A neodymium iron boron material and preparation method thereof

Abstract

The present application discloses a NdFeB material and a preparation method thereof, which relates to the field of rare earth permanent magnet technology. The NdFeB material comprises the following components in parts by weight: 168-175 parts of PrNd, 24-28 parts of DyFe, 355-362 parts of Fe, 26-29 parts of BFe, 5.2-6.5 parts of Co, 0.7-1.1 parts of Cu, 4-4.4 parts of Al, 1.1-1.25 parts of Ca, and 2.9-3.3 parts of Zr; wherein the PrNd is mechanically crushed And / or hydrogenation crushing, then mixed with DyFe, BFe and pressed to obtain rare earth pressed embryos, rare earth pressed embryos are subjected to high temperature sintering, primary tempering and hydrogenation crushing treatment to obtain magnetic powder embryos, finally the magnetic powder embryos are mixed evenly with CuH, hydrogenation crushing treatment and inert gas protection grinding treatment to obtain magnetic powder, the magnetic powder is mixed with Fe, Co, Al, Ca and Zr, after uniform mixing, orientation molding, static pressing molding and sintering, secondary tempering and tertiary tempering are performed to obtain NdFeB material blocks. The present application has the effects of low oxygen content, improving the intercrystalline grain boundary phase of elements and significantly improving magnetic properties.

Description

Technical Field

[0001] The present application relates to the technical field of rare earth permanent magnets, and in particular to a neodymium iron boron material and a preparation method thereof. Background Art

[0002] NdFeB magnets are the most cost-effective commercial magnetic materials to date due to their high coercive force and high magnetic energy product. They are widely used in many areas related to people's livelihood, such as home appliances, transportation, and medical care.

[0003] The advantages of NdFeB are high cost performance and good mechanical properties; the disadvantages are low Curie temperature, poor temperature characteristics, and easy powdering and corrosion. It must be improved by adjusting its chemical composition and adopting surface treatment methods to meet the requirements of practical applications.

[0004] However, the existing NdFeB magnets have simple ingredients, and it is still difficult to obtain high magnetic properties after pressing and surface treatment. They cannot meet the industry's expectations for the magnetic properties of NdFeB magnets and need to be improved. Summary of the invention

[0005] In view of this, the first object of the present application is to provide a NdFeB material to achieve the purpose of low oxygen content, improving the intercrystalline grain boundary phase of the elements and significantly improving the magnetic properties. The specific scheme is as follows:

[0006] A neodymium iron boron material comprises the following components in parts by weight:

[0007] 168-175 parts of PrNd, 24-28 parts of DyFe, 355-362 parts of Fe, 26-29 parts of BFe, 5.2-6.5 parts of Co, 0.7-1.1 parts of Cu, 4-4.4 parts of Al, 1.1-1.25 parts of Ca, 2.9-3.3 parts of Zr;

[0008] The PrNd is crushed mechanically and / or hydrogen-filled, and then mixed with DyFe and BFe and pressed to obtain a rare earth pressed embryo. The rare earth pressed embryo is subjected to high-temperature sintering, primary tempering, and hydrogen-filled crushing to obtain a magnetic powder blank. Finally, the magnetic powder blank is evenly mixed with CuH, and hydrogen-filled crushing and inert gas protection grinding are performed to obtain a magnetic powder material. The magnetic powder material is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, orientation molding, static pressing molding and sintering, secondary tempering and tertiary tempering are performed to obtain a NdFeB material block.

[0009] Preferably: the NdFeB material block is electroplated to form an electroplated copper protective layer; the electroplating treatment is added with a crown ether compound with a concentration of 0.1g-0.2g / mol and EDTA with a concentration of 0.2-0.4g / mol.

[0010] Preferably, the high temperature sintering temperature is 1010-1060° C. and the sintering time is 2-4 hours.

[0011] Preferably, the mass ratio of the CuH to the magnetic powder blank is 1:220-260.

[0012] Preferably, the magnetic field strength of the orientation molding is 1.1-1.3 T, and the pressure during the static pressure molding is controlled at 720-800 MPa.

[0013] Preferably, during the sintering, the temperature is controlled to be 1025-1085° C. and maintained for 4.5-6 hours.

