JPH10241923A - Rare-earth magnet material, its manufacture, and rare-earth bond magnet using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnet material having a peculiar large coercive force which has a small temperature coefficient by forming a crystalline structure containing monoclinic and/or hexagonal R3 (Fe, M, B)29 Ny as a main phase by using an R-Fe-B-N magnet material having a specific ratio of components. SOLUTION: A rare-earth magnet material has a composition of RαFe100-(α+β+γ+δ) Mβ Bγ Nδcontaining monoclinic and/or hexagonal R3 (Fe, M, B)29 Ny as a main phase. The R and Y respectively represent one or two or more kinds of rare-earth elements including Y and one or two or more kinds of elements selected from among Al, Ti, V, Cr, Mn, Cu, Ga, Zr, Nb, Mo, Hf, Ta, and W and the α, β, γ, and δ are atomic percentages respectively set at 5<=α<=18, 1<=β<=50, 0.1<=γ<=5, and 4<=δ<=30. Therefore, a rare-earth magnet material and a bond magnet having high Curie temperatures and high thermal stability can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rare earth magnet material, a method for producing the same, and a rare earth bonded magnet using the same.

[0002]

2. Description of the Related Art Conventionally, ultra-quenched Nd-Fe-B-based magnetic powder has been frequently used as a rare earth bonded magnet magnetic powder.
Since the Curie temperature is as low as about 300 ° C. and the temperature coefficient (η) of the intrinsic coercive force (hereinafter referred to as iHc) is large, use at high temperatures has been restricted. Recently, the Sm2Fe17 compound has a Curie temperature of 470 ° C., which is 160 ° C. higher than that of the Nd2Fe14B compound due to storage of nitrogen, and its anisotropic magnetic field is 260 kOe, which is much larger than the anisotropic magnetic field (75 kOe) of the Nd2Fe14B compound. It has been reported that industrialization as a magnetic powder for bonded magnets is being studied. Sm2Fe17 nitride, Sm2Fe17Nx, is produced by a gas nitriding method or the like. However, unless the particle size of the Sm2Fe17Nx magnetic powder is reduced to about several micrometers, a high coercive force of 5 kOe or more cannot be obtained, and the magnetic powder having this particle size is easily oxidized. At the present time, it is difficult to put the magnet into practical use because of the deterioration of its magnet properties and the danger of ignition accompanying rapid oxidation.
Since this Sm2Fe17Nx magnetic powder has a particle size of several μm, when compacting it into a bonded magnet, the density of the compact cannot be increased, and a rare-earth bonded magnet with a high energy product cannot be obtained, and the formability is extremely poor. There is a problem that the efficiency is significantly reduced. In addition, it has been reported that high coercive force can be obtained by a special manufacturing method such as mechanical alloying method, but this method is suitable for small-scale production on a laboratory scale, but is inferior in cost performance, so mass production is difficult. Not reached. Further, in addition to Sm2Fe17Nx nitride, Nd (Fe, M) having a ThMn12 type crystal structure
12Nx alloy (M is a transition metal such as V, Ti, Mn, Mo)
Also, an SmFe7Nx alloy having a TbCu7 type crystal structure has been studied, but has not been put to practical use because of insufficient magnetic properties, poor productivity and high cost.

[0003] Proc.
Int.Workshop on RE Magnets and Applications,
The R3 (Fe, M) 29 alloy reported in Canbera, pp. 437-444, 1992 (unpublished) also has its nitride R3 (Fe,
M) 29Ny exhibits uniaxial magnetic anisotropy, suggesting that it is promising as a permanent magnet material. Bo-Ping Hu et al. (J. Phys .: Condens. M.) found that the coercive force can be increased by finely pulverizing this alloy-based Sm3 (Fe, Ti) 29 Ny alloy with a ball mill to an average particle size of 15 μm.
atter 6 (1994) L197-L200). However, these powders also have a small average particle size of 15 μm, so that it is difficult to put them into practical use as magnetic powders for bonded magnets because of insufficient compact density and poor moldability. On the other hand, Margarian e
t al., in J. Appl. Phys. 76 (1994) 6135-6155, this R3 (Fe, M) 29 alloy is very unstable and 900-1
Reported to decompose into other phases at 000 ° C. Therefore, it can be said that this R3 (Fe, M) 29 alloy is a phase that exists stably only at high temperatures. This has been confirmed by the experiments of the present inventors.
It is very difficult to obtain a single phase of (Fe, M) 29 alloy,
R having a crystal structure of ThMn12 type or Th2Zn17 type
(Fe, M) alloy and Fe-M alloy are very easy to form.

In Japanese Patent Application Laid-Open No. Hei 8-111305, this R3
It is disclosed that a high coercive force can be obtained with a coarse powder by introducing N or C using an (Fe, M) 29 alloy,
After preparing an R3 (Fe, M) 29 mother alloy, nitriding or carburizing treatment is performed using ammonia gas or methane gas, whereby N and C become R3 ( The spontaneous magnetization and the Curie temperature increase by increasing the interstitial distance of the (Fe, M) 29 phase. That is, N or C is introduced for the purpose of increasing the interstitial distance, and this object can be achieved by adding each element alone. When both N and C are used, a method may be considered in which C is contained in the master alloy and then N is introduced. However, in Japanese Patent Application Laid-Open No. H08-111305, C is contained in the master alloy before the nitriding treatment, whereby R3 ( Stabilization of the (Fe, M, C) 29 phase or R3 (Fe,
M, C) does not play a role in increasing the proportion of 29 phases.

