JPH10259459A - Raw material alloy for producing rare earth magnet powder and production of rare earth magnet powder using this raw material alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a raw material alloy producing rare earth magnet powder having excellent magnetic properties by composing the intergranular precipitates of a raw material alloy in which the componental compsn. and structure are specified of intermetallic compound phases and boride phases. SOLUTION: A raw material alloy for producing rare earth magnet powder having a compsn. contg., by at.%, 10.0 to 16.0% rare earth element including Y (R), 5.0 to 30.0% Co or Ni (T), 4.0 to 10.0% B, one or more kinds among Zr, Hf, Ti and Ni (M1) by 0.001 to 3.0% one or more kinds among Ga, Al and Sn (M2) by 0.001 to 5.0%, and the balance Fe with inevitable impurities and consisting of the main phases composed of R2 (Fe, T)14 B type intermetallic compound phases in which M1 and M2 are partially allowed to enter into solid solutions and intergranular precipitates precipitated into the boundaries of the crystal grains thereof is prepd. This intergranular precipitates are composed of Ra (Fe, T)100-a intermetallic compound phases, Rb T100-b intermetallic compound phases, M1c B100-c boride phases, Rd Te M2100-(d+e) intermetallic compound phases and Rf (Fe, T)g B100-(f+g) intermetallic compound phases.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a raw material alloy for producing a rare earth magnet powder having excellent magnetic properties and a method for producing a rare earth magnet powder having even more excellent magnetic properties by using the raw material alloy. It is about.

[0002]

2. Description of the Related Art In order to produce a rare earth magnet powder having a texture of a fine rare earth intermetallic compound phase, 500 parts are added to the R ₂ Fe ₁₄ B phase of an ingot having an R ₂ F ₁₄ B intermetallic compound phase as a main phase. By absorbing hydrogen in hydrogen at ~ 1000 ° C, R
After undergoing phase transformation into three phases of H ₂ , Fe and Fe ₂ B, and subsequently maintaining in a vacuum atmosphere in the same temperature range and performing dehydrogenation,
After cooling to room temperature in an inert gas atmosphere and then pulverizing, RH ₂ , Fe and F
The three phases of e ₂ B are re-transformed into R ₂ Fe ₁₄ B phase by dehydrogenation, and a rare earth magnet powder having a fine recrystallized texture of R ₂ Fe ₁₄ B intermetallic compound and excellent in magnetic properties is obtained.
This process involves the steps of hydrogenation and phase decomposition (Deco
mposition), dehydrogenation (Desorption) and recombination (Recombination)
Called processing.

[0003] As a raw material alloy to be subjected to the HDDR treatment,
Rare earth elements containing Y (hereinafter, indicated by R): 10.0 to 1
6.0 atomic%, Co or Ni (hereinafter, referred to as T):
5.0 to 30.0 atomic%, B: 4.0 to 10.0 atomic%, at least one or more of Zr, Hf, Ti and Nb (hereinafter, referred to as M1): 0.001 to 3. 0 atomic%, at least one or more of Ga, Al and Sn (hereinafter, referred to as M2): 0.001 to 5.0 atomic%, the balance being: a component composition comprising Fe and unavoidable impurities, And R ₂ (F
e, T) ₁₄ M type intermetallic consists compound phase of the main phase crystal grains and the crystal grains of the material alloy having a structure consisting of grain boundary precipitates are precipitated in the grain boundaries [hereinafter, the material alloy R- (F
e, T) -M1-M2 raw material alloy] is also known.

As raw material alloys to be subjected to HDDR treatment, R: 10.0-16.0 at%, T: 5.0-3%
0.0 atomic%, B: 4.0 to 10.0 atomic%, M1:
R ₂ (Fe, T) ₁₄ M-type intermetallic compound phase containing 0.001 to 3.0 atomic%, the balance being: having a component composition of Fe and unavoidable impurities, and in which M1 is partially dissolved. Raw material alloy having a structure composed of main phase crystal grains composed of the following and grain boundary precipitates precipitated at the grain boundaries of the crystal grains [hereinafter, this raw material alloy is referred to as an R- (Fe, T) -M1-based raw material alloy] ] Is also known to be used.

