Neodymium-iron-boron magnet material, method for producing same, use thereof, electric machine

Abstract

The application discloses a neodymium-iron-boron magnet material and a preparation method, application and motor thereof. The neodymium-iron-boron magnet material comprises an amorphous RE-rich phase in a grain boundary phase, the element composition and atomic ratio of the amorphous RE-rich phase are TM:RE:Cu:Ga=(15-30):(40-60):(10-25):(10-30), and the volume ratio of the amorphous RE-rich phase in the grain boundary phase is 3-8%. TM is Fe and Co, and RE is a rare earth element. The neodymium-iron-boron magnet material can improve coercivity without using or using heavy rare earth elements, while maintaining high remanence and magnetic energy product.

Description

Technical Field

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

[0002] With Nd2Fe 14 Neodymium iron boron (RE-TB) permanent magnets, with boron as their main component, possess high remanence, coercivity, and maximum energy product, exhibiting excellent overall magnetic properties. They are widely used in high-tech fields such as computers, communications, and national defense. Motors are a major application area for NdFeB permanent magnets, with their application in hybrid electric vehicles (HEVs) being particularly noteworthy. Materials used in automobiles generally have a service life exceeding 10 years, thus requiring long-term stable and reliable performance. The performance of magnetic materials is generally characterized by four parameters: remanence (BRE), coercivity (Hcb), intrinsic coercivity (Hcj), and maximum energy product (BHmax). Extensive research has been conducted both domestically and internationally to further improve the magnetic properties of NdFeB permanent magnets.

[0003] Existing technologies include adding certain amounts of heavy rare earth elements Tb and Dy to sintered NdFeB master alloys to improve magnet coercivity. However, Tb and Dy are strategic metals with limited reserves and high prices, and while increasing coercivity, they sacrifice remanence and energy product. Currently, NdFeB magnets without heavy rare earth elements have an intrinsic coercivity of less than 19 kOe at a remanence of 14.0 kGs, less than one-third of the theoretical intrinsic coercivity of NdFeB. Therefore, how to improve the intrinsic coercivity of RE-TB permanent magnet materials without using or with minimal use of heavy rare earth elements, while ensuring remanence and energy product, is a problem that has been urgently needed to be solved in this field. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of existing technologies that improve coercivity by adding heavy rare earth elements, such as high cost, scarcity of raw materials, and reduced remanence and energy product. This invention provides neodymium iron boron (NdFeB) magnet materials, their preparation methods, applications, and motors. The NdFeB magnet material of this invention can improve coercivity without using heavy rare earth elements, while maintaining high remanence and energy product.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] This invention provides a neodymium iron boron magnet material comprising an amorphous RE-rich phase located at the grain boundary phase. The elemental composition and atomic ratio of the amorphous RE-rich phase are TM:RE:Cu:Ga = (15-30):(40-60):(10-25):(10-30). The amorphous RE-rich phase accounts for 3-8% of the volume of the grain boundary phase. TM represents Fe and Co, and RE represents rare earth elements.

[0007] The inventors discovered in their research that the presence of the amorphous RE-rich phase in this invention lowers the melting point of the grain boundary phase, improves the fluidity of the grain boundary phase, and facilitates the formation of a continuous and uniform intergranular Nd-rich phase. This enhances the demagnetizing coupling ability of the grain boundary phase and improves the intrinsic coercivity of the magnet.

[0008] In this invention, the term "grain boundary phase" can be interpreted in the conventional sense, generally referring to a two-grain grain boundary phase and an intergranular triangular region. The two-grain grain boundary phase is typically the grain boundary phase between two main phase grains.

[0009] In this invention, preferably, the atomic percentage of TM in the amorphous RE-rich phase is 15-30%, more preferably 15-25%, for example 16%, 17%, 18%, 19% or 25%.

[0010] In some preferred embodiments of the present invention, the TM is only Fe.

[0011] In this invention, preferably, the atomic percentage of RE in the amorphous RE-rich phase is 40-60%, more preferably 40-50%, for example 41%, 45%, 46%, 47%, 49% or 50%.

[0012] In this invention, preferably, the atomic percentage of Ga in the amorphous RE-rich phase is 10-20%, for example 11%, 12%, 14%, 16%, 18% or 19%.

[0013] In this invention, preferably, the atomic percentage of Cu in the amorphous RE-rich phase is 12-25%, for example 19%, 20%, 21%, 24% or 25%.

[0014] In some preferred embodiments of the present invention, the amorphous RE-rich phase is composed of Fe. 15～19 RE 45～50 Ga 12～ 19 Cu 19～21 The numbers represent the atomic percentage of each element in the amorphous RE-rich phase.

[0015] In some preferred embodiments of the present invention, the amorphous RE-rich phase is composed of Fe.18 RE 47 Ga 14 Cu 21 The numbers represent the percentage of atoms of each element.