[0014] Preferably, during the secondary tempering, the tempering temperature is controlled to be 820-880°C, and the tempering time is 4-5h; during the tertiary tempering, the tempering temperature is controlled to be 460-520°C, and the tempering time is 6-9h.

[0015] The second object of the present invention is to provide a method for preparing a NdFeB material, which is used to prepare a NdFeB material as described above, including a material preparation stage, a mixing processing stage and a protective film layer stage; the material preparation stage includes preparing 168-175 parts by weight of PrNd, 24-28 parts of DyFe, 355-362 parts of Fe, 26-29 parts of BFe, 5.2-6.5 parts of Co, 0.7-1.1 parts of Cu, 4-4.4 parts of Al, 1.1-1.25 parts of Ca, and 2.9-3.3 parts of Zr; the mixing processing stage includes mechanically crushing PrNd and / or hydrogen-filled and crushed, and then mixed with DyFe and BFe and pressed to obtain a rare earth pressed embryo; the rare earth pressed embryo is subjected to high-temperature sintering, one-time tempering and then hydrogen-filled and crushed to obtain a magnetic powder blank; finally, the magnetic powder blank is evenly mixed with CuH, and hydrogen-filled and crushed and inert gas-protected grinding is performed to obtain a magnetic powder material; the magnetic powder material is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, compression molding and sintering, secondary and tertiary tempering are performed to obtain a NdFeB material block; the protective film layer stage includes electroplating the NdFeB material block using an electroplating process, and forming an electroplated copper protective layer on the surface of the NdFeB material block.

[0016] Preferably, the electroplating treatment includes adding a crown ether compound with a concentration of 0.1 g-0.2 g / mol and EDTA with a concentration of 0.2-0.4 g / mol.

[0017] Preferably, the crown ether compound is 15-crown-5, dipyrido-18-crown-6 and / or 4,13-diazabenzo-18-crown-6; wherein the chemical formula of dipyrido-18-crown-6 is .

[0018] It can be seen from the above scheme that the present application provides a NdFeB material and a preparation method thereof, wherein the NdFeB material optimizes metal elements by combining corresponding weight portions of PrNd, DyFe, Fe, BFe, Co, Cu, Al, Ca, and Zr, thereby significantly improving magnetic properties. The preparation method of the NdFeB material achieves the effect of improving the comprehensive magnetic properties of the magnet and reducing the difficulty of the preparation process by mixing and pressing PrNd, DyFe, and BFe, thereby compounding the elemental materials; and mixing cuprous hydride with the magnetic powder blank, hydrogenating, crushing, and grinding, thereby effectively improving the intercrystalline grain boundary phase between PrNd, DyFe, and BFe elements and the copper element while controlling the oxygen content; at the same time, after the magnetic powder is mixed with Fe, Co, Al, Ca, and Zr, the NdFeB material block obtained after orientation molding, static pressing molding, and sintering will achieve the purpose of low oxygen content, improving the intercrystalline grain boundary phase of the element, and significantly improving magnetic properties.

[0019] The CuH, copper element and the electroplated copper protective layer formed by electroplating treatment are combined, so that the NdFeB material can improve the magnetic properties while overcoming the problem of the grain boundary phase between the elements caused by the differences between the elements in the NdFeB material, generating a continuous grain boundary phase and reducing the static magneto-coupling effect between the grains. DETAILED DESCRIPTION

[0020] The following will be clearly and completely described in conjunction with the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] The NdFeB material and its preparation method of the present application will be described in detail below.

[0022] A neodymium iron boron material comprises the following components in parts by weight:

[0023] 168-175 parts of PrNd, 24-28 parts of DyFe, 355-362 parts of Fe, 26-29 parts of BFe, 5.2-6.5 parts of Co, 0.7-1.1 parts of Cu, 4-4.4 parts of Al, 1.1-1.25 parts of Ca, 2.9-3.3 parts of Zr;

