WO2013073640A1

WO2013073640A1 - Magnetic member and process for producing magnetic member

Info

Publication number: WO2013073640A1
Application number: PCT/JP2012/079706
Authority: WO
Inventors: 前田　徹
Original assignee: 住友電気工業株式会社
Priority date: 2011-11-18
Filing date: 2012-11-15
Publication date: 2013-05-23
Also published as: JP2013110225A

Abstract

Provided are a magnetic member which is excellent in terms of magnetic properties and productivity and a process for producing the magnetic member. A powder (20) of a soft-magnetic metal and a multiphase powder (30) composed of multiphase particles in which a phase of a hydride of a rare-earth element and a phase of a substance comprising Fe are present are fed to a molding die (100A), and both powders (10, 20) are simultaneously pressed and compacted to form a powder compact (10A). The powder compact (10A) is subjected to a heat treatment, thereby separating the hydrogen from the multiphase particles to yield a recombination alloy in which the rare-earth element has combined with the substance comprising Fe. Through these steps, a magnetic member (1A) comprising a soft-magnetic region (2A) and a magnet region (3A) constituted of the recombination alloy (alloy comprising the rare-earth element and Fe) is formed. Since both powders (10, 20) are simultaneously molded, the number of steps is small and the productivity is excellent. The magnetic member (1A) has no fine gap that may occur in the case where a soft-magnetic member and a magnet are used as separate members, and is hence inhibited from suffering the decrease in magnetic property caused by the gap. Thus, the magnetic member (1A) has excellent magnetic properties.

Description

Magnetic member and method of manufacturing magnetic member

The present invention relates to a magnetic member including a portion made of a soft magnetic material and a magnet portion, a manufacturing method thereof, a rotating machine including the magnetic member, a coil component, and an electromagnetic valve. In particular, the present invention relates to a magnetic member having excellent magnetic properties and productivity.

Magnetic members comprising a member made of a soft magnetic material such as iron and a permanent magnet are used in various fields. An example of such a magnetic member is a rotor of a motor. Patent Document 1 describes a rotor of a radial gap type motor. This rotor has a cylindrical rotor body made of a compacted magnetic body (compacted compact) obtained by press-molding soft magnetic metal powder such as iron powder, and a permanent magnet insertion slot (slot) provided in the rotor body. With a permanent magnet inserted into the. Patent Document 2 describes a rotor of an axial gap type motor. The rotor includes a rotor body made of a soft magnetic material such as iron, and a permanent magnet fixed to the rotor body.

As permanent magnets used for motors and the like, rare earth magnets are widely used (paragraph 0027 of the specification of Patent Document 2). As rare earth magnets, for example, Nd (neodymium) -Fe (iron) -B (boron) R (R is a rare earth element) -Fe-B alloy or Sm (samarium) -Fe-N (nitrogen) alloy And a bonded magnet formed by molding a mixture of the R-Fe-N alloy powder and the binding resin. Bond magnets have a higher degree of freedom in shape than sintered magnets, and can be easily formed into a desired shape.

On the other hand, Patent Document 3 discloses that a rare earth magnet having excellent moldability and excellent magnet characteristics is obtained as a magnet powder by hydrogenating an alloy containing rare earth elements and Fe (for example, Sm ₂ Fe ₁₇ ) A multiphase powder having a structure in which rare earth element hydride phases (for example, SmH ₂ ) exist discretely in the contained phase has been proposed. By using this magnet powder, a powder compact having a high relative density can be obtained. By performing dehydrogenation treatment and then nitriding treatment in order on this powder compact, a rare earth magnet having a high magnetic phase ratio and excellent magnet characteristics can be obtained.

JP 2005-318760 JP 2008-301666 A JP 2011-137218 A

Improvement of productivity of the above magnetic member is desired.

For example, the rotor of a motor is manufactured by separately manufacturing a compact of green compacts and electromagnetic steel sheets that will be the rotor body, and permanent magnets such as rare earth magnets, and then inserting the permanent magnets into the slots of the rotor body or bonding them. The permanent magnet is fixed to the rotor body with the agent. Therefore, in manufacturing a magnetic member having a portion made of a soft magnetic material and a magnet portion, the conventional manufacturing method has a large number of steps, resulting in a decrease in productivity.

Also, it is desired to improve the magnetic characteristics of the magnetic member.

As described above, if the portion made of the soft magnetic material and the permanent magnet are independent members, for example, the slot of the rotor body needs to be provided with a fitting allowance (likelihood) for inserting the permanent magnet. If there is a fitting allowance, a minute gap based on the fitting allowance is generated. This gap becomes a magnetic gap, resulting in loss of magnetic transmission such as leakage of magnetic flux, leading to deterioration of magnetic characteristics. When the manufacturing tolerances of both the slot and the permanent magnet are large, the magnetic gap is further increased, resulting in further deterioration of the magnetic characteristics.

On the other hand, in the above-described bonded magnet, the mixture of the alloy powder and the binding resin is excellent in fluidity. Therefore, after the mixture is extruded into the slot, the resin is cured and the rotor body and the bonded magnet are integrally formed. Thus, the magnetic gap can be eliminated. However, since the bonded magnet has a binding resin, the magnetic phase is small, and even if the rotor body and the bonded magnet are integrally molded as described above, the bonded magnet becomes a magnetic member having inferior magnetic properties.

Therefore, one of the objects of the present invention is to provide a magnetic member that is excellent in productivity and magnetic characteristics. Another object of the present invention is to provide a method for producing a magnetic member that can produce a magnetic member having excellent magnetic properties with high productivity. Furthermore, another object of the present invention is to provide a rotating machine, a coil component, and an electromagnetic valve having the magnetic member having excellent productivity and magnetic characteristics.

Since the above-mentioned multiphase powder is excellent in moldability, it can be handled in the same manner as soft magnetic metal powders such as pure iron powder and iron alloy powder used in compacted compacts. Therefore, the present inventor examined simultaneous molding of the above-described multiphase powder and soft magnetic metal powder. In addition, when the above-described multiphase powder is used, after the molding, the powder compact is subjected to a heat treatment such as a dehydrogenation treatment or a nitriding treatment. When the simultaneous molding is performed, the heat treatment is performed on the soft magnetic region after the molding. Can be used as a heat treatment for strain relief. Therefore, when the above-described multiphase powder and soft magnetic metal powder were simultaneously molded and subjected to heat treatment such as dehydrogenation, a magnetic member having excellent magnetic properties was obtained as shown in a test example described later. In addition, the obtained magnetic member includes a region composed of soft magnetic metal powder (soft magnetic region) and a recombination alloy powder (or further subjected to nitriding treatment) produced by dehydrogenation treatment of the multiphase powder. There was no clear boundary with the region (magnet region) composed of the alloy powder), and a region where the powder composing each region was intermingled was formed, and both regions were combined. The present invention is based on the above findings.

The method for producing a magnetic member according to the present invention relates to a method for producing a magnetic member by press-molding magnetic powder and subjecting the obtained powder compact to a heat treatment. Provide elementary processes.
Preparation process The process which prepares the following multiphase powder and soft-magnetic metal powder as raw material powder.
The multiphase powder is a powder composed of multiphase particles having a structure in which a phase of a hydrogen compound of a rare earth element and a phase of an Fe-containing material exist discretely.
Molding process After supplying one powder of the multiphase powder and the soft magnetic metal powder to the molding die, and then supplying the other powder, press both powders filled in the molding die simultaneously Compressing to form a powder compact.
The relative density of the region composed of the multiphase powder in the powder compact is set to 85% or more.
Dehydrogenation step In an inert atmosphere or a reduced-pressure atmosphere, heat treatment is performed on the powder compact at a temperature equal to or higher than the recombination temperature of the multiphase particles to separate hydrogen from the multiphase particles, and the rare earth element and the above A step of forming a recombination alloy combined with Fe-containing material to form the following magnetic member.
The magnetic member includes a soft magnetic region composed of the soft magnetic metal powder and a magnet region composed of the recombination alloy.

The method for producing a magnetic member of the present invention comprises a compacted body made of a permanent magnet and soft magnetic powder in order to simultaneously form the above-described multiphase powder and soft magnetic metal powder, and then heat-treat it into an integral product. As compared with the case where each is manufactured separately and integrated, the number of processes is small, and the magnetic member can be manufactured with high productivity.

Moreover, since the manufacturing method of the magnetic member of this invention manufactures an integrated object through simultaneous shaping | molding and heat processing as mentioned above, a micro clearance gap like the case where an independent member is combined is a soft magnetic area | region and a magnet. Does not occur between areas. Therefore, there is no deterioration of the magnetic characteristics based on this minute gap, and the magnetic member manufacturing method of the present invention can manufacture a magnetic member having excellent magnetic characteristics.

Furthermore, both the above-mentioned multiphase powder and soft magnetic metal powder are deformed in the molding step, and the particles constituting each powder can be meshed by the irregularities on the particle surface. Further, the particles of the multiphase powder and the particles of the soft magnetic metal powder can be meshed with each other. Therefore, the method for producing a magnetic member of the present invention expresses so-called necking strength between the multiphase particles constituting the multiphase powder, between the metal particles constituting the soft magnetic metal powder, and between the multiphase particles and the metal particles. Thus, a powder molded body having excellent bonding property between particles can be obtained. This powder compact is excellent in strength due to the expression of the necking strength, and is difficult to disintegrate during production. By using such a powder molded body having excellent strength as a material, the magnetic member manufacturing method of the present invention can stably manufacture a magnetic member having excellent strength.

As described above, the method for producing a magnetic member of the present invention can stably produce a magnetic member having excellent magnetic properties and strength, and can be suitably used for mass production of such a magnetic member. In addition, since the magnetic member manufacturing method of the present invention uses powder as a raw material, the degree of freedom in shape is high, and a magnetic member having a desired shape can be easily manufactured.

The magnetic member of the present invention is composed of a compact obtained by pressure-molding magnetic powder, and a magnet composed of a soft magnetic region composed of soft magnetic metal powder and an alloy powder containing rare earth elements and Fe. With areas. The filling rate of the alloy powder in the magnet region is 80% by volume or more. The magnetic member includes a mixed region in which the soft magnetic metal powder and the alloy powder are mixed and present between the soft magnetic region and the magnet region.

Since the magnetic member of the present invention has the above-mentioned mixing region, the soft magnetic metal powder and the above-mentioned specific alloy powder (or the precursor powder from which this alloy powder can be produced by the manufacturing process. It can be said that the powder was manufactured by pressure molding at the same time. From this, the magnetic member of the present invention has a smaller number of steps compared to the case where the permanent magnet and the compacted body made of soft magnetic powder are independent members and separately integrated as described above, Excellent productivity. Such a magnetic member of the present invention can be manufactured, for example, by the above-described method for manufacturing a magnetic member of the present invention.

Also, the magnetic member of the present invention does not have a minute gap between the soft magnetic region and the magnet region as in the case where independent members are combined as described above. Therefore, no leakage or turbulence of magnetic flux occurs in the gap, and the magnetic member of the present invention can construct a magnetic circuit having excellent magnetic characteristics. Furthermore, in the magnetic member of the present invention, the magnet region has a sufficiently high filling rate of the above-mentioned specific alloy powder, and is excellent in magnetic characteristics as compared to the bonded magnet (for example, the magnetic flux density is sufficiently large), The magnetic member of the present invention is excellent in magnetic properties.

In addition, the magnetic member of the present invention does not have a clear boundary (interface) between the magnet region and the soft magnetic region as in the case of separate integration. By being composed of a mixed region in which alloy powder and soft magnetic metal powder are mixed, cracks and breaks are hardly generated at the boundary portion, and the strength is excellent.

