WO2004030000A1 - Methode de production d'un aimant permanent a elements des terres rares en alliage de r-t-b - Google Patents

Methode de production d'un aimant permanent a elements des terres rares en alliage de r-t-b Download PDF

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Publication number
WO2004030000A1
WO2004030000A1 PCT/JP2003/012492 JP0312492W WO2004030000A1 WO 2004030000 A1 WO2004030000 A1 WO 2004030000A1 JP 0312492 W JP0312492 W JP 0312492W WO 2004030000 A1 WO2004030000 A1 WO 2004030000A1
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phase
alloy
rare earth
permanent magnet
product
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PCT/JP2003/012492
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English (en)
Japanese (ja)
Inventor
Chikara Ishizaka
Gouichi Nishizawa
Tetsuya Hidaka
Akira Fukuno
Nobuya Uchida
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Tdk Corporation
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Priority to DE60311960T priority Critical patent/DE60311960T2/de
Priority to JP2004539584A priority patent/JP4076179B2/ja
Priority to EP03748613A priority patent/EP1460651B1/fr
Publication of WO2004030000A1 publication Critical patent/WO2004030000A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/02—Making ferrous alloys by powder metallurgy
    • C22C33/0207—Using a mixture of prealloyed powders or a master alloy
    • C22C33/0228—Using a mixture of prealloyed powders or a master alloy comprising other non-metallic compounds or more than 5% of graphite
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/02—Making ferrous alloys by powder metallurgy
    • C22C33/0257—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
    • C22C33/0278—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements with at least one alloying element having a minimum content above 5%
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/0555—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 pressed, sintered or bonded together
    • H01F1/0557—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 pressed, sintered or bonded together sintered
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
    • H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
    • H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
    • B22F2998/10—Processes characterised by the sequence of their steps
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C2202/00—Physical properties
    • C22C2202/02—Magnetic

Definitions

  • R is one or more rare earth elements, but the rare earth element is a concept including Y
  • T is Fe or at least one or more of which requires Fe and Co as essential
  • a transition metal element A transition metal element
  • B boron
  • R-T-B Rare Earth Permanent Magnets are increasing in demand year by year due to their excellent magnetic properties, and the abundant resource of Nd, which is a major component, and their relatively low cost. ing.
  • R & T-B rare-earth permanent magnets are also being actively researched and developed to improve their magnetic properties.
  • Japanese Patent Application Laid-Open No. 1-219143 by adding 0.02-0.5 at% of Cu to an RTB-based rare earth permanent magnet, the magnetic properties are improved, and the heat treatment conditions are improved. Have also been reported to be improved.
  • the method described in Japanese Patent Application Laid-Open No. 11-219143 requires high magnetic properties required for high-performance magnets, specifically, high coercive force (He J) and residual magnetic flux density (Br). Was inadequate.
  • the magnetic properties of the R-T-B rare earth permanent magnets obtained by sintering may depend on the sintering temperature.
  • the temperature range in which desired magnetic properties can be obtained is referred to as the sintering temperature range.
  • JP-A-2002-7571-7 discloses that a fine ZrB compound is contained in an R—T—B-based rare earth permanent magnet containing Co, Al, Cu, and further Zr, Nb, or Hf. It has been reported that by uniformly dispersing and depositing an NbB compound or an HfB compound (hereinafter, MB compound), the grain growth during the sintering process is suppressed and the magnetic properties and sintering temperature range are improved. ing.
  • the sintering temperature range is expanded by dispersing and precipitating the MB compound.
  • the sintering temperature range is as narrow as about 20 ° C. Therefore, in order to obtain high magnetic properties in mass production furnaces, it is desirable to further increase the sintering temperature range. In order to obtain a sufficiently wide sintering temperature range, it is effective to increase the amount of added Zr. However, as the amount of added Zr increases, the residual magnetic flux density decreases, and the originally desired high characteristics cannot be obtained.
  • an object of the present invention is to provide a method for producing an RTB-based rare earth permanent magnet that can suppress grain growth while minimizing deterioration in magnetic properties and further improve the sintering temperature range.
  • the inventor of the present invention has determined that the R—T—B-based rare earth permanent magnet containing Zr in a specific form, more specifically, the R 2 T 14 B phase constituting the main phase of the R_T—B-based rare earth permanent magnet has Z It has been found that when a product rich in r is present, it is possible to suppress grain growth while minimizing deterioration of magnetic properties and improve the sintering temperature range.