[0024] The PrNd is mechanically crushed and / or hydrogen-filled, crushed, and then mixed with DyFe and BFe to obtain a rare earth pressed embryo. The rare earth pressed embryo is subjected to high-temperature sintering, one tempering, and then hydrogen-filled and crushed to obtain a magnetic powder blank. Finally, the magnetic powder blank is evenly mixed with CuH, and hydrogen-filled and crushed and inert gas-protected grinding is performed to obtain a magnetic powder. The magnetic powder is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, orientation molding, static pressing molding and sintering, secondary tempering and tertiary tempering are performed to obtain a NdFeB material block. The NdFeB material block is electroplated to form an electroplated copper protective layer. The electroplating treatment adds a crown ether compound with a concentration of 0.1g-0.2g / mol and 0.2-0.4g / mol of EDTA. The crown ether compound is 15-crown-5, dipyrido-18-crown-6 and / or 4,13-diazabenzo-18-crown-6; wherein the chemical formula of the dipyrido-18-crown-6 is The dipyrido-18-crown ether-6 in the examples of the present application is synthesized by using 3,4-2-hydroxypyridine and bis(2-chloroethyl) ether.

[0025] It should be mentioned that the high temperature sintering temperature is 1010-1060℃, and the time is 2-4h. The mass ratio of CuH to magnetic powder blank is controlled to be 1:220-260. The magnetic field intensity of orientation molding is 1.1-1.3T, and the pressure is controlled to be 720-800MPa during static pressing. During sintering, the temperature is controlled to be 1025-1085℃ and maintained for 4.5-6h.

[0026] The sintered material is subjected to secondary tempering with a controlled tempering temperature of 820-880°C and a tempering time of 4-5h, and tertiary tempering with a controlled tempering temperature of 460-520°C and a tempering time of 6-9h, thereby obtaining a NdFeB material with low oxygen content, improved intercrystalline grain boundary phase of elements and significantly improved magnetic properties.

[0027] A method for preparing a neodymium iron boron material includes a material preparation stage, a mixing processing stage and a protective film layer stage. The material preparation stage includes preparing 168-175 parts by weight of PrNd, 24-28 parts of DyFe, 355-362 parts of Fe, 26-29 parts of BFe, 5.2-6.5 parts of Co, 0.7-1.1 parts of Cu, 4-4.4 parts of Al, 1.1-1.25 parts of Ca, and 2.9-3.3 parts of Zr. The mixing processing stage includes mechanically crushing and / or hydrogen-filling crushing of PrNd, and then mixing it with DyFe and BFe and pressing it to obtain a rare earth pressed embryo. The rare earth pressed embryo is subjected to high-temperature sintering, one tempering, and then hydrogen-filling and crushing treatment to obtain a magnetic powder blank. Finally, the magnetic powder blank is evenly mixed with CuH, and hydrogen-filling and crushing treatment and inert gas protection grinding treatment are performed to obtain magnetic powder. The magnetic powder is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, molding and sintering, secondary and tertiary tempering are performed to obtain NdFeB material blocks. The protective film layer stage includes electroplating the NdFeB material blocks using an electroplating process, and forming an electroplated copper protective layer on the surface of the NdFeB material blocks. In view of the fact that the electroplating process is a prior art, it only needs to adjust the parameters in the process of electroplating the copper protective layer, which will not be elaborated here.

[0028] Embodiment 1

[0029] A neodymium iron boron material comprises the following components in parts by weight:

[0030] 168 parts PrNd, 24 parts DyFe, 355 parts Fe, 26 parts BFe, 5.2 parts Co, 0.7 parts Cu, 4 parts Al, 1.1 parts Ca, 2.9 parts Zr.

[0031] Among them, after PrNd is treated with hydrogenation and crushing, it is mixed with DyFe and BFe and then pressed to obtain a rare earth pressed embryo. After high-temperature sintering and one tempering, the rare earth pressed embryo is treated with hydrogenation and crushing to obtain a magnetic powder blank. Finally, the magnetic powder blank is evenly mixed with CuH, and hydrogenation and crushing and inert gas protection grinding are performed to obtain magnetic powder. The magnetic powder is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, orientation molding, static pressing molding and sintering, secondary tempering and tertiary tempering are performed to obtain a NdFeB material block. The NdFeB material block is electroplated to form an electroplated copper protective layer. Among them, the electroplating treatment adds a crown ether compound with a concentration of 0.1g / mol and 0.2g / mol EDTA. The crown ether compound is 15-crown-5.