From the above, the magnetic member of the present invention is excellent in productivity, excellent in magnetic properties and strength, and sufficiently has practical performance as a magnetic member.

As an embodiment of the magnetic member of the present invention, the thickness of the mixed region is equal to or greater than the larger average particle size of the average particle size of the soft magnetic metal powder and the average particle size of the alloy powder. Is mentioned.

The above form is excellent in strength because it has a mixed region in which both powders are sufficiently mixed.

As an embodiment of the magnetic member of the present invention, the alloy powder includes RE as one or more elements selected from Y, La, Pr, Nd, Sm, Dy and Ce, and Me as Fe or Fe and Co, Ni. 1 or more elements selected from Mn, Ti, and when x = 1.5 to 3.5, RE ₂ Me ₁₄ B, RE ₂ Me ₁₄ C, RE ₂ Me ₁₇ N _x , RE ₁ Me ₁₂ N _x and A form composed of one or more alloys selected from RE ₁ Me ₁₂ can be mentioned.

RE ₂ Me ₁₄ B, RE ₂ Me ₁₄ C, RE ₂ Me ₁₇ N _x , RE ₁ Me ₁₂ N _x , RE ₁ Me ₁₂ (x = 1.5 to 3.5) are all excellent in magnetic properties. The said form which comprises the magnet area | region which consists of compositions is excellent in a magnetic characteristic.

As an embodiment of the method for producing a magnetic member of the present invention, there is an embodiment in which the magnetic member that has undergone the dehydrogenation step is further provided with an annealing step in which heat treatment is performed in an inert atmosphere or a reduced pressure atmosphere.

In the method for producing a magnetic member of the present invention, thermal strain may remain on the material during cooling in the dehydrogenation process. Here, the multiphase particles and metal particles used for the raw material expand and contract according to their own thermal expansion coefficient. Since both particles are made of different materials, the above-described thermal strain can occur depending on the difference in thermal expansion coefficient between the particles. Further, as the volume decreases due to the dehydrogenation treatment, stress may be generated at the interface of the recombined alloy particles generated after the dehydrogenation treatment. If the member having the thermal strain or the interface stress is used in an environment that weakens the magnetocrystalline anisotropy, the thermal strain or the interface stress may cause a decrease in magnetic properties. Therefore, it is desired to remove (relax) the thermal strain and interface stress. The above-described form including the annealing step can remove the thermal strain and interfacial stress, and can produce a magnetic member having excellent magnetic properties.

As one form of the method for producing a magnetic member of the present invention, the material subjected to the dehydrogenation step is subjected to heat treatment at a temperature not lower than the nitriding temperature of the recombined alloy and not higher than the nitrogen disproportionation temperature in an atmosphere containing nitrogen element. The form which comprises a nitriding process is mentioned.

When the magnet region is composed of a nitrogen-containing component such as a RE-Me-N alloy, the above embodiment can produce a magnetic member having excellent magnetic properties by performing nitriding on the material after dehydrogenation. . The nitriding treatment can also serve as an annealing treatment for removing the thermal strain. Therefore, in the said form, the above-mentioned annealing process can be abbreviate | omitted and the magnetic member excellent in a magnetic characteristic can be manufactured with sufficient productivity.

As an embodiment of the method for producing a magnetic member of the present invention, in the dehydrogenation step, there is an embodiment in which the heat treatment is performed by applying a magnetic field of 2 T or more to the powder compact. The application direction of the magnetic field is a magnetic flux direction of a magnetic circuit in which the magnetic member is used.

In the dehydrogenation step, hydrogen is removed from the multiphase particles, and a reaction is typically performed in which rare earth elements and Fe are combined. A liquid phase (rare earth rich phase) having a high content of rare earth elements exists around crystal nuclei generated by this reaction. When the above-described specific strong magnetic field is applied in this state, the crystal orientation of the crystal nucleus is easily oriented in a certain direction, and when the above reaction is completed, the easy axis of magnetization of the crystal is in a certain direction (for example, the application direction of the magnetic field). To be aligned. Therefore, in the above-described embodiment in which the above-described specific magnetic field is applied, the magnet region can be oriented, and an effect due to magnetic anisotropy can be obtained. Therefore, a magnetic member having further excellent magnetic characteristics can be manufactured. .

As a form comprising the above nitriding step, in the dehydrogenation step, the heat treatment (dehydrogenation treatment) is performed by applying a magnetic field of 3 T or more to the powder compact, and in the nitriding step, the dehydrogenation step is performed. There is a mode in which the heat treatment (nitriding treatment) is performed by applying a magnetic field of 3.5 T or more to the material. The application direction of the magnetic field in both steps is the magnetic flux direction of the magnetic circuit in which the magnetic member is used.

When the above-mentioned specific strong magnetic field is applied in the nitriding process, the crystal lattice of the crystal grains constituting the recombination alloy containing Fe is distorted by the magnetostrictive effect, and a magnetic field is applied between the Fe atoms and Fe atoms constituting the crystal lattice. Can stretch in the direction. In addition, N atoms easily enter between the stretched Fe atoms and Fe atoms. That is, the said form can control the penetration | invasion direction of N atom in a nitriding process. For this reason, the above-described embodiment facilitates the arrangement of N atoms at ideal positions in the crystal lattice, and can efficiently produce an alloy (for example, Sm ₂ Fe ₁₇ N ₃ ) having an ideal atomic ratio. Moreover, the said form can also obtain the effect by magnetic anisotropy by applying the above-mentioned specific strong magnetic field also at the time of a dehydrogenation process, and setting it as an orientation structure | tissue. Therefore, the said form can manufacture the magnetic member which is further excellent in a magnetic characteristic.

The magnetic member of the present invention can be applied to various uses. For example, the rotating machine of the present invention includes a machine including the magnetic member of the present invention.

The rotating machine of the present invention includes the magnetic member of the present invention having excellent magnetic characteristics as described above. For example, a motor has a high torque, and a generator has a high excitation voltage.

Examples of the coil component of the present invention include those having the magnetic member of the present invention.

Since the coil component of the present invention has a configuration in which a magnet component of a magnet region is added to a magnetic core made of a soft magnetic material, for example, when configured to cancel a DC magnetic field generated by a superimposed current to be used, a magnetization curve It is possible to process a high-frequency component magnetic field in a region having a high linear response. Therefore, when the coil component of the present invention is used for a reactor or the like, the operation of the reactor can be stabilized.

Examples of the electromagnetic valve of the present invention include those having the magnetic member of the present invention.

The electromagnetic valve of the present invention can reinforce the magnetic force by the electromagnet by the magnetic force in the magnet region. Therefore, the force of the spring used for the opening / closing operation of the valve portion may be smaller than when there is no magnet region. For example, the electromagnetic valve of the present invention can reduce the diameter of the wire constituting the spring or reduce the number of turns of the spring. By reducing the size of the spring, the solenoid valve of the present invention can be reduced in size. Or the solenoid valve of this invention can make small the energization electric current value to an electromagnet.

The magnetic member of the present invention is excellent in magnetic properties and productivity. The method for producing a magnetic member of the present invention can produce a magnetic member having excellent magnetic properties with high productivity.

FIGS. 4A to 4C are process explanatory views showing an example of a forming process in the method for producing a magnetic member of the present invention, and FIG. 4D is a schematic perspective view showing the magnetic member of Embodiment 1. FIGS. FIGS. 4A to 4C are process explanatory views showing another example of the forming process in the method for manufacturing a magnetic member of the present invention, and FIG. 4D is a schematic perspective view showing the magnetic member of Embodiment 2. FIGS. 6 is a plan view showing a magnetic member according to Embodiment 3. FIG. (A) is a plan view showing a magnetic member of Embodiment 4, and (B) is a plan view showing a magnetic member of Embodiment 5. FIG. 4 is a photomicrograph showing the vicinity of a region (mixed region) between a soft magnetic region and a magnet region in the cross section of the magnetic member of the present invention produced in Test Example 1. FIG. 5 is an explanatory view for explaining a rotating machine produced in Test Example 2. FIG. 5 is an explanatory diagram for explaining a coil component produced in Test Example 3. FIG. 6 is an explanatory diagram for explaining a solenoid valve produced in Test Example 4. FIG.

Hereinafter, the present invention will be described in more detail. First, the method for producing a magnetic member of the present invention will be described, and then the magnetic member of the present invention will be described.

[Method of manufacturing magnetic magnetic material]
(Preparation process)
A soft magnetic metal powder for forming a soft magnetic region and the above-described multiphase powder are prepared as a precursor powder that becomes a recombination alloy by dehydrogenation.

[Soft magnetic metal powder]
As the soft magnetic metal powder, powders made of soft magnetic materials having various compositions conventionally used for compacted products can be used. Specific examples of soft magnetic materials include ferromagnetic transition element metals such as Fe, Co, and Ni and alloys containing ferromagnetic transition metal elements. For example, pure iron composed of Fe and unavoidable impurities, iron alloys mainly composed of Fe (for example, Fe-Si alloys, Fe-Ni alloys, Fe-Al alloys, Fe-Co alloys, Fe-Cr alloys) Iron-based materials such as alloys, Fe-Si-Al alloys, and various steels. The iron-based material can easily obtain a soft magnetic region having a higher saturation magnetic flux density than a spinel ferrite material made of iron oxide or the like. Among iron-based materials, in particular, pure iron and iron alloys with a small amount of additive elements (for example, Fe-Si alloys with an Si content of 2.5% by mass or less, Fe-Al alloys, Fe-Ni alloys, etc.) ) Is excellent in moldability. A plurality of types of soft magnetic metal powders having different materials can be used in combination.

It is possible to provide an insulating coating on the surface of the metal particles constituting the soft magnetic metal powder. In this case, the soft magnetic region of the obtained magnetic member has an electrical resistance due to an insulating film (or an insulator generated by a heat treatment such as a dehydrogenation process, a subsequent nitriding process, or an annealing process) interposed between metal particles. For example, eddy current loss can be reduced. The material of the insulating coating can be selected as appropriate. In applications where the electrical resistance may be low (for example, a motor operating at a low rotation, a rotor of a generator, etc.), the insulating coating may not be provided. The same applies to the multiphase particles described later.

The average particle size of the soft magnetic metal powder is preferably about 10 μm or more and 500 μm or less because it is easy to handle and has excellent moldability. A plurality of powders having different average particle sizes may be used. In particular, when a hard alloy powder is used, by using a finely mixed powder, the relative density of the powder compact can be increased and a dense soft magnetic region can be formed.

[Multiphase powder]
The multiphase powder is in a hydrogen disproportionation decomposition state. Typically, the phase of the Fe-containing material is the parent phase (the content of the Fe-containing material is 60% by volume or more). It is composed of multiphase particles having a structure in which elemental hydrogen compounds (more than 0% by volume, preferably 10% by volume or more) are dispersed. In the above structure, the spacing between the phases of the rare earth element hydrogen compounds adjacent to each other through the Fe-containing material phase is typically 0.5 μm or more (preferably 1 μm or more) and 3 μm or less. Fe content is (1) Fe (pure iron) only, (2) at least one element selected from Co, Ga, Cu, Al, Si, Cr and Nb (hereinafter referred to as a substitution element) and Fe, (3) Any one of (1) to (4), including a compound containing Fe (eg, FeTi, FeMn, Fe ₃ B, Fe ₂ B, FeB, etc.) and Fe, (4) a substitution element, the above compound and Fe The form is mentioned. A plurality of types of multiphase powders having different materials can be used in combination.

The multiphase powder is obtained by subjecting the starting alloy powder to a hydrogenation treatment, and the production method described in Patent Document 3 can be suitably used for its production.