[0016] In some preferred embodiments of the present invention, the amorphous RE-rich phase is composed of Fe. 15 RE 49 Ga 16 Cu 20 The numbers represent the percentage of atoms of each element.

[0017] In some preferred embodiments of the present invention, the amorphous RE-rich phase is composed of Fe. 25 RE 40 Ga 11 Cu 24 The numbers represent the percentage of atoms of each element.

[0018] In some preferred embodiments of the present invention, the amorphous RE-rich phase is composed of Fe. 16 RE 45 Ga 14 Cu 25 The numbers represent the percentage of atoms of each element.

[0019] In some preferred embodiments of the present invention, the amorphous RE-rich phase is composed of Fe. 17 RE 45 Ga 18 Cu 20 The numbers represent the percentage of atoms of each element.

[0020] In some preferred embodiments of the present invention, the amorphous RE-rich phase is composed of Fe. 19 RE 41 Ga 18 Cu 12 The numbers represent the percentage of atoms of each element.

[0021] In some preferred embodiments of the present invention, the amorphous RE-rich phase is composed of Fe. 16 RE 46 Ga 19 Cu 19 The numbers represent the percentage of atoms of each element.

[0022] In some preferred embodiments of the present invention, the amorphous RE-rich phase is composed of Fe. 17 RE 50 Ga 12 Cu 21 The numbers represent the percentage of atoms of each element.

[0023] In this invention, the amorphous RE-rich phase preferably accounts for 3.5% to 7% of the volume of the grain boundary phase, for example, 4.2%, 4.3%, 4.4%, 4.5%, 5.6%, 6.2%, or 6.5%.

[0024] In this invention, as will be readily understood by those skilled in the art, the neodymium iron boron magnet material generally further includes a main phase, the composition of which is generally RE2Fe. 14 B, where the numbers represent the atomic ratio of each element.

[0025] In this invention, the grain size of the neodymium iron boron magnet material can be conventional in the art, generally 5 to 10 μm.

[0026] The present invention also provides a neodymium iron boron magnet material, which comprises, by mass percentage, the following components:

[0027] B: 0.85–1.2 wt%;

[0028] Cu: 0.05–0.6 wt%;

[0029] Al: 0–0.60 wt%;

[0030] Ga: 0.05–0.6 wt%;

[0031] The contents of Ga, Cu and B satisfy the following formula: (B-0.4)Ga≤Cu≤(Ga+Cu) / 2; the sum of the contents of each component of the NdFeB magnet material is 100%; the NdFeB magnet material includes the amorphous RE-rich phase as described above.

[0032] In this invention, the content of B is preferably 0.9 to 1.0 wt%, for example 0.92 wt%, 0.95 wt%, 0.96 wt%, or 0.94 wt%.

[0033] In this invention, the Cu content is preferably 0.1 to 0.4 wt%, for example 0.15 wt%, 0.20 wt%, 0.32 wt%, 0.35% or 0.38%.

[0034] In this invention, the content of Al is preferably 0 to 0.5 wt%, for example 0.2 wt%.

[0035] In this invention, the content of Ga is preferably 0.1 to 0.5 wt%, for example 0.2 wt%, 0.22 wt%, 0.35 wt%, 0.39% or 0.45 wt%.

[0036] In this invention, those skilled in the art will understand that the neodymium iron boron magnet material also includes rare earth elements RE, and the RE includes at least Nd.

[0037] The percentage of RE in the NdFeB magnet material can be conventional in the art, preferably 27-33 wt%, more preferably 28-32 wt%, for example 29.1 wt%, 29.6 wt%, 29.8 wt%, 30.2% or 31 wt%.

[0038] The RE preferably includes Nd and Pr.

[0039] The Nd content in the neodymium iron boron magnet material is preferably 21-27 wt%, more preferably 22-25 wt%, for example 22.35 wt%, 22.4%, 23.25 wt%, 23.8% or 24.6%.

[0040] The Pr content in the NdFeB magnet material is preferably 4-9 wt%, more preferably 5-8 wt%, for example 5.2 wt%, 5.5 wt%, 6.5 wt%, 7.40 wt%, 7.45 wt%, or 7.75 wt%.

[0041] In some preferred embodiments of the present invention, the RE does not include heavy rare earth elements. The heavy rare earth elements generally include Dy and / or Tb.

[0042] In some preferred embodiments of the present invention, the RE further includes heavy rare earth elements, including Dy and / or Tb.

[0043] Preferably, the heavy rare earth elements account for 0 to 2 wt% of the mass of the neodymium iron boron magnet material, for example, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or 1.5 wt%.

[0044] In this invention, the neodymium iron boron magnet material preferably also includes Co.

[0045] The proportion of Co in the NdFeB magnet material is preferably 0.3 to 1.2 wt%, more preferably 0.4 to 0.8 wt%, for example 0.42 wt%, 0.45 wt%, 0.5 wt%, or 0.52 wt%.