Further, as raw material alloys to be subjected to HDDR treatment, R: 10.0 to 16.0 atomic%, T: 5.0 to 3
0.0 atomic%, B: 4.0 to 10.0 atomic%, M2:
R ₂ (Fe, T) ₁₄ M-type intermetallic compound phase containing 0.001 to 5.0 atomic%, the balance being: having a component composition of Fe and unavoidable impurities, and in which M2 is partially dissolved. Alloy having a structure consisting of a main phase crystal grain composed of the following and grain boundary precipitates precipitated at the grain boundary of the crystal grain [hereinafter, this material alloy is referred to as an R- (Fe, T) -M2-based material alloy. ] Is also known to be used.

[0006]

The above R- (Fe, T)
-M1-M2 material alloy, R- (Fe, T) -M1 material alloy or R- (Fe, T) -M2 material alloy
Rare earth magnet powder which does not show sufficient magnetic anisotropy even if it is subjected to a hydrogen absorbing treatment in a temperature range of 0 ° C. to 1000 ° C. and subsequently subjected to an HDDR treatment in which it is subjected to a dehydrogenation treatment in that temperature range. Has not been obtained.

[0007]

Means for Solving the Problems Accordingly, the present inventors have
Obtain rare earth magnet powder with better magnetic properties than before
Rare earth obtained by HDDR processing
The magnetic properties of similar magnet powders depend on the structure of the raw material alloy used,
The precipitates at the grain boundaries have a great effect on (a) R-
The structure of the (Fe, T) -M1-M2 raw material alloy was changed to M1 and M1.
And R in which M2 and M2 are partially dissolved_Two(Fe, T)₁₄B mold
Grains of main phase composed of intergeneric compound phases and grain boundaries of the grains
Having a structure composed of grain boundary precipitates precipitated on
In the (Fe, T) -M1-M2 raw material alloy, the particles
The boundary precipitate is R_a(Fe, T)_{100- a}Intermetallic compound phase, R
_bT_100-bIntermetallic compound phase, M1_cB_100-cBor compound
Phase, R_dT_eM2_{100- (d + e)}Intermetallic compound phase and R_f
(Fe, T)_gB_{100- (f + g )}Intermetallic compound phase (however, 3
0.0 <a <40.0, 65.0 <b <75.0, 3
0.0 <c <40.0, 60.0 <d <70.0, 2
0.0 <e <30.0, 85.0 <d + e <99.9,
10.0 <f <15.0, 40.0 <g <50.0, 5
0.0 <f + g <65.0) (a to g are in atomic%,
R- (Fe, T) -M1-
HDDR treatment of M2-based raw material alloys,
A magnet powder having excellent magnetic anisotropy can be obtained.
The structure of the (Fe, T) -M1 raw material alloy is such that M1 is partially solidified.
R dissolved _Two(Fe, T)₁₄From B-type intermetallic compound phase
Grains of the main phase and grains precipitated at the grain boundaries of the grains
R- (Fe, T) -M1 having structure composed of intergranular precipitates
In the base material alloy, the grain boundary precipitate is R_a(Fe,
T)_100-aIntermetallic compound phase, R_bT_100-bIntermetallic compound
Phase, M1_cB_100-cBorate phase and R_f(Fe,
T)_gB_{100- (f + g)}Intermetallic compound phase (however, 30.0 <
a <40.0, 65.0 <b <75.0, 30.0 <c
<40.0, 10.0 <f <15.0, 40.0 <g <
50.0, 50.0 <f + g <65.0)
R- (Fe, T) -M1-M2 raw material alloy
When the R treatment is performed, the magnetic anisotropy that is more excellent
(C) R- (Fe, T) -M2-based material from which stone powder is obtained
The structure of the material alloy is changed to R in which M2 is partially dissolved. _Two(Fe,
T)₁₄Main phase crystal grains composed of B-type intermetallic compound phase
The structure consisting of grain boundary precipitates precipitated at the grain boundaries of crystal grains
R- (Fe, T) -M2-based raw material alloy having
The grain boundary precipitate is R_a(Fe, T)_100-aIntermetallic compound
Phase, R_bT_100-bIntermetallic compound phase, R_dT_eM2
_{100- (d + e)}Intermetallic compound phase and R_f(Fe, T)_gB
_{100- (f + g)}Intermetallic compound phase (however, 30.0 <a <4
0.0, 65.0 <b <75.0, 60.0 <d <7
0.0, 20.0 <e <30.0, 85.0 <d + e <
99.9, 10.0 <f <15.0, 40.0 <g <5
0.0, 50.0 <f + g <65.0)
R- (Fe, T) -M2 material alloy
Then, a magnet powder with more excellent magnetic anisotropy than before
The research result was obtained.

