Preparation method of low-rare-earth high-performance sintered neodymium iron boron and hydrogen decrepitation device

Abstract

The invention relates to the technical field of neodymium iron boron preparation, in particular to a preparation method of low-rare-earth high-performance sintered neodymium iron boron and a hydrogen decrepitation device. Carrying out coarse crushing on the rare earth elementary substance without the oxide layer; the crushed rare earth elementary substance is mixed with the low-rare earth rapid hardening sheet to be subjected to hydrogen decrepitation; the crushed rare earth elementary substance and the low-rare earth rapid hardening sheet to be subjected to hydrogen breaking are subjected to hydrogen breaking together through a hydrogen breaking furnace, and a diffusion channel is opened; carrying out powder mixing and jet milling on the material subjected to hydrogen demolishing in sequence, and carrying out orientation forming; sintering after isostatic pressing treatment to obtain an internal diffusion magnet; performing external diffusion treatment by taking the internal diffusion magnet as a base material; performing diffusion heat treatment and secondary tempering to obtain a final magnet; the technical problem of how to prepare the low-rare-earth high-performance sintered neodymium-iron-boron magnet is solved.

Description

Technical Field

[0001] This invention relates to the field of neodymium iron boron (NdFeB) preparation technology, specifically to a method for preparing low-rare-earth, high-performance sintered NdFeB and a hydrogen crushing apparatus. Background Technology

[0002] In recent years, the advancement of industrial robot and humanoid robot manufacturing technologies has led to an increasing demand for sintered NdFeB magnets with high remanence and high coercivity due to their low rare earth content. For some small-sized magnets, coating, patching, physical vapor deposition, and screen printing techniques can significantly improve the coercivity, but the remanence will also decrease to varying degrees. Due to the low rare earth content and narrow grain boundaries in low rare earth sintered NdFeB magnets, directly using external diffusion methods to diffuse low rare earth sintered NdFeB magnets presents the problem of narrow diffusion channels and wastes rare earth resources. Therefore, it is difficult to produce magnets with high remanence (≥14.8 kGs).

[0003] Therefore, there is a need for a preparation method that can significantly improve the coercivity of a magnet while ensuring high remanence and using less heavy rare earth elements. Summary of the Invention

[0004] The first aspect of this application proposes a method for preparing low-rare-earth, high-performance sintered NdFeB magnets, which at least solves the problem of how to prepare low-rare-earth, high-performance sintered NdFeB magnets.

[0005] A method for preparing low-rare-earth, high-performance sintered NdFeB magnets includes the following steps:

[0006] Step 1: The rare earth elements with the oxide layer removed are coarsely crushed;

[0007] Step 2: Mix the crushed rare earth elements with the low rare earth rapid solidification sheets to be hydrogen-crushed;

[0008] Step 3: The crushed rare earth elements and the low rare earth rapid solidification sheets to be hydrogen-crushed are hydrogen-crushed together in a hydrogen crushing furnace, which opens up the diffusion channels.

[0009] Step 4: The material after hydrogenation is successively processed through powder mixing and air jet milling, and then oriented and shaped.

[0010] Step 5: After isostatic pressing, sintering is performed to obtain an internally diffused magnet;

[0011] Step 6: Using the internally diffused magnet as a substrate, perform external diffusion treatment; the external diffusion treatment is performed using methods such as coating, patching, magnetron sputtering, or screen printing.

[0012] Step 7: After diffusion heat treatment and secondary tempering, the final magnet is obtained;

[0013] Hold at 850-950℃ for 0.5-24 hours, then perform a second tempering at 450-560℃ for 2-5 hours.

[0014] The second aspect of this application proposes a hydrogen crushing device, which aims to solve the problems of automatic feeding and discharging in a hydrogen crushing furnace.

[0015] A hydrogen crushing device includes a hydrogen crushing unit and a feeding unit disposed on one side of the hydrogen crushing unit. The feeding unit assists in feeding and discharging materials from the hydrogen crushing unit. The feeding unit includes a lifting mechanism disposed opposite to the lifting mechanism and a feeding mechanism disposed between the lifting mechanisms. The lifting mechanism drives the feeding mechanism to lift as a whole, and the feeding mechanism is used to dock with the hydrogen crushing unit for guiding and discharging materials. The feeding mechanism includes a reversing component and a guiding component disposed between the reversing components. The reversing component includes a reversing base frame, with a swing limiting block rotatably fitted on the upper side of the reversing base frame, and a through guide hole on the lower side of the swing limiting block. A rotating shaft passes through the outer side of the steering head. The bearing enables a rotatable connection with the lower side of the reversing base frame. The inner side of the steering head is equipped with a swing output shaft, which is connected to the material guide assembly. The upper side of the steering head is fitted with a groove, and a pivot is installed inside the groove. The switching pressure rod is rotatably engaged with the pivot in the groove through a bushing. The upper side of the switching pressure rod is slidably engaged with the guide hole. A switching spring is fitted on the switching pressure rod, and the switching spring is locked between the swing limit block and the bushing. The left side of the steering head is equipped with a swing input plate. The reversing base frame is equipped with two positioning columns, and the swing input plate is located between the two positioning columns. The upper and lower sides of the lifting mechanism are respectively equipped with an upper reversing pressure plate and a lower reversing pressure plate.

[0016] The beneficial effects achieved by this invention are as follows:

[0017] 1. This invention combines internal and external diffusion techniques. In the internal diffusion stage, a small amount of rare earth elements are added during hydrogen destruction, and two interdiffusions are completed during hydrogen absorption, hydrogen release, and sintering. This not only achieves an initial improvement in coercivity but also effectively opens the diffusion channels of the low-rare-earth magnet, providing a good foundation for external diffusion. In the external diffusion stage, based on optimized diffusion sources and processes, the coercivity is further improved. Under the dual effect, the cumulative improvement in the magnet's coercivity is significant.

