Sintering jig for grain boundary diffusion

Abstract

The utility model discloses a sintering jig for grain boundary diffusion. The sintering jig comprises a bottom plate, the mounting frame is arranged on the bottom plate, an open containing space is formed between the mounting frame and the bottom plate, the mounting frame is composed of a left side plate, a rear panel and a right side plate which are distributed in a U shape, and a plurality of left grooves which are arranged in parallel are formed in the left side plate; right grooves and rear grooves horizontally corresponding to the left grooves are formed in the right side plate and the rear panel respectively, and the left grooves, the rear grooves and the right grooves which are located on the same horizontal plane form clamping grooves; according to the utility model, the drawing plates are arranged in the accommodating space formed by the mounting frame and the bottom plate in a drawable manner, and the drawing plates at any position can be drawn, so that during grain boundary diffusion, the alignment and rapid transfer of magnets are good, and the turnover performance is good; and the exhaust grooves are formed in the two sides of the drawing plate, so that air discharged from the magnet can be effectively discharged during grain boundary diffusion, and the performance of the product is improved.

Description

Technical Field

[0001] This utility model relates to a sintering fixture, and more particularly to a sintering fixture for grain boundary diffusion. Background Technology

[0002] Sintered NdFeB magnets, as third-generation rare-earth permanent magnet materials, are widely used in various fields due to their excellent magnetic properties, especially in high-tech equipment. These high-tech devices have even higher requirements for the magnetic properties of sintered NdFeB permanent magnets. Therefore, using grain boundary diffusion technology is an effective method to improve the magnetic properties of sintered NdFeB permanent magnets.

[0003] The fabrication processes for grain boundary diffusion technology in the industry include vapor deposition diffusion, magnetron sputtering, and surface coating. During the grain boundary diffusion process, after rare earth compounds are deposited on the surface of the NdFeB magnet, it needs to be transported to a high-temperature environment for high-temperature diffusion treatment, followed by cooling and packaging for further processing. This process requires the magnets to undergo high-temperature treatment and multiple transfers. Repeated handling can easily cause the NdFeB magnets to bump and dent, resulting in defects and damage. Therefore, sintering fixtures are used to place the magnets for high-temperature treatment and to assist in the transfer process.

[0004] Currently, the sintering fixtures used in grain boundary diffusion preparation processes include: For example, patent CN 116652182 provides a single-layer NdFeB graphite box, which consists of a sintered material box and a cover plate. The side wall of the material box has four grooves, a simple structure that balances airtightness and venting, but the transfer efficiency of this graphite box is low during mass production; patent CN 218566180 provides an inner and outer double-layer NdFeB graphite box, which has an inner and outer nested structure. When used with a cover plate, it provides a certain degree of sealing. The inner box side wall has elongated ventilation holes to ensure rapid cooling of the magnets in both the inner and outer boxes; however, during mass production, the transfer efficiency of this graphite box is improved compared to the single-layer NdFeB graphite box, but it also has the drawbacks of difficulty in removing magnets when a large number of graphite boxes are stacked, and inconvenient removal of the outer box magnet within the same graphite box.

[0005] The graphite boxes mentioned above are inconvenient to handle and have relatively complex structures, which cannot meet the grain boundary diffusion needs of small and medium-sized enterprises. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of the prior art by providing a sintering fixture for grain boundary diffusion that is low in cost, versatile and reusable, and produces high-performance products.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is: a sintering fixture for grain boundary diffusion, comprising:

[0008] Base plate;

[0009] A mounting frame is disposed on the base plate, and an open receiving space is formed between the mounting frame and the base plate. The mounting frame consists of three U-shaped left side plates, a rear plate, and a right side plate. The left side plates have multiple parallel left grooves. The right side plates and the rear plate have right grooves and rear grooves that are horizontally corresponding to the multiple left grooves, respectively. The left grooves, rear grooves, and right grooves located on the same horizontal plane form a slot.

[0010] A pull-out plate, wherein multiple pull-out plates are sequentially and pull-outly disposed within the slot, and the pull-out plates have venting grooves on both sides, and the pull-out plates are used to hold magnets.

[0011] In one embodiment, the upper surface of the pull-out plate is also evenly distributed with protrusions to provide a gap when in contact with the magnet; wherein each protrusion has a diameter of 1 to 2 mm, a height of 0.1 to 0.3 mm, and a spacing of 1 to 2 mm between each protrusion.

[0012] In one embodiment, the base plate and the mounting frame are made of graphite.

[0013] In one embodiment, the pull-out plate is made of molybdenum.