[0008] The present invention is based on the results of such research.
(1) R- (Fe, T) -M1-
M1 and M2 are partially dissolved in the structure of the M2 material alloy.
R_Two(Fe, T)₁₄Consists of B-type intermetallic compound phase
Main phase grains and grain boundary precipitates precipitated at the grain boundaries of the grains
R- (Fe, T) -M1-M having a structure consisting of exudates
In the binary raw material alloy, the grain boundary precipitate is R_a(Fe,
T)_100-a(30.0 <a <40.0) intermetallic compound
Phase, R_bT_100-b(65.0 <b <75.0) intermetallic
Compound phase, M1_cB_100-c(30.0 <c <40.0)
Uride phase, R_dT_eM2_{100- (d + e)}(60.0 <d <7
0.0, 20.0 <e <30.0, 85.0 <d + e <
99.9) Intermetallic compound phase, and R_f(Fe, T)_g
B_{100- (f + g)}(10.0 <f <15.0, 40.0 <g
<50.0, 50.0 <f + g <65.0) Intermetallic compound
Raw material alloy for the production of rare earth magnet powder composed of solid phase,
(2) The structure of the R- (Fe, T) -M1-based raw material alloy is represented by M
R in which 1 is partially dissolved _Two(Fe, T)₁₄Type B intermetallic
Crystal grains of the main phase composed of compound phase and precipitation at grain boundaries of the crystal grains
R- (Fe, having a structure consisting of grain boundary precipitates
T) In the -M1-based raw material alloy, the grain boundary precipitate is R_a
(Fe, T)_100-a(30.0 <a <40.0) between metals
Compound phase, R_bT_100-b(65.0 <b <75.0) gold
Intergeneric compound phase, M1_cB_100-c(30.0 <c <40.
0) boride phase and R_f(Fe, T)_gB
_{100- (f + g)}(10.0 <f <15.0, 40.0 <g <
50.0, 50.0 <f + g <65.0) Intermetallic compound
Raw material alloy for the production of rare earth magnet powder composed of phases,
(3) The structure of the R- (Fe, T) -M2 raw material alloy is represented by M
R in which 2 is partially dissolved _Two(Fe, T)₁₄Type B intermetallic
Crystal grains of the main phase composed of compound phase and precipitation at grain boundaries of the crystal grains
R- (Fe, having a structure consisting of grain boundary precipitates
T) In the -M2-based raw material alloy, the grain boundary precipitate is R_a
(Fe, T)_100-a(30.0 <a <40.0) between metals
Compound phase, R_bT_100-b(65.0 <b <75.0) gold
Intergeneric compound phase, R_dT_eM2_{100- (d + e)}(60.0 <d
<70.0, 20.0 <e <30.0, 85.0 <d +
e <99.9) intermetallic compound phase, and R_f(Fe,
T)_gB_{100- (f + g)}(10.0 <f <15.0, 40.
0 <g <50.0, 50.0 <f + g <65.0) Metal
For the production of rare earth magnet powder composed of intermetallic compound phases
Alloys.

