JP2013161829A - Rare earth magnet compact and manufacturing method of the same, and magnet motor with rare earth magnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide, by a cold spray method, a rare earth magnet compact improved in peeling of deposits due to a residual strain and having excellent magnetic characteristics.SOLUTION: In a rare earth magnet compact, by a cold spray method, non-magnetic metal particles having an elastoplastic ratio of 50% or less, as well as rare earth magnet particles, are added, to reduce a residual strain and/or a repulsive force. In a solidification formation process, deposits are not peeled off to provide a compact having a thick film, and a theoretical density of 80% or more is achieved.

Description

  The present invention relates to a rare earth magnet molded body, a method for producing the same, and a magnet motor including a rare earth magnet.

  Currently used rare earth magnets are classified into sintered magnets and bonded magnets.

  A sintered magnet is a magnet obtained by sintering magnet powder. Since the magnet component occupies most of the produced sintered magnet, the sintered magnet has excellent magnetic properties. However, sintered magnets are usually manufactured by heating to about 1200 ° C., and at this time, densification due to volume shrinkage occurs, and thus there has been a problem that dimensional accuracy is deteriorated.

  On the other hand, a bonded magnet is a magnet obtained by mixing a magnet with a binder such as resin and molding and solidifying it. Since the bond magnet uses a binder, the resulting magnet has a high degree of freedom in shape and high dimensional accuracy. However, since the resin is used as the binder, the heat resistance is low, and the content of the magnet component in the bonded magnet is relatively reduced by including a non-magnetic part (binder), resulting in insufficient magnetic properties. It was reported.

  In general, sintered magnets and bonded magnets differ in the magnet raw material powder used based on differences in their manufacturing processes. In the sintered magnet, a magnet raw material that exhibits excellent magnetic properties when heated to a high temperature is used. Specific examples include ferrite magnets and anisotropic neodymium (Nd) magnets. On the other hand, in the bonded magnet, a magnet material having high magnetic properties is used. Specific examples include isotropic neodymium (Nd) magnets and samarium iron nitrogen (SmFeN) magnets.

  Neodymium magnets and samarium iron nitrogen magnets have magnetic properties superior to ferrite magnets, but the magnetic properties may deteriorate when heated to high temperatures. In particular, samarium-iron-nitrogen magnets cannot be applied to sintered magnets because they can lose their magnetic properties due to changes in chemical composition and crystal structure when heated at high temperatures, and have generally been used for bonded magnets. However, as described above, since the bonded magnet includes a binder such as a resin, it cannot be said that the magnetic characteristics are sufficient.

  In recent years, with the improvement in performance of rotating devices such as motors, it has been desired to develop a magnet molded body that is formed with high magnetic properties while maintaining the properties using powders for bonded magnets having high magnetic properties.

  Non-Patent Document 1 discloses a rare earth magnet molded body in which a rare earth magnet raw material powder is bulked at a high density as a magnet molded body that further improves magnetic properties. The rare earth magnet compact is manufactured by an aerosol deposition (AD) method in which a rare earth magnet raw material that has been aerosolized in a vacuum is sprayed to deposit a rare earth magnet raw material powder.

IEEJ Transactions A Vol. 124 (2004), no. 10 pp. 887-891

  However, the bulk magnet molded body obtained by the method described in Non-Patent Document 1 has poor adhesion between particles and does not necessarily contain a rare earth magnet raw material powder at a high density. For this reason, it has been found that the magnetic properties are still insufficient, and it cannot be said that the high performance desired for a rotating device is obtained.

  Then, an object of this invention is to provide the rare earth magnet molded object which the magnetic characteristic improved more by containing a magnet component by a still higher density.

  The present inventors have intensively studied to solve the above problems. As a result, it has been found that the magnetic characteristics are improved in proportion to the density of the magnet component, and the present invention has been completed. That is, this invention relates to the rare earth magnet molded object containing a rare earth magnet particle and a nonmagnetic metal particle. At this time, the nonmagnetic metal particles are characterized in that the elastic-plastic ratio is 50% or less and the theoretical density of the rare earth magnet compact is 80% or more.

  According to the present invention, it is possible to provide a rare earth magnet molded article having excellent magnetic properties.

It is the schematic of the rare earth magnet molded object which concerns on one Embodiment of this invention. It is the schematic which represented typically the experimental apparatus used for the nanoindentation method. It is a graph showing the relationship between the press-fit depth (h) and load (P) obtained by the experimental apparatus of FIG. 2a. It is the schematic which represents typically the structure of the apparatus used for the cold spray method which is a manufacturing method of the rare earth magnet molded object which concerns on one Embodiment of this invention. It is the schematic of the chamber which has a carrier gas acceleration part used in the manufacturing method of the rare earth magnet molded object which concerns on one Embodiment of this invention. It is a cross-sectional schematic surface which represents typically the rotor structure of an embedded magnet type synchronous motor (IMP). It is a cross-sectional schematic surface which represents typically the rotor structure of a surface magnet type synchronous motor (SMP).

First Embodiment: Rare Earth Magnet Molded Body
The 1st form of this invention is related with the rare earth magnet molded object containing a rare earth magnet particle and the nonmagnetic metal particle whose elastic-plastic ratio is 50% or less. Under the present circumstances, the theoretical density of the said rare earth magnet molded object is 80% or more, It is characterized by the above-mentioned.

  Hereinafter, the present embodiment will be described with reference to the drawings. However, the technical scope of the present invention should be determined based on the description of the scope of claims, and is not limited to the following embodiments. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

[Rare earth magnet compact]
FIG. 1 is a schematic view of a rare earth magnet molded body according to an embodiment of the present invention. According to FIG. 1, the rare earth magnet molded body 1 of the present embodiment includes rare earth magnet particles 3 that are mainly Sm ₂ Fe ₁₄ N _n (n = 2 to 3). In the rare earth magnet compact 1, impurities 7 such as nonmagnetic metal particles 5 that are copper (Cu) particles and samarium (Sm) oxide are present in voids 9 that are formed between the rare earth magnet particles 3.

  The theoretical density of the rare earth magnet compact 1 of FIG. 1 is 95.3%. At this time, the theoretical density means the density of the rare earth magnet particles 3 in the magnet molded body 1 with respect to the density when the magnet molded body 1 is assumed to be composed only of the rare earth magnet particles 3. The assumed density value can be obtained from the lattice constant of the rare earth magnet particles 3, and the lattice constant can be obtained from an X-ray crystal structure analysis.

  The residual magnetic flux density (Br) of the rare earth magnet compact 1 of FIG. 1 expressed as a relative value to the residual magnetic flux density of the rare earth magnet particles is 95%. Therefore, the rare earth magnet compact 1 is a rare earth magnet having excellent magnetic properties.

  Hereafter, each component of the rare earth magnet molded object 1 of the form shown in FIG. 1 is demonstrated in detail. However, the technical scope of the present invention is not limited to the following specific forms.

