TWI676998B - Sintered body for forming rare earth magnets and rare earth sintered magnet - Google Patents

Abstract

The present invention relates to a sintered body for forming a rare earth magnet and a rare earth sintered magnet, and provides: in an arbitrary minute segment in the cross section of the magnet, the magnetization of each magnetic material particle is easy to axis for the angle of the alignment axis of the magnetic material particle. The misalignment of the alignment angle is a sintered body for forming a rare-earth magnet and a sintered rare-earth magnet that are configured to be maintained within a specific range. The sintering system for forming a rare-earth magnet has a length dimension having a length direction, a thickness dimension in a thickness direction between a first surface and a second surface in a cross section perpendicular to the length direction of the transverse direction, and a thickness direction for the thickness direction. A three-dimensional shape with a width dimension orthogonal to the width direction. Among the alignment angles of the plurality of magnet material particles in a quadrangular segment located at arbitrary positions in the plane including the thickness direction and the width direction with respect to the easy-to-magnetize axis of the preset reference line, the most frequent Regarding the angle of the alignment axis defined by the alignment angle, the unevenness angle of the alignment angle determined based on the difference in the alignment angle of each of the easy-to-magnetize axes of the magnet material particles is 9.0 ° or less. In one aspect, the segmentation is determined by setting the magnet material particles as 30 or more, for example, quadrangular segments including 200 or 300. A quadrangular segment is preferably a square. In other forms, the segment is defined as a square segment with a side of 35 μm.

Description

Sintered body for forming rare earth magnet and rare earth sintered magnet

The present invention relates to a sintered body for forming a rare earth magnet for forming a rare earth sintered magnet and a rare earth sintered magnet obtained by magnetizing the sintered body. In particular, the present invention relates to a sintered body for forming a rare-earth magnet having a structure in which a plurality of magnet material particles each containing a rare-earth substance and each having an easily magnetizable axis are integrally sintered, and a rare-earth material obtained by magnetizing the sintered body Sintered magnet.

Rare-earth sintered magnets have attracted attention as high-performance permanent magnets that can expect high coercive force and residual magnetic flux density, have been put into practical use, and development has been progressed for further high-performance. For example, the title "High Coercivity of Nd-Fe-B Junction Magnets Formed by Crystals and Micronization" described by Ugen Kangyu and others in Japanese Society of Metals, Vol. 76, No. 1 (2012), pages 12-16. The paper (Non-Patent Document 1) is based on the understanding that the coercive force increases when the particle size of the magnet material is refined. For the high coercive force of the Nd-Fe-B system sintered magnet, the average value is used. An example of manufacturing a rare earth sintered magnet with particles of a material for forming a magnet having a powder particle diameter of 1 μm is described. Rare earth burning described in Non-Patent Document 1 In the method for manufacturing a knotted magnet, a mixture of a lubricant made of mixed magnet material particles and a surfactant is filled in a carbon model, and a pulse magnetic field is applied by fixing the model in an air-core coil. To align the magnet material particles. However, in this method, the orientation of the magnetic material particles is uniquely determined by the pulsed magnetic field applied through the air-core coil. It is not possible to obtain the orientation of the magnetic material particles at different positions in the magnet. Permanent magnet for direction. In addition, in this Non-Patent Document 1, as for the axis of easy magnetization of the magnetic material particles aligned by the application of a pulsed magnetic field, the point of how much the direction of the intended alignment is deviated, and the alignment angle is deviated. The point that how much influence the performance of the magnet has on the system has not been studied.

Japanese Unexamined Patent Publication No. 6-302417 (Patent Document 1) discloses that during the manufacture of a rare earth permanent magnet using the rare earth elements R, Fe, and B as basic constituent elements, the magnetization of the particles of the bonded magnetic material is easy to be performed. A method of maintaining a state of a plurality of magnet bodies aligned in different directions and maintaining a high-temperature heating state, and then passing between the magnets to form a permanent magnet having an easy-to-magnetize axis of the particles of the magnet material and then orienting a plurality of permanent magnets in different directions . According to the method for forming a permanent magnet described in this patent document 1, it is possible to produce rare-earth permanent magnets formed of a plurality of ranges, including magnetizable material particles that are arbitrarily and oriented in different directions, including the axis of easy magnetization. By. However, this patent document 1 does not describe the point to which the alignment of the magnet material particles given to the respective magnet bodies deviates to some extent from the intended alignment direction.

Japanese Patent Application Publication No. 2006-222131 (Patent Document 2) A method for manufacturing a ring-shaped rare earth permanent magnet in which an even number of permanent magnet pieces are arranged in the circumferential direction and connected to each other is disclosed. The manufacturing method of a rare earth permanent magnet disclosed in this patent document 2 is to form a fan-shaped permanent magnet piece having a fan-shaped main surface and a pair of side surfaces using a powder punching device having fan-shaped die holes. The fan-shaped die hole is filled with the rare-earth alloy powder, and the rare-earth alloy powder in the die-hole is applied with an alignment magnetic field through a punch having an alignment coil above and below, and the rare-earth alloy powder is punched and formed. After this process, a permanent magnet piece with extremely anisotropy is formed between the N pole and the S pole of each main surface. When described in detail, it is formed to have a corner portion that intersects from one principal surface and one lateral surface, is curved in an arc shape in the direction of the other principal surface, and extends to the principal surface of the other and the other side. Permanent magnet pieces with magnetized alignment aligned in the direction of the intersecting corners. An even number of the extremely anisotropic permanent magnet pieces thus formed are connected in a ring shape with the opposite polarities of the adjacent permanent magnet pieces to obtain a ring-shaped permanent magnet.

Patent Document 2 also describes that among the even number of fan-shaped permanent magnet pieces connected in a ring shape, the magnetization direction of the magnet pieces arranged one by one is taken as the axial direction, and these axial directions are shown. The magnetization direction of the magnet pieces arranged between the magnetized magnet pieces is aligned as the arrangement of the magnet pieces in the radial direction. In this configuration, it is explained that the polarities of the major surfaces of the magnet pieces that are magnetized in the direction of the axis arranged one after the other become mutually different polarities, and the magnetization that is arranged between the magnet pieces that are magnetized in the axis direction is placed in the other one. When the magnet pieces in the radial direction are opposed to each other with the same poles, the magnetic flux can be concentrated in one of the axial directions. One of the main faces of the magnet pieces has a magnetic pole on the main surface, and the magnetic flux from the magnetic pole is efficiently collected on one of the main faces of the other magnet piece magnetized in the axial direction. However, this patent document 2 also does not describe the point to which the alignment given to each magnet material particle is shifted to some extent in the intended alignment direction.

Japanese Unexamined Patent Publication No. 2015-32669 (Patent Document 3) and Japanese Unexamined Patent Publication No. 6-244046 (Patent Document 4) disclose that a magnetic material powder containing the rare earth elements R, Fe, and B is formed into a flat plate by press molding. The pressed powder body is applied with a parallel magnetic field to perform magnetic field alignment, and then sintered at a sintering temperature to form a sintered magnet. Then, based on a temperature condition that does not exceed the sintering temperature, the pressing portion is arc-shaped. When the sintered magnet is pressure-molded into a circular arc shape by a mold, the direction of the rare earth permanent magnet with radial alignment is formed. This Patent Document 3 discloses a method capable of forming a radially aligned magnet using a parallel magnetic field. However, the curved shape from a flat plate shape to a circular arc shape is performed after the magnet material is sintered, and the forming is difficult. It is impossible to perform large deformation or deformation of complicated shapes. Accordingly, the magnet system that can be manufactured by this method is limited to the radial alignment magnet described in Patent Document 4. Furthermore, this patent document 4 does not describe the point to which the alignment given to each magnet material particle is shifted to some extent in the intended alignment direction.

Japanese Patent No. 5444630 (Patent Document 5) discloses a flat-plate-shaped permanent magnet used in a buried-magnet-type motor. The permanent magnet disclosed in this patent document 5 In terms of direction, the inclination angle of the easy axis of magnetization is a radial alignment that continuously changes from both ends in the width direction toward the center in the width direction. When specifically described, the magnetization-easy shafting of the magnet is aligned at one point on an imaginary line extending from the central portion in the width direction in the cross section of the magnet to the thickness direction. As a method of manufacturing a permanent magnet having such a radial orientation of an easy-to-magnet shaft, Patent Document 5 describes that it can be formed by realizing easy magnetic field alignment during molding, and it is easy to manufacture. The method disclosed in this Patent Document 5 is a method in which a magnetic field concentrated on a point outside the magnet is applied during the formation of the magnet, and the orientation of the easily magnetized axis of the formed magnet is limited to a radial orientation. Accordingly, for example, in the widthwise central range that cannot be formed in the cross section, it is oriented parallel to the thickness direction, and in the range of both ends in the width direction, it is oriented obliquely. Permanent magnet. This patent document 5 also does not describe the point to which the alignment given to each magnet material particle is shifted to some extent in the intended alignment direction.

Japanese Patent Application Laid-Open No. 2005-44820 (Patent Document 6) discloses a method for manufacturing an extremely anisotropic rare-earth sintered ring magnet that does not substantially generate cogging torque when assembled in a motor. The rare earth sintered ring magnet disclosed here has a magnetic pole at a plurality of positions spaced from the circumferential direction, and the magnetization direction becomes a normal direction at the magnetic pole position and becomes an intermediate position of the adjacent magnetic poles. Magnetize the wiring direction. The manufacturing method of the rare earth sintered ring magnet described in this patent document 6 is limited to the manufacturing of extremely anisotropic magnets, and the manufacturing method is here However, in a single sintered magnet, it is impossible to produce magnets in which the magnet material particles are provided with orientations in different directions within an arbitrary plural range. In addition, this patent document 6 does not describe the point to which the alignment given to each magnet material particle is shifted to some extent in the intended alignment direction.