[0005]

In order to improve the heat resistance of the bonded magnet, the absolute value of iHc must be increased and i
Since it is necessary to reduce the temperature coefficient (η) of Hc, a rare-earth magnet powder having a large anisotropic magnetic field and a high Curie temperature is required. As described above, the R-Fe-N alloy is expected to be a material having a small temperature coefficient (η) of iHc because the R-Fe-N alloy has a larger anisotropic magnetic field and a higher Curie temperature than the conventional Nd-Fe-B alloy. But R-Fe-
In order to obtain a high iHc of 5 kOe or more with an N-based alloy, it is necessary to form a fine powder of several μm as described above, and this fine powder is formed at a molding pressure of about 6 to 10 ton / cm ² which is usually used in industrial production. The density of the molded body of the bonded magnet cannot be sufficiently increased to obtain a high energy product, and it is easily oxidized and unstable, and the formability is very poor. In view of the above conventional problems, the problem of the present invention is i
An object of the present invention is to provide a rare-earth magnet material having a large Hc and a small temperature coefficient (η) of iHc as compared with the related art and having excellent thermal stability, a method for producing the same, and a rare-earth bonded magnet using the same. As a result of intensive studies, the present inventors have developed a unique magnet powder having a high anisotropic magnetic field and a high Curie temperature for bonded magnets. According to the present invention, a coarse powder having a large particle size has a high iHc and It has an excellent feature that a rare earth magnet material having a small temperature coefficient (η) of iHc can be provided. That is, the role of B in the present invention is completely different from that of C and N described above, and contributes to the stabilization of the R3 (Fe, M, B) 29 phase by forming a solid solution in its main phase. Ideally, a master alloy can be composed of this single phase. By introducing N into the master alloy, the conventional R3
Rare earth magnet materials having a high energy product, iHc being large and iHc having a small temperature coefficient (η) and having a high Curie temperature of about 480 ± 20 ° C. Rare earth bonded magnets can be provided.

[0006]

Means for Solving the Problems The inventors of the present invention aimed at ensuring the ease of molding in the molding step of bonded magnets and the good oxidation resistance and high magnet properties of the rare-earth magnet powder used therefor, and the average particle diameter was assured. In order to obtain R-Fe-N magnet powder having high iHc and saturation magnetization and low iHc temperature coefficient (η) in coarse powder having a particle size of 20 μm or more, additives were added to various R-Fe-N alloys. As a result of intensive studies on the composition
The inventors have found an e-MBN-based magnet material and have accomplished the present invention. That is, in the present invention, the component composition is RαFe100- (α +
β + γ + δ) MβBγNδ, R3 (Fe, M, B) 29Ny having a monoclinic and / or hexagonal crystal structure
Wherein R is any one or more of rare earth elements including Y, and M is Al, T
i, V, Cr, Mn, Cu, Ga, Zr, Nb, Mo,
A rare earth magnet material comprising at least one of Hf, Ta, and W, wherein α, β, γ, and δ are in the following ranges in atomic percentage. 5 ≦ α ≦ 18 1 ≦ β ≦ 50 0.1 ≦ γ ≦ 5 4 ≦ δ ≦ 30

The rare earth elements R include Y, La, C
e, Pr, Nd, Sm, Eu, Gd, Tb, Dy, H
At least one of o, Er, Tm, Yb, and Lu may be included, and a mixture of two or more rare earth elements such as misch metal and dymium may be used. Preferred rare earth elements R include Y, Ce, Pr, Nd, Sm, Gd,
Any one or more of Dy and Er, and more preferably any one of Y, Ce, Pr, Nd and Sm
Species or a combination of two or more, and particularly preferred is Sm. Here, the rare earth element R may have a purity that can be obtained by industrial production, and O, H, C, which cannot be avoided in production.
Impurity elements such as Al, Si, Na, Mg, and Ca may be contained. The rare earth magnet material of the present invention has an R component of 5
-18 atomic%. When the R component is less than 5 atomic%, the precipitation of a soft magnetic phase containing a large amount of iron component is promoted to lower iHc. When the R component exceeds 18 atomic%, a non-magnetic R-rich compound is precipitated to lower the saturation magnetic flux density. It is not preferable.
A more preferable range of the R component is 6 to 12 atomic%.

It is preferable that Fe contains 47 atomic% or more. If Fe is less than 47 atomic%, the saturation magnetization is undesirably small.

[0009] The above-mentioned M element is used in the presence of R
This is effective for stabilizing the 3 (Fe, M, B) 29 phase and increasing the decomposition temperature during nitriding as described later. R3
The amount of the M element required to form the (Fe, M, B) 29 phase varies depending on the type of the M element. However, if any of the M elements exceeds 50 atomic%, a ThMn12 type crystal structure is obtained. The generation rate of the R (Fe, M, B) 12 phase increases, and iHc drops sharply. If the M element is less than 1 atomic%, R2 (Fe, M, B) having a Th2 Zn17 type crystal structure
The generation rate of the 17 phase is increased, and the abundance ratio of the R3 (Fe, M, B) 29 phase is relatively reduced, and neither is preferable. Therefore, the preferable addition amount of the element M is 1 to 50 atomic%.
Preferred elements among the M elements are Ti, Mn, Cr, and Z.
Any one or two or more of r and V. R3 (F
The element M is essential to form the e, M, B) 29 phase, but the R 3 (Fe, M) 29 phase containing no B is unstable as described above, Therefore, it is very difficult to obtain a single-phase R3 (Fe, M) 29 Ny rare earth magnet powder.