[0046] In this invention, the neodymium iron boron magnet material preferably also includes Zr.

[0047] The Zr content in the neodymium iron boron magnet material is preferably 0 to 0.5 wt%, for example, 0.15 wt%, 0.18 wt%, 0.35 wt%, 0.45 wt%, or 0.46 wt%.

[0048] In this invention, the neodymium iron boron magnet material may further include Ti.

[0049] Preferably, the mass percentage of Ti in the neodymium iron boron magnet material is 0 to 0.3 wt%, for example, 0.1 wt%.

[0050] In this invention, the neodymium iron boron magnet material may further include Nb.

[0051] The Nb content can be conventional in the art, preferably 0 to 0.3 wt%, and more preferably 0.1 wt%.

[0052] In this invention, those skilled in the art will understand that the neodymium iron boron magnet material also includes Fe.

[0053] The mass percentage of Fe in the NdFeB magnet material can be, as is conventional in the art, such that the sum of the contents of all components of the NdFeB magnet material is 100%, preferably 62-72 wt%, more preferably 65-70 wt%, for example 68.04 wt%, 66.14 wt%, 67.74 wt%, 66.74 wt%, 68.33 wt%, 67.85 wt%, or 67.25 wt%.

[0054] In some preferred embodiments of the present invention, the neodymium iron boron magnet material comprises the following components in the following mass percentages: 22.00-25.00% Nd, 5.00-7.00% Pr, 0.20-0.40% Dy, 0.30-0.40% Cu, 0.20-0.50% Ga, 0.40-0.60% Co, 0.30-0.50% Zr, 0.90-1.00% B, and the balance Fe.

[0055] In some preferred embodiments of the present invention, the neodymium iron boron magnet material comprises the following components in the following mass percentages: 22.35% Nd, 7.45% Pr, 0.20% Al, 0.15% Cu, 0.20% Ga, 0.50% Co, 0.15% Zr, 0.96% B and 68.04% Fe.

[0056] In some preferred embodiments of the present invention, the neodymium iron boron magnet material comprises the following components in the following mass percentages: 23.25% Nd, 7.75% Pr, 0.50% Al, 0.20% Cu, 0.22% Ga, 0.80% Co, 0.10% Nb, 0.10% Ti, 0.94% B and 66.14% Fe.

[0057] In some preferred embodiments of the present invention, the neodymium iron boron magnet material comprises the following components in the following mass percentages: 22.20% Nd, 7.40% Pr, 0.50% Dy, 0.20% Al, 0.15% Cu, 0.20% Ga, 0.50% Co, 0.15% Zr, 0.94% B and 67.74% Fe.

[0058] In some preferred embodiments of the present invention, the neodymium iron boron magnet material comprises the following components in the following mass percentages: 29.60% Nd, 1.50% Dy, 0.20% Al, 0.15% Cu, 0.20% Ga, 0.50% Co, 0.15% Zr, 0.96% B and 66.74% Fe.

[0059] In some preferred embodiments of the present invention, the neodymium iron boron magnet material comprises the following components in the following mass percentages: 22.40% Nd, 6.50% Pr, 0.20% Dy, 0.38% Cu, 0.45% Ga, 0.45% Co, 0.35% Zr, 0.94% B and 68.33% Fe.

[0060] In some preferred embodiments of the present invention, the neodymium iron boron magnet material comprises the following components in the following mass percentages: 23.80% Nd, 5.50% Pr, 0.30% Dy, 0.33% Cu, 0.39% Ga, 0.42% Co, 0.45% Zr, 0.95% B and 67.87% Fe.

[0061] In some preferred embodiments of the present invention, the neodymium iron boron magnet material comprises the following components in the following mass percentages: 24.60% Nd, 5.20% Pr, 0.40% Dy, 0.30% Cu, 0.35% Ga, 0.52% Co, 0.46% Zr, 0.92% B and 67.25% Fe.

[0062] This invention also provides a method for preparing neodymium iron boron magnet material, which includes the following steps:

[0063] S1: The components of the neodymium iron boron magnet material described above are used to make a magnet blank;

[0064] S2: The magnet blank is subjected to aging treatment to obtain the desired result; wherein the aging treatment includes first-level aging and second-level aging, and the cooling rate after first-level aging is 23-150℃ / min.

[0065] In this invention, the first-stage aging can be carried out using conventional methods in the art, generally involving heating.

[0066] In this invention, the temperature for the first-stage aging can be conventional in the art, preferably 860-940°C, more preferably 880-920°C, for example 890°C, 900°C, or 910°C.

[0067] In this invention, the time for the first-level aging process can be conventional in the art, preferably 2 to 4 hours, for example 3 hours.

[0068] In this invention, the cooling rate is preferably 35-150°C / min, more preferably 40-80°C / min, for example 42°C / min, 45°C / min, 48°C / min, 50°C / min, 52°C / min, 56°C / min or 66°C / min.