[Rare earth magnet particles]
The rare earth magnet particle is a main component of the rare earth magnet molded body of the present embodiment and contributes to the magnetic properties of the rare earth magnet molded body. The rare earth magnet particles of the present embodiment have excellent magnetic properties, and the following formula (1):

(Wherein R is Nd or Sm, M is Fe or Co, and X is N or B)
It is represented by Specifically, Nd—Fe—N, Nd—Fe—B, Nd—Co—N, Nd—Co—B, Sm—Fe—N, and Sm—Fe— in which R, M, and X are respectively combined. B, Sm-Co-N, and Sm-Co-B. Among these, from the viewpoint of magnetic properties, the rare earth magnet particles are preferably Nd—Fe—B or Sm—Fe—N, and more preferably Sm—Fe—N. Further, the composition ratio of R, M, and X of the rare earth magnet particles is not particularly limited, and rare earth magnet particles having a known composition ratio are used. Specifically, although not particularly limited, Nd ₂ Fe ₁₇ N _x (where x is preferably 1 to 6, more preferably 1.1 to 5, further preferably 1.2 to 3.8, particularly Preferably 1.7 to 3.3, most preferably 2.2 to 3.1), Nd ₇ Fe ₉₃ N _x (where x is preferably 1 to 20), Nd _1.1 Fe ₄ B ₄ , Nd ₂ Fe ₁₄ B, Nd _3.5 Fe ₇₈ B _18.5 , Nd ₄ Fe _76.5 B _18.5 , Nd ₄ Fe _77.5 B _18.5 , Nd ₄ Fe ₈₀ B ₂₀ Nd _4.5 Fe ₇₇ B _18.5 , Nd ₇ Fe ₃ B ₁₀ , Nd _11.77 Fe _82.35 B _5.88 , Nd ₁₅ Fe ₇₇ B ₅ , Nd _1.1 Co ₄ B ₄ , Nd _{2 Co 14 B, Nd 7 Co 3} B 10, Nd 11.7 _{Co 82.35 B 5.88, Nd 15 Co} 77 B 5, Nd 2 Co 17 N x ( wherein, x is preferably _{1~6), Sm 2 Fe 17 N} x ( wherein, x is (Preferably 1 to 6, more preferably 1.1 to 5, still more preferably 1.2 to 3.8, particularly preferably 1.7 to 3.3, most preferably 2.2 to 3.1) , Sm ₇ Fe ₉₃ N _x (where x is preferably 1 to 20), Sm _1.1 Co ₄ B ₄ , Sm ₂ Co ₁₄ B, Sm ₇ Co ₃ B ₁₀ , Sm _11.77 Co _82.35 B _5.88 , Sm ₁₅ Co ₇₇ B ₅ , Sm ₂ Co ₁₇ N _x (where x is preferably 1 to 6), Sm _1.1 Fe ₄ B ₄ , Sm ₂ Fe ₁₄ B _{, Sm 3.5 Fe 78 B 18.5,} Sm 4 Fe 76 _{5 B 18.5, Sm 4 Fe 77.5} B 18.5, Sm 4 Fe 80 B 20, Sm 4.5 Fe 77 B 18.5, Sm 7 Fe 3 B 10, Sm 11.77 Fe 82.35 B _5.88 , Sm ₁₅ Fe ₇₇ B ₅ may be mentioned.

The rare earth magnet particles include other elements such as Ga, Al, Zr, Ti, Cr, V, Mo, W, Si, Re, Cu, Zn, Ca, Mn, Ni, C, La, Ce, Pr, Pm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Th, and the like may be further included. Specifically, although not particularly _{limited, Nd 10 Fe 74 Co 10 SiB} 5, Nd 4.5 Fe 72 Cr 2 Co 3 B 18.5, Nd 4.5 Fe 71 Cr 3 Co 3 B 18.5, Nd _5.5 Fe ₆₆ Cr ₅ Co ₅ B _18.5 , Nd _4.5 Fe ₇₃ V ₃ SiB _18.5 , Nd _3.5 DyFe ₇₃ Co ₃ GaB _18.5 , Nd _4.5 Fe ₇₃ Co ₃ GaB _{18 .5} , Nd _5.5 Fe ₆₆ Cr ₅ Co ₅ B _18.5 , (Nd _0.95 Dy _0.05 ) ₁₅ Fe _77.5 B ₇ Al _0.5 , (Nd _0.95 Dy _0.05 ) ₁₅ (Fe _0.95 Co _0.05 ) _77.5 B _6.5 Al _0.5 Cu _0.2 , (Nd ₈ Zr ₃ Fe ₈₄ ) ₈₅ N ₁₅ , (Sm _0.95 Dy _0.05 ) ₁₅ Fe _{7.5 B 7 Al 0.5, (Sm} 0.95 Dy 0.05) 15 (Fe 0.95 Co 0.05) 77.5 B 6.5 Al 0.5 Cu 0.2, (Sm 8 Zr ₃ Fe ₈₄ ) ₈₅ N ₁₅ , Sm _4.5 Fe ₇₁ Cr ₃ Co ₃ B _18.5 , Sm _4.5 Fe ₇₂ Cr ₂ Co ₃ B _18.5 , Sm _5.5 Fe ₆₆ Cr ₅ Co ₅ B _{18.5, Sm 4.5 Fe 73 V 3} SiB 18.5, Sm 4.5 Fe 73 Co 3 GaB 18.5, Sm 10 Fe 74 Co 10 SiB 5, Sm 3.5 DyFe 73 Co 3 GaB 18. ₅ etc. are mentioned.

  These rare earth magnet particles may be used alone or in combination of two or more.

  Furthermore, other rare earth magnet particles may be included as necessary. Other rare earth magnet particles include, for example, ferrite magnets, alnico magnets, Fe—Cr—Co magnets, Fe—Pt magnets, Co—Pt magnets, Mn—Al magnets, Pr—Fe—B magnets, And Pr—Co magnets. The other rare earth magnet particles may be included within a range that does not significantly impair the magnetic properties, but are preferably not included from the viewpoint of magnetic properties.

  The shape of the rare earth magnet particles is not particularly limited, and may be any shape as long as the effects of the present invention are not impaired. For example, the shape may be spherical, elliptical, cylindrical, polygonal, needle, rod, plate, disk, flake, scale, indefinite, or the like.

  The average particle diameter of the rare earth magnet particles is preferably 1 to 10 μm, more preferably 2 to 8 μm, and further preferably 3 to 6 μm. When the average particle size is within the above range, it is advantageous when producing a rare earth magnet molded article having a high theoretical density. Compared with the conventionally used rare earth magnet particles having an average particle diameter of 25 to 500 μm, the rare earth magnet particles of the present embodiment have a small average particle diameter, and a highly compacted magnet compact can be obtained. Can be a thing. In this specification, “average particle diameter” means a value measured and calculated from an image obtained by a transmission electron microscope (TEM) or a scanning electron microscope (SEM) unless otherwise specified. To do. In this case, the “particle diameter” means the maximum length of the distance between two points on the contour line of the rare earth magnet particle.

[Nonmagnetic metal particles]
The nonmagnetic metal particles are one of the constituent elements of the rare earth magnet molded body of the present embodiment, and exist in the gaps between the rare earth magnet particles.