[0010] R3 (Fe, M) 2 in the master alloy to be subjected to nitriding
If the ratio of the 9 phases is low, the nitride R3 (Fe,
M) Since the production ratio of 29Ny is low, good magnet properties cannot be obtained. In view of this point, the present inventors consider that when the above-mentioned elements B and M coexist, the content is 60% by volume or more, preferably 75% by volume.
Stable R3 (Fe, M, B) 29 close to a single phase with volume% or more
It has been found that a phase is obtained. Therefore, the proportion of the R3 (Fe, M, B) 29 phase in the master alloy before the nitriding treatment can be significantly increased, and R3 (Fe, M, B) 29 Ny occupying in the rare earth magnet material after the nitriding treatment. Since the proportion of the phase is remarkably increased as compared with the conventional case where the R3 (Fe, M) 29 phase not containing B is nitrided, a high magnetic flux density and a high coercive force can be generated. In the present invention, B
Is preferably 0.1 to 5 atomic%. B is 0.1
If it is less than 5 atomic% or more than 5 atomic%, R3 (Fe, M,
B) It is not preferable because the 29Ny nitride phase becomes unstable and is easily decomposed into another phase. That is, R3 (Fe, M,
B) The effect of stabilizing the 29 phase is exhibited when the content of B is in the above range. The effectiveness of adding such a small amount of B has not been known so far. For example, Sm2
Regarding the solid solubility limit when B, C and N were added to the Fe17 alloy, H. Horiuchi et al (J. Alloys. Comp. 222 (19
95) 131-135) reports that C is about 7 atomic% and N is about 1%.
While B forms a solid solution up to 4 atomic%, B forms a solid solution only up to about 1 atomic%, and it is said that the expansion of the lattice and the increase in Curie temperature due to the solid solution of B are very small. These are all intended to expand interstitial distance by introducing C, N, and B as interstitial elements, and to stabilize the main phase by adding a small amount of B as in the present invention. The technique of trying to achieve this has not been found so far.
The coexistence effect of the B and M elements in the present invention increases the proportion of the R3 (Fe, M, B) 29 phase in the master alloy as described above,
It has an effect of suppressing decomposition of αFe or the like into another phase in the homogenization treatment or the nitriding treatment. For example, conventionally, in the homogenization treatment, the heating temperature range in which the R3 (Fe, M) 29 phase is stable is narrow, and when the nitriding temperature is high or when nitriding is performed for a long time, the nitrided phase once formed: R3 (Fe, M). ) 29Ny is unstable and αFe etc. are generated, and the coercive force of the obtained magnetic material is greatly reduced. In the case of the present invention, however, by adding an appropriate amount of B, a wide range of homogenization temperature and nitriding temperature can be obtained. It can be adopted and is effective for improving productivity and stabilizing the magnet quality of rare earth magnet materials. Further, by adding B, R
The content range of the M element contributing to the stabilization of the 3 (Fe, M, B) 29 phase is wider than that of the conventional R3 (Fe, M) 29 phase, and at the same time, the M element can be reduced more than before so that the saturation is achieved. It also has the effect of increasing the magnetic flux density (residual magnetic flux density), that is, the energy product.

The nitrogen N introduced into the R3 (Fe, M, B) 29 phase is preferably 4 to 30 atomic%. If the nitrogen N content is less than 4 at%, the magnetization becomes low and
If it exceeds, it is difficult to improve the coercive force. More preferably, the content of nitrogen N is 10 to 20 atomic%.

Further, 0.01 to 30 atomic% of Fe is Co
And / or Ni is preferred, and the introduction of Co and / or Ni has the effect of increasing the Curie temperature and improving the temperature coefficient (η) of iHc and oxidation resistance. Fe by Co and / or Ni
A more preferable range of the substitution amount is 1 to 20 atomic%. If the substitution amount exceeds 30 atomic%, the saturation magnetic flux density and iHc
Is significantly reduced, and at less than 1 atomic%, C
No effect of adding o and / or Ni is observed.

By making 50% by atom or more, preferably 70% or more of the R component of the present invention Sm, a remarkably high i
This is preferable because Hc is obtained. Further, it is preferable that the rare earth magnet material of the present invention has an average particle diameter of 20 to 500 μm. If it is less than 20 μm, quality deterioration and formability deterioration due to oxidation become remarkable, and if it exceeds 500 μm, under normal nitriding conditions, the diffusion distance of nitrogen tends to be insufficient for powder particles having a large particle diameter, and nitrides are uniformly formed in the powder particles. Is not preferred because of the disadvantage that no is formed. A more preferable range of the average particle size is 30 to 400 μm. Also, R3
High iHc when the (Fe, M, B) 29Ny phase crystal grains have a structure in which M element or M compound is precipitated;
A low temperature coefficient (η) of iHc can be obtained.

Further, according to the present invention, it is possible to easily provide a rare earth magnet material having an R3 (Fe, M, B) 29Ny phase having an abundance of 60% by volume, preferably 75% by volume.

Further, the present invention provides a rare earth magnet material in which the magnet powder is bonded by any one of a polymer, a pure metal, and an alloy to form a bonded magnet, wherein the magnet powder at 25 to 100 ° C. A rare earth magnet material characterized in that the temperature coefficient (η) of the intrinsic coercive force (iHc) is −0.45 or more and the intrinsic coercive force (iHc) at 25 ° C. is 8 kOe or more.

Further, according to the present invention, the component composition is RαFe100-
(α + β + γ + δ + ε + ζ) MβBγNδHεOζ, which has a monoclinic and / or hexagonal crystal structure of R3 (F
e, M, B) 29Ny as a main phase, R is one or more of rare earth elements including Y, and M is Al, Ti, V, Cr, Mn, Cu, Ga, Z
a rare earth element comprising at least one of r, Nb, Mo, Hf, Ta, and W, wherein α, β, γ, δ, ε, and あ る are in the following ranges in atomic percentage. It is a magnet material. 5 ≦ α ≦ 18 1 ≦ β ≦ 50 0.1 ≦ γ ≦ 5 4 ≦ δ ≦ 30 0.5 ≦ ε ≦ 10 1 ≦ ζ ≦ 5 The rare earth magnet material of the present invention is subjected to hydrogen treatment in the process until it is subjected to nitriding. By adjusting the grinding particle size by applying
In the final nitrided magnetic powder, hydrogen H is 0.5 to 10 atomic%.
And / or 1 to 5 atomic% of oxygen O. When containing 0.5 to 10 atomic% of hydrogen, there is an effect of improving the efficiency of nitriding. This is already R3 (Fe,
It is considered that nitrogen can diffuse into the R3 (Fe, M, B) 29 phase in a short time because nitrogen replaces hydrogen existing in the (M, B) 29 phase. However, when hydrogen is 0.5
If the content is less than 10 atomic%, the effect is not recognized. If the content is more than 10 atomic%, the saturation magnetization decreases and the diffused hydrogen becomes excessive, so that it becomes chemically unstable. Next, the temperature coefficient (η) of iHc when oxygen is contained at 1 to 5 atomic%.
The effect of increasing is recognized. If oxygen is less than 1 atomic%, its effectiveness is not recognized, and if it exceeds 5 atomic%, magnetization and iHc are remarkably reduced, which is not preferable.