[0032] It should be mentioned that the high temperature sintering temperature is 1010℃ and the time is 4h. The mass ratio of CuH to magnetic powder blank is controlled to be 1:220. The magnetic field intensity of orientation molding is 1.1T, and the pressure is controlled to be 720MPa during static pressing. During sintering, the temperature is controlled to be 1025℃ and maintained for 6h.

[0033] The sintered material is subjected to secondary tempering with a controlled tempering temperature of 820°C and a tempering time of 5 hours, and tertiary tempering with a controlled tempering temperature of 460°C and a tempering time of 9 hours, thereby obtaining a NdFeB material with low oxygen content, improved intercrystalline grain boundary phase of elements and significantly improved magnetic properties.

[0034] A method for preparing NdFeB material includes a material preparation stage, a mixing and processing stage, and a protective film layer stage. The material preparation stage includes preparing 168 parts by weight of PrNd, 24 parts of DyFe, 355 parts of Fe, 26 parts of BFe, 5.2 parts of Co, 0.7 parts of Cu, 4 parts of Al, 1.1 parts of Ca, and 2.9 parts of Zr. The mixing and processing stage includes mechanically crushing PrNd, mixing it with DyFe and BFe, and then pressing it to obtain a rare earth pressed embryo, the rare earth pressed embryo is subjected to high-temperature sintering, a tempering, and then hydrogenation and crushing treatment to obtain a magnetic powder blank, finally the magnetic powder blank is evenly mixed with CuH, hydrogenation and crushing treatment and inert gas protection grinding treatment are performed to obtain magnetic powder, the magnetic powder is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, compression molding and sintering, secondary tempering and tertiary tempering are performed to obtain a NdFeB material block. The protective film layer stage includes electroplating the NdFeB material block using an electroplating process and forming an electroplated copper protective layer on the surface of the NdFeB material block.

[0035] Embodiment 2

[0036] A neodymium iron boron material comprises the following components in parts by weight:

[0037] 170 parts of PrNd, 26 parts of DyFe, 360 parts of Fe, 28 parts of BFe, 6 parts of Co, 1 part of Cu, 4.2 parts of Al, 1.2 parts of Ca, and 3 parts of Zr.

[0038] Among them, PrNd is treated by hydrogenation and crushing, and then mixed with DyFe and BFe and pressed to obtain rare earth pressed embryos. The rare earth pressed embryos are treated by high-temperature sintering, one tempering, hydrogenation and crushing to obtain magnetic powder embryos. Finally, the magnetic powder embryos are mixed evenly with CuH, hydrogenation and crushing and inert gas protection grinding to obtain magnetic powder. The magnetic powder is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, orientation molding, static pressing and sintering, secondary tempering and tertiary tempering are performed to obtain NdFeB material blocks. The NdFeB material blocks are electroplated to form an electroplated copper protective layer. Among them, the electroplating treatment adds a crown ether compound with a concentration of 0.15g / mol and 0.3g / mol EDTA. The crown ether compound is 4,13-diazabenzo-18-crown-6.

[0039] It should be mentioned that the high temperature sintering temperature is 1030℃ and the time is 3h. The mass ratio of CuH to magnetic powder blank is controlled to be 1:250. The magnetic field intensity of orientation molding is 1.2T, and the pressure is controlled to be 760MPa during static pressing. During sintering, the temperature is controlled to be 1050℃ and maintained for 5h.

[0040] The sintered material is subjected to secondary tempering with a controlled tempering temperature of 850°C and a tempering time of 4.5 hours, and tertiary tempering with a controlled tempering temperature of 500°C and a tempering time of 7 hours, thereby obtaining a NdFeB material with low oxygen content, improved intercrystalline grain boundary phase of elements and significantly improved magnetic properties.

