JP3238779B2 - Rare earth magnet alloy powder and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnet roll,
The present invention relates to an alloy powder for a rare earth bonded magnet which is most suitable for a speaker, a magnetic circuit for a magnetic sensor, various kinds of meters and focusing magnets, a motor and an actuator, and a method for producing the same, and a specific composition of Fe-V-B having a low rare earth element content. -R, Fe-V-B-R-M (M =
Al, Si) super-quenching method using a rotating roll of molten alloy,
An amorphous structure is formed by a splat quenching method, a gas atomizing method, or a combination thereof, and a boride phase mainly composed of iron having a body-centered tetragonal Fe ₃ P type crystal structure and Nd ₂ Fe ₁₄ B type by a specific heat treatment. By obtaining an alloy powder comprising a fine crystal aggregate with a constituent phase of a crystal structure and bonding the obtained alloy powder with a resin, a Fe—
The present invention relates to a rare earth magnet alloy powder capable of obtaining a BR-based magnet and a method for producing the same.

[0002]

2. Description of the Related Art Permanent magnets used in magnet rolls for electrostatic development, motors for electrical components, actuators, and the like have been mainly limited to hard ferrite magnets. There is a problem that the ceramic material has a low mechanical strength due to a low mechanical strength, so that cracking and chipping are likely to occur, and a complicated shape is difficult to obtain.

[0003] Today, there is a strong demand for automobiles to improve fuel efficiency by reducing the weight of the vehicles in order to save resources, and it is required to further reduce the size and weight of electrical components for automobiles. Also,
Designs to maximize the performance-to-weight ratio are also being considered for applications such as motors for home appliances other than automotive electrical components, and the current motor structure is optimal for magnet materials with a Br material of about 5 to 7 kG. It has been. That is,
When Br of the magnet material to be used is 8 kG or more, the current motor structure needs to increase the cross-sectional area of the iron plate of the rotor or the stator which becomes the magnetic path, which leads to an increase in weight. If so, the performance to weight ratio can be maximized.

Accordingly, a magnetic material for a small motor is required to have a residual magnetic flux density Br of at least 5 kG in terms of magnetic properties, but cannot be obtained with a conventional hard ferrite magnet. For example, an Nd—Fe—B-based bonded magnet satisfies such magnetic properties, but Nd or the like, which requires a large number of steps and large-scale facilities for metal separation and purification or reduction reaction, is required.
Since it contains １５15 at%, it is significantly more expensive than a hard ferrite magnet, and at present, a magnet material having Br of about 5 to 7 kG that can be mass-produced and can be provided at low cost has not been found.

[0005]

On the other hand, Nd-Fe-B
In the system magnet, _{recently, Nd 4 Fe 77 B 19 (} at%) magnetic material is proposed as a main phase an Fe ₃ B of compound in the vicinity (R.
Coehorn et al. de Phys. , C8,1
988, 669-670). This magnet material has a metastable structure having a crystal texture of Fe ₃ B and Nd ₂ Fe ₁₄ B by heat-treating an amorphous ribbon. However, the iHc is as low as about 2 to 3 kOe.
The heat treatment conditions for obtaining c are narrow and limited, and are not practical for industrial production.

[0006] The Fe ₃ B of compound was multicomponenting adding additive elements to the magnet material as a main phase, it has been published studies which aimed to improve the performance. One of them is to improve iHc by using Dy and Tb in addition to Nd as a rare earth element. In addition to the problem of adding an expensive element, the added rare earth element has a magnetic moment of Nd or Fe. There is a problem that magnetization decreases due to coupling in anti-parallel to the moment (R. Coehorn, J. Magn, Magn, M
at. , 83 (1990) 228-230).

[0007] Other studies (Shen Bao-gen et al.,
J. See Magn, Magn, Mat. , 89 (199
1) pp. 335-340) is to improve the temperature coefficient of iHc by replacing a part of Fe with Co to increase the Curie temperature, but there is a problem that Br is decreased with the addition of Co. .

