A process for producing a ta c composite coating based on a carbon nanostructure transition layer and the product thereof

Abstract

The application relates to the technical field of semiconductor material preparation, and provides a TaC composite coating process based on a carbon nanostructure transition layer and a product thereof. The method comprises the following steps: a) groove formation through pretreatment of a substrate surface; b) carbon source gas is introduced, and carbon nanoparticles are grown through first chemical vapor deposition under the action of a metal salt catalyst, so that the transition layer deposition substrate is obtained through deposition on the pretreated substrate in step a); and c) a tantalum source is gasified, mixed with carbon source gas, reaction gas and carrier gas, and subjected to second chemical vapor deposition, so that a fine-grained particle layer is filled and formed in the transition layer deposition substrate, then a coarse-grained particle layer is continuously deposited on the surface of the transition layer deposition substrate, and finally a TaC composite coating is obtained. The method can increase the compactness of the coating, enhance the bonding strength between the coating and the substrate, improve the performance of the TaC composite coating, and prolong the service life and reliability of the TaC composite coating.

Description

Technical Field

[0001] This invention relates to the technical field of semiconductor material preparation, and more specifically, to a TaC composite coating process and its products based on a carbon nanostructure transition layer. Background Technology

[0002] In critical fields such as semiconductor epitaxial growth and high-temperature structural component protection, tantalum carbide (TaC) coatings have become a core material for improving the service life and performance of substrates due to their excellent high-temperature stability, high hardness, and chemical inertness. However, TaC coatings exhibit a significant difference in the coefficient of thermal expansion compared to commonly used substrates such as metals and ceramics. This inherent characteristic makes the coating prone to internal stress during preparation and service, leading to failure problems such as cracking and peeling, which severely restricts its application in high-precision and high-reliability scenarios (such as epitaxial cavity components).

[0003] To address the aforementioned thermal expansion mismatch problem, existing technologies generally employ the approach of introducing a second phase to construct a composite coating. For example, methods such as physical vapor deposition (PVD) and chemical vapor deposition (CVD) are used to dope SiC, pure Ta, or other phases into the TaC composite coating, hoping to form a composite coating through the adjustment of the second phase. However, this approach has significant limitations: firstly, the introduction of a heterogeneous phase disrupts the compositional homogeneity of the TaC composite coating, potentially leading to a decrease in the overall high-temperature resistance and chemical stability of the coating, making it difficult to meet the demands of harsh operating conditions; secondly, new interfacial bonding problems may still exist between the heterogeneous phase, the TaC phase, and the substrate, failing to fundamentally eliminate the failure risk caused by thermal expansion differences. Furthermore, when localized peeling occurs, the detached coating fragments can easily enter the epitaxial chamber, contaminating the epitaxial wafer and directly affecting product quality.

[0004] Furthermore, in existing TaC composite coating preparation processes, pores easily form within the coating due to limitations in the deposition process. These pores not only reduce the coating's density and protective performance but also become stress concentration points, accelerating coating failure. Although some techniques attempt to reduce porosity by optimizing deposition parameters, the effects are limited, and it is difficult to simultaneously maintain the bonding strength between the coating and the substrate. Therefore, it is necessary to develop a TaC composite coating preparation process that does not require the introduction of a heterogeneous phase, can effectively fill coating pores, and improve the bonding stability between the coating and the substrate. Summary of the Invention

[0005] In view of this, the present invention aims to at least partially solve the aforementioned existing technical problems. Therefore, the present invention provides a TaC composite coating process and product based on a carbon nanostructure transition layer. By controlling the internal structure and process of the TaC composite coating, without introducing a heterogeneous phase, the internal stress of the coating is dispersed, improving the coating's bonding strength, enhancing its thermal shock resistance, and extending the product's lifespan.