Japanese Patent Application Laid-Open No. 2000-208322 (Patent Document 7) discloses a structure in which a plurality of magnetic material particles are aligned in different directions, a single plate-shaped, sector-shaped permanent magnet. In Patent Document 7, a plurality of ranges are formed in the permanent magnet. In one range, the particles of the magnet material are aligned in a pattern parallel to the thickness direction, and in the other ranges adjacent to this, the magnet is formed. For the material particles, an orientation having an angle with respect to the alignment direction of the magnetic material particles in the one range is added. Patent Document 7 describes that a permanent magnet having such an orientation of magnetic material particles is powder metallurgy, and when pressure forming is performed in a metal mold, an appropriate orientation can be applied via a self-aligning member. Magnetic fields are created from time to time. However, the method for manufacturing a permanent magnet described in Patent Document 7 is also applicable only to the manufacture of a magnet having a specific orientation, and it is also limited to the shape of the manufactured magnet. In addition, this patent document 7 does not describe the point to which the alignment given to each magnet material particle is shifted to some extent in the intended alignment direction.

International Patent Application Publication No. WO2007 / 119393 (Patent Document 8) describes that a mixture of magnetic material particles containing rare earth elements and a binder is formed into a specific shape, and a parallel magnetic field is applied thereto. When the formed body has an orientation parallel to the magnet material particles, and when the formed body is deformed into another shape, the orientation of the magnet material particles is used as a method for manufacturing a non-parallel permanent magnet. The magnet system disclosed in this patent document 8 has a structure in which particles of a magnetic material are bonded via a resin composition, and is a so-called bonded magnet rather than a sintered magnet. The bonded magnet has a structure in which a resin composition is interposed between particles of the magnet material. Compared with a sintered magnet, the bonded magnet has a structure in which the magnetic characteristics are deteriorated, and a high-performance magnet cannot be formed.

Japanese Unexamined Patent Publication No. 2013-191612 (Patent Document 9) discloses that a mixture of rare earth element-containing magnetic material particles and a resin binder is formed, and the mixture is formed into a sheet shape to form a green sheet. A method for magnetic field alignment by applying a magnetic field to the green sheet, and calcining the green sheet aligned with the magnetic field to decompose the resin binder, spray it, and then sinter it at the firing temperature to form a rare earth sintered magnet. . The magnetized easy-to-magnet shaft manufactured by the method described in Patent Document 9 is configured to be oriented in one direction. However, in this method, it cannot be manufactured in a single sintered magnet, and within an arbitrary plural range, As for the particles of the magnetic material, those having orientations in different directions are provided. In addition, this Patent Document 9 does not describe the point to which the alignment given to each magnet material particle is shifted to some extent in the intended alignment direction.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Unexamined Patent Publication No. 6-302417

[Patent Document 2] Japanese Patent Laid-Open No. 2006-222131

[Patent Document 3] Japanese Patent Laid-Open No. 2015-32669

[Patent Document 4] Japanese Patent Laid-Open No. 6-244046

[Patent Document 5] Japanese Patent No. 5444630

[Patent Document 6] Japanese Patent Laid-Open No. 2005-44820

[Patent Document 7] Japanese Patent Laid-Open No. 2000-208322

[Patent Document 8] International Application Publication Re-publication Publication No. WO2007 / 119393

[Patent Document 9] Japanese Patent Laid-Open No. 2013-191612

[Patent Document 10] Japanese Patent Laid-Open No. 2001-210508

[Non-patent literature]

[Non-Patent Document 1] Journal of the Japanese Metal Society, Vol. 76, No. 1 (2012), pages 12 to 16.

As described above, any of the patent documents and non-patent documents related to the production of rare earth permanent magnets does not make any description about the uneven orientation of the axis of the magnetization particles of the magnet material in the cross section of the magnet. The inventors have aligned the magnet material particles in different desired directions at different positions in the magnet. The rare earth sintered magnets described in the above documents and the practically used rare earth sintered magnets have been verified based on the definitions described below. The unevenness of the alignment angle was confirmed, but it was confirmed that the unevenness of the alignment angle was larger than 9 °. However, in the cross section of the magnet, the orientation of the easy magnetization axis of the plurality of magnet material particles contained in the micro-segment is shifted from the intended alignment direction. The larger the shift, the lower the performance of the magnet.

Accordingly, the main object of the present invention is to provide: in an arbitrary minute segment in the cross section of the magnet, the orientation angle of the axis of each magnet material particle is easy to be shifted with respect to the angle of the orientation axis of the magnet material particle, and then the Those who maintain the sintered body for forming rare earth magnets and the rare earth based sintered magnets configured in a specific range. In other words, the present invention provides a rare-earth sintered magnet having a novel high-precision alignment that has not existed before, and a sintered body for forming such a magnet.

In order to achieve the above-mentioned object, the present invention provides, in one aspect, a sintered body for forming a rare-earth magnet having a structure including a rare-earth substance and integrally sintering a plurality of magnet material particles each having an easy-to-magnetize axis. This sintering system for forming a rare-earth magnet has a length dimension having a length direction, a thickness dimension in a thickness direction between a first surface and a second surface in a cross section perpendicular to the lengthwise direction in the transverse direction, and a thickness for the thickness. The three-dimensional shape of the width dimension of the width direction orthogonal to the direction. Among the alignment angles of the plurality of magnet material particles in a quadrangular segment located at arbitrary positions in the plane including the thickness direction and the width direction with respect to the easy-to-magnetize axis of the preset reference line, the most frequent Regarding the angle of the alignment axis defined by the alignment angle, according to the aforementioned magnet material The misalignment angle of the alignment angle determined by the difference in the alignment angle of each easy-to-magnetize axis of the particles is 9.0 ° or less. In one aspect, the segmentation is determined by setting the magnet material particles as 30 or more, for example, quadrangular segments including 200 or 300. A quadrangular segment is preferably a square. In other forms, the segment is defined as a square segment with a side of 35 μm.

In the above aspect of the present invention, the average particle diameter of the magnetic material particles is preferably 3 μm or less. Furthermore, in the above aspect of the present invention, it is preferable that the difference in the angle of the alignment axes among the plural quadrangular segments is 10 ° or less. In a more desirable form, the difference in the angle of the alignment axis is 5 ° or less. An alignment system with such a small angular difference in the alignment axis can be referred to as a parallel alignment.

In another aspect of the present invention, there is provided a rare-earth sintered magnet formed by being magnetized to the above-mentioned sintered body for forming a rare-earth magnet.

The sintering system for forming a rare-earth magnet according to the present invention having the above-mentioned structure is a structure having a large number of magnet material particles integrally sintered. Compared with the bonded magnet disclosed in Patent Document 8, for example, the density of the magnet material particles is larger. The amplitude becomes higher. Accordingly, the rare-earth sintered magnet obtained by magnetizing the rare-earth magnet forming sintered body exhibits superior magnetic performance that cannot be compared with a bonded magnet. In addition, the sintering system uses 30 or more particles of the magnetic material, for example, The orientation angle of the axis of the magnetization of the plurality of particles of the magnet material in the arbitrary quadrangular segment defined as a square segment with a side of 35 μm is determined by including 200 or 300 quadrangular segments. The average angle is used as a highly accurate alignment in a small range of 9.0 °. The rare earth sintered magnet obtained by magnetizing the sintered body is superior to the conventional rare earth sintered magnets. Magnetist.

1‧‧‧ Sintered body for forming rare earth permanent magnets

2‧‧‧ top

3‧‧‧ below

4,5‧‧‧face

6‧‧‧ Central Range

7,8‧‧‧end range

20‧‧‧ Electric motor

21‧‧‧rotor core

21a‧‧‧ weekly

22‧‧‧Air gap

23‧‧‧ stator

23a‧‧‧Tooth

23b‧‧‧Magnetic coil

24‧‧‧Magnet insertion slot

24a‧‧‧Straight central part

24b‧‧‧ Inclined

30‧‧‧ Rare Earth Magnet

117‧‧‧ Composite

118‧‧‧Support substrate

119‧‧‧Green sheet

120‧‧‧Seam Casting Mould

123‧‧‧ processing sheet

125‧‧‧ Sintered sheet

C‧‧‧ Easy to magnetize shaft

θ‧‧‧ tilt angle

FIG. 1 (a) is a schematic view showing the alignment angle and the angle of the alignment axis, and is a cross-sectional view showing an example of the orientation of the axis of the magnet material particles of the rare earth magnet that is easy to be magnetized.

FIG. 1 (b) is a schematic enlarged view showing the alignment angle and the angle of the alignment axis, and is a schematic enlarged view showing a procedure for setting the "alignment angle" and the "alignment axis angle" of the magnetization-easy axis of each magnetic material particle.

FIG. 2 is a graph showing the steps for obtaining the misalignment angle of the alignment angle.

FIG. 3 (a) is a perspective view showing a display of an alignment angle distribution according to an EBSD analysis, showing a direction of an axis of a rare earth magnet.

FIG. 3 (b) shows an example of the display of the alignment angle distribution according to the EBSD analysis, showing an example of a pole figure obtained by EBSD analysis at the central portion and both end portions of the magnet.

Fig. 3 (c) shows the display of the alignment angle distribution according to the EBSD analysis, and the alignment axis angle of the cross section of the magnet along the A2 axis shown in (a) is shown.

4 is a cross-sectional view showing an example of a sintered body for forming a rare-earth magnet according to an embodiment of the present invention in a cross-section.

5 (a) is a cross-sectional view showing an example of a sintered body for forming a rare-earth magnet according to another embodiment of the present invention in a cross-section, and shows a cross-sectional view of the whole.