  • R— T-B based rare earth permanent magnets have R 2 T 14 B phase (R is one or more rare earth elements (the rare earth element is a concept including Y), T is Fe or Fe and Co R-T-B alloy containing Zr and containing R more than R-T-B alloy, and R mainly containing R and T —
  • R is one or more rare earth elements (the rare earth element is a concept including Y)
  • T is Fe or Fe and Co R-T-B alloy containing Zr and containing R more than R-T-B alloy, and R mainly containing R and T —
  • a step of producing a T alloy a step of obtaining a mixture of a powder composed of an RTB alloy and a powder composed of an RT alloy; and a step of producing a compact having a predetermined shape composed of the mixture.
  • phase It is important to generate methane in the sintering process.
  • This in-phase product has a plate-like or needle-like form.
  • the sintered body according to the present invention comprises: R: 25 to 35 wt%, B: 0.5 to 4.5 wt%, one or two of A1 and Cu: 0.02 to 0.6 wt%, Zr: 0.03 to 0.25 wt%, C o: 4 wt% or less (excluding 0), the balance is desirably substantially composed of Fe. Further, R: 28 to 33 wt%, B: 0.5 to 1.5 wt%, A1: 0.03 to 0.3 wt%, Cu: 0.03 to 0.15 wt%, Zr: 0.05 to 0.2 wt%, Co : 0.1 to 2.0 wt% or less, with the balance being substantially composed of Fe. Among these, it is particularly desirable to set Z i iO. 1 to 0.15 wt%. BRIEF DESCRIPTION OF THE FIGURES
  • FIG. 1 is a table showing the combination of low R alloy and high R alloy used in the first embodiment and the composition of the obtained permanent magnet.
  • Fig. 2 shows the magnetic properties of the permanent magnet obtained in the first embodiment.
  • FIG. 3 is a graph showing the relationship between the amount of additive element M (Zr or T i) and the residual magnetic flux density (Br) of the permanent magnet obtained in the first embodiment, and
  • FIG. 5 is a graph showing the relationship between the amount of additive element M (Zr or Ti) of the permanent magnet obtained in the example and the coercive force (He J).
  • FIG. 5 is a graph showing the relationship between the permanent magnet obtained in the first example.
  • FIG. 6 is a graph showing the relationship between the amount of the added element M (Zr or T i) and the squareness ratio (HkZHc J).
  • FIG. 6 shows a sample of Example 1 (1: a sample having an amount of 0.1 Owt%).
  • TEM Transmission Electron Microscope (transmission electron microscope) Photograph
  • FIG. 7 (a) shows EDS (Energy Dispersive X-ray Fluorescence Spectroscopy) of the product present in the sample of Example 1 (sample having a Zr content of 0.10 wt%): shows the energy dispersive X-ray analyzer spectroscopy) Purofuai Le
  • FIG. 7 (b) is in the first embodiment sample (Z r amount of R 2 T ⁇ 4 B phase in 0.
  • Fig. 8 shows an EDS profile.
  • Fig. 8 shows a TEM high-resolution photograph of the sample of Example 1 (a sample having an amount of 0.10 wt%).
  • Fig. 9 shows the sample of Example 1 (a Zr amount of 0.10 wt%).
  • % Sample) Fig. 10 is a TEM photograph of the sample of Example 1 (sample having a Zr content of 0.10 wt%), and
  • Fig. 11 (a) is a sample of Example 1. The same as the photo (lower) showing the Zr matting results of an EPMA (Electron Probe Micro Analyzer) of the sample (Zr content 0.10 wt%) and the Zr mapping result (lower) Pair of fields of view Fig.
  • EPMA Electro Probe Micro Analyzer
  • FIG. 11 (b) is a photograph showing the imaging (upper), and Fig. 11 (b) is a photograph (lower) showing the results of Zr mapping of the sample of Comparative Example 2 (sample having a Zr content of 0.10 wt%) by EPMA (lower).
  • FIG. 12 is a table showing the magnetic properties of the permanent magnet obtained in the second example
  • FIG. 13 is a second example.
  • FIG. 14 is a graph showing a relationship between the sintering temperature and the coercive force (He J) in the second embodiment, and FIG.
