JP2012164983A - Method for manufacturing solid material for magnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a solid material for magnet based on rare-earth, iron, nitrogen, hydrogen and oxygen, which has a high density and a high magnetic characteristic and is excellent in thermal stability and oxygen resistance.SOLUTION: The method for manufacturing the solid material for the magnet containing a magnetic material based on rare-earth, iron, nitrogen, hydrogen and oxygen of 50-100 vol.% includes shock-compressing and solidifying a raw material powder of the magnetic material based on rare-earth, iron, nitrogen, hydrogen and oxygen by using underwater shock waves of 3-40 GPa, and obtaining the solid material for the magnet mainly containing the R-Fe-N-H-O-based magnetic material by utilizing the features such as ultra high pressure shearing performance, an activating action and a short-time phenomenon which a shock-compression technique has.

Description

The present invention relates to a solid material for a rare earth-iron-nitrogen-hydrogen-oxygen magnet having high density, high magnetic properties, and excellent thermal stability and oxidation resistance.
The present invention also relates to a method for producing a solid material for a magnet, in which a magnetic material powder is impact-compressed to obtain a high-density and high-performance permanent magnet while preventing decomposition and denitrification.

  As high-performance rare earth magnets, for example, Sm—Co magnets and Nd—Fe—B magnets are known. The former is widely used because of its high thermal stability and corrosion resistance, and the latter is widely used because of its extremely high magnetic properties, low cost, and stability of raw material supply. Today, rare earth magnets having both higher thermal stability and higher magnetic properties and lower raw material costs are demanded as actuators for electrical equipment, various FAs, or magnets for rotating machines.

On the other hand, when a rare earth-iron compound having a rhombohedral or hexagonal crystal structure is reacted at a relatively low temperature of 400 to 600 ° C. in a mixed gas of NH ₃ and H ₂ , a nitrogen atom and a hydrogen atom Has been reported in Patent Document 1 to penetrate into interstitial positions of the above-mentioned crystal, for example, a Th ₂ Zn _17- type compound, and cause a marked increase in Curie temperature and magnetic anisotropy.
In recent years, the rare earth-iron-nitrogen-hydrogen magnetic material is expected to be put to practical use as a new magnet material that meets the above-mentioned demand.

  A rare earth-iron-nitrogen-hydrogen magnetic material (hereinafter referred to as R-Fe-N-H magnetic material) containing nitrogen and hydrogen in the intermetallic compound lattice and having the rhombohedral or hexagonal crystal structure. ) Is generally obtained in a powder state, but is easily decomposed into an α-Fe decomposition phase and a rare earth nitride phase at a temperature of about 600 ° C. or higher under normal pressure. It is very difficult to do so by ordinary industrial methods. Therefore, as a magnet using an R—Fe—N—H magnetic material, a bonded magnet using a resin as a binder is produced and used. However, many of the magnets made using this material have a Curie temperature of 400 ° C. or higher, and use magnetic powder that does not lose its magnetization even at temperatures of 200 ° C. or higher. According to Patent Document 1, the heat resistant temperature of a binder such as 12-nylon resin is low, and the coercive force temperature coefficient is about -0.5% / ° C, whereas the coercive force is as small as 0.6 MA / m. As a result, the irreversible demagnetization factor increases, and is generally used only at temperatures below 100 ° C. That is, when a brushless motor or the like as a power source used in a high temperature environment of 150 ° C. or higher is made in response to the recent demand for high loads, there is a problem that this bond magnet cannot be used.

In addition, when producing a compression-bonded bonded magnet using a resin as a binder, an industrially difficult molding pressure of 1 GPa or more is required to improve the filling rate and improve the performance. In many cases, the mixing ratio of the magnetic material must be less than 80% in terms of volume fraction, and the excellent basic magnetic properties of the R—Fe—N—H magnetic material cannot be sufficiently exerted depending on the compression molded bond magnet. There was a problem.
For example, among bonded magnets made from R—Fe—N—H based magnetic materials, non-patent document 2 discloses a compression molded bonded magnet having (BH) _max = 186 kJ / m ³ as having extremely high magnetic properties. However, compared to conventional Sm-Co-based and Nd-Fe-B-based sintered magnets, the high basic magnetic properties of R-Fe-NH magnetic materials can be fully demonstrated. Not.

In order to solve the above problems, Patent Document 2 proposes a method of manufacturing a permanent magnet using a rare earth-iron-nitrogen based magnetic material that does not contain a resin binder. However, according to this method, in order to suppress the residual temperature after impact compression below the decomposition temperature of the Th ₂ Zn ₁₇ type rare earth-iron-nitrogen based magnetic material, the pressure during impact compression is kept within a certain narrow range. There was the disadvantage of having to limit. This is because when a conventional shock wave is used, although the duration of the shock wave itself is short, the temperature of the magnetic material is high and the magnetic material is very easily decomposed as a result of being held for a long time. is there.

In addition, according to the method, the density of the product obtained was only 7.28 g / cm ³ at the maximum. Furthermore, according to this method, since the decomposition of the rare earth-iron-nitrogen based magnetic material cannot be sufficiently suppressed, the coercive force is as low as 0.21 MA / m at the maximum.
Patent Document 3 discloses a method of compressing and solidifying a Th ₂ Zn ₁₇ type rare earth-iron-nitrogen based magnetic material using a cylindrical convergent shock wave for the purpose of obtaining a large and compact molded body free from cracks and chips. However, even in the magnet obtained by this method, the maximum density was 7.43 g / cm ³ and the maximum coercive force was 0.62 MA / m, which was not satisfactory.

In addition, as an example of a Th ₂ Zn ₁₇ type rare earth-iron-nitrogen based magnetic material formed by shock wave compression, there is one reported in Non-Patent Document 3, but the filling rate is low at 10 GPa and α-Fe at 20 GPa. Since the decomposition into the decomposition phase and the SmN phase proceeds, the density of the molded body under each impact compression condition often does not necessarily exceed 7.45 g / cm ^3, and the maximum value of the magnetic characteristics is 0.57 MA / coercivity. m, (BH) _max = 134 kJ / m ^3, and it cannot be said that the Th ₂ Zn ₁₇ type R—Fe—N—H based bond magnet has sufficiently high magnetic properties.
As described above, there is a strong demand for solid materials for magnets having high density, no decomposition, high magnetic properties, and good thermal stability.

Apart from these high-performance magnets, on the other hand, there is also a demand for light weight and high-performance in applications for home appliances / OA devices and electric vehicles. When these magnets are mounted, the density of Sm-Co magnets is about 8.4 g / cm ^{3 and} the density of Nd-Fe-B magnets is about 7.5 g / cm ^3. In some cases, the energy efficiency is inferior. In addition, depending on the application, there is a margin in the magnetic characteristics, so even if the weight can be reduced by downsizing the magnet, it is not necessarily advantageous in terms of cost in consideration of the yield by processing. For example, since the cutting waste is proportional to the cutting area, the yield per unit volume of the product becomes worse as the volume becomes smaller.

As described above, various bonded magnets that compensate for the disadvantages are inferior in thermal stability, so that magnets that are lightweight but have high magnetic properties, excellent thermal stability, and high cost performance have not yet been developed.
Patent Document 4 proposes a rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material (hereinafter referred to as R—Fe—N—H—O based magnetic material) having excellent magnetic properties, and controls the oxygen component. By doing so, it is a material having excellent magnetic properties and corrosion resistance. The main features are that it has stable magnetic properties accompanying an improvement in coercive force and that oxidation resistance is relatively high, and that rust is unlikely to occur.

  However, this R—Fe—N—H—O-based magnetic material, as disclosed in Patent Document 5 and Patent Document 6, preferably uses the aforementioned R—Fe—N—H-based material as a bonded magnet. No examples have been reported yet, which have been invented as a solid material for magnets.

Japanese Patent No. 2703281 Japanese Patent No. 3108232 JP 2001-6959 A Japanese Patent No. 2708568 Japanese Patent No. 2857476 Japanese Patent No. 2708578 IEEJ Technical Report 729, IEEJ, 41 Appl. Phys. Lett. 75, No. 11, p. 1601 J. et al. Appl. Phys. Volume 80, Issue 1, Page 356

  The first object of the present invention is to provide an R—Fe—N—H—O magnet solid material having high density, high magnetic properties, excellent thermal stability and oxidation resistance, and a method for producing the same. That is. The present invention provides a solid material for a magnet including a magnet that is magnetized by magnetization or the like.

  As a result of intensive studies on the above problems, the present inventors have made an R—Fe—N—H—O-based magnetic material excellent in magnetic properties and oxidation resistance into a green compact in a magnetic field or without a magnetic field. After that, it is solidified by impact compression using underwater shock waves, and mainly contains R-Fe-N-H-O-based magnetic materials, taking advantage of the features of shock compression such as ultra-high pressure shearing, activation and short-time phenomenon. The present invention has been completed by finding that a solid material for a magnet can be obtained.

In addition, when the above-described underwater shock wave is used, the present inventors have prepared an R—Fe—N—H—O based magnetic material and a hard magnetic and / or soft magnetic powder or solid, or a non-magnetic material powder or The inventors have also found that solid materials can be easily integrated and completed the present invention.
Further, the present inventors further include an R—Fe—N—H—O-based magnetic material having a rhombohedral or hexagonal crystal structure, which is lightweight and has high magnetic properties and high stability. In order to obtain the material, the raw material composition and the content rate, and the manufacturing method thereof were intensively studied. Using magnetic material powder containing not only nitrogen but also hydrogen and oxygen, the volume fraction was set to 80 to 97% by volume, After forming a green compact in a magnetic field, the green compact is shock-compressed with an underwater shock wave having a constant shock wave pressure, and can be used at a density of 6.15 g / cm ³ or higher and 100 ° C. or higher. The present invention was completed with the knowledge that a solid material for R—Fe—N—H—O magnets solidified by bonding can be easily obtained.
That is, the aspects of the present invention are as follows.

