A method for preparing a heating element for a molecular beam source furnace

Abstract

The application relates to the technical field of heating tool, in particular to a preparation method of a heating body for a molecular beam source furnace, preparation of metal slurry and two ceramic green compacts; the metal slurry is printed on the surface of the first ceramic green compact to obtain a conductive circuit; the second ceramic green compact is laminated on the surface of the first ceramic green compact printed with the metal slurry to form a laminated body, the laminated body is rolled into a cylindrical shape and is hot-pressed by a hot press to obtain a first sample; the first sample is sintered to obtain the heating body; the heating wire does not need to be manually wound, the production is simple, mass production is suitable, and the production cost is effectively reduced.

Description

Technical Field

[0001] This application relates to the field of heating tooling technology, and more specifically, to a method for preparing a heating element for a molecular beam source furnace. Background Technology

[0002] The prior art CN112430799A discloses that multiple wire-passing holes are provided circumferentially on the side wall of the insulating crucible body. Each wire-passing hole extends along the axial direction of the insulating crucible body and passes through both ends of the insulating crucible body. The heating wire passes through each wire-passing hole in sequence to obtain a thermal evaporation crucible (which is a heating body used in a molecular beam source furnace). However, the winding of this heating wire requires manual winding, which is complicated and time-consuming, and is not suitable for mass production.

[0003] There is currently no effective technical solution to the above problems. Summary of the Invention

[0004] The purpose of this application is to provide a method for preparing a heating element for a molecular beam source furnace, which eliminates the need for manual winding of heating wires, is simple to manufacture, is suitable for mass production, and effectively reduces production costs.

[0005] This application provides a method for preparing a heating element for a molecular beam source furnace, including the following steps:

[0006] S1. Prepare metal slurry and two ceramic green bodies;

[0007] S2. The metal paste is printed on the surface of the first ceramic green body to obtain conductive lines;

[0008] S3. The second ceramic green body is stacked on the surface of the first ceramic green body printed with the metal paste to form a laminate. The laminate is rolled into a cylindrical shape and hot-pressed by a hot press to obtain the first sample.

[0009] S4. Sinter the first sample to obtain a heating body.

[0010] With the above setup, there is no need to manually wind the heating wire, making it simple to manufacture, suitable for mass production, and effectively reducing production costs.

[0011] Optionally, step S1 includes:

[0012] Two ceramic green bodies were prepared using a tape casting method;

[0013] Preparation of organic carriers for metal powders and slurries;

[0014] The metal slurry is prepared using the metal powder and the slurry organic carrier.

[0015] This application uses a casting method to prepare two ceramic green bodies, which simplifies the process and makes it easy to mass-produce.

[0016] Optionally, the step of preparing two ceramic green bodies using the tape casting method includes:

[0017] Add sintering aid, solvent and dispersant to Al2O3 powder with a purity ≥ 99.99% and stir until homogeneous;

[0018] Add a binder and plasticizer in a mass ratio of 1:1, wherein the binder content is 6wt%-13wt%, and stir again;

[0019] Then add alumina balls to obtain a mixture. The mixture is ball-milled for 24 hours to remove small balls and large particles, and to remove bubbles, resulting in a stable slurry.

[0020] The stabilized slurry is poured into a casting coating machine for casting. After drying, the cast film is peeled off to obtain the ceramic green body.

[0021] Optionally, the step of preparing the metal powder and slurry organic carrier includes:

[0022] Tungsten powder and manganese powder are mixed at a mass ratio of 9:1 to obtain a mixed powder. 3 wt% vanadium is added and stirred. Then anhydrous ethanol is added and ball milled for 4 hours. Finally, the powder is dried to obtain the metal powder. The mass ratio of the mixed powder, the vanadium and the anhydrous ethanol is 1:1.5:1, and the ball milling speed is 500 r / min.

[0023] Terpineol, ethyl cellulose and anhydrous ethanol were mixed in a mass ratio of 94:5:1, heated in an 80°C water bath, and stirred for 10-30 minutes at a stirring speed of 300 r / min to obtain the slurry organic carrier.

