Grain boundary diffusion material, neodymium-iron-boron magnet material and preparation method and application thereof

Abstract

The application discloses a grain boundary diffusion material, a neodymium-iron-boron magnet material and a preparation method and application thereof. The grain boundary diffusion material comprises a sintered body and a diffusion source. The sintered body comprises the following components: R: 29-32 wt.%, R being a rare earth element; M: 0.1-2 wt.%, M comprising one or more of Cu, Ga and Co; B: 0.9-1.0 wt.%; Fe: 65-70 wt.%, wt.% being the percentage of the mass of each component to the total mass of the sintered body. The diffusion source comprises the following components: Tb: 60-85 wt.%; Ga: 10-30 wt.%; Cu: 5-20 wt.%, wt.% being the percentage of the mass of each component to the total mass of the diffusion source. The grain boundary diffusion material can significantly improve the coercivity of the neodymium-iron-boron magnet material, while maintaining high remanence and high-temperature stability of the magnetic performance.

Description

Technical Field

[0001] This invention relates to a grain boundary diffusion material, a neodymium iron boron magnet material, its preparation method, and its application. Background Technology

[0002] Neodymium iron boron (NdFeB) magnets possess excellent magnetic properties and have been widely used in hybrid electric vehicles, electrical engineering, and electronic information fields. Currently, the main methods for improving the coercivity of sintered NdFeB magnets include alloying, grain refinement, and grain boundary diffusion. Among these, grain boundary diffusion involves depositing a layer of heavy rare earth powder on the magnet surface using methods such as sputtering, vapor deposition, electrophoresis, or coating. Heat treatment then allows the heavy rare earth elements on the magnet surface to diffuse into the magnet's interior, forming a magnetohardened shell at the main phase grain boundary layer to enhance coercivity. This method requires only a small amount of heavy rare earth elements to significantly improve coercivity.

[0003] Japanese patent documents JP2021057565A and JP2021057565A both disclose a neodymium iron boron magnet material. JP2021057565A uses Nd, Tb, and Cu as diffusion sources during the diffusion process, and employs a two-stage diffusion process. The first diffusion process uses Pr, Ga, Tb, and Cu as diffusion sources, while the second diffusion process uses Pr, Ga, and Cu as diffusion sources. While these diffusion sources improve the coercivity of the sintered body to some extent, the improvement is limited and cannot produce higher-performance products, thus exhibiting significant limitations. Furthermore, the addition of light rare earth elements may pose safety hazards, hindering large-scale production.

[0004] The technical problem that needs to be solved is how to obtain materials with the required magnetic properties while further reducing the amount of heavy rare earth elements used. Summary of the Invention

[0005] This invention aims to overcome the limitation of existing technologies where grain boundary diffusion materials cannot significantly improve the coercivity of NdFeB magnets. Instead, it provides a grain boundary diffusion material, a NdFeB magnet material, its preparation method, and its applications. The grain boundary diffusion material of this invention can significantly improve the coercivity of NdFeB magnets while maintaining high remanence and high-temperature stability of magnetic properties.

[0006] The present invention mainly solves the above technical problems through the following technical solutions.

[0007] This invention provides a grain boundary diffusion material, comprising a sintered body and a diffusion source;

[0008] The sintered body comprises the following components:

[0009] R: 29-32 wt.%, where R is a rare earth element;

[0010] M: 0.1–2 wt.%; M includes one or more of Cu, Ga, and Co;

[0011] B: 0.9–1.0 wt.%;

[0012] Fe: 65-70 wt.%, where wt.% is the percentage of the mass of each component in the sintered body to the total mass of the sintered body;

[0013] The diffusion source comprises the following components:

[0014] Tb: 60-85 wt.%;

[0015] Ga: 10-30 wt.%;

[0016] Cu: 5-20 wt.%, where wt.% is the percentage of the mass of each component in the diffusion source to the total mass of the diffusion source.

[0017] In this invention, the content of R in the sintered body is preferably 29 to 31.5 wt.%, for example 29.2 wt.%, 30 wt.%, or 31.2 wt.%.

[0018] In this invention, the R in the sintered body can be conventional in the art, and generally contains at least the light rare earth element LR.

[0019] The LR mentioned above includes, for example, Nd and / or Pr.

[0020] When the LR contains Nd, the Nd content can be conventional in the art, preferably 23-32 wt.%, for example 25 wt.%, 25.2 wt.%, or 26.5 wt.%.

[0021] When the LR contains Pr, the content of Pr can be conventional in the art, preferably less than 10 wt.%, for example 3%, 3.34 wt.%, or 6 wt.%.

[0022] In this invention, the R in the sintered body preferably also contains the heavy rare earth element HR.

[0023] The types of HR can be conventional in the art, such as including Dy and / or Tb.

[0024] When the HR contains Dy, the content of Dy is preferably less than 1.5 wt.%, for example 0.1 wt.%, 0.2 wt.%, or 1 wt.%.

[0025] In this invention, the content of B is preferably 0.9 to 0.99 wt.%, for example 0.91 wt.%, 0.95 wt.%, or 0.98 wt.%.

[0026] In this invention, those skilled in the art will understand that the Fe content is generally the difference between the total mass of the sintered body and the total mass content of the other elements (R, M, and B) in the sintered body. The Fe content is preferably 65–70 wt.%, for example, 65.99 wt.%, 67.55 wt.%, or 69.02 wt.%.

[0027] In this invention, the content of M in the sintered body is preferably 0.5 to 1.9 wt.%, for example 0.8 wt.% or 1.5 wt.%.

[0028] In this invention, when M in the sintered body contains Cu, the content of Cu is preferably 0.1 to 1 wt.%, for example 0.2 wt.%, 0.4 wt.%, or 0.5 wt.%.

[0029] In this invention, when M in the sintered body contains Ga, the content of Ga is preferably 0.1 to 1 wt.%, for example 0.2 wt.%, 0.4 wt.%, or 0.5 wt.%.

[0030] In this invention, when M in the sintered body contains Co, the content of Co is preferably 0.1 to 1 wt.%, for example 0.3 wt.%, 0.5 wt.%, or 0.9 wt.%.

[0031] In this invention, the M in the sintered body may also include other additive elements conventional in the art, such as one or more of Al, Zr and Ti.

[0032] Wherein, when M contains Al, the content of Al can be 0.05 to 0.2 wt.%, for example 0.1 wt.%.

[0033] Wherein, when M contains Zr, the Zr content can be 0.05 to 0.5 wt.%, for example 0.1 wt.%.

[0034] Wherein, when M contains Ti, the Ti content can be 0.05 to 0.5 wt.%, for example 0.1 wt.%.

[0035] In a specific embodiment of the present invention, the sintered body is composed of the following components: Nd 25 wt.%, Pr 6 wt.%, Dy 0.2 wt.%, Fe 65.99 wt.%, Co 0.9 wt.%, Cu 0.4 wt.%, Ga 0.5 wt.%, Zr 0.1 wt.%, and B 0.91 wt.%, where wt.% is the percentage of the mass of each component to the total mass of the sintered body.