The starting alloy, for example, RE is one or more elements selected from Y, La, Pr, Nd, Sm, Dy and Ce, and Me is selected from Fe alone or selected from Co, Ni, Mn and Ti One or more elements selected from RE _x Me ₁₄ B, RE _x Me ₁₄ C, RE _x Me ₁₇ and RE _{x / 2} Me ₁₂ when x = 2.0 to 2.2 when elements are Fe and more than species. . More specifically, RE _x Me ₁₄ B is Nd ₂ Fe ₁₄ B, Nd ₂ (Co ₁ Fe ₁₃ ) B, RE _x Me ₁₄ C is Nd ₂ Fe ₁₄ C, RE _x Me ₁₇ is Sm ₂ Fe ₁₇ , Y ₂ Fe ₁₇ , RE _{x / 2} Me ₁₂ are Sm ₁ (Ti ₁ Fe ₁₁ ), Sm ₁ (Mn ₁ Fe ₁₁ ), Y ₁ (Ti ₁ Fe ₁₁ ), Y ₁ (Mn ₁ Fe ₁₁ ). In particular, an alloy containing Sm or Nd provides a magnetic member having a magnet region with excellent magnetic properties. In addition, the starting alloy allows an element containing an element (for example, Cu, Al, Si, Ga, Nb, etc.) that controls crystal growth when changing from a multiphase structure to a recombination alloy structure. A starting alloy powder is obtained by preparing a starting alloy having a desired composition and using a known powder manufacturing method (such as a gas atomizing method or a method including pulverization) as described in Patent Document 3. In particular, the atomization method is easy to produce a powder having a high sphericity and excellent filling properties at the time of molding.

The conditions for the hydrogenation treatment are as follows: atmosphere is a single atmosphere of only hydrogen (H ₂ ), or a mixed atmosphere of hydrogen (H ₂ ) and an inert gas such as argon (Ar) or nitrogen (N ₂ ), and the temperature is The disproportionation temperature is 1100 ° C. or less, and the holding time is 0.5 hours or more and 5 hours or less. The specific temperature is 700 ° C. or more and 900 ° C. or less, Nd ₂ Fe ₁₄ B, Nd ₂ when the starting alloy is Sm ₂ Fe ₁₇ , Sm ₁ (Ti ₁ Fe ₁₁ ), Sm ₁ (Mn ₁ Fe ₁₁ ), etc. In the case of (Co ₁ Fe ₁₃ ) B, Nd ₂ Fe ₁₄ C, etc., 750 ° C. to 900 ° C. can be mentioned. For the hydrogenation treatment, the disproportionation conditions in the known HDDR treatment can be applied.

The average particle size of the multiphase powder is preferably 10 μm or more and 500 μm or less, considering the moldability and filling rate, and 30 μm or more, and more preferably 100 μm or more and 350 μm or less. Since the size of the multiphase powder depends on the size of the starting alloy powder, the size of the starting alloy powder and the hydrogenation conditions may be adjusted so that the multiphase powder has a desired size. A plurality of powders having different average particle sizes may be used. By using finely mixed powder, the relative density of the powder compact can be increased, and a dense magnet region can be formed.

The soft magnetic metal powder and the multiphase powder may have different average particle diameters or may be equal. When both powders have the same average particle size, depending on the strength and hardness of both powders, it is easy to adjust the pressing pressure during molding, and it is possible to perform uniform pressing, and powder molding with excellent dimensional accuracy and appearance. Easy to get a body.

In addition, as described in Patent Document 3, when the form is provided with an anti-oxidation layer and an insulating film so as to cover the entire circumference of the multiphase particles, the anti-oxidation of the new surface generated at the time of molding, the electricity of the magnetic member (magnet region) The resistance can be increased.

(Molding process)
A molding die is selected so as to obtain a desired magnetic member, and the soft magnetic metal powder and the multiphase powder are supplied to the molding die, and simultaneously pressed and compressed to form a powder molded body. Form. The higher the relative density (actual density with respect to the true density of the powder molded body), the higher the density of the powder molded body, the higher the density in the soft magnetic region and the higher the proportion of the magnetic phase in the magnet region. Easy to get. Accordingly, it is preferable to adjust the pressure so that the relative density of the powder compact is 85% or more, preferably 90% or more. In the embodiment provided with the above-described antioxidant layer, when the relative density of the region formed of the multiphase powder in the powder molded body is set to about 90% or more and 95% or less, the antioxidant layer can be easily removed by heat treatment in the subsequent step.

The soft magnetic metal powder and the multiphase powder may be sequentially filled in a molding die so that a desired magnetic member can be obtained, and the order of powder feeding is not particularly limited.

Similar to the soft magnetic metal powder used as the raw material of the conventional compacted body, the multiphase powder is also excellent in moldability, so that the pressure during molding can be made relatively small. For example, the pressure at the time of molding is 8 ton / cm ² or more and 15 ton / cm ² or less.

Since multiphase powders containing rare earth elements are particularly susceptible to oxidation, it is preferable to use a non-oxidizing atmosphere in the molding process because it can prevent oxidation of multiphase powders and soft magnetic metal powders. In the form in which the multiphase powder includes the above-described antioxidant layer, the forming step may be performed in an oxygen-containing atmosphere such as an air atmosphere.

In addition, in the molding process, by appropriately heating the molding die, deformation of the multiphase powder and the like can be promoted, and a high-density powder molded body and a powder molded body having a complicated shape can be easily obtained. Moreover, it is easy to release the powder compact by applying a lubricant to the molding die as appropriate.

Further, the molding process may be pressurized and compressed in multiple stages. In the case of multi-stage molding, in the middle stage, the pressure during molding is relatively small, and the powder is moved to some extent so that the stress due to density difference due to pressurization in multiple stages is relieved. If the pressure is increased after completing the above, it is easy to mold and densify. Specific conditions, the pressure of the middle stage, so that the degree 1 ton / cm ² or more 3 ton / cm ² or less, the relative density of the molded body (preformed body) in the middle stages, the extent of 75% or less To be molded. When molding various three-dimensional shaped powder compacts with multiple powders, pressurizing in multiple stages can fill the next powder without collapsing the powder already filled in the molding die. Can be integrally molded well. Alternatively, a shape-retaining material made of a material (for example, paraffin or the like) that can be lost by heat treatment after molding (such as dehydrogenation) may be appropriately placed in the molding die during molding. Also in this case, the collapse of the powder already filled in the molding die can be prevented.

The obtained powder compact has a metal powder region made of soft magnetic metal powder and a multiphase powder region made of multiphase powder. In the metal powder region, metal particles made of soft magnetic metal mesh with each other, and in the multiphase powder region, multiphase particles mesh with each other. And between both area | regions, a metal particle and multiphase particle | grains are mixed and comprised, and there is no clear boundary. In the region where the different kinds of particles are mixed, the metal particles and the multiphase particles are meshed with each other. Therefore, the obtained powder compact has high strength due to the above-described meshing and is not easily disintegrated during production. The thickness of the region where the metal particles and the multiphase particles are mixed varies depending on the particle diameters of the two powders, and depends on the powder having the larger average particle diameter.

(Dehydrogenation process)
In the dehydrogenation step, in the multiphase powder, hydrogen is separated from the multiphase particles, and the rare earth element and the Fe-containing material are combined to form a single-phase structure composed of a recombination alloy from the multiphase structure. It is a process. Further, the dehydrogenation step is a step for removing distortion introduced by molding in the soft magnetic metal powder. For the hydrogen separation, the heat treatment (dehydrogenation treatment) atmosphere in the dehydrogenation step is a non-hydrogen atmosphere such as an inert atmosphere or a reduced pressure atmosphere. Examples of the inert atmosphere include Ar and N ₂ . The reduced pressure atmosphere refers to a vacuum state in which the pressure is lower than that of a standard air atmosphere. The degree of vacuum in the reduced pressure atmosphere is preferably 100 Pa or less, and the final degree of vacuum is preferably 10 Pa or less, more preferably 1 Pa or less. When a reduced pressure atmosphere is used, rare earth element hydrogen compounds are unlikely to remain, and a decrease in magnetic characteristics due to the remaining rare earth element hydrogen compounds can be suppressed, and a magnetic member having a magnet region with excellent magnetic characteristics can be obtained.

The temperature of the dehydrogenation treatment is equal to or higher than the recombination temperature of the multiphase particles. Typically, the temperature is 600 ° C. or higher when Sm is included, and 700 ° C. or higher when Nd is included, although it varies depending on the composition. The higher the temperature of the dehydrogenation treatment, the easier it is to remove the introduced strain in the metal particles constituting the soft magnetic metal powder, and in the multiphase particles, hydrogen can be sufficiently removed and recombination can proceed. However, if the temperature of the dehydrogenation treatment is too high, there is a concern about volatilization of rare earth elements and coarsening of crystals of the recombination alloy. The retention time for the dehydrogenation treatment is 10 minutes or more and 600 minutes or less. The conditions for the dehydrogenation process can be the conditions for the DR process in the known HDR process.

In the dehydrogenation step, the dehydrogenation process can be performed in a state where a strong magnetic field of 2 T or more is applied to the powder compact. In this embodiment, since the crystal orientation of the crystal nuclei of the recombination alloy can be oriented in one direction by magnetostriction as described above, the magnet region in the magnetic member can be oriented. With this orientation structure (crystal magnetization easy axis, typically a structure in which the c-axis is oriented in one direction), a magnet region having excellent magnetic characteristics can be obtained. Since the orientation is improved as the magnetic field is increased, the applied magnetic field can be 3 T or more, further 3.2 T or more, particularly 4 T or more.

The application direction of the magnetic field is preferably the magnetic flux direction of a magnetic circuit in which a magnetic member is used. By doing so, when the magnetic member of the present invention is assembled in a magnetic circuit, the magnetic characteristics of the magnet region can be fully utilized. Further, the application direction of the magnetic field is preferably the same as the molding direction (compression direction) when molding the powder compact.

When a high-temperature superconducting magnet is used for the application of the magnetic field, (1) a strong magnetic field can be stably formed, (2) the magnetic field can be changed at high speed, so (2-1) heat treatment time is shortened, (2-2 ) It has advantages such as suppression of coarsening of crystal grains and (2-3) continuous processing. This point can also be applied to the application of a magnetic field in a nitriding step described later.

As a multiphase powder, the above-mentioned RE _x Me ₁₄ B, RE _x Me ₁₄ C, and RE _{x / 2} Me ₁₂ are used as starting alloys, for example, a phase of RE hydride such as Nd, Fe, Fe ₃ B, etc. When using a powder composed of multiphase particles including a phase of Fe-containing material, the magnet region is made of RE ₂ Me ₁₄ B, RE ₂ Me ₁₄ C, RE ₁ Me _12, etc. A magnetic member made of an alloy (recombined alloy) powder is obtained.

(Nitriding process)
On the other hand, as a multiphase powder, the above-mentioned RE _x Me ₁₇ and RE _{x / 2} Me ₁₂ are used as a starting alloy, for example, a phase of a hydrogen compound of RE such as Sm and a phase of an Fe-containing material such as Fe or FeTi. When a powder composed of multiphase particles is used, an alloy such as RE ₂ Me ₁₇ N _x , RE ₁ Me ₁₂ N _x (re- A magnetic member composed of a powder of an alloy obtained by nitriding a binding alloy is obtained.

