Crucible device and equipment for synthesizing silicon carbide powder
By installing sealed graphite plates and connecting plates in silicon carbide powder synthesis equipment using clamping method, the problem of difficulty in opening the crucible caused by atmosphere corrosion is solved, extending the service life of graphite parts and reducing costs.
Patent Information
- Application Number
- CN202420862351.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-24
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-04-24
AI Technical Summary
During the synthesis of silicon carbide powder, the corrosion of the crucible connection structure by the atmosphere makes it difficult to open the crucible, which increases the synthesis cost.
The sealed graphite plate and the connecting plate are installed by clamping to avoid corrosion and damage of the threaded structure, and the connection between the connecting plate and the lifting handle is facilitated to lift the graphite crucible.
It extends the service life of graphite parts, reduces the cost of synthesis of silicon carbide powder, and improves the reliability of the equipment.
Smart Images
Figure CN222761365U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of silicon carbide powder synthesis, in particular to a crucible device and equipment for synthesizing silicon carbide powder. Background Art
[0002] Silicon carbide is a compound formed by carbon and silicon. Currently, more than 200 isomorphous crystal structures of silicon carbide have been discovered. Among them, the hexagonal 4H-SiC (4H-SiC) has the advantages of high critical breakdown electric field and high electron mobility. It is an excellent semiconductor material for manufacturing high-voltage, high-temperature, and radiation-resistant power semiconductor devices. It is also the third-generation semiconductor material with the best comprehensive performance, the highest degree of commercialization, and the most mature technology.
[0003] As the raw material for growing silicon carbide crystals, the morphology, density and purity of silicon carbide powder have a direct impact on the quality of the grown crystals. At present, the commonly used method for synthesizing silicon carbide powder is the solid-heat reaction method, which is to mix high-purity carbon powder and silicon powder, and then heat them up to form silicon carbide through solid-phase reaction. This method has the characteristics of low cost and high purity of the reaction synthesis material. However, since graphite parts are mostly used in the synthesis of silicon carbide powder, the powder easily corrodes the graphite parts, resulting in a reduction in the service life of the graphite parts, especially for crucibles with threaded structures, resulting in high synthesis costs for silicon carbide powder.
[0004] Therefore, it is necessary to provide a crucible device and equipment for synthesizing silicon carbide powder to solve the problem that the crucible is difficult to open due to corrosion of the crucible connection structure by the atmosphere during the synthesis of silicon carbide powder. Utility Model Content
[0005] In view of the above shortcomings of the prior art, the utility model provides a crucible device and equipment for synthesizing silicon carbide powder, so as to improve the problem that the crucible is difficult to open due to corrosion of the crucible connection structure by the atmosphere during the synthesis of silicon carbide powder.
[0006] To achieve the above-mentioned purpose and other related purposes, the utility model provides a crucible device for synthesizing silicon carbide powder, the crucible device comprising: a graphite crucible, a sealed graphite plate, a connecting plate and a handle, the graphite crucible having a cavity for placing raw materials; the sealed graphite plate is clamped on the top of the cavity to seal the cavity; the connecting plate is arranged above the sealed graphite plate and is clamped with the graphite crucible; the handle is detachably connected to the connecting plate.
[0007] In an example of the utility model, a protrusion extending radially inward is provided on the top side wall of the cavity, the protrusion surrounds the circumference of the cavity, and the sealing graphite plate is clamped on the protrusion.
[0008] In an example of the present invention, the sealing graphite plate includes a coaxially arranged cylindrical first graphite plate and a second graphite plate, the first graphite plate is clamped on the inner side of the protrusion, and the second graphite plate is stopped on the protrusion.
[0009] In an example of the utility model, a connecting column is provided on a side of the connecting plate away from the sealing graphite plate, and the carrying handle is threadedly connected to the connecting column.
[0010] In an example of the present invention, an internal thread is provided on the inner wall of the handle, and an external thread matching the internal thread is provided on the outer side of the connecting column.
[0011] In an example of the present utility model, an annular groove is provided on the side wall of the cavity above the protrusion, and the connecting plate is clamped in the annular groove.