[0069] In this invention, the temperature after cooling during the first-stage aging process can be conventional in the art, preferably 420-480°C, and more preferably 450°C.

[0070] In this invention, the temperature for the secondary aging process can be conventional in the art, preferably 430–550°C, for example 480°C.

[0071] In this invention, the time for the secondary aging process can be conventional in the art, preferably 1 to 4 hours, for example 3.5 hours.

[0072] In S1, the preparation method of the magnet blank can be conventional in the art. Generally, the components of the neodymium iron boron magnet material are sequentially melted, cast, crushed, shaped and sintered.

[0073] The melting temperature can be conventional in the art, preferably below 1550°C, more preferably 1480-1550°C, for example 1520°C.

[0074] The melting process is typically carried out under a vacuum environment. The pressure of the vacuum environment can be conventional in the art, but is preferably 2 × 10⁻⁶. -2 Pa~8×10 -2 Pa, for example 5 × 10 -2 Pa.

[0075] The casting method can be conventional in the art, and preferably is the rapid solidification casting method.

[0076] The casting temperature can be conventional in the art, preferably 1390-1460°C, for example 1410°C.

[0077] The thickness of the alloy casting obtained after casting can be conventional in the art, preferably 0.25 to 0.40 mm.

[0078] The pulverization method can be conventional in the art, and preferably, hydrogen pulverization and air jet milling are performed sequentially.

[0079] The hydrogen crushing process generally includes hydrogen absorption, dehydrogenation, and cooling.

[0080] The hydrogen pressure during the hydrogen absorption process can be conventional in the art, preferably 0.05 to 0.12 MPa, and more preferably 0.085 MPa.

[0081] The dehydrogenation can be carried out using conventional methods in the art, preferably by heating under vacuum conditions. The temperature after heating can be conventional in the art, preferably 300–600°C, for example 500°C.

[0082] The atmosphere for the air jet milling can be conventional in the art, preferably with an oxidizing gas content not exceeding 100 ppm. The oxidizing gas generally includes oxygen and / or water vapor.

[0083] The pressure in the grinding chamber of the air jet mill can be conventional in the art, preferably 0.5 to 1 MPa, and more preferably 0.7 MPa.

[0084] The particle size after air jet milling can be conventional in the art, preferably 3 to 6 μm, for example 4.2 μm.

[0085] Preferably, a lubricant is added to the powder obtained after pulverization.

[0086] The lubricant may be conventional in the art, but is preferably zinc stearate.

[0087] The amount of lubricant added can be conventional in the art, preferably 0.05 to 0.15%, for example 0.10%, wherein the percentage is the mass percentage of the lubricant to the powder.

[0088] The forming method can be conventional in the art, but preferably magnetic field forming.

[0089] The strength of the magnetic field in the magnetic field shaping process can be conventional in the field, preferably 1.8 to 2.5 T.

[0090] The magnetic field shaping is preferably performed in a protective atmosphere. The protective atmosphere can be conventional in the art, such as nitrogen.

[0091] The sintering temperature can be conventional in the art, preferably 1000-1100℃, for example 1085℃.

[0092] The sintering time can be conventional in the art, preferably 4 to 8 hours, for example 6 hours.

[0093] In S1, the sintering process preferably further includes a cooling process.

[0094] The cooling process is preferably carried out under an inert atmosphere.

[0095] The inert atmosphere can be a conventional gas that does not participate in the chemical reaction of the present invention, preferably nitrogen or an inert gas, and more preferably argon.

[0096] The pressure of the inert atmosphere can be conventional in the art, preferably 0.01 to 0.1 MPa, and more preferably 0.05 MPa.

[0097] The present invention also provides a neodymium iron boron magnet material prepared by the preparation method described above.

[0098] The present invention also provides an application of the neodymium iron boron magnet material as described above in an electric motor.

[0099] The present invention also provides a motor comprising neodymium iron boron magnet material as described above.

[0100] 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.

[0101] The reagents and raw materials used in this invention are all commercially available.

[0102] The positive and progressive effects of this invention are as follows:

[0103] (1) The present invention can increase the intrinsic coercivity to more than 19 kOe, or even as high as 20.60 kOe, without using heavy rare earth elements and with a remanence of more than 14 kGs; at the same time, the maximum magnetic energy product can be higher than 48 MGOe, or even as high as 50.95 MGOe.

[0104] (2) When a small amount (≤1.5wt%) of heavy rare earth elements are added, the remanence can be higher than 13.5kGs, the intrinsic coercivity can be increased to more than 21kOe, or even as high as 23.3kOe, and the maximum magnetic energy product can be higher than 43MGOe, or even as high as 46.13MGOe. Attached Figure Description

[0105] Figure 1 The TEM image of the neodymium iron boron magnet material in Example 1 is shown.