(1) A solid material for a magnet containing 50 to 100% by volume of a rare earth-iron-nitrogen-hydrogen-oxygen magnetic material.
(2) The solid material for a magnet according to (1) above, wherein the magnetic material contains a rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material having a rhombohedral or hexagonal crystal structure.
(3) rare earth - iron - nitrogen - hydrogen - at least one oxygen-based magnetic material is represented by the general formula _{R α Fe 100-α-β} -γ-δ N β H γ O δ, R is selected from rare earth elements In addition, α, β, γ, and δ are atomic percentages, 3 ≦ α ≦ 20, 5 ≦ β ≦ 25, 0.01 ≦ γ ≦ 5, and 0.01 ≦ δ ≦ 10. The solid material for magnets according to (1) or (2) above, which contains an iron-nitrogen-hydrogen-oxygen magnetic material.
(4) 10 atomic% or less of the R and / or Fe is Ni, Ti, V, Cr, Mn, Zn, Cu, Zr, Nb, Mo, Ta, W, Ru, Rh, Pd, Hf, Re, Os The solid material for magnets according to the above (1) to (3), wherein at least one element selected from Ir is substituted.
(5) Any one of (1) to (4) above, wherein 10 atomic% or less of N and / or H is substituted with at least one element selected from C, P, Si, S, and Al Solid material for magnets.
(6) a rare earth - iron - nitrogen - hydrogen - oxygen-based magnetic material is represented by the general formula _{R α Fe 100-α-β} -γ-δ N β H γ O δ M ε, R is a rare earth element including Y At least one element selected from the group consisting of Li, Na, K, Mg, Ca, Sr, Ba, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Pd, Cu, At least one element selected from Ag, Zn, B, Al, Ga, In, C, Si, Ge, Sn, Pb, Bi and / or an oxide of oxide, fluoride, carbide, nitride, hydride, carbonic acid It is at least one selected from salts, sulfates, silicates, chlorides and nitrates, and α, β, γ, δ and ε are molar percentages, 3 ≦ α ≦ 20, 5 ≦ β ≦ 30, 0 .01 ≦ γ ≦ 10, 0.01 ≦ δ ≦ 10, 0.1 ≦ ε ≦ 40, (1) to ( Solid material for magnets as described in 5).
(7) The solid material for magnets according to any one of (1) to (6) above, wherein 50 atomic% or more of R is Sm.
(8) The solid material for a magnet according to any one of the above (1) to (7), wherein 0.01 to 50 atomic% of the Fe is substituted with Co.
(9) The solid material for a rare earth-iron-nitrogen-hydrogen-oxygen magnet according to any one of (1) to (8) above, wherein the crystalline phase (island) and the amorphous phase (sea A solid material for magnets having a sea-island structure including
(10) The solid material for a magnet according to any one of the above (1) to (9), which contains a rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material and has a density higher than 6.15 g / cm ³ .
(11) The solid material for a magnet according to any one of (1) to (9) above, which contains 80 to 97% by volume of a rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material.
(12) The solid for a magnet according to (11) above, wherein the component other than the rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material is an element, a compound or a mixture thereof having a density of 6.5 g / cm ³ or less. material.
(13) The magnet according to any one of (11) to (12) above, wherein the portion other than the rare earth-iron-nitrogen-hydrogen-oxygen magnetic material contains at least one of air and inert gas. Solid material.
(14) The portion other than the rare earth-iron-nitrogen-hydrogen-oxygen-based magnetic material is at least one of oxide, fluoride, carbide, nitride, hydride, carbonate, sulfate, silicate, chloride, and nitrate. 1 type of solid material for magnets in any one of said (11)-(13) characterized by the above-mentioned.
(15) The magnet solid material according to any one of (11) to (14) above, wherein an organic substance is contained in a portion other than the rare earth-iron-nitrogen-hydrogen-oxygen magnetic material.
(16) When the relationship between the residual magnetic flux density B _r at normal temperature, the coercive force H _{cJ at} normal temperature, the permeance coefficient P _c when used as a magnet, and the maximum operating temperature T _max is μ ₀ , the permeability of vacuum is
B _r ≦ μ ₀ H _cJ (P _c +1) (11000−50T _max ) / (10000−6T _max )
The solid material for magnets according to any one of (1) to (15) above, wherein
(17) The magnet solid according to any one of (1) to (16) above, wherein the coercive force H _cJ is 0.76 MA / m or more and the squareness ratio B _r / J _s is 95% or more. material.
(18) The soft magnetic material containing at least one element selected from Fe, Co, and Ni is uniformly dispersed and integrated with the rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material. (1) -Solid material for magnets in any one of (17).
(19) At least one magnetic material selected from a rare earth-iron-boron magnetic material, a rare earth-cobalt magnetic material, and a ferrite magnetic material is uniformly added to the rare earth-iron-nitrogen-hydrogen-oxygen magnetic material The magnet solid material according to any one of the above (1) to (18), which is mixed and integrated.
(20) The solid material for a magnet according to any one of (1) to (19) above, wherein a nonmagnetic phase is present at the grain boundary of the magnetic material.
(21) A solid material for a magnet, wherein the solid material for a magnet according to any one of (1) to (20) and a soft magnetic solid metal material are joined and integrated.
(22) A solid for a magnet having a soft magnetic layer, wherein the soft magnetic layer and the solid material for magnet of any one of (1) to (21) are alternately laminated and integrated. material.
(23) A solid material for a magnet, wherein at least a part of the solid material for a magnet according to any one of (1) to (22) is covered with a nonmagnetic solid material.
(24) The solid material for magnets according to any one of (1) to (23), wherein magnetic anisotropy is imparted.
(25) A solid material for a magnet according to any one of (1) to (24) above, which is formed into a prismatic shape, a cylindrical shape, a ring shape, a disc shape, or a flat plate shape.
(26) A magnetic material obtained by reacting Zn with the grain boundary or surface of any one of the magnetic materials (1) to (7).
(27) The raw material powder of a rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material is shock-compressed and solidified using an underwater shock wave. A method for producing a solid material.
(28) The method for producing a solid material for a magnet according to any one of (1) to (26) above, wherein the shock wave is solidified by impact compression using an underwater shock wave having a shock wave pressure of 3 to 40 GPa.
(29) The method for producing a solid material for a magnet according to the above (9), wherein the shock wave is solidified by impact compression using an underwater shock wave having a shock wave pressure of 3 to 30 GPa.
(30) The method for producing a solid material for a magnet according to (10) above, wherein the shock wave is solidified by impact compression using an underwater shock wave having a shock wave pressure of 8 to 40 GPa.
(31) The method for producing a solid material for a magnet according to any one of the above (11) to (15), wherein the shock wave is compressed and solidified using an underwater shock wave having a shock wave pressure of 3 to 22 GPa.
(32) The method for producing a solid material for a magnet according to any one of the above (1) to (26), wherein the raw material powder is compacted in a magnetic field.
(33) The method for producing a solid material for a magnet according to any one of the above (1) to (26), wherein the raw material powder is compacted and then impact-compressed and solidified using an underwater shock wave.
(34) The method for producing a solid material for a magnet according to the above (1) to (26), wherein the raw material powder is compacted in a magnetic field and then subjected to impact compression solidification using an underwater shock wave.
(35) The method for producing a solid material for a magnet according to the above (1) to (26), wherein the method is formed by cutting and / or plastic working.
(36) The method for producing any one of (28) to (36) of a solid material for a magnet, comprising a step of heat-treating the material at least once at a temperature of 100 ° C. or higher and lower than a decomposition temperature.
(37) A component for use in an apparatus that uses a static magnetic field of a magnet, the component using the magnet solid material according to any one of (1) to (26) above.
(38) An apparatus having a maximum operating temperature T _max that utilizes a static magnetic field of a magnet of 100 ° C. or higher, wherein the part (38) is used as the part.
Is to provide.

The solid material here refers to a massive material. Furthermore, the solid material for magnets mentioned here refers to a massive magnetic material, and the magnetic material powders constituting the solid material for magnets are continuously bonded directly or via a metal phase or an inorganic phase. However, the magnetic material is in the form of a lump as a whole. The state of being magnetized by magnetization and expressing the residual magnetic flux density is particularly called a magnet, but the magnet also belongs to the category of the solid material for magnets mentioned here.
The rare earth element referred to here is Y in the periodic table group IIIa and La group 15 elements having atomic numbers 57 to 71, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho. , Er, Tm, Yb, and Lu.
The term “decomposition” as used herein means that an α-Fe decomposed phase is generated as the crystal structure of the R—Fe—N—H—O based magnetic material powder changes, and this α-Fe decomposed phase exists. Has a detrimental effect on the magnetic properties, so the above-mentioned decomposition should be prevented. However, the oxygen-containing layer may become amorphous in the manufacturing process of the raw material used in the present invention and the manufacturing process of the solid material for magnet of the present invention. This phenomenon is distinguished from the decomposition in the present invention. .

  By compacting rare earth-iron-nitrogen-hydrogen-oxygen magnetic powder having a rhombohedral or hexagonal crystal structure as in the present invention, and compressing the impact using an underwater shock wave, the binder is obtained. Therefore, it is possible to obtain a high-density and high-performance solid material for magnets without using self-sintering and preventing decomposition and denitrification. Furthermore, it is possible to obtain a solid material for a magnet that is lightweight but has high performance, in particular, high stability of magnetic properties.

It is explanatory drawing which shows an example of the cross section of the solid material for magnets obtained by joining and integrating a rare earth-iron-nitrogen-hydrogen-oxygen type magnetic material and a soft magnetic solid metal. It is explanatory drawing which shows an example of the cross section of the solid material for magnets which the rare earth-iron-nitrogen-hydrogen-oxygen type | system | group magnetic material layer and the soft-magnetic layer were laminated | stacked alternately, and were integrated. It is explanatory drawing which shows the example of the cross section of the solid material for magnets which covered a part or all of the circumference | surroundings of the layer mainly containing a rare earth-iron-nitrogen-hydrogen-oxygen type magnetic material with the nonmagnetic solid material. It is explanatory drawing which shows an example of the cross section of the solid material for magnets. It is an example of the rotating shaft cross section structure of a surface magnet structure rotor in the case of using the magnet solid material of this invention for a permanent magnet synchronous motor. It is an example of the rotating shaft cross section structure of a surface magnet structure rotor in the case of using the magnet solid material of this invention for a permanent magnet synchronous motor. It is an example of the rotating shaft cross section structure of an embedded magnet structure rotor in the case of using the magnet solid material of the present invention for a permanent magnet synchronous motor. It is an example of the rotating shaft cross section structure of an embedded magnet structure rotor in the case of using the magnet solid material of the present invention for a permanent magnet synchronous motor. It is an example of the rotating shaft cross section structure of an embedded magnet structure rotor in the case of using the magnet solid material of the present invention for a permanent magnet synchronous motor. It is an example of the rotating shaft cross section structure of an embedded magnet structure rotor in the case of using the magnet solid material of the present invention for a permanent magnet synchronous motor. It is an example of the rotating shaft cross section structure of an embedded magnet structure rotor in the case of using the magnet solid material of the present invention for a permanent magnet synchronous motor. It is an example of the rotating shaft cross section structure of an embedded magnet structure rotor in the case of using the magnet solid material of the present invention for a permanent magnet synchronous motor. It is explanatory drawing which shows an example of the means to implement the impact compression method using an underwater shock wave. It is explanatory drawing which shows an example of the means used in the comparative example which implements the impact compression method using the detonation wave of the explosive directly.

Hereinafter, the present invention will be described in detail focusing on particularly preferred embodiments.
The R—Fe—N—H—O-based magnetic material used for the solid material for a magnet of the present invention is prepared by a known method.
For example, a rare earth-iron alloy is prepared by a high frequency method, an ultra-quenching method, an R / D method, an HDDR method, a mechanical alloying method, a mechanical grinding method, etc., coarsely pulverized to about several tens to several hundreds μm, and then nitrogen. -A hydrogen nitride treatment is performed in an atmosphere such as a hydrogen mixed gas or an ammonia-hydrogen mixed gas to finely pulverize to prepare an R-Fe-N-H-O-based magnetic material. In these steps, it is important to control the type and concentration of the oxygen source. Depending on the composition of the magnetic material, the alloy processing method and the nitriding method, coarse pulverization or fine pulverization may not be performed.

  In the present invention, it is important to introduce hydrogen as well as nitrogen by bringing it into contact with a hydrogen source such as hydrogen gas, ammonia gas, or a compound containing hydrogen at any stage of the process. That is, the hydrogen content of the R—Fe—N—H—O based magnetic material is preferably 0.01 atomic% or more. When the amount of hydrogen is less than 0.01 atomic%, an α-Fe decomposition phase and a rare earth nitride decomposition phase are often generated, the coercive force is lowered, and the corrosion resistance may be further lowered. If it contains 0.1 atomic% or more of hydrogen, it will become a more preferable raw material of the solid material for magnets.

  Similarly, in the present invention, in the atmosphere in which the powder is processed at any stage of the process, for example, gas and solvent during the pulverization process, pulverization jig such as a container, gas composition and vacuum degree during the heat treatment process, etc. It is important to introduce oxygen while making contact with an oxygen source which is a substance containing oxygen such as dissolved oxygen, moisture, and oxide. That is, the oxygen content of the R—Fe—N—H—O based magnetic material is preferably 0.01 atomic% or more. If the oxygen content is less than 0.01 atomic%, the coercive force is lowered, and the corrosion resistance may be further lowered. Further, in order to obtain a stable material having a high coercive force, it is desired that the oxygen content is 0.1 atomic% or more, more preferably 1 atomic% or more.

In addition, as the crystal structure of the R—Fe—N—H—O-based magnetic material, which can be introduced while simultaneously controlling hydrogen and oxygen by controlling the amount of water vapor and moisture in the pulverizing atmosphere, A rhombohedral crystal having a Th ₂ Zn ₁₇ type crystal structure or the like or a crystal structure similar thereto, or a hexagonal crystal having a Th ₂ Ni ₁₇ , TbCu ₇ , CaZn ₅ type crystal structure or the like or a crystal structure similar thereto, and further R ₂ Fe ₁₄ BN _{x type,} such as tetragonal with a R _{2 Fe} 14 CN _x type and _{R (Fe 1-y M y} ) 12 N x type, etc. or similar crystal structure and the like, must be of them containing at least one It is. Among them, a rhombohedral crystal having a Th ₂ Zn ₁₇ type crystal structure or the like or a crystal structure similar thereto, or a hexagonal crystal having a Th ₂ Ni ₁₇ , TbCu ₇ , CaZn ₅ type crystal structure or the like or a crystal structure similar thereto is entirely formed. The R—Fe—N—H—O based magnetic material is preferably contained in an amount of 50% by volume or more, and a rhombohedral crystal having a Th ₂ Zn ₁₇ type crystal structure or the like or a similar crystal structure is present in the entire R—Fe It is most preferable that 50% by volume or more of the —N—H—O-based material is contained.