[0018] 2. This invention only requires the addition of 0.1-1.5 wt.% rare earth elements to achieve a significant improvement in coercivity. Compared with the 2-3 wt.% heavy rare earth addition in the prior art, this significantly reduces the amount of rare earth used, lowers the manufacturing cost, and avoids the problem of remanence reduction caused by excessive addition of heavy rare earth elements. The final remanence reduction range of the magnet is controlled within 0.01-0.1 kGs, and a high remanence performance of ≥14.8 kGs can be achieved.

[0019] 3. Ultimately, a distinct double-core-shell structure is formed within the magnet. This structure helps stabilize the magnet's magnetic properties and further ensures the magnet's high remanence and high coercivity characteristics. Attached Figure Description

[0020] Figure 1 This is a process flow diagram for the preparation of low-rare-earth, high-performance sintered NdFeB.

[0021] Figure 2 This is a heating curve of the sintering and diffusion treatment of the present invention.

[0022] Figure 3 This is an EPMA diagram of the core-shell structure of the present invention.

[0023] Figure 4 This is a schematic diagram of the dual-shell structure of the present invention.

[0024] Figure 5 This is a schematic diagram of the overall structure of the hydrogen crushing device of the present invention.

[0025] Figure 6 This is a schematic diagram of the overall structure of the present invention.

[0026] Figure 7 This is a schematic diagram of the feeding mechanism of the present invention.

[0027] Figure 8 This is a schematic diagram of the commutation component structure of the present invention. Figure 1 .

[0028] Figure 9 This is a schematic diagram of the commutation component structure of the present invention. Figure 2 .

[0029] Figure 10 This is a schematic diagram of the material discharge process of the present invention.

[0030] Figure 11 This is a schematic diagram of the feeding process of the present invention.

[0031] Figure 12 This is a schematic diagram of the material guiding component structure of the present invention. Figure 1 .

[0032] Figure 13 This is a schematic diagram of the material guiding component structure of the present invention. Figure 2 .

[0033] Figure 14 This is a schematic diagram of the structure of the driving spiral guide component of the present invention.

[0034] Figure 15 This is a schematic diagram of the linkage guide frame structure of the present invention.

[0035] Figure 16 This is a schematic cross-sectional view of the drive spiral guide component of the present invention.

[0036] Figure 17 This is a schematic diagram of the hydrogen fragmentation unit structure of the present invention.

[0037] In the diagram, 1. Lifting seat; 2. Lifting frame; 3. Mounting support plate; 4. Lifting motor; 5. Lifting screw; 6. Lifting slide plate; 7. Reversing base frame; 8. Swing limit block; 9. Guide hole; 10. Steering head; 11. Rotating shaft; 12. Swing output shaft; 13. Slot; 14. Pivot; 15. Switching pressure rod; 16. Bushing; 17. Switching spring; 18. Swing input plate; 19. Positioning column; 20. Upper reversing pressure plate; 21. Lower reversing pressure plate; 22. Guide hopper; 23. Discharge sealing plate; 24. Guide pipe; 25. Docking sleeve plate; 26. Docking fixing frame; 27. Docking cylinder; 28. Docking connecting plate; 29. ​​Drive base frame; 30. Guide switching cylinder 31. Motor base; 32. Material guide motor; 33. Spiral material guide component; 34. External material guide pipe; 35. Material guide shaft; 36. Material guide blade; 37. Telescopic chute; 38. Telescopic slider; 39. Discharge cylinder; 40. Guide wheel; 41. Linkage guide frame; 42. Linkage rope; 43. Linkage spring; 44. Hydrogen crushing furnace; 45. Electric furnace hood; 46. First furnace shell support; 47. Second furnace shell support; 48. Support ear; 49. First hydrogen crushing adjustment frame; 50. Second hydrogen crushing adjustment frame; 51. Adjustment cylinder; 52. Furnace body drive frame; 53. Furnace body drive rail; 54. Furnace body drive shaft; 55. Furnace body drive wheel; 56. Motor bracket; 57. Hydrogen crushing motor. Detailed Implementation

[0038] To facilitate understanding of the present invention by those skilled in the art, specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood through the specific circumstances.

[0040] like Figure 1 As shown, this invention provides a method for preparing low-rare-earth, high-performance sintered NdFeB, comprising the following steps:

[0041] Internal diffusion system internal diffusion magnet

[0042] Step 1: After removing the oxide layer from the rare earth elements, coarsely crush them so that the particle size of the crushed rare earth elements is less than 10mm×10mm×10mm; the rare earth elements are selected from one or more of Tb, Dy, Ho, Gd, Er, Y, Nd, and Ce.

[0043] Step 2: Mix the crushed rare earth elements with the low rare earth base quick-setting tablets to be hydrogen-crushed. The total rare earth content of the low rare earth base quick-setting tablets is 15wt.%≤Re≤29.5wt.%, and the amount of rare earth elements added is 0.1-1.5wt.%.

[0044] Step 3: The crushed rare earth elements and the low rare earth rapid solidification sheets to be hydrogen-crushed are hydrogen-crushed together in a hydrogen crushing furnace.

[0045] Step 301: The mixture is fed into the hydrogen crusher. The temperature is first raised to 120-200℃ and held for 0.5-2 hours before hydrogen absorption begins. The hydrogen absorption pressure is controlled at 0.1-0.35 MPa. The hydrogen absorption time is adjusted according to the loading amount: <300 kg, hydrogen absorption time ≥2 hours; 300 kg < ≤600 kg, hydrogen absorption time ≥2.5 hours; 600 kg < ≤1200 kg, hydrogen absorption time ≥3 hours; 1200 kg < ≤1800 kg, hydrogen absorption time ≥3.5 hours; 1800 kg < ≤2400 kg, hydrogen absorption time ≥4 hours.

