Method for manufacturing tantalum carbide on graphite surface and graphite workpiece

Abstract

The invention relates to the technical field of composite materials, in particular to a method for manufacturing tantalum carbide on the surface of graphite and a graphite workpiece. The preparation method comprises the steps that the surface of the graphite piece is pretreated, so that a polished surface is formed on the surface of the graphite piece; sequentially superposing tantalum foil and graphite paper on the polished surface of the graphite piece to form an intermediate workpiece; and the intermediate workpiece is subjected to heat preservation treatment at the temperature of 2000-2100 DEG C under the vacuum condition, so that a tantalum carbide layer is formed on the surface of the graphite piece. The tantalum carbide is formed on the polished surface of the graphite piece in situ, so that the bonding strength of the tantalum carbide and the graphite piece can be improved, and under the conditions of high temperature and long-time use, higher stability can be kept, the heat corrosion resistance of the graphite piece is improved, the probability of stripping of the tantalum carbide on the surface of the graphite piece is reduced, and the service life of the graphite piece is prolonged.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, and more specifically to a method for fabricating tantalum carbide on a graphite surface and a graphite workpiece. Background Technology

[0002] Graphite is commonly used as a material for heating workpieces, such as crucibles or heaters. However, prolonged and intense thermal corrosion can cause the graphite surface of the heated workpiece to pulverize, which not only shortens the service life of the graphite parts but also adversely affects the quality of products processed at high temperatures. For example, it negatively impacts the growth of products such as silicon carbide (SiC), as graphite surface pulverization leads to excessive carbon encapsulation during silicon carbide growth, reducing the purity and performance of the silicon carbide crystals.

[0003] Surface coating technology is commonly used to improve the heat and corrosion resistance of graphite. However, these coatings still have problems such as insufficient adhesion and easy peeling under extreme high temperature environments, and cannot completely solve the problems of graphite surface pulverization and carbon encapsulation in products such as silicon carbide. Summary of the Invention

[0004] In view of this, this application provides a method for fabricating tantalum carbide on a graphite surface and a graphite workpiece, which can improve the bonding strength of the tantalum carbide layer on the graphite surface.

[0005] The first technical solution of this application includes a method for fabricating tantalum carbide on the surface of graphite, comprising pre-treating the surface of a graphite part to form a polished surface; sequentially stacking tantalum foil and graphite paper on the polished surface of the graphite part to form an intermediate workpiece; and heat-treating the intermediate workpiece under vacuum conditions at 2000-2100℃ to form a tantalum carbide layer on the surface of the graphite part.

[0006] The process of stacking tantalum foil and graphite paper sequentially on the polished surface of a graphite part to form an intermediate workpiece includes: stacking tantalum foil and graphite paper sequentially on the polished surface of a graphite part; and using a graphite block or clamp to press the graphite part, tantalum foil, and graphite paper together so that the tantalum foil adheres to the polished surface to form the intermediate workpiece.

[0007] The heating rate under vacuum conditions is 2-5℃ / min.

[0008] The heat treatment time at 2000-2100℃ is 2-10 hours.

[0009] The cooling rate after heat preservation treatment at 2000-2100℃ is 2-10℃ / min.

[0010] The process of pre-treating the surface of the graphite part to form a polished surface includes polishing the surface of the graphite part to achieve a surface roughness of 0.16µm-1.25µm.

[0011] The thickness of the tantalum foil is 0.1mm-0.5mm.

[0012] The thickness of the graphite paper is 0.1mm-0.5mm.

[0013] Among them, the projection of graphite paper onto the surface of tantalum foil overlaps.

[0014] The second technical solution of this application includes a graphite workpiece manufactured by the above method, the workpiece comprising a graphite part and a tantalum carbide layer located on the surface of the graphite part.

[0015] Beneficial effects:

[0016] (1) The method of making tantalum carbide on the graphite surface of this application involves pre-treating the graphite part to form a polished surface, covering it with tantalum foil, and forming a tantalum carbide layer in situ on the polished surface of the graphite part by high-temperature carbonization. This can improve the bonding strength between tantalum carbide and graphite part, maintain high stability under high temperature and long-term use conditions, improve the heat corrosion resistance of graphite part, reduce the probability of tantalum carbide peeling off the graphite part surface, and improve the service life of graphite part.