[0041] A method for preparing NdFeB material includes a material preparation stage, a mixing and processing stage, and a protective film layer stage. The material preparation stage includes preparing 170 parts by weight of PrNd, 26 parts of DyFe, 360 parts of Fe, 28 parts of BFe, 6 parts of Co, 1 part of Cu, 4.2 parts of Al, 1.2 parts of Ca, and 3 parts of Zr. The mixing and processing stage includes hydrogenating and crushing PrNd, and then mixing it with DyFe and BFe and pressing it to obtain a rare earth pressed embryo, and the rare earth pressed embryo is subjected to high-temperature sintering, a tempering, and then hydrogenating and crushing to obtain a magnetic powder blank, and finally the magnetic powder blank is mixed evenly with CuH, and hydrogenated and crushed and ground under inert gas protection to obtain a magnetic powder, and the magnetic powder is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, compression molding and sintering, it is subjected to secondary and tertiary tempering to obtain a NdFeB material block. The protective film layer stage includes electroplating the NdFeB material block using an electroplating process and forming an electroplated copper protective layer on the surface of the NdFeB material block.

[0042] Embodiment 3

[0043] A neodymium iron boron material comprises the following components in parts by weight:

[0044] 175 parts of PrNd, 28 parts of DyFe, 362 parts of Fe, 29 parts of BFe, 6.5 parts of Co, 1.1 parts of Cu, 4.4 parts of Al, 1.25 parts of Ca, and 3.3 parts of Zr.

[0045] The PrNd is crushed by hydrogenation, and then mixed with DyFe and BFe and pressed to obtain a rare earth pressed embryo. The rare earth pressed embryo is subjected to high-temperature sintering, one tempering, and then hydrogenation and crushing to obtain a magnetic powder blank. Finally, the magnetic powder blank is evenly mixed with CuH, and hydrogenation and crushing and inert gas protection grinding are performed to obtain magnetic powder. The magnetic powder is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, orientation molding, static pressing molding and sintering, secondary tempering and tertiary tempering are performed to obtain a NdFeB material block. The NdFeB material block is electroplated to form an electroplated copper protective layer. The electroplating treatment adds a crown ether compound with a concentration of 0.2 g / mol and 0.4 g / mol EDTA. The crown ether compound is 15-crown-5.

[0046] It should be mentioned that the high temperature sintering temperature is 1060℃ and the time is 2h. The mass ratio of CuH to magnetic powder blank is controlled to be 1:260. The magnetic field intensity of orientation molding is 1.3T, and the pressure is controlled to be 800MPa during static pressing. During sintering, the temperature is controlled to be 1085℃ and maintained for 4.5h.

[0047] The sintered material is subjected to secondary tempering with a controlled tempering temperature of 880°C and a tempering time of 4 hours, and tertiary tempering with a controlled tempering temperature of 520°C and a tempering time of 6 hours, thereby obtaining a NdFeB material with low oxygen content, improved intercrystalline grain boundary phase of elements and significantly improved magnetic properties.

[0048] A method for preparing NdFeB material includes a material preparation stage, a mixing and processing stage, and a protective film layer stage. The material preparation stage includes preparing 175 parts of PrNd, 28 parts of DyFe, 362 parts of Fe, 29 parts of BFe, 6.5 parts of Co, 1.1 parts of Cu, 4.4 parts of Al, 1.25 parts of Ca, and 3.3 parts of Zr by weight. The mixing and processing stage includes hydrogenating and crushing PrNd, and then mixing it with DyFe and BFe and pressing it to obtain a rare earth pressed embryo, and the rare earth pressed embryo is subjected to high-temperature sintering, a tempering, and then hydrogenating and crushing to obtain a magnetic powder blank, and finally the magnetic powder blank is mixed evenly with CuH, and hydrogenated and crushed and ground under inert gas protection to obtain a magnetic powder, and the magnetic powder is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, compression molding and sintering, it is subjected to secondary and tertiary tempering to obtain a NdFeB material block. The protective film layer stage includes electroplating the NdFeB material block using an electroplating process and forming an electroplated copper protective layer on the surface of the NdFeB material block.

[0049] Embodiment 4

[0050] The difference between Example 4 and Example 1 is that the crown ether compound in Example 4 is dipyrido-18-crown-6. The chemical formula of dipyrido-18-crown-6 is The dipyrido-18-crown ether-6 in Example 4 of the present application is synthesized by using 3,4-2-hydroxypyridine and bis(2-chloroethyl) ether.