5 (b) is a cross-sectional view showing an example of a sintered body for forming a rare earth magnet according to another embodiment of the present invention in a cross-section, and an enlarged view of an end portion is shown.

6 is a cross-sectional view of a rotor portion showing an example of a magnet insertion groove provided in a rotor core of an electric motor in which a rare earth sintered magnet according to an embodiment of the present invention is embedded.

FIG. 7 is an end view of a rotor portion showing a state where a permanent magnet is embedded in the rotor core shown in FIG. 5. FIG.

FIG. 8 is a cross-sectional view of an electric motor to which the permanent magnet of the present invention can be applied.

FIG. 9 is a diagram showing a magnetic flux density distribution of a rare earth permanent magnet formed from a sintered body according to the embodiment shown in FIG. 5.

FIG. 10 (a) is an embodiment of the present invention, showing a schematic view of a manufacturing process of the sintered body for forming a permanent magnet shown in FIG. 1, and showing various stages up to the formation of a green sheet.

FIG. 10 (b) is an embodiment of the present invention, showing a schematic view of a manufacturing process of the sintered body for forming a permanent magnet shown in FIG. 1, and showing various stages up to the formation of a green sheet.

FIG. 10 (c) is an embodiment of the present invention, showing A schematic view of a manufacturing process of a sintered body for forming a permanent magnet is shown at each stage until the green sheet is formed.

FIG. 10 (d) is an embodiment of the present invention, showing a schematic view of a manufacturing process of the sintered body for forming a permanent magnet shown in FIG. 1, and showing various stages up to the formation of a green sheet.

FIG. 11 (a) is a cross-sectional view showing a processing sheet in which the magnetization of the magnetic material particles in this embodiment is easy to be aligned with the axis, and shows the cross-sectional shape of the sheet when a magnetic field is applied.

FIG. 11 (b) is a cross-sectional view showing a processing sheet that is easy to align the magnetization axis of the magnet material particles in this embodiment, and shows a cross-sectional shape of a sintering process sheet that is subjected to a deformation process after a magnetic field is applied.

Fig. 11 (c) is a cross-sectional view of a processing sheet showing the easy-to-axis alignment processing of the magnetized particles of the magnet material in this embodiment, and shows a bending deformation process in which a first formed body is made into a second formed body.

FIG. 12 is a graph showing an ideal heating rate in the calcination process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Prior to the description of the embodiment, the definition of terms and the measurement of the alignment angle will be described.

(Alignment angle)

The alignment angle means an angle in a direction in which the magnetization of the magnetic material particles is easy to the axis for a predetermined reference line.

(Alignment axis angle)

Among the specific angles of the magnet, among the alignment angles of the magnet-forming material particles located in a predetermined segment, the most frequent alignment angle. In the present invention, the segment defining the angle of the alignment axis is a quadrangular segment containing 30 or more magnet material particles, or a square segment with a side of 35 μm.

The alignment angle and the alignment axis angle are shown in FIG. 1. FIG. 1 (a) is a cross-sectional view showing an example of the orientation of the axis of easy magnetization of the magnetic material particles of the rare earth magnet. The rare earth magnet M has a first surface S-1 and is located on the first surface S. -1, the second surface S-2 having a position separated only by the thickness t, and the width W, and both end portions in the width W direction are formed with end faces E-1, E-2. In the example of the figure, the first surface S-1 and the second surface S-2 are flat surfaces parallel to each other, and in the cross section shown in the figure, these first surface S-1 and second surface S-2 It is represented by two straight lines parallel to each other. The end surface E-1 is an inclined surface inclined to the upper right direction for the first surface S-1. Similarly, the end surface E-2 is an inclined surface inclined to the upper left direction for the second surface S-2. . The arrow B-1 schematically shows the direction of the alignment axis of the magnetization-easy axis of the magnet material particles in the center range in the width direction of the rare earth magnet M. In this regard, the arrow B-2 shows the direction of the orientation axis of the magnetization easy axis of the magnet material particles in a range adjacent to the end face E-1. Similarly, the arrow B-3 shows the direction of the orientation axis of the easy-to-magnetize axis of the magnet material particles in a range adjacent to the end surface E-2.

"Alignment axis angle" is the angle between the alignment axis indicated by arrows B-1, B-2, and B-3 and a reference line. The reference line can be set arbitrarily. However, as shown in the example of FIG. 1 (a), for the case where the cross section of the first surface S-1 is represented by a straight line, the cross section of the first surface S-1 is used as the reference line. For convenience. FIG. 1 (b) is a schematic enlarged view showing a step of setting the "alignment angle" and the "alignment axis angle" of the magnetization-easy axis of each magnetic material particle. Any place of the rare earth magnet M shown in Fig. 1 (a), for example, the quadrangular segment R shown in Fig. 1 (a) is enlarged and shown in Fig. 1 (b). The quadrangular segment R includes a plurality of magnet material particles P of more than 30, for example, 200 or 300. The larger the number of particles of the magnet material contained in the quadrangular segment, the higher the accuracy of the measurement, but even if it is 30 degrees, it can be measured with sufficient accuracy. Each magnet material particle P has an easy magnetization axis P-1. The easy-to-magnetize axis P-1 generally does not have a directivity, but becomes a vector having a directivity when the magnet material particles are added. In FIG. 1 (b), the magnetization is performed with a predetermined polarity in mind, and the arrow is shown to give directionality to the axis of easy magnetization.

As shown in FIG. 1 (b), the easy-to-magnetize axis P-1 of each of the magnetic material particles P is a "alignment angle" having an angle between the direction in which the easy-to-magnetize axis points and the reference line. In addition, among the "alignment angles" of the easy-to-magnetize axis P-1 of the magnetic material particles P in the quadrangular segment R shown in FIG. 1 (b), the most frequent alignment angle is taken as the "alignment axis angle" B .

(Alignment angle uneven angle)

Find the angle of the alignment axis at any of the quadrangular segments, and For all the particles of the magnet material existing in the segment, the difference in the alignment angle of the easy-to-magnetize axis will be the value of the angle expressed by the half-value width of the distribution of the difference in the alignment angle as the alignment angle. Both angles. FIG. 2 is a graph showing the steps for obtaining the misalignment angle of the alignment angle. In FIG. 2, the distribution of the difference Δθ in the alignment angle of the magnetization easy axis of each magnet material particle for the magnetization easy axis is represented by a curve C. The position where the cumulative frequency displayed on the vertical axis becomes the maximum is taken as 100%, and the value of the alignment angle difference Δθ whose cumulative frequency becomes 50% is the half-value width.

(Measurement of alignment angle)

The alignment angle system at the easy-to-magnetize axis P-1 of each magnet material particle P can be obtained by the "electron backscatter diffraction analysis method" (EBSD analysis method) based on a scanning electron microscope (SEM) image. As a device for this analysis, a scanning electron microscope equipped with an EBSD detector (AZtecHKL EBSD NordlysNano Integrated) manufactured by Oxford Instruments, and JSM-70001F or EDAX manufactured by Japan Electronics Co., Ltd. located in Akishima, Tokyo, Japan. Scanning electron microscope of Hikari High Speed EBSD Detector manufactured by the company, SUPRA40VP manufactured by ZEISS. In addition, as an entity that conducts EBSD analysis through external commissions, there are JFE Techno-Research Co., Ltd., located in Nihonbashi, Chuo-ku, Tokyo, Japan, and Japan Nitto Analysis Center, located in Ibaraki, Osaka, Japan. According to the EBSD analysis, the orientation angle and orientation axis angle of the magnetization-easy axis of the magnetic material particles existing in a specific segment can be obtained. Based on these values, Those with uneven alignment angles can also be obtained. Fig. 3 shows an example of the orientation of the axis of easy magnetization by the EBSD analysis method. Fig. 3 (a) is a perspective view showing the direction of the axis of the rare earth magnet, and Fig. 3 (b) shows the center and both ends through the same. An example of a pole figure obtained by EBSD analysis. In addition, FIG. 3 (c) shows the alignment axis angle of the cross section of the magnet along the A2 axis. The alignment angle system can divide the alignment vector of the easy-to-magnetize axis of the magnet material particles into components on a plane including the A1 axis and the A2 axis, and components on a plane including the A1 axis and the A3 axis. The A2 axis is in the width direction and the A1 axis is in the thickness direction. The center of FIG. 3 (b) shows the center of the magnet in the width direction, and the orientation of the axis of easy magnetization is slightly along the direction of the A1 axis. In contrast, the left diagram in FIG. 3 (b) shows the orientation of the easy-to-magnetize axis at the left end of the magnet in the width direction, and the upper-right direction is tilted from below to the plane along the A1-A2 axis. Similarly, the graph on the right in FIG. 3 (b) shows the orientation of the easy-to-magnetize axis at the right end of the magnet in the width direction, and the one tilted along the plane of the A1-axis and A2-axis from the bottom to the top-left direction. Such an alignment is shown in FIG. 3 (c) as an alignment vector.

(Crystal orientation map)

For each magnet material particle existing in an arbitrary segment, a graph showing an inclination angle of the axis of easy magnetization of the magnet material particle with respect to the axis perpendicular to the observation surface. This image can be created based on a scanning electron microscope (SEM) image.

(Ideal implementation)

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 4 is a cross-sectional view showing a sintered body 1 for forming a rare earth magnet according to an embodiment of the present invention. The sintered body 1 has an upper side 2 called a second surface and an lower side 3 called a first surface, and is orthogonal to the figure. A rectangular parallelepiped shape with a length in the direction of the paper surface. That is, the upper side 2 and the lower side 3 extend parallel to each other, and the interval between the upper side 2 and the lower side 3 becomes a thickness. In FIG. 4, the direction along the upper side 2 and the lower side 3 is the width direction, and the two end portions 4 and 5 define the width dimension.