  In the present invention, the volume fraction of the R—Fe—N—H—O-based magnetic material with respect to the entire solid material for magnets is preferably 50 to 100% by volume. However, when the solid material for magnets is composed of only the R—Fe—N—H—O-based magnetic material, or when it is a composite material with gas or organic matter, the R— The volume fraction of the Fe—N—H—O based magnetic material is preferably 80 to 100% by volume. If it is less than 80% by volume, the continuous bonding between the magnetic powders is insufficient, and a solid material for magnets cannot be formed. However, in addition to R—Fe—N—H—O based magnetic materials, hard magnetic materials such as rare earth-iron-boron based magnetic materials, soft magnetic materials such as Co, and non-magnetic phases such as metals and inorganic substances are included. The solid material volume fraction, which is a value obtained by combining these volume fractions and the volume fraction of the R—Fe—N—H—O-based magnetic material, may be in the range of 80 to 100% by volume.

The volume fraction referred to here is the ratio of the volume occupied by the magnetic material to the entire volume including the gap of the magnet solid material.
The above R—Fe—N—H—O-based magnetic material is preferably obtained as a powder having an average particle diameter of 0.1 to 100 μm and supplied as a raw material for a solid material for a magnet. When the average particle size is less than 0.1 μm, the magnetic field orientation tends to be insufficient and the residual magnetic flux density tends to be low. On the other hand, if the average particle diameter exceeds 100 μm, the coercive force may be lowered depending on the material composition, and the manufacturing conditions for increasing the density may be severe, and thus the practicality tends to be poor. In order to impart excellent magnetic field orientation, a more preferable range of the average particle diameter is 1 to 100 μm.

The R—Fe—N—H—O-based magnetic material is characterized by having high magnetic anisotropy as well as high saturation magnetization and high Curie point. Therefore, in an R—Fe—N—H—O-based magnetic material that can be made into a single crystal powder, a magnetic material can be easily oriented by an external magnetic field, and has a high magnetic property. can do.
As raw materials for the solid material for magnets having both high magnetization and coercive force, the preferred ranges of R and Fe are 5 ≦ α ≦ 20 and 10 ≦ β ≦ 25, respectively.

The preferable range of the M component in the raw material powder for obtaining a solid material for a magnet having a solid metal bond with an overall filling rate of almost 100% and realized by the method of the present invention is 0.1 ≦ ε ≦ 10. is there. Furthermore, the preferable range of the M component that has a coercive force higher than that of the metal binder magnet and has a sufficiently high magnetization is 0.1 ≦ ε ≦ 5, and a more preferable range is 0.1 ≦ ε ≦ 3. In order to make the magnetization and (BH) _max value very high, the range of 0.1 ≦ ε ≦ 1 is sufficient. In this case, however, the coercive force value tends to become unstable.

Nd-Fe-B-based sintered magnets have extremely high magnetic properties and are widely used in actuators and various motors such as VCM. However, the surface is easily oxidized even in the air at room temperature, so the purpose of preventing rust removal Therefore, it is essential to perform surface treatment by nickel plating or epoxy resin coating.
On the other hand, in the case of a magnet using an R—Fe—N—H—O-based magnetic material, the above-described surface treatment is not required or can be simplified. That is, not only is it advantageous in terms of cost, but also when used as an actuator or motor, the gap between the stator and the rotor can be narrowed by the surface layer with low magnetism, so there is an advantage that a large torque can be obtained for rotation and repetitive motion. , Make the most of the magnet's magnetic force. For this reason, for example, even when the (BH) _max value at room temperature is inferior to that of an Nd—Fe—B magnet, the same performance can be exhibited. In a magnet containing an R—Fe—N—H—O-based magnetic material, when a surface treatment is not required, a preferred magnet having excellent cost performance if the (BH) _max value at room temperature is 200 kJ / m ³ or more. More preferably, it is 240 kJ / m ³ or more. However, in the present invention, in a solid material for a magnet having a pinning type magnetization reversal mechanism, the raw magnetic powder itself is very excellent in thermal stability and corrosion resistance. _{Even if the max} value is less than 200 kJ / m ³ , it is preferably used, but even in that case, it is desirable that the (BH) _max value at room temperature is 100 kJ / m ³ or more.

Furthermore, isotropic solid materials for magnets are suitable for applications with further low permeance applications and multipolar magnetization, in which case the (BH) _max value at room temperature is less than 150 kJ / m ^3. However, it is desirable that the (BH) _max value at room temperature is 50 kJ / m ³ or more.
The 1st aspect in the solid material for magnets of this invention is a solid material for R-Fe-N-O-type magnets characterized by having a density higher than 7.45 g / cm < ³ >. Since the magnetization and magnetic flux density are proportional to the filling factor, the residual magnetic flux density decreases and the maximum energy product decreases as the density decreases. Generally, a solid material for a magnet with a high filling factor is preferably used for a high-performance magnet. . In addition, since the R—Fe—N—H—O based magnet material is often a fine powder, if there are many passages of oxygen such as voids that are continuous holes, the surface of the fine powder is oxidized and deteriorated, resulting in a coercive force. Is a factor that decreases. Therefore, depending on the material composition and application, it is necessary to sufficiently increase the density and prevent the ingress of oxygen from the surface, and the filling rate is required to be 95% or more, preferably 98% or more. The filling rate near the surface may be required to be close to 100%.

  The filling rate mentioned here means that when the solid material for magnet of the present invention is composed only of the R—Fe—N—H—O based magnetic material, the solid material for R—Fe—N—H—O based magnet is used. It is the ratio of the density to the true density. Moreover, the true density said here is density w / v calculated | required from the sum total w of the atomic weight of the atom which comprises the volume v of the R-Fe-N unit cell calculated | required from the X-ray, and the unit cell. Yes, it is generally called X-ray density Dx, and the density Dm of the magnet solid material can be determined by a macro method such as Archimedes method or volume method.

In a combination of material composition and application in which oxidative deterioration is significant, the density of the solid material for magnets is preferably greater than 7.45 g / cm ^3, more preferably greater than 7.50 g / cm ³ , and More preferably, it is more than 55 g / cm ^{3, and} most preferably 7.60 g / cm ³ or more. Also, depending on the composition of the raw material, when the density exceeds 8.0 g / cm ³ , conversely, a phase other than the R—Fe—N—H—O phase having high magnetic properties is generated, and the magnetic properties are deteriorated. This is not preferable because it often occurs. Oxidation degradation is a phenomenon that involves undesirable addition of oxygen to the magnetic properties of solid materials for magnets and the accompanying decomposition of R—Fe—N—H—O-based magnetic materials due to an external oxygen source. The solid material for magnets and the introduction of oxygen into the raw material powder have different properties.

Depending on the manufacturing method and conditions, the filling rate in the interior may decrease as the volume of the solid material for the magnet increases, but even in that case, the filling rate of the surface layer is sufficiently increased and the thickness thereof is sufficiently large. For example, it can be used as a practical magnet.
However, if the solid material for the magnet is composed of only the R—Fe—N—H—O-based material and the density is 6.15 g / cm ³ or less when the balance is the atmosphere, any shape and volume of magnet can be obtained. Even when the magnet is formed, the magnet contains a lot of voids, and often tends to cause cracks and cracks that develop into chipping or collapse due to impact or load, or to reduce the coercive force as described above.

According to the method of the present invention, when preparing a solid material for a magnet of 5 cm ³ or less using only an R—Fe—N—H—O-based magnetic material as a raw material, a material having a density exceeding 7.60 g / cm ³ is used. For example, when a magnet solid material having a volume of 0.1 m ³ is produced, a portion having a density of 7.45 g / cm ³ or less may be formed inside depending on the form. However, even in such a case, if it is a solid material for a magnet having a density exceeding 7.60 g / cm ³ at least in the surface layer portion, it has oxidation resistance and high magnetic properties. Therefore, it can be said that it belongs to the category of the solid material for magnets of the present invention.

By the way, the Th ₂ Zn ₁₇ type R—Fe—N based magnetic material containing no hydrogen has a nitrogen content of less than 3 per R ₂ Fe ₁₇ when the magnetic properties are to be optimized, An unstable R ₂ Fe ₁₇ N _3-Δ phase is formed. This phase is easily decomposed into an α-Fe decomposition phase and a rare earth nitride by thermal and mechanical energy. As a result, the conventional shock wave compression method cannot be a high-performance magnet solid material.
On the other hand, if the hydrogen is controlled within the range defined above, the main phase is usually a thermodynamically stable R ₂ Fe ₁₇ N ₃ H _x phase or R ₂ Fe ₁₇ containing excess nitrogen. Decomposition into an α-Fe decomposition phase and a rare earth nitride by thermal and mechanical energy in the N _{3 + Δ} H _x phase (usually x is in the range of about 0.01 to 2) causes Th ₂ Zn ₁₇ not containing H. This is significantly suppressed as compared with the type R—Fe—N magnetic material.

This is nothing but an important finding for obtaining a solid material for a magnet having a high density, high magnetic properties, excellent thermal stability and oxidation resistance.
Further, the oxygen in the R—Fe—N—H—O-based raw material powder does not necessarily need to be entirely contained in the stable R ₂ Fe ₁₇ N ₃ H _x phase, and is localized around the ferromagnetic layer. R—Fe—N—H—O, R—Fe—H—O, R—Fe—O, R—Fe—N—H—O—M, R—Fe—H—O—M, R— When it is preferable in terms of stability of magnetic properties to adopt a structure in which an amorphous phase having an arbitrary composition containing O and at least one of R, Fe, N, H, M such as Fe-OM is formed There is. As an example of the structure of such a magnetic powder, J.A. Alloys and Compounds. 193, 235, there is an amorphous layer of about 100 nm enriched with oxygen on the surface of R-Fe-N-H-O fine powder showing ferromagnetism produced under certain conditions. It has been reported to take a structure. When this oxygen-rich layer decomposes and changes to the α-Fe decomposition phase, the coercive force is greatly reduced. The conventional shock wave compression method also induces the decomposition of this amorphous phase, which is another reason why the R—Fe—N—H—O-based material is difficult to become a high-performance magnet solid material by the conventional method. It has become.

The R—Fe—N—H—O based magnetic material used in the present invention is made of various magnetic materials having different magnetization reversal mechanisms, such as nucleation type, pinning type, exchange spring type, and exchange coupling type, as solid materials for magnets. Can do. Since all these magnetic materials undergo a decomposition reaction at a temperature exceeding 600 ° C., they cannot be made into a solid material for magnets by a sintering method in which the density is increased at a high temperature. It is a group of materials that are very effective to be molded using the method.
As described above, the R—Fe—N—H—O based magnetic material is significantly less decomposed by thermal and mechanical energy than the R—Fe—N based magnetic material containing no H, If this decomposes and an α-Fe decomposition phase and a rare earth nitride phase having a large particle diameter exceeding about 100 nm are produced, the α-Fe decomposition occurs despite the fact that a lot of expensive rare earths are contained. The phase becomes a bud of a reverse magnetic domain, and the coercive force is greatly reduced, which is not preferable.

  Therefore, as a secondary phase of the R—Fe—N—H—O based magnetic material, Fe—Ni, Fe—Co—Ni such as Fe, Co, Fe—Co, and permalloy, and nitrides thereof, and more components And a soft magnetic phase such as an alloy or a compound with the above-described M component, by preparing the soft magnetic phase so that the particle size or thickness of the soft magnetic phase is about 5 to 100 nm, In addition to being able to maintain, the amount of expensive rare earths can be saved, and a magnet with high cost performance can be obtained.

These soft magnetic subphases have an effect of improving the residual magnetic flux density of the R—Fe—N—H—O based magnetic material. However, if the particle size or thickness of the soft magnetic phase is less than 5 nm, the saturation magnetization becomes small, and if it exceeds 100 nm, the soft magnetic phase, the hard magnetic phase, and the anisotropy due to exchange coupling between the soft magnetic phases. Is not preferable, and the coercive force is lowered due to buds of reverse magnetic domains.
In order to achieve such a microstructure, as a method for preparing the R-Fe raw material, a known method, a mechanical alloying method, or mechanical grinding, in which an M component is added and an R-Fe-M raw material is obtained by a rapid quenching method. A known method such as a method, or a method of producing an R—Fe or R—Fe—M raw material by a pulverization method according to the method can be employed.
At this time, the amount of the soft magnetic subphase is preferably 5 to 50% by volume. If it is less than 5% by volume, the coercive force is relatively high, but the residual magnetic flux density is not so high as in the case of the R—Fe—N—H—O-based material alone. Although the magnetic flux density is increased, the coercive force is decreased, and in any case, there is a tendency that a high (BH) _max cannot be obtained. A more preferable range of the soft magnetic phase amount is 10 to 40% by volume.