[0036] In a specific embodiment of the present invention, the sintered body is composed of the following components: Nd 25.2 wt.%, Pr 3 wt.%, Dy 1 wt.%, Fe 69.02 wt.%, Co 0.3 wt.%, Cu 0.2 wt.%, Ga 0.2 wt.%, Ti 0.1 wt.%, and B 0.98 wt.%, where wt.% is the percentage of the mass of each component to the total mass of the sintered body.

[0037] In a specific embodiment of the present invention, the sintered body is composed of the following components: Nd 26.5 wt.%, Pr 3 wt.%, Dy 0.1 wt.%, Fe 67.55 wt.%, Al 0.1 wt.%, Co 0.5 wt.%, Cu 0.5 wt.%, Ga 0.4 wt.%, and B 0.95 wt.%, where wt.% is the percentage of the mass of each component to the total mass of the sintered body.

[0038] In this invention, the percentage of the mass of the diffusion source to the mass of the sintered body can be added according to the actual situation, generally above 0.05 wt.%, preferably 0.1 to 5 wt.%, for example 0.5 wt.%, 1 wt.%, 1.5 wt.%, 2 wt.%, or 3 wt.%.

[0039] In this invention, the percentage of the total mass of Tb, Ga, and Cu in the diffusion source to the total mass of the diffusion source is preferably above 80 wt.%, for example, 95 wt.% or 100 wt.%.

[0040] In this invention, the Tb content in the diffusion source is preferably 60-80 wt.%, for example 70 wt.%.

[0041] In this invention, the content of Ga in the diffusion source is preferably 10-15 wt.%.

[0042] In this invention, the Cu content in the diffusion source is preferably 5-10 wt.%.

[0043] In this invention, the diffusion source preferably does not contain the rare earth element LR.

[0044] The types of LR include, for example, Pr and / or Nd.

[0045] In this invention, the diffusion source may further include Dy.

[0046] When the diffusion source contains Dy, the content of Dy is preferably less than 10 wt.% but not 0 wt.%, for example 5 wt.%, where wt.% refers to the percentage of the total mass of the diffusion source.

[0047] In this invention, the diffusion source may further include Fe.

[0048] Wherein, when the diffusion source contains Fe, the content of Fe is preferably less than 10 wt.% but not 0 wt.%, for example 5 wt.%, where wt.% refers to the percentage of the total mass of the diffusion source.

[0049] In one specific embodiment of the present invention, the diffusion source is composed of the following components: 60 wt.% Tb, 10 wt.% Cu and 30 wt.% Ga, where wt.% is the percentage of the mass of each component to the total mass of the diffusion source.

[0050] In a specific embodiment of the present invention, the diffusion source is composed of the following components: Tb 70 wt.%, Cu 10 wt.%, Ga 15 wt.%, and Fe 5 wt.%, where wt.% is the percentage of the mass of each component to the total mass of the diffusion source.

[0051] In one specific embodiment of the present invention, the diffusion source is composed of the following components: 80 wt.% Tb, 5 wt.% Dy, 5 wt.% Cu and 10 wt.% Ga, where wt.% is the percentage of the mass of each component to the total mass of the diffusion source.

[0052] In a specific embodiment of the present invention, the diffusion source is composed of the following components: Tb 70 wt.%, Cu 10 wt.%, Ga 15 wt.%, and Fe 5 wt.%, where wt.% is the percentage of the mass of each component to the total mass of the diffusion source.

[0053] In this invention, the preparation process of the sintered body can be conventional in the art, generally involving the raw material mixture prepared according to the composition of the sintered body being successively smelted, cast, micro-pulverized, magnetically formed and sintered.

[0054] As those skilled in the art will know, the raw material composition of the sintered body is substantially consistent with the composition of the final sintered body. Those skilled in the art can prepare the raw materials according to the required composition of the sintered body, taking into account the loss of rare earth elements during preparation. It should be noted that variations within a certain error range may occur during the preparation process.

[0055] The melting temperature is preferably below 1500°C, for example, 1400-1500°C.

[0056] Preferably, the vacuum degree of the melting process is 5×10⁻⁶. -2 Pa.

[0057] The casting environment is, for example, an inert atmosphere, such as argon.

[0058] The ambient pressure for casting is, for example, 55,000 kPa.

[0059] In this process, after casting and before micro-pulverization, a rapid cooling treatment is generally performed to obtain a rapidly cooled alloy.

[0060] The cooling rate of the rapid cooling process is, for example, 10. 2 ℃ / sec -10 4 ℃ / second.

[0061] The micro-pulverization can be a conventional crushing process in the art, such as sequential hydrogen absorption, dehydrogenation and air jet milling.

[0062] The magnetic field strength for forming the magnetic field can be 1.5 to 2T, for example, 1.6T.

[0063] The sintering can be carried out under vacuum conditions, for example at 5 × 10⁻⁶. -3 The sintering is carried out under vacuum conditions of Pa, and the sintering temperature is preferably 1000-1100℃, for example 1030℃ or 1040℃.

[0064] The sintering time is, for example, 2.5 to 5 hours, such as 3 hours or 4 hours. For example, sintering at 1030°C for 3 hours, followed by sintering at 1040°C for 1 hour.

[0065] Preferably, before sintering and after forming, heat treatment is performed sequentially at temperatures of 300°C, 600°C, and 800°C.

[0066] After sintering, a cooling process is generally performed, which may involve cooling the sintered magnet material to 90-110°C, for example, 100°C; the cooling rate of the cooling process may be 10°C / min.

[0067] In this invention, the dimensions of the sintered body can be cut according to actual needs. For example, the length and width are 20mm, the thickness is 2mm, and the thickness direction is the magnetic field direction.

[0068] In this invention, the diffusion source is preferably an alloy powder formed from the components.

[0069] Preferably, the particle size D50 of the alloy powder is 1–10 μm.

[0070] This invention also provides a method for preparing neodymium iron boron magnet material, which includes the following steps:

[0071] The sintered body is subjected to grain boundary diffusion treatment;

[0072] The grain boundary diffusion treatment uses the aforementioned diffusion source; the temperature of the grain boundary diffusion treatment is 920–980°C.

[0073] In this invention, the temperature of the grain boundary diffusion treatment is preferably 930–970°C, for example 950°C.

[0074] In this invention, the time for the grain boundary diffusion treatment can be conventional in the art, and can be 2 to 8 hours, for example 3 hours or 4 hours.

[0075] In this invention, the grain boundary diffusion treatment preferably further includes a secondary grain boundary diffusion treatment, and the temperature of the secondary grain boundary diffusion treatment is preferably 850-920°C, for example 880-900°C.

[0076] The duration of the secondary grain boundary diffusion treatment is preferably 3 to 9 hours, for example, 4 hours, 6 hours or 8 hours.

[0077] In this invention, during the grain boundary diffusion process, the diffusion source is preferably diffused by coating or PVD.

[0078] In this invention, after the grain boundary diffusion treatment, a tempering treatment is generally also included.

[0079] The tempering temperature is preferably 440–600°C, for example, 500°C.

[0080] The tempering process can last for 2 to 4 hours, for example, 3 hours.