[0014] In one embodiment, the plurality of left grooves are distributed at equal intervals, and the distance between any two left grooves is 5 to 8 mm.

[0015] In one embodiment, the widths of the left groove, the rear groove, and the right groove are all the same, ranging from 2 to 3 mm.

[0016] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:

[0017] The sintering fixture for grain boundary diffusion of this invention features a pull-out plate arranged in a pull-out manner within a receiving space consisting of a mounting frame and a base plate. This allows magnets to be pulled out from any position on the pull-out plate, facilitating the alignment and rapid transfer of magnets during grain boundary diffusion and providing good turnover performance.

[0018] Secondly, venting grooves are opened on both sides of the pull-out plate, so that the magnet venting can be effectively discharged during grain boundary diffusion after screen printing, which is beneficial to the improvement of product performance.

[0019] In addition, there are evenly distributed protrusions on the pull-out panel, which can effectively reduce the possibility of the pull-out panel sticking to the magnet. Attached Figure Description

[0020] The technical solution of this utility model will be further described below with reference to the accompanying drawings:

[0021] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present utility model;

[0022] Figure 2 This is a perspective view of an embodiment of the present invention with the pull-out plate omitted.

[0023] Figure 3 This is a schematic diagram showing the use of one of the pull-out panels in the extended state in step 1.

[0024] Figure 4 This is a schematic diagram showing the use of a pull-out plate in the pulled-out state in another embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the usage state of this utility model after the magnet is installed;

[0026] The components include: 1. Base plate; 2. Mounting frame; 3. Pull-out plate; 4. Magnet; 10. Accommodation space; 20. Left side plate; 21. Rear panel; 22. Right side plate; 30. Vent groove; 31. Protrusion; 200. Left groove; 220. Right groove; 210. Rear groove. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0028] This invention provides a sintering fixture for grain boundary diffusion, which solves the problems of complex structure, inconvenience in rotating magnets, and poor product performance of existing grain boundary diffusion fixtures.

[0029] For ease of understanding, the specific processes in the embodiments of this application are described below. Please refer to [link / reference]. Figures 1 to 3A sintering fixture for grain boundary diffusion in this application embodiment includes a base plate 1, a mounting frame 2, and a pull-out plate 3. The mounting frame 2 is disposed on the base plate 1, and an open-shaped receiving space 10 is formed between the mounting frame 2 and the base plate 1. The mounting frame 2 is composed of three U-shaped left side plates 20, a rear panel 21, and a right side plate 22. The left side plate 20 has a plurality of parallel left grooves 200. The right side plate 22 and the rear panel 21 have right grooves 220 and rear grooves 210 that are horizontally corresponding to the plurality of left grooves 200, respectively. The left grooves 200, rear grooves 210, and right grooves 220 located on the same horizontal plane form a slot for placing the pull-out plate 3.

[0030] Multiple pull-out plates 3 are sequentially and retractably disposed within the slots. Magnets 4 are placed on top of each pull-out plate 3. Venting grooves 30 are symmetrically distributed on both the front and rear sides of each pull-out plate 3. Specifically, severe gas release occurs during grain boundary diffusion after screen printing. Adding venting grooves 30 to both sides of the pull-out plates allows for effective gas release from the magnets, thereby improving product performance.

[0031] In one embodiment, see Figure 4 The pull-out plate 3 has evenly distributed protrusions 31, each with a diameter of 1-2 mm and a height of 0.1-0.3 mm, and the protrusions are spaced 1-2 mm apart. In use, the magnet 4, after screen printing, easily adheres to the surface of the pull-out plate. The evenly distributed protrusions 31 on the pull-out plate 3 effectively reduce the adhesion between the pull-out plate 3 and the magnet 4, ensuring easy access to the magnet.

[0032] The sintering fixture of this utility model uses a pull-out plate 3 located in the slot to place magnets. When magnets with a spacing of more than two slots are used, two layers can be used together, which greatly enhances the versatility of the sintering fixture and improves the space utilization. Due to the multi-layer pull-out design, the bottom magnet can be easily removed while improving the space utilization, which is convenient for turnover.

[0033] Secondly, a relatively enclosed containment space consisting of a base plate 1 and a mounting frame 2 is adopted. Both the base plate and the mounting frame are made of materials with good thermal conductivity. This allows the magnets in a single zone to be heated quickly and evenly during high-temperature diffusion, resulting in good grain boundary diffusion of the magnets.