Further, the present invention relates to a rare earth bonded magnet comprising the above-mentioned characteristic magnet powder bound by a binder of a polymer, a pure metal, or an alloy, wherein the rare earth bonded magnet has a specific property at 25 to 100 ° C. The temperature coefficient (η) of the coercive force (iHc) is -0.45 or more,
A rare-earth bonded magnet having a coercive force (bHc) at 6 ° C. of 6 kOe or more.

Further, according to the present invention, the component composition is RαFe100-
(α + β + γ + δ) MβBγNδ and R3 (Fe, M, B) 29 having a monoclinic and / or hexagonal crystal structure
N is contained as a main phase, R is any one or more of rare earth elements including Y, M is Al,
Ti, V, Cr, Mn, Cu, Ga, Zr, Nb, M
o, Hf, Ta, W or one or more of them, wherein α, β, γ, and δ are in atomic percentage in the following range. A method for producing a rare-earth magnet material, wherein a homogenization treatment is performed at 1250 ° C. 5 ≦ α ≦ 18 1 ≦ β ≦ 50 0.1 ≦ γ ≦ 5 4 ≦ δ ≦ 30

Further, the present invention relates to the present invention, wherein the component composition is RαFe100-
(α + β + γ + δ + ε + ζ) MβBγNδHεOζ, which has a monoclinic and / or hexagonal crystal structure of R3 (F
e, M, B) 29Ny as a main phase, R is one or more of rare earth elements including Y, and M is Al, Ti, V, Cr, Mn, Cu, Ga, Z
r, Nb, Mo, Hf, Ta, W, or any one or more of the above, α, β, γ, δ, ε, and ζ produce a rare earth magnet material in the following range in atomic percentage. In this case, a homogenization treatment is performed at 700 to 1250 ° C. before the nitriding treatment.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The rare earth magnet material of the present invention is ideally a single phase of R3 (Fe, M, B) 29Ny phase having a monoclinic and / or hexagonal crystal structure. (Hereinafter referred to as a subphase). Th2 Zn17 type, TbCu7 type, T2
Although it may contain an R-Fe-MBN-based magnetic compound having a crystal structure such as hMn12 type, the content ratio of the main phase of the present invention is preferably 60% by volume or more, and 75% by volume as described above. The above is more preferable. R3 (Fe, M, B) 29Ny
The main phase is R3 which mainly constitutes the entire master alloy or the master alloy.
Nitrogen invades between the crystal lattices of the (Fe, M, B) 29 phase and expands the crystal lattice. The crystal structure has the same symmetry as the R3 (Fe, M, B) 29 phase. Having. For example, as mother alloy powder,
If a composition of 9.4Fe84.0B2.0Ti4.5 is selected,
By introducing nitrogen, the magnetocrystalline anisotropy changes from in-plane anisotropy to uniaxial anisotropy, making the material suitable as a permanent magnet material.

The rare earth bonded magnet according to the present invention is obtained by solidifying the above rare earth magnet material with a binder such as a polymer, a pure metal or an alloy. A thermosetting resin represented by a phenol resin, a thermoplastic resin such as a polyamide resin or an EEA resin, or a known resin such as a synthetic rubber or a natural rubber can be used. In addition, as the pure metal or alloy, a known low melting point metal or alloy such as zinc or tin can be used. Further, as a molding method of the rare earth bonded magnet, a known molding method such as compression molding or injection molding can be adopted.

According to the present invention, R 3 (Fe, M, B) 29
The Curie temperature is about 480 ± 20 ° C. because a rare earth magnet material having a high proportion of the Ny main phase can be easily and stably manufactured.
And high thermal stability and an average particle size of 20 to 50
It is possible to provide a rare earth magnet powder having a substantially constant high iHc and a low iHc temperature coefficient (η) over a wide particle diameter of 0 μm, and at the same time easily manufacture an isotropic or anisotropic bonded magnet having high magnet properties. be able to.

Next, a typical manufacturing process of the present invention will be described.

(Adjustment of Master Alloy) The magnet material of the present invention is subjected to nitriding treatment by adding a complex of B and M elements to R-Fe-M.
The content ratio of the R3 (Fe, M, B) 29 phase in the -B-based master alloy is increased. The R-Fe-MB base alloy is alloyed using any one of, for example, a high-frequency melting method, an arc melting method, a super-quenching method, a strip casting method, a gas atomizing method, a reduction diffusion method, and a mechanical alloying method. . The alloy obtained by the above-described method may be heated and held under a hydrogen atmosphere, followed by a dehydrogenation treatment to decompose the hydride and recombine it with the mother alloy phase. Here, when the high-frequency melting method or the arc melting method is used, a soft magnetic phase containing αFe as a main component is likely to precipitate when the above alloy is solidified, but this soft magnetic phase remains and remains after nitriding. It is not preferable because it causes a reduction in magnetic force. In order to suppress the formation of the soft magnetic phase, the molten master alloy is heated in a vacuum or in an argon gas atmosphere at 700 to 12 mm.
It is desirable to perform the homogenization treatment under heating conditions of 50 ° C. × 0.5 to 100 hours. While the conventional R3 (Fe, M) 29 phase decomposes at 900 to 1000 ° C as described above, the present invention has the advantage that a wide homogenization treatment temperature of 700 to 1250 ° C can be tolerated.