  • Fig. 15 is a graph showing a relationship between the sintering temperature and the coercive force (He J) in the second embodiment.
  • Fig. 16 is a graph showing the relationship between the sintering temperature and the squareness ratio (Hk / HcJ) in the example.
  • Fig. 16 shows the residual magnetic flux density (Br) and the squareness ratio (HkZHcJ) at each sintering temperature in the second embodiment.
  • Fig. 17 is a chart showing the combination of the low R alloy and the high R alloy used in Example 3 and the composition of the obtained permanent magnet.
  • Fig. 18 is a table showing the magnetic properties of the permanent magnet obtained in the third embodiment, and Fig.
  • FIG. 19 is a combination of the low R alloy and the high R alloy used in the fourth embodiment and the composition of the obtained permanent magnet.
  • FIG. 20 is a chart showing the composition, and FIG. 20 is a chart showing the magnetic properties of the permanent magnet obtained in the fourth example.
  • the rare earth permanent magnet obtained by the present invention has an R 2 T 14 B phase (R is one or more rare earth elements (where the rare earth element is a concept including Y), T Contains at least a main phase composed of one or more of Fe or Fe and Co transition metal elements, and a grain boundary phase containing more R than the main phase.
  • R is one or more rare earth elements (where the rare earth element is a concept including Y)
  • T Contains at least a main phase composed of one or more of Fe or Fe and Co transition metal elements, and a grain boundary phase containing more R than the main phase.
  • the present invention is characterized in that a Zr-rich product is present in the R 2 T 14 B phase.
  • the R-T-B rare-earth permanent magnet in which this product exists can suppress grain growth while minimizing deterioration of magnetic properties and can obtain a wide sintering temperature range.
  • This product must be present in the R 2 T 14 B phase, but need not be present in all R 2 T 14 B phases. This product may be present
  • Ti is conventionally known as an additional element that forms a product in the R 2 T 14 B phase (for example). Appl. Phys. 69 (1991) 6055). The present inventors have found that the formation of a product in the R 2 T, 4 B phase by adding Zr and Ti is effective for increasing the sintering temperature range.
  • Zr the magnetic properties, specifically the residual magnetic flux density (Br)
  • Br residual magnetic flux density
  • the present inventor has confirmed that there are some manufacturing requirements for the Zr-rich product to be present in the R 2 T 14 B phase. As will be described later series of steps of a method of manufacturing a permanent magnet according to the present invention, wherein the enriched product Z r is described requirements for existing in R 2 T ⁇ 4 B Aiuchi.
  • R—T—B based rare earth permanent magnets can be produced by using a single alloy that matches the desired composition as the starting material (hereinafter referred to as “single method”) or by using a plurality of alloys having different compositions. There are two methods: You.
  • the mixing method typically uses an alloy mainly composed of the R 2 T 14 B phase (low R alloy) and an alloy containing more R than the low R alloy (high R alloy) as starting materials.
  • the present inventor obtained an RTB-based rare earth permanent magnet by adding Zr to either the low R alloy or the high R alloy. As a result, it was confirmed that when a permanent magnet was prepared by adding Zr to a low-R alloy, a Zr-rich product was present in the R 2 T 14 B phase. On the other hand, if it is contained Z r on ⁇ R alloys it was confirmed that the product-rich Z r is not present in the R 2 T ⁇ 4 B Aiuchi.
  • the chemical thread here means the chemical thread after sintering.
  • the rare earth permanent magnet of the present invention contains 25 to 35 wt% of R.
  • R is one or two selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu and Y. More than species. If the amount of R is less than 25 wt%, the generation of the R 2 T 14 B phase which is the main phase of the rare earth permanent magnet is not sufficient. For this reason, ⁇ -Fe with soft magnetism is precipitated, and the coercive force is significantly reduced. On the other hand, when the amount of R exceeds 35 wt%, the volume ratio of the main phase, R 2 T 14 B phase, decreases, and the residual magnetic flux density decreases. If the amount of R exceeds 35 wt%, R reacts with oxygen, increasing the amount of oxygen contained.
  • the amount of R should be 25-35 wt%. Desirable amount of R is 28-33 wt%, and more desirable amount of R is 29-32 wt%.
  • the main component of R be Nd.
