Batch preparation device and method for thermoelectric material wires

Abstract

The invention discloses a batch preparation device and method for thermoelectric material wires, and the device comprises a heating device which is used for heating raw materials; the quartz tube penetrates through the heating device and can move relative to the heating device, the quartz tube is further provided with an air pressure adjusting device, the air pressure adjusting device is used for adjusting the air pressure in the quartz tube, and the interior of the quartz tube can be in a vacuum environment during heating; the capillary tube device is fixed inside the quartz tube, the capillary tube device comprises a crucible, the crucible is used for containing raw materials, meshes are formed in the bottom of the crucible, and the molten raw materials flow out from the meshes; each capillary tube is inserted into the corresponding mesh hole to be connected with the interior of the crucible, the capillary tubes are used for receiving the molten raw materials flowing out under the action of gravity, so that the interior of the crucible is filled with the molten raw materials, and thermoelectric material wires are obtained after cooling. The batch preparation device can prepare uniform thermoelectric material wires in batches.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermoelectric material wire preparation, and in particular relates to a batch preparation device and method for thermoelectric material wires. Background Art

[0002] Thermoelectric devices based on thermoelectric functional materials can realize the mutual conversion of thermal energy and electrical energy, and are widely used in aerospace, sensing, military, petrochemical, automobile, chip manufacturing and other fields. A typical thermoelectric device is composed of an array of p-type and n-type thermoelectric arms connected in series through electrodes. The size and arrangement of the thermoelectric arms affect the performance of the device.

[0003] With the development of the Internet of Things and chip technology, thermoelectric devices are required to develop in the direction of miniaturization and high-density integration, forcing the size of thermoelectric arms to reach the level of hundreds of microns. At present, the commercial process of preparing thermoelectric arms mainly includes three steps. First, large-diameter thermoelectric material ingots are prepared by zone melting, hot extrusion and other processes, then the ingots are cut into wafers of a certain thickness, and finally the wafers are cut into thermoelectric arm particles of a certain length and width. After three cuts, not only is the process time-consuming, but also the material loss is huge. Especially when preparing thermoelectric arms of hundreds of microns, because the size of the cutting blade is comparable to the thermoelectric particles, the material yield is less than 1 / 4, resulting in high cost of thermoelectric device manufacturing, and also generating a lot of material waste and environmental pollution. In addition, some new thermoelectric materials, such as SnSe single crystals, are not suitable for traditional cutting processes due to their brittleness, which limits the development of their applications. Therefore, it is necessary to avoid the material forming method of the cutting process and develop a new thermoelectric arm preparation technology.

[0004] The invention patent application with the publication number CN114649466A discloses a method for preparing a thermoelectric device based on filling capillaries, which relates to the field of thermoelectric exchange device manufacturing technology. The preparation method includes: preparing a device block; preparing an electrode on the device block; spraying an insulating thermal conductive material on the surface of the electrode to form an insulating thermal conductive layer to prepare a thermoelectric device. The patent application fills thermoelectric materials into capillaries to obtain thermoelectric arms of various sizes; the thermoelectric arms are arranged in a high-density array and infused with insulating materials to prevent the thermoelectric materials from oxidation and moisture; the conductive connection between the P / N materials can be achieved by a simple spraying or sputtering process, and no ceramic substrate is required for support, which greatly improves the structural strength of the device. In addition, the heat transfer surface of the thermoelectric device provided by the present invention can be processed into any shape, which can effectively fit the curved heat source to obtain maximum efficiency.

[0005] The method disclosed in the above patent application can avoid the traditional cutting process. However, this method requires complex gas path design to prepare capillary-filled thermoelectric arms, and only a single thermoelectric material can be obtained each time, which makes it difficult to achieve mass production. Summary of the invention

[0006] The invention discloses a batch preparation device for thermoelectric material wires, which can prepare relatively uniform thermoelectric material wires in batches.

