JP4702542B2 - Manufacturing method of RTBC type sintered magnet - Google Patents

Description

  The present invention relates to a method for manufacturing a RTBC type sintered magnet, and is particularly useful in the industrial field of motors, electronic components, and electrical equipment, and suppresses heat generation due to eddy currents in a varying magnetic field and reduces loss. The present invention relates to a method for manufacturing an RTBC type sintered magnet having high magnetic properties.

  Rare earth magnets can be manufactured with high-performance magnets with a composition (BH) max of 50 MGOe or more and a coercive force (iHc) of 30 kOe or more by the development and efficiency improvement of the composition, manufacturing method, and the voice coil motor used so far. (VCM), CD and DVD pick-up sensors and other computer-related fields, MRI and other medical-related fields, and in recent years, electric and electronic parts such as motors and sensors have also been used.

  For example, in a permanent magnet type motor, an inexpensive ferrite magnet has been conventionally used. However, replacement with a rare earth magnet is progressing in response to a demand for miniaturization and high efficiency of the motor. Among commonly used rare earth magnets, Sm—Co magnets have a high Curie temperature, and therefore the temperature change of magnetic characteristics is small. It also has high corrosion resistance and does not require surface treatment. However, the composition is very expensive because it contains a lot of Co. On the other hand, Nd-Fe-B magnets have the highest saturation magnetization among the permanent magnets and are inexpensive because they contain inexpensive Fe as a main component. However, since the Curie point is low, the temperature change of the magnetic characteristics is large and the heat resistance is poor. At the same time, the corrosion resistance is also inferior, so it is necessary to perform an appropriate surface treatment depending on the application.

  Since the rare earth magnet is a metal, the specific electric resistance is about 150 μΩ · cm, which is two orders of magnitude lower than the specific electric resistance of the ferrite magnet. Therefore, when this rare earth magnet is used in a rotating device such as a motor, an eddy current generated by electromagnetic induction flows because a fluctuating magnetic field is applied to the magnet, and the permanent magnet generates heat due to Joule heat caused by the current. When the temperature of the permanent magnet is increased, especially in the case of an Nd—Fe—B based sintered magnet, since the temperature change of the magnetic property is large, the magnetic property is lowered, and as a result, the efficiency of the motor is also deteriorated. This deterioration is called eddy current loss.

As a countermeasure,
(1) Increase the coercive force of the magnet,
(2) The magnet is subdivided in the magnetization direction.
(3) An insulating layer is provided inside the magnet.
(4) Methods such as increasing the specific electrical resistance of magnets have been studied and proposed.

In the method (1), a portion of Nd—Fe—B is substituted with a heavy rare earth such as Dy to increase the magnetocrystalline anisotropy and increase the coercive force. However, heavy rare earth elements that are partially substituted are scarce in resources and expensive, and as a result, the cost of a single magnet is increased, which is not preferable.
In the method (2), the amount of heat generation is suppressed by dividing the magnet and reducing the area through which the magnetic flux passes or by optimizing the aspect ratio of the area through which the magnetic flux passes. Increasing the number of divisions can further reduce the amount of heat generation, but this is not preferable because the processing cost increases.
The method (3) is effective when the fluctuation of the external magnetic field is parallel to the magnetization direction of the magnet, but is not effective when the fluctuation direction of the external magnetic field is not constant in an actual motor.
In the method (4), the specific electrical resistance at room temperature is increased by adding an insulating phase, but depending on the method of selecting an insulator, it is difficult to increase the density, so that the magnetic properties and corrosion resistance deteriorate. Moreover, it is necessary to adopt a special sintering method for densification.

In addition, the following are mentioned as prior literature relevant to the present invention.
Japanese Patent Laid-Open No. 2003-070214 JP 2001-068317 A JP 2002-0664010 A JP 10-163055 A JP 2003-022905 A

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for producing an RTBC type sintered magnet having high magnetic characteristics that suppresses heat generation due to eddy current and reduces loss in a changing magnetic field. .