  • Dy is effective in increasing the anisotropic magnetic field of the R 2 T 14 B phase and improving the coercive force. Therefore, it is desirable to select Nd and Dy as R and make the sum of Nd and Dy 25 to 33 wt%. In this range, the amount of 0 is preferably 0.1 to 8 wt%.
  • the amount of Dy is desirably determined within the above range depending on which of the residual magnetic flux density and the coercive force is important. In other words, it is desirable to set the Dy amount to 0.1 to 3.5 wt% to obtain a high residual magnetic flux density, and to set the Dy amount to 3.5 to 8 wt% to obtain a high coercive force. .
  • the rare earth permanent magnet of the present invention contains boron (B) in an amount of 0.5 to 4.5 wt%. If B is less than 0.5 wt%, a high coercive force cannot be obtained. However, when the B force exceeds 4.5 wt%, the residual magnetic flux density tends to decrease. Therefore, the upper limit is set to 4.5 wt%.
  • a desirable amount of B is 0.5 to 1.5 wt%, and a more desirable amount of B is 0.8 to 1.2 wt%.
  • the RTB-based rare earth permanent magnet of the present invention can contain one or two of A1 and Cu in a range of 0.02 to 0.6 wt%. In this range, A 1 and Cu By including one or two kinds, it is possible to increase the coercive force, the corrosion resistance, and the temperature characteristics of the obtained permanent magnet.
  • A1 a desirable amount of A1 is 0.03 to 0.3 wt%, and a more desirable amount of A1 is 0.05 to 0.25 wt%.
  • the amount of ⁇ 11 is 0.3 wt% or less (not including 0), preferably ⁇ .15 wt% or less (not including 0). The amount is 0.03-0.08 wt%.
  • the R—T_B-based rare earth permanent magnet of the present invention desirably contains 0.03 to 0.25 wt% of Zr in order to generate a Zr-rich product in the R 2 T 14 B phase.
  • Zr exerts the effect of suppressing the abnormal growth of crystal grains during the sintering process, and changes the structure of the sintered body. Make it uniform and fine. Therefore, the effect of Zr becomes remarkable when the oxygen content is low.
  • the desirable amount of Zr is 0.05 to 0.2 wt%, and the more desirable amount is 0.1 to 0.1 wt%.
  • the R—T—B rare earth permanent magnet of the present invention has an oxygen content of 2000 ppm or less. If the amount of oxygen is large, the oxide phase, which is a non-magnetic component, increases, and the magnetic properties deteriorate. Therefore, in the present invention, the amount of oxygen contained in the sintered body is set to 2000 ppm or less, preferably 1500 ppm or less, and more preferably lOOOppm or less. However, simply reducing the amount of oxygen reduces the oxide phase that had the effect of suppressing grain growth, and grain growth easily occurs in the process of obtaining a sufficient density increase during sintering. Thus, in the present invention, a predetermined amount of Zr, which has an effect of suppressing abnormal growth of crystal grains during the sintering process, is contained in the RTB-based rare earth permanent magnet.
  • the R-T-B-based rare earth permanent magnet of the present invention has a Co of 4 wt% or less (excluding 0), preferably 0. ⁇ 2.0 wt%, more preferably 0.3 ⁇ ; I. Owt%. Co forms the same phase as Fe, but has the effect of improving the Curie temperature and improving the corrosion resistance of the grain boundary phase.
  • the present invention produces an R—T-B permanent magnet using an alloy mainly composed of R 2 T 14 B phase (low R alloy) and an alloy containing more R than high R alloy (high R alloy). I do.
  • a low R alloy and a high R alloy are obtained by strip-casting a raw metal in a vacuum or an inert gas, preferably in an Ar atmosphere.
  • care must be taken to prevent the Zr-rich product from being formed in the R 2 Ti 4 B phase in the obtained strip, particularly in the low R alloy strip.
  • the peripheral speed of the cooling roll is set in the range of 1.0 to 1.8 mZs. Desirable peripheral speed of cooling unit is 1.2 ⁇ : 1. SmZs.
  • a characteristic feature of the present embodiment is that Zr is added from a low R alloy. This is because the addition of Zr from a low R alloy in which a Zr-rich product does not occur in the R 2 T 14 B phase as described in the section This is because a Zr-rich product can be present in the R 2 T 14 B phase of the rare-earth permanent magnet.