[0012] In one example of the utility model, the connecting plate includes a plurality of fan-shaped graphite plates, the thickness of the fan-shaped graphite plates is consistent with the height of the annular groove, and the plurality of fan-shaped graphite plates are arranged in sequence to form a connecting plate matching the groove.
[0013] In an example of the present invention, the cavity side walls on the upper and lower sides of the annular groove respectively form a first clamping platform and a second clamping platform, and the inner diameters of the first clamping platform and the second clamping platform are consistent with the diameter of the second graphite plate.
[0014] In an example of the present invention, the ratio of the wall thickness to the inner diameter of the crucible is 1:(10-500); and / or the ratio of the inner diameter of the crucible to the axial height of the crucible is 1:(1-20).
[0015] The utility model also provides a device for synthesizing silicon carbide powder, wherein the device comprises any one of the above-mentioned crucible devices of the present invention.
[0016] The crucible device of the utility model adopts a clamping method to seal the crucible with a graphite plate, and the graphite crucible is lifted by connecting the connecting plate with the handle, which can avoid the problem of corrosion damage of the thread structure caused by the synthesis process of silicon carbide powder and the graphite crucible that cannot be opened, thereby extending the service life of the graphite parts. On the other hand, the connecting plate is composed of multiple fan-shaped graphite plates, which has a simple structure and is easy to install. The damaged part can also be replaced, which greatly reduces the cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0018] Figure 1 It is a structural schematic diagram of a crucible device for synthesizing silicon carbide powder in one embodiment of the utility model;
[0019] Figure 2 This is a schematic structural diagram of a graphite crucible in one embodiment of a crucible device for synthesizing silicon carbide powder according to the utility model;
[0020] Figure 3 It is a side view schematic diagram of a sealed graphite plate in one embodiment of a crucible device for synthesizing silicon carbide powder according to the utility model;
[0021] Figure 4 It is a top view schematic diagram of a sealed graphite plate in one embodiment of a crucible device for synthesizing silicon carbide powder of the utility model;
[0022] Figure 5 It is a side view schematic diagram of a connecting plate of a crucible device for synthesizing silicon carbide powder in one embodiment of the utility model;
[0023] Figure 6 It is a top view schematic diagram of a connecting plate of a crucible device for synthesizing silicon carbide powder in one embodiment of the utility model;
[0024] Figure 7 It is a side view schematic diagram of a handle of a crucible device for synthesizing silicon carbide powder in one embodiment of the utility model;
[0025] Figure 8 The utility model is a schematic top view of a handle of a crucible device for synthesizing silicon carbide powder in one embodiment.
[0026] Component number description
[0027] 100, graphite crucible; 110, cavity; 111, protrusion; 112, annular groove; 113, first fixture; 114, second fixture; 200, sealing graphite plate; 210, first graphite plate; 220, second graphite plate; 300, connecting plate; 310, fan-shaped graphite plate; 320, connecting column; 321, external thread; 400, handle; 410, internal thread; 500, raw material. DETAILED DESCRIPTION
[0028] The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations. The details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.
[0029] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.
[0030] In the following description, a large number of details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.
[0031] Graphite crucibles have good thermal conductivity and thermal stability, can effectively transfer and disperse heat, prevent overheating or local high temperature during the synthesis process, and can provide a pure reaction environment at high temperature to avoid contamination by impurities. Therefore, graphite crucibles are widely used in the synthesis process of silicon carbide as a container for carrying and conducting high-temperature reactions to ensure the efficiency and quality of silicon carbide synthesis. However, during the synthesis of silicon carbide powder, the powder is prone to corrode the graphite parts, resulting in a reduction in the service life of the graphite parts, especially for crucibles with threaded structures, which has a great impact and increases the synthesis cost.
[0032] In order to solve the above problems, the present application provides a crucible device for synthesizing silicon carbide powder and an apparatus comprising the crucible device. By snap-connecting the graphite crucible with the sealing graphite plate and the connecting plate, the problem of the crucible being difficult to open due to corrosion of the graphite parts by the atmosphere during the synthesis of silicon carbide powder can be significantly improved.
