• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    rare earth magnet production method. a method of producing a rare earth magnet, comprising a step of producing a compact obtained by applying hot work to impart anisotropy to a sintered body having a rare earth magnet composition in contact with a melting point melting alloy low containing a rare earth element, wherein said low melting alloy alloy containing a rare earth element, is composed of an alloy having a melting point of less than 700 <198> c. the production method according to claim 1, wherein said low melting alloy melting containing a rare earth element is composed of an alloy of at least one rare earth element selected from the group consisting of it, ce, pr and nd and at least one metal selected from the group consisting of fe, co, ni, zn, ga, al, au, ag, in and cu. production method according to claim 2, wherein the rare earth element contained in said low melting alloy melt is nd or pr. production method according to claim 3, wherein the rare earth element contained in said low melting alloy melt is nd. production method according to claim 4 wherein said low melt containing a rare earth element is ndal. production method according to claim 4, wherein said low melting alloy melting containing a rare earth element is ndal. production method according to claim 1, wherein said sintered body is obtained by the formation of an extinct body resulting from the extinction of a fusion alloy, by pressurization and sintering. production method according to claim 7, wherein said extinct body has a nanocrystalline texture. production method according to claim 7 or 8, wherein said compound is an amorphous particle. The production method according to claim 1, wherein said hot work for checking anisotropy contains a step of unidirectionally compressing the sintered body at a temperature of 450 <198> c to less than 800 <198> c. The production method according to claim 1, wherein the contacting step is carried out at a temperature of 700 <198> c or less for 1 minute to less than 3 hours. production method according to claim 1, wherein the contact step is carried out from 580 to 700 <198> c for 10 minutes to less than 3 hours. production method according to claim 1, wherein said sintering body has a composition.
    公开号:BR112013006106B1
    申请号:R112013006106-5
    申请日:2011-09-13
    公开日:2020-03-03
    发明作者:Tetsuya Shoji；Noritaka Miyamoto；Shinya OMURA；Daisuke Ichigozaki；Takeshi Yamamoto
    申请人:Toyota Jidosha Kabushiki Kaisha；
    IPC主号:
    专利说明:

    Descriptive Report of the Patent of Invention for METHOD OF PRODUCTION OF MAGNET OF RARE TERRA.
    TECHNICAL FIELD [0001] The present invention relates to a method of producing a rare earth magnet capable of being intensified in coercivity. More specifically, the present invention relates to a method of producing a rare earth magnet capable of being intensified in coercivity without adding a large quantity of a rare metal such as Dy and Tb.
    BACKGROUND OF THE TECHNIQUE [0002] Magnet materials are roughly classified as a hard magnetic material and a soft magnet material, and when both materials are compared, a high coercivity is required of the hard magnetic material, while high maximum magnetization is required of the soft magnet material, although coercivity may be small.
    [0003] The coerciveness characteristic of the hard magnetic material is a property related to the stability of the magnet, and as the coercivity increases higher, the magnet can be used at a higher temperature.
    [0004] A known magnet that uses a hard magnetic material is an NdFeB-based magnet that may contain a microcrystalline texture. It is also known that a high coercivity-cooled tape, containing a microcrystalline texture, can be improved in temperature characteristics and thereby improved in high temperature coercivity. However, the coercivity of the NdFeB-based magnet containing microcrystalline texture decreases during volume sintering as well as during orientation control after sintering. [0005] With respect to this magnet based on NdFeB, several proposals have been made in order to improve characteristics such as coercivity and density of residual magnetic flux.
    Petition 870190097651, of 09/30/2019, p. 6/35
    2/23 [0006] For example, in patent document 1, a permanent magnet in which an alloy based on R-Fe-B- (R is a rare earth element including Y) prepared by melting and cooling is given with magnetic anisotropy through plastic work and where the average crystal grain size is 0.1 to 0.5 pm and the volume percentage of a crystal grain, having a crystal grain size of more than 0 , 7 pm, is less than 20% is described and it is shown that in the case where the average crystal grain size after plastic work is less than 0.1 pm, anisotropic orientation of crystal grains does not advance sufficiently . In addition, as a specific example of the production method, a case of obtaining a rare earth magnet through softening by tempering a molten alloy, forming cold orientation, hot and anisotropic pressure by plastic work is described.
    [0007] Furthermore, in patent document 2, a method of producing a rare-earth permanent magnet is described, in which a body sintered with a composition of Ra-T1b-Bc (where R is an element or two or more elements selected from rare earth elements including Y and Sc, T1 is one or two members of Fe and Co, and each of a, b and b represents an atomic percentage) is heat treated while allowing a binder powder having a composition of M1d-M2e (where each of M1 and M2 is an element or two or more elements selected from Al, Si, C, P, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, Hf, Ta, W, Pb and Bi, Mi and M2 are different from each other, and each dee represents an atomic percentage) and containing 70% in volume or more than one phase of intermetallic compound to be present on the surface of the sintered body, at a temperature of no more than the sintering temperature of the vacuum sintered body or in a gas are inert and, thus, an element or two or more elements Mi and M2 energy contained in
    Petition 870190097651, of 09/30/2019, p. 7/35
    3/23 are diffused near part of the grain boundary within the sintered body and / or the boundary part of the grain in the main phase grains of the sintered body.
    RELATED TECHNIQUE
    PATENT DOCUMENT [0008] Patent Document 1: Japanese Patent No. 2693601 [0009] Patent Document 2: Kokai (Patent Publication
    Japanese (unexamined) No. 2008-235343
    SUMMARY OF THE INVENTION
    PROBLEMS TO BE SOLVED BY THE INVENTION [00010] However, a rare earth magnet having satisfactory coercivity cannot be obtained even by these known techniques. [00011] Therefore, an objective of the present invention is to provide a method of producing an anisotropic rare earth magnet capable of being enhanced in coercivity without adding a large quantity of a rare metal such as Dy and Tb.
    MEANS TO SOLVE PROBLEMS [00012] The present invention relates to a method of producing a rare earth magnet, comprising a step of producing a compact (formed body) obtained by applying hot work to confer anisotropy to a body sintered having a rare earth magnet composition in contact with a low melting alloy melt containing a rare earth element.
    EFFECTS OF THE INVENTION [00013] According to the present invention, an anisotropic rare earth magnet having an enhanced coercivity can be easily obtained without adding a large amount of a rare metal like Dy and Tb.