[0051] Embodiment 5

[0052] The difference between the fifth embodiment and the fourth embodiment is that the PrNd in the fifth embodiment is subjected to hydrogen charging and crushing treatment.

[0053] Comparative Example 1

[0054] The difference between Comparative Example 1 and Example 4 is that in Comparative Example 1, the magnetic powder material is mixed with Fe, Co, Al, Ca and Zr, mixed evenly, molded and sintered, and then naturally cooled to room temperature.

[0055] Comparative Example 2

[0056] The difference between the comparative example 2 and the embodiment 4 is that in the comparative example 2, the magnetic powder blank is directly mixed with Fe, Co, Al, Ca and Zr, and after being uniformly mixed, oriented, statically pressed and sintered,

[0057] Comparative Example 3

[0058] The difference between Comparative Example 3 and Example 1 is that no crown ether compound is added in Comparative Example 3.

[0059] Performance tests were conducted on Example 1, Example 3 to Example 5 and Comparative Example 1, Comparative Example 2 and Comparative Example 3, and the tests included a magnetic flux attenuation test and a magnetic property test.

[0060] 1. Magnetic property test is carried out according to GB / T 3217-2013 "Magnetic property test method for permanent magnetic (hard magnetic) materials";

[0061] 2. Magnetic flux attenuation test is carried out based on the magnetic flux test before and after coating; the average of multiple parameters is used for processing and comparison.

[0062] The test results are shown in Table 1 and Table 2.

[0063] Table 1 Magnetic properties test results

[0064]

[0065] Table 2 Magnetic flux attenuation test results

[0066]

[0067] According to Table 1, the embodiments of the present application have higher Br, Hcj and (BH) than the comparative examples. max , while ensuring the overall antioxidant capacity during the preparation process, it has the function of maintaining high magnetic properties. At the same time, in view of the fact that the thickness of the grain boundary phase between the crystals of the material is not complete due to the lack of tempering in Comparative Example 1, the magnetic properties are reduced; in Comparative Example 2, the CuH mixing treatment is not performed, which reduces the thin grain boundary phase formed by Cu insertion, and it is difficult to combine with the electroplated copper protective layer to achieve a stable antioxidant composite structure, thereby affecting the magnetic properties of the material.

[0068] At the same time, the combination of the crown ether compound and EDTA achieves a significant demagnetization improvement effect, thereby achieving the purpose of controlling the attenuation ratio below 3%. And when dipyrido-18-crown-6 is used as the crown ether compound to achieve the demagnetization improvement material, it can achieve a significant attenuation ratio control effect, and it is lower than 1.5%.

[0069] At the same time, oxygen content tests were carried out on Examples 1 to 5 of the present application, and the measured oxygen contents were all lower than 1080 ppm. Therefore, the NdFeB material prepared by the preparation method of the NdFeB material of the present application has the effect of low oxygen content.

[0070] In summary, the present application provides a NdFeB material and a preparation method thereof, wherein the NdFeB material optimizes metal elements by combining corresponding weight portions of PrNd, DyFe, Fe, BFe, Co, Cu, Al, Ca, and Zr, thereby significantly improving magnetic properties. The preparation method of the NdFeB material achieves the effect of improving the comprehensive magnetic properties of the magnet and reducing the difficulty of the preparation process by mixing and pressing PrNd, DyFe, and BFe, thereby compounding the elemental materials; and mixing cuprous hydride with magnetic powder blanks, hydrogenating, crushing, and grinding, thereby effectively improving the intercrystalline grain boundary phase between PrNd, DyFe, and BFe elements and copper elements while controlling the oxygen content; at the same time, after the magnetic powder is mixed with Fe, Co, Al, Ca, and Zr, the NdFeB material block obtained after orientation molding, static pressing molding, and sintering will achieve the purpose of low oxygen content, improving the intercrystalline grain boundary phase of the elements, and significantly improving magnetic properties.

[0071] The CuH, copper element and the electroplated copper protective layer formed by electroplating treatment are combined, so that the NdFeB material can improve the magnetic properties while overcoming the problem of the grain boundary phase between the elements caused by the differences between the elements in the NdFeB material, generating a continuous grain boundary phase and reducing the static magneto-coupling effect between the grains.