[0024] Optionally, the step of preparing the metal slurry using the metal powder and the slurry organic carrier includes:

[0025] The metal powder and the slurry organic carrier are mixed at a mass ratio of 9:1 and then ball-milled for 6 hours at a ball milling speed of 500 r / min to uniformly disperse the metal powder in the slurry organic carrier. After ball milling, the metal slurry is obtained.

[0026] Optionally, step S2 includes:

[0027] The conductive lines are formed by printing the metal paste onto the surface of the first ceramic green body using a screen printing machine. The screen printing machine has multiple sets of slots, and the weight range of the metal paste printed onto the surface of the first ceramic green body by each set of slots is 23 mg / cm² - 24 mg / cm².

[0028] With the above setup, there is no need to manually wrap heating wires around the ceramic body, which is simple to operate and helps to improve production efficiency.

[0029] Optionally, the hot press operates at a temperature of 50℃-70℃ and a hot pressing pressure of 8MPa-13MPa.

[0030] Optionally, step S4 includes:

[0031] The first sample was placed in a high-temperature sealed sintering furnace with a sintering atmosphere of wet hydrogen. The binder was removed at 600°C for 6 hours. After the binder was removed, the first sample was heated to 1650°C for 10 hours and held at that temperature for 2 hours. Then, the first sample was cooled to room temperature for 6 hours to obtain the heating body.

[0032] Optionally, the wet hydrogen is obtained by passing a mixture of nitrogen and hydrogen produced by an ammonia decomposition generator through water at 37°C.

[0033] Optionally, after step S4, the method further includes:

[0034] S5. Locate the preset electrode of the conductive circuit on the heating element by ultrasonic positioning;

[0035] S6. Laser ablation is used to ablate the ceramic on the surface of the heating element, so that the preset electrode is exposed;

[0036] S7. The preset electrode end and the external heating wire are connected by brazing, and the external heating wire is connected to a DC power supply.

[0037] Beneficial Effects: This application provides a method for preparing a heating element for a molecular beam furnace. Metal paste is printed onto the surface of a first ceramic green body to obtain conductive lines, eliminating the need for manual winding of heating wires. This simplifies manufacturing and effectively reduces production costs. The laminate is rolled into a cylindrical shape and hot-pressed using a hot press, thus embedding the conductive lines within the heating element's wall. This effectively reduces energy loss through thermal radiation, allowing the heating element to heat up faster and save energy. Furthermore, in ultra-high vacuum environments, the heating element prepared in this application reduces the adverse effects of heavy metal leakage caused by heating wire heating on the experimental environment. Moreover, sintering enhances the structural strength of the heating element. The preparation method of this application reduces the overall manufacturing time of the heating element, making it suitable for mass production. Attached Figure Description

[0038] Figure 1 This is a schematic flowchart illustrating the preparation method of the heating element for the molecular beam source furnace provided in this application.

[0039] Figure 2 A schematic diagram of the structure of the laminate provided in this application.

[0040] Figure 3 This is a schematic diagram of the conductive circuit provided in this application.

[0041] Figure 4 This is a schematic diagram illustrating the effect of rolling the laminated body provided in this application into a cylindrical shape.

[0042] Figure 5 This is a schematic diagram of the structure of the heating element provided in this application.

[0043] Labeling explanation: 10. Ceramic green body; 11. Conductive circuit; 12. External heating wire. Detailed Implementation

[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0045] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0046] Please refer to Figures 1-5 , Figure 1 This is a schematic flowchart of a method for preparing a heating element for a molecular beam source furnace according to an embodiment of this application. It eliminates the need for manual winding of heating wires, simplifies the manufacturing process, reduces the overall manufacturing time of the heating element, and is suitable for mass production.