    BRIEF DESCRIPTION OF THE DRAWINGS [00014] Figure 1 is a graph showing demagnetization curves
    Petition 870190097651, of 09/30/2019, p. 8/35
    4/23 of a magnet in one embodiment of the present invention and a magnet outside the scope of the present invention.
    [00015] Figure 2 is a schematic view illustrating the steps in an embodiment of the present invention.
    [00016] Figure 3 is a schematic view illustrating nanocrystalline textures of a sintered body in each step according to one embodiment of the present invention, a compact after hot work, and a magnet after the contact step.
    [00017] Figure 4 is a schematic graph showing contributions of a factor attributed to the particle diameters of a raw material powder (fine belt) in each step, according to one embodiment of the present invention), a sintered, compact body by hot work, and an anisotropic magnet obtained in the step of contact with a melting of low melting point alloy, and a factor attributed to the decoupling characteristic between grains.
    [00018] Figure 5 is a graph comparatively showing coercivity temperature dependencies of several magnets.
    [00019] Figure 6 is a graph comparatively showing relationships between Hc / Ms and Ha / Ms of several magnets.
    [00020] Figure 7 is a comparatively graph showing results of evaluation of magnetic properties of magnets obtained by changing the contact time in the examples and results of evaluation of magnetic properties of a magnet before contact treatment.
    [00021] Figure 8 is a comparatively graph showing rare earth magnet property evaluation results obtained by changing the melting type of low melting point alloy in the examples and property evaluation results of a magnet before contact treatment .
    [00022] Figure 9 is a comparatively graphic showing
    Petition 870190097651, of 09/30/2019, p. 9/35
    5/23 rare earth magnet property evaluation results obtained by changing the temperature when contacting low melting point alloy fusion in the examples and property evaluation results of a magnet before contact treatment.
    MODE FOR CARRYING OUT THE INVENTION [00023] According to the present invention, an anisotropic rare earth magnet increased in coercivity can be obtained by a method of producing a rare earth magnet, comprising a step of bringing a compact obtained by applying hot work to impart anisotropy to a sintered body having a rare earth magnet composition in contact with a low melting alloy melt containing a rare earth element.
    [00024] In the description of the present invention, low melting alloy melting means that the melting point of the alloy is low compared to the melting point of the Nd2Fe14B phase.
    [00025] The present invention is described below with reference to Figures 1 to 4.
    [00026] As shown in Figure 1, it is understood that a magnet after a treatment produces a compact obtained by applying hot work to impart anisotropy to a sintered body in contact with a low melting alloy melt containing an element of rare earth, according to a modality of the present invention, has a great coercivity compared to any magnet composed of a compact by hot work, a magnet applied with a history of heat in place of the contact treatment, and a magnet obtained by the contact treatment of a sintered body, which are outside the scope of the present invention.
    [00027] In the description of the present invention, when the degree of deformation (indicated by a compression ratio) by the hot work described above is large, that is, when the compression ratio
    Petition 870190097651, of 09/30/2019, p. 10/35
    6/23 is 10% or more, for example, 20% or more, usually this is sometimes referred to as strong hot deformation.
    [00028] In addition, as shown in Figure 2, in one embodiment of the present invention, the production method may comprise, for example, a step of sintering a thin tempered belt (sometimes referred to as quenched ribbon) obtained from an alloy of fusion having a composition giving a rare earth magnet, under pressure to obtain a sintered body, a step of applying hot work to confer anisotropy to the sintered body, thus obtaining a compact, and a step of producing the compact obtained in contact with the melting of low melting point alloy containing a rare earth.
    [00029] Furthermore, as shown in Figure 3, in one embodiment of the present invention, the sintered body (A) obtained by sintering an extinct ribbon is isotropic. This sintered body is hot worked to give anisotropy, and the resulting compact (B) is anisotropic and contains a crystalline nanoparticle, in which the deformation by slightly rough work the crystal grain and pushes the grain boundary phase, producing direct contact of the crystal grains with each other and the occurrence of magnetic coupling, and furthermore, coercivity decreases because of the internal residual strain. This compact is contacted with the fusion of the low melting point alloy containing the rare earth element, and the obtained magnet (C) is anisotropic, in which the liquid phase of the low melting point intrudes into the magnet and penetrates between the crystal grains, causing refinement of the reverse magnetization unit to demagnetize and release internal stress, as a result coercivity is intensified.
    [00030] The reason why the rare earth magnet obtained by the method of the present invention has good coercivity is not theoretically clarified, but it is considered that the use of a compact obtained by applying hot work to confer anisotropy to a body
    Petition 870190097651, of 09/30/2019, p. 11/35
    7/23 sintered and contact with a low melting point alloy fusion containing a rare earth element are combined and thanks to their synergistic effect, that is, the residual strain produced due to hot work is removed by contact with the fusion and the magnetic decoupling characteristic is enhanced by sufficient penetration of a low melting point alloy containing rare earth element at the edge of the crystal grain, the coercivity of the obtained rare earth magnet is enhanced.
    [00031] As shown in Figure 4, in the sintered body obtained by sintering raw material from extinct tape, according to a modality of the present invention, the Neff value as a size dependent factor (mainly attributed to the grain size) of the unit to be altered in the demagnetization of the magnet, which is determined by the method described in detail in the examples later, is small, and the α factor depending on the degree of magnetic isolation of the crystal grain, that is, the magnetic decoupling characteristic ( mainly attributed to the thickness of the grain boundary phase), is small. That is, as the grain size of the grain is smaller, the decoupling characteristic between grains is lower. On the other hand, in the sintered magnet, the decoupling characteristic between grains is high, but as described above, the Neff value is large, that is, the grain size of the crystal grain is large. In the compact obtained by strong hot deformation of the sintered body after sintering, the decoupling characteristic between grains is slightly high and the grain size of the crystal grain is large compared to the sintered body. In the magnet obtained producing the compact by strong hot deformation after sintering the raw material powder in contact with a low melting point alloy melting containing a rare earth element, as described above, the Neff value is small and α is large. That is, the grain size of the grain is small and the characteristic
    Petition 870190097651, of 09/30/2019, p. 12/35
    8/23 decoupling between grains is large. In this way, when the compact obtained by strong hot deformation after sintering is treated by contact with a melting of low melting point alloy containing a rare earth element, the refinement of the unit to be changed when demagnetizing the magnet and the intensification of the magnetic decoupling characteristic are carried out, and it is revealed that coercivity is enhanced by the synergistic effect described above.