Furthermore, such Nd-Fe-B type rare earth - iron - boron Motokei magnetic material, SmCo ₅ type or _Sm 2 _{Co 17} based rare earth such as - cobalt based magnetic material, the hard magnetic powder such as ferrite-based magnetic material By mixing one or more of them with an R—Fe—N—H—O-based magnetic material within a range of 50% by volume or less, various properties such as magnetic properties, thermal stability, cost, etc. depending on the application. It is possible to obtain a solid material for a magnet having optimized practical application requirements.

In general, the more the rare earth-iron-boron-based material is included, the higher the overall magnetic properties, but the corrosion resistance is reduced and the cost is increased, and the more the rare-earth-cobalt-based magnetic material is included, the better the thermal stability. However, the magnetic properties are lowered, the cost is increased, and the more ferrite-based magnetic materials are contained, the lower the cost is and the temperature properties are improved, but the magnetic properties are greatly lowered. When the R—Fe—N—H—O based magnetic material and another magnetic material having extremely different particle diameters are mixed, there is an advantage that the condition for increasing the filling rate becomes wider.
The solid material for magnets of the present invention may have a non-magnetic phase present at the grain boundaries of the R—Fe—N—H—O based magnetic material for the purpose of forming a magnet having a high coercive force and a high squareness ratio. it can.

  As the method, known methods such as Japanese Patent No. 2739860 and Japanese Patent No. 2705985, for example, a method in which magnetic powder and a nonmagnetic component are mixed and heat-treated, and a method in which the surface of magnetic powder is plated are used. , A method of coating the surface of the magnetic powder with a non-magnetic component by various vapor deposition methods, a method of coating the surface of the powder as a metal component by treating the magnetic powder with an organic metal and photolyzing the organic metal. . Further, it is possible to use a method in which an R—Fe—N—H—O-based magnetic material and a nonmagnetic component are mixed and compression molded, and then compressed by a shock wave. Since the solid material for magnets has a strong and dense grain boundary structure, a high coercive force and a filling rate can be achieved with less binder than a metal binder magnet, and oxidation resistance is improved. In these materials, if the R—Fe—N—H—O-based magnetic material powder has a strong bond that does not involve any non-magnetic phase even if part of the powder, the solid material for magnets that satisfies the mechanical strength It can be.

  As the non-magnetic component, either an inorganic component or an organic component can be used, but each low melting point metal having a melting point of 1000 ° C. or less, preferably 500 ° C. or less, such as Zn, In, Sn, Ga, etc. is preferable, and Zn is particularly preferable. When used, the coercive force is dramatically increased and the thermal stability is improved. In order to realize high magnetic properties, the volume fraction of the nonmagnetic phase including the amount previously contained in the R—Fe—N—H—O-based magnetic material is preferably 10% by volume or less, and further 5 The volume% or less is preferable, and the volume% or less is most preferable. On the other hand, if it is less than 0.1% by volume, the effect of the nonmagnetic phase on the coercive force is hardly observed.

The solid material for magnets of the present invention can realize higher cost performance by joining and integrating with a soft magnetic solid metal material. By combining Fe material, Fe—Co material, silicon steel plate and the like with solid material for R—Fe—N—H—O magnet, the magnetic flux density can be enhanced, and further, those materials, Ni or By laminating materials containing Ni, workability and corrosion resistance can be further increased.
An example in which a solid material for an R—Fe—N—H—O magnet and a soft magnetic material are joined and integrated is shown in FIGS.

FIG. 1 is a cross section of a solid material for a magnet obtained by joining and integrating an R—Fe—N—H—O based magnetic material (hard magnetic layer) and a soft magnetic solid metal (soft magnetic layer). An example is shown.
FIG. 2 shows an example of a cross section of a solid material for a magnet in which R—Fe—N—H—O-based magnetic material layers (hard magnetic layers) and soft magnetic layers are alternately laminated and integrated. When the configuration as shown in FIG. 2 is adopted, the cost can be reduced without impairing the surface magnetic flux density of the magnet.

As a feature of the present invention, when the R—Fe—N—H—O-based magnetic material powder and the soft magnetic bulk material or powder are mixed at the same time and subjected to shock wave compression, R—Fe—N—H -O-based magnetic material can be solidified and integrated with soft magnetic material at the same time, and there is no need to perform cutting, welding, adhesive bonding, etc. large.
As shown in FIG. 3, the solid material for magnets of the present invention can cover a part or all of its surface with a nonmagnetic solid material.

  FIG. 3 illustrates a cross section of a solid material for a magnet covered with a nonmagnetic material. The solid material for magnets that covers the entire surface with non-magnetic material also has the effect of increasing corrosion resistance, and for applications in harsh environments of high temperature and high humidity, it was coated with non-magnetic material even at the expense of some magnetic properties. In some cases, this is preferable. Examples of non-magnetic materials include organic substances, polymers, inorganic substances, non-magnetic metals and the like having a high decomposition temperature and melting point, but coating with non-magnetic metals or inorganic substances is preferred in applications where thermal stability is particularly required. Also in this case, when the R—Fe—N—H—O-based magnetic material powder and the non-magnetic solid material or powder are charged simultaneously without mixing and subjected to shock wave compression, R—Fe—N—H— Solidification of the O-based magnetic material and integration with the non-magnetic material can be performed simultaneously.

  In order to make the solid material for magnets anisotropic and to make a magnet, normal magnetization is performed. At this time, the solid material for magnets is subjected to a large impact, and the R—Fe—N—H—O system is solidified densely. Even if it has a solid material for magnets, it may cause cracks. Therefore, depending on the magnetizing magnetic field and the magnetizing method, it is preferable to cover a part or all of the magnet surface with a non-magnetic solid material to obtain a solid material for a magnet having high impact resistance.

FIG. 4 shows an example of a cross section of another magnet solid material of the present invention. That is, a solid material for a magnet as shown in FIG. 4 can be formed by combining an R—Fe—N—H—O-based magnetic material with a soft magnetic material and a non-magnetic material.
The solid material for magnets of the present invention is characterized by excellent magnetic properties after magnetization. When the R—Fe—N—H—O-based material is a magnetic anisotropic material, it is desirable to orient the magnetic powder in a magnetic field of 80 kA / m or more, preferably 800 kA / m or more during compression molding. . Furthermore, it is desirable to increase the residual magnetic flux density and the coercive force by magnetizing with a static magnetic field or pulsed magnetic field of 1.6 MA / m or more, more preferably 2.4 MA / m or more after shock wave compression molding.
When the R—Fe—N—H—O-based magnetic material is an isotropic material, magnetic field orientation during compression molding is not necessary, but magnetization is performed as described above to make it sufficiently anisotropic. It is essential to do.

  In addition, when the magnet solid material is magnetized and used as a magnet, various shapes are required depending on the application. The solid material for magnets does not contain a resin binder, has a high density, and can be easily processed into an arbitrary shape by a normal processing machine by cutting and / or plastic processing. In particular, it is a great feature that it can be easily processed into a prismatic shape, a cylindrical shape, a ring shape, a disc shape or a flat plate shape having high industrial utility value. Once these shapes are processed, they can be further processed by cutting or the like to form tiles or quadrangular columns having an arbitrary bottom shape. In other words, from any shape, any shape surrounded by a curved surface and a plane including a cylindrical surface can be easily formed by cutting and / or plastic working. The cutting process mentioned here is a general metal material cutting process, which is machining by a saw, a lathe, a milling machine, a drilling machine, a grindstone, etc., and a plastic process is a die cutting, forming, rolling, or explosion by a press. For example, molding. Further, in order to remove strain after cold working, heat treatment such as annealing at a temperature lower than the decomposition temperature of the magnetic material powder can be performed. Depending on the composition of the magnetic material powder, the magnetic anisotropy can be imparted or strengthened by plastic working, and the coercive force can be adjusted by combining with heat treatment. The heat treatment can be used for annealing the generated strain after shock wave compression, which will be described later, or adjusting various microstructures to improve various magnetic properties. Furthermore, when the low-melting point metal is included in the R—Fe—N—H—O-based magnetic material, heat treatment is performed simultaneously with or before and after the compacting to strengthen the temporary bond between the magnetic powders, and thereafter It can also be used to facilitate the handling of The heat treatment temperature is selected in the range of 100 ° C. or higher and lower than the decomposition temperature. Besides the above-mentioned examples, before, during and after each step of producing the magnet solid material of the present invention, further for the magnet solid material of the present invention The heat treatment can be performed at any stage such as the raw material manufacturing process selected in the above.

The 2nd aspect in the solid material for magnets of this invention is a material which contained 80-97 volume% of R-Fe-N-H-O type magnetic materials. This aspect is intended to provide a solid material for a magnet that is lightweight and has excellent magnetic properties and stability, and its purpose is completely different from that of the first aspect. In this embodiment, the portion of 3 to 20% by volume other than the R—Fe—N—H—O-based material may be air, depending on the application and material composition, but may be vacuum or density 6.5 g / cm. ^It may be ³ or less elements, compounds, or a mixture thereof.

The density of the magnet solid material according to the second aspect of the present invention is preferably 6.15 to 7.45 g / cm ^{3 in} order to take advantage of the characteristics. Even if it is less than 6.15 g / cm ³ , it may be preferable if the component of the R—Fe—N—H—O-based magnetic material is 80% by volume or more. Further, even if the R—Fe—N—H—O-based magnetic material is 97% by volume or less, it may exceed 7.45 g / cm ³ , and the weight of the solid material for magnets of the present invention, which is lighter than existing solid magnets, Features may not be useful. For example, the true density of Sm ₂ Fe ₁₇ N ₃ H _0.1 magnetic material is 7.69 g / cm ³ (see IEEE Trans. If the oxygen content is 0.1 atomic% or less and the content of the magnetic material is 80 to 97% by volume, assuming that the portion other than the magnetic material is sufficiently negligible, R-Fe-N The density of the solid material for the —HO—magnet is 6.15 to 7.46.

In addition, since the solid material for magnets of the present invention is a polycrystal and may contain an interface phase different from the R—Fe—N—H—O main phase, Dm is It does not necessarily match Dx. Therefore, in the present invention, it is often appropriate to use the value of Dm itself as a guide rather than judging the degree of packing of the magnet solid material from the filling rate Dm / Dx.
Depending on the composition of the R—Fe—N—H—O based material and the type of the part other than the magnetic material, the relationship between the volume fraction and the density of the R—Fe—N—H—O based material varies, but the thermal stability A magnetic material content of 80% by volume or more is required to obtain a good solid material for magnets, and a density of 7.45 g / cm ³ or less is required to obtain a lightweight solid material for magnets. The solid material for use contains 80 to 97% by volume of an R—Fe—N—H—O-based magnetic material and has a density in the range of 6.15 to 7.45 g / cm ³ .

More specifically, the range of the volume fraction of the R—Fe—N—H—O-based magnetic material or the density of the solid material for the magnet is described, and it is 83 to 97% by volume particularly for applications requiring thermal stability. A density of 6.35 to 7.45 g / cm ³ is selected, and in order to obtain a lightweight magnet with excellent mechanical strength, magnetic properties, and thermal stability, the density is 85 to 96% by volume and the density is 6 A range of .50 to 7.40 g / cm ³ is selected.
In the solid material for magnets of the present invention, the components other than the R—Fe—N—H—O-based magnetic material are preferably elements, compounds or mixtures thereof having a density of 6.5 g / cm ³ or less. When the density is more than 6.5 g / cm ³ , the density of the whole solid material for magnets often exceeds 7.45 g / cm ³ even if the volume fraction of the magnetic material is limited to 80%. It is not preferable because the feature of the second aspect of the present invention, which is lightweight, cannot be used.