  The nonmagnetic metal particles are not particularly limited as long as the elastic-plastic ratio is 50% or less, and known particles can be used. Examples include copper (Cu) particles, aluminum (Al) particles, and zinc (Zn) particles. The elasto-plastic ratio of the nonmagnetic metal is 50% or less, preferably 2.5 to 50%, more preferably 2.5 to 45%, and particularly preferably 2.5 to 40%. For example, the elastic-plastic ratio of Cu particles is 22%, the elastic-plastic ratio of Al particles is 38%, and the elastic-plastic ratio of Zn particles is 30%. In this specification, the elasto-plastic ratio represents the ease of deformation of a metal and is measured by the nanoindentation method. The nanoindentation method measures the degree of plasticity of a sample. FIG. 2a is a schematic diagram schematically showing an experimental apparatus used for the nanoindentation method, and FIG. 2b shows the relationship between the press-fit depth (h) and the load (P) obtained by the experimental apparatus of FIG. 2a. It is a graph to represent. More specifically, the nanoindentation method is a load in which a diamond pyramid indenter 21 made of diamond is placed on the surface of a sample 23 placed on a substrate (not shown) of the experimental apparatus 20 as shown in FIG. 2a. (Push-in) until the indenter 21 is removed (unloading) and the relationship (press-fit (load) -unloading curve) between the load (P) and the displacement (press-in depth h) is measured. is there. In FIG. 2b, the press-fit (load) curve reflects the elastic-plastic deformation behavior of the material, and the unloading curve is obtained by the elastic-plastic recovery behavior. The area surrounded by the load curve, unload curve, and horizontal axis (solid hatched portion) in FIG. 2b is the energy Ep consumed for plastic deformation. Further, an area surrounded by a perpendicular line extending from the maximum load point of the load curve to the horizontal axis and the unloading curve (broken hatched portion) is energy Ee absorbed by elastic deformation. At this time, the elastic-plastic ratio can be obtained from the following equation.

  It can be said that the smaller the value of the elasto-plastic ratio, the easier it is for the deformed object to return to its original shape, and it can be said that the metal particles have high elasticity.

  As described above, the nonmagnetic metal particles are present in the voids formed between the rare earth magnet particles in the rare earth magnet molded body. Therefore, the nonmagnetic metal particles exist in various shapes.

  The content of the nonmagnetic metal particles is not particularly limited, but is preferably contained in an amount of more than 1% by mass and less than 20% by mass with respect to the mass of the rare earth magnet particles. More preferably, it is contained. If the content of the nonmagnetic metal particles exceeds 1% with respect to the mass of the rare earth magnet particles, it is advantageous in the production process, and if the content of the nonmagnetic metal particles is less than 20%, the magnetic properties are excellent. It is preferable because a rare earth magnet compact is obtained.

[impurities]
Impurities can be included in the production of the rare earth magnet compact of this embodiment, and are an optional component of the rare earth magnet compact. The impurities may be unavoidably included in the manufacturing process or intentionally contained in the rare earth magnet compact. Such impurities can have a favorable effect on the magnetic properties. Therefore, the impurities need not be particularly removed, and the rare earth magnet molded body may contain impurities. The impurities may be completely removed, but generally it is difficult to remove them completely.

The impurities are not particularly limited and may be known ones. Examples thereof include rare earth metals such as samarium (Sm) and neodymium (Nd); compounds of the rare earth metals and iron (Fe); rare earth metal oxides such as samarium oxide (SmO ₂ ); and iron (Fe). .

  Impurities are mainly present in voids formed between rare-earth magnet particles in the rare-earth magnet compact as in the case of the nonmagnetic metal particles. Therefore, the impurity exists in various shapes.

  In this embodiment, the theoretical density of the rare earth magnet compact is 80% or more, preferably 85% or more, more preferably 90% or more, and further preferably 95% or more. In this embodiment, since the rare earth magnet compact includes nonmagnetic metal particles, the theoretical density does not become 100%. A large theoretical density means that the amount of rare earth magnet particles contained in the rare earth magnet compact (the amount of net components of the rare earth magnet particles) is large, and the higher the theoretical density, the better the magnetic properties.

(Second Embodiment: Manufacturing Method of Rare Earth Magnet Molded Body)
As described above, Non-Patent Document 1 discloses a method of obtaining a rare earth magnet molded body bulked by an aerosol deposition (AD) method. The AD method is a method in which rare earth magnet particles are deposited by spraying a rare earth magnet particle on a substrate under a vacuum condition at a low temperature (room temperature) as a carrier at a high speed (about 500 m / s). According to the AD method, since it is manufactured at a low temperature, rare earth magnets such as neodymium magnets and samarium iron nitrogen magnets are not easily deteriorated by heat, and the magnetic characteristics of the magnets can be maintained. Moreover, since the rare earth magnet particles are injected at a high gas velocity, the deposit (rare earth magnet compact) formed on the substrate can contain the rare earth magnet particles at a high density. However, the theoretical density of the rare earth magnet compact obtained by this method is about 75%, and the magnetic properties are not satisfactory. In addition, the depositable thickness has a certain limit and is not large enough for practical use. Furthermore, since the AD method requires vacuum conditions, there is a problem that an expensive apparatus is required.

  Therefore, in a second embodiment of the present invention, a method for manufacturing a rare earth magnet molded body (cold spray method) that can solve the above-described problems is provided. Specifically, (1) an introduction step of introducing rare earth magnet particles and nonmagnetic metal particles into a carrier gas, (2) an injection step of injecting the rare earth magnet particles and nonmagnetic metal particles onto a substrate, and ( 3) A method for producing a rare earth magnet, comprising a solidification forming step of depositing the rare earth magnet particles and the nonmagnetic metal particles on the substrate to obtain a deposit. At this time, the gas temperature in the injection stage is equal to or lower than the decomposition temperature of the nitride of the rare earth magnet, and the solidification molding stage is performed under atmospheric pressure.

  In this method, the gas temperature in the injection stage can be heated to a temperature that does not impair the magnetic properties of the rare earth magnet particles (below the decomposition temperature of the nitride of the rare earth magnet). Therefore, a higher gas velocity (600 m / s or more) can be realized as the gas velocity in the injection stage as compared with the gas velocity of the AD method (approximately 500 m / s). As a result, a thick deposit containing rare earth magnet particles at a high density can be obtained, and a rare earth magnet compact with excellent magnetic properties can be obtained. Moreover, according to the said manufacturing method, since a solidification formation stage can be performed under atmospheric pressure, an expensive apparatus becomes unnecessary and it is economically high.

[Cold spray method]
FIG. 3 is a schematic view schematically showing a configuration of an apparatus used in a cold spray method which is a method for manufacturing a rare earth magnet molded body according to an embodiment of the present invention. According to FIG. 3, the first stage of the manufacturing method of this embodiment is a stage in which rare earth magnet particles and non-magnetic metal particles are introduced into the carrier gas acceleration part together with the raw material input gas from the supply device. The second stage is a stage in which a secondary carrier gas containing rare earth magnet particles and non-magnetic metal particles is injected from the nozzle gun onto the substrate in the carrier gas acceleration section in the chamber. The secondary carrier gas is a raw material input gas containing rare earth magnet particles and non-magnetic metal particles supplied in the input stage, which is the first stage, and a primary gas supplied from a high-pressure carrier gas generator through a carrier gas heater. And a carrier gas. In the second stage, the gas temperature of the secondary carrier gas to be injected is not higher than the decomposition temperature of the nitride of the rare earth magnet particles, and the gas temperature of the secondary carrier gas is the temperature of the primary carrier gas and the raw material powder gas, and It is controlled by appropriately adjusting the supply pressure. The third stage is a solidification molding stage in which rare earth magnet particles and nonmagnetic metal particles are deposited on the base material in the base material holding part in the chamber to obtain a deposit. The solidification molding step is performed under atmospheric pressure conditions, and a rare earth magnet molded body as a deposit is obtained by scanning the nozzle a plurality of times on the substrate.