M1 _c B _100-c constituting the grain boundary precipitate
(30.0 <c <40.0) The boride phase has a convex lens shape, and M1 _c B having this convex lens shape
_The microstructure of the cut surface of the _100-c (30.0 <c <40.0) boride phase has a major axis of 1 to 50 μm and a minor axis of 0.01.
It has a size of 〜１０10 μm. _{Furthermore, R d T e M2 100- (} d + e) constituting the grain boundary precipitates (60.0 <d <
70.0, 20.0 <e <30.0, 85.0 <d + e
<99.9) intermetallic compound _{phase, R b T 100-b (} 65.
0 <b <75.0) It is unevenly distributed in the peripheral part in the intermetallic compound phase.

The raw material alloy for producing a rare earth magnet alloy according to the present invention having the above-mentioned structure is an ingot of an R- (Fe, T) -M1-M2 type raw material alloy, and an ingot of an R- (Fe, T) -M1 type raw material alloy. Alternatively, it can be obtained by improving the heat treatment applied to the ingot of the R- (Fe, T) -M2 raw material alloy. One specific method for producing a raw material alloy for producing a rare earth magnet alloy according to the present invention is to raise the temperature of the ingot in an Ar atmosphere at a rate of temperature increase of 5 to 10 ° C./min. 5 at 1200 ° C
After holding for 50 hours, the cooling rate is 2 to 4 ° C./min, and the temperature is cooled to 550 to 650 ° C.
Hold for 1 hour, and further in an Ar atmosphere, 470-550 ° C
Cooling rate: less than 2 to 4 ° C./min, hold at that temperature for 0.5 to 2 hours,
After cooling at a cooling rate of 2 to 4 ° C./min to 50 to less than 470 ° C., the temperature is maintained for 0.5 to 2 hours.
r atmosphere, cooling rate: 2 to 4 ° C./min, temperature: 15
After cooling to 0 to 250 ° C., the temperature is maintained for 0.5 to 4 hours, and finally the cooling rate to room temperature in an Ar atmosphere is:
It is obtained by cooling at 4 ° C./min. But,
The invention is not limited to this method.

The raw material alloy for producing a rare earth magnet alloy of the present invention is made to absorb hydrogen in hydrogen at 500 to 1000 ° C., and is subsequently dehydrogenated in a vacuum atmosphere in the same temperature range. A known rare earth magnet powder having excellent magnetic properties can be obtained by performing a known HDDR process of cooling and then grinding. In this HDDR process, cooling in an inert gas atmosphere is performed at a two-stage cooling rate, As shown in FIG. 4, after the completion of the dehydrogenation, the first cooling rate: 5 to 15 ° C./min. Cool with 300 ~ 40
After holding at an intermediate temperature in the range of 0 ° C. for 30 to 60 minutes,
Further, a second cooling rate: 1 to 4 ° C / min. It was found that cooling to room temperature at room temperature gave a rare earth magnet powder having even better magnetic properties.

Therefore, the present invention provides the above (1) to
(3) The raw material alloy for producing rare earth magnet powder described in
Absorb hydrogen in hydrogen at ~ 1000 ° C, followed by 5
After dehydrogenation while maintaining a vacuum atmosphere of 00 to 1000 ° C, the first cooling rate is 5 to 15 ° C / in an inert gas atmosphere.
min. After maintaining at an intermediate temperature in the range of 300 to 400 ° C. for 30 to 60 minutes, a second cooling rate:
1-4 ° C / min. The method is characterized by a method of producing a rare earth magnet powder which is cooled to room temperature and then pulverized, and a rare earth magnet powder obtained by this production method.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Alloys a to i having the component compositions shown in Table 1 are prepared as R- (Fe, T) -M1-M2 raw material alloys, and are used as R- (Fe, T) -M1 raw material alloys. Alloys m to p having the component compositions shown in Table 1 were prepared, and R- (F
e, T) -M2 based alloys q to s having the composition shown in Table 1 were prepared, and the alloys a to s were melted in a plasma arc melting furnace in an Ar atmosphere to obtain a melt of the alloys a to s. Was cast to produce an ingot.