[0046] Step 302: When the hydrogen absorption pressure drops to within 10 kPa within 10 minutes, hydrogen absorption is considered saturated, and dehydrogenation begins. The dehydrogenation temperature is controlled at 550-600℃, and the dehydrogenation time is adjusted according to the furnace charge: 4-6 hours for a charge ≤ 300 kg; 5-7 hours for a charge < 300 kg ≤ 600 kg; 6-8 hours for a charge < 600 kg ≤ 1200 kg; 7-9 hours for a charge < 1200 kg ≤ 1800 kg; and 8-10 hours for a charge < 1800 kg ≤ 2400 kg.

[0047] Step 303, hydrogen crushing cooling stage: when the furnace charge is ≤800kg, the cooling time is ≥2h; when the furnace charge is ≤2400kg, the cooling time is ≥4h, ensuring that the hydrogen crushing discharge temperature is <40℃.

[0048] Step 4: The hydrogen-broken material is sequentially processed through mixing and air jet milling, and then oriented and shaped.

[0049] Step 5: After isostatic pressing, sintering is carried out. During the sintering process, the temperature is kept at 800-1000℃ for 0.2-1h to enhance the dehydrogenation effect, and finally an internal diffusion magnet is obtained. The coercivity of the magnet is increased by 3-10kOe compared with the basic rapid solidification sheet, and it serves as the diffusion substrate for external diffusion.

[0050] Step 6: Select an inner diffusion magnet with a thickness of 1-10mm as the outer diffusion substrate and perform outer diffusion treatment.

[0051] External diffusion treatment is performed by coating, patching, magnetron sputtering or screen printing. The diffusion source is a compound composed of one or more elements selected from Pr, Nd and Al, Ga, Cu, Zr, Co, Ti and Nb, and the rare earth content of the diffusion source is 60-90 wt.%.

[0052] Step 7, diffusion heat treatment, hold at 850-950℃ for 0.5-24h, followed by secondary tempering at 450-560℃ for 2-5h;

[0053] After external diffusion treatment, the coercivity of the magnet is further increased by 3-10 kOe, and the remanence of the magnet is reduced within the range of 0.01-0.1 kGs, ultimately forming a distinct double core-shell structure within the magnet.

[0054] Example 1:

[0055] Elemental Tb, after removing its oxide layer, is coarsely crushed into particles of 2 mm × 2 mm × 2 mm size, along with Nd to be hydrogen-processed. 28 Fe bal M 0.5 B 0.9 (M = Co, Al, Zr, Cu, Ti, Nb); 300 kg of coarsely crushed powder and rapidly solidified flakes were mixed at a ratio of 98.5 wt.%:1.5 wt.% to obtain the final product. The furnace was heated to 200℃ and held for 1 hour to begin hydrogen absorption. The hydrogen absorption pressure was 0.3 MPa, and the absorption time was 2 hours. Hydrogen absorption saturation was indicated when the hydrogen absorption pressure dropped to within 10 kPa within 10 minutes, at which point dehydrogenation began. The dehydrogenation temperature was 560℃, the dehydrogenation time was 5 hours, and the cooling time was 2 hours. The furnace exit temperature was controlled below 40℃. After powder mixing, air jet milling, orientation molding, and isostatic pressing, an internally diffused magnet was obtained by sintering at 1070℃ for 5 hours. The sintered magnet was then cut into 5 mm thick blocks perpendicular to the C-axis using wire cutting. The internally diffused magnet was then externally diffused using a patch method. The external diffusion source was composed of Pr. 70 Al 10 Cu 15 Ga5, press Pr 70 Al 10 Cu 15 The Ga5 alloy components were batched and melted into metal ingots using an electric arc melting furnace. The metal ingots were melted three times to ensure their uniformity. The metal ingots were then wire-cut into thin sheets with a thickness of 0.2 mm according to the size of the diffusion substrate. One sheet was placed at the bottom of the diffusion substrate and another sheet was placed on top of the substrate. Diffusion heat treatment was then performed, holding at 900℃ for 10 hours and then at 500℃ for 5 hours.

[0056] Comparative Example 1:

[0057] Elemental Tb is used with its oxide layer removed for formulation purposes, with the nominal component being Nd. 27.58 Tb 1.5 Fe bal M 0.5 B 0.9 (M = Co, Al, Zr, Cu, Ti, Nb); Rapidly solidified sheets were prepared using a melting furnace. 300 kg of these sheets were placed in a hydrogen-breaking furnace for hydrogen absorption. Hydrogen absorption began at a pressure of 0.3 MPa for 2 hours. Hydrogen saturation was indicated when the absorption pressure dropped to within 10 kPa over 10 minutes, at which point dehydrogenation began at 560℃ for 5 hours, followed by a 2-hour cooling period. The furnace exit temperature was controlled below 40℃. After powder mixing, air jet milling, orientation molding, and isostatic pressing, an internally diffused magnet was obtained by sintering at 1070℃ for 5 hours. The sintered magnet was then cut into 5 mm thick blocks perpendicular to the C-axis using wire cutting. The internally diffused magnet was then externally diffused using a patch method. The external diffusion source was composed of Pr. 70 Al 10 Cu 15 Ga5, press Pr 70 Al 10 Cu 15 The Ga5 alloy components were batched and melted into metal ingots using an electric arc melting furnace. The metal ingots were melted three times to ensure their uniformity. The metal ingots were then wire-cut into thin sheets with a thickness of 0.2 mm according to the size of the diffusion substrate. One sheet was placed at the bottom of the diffusion substrate and another sheet was placed on top of the substrate. Diffusion heat treatment was then performed, holding at 900℃ for 10 hours and then at 500℃ for 5 hours.