[0047] This application provides a method for preparing a heating element for a molecular beam source furnace, including the following steps:

[0048] S1. Prepare metal slurry and two ceramic green bodies 10;

[0049] S2. The metal paste is printed on the surface of the first ceramic green body 10 to obtain the conductive line 11;

[0050] S3. The second ceramic green body 10 is stacked on the surface of the first ceramic green body 10 printed with metal paste to form a laminate. The laminate is rolled into a cylindrical shape and hot-pressed by a hot press to obtain the first sample.

[0051] S4. Sinter the first sample to obtain the heating body.

[0052] Specifically, such as Figure 1 and Figure 2 As shown, metal paste is printed onto the surface of the first ceramic green body 10 to obtain conductive lines 11. This eliminates the need for manually winding heating wires, simplifying the process compared to existing technologies and effectively reducing production costs. The laminate is then rolled into a cylindrical shape and hot-pressed using a hot press, thus embedding the conductive lines 11 within the wall of the heating element. This effectively reduces energy loss through thermal radiation, enabling the heating element to heat up faster and save energy. Furthermore, in ultra-high vacuum environments, the heating element produced in this application reduces the adverse effects of heavy metal leakage caused by heating wire heating on the experimental environment. Moreover, the heating element is obtained through sintering, such as... Figure 5 As shown, the structural strength of the heating element is enhanced, and the preparation method of this application can reduce the overall manufacturing time of the heating element, making it suitable for mass production.

[0053] In some implementations, step S1 includes:

[0054] Two ceramic green bodies 10 were prepared based on a tape casting method;

[0055] Preparation of organic carriers for metal powders and slurries;

[0056] Metal slurry is prepared using metal powder and organic carrier slurry.

[0057] Specifically, due to the advantages of tape casting, such as simple equipment, continuous operation, high production efficiency, high level of automation, stable process, high repeatability of the properties of the formed green body, high consistency of dimensions, and uniform properties of the green body, it has been widely used in the forming process of ceramic materials. Therefore, the tape casting method is used to prepare two ceramic green bodies 10, which makes the process simple and easy to mass-produce.

[0058] In some embodiments, the steps of preparing two ceramic green bodies 10 based on the tape casting method include:

[0059] Add sintering aid, solvent and dispersant to Al2O3 powder with a purity ≥ 99.99% and stir until homogeneous;

[0060] Add binder and plasticizer in a 1:1 mass ratio, with the binder content being 6wt%-13wt%, and stir again;

[0061] Then add alumina balls to obtain a mixture. The mixture is ball-milled for 24 hours to remove small balls and large particles, and to remove bubbles, resulting in a stable slurry.

[0062] The stabilized slurry is poured into a casting coating machine for casting. After drying, the cast film is peeled off to obtain ceramic green body 10.

[0063] Specifically, through the above preparation steps, two ceramic green bodies 10 with the same shape, thickness, and size can be prepared respectively; wherein, the average particle size of Al2O3 powder is approximately 380μm, 0.4wt% magnesium oxide and 0.75wt% yttrium oxide are used as sintering aids, a mixture of alcohol and butanone is used as the solvent, and a certain amount of TEA (triethanolamine) is used as the dispersant, and PVB (polyvinyl butyral) is used. PEG400 (polyethylene glycol 400) and DBP (dibutyl phthalate) are used as binders and plasticizers. In this application, the stirring tool is preferably a glass rod, but it is not limited to this in actual use. The mixture is ball-milled for 24 hours using a planetary ball mill, which is a prior art technology. Four grinding jars are mounted on the same turntable. When the turntable rotates, the grinding jars revolve around the turntable axis and rotate around their own axis, making planetary motion. The grinding balls in the grinding jars collide with each other in high-speed motion, thereby grinding the material in the grinding jars and mixing all the materials in the grinding jars. After ball milling, small balls and large particles are removed, and bubbles are removed, thereby obtaining a stable slurry.