    [00032] In Figure 4, Hc, Neff, a, Ha and Ms mean the following and satisfy the relationship of Hc = aHa-NeffMs, and it is understood that as a is greater and as Neff is less, coercivity Hc is greater .
    Hc: Magnet coercivity
    Neff: Factor attributed to the grain size a: Factor attributed to the decoupling characteristic between grains
    Ha: Magnetic crystal anisotropy
    Ms: Saturated magnetization [00033] The sintered body for use in the present invention is arbitrary since a rare earth magnet is obtained. Examples of the same include a compact obtained by producing a thin quenched belt (sometimes referred to as quenched ribbon) by a method of quenching a fusion alloy having a rare earth magnet composition, and pressurizing and sintering the resulting fine quenched belt.
    [00034] The sintered body above is obtained, for example, from an extinct ribbon obtained by extinguishing a fusion alloy having an Nd-Fe-Co-BM composition (where M is Ti, Zr, Cr, Mn, Nb, V , Mo, W, Ta, Si, Al, Ge, Ga, Cu, Ag or Au, Nd is more than 12 in% to 35 in%, Nd: B (atomic fraction ratio) is 1.5: 1 to 3 : 1, Co is 0 to 12%, M is 0 to 3%, and the balance is Fe). In addition, an amorphous portion may be contained in the defunct tape.
    Petition 870190097651, of 09/30/2019, p. 13/35
    9/23 [00035] As the method for obtaining an extinct tape containing an amorphous portion, a magnetic separation method or a gravity separation method can be used.
    [00036] In order to obtain a sintered body of high coercivity, the Nd-Fe-Co-BM composition described above in one embodiment of the present invention, is preferably a composition containing Nd and B in such amounts that Nd or B is more richer than the stoichiometric region (Nd2Fe14B). In addition, in order to develop high coercivity, the amount of Nd is preferably 14% or more. In addition, in order to develop high coercivity, when the amount of Nd is 14% or less, it is preferred to enrich B. In addition, for example, an excess part of B can be replaced by another element such as Ga to make Nd-Fe-Co-B-Ga.
    [00037] For example, in an embodiment of the present invention, with respect to the composition of Nd-Fe-Co-BM, the crystal structure of the isotropic magnet based on NdFeB- before hot work, can be made to carry a texture microcrystalline, applying pressurization / hot sintering.
    [00038] In addition, in one embodiment of the present invention, the sintered body above is hot worked, for example, at a temperature of 450 ° C to less than 800 ° C, for example, at a temperature of 550 to 725 ° In this way, a microcrystalline texture, no more than an anisotropic single domain particle size (<300 nm), can be maintained.
    [00039] In one embodiment of the present invention, an alloy ingot is produced, for example, using predetermined amounts of Nd, Fe, Co, B and M in a proportion giving an above atomic number ratio in a melting furnace as a arc melting furnace, and the alloy ingot obtained is treated in a smelting apparatus, for example, a roller furnace equipped with a
    Petition 870190097651, of 09/30/2019, p. 14/35
    10/23 melt to reserve an alloy melt, a nozzle to supply the melt, a cooled roll, an engine to cool the roll, a cooler to cool the roll, and the like, in this way the extinct Nd-Fe-CoB tape -M can be obtained.
    [00040] In an embodiment of the present invention, the extinct Nd-Fe-Co-BM tape is sintered, for example, by a method of electrically heating and sintering the extinct tape using an electrically heated and sintering apparatus equipped with a mold , a temperature sensor, a control unit, a power supply unit, a heating element, an electrode, a heat insulating material, a metal support, a vacuum chamber and the like.
    [00041] The above sintering can be carried out by electric heating and sintering, for example, under the conditions of a contact pressure during sintering of 10 to 1,000 MPa, a temperature of 450 to 650 ° C, a vacuum of 10 -2 MPa or less, and from 1 to 100 minutes. [00042] In sintering, only the sintering chamber of the sintering machine can be isolated from the outside air to create an inert sintering atmosphere, or the entire system can be surrounded by a housing to create an inert atmosphere.
    [00043] As for hot work, a work known as plastic work to confer anisotropy, such as compression work, advanced extrusion, anterior extrusion and repression can be employed.
    [00044] Hot working conditions are, for example, a temperature of 450 ° C to less than 800 ° C, for example, a temperature of 550 to 725 ° C, an atmospheric pressure or a vacuum degree of 10 - 5 to 10 -1 Pa, and 10 -2 to 100 seconds.
    [00045] In addition, hot work can be carried out, for example, at a strain rate of 0.01 to 100 / s.
    Petition 870190097651, of 09/30/2019, p. 15/35
    11/23 [00046] The compression ratio of sintered body thickness by hot work [(sample thickness before compression - sample thickness after compression) x100 / sample thickness before compression] (%) can be appropriately from 10 to 99%, particularly from 10 to 90%, for example, from 20 to 80%, and, for example, from 25 to 80%.
    [00047] In the present invention, it is necessary to include a production step of the compact obtained in the above step in contact with a low melting point alloy metal containing a rare earth element. [00048] The melting of the low melting point alloy containing a rare earth element includes, for example, a melting composed of an alloy having a melting point of less than 700 ° C, for example, from 475 to 675 ° C, particularly from 500 to 650 ° C, that is, for example, a fusion composed of an alloy containing at least one element of rare earths selected from the group consisting of La, Ce, Pr and Nd, particularly Nd or Pr, above all, an alloy containing Nd and at least one metal selected from the group consisting of Fe, Co, Ni, Zn, Ga, Al, Au, Ag, In and Cu, particularly an alloy with Al or Cu, more particularly an alloy having a rare earth element containing 50% or more, for example, in the case of an alloy with Cu, an alloy in which Cu represents 50% or less, and in the case of an alloy with Al, an alloy in that Al represents 25% or less.
    [00049] As the alloy, PrCu, NdGa, NdZn, NdFe, NdNi, and MmCu (Mm: misch metal) may also be appropriate. In describing the present invention, the formula representing the type of alloy indicates a combination of two types of elements and does not indicate the proportion of the composition.
    [00050] In the step of putting the compact in contact with the melt, the melting temperature of the alloy is preferably higher than the contact time with the melting of the alloy is short, and can be lower when the contact time with the melting of the alloy alloy is relatively long, and for
    Petition 870190097651, of 09/30/2019, p. 16/35
    For example, the step is performed at an alloy melting temperature of 700 ° C or less for approximately 1 minute to less than 3 hours, suitably at a temperature of 580 to 700 ° C for approximately 10 minutes at 3 hours.