The conditions described in Patent Document 3 can be used as the nitriding conditions. Specifically, the atmosphere includes an atmosphere containing nitrogen element, the temperature is from the nitriding temperature to the nitrogen disproportionation temperature, and the holding time is from 10 minutes to 600 minutes. Specific atmospheres include (1) a single atmosphere containing only nitrogen, (2) an ammonia (NH ₃ ) atmosphere, (3) a gas containing a nitrogen element such as nitrogen (N ₂ ) or ammonia, and an inert gas such as Ar. One of (1) to (4) is mentioned, for example, a mixed gas atmosphere, and (4) a mixed gas atmosphere of a gas containing nitrogen and hydrogen (H ₂ ). Since the atmosphere containing hydrogen gas is a reducing atmosphere, the generated nitride can be prevented from being oxidized or excessively nitrided. The nitriding temperature and the nitrogen disproportionation temperature vary depending on the alloy composition before nitriding.For example, in the case of Sm ₂ Fe ₁₇ , Sm ₁ Fe ₁₁ Ti ₁ , it is 200 ° C or higher and 550 ° C or lower, and further 200 ° C or higher and 450 ° C or lower. In particular, a temperature of 200 ° C. to 300 ° C. is mentioned.

In the nitriding step in addition to the dehydrogenating step, the nitriding treatment can be performed with a strong magnetic field applied. In this form, as described above, the crystal lattice of the recombination alloy is easily stretched in one direction, and N atoms are preferentially penetrated between the stretched Fe atoms-Fe atoms, and nitrides having an atomic ratio in an ideal state ( For example, it is easy to obtain Sm ₂ Fe ₁₇ N ₃ ). When the magnet region of the magnetic member is made of a nitride having an ideal atomic ratio and has an oriented structure as described above, the magnet region can be further improved in magnetic properties. The larger the magnetic field is, the more the magnetic field to be applied can be controlled. Therefore, the applied magnetic field is preferably 3T or more, more preferably 3.5T or more, particularly 3.7T or more, especially 4T or more. The application direction of the magnetic field in the nitriding step is preferably the magnetic flux direction of the magnetic circuit in which the magnetic member is used as described above. That is, it is preferable that the application direction of the magnetic field is the same in the dehydrogenation step and the nitridation step. By doing so, it is easy to maintain the oriented structure.

(Annealing process)
When heat treatment (annealing) is further performed on the magnetic member that has undergone the dehydrogenation process, the thermal strain and interface stress that can remain on the magnetic member due to the dehydrogenation treatment can be removed, resulting in deterioration of characteristics due to thermal strain and interface stress, etc. Can be suppressed. The annealing conditions include an inert atmosphere or a reduced pressure atmosphere, a temperature of 250 ° C. to 450 ° C., and a holding time of 1 minute to 600 minutes. The matter described in the dehydrogenation process can be applied to the specific atmosphere.

When performing the above-described nitriding step, the nitriding treatment also serves as an effect of the annealing treatment, so that it is not necessary to perform the annealing treatment separately and can be omitted.

When the above-described strong magnetic field is applied in the dehydrogenation process or the nitriding process, dehydration can be performed by applying the above-described strong magnetic field (2T or more, preferably 3T or more) in the same direction as in the dehydrogenation process even in the annealing process. It is easy to maintain an aligned structure that is aligned in the elementary process.

[Magnetic member]
The magnetic member of the present invention is composed of a plurality of different magnetic powder compacts. Specifically, it includes a soft magnetic region formed by pressure-molding the soft magnetic metal powder described above, and a magnet region formed of an alloy powder containing a rare earth element and Fe. In short, the magnetic member of the present invention is a member in which a dust compact (soft magnetic region) and a dust magnet (magnet region) are integrated. The magnet region is used as a permanent magnet. The soft magnetic region supports a magnet region that becomes a permanent magnet and is typically used as a magnetic path.

The magnetic member of the present invention is formed by combining a plurality of different powders individually manufactured by simultaneously forming a plurality of different powders and performing an appropriate heat treatment as described above. Unlike the case described above, the greatest feature is that the boundary between the soft magnetic region and the magnet region is unclear and there is no clear boundary.

The metal particles constituting the soft magnetic region are composed of the above-described pure iron, iron alloy, or the like in order to maintain the composition of the soft magnetic metal powder used as a raw material.

The alloy particles constituting the magnet region are typically recombined alloys produced by pressing the above-mentioned multiphase powder and then subjected to dehydrogenation treatment, and alloys nitrided by further nitriding treatment. The thing which consists of is mentioned. The specific composition is RE ₂ Me ₁₄ B, RE ₂ Me ₁₄ C, RE ₂ Me ₁₇ N _x , RE ₁ Me ₁₂ N using the above-mentioned RE and Me (where x = 1.5 to 3.5). One or more alloys selected from _x and RE ₁ Me ₁₂ may be mentioned. More specifically, RE ₂ Me ₁₄ B is Nd ₂ Fe ₁₄ B, Nd ₂ (Co ₁ Fe ₁₃ ) B, RE ₂ Me ₁₄ C is Nd ₂ Fe ₁₄ C, RE ₂ Me ₁₇ N _x is Sm ₂ Fe ₁₇ N ₃ , Y ₂ Fe ₁₇ N ₃ , RE ₁ Me ₁₂ N _x are Sm ₁ (Ti ₁ Fe ₁₁ ) N ₂ , Sm ₁ (Mn ₁ Fe ₁₁ ) N ₂ , Y ₁ (Ti ₁ Fe ₁₁ ) N ₂ , Y ₁ (Mn ₁ Fe ₁₁ ) N ₂ , RE ₁ Me ₁₂ are Sm ₁ (Ti ₁ Fe ₁₁ ), Sm ₁ (Mn ₁ Fe ₁₁ ), Y ₁ (Ti ₁ Fe ₁₁ ), Y ₁ (Mn ₁ Fe ₁₁ ) and the like. In particular, an alloy in which RE is Nd or Sm, more specifically an Nd—Fe—B alloy or an Sm—Fe—N alloy is preferable because of excellent magnetic properties. The alloy particles constituting the magnet region are allowed to contain the above-described Cu, Al, Cr, Si, Ga, Nb and the like.

The magnetic member of the present invention has a high filling rate of alloy particles in the magnet region and is 80% by volume or more. The filling rate is likely to increase as the relative density of the powder compact is increased, and can be 80% by volume or more by using a powder compact having a relative density of 85% or greater as described above. The higher the filling rate, the more excellent the magnetic properties of the magnet region. Therefore, the filling rate is more preferably 85% by volume or more.

The average particle size of the metal particles constituting the soft magnetic region is 10 μm or more and 500 μm or less, further 30 μm or more and 200 μm or less, and the average particle size of the alloy particles constituting the magnet region is 10 μm or more and 500 μm or less, further 100 μm or more and 350 μm or less. It is done. Since the average particle size of the soft magnetic region and the average particle size of the magnet region depend on the average particle size of the soft magnetic metal powder or multiphase powder used as the raw material, the particles in each region have a desired size. It is better to adjust the size of the raw material powder. If the alloy particles that make up the magnet region have a large particle size, deterioration of the magnetic properties due to surface layer oxidation can be suppressed. Therefore, if a multiphase powder having a relatively large particle size is used as a raw material, a magnet region having excellent magnetic properties can be formed. Can be produced and has excellent productivity.

The thickness of the mixed region depends on the size of the metal particles constituting the soft magnetic region and the alloy particles constituting the magnet region. The specific thickness may be equal to or greater than the larger average particle size of the average particle size of the soft magnetic metal powder and the average particle size of the alloy powder. In this case, the particles having a smaller average particle diameter can be sufficiently interposed in the gap formed by the larger particles. A more specific thickness is, for example, 100 μm or more.

[Usage]
The magnetic member of the present invention can be diverted to a conventional member in which a permanent magnet is appropriately attached to a member made of a soft magnetic material with an adhesive or the like. Specifically, a constituent member of a rotating machine such as a radial gap type or an axial gap type motor or a generator, more specifically, a rotor may be mentioned. Or a member having a magnetic core made of a soft magnetic material and capable of adding a magnet component, for example, a coil component such as a reactor or a choke coil, an electromagnetic having a movable core and a fixed core made of a soft magnetic material The magnetic member of the present invention can also be used for components such as valves. By adding permanent magnets to coil parts and solenoid valves, the linear response area (linearity) is improved by expanding the linear response area (linearity area) in coil parts, and the attraction force increases or separates in solenoid valves. For example, the force can be increased, the energization current to the solenoid coil can be reduced, and the movable spring disposed on the movable core can be downsized by reducing the diameter.

Hereinafter, more specific embodiments of the present invention will be described with reference to the drawings. In the figure, the same reference numerals indicate the same names.

[Embodiment 1]
As the magnetic member of the present invention, for example, a magnetic member 1A shown in FIG. 1 (D) is composed of a soft magnetic region 2A composed of a soft magnetic metal powder and an alloy powder containing a rare earth element and Fe. In other words, there is a configuration in which a molded body having a laminated structure in which the magnet region 3A is laminated. In FIG. 1 (D), for convenience of explanation, it is shown by a straight line, but between the soft magnetic region 2A and the magnet region 3A, there is a mixed region in which both the above-mentioned powders are mixed, both regions 2A, There is no clear boundary between 3A.

Here, the magnetic member 1A has a two-layer structure, but can have three or more layers. Here, the magnetic member 1A is a cylindrical body having a through-hole 10h in the center, but can be formed in various shapes such as a form having no through-hole or a rectangular tube-shaped body. The point regarding the shape is the same for the embodiments described later. Furthermore, the thickness (the length along the axial direction of the through-hole 10h) of each

region

2A, 3A of the magnetic member 1A can be selected as appropriate, and the thickness of each

region

2A, 3A is equal or different It can be.

The magnetic member 1A having such a laminated structure is prepared, for example, by using the soft magnetic metal powder 20 and the multiphase powder 30 as raw materials as described above, and using a molding die 100A shown in FIG. It can be manufactured by forming a powder compact 10A (FIG. 1 (C)) and subjecting the powder compact 10A to dehydrogenation treatment, nitriding treatment or annealing treatment as appropriate.

The molding die 100A includes a die 101 provided with a through-hole (here, a circular hole), a cylindrical (here cylindrical) upper punch 102 (FIG. 1C), and a lower punch 103 that are arranged to face each other. And a rod-shaped (here, columnar) rod 110 that is inserted through the die 101 and forms the through-hole 10h. In the case where the through hole is not provided, the rod 110 may be omitted, and the upper punch and the lower punch may be columnar. The points related to the rod are the same in the embodiments described later.

The powder compact 10A is molded as follows. As shown in FIG. 1 (A), the rod 110 and the lower punch 103 are disposed in the through hole of the die 101, the end surface of the die 101 and the end surface of the rod 110 are aligned, and the lower punch 103 is placed at an appropriate position. Deploy. By doing so, a cavity is formed by the inner peripheral surface of the through hole of the die 101, the outer peripheral surface of the rod 110, and the end surface (pressing surface) of the lower punch 103. This cavity is filled with one of the soft magnetic metal powder 20 and the multiphase powder 30 (here, the multiphase powder 30) by a powder feeder. The position of the lower punch 103 or the filling amount is adjusted so that the multiphase powder 30 filled in the cavity has a desired thickness (length in the vertical direction in FIG. 1).

Next, here, as shown in FIG. 1 (B), the lower punch 103 is moved downward, and the inner peripheral surface of the through hole of the die 101, the rod above the multiphase powder 30 filled in the die 101. A cavity composed of the outer peripheral surface of 110 and the multiphase powder 30 is formed, and the other powder (here, soft magnetic metal powder 20) is filled by a powder feeder. In the case of three or more layers, a cavity is formed in the same manner, and powder feeding is repeated. Instead of moving the lower punch 103, the die 101 may be moved upward. Alternatively, if there is a space that can be filled with one powder (here, the multiphase powder 30) and the other powder (here, the soft magnetic metal powder 20), the lower punch 103 and the die 101 do not move. May be. In addition, after filling one powder, after lightly pressing with the upper punch 102 (this pressure is, for example, a pressure smaller than the simultaneous compression described later), a cavity for filling the other powder is formed. May be. When temporary molding is performed in the middle (for example, when a temporary molded body having a relative density of about 70% to 75% is formed), the powder already filled is not easily broken. The point regarding temporary molding is the same for the embodiments described later.