[0064] In some embodiments, the steps of preparing the metal powder and slurry organic carrier include:

[0065] Tungsten powder and manganese powder were mixed at a mass ratio of 9:1 to obtain a mixed powder. 3 wt% vanadium was added and stirred. Then anhydrous ethanol was added and ball milled for 4 hours. Finally, the powder was dried to obtain metal powder. The mass ratio of the mixed powder, vanadium and anhydrous ethanol was 1:1.5:1 and the ball milling speed was 500 r / min.

[0066] Terpineol, ethyl cellulose and anhydrous ethanol were mixed in a mass ratio of 94:5:1, heated in an 80°C water bath and stirred for 10-30 minutes at a stirring speed of 300 r / min to obtain a slurry organic carrier.

[0067] Specifically, the above methods can be used to prepare organic carriers for metal powders and slurries.

[0068] In some embodiments, the step of preparing the metal paste using metal powder and a slurry organic carrier includes:

[0069] Metal powder and organic slurry carrier were mixed at a mass ratio of 9:1 and then ball-milled for 6 hours at a speed of 500 r / min to ensure uniform dispersion of the metal powder in the organic slurry carrier. The resulting metal slurry had a viscosity of 20 Pa·s to 24 Pa·s, preferably 22 Pa·s.

[0070] In some implementations, step S2 includes:

[0071] A screen printing machine is used to print metal paste onto the surface of the first ceramic green body 10 to form conductive lines 11. The screen printing machine is equipped with multiple sets of slots, and the weight range of the metal paste printed onto the surface of the first ceramic green body 10 by each set of slots is 23mg / cm-24mg / cm.

[0072] Specifically, a metal paste is printed onto the surface of the first ceramic green body 10 using a screen printing machine (existing technology) to form conductive lines 11. The grooves are specifically set according to the required shape of the conductive lines 11. Figure 3 This is one type of conductive circuit 11 illustrated in this application. The specific shape of the conductive circuit 11 can be set according to actual needs and is not specifically limited here. The process is simple and easy to operate, thus eliminating the need to manually wrap heating wires on the ceramic body, which helps to improve production efficiency.

[0073] In some implementations, the hot press operates at a temperature of 50°C to 70°C and a hot pressing pressure of 8MPa to 13MPa.

[0074] In some implementations, step S4 includes:

[0075] The first sample was placed in a high-temperature sealed sintering furnace under a wet hydrogen atmosphere. Debinding was performed at 600℃ for 6 hours. After debinding, the first sample was heated to 1650℃ for 10 hours and held at that temperature for 2 hours. Subsequently, the first sample was cooled to room temperature for 6 hours to obtain the heating body. This improved the structural strength of the heating body.

[0076] In some embodiments, wet hydrogen is obtained by passing a mixture of nitrogen and hydrogen produced by an ammonia decomposition generator through water at 37°C.

[0077] In some implementations, step S4 is followed by:

[0078] S5. Locate the preset electrode of the conductive line 11 on the heating element by ultrasonic positioning;

[0079] S6. Laser ablation is used to ablate the ceramic on the surface of the heating element to expose the preset electrode terminals;

[0080] S7. The preset electrode end and the external heating wire 12 are connected by brazing, and the external heating wire 12 is connected to a DC power supply.

[0081] Specifically, the printed conductive line 11 includes two electrode terminals, which are preset electrode terminals. By ultrasonic positioning, the preset electrode terminals of the conductive line 11 are located on the heating element and exposed, allowing the external heating wire 12 (e.g., Figure 4 (As shown) is connected to a DC power supply, and is powered by the DC power supply, thereby enabling the conductive circuit 11 in the heating body to work. The preparation method of this application is simple and easy to operate, and can realize the rapid mass production of the heating body.