[0006] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0007] According to one aspect of the present invention, a TaC composite coating process based on a carbon nanostructure transition layer is provided, characterized by comprising the following steps:

[0008] A TaC composite coating process based on a carbon nanostructure transition layer is characterized by comprising the following steps:

[0009] a) Pretreatment of the substrate surface to form grooves;

[0010] b) Carbon source gas is introduced and carbon nanoparticles are grown by first chemical vapor deposition under the action of metal salt catalyst. The substrate pretreated in step a) is deposited to obtain a transition layer substrate.

[0011] c) After the tantalum source is vaporized, it is mixed with carbon source gas, reaction gas and carrier gas to perform a second chemical vapor deposition. A fine-grained particle layer is formed inside the transition layer deposition substrate, and then a coarse-grained particle layer is formed on the surface of the transition layer deposition substrate to finally obtain a TaC composite coating.

[0012] In some of these embodiments, in step a), the substrate includes at least one of graphite, carbon fiber reinforced composite material, silicon carbide, silicon nitride, and alloy material;

[0013] In some of these embodiments, in step a), the pretreatment includes at least one of oxidation etching, laser etching, electrochemical etching, wet chemical etching, and plasma dry etching.

[0014] In some of these embodiments, in step a), the depth of the trench is 1 μm to 5 μm.

[0015] In some of these embodiments, in step b), the carbon source gas includes at least one of methane, ethane, propane, ethylene, and acetylene.

[0016] In some of these embodiments, in step b), the carbon source gas is introduced at a rate of 1 L / min to 10 L / min.

[0017] In some of these embodiments, in step b), the metal salt catalyst includes at least one of nickel chloride, ferric chloride, cobalt chloride, ferric nitrate, and nickel nitrate.

[0018] In some embodiments, in step b), the amount of the metal salt catalyst consumed is 0.1 mol to 0.5 mol.

[0019] In some of these embodiments, in step b), the diameter of the carbon nanoparticles is between 20 nm and 100 nm;

[0020] In some embodiments, in step b), the thickness of the transition layer deposition substrate is 0.5 μm to 5 μm.

[0021] In some of these embodiments, in step b), the reaction temperature of the first chemical vapor deposition reaction is 1000°C to 1200°C, the reaction time is 5 min to 60 min, and the reaction pressure is 1 kPa to 20 kPa.

[0022] In some of these embodiments, in step c), the tantalum source includes at least one of tantalum pentachloride, tantalum pentafluoride, tantalum pentabromide, and tantalum oxychloride.

[0023] In some of these embodiments, in step c), the tantalum source is introduced at a rate of 100 g / min to 250 g / min.

[0024] In some of these embodiments, in step c), the reactant gas includes hydrogen.

[0025] In some embodiments, in step c), the carrier gas includes at least one of argon, helium, and neon. In a preferred embodiment of this application, the carrier gas includes argon.

[0026] In some embodiments, in step c), the molar ratio of the tantalum source, the carbon source gas, the reactant gas, and the carrier gas is 1:0.1~0.4:5~20:20~150.

[0027] In some of these embodiments, in step c), the reaction temperature of the second chemical vapor deposition reaction is 1300°C to 1800°C, the reaction time is 100 min to 300 min, and the reaction pressure is 0.5 kPa to 5 kPa.

[0028] In some of these embodiments, in step c), the thickness of the TaC composite coating is 10 μm to 40 μm.

[0029] In some embodiments, in step c), the fine-grained particle layer comprises fine-grained particles with a particle size of 0.5 μm to 1.5 μm.

[0030] In some of these embodiments, in step c), the thickness of the fine-grained particle layer is 0.5 μm to 5 μm.

[0031] In some of these embodiments, in step c), the coarse-grained particle layer comprises coarse-grained particles with a particle size of 5 μm to 30 μm.

[0032] In some of these embodiments, in step c), the thickness of the coarse-grained layer is 10 μm to 30 μm.

[0033] According to another aspect of the present invention, the present invention provides a TaC composite coating prepared by the above coating process.