[0106] Figure 2 The TEM image of the neodymium iron boron magnet material in Example 1 is shown. Figure 2 The arrow points to the amorphous RE-rich phase. Detailed Implementation

[0107] 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.

[0108] Examples 1-7 and Comparative Examples 1-7

[0109] The raw materials are prepared according to the composition table in Table 1, and the preparation steps are as follows:

[0110] (1) Smelting: Place the prepared raw materials into an absolute pressure of 5×10 -2 In a high-frequency vacuum induction melting furnace, Pa is melted into a liquid at a temperature of 1520°C.

[0111] (2) Casting: The alloy castings are obtained by rapid solidification casting method, and the casting temperature is 1410℃.

[0112] (3) Crushing: Hydrogen crushing and air jet milling are carried out in sequence.

[0113] The hydrogen crushing process includes hydrogen absorption, dehydrogenation, and cooling. Hydrogen absorption is carried out under a hydrogen pressure of 0.085 MPa, while dehydrogenation is carried out under conditions of simultaneous vacuuming and heating, with a dehydrogenation temperature of 500℃.

[0114] The air jet milling was performed under conditions where the oxidizing gas content was below 100 ppm, resulting in a particle size of 4.2 μm. Oxidizing gases refer to oxygen and water vapor. The grinding chamber pressure was 0.70 MPa. After milling, zinc stearate, a lubricant, was added at a rate of 0.10% of the weight of the resulting powder.

[0115] (4) Molding: Magnetic field molding is carried out under a magnetic field strength of 1.8 to 2.5T and a nitrogen atmosphere.

[0116] (5) Sintering: at an absolute pressure of 5×10 -3 The sintering process was carried out under vacuum conditions of Pa, with a sintering temperature of 1085℃ and a sintering time of 6 hours.

[0117] (6) Cooling: Argon gas is introduced to reach a pressure of 0.05 MPa for cooling.

[0118] (7) Aging treatment: The temperature of the first aging is 900℃ and the time is 3h; after the first aging, it is cooled to 450℃, and the cooling rate is shown in Table 2; then the second aging is carried out, the temperature of the second aging is 480℃ and the time is 3.5h, and neodymium iron boron magnet material is obtained.

[0119] As those skilled in the art will understand, the content of each component in neodymium iron boron magnet materials is almost identical to that in their raw materials. Therefore, the content of each component in the neodymium iron boron magnet materials obtained in each embodiment and comparative example is shown in Table 1.

[0120] Table 1. Raw material composition of NdFeB magnet materials in the examples and comparative examples.

[0121]

[0122] In Table 1, " / " indicates that the element was not added or was not detected; "balance" is 100% minus the content of other elements. Those skilled in the art will know that the Fe content includes some impurities that are unavoidably introduced during the preparation process.

[0123] Effect Example

[0124] 1. Testing of magnetic properties

[0125] The NdFeB magnet materials obtained in Examples 1-4 and Comparative Examples 1-7 were subjected to magnetic performance tests using the NIM-62000 closed-loop demagnetization curve testing equipment prepared by the National Institute of Metrology of China. The test temperature was 20℃. The data of remanence (BRE), intrinsic coercivity (Hcj), maximum energy product (BHmax), and squareness (Hk / Hcj) were obtained. The test results are shown in Table 2.

[0126] 2. Characterization of the volume ratio of amorphous RE-rich phase

[0127] TEM tests were performed on the NdFeB magnet materials obtained in the examples and comparative examples to characterize the volume ratio of the amorphous RE-rich phase to the grain boundary phase. Specifically, TEM was used to perform diffraction pattern analysis on the grain boundary phase, and the amorphous NdFeB-rich phase was identified and labeled based on the inherent annular diffraction patterns of the amorphous phase. Figure 1 Then, using scanning transmission electron imaging (TEM) Figure 2 The volume percentage of amorphous RE-rich phases was statistically analyzed, and the results are shown in Table 2.

[0128] 3. Composition determination of amorphous RE-rich phases

[0129] The composition of the amorphous RE-rich phase was quantitatively analyzed using TEM-EDS (energy dispersive spectroscopy), and the results are shown in Table 3.

[0130] Table 2. Magnetic property characterization results of the examples and comparative examples.

[0131]

[0132]

[0133] Table 3. Composition of amorphous RE-rich phases in the examples and comparative examples.