Then, as shown in FIG. 1 (C), the upper punch 102 is arranged so that the end surface (pressing surface) of the upper punch 102 faces the end surface of the lower punch 103, and the soft magnetic metal powder 20 and The multiphase powder 30 is simultaneously pressed and compressed. Through the above process, a powder molded body 10A having a multilayer structure is obtained.

[Embodiment 2]
As another form of the magnetic member of the present invention, for example, it contains soft magnetic regions 2Bi and 2Bo made of soft magnetic metal powder as in the magnetic member 1B shown in FIG. 2 (D), and a rare earth element and Fe. An example is a configuration in which a molded body having a coaxial structure in which a magnet region 3B made of an alloy powder is concentrically arranged. In FIG. 2 (D), for the sake of convenience of explanation, although shown by a smooth curve, both the above-mentioned powders are present between the soft magnetic region 2Bi and the magnet region 3B and between the soft magnetic region 2Bo and the magnet region 3B. There is a mixed region that exists in a mixed manner, and there is no clear boundary between both regions 2Bi and 3B and between both regions 2Bo and 3B.

Here, the magnetic member 1B is a cylindrical body having a through-hole 10h in the center, and is lined with the soft magnetic region 2Bi, the magnet region 3B, and the soft magnetic region 2Bo from the inner side, and the innermost and outermost side is a soft magnetic metal. It is composed of powder and the magnet region 3B is sandwiched. In addition, a magnet region can be provided inside and outside the soft magnetic region so as to sandwich the soft magnetic region. Here, the magnetic member 1B has a triple structure, but may have a double structure or a quadruple structure or more. The order of the soft magnetic region and the magnet region can also be selected as appropriate. The thickness of the magnetic member 1B (the length along the axial direction of the through hole 10h) and the width of each region (the length in the radial direction) can be appropriately selected.

Such a coaxial-shaped magnetic member 1B is provided with a soft magnetic metal powder 20 and a multiphase powder 30 in the same manner as in Embodiment 1, and using a molding die 100B shown in FIG. The molded body 10B (FIG. 2C) is formed, and the powder molded body 10B can be manufactured by performing dehydrogenation treatment, nitriding treatment or annealing treatment as appropriate as described above.

The basic configuration of the molding die 100B is the same as that of the molding die 100A described in the first embodiment. The die 101 and the upper punch 102 (FIG. 2 (C)) are divided into a plurality of parts and are coaxial. And

lower rods

103a, 103b, and 103c, and a rod 110. The lower punch may be divided according to the number of regions formed concentrically (number of divisions = number of regions).

The powder compact 10B is molded as follows. As shown in FIG. 2 (A), the rod 110 and the lower punches 103a to 103c are arranged in the through hole of the die 101, and the end surface of the die 101, the end surface of the rod 110, and the end surfaces of the

lower punches

103a and 103c are aligned. The lower punch 103b is disposed at an appropriate position. Thus, a cavity is formed by the outer peripheral surface of the lower punch 103a, the inner peripheral surface of the lower punch 103c, and the end surface (pressing surface) of the lower punch 103b. This cavity is filled with one of the soft magnetic metal powder 20 and the multiphase powder 30 (here, the multiphase powder 30) by a powder feeder. The position of the lower punch 103b is adjusted so that the multiphase powder 30 filled in the cavity has a desired thickness (length in the vertical direction in FIG. 2). Here, the cavity of the multiphase powder 30 is formed first, but the cavity of the soft magnetic metal powder 20 can be formed first. In this case, the magnetic member 1B can be formed by replacing “lower punch 103b” described above and later with “

lower punches

103a, 103c” and substantially the same.

After filling with the multiphase powder 30, after lightly pressing and temporarily forming, the

lower punches

103a and 103c are moved downward until the end faces of the lower punches 103a to 103c are aligned as shown in FIG. Alternatively, the die 101 is moved upward). In this way, a cavity is formed by the inner peripheral surface of the through-hole of the die 101, the outer peripheral surface of the rod 110, the peripheral surface of the multiphase powder 30, and the end surfaces of the

lower punches

103a and 103c. Then, the soft magnetic metal powder 20) is filled. By performing the temporary molding (for example, by forming a temporary molded body having a relative density of about 70% or more and about 75% or less), the multiphase powder 30 is not easily broken in forming the cavity.

Then, as shown in FIG. 2C, the upper punch 102 is arranged so that the end surface (pressing surface) of the upper punch 102 faces the end surfaces of the lower punches 103a to 103c, and the upper punch 102 is softened by both the

punches

102 and 103a to 103c. The magnetic metal powder 20 and the multiphase powder 30 are simultaneously pressed and compressed. Through the above steps, a powder compact 10B having a coaxial structure is obtained.

[Embodiment 3]
As another form of the magnetic member of the present invention, like the magnetic member 1C shown in FIG. 3, it is a C-shaped body, and is composed of a pair of U-shaped part and I-shaped part. The shape is such that the letter-shaped part is a soft magnetic region 2C _l , 2C _r composed of soft magnetic metal powder, and the I-shaped part is a magnet region 3C composed of an alloy powder containing rare earth elements and Fe It is done. In Figure 3, for convenience of explanation, indicated by the straight line, between the soft magnetic region 2C _l and magnet region 3C, and between the soft magnetic region 2C _r and the magnet area 3C, and mixing both powders described above There is an existing mixed region, and there is no clear boundary between the two regions 2C ₁ and 3C and between the two regions 2C _r and 3C. This is also true for FIG. 4 described later.

Here, the magnetic member 1C is a C-shaped body having a gap 10g in which a part of the annular body in the circumferential direction is divided, but as shown in FIG. 4 to be described later, can do. Here, the magnet region 3C is formed at the center of the C-shape, but can be selected as appropriate. The length of the magnet region 3C (the length along the circumferential direction of the C shape) can also be selected as appropriate. The number and shape of the magnet regions 3C can also be selected as appropriate. FIG. 4 described later shows an example in which the numbers and shapes of the soft magnetic regions and the magnet regions are different.

Such a C-shaped magnetic member 1C can be manufactured, for example, by using a powder compact produced using a molding die as described below. In the molding die 100A shown in FIG. 1, the die 101 is replaced with a die that protrudes from the inner peripheral surface of the die and has a protrusion that forms a gap 10g, and the lower punch 103 is combined to form a C shape. Replace with a lower punch (here, a pair of U-shaped lower punch and I-shaped lower punch) divided into a plurality (here, three) in the circumferential direction of the character. Then, as described in the second embodiment, the divided lower punch (or die) is moved over a plurality of stages, and by appropriately temporarily forming, each of the soft magnetic metal powder and the multiphase powder can be supplied. it can.

[Embodiment 4]
As another embodiment of the magnetic member of the present invention, it is possible to form an annular body (here, an annular shape) having no gap, like

magnetic members

1D and 1E shown in FIG. 4 (A). The

magnetic members

1D and 1E are toroids having different outer diameters, and each includes a plurality of

magnet regions

3D and 3E and a plurality of soft

magnetic regions

2D and 2E. The

magnetic members

1D and 1E have soft

magnetic regions

2D and 2E and

magnet regions

3D and 3E in a sector shape with a predetermined inner angle. The

magnetic members

1D and 1E can also be manufactured by using, for example, a powder molded body manufactured using a molding die as described below. The lower punch 103 in the molding die 100A shown in FIG. 1 is divided into a plurality of (here, eight) lower punches 103 (here, the end surface serving as the pressing surface is a fan-shaped lower punch) ). Then, as described in the second embodiment, the divided lower punch (or die) is moved over a plurality of stages, and by appropriately temporarily forming, each of the soft magnetic metal powder and the multiphase powder can be supplied. it can.

By combining the

magnetic members

1D and 1E of Embodiment 4, the magnet region (3D) of one magnetic member (for example, 1D) is N pole, and the magnet region (3E) of the other magnetic member (1E) is S pole. It can be.

[Embodiment 5]
The magnetic member 1F shown in FIG. 4 (B) is also formed of an annular body (annular shape here) having no gap, and includes soft magnetic regions 2Fi, 2Fo and a magnet region 3Fi concentrically as in the first embodiment. Further, the magnetic member 1F includes a plurality of magnet regions 3Fo (here, a fan shape with a predetermined inner angle) so as to divide the periphery of the soft magnetic region 2Fo on the outer peripheral side. The magnetic member 1F can be manufactured, for example, by using a powder compact manufactured using a molding die as described below. The lower punch 103c on the outer peripheral side of the molding die 100B shown in FIG. 2 is divided into a plurality of (here, five) lower punches (here, the end surface serving as the pressing surface is a fan shape). 4 lower punches and a gear-like lower punch to which these lower punches are assembled). Then, as described in the second embodiment, the divided lower punch (or die) is moved over a plurality of stages, and by appropriately temporarily forming, each of the soft magnetic metal powder and the multiphase powder can be supplied. it can.

Since the magnetic member 1F of the fifth embodiment includes a plurality of magnet regions 3Fi and 3Fo in one magnetic member, for example, one magnet region (for example, 3Fi) on the inner peripheral side and the outer peripheral side has an N pole and the other The magnet region (3Fo) can be the south pole.

As shown in Embodiments 1 to 5, a magnetic member having various shapes and numbers of magnet regions and soft magnetic regions can be obtained.

Next, with reference to a test example, a more specific form of use and characteristics of the magnetic member of the present invention having a soft magnetic region and a magnet region will be described.

[Test Example 1]
In this test, a magnetic member composed of a molded body having a laminated structure shown in FIG. 1 (D) was prepared, cut so that the laminated state could be seen, and the cross section was observed with a microscope to obtain a soft magnetic region and a magnet region. The binding part was investigated.

In Test Example 1, pure iron powder having an average particle size of 50 μm (ABC100.30 manufactured by Höganäs AB) was prepared as a raw soft magnetic metal powder. Further, as a multiphase powder of a raw material, it is a powder having an average particle diameter of 100 μm, and has a structure in which granular NdH ₂ exists discretely in an Fe-containing material composed of Fe, Fe ₃ B, Fe ₂ B, etc. An alloy was prepared. The multiphase powder is made of a rare earth-iron-boron alloy (Nd ₂ Fe ₁₄ B), and heat-treated (powder annealing. 1050 ° C. × 120 minutes, in high concentration argon) to gas atomized powder with an average particle size of 100 μm, The mixture was once cooled and then subjected to hydrogenation treatment at 800 ° C. for 1 hour in a hydrogen (H ₂ ) atmosphere. As for the average particle diameter, the particle diameter (50% particle diameter) at which the cumulative weight becomes 50% was measured by a laser diffraction particle size distribution apparatus.

In Test Example 1, a powder compact having a laminated structure as described in Embodiment 1 was formed (the pressure during molding was 10 ton / cm ² ). Here, the rod 110 is omitted in the molding die 100A shown in FIG. 1, and a soft magnetic region layer exists so as to sandwich the magnet region layer by using a molding die having columnar upper and lower punches. A three-layered cylindrical powder compact was produced. The powder compact was successfully manufactured. When the relative density of the obtained powder compact was examined, it was 90%. As described in Patent Document 3, the relative density was measured by measuring the actual density with a commercially available density measuring device and calculating the true density by calculation.