Elements having a density of 6.5 g / cm ³ or less include Al, Ar, B, Be, Br, C, Ca, Cl, F, Ga, Ge, H, He, Kr, Mg, N, Ne, O, P , S, Se, Si, Te, Ti, V, Y, Zr and the like. Even when these compounds, alloys, and elements having a density of 6.5 g / cm ³ or more are contained, the density of the compounds and alloys such as Mn—Al—C and Al—Cu—Mg alloys is 6 .5g / cm ³ or less and comprising one or a volume ratio of 1: it is preferable to select such a density 6.5 g / cm ³ or less what will become in a mixture, such as 1 Bi-Al.
Gas other than the R—Fe—N—H—O-based magnetic material having a density of 6.5 g / cm ³ or less, for example, at least one of inert gases such as nitrogen gas, He, Ar, Ne, and hydrogen A reducing gas such as gas or ammonia gas may be used. These magnetic material-gas composite magnet solid materials are characterized by being lightweight.

Further, the portion other than the R—Fe—N—H—O-based magnetic material has a density of 6.5 g / cm ³ or less, such as MgO, Al ₂ O ₃ , ZrO ₂ , SiO ₂ , oxides such as ferrite, CaF ₂ , AlF Preferred are fluorides such as ₃ , carbides such as TiC, SiC, and ZrC, and nitrides such as Si ₃ N ₄ , ZnN, and AlN. Besides, hydrides, carbonates, sulfates, silicates, chlorides, etc. Products, nitrates or mixtures thereof.
Of these, especially BaO · _6Fe 2 _{O 3} system, SrO · _6Fe 2 _{O 3} system, hard magnetic ferrite such as La-added ferritic, optionally Mn-Zn-based, is contained and Ni-Zn-based soft magnetic ferrite As a result, the magnetic properties and the stability thereof can be improved. These solid materials for magnetic materials and inorganic composite magnets have high mechanical strength and are excellent in thermal stability and magnetic properties.

Further, the portion other than the R—Fe—N—H—O based magnetic material may be an organic substance having a density of 6.5 g / cm ³ or less. For example, resins called engineering resins such as polyamide, polyimide, polyphenylene oxide, wholly aromatic polyester, liquid crystal polymers, epoxy resins, phenol-modified epoxy resins, unsaturated polyester resins, alkyd resins, fluorine resins, etc. Or, if it is an organic substance having a glass transition point, softening point, melting point, and decomposition point of 100 ° C or higher, such as thermosetting resin, organosilicon compound such as silicone rubber, organometallic compound such as coupling agent and lubricant, etc. It can be used as a component of the solid material for magnets of the invention.

  However, the volume fraction is 20% or less, preferably 17% or less, more preferably 10% or less, and most preferably 5% or less, which is due to the metal bond of the R—Fe—N—H—O-based magnetic material. It must not prevent solidification. This solid material for a magnetic material-organic composite magnet is excellent in impact resistance in spite of its light weight. However, in a severe environment of high temperature and high humidity, it may be better not to use a solid material for a magnetic material-organic composite magnet.

  Two or more of the above gases, inorganic substances, and organic substances can be simultaneously contained in a portion other than the R—Fe—N—H—O-based magnetic material of the solid material for magnets of the present invention. For example, a solid material for R—Fe—N—H—O-based magnetic material-inorganic-organic composite magnet having an air gap and silica-dispersed silicone rubber, and nitrogen gas that is an inert gas in the gap R-Fe-N-H-O-based magnetic material containing a silicone rubber with silica dispersed therein-gas-inorganic-organic solid material for organic composite magnet, etc. It is desirable to use properly.

By the way, among the solid materials for magnets of the present invention using the R—Fe—N—H—O based magnetic material, there is a material group having the following characteristic microstructure. It has a filling rate of 80% by volume or more, and magnetic powders are connected to form a continuous phase, and at the same time, only an amorphous portion enriched with oxygen forms a continuous phase. In this structure, the crystal phases existing in each are isolated in the amorphous phase. It can be said that the crystal phase forms a kind of sea-island structure floating as if in an amorphous phase like an island.
The crystalline phase does not contain oxygen or has less oxygen than the amorphous phase. From this tendency, the crystal phase becomes a ferromagnetic phase with particularly high magnetization, and the amorphous phase tends to become a low magnetization phase including a nonmagnetic phase or a paramagnetic material. Moreover, since the crystalline phase and the amorphous phase are firmly bonded and united to form the solid material for a magnet of the present invention, the mechanical strength is high, the magnetic properties, particularly the squareness ratio is high, and the magnetic properties are stable. Especially, it becomes a material having high stability of coercive force.

In this sea-island structure, the volume fraction of the R—Fe—N—H or R—Fe—N—H—O crystal phase is greater than 25% by volume because the magnetization and (BH) max are larger and practical. Is. Preferably it is 50 volume% or more, More preferably, it is 75 volume% or more. Of course, since both the sea (amorphous phase) and the island (crystal phase) form part of the R—Fe—N—H—O based magnetic material of the present invention, both the sea and the island are used. The value obtained by adding the volume fraction, and in some cases, the value obtained by adding the volume fraction of the M component to the volume fraction of the entire solid material for magnets of the R—Fe—N—H—O based magnetic material. .
When manufacturing a solid material for a magnet having the above-described structure, it is often necessary to control the shock wave pressure within a small range so that the amorphous phase is not decomposed to deteriorate the magnetic properties and the stability thereof.

In the solid material for magnets of the present invention, the relationship between the residual magnetic flux density B _r at normal temperature, the coercive force H _{cJ at} normal temperature, the permeance coefficient P _c when used as a magnet, and the maximum operating temperature T _max is such that μ ₀ is not permeable to vacuum. When using magnetic susceptibility,
B _r ≦ μ ₀ H _cJ (P _c +1) (11000−50T _max ) / (10000−6T _max )
If so, it is more desirable.
The above relational expression is an expression that determines the conditions under which the magnet does not significantly demagnetize, and its meaning will be supplemented below. Here, remarkable demagnetization refers to irreversible and large demagnetization, for example, demagnetization such that the irreversible demagnetization rate exceeds −20% within 1000 hours.

The H coordinate of the bending point on the BH curve representing the change in magnetization with respect to the reverse magnetic field of the magnet is approximately H _cJ when the squareness ratio is approximately 100%. If the operating point of the magnet comes to the higher magnetic field side than the bending point, it will demagnetize suddenly and the performance of the magnet cannot be exhibited effectively, so the operating point should be on the lower magnetic field side than the bending point. is there. Accordingly, the ratio of the magnetic flux density to the demagnetizing field determined by the shape of the magnet is incorporated into a magnetic circuit or device as an internal permeance coefficient P _c0 , and then the permeance at each operating point determined by the magnitude of the reverse magnetic field applied to the magnet during operation. When the smallest permeance coefficient among the coefficients is P _c , if the smaller value of P _c0 and P _c is P _cmin , at least if it is not within the range of the following formula (1), significant demagnetization Will occur.

Equation (1) is a conditional equation at room temperature. At a temperature T ° C., the temperature coefficient [α (B _r )] of the residual magnetic flux density and the temperature coefficient [α (H _cJ )] of the coercive force are used. By rewriting as (2), the conditions under which no significant demagnetization occurs are determined.

Here, when P _c0 is smaller than P _c and demagnetization occurs immediately after the magnetic field is removed even after magnetization, significant demagnetization is avoided by magnetizing after incorporating a magnet in a yoke or the like in advance. However, significant demagnetization due to the use of a magnet cannot be avoided unless at least the condition defined by equation (2) is satisfied.
The values of α (B _r ) and α (H _cJ ) vary depending on the composition and temperature range of the R—Fe—N—H—O-based material, but almost α (B _r ) is −0.06% / ° C., α (H _cJ ) is −0.5% / ° C. Since the absolute value of α (H _cJ ) is larger than the value of α (B _r ) and both are negative values, the higher the T, the higher the combination of positive values (B _r , H _cJ ) region becomes smaller. Accordingly, magnet made using a magnet for solid materials of the present invention, when used under the condition of permeance coefficient P _c, B in a range that is determined in (2) below the temperature T _max ° C. which is greatest during operation _{r And} by controlling H _cJ , demagnetization of the magnet can be mitigated.
Substituting T = T _max , α (B _r ) = − 0.06, α (H _cJ ) = − 0.5 into the equation (2) and rearranging, the following equation (3) is obtained.

That is, when a magnet is used, if B _r , H _cJ , P _c , and T _max satisfy the expression (3), it can be said that the magnet does not cause significant demagnetization. Further, according to the equation _(3), as _{H cJ} is large, the possible values of _{B r} increases. High thermal stability, in order to magnet high magnetic properties, who H _cJ is a solid material for a magnet exceeding 0.62MA / m are preferred.

In the solid material for magnets of the present invention, the most preferable aspect is that the solid material for magnets with increased Br by increasing the magnetic material volume fraction, specifically, the Th ₂ Zn ₁₇ type crystal structure or the like or the like. The R—Fe—N—H—O-based magnetic material having rhombohedral crystals having a simple crystal structure has a filling rate of 95% or more, preferably 98% or more, and most preferably 99% or more. the density of the solid material, 7.45 g / cm ³ or more, more preferably 7.50 g / cm ³ or more, and most preferably a 7.60 g / cm ³ or more, and a high maximum energy product (BH) max at room temperature magnet The solid material for a magnet is a solid material for a magnet having magnetic properties satisfying the expression (3) in the intended use environment.

By the way, even if the volume fraction of the magnetic material is increased so that _Br is increased to obtain a solid material for a magnet having a high maximum energy product (BH) _{max at} room temperature, T _max is, for example, 100 ° C. or more. If departing from the scope of the high a temperature (3), demagnetization becomes remarkable, there is a case where the volume fraction of the magnetic material can no longer change is less solid material for a magnet and performance of low B _r. That is, by the _{H cJ} of _{P c} and _{T max} combinations and solid material for a magnet, it is meaningless to increase the R-Fe-N-H- O system _{B r} to increase the volume fraction of the magnetic material. Rather, lowering the volume fraction of the magnetic material results in a magnet solid material that is lighter and has higher cost performance.

A specific example will be described. _Using R—Fe—N—H—O-based magnetic powder with H _cJ = 0.62 MA / m as a raw material and using shock wave compression, a solid for magnets having a volume fraction of almost 100% under certain conditions Can be a material. _{B r} at this time exceeds 1.2 T.
_However, if the _{P c = 1, T max =} 100 ℃ at which application (3) from the equation, it is not necessary to attach more than 0.99T and _{B r.} That is, in this case, demagnetized by the operation or use of the magnet as was the solid material for a magnet having high B _r than 0.99T, the magnet and performance having a B _r of 0.99T is not changed It is. Therefore, it is preferable to lower the volume fraction of the magnetic material to about 83 to 85% to make a magnet of B _r = 0.99T, and to make it a lightweight and inexpensive magnet.

The above describes the minimum permeance coefficient determined by the shape or magnetic circuit of the magnet, the operation, and the thermal stability determined by the magnetic properties of the magnetic material such as B _r , H _cJ , α (B _r ), α (H _cJ ). This is a property that is generally referred to as a temperature characteristic of a magnet.
In addition to this, a major cause of a decrease in thermal stability is that the magnetic powders are not sufficiently solidified by bonding with metal bonds. Originally, permanent magnets have the same easy magnetization direction of crystals in order to create a magnetostatic potential in the outside world, but they are in a magnetically non-equilibrium state, so the magnetic powders are not sufficiently bonded and fixed. If this is the case, each magnetic powder rotates in the matrix and changes the direction of the easy magnetization direction, and the stored magnetostatic energy gradually decreases.

  For materials with a magnetic powder filling rate of less than 80%, such as bonded magnets, if the resin is softened or deteriorated at a high temperature of 100 ° C. or higher, the above relaxation occurs relatively easily, and significant demagnetization occurs. . As the name suggests, a bonded magnet is a magnet bonded by a binder, not a magnet solidified by metal bonding or ionic bonding. It can be said that the lack of thermal stability is a problem resulting from this. On the other hand, among the materials of the present invention, if the magnetic powder integration rate is 80% or more, preferably 83% or more, more preferably 90% or more, and most preferably 95% or more, the magnetic powders are solidified by metal bonds. And such mitigation does not occur. As described above, in order to achieve satisfactory thermal stability at 100 ° C. or higher, it is necessary to set the lower limit and upper limit of the volume fraction of the magnetic material within a specific range according to the magnetic properties and applications of the material. There is.