[0033] See also Figure 1In the first aspect, the present invention provides a crucible device for synthesizing silicon carbide powder, which includes a graphite crucible 100, a sealed graphite plate 200, a connecting plate 300 and a handle 400. The graphite crucible 100 is used as a reaction container for silicon carbide powder, and has a cavity 110 for placing raw materials (high-purity carbon powder and silicon powder) 500 inside. The sealed graphite plate 200 is arranged at the top of the cavity 110 to seal the cavity 110 to provide a closed reaction environment for silicon carbide synthesis; the connecting plate 300 is arranged above the sealed graphite plate 200, and the connecting plate 300 and the handle 400 cooperate to facilitate the lifting of the graphite crucible 100 and the transportation of the graphite crucible 100. In order to improve the situation in which the graphite parts cannot be opened due to atmospheric corrosion during the synthesis of silicon carbide powder, the present application abandons the conventional threaded connection method and adopts a clamping method to install the sealed graphite plate 200 and the connecting plate 300, which has a simple structure and is easy and quick to disassemble.
[0034] See also Figure 1 and Figure 2 The graphite crucible 100 can be any three-dimensional structure with a cavity 110 inside, such as a rectangular parallelepiped, a cube, a cylinder, a sphere, etc. Preferably, the graphite crucible 100 is a cylindrical structure. The cylindrical crucible can distribute heat more evenly during the heating process, which helps the material to be heated evenly inside the crucible, thereby improving the efficiency and quality of the synthesis or reaction; it is also conducive to the uniform transfer of heat flow, reducing the problem of local overheating or insufficient heating; and the cylindrical crucible has high space utilization and good structural stability, which helps the crucible to maintain the integrity of its shape and structure under high temperature and heavy load conditions; it has strong adaptability and can be applied to a variety of different heating and smelting equipment, including electric furnaces, gas furnaces, etc. The following description takes a cylindrical graphite crucible as an example. The graphite crucible 100 can have a variety of sizes, which are selected according to actual production needs.
[0035] Further, the ratio of the wall thickness (t) to the inner diameter (d) of the graphite crucible 100 is 1:(10-500). In some embodiments, the ratio t:d of the wall thickness to the inner diameter of the graphite crucible 100 may be 1:10, or 1:100, or 1:300, or 1:500, and so on.
[0036] Further, the ratio of the inner diameter (d) of the graphite crucible 100 to the axial height (h) of the graphite crucible 100 is 1:(1-20). In some embodiments, the ratio d:h of the inner diameter of the graphite crucible 100 to the axial height of the graphite crucible 100 may be 1:1, or 1:10, or 1:20, etc. Selecting a graphite crucible 100 with a suitable ratio can maintain a certain synthesis efficiency and prevent the crucible from cracking.
[0037] See also Figures 1 to 4The sealing graphite plate 200 is mounted on the top of the cavity 110 of the graphite crucible 100 to seal the cavity 110 and prevent the silicon-rich gas from corroding the connecting plate 300 during the synthesis of the silicon carbide powder. In one embodiment, the top side wall of the cavity 110 of the graphite crucible 100 protrudes radially inward to form a protrusion 111, which is arranged around the inner wall of the graphite crucible 100. It can be a continuous annular protrusion or a plurality of small protrusions arranged at intervals along the circumference of the inner wall of the graphite crucible 100. The sealing graphite plate 200 can be directly mounted or placed on the protrusion 111. Furthermore, the sealing graphite plate 200 includes a first graphite plate 210 and a second graphite plate 220 which are coaxially arranged. The first graphite plate 210 and the second graphite plate 220 are both cylindrical. The diameter of the first graphite plate 210 is consistent with the inner diameter of the annular ring formed by the protrusion 111, and the diameter of the second graphite plate 220 is larger than the diameter of the first graphite plate 210. In this arrangement, the first graphite plate 210 is embedded in the inner side of the protrusion 111 to block the silicon-rich gas phase; the second graphite plate 220 is stopped above the protrusion 111 to further seal the clamping point between the first graphite plate 210 and the protrusion 111.