[0007] A specific embodiment of the present invention provides a batch preparation device for thermoelectric material wires, comprising:

[0008] A heating device, the heating device is used to heat the raw material;

[0009] A quartz tube, which passes through the heating device and can move relative to the heating device, and the quartz tube is also provided with an air pressure regulating device, which is used to regulate the air pressure in the quartz tube, wherein the interior of the quartz tube can be made into a vacuum environment during heating;

[0010] A capillary device is fixed inside the quartz tube, and the capillary device comprises:

[0011] A crucible, the crucible is used to hold raw materials, the bottom of the crucible is provided with mesh holes, and the molten raw materials flow out from the mesh holes;

[0012] A plurality of capillaries are provided, each capillary being inserted into the corresponding mesh hole and connected to the interior of the crucible. The capillaries are used to receive the molten raw materials flowing out under the action of gravity, so that the molten raw materials fill the interior, and thermoelectric material wires are obtained after cooling.

[0013] Preferably, the batch preparation device for thermoelectric material wires further comprises:

[0014] stand; stand;

[0015] A slide rail is fixed on the stand, and the heating device is fixed on the slide rail, and the slide rail is used to drive the heating device to move up and down, so that the heating device heats the raw material in the capillary device;

[0016] A quartz tube support, the quartz tube support comprising:

[0017] A quartz tube upper bracket is fixed to the upper end of the base and connected to the upper end of the quartz tube, and the quartz tube upper bracket is used to fix the upper end of the quartz tube;

[0018] The quartz tube lower bracket is fixed at the lower end of the base and connected to the lower end of the quartz tube. The quartz tube lower bracket is used to fix the lower end of the quartz tube.

[0019] The present invention can fix the quartz tube relatively firmly through the quartz tube bracket, and can also slide the heating device through the slide rail so that the heating device heats the crucible and the capillary tube.

[0020] Preferably, the heating device comprises a heating wire, a heat-insulating layer and an outer shell from the inside to the outside, wherein the heating wire is used to heat the raw material.

[0021] Preferably, the air pressure regulating device comprises an air inlet and an air extraction port, and both the air inlet and the air extraction port are at the bottom of the quartz tube;

[0022] The air inlet is used to exchange air before heating and melting the raw materials, and to fill gas when cooling and taking out the thermoelectric material;

[0023] The vacuum port is used to extract air before heating and melting the raw materials, so that the inside of the quartz tube is a vacuum environment. A vacuum gauge is provided on the vacuum port, and the vacuum gauge is used to monitor the vacuum degree in the quartz tube.

[0024] The present invention utilizes an air inlet to achieve ventilation before heating, thereby avoiding the influence of original air on raw materials during the heating process. At the same time, after cooling, an inert gas is introduced to increase the pressure to more conveniently remove the capillary device. The present invention utilizes an exhaust port to place the capillary device in a vacuum environment before heating, which is conducive to obtaining uniform thermoelectric materials.

[0025] Preferably, the quartz tube further comprises:

[0026] A sampling port, located at the top of the quartz tube, and used for placing and taking out the capillary device;

[0027] A support screw is connected to the capillary device, and the support screw is used to fix the capillary device.

[0028] Preferably, the capillary device further comprises:

[0029] A bottom support connected to the bottom of the capillary tube and used to support each capillary tube;

[0030] A fixing device, the fixing device comprising a fixing screw, a crucible clamping ring and a limiting flange;

[0031] The crucible clamping rings are located at the top and bottom of the crucible and are used to fix the crucible;

[0032] The limiting flange is used to separate each capillary from each other;

[0033] The fixing screw is fixed to the base and passes through the crucible clamping ring and the limiting flange, so as to limit the crucible clamping ring and the limiting flange;

[0034] A lifting ring is located on the top of the crucible clamping ring, and is used to assist in lifting the capillary device.

[0035] Preferably, the gap between the mesh and the inserted capillary is sealed by high temperature glue.

[0036] Preferably, the inner diameter of the capillary is 100-2000 microns, and the material of the capillary is glass, silicon dioxide, aluminum oxide or zirconium oxide.

[0037] Preferably, a crucible cover is further provided on the top of the crucible, and the crucible cover is used to prevent the raw materials from volatilizing.

[0038] On the other hand, a specific embodiment of the present invention further provides a method for batch preparation of thermoelectric material wires, wherein the method uses the batch preparation device for thermoelectric material wires to batch prepare thermoelectric material wires, comprising:

[0039] Add the raw materials into the crucible, evacuate and ventilate the chamber to create a vacuum environment inside the quartz tube;

[0040] The heating device is moved to heat the raw materials in the crucible first, and the raw materials melt and enter into a plurality of capillaries. After the raw materials in the crucible are melted, the heating device is continued to move downward to fill the capillaries with the raw materials;

[0041] The temperature of the heating device is lowered, an inert gas is filled in through the gas pressure regulating device, and a plurality of capillaries containing thermoelectric material wires are taken out, thereby obtaining the encapsulated thermoelectric material wires.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention uses the mesh holes at the bottom of the crucible to fill the molten raw material into the capillary, and heats the capillary through relative movement of the quartz tube and the heating device so that the capillary is filled with the molten raw material, thereby obtaining a thermoelectric material wire after cooling.