[0072] The "first", "second", "third", "fourth", etc. (if any) referred to in this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods or devices.

[0073] It should be noted that the descriptions involving "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0074] Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A neodymium iron boron material, characterized in that: The composition comprises the following components in parts by weight: 168-175 parts of PrNd, 24-28 parts of DyFe, 355-362 parts of Fe, 26-29 parts of BFe, 5.2-6.5 parts of Co, 0.7-1.1 parts of Cu, 4-4.4 parts of Al, 1.1-1.25 parts of Ca, 2.9-3.3 parts of Zr; The PrNd is mechanically crushed and / or hydrogen-charged and crushed, and then mixed with DyFe and BFe and pressed to obtain a rare earth pressed embryo. The rare earth pressed embryo is subjected to high-temperature sintering, primary tempering, hydrogen-charged and crushed to obtain a magnetic powder blank. Finally, the magnetic powder blank is uniformly mixed with CuH, and hydrogen-charged and crushed and inert gas-protected grinding is performed to obtain a magnetic powder material. The magnetic powder material is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, orientation molding, static pressing molding and sintering, secondary tempering and tertiary tempering are performed to obtain a NdFeB material block. The high-temperature sintering temperature is 1010-1060°C, and the time is 2-4h. The mass ratio of the CuH to the magnetic powder blank is 1:220-260.

2. A NdFeB material according to claim 1, characterized in that: The NdFeB material block is electroplated to form an electroplated copper protective layer; the electroplating treatment adds a crown ether compound with a concentration of 0.1g-0.2g / mol and 0.2-0.4g / mol EDTA.

3. The NdFeB material according to claim 1, characterized in that: The magnetic field intensity of the orientation molding is 1.1-1.3T, and the pressure of the static pressure molding is controlled at 720-800MPa.

4. The NdFeB material according to claim 1, characterized in that: During the sintering, the temperature is controlled to be 1025-1085° C. and maintained for 4.5-6 hours.

5. The NdFeB material according to claim 1, characterized in that: During the secondary tempering, the tempering temperature is controlled to be 820-880° C. and the tempering time is 4-5 hours; during the tertiary tempering, the tempering temperature is controlled to be 460-520° C. and the tempering time is 6-9 hours.

6. A method for preparing a NdFeB material, used for preparing a NdFeB material as claimed in any one of claims 1 to 5, characterized in that: The invention comprises a material preparation stage, a mixing and processing stage and a protective film layer stage; the material preparation stage comprises preparing 168-175 parts by weight of PrNd, 24-28 parts by weight of DyFe, 355-362 parts by weight of Fe, 26-29 parts by weight of BFe, 5.2-6.5 parts by weight of Co, 0.7-1.1 parts by weight of Cu, 4-4.4 parts by weight of Al, 1.1-1.25 parts by weight of Ca, and 2.9-3.3 parts by weight of Zr; the mixing and processing stage comprises mechanically crushing and / or hydrogenating crushing of PrNd, and then mixing with DyFe and BFe and pressing The rare earth pressed embryo is obtained, and the rare earth pressed embryo is subjected to high-temperature sintering, primary tempering, hydrogen charging and crushing to obtain a magnetic powder embryo, and finally the magnetic powder embryo is evenly mixed with CuH, and hydrogen charging and crushing and inert gas protection grinding are carried out to obtain a magnetic powder material, and the magnetic powder material is mixed with Fe, Co, Al, Ca and Zr, and after uniform mixing, compression molding and sintering, secondary tempering and tertiary tempering are carried out to obtain a NdFeB material block; the protective film layer stage includes electroplating the NdFeB material block by using an electroplating process, and forming an electroplated copper protective layer on the surface of the NdFeB material block.

7. The method for preparing a NdFeB material according to claim 6, characterized in that: The electroplating treatment adds a crown ether compound with a concentration of 0.1 g-0.2 g / mol and EDTA with a concentration of 0.2-0.4 g / mol.

8. The method for preparing a NdFeB material according to claim 7, characterized in that: The crown ether compound is 15-crown-5, dipyrido-18-crown-6 and / or 4,13-diazabenzo-18-crown-6; wherein the chemical formula of dipyrido-18-crown-6 is .

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