, (BH) max ≧ 8 MGOe
It is possible to obtain a permanent magnet alloy powder having the above magnetic characteristics and excellent temperature characteristics.

[0025]

【Example】

Example 1 No. 1 in Table 1 Purity of 99.
5% or more of Fe, Co, Mn, Al, Si, S, Ni,
Cu, Zn, Ga, Ag, Pt, Au, Pb, B, N
d, Pr metal was weighed so that the total amount was 30 gr, put into a quartz crucible having a 0.8 mm diameter orifice at the bottom, and melted by high frequency heating in an Ar atmosphere with a pressure of 56 cmHg to melt. After the temperature was set to 1400 ° C., the molten metal surface was pressurized with Ar gas, and the molten metal was jetted from a height of 0.7 mm onto the outer peripheral surface of a Cu roll that rotates at high speed at a roll peripheral speed of 20 m / sec at room temperature. , Width 2-3m
m, and a super-quenched ribbon having a thickness of 20 μm to 40 μm was produced.
The obtained ultra-quenched ribbon was confirmed to be amorphous by the characteristic X-ray of CuKα.

This ultra-quenched ribbon was rapidly heated to 580 ° C. to 600 ° C. at which crystallization started in Ar gas, and then 580
The temperature is raised at a temperature rising rate shown in Table 1 above, held at the heat treatment temperature shown in Table 1 for 7 minutes, then cooled to room temperature to take out a ribbon, and the width is 2-3 mm, the thickness is 20 μm-40 μm, and the length is A sample having a size of 3 mm to 5 mm was prepared and its magnetic characteristics were measured using VSM. The measurement results are shown in Table 2. As a result of investigating the constituent phases of the sample by the characteristic X-ray of CuKα, when the Mn amount is less than 3 at%, α-Fe phase, Fe ₃ B phase, N
Although it was a multiphase structure in which d ₂ Fe ₁₄ B phase was mixed, when the Mn content was 3 at% or more, α-Fe phase and Nd ₂ Fe ₁₄ B phase were obtained.
Although the phases were confirmed, the boride phase containing iron as a main component could not be confirmed because the amount thereof was small. Note that Mn and Co replace part of Fe in each of these phases. The average crystal grain size was 30 nm or less in all cases.

Comparative Example No. 1 in Table 1 An ultra-quenched ribbon was prepared under the same conditions as in Example 1 using Fe, B, and Nd having a purity of 99.5% or more so as to have a composition of 11. The obtained ribbon was subjected to heat treatment under the same conditions as in Example 1, cooled, and then sampled under the same conditions as in Example 1 (Comparative Example No. 11), and the magnetic characteristics were measured using VSM. The measurement results are shown in Table 2. The constituent phase of the sample is F
It has a multi-phase structure in which the α-Fe phase having the e ₃ B phase as the main phase and the Nd ₂ Fe ₁₄ B phase coexist, and the average crystal grain size is around 50 nm and that of Example No. 1-No. It was coarse compared to 10.

Example 2 Composition No. of Table 1 obtained in Example 1 After the heat treatment shown in Table 1, the ultra-thin quenched thin ribbons Nos. 2 and 7 were crushed to an average particle diameter of 150 μm or less, and a binder made of an epoxy resin was mixed at a ratio of 3 wt%, and then a bond magnet having a size of 12 mm × 12 mm × 8 mm was prepared. Created. The obtained bonded magnet (composition N
o. The magnetic properties of 2) are: density 6.0 g / cm ³ , iHc
= 6.4 kOe, Br = 8.5 kG, (BH) max =
It was 8.7 MGOe. The obtained bonded magnet (composition N
o. The magnetic properties of 6) are as follows: density 6.0 g / cm ³ , iHc
= 6.0 kOe, Br = 8.6 kG, (BH) max =
It was 9.0 MGOe.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

INDUSTRIAL APPLICABILITY According to the present invention, a (Fe, M) -Mn-BR alloy melt or a (Fe, M, Co) -Mn-BR alloy melt (R having a specific composition with a low content of rare earth elements) Is Nd or Pr) having a substantially amorphous structure or a structure in which fine crystals and amorphous are mixed by a super-quenching method, and subjecting the obtained ribbons, flakes and spherical powders to crystallization heat treatment under specific conditions, -Iron and a ferromagnetic soft magnetic phase containing iron as a main component and a hard magnetic phase having an Nd ₂ Fe ₁₄ B type crystal structure coexist in the same powder particle, and the average crystal grain size of each constituent phase is 1 nm. To obtain a microcrystalline aggregate in the range of up to 50 nm. At this time, by adding Mn, the structure is refined to about 1/2 to 1/3 of the composition not containing Mn. R ₂ Fe whose part is a hard magnetic phase
By improving the anisotropy constant of the R ₂ Fe ₁₄ B phase by substituting the Fe atoms of ₁₄ B phase, iHc is improved, Moreover, Mn is magnetic coupling between Fe is antiferromagnetic Therefore, the magnetization is lowered, but the additive element M (Al, Si,
S, Ni, Cu, Zn, Ga, Ag, Pt, Au, Pb
1 type or 2 types or more of Fe-M, Mn
Since an intermetallic compound having a ferromagnetism of -M or Fe-Mn-M is produced, iHc can be improved without causing a large decrease in magnetization, and a part of Fe is replaced with a part of Co. As a result, the decrease in magnetization is further suppressed, and iHc can be improved without impairing the squareness of Br and the demagnetization curve. Further, a part of Fe in the R ₂ Fe ₁₄ B phase is C
Substitution with o raises the Curie temperature,
The temperature coefficient of Hc is improved, iHc ≧ 5 kOe, Br ≧
It is possible to obtain a permanent magnet alloy powder having a magnetic characteristic of 6.5 kG and (BH) max ≧ 8 MGOe and excellent temperature characteristics. In addition, the permanent magnet alloy powder according to the present invention has a low content of rare earth elements, a simple manufacturing method, and is suitable for mass production. It is possible to provide a bonded magnet having magnetic performance exceeding that of a magnet.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01F 1/053