[0134] Examples / Comparative Examples Composition of amorphous RE-rich phase (at%) Example 1 <![CDATA[Fe 18 RE 47 Ga 14 With 21 ]]> Example 2 <![CDATA[Fe 15 RE 49 Ga 16 With 20 ]]> Example 3 <![CDATA[Fe 25 RE 40 Ga 11 With 24 ]]> Example 4 <![CDATA[Fe 16 RE 45 Ga 14 With 25 ]]> Example 5 <![CDATA[Fe 19 RE 41 Ga 18 With 12 ]]> Example 6 <![CDATA[Fe 16 RE 46 Ga 19 With 19 ]]> Example 7 <![CDATA[Fe 17 RE 50 Ga 12 With 21 ]]> Comparative Example 1 <![CDATA[Fe 17 RE 48 Ga 14 With 21 ]]> Comparative Example 2 <![CDATA[Fe 19 RE 47 Ga 14 With 20 ]]> Comparative Example 3 <![CDATA[Fe 18 RE 44 Ga 14 With 24 ]]> Comparative Example 4 <![CDATA[Fe 20 RE 45 Ga 14 With 21 ]]> Comparative Example 5 <![CDATA[Fe 21 RE 47 Ga 14 With 18 ]]> Comparative Example 6 <![CDATA[Fe 19 RE 49 Ga 11 With 21 ]]> Comparative Example 7 <![CDATA[Fe 23 RE 42 Ga 14 With 21 ]]>

[0135] In Table 3, the numbers in the amorphous RE-rich phase compositions of each embodiment and comparative example represent the atomic percentage of each element.

[0136] As shown in Table 2, the specific element ratios and preparation process of this invention enable the formation of a specific volume proportion of amorphous NdFeB-rich phases in the grain boundary phase. Therefore, NdFeB magnet materials prepared without the addition of heavy rare earth elements exhibit remanence (BRE) higher than 14 kGs and intrinsic coercivity (Hcj) higher than 19 kOe, even reaching 20.60 kOe. With the addition of small amounts of heavy rare earth elements, the NdFeB magnet materials prepared exhibit remanence (BRE) higher than 13.50 kGs and intrinsic coercivity (Hcj) higher than 21 kOe, even reaching 23.30 kOe. The element ratios of Comparative Examples 1, 2, and 7 do not satisfy the (B-0.4)Ga≤Cu≤(Ga+Cu) / 2 of this invention, resulting in an area ratio of less than 3% for the amorphous NdFeB-rich phases formed in the grain boundary phase. Consequently, the resulting NdFeB magnet materials have lower intrinsic coercivity (Hcj), all below 19 kOe. The elemental ratios of Comparative Examples 3 and 4 satisfy the requirement of formula (B-0.4)Ga≤Cu≤(Ga+Cu) / 2, but the Cu content is lower or higher than the range defined in this application, resulting in the area ratio of the amorphous NdFeB-rich phase formed in the grain boundary phase being too small or too large, causing the intrinsic coercivity Hcj of the NdFeB magnet material to be lower than 19 kOe. The cooling rates after first-stage aging of Comparative Examples 5 and 6 are lower and higher than the range defined in this invention, respectively, resulting in the area ratio of the amorphous NdFeB-rich phase formed in the grain boundary phase being too small or too large, and the intrinsic coercivity Hcj of the obtained NdFeB magnet material to be lower than 18 kOe.

Claims

1. A neodymium iron boron magnet material, characterized in that, It includes an amorphous RE-rich phase located in the grain boundary phase, wherein the elemental composition and atomic ratio of the amorphous RE-rich phase are TM:RE:Cu:Ga = (15~30):(40~60):(10~25):(10~30); the amorphous RE-rich phase accounts for 3~8% of the volume of the grain boundary phase; wherein TM is Fe and Co, and RE is rare earth element.

2. The neodymium iron boron magnet material as described in claim 1, characterized in that, In the amorphous RE-rich phase, the atomic percentage of TM is 15-30%. And / or, the TM is only Fe; And / or, in the amorphous RE-rich phase, the atomic percentage of RE is 40-60%; And / or, in the amorphous RE-rich phase, the atomic percentage of Ga is 10-20%; And / or, in the amorphous RE-rich phase, the atomic percentage of Cu is 12-25%; Alternatively, the composition of the amorphous RE-rich phase is Fe. 15~19 RE 45~50 Ga 12~19 Cu 19~21 The numbers represent the atomic percentage of each element in the amorphous RE-rich phase. Alternatively, the composition of the amorphous RE-rich phase is Fe. 18 RE 47 Ga 14 Cu 21 Fe 15 RE 49 Ga 16 Cu 20 Fe 25 RE 40 Ga 11 Cu 24 Fe 16 RE 45 Ga 14 Cu 25 Fe 17 RE 45 Ga 18 Cu 20 Fe 19 RE 41 Ga 18 Cu 12 Fe 16 RE 46 Ga 19 Cu 19 or Fe 17 RE 50 Ga 12 Cu 21 The numbers represent the atomic percentage of each element in the amorphous RE-rich phase. And / or, the volume ratio of the amorphous RE-rich phase to the grain boundary phase is 3.5~7%.