[0044] Since the present invention heats the raw material in a vacuum environment and uses gravity to fill the molten raw material into the capillary, the volatilization of elements caused by airflow is avoided and the uniformity of the wire composition can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic diagram of a batch preparation device for thermoelectric material wires provided in a specific embodiment of the present invention;

[0046] Figure 2 A schematic diagram of a capillary device provided in a specific embodiment of the present invention.

[0047] Among them, 1-sampling port; 2-outer shell; 3-insulation layer; 4-heating wire; 5-capillary bracket; 6-support screw; 7-vacuum gauge; 8-exhaust port; 9-air inlet; 10-lower bracket of quartz tube; 11-quartz tube; 12-slide rail; 13-stand; 14-upper bracket of quartz tube; 1'-fixing screw; 2'-lifting ring; 3'-crucible; 4'-capillary; 5'-bottom support; 6'-capillary limiting flange; 7'-crucible clamping ring. DETAILED DESCRIPTION

[0048] In conjunction with the accompanying drawings, a specific embodiment of the present invention describes in detail a device for batch preparation of thermoelectric material wires.

[0049] A specific embodiment of the present invention provides a batch preparation device for thermoelectric material wires, such as Figure 1 As shown, it specifically includes 1-sampling port; 2-outer shell; 3-insulation layer; 4-heating wire; 5-capillary bracket; 6-support screw; 7-vacuum gauge; 8-exhaust port; 9-air inlet; 10-quartz tube lower bracket; 11-quartz tube; 12-slide rail; 13-stand; 14-quartz tube upper bracket.

[0050] The quartz tube 11 provided in the specific embodiment of the present invention is fixed on the L-shaped stand 13 through the quartz tube upper bracket 14 and the quartz tube lower bracket 10. The heating device is penetrated by the quartz tube 11 and fixed on the slide rail 12. It can move up and down through the stepping electrode control.

[0051] The heating device provided in the specific embodiment of the present invention is mainly composed of an outer shell 2, a heating wire 4 and an insulation layer 3. The temperature is controlled by a thermocouple and a meter head, and the temperature range is from room temperature to 1200°C. The upper and lower ports of the quartz tube 11 are closed, and the lower port is connected to an exhaust port 8 and an air inlet 9 communicated with the inside of the quartz tube for vacuuming and air intake. A vacuum gauge 7 is also installed on the exhaust port 8 to monitor the air pressure in the quartz tube. The upper port of the quartz tube 11 is provided with a sampling port 1 that can be opened by a rubber ring seal. The capillary device 5 is placed in the quartz tube 11 through the sampling port 1 and docked on the support screw 6. The lower end of the support screw 6 is placed on the seal at the lower end of the quartz tube. The position height of the capillary device 5 in the quartz tube 11 can be adjusted by changing the length of the support screw 6.

[0052] The capillary device 5 provided in the specific embodiment of the present invention has the following structure: Figure 2 As shown, it specifically includes 1'-fixing screw; 2'-hanging ring; 3'-crucible; 4'-capillary; 5'-bottom support; 6'-capillary limiting flange; 7'-crucible clamping ring. The fixing screw 1' passes through the hanging ring 2', the crucible clamping ring 7', the capillary limiting flange 6', and the bottom support 5', and the positions of each component are fixed by screw limiting, providing structural support for the capillary bracket.

[0053] The crucible 3' provided in the specific embodiment of the present invention is a cylindrical structure with an opening at the upper end and a mesh at the bottom end. The crucible has a crucible cover on the upper opening. After the raw materials are filled, the crucible cover is covered to prevent the raw materials from volatilizing. The crucible clamping ring 7' limits and fixes the covered crucible 3' at the upper end position of the capillary device 5.