As a result of various studies conducted by the present inventor to solve such problems, the R-T-B-C type low-loss sintered magnet (where R is at least one selected from Ce, Pr, Nd, Tb, and Dy). In producing a rare earth element, T is Fe or Fe and at least one other transition metal), 25 mass% ≦ R ≦ 35 mass%, 0.8 mass% ≦ B ≦ 1.4 mass% 0.01% by mass ≦ C ≦ 0.5% by mass, 0.1% by mass ≦ Al ≦ 1.0% by mass, and the balance is an alloy powder containing R—T—B—C composed of T as a main phase (I ), 50 mass% ≦ R ≦ 65 mass%, 0.3 mass% ≦ B ≦ 0.9 mass%, 0.01 mass% ≦ C ≦ 0.5 mass%, 0.1 mass% ≦ Al ≦ 1 0.0% by mass, 0.1% by mass ≦ Cu ≦ 5.0% by mass, R—T—B—C type sintering additive alloy (II) having an R-rich composition in which the balance is T, and R _{O 1-x -F 1 + 2x} ( where, R represents Ce, Pr, Nd, Tb, at least one rare earth element selected from Dy, x is an arbitrary real number of 0 to 1) and / or R-F _y (where R is at least one rare earth element selected from Ce, Pr, Nd, Tb, and Dy, y is 2 or 3) After mixing an appropriate amount of powder (III), it is pulverized by a jet mill in a nitrogen stream R-TBC type sintering aid alloy powder (II) and R-O1 _-x -F1 _{+ 2x} and / or R- _Fy powder (III) having an R-rich composition It was found that fine dispersion is effective.

Accordingly, the present invention provides an R-T-B-C type sintered magnet (where R is at least one rare earth element selected from Ce, Pr, Nd, Tb, Dy, T is Fe or Fe and other 50 mass% ≦ R ≦ 65 mass%, 0.3 mass% ≦ B ≦ 0.9 mass%, 0.01 mass% ≦ C ≦ 0.5 mass) in the production method of at least one transition metal) %, 0.1% by mass ≦ Al ≦ 1.0% by mass, 0.1% by mass ≦ Cu ≦ 5.0% by mass, R-T-B-C type sintering of R-rich composition with the balance being T Auxiliary alloy (II) 1 to 20% by mass and R—O _1-x —F _{1 + 2x} (where R is at least one rare earth element selected from Ce, Pr, Nd, Tb, Dy, x at least one of rare earth any real number) and / or R-F _y 0-1 (wherein, R represents selected Ce, Pr, Nd, Tb, from Dy Element, y is 2 or 3) 10 to 50% by mass of powder (III), and the rest is 25% by mass ≦ R ≦ 35% by mass, 0.8% by mass ≦ B ≦ 1.4% by mass, 0.01% by mass ≦ C ≦ 0.5% by mass, 0.1% by mass ≦ Al ≦ 1.0% by mass, and after mixing with alloy powder (I) having R—T—B—C composed of the balance T as the main phase The present invention provides a method for producing an R-T-B-C type sintered magnet, which is pulverized by a jet mill in a nitrogen stream and then molded, sintered and heat-treated in a magnetic field.

In this case, R—O _1−x −F _{1 + 2x} (where R is at least one rare earth element selected from Ce, Pr, Nd, Tb, and Dy, x is any real number from 0 to 1) and / Or R-F _y (where R is at least one rare earth element selected from Ce, Pr, Nd, Tb, Dy, y is 2 or 3) The average particle size of the powder (III) is 0.5 to It is preferable that it is 50 micrometers.

Further, alloy powder (I) having R-T-B-C as a main phase, R-T-B-C type sintering aid alloy (II) having an R-rich composition, R-O _1-x -F _{1 + 2x} (where R is at least one rare earth element selected from Ce, Pr, Nd, Tb, Dy, x is any real number from 0 to 1) and / or R-F _y (where R is at least one rare earth element selected from Ce, Pr, Nd, Tb, and Dy, y is 2 or 3) After mixing the powder (III), the average particle size is 0.01- Finely pulverized to 30 μm, molded at a press pressure of 90 to 150 MPa in a magnetic field of 800 to 1,760 kA / m, sintered in a vacuum atmosphere at 1,000 to 1,200 ° C., and then in an Ar atmosphere at 400 to 600 ° C. An aging treatment is preferred.

According to the present invention, there is a high coercive force, a large specific electric resistance that can suppress the generation of eddy currents even under use conditions such as exposure to an alternating magnetic field such as a motor, and a high temperature coefficient of specific electric resistance. A magnet can be manufactured at low cost using existing equipment. That is, the manufacturing method of the present invention can provide an RTBC low-loss sintered magnet having a large specific electric resistance and suppressing generation of eddy currents.
In particular, the production method of the present invention is suitable for producing a low-loss sintered magnet having a specific electric resistance of 180 μΩ · cm or more, preferably 250 μΩ · cm or more without impairing the magnet characteristics. In addition, the manufacturing method of the present invention has magnetic characteristics in which the holding force is 1,500 [kA / m] or more, the squareness ratio is 0.92 or more, and the specific electric resistance is 250 to 450 μΩ · cm. It is suitable for manufacturing a low-loss sintered magnet in the range of.

