Crucible for sintering micron-sized ceramic powder

Abstract

A crucible for sintering micron-sized ceramic powder belongs to the technical field of crucibles and is characterized in that a powder spill-proof plate is arranged on the bottom surface of a cover plate, a reserved gap is reserved between the powder spill-proof plate and the cover plate, when powder in a crucible body flows to an exhaust hole along with generated gas, the gas firstly contacts with the powder spill-proof plate, and the powder spill-proof plate is in contact with the exhaust hole; at the moment, under the action of the powder spill-proof plate, the flowing direction of the gas can be changed, the gas flows to the exhaust hole from the reserved gap, and the powder in the gas can be attached to the powder spill-proof plate, so that the powder is prevented from overflowing out of the crucible body along with the flowing of the gas.

Description

Technical Field

[0001] The present application belongs to the technical field of crucibles, and in particular relates to a crucible used for sintering micron-sized ceramic powders. Background Art

[0002] With the rapid development of power electronics, new energy and other industries, especially the rapid popularization of new energy vehicles, the use of high thermal conductivity materials has also increased dramatically. As a key link in connecting electronic components, batteries and other heat-prone parts, thermal management materials must have excellent thermal conductivity. Because carbides, nitrides and some oxide ceramics often have high thermal conductivity, they are used in large quantities as thermal conductive media. Ceramic materials are usually made by adding sintering aids to the corresponding powders, forming and sintering to produce products. Since a large part of ceramic thermal conductive materials are used in the form of micro-particles ranging from tens of microns to hundreds of microns, they will volatilize during the vacuum sintering process as the sintering furnace is evacuated and filled with gas, overflowing the sintering container, polluting the sintering furnace cavity and the vacuum pump pipeline, causing damage to the sintering furnace.

[0003] At the same time, by analyzing the gas discharge process in the container during sintering, it was found that the gas was generated mainly by the volatilization of organic matter in the sintering aid at the initial stage of sintering, which led to a pressure difference between the inside of the sintering container and the furnace body. When the gas in the sintering container is discharged at a faster rate, the powder in the container will be carried out.

[0004] Therefore, it is necessary to have a sintering container that can prevent the ceramic powder from volatilizing and overflowing during sintering. Summary of the invention

[0005] In view of this, it is necessary to provide a sintering container that can exhaust gas in time and prevent ceramic powder from overflowing during the exhaust process.

[0006] The solution of this application to solve the technical problem is:

[0007] A crucible for sintering micron-sized ceramic powders comprises a crucible body, a cover plate and a plurality of powder overflow prevention plates, the cover plate being provided with a plurality of exhaust holes, the powder overflow prevention plates being detachably arranged below the cover plate and having a reserved gap between the cover plate and the plurality of powder overflow prevention plates and the plurality of exhaust holes being arranged one-to-one, and in a direction perpendicular to the cover plate, the projection of the powder overflow prevention plates covers the projection of the exhaust holes.

[0008] Preferably, the powder overflow prevention plate is a straight plate, and a groove is formed on a side of the straight plate facing the cover plate.

[0009] Preferably, the groove is any one of a straight groove, a cross groove and a pound-shaped groove.

[0010] Preferably, the powder overflow prevention plate is a curved plate, and both ends of the curved plate are detachably connected to the cover plate.

[0011] Preferably, the curved plate is any one of a C-shaped curved plate and a W-shaped curved plate.

[0012] Preferably, a plurality of layers of exhaust heat conducting pipes are arrayed in the crucible body.

[0013] Preferably, several layers of the exhaust heat conducting pipes are arranged in a staggered manner.

[0014] Preferably, the exhaust heat conducting pipe is provided with a plurality of vent holes, and the side wall of the crucible body is provided with a plurality of mounting holes along the height direction, and the plurality of mounting holes are provided in one-to-one correspondence with the plurality of exhaust heat conducting pipes and are connected.

[0015] Preferably, a protrusion is provided at a bottom corner of the crucible body.

[0016] Beneficial effects: The present application discloses a crucible for sintering micron-sized ceramic powders, wherein a powder overflow prevention plate is arranged on the bottom surface of a cover plate, and a reserved gap is arranged between the cover plate and the crucible body. When the powder in the crucible body flows toward the exhaust hole along with the generated gas, the gas first contacts with the powder overflow prevention plate. At this time, under the action of the powder overflow prevention plate, the gas will change its flow direction and flow from the reserved gap toward the exhaust hole, and the powder in the gas will adhere to the powder overflow prevention plate, thereby preventing the powder from overflowing the crucible body along with the flow of the gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a diagram of a crucible used for sintering micron-sized ceramic powders in this application;

[0018] Figure 2 A front view of a crucible used for sintering micron-sized ceramic powders in the present application;

[0019] Figure 3 It is a front view of a cover plate in a crucible used for sintering micron-sized ceramic powders in the present application;

[0020] Figure 4 A bottom view of a cover plate in a crucible used for sintering micron-sized ceramic powders in the present application;

[0021] Figure 5 This is a partial enlarged view of the powder overflow prevention plate;

[0022] Figure 6 is a schematic diagram of an exhaust heat pipe;

[0023] Figure 7 A schematic diagram of a W-shaped powder overflow prevention plate;

[0024] Figure 8A schematic diagram of a straight powder anti-overflow plate.