[0038] See also Figure 1 , Figure 2 , Figure 5 and Figure 6 , the connecting plate 300 is clamped on the inner wall of the crucible above the sealing graphite plate 200, and is used to cooperate with the handle 400 to facilitate the transportation of the graphite crucible 100. In one embodiment, an annular clamping groove 112 is provided on the inner wall of the graphite crucible 100 above the protrusion 111, and the connecting plate 300 is clamped in the annular clamping groove 112. As an example, the annular clamping groove 112 is a groove extending radially outward from the inner wall of the graphite crucible 100, and the upper and lower sides of the annular clamping groove 112 form a first clamping platform 113 and a second clamping platform 114 respectively. The inner diameter formed by the first clamping platform 113 and the second clamping platform 114 around a circle matches the diameter of the second graphite plate 220 of the sealing graphite plate 200, and the diameter of the connecting plate 300 is larger than the inner diameter formed by the first clamping platform 113, and is equal to or slightly smaller than the inner diameter of the annular clamping groove 112, so as to limit the connecting plate 300 in the annular clamping groove 112.
[0039] In one embodiment, the connecting plate 300 includes a plurality of fan-shaped graphite plates 310, and the radius of the plurality of fan-shaped graphite plates 310 is the same, and the curvature may be the same or different. During installation, the plurality of fan-shaped graphite plates 310 are sequentially inserted into the annular groove 112, and the last fan-shaped graphite plate 310 is inserted into the annular groove 112 by pushing the fan-shaped graphite plate 310 inserted into the annular groove 112 to form a complete circular connecting plate 300. The number of fan-shaped graphite plates 310 may be two, three, four or more, and no specific restrictions are made here. The more the number of fan-shaped graphite plates 310, the easier it is to insert into the annular groove. Further, the thickness of the fan-shaped graphite plate 310 is consistent with the height of the annular groove 112 (the distance between the first card platform 113 and the second card platform 114). The connecting plate 300 adopts a split structure, which is convenient for the installation of the connecting plate 300 on the one hand, and on the other hand, when one of the fan-shaped graphite plates 310 is damaged, an equivalent replacement can be performed.
[0040] A connecting column 320 is provided on the side of the connecting plate 300 facing away from the sealing graphite plate 200, and the handle 400 is detachably connected to the connecting column 320. When the graphite crucible 100 is installed or needs to be taken out of the equipment, the handle 400 is connected to the connecting column 320, and the graphite crucible 100 can be lifted by pulling the handle 400. It should be noted that the connecting plate 300 is formed by assembling a plurality of fan-shaped graphite plates 310, and the connecting column 320 is also formed by assembling a plurality of split parts, and the plurality of split parts of the connecting column 320 are fixed to the plurality of fan-shaped graphite plates 310 accordingly.
[0041] See also Figure 1 , Figure 7 and Figure 8 In one embodiment, the handle 400 is threadedly connected to the connecting column 320, that is, an external thread 321 is provided on the outer wall of the connecting column 320, and an internal thread 410 matching the external thread is provided on the inner wall of the handle 400. When installing, the handle 400 is clamped on the periphery of the connecting column 320, and the two are connected and fixed by the external thread 321 and the internal thread 410. In other embodiments, a connecting screw hole may be provided on the connecting column 320, and the handle 400 may be provided with an external thread matching the connecting screw hole. When in use, the handle 400 may be inserted into the connecting screw hole, and the threaded connection between the handle 400 and the connecting column 320 may also be achieved.
[0042] The connection method between the handle 400 and the connecting column 320 includes but is not limited to a threaded connection. In other embodiments, the handle 400 and the connecting column 320 can also be connected by a snap-on connection, that is, a snap-on groove is provided on the connecting column 320, and a protrusion that matches the connecting column 320 is provided on the handle 400.
[0043] The utility model also provides a device for synthesizing silicon carbide powder, which comprises a furnace body and the above-mentioned crucible device of the utility model, wherein the crucible device is installed in the furnace body.