In any case, the main phase is an Fe ₃ B compound.
That Nd-Fe-B based magnet, after amorphous by rapid quenching, can be hard magnet material by being heat-treated, i
Hc is low, and the heat treatment conditions are narrow, and when increasing the iHc with an additional element, the magnetic energy product is reduced.
Stable industrial production is not possible, and it cannot be provided inexpensively as a substitute for hard ferrite magnets.

The present invention focuses on a Nd—Fe—B-based magnet (R is a rare earth element) having an Fe ₃ B compound as a main phase .
A method for improving iHc and (BH) max to establish a manufacturing method capable of stable industrial production, and having a residual magnetic flux density Br of 5 kG or more, having a cost performance comparable to a hard ferrite magnet, and providing Fe at a low cost ₃ B compound
It is an object of the present invention to provide a rare earth magnet alloy powder for obtaining an Fe-BR based magnet as a main phase and a method for producing the same.

[0010]

Means for Solving the Problems] The present invention, Fe ₃ B of
Of iHc and (BH) of Fe-BR magnet having compound as main phase
As a result of various studies aimed at a production method capable of improving the max and achieving stable industrial production, the content of the rare earth element is small, and V or further a specific composition of an iron group to which a small amount of at least one of Al and Si is added. By forming the molten alloy into an amorphous structure by a rapid quenching method or the like and obtaining a fine crystal aggregate by heat treatment at a specific heating rate, a residual magnetic flux density B of 5 kG or more, which cannot be obtained with a hard ferrite magnet,
The present inventors have found that a rare earth magnet alloy powder optimal for a bonded magnet having r can be obtained, and completed the present invention.

According to the present invention, the composition formula is represented by Fe _100-xyz V _x B
_y R _z (where R is one or two of Pr or Nd), or the composition formula is Fe _100-xyz V _x B
_y R _z M _w (where R is one of Pr or Nd or 2
And M is one or two of Al or Si), and the symbols x, y, z, and w that limit the composition range satisfy the following values, and have the body-centered tetragonal Fe ₃ P-type crystal structure. And a constituent phase having a Nd ₂ Fe ₁₄ B-type crystal structure coexists in the same powder particles, and the average crystal grain size of each constituent phase is in the range of 5 nm to 100 nm. The diameter is 3 μm to 500 μm, the magnetic properties are iHc ≧ 3 kOe, B
A rare earth alloy powder characterized in that r ≧ 6 kG and (BH) max ≧ 7MGOe. 0.01 ≦ x ≦ 10 at% 16 ≦ y ≦ 22 at% 3 ≦ z ≦ 5.5 at% 0.1 ≦ w ≦ 3 at%

Further, the present invention is, (1) the composition formula _{Fe 100-xyz V x B y} R z ( where R is P
It represents r or one or two of Nd) with, or in addition, one or two of the compositional formula _{Fe 100-xyz V x B y} R z M w ( where R is Pr or Nd, M is Al or Si
And the symbols x, y, z, and w, which limit the composition range, satisfy the above-mentioned values. An ultra-rapid cooling method using a rotating roll, a splat quenching method, a gas atomizing method, or any of these methods. And quenched, practically 9
0% or more has an amorphous structure. (2) During the heat treatment, the temperature is raised from 1 ° C./min from around the temperature at which a boride phase mainly composed of iron having an Fe ₃ P type crystal structure is precipitated. 620 ℃ by heating up to ~ 15 ℃ / min
Heat treatment of holding to 750 ° C. for 10 seconds to 6 hours, (3) and the boride phase composed mainly of iron with a Fe ₃ P type crystalline structure, configuration that having a Nd ₂ Fe ₁₄ B crystal structure After obtaining a microcrystalline aggregate in which the phase coexists in the same powder particles and the average crystal grain size of each constituent phase is in the range of 5 nm to 100 nm, (4) the amorphous phase is formed under the above-mentioned quenching and amorphous structure conditions.
Since the form is different, if necessary, the average particle size is 3 μm.
A method for producing a rare earth alloy powder, characterized in that a magnet alloy powder is obtained by pulverizing the magnet alloy powder to m to 500 μm.