[0058] Example 2:

[0059] Elemental Dy, after removing its oxide layer, is coarsely crushed into particles of 1 mm × 1 mm × 1 mm in size, and Nd is prepared for hydrogen crushing. 28.5 Fe bal M 0.5 B 0.9(M=Co, Al, Zr, Cu, Ti, Nb), with a coarse powder to quick-setting flake ratio of 99.1 wt.%:0.9 wt.%, a total of 600 kg of powder was used. The furnace was heated to 200℃ and held for 0.8 h to begin hydrogen absorption. The hydrogen absorption pressure was 0.3 MPa, and the absorption time was 2.5 h. Hydrogen absorption saturation was indicated when the hydrogen absorption pressure dropped to within 10 kPa within 10 minutes, at which point dehydrogenation began. The hydrogen temperature was 550℃, the dehydrogenation time was 5 h, and the cooling time was 2 h. The furnace exit temperature was controlled below 40℃. After powder mixing, air jet milling, orientation molding, isostatic pressing, and sintering, an internally diffused magnet was obtained. The sintering temperature was 1065℃ and held for 5 h. The sintered magnet was then cut into 4 mm thick blocks perpendicular to the C-axis using wire cutting. PrH was then diffused into the magnet using a coating method. x Mix with coupling agent and apply, then perform diffusion heat treatment, holding at 890℃ for 12 hours; then at 500℃ for 5 hours.

[0060] Comparative Example 2:

[0061] Elemental Dy is used in formulations after removing the oxide layer, with the nominal component being Nd. 28.243 Dy 0.9 Fe bal M 0.5 B 0.9 (M = Co, Al, Zr, Cu, Ti, Nb) Rapidly solidified sheets were prepared using a melting furnace. 600 kg of these sheets were placed in a hydrogen-breaking furnace for hydrogen absorption. Hydrogen absorption began at a pressure of 0.3 MPa for 2.5 hours. Hydrogen saturation was indicated when the absorption pressure dropped to within 10 kPa over 10 minutes, at which point dehydrogenation began at 550℃ for 5 hours and a cooling time of 2 hours. The furnace exit temperature was controlled below 40℃. After powder mixing, air jet milling, orientation molding, and isostatic pressing, an internally diffused magnet was obtained. The sintering temperature was 1065℃ for 5 hours. The sintered magnet was then cut into 4 mm thick blocks perpendicular to the C-axis using wire cutting. PrH was then diffused into the magnet using a coating method. x Mix with coupling agent and apply, then perform diffusion heat treatment, holding at 890℃ for 12 hours; then at 500℃ for 5 hours.

[0062] Example 3:

[0063] Elemental Ho was deoxidized and coarsely crushed into particles of 1.5 mm × 1.5 mm × 1.5 mm, along with Nd to be hydrogenated. 29 Fe bal M 0.5 B 0.9(M=Co, Al, Zr, Cu, Ti, Nb), with a coarse powder to rapid-setting flake ratio of 99.6 wt.%:0.4 wt.%, a total of 800 kg of powder was used. The furnace was heated to 180℃ and held for 0.5 h to begin hydrogen absorption. The hydrogen absorption pressure was 0.3 MPa, and the absorption time was 3 h. Hydrogen saturation was achieved when the hydrogen absorption pressure dropped to within 10 kPa within 10 minutes. The dehydrogenation temperature was 550℃, the dehydrogenation time was 6 h, and the cooling time was 2 h. The furnace exit temperature was controlled below 40℃. After powder mixing, air jet milling, orientation molding, isostatic pressing, and sintering, an internally diffused magnet was obtained. The sintering temperature was 1060℃ and held for 5 h. The sintered magnet was cut into 4 mm thick blocks perpendicular to the C-axis using wire cutting. Magnet diffusion was then performed using screen printing to diffuse Nd... 70 Cu 20 Ga 10 The smelted metal ingots are hydrogen-crushed, and then the alloy ingots are ball-milled into small particles; subsequently, they undergo diffusion heat treatment, holding at 890℃ for 12 hours and at 500℃ for 5 hours.

[0064] Comparative Example 3:

[0065] Elemental Ho is used in formulations after removing its oxide layer, with the nominal component being Nd. 28.29 Ho 0.4 Fe bal M 0.5 B 0.9 (M = Co, Al, Zr, Cu, Ti, Nb) 800 kg of rapidly solidified sheets were prepared using a melting furnace. Hydrogen absorption was initiated at a pressure of 0.3 MPa for 3 hours. The hydrogen absorption pressure decreased to 10 kPa within 10 minutes. The dehydrogenation temperature was 550℃ for 6 hours, followed by a cooling time of 2 hours. The furnace exit temperature was controlled below 40℃. After powder mixing, air jet milling, orientation molding, and isostatic pressing, an internally diffused magnet was obtained by sintering at 1060℃ for 5 hours. The sintered magnet was then cut into 4 mm thick blocks perpendicular to the C-axis using wire cutting. Magnet diffusion was performed using screen printing to diffuse Nd... 70 Cu 20 Ga 10 The smelted metal ingots are hydrogen-crushed and then ball-milled into small particles; subsequently, they undergo diffusion heat treatment, holding at 890℃ for 12 hours and at 500℃ for 5 hours.

[0066] Table 1. Performance Comparison Table of Examples and Comparative Examples

[0067]

[0068] As can be seen from the table above, the magnet prepared in the embodiments of the present invention has a significantly higher coercivity than the comparative example without any reduction in remanence, which fully demonstrates the superiority of the technical solution of the present invention.