[0025] In the figure: a crucible body 10 , an exhaust heat conducting pipe 110 , a vent hole 111 , a mounting hole 120 , a protrusion 130 , a cover plate 20 , an exhaust hole 210 , a powder overflow prevention plate 220 , and a groove 221 . DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Please see Figures 1 to 8 A crucible for sintering micron-sized ceramic powders comprises a crucible body 10, a cover plate 20 and a plurality of powder overflow prevention plates 220, wherein the cover plate 20 is provided with a plurality of exhaust holes 210, the powder overflow prevention plates 220 are detachably arranged below the cover plate 20, and a reserved gap is provided between the cover plate 20, the plurality of powder overflow prevention plates 220 and the plurality of exhaust holes 210 are arranged one by one, and in a direction perpendicular to the cover plate 20, the projection of the powder overflow prevention plates 220 covers the projection of the exhaust holes 210.

[0028] The granulated ceramic powder in the crucible body 10 needs to be sintered for the second time to remove moisture and other impurities in the ceramic powder. At this time, a large amount of steam and gas will be generated in the crucible body 10. At present, the steam and gas generated by the sintering of the crucible body 10 are discharged from the exhaust hole 210 opened on the cover plate 20. Such an exhaust method will cause part of the ceramic powder to enter the air along with the gas. In order to avoid this situation, the powder overflow prevention plate 220 is arranged below the exhaust hole 210. When the gas is discharged from the crucible body 10, it will first contact the powder overflow prevention plate 220, and the flow path of the gas will change. Under the action of the powder overflow prevention plate 220, the gas originally flowing vertically upward into the exhaust hole is blocked, thereby changing the direction of gas flow, so that the gas is dispersed and flows out along the bottom of the powder overflow prevention plate 220, and then flows to the exhaust hole 210 from the reserved gap formed between the powder overflow prevention plate 220 and the cover plate 20 (after the gas contacts the powder overflow prevention plate 220, it flows to the surroundings along the powder overflow prevention plate 220, and then flows to the exhaust hole 210 from the reserved gap formed between the cover plate 20 and the powder overflow prevention plate 220), and then is discharged from the crucible body 10. During this process, most of the ceramic powder contained in the gas will fall into the crucible body 10 under the obstruction of the powder overflow prevention plate 220, a small part of the ceramic powder will stick to the powder overflow prevention plate 220, and only a very small part of the ceramic part will overflow from the exhaust hole 210, thereby preventing most of the ceramic powder in the gas from volatilizing or overflowing into the crucible body 10 with the flow of the gas, and the powder overflow prevention plate 220 also prevents the ceramic powder from clogging the exhaust hole 210 (reason: most of the ceramic powder falls into the crucible body 10 under the obstruction of the powder overflow prevention plate 220).

[0029] At the same time, when setting the powder overflow prevention plate 220, the powder overflow prevention plate 220 can be tilted and set below the cover plate 20, as long as a reserved gap is ensured between the cover plate 20 and the powder overflow prevention plate 220; at the same time, the opening of the exhaust hole 210 and the design of the powder overflow prevention plate 220 ensure that the gas inside the crucible body 10 is smoothly discharged during the sintering process. The exhaust hole 210 is designed on the cover plate 20, and the number of holes is not limited to 5, and the hole diameter is not limited to 20 mm.

[0030] To verify the effectiveness of the design, ordinary crucibles and crucibles designed by the present invention were used to sinter micron-sized silicon carbide ceramic particles. 4000g of micron-sized powder was placed in each of the two crucibles, and the two crucibles were placed in the same position in the sintering furnace in a horizontal and parallel arrangement. After sintering, the ceramic powders in the crucibles were weighed. Excluding the 10% weight loss caused by the volatilization of the sintering aid during sintering, the theoretical weight should be 3600g. After weighing, the ceramic powder in the ordinary crucible was 2459g, and the mass of the powder overflowed during the exhaust process accounted for as high as 31.7%, which caused extremely serious pollution to the furnace body; the ceramic powder in the crucible designed by the present invention was 3562g, and the mass of the powder overflowed during the exhaust process accounted for only 1.1%, which can effectively solve the overflow problem of micron-sized ceramic powder during sintering.