Reasons for Restriction of Composition Only when the rare earth element R contains one or two kinds of Pr or Nd in a specific amount, high magnetic properties can be obtained.
For example, in Ce and La, iHc characteristics of 2 kOe or more cannot be obtained, and middle rare earth elements and heavy rare earth elements after Sm cause deterioration of magnetic characteristics and make the magnet expensive, which is not preferable. If R is less than 3 at%, iHc of 2 kOe or more cannot be obtained, and if it exceeds 5.5 at%, F
R ₂ F, a metastable phase that does not produce e ₃ B phase and shows no hard magnetism
Since e ₂₃ B ₃ phase folding out iHc is not preferable because it decreases significantly, and the range of 3~5.5at%.

If B is less than 16 at% or more than 22 at%, iHc of 2 kOe or more cannot be obtained.
２２22 at%.

V is effective for improving iHc.
If it is less than 01 at%, such an effect cannot be obtained and 10 at%
Is exceeded, the squareness of Br and the demagnetization curve is significantly reduced, and Br of 6 kG or more cannot be obtained.
The range is 0 at%.

Al and Si increase the temperature range of the heat treatment and improve the squareness of the demagnetization curve.
H) has an effect of increasing max, and at least 0.1 at% or more is required to obtain such an effect, but if it exceeds 3 at%, the squareness is rather deteriorated,
Since (BH) max also decreases, the range is 0.1 to 3 at%.

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

Reasons for Limiting Manufacturing Conditions In the present invention, the temperature at which the molten alloy having the above-mentioned specific composition is made amorphous by a rapid quenching method and a boride phase mainly composed of iron having an Fe ₃ P type crystal structure is precipitated. The temperature is raised from 1 ° C / min to 15 ° C / min.
By performing heat treatment at 750 ° C. for 10 seconds to 6 hours, a Fe ₃ B phase having a Fe ₃ P type crystal structure and a Nd ₂ Fe ₁₄ B type crystal structure which are thermodynamically Ferromagnetic phases coexist and the average crystal grain size of each constituent phase is 5n
It is most important to obtain a microcrystal aggregate in the range of m to 100 nm. For the ultra-quenching treatment of the molten alloy, a known ultra-quenching method using a rotating roll can be employed.
If an amorphous content of not less than% is obtained, a splat quenching method, a gas atomizing method, or a quenching method combining these may be employed in addition to the ultra-quenching method using a rotating roll. For example, when a Cu roll is used, it is preferable that the roll surface peripheral speed is in the range of 10 to 50 m / sec because a suitable structure can be obtained. In other words, if the peripheral speed is less than 10 m / sec, it does not become amorphous and the precipitation amount of the α-Fe phase increases, which is not preferable. If the roll surface peripheral speed exceeds 50 m / sec, a quenched alloy is formed as a continuous ribbon. However, the alloy pieces are scattered, and the recovery rate and recovery efficiency when recovering the alloy from the apparatus are undesirably reduced. However, even if a trace amount of the α-Fe phase is present in the quenched ribbon, the characteristics are not remarkably deteriorated but are acceptable.

In the present invention, after the molten alloy having the above-mentioned specific composition is made to be substantially 90% or more amorphous by the ultra-quenching method, the heat treatment for maximizing the magnetic properties depends on the composition. If the temperature is lower than 620 ° C., Nd ₂ Fe ₁₄ B
No phase was precipitated, iHc of 3 kOe or more was not obtained, and when the temperature exceeded 750 ° C., the α-Fe phase, which is a thermal equilibrium phase, and Fe ₂
Since the B or Nd _1.1 Fe ₄ B ₄ phase is formed and iHc is not generated, the heat treatment temperature is limited to 620 to 750 ° C. or less. The heat treatment atmosphere is Ar gas of any inert gas atmosphere is preferable. Although the heat treatment time may be short, if it is less than 10 seconds , a sufficient microstructure is not formed, iHc and the squareness of the demagnetization curve deteriorate, and if it exceeds 6 hours, 3 kOe
Since the above iHc cannot be obtained, the heat treatment holding time is set at 10
Limited to seconds to 6 hours.