[0069] The hydrogen crushing furnace 44, also known as a hydrogen crushing furnace or hydrogen crushing device, is a processing equipment for neodymium iron boron alloy materials. Its principle is to utilize the characteristics of rare earth permanent magnet alloys during hydrogen absorption and dehydrogenation, which cause the alloy to pulverize, thereby obtaining alloy powder of a certain particle size. In the existing hydrogen crushing device, the furnace body is tilted upward during the feeding operation, and the material is poured into the furnace body by an operator standing on the operating platform. During the unloading operation, the furnace body is tilted downward to facilitate material discharge. The problem with the existing technology is how to realize the feeding and unloading of the hydrogen crushing furnace 44.

[0070] The second aspect of this application proposes a hydrogen crushing device, aimed at solving the auxiliary feeding and discharging problems of the hydrogen crushing furnace 44, such as... Figure 5 As shown, the hydrogen crushing device includes a hydrogen crushing unit and a feeding unit located on one side of the hydrogen crushing unit. The feeding unit assists in the feeding and discharging of the hydrogen crushing unit; as shown... Figure 6 As shown, the feeding unit includes a lifting mechanism arranged opposite to the lifting mechanism and a feeding mechanism located between the lifting mechanisms. The lifting mechanism is used to drive the feeding mechanism to lift as a whole, and the feeding mechanism is used to dock with the hydrogen crushing unit for guiding and discharging materials. The lifting mechanism includes a lifting base 1 and a lifting frame 2 mounted on the lifting base 1. The lifting frame 2 has an n-shaped structure. A lifting motor 4 is fixed to the lower side of the lifting frame 2 by a mounting plate 3. The motor shaft of the lifting motor 4 extends upward from the mounting plate 3 and is fixed to one side of the lifting screw 5 by a coupling. The other side of the lifting screw 5 is rotatably engaged with the upper side of the lifting frame 2 by a bearing. A lifting slide plate 6 is slidably engaged on the lifting frame 2. The lifting slide plate 6 is threadedly engaged with the lifting screw 5, and the feeding mechanism is fixed on the lifting slide plate 6. Figure 7 As shown, the feeding mechanism includes a reversing assembly and a guiding assembly disposed between the reversing assemblies, such as... Figure 8-9 As shown, the reversing assembly includes a reversing base frame 7 with a U-shaped cross-section. A swing limiting block 8 is rotatably fitted on the upper side of the reversing base frame 7, and a through guide hole 9 is provided on the lower side of the swing limiting block 8. The outer side of the steering head 10 is rotatably connected to the lower side of the reversing base frame 7 via a rotating shaft 11 and a bearing. A swing output shaft 12 is provided on the inner side of the steering head 10, and the swing output shaft 12 is connected to the material guiding assembly. A groove 13 is fitted on the upper side of the steering head 10, and a pivot 14 is installed inside the groove 13. A switching pressure rod 15 is rotatably fitted with the pivot 14 in the groove 13 via a bushing 16. The upper side of the switching pressure rod 15 is slidably fitted with the guide hole 9. A switching spring 17 is fitted on the switching pressure rod 15, and the switching spring 17 is fitted between the swing limiting block 8 and the bushing 16. A swing input plate 18 is provided on the left side of the steering head 10, and two positioning posts 19 are provided on the reversing base frame 7. The swing input plate 18 is located between the two positioning posts 19. Figure 6 As shown, the upper and lower sides of the lifting frame 2 are respectively provided with an upper reversing pressure plate 20 and a lower reversing pressure plate 21; Figure 10-11As shown, during feeding, the lifting motor 4 drives the lifting slide plate 6 to move upward; the swing input plate 18 contacts the upper reversing pressure plate 20, driving the steering head 10 to rotate to the right, and the swing input plate 18 contacts the lower positioning column 19. The material guide assembly tilts downward and aligns with the upwardly tilted hydrogen crushing unit to assist in feeding; during discharging, the lifting motor 4 drives the lifting slide plate 6 to move downward; the swing input plate 18 contacts the lower reversing pressure plate 21, driving the steering head 10 to rotate to the left, and the swing input plate 18 contacts the upper positioning column 19. The material guide assembly tilts upward and aligns with the downwardly tilted hydrogen crushing unit to assist in discharging.

[0071] The hydrogen crushing device effectively solves the feeding and discharging problems of the hydrogen crushing furnace 44 through the coordinated work of the feeding unit and the hydrogen crushing unit. It can achieve bidirectional adaptation of "upward tilting discharge" and "downward tilting feeding" through the reversing component, without the need to set up separate devices for feeding and discharging.

[0072] The feeding assembly is used to feed or discharge material into the hydrogen crushing furnace 44 after alignment with the hydrogen crushing unit; such as Figure 12-13 As shown, the material guiding assembly includes a conical material guiding hopper 22 and a discharge sealing plate 23 (slidingly fitted through a groove) slidably fitted to the bottom of the material guiding hopper 22. The discharge sealing plate 23 is semi-arc-shaped. A material guiding pipe 24 is provided at the lower side of the material guiding hopper 22, and the material guiding pipe 24 is connected to the interior of the material guiding hopper 22. A docking sleeve 25 is rotatably fitted on the other side of the material guiding pipe 24. The docking sleeve 25 is used to dock with the feed end of the hydrogen crushing furnace 44. The swing output shaft 12 of the reversing assembly is connected to an L-shaped docking fixing frame 26. The swing output shaft 12 drives the entire material guiding assembly to rotate through the docking fixing frame 26. A docking cylinder 27 is provided on the docking fixing frame 26. The push head of the docking cylinder 27 passes through the docking fixing frame 26 and is fixed to one side of the docking connecting plate 28. The other side of the docking connecting plate 28 is fixed to the outside of the material guiding pipe 24. An L-shaped drive base 29 is provided on the side of the material guiding hopper 22. A material guiding switching cylinder 30 is provided on the drive base 29. Figure 14 As shown, the pusher of the material guiding switching cylinder 30 passes through the drive base 29 and is fixed to the U-shaped motor base 31. The material guiding motor 32 is fixed inside the motor base 31. The motor shaft of the material guiding motor 32 passes through the motor base 31 and is fixed to the spiral material guiding component 33. The spiral material guiding component 33 is rotatably engaged in the material guiding hopper 22 and the material guiding pipe 24. The material guiding motor 32 drives the spiral material guiding component 33 to rotate to assist in feeding or discharging materials.