Claims (4)

[Claims] The method according to claim 1] composition formula _{(Fe 1-a M a)} 100-xyz Mn x
B _y R _z (wherein R is one or two of Pr or Nd,
M is Al, Si, S, Ni, Cu, Zn, Ga, Ag,
Pt, Au, Pb) or two or more), and the symbols x, y, z, and a that limit the composition range satisfy the following values,
α-iron and a ferromagnetic soft magnetic phase containing iron as a main component, and Nd
A hard magnetic phase having a ₂ Fe ₁₄ B type crystal structure coexists in the same powder particle, and the average crystal grain size of each constituent phase is 1 nm to 50 nm.
nm range, average particle size of 3 μm to 500 μm, magnetic properties of iHc ≧ 5 kOe, Br ≧ 5.5 kG, (B
H) A permanent magnet alloy powder, characterized in that max ≧ 7 MGOe. 0.01 ≦ x ≦ 7 at% 10 ≦ y ≦ 30 at% 3 ≦ z ≦ 6 at% 0.005 ≦ a ≦ 0.3 2. A method composition formula _{(Fe 1-ab M a Co} b)
_{100-xyz Mn x B y R} z ( where R is 1 Pr or Nd
Or two, M is Al, Si, S, Ni, Cu, Z
n, Ga, Ag, Pt, Au, Pb), and symbols x, y, z, a, which limit the composition range.
b satisfies the following values, and α-iron and a ferromagnetic soft magnetic phase containing iron as a main component and a hard magnetic phase having an Nd ₂ Fe ₁₄ B type crystal structure coexist in the same powder particle. The average crystal grain size of the constituent phases is in the range of 1 nm to 50 nm, and the average grain size is 3
μm to 500 μm, magnetic characteristics iHc ≧ 5 kOe, Br
Permanent magnet alloy powder characterized in that ≧ 6 kG and (BH) max ≧ 7 MGOe. 0.01 ≦ x ≦ 7 at% 10 ≦ y ≦ 30 at% 3 ≦ z ≦ 6 at% 0.005 ≦ a ≦ 0.3 0.005 ≦ b ≦ 0.5 The 3. A composition formula _{(Fe 1-a M a)} 100-xyz Mn x
B _y R _z (wherein R is one or two of Pr or Nd,
M is Al, Si, S, Ni, Cu, Zn, Ga, Ag,
(Pt, Au, Pb, one or more types), and the alloy melts whose symbols x, y, z, and a that limit the composition range satisfy the following values: Ultra rapid quenching method using a rotating roll, splat quenching method The gas atomization method or a combination thereof is rapidly cooled to form an amorphous structure or a structure in which fine crystals and amorphous are mixed, and the temperature rising rate from the temperature near the start of crystallization to a processing temperature of 600 ° C to 750 ° C is 10 ° C. / Min ~ 50 ° C / second heat treatment for crystallization,
α-iron and a ferromagnetic soft magnetic phase containing iron as a main component, and Nd
A hard magnetic phase having a ₂ Fe ₁₄ B type crystal structure coexists in the same powder particle, and the average crystal grain size of each constituent phase is 1 nm to 50 nm.
A method for producing a permanent magnet alloy powder, which comprises obtaining a fine crystal aggregate in the range of nm and then pulverizing this to an average particle diameter of 3 μm to 500 μm to obtain a permanent magnet alloy powder, if necessary. 0.01 ≦ x ≦ 7 at% 10 ≦ y ≦ 30 at% 3 ≦ z ≦ 6 at% 0.005 ≦ a ≦ 0.3 The 4. A composition formula _{(Fe 1-ab M a Co} b)
_{100-xyz Mn x B y R} z ( where R is 1 Pr or Nd
Or two, M is Al, Si, S, Ni, Cu, Z
n, Ga, Ag, Pt, Au, Pb), and symbols x, y, z, a, which limit the composition range.
A molten alloy whose b satisfies the following value is rapidly cooled by using a rotating roll, a splat quenching method, a gas atomizing method or a combination thereof to form an amorphous structure or a structure in which fine crystals and amorphous are mixed, and further crystallized. Is subjected to crystallization heat treatment at a temperature rising rate of 10 ° C./min to 50 ° C./sec from a temperature near the start point to a treatment temperature of 600 ° C. to 750 ° C. to obtain α-iron and a ferromagnetic material containing iron as a main component. A soft magnetic phase and a hard magnetic phase having an Nd ₂ Fe ₁₄ B type crystal structure coexist in the same powder particle, and a fine crystal aggregate having an average crystal grain size of each constituent phase in the range of 1 nm to 50 nm is obtained. After that, if necessary, the average particle diameter is 3 μm to 500 μm.
A method for producing a permanent magnet alloy powder, which comprises pulverizing to a particle size of 袖 m to obtain a permanent magnet alloy powder. 0.01 ≦ x ≦ 7 at% 10 ≦ y ≦ 30 at% 3 ≦ z ≦ 6 at% 0.005 ≦ a ≦ 0.3 0.005 ≦ b ≦ 0.5