(Pulverization) It is also possible to directly nitride the mother alloy ingot smelted by the above method or mechanically alloyed. However, if the size of the nitrided product is large, the nitridation time will be long, so coarse grinding is performed. Go to average particle size 500μ
It is desirable to nitride after coarse grinding to not more than m. Coarse pulverization can be performed using a pulverizer such as a disc mill, a bantam mill, a jaw crusher, and a ball mill. Further, a method in which hydrogen is occluded in the master alloy and then coarsely pulverized by the above pulverizer or a method in which hydrogen is occluded and released repeatedly to coarsely pulverize may be used. Further, after coarse pulverization, it is preferable to classify and nitride with a sieve, since a homogeneous main phase of nitride can be formed in the mother alloy.
Less than 00 μm, 100 μm to less than 200 μm, 200 μm
m to less than 300 μm, 300 to less than 400 μm, 4
When sieved so as to be less than 00 μm to less than 500 μm, the magnet powder after the nitriding treatment has almost the sieved particle size, and together with the above uniform nitride forming effect, the formability required according to the bond magnet shape. These magnet powders having a particle size of approximately sieve can be appropriately used according to the difficulty, so that they are practically suitable. Further, after the coarse pulverization, annealing at 500 to 1000 ° C. for 0.5 to 100 hours in an argon gas atmosphere or vacuum improves the magnetic properties. This effect is because the strain introduced by the coarse pulverization is reduced. Conceivable.

(Nitriding) In the present invention, a known nitriding treatment method (for example, a gas nitriding method, an ion nitriding method, etc.) can be adopted. As an example, a gas nitriding method will be described. In the gas nitriding method, any one of nitrogen gas, ammonia gas, a mixed gas of nitrogen gas and hydrogen gas, a mixed gas of ammonia gas and hydrogen gas, or the like is brought into contact with the above-mentioned mother alloy mass or the coarsely pulverized powder of the above-mentioned mother alloy to form a crystal lattice. This is a step of introducing nitrogen into the inside. The nitriding reaction can be controlled by selecting the above gas species, heating temperature, heating time, and gas pressure. Among these, the heating temperature varies depending on the mother alloy composition, but is preferably 300 to 650 ° C. Irrespective of the type of the mother alloy, if the temperature is lower than 300 ° C., nitriding hardly proceeds, and if the temperature is higher than 650 ° C., the nitride once formed is decomposed to generate a soft magnetic phase such as αFe, which is not preferable. After nitriding, 300 to 6 in an inert gas such as argon or in a vacuum or hydrogen gas.
Coercive force, iH
c, saturation magnetization, etc. may be improved. This is presumably because nitrogen is further diffused into the crystal grains of the mother alloy by annealing to increase the proportion of the main phase nitride phase, and that nitrides are uniformly formed in the powder particles.

(Magnetic field molding) In order to produce an anisotropic bonded magnet using the rare earth magnet material powder of the present invention prepared as described above, the magnet powder and a thermosetting resin or a low melting point metal (low melting point metal) are used. Alloy) at a proper ratio and then compression-molded in a magnetic field of, for example, 10 kOe or more. A compound obtained by blending the magnet powder and the thermoplastic resin at a proper ratio and kneading with heat is used to obtain a compound of, for example, 10 kOe or more. A method of injection molding in a magnetic field can be adopted. When producing an isotropic bonded magnet, the rare earth magnet material powder of the present invention is mixed with the above-mentioned resin or metal (alloy) binder powder at an appropriate ratio and mixed for homogenization, and then molded without a magnetic field. Is formed, and then a heat curing treatment may be performed.

(Magnetization) The magnetizing operation for imparting a sufficient magnetic force to the bond magnet is preferably 15 kOe or more.
More preferably, it is general that the magnetization is performed with a magnetizing magnetic field of 20 kOe or more.

Next, the method for evaluating each physical property value of the present invention will be specifically described. (Measurement of Average Particle Size) The average particle size of the above magnet material powder was measured by a laser diffraction type particle size distribution analyzer (CIS, manufactured by GALAI).
(-1 type) was used to measure the volume equivalent diameter distribution, and the average particle diameter was determined from the distribution curve. (Measurement of magnetic properties) For the iHc and saturation magnetization (σ) of the magnet material, a predetermined amount of the magnet powder was mixed with a resin and packed in a copper container, and a vibrating sample magnetometer (VS manufactured by Toei Kogyo Co., Ltd.)
M-3). The iHc, residual magnetic flux density (Br), and temperature coefficient (η) of iHc of the bonded magnet were measured using a self-recording magnetometer (TRF-5H manufactured by Toei Kogyo Co., Ltd.).

(Component Analysis) Among the constituent elements of the above magnet material, nitrogen, hydrogen and oxygen were detected by gas chromatography heat conduction detection using an N, O, H gas analyzer (EMGA1300 manufactured by Horiba, Ltd.). Was analyzed by In addition, rare earth elements such as Sm are oxalate gravimetric method, Fe is 2
Potassium chromate capacity method, M element such as Ti and B were analyzed by inductively coupled plasma emission spectrometry.

(Evaluation of Oxidation Resistance) The rare earth magnet powder was left in the air at a constant temperature of 100 ° C. × 90% RH for 168 hours, taken out and measured for iHc at 25 ° C. Oxidation resistance, which is a decrease rate as compared with iHc at 25 ° C. before being put in the bath, was determined. That is, (oxidation resistance) = (iHc at 25 ° C. of magnet powder after thermostatic bath treatment) ÷ (iHc at 25 ° C. of magnet powder before thermostatic bath treatment) × 100 (%). The smaller this value is, the more excellent the oxidation resistance is.