  • Low R alloys can contain Cu and A1 in addition to rare earth elements, Fe, Co and B.
  • the high-R alloy can contain Cu and A1 in addition to the rare-earth elements, Fe and Co.
  • B can be contained in the high R alloy.
  • the pulverizing step includes a coarse pulverizing step and a fine pulverizing step.
  • the raw material alloy is roughly pulverized to a particle size of about several hundred ⁇ . It is desirable that coarse grinding be performed in an inert gas atmosphere using a stamp mill, jaw crusher, brown mill, or the like. In order to improve the coarse pulverizability, it is effective to perform the coarse pulverization after absorbing hydrogen. Also, after absorbing hydrogen, release hydrogen. And coarse grinding can be carried out.
  • the process proceeds to the fine grinding step.
  • a jet mill is mainly used, and coarse pulverized powder having a particle diameter of about several hundred ⁇ is pulverized until the average particle diameter becomes 3 to 5 ⁇ m.
  • the jet mill releases a high-pressure inert gas (for example, nitrogen gas) from a narrow nozzle to generate a high-speed gas flow, accelerates the coarsely pulverized powder by this high-speed gas flow, and causes the coarsely pulverized powder to collide This is a method of crushing by generating collisions with the target or the vessel wall.
  • a high-pressure inert gas for example, nitrogen gas
  • the pulverized low R alloy powder and the high R alloy powder are mixed in a nitrogen atmosphere.
  • the mixing ratio of the low R alloy powder and the high R alloy powder may be about 80:20 to 97: 3 by weight.
  • the mixing ratio may be about 80:20 to 97: 3 by weight.
  • a mixed powder composed of a low R alloy powder and a high R alloy powder is filled in a mold held by an electromagnet, and is formed in a magnetic field with its crystal axes oriented by applying a magnetic field.
  • This molding in a magnetic field may be performed in a magnetic field of 12.0 to 1.7 O k O e at a pressure of about 0.7 to 1.5 tZ cm 2 .
  • the compact After compacting in a magnetic field, the compact is sintered in a vacuum or inert gas atmosphere.
  • the sintering temperature needs to be adjusted according to various conditions such as the composition, grinding method, difference in particle size and particle size distribution, etc., but it is necessary to perform sintering at 100 to 1100 for 1 to 5 hours. Les ,.
  • a Zr-rich product is generated in the R 2 T 14 B phase in this sintering step.
  • the mechanism by which the Zr-rich product that is not present at the low R alloy stage is formed after sintering is not clear, but it forms a solid solution in the R 2 Ti 4 B phase at the low R alloy stage. Zr may precipitate in the R 2 T 4 B phase during the sintering process.
  • the obtained sintered body can be subjected to an aging treatment.
  • Aging is important in controlling coercivity.
  • the aging process is performed in two stages, it is effective to maintain a predetermined time at around 800 ° C. or around 600 ° C. Around 800 ° C
  • the heat treatment is performed after sintering, the coercive force increases, which is particularly effective in the mixing method.
  • the coercive force is greatly increased by the heat treatment at around 600 ° C., when performing the aging treatment in one stage, it is preferable to perform the aging treatment at around 600 ° C. (Example)
  • R-T-B system rare earth permanent magnets were manufactured by the following manufacturing process.
  • a raw material alloy (strip) having the composition and thickness shown in FIG. 1 was produced by a strip casting method.
  • the roll peripheral speed was 1.5 mZ s for the low R alloy and 0.6 m / s for the high R alloy.
  • the thickness of the alloy is the average value of the thickness of 50 strips.
  • the roll peripheral speed was 0.6 mZ s.
  • the low-R alloy according to Example 1 in FIG. 1 did not contain a Zr-rich product (hereinafter referred to as “in-phase product”) in the R 2 T 14 B phase, whereas Comparative Example 3 It was confirmed that the in-phase products existed in the R 2 T 14 B phase in the low-R alloy according to (1).
  • each process from hydrogen grinding (recovery after grinding) to sintering (put into the sintering furnace) Is controlled to an oxygen concentration of less than 100 ppm.
  • the additives are mixed before milling.
  • the type of the additive is not particularly limited, and additives that contribute to the improvement of the pulverizability and the orientation during molding may be appropriately added.