The solid material for a magnet of the present invention has a coercive force _HcJ of 0.76 MA / m or more and a squareness ratio B _r / J _s of 95% or more without using a special method. It can also be used as a solid material. However, J _s is saturation magnetization at room temperature, and in the present invention, it is a magnetization value when the external magnetic field is 1.2 MA / m.
For example, since the Sm ₂ Fe ₁₇ N ₃ H _0.1 O _x material has a nucleation-type magnetic field reversal mechanism, the particle size and the coercive force H _cJ have a substantially inversely proportional relationship. If it is less than 2 μm, the coercive force exceeds 0.76 MA / m, but in this region, the magnetic powder tends to aggregate as the particle size of the magnetic powder becomes smaller. The degree drops sharply and the squareness ratio decreases.

An R—Fe—N—H—O-based magnetic material (oxygen content of 0.1 to 5 atom%) obtained by pulverizing Sm ₂ Fe ₁₇ N ₃ H _0.1 coarse powder with a ball mill is 1.2 MA / m. in compact filling of 80% was formed a magnetic field compressed external magnetic field _{of, H cJ} is reduced abruptly squareness ratio exceeds 0.74MA / _{m, H cJ} is in more areas 0.76MA / m 95% or less.
The solid material for magnets according to the present invention can make the structure finer when the shock wave is compressed and solidified. Therefore, a compact with a high squareness ratio using a magnetic powder having a coercive force of less than 0.76 MA / m. A body is prepared, and this is compressed and solidified by shock waves, and at the same time the coercive force is improved, and a solid material for a magnet having both a high squareness ratio and a high coercive force can be obtained. When the coercive force is in the range of 0.8 to 1.2 MA / m, the squareness ratio can be adjusted in the range of approximately 100% from 95% by adding devices such as the magnetic field orientation method and the magnetic material components. Is possible.

Next, a method for producing a solid material for magnets according to the present invention, particularly shock wave compression enabling realization of the solid material for magnets according to the present invention will be described. However, the production method of the present invention is not limited to this.
As an impact compression method using an underwater shock wave, the powder is compacted in the innermost part of a double tube, water is placed in the middle part, an explosive is placed on the outer peripheral part, and the explosive is detonated. A method of compressing the innermost powder and introducing the shock wave into the water of the part, or compacting the powder into a sealed container, throwing it into the water, detonating the explosive in water, and the shock wave The method of compressing the powder and the method according to Japanese Patent No. 2951349 or Japanese Patent No. 3220212 can be selected. In any method, the following advantages of shock compression by underwater shock waves can be obtained.

  In the compression and solidification process by the shock compression method of the present invention using an underwater shock wave, the ultra-high pressure shearing and activation action of the shock wave induces solidification action due to metallic bonding of the powder and refinement action of the structure. It is possible to increase the coercive force with solidification. At this time, although the duration of the impact pressure itself is longer than when using the conventional shock wave, the temperature rise due to the increase in entropy based on the nonlinear phenomenon of volume compression and shock wave disappears in a very short time (several μs or less). Decomposition and denitrification hardly occur. There is a residual temperature even after compression using underwater shock waves. If this residual temperature is equal to or higher than the decomposition temperature (normal pressure of about 600 ° C.), the R—Fe—N—H—O-based compound and the like are also started to decompose, and the magnetic properties are deteriorated. However, in the case of underwater shock waves, it is much easier to keep the residual temperature lower than in the case of conventional shock waves.

That is, the underwater shock wave has the following characteristics.
(1) The pressure of the underwater shock wave is determined by the Yugonio relationship between explosives and water, and the pressure P is approximately expressed by the following equation.
P = 288 (MPa) {(ρ / ρ ₀ ) ^7.25 −1}
From the above equation, when an underwater shock wave is used, the amount of increase in the pressure P related to the change of the density ρ of the water with respect to the reference value ρ ₀ is very large. The temperature of the magnetic material at that time is easily maintained at a low temperature as compared with the case of using a conventional shock wave.
(2) The duration of the impact pressure itself is long.
(3) The temperature rise of the magnetic material due to the increase in entropy based on the nonlinear phenomenon of volume compression and shock wave disappears in a very short time.
(4) The temperature of the magnetic material is rarely kept high thereafter and is rarely kept long.
(5) Impact pressure is uniformly applied to the object to be compressed.
For the first time due to these excellent features of underwater shock waves, the R—Fe—N—H—O-based material does not undergo thermal decomposition and is easily compacted to a high density.
Furthermore, by performing compaction molding in a magnetic field, the easy magnetization axis of the magnetic material powder can be aligned in one direction. Even if the obtained compact is solidified by impact compression solidification, the orientation is lost. Accordingly, a magnetic solid material having magnetically uniaxial anisotropy is obtained.

In the present invention, by compressing and solidifying using an underwater shock wave with a shock wave pressure of 3 to 40 GPa, for a magnet having a density exceeding 80% with respect to the true density (for example, 7.7 g / cm ³ ) of the raw magnetic powder. A solid material can be obtained. When the shock wave pressure is lower than 3 GPa, it is not always possible to obtain a solid material for a magnet having a filling rate exceeding 80%. On the other hand, if the shock wave pressure is higher than 40 GPa, a decomposition product such as an α-Fe decomposition phase tends to be generated, which is not preferable. In addition, when the R—Fe—N—H—O-based raw material magnetic powder of the present invention has an oxygen-enriched amorphous phase on the surface, the amorphous phase is not decomposed. The following is preferable.

  In the case of compressing and solidifying using an underwater shock wave having a shock wave pressure of 3 to 40 GPa, it is possible to obtain a solid material for a magnet having a density exceeding 80% with respect to the true density of the raw magnetic powder with good reproducibility. Moreover, when the underwater shock wave whose shock wave pressure is 6-40 GPa is used, the high-density solid material for magnets with a filling rate exceeding 90% can be obtained. However, in addition to the R—Fe—N—H—O based magnetic material, a hard magnetic material such as a soft magnetic material, a rare earth-iron-boron based magnetic material, or a solid component such as a nonmagnetic phase, This condition is not determined only by the volume fraction of the R—Fe—N—H—O-based raw magnetic powder with respect to the magnet solid material. However, in order to obtain a solid material for a magnet having a volume fraction of 50% by volume or more of the R—Fe—N—H—O-based magnetic material without being decomposed, as in the above case, underwater within a range of shock wave pressure of 3 to 40 GPa. It is necessary to control the shock wave. Also in this case, when the R—Fe—N—H—O-based raw material magnetic powder has the amorphous phase, it is preferable to control the shock wave pressure in the range of 3 to 30 GPa.

Next, when producing a high-density magnet solid material which is the first aspect of the magnet solid material of the present invention, it is necessary to use an underwater shock wave having a shock wave pressure of 8 to 40 GPa. When the shock wave pressure is lower than 8 GPa, a bulk magnet having a density of 7.45 g / cm ³ or more cannot always be obtained. When the shock wave pressure is higher than 40 GPa, a decomposition product such as an α-Fe decomposition phase may be generated, which is not preferable. In addition, when the R—Fe—N—H—O-based raw material magnetic powder of the present invention has an oxygen-enriched amorphous phase on the surface, the amorphous phase is not decomposed. The following is preferable.

Furthermore, in the case of producing a solid material for a magnet that is light and excellent in high temperature characteristics, which is the second aspect of the present invention, in order to suppress the temperature rise of the green compact during impact compression, It is preferable to use an underwater shock wave with a shock wave pressure of 3 to 22 GPa. When the shock wave pressure is lower than ³ GPa, a magnet solid material having a density of 6.15 g / cm ³ or more cannot always be obtained. When the shock wave pressure is higher than 22 GPa, it often becomes a solid material for magnets having a density of 7.45 g / cm ³ or more. When the shock wave pressure is higher than 40 GPa, decomposition products such as α-Fe decomposition phase may be generated. It is not preferable. Similarly to the above, when the R—Fe—N—H—O type raw material of the present invention has an amorphous phase enriched with oxygen on the surface, the shock wave pressure is preferably 30 GPa or less.

Further, in order to obtain a solid material for a magnet having a density in the range of 6.35 to 7.45 g / cm ³ , and further in the range of 6.50 to 7.40 g / cm ³ with good reproducibility, the shock wave pressure of the underwater shock wave is 3 to 3. This is achieved by setting the pressure of 20 GPa and the shock wave pressure to 4 to 15 GPa. However, in a solid material for a magnetic material-gas composite magnet, if the impact pressure is too high, the magnetic solid material easily has a density exceeding 7.45 g / cm ³ , so an underwater shock wave with a shock wave pressure of 3 to 15 GPa is applied. It is preferable to use it.
As described above, it is important to introduce the oxygen component and the hydrogen component by bringing the oxygen source or the hydrogen source and the oxygen source into contact with each other in the production method of the R—Fe—N—H—O based magnetic material. A method of forming a solid material for a magnet having a target composition by bringing an oxygen source or a hydrogen source into contact with the compressed atmosphere is also effective.

In the method for producing a magnet solid material of the present invention, in order to impart anisotropy to the magnet solid material, the raw powder can be compacted in a magnetic field, and the raw powder is compacted. Thereafter, it can be solidified by impact compression using an underwater shock wave. In addition, after the raw material powder is compacted in a magnetic field, it can be impact-compressed and solidified using an underwater shock wave.
As described above, an R—Fe—N—H—O-based material containing hydrogen that is thermally stable and difficult to precipitate an α-Fe decomposition phase is selected as the magnetic powder, and the above-described underwater shock wave compression solidification method is used. The solid material for a magnet of the present invention can be produced for the first time by solidifying, and the magnet manufactured using this solid material for magnet has high magnetic properties, excellent oxidation resistance, and is like a bonded magnet. Since it does not contain a resin component as a binder of magnetic powder, it has a feature of excellent thermal stability.

Next, the component or apparatus containing the solid material for the R—Fe—N—H—O magnet according to the third aspect of the present invention will be described.
For applications where the maximum operating temperature Tmax is 100 ° C. or higher, a conventional R—Fe—N—H—O-based bonded magnet contains a resin component and the magnetic powders are not solidified by metal bonds. Furthermore, it was inferior in thermal stability and was difficult to use. If it is the solid material for magnets of this invention, even if it contains the resin component, it is excellent in thermal stability since R-Fe-N-H-O type magnetic powder is solidified by the metal bond. Furthermore, if B _r and H _cJ of the solid material for the magnet are in the region defined by P _c and T _max and the equation (3) when used as a magnet, they are not greatly demagnetized, are lightweight and have high cost performance. In addition, it is possible to obtain a magnet having further excellent thermal stability.
The upper limit of T _max is in the vicinity of the Curie point of the R—Fe—N—H—O-based material and exceeds 400 ° C., but the upper limit of T _max is 400 depending on the composition and composition of the solid material for magnets and how it is used as a magnet. Take various values below ℃. For example, even when an R—Fe—N—H—O-based material with H _cJ = 1.6 MA / m coated with Zn is used, when T _max is 220 ° C. or higher, the solid material for magnets of the present invention is used. It is not preferable to use it as a magnet.

The magnet obtained from the magnet solid material of the present invention has a P _c0 of 0.01 to 100, more preferably 0.1 to 10, and a combination of the values of P _c0 , B _r and H _cJ is (1). When deviating from the range of the equation, it is preferable to perform magnetization after increasing the _Pc0 after mounting a yoke or the like.

Various actuators, voice coil motors using the static magnetic field of the magnet obtained by the solid material for magnet of the present invention, especially the solid material for magnet of the second aspect, or the solid material for magnet satisfying the formula (3), Linear motors, motors for rotating machines as rotors or stators, among them magnetic fields for industrial machines and motors for motors, medical devices and metal sorters, as well as magnetic fields for analyzers such as VSM devices, ESR devices and accelerators Equipment, parts such as OA equipment, undulator, wiggler, retarder, magnet roll, magnet chuck, various magnetic sheets, etc., special applications such as stepping motors with extremely small _Pc Except for, it is stable without significant demagnetization even in an environment of 100 ° C or higher. Can be used for

Depending on the application, it can be used even at a temperature of 125 ° C. or higher. For example, H _cJ > 0.7 (MA / m) and P _c > 1. Furthermore, it can be used at 150 ° C. or higher. For example, there is a case where H _cJ > 0.8 (MA / m) and P _c > 2.
In addition, when used in these devices or parts, the solid material for magnets of the present invention is subjected to various processing, and then used in combination after bonding, adhering, closely bonding, and bonding various shaped yokes and hole pieces, and various magnetic shunt materials. May be.
When the solid material for magnets of the present invention is used as a rotor for a permanent magnet synchronous motor or as a hard magnetic material of the constituent material, the surface magnet structure rotor of the present invention is shown in cross section of the rotating shaft shown in FIGS. It can be a structure. Moreover, it can be set as the rotary shaft cross-section structure shown in FIGS.