  Hereinafter, each stage of the cold spray method, which is a method for producing the rare earth magnet molded body having the form shown in FIG. 3, will be described in detail. However, the technical scope of the present invention is not limited to the following specific forms.

[Input stage]
The charging stage is a stage in which rare earth magnet particles and non-magnetic metal particles are charged into a carrier gas.

  In the form shown in FIG. 3, the rare earth magnet particles and the nonmagnetic metal particles are introduced into the carrier gas acceleration section together with the powder raw material gas.

(Rare earth magnet particles)
The rare earth magnet particle is a main component in the rare earth magnet molded body produced in this embodiment, and contributes to the magnetic properties of the rare earth magnet molded body.

  The rare earth magnet particles that can be used are not particularly limited, and those similar to the rare earth magnet particles in the first embodiment can be used. In particular, the rare earth magnet particles represented by the formula (1) are preferable. At this time, the composition ratio of the rare earth magnet particles is not particularly limited, and those having a known composition ratio can be used.

  The shape of the rare earth magnet particles is not particularly limited, and may be any shape as long as the effects of the present invention are not impaired. For example, the shape may be spherical, elliptical, cylindrical, polygonal, needle, rod, plate, disk, flake, scale, indefinite, or the like. The shape of the rare earth magnet particle is not particularly limited as long as it does not exhibit particle velocity and elastic behavior that are extremely poor in adhesion, but a flat shape is difficult to accelerate, so it must be nearly spherical. Is preferred.

  The average particle diameter of the rare earth magnet particles is preferably 1 to 10 μm, more preferably 2 to 8 μm, and further preferably 3 to 6 μm. When the average particle diameter of the rare earth magnet particles is 1 μm or more, it is preferable because the particle speed becomes too fast and the substrate is not scraped, and can collide and adhere to the base material at an optimum speed and be deposited. On the other hand, if the average particle size of the rare earth magnet particles is 10 μm or less, the particle speed will be too slow, and it will not collide with the base material and will not be bounced back. It is preferable because it can be converted.

(Non-magnetic metal particles)
Non-magnetic metal particles are added in order to improve a specific problem based on the cold spray method that was not found in the conventional AD method when depositing rare earth magnet particles. The said problem is peeling of the deposit by the residual stress which arises in rare earth magnet particles. In the second injection stage, the gas temperature of the secondary carrier gas is lower than or equal to the decomposition temperature of the nitride of the rare earth magnet, so that the gas velocity of the secondary carrier gas of the rare earth magnet particles can be 600 m / s or more. Along with this, in the subsequent solidification molding stage, when the rare earth magnet particles collide with the substrate, the temperature rises and the rare earth magnet particles are deformed. Thereafter, the deformed rare earth magnet particles undergo thermal shrinkage, and the deposited rare earth magnet compact may be peeled off due to the stress (residual stress) generated at this time. Further, when the rare earth magnet particles collide with the substrate at such a high speed, the rare earth magnet molded body formed by the repulsive force that the rare earth magnet particles receive from the substrate at the time of the collision may occur. In such a case, when the nonmagnetic metal particles having an elastoplastic ratio of 50% or less are added together with the rare earth magnet particles, the residual stress and / or the repulsive force is relaxed, and the deposit does not peel off in the solidification formation stage, and the A molded body of the film can be obtained.

  The nonmagnetic metal particles that can be used are not particularly limited, and the same nonmagnetic metal particles as those in the first embodiment can be used.

  The shape of the nonmagnetic metal particles is not particularly limited, and may be any shape as long as it does not impair the effects of the present invention. For example, the shape may be spherical, elliptical, cylindrical, polygonal, needle, rod, plate, disk, flake, scale, indefinite, or the like. The shape of the rare earth magnet particle is not particularly limited as long as it does not exhibit particle velocity and elastic behavior that are extremely poor in adhesion, but a flat shape is difficult to accelerate, so it must be nearly spherical. Is preferred. Note that the nonmagnetic metal particles are present in the voids formed between the rare earth magnet particles in various solid shapes in the solidified rare earth magnet compact.

  The average particle size of the nonmagnetic metal particles is preferably 1 to 10 μm, more preferably 2 to 8 μm, and further preferably 3 to 6 μm. When the average particle diameter of the rare earth magnet particles is 1 μm or more, it is preferable because the particle speed becomes too fast and the substrate is not scraped, and can collide and adhere to the base material at an optimum speed and be deposited. On the other hand, if the average particle size of the rare earth magnet particles is 10 μm or less, the particle speed will be too slow, and it will not collide with the base material and will not be bounced back. It is preferable because it can be converted.

  The amount of the nonmagnetic metal particles to be added is not particularly limited, but is preferably contained in an amount of more than 1% by mass and less than 20% by mass with respect to the mass of the rare earth magnet particles, and more than 1% by mass and 10% by mass. % Or less is preferable. If the content of the nonmagnetic metal particles exceeds 1% with respect to the mass of the rare earth magnet particles, the internal stress can be sufficiently relaxed, and if the content of the nonmagnetic metal particles is less than 20%, the magnetic characteristics are excellent. It is preferable because a rare earth magnet compact is obtained.

(Raw material input gas)
The raw material input gas serves as a medium for transporting the rare earth magnet particles and the nonmagnetic metal particles to the carrier gas acceleration unit.

The raw material input gas that can be used is not particularly limited, and known materials can be used. Among these, it is preferable to use an inert gas from the viewpoint of preventing deterioration of the magnetic properties of the rare earth magnet particles. Specifically, noble gases (He, Ne, Ar, Kr, Xe, Rn), nitrogen (N ₂ ) gas, helium (He) gas, and the like can be given. Of these, it is more preferable to use He gas or N ₂ gas which is easily available and inexpensive. N ₂ gas is less likely to decompose nitrides and can improve heat resistance. Also, since the He gas has a low molecular weight, a higher gas velocity can be realized. These raw material input gases may be used alone or in combination of two or more. Furthermore, from the viewpoint of preventing oxidation, the raw material input gas may contain hydrogen (H ₂ ) gas. For example, N ₂ —H ₂ mixed gas can be obtained as an ammonia decomposition gas at low cost, and is preferable from the viewpoint of economy.

  The temperature of the raw material input gas is not particularly limited as long as it does not impair the magnetic properties of the rare earth magnet particles, but it needs to be lower than the decomposition temperature of the nitride of the rare earth magnet. When setting the temperature of the raw material input gas, the supply pressure of the raw material input gas, which will be described later, and the temperature and pressure of the primary carrier gas, which will be described later, are appropriately taken into consideration so that the secondary carrier gas has a desired temperature. It is preferable. The decomposition temperature of the nitride of the rare earth magnet particles is generally 520 to 530 ° C.

  The supply pressure of the raw material input gas is not particularly limited as long as it does not impair the magnetic characteristics of the rare earth magnet particles. When setting the supply pressure of the raw material input gas, the temperature of the raw material input gas and the temperature and pressure of the primary carrier gas described later are appropriately taken into consideration so that the secondary carrier gas has a desired temperature. Is preferred.

  The flow rate of the raw material input gas is not particularly limited as long as it does not impair the magnetic properties of the rare earth magnet particles.

[Injection stage]
The spraying step is a step of spraying rare earth magnet particles and nonmagnetic metal particles onto the substrate. At this time, the gas temperature is not higher than the decomposition temperature of the nitride of the rare earth magnet particles.