As an important feature of the present invention, there is a heating rate from a temperature of 580 ° C. or more at which the Fe ₃ B phase precipitates during the heat treatment. At a heating rate of less than 1 ° C./min, Nd ₂ Fe The crystal grain size of the ₁₄ B phase and the Fe ₃ B phase grows so large that iHc deteriorates, and iHc of 3 kOe or more cannot be obtained. At a heating rate exceeding 15 ° C./min,
The precipitation of the Nd ₂ Fe ₁₄ B phase generated after passing through 20 ° C. is not sufficiently performed, and the precipitation amount of the α-Fe phase increases, and the magnetization decreases in the second quadrant of the magnetization curve near the Br point. This results in a certain demagnetization curve, which is not preferable because (BH) max deteriorates. However, the presence of a small amount of the α-Fe phase is acceptable. The temperature at which the Fe ₃ B phase precipitates during the heat treatment is 580 ° C.
The heating rate is arbitrary up to the lower limit, and the processing efficiency can be increased by applying rapid heating or the like.

The crystal phase of the rare earth magnet and the rare earth magnet alloy powder according to the present invention is mainly composed of a boride mainly composed of iron having a Fe ₃ P type crystal structure, and has a Nd ₂ Fe ₁₄ B type crystal structure. Having an average crystal grain size of 5 nm to 100 n
It is characterized by comprising a fine crystal aggregate of m. In the present invention, the average grain size of the magnet alloy is 100 nm.
Is exceeded, the squareness of the demagnetization curve is significantly deteriorated, and Br ≧
Magnetic properties of 6 kG and (BH) max ≧ 7 MGOe cannot be obtained. The average crystal grain size is preferably as small as possible, but it is difficult to obtain an average crystal grain size of less than 5 nm in industrial production, so the lower limit is set to 5 nm.

Magnetization Method A molten alloy having a specific composition was made amorphous by the above-mentioned ultra-quenching method, and the temperature was raised at a temperature of 580 ° C. or more at which the Fe ₃ B phase was precipitated at a rate of 1 to 15 ° C./min. Later, 620-75
In order to magnetize using the rare earth magnet alloy powder according to the present invention obtained as a fine crystal aggregate having an average crystal grain size of 5 nm to 100 nm by performing a heat treatment at 0 ° C. for 10 seconds to 6 hours, 750 ° C. hereinafter solidification, none of the known sintered magnet method and a bonded magnet method capable compaction can be employed, for example, a ribbon Ya by rotating roll
Rapid cooling method such as flakes with splats and its amorphous
When pulverization is necessary depending on the organization conditions, the alloy is pulverized into an alloy powder having an average particle diameter of 3 to 500 μm, and then mixed with a known binder to form a required bond magnet, thereby obtaining a residual magnetic flux of 5 kG or more. A bond magnet having a density Br can be obtained.

[0023]

According to the present invention, a molten Fe—V—B—R alloy having a specific composition containing a small amount of rare earth element (R is Nd or Pd)
r) or Fe-VBRM alloy melt (M is A
(1 or 2 types of Si) by the above-mentioned ultra-quenching method to form substantially 90% or more of an amorphous structure, and to obtain the obtained ribbon, flake, and spherical powder from 1 to 15 from the Fe ₃ B precipitation temperature or higher. After raising the temperature at a rate of 60 ° C./min,
By performing heat treatment at 50 ° C. for 10 seconds to 6 hours, thermodynamically, it has a Fe ₃ B phase having a Fe ₃ P type crystal structure and a Nd ₂ Fe ₁₄ B type crystal structure, which are metastable phases. Ferromagnetic phases coexist, and the average crystal grain size of each structural phase is 5 nm to 1
A microcrystalline aggregate in the range of 00 nm is obtained. At this time, V
In a composition containing no, when the temperature exceeds 700 ° C., an α-Fe phase and a Fe ₂ B phase, which are thermal equilibrium phases, or Nd _1.1 Fe ₄ B ₄ are formed and iHc is not expressed, whereas in a composition containing V, the Fe ₃ B phase and Nd _{The 2} Fe ₁₄ B phase is more thermally stable than the composition without V, and exhibits higher iHc than the composition without V in a wide temperature range of about 620 ° C. to 750 ° C.
Further, by containing one or two kinds of Al and Si simultaneously with V, it is possible to improve the deterioration of Br and the square shape of the demagnetization curve when V is contained, and iHc ≧ 3 kG, Br ≧ 7 k
G, an optimal magnet alloy powder can be obtained as a bonded magnet raw material having magnetic properties of (BH) max ≧ 8 MGOe.