The manufacturing method of the RTBC type sintered magnet according to the present invention is as follows:
(I) Alloy powder having R-T-B-C as the main phase (R-T-B-C type magnet alloy),
(II) R-T-B-C type sintering aid alloy having an R-rich composition;
(III) R—O _1-x —F _{1 + 2x} and / or R—F _y powders are mixed and then pulverized by a jet mill in a nitrogen stream, and then molded, sintered, and heat treated in a magnetic field. .

  Where R is one or more rare earth elements selected from Ce, Pr, Nd, Tb, and Dy, T is Fe or at least one other transition metal such as Fe and Co, and x is 0 Arbitrary real number of ~ 1, y is 2 or 3.

Here, the R—O _1-x —F _{1 + 2x} or R—F _y powder (III) is preferably added together with the R-rich composition sintering aid alloy (II) before pulverization. Alloy powder for pulverized magnet, by performing at the same time as the sintering aid alloy powder, alloy powder and _{R-O 1-x -F 1} + 2x or R-F _y powder magnet are mixed well, pulverized The surface of the fine powder of the magnet alloy obtained by the above can be coated with fine R—O _1-x —F _{1 + 2x} or R—F _y powder. Further, the particle size can be controlled. By this method, the R-O _1-x -F _{1 + 2x} or R-F _y phase can be finely dispersed in the sintered body, and as a result, the specific electrical resistance is increased without deteriorating the magnetic properties. can do. When added to finely pulverized alloy powder for magnet powder, mixing with R- _{O1 -x} -F1 _{+ 2x} or R- _Fy powder tends to be insufficient, and R-O1 _-x- F _{1 + 2x} or R-F _y powder is distributed in a patchy manner, and magnetic characteristics and specific electrical resistance become nonuniform, which is not preferable.

In the R-O1 _-x -F1 _{+ 2x} or R- _Fy powder, R is a magnet constituent element such as Ce, Pr, Nd, Tb, and Dy. In the case of alkali metal, alkaline earth metal fluorides and rare earth fluorides other than those described above, densification by sintering is hindered, and magnetic properties deteriorate.

The amount of R-O1 _-x -F1 _{+ 2x} or R- _Fy powder added is preferably 10 to 50 mass%, more preferably 10 to 30 mass%. If it exceeds 50% by mass, the density does not increase in normal vacuum sintering, and it is necessary to employ special sintering such as HIP. If it is less than 10% by mass, no effect is seen in the increase of specific electric resistance.

The particle size of the powder at the time of addition should just be 50 micrometers or less, Preferably it is 30 micrometers or less, More preferably, 15 micrometers or less are good. The average particle size of the finely pulverized powder may be 3 μm or less, preferably 1 μm or less. The specific electrical resistance at room temperature of the sintered body can be increased by finely dispersing the R- _{O1 -x} -F1 _{+ 2x} or R- _Fy powder in the sintered body by the above-described method. .

  In the production method of the present invention, 50 mass% ≦ R ≦ 65 mass%, 0.3 mass% ≦ B ≦ 0.9 mass%, 0.01 mass% ≦ C ≦ 0.5 mass%, 0.1 mass % ≦ Al ≦ 1.0% by mass, 0.1% by mass ≦ Cu ≦ 5.0% by mass (preferably 0.1% by mass ≦ Cu ≦ 1.0% by mass), the balance being T-rich composition R-T-B-C type sintering aid alloy (II) of 1 to 20% by mass, particularly 3 to 15% by mass, is added, and if this addition amount is less than 1% by mass, sintering is performed. It becomes difficult, the density after sintering does not increase sufficiently, and if the amount added exceeds 20% by mass, it is not preferable because sufficient magnetic properties cannot be obtained.