[0014]

[Table 1]

Examples 1 to 19 The ingots of these alloys a to s were heated in an Ar atmosphere at a rate of temperature increase of 10 ° C./min.
It is kept at 100 ° C. for 10 hours, then cooled in an Ar atmosphere at a cooling rate of 3 ° C./min to 600 ° C., kept at that temperature for 1 hour, and further cooled in an Ar atmosphere at a cooling rate of 3 ° C.
/ Min at a temperature of 500 ° C.
Hold for a time and further in an Ar atmosphere, cooling rate: 3 ° C./m
After cooling to 450 ° C. in, the temperature was maintained for 1 hour, and further, in an Ar atmosphere, cooling rate: 3 ° C./min.
After cooling to 200 ° C., the temperature is maintained for 2 hours, and finally to room temperature in an Ar atmosphere at a cooling rate of 3 ° C./m.
By cooling in, raw material alloys (hereinafter, referred to as raw material alloys) 1 to 19 of the present invention for producing rare earth magnet powder are produced, and grains of main phases of the obtained raw material alloys 1 to 19 of the present invention are obtained. Grain boundary precipitates precipitated in the boundaries were identified by EPMA (X-ray microanalyzer), and the results are shown in Tables 2 and 3.

[0016]

[Table 2]

[0017]

[Table 3]

The structure of the grain boundary precipitation portion of the raw material alloy for producing a rare earth magnet powder according to the present invention will be described more specifically. FIG. 1 shows a micrograph of a microstructure of a raw material alloy 1 of the present invention, which is a typical alloy among the R- (Fe, T) -M1-M2 raw material alloys of the present invention. As shown in FIG. 1, the present invention starting alloy 1 is Zr and Ga is dissolved part main phase (Nd _{12 .5}
Co _17.2 B _5.6 Zr _0.06 Ga _0.14 Fe _64.5 intermetallic compound phase) and grain boundary precipitates precipitated at the grain boundaries of the crystal grains, and the grain boundary precipitate is Nd _35.1 Co
_33.1 Fe _31.8 intermetallic compound phase, Nd _71.9 Co _21.8 intermetallic compound phase, Zr _31.4 B _68.6 boride phase, Nd _64.8 Co
_24.0 Ga _11.2 intermetallic compound phase, Nd _13.3 Co _10.9 B _41.5
It can be seen that it is composed of the Fe _34.2 intermetallic compound phase.

R- (Fe, T) -M1 raw material of the present invention
Boundary precipitation of the material alloy 13 of the present invention as a typical alloy
FIG. 2 shows a sketch of the microstructure of the portion. Shown in FIG.
As described above, in the material alloy 13 of the present invention, Zr is partially dissolved.
Main phase (Nd_12.5Co_17.2B _5.6Zr_0.06Fe_65.9metal
Intergranular phase) and precipitated at the grain boundaries of the crystal grains.
Having a structure consisting of grain boundary precipitates, wherein the grain boundary precipitates
Nd_35.1Co_33.1Fe_31.8Intermetallic compound phase, Nd_71.9C
o_21.8Intermetallic compound phase, Zr_31.4B_68.6Boride phase, N
d_13.3Co_10.9B_41.5Fe_34.2Consists of an intermetallic compound phase
You can see that it is.

The R- (Fe, T) -M2 of the present invention
Of the alloy 17 of the present invention, which is a typical alloy of the base alloy
FIG. 3 shows a sketch of the microstructure of the boundary precipitation portion. In FIG.
As shown, in the material alloy 17 of the present invention, Ga was partially dissolved.
Main phase (Nd_12.5Co _17.2B_5.6Ga_0.14Fe
_64.56Intergranular phase) and the grain boundaries of the crystal grains
Having a structure consisting of precipitated grain boundary precipitates, wherein the grain boundary
The precipitate is Nd_35.1Co_33.1Fe_31.8Intermetallic compound phase,
Nd_71.9Co_21.8Intermetallic compound phase, Nd_64.8Co_24.0G
a_11.2Intermetallic compound phase, Nd_13.3Co_10.9B_41.5Fe
_34.2It can be seen that it is composed of an intermetallic compound phase.