    [00051] By virtue of having a step of putting the compact in contact with a low melting alloy melting containing a rare earth element, a rare earth magnet enhanced in coercivity can be obtained.
    [00052] The rare earth magnet obtained by the present invention generally has a small particle diameter when compared to normal magnets and, for example, it can be a magnet in which the average particle diameter is less than 200 nm, for example, less than 100 nm, for example, tens of nm, and the crystals are oriented in an aligned manner.
    [00053] In the method of the present invention, the use of a compact obtained by applying hot work to impart anisotropy to the sintered body and contact of the compact with a low melting alloy melting containing a rare earth element . In the case of a magnet obtained only by hot work, but not going through a contact stage with a low melting alloy melting containing a rare earth element or a contact obtained magnet treating a sintered body not subjected to work hot to give anisotropy to the sintered body, a magnet enhanced in coercivity cannot be obtained. In addition, in the case of a magnet obtained by applying only a heat history without performing the contact treatment described above, a magnet enhanced in coercivity cannot be obtained. Furthermore, when a fusion is not used, but a diffusion method is employed, exposure to a high temperature for a long time is required in order to effect diffusion and during exposure to a
    Petition 870190097651, of 09/30/2019, p. 17/35
    13/23 high temperature for a long time, in the case of a nanocrystalline texture, crystal hardening and great deterioration of the magnetic characteristics are caused, failing to obtain an effect of intensifying the characteristics by the diffusion treatment. The diffusion can also be carried out by a bombardment treatment, but the intensification of the characteristics is limited to just the surface layer and an effect, like the entire magnet, cannot be expected. Furthermore, even when an alloy containing a rare earth element is diffused into a raw material powder and the raw material powder is sintered, the characteristics cannot be expected to be intensified.
    [00054] The compact for use in the present invention, which is brought into contact with a low melting point alloy, is a compact suitably obtained by the strong deformation in a compression ratio of 10% or more, for example, from 10 to 99%, for example, 10 to 90%, for example, 20 to 80%, and, for example, 25 to 80%. [00055] According to the method of the present invention, a rare earth magnet capable of being intensified in coercivity without adding a large amount of a rare metal, such as Dy and Tb, can be obtained.
    [00056] In the previous pages, the present invention is described based on the modalities of the present invention, but the present invention is not limited to those modalities and can be applied within the scope of the claims of the present invention.
    EXAMPLES [00057] Examples of works of the present invention are described below.
    [00058] In the following examples, characteristics of an extinct ribbon, a sintered body, a compact by hot work, and a magnet obtained through an immersion step were measured by Vibrating Sample Magnetometer System.
    Petition 870190097651, of 09/30/2019, p. 18/35
    14/23
    Vibratory). Specifically, for the device, the measurement was performed using a VSM measuring device manufactured by Lake Shorc. In addition, the demagnetization curve was measured by an excitation-type magnetic property evaluation device. [00059] Also, the size of the crystal grains on the extinct ribbon and the magnet were measured by a SEM image and a TEM image.
    [00060] In the examples, the production of an extinct ribbon, pressurization sintering, and strong hot deformation were carried out using a single-roll furnace, an SPS device, and a pressurization device (with a control unit capable of controlling the thickness compression to a predetermined thickness of 15 mm) shown in Figure 2 (A), Figure 2 (B) and Figure 2 (C), respectively.
    [00061] In addition, a and Neff can be determined as follows. In the following formula, (T) indicates that each parameter is a function of temperature.
    [00062] As described above, since there is a relationship of Hc (T) = aHa (T) -NeffMs (T), when both sides are divided by Ms (T),
    Hc (T) / Ms (T) = aHa (T) / Ms (T) -Neff results, and the formula can be divided into a temperature dependent term (Hc (T) / Ms (T), Ha (T) / Ms (T)) and a constant Neff term. Therefore, in order to determine ae Neff, as shown in Figure 5, the coercivity temperature dependency is measured and at the same time, as shown in Figure 6, Hc (T) / Ms (T) is plotted as a function with respect to Ha (T) / Ms (T) from the dependence of saturated magnetization temperature (Ms) and the dependence of anisotropic magnetic field temperature (Ha). The graphs obtained from Hc (T) / Ms (T) vs. Ha (T) / Ms (T) are approximated in a straight line by the least squares method, and a and Neff can be
    Petition 870190097651, of 09/30/2019, p. 19/35
    15/23 determined from the gradient and the intercept, respectively.
    [00063] Incidentally, as for the expression of Ha, the following expression approximated by a primary expression with respect to the temperature between 300 and 440 K based on the values in the following publications is used:
    Ha = -0.24T + 146.6 (T: absolute temperature) [00064] Also, as for the expression of Ms, the following expression approximated by the quadratic expression with respect to the temperature between 300 and 440 based on the values in the following publications is used : Ms = -5.25x10 -6 T 2 + 1.75x10 -3 T +1.55 (T: absolute temperature) [00065] From the expressions above and the temperature dependence of the measured coercivity (Hc), α and Neff are computed.
    [00066] It has been found that due to a combination of strong hot deformation, with contact treatment of the present invention, α is intensified and Neff is decreased. Neff is a parameter dependent on the size (mainly attributed to the grain size) of the unit to be reversed when demagnetizing the magnet, α is an amount dependent on the degree of magnetic insulation (mainly attributed to the thickness of the grain boundary phase) of the grain crystal , and when Neff is small and α is large, coercivity is high.
    [00067] Magnetic anisotropy:
    R. Grossinger et al., J. Mag. Mater., 58 (1986) 55-60 [00068] Saturated magnetization:
    M. Sagawa et al., 30th MMM conf. San Diego, California (1984) Example 1:
    1. Production of Extinct Tape [00069] Predetermined amounts of Nd, Fe, Co, B and Ga were weighed in such a proportion that the proportion of atomic number of Nd,
    Petition 870190097651, of 09/30/2019, p. 20/35
    16/23
    Fe, Co, B and Ga is 14: 76: 4: 5.5: 0.5, and an alloy ingot was produced in an arc melting furnace. Subsequently, the alloy ingot was melted by high frequency in a single roller furnace and sprayed on a copper roller under the conditions of using a single roller furnace to produce an extinct ribbon.