Hereinafter, the present invention will be described based on examples. The degree of decomposition of the R—Fe—N—H—O-based magnetic material is based on the Th ₂ Zn ₁₇ type based on the X-ray diffraction pattern (Cu—Kα ray) of the molded solid material for magnets. The ratio b / a of the height b of the diffraction line derived from the α-Fe decomposition phase near 2θ = 44 ° with respect to the height a of the strongest line in the diffraction line derived from the rhombohedral or hexagonal crystal structure. . If this value is 0.2 or less, it can be said that the degree of decomposition is small. Preferably it is 0.1 or less. More preferably, it is 0.05 or less, and in this case, it can be said that there is almost no decomposition.
However, in the above determination method, an R—Fe—N—H—O-based magnetic material that is a raw material for a magnet solid material originally contains a material having a peak near 44 °, such as an Fe soft magnetic material. The case is not applicable. In this case, the presence or absence of decomposition can be determined by the relative ratio of b / a in the raw material including the R—Fe—N—H—O-based magnetic material and the solid material for the magnet.
The technical scope of the present invention is not limited by the following specific examples.

[Production Example 1]
6. Sm ₂ Fe ₁₇ master alloy having an average particle size of 60 μm is subjected to NH ₃ partial pressure 0.35 atm, H ₂ partial pressure 0.65 atm and oxygen partial pressure 10 ⁻³ atm or less in an ammonia-hydrogen mixed gas stream at 465 ° C. after 2ks oxynitride hydride performs 1.8ks annealed at an oxygen partial pressure of ¹⁰ -5 atm stream of argon, dissolved oxygen 40 ppm, of ¹⁰ -1 atm using a hydrocarbon solvent water content 20ppm as a grinding solvent An R—Fe—N—H—O-based magnetic material powder was obtained by pulverization with a ball mill charged in a nitrogen stream so that the average particle size was about 2 μm. A compact was obtained by compacting the powder while aligning the magnetic field in a magnetic field of 1.2 MA / m. FIG. 13 is an explanatory diagram showing an example of an apparatus for performing an impact compression method using underwater shock waves. The obtained molded body was put into a copper pipe 1 and fixed to a copper plug 2 as shown in FIG. Further, the copper pipe 3 is fixed to the copper plug 2, and further, the gap is filled with water, a uniform gap is provided in the outer peripheral portion, the paper tube 4 is disposed, and 280 g is placed in the gap between the copper pipe 3 and the paper tube 4. The ammonium nitrate-based explosive 5 was loaded, and the explosive was detonated from the detonator 6 to detonate the explosive. At this time, the shock wave pressure was 16 GPa.

Solid material for magnet having composition of Sm _8.5 Fe _72.3 N _12.7 H _2.8 O _3.7 which is R—Fe—N—H—O-based magnetic material solidified from pipe 1 after impact compression As a result of magnetizing with a pulsed magnetic field of 4.0 MA / m and measuring magnetic properties, residual magnetic flux density B _r = 1.18 T, coercive force H _cJ = 0.78 MA / m, (BH) _max = 264 kJ / and the results of m ^3. Moreover, as a result of measuring a density by the Archimedes method, the density was 7.60 g / cm ³ and the filling rate was 99%.

Furthermore, as a result of analysis by the X-ray diffraction method, the solidified solid material for magnets has almost no precipitation of α-Fe decomposition phase and has a crystal structure of Th ₂ Zn ₁₇ type rhombohedral crystal. confirmed.
The same experiment was repeated many times by adjusting the amount of explosives.
It was confirmed that when the shock wave pressure is lower than 4 GPa, the filling rate of the obtained magnet solid material does not necessarily exceed 80%, and when the shock wave pressure is higher than 30 GPa, a decomposition product such as an α-Fe decomposition phase is generated. It was also found that the shock wave pressure is preferably 3 to 30 GPa in order to obtain a solid material for magnets with a filling rate exceeding 80% with good reproducibility. It was also confirmed that by setting the shock wave pressure to 6 to 30 GPa, a solid material for magnets with a filling rate exceeding 90% can be obtained with good reproducibility.

It was also found that the shock wave pressure is preferably 3 to 15 GPa in order to obtain a solid magnet material having a density of 6.15 to 7.45 g / cm ³ with better reproducibility. .
Furthermore, in order to obtain a bulk magnet having a density exceeding 7.45 g / cm ³ with better reproducibility, it was also found that this shock wave pressure is preferably 10 to 30 GPa. It was also confirmed that a bulk magnet having a density exceeding 7.55 g / cm ³ can be obtained with good reproducibility at a shock wave pressure of 12 to 30 GPa.

[Comparative Example 1]
Similar to Production Example 1 except that Sm ₂ Fe ₁₇ master alloy having an average particle size of 20 μm is nitrided in N ₂ gas stream at 495 ° C. for 72 ks, except that the shock wave pressure is 18 GPa, so that Sm _9.1 Fe _A solid material for a magnet having a composition of _77.7 N _13.2 was produced. As a result of magnetizing the magnet solid material with a pulse magnetic field of 4.0 MA / m and measuring the magnetic characteristics, the residual magnetic flux density B _r = 0.96 T, the coercive force H _cJ = 0.36 MA / m, (BH) _max = 120 kJ / m ³ was obtained. Further, the density was measured as 7.50 g / cm ³ by Archimedes method.
In the X-ray diffraction pattern of this material, a diffraction line derived from the α-Fe decomposition phase was also observed in addition to the crystal structure of the Th ₂ Zn ₁₇ type rhombohedral crystal. The intensity ratio b / a between the diffraction line of the α-Fe decomposition phase near 44 ° and the (303) strongest line showing the crystal structure of the Th ₂ Zn ₁₇ type rhombohedral crystal was 0.21.

[Comparative Example 2]
FIG. 14 is an explanatory diagram illustrating an example of an apparatus that performs shock compression using a detonation wave of explosives directly. Using this apparatus, the R—Fe—N—H—O-based magnetic powder having an average particle diameter of 2 μm obtained in Production Example 1 is placed in a copper pipe 1 and fixed to a copper plug 2, and a uniform gap is formed on the outer periphery. The paper tube 4 was placed, and the same amount of ammonium nitrate explosive 5 as that of the example was loaded in the gap, and the explosive was detonated from the detonator 6 to detonate the explosive. After impact compression, the solidified sample was taken out from the pipe 1 and analyzed by X-ray diffraction. As a result, it was found that after impact compression, SmN and a large amount of α-Fe decomposition phase were formed. It was found that the Fe—N—H—O compound was decomposed. At this time, the intensity ratio b / a of the diffraction line was about 3.

[Example 1]
After mechanical alloying treatment for 180 ks with a vibrating ball mill with a ball of a predetermined amount of Sm and Fe metal powder (weight ratio 16.85: 83.15), it is performed at 600 ° C. in a vacuum of 10 ⁻⁵ atm or less. Heat treated for 2 ks. This powder contained about 30% by volume of Fe soft magnetic material. This powder was hydronitrided in an ammonia-hydrogen mixed gas stream of NH ₃ partial pressure 0.35 atm and H ₂ partial pressure 0.65 atm with an oxygen partial pressure of 10 ⁻³ atm or less at 380 ° C. and 1.2 ks. Followed by heat treatment for 300 s in hydrogen at the same temperature. Using this powder, in the same manner as in Production Example 1, except that the shock wave pressure was set to 18 GPa, a solid for magnet having a composition of Sm _5.9 Fe _78.5 N _8.8 H _3.0 O _{3.8 was} used. The material was made.

As a result of magnetizing the magnet solid material with a pulse magnetic field of 4.0 MA / m and measuring the magnetic properties, the residual magnetic flux density B _r = 1.22 T, the coercive force H _cJ = 0.43 MA / m, (BH) _max A result of = 215 kJ / m ³ was obtained. Further, the density was measured by Archimedes method, and it was 7.74 g / cm ³ .
In the X-ray diffraction pattern of this material, a diffraction line derived from α-Fe was observed in addition to the crystal structure of the Th ₂ Zn ₁₇ type rhombohedral crystal, but this material was originally an Fe soft magnetism which is not an α-Fe decomposition phase. Since it is a material containing a material, whether or not an α-Fe decomposition phase was generated by solidification could not be strictly determined by an X-ray diffraction method. As a result of observation with a transmission electron microscope, the volume fraction of the Fe soft magnetic phase was about 30%, the crystal grain size was about 10 to 50 nm, and the R—Fe—N—H—O based magnetic material A solid material for a magnet having a volume fraction of about 70% was obtained.

[Example 2]
An R—Fe—N—H—O-based powder having an average particle size of about 2 μm obtained in Production Example 1 and an average particle size of about 25 μm and a composition of Sm _11.5 Co _57.6 Fe _24.8 Cu _4.4 An Sm—Co-based powder of Zr _1.7 was charged into an agate mortar so as to have a volume ratio of 50:50, and wet-mixed in cyclohexane having a dissolved oxygen content of 40 ppm and a water content of 30 ppm. This operation was performed in a glove box having an oxygen partial pressure of 10 ⁻¹ atm.
Using this mixed powder, in the same manner as in Production Example 1, except that the shock wave pressure was 14 GPa, the R—Fe—N—H—O-based magnetic material had a volume fraction of 50% R—Fe—N—. A solid material for an HO-based magnet (oxygen amount 1.7 atomic%) was produced. As a result of magnetizing the solid material for a magnet with a pulse magnetic field of 4.0 MA / m and measuring the magnetic properties, the residual magnetic flux density B _r = 1.08 T, the coercive force H _cJ = 0.85 MA / m, (BH) _max = 215 kJ / m ³ .

[Example 3]
An Sm—Fe—Co—N—H—O magnetic material having an average particle diameter of about 1 μm, which is obtained by coating the surface of an R—Fe—N—H—O based magnetic material with Zn metal by a known photolysis method using diethyl zinc. A powder was prepared, and this powder was used in the same manner as in Production Example 1, except that the shock wave pressure was 16 GPa, so that the volume fraction of the R—Fe—N—O—O-based magnetic material was 100%. A solid material for a magnet having a composition of Sm _8.2 Fe _62.6 Co _6.9 N _12.2 H _3.3 O _3.8 Zn _3.0 was produced.
As a result of magnetizing this magnet solid material with a pulse magnetic field of 4.0 MA / m and measuring the magnetic characteristics, the residual magnetic flux density B _r = 1.24 T, the coercive force H _cJ = 0.79 MA / m, (BH) _max = 263 kJ / m ³ . The density was 7.71 g / cm ³ . Furthermore, as a result of analysis by an X-ray diffraction method, it was confirmed that the solidified magnet solid material has a crystal structure of a Th ₂ Zn ₁₇ type rhombohedral crystal. The intensity ratio b / a between the diffraction line of the α-Fe decomposition phase near 44 ° and the (303) strongest line showing the crystal structure of the Th ₂ Zn ₁₇ type rhombohedral crystal was 0.08.

[Example 4]
As an R—Fe—N—H—O-based magnetic material, Sm—Fe—Co—Mn having an average particle diameter of 30 μm, which is a pinning type magnetization reversal mechanism, obtained by a known method (Japanese Patent Laid-Open No. 8-55712). Using —N—H—O magnetic powder, the volume fraction of the R—Fe—N—H—O-based magnetic material is 100% as in Production Example 1, except that the shock wave pressure is 14 GPa. A solid material for a magnet having a composition of Sm _8.5 (Fe _0.89 Co _0.11 ) _66.6 Mn _3.6 N _18.5 H _2.6 O _0.2 was prepared. As a result of magnetizing this magnet solid material with a pulse magnetic field of 4.0 MA / m and measuring magnetic properties, residual magnetic flux density B _r = 1.08 T, coercive force H _cJ = 0.39 MA / m, (BH) _max = 128 kJ / m ³ . The density determined by the volume method was 7.70 g / cm 3. Further, in the X-ray diffraction pattern of this material, in addition to the crystal structure of the Th ₂ Zn ₁₇ type rhombohedral crystal, diffraction lines derived from the α-Fe decomposition phase were also observed. The intensity ratio b / a between the diffraction line of the α-Fe decomposition phase near 44 ° and the (303) strongest line showing the crystal structure of the Th ₂ Zn ₁₇ type rhombohedral crystal was 0.06.