[0081] The vacuum degree of the tempering process is, for example, 9 × 10⁻⁶. -3 Pa.

[0082] The present invention also provides a neodymium iron boron magnet material, which is prepared by the aforementioned preparation method.

[0083] The present invention also provides a neodymium iron boron magnet material, which comprises the following components:

[0084] R: 29-32 wt.%, where R is a rare earth element;

[0085] M: 0.1–2.5 wt.%; M includes one or more of Cu, Ga, and Co;

[0086] B: 0.9–1.0 wt.%;

[0087] Fe: 65-70 wt.%, where wt.% is the percentage of the mass of each component to the total mass of the NdFeB magnet material; M includes at least Cu and Ga, and the NdFeB magnet material also includes Tb;

[0088] The NdFeB magnet material contains a TbCuGa phase in its grain boundary phase, wherein the molar ratio of Tb:Cu:Ga in the TbCuGa phase is 1:(8-9.6):(8.5-9.5); and the area of ​​the TbCuGa phase accounts for 1-8% of the total area of ​​the grain boundary phase.

[0089] In this invention, the area of ​​the TbCuGa phase in the NdFeB magnet material is generally determined by selecting the area of ​​the TbCuGa phase in the measured vertical orientation plane during actual measurement. The total area of ​​the grain boundary phase is equivalent to the total area of ​​the grain boundary phase in the selected vertical orientation plane during actual measurement. Therefore, the area ratio of the TbCuGa phase in the measured grain boundary phase of the vertical orientation plane is equivalent to the ratio of the area of ​​the TbCuGa phase to the total area of ​​the grain boundary phase in the NdFeB magnet material.

[0090] In this invention, the molar ratio of Tb:Cu:Ga in the TbCuGa phase is preferably 1:(8-9.5):(8.5-9.5), for example 1.11:9.86:10.52, 1.24:10.58:10.62 or 1.25:10.45:11.04.

[0091] In this invention, the percentage of the area of ​​the TbCuGa phase to the total area of ​​the grain boundary phase is preferably 1.6% to 7.5%, for example 4.5%, 6.3% or 7.2%.

[0092] In this invention, the content of R is preferably 29.5 to 31.5 wt.%, for example 29.64 wt.%, 29.88 wt.%, 30.3 wt.%, or 31.62 wt.%.

[0093] In this invention, R can be conventional in the art, and generally contains at least the light rare earth element LR.

[0094] The LR includes, for example, Nd and / or Pr.

[0095] When the LR contains Nd, the Nd content can be conventional in the art, preferably 23 to 32 wt.%, for example 24.95 wt.%, 25.01 wt.%, 25.15 wt.%, or 26.46 wt.%, where wt.% is the percentage of the total mass of the NdFeB magnet material.

[0096] When the LR contains Pr, the content of Pr can be conventional in the art, preferably less than 10 wt.%, for example 2.75 wt.%, 2.83 wt.%, 3.34 wt.%, or 5.89 wt.%, where wt.% is the percentage of the total mass of the NdFeB magnet material.

[0097] In this invention, R preferably also includes HR, where HR is a heavy rare earth element.

[0098] Preferably, the content of HR is less than 2 wt.%, for example, 0.5 wt.%, 0.78 wt.%, 1.88 wt.%, or 1.9 wt.%, where wt.% is the percentage of the total mass of the NdFeB magnet material.

[0099] Those skilled in the art, based on the aforementioned NdFeB magnet material, will know that the HR generally also contains Tb. The Tb content is preferably below 2 wt.%, for example, 0.2 wt.%, 0.39 wt.%, 0.58 wt.%, 0.9 wt.%, 0.91 wt.%, or 1 wt.%, where wt.% is the percentage of the total mass of the NdFeB magnet material.

[0100] The HR may also include Dy.

[0101] When the HR contains Dy, the content of Dy is preferably less than 1.5 wt.%, for example 0.11 wt.%, 0.2 wt.%, 0.98 wt.%, or 0.99 wt.%, where wt.% is the percentage of the total mass of the NdFeB magnet material.

[0102] In this invention, the content of B is preferably 0.9 to 0.99 wt.%, for example 0.91 wt.%, 0.94 wt.%, or 0.98 wt.%.

[0103] In this invention, those skilled in the art will understand that the Fe content is generally the difference between the total mass of the sintered body and the total mass content of the other elements (R, M, and B) in the sintered body. The Fe content is preferably 65–70 wt.%, for example, 65.39 wt.%, 67.14 wt.%, 68.12 wt.%, or 68.39 wt.%.

[0104] In this invention, the content of M is preferably 0.5 to 2 wt.%, for example 0.96 wt.%, 0.99 wt.%, 1.54 wt.%, or 1.99 wt.%.

[0105] In this invention, when M contains Cu, the content of Cu is preferably 0.1 to 1 wt.%, for example 0.34 wt.%, 0.35 wt.%, 0.46 wt.%, or 0.52 wt.%, where wt.% is the percentage of the total mass of the NdFeB magnet material.

[0106] In this invention, when M contains Ga, the content of Ga is preferably 0.1 to 1 wt.%, for example 0.23 wt.%, 0.25 wt.%, 0.41 wt.%, or 0.54 wt.%, where wt.% is the percentage of the total mass of the neodymium iron boron magnet material.

[0107] In this invention, when M contains Co, the content of Co is preferably 0.1 to 1 wt.%, for example 0.29 wt.%, 0.3 wt.%, 0.49 wt.%, or 0.9 wt.%, where wt.% is the percentage of the total mass of the NdFeB magnet material.

[0108] In this invention, M may also include other additive elements conventional in the art, such as one or more of Al, Zr and Ti.

[0109] Wherein, when M contains Al, the content of Al can be 0.01 to 0.2 wt.%, for example 0.11 wt.% or 0.12 wt.%, where wt.% is the percentage of the total mass of the NdFeB magnet material.

[0110] Wherein, when M contains Zr, the Zr content can be 0.05 to 0.5 wt.%, for example 0.09 wt.%, where wt.% is the percentage of the total mass of the NdFeB magnet material.

[0111] Wherein, when M contains Ti, the Ti content can be 0.05 to 0.5 wt.%, for example 0.09 wt.% or 0.1 wt.%, where wt.% is the percentage of the total mass of the NdFeB magnet material.

[0112] In a specific embodiment of the present invention, the neodymium iron boron magnet material is composed of the following components: Nd 24.95 wt.%, Pr 5.89 wt.%, Dy 0.2 wt.%, Tb 0.58 wt.%, Fe 65.39 wt.%, Co 0.9 wt.%, Cu 0.46 wt.%, Ga 0.54 wt.%, Zr 0.09 wt.%, and B 0.91 wt.%, where wt.% is the percentage of the mass of each component to the total mass of the neodymium iron boron magnet material. The grain boundary phase of the neodymium iron boron magnet material contains a TbCuGa phase, wherein the molar ratio of Tb:Cu:Ga in the TbCuGa phase is 1.11:9.86:10.52, and the area of ​​the TbCuGa phase accounts for 4.5% of the total area of ​​the grain boundary phase.