[0031] Furthermore, the powder overflow prevention plate 220 is a straight plate, and a groove 221 is formed on a side of the straight plate facing the cover plate 20 .

[0032] When setting, the powder overflow prevention plate 220 is a straight plate, which is arranged parallel to the bottom of the exhaust hole 210 and is detachably connected to the cover plate 20 (connected by bolts, and protrusions are provided on both sides of the powder overflow prevention plate 220 to ensure that an exhaust channel is left after being connected to the cover plate 20. The size of the powder overflow prevention plate 220 is larger than the opening size of the exhaust hole 210 to ensure that the powder can be blocked from overflowing during the exhaust process), which is convenient for cleaning the powder overflow prevention plate 220, and a groove 221 can be set on the straight plate so that the gas moves along the shape of the groove 221, and ceramic powder can also be stored in the groove 221.

[0033] At the same time, the shape of the straight plate can be a circular straight plate, a rectangular straight plate or a trapezoidal straight plate. When selecting the shape of the powder overflow prevention plate 220, it is selected according to the usage scenario, and in some occasions, the size of the powder overflow prevention plate 220 should be considered (if the exhaust holes 210 are arranged closely, if the powder overflow prevention plate 220 is too large, it will cause some exhaust holes 210 to have no powder overflow prevention plate 220 under them).

[0034] At the same time, the material of the powder overflow prevention plate 220 should be resistant to high temperatures, and the powder overflow prevention plate 220 made of high-purity graphite can be selected.

[0035] Specifically, the groove 221 is any one of a straight groove, a cross groove and a pound-shaped groove.

[0036] Different shapes of the groove 221 are selected according to the application scenarios. If the shape of the groove 221 is a cross-shaped groove, the gas will move in the groove 221 according to the nature of the gas flow. At this time, the contact time between the gas and the powder overflow prevention plate 220 is prolonged, so that more ceramic powder is retained on the powder overflow prevention plate 220, reducing the overflow rate of the ceramic powder. If a straight groove is set, multiple parallel straight grooves can be set on the powder overflow prevention plate 220.

[0037] Please see Figure 7 Furthermore, the powder overflow prevention plate 220 is a curved plate, and both ends of the curved plate are detachably connected to the cover plate 20.

[0038] In order to increase the contact time between the gas and the powder overflow prevention plate 220 (the gas will flow into the exhaust hole along the shape of the curved plate), the powder overflow prevention plate 220 can be set as a curved plate, and the two ends of the curved plate are connected to the cover plate 20. When the curved plate is connected to the cover plate 20, a bolt connection is adopted (through holes are opened on the cover plate 20 and the powder overflow prevention plate 220, and the screws are inserted into the through holes, and then fixed with nuts), and the curved plate can be a C-shaped curved plate or a W-shaped curved plate.

[0039] Taking the C-shaped powder anti-overflow plate 220 as an example, both ends (horizontally) of the C-shaped powder anti-overflow plate 220 are connected to the cover plate 20, and the gas flows along the two sides (vertically) of the C-shaped powder anti-overflow plate 220 to the reserved gap formed between the powder anti-overflow plate 220 and the cover plate 20. At this time, the path of the gas changes from upward flow to upward flow, then horizontal flow, and then upward flow. It is common sense that the straight line between two points is the shortest. Therefore, it can be seen that the C-shaped powder anti-overflow plate 220 prolongs the contact time and path of the ceramic powder with the C-shaped powder anti-overflow plate 220, and the material of the C-shaped powder anti-overflow plate 220 is the same as that of the straight plate powder anti-overflow plate 220.

[0040] In a preferred embodiment, a plurality of layers of exhaust heat pipes 110 are arranged in an array in the crucible body 10 .

[0041] Several layers of exhaust heat pipes 110 are arranged in the crucible body 10 to increase the overall uniformity of the temperature of the crucible body 10 (during sintering, the exhaust heat pipes 110 transfer the heat from the edge of the crucible body 10 to the middle part of the crucible body 10 to avoid the situation where the middle is cool and the edges are hot), such as: 4 layers of exhaust heat pipes 110 are arranged in sequence along the height direction; and the exhaust heat pipes 110 have a certain support for the ceramic powder to prevent the ceramic powder from being compacted in the crucible body 10, so that when the ceramic powder is sintered, the gas generated will be discharged from the gaps between the ceramic powders or from the contact surface between the ceramic powder and the exhaust heat pipes, thereby increasing the exhaust performance of the crucible body 10; and the exhaust heat pipes 110 are made of isostatic graphite and have high strength.

[0042] The overall beneficial effect is: the temperature uniformity of the crucible body 10 is improved, and the heat preservation effect is played; at the same time, it can support the powder in the crucible body 10, and further improve the exhaust performance of the sintering container.