[0054] The capillary 4' provided in the specific embodiment of the present invention is inserted into the mesh at the bottom of the crucible 3' and connected to the inside of the crucible. The gap between the crucible mesh and the capillary is sealed with high-temperature glue, so that the molten material in the crucible can flow into the capillary without leakage. The material of the capillary 4' can be glass, silicon dioxide, aluminum oxide, zirconium oxide, etc., but is not limited to the materials listed. The inner diameter of the capillary is generally 100-2000 microns. The lower ends of all capillaries fall on the bottom bracket 5', and two capillary limiting flanges 6' are used in the middle to separate the capillaries from each other. The capillary limiting flange 6' is a mesh structure with the same size and distribution as the lower end of the crucible 3', so that each capillary is parallel and aligned to each other. The capillary bracket can be placed and extracted in the quartz tube by hanging the uppermost ring 2' of the capillary bracket with a rope hook. The device can prepare one-dimensional thermoelectric materials and can also be used to prepare other alloy wire materials. The materials include Bi2Te3, SnSe, etc., but are not limited to the materials listed.

[0055] A specific embodiment of the present invention further provides a method for batch preparation of thermoelectric material wires, wherein the method adopts the batch preparation device for thermoelectric material wires to batch prepare thermoelectric material wires, comprising:

[0056] Loading: First, pass several capillaries through the capillary limiting flange 6' and place them on the bottom support 5'. Figure 2 On the crucible clamp ring in the crucible, after the mesh holes at the bottom of the crucible are aligned with the capillary array, the capillary is inserted into the mesh holes at the bottom of the crucible, and the insertion depth of the capillary is not less than 1mm. Use high-temperature sealant to apply to the joint between the capillary and the crucible to ensure sealing. Then fill the particles or ingots of thermoelectric materials into the crucible. The particle diameter is generally larger than the inner diameter of the capillary. After closing the crucible cover, install the lifting ring 2'. Use a rope hook to lift the capillary bracket as a whole through the lifting ring, and Figure 1 The sampling port 1 shown is placed in a quartz tube 11 and placed on the support screw 6, and the rope hook is taken away to close the sampling port 1.

[0057] Melting and casting: Close the valve of the air inlet 9, open the valve of the air exhaust port 8, and evacuate the quartz tube 11. The vacuum degree is monitored by the vacuum meter 7. When the vacuum reaches 0.1 atmosphere, close the valve of the air exhaust port 8, open the valve of the air inlet 9, and fill the quartz tube with argon or nitrogen until the pressure reaches 1 atmosphere. Then repeat the above air extraction and air intake operations for no less than 5 times to complete the air cleaning inside the quartz tube and achieve 99.999% air replacement. Then close the valve of the air inlet 9, open the valve of the air exhaust port 8 to evacuate, and keep the air pressure inside the quartz tube not higher than 0.1 atmosphere. Move the heating device through the slide rail 12 so that the crucible just enters the lower end of the furnace and the capillary is placed outside the furnace. Start the furnace heating, the target temperature is the melting point of the filled thermoelectric material, so that the material inside the crucible melts, and the molten material flows into the capillary from the bottom of the crucible for a distance, and solidifies at a place where the capillary temperature is lower, which can ensure that the material in all capillaries has the same filling length. After all the materials in the crucible are fully melted, the heating device is slowly moved downwards at a speed of 0.01mm / s-1mm / s. The capillary gradually enters the furnace and heats up. The solidified material inside will melt again. Due to the effect of gravity, the entire capillary is gradually filled as the furnace moves downwards. The furnace has a sufficient constant temperature zone length so that the crucible remains in the furnace during the entire downward movement of the furnace.

[0058] After the entire length of the capillary is filled with thermoelectric material, slowly lower the temperature of the furnace to room temperature. Close the valve of the exhaust port 8, open the valve of the air inlet 9 and fill in argon or nitrogen until the pressure reaches 1 atmosphere. Open the cover of the sampling port 1, and use the rope hook to take the capillary bracket out of the quartz tube 11. Cut off the connection between the capillary and the crucible, take out the capillary filled with material, and obtain the encapsulated thermoelectric material wire. The shell of the capillary can also be broken by a shell breaking device to obtain the exposed thermoelectric material wire.