  • zinc stearate was added with 0.05 wt%
  • the low R alloy and the high R alloy were mixed for 30 minutes using a Nauta mixer.
  • the mixture ratio of the low R alloy and the high R alloy was 90:10. Then, it was pulverized with a jet mill to an average particle size of 4.8 to 5. ⁇ ⁇ .
  • the resulting fine powder was compacted in a magnetic field of 15.0 kOe at a pressure of 1.2 tZcm 2 to obtain a compact.
  • This compact was sintered at 1070 ° C. for 4 hours in a vacuum and then rapidly cooled. Next, the sintered body obtained was subjected to two-stage aging at 800 ° C for 1 hour and 550 ° C for 2.5 hours (both in an Ar atmosphere).
  • the magnetic properties of the obtained permanent magnet were measured using a BH laser. The results are shown in Figs.
  • Br indicates the residual magnetic flux density
  • He J indicates the coercive force
  • rtik / Hc indicates the squareness ratio.
  • the squareness ratio (Hk / Hc J) is an index of magnet performance, and indicates the degree of angularity in the second quadrant of the magnetic hysteresis loop.
  • Hk is the external magnetic field strength when the magnetic flux density becomes 90% of the residual magnetic flux density in the second quadrant of the magnetic hysteresis loop.
  • ⁇ is shown for products in which in-phase products were confirmed, and X is given for products which were not confirmed.
  • the product When subjected to a milling process in this state, the product results to be separated from the R 2 T 14 B phase, the product is a R 2 T 14 B phase without being included in the R 2 T 14 B Aiuchi Exists independently. Therefore, it is considered that the RTB-based rare earth permanent magnet according to Comparative Example 3 contains a Zr-rich product only in the grain boundary phase even after the sintering process.
  • the R_T_B-based rare earth permanent magnet having a Zr power of 10 wt% according to Example 1 was observed by TEM in the same manner as described above.
  • the observation results are shown in Figs.
  • Fig. 6 is a TEM photograph of a sample with a Zr content of 0.10 wt%
  • Fig. 7 is the product present in the sample and the EDS (Energy Dispersive X-ray) of the R 2 T 14 B phase in the sample.
  • Fig. 8 is a TEM high-resolution photograph of the sample.
  • an in-phase product having a large axial ratio can be confirmed in the R 2 T 14 B phase.
  • This product has a plate-like or needle-like form. Since FIG. 6 shows the cross section of the sample, it is difficult to specify whether the in-phase product is in the form of a plate-like force needle. Considering also the observation results of other samples and FIG. 8, the in-phase product has a length of several 100 nm and a width of several nm to 15 nm. This in-phase product Although the detailed chemical composition of is not clear, it can be confirmed from Fig. 7 (a) that this in-phase product is at least rich in Zr.
  • Example 1 in addition to in-phase products with a large axial ratio, amorphous and circular in-phase products may be observed as shown in FIGS. 9 and 10. it can.
  • Example 1 as a result of observing 20 crystal grains (R 2 T 14 B phase), an in-phase product was observed in 6 crystal grains.
  • Comparative Example 2 no in-phase product was observed for all 2 ° crystal grains (R 2 T 14 B phase).
  • the lower part of Fig. 11 (a) shows the result of Zr mapping of a sample having a Zr power of SO. 10 wt% of Example 1 by using an electron probe micro analyzer (EPMA).
  • the upper part of Fig. 11 (a) shows the composition image of the same field of view as the Zr mapping result shown in the lower part of Fig. 11 (a).
  • the lower part of Fig. 11 (b) shows the result of Zr matting by EPMA of the sample of Comparative Example 2 having a Zr amount of 0.10 wt%.
  • the upper part of Fig. 11 (b) shows the composition image of the same field of view as the Zr matting result shown in the lower part of Fig. 11 (b).
  • FIG. 11 (a) shows that in Example 1, the presence of the Zr-rich R 2 T 14 B phase and the presence of Zr in the grain boundary phase I understand.
  • FIG. 11 (b) shows that the R 2 T 14 B phase rich in Zr is not confirmed in Comparative Example 2, and Zr is present only in the grain boundary phase.
  • each sample was sintered for 4 hours in a temperature range of 110 ° C to 1090 ° C, respectively.