[0034] Implementing the technical solution of the present invention has at least the following beneficial effects:

[0035] By controlling the internal structure and process of the TaC composite coating, the thermal stress problem caused by the large difference in the coefficient of thermal expansion inside the coating is effectively eliminated without the introduction of heterogeneous phases. This also improves the density of the coating, enhances its thermal shock resistance, and extends the product lifespan.

[0036] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0037] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0038] Figure 1 This is a schematic diagram of a TaC composite coating structure provided in an embodiment of the present invention.

[0039] Figure 2 An electron microscope image of a TaC composite coating provided in an embodiment of the present invention.

[0040] Explanation of reference numerals in the attached figures:

[0041] The accompanying drawings have illustrated specific embodiments of the invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0042] The present application will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present application.

[0043] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges or individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0044] In the description of this application, "same chemical composition" should be interpreted broadly, that is, the main components of the two have the same chemical composition, or the two have substantially the same chemical composition, but may have errors or impurities within the acceptable range that can be understood by those skilled in the art.

[0045] In the description of this application, "A and / or B" can include any of the cases of A alone, B alone, or A and B, where A and B are merely examples and can be any technical feature connected by "and / or" in this application.

[0046] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0047] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0048] Unless otherwise specified, all technical features and optional technical features of this invention can be combined to form new technical solutions.

[0049] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0050] Currently, due to the difference in thermal expansion between the TaC composite coating and the substrate, long-term operation may lead to coating performance degradation, failure, or even damage to the substrate. Based on this, the TaC composite coating prepared by the TaC composite coating process based on the carbon nanostructure transition layer provided in this application will not cause excessive stress due to excessive thermal expansion difference inside the coating, nor will it reduce the operating temperature of the coating. At the same time, it can also improve the performance of the coating and the substrate. Even if the coating falls off, because the columnar, granular, rod-shaped, linear, and tubular TaC structures formed by the transition layer connect the substrate, large areas of coating will not fall off.

[0051] [TaC Composite Coating Process]

[0052] According to a first aspect of this application, this application provides a TaC composite coating process based on a carbon nanostructure transition layer, characterized by comprising the following steps:

[0053] A TaC composite coating process based on a carbon nanostructure transition layer is characterized by comprising the following steps:

[0054] a) Pretreatment of the substrate surface to form grooves;

[0055] b) Carbon source gas is introduced and carbon nanoparticles are grown by first chemical vapor deposition under the action of metal salt catalyst. The substrate pretreated in step a) is deposited to obtain a transition layer substrate.

[0056] c) After the tantalum source is vaporized, it is mixed with carbon source gas, reaction gas and carrier gas to perform a second chemical vapor deposition. A fine-grained particle layer is formed inside the transition layer deposition substrate, and then a coarse-grained particle layer is formed on the surface of the transition layer deposition substrate to finally obtain a TaC composite coating.

[0057] In this application, in step a, trenches are formed on the substrate surface through pretreatment, which helps the carbon nanoparticles in step b to fill the substrate. This ensures that the TaC composite coating formed by steps b and c is tightly bonded to the substrate, effectively improving the bonding ability between the TaC composite coating and the substrate. Since a transition layer containing porous carbon nanostructures is deposited first in step b, the tantalum source can better penetrate into the interior of the carbon nanostructures, resulting in a dense coating. This reduces the porosity inside the composite coating, disperses internal stress, and effectively prevents coating failure. It should be further noted that after the transition layer is formed, in step c, it reacts with TaCl5, transforming the carbon nanostructures into columnar, granular, rod-shaped, fibrous, or tubular structures (C is converted to TaC). Therefore, the carbon nanoparticles in step b are all converted to TaC after step c, and then deposited in step c to produce the TaC composite coating. Thus, the composite coating consists entirely of TaC, without any heterogeneous phases. This effectively eliminates the thermal stress problem caused by the large difference in thermal expansion coefficients between different phases introduced into the coating. Furthermore, the TaC formed by the transformation of the carbon nanostructure... C is a fine-grained layer located in the first deposited intermediate layer. This structure itself has a toughening effect. Even if TaC falls off, it will be firmly connected to the substrate and will not fall into the epitaxial cavity, nor will it affect the quality of the epitaxial wafer. It plays a role in toughening and increasing the bonding strength. Then, under the action of step c, the composite coating continues to be deposited, forming a coarse-grained layer on the outer layer of the TaC composite coating. The TaC composite coating thus has a certain toughness and good density inside, while the outer layer has good high temperature resistance, which improves the overall performance of the TaC composite coating.