Further, from FIGS. 1 to 3, M1_cB_100-c
(30.0 <c <40.0) Zr as an example of a boride phase
_31.4B_68.6The boride phase has a convex lens shape, and
R_dT _eM2_{100- (d + e)}(60.0 <d <70.0, 2
0.0 <e <30.0, 85.0 <d + e <99.9)
Nd as an example of an intermetallic compound phase_64.8Co_24.0Ga_11.2metal
The inter-compound phase is R_bT_100-b(65.0 <b <75.0)
It can also be seen that it is unevenly distributed at the periphery in the intermetallic compound phase
You.

The ingots of the alloys 1 to 19 of the present invention having the component composition shown in Table 1 and the grain boundary precipitates shown in Tables 2 and 3
After performing a hydrogenation treatment at 850 ° C. for 1 hour in a hydrogen atmosphere at a pressure of 5 atm.
The atmosphere was replaced for a minute, followed by a dehydrogenation treatment while maintaining the temperature at 850 ° C. in a vacuum. Then, the degree of vacuum is set to 7.0.
After confirming that the pressure reached × 10 ^-2 Torr, the mixture was cooled to room temperature with Ar gas. The ingots of the raw material alloys 1 to 19 of the present invention which have been subjected to the hydrogen treatment and the dehydrogenation treatment are pulverized under 500 μm to produce a rare earth magnet powder, and 3.0% by weight of the epoxy resin based on the obtained rare earth magnet powder. And molding pressure: 6.0 t / cm in a magnetic field of 20 kOe.
^And compression molding in step ^2.
A bond magnet was produced by performing a curing treatment of holding at 1 ° C. for 1 hour. The magnetic properties of the bond magnet thus obtained were measured using a BH loop tracer, and the results are shown in Tables 4 and 5.

Conventional Examples 1 to 19 Ingots of alloys a to s shown in Table 1 were subjected to the same hydrogen treatment and dehydrogenation treatment as in Examples 1 to 19,
An epoxy resin of 3.0% by weight was kneaded with the rare earth magnet powder obtained by pulverizing the powder to under 00 μm, and 20 kO
compression molding at a molding pressure of 6.0 t / cm ² in a magnetic field of e, and a hardening treatment of holding the obtained molded body at a temperature of 50 ° C. for 1 hour in the air. Magnetic properties were measured using a BH loop tracer,
The results are shown in Tables 4 and 5.

[0024]

[Table 4]

[0025]

[Table 5]

From the results shown in Table 4, the magnetic properties of the bonded magnet of the rare earth magnet powder manufactured using the raw material alloy 1 of the present invention and the magnetic properties of the bonded magnet of the rare earth magnet powder manufactured using the conventional raw material alloy 1 are shown. Comparing the characteristics, Br and B
Since both Hmax are improved, the rare earth magnet powder obtained by using the material alloy 1 of the present invention is different from the rare earth magnet powder obtained by using the conventional material alloy 1 even if the component composition is the same. It can be seen that excellent magnetic characteristics are shown.

Similarly, from the results shown in Tables 4 and 5, the magnetic properties of the bonded magnets of the rare earth magnet powders manufactured using the raw material alloys 2 to 19 of the present invention and the conventional raw material alloys 2 to 1 are shown.
9, the magnetic properties of the bond magnets of the rare earth magnet powders manufactured using Br. 9 were both Br and BHma.
From the fact that x is improved, the rare earth magnet powder obtained by using the material alloys 2 to 19 of the present invention is the same as the rare earth magnet powder obtained by using the material alloys 2 to 19 of the present invention, even if the component composition is the same. It can be seen that the magnetic properties are superior to those of the powder.