Claims

1. A batch preparation device for thermoelectric material wires, characterized in that: include: A heating device, the heating device is used to heat the raw material; A quartz tube, which passes through the heating device and can move relative to the heating device, and the quartz tube is also provided with an air pressure regulating device, which is used to regulate the air pressure in the quartz tube, wherein the interior of the quartz tube can be made into a vacuum environment during heating; A capillary device is fixed inside the quartz tube, and the capillary device comprises: A crucible, the crucible is used to hold raw materials, the bottom of the crucible is provided with mesh holes, and the molten raw materials flow out from the mesh holes; A plurality of capillaries are provided, each capillary being inserted into the corresponding mesh hole and connected to the interior of the crucible. The capillaries are used to receive the molten raw materials flowing out under the action of gravity, so that the molten raw materials fill the interior, and thermoelectric material wires are obtained after cooling.

2. The batch preparation device of thermoelectric material wire according to claim 1, characterized in that: Also includes stand; stand; A slide rail is fixed on the stand, and the heating device is fixed on the slide rail, and the slide rail is used to drive the heating device to move up and down, so that the heating device heats the raw material in the capillary device; A quartz tube support, the quartz tube support comprising: A quartz tube upper bracket is fixed to the upper end of the base and connected to the upper end of the quartz tube, and the quartz tube upper bracket is used to fix the upper end of the quartz tube; The quartz tube lower bracket is fixed at the lower end of the base and connected to the lower end of the quartz tube. The quartz tube lower bracket is used to fix the lower end of the quartz tube.

3. The batch preparation device of thermoelectric material wire according to claim 1, characterized in that: The heating device comprises a heating wire, a heat-insulating layer and an outer shell in sequence from the inside to the outside, wherein the heating wire is used to heat the raw material.

4. The batch preparation device of thermoelectric material wire according to claim 1, characterized in that: The air pressure regulating device comprises an air inlet and an air extraction port, and both the air inlet and the air extraction port are at the bottom of the quartz tube; The air inlet is used to exchange air before heating and melting the raw materials, and to fill gas when cooling and taking out the thermoelectric material; The vacuum port is used to evacuate air before heating and melting the raw materials, so that the interior of the quartz tube is a vacuum environment. A vacuum gauge is provided on the vacuum port, and the vacuum gauge is used to monitor the vacuum degree in the quartz tube.

5. The batch preparation device of thermoelectric material wire according to claim 1, characterized in that: The quartz tube also includes: A sampling port, located at the top of the quartz tube, and used for placing and taking out the capillary device; A support screw is connected to the capillary device, and the support screw is used to fix the capillary device.

6. The batch preparation device of thermoelectric material wire according to claim 1, characterized in that: The capillary device further comprises: A bottom support connected to the bottom of the capillary tube and used to support each capillary tube; A fixing device, the fixing device comprising a fixing screw, a crucible clamping ring and a limiting flange; The crucible clamping rings are located at the top and bottom of the crucible and are used to fix the crucible; The limiting flange is used to separate each capillary from each other; The fixing screw is fixed to the base and passes through the crucible clamping ring and the limiting flange, so as to limit the crucible clamping ring and the limiting flange; A lifting ring is located on the top of the crucible clamping ring, and is used to assist in lifting the capillary device.

7. The batch preparation device of thermoelectric material wire according to claim 1, characterized in that: The gap between the mesh and the inserted capillary is sealed by high temperature glue.

8. The batch preparation device of thermoelectric material wire according to claim 1, characterized in that: The inner diameter of the capillary is 100-2000 microns, and the material of the capillary is glass, silicon dioxide, aluminum oxide or zirconium oxide.

9. The batch preparation device of thermoelectric material wire according to claim 1, characterized in that: A crucible cover is also provided on the top of the crucible, and the crucible cover is used to prevent the raw materials from volatilizing.

10. A method for batch preparation of thermoelectric material wires, characterized in that: The batch preparation of thermoelectric material wires using the batch preparation device of thermoelectric material wires according to any one of claims 1 to 9 comprises: Add the raw materials into the crucible, evacuate and ventilate the chamber to create a vacuum environment inside the quartz tube; The heating device is moved to heat the raw materials in the crucible first, and the raw materials melt and enter into a plurality of capillaries. After the raw materials in the crucible are melted, the heating device is continued to move downward so that the capillaries are filled with the raw materials; The temperature of the heating device is lowered, an inert gas is filled in through the gas pressure regulating device, and a plurality of capillaries containing thermoelectric material wires are taken out, thereby obtaining the encapsulated thermoelectric material wires.

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