An example of an electric motor in which a sintered body for forming a rare earth magnet and a permanent magnet formed from the sintered body are assembled is shown in FIG. 5 to FIG. 8. In FIG. 5 to FIG. 8, parts corresponding to the parts of the embodiment shown in FIG. 4 are shown with the same symbols as in FIG. 4. In any of the embodiments shown in FIG. 4 and the embodiments shown in FIGS. 5 to 8, the sintered body 1 for forming a rare earth magnet is used as a magnet material, and includes a Nd—Fe—B based magnet material. Typically, Nd-Fe-B-based magnet materials contain Nd at a ratio of 27 to 40% by weight, B at a ratio of 0.8 to 2% by weight, and Fe of electrolytic iron at a ratio of 60 to 75% by weight. This magnet material is for the purpose of improving magnetic properties, and contains a small amount of Dy, Tb, Co, Cu, Al, Si, Ga, Nb, V, Pr, Mo, Zr, Ta, Ti, W, Ag, Bi, Zn, Other elements such as Mg are also possible.

In the embodiment shown in FIG. 4, the sintered body 1 for forming a rare-earth magnet is integrally sintered to form the fine particles of the above-mentioned magnet material, and has the magnetism of the magnet material particles directed from the bottom 3 to the top 2 The orientation of the shaft is easily changed, and the orientation system of this magnetization is completely parallel to each other.

When referring to FIG. 5 (a), the fine particles of the above-mentioned magnet material are integrally sintered through the sintered body 1 for forming a magnet in this embodiment, which has upper sides 2 and lower sides 3 parallel to each other, and end faces on the left and right ends. 4, 5, and the end faces 4, 5 are different from the embodiment of FIG. 4 and are formed as inclined surfaces inclined to the upper side 2 and the lower side 3. The upper side 2 is an edge corresponding to the cross section of the second surface, and the lower side 3 is an edge corresponding to the cross section of the first surface. The inclination angle of the end faces 4, 5 is defined as the angle θ between the extension lines 4a, 5a of the end faces 4, 5 and the upper side 2. In an ideal form, the inclination angle θ is 45 ° or even 80 °, and more preferably 55 ° or even 80 °. As a result, the sintered body 1 for magnet formation is formed in the shape which has the width | variety cross section of the mesa shape which has the upper side 2 and is shorter than the lower side 3.

The sintered body 1 for magnet formation has a plurality of ranges of a central range 6 divided into a specific size and end ranges 7 and 8 on both end sides along the width direction of the upper side 2 and the lower side 3. In the central range 6, the magnetic material particles contained in the range 6 become the axis of easy magnetization, and the upper side 2 and the lower side 3 are aligned at substantially right angles in parallel and parallel in the thickness direction. In this regard, in the end range 7,8, the magnetization of the magnetic material particles contained in the range 7,8 is easy to magnetize. For the thickness direction, from bottom to top, the alignment direction is inclined to the direction of the central range 6, The inclination angle is an angle along the inclination angle θ of the end faces 4 and 5 in a position adjacent to the end faces 4 and 5, and a slightly right angle to the upper side 2 in a position adjacent to the central range 6. , Accompanied by self-adjacent to the end face The positions of 4, 5 are closer to the central range 6 and gradually become larger. Such an easy magnetization of the axis alignment is shown in FIG. 5 (a) by the arrow 9 for the parallel alignment of the center range 6 and the tilted alignment of the end ranges 7 and 8 by the arrow 10. Regarding the oblique alignment of the end ranges 7, 8 as another expression, the magnetization of the magnetic material particles contained in these ranges is easy to be axised from the intersection of the upper side 2 and the end faces 4, 5 toward the central portion, showing agglomeration. Orientation is performed in a specific range corresponding to the widthwise dimensions of the end ranges 7,8. As a result of this alignment, in the end ranges 7, 8 the density of the magnet material particles which are easily oriented to the axis of magnetization on the upper side 2 becomes higher than that in the center range 6. In an ideal form of the present invention, the ratio in the width direction of the upper side 2 of the central range 6, that is, the parallel length P, and the ratio L in the width direction of the upper side 2, that is, the parallelism ratio P / L becomes 0.05. It is even 0.8, more preferably 0.2 or 0.5, and the sizes of the central range 6 and the end ranges 7, 8 are determined.

The magnetization of the magnet material in the above-mentioned end range 7, 8 is easy to align the axis, and the end range 7 is exaggerated and shown in FIG. 5 (b). In FIG. 5 (b), each magnetization easy axis C of the magnet material particles is aligned in a portion adjacent to the end surface 4 along the end surface 4, and only the inclination angle θ of the end surface 4 is inclined. In addition, the tilt angle gradually increases as the end portion approaches the center portion. That is, the orientation system of the axis C of the magnetization particles of the magnetic material particles is aggregated from the lower side 3 toward the upper side 2, and the density of the magnet material particles directed to the magnetization axis C on the upper side 2 is compared to the case of parallel alignment. Becomes high.

Figure 6 is an enlarged display suitable for embedding via A cross-sectional view of a rotor core portion of an electric motor 20 using a rare-earth magnet formed when the sintered body 1 for forming a magnet whose axis is easy to be magnetized is magnetized. The rotor core 21 is such that the peripheral surface 21 a of the rotor core 21 faces the stator 23 through the air gap 22 and is rotatably disposed in the stator 23. The stator 23 includes a plurality of teeth 23a arranged at intervals in the circumferential direction, and a magnetic field coil 23b is wound around the teeth 23a. The above-mentioned air gap 22 is formed between the end surface of each tooth 23 a and the peripheral surface 21 a of the rotor core 21. The rotor core 21 is formed with a magnet insertion groove 24. This groove 24 has a linear central portion 24a, and an inclined portion 24b opposite to the central portion 24a. The inclined portion 24b extends in one direction from the peripheral surface 21a of the rotor core 21. As can be understood from FIG. 6, the inclined portion 24 b is located at a position close to the peripheral surface 21 a of the rotor core 21 at the end portion.

A state in which a rare-earth magnet 30 formed by magnetizing a sintered body 1 for forming a magnet having the above-mentioned easy-to-magnet orientation is inserted into the magnet insertion groove 24 of the rotor core 21 shown in FIG. 6.于 图 7。 In Figure 7. As shown in FIG. 7, the rare-earth permanent magnet 30 is inserted into the linear central portion 24 a of the magnet insertion slot 24 formed in the rotor core 21 with its upper side 2 facing outward, that is, on the stator 23 side. The two sides of the inserted magnet 30 are outside, and a part of the linear central portion 24a and the inclined portion 24b of the remaining groove 24 are provided as a gap portion. In this way, the entire electric motor 20 formed by inserting a permanent magnet into the slot 24 of the rotor core 21 is shown in a cross-sectional view in FIG. 8.

FIG. 9 shows the distribution of the magnetic flux density of the rare-earth permanent magnet 30 formed by the above embodiment. As shown in FIG. 9, the magnetic flux density D of the range 7 and 8 at both end portions of the magnet 30 is higher than the magnetic flux density E of the central range 6. Therefore, when the magnet 30 is embedded in the rotor core 21 of the electric motor 20 and operated, even if a magnetic flux from the stator 23 is generated at the end of the magnet 30, the reduction of the end of the magnet 30 can be suppressed. It is magnetic, and the end of the magnet 30 becomes a person with sufficient magnetic flux remaining after demagnetization, and a decrease in the output of the motor 20 is prevented.

[Manufacturing method of sintered body for forming rare earth permanent magnet]

Next, a manufacturing method for manufacturing a sintered body 1 for forming a rare earth magnet through the embodiment shown in FIG. 4 and the embodiments shown in FIG. 5 to FIG. 9 through one embodiment of the present invention will be described with reference to FIG. 10. Instructions. FIG. 10 is a schematic diagram showing a manufacturing process of the sintered body 1 for forming a permanent magnet through the above two embodiments.

First, an ingot of a magnetic material made of a Nd-Fe-B alloy with a specific fraction is produced by a casting method. Typically, Nd-Fe-B alloys used in neodymium magnets contain Fe in an amount of 30% by weight, electrolytic iron in an amount of 67% by weight, and Fe in an amount of 1.0% by weight. The composition of B. Next, this ingot was coarsely pulverized to a size of about 200 μm using a known method such as a masher or a pulverizer. Alternatively, it is also possible to dissolve the ingot, make a flake through a sheet casting method, and make a coarse powder by a hydrogen decomposition method. Coarse crushed The magnetic material particles 115 (see FIG. 10 (a)).

Next, the coarsely pulverized magnet material particles 115 are finely pulverized by a wet method using a bead mill 116 or a dry method using a jet mill. For example, in the fine pulverization using the wet method through the bead mill 116, the particle size of the coarsely pulverized magnet particles 115 in the solvent is, for example, 0.1 μm to 5.0 μm in a specific range, and the ideal average particle diameter is It is finely pulverized to 3 μm or less so that the magnet material particles are dispersed in a solvent (see FIG. 10 (b)). Thereafter, the magnet particles contained in the wet-pulverized solvent are taken out by means such as a vacuum drying method, and the dried magnet particles (not shown) are taken out. Here, the type of the solvent used for the pulverization is not particularly limited, and alcohols such as isopropanol, ethanol, and methanol, esters such as ethyl acetate, and lower hydrocarbons such as pentane and hexane can be used. , Organic solvents such as aromatics such as benzene, toluene, xylene, ketones, and mixtures thereof, or inorganic solvents such as liquefied argon, liquefied nitrogen, and liquefied helium. In this case, it is preferable to use a solvent that does not contain an oxygen atom in the solvent.