Examples 20 to 38 Ingots of the alloys 1 to 19 of the present invention having the component compositions shown in Table 1 and the grain boundary precipitates shown in Tables 2 and 3 were maintained at 850 ° C. for 1 hour in a hydrogen atmosphere at 1 atm. After the hydrogenation treatment, the atmosphere was replaced with Ar for 5 minutes while maintaining the temperature at 850 ° C., and subsequently the dehydrogenation treatment was performed while maintaining the temperature at 850 ° C. in a vacuum. Thereafter, the degree of vacuum is 7.0 × 10 ⁻² T.
orr was confirmed, and Ar gas was used to confirm Table 6 and Table 7.
After cooling at a first cooling rate shown in Table 6 and maintaining at an intermediate temperature shown in Tables 6 and 7 for the time shown in Tables 6 and 7, room temperature was further reduced at a second cooling rate shown in Tables 6 and 7 And then pulverized to 500 μm under to prepare a rare earth magnet powder according to the method of the present invention, kneaded with 3.0% by weight of an epoxy resin based on the obtained rare earth magnet powder, and molded under a magnetic field of 20 kOe: Compression molding was performed at 6.0 t / cm ² , and the obtained molded body was subjected to a curing treatment in air at a temperature of 50 ° C. for 1 hour to produce a bonded magnet. The magnetic properties of the bond magnet thus obtained were measured using a BH loop tracer, and the results are shown in Tables 6 and 7.

[0029]

[Table 6]

[0030]

[Table 7]

From the results shown in Tables 6 and 7, the magnetic properties of the bonded magnets of the rare earth magnet powders manufactured by the method of the present invention in Examples 20 to 38 using the alloys 1 to 19 of the present invention are shown in the examples. It can be seen that the bonded magnets of the rare-earth magnet powders manufactured in Nos. 1 to 19 exhibit even more excellent magnetic properties.

[0032]

As described above, when the raw material alloy of the present invention is used, it is possible to produce a rare earth magnet powder having superior magnetic properties as compared with the conventional one, and it has excellent industrial effects.

[Brief description of the drawings]

FIG. 1 is a sketch of the structure of a raw material alloy for producing a rare earth magnet powder according to the present invention.

FIG. 2 is a sketch of a structure of a raw material alloy for producing a rare earth magnet powder according to the present invention.

FIG. 3 is a sketch of a structure of a raw material alloy for producing a rare earth magnet powder according to the present invention.

FIG. 4 is a pattern diagram for explaining a method of producing a rare earth magnet powder using the raw material alloy for producing a rare earth magnet powder of the present invention.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01F 1/053 H01F 1/04 H 1/06 1/06 A

Claims (8)