Next, the present invention will be described with reference to examples, but the present invention is not limited by these examples. (Examples 1 to 12) Rare earth magnet powders shown in Table 1 were prepared and evaluated in order to observe the correlation between the amount of added B and the magnet properties.
First, using Sm, Fe, Ti, and B having a purity of 99.9%, each was blended so as to have a mother alloy composition corresponding to the nitride magnet powders of Examples 1 to 12 in Table 1, and a high-frequency gas in an argon gas atmosphere was used. Each mother alloy corresponding to Examples 1 to 12 was melted by melting in a melting furnace. Then, in an argon gas atmosphere, 11
Homogenization treatment was performed at 50 ° C. for 20 hours, and then this mother alloy mass was pulverized using a jaw crusher and a disc mill. When X-ray diffraction of these mother alloy powders was performed using Cu-Kα radiation, all the diffraction lines were R3 (Fe, M,
B) It was confirmed that indexing was possible as 29 phases. Next, each of the above mother alloy powders was charged into an atmosphere heating furnace, heated and held at 450 ° C. in a stream of nitrogen gas of 1 atm for 5 hours to perform a nitriding treatment, and then annealed at 420 ° C. for 1 hour in an argon stream. X-ray diffraction of each of the nitrided powders showed that the X-ray diffraction pattern of the R3 (Fe, M, B) 29 phase obtained from the mother alloy shifted to a lower diffraction angle side, and N atoms were It was confirmed that the crystal lattice was expanded by invading the mother alloy crystal. The composition, average particle diameter, and composition of the nitride magnet powders of Examples 1 to 12 thus obtained were
Saturation magnetization intensity (σ) at 5 ° C. and iHc, 25
Table 1 shows the results of measuring the temperature coefficient (η) of iHc at １００100 ° C. Here, each measurement in each of the following Examples and Comparative Examples was performed under the same conditions as those in Table 1.

(Comparative Examples 1 to 6) Comparative Examples 1 to 6 shown in Table 1 were carried out in the same manner as in Example 1 except that a mother alloy composition containing no B was used and the average particle size was changed as shown in Table 1. 6
Was produced and evaluated. The mother alloy powder before nitriding in Comparative Examples 1 to 6 containing no B is Th
2Zn17 type Sm2 (Fe, Ti, B) 17 phase and αFe
And / or formation of an Fe—Ti phase was observed.

[0034]

[Table 1]

Table 1 clearly shows the effect of the complex addition of the B and M elements. That is, in Examples 1 to 12 containing 0.1 to 5 atomic% of B, high iHc of 8 kOe or more was obtained over an average particle size of 20 to 500 μm, and i
It can be seen that the temperature coefficient (η) of Hc is -0.45 or more, indicating that it has good heat resistance. On the other hand, all of the comparative examples containing no B had iHc of less than 3 kOe, and the temperature coefficient (η) of iHc was -0.53 or less, indicating poor heat resistance.

(Examples 13 to 15) In order to observe the correlation between the R component content and the type of the R component and the magnet properties, the magnet powder composition shown in Table 2 was used and the average particle size was set to 72 μm. By the same operation as in Example 1, the magnet powder shown in Table 2 was manufactured, and the saturation magnetization (σ), i
Temperature coefficients (η) of Hc and iHc were measured. (Comparative Examples 7 to 10) Except that the magnet powder compositions shown in Table 2 were used, the magnet powders shown in Table 2 were produced in the same manner as in Examples 13 to 15, and the saturation magnetization (σ), iHc, iH
The temperature coefficient (η) of c was measured.

[0037]

[Table 2]

From Table 2, it can be seen that the temperature coefficient (η) of high iHc and low iHc can be obtained when the Sm ratio in the R component is 50 atomic% or more.

(Examples 16 to 20) Following Table 2 above, R
In order to see the correlation between the component content and the type of the R component and the magnet properties, the magnet powder composition shown in Table 3 was used and the average particle size was changed to 130 μm. And the temperature coefficient (η) of magnetization, iHc and iHc were measured. (Comparative Examples 11 to 14) Evaluations were made in the same manner as in Examples 16 to 20, except that the magnet powder compositions shown in Table 3 were used.

[0040]

[Table 3]

From Table 3, it can be seen that high iH is obtained when the Sm ratio in the R component is 50 atomic% or more and the R component is 5 to 18 atomic%.
It can be seen that a temperature coefficient (η) of iHc as low as c can be obtained.

(Examples 21 to 24) In order to observe the correlation between the nitrogen content and the magnet properties, the table was prepared in the same manner as in Example 1 except that the magnet powder composition and the average particle size shown in Table 4 were set to 120 μm. 4 and the saturation magnetization (σ), iHc, and the temperature coefficient (η) of iHc were measured. (Comparative Examples 15 and 16) Evaluations were made in the same manner as in Examples 21 to 24 except that the magnet powder compositions shown in Table 4 were used.

[0043]

[Table 4]

From Table 4, it can be seen that in Examples 21 to 24 containing 4 to 30 atomic% of nitrogen, a high iHc and a low iHc temperature coefficient (η) can be obtained. Comparative Examples 15 and 16
As shown in the figure, when the amount of nitrogen is less than 5 atomic%,
When it is more than 0 atomic%, iHc is low and is less than 3 kOe.

(Examples 25 to 29) In order to check the magnet properties when the Fe component was replaced with Co or Ni, the composition was changed to the magnet powder composition shown in Table 5 and the average particle size was changed to 170.
By the same operation as in Example 1 except that μm was used,
While obtaining the magnet powder of Table 5, the saturation magnetization (σ), iH
c, the temperature coefficient (η) of iHc was measured. (Comparative Examples 17 to 19) Evaluations were made in the same manner as in Examples 25 to 29 except that the magnet powder compositions shown in Table 5 were used.

[0046]

[Table 5]

As shown in Table 5, when a part of Fe is replaced with Co and / or Ni in the range of 0.01 to 30 atomic%, the oxidation resistance is improved and the temperature coefficient (η) of high iHc and low iHc is increased. It can be seen that it has been obtained.