[Example 5]
Components other than the R—Fe—N—H—O based magnetic material are Al ₂ O _{3 so} that the volume fraction of the R—Fe—N—H—O based magnetic material produced in Production Example 1 is 96%. In the same manner as in Production Example 1, a solid material for a magnet with a reduced amount of the mixed powder was prepared. However, the shock wave pressure was 15 GPa. Then, magnetized with a pulse magnetic field of _{4.0MA / m, B r, H} cJ, remanence ratio _B r _/ J s, a _{(BH) max} was determined.
The results are shown in Table 1. Even though the coercive force _HcJ was a large value of 0.83 MA / m, a squareness ratio of 96% could be obtained.

[Examples 6 to 8]
A solid material for a magnet was produced in the same manner as in Production Example 1 except that the components other than the R—Fe—N—H—O-based magnetic material and the shock wave pressure were as shown in Table 1, and Example 5 and Similarly, various magnetic properties were measured. The results are shown in Table 1.

[Example 9]
Using an R—Fe—N—H—O-type HDDR isotropic magnetic powder having an average particle diameter of 30 μm produced by a known method, R—Fe—N—H—O is produced in the same manner as in Production Example 1. A solid material for a magnet having a composition of Sm _8.3 Fe _76.1 B _0.9 Ti _2.4 N _12.0 H _0.1 O _{0.2, in} which the volume fraction of the magnetic material is 100% did.
As a result of magnetizing the magnet solid material with a pulse magnetic field of 4.0 MA / m and measuring the magnetic characteristics, the residual magnetic flux density B _r = 0.70 T, the coercive force H _cJ = 1.05 MA / m, (BH) _max A result of 75.4 kJ / m ³ was obtained. Further, the density was measured by Archimedes method and found to be 7.45 g / cm ³ .
In the X-ray diffraction pattern of this material, in addition to the rhombohedral and hexagonal crystal structures, diffraction lines derived from the α-Fe decomposition phase were also observed, and the ratio b / a was 0.15.

[Example 10]
6. Sm ₂ Fe ₁₇ master alloy having an average particle size of 60 μm is subjected to NH ₃ partial pressure 0.35 atm, H ₂ partial pressure 0.65 atm and oxygen partial pressure 10 ⁻³ atm or less in an ammonia-hydrogen mixed gas stream at 465 ° C. after 2ks oxynitride hydride performs 7.2ks annealed in a stream of argon with an oxygen partial pressure of ¹⁰ -3 atm, dissolved oxygen 45 ppm, ^{10 -1} using a hydrocarbon solvent water content 20ppm as a grinding solvent It grind | pulverized so that an average particle diameter might be set to about 2 micrometers with the ball mill prepared in the nitrogen stream of atm. Using this powder, as in Production Example 1, the shock wave pressure is 25 GPa, and the volume fraction of the R—Fe—N—H—O-based magnetic material is 100%. Sm _8.0 Fe _67.8 A solid material for a magnet having a composition of N _11.9 H _2.6 O _9.7 was obtained. At this time, the copper pipe 1 holding the compact was filled with air having humidity. As a result of magnetizing this magnet solid material with a pulse magnetic field of 4.0 MA / m and measuring magnetic properties, residual magnetic flux density B _r = 1.06 T, coercive force H _cJ = 0.73 MA / m, (BH) A result of _max = 158 kJ / m ³ was obtained. As a result of measuring the density by Archimedes method, the density was 7.55 g / cm ³ and the filling rate was 99%.

Furthermore, as a result of analysis by the X-ray diffraction method, the solidified solid material for magnets has almost no precipitation of α-Fe decomposition phase and has a crystal structure of Th ₂ Zn ₁₇ type rhombohedral crystal. confirmed.
The surface of this sample is mirror-polished and then corroded with 5% nital corrosion solution for 30 seconds and observed with FE-SEM. It was found to have a two-phase structure with the part. As a result of observing the crystal orientation of each part by EBSP, it was confirmed that the granular part was observed to have a Th ₂ Zn ₁₇ type rhombohedral crystal structure, and the other part was amorphous. From the area ratio of the observed cross section, it was found that the Th ₂ Zn ₁₇ type rhombohedral crystal part (crystalline phase) to the amorphous part (amorphous phase) existed in a volume ratio of 6 to 4.

1 Copper pipe (used to hold powder)
2 Copper plug 3 Copper pipe (used to hold water)
4 paper tubes (used to hold explosives)
5 Explosive 6 Initiation part 7 Water 8 Sample part (sample including rare earth-iron-nitrogen-hydrogen-oxygen magnetic material)

(1) A method for producing a solid material for a magnet containing 80 to 100% by volume of a rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material having a rhombohedral or hexagonal crystal structure, the rare earth-iron -A magnet characterized in that a raw material powder containing powder of nitrogen-hydrogen-oxygen-based magnetic material in an amount of 80 to 100% by volume with respect to the whole raw material powder is subjected to impact compression solidification using an underwater shock wave of 3 to 40 GPa. Method for manufacturing solid material.
(2) the rare earth - iron - nitrogen - hydrogen - oxygen-based magnetic material is represented by the general formula _{R α Fe 100-α-β} -γ-δ N β H γ O δ, at least R is selected from rare earth elements Α, β, γ, and δ are atomic percentages, and 5 ≦ α ≦ 20, 10 ≦ β ≦ 25, 0.1 ≦ γ ≦ 3.3, and 0.01 ≦ δ ≦ 10. The manufacturing method of the solid material for magnets as described in (1) characterized by the above-mentioned.
(3) the rare earth - iron - nitrogen - hydrogen - oxygen-based magnetic material is represented by the general formula _{R α Fe 100-α-β} -γ-δ N β H γ O δ M ε, rare earth R is including Y M is at least one element selected from Zn, In, Sn, Ga, Al, B, C, Ca, Ge, Mg, Si, Ti, V, Zr, Co, and Mn. And / or Mn—Al—C alloy, Al—Cu—Mg alloy, MgO, Al ₂ O ₃ , ZrO ₂ , SiO ₂ , ferrite, CaF ₂ , AlF ₃ , TiC, SiC, ZrC, Si ₃ N ₄ , at least one selected from ZnN and AlN, and α, β, γ, δ, and ε are molar percentages, 5 ≦ α ≦ 20, 10 ≦ β ≦ 25, 0.1 ≦ γ ≦ 3.3. characterized in that it is a 0.01 ≦ δ ≦ 10,0.1 ≦ ε ≦ 10 (1 Method for producing a magnet solid material according to.
(4) The raw material powder includes a hard magnetic material powder as a component other than the rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material powder (1) to (3) The manufacturing method of the solid material for magnets in any one.
(5) The raw material powder includes a powder of a soft magnetic material as a component other than the powder of the rare earth-iron-nitrogen-hydrogen-oxygen magnetic material. (1) to (3) The manufacturing method of the solid material for magnets in any one.
(6) The raw material powder includes a powder of a nonmagnetic material as a component other than the powder of the rare earth-iron-nitrogen-hydrogen-oxygen-based magnetic material. (1) to (3) The manufacturing method of the solid material for magnets in any one.
(7) The method for producing a solid material for a magnet according to any one of (1) to (6), wherein the raw material powder is compacted and then impact-compressed and solidified using an underwater shock wave.
(8) The method for producing a solid material for a magnet according to (7), wherein the raw material powder is compacted in a magnetic field.
(9) The method for producing a magnet solid material according to any one of (1) to (8), further including a step of forming the magnet solid material by cutting and / or plastic working.
(10) The method for producing a solid material for a magnet according to (9) , wherein the solid material for a magnet is formed into a prismatic shape, a cylindrical shape, a ring shape, a disc shape, or a flat plate shape .
(11) The method for producing a solid material for a magnet according to any one of (1) to (10), further comprising a step of heat-treating the magnetic solid material at least once at a temperature of 100 ° C. or higher and lower than a decomposition temperature. Method.
(12) The method for producing a solid material for a magnet according to any one of (1) to (11), wherein the pressure of the underwater shock wave is 3 to 30 GPa.
(13) The method for producing a solid material for a magnet according to (12), wherein the pressure of the underwater shock wave is 3 to 22 GPa.

Claims (16)

  A solid material for a magnet containing 50 to 100% by volume of a rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material.   2. The solid material for a magnet according to claim 1, comprising a rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material having a rhombohedral or hexagonal crystal structure. Rare earth - iron - nitrogen - hydrogen - oxygen-based magnetic material is represented by the general formula _{R α Fe 100-α-β} -γ-δ N β H γ O δ, R is at least one element selected from rare earth elements And α, β, γ, and δ are atomic percentages, 3 ≦ α ≦ 20, 5 ≦ β ≦ 25, 0.01 ≦ γ ≦ 5, and 0.01 ≦ δ ≦ 10. Solid material for magnets. Rare earth - iron - nitrogen - hydrogen - oxygen-based magnetic material is represented by the general formula _{R α Fe 100-α-β} -γ-δ N β H γ O δ M ε, R is selected from rare earth elements including Y At least one element, M is Li, Na, K, Mg, Ca, Sr, Ba, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Pd, Cu, Ag, Zn , B, Al, Ga, In, C, Si, Ge, Sn, Pb, Bi, and / or R oxide, fluoride, carbide, nitride, hydride, carbonate, sulfuric acid It is at least one selected from a salt, a silicate, a chloride, and a nitrate, and α, β, γ, δ, and ε are mole percentages, 3 ≦ α ≦ 20, 5 ≦ β ≦ 30, 0.01 ≦ The γ ≦ 10, 0.01 ≦ δ ≦ 10, and 0.1 ≦ ε ≦ 40, respectively. Solid material for magnets. Rare earth - iron - nitrogen - hydrogen - oxygen-based one solid material for a magnet of claims 1 to 4 having a density greater than 6.15 g / cm ³ containing a magnetic material. 6. The solid material for a magnet according to claim 5, wherein the component other than the rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material is an element, a compound or a mixture thereof having a density of 6.5 g / cm ³ or less. When the relationship between the room temperature residual magnetic flux density B _r , the room temperature coercive force H _cJ , the permeance coefficient P _c when used as a magnet, and the maximum operating temperature T _max is μ ₀ , the permeability of vacuum is
B _r ≦ μ ₀ H _cJ (P _c +1) (11000−50T _max ) / (10000−6T _max )
The solid material for a magnet according to any one of claims 1 to 6, wherein   The soft magnetic material containing at least one element selected from Fe, Co, and Ni is uniformly dispersed and integrated with the rare earth-iron-nitrogen-hydrogen-oxygen based magnetic material. 7. A solid material for a magnet according to any one of 7 above.   At least one magnetic material selected from a rare earth-iron-boron magnetic material, a rare earth-cobalt magnetic material, and a ferrite magnetic material is uniformly added and mixed with the rare earth-iron-nitrogen-hydrogen-oxygen magnetic material, The solid material for magnets according to any one of claims 1 to 8, which is integrated.   The solid material for a magnet according to claim 1, wherein a nonmagnetic phase is present at a grain boundary of the magnetic material.   A solid material for a magnet, wherein the solid material for a magnet according to claim 1 and a soft magnetic solid metal material are joined and integrated.   A solid material for a magnet having a soft magnetic layer, wherein the soft magnetic layer and the solid material for magnet according to claim 1 are alternately laminated and integrated.   A solid material for a magnet, wherein at least a part of the solid material for a magnet according to claim 1 is covered with a nonmagnetic solid material.   The solid material for a magnet according to any one of claims 1 to 13, which is formed into a prismatic shape, a cylindrical shape, a ring shape, a disc shape or a flat plate shape.   The method for producing a solid material for a magnet according to any one of claims 1 to 14, wherein the raw material powder of the rare earth-iron-nitrogen-hydrogen-oxygen-based magnetic material is shock-compressed and solidified using an underwater shock wave.   A method for producing a solid material for a magnet according to any one of claims 1 to 14, comprising a step of heat-treating the material at least once at 100 ° C and lower than a decomposition temperature. Manufacturing method.

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