On the other hand, in the fine pulverization using the dry method via a jet mill, as the coarsely pulverized magnetic material particles 115, (a) the nitrogen content is 0.5% or less, and ideally substantially 0% nitrogen, Ar Gas, He gas and other inactive gases, or (b) Nitrogen with an oxygen content of 0.0001 or 0.5%, Ar gas, He gas and other inactive gases, through a jet mill The finely pulverized particles are fine particles having an average particle diameter in a specific range of 6.0 μm or less, for example, 0.7 μm to 5.0 μm. Here, the oxygen concentration of substantially 0% means that the oxygen concentration is completely 0% without limitation, and means that the surface of the fine powder contains only a small amount of It is also possible to oxidize the amount of oxygen of the coating level.

Next, the magnetic material particles finely pulverized by the bead mill 116 or the like are formed into a desired shape. For the formation of the magnetic material particles, a mixture of the magnetic material particles 115 and the adhesive made of the resin material, which are finely pulverized as described above, is prepared, that is, a composite material. The resin used as the adhesive is preferably a polymer that does not contain an oxygen atom in the structure and has a depolymerizable property. In addition, as described later, in order to make the composite material of the magnet particles and the adhesive as a remnant of the composite material generated when the composite material is formed into a desired shape and to be softened by heating the composite material, For magnetic field alignment, it is better to use thermoplastic resin as the resin material. Specifically, a polymer formed from one or more polymers or copolymers formed from a monomer represented by the following general formula (1) is preferably used.

(但，R₁及R₂係表示氫原子，低級烷基，苯基或乙烯基)

(However, R ₁ and R ₂ represent a hydrogen atom, a lower alkyl group, a phenyl group or a vinyl group.)

Polymers meeting the above conditions are, for example, polyisobutylene (PIB) having a polymer of isobutylene, and polyisoprene (isoprene rubber, IR) having a polymer of isoprene, 1,3- Polybutadiene (butadiene rubber, BR), a polymer of butadiene, polystyrene, a polymer of styrene, and a styrene-isoprene copolymer of a copolymer of styrene and isoprene (SIS), isobutylene and isoprene copolymer butyl rubber (IIR), styrene and butadiene copolymer styrene-butadiene segment copolymer (SBS), styrene and ethylene, butadiene Diene copolymers styrene-ethylene-butadiene-styrene copolymers (SEBS), styrene and ethylene, propylene copolymers styrene-ethylene-propylene-styrene copolymer (SEPS), ethylene and Ethylene-propylene copolymer (EPM) of propylene copolymer, 2-methyl-1-pentene of EPDM, 2-methyl-1-pentene copolymer of ethylene, propylene copolymerizing diene monomer at the same time Olefin polymer resin, 2-methyl-1-butene polymer resin of 2-methyl-1-butene polymer, and the like. In addition, the resin used for the adhesive is a polymer or copolymer (for example, polybutyl methacrylate or polymethyl methacrylate) containing a small amount of monomers containing oxygen and nitrogen atoms. can. In addition, a monomer that does not meet the general formula (1) may be copolymerized as a part. In this case, the object of the invention can also be achieved.

However, as the resin used for the adhesive, a thermoplastic resin softened at 250 ° C or lower is used for proper magnetic field alignment, and more specifically, a thermoplastic having a glass transition point or a flow start temperature of 250 ° C or lower Resin is preferred.

In order to disperse the magnet material particles in the thermoplastic resin, an appropriate amount of a dispersant (alignment lubricant) is preferably added. As dispersant, alcohols, carboxylic acids, ketones, ethers, esters, amines, imines, amidines, amidines, cyanides, phosphorous functional groups, sulfonic acids, unsaturated bonds with double or triple bonds, etc. Of the compounds and the liquid saturated hydrocarbon compound, at least one is preferably added. A plurality of these substances may be mixed and used. And, as As will be described later, when a magnetic field is applied to a mixture of a magnet material particle and an adhesive, that is, a composite material, the magnetic material is aligned to the magnetic material, and the magnetic field alignment treatment is performed while the mixture is heated while the adhesive component is softened.

When an adhesive that satisfies the above conditions is used as an adhesive mixed with the magnetic material particles, it becomes the amount of carbon and oxygen that can remain in the sintered body for forming a rare earth permanent magnet after sintering. Specifically, the amount of carbon remaining in the sintered body for magnet formation after sintering can be 2,000 ppm or less, and more preferably 1,000 ppm or less. The amount of oxygen remaining in the sintered body for magnet formation after sintering can be 5,000 ppm or less, and more preferably 2000 ppm or less.

The addition amount of the adhesive is in the case of forming a slurry or heating and melting a composite material. The thickness accuracy of the formed body obtained as a result of the molding is increased, and it is suitable for filling the gaps between the particles of the magnet material appropriately. the amount. For example, for the total amount of the magnetic material particles and the adhesive, the ratio of the adhesive is 1 wt% to 40 wt%, more preferably 2 wt% to 30 wt%, and still more preferably 3 wt% to 20 wt%.

In the following embodiments, in the state where the composite material is once formed into a shape other than the product shape, a parallel magnetic field is applied to align the magnetic material particles in the magnetic field. The embodiments shown in FIG. 5 to FIG. 9 In the case of this, the molded body is further formed into a desired product shape, and then subjected to a sintering treatment, and is used as, for example, a sintered magnet having a desired product shape in a mesa shape as shown in FIG. 5 (a). In particular, in the following embodiment, the composite material 117, which is a mixture of the particles of the magnetic material and the adhesive, is once formed into a sheet shape. The green compact (hereinafter referred to as "green sheet") is used as the shape of the green compact for alignment processing. In the case where the composite material is specifically formed into a sheet shape, a hot melt coater formed by heating the composite material 117, such as a mixture of magnet material particles and an adhesive, into a sheet shape, or A method of heating and pressing the composite material 117 of a mixture of agents into a molding mold, or forming a sheet-like slurry by coating a slurry containing magnet material particles, an adhesive, and an organic solvent on a substrate. Formers such as painters.

Hereinafter, a green sheet molding using a hot melt coater will be described in particular, but the present invention is not limited to such a specific molding method. For example, when the composite material 117 is put into a molding mold and heated to room temperature to 300 ° C., and it is pressurized at a pressure of 0.1 to 100 MPa, the molding may be performed. In this case, more specifically, it is possible to adopt a method in which the composite material 117 heated to a temperature at which softening is performed, and the injection pressure is added to the mold to be filled.

As described above, when the magnetic material particles that are finely pulverized by a bead mill 116 or the like are mixed with the adhesive, a clay-like mixture of the magnetic material particles and the adhesive is produced, that is, a composite material 117. Here, as the adhesive, a mixture of a resin and a dispersant can be used as described above. For example, as the resin material, it is preferable to use a thermoplastic resin made of a polymer that does not contain oxygen atoms in the structure and has depolymerization properties. On the other hand, it has alcohol, carboxylic acid, ketone, and ether as a dispersant. , Esters, amines, imines, amines, amines, cyanamides, cyanide, phosphorus-based functional groups, sulfonic acids, compounds with unsaturated bonds such as double or triple bonds, at least one Individual is better. In addition, the amount of the adhesive is the ratio of the adhesive to the total amount of the magnetic material particles of the composite material 117 and the adhesive as described above. The ratio is 1 wt% to 40 wt%, more preferably 2 wt% or even 30 wt%, and more preferably 3 wt% or even 20 wt%.

Here, the amount of the dispersant added is preferably determined according to the particle diameter of the magnetic material particles, and it is recommended that the smaller the particle diameter of the magnetic material particles, the larger the amount of the additive be added. The specific addition amount is 0.1 parts by weight to 10 parts by weight, and more preferably 0.3 parts by weight or 8 parts by weight, for 100 parts by weight of the magnet material particles. In the case where the amount of addition is small, the dispersion effect is small, and the alignment may be reduced. In addition, when the amount of addition is excessive, there is a concern that the particles of the magnetic material may be contaminated. The dispersant added to the magnet material particles adheres to the surface of the magnet material particles, disperses the magnet material particles to give a clay-like mixture, and acts to assist the rotation of the magnet material particles in an alignment process of a magnetic field described later. . As a result, alignment can be easily performed when a magnetic field is applied, and the axis direction of the magnetization of the magnet particles can be made to be almost the same, that is, the alignment degree can be improved. In particular, when the adhesive is mixed with the particles of the magnet material, the presence of the adhesive on the surface of the particles causes the frictional force during magnetic field alignment treatment to increase. Therefore, the alignment of the particles may be reduced, and a dispersant is added. The effect is even higher.

The mixing of the magnetic material particles and the adhesive is preferably performed on an environmental basis made of an inert gas such as nitrogen, Ar gas, He gas, or the like. The mixing of the magnetic material particles and the adhesive is, for example, putting the magnetic material particles and the adhesive into a mixer, and by mixing them with a mixer, get on. In this case, heating and stirring may be performed in order to promote kneadability. Furthermore, it is preferable that the mixing of the magnet material particles and the adhesive is performed in an environment made of an inert gas such as nitrogen, Ar gas, and He gas. In addition, particularly in the case of pulverizing the magnetic material particles by the wet method, the magnetic particles are not taken out from the solvent used for pulverization, and an adhesive is added to the solvent to knead it, and then the solvent is volatilized to obtain the obtained product. The composite material 117 may be used.

Then, when the composite material 117 is formed into a sheet shape, the aforementioned green sheet is formed. In the case where a hot-melt coater is used, the composite material 117 is melted by heating the composite material 117 to form a fluid state, and then the coater is applied to the support base material 118. Thereafter, the composite material 117 is solidified by exothermic heat, and a long thin sheet-like green sheet 119 is formed on the support substrate 118 (see FIG. 10 (d)). In this case, the temperature when the molten composite material 117 is heated varies depending on the type or amount of the adhesive used, but it is usually 50 ° C to 300 ° C. However, it is necessary to make the temperature higher than the flow start temperature of the used adhesive. However, in the case of using a slurry coater, the magnet material particles and the adhesive are dispersed in a large amount of a solvent, and any optional additive that promotes the orientation is dispersed, so that the slurry coater is coated on the supporting substrate 118. Thereafter, when the solvent is volatilized by drying, a long thin sheet-like green sheet 119 is formed on the support substrate 118.