[0082] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0083] The above are merely embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for producing a heating element for a molecular beam source oven, characterized by, The method comprises the steps of: S1. Preparing a metal slurry and two ceramic green bodies (10); S2. Printing the metal slurry on the surface of the first ceramic green body (10) to obtain a conductive circuit (11); S3. Laminating the second ceramic green body (10) on the surface of the first ceramic green body (10) printed with the metal slurry to form a laminated body, rolling the laminated body into a cylindrical shape and hot pressing it by a hot press to obtain a first sample; S4. Sintering the first sample to obtain a heating body; After step S4, the method further comprises the steps of: S5. Locating the preset electrode end of the conductive circuit (11) on the heating body by ultrasonic positioning; S6. Ablating the ceramic on the surface of the heating body by laser ablation to expose the preset electrode end; S7. Connecting the preset electrode end and an external heating wire (12) by brazing, and the external heating wire (12) is connected to a direct current power supply.

2. The method of producing a heating element for a molecular beam source oven according to claim 1, characterized in that, Step S1 comprises: Preparation of two ceramic green bodies (10) based on a tape casting method; Preparation of metal powder and slurry organic carrier; Preparation of the metal slurry with the metal powder and the slurry organic carrier.

3. The method for preparing a heating element for a molecular beam source furnace according to claim 2, characterized in that, The step of preparing two ceramic green bodies (10) based on the tape casting method comprises: Adding a sintering aid, a solvent and a dispersant to Al2O3 powder with a purity of ≥99.99% and stirring uniformly; Adding a binder and a plasticizer with a mass ratio of 1:1, and the content of the binder is 6wt%-13wt%, and stirring again; Adding alumina pellets again to obtain a mixture, ball milling the mixture for 24h, screening out small pellets and large particles, and removing bubbles to obtain a stable slurry; Pouring the stable slurry into a tape coating machine for tape casting, and after drying, the tape is removed to obtain the ceramic green body (10).

4. The method for preparing a heating element for a molecular beam source furnace according to claim 2, characterized in that, The step of preparing metal powder and slurry organic carrier comprises: Mixing tungsten powder and manganese powder with a mass ratio of 9:1 to obtain a mixed powder, adding 3wt% vanadium for stirring, adding anhydrous ethanol for ball milling for 4h, and finally drying to obtain the metal powder, wherein the mass ratio of the mixed powder, the vanadium and the anhydrous ethanol is 1:1.5:1, and the ball milling speed is 500r / min; Mixing terpineol, ethyl cellulose and the anhydrous ethanol according to a mass ratio of 94:5:1, heating with a water bath at 80℃, and stirring for 10min-30min at a stirring speed of 300r / min to obtain the slurry organic carrier.

5. The method for preparing a heating element for a molecular beam source furnace according to claim 2, characterized in that, The step of preparing the metal slurry with the metal powder and the slurry organic carrier comprises: Mixing the metal powder and the slurry organic carrier according to a mass ratio of 9:1 and ball milling for 6h at a ball milling speed of 500r / min to uniformly disperse the metal powder in the slurry organic carrier, and the metal slurry is obtained after the ball milling is completed.

6. The method for preparing a heating element for a molecular beam source furnace according to claim 1, characterized in that, Step S2 comprises: The metal paste is printed on the surface of the first ceramic green body (10) to form the conductive circuit (11) by using a screen printing machine, a plurality of slot groups are arranged on the screen printing machine, and the weight of the metal paste printed on the surface of the first ceramic green body (10) by each slot group ranges from 23 mg / cm to 24 mg / cm.

7. The method for preparing a heating element for a molecular beam source furnace according to claim 1, characterized in that, The working temperature of the hot press is 50-70 DEG C, and the hot pressing pressure is 8-13 MPa.

8. The method for preparing a heating element for a molecular beam source furnace according to claim 7, characterized in that, The step S4 comprises: The first sample is placed in a high-temperature sealed sintering furnace, a sintering atmosphere is wet hydrogen, degassing is performed at a temperature of 600 DEG C for 6 hours, after degassing, the first sample is heated to 1650 DEG C for 2 hours, and then the first sample is cooled to room temperature for 6 hours to obtain a heating body.

9. The method for preparing a heating element for a molecular beam source furnace according to claim 8, characterized in that, The wet hydrogen is a mixed gas of nitrogen and hydrogen prepared by an ammonia decomposition generator and obtained after passing through 37 DEG C water.

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