The obtained powder compact was heated to 750 ° C in a hydrogen atmosphere, then switched to vacuum (VAC) and dehydrogenated in vacuum (VAC) (final vacuum 1.0 Pa) at 750 ° C x 60 min. gave. After the dehydrogenation treatment, an annealing treatment was performed by holding at 400 ° C. for 120 minutes in an argon atmosphere. The cylindrical magnetic member obtained thereafter had a diameter of 11 mm, and the thickness of each region was 10 mm (30 mm in total).

FIG. 5 is a photomicrograph of a cross section of the obtained magnetic member observed with a transmission electron microscope (SEM). As shown in FIG. 5, it can be seen that a plurality of regions made of powders of different materials are laminated on this magnetic member. When the composition of each region was examined with an EDX apparatus, it was confirmed that in the upper region in FIG. 5, Nd ₂ Fe ₁₄ B was the main phase (85% by volume or more), and hydrogen was removed by the dehydrogenation treatment. did it. Further, the lower region in FIG. 5 was pure iron. Therefore, this magnetic member is composed of a soft magnetic region 2 composed of soft magnetic metal powder (here, pure iron powder) and an alloy containing rare earth elements (here, Nd) and Fe (here, Nd ₂ Fe ₁₄ B It was confirmed that the magnet region 3 composed of powder made of

Further, the filling rate of the alloy powder in the magnet region was 87% by volume, and it was confirmed that it was 80% by volume or more. The filling rate was determined as follows. A magnet region is separated from the obtained magnetic member, and a density (hereinafter referred to as an actual density) is measured by Archimedes method. Further, the alloy powder constituting the magnet region is subjected to X-ray analysis, and the density (true density) of the magnet phase (alloy component) is measured. Then, a ratio between the actually measured density and the true density, that is, (actually measured density / true density) × 100 was calculated, and this ratio was used as the filling rate. When a phase other than the magnet phase is present in the alloy powder constituting the magnet region, the true density of the alloy powder should be determined in consideration of the true density of the phase and the volume fraction of the phase in the alloy powder. Can do. The volume ratio of phases other than the magnet phase can be calculated from the peak ratio of X-rays, for example. When the phase other than the magnet phase is a non-magnetic phase (such as air or resin), the volume ratio can be obtained from the saturation magnetization value. When the filling rate of the soft magnetic metal powder in the soft magnetic region was measured in the same manner, it was 93% by volume. From this, it was confirmed that even if the soft magnetic metal powder and the multiphase powder were simultaneously molded, a dense molded body having a filling rate of 80% by volume or more was obtained.

As shown in FIG. 5, it can be seen that there is a portion where the soft magnetic metal powder and the alloy powder are mixed and present between the soft magnetic region 2 and the magnet region 3. In the produced magnetic member, only a portion where only the soft magnetic metal powder is present and only the alloy powder are present on a plane orthogonal to the stacking direction (here, a plane parallel to the circular end surface; indicated by two broken lines in FIG. 5). When the existing portion is separated, the region sandwiched between the two planes (two broken lines) is a mixed region 4 in which soft magnetic metal powder and alloy powder are mixed. Here, the thickness of the mixed region 4 is about 300 μm, and the larger of the average particle diameter of the soft magnetic metal powder and the average particle diameter of the alloy powder (here, the average particle diameter of the alloy powder is 100 μm). Was also confirmed to be large. It was also confirmed that there was no clear boundary between the soft magnetic region 2 and the magnet region 3, and there was no fine gap as in the case of combining independent members.

Note that the average particle diameter of the soft magnetic metal powder constituting the magnetic member and the average particle diameter of the alloy powder are substantially the same as the average particle diameter of the soft magnetic metal powder used as the raw material and the average particle diameter of the multiphase powder. It is confirmed that it is maintained. The average particle diameter of the soft magnetic metal powder of the magnetic member and the average particle diameter of the alloy powder are determined as follows. Set the measurement area (10 mm x 10 mm area here) from the micrograph of the cross section above, extract the outlines of all metal particles and alloy particles existing in the measurement area, and extract the equivalent area circle from the outline of each particle Ask for. The diameter of this equivalent area circle is taken as the diameter of each particle. The average value (n ≧ 100) of the diameters of the metal particles is defined as the average particle diameter of the soft magnetic metal powder constituting the soft magnetic region. The average value (n ≧ 100) of the diameters of the alloy particles is defined as the average particle size of the alloy powder constituting the magnet region. Unlike the sintered body, the soft magnetic region and the magnet region can confirm the grain boundaries of the powder (the contours of the alloy particles and the metal particles).

Further, since the produced magnetic member has a three-layer structure of soft magnetic region-magnet region-soft magnetic region, this magnetic member has two spaces between the soft magnetic region and the magnet region. FIG. 5 shows one space, but it is confirmed that the other region is also a mixed region.

[Test Example 2]
A magnetic member 1B having a coaxial structure in which soft magnetic regions and magnet regions are arranged concentrically as shown in FIG. 2 is manufactured, and this magnetic member 1B is used as a rotor of a rotating machine (here, a generator), and the magnetic member 1B is provided. We investigated the characteristics of the rotating machine.

Here, as shown in FIG. 6, a rotating machine having a stator component 50 simulating a stator using a magnetic member 1B as a rotor, a magnet region 3B as a field, and a stator was fabricated. The raw material, molding conditions (pressure), and dehydrogenation conditions of the magnetic member 1B were the same as in Test Example 1. The stator component 50 is configured by spirally winding a columnar (here rectangular parallelepiped) magnetic core 51 made of a soft magnetic material and a winding (a copper wire having an enamel coating) around the outer periphery of the magnetic core 51. A coil 52;

The specifications of the magnetic member 1B and the stator component 50 are as follows. A rotating machine including the magnetic member 1B is designated as Sample No. 1-1.

Material of magnet region 3B: Nd ₂ Fe ₁₄ B (average particle size 100 μm)
Soft magnetic region 2Bi, 2Bo: Pure iron powder (ABC100.30, average particle size 50μm, manufactured by Höganäs AB)
Through hole 10h diameter r _10h = 5mm Soft magnetic region 2Bi outer diameter r _2Bi = 40mm
Magnet area 3B outer diameter r _3B = 50mm Soft magnetic area 2Bo outer diameter r _2Bo = 60mm
Magnetic member 1B thickness 25mm
Gap g _1B = 1mm between magnetic member 1B and stator component 50
Length of one side of magnetic core 51 L ₅₁ = 20mm Thickness of magnetic core 51 25mm
Length of arrangement area of coil 52 in magnetic core 51 l ₅₂ = 25 mm
Number of turns of coil 52 N = 25

For comparison, rotating machines of the following samples No. 1-100 and No. 1-111 to No. 1-114 comprising a magnetic member having a coaxial structure and a coil 52 were produced. Samples No.1-100 and No.1-111 to No.1-114 are all made of pure iron powder (average particle size 50 μm) used to form the soft magnetic region of Sample No.1-1. Two large and small cylindrical compacts (hereinafter referred to as soft magnetic compacts) having the same shape as the soft magnetic regions 2Bi and 2Bo were produced. In both cases, the pressure during molding was 10 ton / cm ² , and the heat treatment for strain relief was 500 ° C. × 1 hour. The finished dimensions (design values) of each soft magnetic compact were the same as the specifications of sample No. 1-1 described above. However, as described later, samples No. 1-111 to No. 1-114, in which the soft magnetic powder material and the magnet are independent members, included the fitting amount in the design value. The design values of the smaller soft magnetic dust material are 5 mm inside diameter, 40 mm outer diameter, 25 mm thickness, and the design values of the larger soft magnetic dust material are 50 mm inner diameter, 60 mm outer diameter, and 25 mm thickness. For the soft magnetic powder material, the filling rate of the soft magnetic metal powder was measured in the same manner as in Test Example 1. The results are shown in Table 1. In the No. 1-100 bonded magnet, the filling rate was lower than that of the other samples by reducing the molding pressure to reduce the resin spring back. This also applies to the test examples described later.

Sample No. 1-100 is a commercially available Nd ₂ Fe ₁₄ B powder (average particle size 50 μm, HDDR-treated powder) and a binder resin (epoxy resin). After filling between the magnetic compacts, the resin was cured. In other words, sample No. 1-100 is formed by bonding resin and soft magnetic powder material integrally with the resin component of the bond magnet, and there is substantially no gap between the bond magnet and soft magnetic powder material. It is a sample. The design values of this bonded magnet are an inner diameter of 40 mm, an outer diameter of 50 mm, and a thickness of 25 mm.

Samples No. 1-111 to No. 1-114 all have the above-mentioned large and small soft magnetic dust materials and magnets as independent members, and an annular magnet is fitted between the large and small soft magnetic dust materials. It is a sample.

Sample No. 1-111 uses the same multiphase powder as the raw material used to form the magnet region of Sample No. 1-1, and Nd ₂ Fe under the same molding conditions and dehydrogenation conditions as Sample No. 1-1. _A cylindrical magnet consisting of ₁₄ B and satisfying the above design values was produced and combined with a large and small soft magnetic compact.

Sample No. 1-112 was prepared by using the same commercially available powder and resin as the raw materials used for forming the bonded magnet of Sample No. 1-100, and using a mixture of this powder and resin, Nd ₂ Fe ₁₄ B Cylindrical bonded magnets containing powder and satisfying the above design values were produced and combined with large and small soft magnetic compacts.

Sample No. 1-113 is a cylindrical commercially available ferrite magnet ((BH) max = 30 kJ / m ³ ) that satisfies the above design value. Sample No. 1-114 is a cylindrical shape that satisfies the above design value. In addition, commercially available sintered magnet processed products made of Nd ₂ Fe ₁₄ B ((BH) max = 300 kJ / m ³ ) were prepared, and each was combined with a large and small soft magnetic powder material.

A rotating shaft (not shown) is inserted into the through hole 10h of the magnetic member of each sample prepared, and the magnetic member is rotated at 60 rpm by a driving device (not shown), and the maximum excitation voltage of the coil 52 at this time Was measured. The results are shown in Table 1. For Sample Nos. 1-100 and 1-111 to No. 1-114, the filling rate of the magnet components in the magnets included in each sample was measured in the same manner as in Test Example 1. The results are also shown in Table 1.

As shown in Table 1, sample No. 1 comprising a magnetic member having a mixed region in which a soft magnetic metal powder and a specific alloy powder functioning as a magnet are mixed between a soft magnetic region and a magnet region. 1 shows that the maximum excitation voltage is high and has excellent characteristics. This is because Sample No. 1-1 differs from Sample No. 1-111 to No. 1-114, which has a magnetic member formed by combining independent members, substantially between the soft magnetic region and the magnet region. This is probably because the current induced in the coil 52 is increased because there is no gap and the leakage magnetic flux in the minute gap is small. In addition, the magnet region of sample No. 1-1 has a higher magnetic phase ratio than the bonded magnet included in sample No. 1-100 and has excellent magnetic properties. It is thought that the current induced by Furthermore, in this test, Sample No. 1-1 has a higher maximum excitation voltage than Sample No. 1-114 using a sintered magnet having a high magnetic phase ratio. From this, it can be said that not only the characteristics of the magnet itself but also the characteristics of the magnetic member as a whole can be improved by adopting a structure that can reduce the leakage magnetic flux in the minute gap described above.

[Test Example 3]
A magnetic member 1C having a magnet region in a part of the C-shaped body shown in FIG. 3 and the other portion being composed of a soft magnetic region, and arranging a coil on this magnetic member 1C to produce a coil component, The characteristics of this coil component were examined.

Here, the magnetic member 1C is a coil component that is regarded as a magnetic core such as a reactor, and the arrangement region of the coil 62 is provided so as to include the magnet region 3C as shown in FIG. The raw material in the magnet region was the same multiphase powder as in Test Example 1, and the soft magnetic metal powder was Fe-Ni alloy powder. The pressure during molding of the magnetic member 1C was 10 ton / cm ² , and the dehydrogenation conditions were the same as in Test Example 1. The coil 62 was formed by spirally winding a copper wire having an enamel coating in the same manner as in Test Example 1.