  In the form shown in FIG. 3, a secondary carrier gas containing rare earth magnet particles and nonmagnetic metal particles obtained by mixing powder raw material gas and primary carrier gas is injected from the nozzle gun to the substrate at a temperature lower than the decomposition temperature of nitride. To do.

(Primary carrier gas)
The primary carrier gas is mixed with the raw material input gas in the carrier gas acceleration section, and becomes a constituent component of the secondary carrier gas described later together with the raw material input gas.

  The primary carrier gas that can be used is not particularly limited, and a known one can be used in the same manner as the raw material input gas. As the primary carrier gas, the same type as the above-mentioned raw material input gas may be used, or a different type may be used, but the same type is used from the viewpoint of suppressing variation in gas velocity in an injection stage to be described later. It is preferable to use those.

  The temperature of the primary carrier gas is not particularly limited, and may be a temperature equal to or higher than the decomposition temperature of the rare earth magnet nitride. The reason for this is that even if the temperature of the primary carrier gas is high, the time until the raw material supply gas containing rare earth magnet particles is mixed with the primary carrier gas and injected as a secondary carrier gas by the nozzle is negligible. Because. That is, the high temperature primary carrier gas is less likely to impair the magnetic properties of the rare earth magnet particles. The temperature of the primary carrier gas is specifically 200 to 1000 ° C., preferably 200 to 600 ° C. When the temperature of the primary carrier gas is 200 ° C. or higher, it is preferable that when mixed with the raw material input gas, the temperature does not decrease more than necessary and the temperature can be easily adjusted as the secondary carrier gas. . On the other hand, when the temperature of the primary carrier gas is 1000 ° C. or less, it is preferable that when mixed with the raw material supply gas, the magnetic properties of the rare earth magnet particles contained in the raw material supply gas are not deteriorated. When setting the temperature of the primary carrier gas, the temperature and supply pressure of the raw material input gas and the supply pressure of the primary carrier gas described later are appropriately taken into consideration so that the secondary carrier gas has a desired temperature. It is preferable.

  The supply pressure of the primary carrier gas is not particularly limited. When setting the supply pressure of the primary carrier gas, the temperature and supply pressure of the raw material input gas and the temperature of the primary carrier gas are appropriately taken into consideration so that the secondary carrier gas has a desired temperature. Is preferred. When the injection stage is performed using a nozzle gun, the supply pressure of the primary carrier gas is preferably adjusted to be equal to or lower than the supply pressure of the raw material input gas to prevent the back flow of the raw material powder.

  The flow rate of the primary carrier gas is not particularly limited, but when the injection stage is performed using a nozzle gun, the flow rate of the primary carrier gas is preferably higher than the flow rate of the raw material input gas.

  According to this embodiment, as described above, the primary carrier gas can be supplied from the high-pressure carrier gas generation unit to the carrier gas acceleration unit via the carrier gas heater. There is no restriction | limiting in particular as a high voltage | pressure carrier gas generation | occurrence | production part, If a primary carrier gas can be supplied, a well-known thing can be used. For example, a high-pressure gas cylinder filled with carrier gas, a high-pressure gas tank, a high-pressure liquefaction cylinder filled with liquefied carrier gas under high pressure, a high-pressure liquefaction tank, and the like can be given. The primary carrier gas pumped from the high-pressure carrier gas generator is transported to the carrier gas heater as a low-temperature gas and heated to the temperature of the above-mentioned primary carrier gas, for example, 200 to 1000 ° C. There is no restriction | limiting in particular as the said carrier gas heater, A well-known thing is used. For example, a configuration (structure) in which the internal piping through which the primary carrier gas passes is coiled and a current is passed through the coil portion and the internal piping is used as a heater to heat the carrier gas in the piping, the interior through which the primary carrier gas passes A structure (structure) that heats the primary carrier gas in the pipe by using a coil as a coil and passing an electric current through the coil part to use the internal pipe as a heater, and a pipe using a far-infrared heater or an electromagnetic induction coil The structure (structure) etc. which heat the primary carrier gas inside are mentioned.

(Secondary carrier gas)
The secondary carrier gas is composed of a raw material supply gas and a primary carrier gas, and serves as a medium for injecting rare earth magnet particles and nonmagnetic metal particles in the injection stage.

  According to this embodiment, the raw material supply gas and the primary carrier gas are mixed in the carrier gas acceleration unit to become the secondary carrier gas. The carrier gas accelerating portion is not particularly limited, and a known one can be used. FIG. 4 shows a schematic view of a chamber having a carrier gas acceleration unit used in the method for producing a rare earth magnet molded body according to one embodiment of the present invention. The chamber 40 includes a carrier gas acceleration unit 41 and a base material holding unit 43, and the carrier gas acceleration unit 41 includes a nozzle gun 45. The raw material supply gas is supplied from the raw material supply gas supply pipe 47 and the primary carrier gas is supplied from the primary carrier gas supply pipe 49 in the upstream part of the carrier gas acceleration part 41, and mixed in the downstream part of the carrier gas acceleration part 41. It becomes a secondary carrier gas. The flow rate of the secondary carrier gas is increased at the narrowed portion in the nozzle gun 45, and the gas velocity is increased and the secondary carrier gas is injected onto the substrate 43. The pressure in the carrier gas accelerating unit 41 decreases as the gas velocity of the secondary carrier gas increases due to the venturi effect. In this embodiment, since the supply pressure of the primary carrier gas is larger than the supply pressure of the raw material supply gas, the raw material input gas flows into the carrier gas acceleration unit 41 in a reduced pressure state. The carrier gas accelerating unit is not limited to the above-described one, and other known ones may be used as long as the gas temperature of the secondary carrier gas can be injected at high speed under the condition of the decomposition temperature of the nitride of the rare earth magnet. May be.

  The gas temperature of the secondary carrier gas can be adjusted to be equal to or lower than the decomposition temperature (520 to 530 ° C.) of the nitride of the rare earth magnet according to the temperature and supply pressure of the raw material input gas and the temperature of the primary carrier gas. The higher the gas temperature of the secondary carrier gas, the higher the energy that can be imparted to the rare earth magnet powder and the nonmagnetic metal particles that are ejected, whereby a high gas velocity (600 m / s or more) can be realized. Therefore, it is preferable that the gas temperature of the secondary carrier gas is heated below the decomposition temperature of the nitride of the rare earth magnet. The gas temperature of the secondary carrier gas is preferably 500 ° C. or lower, more preferably 100 to 500 ° C., further preferably 100 to 400 ° C., and particularly preferably 200 to 300 ° C. If the gas temperature of the secondary carrier gas exceeds the decomposition temperature of the nitride of the rare earth magnet, the magnetic properties of the rare earth magnet particles can be deteriorated.

  The gas pressure of the secondary carrier gas is not particularly limited, and can be set in consideration of the gas temperature of the secondary carrier gas as described above in order to obtain a desired secondary carrier gas injection speed. Specifically, the gas pressure is preferably 0.6 MPa or more, more preferably 0.6 to 5 MPa, and still more preferably 0.8 to 3 MPa. A gas pressure of 0.6 MPa or more is preferable because a thick deposit can be obtained that contains rare earth magnet particles at a high density in the solidification molding step described later.