[0017] (2) The graphite parts produced by the method of making tantalum carbide on the graphite surface of this application can improve the purity and performance of silicon carbide crystals when used to support the production of silicon carbide and other products, thereby improving the performance of the products and reducing the problem of carbon coating on the products.

[0018] (3) By controlling the surface roughness of the graphite parts and the thickness of the tantalum foil, the uniformity and bonding strength of the tantalum carbide layer were optimized.

[0019] By precisely controlling the heating rate, holding time, and cooling rate (temperature reduction rate), the high quality and stability of the tantalum carbide layer are ensured. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the process structure of an embodiment of this application;

[0022] Figure 3 This is a flowchart illustrating another embodiment of this application;

[0023] Figure 4 This is a microscope image of tantalum carbide according to an embodiment of this application;

[0024] Figure 5 This is a scanning electron microscope image of a graphite workpiece according to an embodiment of this application. Detailed Implementation

[0025] The technical solution of the present invention will be further described below with reference to the accompanying drawings, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0026] Example 1

[0027] In related technologies, surface coating techniques are commonly used to improve the heat corrosion resistance of graphite, such as coating with silicon carbide (SiC) or boron carbide (B4C). However, these coatings still suffer from problems such as insufficient adhesion and easy peeling under extreme high-temperature environments, and cannot completely solve the problems of graphite surface pulverization and silicon carbide carbon encapsulation.

[0028] Therefore, the first embodiment of this application provides a method for fabricating tantalum carbide on a graphite surface, such as... Figure 1 As shown, it includes:

[0029] S110: Pre-treat the surface of the graphite part to form a polished surface.

[0030] In this embodiment, the surface of the graphite part can be polished to form a polished surface.

[0031] In one embodiment of this application, the surface roughness of the graphite part is 0.16µm-1.25µm. By controlling the surface roughness of the graphite part within the above range, this embodiment achieves a relatively smooth surface, which facilitates tight adhesion between the tantalum foil and the graphite part surface, and between the tantalum foil and the graphite paper, thus promoting the formation of a uniform tantalum carbide layer on the polished surface. The surface roughness of the graphite part can be 0.16µm, 0.5µm, 1µm, 1.25µm, etc.

[0032] S120: As Figure 2 As shown, tantalum foil 2 and graphite paper 3 are stacked sequentially on the polished surface of graphite part 1 to form an intermediate workpiece.

[0033] In this embodiment, tantalum foil 2 and graphite paper 3 are stacked sequentially on the polished surface of graphite part 1, so that tantalum foil 2 is located on the surface of graphite part 1 and graphite paper 3, which is beneficial for graphite paper 1 and tantalum foil 2 to react and form tantalum carbide layer in situ on the surface of graphite part.

[0034] S130: The intermediate workpiece is heat-treated under vacuum conditions at 2000-2100℃ to form a tantalum carbide layer on the surface of the graphite part.

[0035] In this embodiment of the application, by controlling the reaction temperature to be 2000-2100°C under vacuum conditions, it is beneficial for tantalum foil and graphite paper to react and generate tantalum carbide.

[0036] The technical solution of this application pre-treats the surface of the graphite part to form a polished surface, and uses graphite paper as an intermediate layer to form tantalum carbide in situ on the polished surface of the graphite part. This can improve the bonding strength between tantalum carbide and graphite part, maintain high stability under high temperature and long-term use conditions, improve the heat corrosion resistance of graphite part, reduce the probability of tantalum carbide peeling off from the surface of graphite part, and improve the service life of graphite part.

[0037] The second embodiment of this application provides a method for fabricating tantalum carbide on a graphite surface, such as... Figure 3 As shown, it includes:

[0038] S210: Pre-treat the surface of the graphite part to form a polished surface.

[0039] In this embodiment, the surface of the graphite part can be polished to form a polished surface.

[0040] In one embodiment of this application, the surface roughness of the graphite part is 0.16µm-1.25µm. By controlling the surface roughness of the graphite part within the above range, this embodiment achieves a relatively smooth surface, which facilitates tight adhesion between the tantalum foil and the graphite part surface, and between the tantalum foil and the graphite paper, thus promoting the formation of a uniform tantalum carbide layer on the polished surface. The surface roughness of the graphite part can be 0.16µm, 0.5µm, 1µm, 1.25µm, etc.