  • an RTB rare earth permanent magnet was obtained.
  • the magnetic properties of the obtained permanent magnet were measured in the same manner as in the first example.
  • the results are shown in FIG. 13 to 15 show the change in magnetic properties with sintering temperature.
  • Fig. 16 shows the magnetic properties at each sintering temperature plotted as the squareness ratio (Hk / HcJ) with respect to the residual magnetic flux density (Br).
  • Example 2 in a sintering temperature range of 1030 to 1090 ° C, a residual magnetic flux density (Br) of 13.9 kG or more and 13.0 kOe
  • He J coercive force
  • Hk / Hc J squareness ratio
  • the obtained fine powder was molded in a magnetic field under the same conditions as in the first example, and then sintered at 110 to 100 ° C. for 4 hours.
  • two-stage aging treatment was performed at 800 ° C for 1 hour and at 550 ° C for 2.5 hours.
  • the composition, oxygen content and nitrogen content of the obtained sintered body are shown in FIG. 17, and the magnetic properties are shown in FIG.
  • a coercive force (H e J) of kO e or more and a squareness ratio (HkZH c J) of 95% or more can be obtained.
  • the residual magnetic flux density (Br) is 13.5 kG or more and 15.5 kOe or more in the temperature range of 1030 to 1070 ° C. of A coercive force (He J) and a squareness ratio (HkZHc J) of 95% or more can be obtained.
  • He J A coercive force
  • HkZHc J a squareness ratio
  • Two kinds of low R alloys and two kinds of high R alloys were prepared by strip casting, and two kinds of R_T_B rare earth permanent magnets were obtained by the combination shown in Fig. 19.
  • the mixture ratio of the low R alloy and the high R alloy is 90:10.
  • the mixing ratio of the low R alloy and the high R alloy is 80:20.
  • the low R alloy and the high R alloy shown in FIG. 19 were pulverized with hydrogen in the same manner as in the first embodiment. After the hydrogen crushing treatment, 0.05 wt% of butyl oleate was added, and the low R alloy and the high R alloy were mixed in a Nauta mixer for 30 minutes in the combination shown in FIG.
  • the presence of a Zr-rich product in the R 2 T 14 B phase in the sintering process can suppress grain growth while minimizing deterioration in magnetic properties.

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Abstract

L'invention concerne une méthode de production d'un aimant permanent à éléments des terres rares en alliage de R-T-B. L'aimant permanent est constitué d'un produit fritté, dont la phase principale comprend une phase R2T14B dans laquelle R représente un ou plusieurs éléments des terres rares, y compris Y; et T représente un ou plusieurs éléments des métaux de transition, y compris Fe ou Fe et Co. Le produit fritté comprend également une phase de joint de grain comprenant une teneur du R supérieure à celle de la phase principale. Un produit riche en Zr est présent dans la phase R2T14B. La méthode se caractérise en ce qu'elle consiste à préparer: d'une part, un alliage de R-T-B qui contient une phase R2T14B comme phase principale, contient Zr, et dont la phase R2T14B ne contient pas de produit riche en Zr; d'autre part, un alliage de R-T qui contient R et T comme éléments principaux, et dont la teneur du R est supérieure à celle de l'alliage de R-T-B. La méthode consiste ensuite à: préparer un mélange d'une poudre contenant l'alliage de R-T-B et d'une poudre contenant l'alliage de R-T; produire un article moulé comprenant le mélange et présentant une forme préétablie; et fritter l'article moulé. Le produit riche en Zr est inclus dans la phase R2T14B, pendant l'étape de frittage.