[0058] In this application, in step a), the substrate includes at least one of graphite, carbon fiber reinforced composite material, silicon carbide, silicon nitride, and alloy material. In a preferred embodiment of this application, the matrix material is graphite. It should be further noted that this application does not have any special requirements for the source of the matrix material, and commercially available products or self-made products well known to those skilled in the art can be used.

[0059] In this application, in step a), the pretreatment includes at least one of oxidation etching, laser etching, electrochemical etching, wet chemical etching, and plasma dry etching. In a preferred embodiment of this application, the pretreatment method is laser etching. It should be further noted that this application does not have special requirements for the pretreatment method, as long as it can clean the substrate surface and form trenches that meet the requirements of this invention.

[0060] In this application, in step a), the thickness of the trench is 1μm to 5μm, for example, 1μm, 2μm, 3μm, 4μm, 5μm, or any range between the two. Within the above range, the influence on the thermal conductivity of the graphite and other highly thermally conductive materials can be avoided, and the electrochemical deposition of the subsequent transition layer can be facilitated.

[0061] In this application, in step b), the carbon source gas includes at least one of methane, ethane, propane, ethylene, and acetylene. In a preferred embodiment of this application, methane is selected as the carbon source gas. In this application, there are no special requirements regarding the source of the carbon source; commercially available products or homemade materials well-known to those skilled in the art can be used. The main purpose is to provide activated carbon, which is directionally converted into a regular carbon nanostructure during the electrochemical deposition process.

[0062] In this application, in step b), the flow rate of the carbon source gas is 1 L / min to 10 L / min, for example, 1 L / min, 3 L / min, 5 L / min, 6 L / min, 7 L / min, 8 L / min, 10 L / min, or any range between the two. By controlling the flow rate of the carbon source gas, the supply of carbon source and the catalyst capacity can be matched, which plays an important role in controlling the thickness and uniformity of carbon nanostructures. When the flow rate is too low, deposition growth fails, uniformity is poor, and efficiency is low. When the flow rate is too high, it may lead to the generation of disordered carbon and loss of thickness control.

[0063] In this application, in step b), the metal salt catalyst includes at least one of nickel chloride, ferric chloride, cobalt chloride, ferric nitrate, and nickel nitrate. In a preferred embodiment of this application, ferric chloride is selected as the metal salt catalyst. In this application, the metal salt catalyst is the core "regulatory medium" for realizing the directional conversion of carbon source gas into regular carbon nanostructures. In this application, there are no special requirements for the source of carbon; commercially available products or homemade products well known to those skilled in the art can be used.

[0064] In this application, in step b), the amount of metal salt catalyst consumed is 0.1 mol to 0.5 mol. The amount of metal salt catalyst consumed is controlled to control the number of carbon nanoparticles formed. At the same time, it is also necessary to avoid the agglomeration phenomenon that is easy to occur when the number of metal nanoparticles is too large.

[0065] In this application, in step b), the diameter of the carbon nanoparticles is between 20 nm and 100 nm, for example, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, or any two of these ranges. The diameter of the carbon nanoparticles within the application range can form a regular target carbon structure, which can avoid the agglomeration phenomenon caused by too small a particle size, and can also avoid the reduction in structural flexibility caused by too large a particle size, which would reduce the contact area between the transition layer and the matrix and decrease the overall material bonding force.

[0066] In this application, in step b), the thickness of the transition layer deposition substrate is 0.5 μm to 5 μm. Within the above thickness range, the mismatch of thermal expansion coefficients can be further alleviated, the interfacial stress can be reduced, and the phenomenon of interlayer delamination can be avoided.