[0041] S221: Tantalum foil and graphite paper are sequentially stacked on the polished surface of the graphite part.

[0042] In this embodiment, tantalum foil and graphite paper are stacked sequentially on the polished surface of the graphite part, so that the tantalum foil is located on the surface of the graphite part and the graphite paper, which is conducive to the reaction between the graphite paper and the tantalum foil to form a tantalum carbide layer in situ on the surface of the graphite part.

[0043] In this embodiment, the thickness of the tantalum foil is 0.1mm-0.5mm. Specifically, it can be 0.1mm, 0.3mm, 0.5mm, etc. By controlling the thickness of the tantalum foil within the above range, this embodiment helps to improve the uniformity of tantalum carbide generated on the polished surface of the graphite part.

[0044] In this embodiment, the thickness of the graphite paper is 0.1mm-0.5mm. Specifically, it can be 0.1mm, 0.2mm, 0.5mm, etc. In this embodiment, by controlling the thickness of the graphite paper within the above range, it is beneficial to control the uniformity of tantalum carbide formation and the bonding strength between the formed tantalum carbide and the polished surface of the graphite part, thereby reducing the probability of carbon carbide falling off the surface of the graphite part.

[0045] In this embodiment, the projections of the graphite paper onto the tantalum foil surface overlap. By controlling the areas of the graphite paper and the tantalum foil to be the same, this embodiment achieves better uniformity of tantalum carbide formed on the polished surface of the graphite part.

[0046] S222: The graphite part, the tantalum foil, and the graphite paper are pressed together using a graphite block or clamp, so that the tantalum foil is attached to the polished surface to form an intermediate workpiece.

[0047] In one embodiment of this application, a graphite block is used to press the graphite part, tantalum foil, and graphite paper together, ensuring close direct contact between the graphite part, tantalum foil, and graphite paper. This facilitates the in-situ formation of a uniform tantalum carbide layer on the surface of the graphite part during the subsequent calcination process. In this embodiment, the use of a graphite block for pressing also reduces the generation of byproducts during the subsequent calcination process.

[0048] In another embodiment of this application, a clamp can be used to clamp the graphite part, tantalum foil and graphite paper, which is beneficial to improve the bonding strength of the three, thereby improving the bonding strength of the generated tantalum carbide on the surface of the graphite part.

[0049] In one embodiment of this application, the thickness of the tantalum foil is 0.1 mm to 0.5 mm. In this embodiment, controlling the thickness of the tantalum foil within the above range is beneficial for improving the density of tantalum carbide on the surface of the graphite part, thereby improving the quality of tantalum carbide. The thickness of the tantalum foil can be 0.1 mm, 0.3 mm, 0.5 mm, etc.

[0050] In one embodiment of this application, the thickness of the graphite paper is 0.1 mm to 0.5 mm. Controlling the thickness of the graphite paper within this range helps to improve the uniformity of tantalum carbide on the surface of the graphite part. The thickness of the graphite paper can be 0.1 mm, 0.2 mm, 0.5 mm, etc.

[0051] In this embodiment, the projections of the graphite paper onto the surface of the tantalum foil overlap. In this embodiment, the area of ​​the graphite paper is the same as the area of ​​the tantalum foil, allowing the graphite paper to react effectively with the tantalum foil and improving the reaction yield.

[0052] S230: The intermediate workpiece is heat-treated under vacuum conditions at 2000-2100℃ to form a tantalum carbide layer on the surface of the graphite part.

[0053] In this embodiment, controlling the calcination temperature to 2000-2100℃ under vacuum conditions is beneficial for the reaction between tantalum foil and graphite paper to form tantalum carbide. The calcination temperature can be 2000℃, 2050℃, or 2100℃.

[0054] In this embodiment, the heating rate under vacuum conditions is 2-5°C / min. By controlling the heating rate under vacuum conditions within this range, it is beneficial to control and improve the quality and stability of tantalum carbide. The heating rate can be 2°C / min, 3°C / min, 5°C / min, etc.