[0024]

【Example】

Example 1 No. 1 in Table 1. Purity 99.5 so as to have a composition of 1 to 4.
% Or more of metals of Fe, V, B, Nd, Pr, Al, and Si, weighed so that the total amount becomes 30 gr, and put into a quartz crucible having an orifice with a diameter of 0.8 mm at the bottom and pressure. After melting by high frequency heating in an Ar atmosphere of 56 cmHg and setting the melting temperature to 1300 ° C.,
A molten metal is jetted from a height of 0.7 mm onto the outer peripheral surface of a Cu roll which is pressurized with r gas and rotates at a high speed at a roll peripheral speed of 20 m / sec at room temperature, with a width of 2 to 3 mm and a thickness of 30 to 30 mm.
A 40 μm ultra-quenched ribbon was produced. The obtained ultra-quenched ribbon was confirmed to be amorphous by characteristic X-rays of CuKα.

After the ultra-quenched ribbon was rapidly heated to 580 ° C. in Ar gas, the temperature was raised to 580 ° C. or higher at the temperature raising rate shown in Table 1, and kept at the heat treatment temperature shown in Table 1 for 10 minutes. After cooling to room temperature, take out the ribbon, width 2-3mm,
A sample having a thickness of 30 to 40 μm and a length of 3 to 5 mm is prepared,
Magnetic properties and average crystal grain size were measured using VSM. Table 2 shows the measurement results. The measurement results of the sample show that the main phase is Fe ₃ B phase in which tetragonal and orthorhombic are mixed, and Nd ₂ Fe ₁₄ B
It was a multiphase structure in which a phase and an α-Fe phase were mixed, and the average crystal grain size was 100 nm or less in each case. V substitutes a part of Fe in each of these phases. However, Al and Si could not be analyzed due to the small amount of addition and ultrafine crystals.

Comparative Example No. 1 in Table 1 A super-quenched ribbon was produced under the same conditions as in Example 1 using Fe, B, and Nd having a purity of 99.5% or more so as to obtain a composition of No. 5. The resulting ribbons heat-treated at the same conditions as in Example 1, the magnetic properties using a VSM and a sample of the same conditions as in Example 1 after cooling (Comparative Example No.5), the average crystal grain
The diameter was measured. Table 2 shows the measurement results. Comparative Example No. 5
Was similar to that of Example 1, but the crystal grains were coarser than that of Example 1.

Example 2 In the composition No. of Table 1 obtained in Example 1, After the heat treatment shown in Table 1, the ultra-quenched ribbon No. 4 was pulverized to an average particle size of 150 μm or less, and a binder made of an epoxy resin was mixed at a ratio of 2 wt%, and then a bonded magnet having a size of 12 mm × 12 mm × 8 mm was prepared. . The magnetic properties of the obtained bonded magnet were as follows: density 6.0 g / cm ³ , iHc = 4.7 kOe, B
r = 7 kG, (BH) max = 8 MGOe.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