    [00070] Single Roll Furnace Conditions:
    Spray pressure: 0.4 kg / cm 3
    Roll Speed: from 2,000 to 3,000 rpm
    Fusion Temperature: 1,450 ° C [00071] An extinct tape with a composition of Nd14Fe76Co4B5.5Ga0.5 containing an amorphous portion was collected by magnetic separation.
    [00072] The tape obtained with a nanoparticle texture was partially sampled and measured for magnetic characteristics by VSM, and the tape was confirmed to be hard magnetic. Also, this nanoparticle texture ribbon had a crystal grain size of 50 to 200 nm.
    [00073] The tape with a nanoparticle texture was sintered under the following conditions, using a pressurization device: SPS (Spark Discharge Sintering / Spark Discharge Sintering) shown in Figure 2 (B).
    Sintering Conditions:
    [00074] Keeping at 600 ° C / 100 MPa for 5 minutes (molding density: almost 100%) [00075] The sintered body obtained was subjected to strong hot deformation under the following conditions, using a pressurization device shown in Figure 2 (C) to give anisotropy, so a compact was obtained.
    [00076] Conditions of Strong Hot Deformation:
    60% of Compression work (proportion of work in
    Petition 870190097651, of 09/30/2019, p. 21/35
    17/23 plastic: 60%) at 650 to 750 ° C at a strain rate of 1.0 / s [00077] The compact obtained was treated by contact by placing it in contact with a liquid phase of NdCu at 580 ° C by 1 hour (melting point of the NdCu alloy: 520 ° C, Nd: 70%, Cu: 30%).
    [00078] The rare earth magnet obtained was measured for the demagnetization curve, and the results are shown together with other results in Figure 1. It is seen from Figure 1 that the coercivity of the magnet in example 1 was increased by 8 kOe without Dy as compared to comparative example 2 of curve 1 in which only strong deformation was applied, but contact treatment was not performed.
    [00079] Also, Figure 4 shows α and Neff determined on the nanoparticle texture tape (raw material powder), the sintered body, the compact by hot work, and the magnet after immersion treatment. Example 2:
    [00080] A compact was obtained by giving anisotropy to a sintered body in the same way as in example 1, except for performing strong hot deformation, under the following conditions, using a pressurization device shown in Figure 2 (C), and a Contact treatment in a liquid phase of NdCu at 580 ° C for 1 hour was carried out in the same way as in example 1, except for using the compact obtained above.
    [00081] Strong Hot Deformation Conditions:
    20% compression work (proportion of plastic work: 20%) at 650 to 750 ° C at a strain rate of 1.0 / s [00082] The rare earth magnet obtained was measured by a demagnetization curve, and the results are shown along with other results in Figure 1.
    Example 3:
    [00083] A compact was obtained by giving anisotropy to a sintered body in the same way as in example 1 except for
    Petition 870190097651, of 09/30/2019, p. 22/35
    18/23 perform the strong hot deformation under the following conditions, and a contact treatment in a liquid phase of NdCu at 580 ° C for 1 hour was carried out in the same way as in example 1, except for using the compact obtained above .
    [00084] Conditions of Strong Hot Deformation:
    40% Compression work (plastic work ratio: 40%) at 650 to 750 ° C at a rate of 1.0 / s [00085] The rare earth magnet obtained was measured by demagnetization curve, and the results are shown along with other results in Figure 1.
    Comparative Example 1:
    [00086] A magnet was obtained in the same way as in example 1 except by adding a hot history of 580 ° C for 1 hour instead of the contact treatment in a liquid phase of NdCu at 580 ° C for 1 hour.
    [00087] The obtained rare earth magnet was measured by a demagnetization curve, and the results are shown together with other results in Figure 1.
    Comparative Example 2:
    [00088] A compact was obtained by producing an extinct tape, magnetic separation, sintering and 60% strong hot deformation in the same way as in example 1, except for not performing the contact treatment.
    [00089] The compact obtained was measured by demagnetization curve, and the results are shown together with other results in Figure 1.
    Comparative example 3:
    [00090] A sintered body obtained by performing sintering in the same manner as in example 1 was subjected to a contact treatment in the same manner as in example 1 without performing strong
    Petition 870190097651, of 09/30/2019, p. 23/35
    19/23 hot deformation.
    [00091] The obtained magnet was measured by a demagnetization curve, and the results are shown together with other results in Figure 1.
    [00092] It is understood from Figure 1 that the earth magnets obtained in Examples 1 to 3 have a great coercivity in comparison with any of the magnets composed of a compact by hot work (comparative example 2), the magnet obtained by add only a hot history without performing a contact treatment (comparative example 1), and the magnet obtained by contacting-treating a sintered body (comparative example 3).
    [00093] In addition, when example 1 is compared with example 2 and example 3, the magnet obtained by contact-treating is a compact resulting from 60% strong hot deformation has a great coercivity when compared with the obtained magnets for contacting-treating a compact resulting in 20% or 40% of strong hot deformation, and there is a positive correlation between the degree of deformation (compression rate) conferred by contact over time to control the orientation in the diffusion treatment in the alloy and the degree of intensification of coercivity.
    Examples 4 to 7:
    [00094] A compact was obtained using a sintered body obtained in the same way as in example 1 and giving anisotropy in the same way as in example 1, except for performing the strong hot deformation under the following conditions using a pressurization device shown in Figure 2 (C).
    [00095] Conditions of Strong Hot Deformation:
    80% compression work (proportion of plastic work: 80%) at 700 ° C at a strain rate of 1.0 / s [00096] The obtained compact was contacted-treated by immersion in a liquid phase of NdAl ( melting point of NdAl alloy: 640 ° C,
    Petition 870190097651, of 09/30/2019, p. 24/35
    20/23
    Nd: 85%, Al: 15%) at 650 ° C for 5 minutes (example 4), 10 minutes (example 5), 30 minutes (example 6) or 60 minutes (example 7).
    [00097] The rare earth magnets obtained were measured by demagnetization curve, and the results are shown together with the results of comparative example 4 in Figure 7.
    Comparative example 4:
    [00098] A compact like the base magnet was obtained by producing an extinct tape, magnetic separation, sintering of 80% of strong hot deformation in the same way as in example 4, except for not performing the contact treatment.
    [00099] The compact (base magnet) obtained was measured by a demagnetization curve, and the results are shown together with other results in Figure 7.