[Claims] 1. A rare earth element containing Y (hereinafter, represented by R): 10.0 to 16.0 atomic%, Co or Ni (hereinafter, represented by T): 5.0 to 30.0
Atomic%, B: 4.0 to 10.0 atomic%, at least one of Zr, Hf, Ti and Nb (hereinafter referred to as M1): 0.001 to 3.0 atomic%, Ga, Al and At least one of Sn (hereinafter, M
2): 0.001 to 5.0 atomic%, the balance being: having a component composition consisting of Fe and unavoidable impurities,
And R ₂ (Fe,
T) In a raw material alloy having a structure composed of crystal grains of a main phase composed of a ₁₄ B-type intermetallic compound phase and grain boundary precipitates precipitated at the grain boundaries of the crystal grains, the grain boundary precipitates are a to Assuming that the unit of g is atomic%, R _a (Fe, T) _100-a (30.0 <a <40.0) intermetallic compound phase, R _b T _100-b (65.0 <b <75. 0) intermetallic _{phase, M1 c B 100-c (} 30.0 <c <40.0) boride _{phase, R d T e M2 100- (} d + e) (60.0 <d <70.0 , 2
0.0 <e <30.0, 85.0 <d + e <99.9)
Intermetallic compound phase and R _f (Fe, T) _g B
_{100- (f + g)} (10.0 <f <15.0, 40.0 <g <
(50.0, 50.0 <f + g <65.0) A raw material alloy for producing a rare earth magnet powder, which is constituted by an intermetallic compound phase. 2. M1 _c B among the grain boundary precipitates
_{100-c (30.0 <c <} 40.0) boride phase has a convex lens _{shape, R d T e M2 100- (} d + e) (60.
0 <d <70.0, 20.0 <e <30.0, 85.0
<D + e <99.9) The intermetallic compound phase is R _b T
_{2. The} raw material alloy for producing rare earth magnet powder according to claim 1, wherein _100-b (65.0 <b <75.0) is unevenly distributed at a peripheral portion in the intermetallic compound phase. 3. R: 10.0 to 16.0 at%, T: 5.0 to 30.0 at%, B: 4.0 to 10.0 at%, M1: 0.001 to 3.0 at%. Atomic%, the balance being Fe
And a component composition comprising unavoidable impurities, and M1
Has a structure consisting of crystal grains of the main phase composed of the R ₂ (Fe, T) ₁₄ B type intermetallic compound phase in which a part of the solid solution forms and grain boundary precipitates precipitated at the grain boundaries of the crystal grains. In the raw material alloy, when the unit of a to g is atom%, the intergranular precipitates are R _a (Fe, T) _100-a (30.0 <a <40.0) intermetallic compound phase, R _b T _100-b (65.0 <b <75.0) intermetallic phase, M1 _c B _100-c (30.0 <c <40.0), and R
_{f (Fe, T) g B} 100- (f + g) (10.0 <f <15.
0, 40.0 <g <50.0, 50.0 <f + g <6
5.0) A raw material alloy for producing a rare earth magnet powder, which is composed of an intermetallic compound phase. 4. The M1 _c B _100-c (3
4. The material alloy for producing a rare earth magnet powder according to claim 3, wherein the boride phase has a convex lens shape (0.0 <c <40.0). 5. R: 10.0 to 16.0 at%, T: 5.0 to 30.0 at%, B: 4.0 to 10.0 at%, M2: 0.001 to 5.0 Atomic%, the balance being Fe
And a component composition comprising unavoidable impurities, and M2
Has a structure consisting of crystal grains of the main phase composed of the R ₂ (Fe, T) ₁₄ B type intermetallic compound phase in which a part of the solid solution forms and grain boundary precipitates precipitated at the grain boundaries of the crystal grains. In the raw material alloy, when the unit of a to g is atom%, the intergranular precipitates are R _a (Fe, T) _100-a (30.0 <a <40.0) intermetallic compound phase, R _{b T 100-b (65.0 <b} <75.0) intermetallic _{phase, R d T e M2 100- (} d + e) (60.0 <d <70.0,2
0.0 <e <30.0, 85.0 <d + e <99.9)
Intermetallic compound phase and R _f (Fe, T) _g B
_{100- (f + g)} (10.0 <f <15.0, 40.0 <g <
(50.0, 50.0 <f + g <65.0) A raw material alloy for producing a rare earth magnet powder, which is constituted by an intermetallic compound phase. 6. The R _{d Te} M2 of the grain boundary precipitate.
_{100- (d + e)} (60.0 <d <70.0, 20.0 <e <
30.0,85.0 <d + e <99.9) that the intermetallic compound phase which are unevenly distributed on the periphery of the _{R b T 100-b (65.0} <b <75.0) in the intermetallic compound phase The raw material alloy for producing a rare earth magnet powder according to claim 5, characterized in that: 7. The raw material alloy for producing a rare earth magnet powder according to claim 1, 2, 3, 4, 5, or 6,
Hydrogen in hydrogen at 500 ° C.
After dehydrogenation while maintaining the vacuum atmosphere at 00 ° C, the first cooling rate is 5 to 15 ° C / min. In an inert gas atmosphere. And cooled to an intermediate temperature within the range of 300 to 400 ° C.
After holding for 60 minutes, a second cooling rate: 1-4 ° C. /
min. A method for producing a rare earth magnet powder which is cooled to room temperature and then ground. 8. A rare earth magnet powder obtained by the method for producing a rare earth magnet powder according to claim 7.