[0073] One embodiment of the spiral guide component 33 is the existing spiral guide shaft 35. The discharge port of the hydrogen crushing unit is relatively narrow, and when discharging downwards at an angle, blockage easily occurs, preventing material from the hydrogen crushing unit from entering the guide pipe 24. To solve this problem, such as... Figure 14 , 16As shown, the spiral guide component 33 includes an outer guide tube 34 and a guide shaft 35 that slides inside the outer guide tube 34. The guide shaft 35 is fixed to the guide motor 32 via a coupling. The outer guide tube 34 is rotatably connected to the guide hopper 22. Guide blades 36 are provided on the outer side of the outer guide tube 34. The inner cavity of the outer guide tube 34 is provided with a telescopic groove 37, and the outer side of the guide shaft 35 is provided with a telescopic slider 38, which slides within the telescopic groove 37. During feeding, the lifting mechanism drives the feeding mechanism to rise, and the reversing component tilts the guide component downwards to align with the feed inlet of the hydrogen crushing unit. The docking cylinder 27 drives the docking sleeve 25 to complete the docking. The guide motor 32 drives the spiral guide component 33 to rotate in the forward direction, conveying the material in the guide hopper 22 to the hydrogen crushing unit through the guide tube 24 in a conical shape. The large opening of the feed hopper 22 facilitates batch feeding, and the spiral feeding structure can control the feeding speed to avoid instability in the hydrogen crushing reaction caused by excessive feeding. During discharge, the lifting mechanism drives the feeding mechanism to descend, and the reversing component tilts the feeding component upward and aligns it with the discharge port of the hydrogen crushing unit. Then, the docking cylinder 27 extends, pushing the feed tube 24 forward. The docking sleeve 25 rotates to adjust the angle and fits tightly with the discharge port. Subsequently, the feed switching cylinder 30 extends, pushing the feed shaft 35 into the hydrogen crushing furnace 44 of the hydrogen crushing unit. The feed motor 32 starts and drives the feed shaft 35 to rotate. The feed shaft 35 drives the outer feed tube 34 to rotate synchronously through the telescopic slider 38. The rotation of the feed shaft 35 agitates the material near the furnace opening of the hydrogen crushing furnace 44, and the feed blades 36 of the outer feed tube 34 transport the material into the feed hopper 22.

[0074] like Figure 13 As shown, the discharge sealing plate 23 opens during material discharge. In one embodiment, the opening and closing are controlled by a discharge cylinder 39, which is fixed on the drive base 29. The push head of the discharge cylinder 39 passes through the drive base 29 and is fixed to the discharge sealing plate 23. In another embodiment, the discharge sealing plate 23 is opened and closed in conjunction with a guide switching cylinder 30, as shown... Figure 15 As shown, the lower end of the drive base frame 29 is rotatably fitted with a guide wheel 40. The lower side of the drive base frame 29 is provided with an L-shaped cross-section linkage guide frame 41. One end of the linkage rope 42 is fixed to the discharge sealing plate 23, and the other end of the linkage rope 42 passes through the linkage guide frame 41, goes around the guide wheel 40, and is fixed to the motor base 31. A linkage spring 43 is sleeved on the outside of the linkage rope 42 between the linkage guide frame 41 and the discharge sealing plate 23. The guide switching cylinder 30 extends and pulls the discharge sealing plate 23 to open through the linkage rope 42 to discharge material.

[0075] like Figure 5 , 17As shown, the hydrogen crushing unit includes a hydrogen crushing furnace 44 and an electric furnace cover 45 for heating the hydrogen crushing furnace 44. The electric furnace cover 45 is located on both sides of the hydrogen crushing furnace 44. A first furnace support 46 and a second furnace support 47 are respectively provided on both sides of the hydrogen crushing furnace 44. Support ears 48 are provided opposite to each other on the first furnace support 46. A first hydrogen crushing adjustment frame 49 is rotatably engaged between the support ears 48. The opening side of the hydrogen crushing furnace 44 is rotatably engaged with the first hydrogen crushing adjustment frame 49, and the opposite side of the hydrogen crushing furnace 44 is rotatably engaged with the second hydrogen crushing adjustment frame 50. An adjustment cylinder 51 is provided on the upper side of the second furnace support 47. The push head of the adjustment cylinder 51 extends upward through the second furnace support. 47 is connected to the U-shaped furnace body drive frame 52, and the furnace body drive frame 52 is provided with furnace body drive rails 53 on both sides; the second hydrogen crushing adjustment frame 50 is provided with furnace body drive shafts 54 on both sides, and the end of the furnace body drive shaft 54 ​​is rotatably engaged with the furnace body drive wheel 55, and the furnace body drive wheel 55 is in rolling engagement with the furnace body drive rail 53; the adjusting cylinder 51 extends and retracts, driving the hydrogen crushing furnace 44 to rotate around the support ear 48 for angle adjustment; the side of the second furnace shell support 47 is provided with a motor support 56, and the motor support 56 is provided with a hydrogen crushing motor 57, the motor shaft of the hydrogen crushing motor 57 is fixed to the hydrogen crushing furnace 44, and the hydrogen crushing motor 57 is used to drive the hydrogen crushing furnace 44 to rotate.