According to the present invention, a molten Fe—V—B—R alloy (R is Nd or Pr) or a molten Fe—V—B—R—M alloy (M
Is one or two of Al and Si) by the above-described ultra-quenching method to form substantially 90% or more of an amorphous structure to obtain the obtained ribbon, flake, and spherical powder, which is subjected to heat treatment under specific conditions. By performing this, a Fe ₃ B phase having an Fe ₃ P type crystal structure, which is thermodynamically a metastable phase, and Nd ₂ Fe ₁₄
A microcrystalline aggregate in which a ferromagnetic phase having a B-type crystal structure coexists and the average crystal grain size of each constituent phase is in the range of 5 nm to 100 nm is obtained. At this time, 700 ° C. for a composition containing no V
Is exceeded, the thermal equilibrium phase α-Fe phase and Fe ₂ B phase or Nd _1.1 Fe ₄ B ₄ are formed and iHc is not expressed,
In the V-containing composition, the Fe ₃ B phase and the Nd ₂ Fe ₁₄ B phase are more thermally stable than the composition without V added, and the temperature is 620 ° C. to 7 ° C.
IHc higher than the composition not containing V is exhibited in a wide temperature range of about 50 ° C. Further, by containing one or two kinds of Al and Si simultaneously with V, B containing V
r, by improving the deterioration of the square shape of the demagnetization curve,
Hc ≧ 3 kG, Br ≧ 7 kG, (BH) max ≧ 8MG
An optimum magnet alloy powder can be obtained as a bonded magnet raw material having Oe magnetic properties. In addition, the present invention
Since the content of the rare earth element is small, the manufacturing method is simple and suitable for mass production, it is possible to provide a bonded magnet having a residual magnetic flux density Br of 5 kG or more and a magnetic performance exceeding that of a hard ferrite magnet.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B22F 1/00 B22F 9/04 C22C 38/00 H01F 1/053 H01F 1/06

Claims (6)