Here, the coating method for melting the composite material 117 is preferably a method that is superior in layer thickness control, such as a seam casting method or a rolling method. Especially for achieving high thickness accuracy, especially It is better to use a die coating method or a spot coating method in which the layer thickness is excellent, and a layer with a high accuracy can be coated on the substrate surface. For example, in the seam casting method, the composite material 117 which is heated and has fluidity is pressure-fed via a gear pump to a die, and is sprayed out from the die to perform coating. In addition, in the rolling method, the nip gap of the two heated rollers is fed in to control the amount of the composite material 117, and the roller is rotated while the coating material is melted by the heat of the roller on the supporting substrate 118 The composite material 117. As the supporting substrate 118, for example, a silicone-treated polyester film is preferably used. Furthermore, when using a defoaming agent or heating and vacuum defoaming, it is preferable to perform a defoaming treatment sufficiently without leaving bubbles in the layer of the composite material 117 that is spread by coating. Alternatively, instead of coating on the supporting substrate 118, the molten composite material 117 is formed into a sheet shape by extrusion molding or injection molding, and at the same time it is pressed onto the supporting substrate 118, A green sheet 119 is formed on the base material 118.

In the embodiment shown in FIG. 10, the coating of the composite material 117 is performed using a seam mold 120. In the process of forming the green sheet 119 through the seam casting method, the thickness of the green sheet 119 after the coating process is actually measured, and when the feedback control based on the measured value is adjusted, the thickness of the seam mold 120 and the supporting substrate 118 is adjusted. The nip gap is better. In this case, those who minimize the variation in the amount of the fluid composite material 117 supplied to the seam casting mold 120, for example, suppress the variation to ± 0.1% or less, and also minimize the variation in the coating speed, such as It is better to suppress the change below ± 0.1%. With such control, the green sheet 119 can be made Improved thickness accuracy. However, the thickness accuracy of the formed green sheet 119 is, for example, a design value of 1 mm, within ± 10%, more preferably within ± 3%, and more preferably within ± 1%. In the rolling method, a person who feeds back the suppressor's rolling condition based on the actual measured value similarly can suppress the thickness of the composite material 117 to be transferred to the supporting substrate 118.

The thickness of the green sheet 119 is preferably set to a range of 0.05 mm to 20 mm. When the thickness is made thinner than 0.05 mm, in order to achieve the necessary thickness of the magnet, it is necessary to make it a multilayer product and reduce productivity.

Next, from the green sheet 119 formed on the support base material 118 through the above-mentioned hot-melt coating process, a processing sheet 123 cut out to a size corresponding to a desired magnet size is prepared. This processing sheet 123 corresponds to the shape of the desired magnet in the embodiment shown in FIG. 4. However, in the case of the embodiment shown in FIGS. 5 to 8, it corresponds to the first molded body. The shape is different from the shape of the desired magnet. When described in detail, in the embodiment shown in FIG. 5 to FIG. 8, the processing sheet 123 of the first formed body is applied with a parallel magnetic field to the processing sheet 123, and the magnets contained in the processing sheet 123 are included. The easy-to-magnetize axes of the material particles are aligned in parallel, and then, when the processing sheet 123 is deformed to have a desired magnet shape, the magnet having the desired shape is formed into a desired shape. Its magnetization is easy to align with the shape of the shaft.

In the embodiment shown in FIG. 4, the self-forming green sheet 119 The cut sheet for processing is a rectangular parallelepiped shape as shown in FIG. 4. The actual size of the cut sheet is estimated to be a reduction in the size of the sintering process described later, and is set to a specific magnet size obtained after the sintering process. In contrast, in the embodiment shown in FIG. 5 to FIG. 9, as shown in FIG. 11 (a), the processing sheet 123 of the first formed body has a rare-earth permanent magnet corresponding to the mesa-shaped cross section of the final product. The cross-sectional shape of the linear range 6a of the width direction length of the central range 6 of the sintered compact 1 for formation and the arc-shaped ranges 7a and 8a continuous at both ends of the linear range 6a. The sheet 123 for processing is based on the length dimension of the paper surface in the right angle direction. The size of the cross section and the width dimension are estimated to be reduced in the sintering process described later, and are set to have a specific magnet size obtained after the sintering process. .

In the case of the embodiment shown in FIG. 4, for the processing sheet cut out from the green sheet 119, a parallel external magnetic field is applied in a right-angle direction from the outer side of the lower side 3 to the lower side 3. As a result of the application of a parallel external magnetic field, the axis of magnetization of the magnetic material particles existing in the processing sheet is easily aligned as indicated by arrow 9 in FIG. This alignment is aligned in parallel. When the green sheet 119 is configured as described above, and when a magnetic field is applied by heating as described later, it becomes a person who can make the magnetization easy axis alignment with high accuracy.

In the processing sheet 123 shown in FIG. 11 (a), a parallel magnetic field 121 is also applied in a direction that becomes a right angle on the surface of the linear range 6a. When the magnetic field is applied, the easy magnetization axis of the magnetic material particles contained in the processing sheet 123 is aligned in parallel with the direction of the magnetic field, that is, the thickness direction, as shown by arrow 122 in FIG. 11 (a).

In this process, in any of the embodiments shown in FIG. 4 and the embodiments shown in FIGS. 5 to 9, the processing sheet is stored in a magnetic field having a die hole corresponding to the shape of the processing sheet. In the application mold (not shown), the adhesive contained in the processing sheet is softened by heating. As a result, the particles of the magnet material can be rotated in the adhesive, and can be easily magnetized, and can be aligned in a direction along the parallel magnetic field 121 with high accuracy.

Here, the temperature and time of the sheet for heating processing vary depending on the type and amount of the adhesive used, but they are 40 to 250 ° C and 0.1 to 60 minutes. In any case, in order to soften the adhesive in the processing sheet, the heating temperature must be a temperature above the glass transition point or flow start temperature of the adhesive used. The means for heating the sheet for processing are, for example, a method of heating via a hot plate, or a method of using a heat medium such as silicone oil as a heat source. The intensity of the magnetic field applied to the magnetic field can be 5,000 [Oe] ~ 150000 [Oe], and the ideal system can be 10000 [Oe] ~ 120000 [Oe]. As a result, the axis of easy magnetization of crystals of the magnetic material particles contained in the processing sheet is indicated by the symbol 9 in FIG. 4 or the symbol 122 in FIG. 11 (a) in the direction along the parallel magnetic field 121 , Aligned in parallel. In this magnetic field application process, it is a component which applies a magnetic field to several processing sheets simultaneously. For this purpose, for example, a mold having a plurality of mold holes may be used, or a plurality of molds may be arranged while applying a parallel magnetic field 121 at the same time. The process of applying a magnetic field to the processing sheet may be performed concurrently with the heating process. After the heating process is performed, the process may be performed before the adhesive in the processing sheet is solidified. can.

Next, in the case of the embodiment shown in FIG. 4, an external magnetic field is applied to parallelly align the magnetization particles of the magnetic material particles, and the processing sheet is directly fed to a calcination process and a sintering process described later. In this regard, in the case of the embodiment shown in FIG. 5 to FIG. 9, the magnetic field application process shown in FIG. 11 (a) is used to process the axis of easy magnetization of the magnet material particles in parallel as shown by arrow 122 as shown by arrow 122. The sheet 123 is taken out from the mold for applying a magnetic field, and transferred to the final molding mold 126 having a table-shaped mold hole 124 having a slender length dimension as shown in FIG. 11 (b) (c), and has a shape corresponding to the mold hole 124. The male mold 127 with a convex shape presses the processing sheet 123 in the die hole 124, so that the arc-shaped ranges 7a and 8a at both ends of the processing sheet 123 are continuous and linear in the center of the linear range. It is deformed at 6a and formed into a sintering treatment sheet 125 as shown in FIG. 11 (b). The sintering treatment sheet 125 corresponds to a second formed body.

By this forming, the arc-shaped ranges 7a, 8a at both ends of the processing sheet 123 series are continuous linear shapes for the central linear range 6a, and inclined surfaces 125a, 125b are formed at both ends. , And form an elongated mesa shape. In the sintering processing sheet 125 formed through this forming process, the magnetization of the magnet material particles in the linear region 6a in the center is easily maintained, and the axis system is maintained in a parallel alignment state parallel to the thickness direction. In the end ranges 7a and 8a, the upwardly convex shape is deformed into a linear shape that is continuous with the linear range in the center. As shown in Fig. 11 (b), the magnetization is easy to form a shaft. It is an alignment gathered on each corresponding range.