  Since the gas temperature of the secondary carrier gas is heated below the decomposition temperature of the nitride of the rare earth magnet, a high gas velocity can be realized. The gas velocity of the secondary carrier gas is 600 m / s or more, preferably 700 m / s or more, more preferably 1000 m / s or more, more preferably 1000 to 1300 m / s, which is the sound velocity region. Considering that the gas velocity according to the conventional AD method is about 500 m / s, the gas velocity is very fast, and in the solidification molding stage described later, a thick deposit containing rare earth magnet particles at a higher density is formed. It can be understood that it can be obtained.

[Solidification molding stage]
The solidification step is a step of depositing rare earth magnet powder and nonmagnetic metal particles on a substrate to obtain a deposit. At this time, the solidification molding step is performed under atmospheric pressure. As described above, since the gas velocity of the secondary carrier gas is high, the solidification formation stage can be sufficiently performed even under atmospheric pressure. Therefore, an expensive apparatus for generating a vacuum condition such as the AD method is not necessary, so that the manufacturing method according to this embodiment is highly economical.

  In the form shown in FIG. 3, rare earth magnet particles and nonmagnetic metal particles are deposited under atmospheric pressure on the base material in the base material holding part in the chamber to obtain a deposit.

(Base material)
The base material serves as a holding portion for the rare earth magnet molded body deposited by injecting the rare earth magnet particles and the nonmagnetic metal particles in the solidification forming stage. Therefore, the said base material is not a component of the rare earth magnet molded object which concerns on this form.

  Although it does not specifically limit as a base material which can be used, Base materials, such as copper (Cu), aluminum (Al), a silica, magnesia, a zirconia, and stainless steel (SUS), are mentioned. Of these, a Cu base or an Al base is preferable. When a Cu base material or an Al base material is used, the heat generated when the rare earth magnet particles collide with the base material can easily escape and the film temperature of the rare earth magnet can be homogenized. As a result, the residual stress is reduced, and peeling can be more effectively suppressed. Moreover, Cu base material and Al base material are cheap, and can be used suitably also from an economical viewpoint.

  The shape of the substrate can be appropriately selected according to the use of the obtained rare earth magnet molded body. Specific applications include an embedded magnet type synchronous motor (IMP) or a surface magnet type synchronous motor (SMP), which will be described in detail in a third embodiment described later.

  When the rare earth magnet compact is applied to the IMP, the rare earth magnet compact is once formed on the base material, and then separated from the base material and applied to the motor. Therefore, there is no restriction | limiting in particular in the shape of a base material, The thing of arbitrary shapes can be used. For example, shapes such as a spherical shape, an elliptical shape, a columnar shape, a polygonal column shape, a plate shape, and a disc shape are exemplified. Among these, from the viewpoint of work efficiency, a shape having a planar structure such as a plate shape and a disk shape is preferable.

  In addition, when the rare earth magnet molded body is applied to SMP, a method of directly forming a film on the motor core can be used.

  The base material holding part is installed at a certain distance from the tip of the carrier gas acceleration part. The distance is preferably 5 to 30 mm, more preferably 5 to 20 mm, and still more preferably 5 to 15 mm. When the distance is 5 mm or more, the injected secondary carrier gas is likely to escape to the outside, so that the injected gas speed is hardly reduced. On the other hand, when the distance is 30 mm or less, it is preferable that the injected secondary carrier gas does not decelerate excessively until it collides with the substrate, and deposits can be formed on the substrate while maintaining a high speed state. .

(Sediment)
The deposit, which is a rare earth magnet molded body obtained by the solidification molding step, may contain a rare earth magnet particle at a high density and a thick film. That is, the rare earth magnet molded body obtained by the method includes rare earth magnet particles and nonmagnetic metal particles having an elastoplastic ratio of 50% or less. At this time, the theoretical density of the rare earth magnet compact is 80% or more.

  The rare earth magnet particles and nonmagnetic metal particles contained in the deposit are not limited to rare earth magnet particles and nonmagnetic metal particles having the same layer. For example, the layers may be formed by using different types of rare earth magnet particles for each layer by appropriately changing the types of rare earth magnet particles and / or nonmagnetic metal particles in the above-described charging stage.

  The shape of the deposit varies depending on the deposition method in the solidification molding stage. When the nozzles are scanned on the substrate a plurality of times and sequentially deposited, the deposits have a triangular shape when observed from the horizontal direction with respect to the substrate. In another embodiment, when the nozzle tip is slid little by little and scanned and sequentially deposited, the deposit is trapezoidal when observed from the horizontal direction with respect to the substrate. The deposition method is not limited to the scanning method and the immobilization method, and may be other methods, and the shape of the deposit varies depending on the deposition method. The surface of the resulting deposit may be uneven due to individual deposits and / or due to deposited rare earth magnet particles and non-magnetic metal particles. Therefore, the obtained deposit can be processed into a smooth surface by polishing the surface.

  The thickness of the obtained deposit is not particularly limited, but is preferably 200 μm or more, more preferably 200 to 3000 μm, still more preferably 500 to 3000 μm, and particularly preferably 1000 to 3000 μm. When the thickness of the deposit is 200 μm or more, it is possible to obtain a rare earth magnet molded article having rare earth magnet particles at a high density and excellent in magnetic properties. When the thickness of the deposit is 3000 μm or less, it is preferable because the variation in the theoretical density in the rare earth magnet compact is reduced. The advantage of the manufacturing method according to this embodiment can be understood from the AD method according to Non-Patent Document 1 that only a film thickness of 175 μm is obtained. In the present specification, the “film thickness of the deposit” means that the thickness including the substrate is measured from the top of the deposit using a micrometer after the solidification molding stage, and the thickness of the substrate is calculated from the measured value. It means what was excluded. Further, “thickening” means that the film thickness of the deposit obtained in the solidification stage is 200 μm or more.

  Note that the manufacturing method described above is not limited to this embodiment. Therefore, the injection stage, the injection stage, and the solidification formation stage are included, the gas temperature in the injection stage is equal to or lower than the decomposition temperature of the nitride of the rare earth magnet particles, and the solidification molding stage is performed at atmospheric pressure. For example, you may manufacture a rare earth magnet molded object using another method and apparatus.

(Third embodiment: a magnet motor including a rare earth magnet)
The magnet motor of the present embodiment includes the rare earth magnet molded body according to the first embodiment and / or the rare earth magnet molded body manufactured in the second embodiment. The rare earth magnet molded body according to the first embodiment and the rare earth magnet molded body manufactured in the second embodiment have excellent magnetic properties because they contain rare earth magnet particles at a high density. Therefore, the rare earth magnet can contribute to high performance, light weight, and downsizing of the rotating device. The magnet motor is not limited to a rotating device and can be used for various applications.

  In one embodiment, the magnet motor including the rare earth magnet is classified into an embedded magnet type synchronous motor (IMP) and a surface magnet type synchronous motor (SMP), which will be described below.

[Embedded magnet type synchronous motor (IMP)]
FIG. 5 a shows a schematic cross-sectional surface schematically illustrating the rotor structure of an embedded magnet type synchronous motor (IMP). According to FIG. 5a, an embedded magnet type synchronous motor 50a includes an embedded groove (at least one rare earth magnet molded body 51 of the first and second embodiments formed into a rotor 53 for an embedded magnet type synchronous motor. It is fixed by being press-fitted (inserted) into (not shown). The polished rare earth magnet molded body obtained in the second embodiment is peeled off from the substrate for processing (cutting / polishing), surface treatment (corrosion resistance by nickel coating, aluminum coating, resin coating, etc.), It can be applied to the motor of this embodiment through each step of magnetization.