The specifications of the magnetic member 1C are as follows. A coil component including the magnetic member 1C is designated as sample No. 2-1.

Material of magnet area 3C: Nd ₂ Fe ₁₄ B (average particle size 100 μm)
Soft region _{_{2C l, 2C r: Fe-}} Ni alloy (Daido Steel Co., Ltd. DAPPB average particle size 30 [mu] m)
Magnetic material (C-shaped) major axis L _l = 60 mm, minor axis L _s = 30 mm, gap length g _{10 g} = 5 mm, width W = 10 mm, thickness 3 mm
Magnet area 3C length L _3C = 10mm
Length of arrangement area of coil 62 in magnetic member (C-shaped body) l ₆₂ = 30mm
Number of turns of coil 62 N = 10

As a comparison, the following sample No.2-100, No.2-111 to No.2-114 coil parts comprising a magnetic core comprising a magnet component and a coil 62, comprising only a magnetic core and a coil 62 Sample No. 2-120 coil parts were prepared. Samples No. 2-100 and No. 2-111 to No. 2-114 all use the Fe-Ni alloy powder (average particle size 30 μm) used to form the soft magnetic region of Sample No. 2-1. Te, soft area 2C _l, a pair of U-shaped green compact are the same shape and 2C _r (hereinafter, referred to as soft magnetic powder material) was prepared. In both cases, the pressure during molding was 10 ton / cm ² , and the heat treatment for strain relief was 500 ° C. × 1 hour. The finished dimension (design value) of each soft magnetic powder material was set to the same value as that of the U-shaped portion excluding the magnet region 3C in the sample No. 2-1. However, as will be described later, samples No. 2-111 to No. 2-114 in which the soft magnetic powder material and the magnet are independent members have a fitting amount added to the design value. For the soft magnetic powder material, the filling rate of the soft magnetic metal powder was measured in the same manner as in Test Example 1. The results are shown in Table 2.

Sample No. 2-100 was prepared using the same raw material as Sample No. 1-100 of Test Example 1, and a mixture of Nd ₂ Fe ₁₄ B powder and resin described above with a pair of U-shaped soft magnetic powders After filling between one end faces of the material, the resin was cured. In other words, Sample No. 2-100 is formed with the bonded magnet and the soft magnetic dust material integrally formed by the resin component of the bonded magnet, and there is substantially no gap between the bonded magnet and the soft magnetic dust material. It is a sample. The design values of this bonded magnet are 10 mm in length, 10 mm in width, and 3 mm in thickness.

Samples No. 2-111 to No. 2-114 all have the above-mentioned pair of U-shaped soft magnetic dust materials and magnets as independent members, and a rectangular plate shape between the pair of soft magnetic dust materials. This is a sample fitted with a magnet.

Sample No. 2-111 uses the same multiphase powder as the raw material used for forming the magnet region of Sample No. 1-1 (No. 2-1), and has the same molding conditions and A rectangular plate-shaped magnet made of Nd ₂ Fe ₁₄ B (design values are 10 mm long, 10 mm wide, and 3 mm thick) under dehydrogenation conditions, and a pair of U-shaped soft magnetic powder materials Combined.

For sample No. 2-112, the same commercially available powder and resin as the raw materials used for forming the bonded magnet of sample No. 1-100 (No. 2-100) were prepared, and a mixture of this powder and resin was used. A flat bonded magnet containing Nd ₂ Fe ₁₄ B powder (design values are 10 mm in length, 10 mm in width, 3 mm in thickness), and a pair of U-shaped soft magnetic compacts Combined.

Sample No. 2-113 is a flat ferrite magnet ((BH) max = 30 kJ / m ³ ) with a length of 10 mm, a width of 10 mm, and a thickness of 3 mm. Sample No. 2-114 is the same as sample No. 2-114 A commercially available sintered magnet made of Nd ₂ Fe ₁₄ B ((BH) max = 300 kJ / m ³ ) is prepared and combined with a pair of U-shaped soft magnetic compacts. The

Sample No. 2-120 uses a soft magnetic metal powder (here, Fe-Ni alloy powder with an average particle size of 30 μm as described above) to produce a C-shaped powder compact. A sample with a body. The conditions for producing the green compact were the same as those for soft magnetic compacts No. 2-100 and No. 2-111 to No. 2-114.

Each prepared sample has the same position and size of the arrangement area of the coil 62, the coil 62 is arranged in this arrangement area, a commercially available LCR device is connected to the coil 62, and the coil 62 is not energized inductance (inductance I _0A zero current) was measured inductance I _100A when energized to 100A of current to the coil 62. The results are shown in Table 2. In addition, the reduction rate of the inductance when a current of 100 A was applied to the inductance I ₀ A at zero current was obtained. The results are also shown in Table 2. The rate of decrease was {(I _0A −I _100A ) / I _0A } × 100. Further, for sample No. 2-1, No. 2-100, No. 2-111 to No. 2-114, in the same manner as in Test Example 1, the filling rate of the magnet component in the magnet included in each sample, the sample No. 2-120 measured the filling rate of the soft magnetic metal powder. The results are also shown in Table 2.

As shown in Table 2, sample No. 2- having a magnetic member having a mixed region in which a soft magnetic metal powder and a specific alloy powder functioning as a magnet are mixed between the soft magnetic region and the magnet region. 1 shows that the rate of decrease in inductance is small and the characteristics can be improved as compared with Sample No. 2-120 having no magnet region. It can also be seen that Sample No. 2-1 has excellent characteristics even when compared with samples having other magnets. The reason for this is that sample No. 2-1 is substantially different between the soft magnetic region and the magnet region, unlike Samples No. 2-111 to No. 2-114 which have magnetic members formed by combining independent members. This is probably because the decrease in inductance is suppressed by the fact that there is no gap and the leakage magnetic flux in the minute gap is small. In addition, the magnet area of sample No. 2-1 has a higher ratio of magnetic phase than the bonded magnet included in sample No. 2-100, and has excellent magnet characteristics, so it is considered that the decrease in inductance was suppressed. It is done. Samples No.2-100 and No.2-112 with a low magnetic phase ratio started magnetic saturation at an energization current value of 100A, so they were used for high current applications where the energization current value to the coil exceeded 100A. Is considered unsuitable. It can also be seen that Sample No. 2-113 having a ferrite magnet has a large inductance reduction rate and is completely magnetically saturated at 100A. From this, it is considered that a magnetic member including a ferrite magnet is also unsuitable for use with a large current.

Furthermore, in this test, Sample No. 2-1 has a lower inductance reduction rate than Sample No. 2-114 using a sintered magnet having a high magnetic phase ratio. From this, it can be said that not only the characteristics of the magnet itself but also the characteristics of the magnetic member as a whole can be improved by adopting a structure that can reduce the leakage magnetic flux in the minute gap described above.

[Test Example 4]
Annular magnetic members 1D to 1F having a plurality of magnet regions shown in FIG. 4 and having other portions composed of soft magnetic regions are produced, and these magnetic members 1D to 1F are used as part of a fixed core and a movable core of an electromagnetic valve. The solenoid valve used for the production was manufactured, and the characteristics of this solenoid valve were investigated.

Here, a direct-acting solenoid valve as shown in FIG. 8 was produced. The direct-acting solenoid valve typically includes a T-shaped movable core 70 and a fixed core 71 on which a cylindrical coil 72 serving as an electromagnet is disposed. The movable core 70 includes a flat valve portion 73 and a shaft portion 74 attached so as to be orthogonal to the valve portion 73 and inserted through the coil 72. A spring 75 for linearly moving the valve portion 73 is disposed on the outer periphery of the shaft portion 74. The fixed core 71 is a bottomed double cylindrical body, and a cylindrical coil 72 is accommodated between the inner peripheral wall and the outer peripheral wall. The valve part 73 is brought into non-contact with or comes into contact with the end face of the fixed core 71, so that the valve is opened or closed. The opening / closing operation is typically performed by pushing up the valve portion 73 by the biasing force of the spring 75 to open the valve, energizing the coil 72, using the coil 72 as an electromagnet, and the magnetic force of the electromagnet being the biasing force of the spring 75. Since the valve portion 73 is attracted to the fixed core 71 side and finally comes into contact, the valve is closed.

In Test Example 3, the magnetic member 1F is attached to the valve portion 73 of the movable core 70, and the

magnetic members

1D and 1E are attached to the end surface of the inner peripheral wall and the outer peripheral wall of the fixed core 71, respectively. A solenoid valve including magnetic members 1D to 1F was produced. The magnetic members 1D to 1F are arranged so that the magnet regions of the magnetic members 1D to 1F face each other. All the magnet regions in the magnetic members 1D to 1F are provided equally. The raw materials for the magnet regions in the magnetic members 1D to 1F were the same multiphase powder as in Test Example 1, and the soft magnetic metal powder constituting the soft magnetic region and the Fe-Co alloy powder were used as the raw materials for the

cores

70 and 71. The pressure during molding of the magnetic members 1D to 1F was 10 ton / cm ² , and the dehydrogenation conditions were the same as in Test Example 1. The coil 72 was configured by spirally winding a copper wire having an enamel coating in the same manner as in Test Example 1. The spring 75 is a commercially available compression spring.

The specifications of the solenoid valve are as follows. A solenoid valve including magnetic members 1D to 1F is designated as sample No. 3-1.

Material of magnet region: Nd ₂ Fe ₁₄ B (average particle size 100μm)
Soft magnetic region: Fe-Co alloy (permendule Fe: 50% by mass, Co: 49% by mass, V: 1% by mass, average particle size: 50μm)
Magnetic member 1D inner diameter 6mm, outer diameter 14mm, inner angle of magnet area 30 °, thickness 5mm
Magnetic member 1E inner diameter 20mm, outer diameter 25mm, inner angle of magnet area 30 °, thickness 5mm
Magnetic member 1F inner diameter 6mm, outer diameter 25mm, magnet area 3Fo (Fig. 4) inner angle 30 °, magnet area 3Fi (Fig. 4) inner diameter 10mm, outer diameter 16mm, thickness 5mm
Valve part: 25mm diameter disc Fixed axis length in the axial direction (total length of

magnetic members

1D and 1F and fixed core 71) 15mm
Number of turns of coil 72 N = 30

The fixed core 71 and the valve part 73 of the movable core 70 of the sample No. 3-1, and samples No. 3-100, No. 3-111 to No. 3-114, which will be described later, are made of the Fe-Co alloy powder ( An average particle diameter of 50 μm) was used, and a compacted body was produced with a molding pressure of 10 ton / cm ² and a heat treatment for strain relief of 500 ° C. × 1 hour. The bottomed double cylindrical powder compact like the fixed core 71 uses, for example, a molding die 100B in which the lower punch is divided into a plurality of parts as shown in FIG. In this state, the lower punch 103b can be formed by being pushed up by a predetermined amount relative to the

lower punches

103a and 103c.

As a comparison, the following sample No.3-100, No.3-111 to No.3-114 solenoid valves, core only, coil 72 and spring comprising a core having a magnet component, coil 72 and spring 75 Sample No.3-120 solenoid valve with 75 was prepared. Samples No. 3-100 and No. 3-111 to No. 3-114 all use the Fe-Co alloy powder (average particle size 50 μm) used to form the soft magnetic region of Sample No. 3-1. Thus, a compacted body (hereinafter referred to as a soft magnetic compaction material) having the same shape as the soft

magnetic regions

2D, 2E, 2Fi, 2Fo (FIG. 4) (fan shape, annular shape, irregular shape) was produced. In both cases, the pressure during molding was 10 ton / cm ² , and the heat treatment for strain relief was 500 ° C. × 1 hour. The finished dimensions (design values) of each soft magnetic powder material should be the same values as those in sample No. 3-1 except for the

magnet areas

3D, 3E, 3Fi, 3Fo (see Fig. 4). did. However, as described later, samples No. 3-111 to No. 3-114 in which the soft magnetic powder material and the magnet are independent members have a fitting value added to the design value. For the soft magnetic powder material, the filling rate of the soft magnetic metal powder was measured in the same manner as in Test Example 1. The results are shown in Table 3.