[0067] In this application, in step b), the reaction temperature of the first chemical vapor deposition reaction is 1000℃~1200℃, the reaction time is 5min~60min, and the reaction pressure is 1kPa~20kPa. It should be further noted that the reaction temperature of 1000℃~1200℃ is chosen to ensure efficient decomposition of the carbon source gas, allowing it to be directionally utilized by the metal salt catalyst and resulting in the orderly growth of carbon nanostructures. By controlling the reaction time, the thickness of the transition layer is controlled. In a low-pressure environment, the carbon source gas molecules primarily diffuse, ensuring uniform diffusion and guaranteeing the uniformity of the transition layer thickness.

[0068] In this application, in step c), the tantalum source includes at least one of tantalum pentachloride, tantalum pentafluoride, tantalum pentabromide, and tantalum trichloride. In a preferred embodiment of this application, tantalum pentachloride is selected as the tantalum source. In this application, there are no special requirements for the source of the tantalum source. Commercially available products or self-made products well known to those skilled in the art can be used. The main purpose of the tantalum source is to provide active tantalum in the subsequent reaction to form a tantalum carbide coating.

[0069] In this application, in step c), the tantalum source is introduced at a rate of 100 g / min to 250 g / min, for example, 100 g / min, 120 g / min, 150 g / min, 180 g / min, 200 g / min, 220 g / min, 250 g / min, or any range between the two. It should be further noted that in this application, the core component of the TaC composite coating is tantalum carbide (chemical formula TaC). Therefore, it is necessary to control the tantalum source introduction rate to match the decomposition rate of the carbon source to avoid insufficient tantalum leading to free carbon destroying the crystal structure of TaC, or excessive tantalum leading to metallic tantalum doping in the TaC composite coating, causing the coating to crack.

[0070] In this application, in step c), the reaction gas includes hydrogen. It should be further explained that the purpose of introducing hydrogen is to reduce the tantalum source so that it becomes an active tantalum species and participates in the subsequent reaction with the carbon source to form a TaC composite coating.

[0071] In this application, in step c), the carrier gas includes at least one of argon, helium, and neon. In a preferred embodiment of this application, the carrier gas is preferably argon. It should be further noted that the purpose of introducing the carrier gas is, on the one hand, to achieve uniform transport of tantalum source and carbon source gas, and on the other hand, to maintain a low-pressure environment for the system reaction, protect the substrate and coating, and avoid oxidation pollution.

[0072] In this application, in step c), the molar ratio of the tantalum source, the carbon source gas, the reactant gas, and the carrier gas is 1:0.1~0.4:5~20:20~150, for example, 1:0.1:5:20, 1:0.2:10:60, 1:0.3:15:100, 1:0.4:20:150, or any range between two of these. In the embodiments of this application, the tantalum source is selected as tantalum pentachloride, the carbon source gas is selected as methane, the reactant gas is selected as hydrogen, and the carrier gas is selected as argon. It should be further noted that when the reactant gas hydrogen is within the above range, the reduction reaction of the tantalum source can be more complete, the disproportionation reaction that may occur in the tantalum source can be suppressed, and at the same time, the reaction between tantalum and carbon can be more gradual, resulting in better density of the TaC composite coating. The carrier gas content is within the above range, which can mainly dilute the concentration of the entire system, while ensuring a low-pressure environment to ensure the uniform distribution of TaC in the TaC composite coating, and also avoid the TaC composite coating being carried out in an "oxygen-free environment".

[0073] In this application, in step c), the reaction temperature of the second chemical vapor deposition reaction is 1300℃~1800℃, the reaction time is 100min~300min, and the reaction pressure is 0.5kPa~5kPa. It should be further noted that the reaction temperature of 1300℃~1800℃ is chosen to make the reduction reaction between the tantalum source and hydrogen more efficient, accelerating the formation of TaC from active tantalum and active carbon. By controlling the reaction time, the thickness of the transition layer is controlled. In a low-pressure environment, the tantalum and carbon source gas molecules are mainly diffused, thereby ensuring uniform diffusion of TaC in the TaC composite coating and guaranteeing its uniformity.