[Surface magnet type synchronous motor (SMP)]
FIG. 5 b shows a schematic cross-sectional surface schematically illustrating the rotor structure of the surface magnet type synchronous motor (SMP). According to FIG. 5b, in the surface magnet type synchronous motor 50b, at least one rare earth magnet molded body 55 of the first and second embodiments is directly solidified (or bonded) to the surface of the rotor 57 for the surface magnet type synchronous motor. Is. The polished rare earth magnet molded body obtained in the second embodiment is obtained by directly processing (cutting / polishing) the substrate-rare earth magnet molded body, surface treatment (providing corrosion resistance by nickel coating, aluminum coating, etc.). Then, it can be applied to the motor of this embodiment through each step of magnetization. According to the second embodiment described above, since the rare earth magnet molded body is directly solidified and formed on the motor core, it is strongly bonded to the base material. Therefore, conventionally, peeling due to the centrifugal force when the rotor rotates, which may be a problem when the rare earth magnet molded body is applied to the surface magnet type synchronous motor (SMP), hardly occurs.

  In addition, it is not restricted only to said specific motor, It can apply to another motor. Furthermore, you may apply to various uses only using the rare earth magnet molded object obtained by 1st and 2nd embodiment.

[material]
The raw materials used in the following examples are as follows.

Sm ₂ Fe ₁₄ B _n (n = 2 to 3) (manufactured by Nichia Corporation) was used for the rare earth magnet particles. The average particle diameter of Sm ₂ Fe ₁₄ B _n was 3 μm as analyzed by a scanning electron microscope (SEM) electron beam surface imaging microscope apparatus (manufactured by Carl Zeiss Co., Ltd.), and the shape was spherical. The decomposition temperature was analyzed by a differential scanning calorimetry (DSC) apparatus (manufactured by TA Instruments Inc.) and found to be 450 ° C. or higher.

  Copper (Cu) particles (manufactured by Nippon Atomization Co., Ltd.) were used as the nonmagnetic metal particles. The elastoplastic ratio was 22% as measured by the nanoindentation method using a nanoindenter (manufactured by Nissan Arc Co., Ltd.). When the average particle diameter of Cu particle | grains was analyzed with the scanning electron microscope (SEM) electron beam surface imaging microscope apparatus (made by Carl Zeiss Co., Ltd.), it was 2 micrometers and the shape was spherical.

  A Cu substrate was used as the substrate. The Cu base material is a flat plate having a width of 50 mm, a length of 80 mm, and a thickness of 1 mm.

[Production of rare earth magnet compacts]
Example 1
Rare earth magnet compacts were produced by the cold spray method. As a manufacturing apparatus, a KM apparatus manufactured by INOVATI was used. Sm ₂ Fe ₁₄ B _n (n = 2 to 3) and Cu particles (3% by mass with respect to the mass of Sm ₂ Fe ₁₄ B _n ) were mixed. Next, using the He gas as the raw material supply gas, the raw material was introduced into the carrier gas acceleration unit together with the raw material supply gas at 25 ° C. and 0.8 MPa. The carrier gas acceleration unit was supplied with He gas, which is a primary carrier gas, at 1000 ° C. and 0.8 MPa, and was mixed with the raw material supply gas. The mixed gas is a secondary carrier gas made of He gas containing Sm ₂ Fe ₁₄ B _n (n = 2 to 3) and Cu particles. The temperature of the secondary carrier gas was adjusted by the temperature and supply pressure of the raw material supply gas and the primary carrier gas, and the secondary carrier gas was accelerated and injected by the carrier gas acceleration unit. The gas temperature of the secondary carrier gas was 270 ° C., and the gas pressure was 0.8 MPa. By injecting a secondary carrier gas onto a Cu base placed at a distance of 10 mm from the nozzle of the carrier gas accelerating portion and repeating the scanning while shifting by 0.5 mm at a scanning speed of 50 mm / s, Sm ₂ Fe ₁₄ B _n (N = 2 to 3) and Cu particles were deposited. The surface of the obtained deposit was polished to obtain a rare earth magnet molded body. When the film thickness was measured with a micrometer (manufactured by Mitutoyo Corporation), it was 250 μm.

(Example 2)
A rare earth magnet compact was produced in the same manner as in Example 1 except that 5% by mass of Cu particles was used with respect to the mass of Sm ₂ Fe ₁₄ B _n .

(Example 3)
A rare earth magnet compact was produced in the same manner as in Example 1 except that 10% by mass of Cu particles was used with respect to the mass of Sm ₂ Fe ₁₄ B _n .

Example 4
A rare earth magnet molded body was produced in the same manner as in Example 1 except that 12.5% by mass of Cu particles was used with respect to the mass of Sm ₂ Fe ₁₄ B _n .

(Example 5)
A rare earth magnet compact was produced in the same manner as in Example 1 except that 3% by mass of Al particles with respect to the mass of Sm ₂ Fe ₁₄ B _n was used.

(Example 6)
A rare earth magnet compact was produced in the same manner as in Example 1 except that 5% by mass of Al particles with respect to the mass of Sm ₂ Fe ₁₄ B _n was used.

(Example 7)
A rare earth magnet molded body is produced in the same manner as in Example 3 except that the raw material supply rate is 10.0 g / m, the injection temperature of the secondary carrier gas is 200 ° C., and the injection pressure is 0.6 MPa. did.

(Example 8)
Rare earth magnet in the same manner as in Example 7 except that N ₂ gas is used as the raw material supply gas and the primary carrier gas, the gas temperature of the secondary carrier gas is 300 ° C., and the gas pressure is 2.8 MPa. A molded body was produced.

Example 9
Using 5 mass% Cu particles with respect to the mass of Sm ₂ Fe ₁₄ B _n , the gas temperature of the secondary carrier gas was 320 ° C., the gas pressure was 0.8 MPa, and the scanning speed was 100 mm / s. Except for this, a rare earth magnet compact was produced in the same manner as in Example 8.

(Example 10)
Same as Example 8 except that 5 mass% Cu particles with respect to the mass of Sm ₂ Fe ₁₄ B _n were used, the gas temperature of the secondary carrier gas was 350 ° C., and the gas pressure was 1.2 MPa. A rare earth magnet molded body was produced by the method described above.

(Comparative Example 1)
A rare earth magnet compact was produced in the same manner as in Example 1 except that the nonmagnetic metal particles were not added.

(Comparative Example 2)
A rare earth magnet compact was produced in the same manner as in Example 1 except that 20% by mass of Cu particles was used with respect to the mass of Sm ₂ Fe ₁₄ B _n .

(Comparative Example 3)
A rare earth magnet compact was produced in the same manner as in Comparative Example 1 except that air (Air) was used as the raw material supply gas and the primary carrier gas.

(Comparative Example 4)
Using 1% by mass of Cu particles with respect to the mass of Sm ₂ Fe ₁₄ B _n , the raw material supply rate is 9.0 g / m, N ₂ gas is used as the raw material supply gas and the primary carrier gas, and the secondary carrier gas A rare earth magnet molded body was produced in the same manner as in Example 1 except that the gas temperature was 720 ° C. and the gas pressure was 1.2 MPa.

(Comparative Example 5)
A rare earth magnet molded body is produced in the same manner as in Example 1 except that the raw material supply rate is 10.0 g / m, the gas temperature of the secondary carrier gas is 540 ° C., and the gas pressure is 0.4 MPa. did.