The alloy powder (I) containing R-T-B-C as the main phase blended in the present invention is an alloy for magnets, and is 25 mass% ≦ R ≦ 35 mass%, 0.8 mass% ≦ B ≦ 1. .4% by mass, 0.01% by mass ≦ C ≦ 0.5% by mass, 0.1% by mass ≦ Al ≦ 1.0% by mass, and the balance T. This is R ₂ —Fe. _14- (B, C) type intermetallic compound as the main phase, the mixing amount is the balance, but the R-T-B-C type sintering aid alloy (R-rich composition as a mass ratio) It is preferably 2.3 to 19 times, particularly 5.0 to 19 times that of II).

  In the production method of the present invention, after mixing the components (I), (II), and (III), the mixture is finely pulverized by a jet mill in a nitrogen stream, and molded, sintered, and heat-treated in a magnetic field to obtain RT. -B-C type sintered magnet is produced. In this case, fine pulverization is carried out by jet milling in a nitrogen stream with an average particle size of 0.01 to 30 [mu] m, more preferably 0.1 to 10 [mu] m, still more preferably 0.8. Finely pulverized to 5 to 10 μm, molded at a press pressure of 90 to 150 MPa, particularly 100 to 120 MPa in a magnetic field of 800 to 1,760 kA / m, particularly 1,000 to 1,760 kA / m, and then 1,000 in a vacuum atmosphere It is preferable to produce an R—T—B—C type sintered magnet by sintering at ˜1,200 ° C. and aging treatment at 400-600 ° C. in an Ar atmosphere.

The RTBC type sintered magnet of the present invention thus obtained preferably has the following composition.
R = 25-35% by mass
B = 0.8 to 1.4% by mass
C = 0.01-0.5 mass%
Al = 0.1 to 1.0% by mass
Cu = 0.1-5.0 mass% (preferably 0.1-1.0 mass%)
The balance is T and inevitable impurities (O, N, Si, P, S, Cl, Na, K, Mg, Ca, etc.)

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to these Examples.

[Examples 1 to 3, Comparative Example 1]
In Examples 1 to 3, the R-T-B-C type magnet alloy has Nd with a purity of 99 mass% or more containing 0.04 mass% of C and a purity of 99 mass with 0.04 mass% of C. % Of Dy, Fe and Al with a purity of 99% by mass, and ferroboron are weighed in predetermined amounts, melted in a high frequency in an Ar atmosphere, cooled by a single roll method in an Ar atmosphere, and an alloy ribbon Manufactured.
In addition, the composition of the obtained alloy for RTBC type magnets is Nd25 mass%, Dy 3 mass%, Al 0.2 mass%, B1 mass%, C 0.01 mass%, and others are Fe.
Next, the produced alloy ribbon was coarsely pulverized by hydrogenation coarse pulverization. In the hydrogenation coarse pulverization, hydrogen storage treatment was performed at room temperature for 2 hours, and then heat treatment was performed at 600 ° C. for 2 hours in vacuum to perform dehydrogenation treatment.
On the other hand, the R-T-B-C type sintering aid alloy has a purity of 99% by mass or more containing 0.04% by mass of C and a purity of 99% by mass or more containing 0.04% by mass of C. Dy, Fe, Co, Cu, Al having a purity of 99% by mass or more, and ferroboron were weighed in predetermined amounts and melted at high frequency in an Ar atmosphere to produce an alloy.
The composition of the obtained RTBC type sintering aid alloy is Nd 45 mass%, Dy 13 mass%, Al 0.2 mass%, B 0.5 mass%, Co 20 mass%, Cu 1.2 mass. %, C0.02 mass%, and the others are Fe.

The R-T-B-C type alloy powder for magnets and the R-T-B-C type sintering aid alloy powder obtained as described above were weighed at 8: 2 (mass ratio), and this mixed powder and NdF ₃ powder was weighed at 95: 5, 85:15, and 65:35 (mass ratio), respectively, and mixed with a V blender. The mixed powder was finely pulverized by a jet mill in a nitrogen stream to obtain a fine powder having an average particle size of about 4.8 μm. Thereafter, these fine powders are filled in a mold of a molding apparatus, oriented in a magnetic field of 955 kA / m, press-molded at a pressure of 98.1 MP in a direction perpendicular to the magnetic field, and at 1,050 ° C. for 2 hours. After being sintered in a vacuum atmosphere, it was cooled and further heat treated at 500 ° C. for 1 hour in an Ar atmosphere to prepare permanent magnet materials having various compositions.
Table 1 shows the magnetic properties of the sintered magnets obtained and the specific electrical resistance measured by the four probe method. From the table, it can be seen that as the amount of NdF ₃ added increases, the remanent magnetization (Br) decreases compared to the case of no addition, but the coercive force (iHc) hardly changes.
In a similar manner, to prepare those without added NdF _3, and Comparative Example 1.