[0055] In this embodiment, the heat treatment at 2000-2100℃ is carried out for 2-10 hours. The heat treatment time can be 2 hours, 4 hours, 5 hours, 8 hours, 10 hours, etc. Controlling the heat treatment time within the above range is beneficial to improving the uniformity and density of tantalum carbide.

[0056] In this embodiment of the application, the cooling rate after heat preservation treatment at 2000-2100℃ is 2-10℃ / min.

[0057] In this embodiment of the application, the intermediate workpiece is placed in a graphitization device, and the vacuum degree is evacuated to 10. -2 Below mbar.

[0058] The second technical solution of this application includes a graphite workpiece manufactured by the above-described method. The workpiece comprises a graphite part and a tantalum carbide layer located on the surface of the graphite part. In the embodiments of this application, the tantalum carbide layer is uniformly distributed and highly stable on the surface of the graphite part, the probability of tantalum carbide peeling off from the surface of the graphite part is low, the graphite part has high heat corrosion resistance, and the graphite part has a long service life.

[0059] To facilitate understanding of the technical solutions in this application, specific embodiments are provided.

[0060] Example 1

[0061] The method for fabricating tantalum carbide on a graphite surface includes the following steps:

[0062] Step 1: Polish the surface of the graphite part that needs surface treatment to form a polished surface with a surface roughness of 0.16µm.

[0063] Step 2: Use a 0.1mm thick tantalum foil to contact the polished surface of the graphite part, and place a 0.1mm thick graphite paper on the other side of the tantalum foil. The graphite paper should be the same size and area as the tantalum foil. Press it with a graphite block to form an intermediate workpiece.

[0064] Step 3: Place the assembled intermediate workpiece into the graphitization equipment and evacuate the vacuum level to 10.-2 Below mbar.

[0065] Step 4: Increase the temperature to 2000℃ at a rate of 2℃ / min and hold for 2 hours.

[0066] Step 5: Turn off the heating and wait for the temperature to drop below 50℃.

[0067] Step 6: Remove the workpiece, remove the graphite block and graphite paper to obtain a uniform and dense tantalum carbide layer, thus obtaining the graphite workpiece.

[0068] like Figure 4 The image shown is a scanning electron microscope image of the tantalum carbide layer fabricated according to an embodiment of this application. Figure 4 It can be seen that the formed tantalum carbide layer has a high density. Figure 5 A cross-sectional view of a graphite workpiece fabricated for an embodiment of this application, from... Figure 5 As can be seen, the thickness of the formed tantalum carbide layer is between 224.06μm and 232.81μm, and there are no gaps between the tantalum carbide layer and the graphite workpiece, resulting in a tight bond.

[0069] Example 2

[0070] The method for fabricating tantalum carbide on a graphite surface includes the following steps:

[0071] Step 1: Machin the surface of the graphite part that requires surface treatment to a surface roughness of 1.25µm to form a polished surface.

[0072] Step 2: Use a 0.5mm thick tantalum foil to contact the polished surface of the graphite part, and place a 0.5mm thick graphite paper on the other side of the tantalum foil. The graphite paper should be the same size and area as the tantalum foil. Press it with a clamp to form an intermediate workpiece.

[0073] Step 3: Place the assembled intermediate workpiece into the graphitization equipment and evacuate the vacuum level to 10. -2 Below mbar.

[0074] Step 4: Increase the temperature to 2100℃ at a rate of 5℃ / min and hold for 10 hours.

[0075] Step 5: Turn off the heating and wait for the temperature to drop below 50℃.

[0076] Step 6: Remove the workpiece, remove the graphite block and graphite paper to obtain a uniform and dense tantalum carbide layer.

[0077] Example 3

[0078] The method for fabricating tantalum carbide on a graphite surface includes the following steps:

[0079] Step 1: Polish the surface of the graphite part that needs surface treatment to form a polished surface with a surface roughness of 0.8µm.

[0080] Step 2: Use a 0.3mm thick tantalum foil to contact the polished surface of the graphite part, and place a 0.3mm thick graphite paper on the other side of the tantalum foil. The graphite paper should be the same size and area as the tantalum foil. Press it with a graphite block to form an intermediate workpiece.

[0081] Step 3: Place the assembled intermediate workpiece into the graphitization equipment and evacuate the vacuum level to 10. -3 mbar.

