A device and method for batch preparation of thermoelectric material wires

Abstract

The present invention discloses a batch production device and method for thermoelectric material wires. The batch production device includes a heating device for heating raw materials; a quartz tube that passes through the heating device and can move relative to the heating device. The quartz tube is also provided with an air pressure regulating device for regulating the air pressure within the quartz tube, wherein the interior of the quartz tube can be kept in a vacuum during heating; a capillary device fixed inside the quartz tube, the capillary device including: a crucible for holding the raw materials, the bottom of the crucible having mesh holes through which the molten raw materials flow; and a plurality of capillaries, each capillary being inserted into a corresponding mesh hole and connected to the interior of the crucible. The capillaries are used to receive the flowing molten raw materials under the action of gravity, so that the molten raw materials fill the interior, and the thermoelectric material wires are obtained after cooling. The batch production device can produce relatively 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 device and method for batch preparation of thermoelectric material wires. Background Art

[0002] Thermoelectric devices based on thermoelectric functional materials can convert heat into electricity and vice versa, and are widely used in aerospace, sensing, military, petrochemical, automotive, and chip manufacturing. A typical thermoelectric device consists of an array of p-type and n-type thermoelectric arms connected in series via electrodes. The size and arrangement of the arms influence the device's performance.

[0003] With the development of the Internet of Things (IoT) and chip technology, thermoelectric devices are required to be miniaturized and highly integrated, forcing the size of thermoelectric arms to reach the hundreds of micrometer level. The current commercial process for preparing thermoelectric arms primarily involves three steps: first, a large-diameter thermoelectric material ingot is prepared using processes such as zone melting and hot extrusion. The ingot is then cut into wafers of a certain thickness. Finally, the wafers are cut into thermoelectric arm particles of a certain length and width. These three cuts are not only time-consuming but also result in significant material loss. Especially when preparing thermoelectric arms measuring hundreds of micrometers, the material yield is less than one-quarter, as the cutting blades are comparable in size to the thermoelectric particles. This results in high thermoelectric device manufacturing costs, significant material waste, and environmental pollution. Furthermore, the brittleness of some new thermoelectric materials, such as SnSe single crystals, makes them unsuitable for traditional cutting processes, limiting their application. Therefore, it is necessary to develop a novel material forming method that avoids cutting processes and develop a novel thermoelectric arm fabrication technology.

[0004] The invention patent application with publication number CN114649466A discloses a method for preparing a thermoelectric device based on filled capillaries, relating to the field of thermoelectric exchange device manufacturing technology. The preparation method includes: preparing a device block; preparing electrodes on the device block; spraying an insulating thermally conductive material on the surface of the electrode to form an insulating thermally conductive layer to produce a thermoelectric device. This patent application fills the capillaries with thermoelectric materials to obtain thermoelectric arms of various sizes; the thermoelectric arms are arranged in a high-density array and infused with insulating material to prevent oxidation and moisture. The conductive connection between the P / N materials can be achieved using a simple spraying or sputtering process, without the need for a ceramic substrate as support, greatly improving 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, effectively fitting to curved heat sources to achieve maximum efficiency.

[0005] The method disclosed in the above patent application can avoid the traditional cutting process. However, this method requires a complex gas path design to prepare capillary-filled thermoelectric arms, and only a single thermoelectric material can be obtained each time, making 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, passing through the heating device and capable of relative movement therewith, the quartz tube further being provided with an air pressure regulating device for regulating the air pressure within 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 includes:

[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 obtain thermoelectric material wires after cooling.

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

[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, 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 to 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 for ventilation before heating and melting the raw materials, and for filling gas when cooling and removing 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 meter is provided on the vacuum port 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 the original air on the raw materials during the heating process. At the same time, after cooling, an inert gas is introduced to increase the pressure and 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 is located at the top of the quartz tube, and is used to place and remove 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, 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 tube from each other;

[0033] The fixing screw is fixed to the base and passes through the crucible clamping ring and the limiting flange, and is used 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 μm, and the material of the capillary is glass, silica, alumina or zirconia.

[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 quartz tube to create a vacuum environment;

[0040] The heating device is moved to heat the raw materials in the crucible first, and the raw materials melt and enter the multiple 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 raw materials;

[0041] The temperature of the heating device is lowered, an inert gas is filled in through the gas pressure regulating device, and the multiple capillaries containing the thermoelectric material wires are taken out to obtain 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 tube, and through the relative movement of the quartz tube and the heating device, heats the capillary tube so that the capillary tube is filled with the molten raw material, thereby obtaining a thermoelectric material wire after cooling.

[0044] Since the present invention heats the raw materials in a vacuum environment and uses gravity to fill the molten raw materials into the capillary, 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 production 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'-hanging ring; 3'-crucible; 4'-capillary; 5'-bottom support; 6'-capillary limit flange; 7'-crucible clamping ring. DETAILED DESCRIPTION

[0048] With reference to the accompanying drawings, a specific embodiment of the present invention will be described in detail on 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, and the temperature range is from room temperature to 1200°C. The upper and lower ends of the quartz tube 11 are closed, and the lower end 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 for monitoring the air pressure in the quartz tube. The upper end 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 structure of the capillary device 5 provided in the specific embodiment of the present invention is as follows Figure 2 As shown, the structure specifically includes 1'-fixing screw; 2'-lifting ring; 3'-crucible; 4'-capillary; 5'-base support; 6'-capillary limiting flange; and 7'-crucible retaining ring. The fixing screw 1' passes through the lifting ring 2', crucible retaining ring 7', capillary limiting flange 6', and base support 5'. The screws secure the various components in place, providing structural support for the capillary support.