(Examples 30 to 36) The amounts of H and O contained in the magnet powder of each of the above examples are inevitable impurities. For example, the H content is 50 ppm or less and the O content is 5000 ppm in weight%. It was below. But,
As described above, the magnet powder of the present invention can contain H and O in excess of the inevitable impurity content by appropriately selecting the production conditions. In order to observe the influence of the amounts of H and O positively contained, a magnet powder having the composition shown in Table 6 was produced, and the average particle diameter was changed to 400 μm. To obtain a magnet powder having a saturation magnetization (σ),
iHc and the temperature coefficient (η) of iHc were measured. (Comparative Examples 20 to 24) Evaluations were made in the same manner as in Examples 30 to 36 except that the magnet powder compositions shown in Table 6 were used.

[0049]

[Table 6]

Table 6 shows that when i is 0.5 to 10 atomic% of hydrogen and / or 1 to 5 atomic% of oxygen, high iHc, saturation magnetization (σ) and low temperature coefficient (η) can be obtained. . Further, it can be seen that the temperature coefficient (η) is particularly deteriorated in the comparative examples in which the amount of hydrogen is out of the range of 0.5 to 10 atomic% and / or the amount of oxygen is out of the range of 1 to 5 atomic%.

(Examples 37 to 44) In order to observe the influence of the type and content of the M element on the magnet properties, the magnet powder composition shown in Table 7 was used and the average particle size was changed to 170 μm. The magnet powder of Table 7 was obtained by the same operation, and the saturation magnetization (σ), iHc, and the temperature coefficient (η) of iHc were measured. (Comparative Examples 25 and 26) The same evaluation as in Examples 37 to 44 was performed except that the magnet powders shown in Table 7 were used.

[0052]

[Table 7]

From Table 7, it can be seen that the temperature coefficient (η) of high iHc and low iHc can be obtained when the M element is 1 to 50 atomic%. As shown in Comparative Examples 24 and 25, when the M element was not in this range, Sm3 (Fe, M,
B) It was found that only a small amount of the 29 phase was formed and iHc was not improved by nitriding.

(Example 45) A master alloy corresponding to the following magnet powder composition in which Cr was added as an M element and a part of Fe was replaced with Co was melted under the same melting conditions as in Example 1 above.
The mother alloy was roughly pulverized in a nitrogen stream having an oxygen partial pressure of 1 mol%, and adjusted to an average particle size of 125 μm by sieving. This Sm
-Fe-Co-B-Cr based alloy powder with ammonia partial pressure of 0.35
After nitriding for 5 hours at 460 ° C. in an ammonia-hydrogen mixed gas stream of hydrogen gas partial pressure of 0.65 atm, annealing was performed for 1 hour in an argon gas stream of oxygen partial pressure of 10 ⁻⁵ atm. The obtained Sm _9.4 Fe having an average particle size of 74 μm.
_64.1 Co _4.0 B _1.0 Cr _4.5 N _16.5 H _0.5 was ball milled in cyclohexane for 30 minutes. The composition of this pulverized powder is expressed as atomic% Sm _9.2 Fe _64.0 Co _4.0 B _1.0 Cr _4.5 N
_{At 16.0} H _0.5 O _1.0 , the average particle size was 36 μm. This magnetic powder has an iHc of 8 kOe and a temperature coefficient (η) of iHc of −
The value was as good as 0.31% / ° C.

(Example 46) Sm, F having a purity of 99.9%
e, Co, and B were mixed in the following mother alloy composition corresponding to the nitride powder, and then melted in a high-frequency melting furnace under an argon gas atmosphere. Using a strip caster,
A flaky cast piece having a thickness of about 2 mm was obtained. 50 pieces of the cast piece
After breaking to less than mm square, 1 atm in the atmosphere heat treatment furnace
The hydrogen gas was supplied and heated to 500 ° C. to absorb the hydrogen, and then vacuum was applied to dehydrogenate, collapsed by absorbing hydrogen, and coarsely pulverized to an average particle size of 100 μm. This Sm-Fe-B-Cr-based magnetic powder was charged into an atmosphere heat treatment furnace and the ammonia partial pressure was 0.35a at 460 ° C.
tm and a heat treatment in a mixed gas flow of 0.65 atm of hydrogen gas for 7 hours. Subsequently, annealing was performed at 400 ° C. for 30 minutes in a hydrogen gas stream. The composition of the obtained nitride powder is represented by atom% as Sm _9.4 Fe _67.1 Co _4.0 B _2.0 Cr _4.5 N _18.5 H
_2.5 , saturation magnetization (σ) is 120 emu / g, iHc is 9 kO
e, the temperature characteristic (η) of iHc was −0.34% / ° C. Observation of this magnet powder with an electron microscope revealed that Sm3
Cr-rich precipitates having a size of several tens of nm were observed in the (Fe, Cr, B) 29 phase.

(Examples 47 to 53) In order to evaluate the properties of the bonded magnet, Table 8 was obtained from the magnet powder prepared in the above example.
Were selected and mixed with an epoxy resin, and then a press pressure of 10 ton /
The molded article was compression-molded at ² cm ² and further subjected to a heat treatment at 140 ° C. for 1 hour for curing to produce an isotropic bonded magnet. Table 8 shows the magnetic properties of these isotropic bonded magnets.

[0057]

[Table 8]

Table 8 shows that the isotropic bonded magnet of the present invention has good magnet properties.

The Curie temperature of each of the magnetic powders of the above examples had a good value of 480 ± 20 ° C.

[0060]

According to the present invention, it is possible to easily provide a rare earth magnet having high iHc and a high temperature coefficient (η) of iHc over an average particle diameter of 20 to 500 μm, and to provide a rare earth bonded magnet having excellent oxidation resistance and heat resistance. Can be easily provided,
It is very useful industrially.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaaki Tokunaga 5200 Mikajiri, Kumagaya-shi, Saitama Pref.