In this way, the sintering processing sheet 125 after the alignment of the easy-to-magnetize axis of the magnet material particles is transferred to the calcination process. In the following description, the embodiment shown in FIG. 4 also includes a processing method sheet which is transferred to a calcination process after undergoing magnetic field alignment process. The sheet subjected to the calcination process and the sintering process is referred to as "for sintering process" Sheet 125 ". In any of the embodiment shown in FIG. 4 and the embodiments shown in FIGS. 5 to 9, the calcination process in the calcination process is at atmospheric pressure, or the atmospheric pressure is high or low, for example, The non-oxidizing environment adjusted to 0.1 MPa to 70 MPa, ideally 1.0 Pa to 1.0 MPa, is subjected to a calcination treatment for several hours to several tens of hours, for example, 5 hours, by maintaining the decomposition temperature at the adhesive. In this process, it is recommended to use a hydrogen environment or a mixed gas environment of hydrogen and an inert gas. When the calcination process is performed on the basis of a hydrogen environment, the supply amount of hydrogen during the calcination is, for example, 5 L / min. When the calcination treatment is performed, the organic compound contained in the adhesive is decomposed into monomers through a depolymerization reaction and other reactions, and it can be dispersed and removed. That is, it becomes a decarburization processer who performs the process which reduces the amount of carbon which remains in the sintering process sheet 125. The calcination treatment is preferably performed under the condition that the amount of carbon remaining in the sintering treatment sheet 125 is 2000 ppm or less, and more preferably 1000 ppm or less. As a result, a person who can sinter the entire sintering treatment sheet 125 densely after the sintering treatment becomes a person who can suppress the reduction of the residual magnetic flux density and the coercive force. However, as for the pressure conditions when the above-mentioned calcination treatment is performed, the atmospheric pressure is In the case of high pressure, the pressure is preferably 15 MPa or less. Here, when the pressurization condition is a pressure that is high as the atmospheric pressure, and more specifically 0.2 MPa or more, the effect of reducing the amount of residual carbon is particularly expected.

The decomposition temperature of the adhesive varies depending on the type of the adhesive, but the temperature of the calcination treatment may be 200 ° C or 900 ° C, more preferably 300 ° C or 500 ° C, for example, 450 ° C.

In the above-mentioned calcination treatment, it is better to reduce the temperature increase rate as compared with the sintering treatment of general rare earth magnets. Specifically, when a temperature increase rate is set to 2 ° C / min or less, for example, 1.5 ° C / min, a desired result can be obtained. Accordingly, in the case of the calcination process, as shown in FIG. 12, the temperature is raised at a specific heating rate of 2 ° C./min or less, and reaches a preset temperature, that is, the temperature at which the adhesive decomposes, This set temperature is maintained for several hours or even tens of hours to perform a calcination treatment. As described above, when the heating rate is reduced during the calcination process, the carbon in the sintering treatment sheet 125 is not removed in a hurry, but is removed stepwise, so that it can be left to a sufficient level. The amount of carbon decreases and the density of the sintered body for forming a permanent magnet after sintering increases. That is, by reducing the amount of residual carbon, the gap in the permanent magnet can be reduced. As described above, if the heating rate is about 2 ° C./min, the density of the sintered body for forming a permanent magnet after sintering can be 98% or more, for example, 7.40 g / cm ³ or more, and it can be expected to be used in magnetized magnets. Achieving high magnet characteristics.

Next, a sintering process is performed to sinter the sintering processing sheet 125 which has been calcined through the calcination process. Can also be used as a sintering system In the vacuum-free sintering method, in the embodiment described here, the sintering processing sheet 125 is used to press the sintering processing sheet 125 on one axis in a direction perpendicular to the paper surface of FIG. 4 or FIG. 11. It is preferable to perform uniaxial pressure sintering in the state of the longitudinal direction. In this method, in the case of the embodiment shown in FIG. 4, in a sintering mold (not shown) having a rectangular die hole as shown in FIG. 4, for the embodiment shown in FIGS. 5 to 9 In this case, the sintering molds (not shown) each having a mold hole having the same mesa-shaped cross section as shown in FIG. 11 (b) with the symbol "124" are filled with sintering treatment sheets 125 and the mold is closed. The longitudinal direction of the sintering processing sheet 125 which is pressed in a direction perpendicular to the paper surface of FIG. 4 or FIG. 11 is simultaneously sintered. Regarding the case of the embodiment shown in FIG. 5 to FIG. 9, when a detailed description is given, a rare-earth permanent magnet formed by the self-sintering processing sheet 125 is used and stored in the magnet insertion groove 24 shown in FIG. 6. The sintering is performed in a direction that is the same direction as the axial direction of the rotor core 21, and the sintering treatment sheet 125 is pressed in the longitudinal direction to perform sintering. In any of the embodiments, as the pressure sintering technology, for example, a known technique such as hot-pressing sintering, hot-pressurization (HIP) sintering, ultra-high pressure synthetic sintering, gas pressure sintering, or discharge plasma (SPS) sintering is used. Either can be used. Particularly, it is preferable to use hot-pressing sintering that can be pressed in one axis direction. However, in the case of sintering by hot-press sintering, the pressurizing pressure is, for example, 0.01 MPa to 100 MPa, a vacuum environment of several Pa or less, to 900 ° C. to 1000 ° C., for example, 940 ° C., at 3 ° C./min. ~ 30 ° C / min, for example, a temperature increase rate of 10 ° C / min, to increase the temperature, and thereafter, the rate of change every 10 seconds in the direction of pressure becomes 0 It is better to keep it so far. This holding time is usually about 5 minutes. Then, it was cooled, and it heated up to 300 degreeC-1000 degreeC again for 2 hours, and maintained the heat processing of its temperature. As a result of the sintering process, the sintered body 1 for forming a rare earth permanent magnet of the present invention is produced from the sintering process sheet 125. As described above, if the uniaxial pressure sintering method is performed by sintering the sintering processing sheet 125 in the longitudinal direction, it is possible to suppress the misalignment of the axis of the magnet material particles easily imparted to the sintering processing sheet 125. At this sintering stage, almost all the resin material in the sintering processing sheet 125 is evapotranspiration, and the amount of residual resin is a very small amount structure even if it exists.

However, the sintered resin particles are sintered with each other to form a sintered body. Typically, after the sintering process, among the magnet material particles, the rare earth rich phase with a high rare earth concentration is melted, and the voids existing between the magnet material particles are buried, and at the same time, a R2Fe14B composition is formed (the R system contains yttrium) The rare earth element) is a dense sintered body formed by the rare earth-rich phase.

In the case of the embodiment shown in FIGS. 5 to 9, the sintered body 1 for forming a rare-earth permanent magnet is inserted into the magnet insertion groove 24 of the rotor core 21 shown in FIG. 2 and is inserted in a non-magnetized state. Thereafter, the rare earth permanent magnet forming sintered body 1 inserted into the groove 24 is magnetized along the easy-to-magnetize axis of the magnetic material particles contained therein, that is, the C axis. Specifically, the sintered bodies 1 for forming a plurality of rare-earth permanent magnets that are inserted into the plurality of slots 24 of the rotor core 21 interact with each other along the circumferential direction of the rotor core 21. The ground is arranged with N pole and S pole for magnetization. As a result, a permanent magnet 1 can be manufactured. However, as for the magnetization of the sintered body 1 for forming a rare earth-based permanent magnet, any one of known means such as a magnetized coil, a magnetized yoke, or a capacitive magnetized power supply device can be used. The sintered body 1 for forming a rare-earth permanent magnet may be magnetized before being inserted into the groove 24. As the rare-earth permanent magnet, the magnetized magnet may be inserted into the groove 24.

According to the method for manufacturing a sintered body for forming a rare earth permanent magnet as described above, a composite material including a mixture of magnetic material particles and an adhesive is formed, and a parallel magnetic field is applied from the outside by heating to a temperature exceeding the softening point of the composite material. When processing a sheet, it becomes possible to align the axis of magnetization easily in a desired direction with high accuracy. Therefore, it is possible to prevent unevenness in the alignment direction and improve the performance of the magnet. In addition, because of the mixture of molding and adhesive, compared with the case of using powder molding, there is no one who rotates the magnet particles after the alignment, and it becomes a person who can improve the alignment. For example, when a magnetic field is applied to a composite material of a mixture of magnetic material particles and an adhesive, and the alignment method is performed, the number of windings of the winding wire through a current generated for the magnetic field can be appropriately increased. The strength of the magnetic field during magnetic field alignment and the application of a long-term magnetic field to the static magnetic field make it possible to achieve a high degree of alignment with few variations. In addition, as shown in FIG. 5 to FIG. 9, when the alignment direction is corrected after the alignment, it becomes a person who can achieve high alignment and ensure a high alignment degree with less unevenness.

In this way, it is possible to achieve a high degree of alignment with few variations. The reduction in unevenness associated with shrinkage through sintering. Accordingly, uniformity of the shape of the sintered product can be ensured. As a result, the burden on the external shape processing after sintering is reduced, and the stability of mass production can be expected to be greatly improved. In addition, in the process of magnetic field alignment, when a magnetic field is applied to a composite material of a mixture of magnet particles and an adhesive, in the case of the embodiment shown in FIG. 5 to FIG. The material is transformed into a final shape of the molded body, and the direction of the axis of easy magnetization is manipulated to perform magnetic field alignment. Accordingly, when the composite material is once subjected to magnetic field alignment through deformation, it becomes an alignment direction that can be corrected, and is oriented toward the range of the object to be demagnetized so that the axis of easy magnetization is appropriately gathered. As a result, even if a complicated alignment is provided, it becomes an alignment that can achieve a high degree of accuracy and achieve a small number of variations.

[Example]

Examples of the method of the present invention will be described below.

In the examples described below, materials having the manufacturing numbers shown in Table 1 below were used.

[Example 1]

As Example 1, a sintered body for forming a rare-earth magnet having a shape shown in FIG. 4 was prepared by the steps described below.

<Coarse crushing>

The alloy composition A (Nd: 27.00wt%, Pr: 4.60wt%, B: 1.00wt%, Ga: 0.10wt%, Nb: 0.2wt%, Co: 2.0wt%, Cu) : 0.10% by weight, Fe in the residual portion, and other unavoidable impurities), hydrogen is absorbed at room temperature, and maintained at 0.85 MPa for one day. Then, while cooling with liquefied Ar, and pulverizing by hydrogen while maintaining at 0.2 MPa for one day.