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

[0054] The capillary tube 4' provided in a specific embodiment of the present invention is inserted into the mesh at the bottom end of the crucible 3' and connected to the interior of the crucible. The gap between the crucible mesh and the capillary tube is sealed with high-temperature glue, allowing the molten material in the crucible to flow into the capillary tube without leakage. The material of the capillary tube 4' can be glass, silica, alumina, zirconia, etc., but is not limited to the materials listed. The inner diameter of the capillary tube is generally 100-2000 microns. The lower ends of all capillaries fall on the base 5', and two capillary limiting flanges 6' are used in the middle to separate the capillaries from each other. The capillary limiting flanges 6' have 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 with each other. The capillary tube holder can be placed and removed from the quartz tube by hanging the ring 2' at the top end of the capillary tube holder with a rope hook. This device can be used to prepare one-dimensional thermoelectric materials and can also be used to prepare other alloy wire materials. 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 uses the batch preparation device for thermoelectric material wires to batch prepare thermoelectric material wires, comprising:

[0056] Loading: First, pass several capillaries through the capillary limit flange 6' and place them on the bottom support 5', then place the crucible Figure 2 On the crucible clamp ring, 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. 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 crucible with particles or ingots of thermoelectric materials. 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 then Figure 1 The sampling port 1 shown is placed in the quartz tube 11 and placed on the support screw 6. The rope hook is retracted and the sampling port 1 is closed.

[0057] Melting and Casting: Close the valve at the air inlet 9 and open the valve at the air exhaust 8 to evacuate the quartz tube 11. The vacuum level is monitored using a vacuum gauge 7. When the vacuum reaches 0.1 atmosphere, close the valve at the air exhaust 8 and open the valve at the air inlet 9 to fill the quartz tube with argon or nitrogen until the pressure reaches 1 atmosphere. Repeat this evacuation and filling process at least five times to completely purge the air inside the quartz tube and achieve 99.999% air replacement. Then, close the valve at the air inlet 9 and open the valve at the air exhaust 8 to continue evacuating the air, maintaining the pressure inside the quartz tube at no more than 0.1 atmosphere. Move the heating device using the slide 12 so that the crucible just enters the lower end of the furnace, with the capillary tube positioned outside the furnace. Start heating the furnace to the target temperature of the melting point of the thermoelectric material to be filled. This causes the material inside the crucible to melt. The molten material will flow from the bottom of the crucible into the capillary tube for a distance before solidifying at the cooler temperature of the capillary tube, ensuring that all capillaries have the same fill length. After all the material in the crucible is fully melted, the heating device is slowly moved downward at a speed of 0.01mm / s-1mm / s. The capillary gradually enters the furnace and heats up. The solidified material inside melts again, and gravity gradually fills the capillary as the furnace moves downward. The furnace has a sufficient constant temperature zone to ensure that the crucible remains inside the furnace during the entire downward movement.

[0058] Once the entire length of the capillary tube is filled with thermoelectric material, slowly lower the furnace temperature to room temperature. Close the valve at the exhaust port 8, open the valve at the inlet port 9, and introduce argon or nitrogen until the pressure reaches 1 atmosphere. Open the cover at the sampling port 1 and use a rope hook to remove the capillary tube holder from the quartz tube 11. Cut the connection between the capillary tube and the crucible, remove the filled capillary tube, and you have the encapsulated thermoelectric material wire. Alternatively, use a shell-breaking device to break the capillary tube shell 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, passing through the heating device and capable of relative movement therewith, the quartz tube further being provided with an air pressure regulating device for regulating the air pressure within 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 includes: 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 obtain thermoelectric material wires after cooling.

2. The batch production device for thermoelectric material wires 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, comprising: A quartz tube upper bracket is fixed to the upper end of the stand and connected to the upper end of the quartz tube. The quartz tube upper bracket is used to fix the upper end of the quartz tube; The lower bracket of the quartz tube is fixed at the lower end of the stand and connected to the lower end of the quartz tube. The lower bracket of the quartz tube is used to fix the lower end of the quartz tube.

3. The batch production 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 from the inside to the outside, wherein the heating wire is used to heat the raw material.

4. The batch production device for thermoelectric material wires according to claim 1, characterized in that: The air pressure regulating device includes 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 for ventilation before heating and melting the raw materials, and for filling gas when cooling and removing the thermoelectric material; The vacuum port is used to extract air before heating and melting the raw materials, so that the interior of the quartz tube is a vacuum environment. A vacuum meter is provided on the vacuum port, and the vacuum meter is used to monitor the vacuum degree in the quartz tube.

5. The batch production device for thermoelectric material wires according to claim 1, characterized in that: The quartz tube further comprises: A sampling port is located at the top of the quartz tube, and is used to place and remove 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 production device for thermoelectric material wires 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, 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 tube from each other; The fixing screw is fixed to the base and passes through the crucible clamping ring and the limiting flange, and is used 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 production device for thermoelectric material wires 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 production device for thermoelectric material wires 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 production device for thermoelectric material wires 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 any one of claims 1 to 9 comprises: Add the raw materials into the crucible, evacuate and ventilate the quartz tube to create a vacuum environment; The heating device is moved to heat the raw materials in the crucible first, and the raw materials melt and enter the multiple 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 raw materials; The temperature of the heating device is lowered, an inert gas is filled in through the gas pressure regulating device, and the multiple capillaries containing the thermoelectric material wires are taken out to obtain the encapsulated thermoelectric material wires.

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