Sample No.3-100 is prepared with the same raw materials as Sample No.1-100 of Test Example 1, and a mixture of Nd ₂ Fe ₁₄ B powder and resin between the soft magnetic compacts of various shapes described above. After filling, the resin was cured. In other words, Sample No. 3-100 has the bond magnet and the soft magnetic dust material formed integrally by the resin component of the bond magnet, and there is substantially no gap between the bond magnet and the soft magnetic dust material. It is a sample.

Samples No. 3-111 to No. 3-114 all have the above-mentioned various shapes of soft magnetic compacts and magnets as independent members, and are provided between soft magnetic compacts or between soft magnetic compacts. This is a sample in which a fan-shaped or annular magnet is fitted into the cut-out portion.

Sample No. 3-111 uses the same multiphase powder as the raw material used to form the magnet region of Sample No. 1-1 (No. 3-1), and has the same molding conditions and Fan-shaped and annular magnets made of Nd ₂ Fe ₁₄ B were produced under dehydrogenation conditions and combined with the soft magnetic powder material described above.

Sample No. 3-112 uses the same commercially available powder and resin as the raw materials used to form the bonded magnet of Sample No. 1-100 (No. 3-100), and uses a mixture of this powder and resin. Fan-shaped and annular bonded magnets containing Nd ₂ Fe ₁₄ B powder were prepared and combined with the soft magnetic powder material described above.

Sample No. 3-113 is a fan-shaped and annular commercially available ferrite magnet ((BH) max = 30 kJ / m ³ ), Sample No. 3-114 is fan-shaped and annular, Commercially available sintered magnets ((BH) max = 300 kJ / m ³ ) made of Nd ₂ Fe ₁₄ B were prepared, and each was combined with the above-mentioned soft magnetic powder material.

Sample No. 3-120 is made of only soft magnetic metal powder (here, the above-mentioned Fe-Co alloy powder having an average particle diameter of 50 μm), a disk-shaped dust compact formed as a valve part, and bottomed Samples made of the green compacts were prepared respectively. The conditions for producing the green compact were the same as those for soft magnetic compacts No. 3-100 and No. 3-111 to No. 3-114.

For each sample prepared, first, the adsorption force of the solenoid valve was measured. The measurement was performed as follows. Fixed core (Sample No.3-1, No.3-100, No.3-111 to No.3-114 have a magnet component, and Sample No.3-120 consists only of soft magnetic metal powder. ) House the coil and connect a power supply (not shown). Remove the spring from the shaft and fix the fixed core. In addition, a load cell having an elevating mechanism with an accuracy of 1 μm is disposed on the shaft (tip) of the movable core. Then, a 20 A current is passed through the coil to generate an attractive magnetic force. The distance between the fixed core and the valve portion is set to 100 μm ± 10 μm by the load cell lifting mechanism, and the load at this distance is measured with the load cell, and this load is taken as the adsorption force. The results are shown in Table 3. In addition, the force required for the spring (required spring force) was determined using the above-described adsorption force. Specifically, a spring whose length is adjusted so that the load on the load cell becomes zero when the distance between the valve part and the fixed core is 150 μm ± 10 μm is attached to the shaft part, and set by the lifting mechanism as described above The load when the interval is reached is measured with a load cell, and the value obtained by subtracting the measured value from the adsorption force is defined as the required spring force. The results are shown in Table 3. In addition, the said space | interval can be measured using a laser displacement meter etc.

Further, in the same manner as in Test Example 1, with respect to Samples No. 3-1, No. 3-100, No. 3-111 to No. 3-114, the filling rate of the magnet component in the magnet included in each sample, the sample The filling rate of the soft magnetic metal powder was measured for No.3-120. The results are also shown in Table 3.

As shown in Table 3, the solenoid valve of sample No. 3-120 that does not have a magnet component has an adsorption force of 20 kN or more. However, in order to generate this attractive force by the electromagnet, it is necessary to use a spring having a spring force similar to this attractive force.

On the other hand, since the sample having a magnet component can reinforce the attractive force of the electromagnet by the magnet component, the attractive force of the electromagnet may be small, and as a result, the necessary spring force can be reduced. In particular, as shown in Table 3, sample No. comprising a magnetic member having a mixed region in which a soft magnetic metal powder and a specific alloy powder functioning as a magnet are mixed between the soft magnetic region and the magnet region. It can be seen that 3-1 has a large attractive force (total of electromagnet and magnet) and excellent characteristics as compared with other samples except for sample No. 3-114 having a sintered magnet. The reason for this is that sample No. 3-1 is substantially different between the soft magnetic region and the magnet region, unlike sample No. 3-111 to No. 3-113, which have magnetic members formed by combining independent members. This is probably because the magnetic force was sufficiently utilized because there was no gap and the leakage magnetic flux in the minute gap was small. In addition, the magnet region of sample No. 3-1 has a higher magnetic phase ratio than the bonded magnet provided in sample No. 3-100, and is superior in magnetic properties, so it is considered that the attractive force is increased.

Furthermore, in this test, although sample No. 3-1 has the same attractive force as sample No. 3-114 using a sintered magnet with a high magnetic phase ratio, the required spring force is small. From this, it can be said that not only the characteristics of the magnet itself but also the characteristics of the magnetic member as a whole can be improved by adopting a structure that can reduce the leakage magnetic flux in the minute gap described above.

In Test Example 4, the magnetic member 1F and the valve portion 73 are independent members, and the

magnetic members

1D and 1E and the fixed core 71 are independent members. The

magnetic members

1D and 1E and the fixed core 71 can be integrally formed. In this case, the molding may be performed in multiple stages as described above. Specifically, when pressing with relatively small pressure (about 3 ton / cm ² ) and carrying out temporary molding with a relative density of 70% or more and 75% or less, even a molded object with a complicated three-dimensional shape is accurate. Can be manufactured well.

The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention. For example, the composition and size of soft magnetic metal powder and multi-phase powder, manufacturing conditions (temperature during heat treatment, atmosphere, application of magnetic field, etc.), shape of coil parts, shape and type of solenoid valve, etc. may be changed as appropriate. it can.

Since the magnetic member of the present invention can use a magnet region for a permanent magnet, it can be suitably used for a member having a permanent magnet, for example, a component of a rotating machine (particularly, a rotor) such as various motors and generators. it can. In addition, the magnetic member of the present invention can be suitably used for coil parts such as choke coils and reactors, and component parts such as electromagnetic valves. The manufacturing method of the magnetic member of this invention can be utilized suitably for manufacture of the magnetic member of the said invention. The rotating machine of the present invention is a high-speed motor provided in a hybrid vehicle (HEV) or a hard disk drive (HDD), and the coil component is a power conversion device such as a converter provided in a hybrid vehicle (HEV) or an electric vehicle. For circuit components and the like, the electromagnetic valve can be used as an opening / closing member provided in various fluid flow paths.

1A, 1B, 1C, 1D, 1E, 1F

Magnetic member

2,2A, 2Bi, 2Bo, 2C _l , 2C _r , 2D, 2E, 2Fi, 2Fo Soft

magnetic region

3,3A, 3B, 3C, 3D, 3E, 3Fi , 3Fo Magnet area 4

Mixing area

10A, 10B Powder compact 10g Gap 10h Through hole 20 Soft magnetic metal powder 30 Multiphase powder 50 Stator part 51

Magnetic core

52, 62, 72 Coil 70 Movable core 71 Fixed core 73 Valve part 74 Shaft Part 75

Spring

100A, 100B Mold for die 101 Die 102

Upper punch

103, 103a, 103b, 103c Lower punch 110 Rod

Claims

A magnetic member composed of a compact obtained by pressure-molding magnetic powder,
A soft magnetic region composed of soft magnetic metal powder;
Comprising a magnet region composed of an alloy powder containing rare earth elements and Fe,
The filling ratio of the alloy powder in the magnet region is 80% by volume or more,
A magnetic member comprising a mixed region in which the soft magnetic metal powder and the alloy powder are mixed and present between the soft magnetic region and the magnet region.
2. The magnetic member according to claim 1, wherein the thickness of the mixed region is equal to or greater than the larger average particle size of the average particle size of the soft magnetic metal powder and the average particle size of the alloy powder.
The alloy powder, RE is one or more elements selected from Y, La, Pr, Nd, Sm, Dy and Ce, Me is one selected from Fe or Fe and Co, Ni, Mn and Ti One element selected from RE 2 Me 14 B, RE 2 Me 14 C, RE 2 Me 17 N x , RE 1 Me 12 N x and RE 1 Me 12 when x = 1.5 to 3.5 3. The magnetic member according to claim 1 or 2, comprising the above alloy.
A magnetic member manufacturing method in which magnetic powder is pressure-molded, and the obtained powder compact is subjected to a heat treatment to manufacture a magnetic member,
A preparation step of preparing, as a raw material powder, a multiphase powder composed of multiphase particles having a structure in which a phase of a rare earth element hydrogen compound and a phase of an Fe-containing material exist discretely, and a soft magnetic metal powder; ,
After supplying one powder of the multiphase powder and the soft magnetic metal powder to the molding die, and then supplying the other powder, both powders filled in the molding die are simultaneously pressed and compressed. A forming step of forming a powder compact having a relative density of 85% or more of the region composed of the multiphase powder,
In an inert atmosphere or a reduced-pressure atmosphere, the powder compact is subjected to a heat treatment at a temperature equal to or higher than the recombination temperature of the multiphase particles to separate hydrogen from the multiphase particles, and the rare earth element and the Fe-containing material And a dehydrogenation step of forming a magnetic member comprising a soft magnetic region composed of the soft magnetic metal powder and a magnet region composed of the recombination alloy. Manufacturing method of magnetic member.
5. The method for producing a magnetic member according to claim 4, further comprising an annealing step of subjecting the magnetic member that has undergone the dehydrogenation step to a heat treatment in an inert atmosphere or a reduced pressure atmosphere.
In the dehydrogenation step, the heat treatment is performed by applying a magnetic field of 2 T or more to the powder compact,
6. The method of manufacturing a magnetic member according to claim 4, wherein the magnetic field is applied in the magnetic flux direction of a magnetic circuit in which the magnetic member is used.
5. The magnetic member according to claim 4, further comprising a nitriding step in which the material subjected to the dehydrogenation step is subjected to a heat treatment at a temperature not lower than the nitriding temperature of the recombination alloy and not higher than the nitrogen disproportionation temperature in an atmosphere containing nitrogen element. Manufacturing method.
In the dehydrogenation step, the heat treatment is performed by applying a magnetic field of 3 T or more to the powder compact,
In the nitriding step, the heat treatment is performed by applying a magnetic field of 3.5 T or more to the material that has undergone the dehydrogenation step,
8. The method of manufacturing a magnetic member according to claim 7, wherein the application direction of the magnetic field in both steps is a magnetic flux direction of a magnetic circuit in which the magnetic member is used.
A rotating machine comprising the magnetic member according to any one of claims 1 to 3.
A coil component comprising the magnetic member according to any one of claims 1 to 3.
A solenoid valve comprising the magnetic member according to any one of claims 1 to 3.