<Fine crush>

100 parts by weight of the coarsely pulverized alloy coarse powder was mixed with 1 part by weight of methyl hexanoate, and then pulverized by a helium jet mill pulverizer (device name: PJM-80HE, manufactured by NPK). The collection system of the pulverized alloy particles is separated and recovered through a circulation method to remove ultrafine powder. The feed rate during pulverization was taken as 1 kg / h, the introduction pressure of He gas was 0.6 MPa, the flow rate was 1.3 m ³ / min, the oxygen concentration was 1 ppm or less, and the dew point was -75 ° C or less. The average particle diameter of the obtained magnetic material particles was 1.1 μm.

<Knead>

For 100 parts by weight of the pulverized alloy particles, 1.7 parts by weight of 1-octadecene, 4.3 parts by weight of 1-octadecene, and toluene solution (8% by weight) of 62.5 parts by weight of polyisobutylene (PIB) B150 are added. ) The mixer (device name: TX-0.5, manufactured by Inoue Seisakusho) was heated and stirred at 60 ° C for 1 hour. After toluene distillation, kneading was performed under vacuum for 2 hours to prepare a clay-like composite material.

<Magnetic field alignment>

This composite material was filled and filled with a stainless steel (SUS) mold having mold holes with a width of 50 mm, a length of 37 mm, and a thickness of 3 mm, and then passed through a superconducting solenoid coil (device name: JMTD-12T100, manufactured by JASTEC), An alignment process is performed by applying a parallel magnetic field from the outside. The alignment was performed for 10 minutes based on the conditions of an external magnetic field strength of 7T and an alignment processing temperature of 80 ° C. The external magnetic field is applied parallel to the thickness direction of the die hole. After maintaining the temperature at the alignment treatment, the coil was taken out from the solenoid coil, and then subjected to a demagnetization treatment. The demagnetization treatment is performed at a time when the intensity is changed from -0.2T to + 0.18T, and further to -0.16T, and is gradually reduced to a zero magnetic field.

<Cautering (decarburization) process>

For the composite material after the alignment treatment, decarburization treatment is performed under a hydrogen pressure environment of 0.8Mpa. In this process, the temperature was raised from room temperature to 480 ° C at a temperature increase rate of 0.95 ° C / min, and the temperature was maintained at 480 ° C for 2 hours. The hydrogen flow rate at this time is 2 ~ 3L / min.

<Sintered>

After the decarburization treatment, under a vacuum environment, at a heating rate of 8 The temperature was raised to 980 ° C / min, and sintering was performed while maintaining the temperature for 2 hours.

<Annealing>

The obtained sintered body was heated at room temperature to 500 ° C. for 0.5 hour, and then maintained at 500 ° C. for 1 hour, and then annealed by quenching to obtain a sintered body for forming a rare earth magnet.

[Example 2]

Except changing the conditions described in Tables 2 to 4, the same operation as in Example 1 was performed to obtain a sintered body for forming a rare earth magnet.

Here, in Example 2 in which the 1-octene treatment is described, after pulverizing by a jet mill and before mixing the magnet material particles and the adhesive composition, 40 weight is added to 100 parts by weight of the magnet material particles. Parts of 1-octene were stirred at 60 ° C. for 1 hour via a mixer (device name: TX-0.5, manufactured by Inoue Seisakusho, Ltd.), and 1-octene and its reactants were vacuum-distilled to perform dehydrogenation treatment of magnetic powder.

<Sintered particle diameter>

The sintered particle diameter of the obtained sintered body for forming a rare earth magnet is obtained by surface-treating the surface of the sintered body through SiC paper grinding, polishing, and grinding, and then passing through an EBSD detector (AZtecHKL EBSD NordlysNano Integrated, An SEM (device name: JSM-7001F, manufactured by Japan Electronics Co., Ltd.), or a scanning electron micromirror (SUPRA40VP, manufactured by ZEISS Corporation) equipped with an EBSD detector (Hikari High Speed EBSD Detector) manufactured by EDAX, was analyzed. The viewing angle is set to at least 200 particles, and the pitch is set to 0.1 to 1 μm.

The analysis data is analyzed by Chanel5 (manufactured by Oxford Instruments) or OIM analysis software ver5.2 (manufactured by EDAX), and the grain boundary is determined as the grain boundary where the deviation angle of the crystal orientation is 2 ° or more Layer for data processing. Only the main phase is extracted, and the average value of the number of circles corresponding to the diameter is taken as the diameter of the sintered particles.

<Evaluation of magnetic properties>

Each of the obtained sintered bodies was ground, and a BH tracker (TRF-5BH-25, manufactured by Toyo Industries, Japan) was used to measure the residual magnetic flux density (Br), the _angularity (H _k / H _cj ), Magnetic energy product (BH) _max .

<Measurement of misalignment angle (half-width of △ θ)>

The orientation angle of the obtained sintered body was obtained by surface-treating the surface of the sintered body through SiC paper grinding, polishing, and grinding, and then passing through an SEM equipped with an EBSD detector (AZtecHKL EBSD Nordlys Nano Integrated, Oxford Instruments). (JSM-7001F, made by Japan Electronics), or a scanning electron microscopy (SUPRA40VP made by ZEISS) with an EBSD detector (Hikari High Speed EBSD Detector) made by EDAX. However, the analysis of EBSD was performed at a viewing angle of 35 μm with a pitch of 0.2 μm. In order to improve the accuracy of the analysis, at least 30 sintered particles were placed in the analysis.

An EBSD analysis is used to create a pole diagram as shown in Figure 3 (b). In this pole diagram, the C-axis (001) is oriented in the direction of the highest frequency to create an alignment vector at its analysis point.

Based on the operation of Chanel5 (manufactured by Oxford Instruments) of the analysis software, the above-mentioned alignment vector is prepared to be a pole figure that is corrected to become the center of the pole figure (in the direction of 0 °), and then calculated from the 0 ° direction in pixel units. C axis (001) offset angle, the cumulative ratio of the frequency of the offset angle from 90 ° to 0 °, is plotted on a chart, The cumulative ratio becomes an angle of 50% to make the "alignment angle unevenness angle (the half-value width of Δθ)".

As comparative examples, the characteristics of the rare-earth magnets (Comparative Examples 1 and 2) described in Non-Patent Document 1 and the rare-earth magnets (Comparative Example 3) described in Japanese Patent Laid-Open No. 2001-210508 (Patent Document 10) were investigated. . The results are shown in Table 6. From Table 6, it was confirmed that the magnet described in Non-Patent Document 1 is added to the residual magnetic flux density Br. Even at the maximum magnetic energy product (BH) _max , there is a difference in the superiority as a magnetic characteristic. By. In addition, the magnets described in Patent Application Document 10 also recognize that the maximum magnetic energy product (BH) _max has a superiority as a magnetic characteristic. However, there is no description of the residual magnetic flux density Br in patent application range document 10 series.

In Examples 1 and 2, the half-value width of Δθ, which is an index of the misalignment angle of the alignment angle, was about 8 °, and a rare-earth sintered magnet having a very small variation in the alignment angle was obtained. As a result, as a result of suppressing the uneven angle of the alignment angle, the residual magnetic flux density Br is increased, and (BH) _{max, which is} an index of the energy that can be taken out of the magnet, is also increased. Incidentally, the rare-earth sintered magnet system Br described in Non-Patent Document 1 is 1.43T and (BH) _max is 49.0MGOe, and the magnet system obtained through the present invention can be confirmed to have a magnet that is considered to have the highest performance in the past. Those with superior characteristics.

Claims (5)

A sintered body for forming a rare-earth magnet is a sintered body for forming a rare-earth magnet having a structure including a rare-earth substance and being integrally sintered, each of which has a plurality of magnet material particles having an easy-to-magnetize axis, and is characterized in that The length dimension in the longitudinal direction, and the thickness dimension in the thickness direction between the first surface and the second surface in a cross section perpendicular to the transverse direction of the aforementioned longitudinal direction, and the width in the width direction orthogonal to the aforementioned thickness direction. The three-dimensional shape of the size is located at any position in the plane including the thickness direction and the width direction, and each of the magnet material particles in a quadrangular segment containing 30 or more magnet material particles is set in advance. Among the alignment angles of the easy-to-magnetize axis with respect to the reference line, for the alignment-axis angle defined as the most frequent alignment angle, the alignment angle is determined based on the difference in the alignment angle of each easy-magnetization axis of the magnet material particles. The uneven angle is below 9.0 °. A sintered body for forming a rare-earth magnet is a sintered body for forming a rare-earth magnet having a structure including a rare-earth substance and being integrally sintered, each of which has a plurality of magnet material particles having an easy-to-magnetize axis, and is characterized in that The length dimension in the longitudinal direction, and the thickness dimension in the thickness direction between the first surface and the second surface in a cross section perpendicular to the transverse direction of the aforementioned longitudinal direction, and the width in the width direction orthogonal to the aforementioned thickness direction. The three-dimensional shape of the size is located at any position in the plane including the thickness direction and the width direction, and the magnetization of all the aforementioned magnetic material particles in a square segment with a side of 35 μm on a predetermined reference line Among the alignment angles of the easy axis, for the alignment axis angle defined as the most frequent alignment angle, the misalignment angle of the alignment angle determined based on the difference in the alignment angle of each magnetized easy axis of the magnet material particles is 9.0 Those below °. The sintered body for forming a rare earth magnet as described in the first or second scope of the patent application, wherein the average particle diameter of the magnetic material particles is 3 μm or less. The sintered body for forming a rare earth magnet as described in the first or second scope of the patent application, wherein the difference between the angles of the alignment axes separated by each of the plurality of squares is 10 ° or less. A rare-earth sintered magnet characterized by being formed by magnetizing the sintered body for forming a rare-earth magnet as described in any one of claims 1 to 4 of the scope of patent application.