    [000100] It is seen from Figure 7 that when contacted with an NdAl alloy melt, the time required to complete the contact treatment with a low melting point melt is reduced to 30 minutes as compared to the case of use an NdCu alloy fusion and also, while contact with an NdCu alloy fusion brings an increase in coercivity by 8 kOe when compared to a compressed body, the increase in coercivity produced by contact with the fusion of an NdAl alloy is greater and can be 10 kOe.
    [000101] In addition, by selecting Al as the metal element for an alloy forming a liquid phase, corrosion resistance can be expected to be further intensified. In addition, also in view of the cost, when Cu and Al are compared, Al is advantageous because the cost is higher.
    Examples 8 to 13:
    [000102] A contact treatment was performed by immersing the compact for 60 minutes in the same way as in example 2 except
    Petition 870190097651, of 09/30/2019, p. 25/35
    21/23 for using, in place of the alloy NdCu, MmCu (Mm: misch metal) (example 8), PrCu (example 9), NdNi (example 10), NdGa (example 11), NdZn (example 12) or NdFe ( example 13).
    [000103] The rare-earth magnets obtained were measured by demagnetization curve, and the results are shown together with the results of comparative example 5 in Figure 8.
    [000104] Alloy melting points used in examples 8 to 13 are shown in Table 1 below together with the values of the NdCu alloy used in examples 1 to 3 and the NdAl alloy used in examples 4 to 7.
    Table 1
    RE rare earths Metal X Fusion point Mm Ass 480 ° C Pr Ass 492 ° C Nd Ass 520 ° C Nd Al 640 ° C Nd Ni 600 ° C Nd Zn 645 ° C Nd Ga 651 ° C [000105] The coerciveness of the magnet obtained in each example and the strength
    magnetic strips before contact treatment are shown together below.
    [000106] Alloy: MmCu (melting point: 480 ° C), Hc of the magnet after treatment: 17,584 kOe, Hc of the magnet before treatment: 15.58 kOe [000107] Alloy: PrCu (melting point: 492 ° C) , Hc of the magnet after treatment: 24,014 kOe, Hc of the magnet before treatment: 16.32 kOe [000108] Alloy: NdCu (melting point: 520 ° C), Hc of the magnet after treatment: 26,266 kOe, Hc of the magnet before of treatment: 18.3 kOe [000109] Alloy: NdAl (melting point: 640 ° C), Hc of the magnet after treatment: 26,261 kOe, Hc of the magnet before treatment: 16.3 kOe
    Petition 870190097651, of 09/30/2019, p. 26/35
    22/23 [000110] Alloy: NdNi (melting point: 600 ° C), Hc of the magnet after treatment: 20.35 kOe, Hc of the magnet before treatment: 16.5 kOe [000111] Alloy: NdZn (melting point: 645 ° C), Hc of the magnet after treatment: 20.25 kOe, Hc of the magnet before treatment: 16.1 kOe [000112] Alloy: NdGa (melting point: 651 ° C), Hc of the magnet after treatment: 22.35 kOe, Hc of the magnet before treatment: 16.3 kOe Comparative example 5:
    [000113] A compact was obtained by carrying out the production of an extinct tape, magnetic separation, sintering and 80% strong hot deformation, in the same way as in example 8, except for not performing the contact treatment.
    [000114] The compact obtained was measured by demagnetization curve, and the results are shown together with other results in Figure 8.
    Examples 14 and 15:
    [000115] A compact was obtained using a sintered body and giving anisotropy in the same way as in example 1 except for performing the strong hot deformation under the following conditions using a pressurization device shown in Figure 2 (C). Strong Hot Deformation Conditions:
    20% compression work (plastic work rate: 20%) at 650 to 750 ° C at a strain rate of 1.0 / s [000116] The obtained compact was contacted-treated in a liquid NdCu alloy phase 580 ° C (example 14) or 700 ° C (example 15) for 1 hour. Incidentally, the NdCu alloy used has the same melting point and the same composition as the alloy used in example 1.
    [000117] The obtained rare earth magnets were measured for the demagnetization curve, and the results are shown along with other results in Figure 9.
    Comparative example 6:
    Petition 870190097651, of 09/30/2019, p. 27/35
    23/23 [000118] A compact was obtained by carrying out the production of an extinct tape, magnetic separation, sintering and 20% strong hot deformation in the same way as in example 14, except for not performing the contact treatment.
    [000119] The compact obtained was measured for the demagnetization curve, and the results are shown together with other results in Figure 9.
    [000120] As evident from Figure 9, it is confirmed that the contact treatment by immersion in a low melting NdCu alloy melt can enhance coercivity at a temperature of 580 ° C or 700 ° C.
    INDUSTRIAL APPLICABILITY [000121] According to the present invention, an anisotropic rare earth magnet with high coercivity can be easily produced. REFERENCE LISTING [000122] Curve 1: Only 60% of strong hot deformation (in contact treatment) (comparative example 2) [000123] Curve 2: History of Heat (same temperature and time as in contact treatment) after 60% strong hot deformation (comparative example 1) [000124] Curve 3: Treatment of sintered body contact (comparative example 3) [000125] Curve 4: Contact treatment after 20% strong hot deformation (example 2) [000126] Curve 5: Contact treatment after 40% strong hot deformation ( example 3) [000127] Curve 6: Contact treatment after 60% strong hot deformation (example 1)
    1: Compact with anisotropy
    2: Liquid phase of NdCu alloy
    权利要求:
    Claims (12)
    [1]
    1. Method of production of a rare earth magnet, comprising a step of producing a compact obtained by applying hot work to impart anisotropy to a sintered body having a rare earth magnet composition in contact with a melt of point alloy low melting element containing a rare earth element, in which said sintered body has an Nd-Fe-Co-BM composition, in which M is Ti, Zr, Cr, Mn, Nb, V, Mo, W, Ta, Si, Al, Ge, Ga, Cu, Ag or Au, Nd is more than 12 in% to 35 in%, an atomic fraction ratio of Nd: B is 1.5: 1 to 3: 1, Co is from 0 to 12 in%, M is from 0 to 3 in%, and the balance is Fe, characterized by the fact that said low-melting alloy fusion containing a rare earth element, is composed of an alloy having a melting point of less than 700 ° C, but not less than 475 ° C and containing as the rare earth element at least one element selected from the group consisting of La, Ce, Pr and Nd
    [2]
    2. Production method according to claim 1, characterized in that said low melting alloy melting containing a rare earth element is composed of an alloy of at least one rare earth element selected from from the group consisting of La, Ce, Pr and Nd and at least one metal selected from the group consisting of Fe, Co, Ni, Zn, Ga, Al, Au, Ag, In and Cu.