[0113] In a specific embodiment of the present invention, the neodymium iron boron magnet material is composed of the following components: Nd 25.15 wt.%, Pr 2.83 wt.%, Dy 0.99 wt.%, Tb 0.91 wt.%, Fe 68.12 wt.%, Co 0.29 wt.%, Cu 0.35 wt.%, Ga 0.25 wt.%, Ti 0.1 wt.%, and B 0.98 wt.%, where wt.% is the percentage of the mass of each component to the total mass of the neodymium iron boron magnet material. The grain boundary phase of the neodymium iron boron magnet material contains a TbCuGa phase, wherein the molar ratio of Tb:Cu:Ga in the TbCuGa phase is 1.24:10.58:10.62, and the area of ​​the TbCuGa phase accounts for 6.3% of the total area of ​​the grain boundary phase.

[0114] In a specific embodiment of the present invention, the neodymium iron boron magnet material is composed of the following components: Nd 26.46 wt.%, Pr 3.34 wt.%, Dy 0.11 wt.%, Tb 0.39 wt.%, Fe 67.14 wt.%, Al 0.12 wt.%, Co 0.49 wt.%, Cu 0.52 wt.%, Ga 0.41 wt.%, and B 0.94 wt.%, where wt.% is the percentage of the mass of each component to the total mass of the neodymium iron boron magnet material. The grain boundary phase of the neodymium iron boron magnet material contains a TbCuGa phase, wherein the molar ratio of Tb:Cu:Ga in the TbCuGa phase is 1.25:10.45:11.04, and the area of ​​the TbCuGa phase accounts for 7.2% of the total area of ​​the grain boundary phase.

[0115] In a specific embodiment of the present invention, the neodymium iron boron magnet material is composed of the following components: Nd 25.01 wt.%, Pr 2.75 wt.%, Dy 0.98 wt.%, Tb 0.9 wt.%, Fe 68.39 wt.%, Co 0.3 wt.%, Cu 0.34 wt.%, Ga 0.23 wt.%, Ti 0.09 wt.%, and B 0.99 wt.%, where wt.% is the percentage of the mass of each component to the total mass of the neodymium iron boron magnet material. The grain boundary phase of the neodymium iron boron magnet material contains a TbCuGa phase, wherein the molar ratio of Tb:Cu:Ga in the TbCuGa phase is 1.29:12.26:11.81, and the area of ​​the TbCuGa phase accounts for 1.6% of the total area of ​​the grain boundary phase.

[0116] This invention also provides an application of neodymium iron boron magnet material as an electronic component in an electric motor.

[0117] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0118] The reagents and raw materials used in this invention are all commercially available.

[0119] The positive and progressive effects of this invention are as follows: When using the sintered body and diffusion source of this invention for grain boundary diffusion, a Tb1Cu(8~9.6)Ga(8.5~9.5) phase can be formed in the grain boundary phase. This phase is uniformly distributed along the grain boundary, which can lower the melting point of the grain boundary phase, has good wettability, makes the grain boundary uniform and continuous, and consumes less Tb, which can make the Tb element diffuse deeper and be utilized more effectively. Thus, it can significantly improve the coercivity of the NdFeB magnet material while maintaining the remanence basically unchanged. Attached Figure Description

[0120] Figure 1 This is a microstructure diagram of the neodymium iron boron magnet material in Example 2.

[0121] Figure 2 This is a microstructure diagram of the neodymium iron boron magnet material in Comparative Example 2. Detailed Implementation

[0122] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0123] Example 1

[0124] (1) Preparation of sintered body

[0125] ① Melting and casting: Mix the raw materials required for the sintered body according to the formula in Table 1, and heat them in a high-frequency vacuum induction furnace at 5×10⁻⁶ ℃. -2 Vacuum melting is performed in a vacuum of Pa at a temperature below 1500℃. After vacuum melting, Ar gas is introduced into the furnace to achieve a pressure of 55,000 kPa, followed by casting, and then... 2 ℃ / sec -10 4 A rapidly cooled alloy is obtained by a cooling rate of ℃ / second.

[0126] ② Micronization: At room temperature, the hydrogen pulverizing furnace containing the rapidly cooled alloy is evacuated, and then hydrogen gas with a purity of 99.9% is introduced into the hydrogen pulverizing furnace to maintain a hydrogen pressure of 0.1 MPa; after sufficient hydrogen absorption, the temperature is increased while evacuating the furnace to fully dehydrogenate the alloy; then the furnace is cooled and the hydrogen-pulverized powder is taken out.

[0127] Fine powder was obtained by air jet milling of the hydrogen-oxidized powder for 3 hours under a nitrogen atmosphere with an oxidizing gas content of less than 150 ppm and a grinding chamber pressure of 0.38 MPa. Oxidizing gas refers to oxygen or moisture.

[0128] Zinc stearate is added to the powder after it has been pulverized by an air jet mill. The amount of zinc stearate added is 0.12% of the weight of the mixed powder, and then it is thoroughly mixed with a V-type mixer.

[0129] ③ Molding: A right-angle orientation magnetic field molding machine is used, in an orientation magnetic field of 1.6T and at 0.35ton / cm 2 Under molding pressure, the powder with added zinc stearate was molded into a cube with a side length of 25 mm in one step, and then demagnetized in a magnetic field of 0.2 T after molding.

[0130] ④ Sintering: Transfer each molded part to a sintering furnace for sintering at 5×10⁻⁶ ℃. -3 After being sintered under vacuum for 1 hour each at 300℃, 600℃, and 800℃, the mixture was sintered at 1030℃ for 3 hours, then sintered at 1040℃ for 1 hour. After that, Ar gas was introduced to bring the pressure to 0.1MPa, and then the mixture was cooled to 100℃ at a cooling rate of 10℃ / min.

[0131] (2) Preparation of neodymium iron boron magnet materials

[0132] Prepare the diffusion source according to the formula in Table 1 below.

[0133] The sintered body obtained above was processed into magnets with a length and width of 20 mm and a thickness of 2 mm, with the thickness direction aligned with the magnetic field orientation. After surface cleaning, a diffusion source was coated onto the surface of the sintered body. The coated magnets were dried, and then diffused in a high-purity Ar atmosphere according to the diffusion process in Table 2. After treatment, the magnets were cooled to room temperature. The diffusion source was coated in the form of alloy powder with a D50 particle size of 1–10 μm.

[0134] The diffusion-treated magnet was placed in a 9×10 -3 Under a vacuum of Pa, the neodymium iron boron magnet material is obtained by tempering at 500°C for 3 hours and then cooling to room temperature.

[0135] Table 1

[0136]

[0137]

[0138] Note: wt.% in sintered body refers to the percentage of the mass of each component to the total mass of sintered body; wt.% in diffusion source refers to the percentage of the mass of each component to the total mass of diffusion source.

[0139] Table 2

[0140]

[0141] Note: The first-level grain boundary diffusion treatment refers to the grain boundary diffusion treatment within the temperature range of 920 to 980°C as described above; the second-level grain boundary diffusion treatment refers to the secondary grain boundary diffusion treatment within the temperature range of 850 to 920°C as described above.