[Examples 4 to 6]
In Examples 4 to 6, the R-T-B-C type magnet alloy has Nd of 99% by mass or more containing 0.08% by mass of C and 99% by mass of C containing 0.12% by mass of C. % Of Dy, Fe and Al with a purity of 99% by mass, and ferroboron are weighed in predetermined amounts, melted in a high frequency in an Ar atmosphere, cooled by a single roll method in an Ar atmosphere, and an alloy ribbon Manufactured.
In addition, the composition of the obtained alloy for RTBC type magnets is Nd25 mass%, Dy 3 mass%, Al 0.2 mass%, B1 mass%, C0.02 mass%, and others are Fe.
Next, the produced alloy ribbon was coarsely pulverized by hydrogenation coarse pulverization. In the hydrogenation coarse pulverization, hydrogen storage treatment was performed at room temperature for 2 hours, and then heat treatment was performed at 600 ° C. for 2 hours in vacuum to perform dehydrogenation treatment.
On the other hand, the R-T-B-C type sintering aid alloy has a purity of 99% by mass or more containing 0.06% by mass of C and a purity of 99% by mass or more containing 0.10% by mass of C. Dy, Fe, Co, Cu, Al having a purity of 99% by mass or more, and ferroboron were weighed in predetermined amounts and melted at high frequency in an Ar atmosphere to produce an alloy.
The composition of the obtained RTBC type sintering aid alloy is Nd 45 mass%, Dy 13 mass%, Al 0.2 mass%, B 0.5 mass%, Co 20 mass%, Cu 1.2 mass. %, C0.03% by mass, and the others are Fe.

The R-T-B-C type magnet alloy powder obtained above and the R-T-B-C type sintering aid alloy powder were weighed at 8: 2 (mass ratio), and this mixed powder and DyF ₃ , NdF ₃ + DyF ₃ (mass ratio of NdF ₃ : DyF ₃ = 1: 1), weighed so that the mass ratio with NdOF is 85:15, mixed by V mixer, and in N ₂ gas, Fine pulverization was performed by a jet mill. At this time, the average particle size of the fine powder obtained is 3.0 to 4.8 μm.
Thereafter, these fine powders were filled in a mold of a molding apparatus, oriented in a magnetic field of 955 kA / m, and press-molded at a pressure of 98.1 MPa in a direction perpendicular to the magnetic field. The obtained compact was sintered in a vacuum atmosphere at 1,050 ° C. for 2 hours, then cooled, and further heat-treated in an Ar atmosphere at 500 ° C. for 1 hour to prepare permanent magnet materials of various compositions. . Table 2 shows the magnetic properties of the sintered magnets obtained and the specific electrical resistance measured by the four probe method. It can be seen that the coercive force (iHc) is increased by adding DyF ₃ . Also, an increase in specific electrical resistance can be confirmed.

[Comparative Examples 2 to 5]
The R-T-B-C type magnet alloy includes Nd having a purity of 99% by mass or more containing 0.04% by mass of C, Dy having a purity of 99% by mass or more containing 0.04% by mass of C, purity A predetermined amount of 99% by mass or more of Fe, Al, and ferroboron were weighed, melted at a high frequency in an Ar atmosphere, and cooled by a single roll method in an Ar atmosphere to produce an alloy ribbon.
In addition, the composition of the obtained alloy for RTBC type magnets is Nd25 mass%, Dy 3 mass%, Al 0.2 mass%, B1 mass%, C 0.01 mass%, and others are Fe.
Next, the produced alloy ribbon was coarsely pulverized by hydrogenation coarse pulverization. In the hydrogenation coarse pulverization, hydrogen storage treatment was performed at room temperature for 2 hours, and then heat treatment was performed at 600 ° C. for 2 hours in vacuum to perform dehydrogenation treatment.
On the other hand, the R-T-B-C type sintering aid alloy has a purity of 99% by mass or more containing 0.04% by mass of C and a purity of 99% by mass or more containing 0.04% by mass of C. Dy, Fe, Co, Cu, Al having a purity of 99% by mass or more, and ferroboron were weighed in predetermined amounts and melted at high frequency in an Ar atmosphere to produce an alloy.
The composition of the obtained RTBC type sintering aid alloy is Nd 45 mass%, Dy 13 mass%, Al 0.2 mass%, B 0.5 mass%, Co 20 mass%, Cu 1.2 mass. %, C0.02 mass%, and the others are Fe.