    [3]
    Production method according to claim 2, characterized by the fact that the rare earth element contained in said low melting alloy fusion is Nd or Pr.
    [4]
    4. Production method according to claim 3, characterized by the fact that the rare earth element contained in said low melting alloy fusion is Nd.
    [5]
    5. Production method according to claim 4,
    Petition 870190097651, of 09/30/2019, p. 29/35
    2/2 characterized by the fact that said low melting alloy fusion containing a rare earth element is NdAl.
    [6]
    Production method according to claim 4, characterized in that said low melting alloy melting containing a rare earth element is NdCu.
    [7]
    7. Production method, according to claim 1, characterized by the fact that said sintered body is obtained by the formation of an extinct body resulting from the extinction of a fusion alloy, by pressurization and sintering.
    [8]
    8. Production method according to claim 7, characterized by the fact that said extinct body has a nanocrystalline texture.
    [9]
    9. Production method according to claim 7 or 8, characterized in that said extinct body is composed of an amorphous particle.
    [10]
    10. Production method, according to claim 1, characterized by the fact that said hot work to check anisotropy contains a step of unidirectionally compressing the sintered body at a temperature of 450 ° C to less than 800 ° C.
    [11]
    11. Production method, according to claim 1, characterized by the fact that the contact step is carried out at a temperature of 700 ° C or less for 1 minute to less than 3 hours.
    [12]
    12. Production method, according to claim 1, characterized by the fact that the contacting step is carried out at a temperature of 580 to 700 ° C for 10 minutes to less than 3 hours.
    类似技术:
    公开号 | 公开日 | 专利标题
    BR112013006106B1|2020-03-03|METHOD OF RARE-LAND MAGNET PRODUCTION
    US8388766B2|2013-03-05|Anisotropic rare earth sintered magnet and making method
    CN103915232A|2014-07-09|R-T-B rare earth sintered magnet, alloy for R-T-B rare earth sintered magnet, and method of manufacturing the same
    CN107622854B|2019-09-20|R-T-B based rare earth element permanent magnet
    CN104112580A|2014-10-22|Preparation method of rare earth permanent magnet
    JP4702548B2|2011-06-15|Functionally graded rare earth permanent magnet
    KR101243347B1|2013-03-13|R-Fe-B Sintered magnet with enhancing mechanical property and fabrication method thereof
    ES2879807T3|2021-11-23|Quick quenched alloy and preparation procedure for a rare earth magnet
    US20150279529A1|2015-10-01|Rare earth magnet and method for producing same
    CN107622853B|2019-09-20|R-T-B based rare earth element permanent magnet
    US20150357100A1|2015-12-10|Nanocomposite magnet and method of producing the same
    JP2010182827A|2010-08-19|Production method of high-coercive force magnet
    CN106103776A|2016-11-09|Alloy casting piece, its manufacture method and sintered magnet containing rare earth
    US20150125341A1|2015-05-07|Non-Rare Earth Magnets Having Manganese | and Bismuth | Alloyed with Cobalt |
    JP4034936B2|2008-01-16|Permanent magnet alloy with excellent heat resistance and manufacturing method thereof
    Van Vuong et al.2016|Low temperature phase of the rare-earth-free MnBi magnetic material
    CN105529123A|2016-04-27|Grain boundary diffusion material, rare earth permanent magnet material and preparation method therefor
    JP3735502B2|2006-01-18|Manufacturing method of magnet material
    JP3623564B2|2005-02-23|Anisotropic bonded magnet
    JP2013111599A|2013-06-10|Rare earth based alloy and method for manufacturing the same
    JP2753431B2|1998-05-20|Sintered permanent magnet
    JP2014209547A|2014-11-06|Rare earth magnet
    JP2951006B2|1999-09-20|Permanent magnet material, manufacturing method thereof, and bonded magnet
    JP2581179B2|1997-02-12|Method for producing rare earth-B-Fe sintered magnet with excellent corrosion resistance
    JP4769240B2|2011-09-07|Permanent magnet alloy with excellent heat resistance
    同族专利:
    公开号 | 公开日
    KR101306880B1|2013-09-10|
    RU2538272C2|2015-01-10|
    RU2013111461A|2014-10-20|
    BR112013006106A2|2016-05-31|
    EP2618349A4|2014-06-04|
    CN103098155B|2016-01-06|
    JPWO2012036294A1|2014-02-03|
    KR20120135337A|2012-12-12|
    JP5196080B2|2013-05-15|
    CA2811451C|2016-11-01|
    CN103098155A|2013-05-08|
    EP2618349A1|2013-07-24|
    US20130078369A1|2013-03-28|
    EP2618349B1|2016-11-23|
    US8846136B2|2014-09-30|
    WO2012036294A1|2012-03-22|
    CA2811451A1|2012-03-22|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US4792367A|1983-08-04|1988-12-20|General Motors Corporation|Iron-rare earth-boron permanent|
    JPH0247815A|1988-08-10|1990-02-16|Hitachi Metals Ltd|Manufacture of r-fe-b permanent magnet|
    JPH0282505A|1988-09-19|1990-03-23|Hitachi Metals Ltd|Rare earth-iron-boron cast magnet|
    JPH0644526B2|1989-08-23|1994-06-08|セイコー電子部品株式会社|Rare earth magnet manufacturing method|
    JP2693601B2|1989-11-10|1997-12-24|日立金属株式会社|Permanent magnet and permanent magnet raw material|
    US5037492A|1989-12-19|1991-08-06|General Motors Corporation|Alloying low-level additives into hot-worked Nd-Fe-B magnets|
    RU2082551C1|1993-01-13|1997-06-27|Московский авиационный технологический институт им.К.Э.Циолковского|Method for manufacture of permanent magnets from rare-earth metals|