[0142] Example 1

[0143] 1. Composition determination of neodymium iron boron magnet materials

[0144] The compositions of the sintered bodies and NdFeB magnet materials in Examples 1-4 and Comparative Examples 1-4 were determined using high-frequency inductively coupled plasma optical emission spectrometry (ICP-OES). The compositional test results of the sintered bodies in Examples 1-4 and Comparative Examples 1-4 are shown in Table 3 below. The compositional test results of the NdFeB magnet materials in Examples 1-4 and Comparative Examples 1-4 are shown in Table 4 below.

[0145] Table 3

[0146] wt.% Nd Pr Dy Fe Al Co Cu Ga Zr Ti B Example 1 24.97 5.89 0.21 65.76 0.01 0.91 0.39 0.49 0.09 0.91 Example 2 25.21 2.96 1.01 68.92 0.01 0.29 0.21 0.19 0.1 0.98 Example 3 26.47 3.34 0.09 67.39 0.12 0.49 0.5 0.39 0.94 Example 4 25.21 2.96 1.01 68.92 0.01 0.29 0.21 0.19 0.1 0.98 Comparative Example 1 24.97 5.89 0.21 65.76 0.01 0.91 0.39 0.49 0.09 0.91 Comparative Example 2 25.21 2.96 1.01 68.92 0.01 0.29 0.21 0.19 0.1 0.98 Comparative Example 3 26.47 3.34 0.09 67.39 0.12 0.49 0.5 0.39 0.94 Comparative Example 4 24.94 5.94 0.19 65.39 0.01 1.5 0.4 0.51 0.1 0.8

[0147] Note: wt.% is the percentage of the mass of each element to the total mass of the sintered body. Those skilled in the art will understand that the content of each element in the raw material composition of the sintered body may vary slightly during the preparation process, but all are within the error range. The Al content increases slightly, mainly due to the introduction of a small amount of Al during melting in an aluminum crucible.

[0148] Table 4

[0149] wt.% Nd Pr Dy Tb Fe Al Co Cu Ga Zr Ti B Example 1 24.95 5.89 0.2 0.58 65.39 0.9 0.46 0.54 0.09 0.91 Example 2 25.15 2.83 0.99 0.91 68.12 0.29 0.35 0.25 0.1 0.98 Example 3 26.46 3.34 0.11 0.39 67.14 0.12 0.49 0.52 0.41 0.94 Example 4 25.01 2.75 0.98 0.9 68.39 0.3 0.34 0.23 0.09 0.99 Comparative Example 1 24.95 5.96 0.22 0.57 65.43 0.9 0.44 0.52 0.09 0.9 Comparative Example 2 25.16 2.85 0.98 0.74 68.15 0.3 0.32 0.32 0.09 0.99 Comparative Example 3 26.41 3.32 0.14 0.4 67.24 0.11 0.5 0.51 0.41 0.95 Comparative Example 4 24.91 5.81 0.19 0.58 65.01 1.5 0.49 0.54 0.1 0.8

[0150] Note: wt.% represents the percentage of each element's mass to the total mass of the NdFeB magnet material. It should be noted that rare earth element loss is unavoidable during sintering, and some diffusion sources are inevitably lost during grain boundary diffusion. Furthermore, due to unavoidable impurities in the NdFeB magnet material and testing errors, the total mass of elements in the examples and comparative examples in Table 4 is less than 100%.

[0151] 2. Magnetic property test

[0152] The sintered bodies and NdFeB magnet materials in Examples 1-4 and Comparative Examples 1-4 were tested for their magnetic properties using a PFM pulse demagnetization curve testing device. The test results are shown in Table 5 below.

[0153] Where α refers to the remanence temperature coefficient of the magnet between 20-100℃, and β refers to the coercivity temperature coefficient of the magnet between 20-100℃. Their calculation formulas are shown below:

[0154]

[0155]

[0156] Wherein, ΔHcj refers to the value obtained by subtracting the coercivity of the corresponding pre-diffusion sintered body from the coercivity of the neodymium iron boron magnet materials prepared in Examples 1-4 and Comparative Examples 1-4.

[0157] Table 5

[0158]

[0159] 3. Characterization of microstructure

[0160] The vertical orientation surfaces of the NdFeB magnet materials in Examples 1-4 and Comparative Examples 1-4 were polished and analyzed using a field emission electron probe microanalysis (FE-EPMA) system (JEOL, 8530F). A TbCuGa phase was observed at depths of 0-300 μm from the diffusion surface (the surface coated with the diffusion source during the NdFeB magnet material process), with a molar ratio of Tb, Cu, and Ga of 1:(8-9.6):(8.5-9.5). The content of Tb, Cu, and Ga elements at the grain boundaries in the NdFeB magnet materials was determined by single-point quantitative analysis using FE-EPMA under the following conditions: accelerating voltage 15 kV and probe beam current 50 nA.

[0161] Next, using Image Pro software, the percentage of the area of ​​the TbCuGa phase in the vertically oriented planes selected and tested in Examples 1-4 and Comparative Examples 1-4 to the total area of ​​the grain boundary phase in the vertically oriented planes was tested and calculated, i.e., the area ratio of the TbCuGa phase in Table 6. The test results are shown in Table 6 below.

[0162] Table 6

[0163]

[0164] Combining the experimental data in Tables 3 and 4, it can be seen that this application, through a formulation with a specific content of grain boundary material, and after sintering and diffusion treatment, forms a specific TbCuGa phase in the grain boundary phase. This phase is uniformly distributed along the grain boundaries, which can lower the melting point of the grain boundary phase, has good wettability, makes the grain boundaries uniform and continuous, consumes less Tb, and allows for greater Tb element diffusion depth and more efficient utilization. Figure 1 and Figure 2 The comparison shows that the grain boundary phase of the NdFeB magnet material in the embodiments of this application is more uniform and continuous. If the grain boundary diffusion material of the present invention is not used, the coercivity of the NdFeB magnet material cannot be significantly improved. For example, the diffusion source of Comparative Example 1 contains an excessive amount of Pr element, the diffusion source of Comparative Example 2 has an excessively high Ga content, the diffusion source of Comparative Example 3 has a low Cu content, and the sintered body of Comparative Example 4 has an excessively low B content. None of these results in the formation of a specific TbCuGa phase in the grain boundary phase.

[0165] Meanwhile, the inventors also discovered that further optimization of the grain boundary diffusion process can significantly improve the magnetic properties of NdFeB magnet materials while consuming less Tb.

Claims

1. A method of producing a neodymium-iron-boron magnet material, characterized in that, It comprises the following steps: The sintered body is subjected to grain boundary diffusion treatment; The grain boundary diffusion treatment uses a diffusion source; The temperature of the grain boundary diffusion treatment is 920-980℃; The grain boundary diffusion treatment is followed by secondary grain boundary diffusion treatment, and the temperature of the secondary grain boundary diffusion treatment is 850-920℃; The sintered body comprises the following components: R: 29-32wt.%, the R being a rare earth element; M: 0.1-2wt.%; the M comprising one or more of Cu, Ga and Co; B: 0.9-1.0wt.%; Fe: 65-70wt.%, wt.% being the percentage of the mass of each component in the sintered body to the total mass of the sintered body; The diffusion source comprises the following components: Tb: 60-85wt.%; Ga: 10-30wt.%; Cu: 5-20wt.%, wt.% being the percentage of the mass of each component in the diffusion source to the total mass of the diffusion source; The diffusion source does not contain light rare earth element LR.