[0044] The equipment for synthesizing silicon carbide powder also includes some essential components such as a heating device. The structures not described in detail in the above equipment can be arranged according to the conventional selection in the field and will not be described in detail here.
[0045] The technical solution of the present application is described in detail below through several specific embodiments.
[0046] Example 1
[0047] See also Figures 1 to 8 , this embodiment provides a crucible device, the device comprising:
[0048] A graphite crucible 100 has an outer diameter of 340 mm and a height of 500 mm. An annular protrusion 111 is provided on the inner wall of the crucible. The inner diameter of the annular protrusion 111 is 270 mm and the thickness is 10 mm. An annular groove 112 is provided above the annular protrusion 111. The height of the annular groove 112 is 15 mm. A first card platform 113 and a second card platform 114 are formed on the upper and lower sides of the annular groove 112. The inner diameter of the first card platform 113 is 280 mm and the height is 15 mm. The inner diameter of the second card platform 114 is 280 mm and the height is 10 mm.
[0049] The sealed graphite plate 200 includes a first graphite plate 210 and a second graphite plate 220 which are coaxially arranged. The diameter of the first graphite plate 210 is consistent with the inner diameter of the annular protrusion 111 and the thickness is 10 mm; the diameter of the second graphite plate 220 is consistent with the inner diameter of the second fixture 114 and the thickness is 10 mm.
[0050] The connecting plate 300 includes four identical fan-shaped graphite plates 310 , each of which has a diameter of 320 mm and a thickness of 15 mm. Each fan-shaped graphite plate 310 is provided with a step, and they are spliced together to form a connecting column 320 , and the connecting column 320 is provided with an external thread 321 .
[0051] The handle 400 includes a graphite body, and an internal thread 101 is provided inside the graphite body.
[0052] During installation, first install the sealing graphite plate 200 on the annular protrusion 111, the first graphite plate 210 is clamped on the inner side of the annular protrusion 111, and the second graphite plate 220 is stopped on the annular protrusion 111; then the four fan-shaped graphite plates 310 of the connecting plate 300 are embedded in the annular groove 112 in sequence, and then the handle 400 and the connecting column 320 of the connecting plate 300 are fixed together by threads, and the handle 400 is lifted to place the crucible device in the furnace body of the equipment; after the preparation is completed, the crucible 100 is lifted out of the furnace body by the handle 400.
[0053] Compared with the traditional threaded connection method, the structure provided by this embodiment can significantly extend the service life of the graphite parts, greatly reduce the cost of the graphite parts, and improve competitiveness.
[0054] Example 2
[0055] See also Figures 1 to 8 The difference between this embodiment and embodiment 1 is that:
[0056] A graphite crucible 100 has an outer diameter of 340 mm and a height of 500 mm. An annular protrusion 111 is provided on the inner wall of the crucible. The inner diameter of the annular protrusion 111 is 280 mm and the thickness is 15 mm. An annular groove 112 is provided above the annular protrusion 111. The height of the annular groove 112 is 20 mm and the inner diameter is 320 mm. A first card platform 113 and a second card platform 114 are formed on the upper and lower sides of the annular groove 112. The inner diameter of the first card platform 113 is 300 mm and the height is 20 mm. The inner diameter of the second card platform 114 is 300 mm and the height is 15 mm.
[0057] The sealing graphite plate 200 includes a first graphite plate 210 and a second graphite plate 220 which are coaxially arranged. The diameter of the first graphite plate 210 is consistent with the inner diameter of the annular protrusion 111 and the thickness is 15 mm. The diameter of the second graphite plate 220 is consistent with the inner diameter of the second clamping table 114 and the thickness is 15 mm.
[0058] The connecting plate 300 includes six identical fan-shaped graphite plates 310 , each of which has a diameter of 320 mm and a thickness of 20 mm. Each fan-shaped graphite plate 310 is provided with a step, and they are spliced together to form a connecting column 320 , and the connecting column 320 is provided with an external thread 321 .
[0059] The handle 400 includes a graphite body, and an internal thread 101 is provided inside the graphite body.