[0043] When in use, the exhaust heat pipe 110 has 1 layer, 2 layers, 3 layers, 4 layers, 5 layers, or can be selected according to usage requirements.

[0044] In a preferred embodiment, several layers of the exhaust heat pipes 110 are arranged in a staggered manner.

[0045] When arranging the exhaust heat pipes 110, the exhaust heat pipes 110 are installed in a staggered manner, that is: if 4 layers of exhaust heat pipes 110 are set, 2 layers of the exhaust heat pipes 110 are set in the horizontal direction, and two layers of the exhaust heat pipes 110 are set in the vertical direction, when setting, one layer of the exhaust heat pipes 110 is horizontal, and one layer of the exhaust heat pipes 110 is vertical.

[0046] Furthermore, the exhaust heat conducting pipe 110 is provided with a plurality of vent holes 111 , and the side wall of the crucible body 10 is provided with a plurality of mounting holes 120 along the height direction. The plurality of mounting holes 120 are provided in one-to-one correspondence with the plurality of exhaust heat conducting pipes 110 and are connected.

[0047] A plurality of vent holes 111 are provided on the exhaust heat conducting pipe 110, through which gas enters the exhaust heat conducting pipe 110, flows toward the mounting hole 120 inside the exhaust heat conducting pipe 110, and is then discharged from the mounting hole 120, thereby increasing the exhaust performance of the crucible body 10; and in this process, when the gas flows in the exhaust heat conducting pipe, the heat of the gas is transferred to the exhaust heat conducting pipe 110, thereby better improving the temperature uniformity of the crucible body 10.

[0048] Furthermore, a protrusion 130 is provided at a bottom corner of the crucible body 10 .

[0049] When a plurality of the crucible bodies 10 are stacked, in order to prevent the exhaust hole 210 from being pressed by the upper crucible body 10 when stacking, that is, the bottom of the upper crucible body 10 is tightly attached to the lower crucible body 10, resulting in the exhaust hole 210 being unable to exhaust, the protrusion 130 is provided to ensure that the gas in the crucible body 10 can be discharged.

[0050] For example, when two crucible bodies 10 are stacked, the protrusion 130 on the upper crucible body 10 will contact the lower crucible body 10, so that a distance is generated between the bottom of the upper crucible body 10 and the lower crucible body 10, thereby forming a gas channel, ensuring that the gas in the lower crucible body 10 can be discharged from the gas channel when the crucible bodies 10 are stacked for use.

[0051] What is disclosed above is only a preferred embodiment of the present application, and it certainly cannot be used to limit the scope of rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of implementing the above embodiments and equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A crucible for sintering micron-sized ceramic powders, characterized in that: It includes a crucible body, a cover plate and multiple powder overflow prevention plates, the cover plate is provided with multiple exhaust holes, the powder overflow prevention plates are detachably arranged below the cover plate, and there is a reserved gap between the cover plate, the multiple powder overflow prevention plates are arranged one by one corresponding to the multiple exhaust holes, and in the direction perpendicular to the cover plate, the projection of the powder overflow prevention plates covers the projection of the exhaust holes.

2. The crucible for sintering micron-sized ceramic powder according to claim 1, characterized in that: The powder overflow prevention plate is a straight plate, and a groove is formed on one side of the straight plate facing the cover plate.

3. The crucible for sintering micron-sized ceramic powders according to claim 2, characterized in that: The groove is any one of a straight groove, a cross groove and a pound-shaped groove.

4. The crucible for sintering micron-sized ceramic powders according to claim 1, characterized in that: The powder overflow prevention plate is a curved plate, and both ends of the curved plate are detachably connected to the cover plate.

5. The crucible for sintering micron-sized ceramic powder according to claim 4, characterized in that: The curved plate is any one of a C-shaped curved plate and a W-shaped curved plate.

6. The crucible for sintering micron-sized ceramic powder according to claim 1, characterized in that: A plurality of layers of exhaust heat conducting pipes are arranged in an array in the crucible body.

7. The crucible for sintering micron-sized ceramic powder according to claim 6, characterized in that: Several layers of exhaust heat conducting pipes are arranged in a staggered manner.

8. The crucible for sintering micron-sized ceramic powders according to claim 6, characterized in that: The exhaust heat conducting pipe is provided with a plurality of vent holes, and the side wall of the crucible body is provided with a plurality of mounting holes along the height direction. The plurality of mounting holes are arranged in one-to-one correspondence with the plurality of exhaust heat conducting pipes and are connected.

9. The crucible for sintering micron-sized ceramic powder according to claim 1, characterized in that: A protrusion is provided at a corner of the bottom of the crucible body.

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