2. The method of producing a neodymium-iron-boron magnet material according to claim 1, characterized by, The content of the R is 29-31.5wt.%; And / or, in the sintered body, the R contains at least light rare earth element LR, and the LR comprises Nd and / or Pr; And / or, in the sintered body, the R further comprises heavy rare earth element HR, and the HR comprises Dy and / or Tb; And / or, in the sintered body, the content of the B is 0.9-0.99wt.%; And / or, in the sintered body, the content of the Fe is 65-70wt.%; And / or, in the sintered body, the content of the M is 0.5-1.9wt.%; And / or, the M further comprises one or more of Al, Zr and Ti; And / or, the percentage of the mass of the diffusion source to the mass of the sintered body is 0.05wt.% or more; And / or, the percentage of the total mass of the Tb, the Ga and the Cu in the diffusion source to the total mass of the diffusion source is 80wt.% or more; And / or, the diffusion source further comprises Dy; And / or, the diffusion source further comprises Fe.

3. The method of producing a neodymium-iron-boron magnet material according to claim 2, characterized in that, The content of the R is 29.2wt.%, 30wt.% or 31.2wt.%.

4. The method of producing a neodymium-iron-boron magnet material according to claim 2, characterized by, In the sintered body, when the LR contains Nd, the content of the Nd is 23-32wt.%, wt.% being the percentage of the total mass of the sintered body.

5. The method of producing a neodymium-iron-boron magnet material according to claim 4, characterized in that, The content of the Nd is 25wt.%, 25.2wt.% or 26.5wt.%.

6. The method of producing a neodymium-iron-boron magnet material according to claim 2, wherein In the sintered body, when the LR contains Pr, the content of the Pr is 10wt.% or less, wt.% being the percentage of the total mass of the sintered body.

7. The method of producing a neodymium-iron-boron magnet material according to claim 6, characterized in that, The content of the Pr is 3wt.%, 3.34wt.% or 6wt.%.

8. The method of producing a neodymium-iron-boron magnet material according to claim 2, wherein When the HR contains Dy, the content of the Dy is 1.5wt.% or less, wt.% being the percentage of the total mass of the sintered body.

9. The method of producing a neodymium-iron-boron magnet material according to claim 8, characterized in that, The content of the Dy is 0.1wt.%, 0.2wt.% or 1wt.%.

10. The method of producing a neodymium-iron-boron magnet material according to claim 2, wherein In the sintered body, the content of the B is 0.91wt.%, 0.95wt.% or 0.98wt.%.

11. The method of producing a neodymium-iron-boron magnet material according to claim 2, characterized by, The content of Fe in the sintered body is 65.99 wt.%, 67.55 wt.% or 69.02 wt.%.

12. The method of producing a neodymium-iron-boron magnet material according to claim 2, characterized by, The content of M in the sintered body is 0.8 wt.% or 1.5 wt.%.

13. The method of producing a neodymium-iron-boron magnet material according to claim 2, wherein When M contains Cu, the content of Cu in the sintered body is 0.1-1 wt.%, and wt.% is the percentage of the total mass of the sintered body.

14. The method of producing a neodymium-iron-boron magnet material according to claim 13, characterized by, The content of Cu is 0.2 wt.%, 0.4 wt.% or 0.5 wt.%.

15. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, When M contains Ga, the content of Ga in the sintered body is 0.1-1 wt.%, and wt.% is the percentage of the total mass of the sintered body.

16. The method of producing a neodymium-iron-boron magnet material according to claim 15, characterized by, The content of Ga is 0.2 wt.%, 0.4 wt.% or 0.5 wt.%.

17. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, When M contains Co, the content of Co in the sintered body is 0.1-1 wt.%, and wt.% is the percentage of the total mass of the sintered body.

18. The method of producing a neodymium-iron-boron magnet material according to claim 17, characterized by, The content of Co is 0.3 wt.%, 0.5 wt.% or 0.9 wt.%.

19. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, When Al is contained in M, the content of Al is 0.05-0.2 wt.%, and wt.% is the percentage of the total mass of the sintered body.

20. The method of producing a neodymium-iron-boron magnet material according to Claim 19, characterized by, The content of Al is 0.1 wt.%.

21. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, When Zr is contained in M, the content of Zr is 0.05-0.5 wt.%, and wt.% is the percentage of the total mass of the sintered body.

22. The method of making a neodymium-iron-boron magnet material of claim 21, wherein, The content of Zr is 0.1 wt.%.

23. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, When Ti is contained in M, the content of Ti is 0.05-0.5 wt.%, and wt.% is the percentage of the total mass of the sintered body.

24. The method of producing a neodymium-iron-boron magnet material according to Claim 23, characterized by, The content of Ti is 0.1 wt.%.

25. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, The percentage of the mass of the diffusion source to the mass of the sintered body is 0.1-5 wt.%.

26. The method of producing a neodymium-iron-boron magnet material according to claim 25, wherein The percentage of the mass of the diffusion source to the mass of the sintered body is 0.5 wt.%, 1 wt.%, 1.5 wt.%, 2 wt.% or 3 wt.%.

27. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, The percentage of the total mass of Tb, Ga and Cu in the diffusion source to the total mass of the diffusion source is 95 wt.% or 100 wt.%.

28. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, The content of Tb in the diffusion source is 60-80 wt.%.

29. The method of making a neodymium-iron-boron magnet material of claim 28, wherein, The content of Tb in the diffusion source is 70 wt.%.

30. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, The content of Ga in the diffusion source is 10-15 wt.%.

31. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, The content of Cu in the diffusion source is 5-10 wt.%.

32. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, When Dy is contained in the diffusion source, the content of Dy is 10 wt.% or less but not 0 wt.%, and wt.% refers to the percentage of the total mass of the diffusion source.

33. The method of making a neodymium-iron-boron magnet material of claim 32, wherein, The content of Dy is 5 wt.%.

34. The method of making a neodymium-iron-boron magnet material of claim 2, wherein, When Fe is contained in the diffusion source, the content of Fe is 10 wt.% or less but not 0 wt.%, and wt.% refers to the percentage of the total mass of the diffusion source.

35. The method of making a neodymium-iron-boron magnet material of claim 34, wherein, When Fe is contained in the diffusion source, the content of Fe is 5 wt.%.