[Evaluation of rare earth magnet compacts]
<Theoretical density>
The theoretical density means the density of the rare earth magnet particles in the magnet molded body with respect to the density (hereinafter also referred to as “assumed density”) when the magnet molded body is assumed to be composed of only rare earth magnet particles. The assumed density value of Sm ₂ Fe ₁₄ B _n (n = 2 to 3) was determined from the lattice constant measured by X-ray crystal structure analysis using X′Pert PRO MRD (manufactured by PANaltical). At this time, the measurement conditions for the X-ray crystal structure analysis were a tube voltage of 45 kV and a tube current of 40 mA, and CuKα rays were used as the X-rays. The theoretical density of the obtained rare earth magnet particle compact was determined by subtracting the porosity and the density of nonmagnetic metal particles in the rare earth magnet particle compact from the assumed density. The porosity was measured by the Archimedes method using the substrate. The density of the nonmagnetic metal particles in the rare earth magnet particle compact was measured by wet analysis. Specifically, the rare earth magnet molded body was dissolved in an acid and measured using an SPS-3520 type (manufactured by SII Nanotechnology Co., Ltd.) which is an inductively coupled plasma emission spectroscopic analyzer. When measuring the porosity and the density of the non-magnetic metal particles in the rare earth magnet particle compact, the rare earth magnet compact that is strongly bonded to the Cu substrate is milled, and the rare earth magnet compact is converted to Cu. It measured after peeling from a base material.

<Residual magnetic flux density (Br)>
The residual magnetic flux density (Br) is an index of magnetic characteristics. The residual magnetic flux density was measured using a vibrating sample magnetometer (VSM) manufactured by Toei Kogyo Co., Ltd. after performing pulse magnetization of 4.8 MA / m together with a Cu base material bonded to a rare earth magnet compact. Measured at room temperature. The demagnetizing field correction was performed by subtracting the thickness of the base material from the film thickness. The residual magnetic flux density of the rare earth magnet compact was evaluated as a relative value to the residual magnetic flux density of the rare earth magnet particles.

<Peeling location>
The obtained rare earth magnet compact was visually observed for peeling.

  The evaluation results of Examples and Comparative Examples are shown in Table 1.

  As shown in Table 1 above, according to the results of Examples 1 to 10, a rare earth magnet molded body having a theoretical density of 80% or more and containing rare earth magnet particles at a high density was obtained. From the comparison between the theoretical density and the value of the residual magnetic flux density (Br), it is understood that none of the rare-earth magnet molded bodies obtained by the manufacturing method has impaired magnetic properties in the manufacturing stage (Br is And evaluated as a relative value to the residual magnetic flux density of the rare earth magnet particles). In addition, none of the deposits was separated by mixing the nonmagnetic metal particles.

  According to the results of Comparative Examples 1, 3 and 4, if the Cu particles (nonmagnetic metal particles) are not contained in a sufficient amount, the residual stress and / or repulsive force generated when the rare earth magnet particles collide with the base material. Was not sufficiently relaxed, and the deposits were peeled off.

  According to the result of Comparative Example 2, when the nonmagnetic metal particles are added excessively, the deposits do not peel off, but the proportion of the rare earth magnet particles in the rare earth magnet compact is reduced correspondingly, and the theoretical density is 78.5. % Was low.

  In the results of Comparative Example 3, when the theoretical density and the value of Br were compared, the theoretical density was 94.8%, whereas Br showed a low value of 35%. This is presumed that the magnetic properties of the rare earth magnet particles were impaired by air (Air) as a carrier gas.

  In the result of Comparative Example 4, when the theoretical density and the value of Br were compared, the theoretical density was 93.8%, whereas Br showed a low value of 21%. This is presumed that the magnetic properties of the rare earth magnet particles were impaired under the condition of high temperature (780 ° C.).

  According to the result of Comparative Example 5, since the gas pressure was as low as 0.4 MPa, the gas velocity was lowered to 500 m / s or less accordingly, and no deposit was obtained.

  In the examples, the gas velocity at the injection stage was higher than the gas velocity of the AD method (about 500 m / s). For example, 1130 m / s in Example 1, 1138 m / s in Example 3, 1070 m / s in Example 5, 1047 m / s in Example 7, and 950 m / s in Example 8.

[Presence or absence of peeling due to addition of Cu particles]
The evaluation of peeling by addition of nonmagnetic metal particles was compared in more detail.

  A rare earth magnet molded body was produced in the same manner as in Example 1. At this time, the amount of Cu particles added and the film thickness were appropriately adjusted, and the number of peeled portions per 50 mm was visually observed.

  In Table 2 above, when the results of addition of Cu particles (non-magnetic metal particles) at 0% by mass and 1% by mass were compared, the separation of the deposits was greatly improved only by adding the Cu particles. The result suggests that the nonmagnetic metal particles have an effect of relieving residual stress and / or repulsive force generated when the rare earth magnet particles collide with the base material. Further, when the amount of Cu particles added was increased, it was possible to prevent the exfoliation of the deposit even when the film thickness was 1.5 mm.

1 rare earth magnet molded body,
3 rare earth magnet particles,
5 non-magnetic metal particles,
7 impurities,
9 voids,
20 Nanoindentation experiment equipment,
21 Diamond pyramid indenter,
23 samples,
40 chambers,
41 Carrier gas acceleration section,
43 substrates,
45 nozzle gun,
47 Raw material supply gas supply pipe,
49 Primary carrier gas supply pipe,
50a interior magnet type synchronous motor,
50b Surface magnet type synchronous motor,
51 Rare earth magnet molded body for an embedded magnet type synchronous motor,
53 A rotor for an embedded magnet type synchronous motor,
55 Rare earth magnet moldings for surface magnet type synchronous motors,
57 A rotor for a surface magnet type synchronous motor.

Claims (9)

Following formula (1):

(Wherein R is Nd or Sm, M is Fe or Co, and X is N or B)
Rare earth magnet particles represented by
Non-magnetic metal particles having an elasto-plastic ratio of 50% or less,
A rare earth magnet molded article having a theoretical density of 80% or more.   The rare earth magnet molded article according to claim 1, wherein the nonmagnetic metal particles include at least one selected from the group consisting of Cu, Al, and Zn.   The rare earth magnet compact | molding | casting of Claim 1 or 2 with which the said nonmagnetic metal particle is contained in the quantity of more than 1 mass% and less than 20 mass% with respect to the mass of the said rare earth magnet molded object.   The rare earth magnet molded article according to any one of claims 1 to 3, wherein the rare earth magnet particles are Sm-Fe-N. A charging step of charging rare earth magnet particles and non-magnetic metal particles into a carrier gas;
An injection step of injecting the rare earth magnet particles and the nonmagnetic metal particles onto a substrate;
Solidifying and forming the rare earth magnet powder and the nonmagnetic metal particles on the substrate to obtain a deposit, and
The gas temperature in the injection stage is equal to or lower than the decomposition temperature of the nitride of the rare earth magnet particles;
A method for producing a rare earth magnet molded body, wherein the solidification molding step is performed under atmospheric pressure.   The manufacturing method according to claim 5, wherein the gas pressure in the injection stage is 0.6 MPa or more.   The manufacturing method according to claim 5 or 6, wherein the carrier gas is an inert gas.   The manufacturing method of any one of Claims 5-7 whose thickness of the said deposit is 200 micrometers or more.   The magnet motor containing the rare earth magnet molded object of any one of Claims 1-4.

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