[0060] The crucible device of this embodiment can significantly reduce the corrosion loss at the sealing structure of the graphite crucible. The sealed graphite plate can resist the corrosion of the connecting plate 300 by the silicon-rich atmosphere in the synthetic material being transported upward, thereby increasing the service life of the graphite parts and reducing the synthesis cost of silicon carbide raw materials.
[0061] Example 3
[0062] The difference from Example 1 is that the connecting plate 300 is only used when loading and unloading the crucible, and the connecting plate 300 and the handle 400 are removed during the synthesis of the silicon carbide powder; after the synthesis of the silicon carbide powder is completed, the four fan-shaped graphite plates 310 of the connecting plate 300 are sequentially inserted into the annular groove 112, and the handle 400 is connected to the connecting plate 300 to pull out the graphite crucible 100. In this way, the influence of high temperature on the connecting plate can be avoided, the service life of the graphite parts can be extended to a greater extent, and the cost can be reduced.
[0063] The crucible device of the utility model adopts a clamping method to install the sealing graphite plate and the connecting plate in the graphite crucible, and the graphite crucible is lifted by connecting the connecting plate with the handle, which can avoid the corrosion damage of the threaded structure caused by the synthesis process, the problem of the graphite crucible that cannot be opened, and prolong the service life of the graphite parts. On the other hand, the connecting plate is composed of a plurality of fan-shaped graphite plates, which has a simple structure and is easy to install. The damaged part can also be replaced, which greatly reduces the cost. Therefore, the utility model effectively overcomes some practical problems in the prior art and has a high utilization value and use significance.
[0064] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.
Claims
1. A crucible device for synthesizing silicon carbide powder, characterized in that: include: A graphite crucible having a cavity for placing raw materials; A sealing graphite plate is clamped on the top of the cavity to seal the cavity; A connecting plate, arranged above the sealing graphite plate and clamped with the graphite crucible; and A handle is detachably connected to the connecting plate.
2. The crucible device for synthesizing silicon carbide powder according to claim 1, characterized in that: A protrusion extending radially inward is provided on the top side wall of the cavity, the protrusion surrounds the circumference of the cavity, and the sealing graphite plate is clamped on the protrusion.
3. The crucible device for synthesizing silicon carbide powder according to claim 2, characterized in that: The sealing graphite plate comprises a first cylindrical graphite plate and a second graphite plate which are coaxially arranged, wherein the first graphite plate is clamped on the inner side of the protrusion, and the second graphite plate is stopped on the protrusion.
4. The crucible device for synthesizing silicon carbide powder according to claim 1, characterized in that: A connecting column is provided on one side of the connecting plate away from the sealing graphite plate, and the carrying handle is threadedly connected to the connecting column.
5. The crucible device for synthesizing silicon carbide powder according to claim 4, characterized in that: An inner wall of the handle is provided with an internal thread, and an outer side of the connecting column is provided with an external thread matching the internal thread.
6. The crucible device for synthesizing silicon carbide powder according to claim 3, characterized in that: An annular groove is provided on the side wall of the cavity above the protrusion, and the connecting plate is clamped in the annular groove.
7. The crucible device for synthesizing silicon carbide powder according to claim 6, characterized in that: The connecting plate includes a plurality of fan-shaped graphite plates, the thickness of the fan-shaped graphite plates is consistent with the height of the annular slot, and the plurality of fan-shaped graphite plates are arranged in sequence to form a connecting plate matching the slot.
8. The crucible device for synthesizing silicon carbide powder according to claim 6, characterized in that: The cavity side walls at the upper and lower sides of the annular clamping groove respectively form a first clamping platform and a second clamping platform, and the inner diameters of the first clamping platform and the second clamping platform are consistent with the diameter of the second graphite plate.
9. The crucible device for synthesizing silicon carbide powder according to claim 1, characterized in that: The ratio of the wall thickness to the inner diameter of the graphite crucible is 1:(10-500); and / or the ratio of the inner diameter of the graphite crucible to the axial height of the graphite crucible is 1:(1-20).
10. An apparatus for synthesizing silicon carbide powder, characterized in that: A crucible device comprising any one of claims 1 to 9.