Claims (12)

[Claims] 1. The composition of the composition is RαFe100- (α + β + γ + δ).
MβBγNδ, containing R3 (Fe, M, B) 29Ny having a monoclinic and / or hexagonal crystal structure as a main phase, wherein R is any one or two of rare earth elements including Y M is Al, Ti, V, C
r, Mn, Cu, Ga, Zr, Nb, Mo, Hf, T
a rare earth magnet material comprising at least one of a and W, wherein α, β, γ, and δ are in the following ranges in atomic percentage. 5 ≦ α ≦ 18 1 ≦ β ≦ 50 0.1 ≦ γ ≦ 5 4 ≦ δ ≦ 30 2. The composition according to claim 1, wherein the composition is RαFe100- (α + β + γ + δ +
ε + {) MβBγNδHεO} and R3 (Fe, M, B) 29 having a monoclinic and / or hexagonal crystal structure
N as a main phase, R is one or more of rare earth elements including Y, and M is Al, T
i, V, Cr, Mn, Cu, Ga, Zr, Nb, Mo,
A rare-earth magnet material comprising at least one of Hf, Ta, and W, wherein α, β, γ, δ, ε, and 原子 are in the following ranges in atomic percentages. 5 ≦ α ≦ 18 1 ≦ β ≦ 50 0.1 ≦ γ ≦ 5 4 ≦ δ ≦ 30 0.5 ≦ ε ≦ 10 1 ≦ ζ ≦ 5 3. The method of claim 1, wherein 0.01 to 30 atomic% of the Fe component is Co.
The rare earth magnet material according to claim 1, wherein the rare earth magnet material is substituted with Ni. 4. The rare earth magnet material according to claim 1, wherein 50 atomic% or more of the R component is Sm. 5. The rare-earth magnet material according to claim 1, wherein the rare-earth magnet material has an average particle size of 20 μm or more and 500 μm or less. 6. The rare earth magnet material according to claim 1, wherein the R3 (Fe, M, B) 29Ny phase has a structure in which M element or M compound is precipitated in the crystal grains. . 7. R3 (Fe,
The rare earth magnet material according to any one of claims 1 to 6, wherein the abundance ratio of (M, B) 29Ny phase is 60% by volume or more. 8. The method according to claim 1, wherein the magnet powder is a polymer, a pure metal,
A rare earth magnet material which is bonded by any one of alloys to form a bonded magnet, wherein the magnet powder comprises
The temperature coefficient (η) of the intrinsic coercive force (iHc) at
A rare earth magnet material having a specific coercive force (iHc) at 25 ° C. of 8 kOe or more while being 0.45 or more. 9. The composition having a composition of RαFe100- (α + β + γ + δ)
MβBγNδ, containing R3 (Fe, M, B) 29Ny having a monoclinic and / or hexagonal crystal structure as a main phase, wherein R is any one or two of rare earth elements including Y M is Al, Ti, V, C
r, Mn, Cu, Ga, Zr, Nb, Mo, Hf, T
a, W, or α, β, γ, and δ are powders of a rare-earth magnet material in the following range in atomic percentage, and are selected from polymer polymers, pure metals, and alloys. A rare-earth bonded magnet bonded with the binder, wherein the bond magnet has a temperature coefficient (η) of an intrinsic coercive force (iHc) at 25 to 100 ° C. of −0.45 or more and a coercive force (bHc) at 25 ° C. ) Is 6 kOe or more. 5 ≦ α ≦ 18 1 ≦ β ≦ 50 0.1 ≦ γ ≦ 5 4 ≦ δ ≦ 30 10. A composition having a composition of RαFe100- (α + β + γ + δ
+ ε + ζ) MβBγNδHεOζ, monoclinic and / or
Or R3 (Fe, M, B) 2 having a hexagonal crystal structure
9Ny as a main phase, R is any one or more of rare earth elements including Y, M is Al,
Ti, V, Cr, Mn, Cu, Ga, Zr, Nb, M
o, Hf, Ta, W or any one or more of them, wherein α, β, γ, δ, ε, and ζ are powders of a rare earth magnet material having the following atomic percentages and Coalescing,
A rare earth bonded magnet bonded with a binder of any of a pure metal and an alloy, wherein the bonded magnet has a temperature of 25 to 100 ° C.
Temperature coefficient (η) of intrinsic coercive force (iHc) at
0.45 or more and the coercive force at 25 ° C. (b
Hc) is 6 kOe or more, the rare-earth bonded magnet. 5 ≦ α ≦ 18 1 ≦ β ≦ 50 0.1 ≦ γ ≦ 5 4 ≦ δ ≦ 30 0.5 ≦ ε ≦ 10 1 ≦ ζ ≦ 5 11. A composition comprising RαFe100- (α + β + γ +
δ) MβBγNδ, containing R 3 (Fe, M, B) 29 Ny having a monoclinic and / or hexagonal crystal structure as a main phase, wherein R is any one of rare earth elements including Y or M is Al, Ti, V,
Cr, Mn, Cu, Ga, Zr, Nb, Mo, Hf, T
a, W, or α, β, γ, and δ are in atomic percentages and are in the range described below.
A method for producing a rare earth magnet material, wherein a homogenization treatment is performed at 250 ° C. 5 ≦ α ≦ 18 1 ≦ β ≦ 50 0.1 ≦ γ ≦ 5 4 ≦ δ ≦ 30 12. A composition having a composition of RαFe100- (α + β + γ + δ
+ ε + ζ) MβBγNδHεOζ, monoclinic and / or
Or R3 (Fe, M, B) 2 having a hexagonal crystal structure
9Ny as a main phase, R is any one or more of rare earth elements including Y, M is Al,
Ti, V, Cr, Mn, Cu, Ga, Zr, Nb, M
o, Hf, Ta, W or any one or more of them, wherein α, β, γ, δ, ε, and ζ are atomic percentages and are in the following ranges. A method for producing a rare earth magnet material, wherein a homogenization treatment is performed beforehand at 700 to 1250C. 5 ≦ α ≦ 18 1 ≦ β ≦ 50 0.1 ≦ γ ≦ 5 4 ≦ δ ≦ 30 0.5 ≦ ε ≦ 10 1 ≦ ζ ≦ 5