[0076] The following points need to be explained:

[0077] The accompanying drawings of the embodiments of the present invention only involve the structures involved in the embodiments of the present invention; other structures can refer to general designs.

[0078] For clarity, the thickness of layers or regions is enlarged or reduced in the accompanying drawings used to describe embodiments of the invention; that is, these drawings are not drawn to scale. It is understood that when an element such as a layer, film, region, or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element, or there may be intermediate elements present.

[0079] Where there is no conflict, the embodiments of the present invention and the features thereof can be combined with each other to obtain new embodiments.

[0080] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a low rare earth high performance sintered neodymium-iron-boron, characterized in that, The method comprises the following steps, Step 1, rough crushing of the rare earth element without oxide layer; Step 2, mixing the crushed rare earth element with low-rare earth rapid-setting pieces to be hydrogen broken; Step 3, hydrogen breaking of the crushed rare earth element and the low-rare earth rapid-setting pieces to be hydrogen broken together through a hydrogen breaking furnace, so as to open diffusion channels; Step 4, orientation forming after powder mixing and air flow grinding of the hydrogen broken material; Step 5, sintering after isostatic pressing treatment, to obtain an internal diffusion magnet; Step 6, external diffusion treatment of the internal diffusion magnet as a base material; Step 7, final magnet obtained after diffusion heat treatment and secondary tempering.

2. The preparation method of a low-rare earth high-performance sintered neodymium-iron-boron according to claim 1, characterized in that, The rare earth element is selected from one or more of Tb, Dy, Ho, Gd, Er, Y, Nd and Ce, and the particle size after rough crushing is less than 10 mm x 10 mm x 10 mm.

3. The preparation method of a low-rare earth high-performance sintered neodymium-iron-boron according to claim 1, characterized in that, The step 3 specifically comprises: Step 301, feeding the mixed material into the hydrogen breaking furnace, first heating to 120-200 DEG C, and then holding for 0.5-2 h before starting hydrogen absorption, with the hydrogen absorption pressure controlled at 0.1-0.35 MPa; wherein the hydrogen absorption time is adjusted according to the furnace charge amount: when the furnace charge amount < 300 kg, the hydrogen absorption time is ≥ 2 h; when 300 kg < furnace charge amount ≤ 600 kg, the hydrogen absorption time is ≥ 2.5 h; when 600 kg < furnace charge amount ≤ 1200 kg, the hydrogen absorption time is ≥ 3 h; when 1200 kg < furnace charge amount ≤ 1800 kg, the hydrogen absorption time is ≥ 3.5 h; and when 1800 kg < furnace charge amount ≤ 2400 kg, the hydrogen absorption time is ≥ 4 h; Step 302, when the hydrogen absorption pressure drops within 10 KPa within 10 minutes, it is determined that the hydrogen absorption is saturated, and then the hydrogen is removed, with the hydrogen removal temperature controlled at 550-600 DEG C, and the hydrogen removal time adjusted according to the furnace charge amount: when the furnace charge amount ≤ 300 kg, the hydrogen removal time is 4-6 h; when 300 kg < furnace charge amount ≤ 600 kg, the hydrogen removal time is 5-7 h; when 600 kg < furnace charge amount ≤ 1200 kg, the hydrogen removal time is 6-8 h; when 1200 kg < furnace charge amount ≤ 1800 kg, the hydrogen removal time is 7-9 h; and when 1800 kg < furnace charge amount ≤ 2400 kg, the hydrogen removal time is 8-10 h; Step 303, hydrogen breaking cooling stage, when the furnace charge amount ≤ 800 kg, the cooling time is ≥ 2 h; and when 800 kg < furnace charge amount ≤ 2400 kg, the cooling time is ≥ 4 h, to ensure that the hydrogen breaking discharge temperature is < 40 DEG C.

4. The preparation method of a low-rare earth high-performance sintered neodymium-iron-boron according to claim 1, characterized in that, The diffusion source of the external diffusion is a compound composed of one or more elements selected from Pr, Nd, Al, Ga, Cu, Zr, Co, Ti and Nb, and the rare earth content of the diffusion source is 60-90 wt.%.

5. A hydrogen spallation device characterized by: The application relates to a hydrogen decrepitation device for the preparation method of the low-rare earth high-performance sintered neodymium-iron-boron as claimed in any one of claims 1-4, which comprises a hydrogen decrepitation unit and a feeding unit arranged on one side of the hydrogen decrepitation unit, the feeding unit being used for assisting feeding and discharging of the hydrogen decrepitation unit; the feeding unit comprises oppositely arranged lifting mechanisms and feeding mechanisms arranged between the lifting mechanisms, the lifting mechanisms are used for driving the feeding mechanisms to lift integrally, and the feeding mechanisms are used for guiding and discharging materials in conjunction with the hydrogen decrepitation unit; the feeding mechanisms comprise reversing assemblies and material guiding assemblies arranged between the reversing assemblies, the reversing assembly comprises a reversing base frame (7), an oscillation limiting block (8) is rotationally matched with the upper side of the reversing base frame (7), a through guide hole (9) is formed in the lower side of the oscillation limiting block (8); a steering head (10) is rotationally connected with the lower side of the reversing base frame (7) through a rotating shaft (11) and a bearing, an oscillation output shaft (12) is arranged on the inner side of the steering head (10), and the oscillation output shaft (12) is connected with the material guiding assembly; an embedded groove (13) is arranged on the upper side of the steering head (10), a pivot shaft (14) is arranged in the embedded groove (13), a switching pressure rod (15) is rotationally matched with the pivot shaft (14) in the embedded groove (13) through a shaft sleeve (16), and the upper side of the switching pressure rod (15) is slidably matched with the guide hole (9); a switching spring (17) is sleeved on the switching pressure rod (15), and the switching spring (17) is clamped between the oscillation limiting block (8) and the shaft sleeve (16); an oscillation input plate (18) is arranged on the left side of the steering head (10), the reversing base frame (7) is provided with two positioning columns (19), and the oscillation input plate (18) is located between the two positioning columns (19); and upper and lower reversing pressure plates (20) and (21) are respectively arranged on the upper and lower sides of the lifting mechanisms.