[0034] In one embodiment, the multiple left grooves 200 are equidistantly spaced, and the rear groove 210 and right groove 220 are also equidistantly spaced. When the pull-out plate 3 is inserted into the slot formed by the left grooves 200, rear groove 210, and right groove 220, each pull-out plate 3 can hold a magnet of the same capacity. Furthermore, the spacing between any two left grooves 200 is controlled between 5-8 mm to meet the height requirements for magnet placement.

[0035] In one embodiment, the widths of the left groove 200, the rear groove 210, and the right groove 220 are the same, all being 2-3 mm, and can be adjusted according to actual needs.

[0036] In one embodiment, the base plate 1 and the mounting frame 2 are made of graphite, which has the advantages of high melting point, low coefficient of thermal expansion, stable chemical properties, and good thermal conductivity. The graphite box has high thermal conductivity, which allows it to quickly transfer heat, improve the sintering efficiency of the sintering fixture, and also facilitates rapid heat dissipation after high-temperature treatment.

[0037] In one embodiment, the material of the pull-out plate 3 is molybdenum, which is a high-temperature resistant material. The molybdenum content in the pull-out plate 3 is as high as 99% or more, and a small amount of rare earth oxide lanthanum oxide particles are added, which makes the pull-out plate 3 less prone to becoming brittle under long-term high-temperature environment, and also has better processing performance and a long service life.

[0038] See Figure 5 The actual implementation plan is as follows: This sintering fixture has a total of 8 slots, with a spacing of 5mm between two slots; the slot depth is 4mm and the width is 2mm; the magnet size is 4*3*1.5mm and the quantity is 50k; the thickness of the pull plate is 1.5mm, the diameter of the protrusions on the plate is 1mm, the height of the protrusions is 0.1mm, and the interval between each protrusion is 1mm.

[0039] During grain boundary diffusion, the blank is first cut and ground into magnets, then precipitated with rare earth compounds, and then neatly arranged on multiple pull plates 3. Subsequently, the pull plates 3 with magnets are inserted into the slots of the sintering fixture from bottom to top. Finally, the arranged sintering fixture is transferred to a high-temperature environment for grain boundary diffusion.

[0040] Currently, this sintering fixture has been mass-produced in 5 specifications within the company. Specific data is as follows:

[0041] Product Name size quantity magnet 10*10*1 30K magnet 7*2.4*1.6 40K magnet 6*6*0.8 25K magnet 4*3*1.5 50K magnet 1.5*1.2*1.75 18K

[0042] Based on this, the sintering fixture for grain boundary diffusion of this utility model has no limitation on the size of the magnet, the fixture has strong versatility, greatly improves processing efficiency, and has a simple overall structure, which meets the usage requirements.

[0043] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A sintering fixture for grain boundary diffusion, characterized in that, include: Base plate (1); The mounting frame (2) is set on the base plate (1). The mounting frame (2) and the base plate (1) form an open-shaped receiving space (10). The mounting frame (2) consists of three U-shaped left side plates (20), a rear panel (21) and a right side plate (22). The left side plate (20) has a plurality of parallel left grooves (200). The right side plate (22) and the rear panel (21) have right grooves (220) and rear grooves (210) that are horizontally corresponding to the plurality of left grooves (200). The left grooves (200), rear grooves (210) and right grooves (220) located on the same horizontal plane form a slot. Pull-out plate (3), multiple pull-out plates (3) are sequentially pull-out and are provided in the slot, and the two sides of the pull-out plate (3) are provided with exhaust grooves (30), and the pull-out plate (3) is used to place magnets (4).

2. The sintering fixture for grain boundary diffusion as described in claim 1, characterized in that: The upper surface of the pull-out plate (3) is also evenly distributed with protrusions (31) to provide a gap when in contact with the magnet (4); wherein each protrusion (31) has a diameter of 1 to 2 mm and a height of 0.1 to 0.3 mm, and each protrusion (31) is spaced 1 to 2 mm apart.

3. The sintering fixture for grain boundary diffusion as described in claim 1, characterized in that: The base plate (1) and the mounting frame (2) are made of graphite.

4. The sintering fixture for grain boundary diffusion as described in claim 1, characterized in that: The material of the pull-out plate (3) is molybdenum.

5. The sintering fixture for grain boundary diffusion as described in claim 1, characterized in that: The multiple left grooves (200) are distributed at equal intervals, and the distance between any two left grooves (200) is 5 to 8 mm.

6. The sintering fixture for grain boundary diffusion as described in claim 1, characterized in that: The left groove (200), rear groove (210) and right groove (220) have the same width, which is 2-3 mm.

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