3. The neodymium iron boron magnet material as described in claim 2, characterized in that, In the amorphous RE-rich phase, the atomic percentage of TM is 15-25%; And / or, in the amorphous RE-rich phase, the atomic percentage of RE is 40-50%; And / or, in the amorphous RE-rich phase, the atomic percentage of Ga is 11%, 12%, 14%, 16%, 18%, or 19%; And / or, in the amorphous RE-rich phase, the atomic percentage of Cu is 19%, 20%, 21%, 24%, or 25%; And / or, the volume ratio of the amorphous RE-rich phase to the grain boundary phase is 4.2%, 4.3%, 4.4%, 4.5%, 5.6%, 6.2%, or 6.5%.

4. The neodymium iron boron magnet material as described in claim 3, characterized in that, In the amorphous RE-rich phase, the atomic percentage of TM is 16%, 17%, 18%, 19% or 25%; and / or, in the amorphous RE-rich phase, the atomic percentage of RE is 41%, 45%, 46%, 47%, 49% or 50%.

5. The neodymium iron boron magnet material as described in claim 1 or 2, characterized in that, It comprises the following components in percentage quantities by weight: B: 0.85~1.2wt%; Cu: 0.05~0.6wt% Al: 0~0.60wt% Ga: 0.05~0.6wt% The contents of Ga, Cu and B satisfy the following formula: (B-0.4)Ga≤Cu≤(Ga+Cu) / 2; the sum of the contents of all components of the neodymium iron boron magnet material is 100%.

6. The neodymium iron boron magnet material as described in claim 5, characterized in that, The content of B is 0.9~1.0 wt%; And / or, the Cu content is 0.1~0.4wt%; And / or, the content of Al is 0~0.5wt%; And / or, the Ga content is 0.1~0.5wt%; And / or, the neodymium iron boron magnet material further includes rare earth element RE, wherein the RE includes at least Nd; And / or, the RE further includes heavy rare earth elements; And / or, the neodymium iron boron magnet material further includes Co; And / or, the neodymium iron boron magnet material further includes Zr; And / or, the neodymium iron boron magnet material further includes Ti; And / or, the neodymium iron boron magnet material further includes Nb; And / or, the neodymium iron boron magnet material further includes Fe.

7. The neodymium iron boron magnet material as described in claim 6, characterized in that, The content of B is 0.92wt%, 0.95wt%, 0.96wt%, or 0.94wt%. And / or, the Cu content is 0.15wt%, 0.20wt%, 0.32wt%, 0.35% or 0.38%; And / or, the content of Al is 0.2 wt%; And / or, the Ga content is 0.2wt%, 0.22wt%, 0.35wt%, 0.39%, or 0.45wt%; And / or, the RE accounts for 27-33 wt% of the mass percentage of the NdFeB magnet material; And / or, the RE comprises Nd and Pr; the Nd accounts for 21-27 wt% of the NdFeB magnet material by mass; the Pr accounts for 4-9 wt% of the NdFeB magnet material by mass. And / or, the heavy rare earth elements include Dy and / or Tb; And / or, the Co constitutes 0.3~1.2 wt% of the NdFeB magnet material by mass. And / or, the Zr accounts for 0~0.5wt% of the mass percentage of the NdFeB magnet material; And / or, the Ti accounts for 0~0.3wt% of the mass percentage of the NdFeB magnet material; And / or, the Nb accounts for 0~0.3wt% of the mass percentage of the NdFeB magnet material; And / or, the Fe accounts for 62-72 wt% of the mass of the NdFeB magnet material.

8. The neodymium iron boron magnet material as described in claim 7, characterized in that, The RE accounts for 28-32 wt% of the mass of the NdFeB magnet material; And / or, the Nd content in the NdFeB magnet material is 22-25 wt% by mass; And / or, the Pr accounts for 5-8 wt% of the mass percentage of the NdFeB magnet material; And / or, the heavy rare earth elements account for 0~2wt% of the mass percentage of the neodymium iron boron magnet material; And / or, the Co constitutes 0.4~0.8 wt% of the NdFeB magnet material by mass. And / or, the Zr constitutes 0.15wt%, 0.18wt%, 0.35wt%, 0.45wt%, or 0.46wt% of the NdFeB magnet material by mass. And / or, the Ti accounts for 0.1 wt% of the mass of the NdFeB magnet material; And / or, the Nb accounts for 0.1 wt% of the mass of the NdFeB magnet material; And / or, the Fe accounts for 65-70 wt% of the mass of the NdFeB magnet material.

9. The neodymium iron boron magnet material as described in claim 8, characterized in that, The RE constitutes 29.1 wt%, 29.6 wt%, 29.8 wt%, 30.2%, or 31 wt% of the NdFeB magnet material by mass. And / or, the Nd content in the NdFeB magnet material is 22.35wt%, 22.4%, 23.25wt%, 23.8%, or 24.6% by mass; And / or, the Pr constitutes 5.2 wt%, 5.5 wt%, 6.5 wt%, 7.40 wt%, 7.45 wt%, or 7.75 wt% of the NdFeB magnet material by mass. And / or, the heavy rare earth elements account for 0.2wt%, 0.25wt%, 0.3wt%, 0.4wt%, 0.5wt%, or 1.5wt% of the mass percentage of the neodymium iron boron magnet material; And / or, the Co constitutes 0.42wt%, 0.45wt%, 0.5wt%, or 0.52wt% of the NdFeB magnet material by mass. And / or, the Fe accounts for 68.04 wt%, 66.14 wt%, 67.74 wt%, 66.74 wt%, 68.33 wt%, 67.85 wt%, or 67.25 wt% of the mass of the neodymium iron boron magnet material.