PCT/JP2003/012492 2002-09-30 2003-09-30 Methode de production d'un aimant permanent a elements des terres rares en alliage de r-t-b WO2004030000A1 (fr)

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DE60311960T DE60311960T2 (de) 2002-09-30 2003-09-30 Verfahren zur herstellung eines seltenerdelement-permanentmagneten auf r-t-b-basis
JP2004539584A JP4076179B2 (ja) 2002-09-30 2003-09-30 Ｒ−ｔ−ｂ系希土類永久磁石の製造方法
EP03748613A EP1460651B1 (fr) 2002-09-30 2003-09-30 Methode de production d'un aimant permanent a elements des terres rares en alliage de r-t-b

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EP1462531A2 (fr) * 2003-03-27 2004-09-29 TDK Corporation Aimant permanent à base de terres rares R-T-B
JP2007270163A (ja) * 2006-03-30 2007-10-18 Tdk Corp 希土類永久磁石の製造方法およびその原料合金
CN100366363C (zh) * 2004-04-30 2008-02-06 株式会社新王磁材 稀土类磁铁用原料合金、粉末以及烧结磁铁的制造方法
JP2015023242A (ja) * 2013-07-23 2015-02-02 Tdk株式会社 希土類磁石、電動機、及び電動機を備える装置
JP2020503686A (ja) * 2016-12-29 2020-01-30 北京中科三環高技術股▲ふん▼有限公司Ｂｅｉｊｉｎｇ Ｚｈｏｎｇ Ｋｅ Ｓａｎ Ｈｕａｎ Ｈｉ−Ｔｅｃｈ Ｃｏ．，Ｌｔｄ． 微粒子希土類合金鋳片、その製造方法、および回転冷却ロール装置
CN115359988A (zh) * 2022-08-24 2022-11-18 宁波爱维森材料研发科技有限公司 一种高性能含铈稀土永磁体及其制备方法

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CN101819841A (zh) * 2010-05-17 2010-09-01 上海交通大学 钕铁硼磁性材料及其制备方法
US9997284B2 (en) * 2012-06-22 2018-06-12 Tdk Corporation Sintered magnet
CN106782971A (zh) * 2016-12-05 2017-05-31 湖南航天磁电有限责任公司 一种钕铁硼材料及其制备方法
CN107358998A (zh) * 2017-07-20 2017-11-17 杭州乐荣电线电器有限公司 扁平抗干扰可折叠软数据线
JP7463791B2 (ja) * 2020-03-23 2024-04-09 Tdk株式会社 Ｒ－ｔ－ｂ系希土類焼結磁石およびｒ－ｔ－ｂ系希土類焼結磁石の製造方法

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EP1462531A2 (fr) * 2003-03-27 2004-09-29 TDK Corporation Aimant permanent à base de terres rares R-T-B
EP1462531A3 (fr) * 2003-03-27 2005-03-30 TDK Corporation Aimant permanent a base de terres rares r-t-b
US7199690B2 (en) 2003-03-27 2007-04-03 Tdk Corporation R-T-B system rare earth permanent magnet
CN100366363C (zh) * 2004-04-30 2008-02-06 株式会社新王磁材 稀土类磁铁用原料合金、粉末以及烧结磁铁的制造方法
JP2007270163A (ja) * 2006-03-30 2007-10-18 Tdk Corp 希土類永久磁石の製造方法およびその原料合金
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JP2015023242A (ja) * 2013-07-23 2015-02-02 Tdk株式会社 希土類磁石、電動機、及び電動機を備える装置
JP2020503686A (ja) * 2016-12-29 2020-01-30 北京中科三環高技術股▲ふん▼有限公司Ｂｅｉｊｉｎｇ Ｚｈｏｎｇ Ｋｅ Ｓａｎ Ｈｕａｎ Ｈｉ−Ｔｅｃｈ Ｃｏ．，Ｌｔｄ． 微粒子希土類合金鋳片、その製造方法、および回転冷却ロール装置
CN115359988A (zh) * 2022-08-24 2022-11-18 宁波爱维森材料研发科技有限公司 一种高性能含铈稀土永磁体及其制备方法

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EP1460651A4 (fr) 2005-03-23
CN1572006A (zh) 2005-01-26
EP1460651A1 (fr) 2004-09-22
WO2004029999A1 (fr) 2004-04-08
EP1460650A1 (fr) 2004-09-22
JP4076178B2 (ja) 2008-04-16
DE60311960T2 (de) 2007-10-31
DE60317460D1 (de) 2007-12-27
CN1572005A (zh) 2005-01-26
JPWO2004029999A1 (ja) 2006-01-26
EP1460650B1 (fr) 2007-11-14
EP1460650A4 (fr) 2005-03-30
CN1295713C (zh) 2007-01-17
JP4076179B2 (ja) 2008-04-16
JPWO2004030000A1 (ja) 2006-01-26
CN100334662C (zh) 2007-08-29
DE60311960D1 (de) 2007-04-05
DE60317460T2 (de) 2008-09-18

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