The R-T-B-C type magnet alloy powder and R-T-B-C type sintering aid alloy powder obtained as described above are weighed to 8: 2 (mass ratio) and mixed by a V mixer. Then, it was finely pulverized with a jet mill in N ₂ gas.
At this time, the average particle diameter of the obtained fine powder is 5.0 μm.
The fine powder thus obtained and DyF ₃ , CaF ₂ , Nd ₂ O ₃ , and Dy ₂ O ₃ were weighed so that the mass ratio was 90:10 or 80:20, and then for 20 minutes with a V mixer. Mixed. In the powder after mixing, agglomerated powder of fluoride added in some places was confirmed.
Thereafter, these fine powders are filled in a mold of a molding apparatus, oriented in a magnetic field of 955 kA / m, press-molded at a pressure of 98.1 MP in a direction perpendicular to the magnetic field, and at 1,050 ° C. for 2 hours. Then, after sintering in a vacuum atmosphere, it was cooled and further heat-treated at 500 ° C. for 1 hour in an Ar atmosphere to produce permanent magnet materials of various compositions, which were Comparative Examples 2 to 5.

  Table 3 shows the magnetic properties of the sintered magnets obtained in Comparative Examples 2 to 5 and the specific electric resistance measured by the four-terminal method. From the results in Table 3, although the specific electrical resistance is improved by the method in the comparative example, the deterioration of the magnetic characteristics cannot be suppressed.

Claims (3)

R-T-B-C type sintered magnet (where R is at least one rare earth element selected from Ce, Pr, Nd, Tb, Dy, T is Fe or Fe and at least one other transition metal) 50 mass% ≦ R ≦ 65 mass%, 0.3 mass% ≦ B ≦ 0.9 mass%, 0.01 mass% ≦ C ≦ 0.5 mass%, 0.1 mass R—T—B—C type sintering additive alloys 1 to 20 having an R-rich composition in which% ≦ Al ≦ 1.0% by mass, 0.1% by mass ≦ Cu ≦ 5.0% by mass and the balance being T % By mass and R—O _1-x -F _{1 + 2x} (where R is at least one rare earth element selected from Ce, Pr, Nd, Tb, and Dy, x is an arbitrary real number from 0 to 1) and / or R-F _y (provided that at least one rare earth element R is selected Ce, Pr, Nd, Tb, from Dy, y is 2 or 3) powder 1 -50 mass% and the rest 25 mass% ≦ R ≦ 35 mass%, 0.8 mass% ≦ B ≦ 1.4 mass%, 0.01 mass% ≦ C ≦ 0.5 mass%, 0.1 mass% % ≦ Al ≦ 1.0 mass%, mixed with an alloy powder mainly composed of R—T—B—C composed of the balance T, then finely pulverized with a jet mill in a nitrogen stream, and then molded in a magnetic field , Sintering and heat treatment, a method for producing an RTBC type sintered magnet. R-O1 _-x- F1 _{+ 2x} (where R is at least one rare earth element selected from Ce, Pr, Nd, Tb, Dy, x is any real number from 0 to 1) and / or R -F _y (where, R represents Ce, Pr, Nd, Tb, at least one rare earth element selected from Dy, y is 2 or 3), wherein the average particle size of the powder is 0.5~50μm The manufacturing method of the RTBC type | mold sintered magnet of Claim 1 characterized by the above-mentioned. Alloy powder having R-T-B-C as the main phase, R-T-B-C type sintering aid alloy having R-rich composition, and R-O _1-x -F _{1 + 2x} (however, R is at least one rare earth element selected from Ce, Pr, Nd, Tb, Dy, x is any real number from 0 to 1) and / or R- _Fy (where R is Ce, Pr, Nd, At least one rare earth element selected from Tb and Dy, y is 2 or 3) After mixing the powder, it is finely pulverized to a mean particle size of 0.01 to 30 μm by a jet mill in a nitrogen stream, and 800 to 1,760 kA 2. After forming at a press pressure of 90 to 150 MPa in a magnetic field of / m, sintering at 1,000 to 1,200 ° C. in a vacuum atmosphere, and aging treatment at 400 to 600 ° C. in an Ar atmosphere. Or the manufacturing method of the RTBC type | mold sintered magnet of 2 description.