10. The neodymium iron boron magnet material as described in claim 5, characterized in that, The neodymium iron boron magnet material comprises the following components in the indicated mass percentages: 22.00-25.00% Nd, 5.00-7.00% Pr, 0.20-0.40% Dy, 0.30-0.40% Cu, 0.20-0.50% Ga, 0.40-0.60% Co, 0.30-0.50% Zr, 0.90-1.00% B, and the balance Fe; Alternatively, the neodymium iron boron magnet material comprises the following components in the indicated mass percentages: 22.35% Nd, 7.45% Pr, 0.20% Al, 0.15% Cu, 0.20% Ga, 0.50% Co, 0.15% Zr, 0.96% B and 68.04% Fe; Alternatively, the neodymium iron boron magnet material comprises the following components in the indicated mass percentages: 23.25% Nd, 7.75% Pr, 0.50% Al, 0.20% Cu, 0.22% Ga, 0.80% Co, 0.10% Nb, 0.10% Ti, 0.94% B and 66.14% Fe; Alternatively, the neodymium iron boron magnet material comprises the following components in the following mass percentages: 22.20% Nd, 7.40% Pr, 0.50% Dy, 0.20% Al, 0.15% Cu, 0.20% Ga, 0.50% Co, 0.15% Zr, 0.94% B, and 67.74% Fe; Alternatively, the neodymium iron boron magnet material comprises the following components in the following mass percentages: 29.60% Nd, 1.50% Dy, 0.20% Al, 0.15% Cu, 0.20% Ga, 0.50% Co, 0.15% Zr, 0.96% B and 66.74% Fe; Alternatively, the neodymium iron boron magnet material comprises the following components in the indicated mass percentages: 22.40% Nd, 6.50% Pr, 0.20% Dy, 0.38% Cu, 0.45% Ga, 0.45% Co, 0.35% Zr, 0.94% B and 68.33% Fe; Alternatively, the neodymium iron boron magnet material comprises the following components in the following mass percentages: 23.80% Nd, 5.50% Pr, 0.30% Dy, 0.33% Cu, 0.39% Ga, 0.42% Co, 0.45% Zr, 0.95% B and 67.87% Fe; Alternatively, the neodymium iron boron magnet material comprises the following components in the indicated mass percentages: It contains 24.60% Nd, 5.20% Pr, 0.40% Dy, 0.30% Cu, 0.35% Ga, 0.52% Co, 0.46% Zr, 0.92% B and 67.25% Fe.

11. The method for preparing the neodymium iron boron magnet material according to any one of claims 1-10, characterized in that, It includes the following steps: S1: The components of the neodymium iron boron magnet material as described in any one of claims 5 to 10 are used to make a magnet blank; S2: The magnet blank is subjected to aging treatment to obtain the desired result; wherein the aging treatment includes first-level aging and second-level aging, and the cooling rate after first-level aging is 23~150℃ / min.

12. The method for preparing neodymium iron boron magnet material as described in claim 11, characterized in that, The temperature for the first-stage aging process is 860~940℃; And / or, the time for the first-level time limit is 2 to 4 hours; And / or, the cooling rate is 35~150℃ / min; And / or, the temperature after cooling during the first-stage aging process is 420~480℃; And / or, the temperature for the secondary aging process is 430~550℃; And / or, the duration of the secondary time limit is 1 to 4 hours.

13. The method for preparing the neodymium iron boron magnet material as described in claim 12, characterized in that, The temperature for the first-stage aging process is 880~920℃; And / or, the first-level time limit is 3 hours; And / or, the cooling rate is 40~80℃ / min; And / or, the temperature after cooling during the first stage of aging is 450°C; And / or, the temperature for the secondary aging process is 480°C; And / or, the duration of the secondary time limit is 3.5 hours.

14. The method for preparing the neodymium iron boron magnet material as described in claim 13, characterized in that, The temperature for the first-stage aging process is 890℃, 900℃, or 910℃. And / or, the cooling rate is 42°C / min, 45°C / min, 48°C / min, 50°C / min, 52°C / min, 56°C / min or 66°C / min.

15. A neodymium iron boron magnet material prepared by any one of claims 11 to 14.

16. An application of neodymium iron boron magnet material as described in any one of claims 1 to 10 and 15 in an electric motor.

17. An electric motor comprising neodymium iron boron magnet material as described in any one of claims 1 to 10 and 15.

Images