36. The method of making a neodymium-iron-boron magnet material of claim 1, wherein, The sintered body is composed of the following components: Nd 25wt.%, Pr 6wt.%, Dy 0.2wt.%, Fe 65.99wt.%, Co 0.9wt.%, Cu 0.4wt.%, Ga 0.5wt.%, Zr 0.1wt.% and B 0.91wt.%, wt.% being the percentage of the mass of each component to the total mass of the sintered body; Or, the sintered body is composed of the following components: Nd 25.2wt.%, Pr 3wt.%, Dy 1wt.%, Fe 69.02wt.%, Co 0.3wt.%, Cu 0.2wt.%, Ga 0.2wt.%, Ti 0.1wt.% and B 0.98wt.%, wt.% being the percentage of the mass of each component to the total mass of the sintered body; Or, the sintered body is composed of the following components: Nd 26.5wt.%, Pr 3wt.%, Dy 0.1wt.%, Fe 67.55wt.%, Al 0.1wt.%, Co 0.5wt.%, Cu 0.5wt.%, Ga 0.4wt.% and B 0.95wt.%, wt.% being the percentage of the mass of each component to the total mass of the sintered body; And / or, the diffusion source is composed of the following components: Tb 60wt.%, Cu 10wt.% and Ga 30wt.%, wt.% being the percentage of the mass of each component to the total mass of the diffusion source; Or, the diffusion source is composed of the following components: Tb 70wt.%, Cu 10wt.%, Ga 15wt.% and Fe 5wt.%, wt.% being the percentage of the mass of each component to the total mass of the diffusion source; Or, the diffusion source is composed of the following components: Tb 80wt.%, Dy 5wt.%, Cu 5wt.% and Ga 10wt.%, wt.% being the percentage of the mass of each component to the total mass of the diffusion source; Or, the diffusion source is composed of the following components: Tb 70wt.%, Cu 10wt.%, Ga 15wt.% and Fe 5wt.%, wt.% being the percentage of the mass of each component to the total mass of the diffusion source.

37. The method of producing a neodymium-iron-boron magnet material according to any one of claims 1 to 36, wherein The preparation method of the sintered body comprises the following steps: sequentially subjecting the raw material composition prepared according to the component proportion of the sintered body to melting, casting, micro-pulverization, magnetic field forming and sintering; And / or, the diffusion source is in the form of alloy powder.

38. The method of making a neodymium-iron-boron magnet material of claim 37, wherein, The temperature of the melting is below 1500℃; and / or the vacuum level of the smelting is 5 x 10 -2 Pa; And / or, after the casting, before the micro-pulverization, quenching treatment is further carried out to obtain a quenched alloy; And / or, the micro-pulverization is sequentially subjected to hydrogen absorption, hydrogen desorption and air flow milling treatment; And / or, the magnetic field strength of the magnetic field forming is 1.5-2T; And / or, the temperature of the sintering is 1000-1100℃; And / or, the time of the sintering is 2.5-5h; And / or, before the sintering, after the forming, heat treatment is further carried out at 300℃, 600℃ and 800℃ respectively.

39. The method of making a neodymium-iron-boron magnet material of claim 38, wherein, The temperature of the melting is 1400-1500℃.

40. The method of making a neodymium-iron-boron magnet material of claim 38, wherein, The cooling rate of the quenching treatment is 10 2 °C / sec ~ 10 4 °C / sec.

41. The method of making a neodymium-iron-boron magnet material of claim 38, wherein, The magnetic field strength of the magnetic field shaping is 1.6T.

42. The method of making a neodymium-iron-boron magnet material of claim 38, wherein, The sintering temperature is 1030℃ or 1040℃.

43. The method of making a neodymium-iron-boron magnet material of claim 38, wherein, The sintering time is 3h or 4h.

44. The method of making a neodymium-iron-boron magnet material of claim 38, wherein, The sintering is sintering at 1030℃ for 3h and then sintering at 1040℃ for 1h.

45. The method of making a neodymium-iron-boron magnet material of claim 37, wherein, The particle size D50 of the alloy powder is 1-10μm.

46. The method of making a neodymium-iron-boron magnet material of claim 1, wherein, The grain boundary diffusion treatment time is 2-8h. The secondary grain boundary diffusion treatment temperature is 880-900℃. The secondary grain boundary diffusion treatment time is 3-9h. In the grain boundary diffusion treatment, the diffusion source is diffused by coating or PVD. After the grain boundary diffusion treatment, a tempering treatment is further included.

47. The method of making a neodymium-iron-boron magnet material of claim 46, wherein, The grain boundary diffusion treatment time is 3h or 4h.

48. The method of making a neodymium-iron-boron magnet material of claim 46, wherein, The secondary grain boundary diffusion treatment time is 4h, 6h or 8h.

49. The method of making a neodymium-iron-boron magnet material of claim 46, wherein, The tempering treatment temperature is 440-600℃.

50. The method of making a neodymium-iron-boron magnet material of claim 49, wherein, The tempering treatment temperature is 500℃.

51. The method of making a neodymium-iron-boron magnet material of claim 46, wherein, The tempering treatment time is 2-4h.

52. The method of making a neodymium-iron-boron magnet material of claim 51, wherein, The tempering treatment time is 3h.

53. The method of making a neodymium-iron-boron magnet material of claim 46, wherein, The vacuum degree of the tempering treatment is 9x10 -3 Pa.

54. A neodymium-iron-boron magnet material, characterized in that, The neodymium-iron-boron magnet material is prepared by the method of any one of claims 1-53.

55. A neodymium-iron-boron magnet material, characterized in that, It comprises the following components: R: 29-32wt.%, the R being a rare earth element; M: 0.1-2.5wt.%; the M including one or more of Cu, Ga and Co; B: 0.9-1.0wt.%; Fe: 65-70wt.%, wt.% being the percentage of the mass of each component to the total mass of the neodymium-iron-boron magnet material; the M at least including Cu and Ga, and the neodymium-iron-boron magnet material further including Tb; The grain boundary phase of the neodymium-iron-boron magnet material contains a TbCuGa phase, the molar ratio of Tb:Cu:Ga in the TbCuGa phase being 1:(8-9.6):(8.5-9.5); the ratio of the area of the TbCuGa phase to the total area of the grain boundary phase being 4.5-8%.

56. The neodymium-iron-boron magnet material of claim 55, wherein, The molar ratio of Tb:Cu:Ga in the TbCuGa phase is 1:(8-9.5):(8.5-9.5); And / or, the percentage of the area of the TbCuGa phase to the total area of the grain boundary phase is 4.5-7.5%; And / or, the content of the R is 29.5-31.5wt.%; And / or, the R at least contains a light rare earth element LR, the LR including Nd and / or Pr; And / or, the R further includes a heavy rare earth element HR; And / or, the content of the B is 0.9-0.99wt.%; And / or, the content of the Fe is 65-70wt.%; And / or, the content of the M is 0.5-2wt.%; And / or, the M further includes one or more of Al, Zr and Ti.

57. The neodymium-iron-boron magnet material of claim 56, wherein, The molar ratio of Tb:Cu:Ga in the TbCuGa phase is 1.11:9.86:10.52, 1.24:10.58:10.62 or 1.25:10.45:11.

04.

58. The neodymium-iron-boron magnet material of claim 56, wherein, The percentage of the area of the TbCuGa phase to the total area of the grain boundary phase is 6.3% or 7.2%.

59. The neodymium-iron-boron magnet material of claim 56, wherein, The content of R is 29.64 wt.%, 29.88 wt.%, 30.3 wt.% or 31.62 wt.%.