6. A hydrogen cell apparatus as claimed in claim 5, wherein: The material guiding assembly comprises a material guiding hopper (22) and a material discharging cover plate (23) slidably fitted at the bottom of the material guiding hopper (22), the material discharging cover plate (23) is semicircular; the lower end of the side of the material guiding hopper (22) is provided with a material guiding pipe (24), the material guiding pipe (24) is connected with the inside of the material guiding hopper (22); the other side of the material guiding pipe (24) is rotatably fitted with a butt joint sleeve plate (25), the butt joint sleeve plate (25) is used for butt joint with the feeding end of the hydrogen crusher (44); the swing output shaft (12) of the reversing assembly is connected with a butt joint fixing frame (26), the swing output shaft (12) drives the whole material guiding assembly to rotate through the butt joint fixing frame (26); the butt joint fixing frame (26) is provided with a butt joint air cylinder (27), the push head of the butt joint air cylinder (27) penetrates through the butt joint fixing frame (26) and is fixed with one side of a butt joint connecting plate (28), the other side of the butt joint connecting plate (28) is fixed with the outside of the material guiding pipe (24); the side of the material guiding hopper (22) is provided with an L-shaped driving base frame (29), the driving base frame (29) is provided with a material guiding switching air cylinder (30); the push head of the material guiding switching air cylinder (30) penetrates through the driving base frame (29) and is fixed with a square motor base (31), the motor base (31) is fixedly provided with a material guiding motor (32), the motor shaft of the material guiding motor (32) penetrates through the motor base (31) and is fixed with a spiral material guiding piece (33), the spiral material guiding piece (33) is rotatably fitted in the material guiding hopper (22) and the material guiding pipe (24), the material guiding motor (32) drives the spiral material guiding piece (33) to rotate to assist feeding or discharging.

7. A hydrogen cell apparatus as claimed in claim 6, wherein: The spiral material guiding piece (33) comprises an outer material guiding pipe (34) and a material guiding shaft (35) slidably fitted in the outer material guiding pipe (34), the material guiding shaft (35) is fixed with the material guiding motor (32) through a shaft coupling; the outer material guiding pipe (34) is rotatably fitted with the material guiding hopper (22), the outside of the outer material guiding pipe (34) is provided with a material guiding blade (36); the inner cavity of the outer material guiding pipe (34) is provided with an expansion chute (37), the outside of the material guiding shaft (35) is provided with an expansion sliding block (38), the expansion sliding block (38) is slidably fitted in the expansion chute (37).

8. A hydrogen cell apparatus as claimed in claim 7, wherein: The lower end of the driving base frame (29) is rotatably fitted with a guide wheel (40), the lower side of the driving base frame (29) is provided with a linkage guide frame (41) with an L-shaped cross section, one end of a linkage rope (42) is fixed with the material discharging cover plate (23), the other end of the linkage rope (42) penetrates through the linkage guide frame (41), passes around the guide wheel (40) and is fixed with the motor base (31); the outside of the linkage rope (42) between the linkage guide frame (41) and the material discharging cover plate (23) is sleeved with a linkage spring (43); the material guiding switching air cylinder (30) is elongated, the material discharging cover plate (23) is pulled to open through the linkage rope (42), and discharging is performed.

9. A hydrogen cell apparatus as defined in claim 5, wherein: The hydrogen crushing unit comprises a hydrogen crushing furnace (44) and an electric furnace cover (45) for heating the hydrogen crushing furnace (44), the electric furnace cover (45) is arranged on both sides of the hydrogen crushing furnace (44); first and second furnace body supports (46) and (47) are arranged on both sides of the hydrogen crushing furnace (44); support ears (48) are oppositely arranged on the first furnace body support (46), the first hydrogen crushing adjusting frame (49) is rotatably arranged between the support ears (48), the opening side of the hydrogen crushing furnace (44) is rotatably connected with the first hydrogen crushing adjusting frame (49), and the opposite side of the hydrogen crushing furnace (44) is rotatably connected with the second hydrogen crushing adjusting frame (50); the upper side of the second furnace body support (47) is provided with an adjusting cylinder (51), the pushing head of the adjusting cylinder (51) penetrates the second furnace body support (47) upwards and is connected with a U-shaped furnace body driving frame (52), the two sides of the furnace body driving frame (52) are provided with furnace body driving rails (53); the two sides of the second hydrogen crushing adjusting frame (50) are provided with furnace body driving shafts (54), the end portions of the furnace body driving shafts (54) are rotatably connected with furnace body driving wheels (55), the furnace body driving wheels (55) are rotatably connected with the furnace body driving rails (53); the adjusting cylinder (51) is extended and retracted to drive the hydrogen crushing furnace (44) to rotate around the support ears (48) and to be adjusted in angle; the side of the second furnace body support (47) is provided with a motor support (56), the hydrogen crushing motor (57) is arranged on the motor support (56), the motor shaft of the hydrogen crushing motor (57) is fixed with the hydrogen crushing furnace (44), and the hydrogen crushing motor (57) is used to drive the hydrogen crushing furnace (44) to rotate.

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