(57) [Claims] [Claim 1] represents the composition formula _{Fe 100-xyz V x B y} R z ( where R is Pr or one or two of Nd), symbol x to limit the composition range, y, z are the following value Satisfactory, a boride phase mainly composed of iron having a body-centered tetragonal Fe ₃ P type crystal structure and a constituent phase having an Nd ₂ Fe ₁₄ B type crystal structure coexist in the same powder particle. The average grain size of the phase is in the range of 5 nm to 100 nm, and the average grain size is 3 μm.
５００500 μm, magnetic properties iHc ≧ 3 kOe, Br ≧ 6
A rare earth alloy powder characterized in that kG and (BH) max ≧ 7MGOe. 0.01 ≦ x ≦ 10 at% 16 ≦ y ≦ 22 at% 3 ≦ z ≦ 5.5 at% 2. A method composition formula _{Fe 100-xyz V x B y} R z M w
(Where R is one or two of Pr or Nd, M is Al
Or one or two types of Si), and the symbols x, y, z, and w that limit the composition range satisfy the following values, and are mainly composed of iron having a body-centered tetragonal Fe ₃ P-type crystal structure. The boride phase and the constituent phase having the 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 5n.
m to 100 nm, and the average particle size is 3 μm to 50 μm.
0 μm, magnetic properties iHc ≧ 3 kOe, Br ≧ 7 kG,
(BH) a rare earth alloy powder, wherein max ≧ 8MGOe. 0.01 ≦ x ≦ 10 at% 16 ≦ y ≦ 22 at% 3 ≦ z ≦ 5.5 at% 0.1 ≦ w ≦ 3 at% 3. A represents a composition formula _{Fe 100-xyz V x B y} R z ( where R is Pr or one or two of Nd), symbol x to limit the composition range, y, z are the following value rapid quenching the satisfactory alloy melt using a rotating roll, splat quenching method, and quenched in conjunction gas atomizing method or these, substantially no more than 90% amorphous structure, further during heat treatment, Fe ₃ P type The temperature is raised from about the temperature at which the boride phase mainly composed of iron having a crystal structure is precipitated at a rate of 1 ° C./min to 15 ° C./min to 620 ° C. to 750 ° C.
℃ heat treatment of holding for 10 seconds to 6 hours, Fe ₃ P
A boride phase containing iron as a main component and having a crystalline structure;
A component phase having a d ₂ Fe ₁₄ B type crystal structure coexists in the same powder particle, and the average crystal grain size of each component phase is 5 nm to 10 nm.
After obtaining a microcrystalline aggregate in the range of 0 nm, the method of producing the rare-earth alloy powder, characterized in that this obtain an average particle size 3μm~500μm magnet alloy powder and pulverized into. 0.01 ≦ x ≦ 10 at% 16 ≦ y ≦ 22 at% 3 ≦ z ≦ 5.5 at% The 4. A composition formula _{Fe 100-xyz V x B y} R z M w
(Where R is one or two of Pr or Nd, M is A
g, Al or Si), and the symbols x, y, z, and w that limit the composition range satisfy the following values: a super-quenching method using a rotating roll, a splat quenching method, A gas atomizing method or a combination thereof is quenched to substantially form an amorphous structure of substantially 90% or more, and at the vicinity of a temperature at which a boride phase mainly composed of iron having an Fe ₃ P type crystal structure is precipitated during heat treatment. From 620 ° C to 750 at a rate of 1 ° C / min to 15 ° C / min.
℃ heat treatment of holding for 10 seconds to 6 hours, Fe ₃ P
A boride phase containing iron as a main component and having a crystalline structure;
d ₂ Fe ₁₄ configuration phase and that having a B-type crystal structure coexist in the same powder particle, an average crystal grain size of the constituent phases is 5nm~10
After obtaining a microcrystalline aggregate in the range of 0 nm, the method of producing the rare-earth alloy powder, characterized in that this obtain an average particle size 3μm~500μm magnet alloy powder and pulverized into. 0.01 ≦ x ≦ 10 at% 16 ≦ y ≦ 22 at% 3 ≦ z ≦ 5.5 at% 0.1 ≦ w ≦ 3 at% 5. The composition formula _{Fe 100-xyz V x B y} R z ( however
R is one or two of Pr or Nd)
An alloy in which the symbols x, y, and z that define the range satisfy the following values:
Super quenching method using rotating rolls, splat quenching
Method, gas atomizing method, or a combination of these methods for rapid cooling
And (provided that except in the case of only the super-quenching method using a rotating roll
A) substantially 90% or more of the amorphous structure;
Further, during the heat treatment, iron having an Fe ₃ P type crystal structure
Temperature rise near the temperature at which the boride phase as the main component precipitates
The temperature is raised from 1 ° C / min to 15 ° C / min to 620 ° C to 75 ° C.
0 heat treatment of holding for 10 seconds to 6 hours at ° C., Fe ₃
An iron-based boride phase having a P-type crystal structure;
The same powder as the constituent phase having the Nd ₂ Fe ₁₄ B type crystal structure
Coexist in the particles, and the average crystal grain size of each constituent phase is 5 nm to 1
A crystallite aggregate in the range of 00 nm and an average grain size
It is characterized by obtaining magnet alloy powder with a diameter of 3 μm to 500 μm.
Production method of rare earth alloy powder. 0.01 ≦ x ≦ 10 at% 16 ≦ y ≦ 22 at% 3 ≦ z ≦ 5.5 at% 6. A composition formula _{Fe 100-xyz V x B y} R z M w
(Where R is one or two of Pr or Nd, M is A
g, Al or Si).
If the symbols x, y, z, and w that define the box satisfy the following values:
Super quenching method using molten rolls, splat quenching of molten gold
Method, gas atomizing method, or a combination of these methods for rapid cooling
(Except for the case of only the rapid quenching method using rotating rolls)
A) substantially 90% or more of the amorphous structure;
Further, during the heat treatment, iron having an Fe ₃ P type crystal structure
Temperature rise near the temperature at which the boride phase as the main component precipitates
The temperature is raised from 1 ° C / min to 15 ° C / min to 620 ° C to 75 ° C.
0 heat treatment of holding for 10 seconds to 6 hours at ° C., Fe ₃
An iron-based boride phase having a P-type crystal structure;
The same powder as the constituent phase having the Nd ₂ Fe ₁₄ B type crystal structure
Coexist in the particles, and the average crystal grain size of each constituent phase is 5 nm to 1
A crystallite aggregate in the range of 00 nm and an average grain size
It is characterized by obtaining magnet alloy powder with a diameter of 3 μm to 500 μm.
Production method of rare earth alloy powder. 0.01 ≦ x ≦ 10 at% 16 ≦ y ≦ 22 at% 3 ≦ z ≦ 5.5 at% 0.1 ≦ w ≦ 3 at%