    JPH06302419A|1993-04-13|1994-10-28|Seiko Epson Corp|Rare earth permanent magnet and its manufacture|
    JP3405806B2|1994-04-05|2003-05-12|ティーディーケイ株式会社|Magnet and manufacturing method thereof|
    US6319335B1|1999-02-15|2001-11-20|Shin-Etsu Chemical Co., Ltd.|Quenched thin ribbon of rare earth/iron/boron-based magnet alloy|
    JP3618648B2|2000-08-11|2005-02-09|日産自動車株式会社|Anisotropic magnet, method for manufacturing the same, and motor using the same|
    CN1153232C|2001-11-16|2004-06-09|清华大学|Method for making rareearth permanent magnet material by discharge plasma sintering|
    JP4433282B2|2004-01-23|2010-03-17|Ｔｄｋ株式会社|Rare earth magnet manufacturing method and manufacturing apparatus|
    MY141999A|2005-03-23|2010-08-16|Shinetsu Chemical Co|Functionally graded rare earth permanent magnet|
    JP4482769B2|2007-03-16|2010-06-16|信越化学工業株式会社|Rare earth permanent magnet and manufacturing method thereof|
    JP5093485B2|2007-03-16|2012-12-12|信越化学工業株式会社|Rare earth permanent magnet and manufacturing method thereof|
    MY149353A|2007-03-16|2013-08-30|Shinetsu Chemical Co|Rare earth permanent magnet and its preparations|
    CN101256859B|2007-04-16|2011-01-26|有研稀土新材料股份有限公司|Rare-earth alloy casting slice and method of producing the same|
    JP2010263172A|2008-07-04|2010-11-18|Daido Steel Co Ltd|Rare earth magnet and manufacturing method of the same|
    JP2010114200A|2008-11-05|2010-05-20|Daido Steel Co Ltd|Method of manufacturing rare-earth magnet|KR101542539B1|2011-11-14|2015-08-06|도요타 지도샤（주）|Rare-earth magnet and process for producing same|
    JP5640954B2|2011-11-14|2014-12-17|トヨタ自動車株式会社|Rare earth magnet manufacturing method|
    JP5742813B2|2012-01-26|2015-07-01|トヨタ自動車株式会社|Rare earth magnet manufacturing method|
    JP6003452B2|2012-09-20|2016-10-05|トヨタ自動車株式会社|Rare earth magnet manufacturing method|
    JP5790617B2|2012-10-18|2015-10-07|トヨタ自動車株式会社|Rare earth magnet manufacturing method|
    JP5751237B2|2012-11-02|2015-07-22|トヨタ自動車株式会社|Rare earth magnet and manufacturing method thereof|
    CN102925778B|2012-11-14|2014-12-17|山西汇镪磁性材料制作有限公司|Fusion assisting alloy material for adhering permanent magnet|
    JP5870914B2|2012-12-25|2016-03-01|トヨタ自動車株式会社|Rare earth magnet manufacturing method|
    JP6051922B2|2013-02-20|2016-12-27|日立金属株式会社|Method for producing RTB-based sintered magnet|
    US10186374B2|2013-03-15|2019-01-22|GM Global Technology Operations LLC|Manufacturing Nd—Fe—B magnets using hot pressing with reduced dysprosium or terbium|
    JP5704186B2|2013-04-01|2015-04-22|トヨタ自動車株式会社|Rare earth magnet manufacturing method|
    US9870862B2|2013-04-23|2018-01-16|GM Global Technology Operations LLC|Method of making non-rectangular magnets|
    CN105518809B|2013-06-05|2018-11-20|丰田自动车株式会社|Rare-earth magnet and its manufacturing method|
    JP2015093312A|2013-11-13|2015-05-18|トヨタ自動車株式会社|Forward extrusion forging device and forward extrusion forging method|
    JP5915637B2|2013-12-19|2016-05-11|トヨタ自動車株式会社|Rare earth magnet manufacturing method|
    JP5924335B2|2013-12-26|2016-05-25|トヨタ自動車株式会社|Rare earth magnet and manufacturing method thereof|
    JP6003920B2|2014-02-12|2016-10-05|トヨタ自動車株式会社|Rare earth magnet manufacturing method|
    JP6221978B2|2014-07-25|2017-11-01|トヨタ自動車株式会社|Rare earth magnet manufacturing method|
    JP6112084B2|2014-08-28|2017-04-12|トヨタ自動車株式会社|Rare earth magnet manufacturing method|
    JP2016076614A|2014-10-07|2016-05-12|トヨタ自動車株式会社|Method for manufacturing rare earth magnet|
    JP6102881B2|2014-10-09|2017-03-29|トヨタ自動車株式会社|Rare earth magnet manufacturing method|
    US10079084B1|2014-11-06|2018-09-18|Ford Global Technologies, Llc|Fine-grained Nd—Fe—B magnets having high coercivity and energy density|
    WO2016093379A1|2014-12-08|2016-06-16|엘지전자 주식회사|Hot-pressed and deformed magnet comprising nonmagnetic alloy and method for manufacturing same|
    CN107251176B|2015-02-18|2019-06-28|日立金属株式会社|The manufacturing method of R-T-B based sintered magnet|
    US20180025819A1|2015-02-18|2018-01-25|Hitachi Metals, Ltd.|Method for producing r-t-b system sintered magnet|
    CN107077965B|2015-07-30|2018-12-28|日立金属株式会社|The manufacturing method of R-T-B based sintered magnet|
    JP6471669B2|2015-09-29|2019-02-20|日立金属株式会社|Manufacturing method of RTB-based magnet|
    JP6520826B2|2016-05-27|2019-05-29|トヨタ自動車株式会社|Method of manufacturing rare earth magnet powder|
    US11174537B2|2016-08-17|2021-11-16|Hitachi Metals, Ltd.|R-T-B sintered magnet|
    US10658107B2|2016-10-12|2020-05-19|Senju Metal Industry Co., Ltd.|Method of manufacturing permanent magnet|
    JP6642419B2|2016-12-28|2020-02-05|トヨタ自動車株式会社|Rare earth magnet|
    JP6750543B2|2017-03-24|2020-09-02|日立金属株式会社|R-T-B system sintered magnet|
    CN109585113A|2018-11-30|2019-04-05|宁波韵升股份有限公司|A kind of preparation method of Sintered NdFeB magnet|
    法律状态:
    2018-12-26| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2019-07-23| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2019-12-31| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2020-03-03| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 13/09/2011, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    JP2010-206963|2010-09-15|
    JP2010206963|2010-09-15|
    JP2010275992|2010-12-10|
    JP2010-275992|2010-12-10|
    PCT/JP2011/071289|WO2012036294A1|2010-09-15|2011-09-13|Method for producing rare-earth magnet|
    [返回顶部]