[0082] Step 4: Increase the temperature to 2050℃ at a rate of 3℃ / min and hold for 5 hours.

[0083] Step 5: Turn off the heating and wait for the temperature to drop below 50℃.

[0084] Step 6: Remove the workpiece, remove the graphite block and graphite paper to obtain a uniform and dense tantalum carbide layer, thus obtaining the graphite workpiece.

[0085] Example 4

[0086] The method for fabricating tantalum carbide on a graphite surface includes the following steps:

[0087] Step 1: Polish the surface of the graphite part that needs surface treatment to form a polished surface with a surface roughness of 1µm.

[0088] Step 2: Use a 0.3mm thick tantalum foil to contact the polished surface of the graphite part, and place a 0.4mm thick graphite paper on the other side of the tantalum foil. The graphite paper should be the same size and area as the tantalum foil. Press it with a graphite block to form an intermediate workpiece.

[0089] Step 3: Place the assembled intermediate workpiece into the graphitization equipment and evacuate the vacuum level to 10. -2 Below mbar.

[0090] Step 4: Increase the temperature to 2030℃ at a rate of 4℃ / min and hold for 8 hours.

[0091] Step 5: Turn off the heating and wait for the temperature to drop below 50℃.

[0092] Step 6: Remove the workpiece, remove the graphite block and graphite paper to obtain a uniform and dense tantalum carbide layer, thus obtaining the graphite workpiece.

[0093] Obviously, the above embodiments are merely illustrative examples and do not limit the implementation. Those skilled in the art will recognize that various modifications, equivalent substitutions, and improvements can be made to the methods and principles of this invention based on the above description, and all such changes should be included within the scope of protection of this invention. Therefore, it is not necessary to provide an exhaustive list of all possible implementations, and any obvious changes or modifications derived therefrom also fall within the scope of protection created by this invention.

Claims

1. A method for fabricating tantalum carbide on a graphite surface, characterized in that, include: The surface of the graphite part is pretreated to form a polished surface; tantalum foil and graphite paper are sequentially stacked on the polished surface of the graphite part to form an intermediate workpiece; the intermediate workpiece is heat-treated under vacuum at 2000-2100℃ to form a tantalum carbide layer on the surface of the graphite part.

2. The method for fabricating tantalum carbide on a graphite surface according to claim 1, characterized in that, The step of sequentially stacking tantalum foil and graphite paper on the polished surface of the graphite part to form an intermediate workpiece includes: sequentially stacking tantalum foil and graphite paper on the polished surface of the graphite part; and using a graphite block or clamp to press the graphite part, the tantalum foil, and the graphite paper so that the tantalum foil adheres to the polished surface to form an intermediate workpiece.

3. The method for fabricating tantalum carbide on a graphite surface according to claim 1, characterized in that, The heating rate under the vacuum conditions is 2-5℃ / min.

4. The method for fabricating tantalum carbide on a graphite surface according to any one of claims 1-3, characterized in that, The heat preservation treatment at 2000-2100℃ is carried out for 2-10 hours.

5. The method for fabricating tantalum carbide on a graphite surface according to any one of claims 1-3, characterized in that, The cooling rate after heat preservation treatment at 2000-2100℃ is 2-10℃ / min.

6. The method for fabricating tantalum carbide on a graphite surface according to any one of claims 1-3, characterized in that, The step of pre-treating the surface of the graphite part to form a polished surface includes polishing the surface of the graphite part to make the surface roughness of the graphite part 0.16µm-1.25µm.

7. The method for fabricating tantalum carbide on a graphite surface according to any one of claims 1-3, characterized in that, The thickness of the tantalum foil is 0.1mm-0.5mm.

8. The method for fabricating tantalum carbide on a graphite surface according to any one of claims 1-3, characterized in that, The thickness of the graphite paper is 0.1mm-0.5mm.

9. The method for fabricating tantalum carbide on a graphite surface according to any one of claims 1-3, characterized in that, The graphite paper overlaps with the projection of the tantalum foil on the surface.

10. A graphite workpiece, characterized in that, The workpiece is made by the method according to any one of claims 1-9, wherein the workpiece comprises a graphite part and a tantalum carbide layer located on the surface of the graphite part.

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