60. The neodymium-iron-boron magnet material of claim 56, wherein, When the LR contains Nd, the content of Nd is 23-32 wt.%, wt.% being the percentage of the total mass of the Nd-Fe-B magnet material.

61. The neodymium-iron-boron magnet material of claim 60, wherein, The content of Nd is 24.95 wt.%, 25.01 wt.%, 25.15 wt.% or 26.46 wt.%.

62. The neodymium-iron-boron magnet material of claim 56, wherein, When the LR contains Pr, the content of Pr is 10 wt.% or less, wt.% being the percentage of the total mass of the Nd-Fe-B magnet material.

63. The neodymium-iron-boron magnet material of claim 62, wherein, The content of Pr is 2.75 wt.%, 2.83 wt.%, 3.34 wt.% or 5.89 wt.%.

64. The neodymium-iron-boron magnet material of claim 56, wherein, The content of HR is 2 wt.% or less, wt.% being the percentage of the total mass of the Nd-Fe-B magnet material.

65. The neodymium-iron-boron magnet material of claim 64, wherein, The content of HR is 0.5 wt.%, 0.78 wt.%, 1.88 wt.% or 1.9 wt.%.

66. The neodymium-iron-boron magnet material of claim 56, wherein, The HR contains Tb, and the content of Tb is 2 wt.% or less, wt.% being the percentage of the total mass of the Nd-Fe-B magnet material.

67. The neodymium-iron-boron magnet material of claim 66, wherein, The content of Tb is 0.2 wt.%, 0.39 wt.%, 0.58 wt.%, 0.9 wt.%, 0.91 wt.% or 1 wt.%.

68. The neodymium-iron-boron magnet material of claim 56, wherein, The HR also contains Dy, and the content of Dy is 1.5 wt.% or less, wt.% being the percentage of the total mass of the Nd-Fe-B magnet material.

69. The neodymium-iron-boron magnet material of claim 68, wherein, The content of Dy is 0.11 wt.%, 0.2 wt.%, 0.98 wt.% or 0.99 wt.%.

70. The neodymium-iron-boron magnet material of claim 56, wherein, The content of B is 0.91 wt.%, 0.94 wt.% or 0.98 wt.%.

71. The neodymium-iron-boron magnet material of claim 56, wherein, The content of Fe is 65.39 wt.%, 67.14 wt.%, 68.12 wt.% or 68.39 wt.%.

72. The neodymium-iron-boron magnet material of claim 56, wherein, The content of M is 0.96 wt.%, 0.99 wt.%, 1.54 wt.% or 1.99 wt.%.

73. The neodymium-iron-boron magnet material of claim 56, wherein, When the M contains Cu, the content of Cu is 0.1-1 wt.%, wt.% being the percentage of the total mass of the Nd-Fe-B magnet material.

74. The neodymium-iron-boron magnet material of claim 73, wherein, The content of Cu is 0.34 wt.%, 0.35 wt.%, 0.46 wt.% or 0.52 wt.%.

75. The neodymium-iron-boron magnet material of claim 56, wherein, When the M contains Ga, the content of Ga is 0.1-1 wt.%, wt.% being the percentage of the total mass of the Nd-Fe-B magnet material.

76. The neodymium-iron-boron magnet material of claim 75, wherein, The content of Ga is 0.23 wt.%, 0.25 wt.%, 0.41 wt.% or 0.54 wt.%.

77. The neodymium-iron-boron magnet material of claim 56, wherein, When the M contains Co, the content of Co is 0.1-1 wt.%, wt.% being the percentage of the total mass of the Nd-Fe-B magnet material.

78. The neodymium-iron-boron magnet material of claim 77, wherein, The content of Co is 0.29 wt.%, 0.3 wt.%, 0.49 wt.% or 0.9 wt.%.

79. The neodymium-iron-boron magnet material of claim 56, wherein, When the M contains Al, the content of Al is 0.01-0.2 wt.%, wt.% being the percentage of the total mass of the Nd-Fe-B magnet material.

80. The neodymium-iron-boron magnet material of claim 79, wherein, The content of Al is 0.11wt.% or 0.12wt.%.

81. The neodymium-iron-boron magnet material of claim 56, wherein, When Zr is contained in M, the content of Zr is 0.05-0.5wt.% and wt.% is the percentage of the total mass of the Nd-Fe-B magnet material.

82. The neodymium-iron-boron magnet material of claim 81, wherein, The content of Zr is 0.09wt.%.

83. The neodymium-iron-boron magnet material of claim 56, wherein, When Ti is contained in M, the content of Ti is 0.05-0.5wt.% and wt.% is the percentage of the total mass of the Nd-Fe-B magnet material.

84. The neodymium-iron-boron magnet material of claim 83, wherein, The content of Ti is 0.09wt.% or 0.1wt.%.

85. The neodymium-iron-boron magnet material of any of claims 55-84, wherein, The Nd-Fe-B magnet material is composed of the following components: Nd 24.95wt.%, Pr 5.89wt.%, Dy 0.2wt.%, Tb 0.58wt.%, Fe 65.39wt.%, Co 0.9wt.%, Cu 0.46wt.%, Ga 0.54wt.%, Zr 0.09wt.% and B 0.91wt.%, wt.% is the percentage of the mass of each component to the total mass of the Nd-Fe-B magnet material; the grain boundary phase of the Nd-Fe-B magnet material contains a TbCuGa phase, the molar ratio of Tb:Cu:Ga in the TbCuGa phase is 1.11:9.86:10.52, and the percentage of the area of the TbCuGa phase to the total area of the grain boundary phase is 4.5%; Alternatively, the Nd-Fe-B magnet material is composed of the following components: Nd 25.15wt.%, Pr 2.83wt.%, Dy 0.99wt.%, Tb 0.91wt.%, Fe 68.12wt.%, Co 0.29wt.%, Cu 0.35wt.%, Ga 0.25wt.%, Ti 0.1wt.% and B 0.98wt.%, wt.% is the percentage of the mass of each component to the total mass of the Nd-Fe-B magnet material; the grain boundary phase of the Nd-Fe-B magnet material contains a TbCuGa phase, the molar ratio of Tb:Cu:Ga in the TbCuGa phase is 1.24:10.58:10.62, and the percentage of the area of the TbCuGa phase to the total area of the grain boundary phase is 6.3%; Alternatively, the Nd-Fe-B magnet material is composed of the following components: Nd 26.46wt.%, Pr 3.34wt.%, Dy 0.11wt.%, Tb 0.39wt.%, Fe 67.14wt.%, Al 0.12wt.%, Co 0.49wt.%, Cu 0.52wt.%, Ga 0.41wt.% and B 0.94wt.%, wt.% is the percentage of the mass of each component to the total mass of the Nd-Fe-B magnet material; the grain boundary phase of the Nd-Fe-B magnet material contains a TbCuGa phase, the molar ratio of Tb:Cu:Ga in the TbCuGa phase is 1.25:10.45:11.04, and the percentage of the area of the TbCuGa phase to the total area of the grain boundary phase is 7.2%.

86. Use of a neodymium-iron-boron magnet material as defined in any one of claims 54 to 85 as an electronic component in an electrical machine.

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