[0074] In this application, in step c), the thickness of the TaC composite coating is 10μm to 40μm, for example, 10μm, 15μm, 20μm, 25μm, 40μm, or any two of these ranges. The TaC composite coating includes a fine-grained particle layer and a coarse-grained particle layer. By controlling the coating thickness within the above range, it can be ensured that the fine-grained particle layer of the TaC composite coating has the function of toughening and increasing bonding strength, while the coarse-grained particle layer has high-temperature wear resistance, extending the service life of the component, balancing the interfacial bonding force and thermal stress, and preventing coating cracking.

[0075] In this application, in step c), the fine-grained particle layer comprises fine-grained particles with a particle size of 0.5 μm to 1.5 μm and a thickness of 0.5 μm to 5 μm. It should be further explained that the formation of the fine-grained particle layer mainly occurs during the second vapor deposition process, where tantalum-rich gas is deposited within the porous carbon nanostructure of the transition layer substrate formed by the first vapor deposition. This results in the formation of smaller fine grains that are tightly bonded to the carbon nanostructure. The bonding strength is increased because the tantalum-rich gas fully fills the interior of the carbon nanostructure. Simultaneously, under the conditions of the second vapor deposition, the carbon nanoparticles transform from C to TaC, eliminating the thermal expansion differences within the coating. Controlling the particle size and thickness of the fine-grained particle layer within the above-mentioned range can improve the bonding strength and toughness between the TaC coating and the substrate.

[0076] In this application, in step c), the coarse grain layer includes coarse grains with a particle size of 5μm to 30μm and a thickness of 10μm to 30μm. It should be further noted that the coarse grains are mainly obtained by reacting with tantalum source and carbon source in the second vapor deposition. The main purpose of the coarse grain layer is to maintain the high temperature resistance of the TaC coating. By controlling the thickness of the coarse grain layer to be between 10μm and 30μm, the high temperature resistance and oxidation resistance of the product can be greatly improved. At the same time, it can also avoid the accumulation of internal stress in the coating caused by excessive coating thickness, which can lead to cracking or peeling due to impact.

[0077] In a second aspect of the invention, this application provides a TaC composite coating, which is prepared by the aforementioned TaC composite coating process.

[0078] In the context of this specification, including the following embodiments and comparative examples, tests were conducted as follows:

[0079] (1) Seismic performance evaluation: The sample is placed in a furnace at 360°C and kept at that temperature for 30 minutes. The sample is then quickly removed from the furnace and placed in a constant temperature water bath. The depth of the water bath should be such that the sample can be completely submerged. After soaking in the water for 5 minutes, the sample is removed from the water bath and the surface moisture is dried with nitrogen gas. The surface of the sample is then observed for coating peeling, chipping, cracks, etc. If any of the above failure conditions occur, the test is stopped. If the termination condition is not met, the thermal shock cycle is repeated until the number of repetitions reaches 50.

[0080] (2) Evaluation of bond strength: 1. Prepare a cross-shaped specimen, and bond two fine ceramic specimens vertically to form a cross. The bonding surface must be flat. 2. Install the specimen into the testing machine fixture and ensure that the force axis is aligned with the center of the bonding surface. 3. Apply tensile or shear loads at the rate set according to the standard. 4. Record the maximum failure load and calculate the bond strength according to the formula. 5. Observe the failure mode, determine whether the failure is due to the bonding surface, and compile the data to obtain the evaluation results.

[0081] The present application will be described in detail below with reference to the accompanying drawings and embodiments. However, the implementation and protection of the present invention are not limited thereto. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0082] Example 1

[0083] Step a): Grooves were formed on the surface of a commercial graphite substrate (purchased from Japan) using laser etching technology, with an etching depth of 3 μm;

[0084] Step b): Methane was introduced at a flow rate of 3 L / min, and 0.3 mol of ferric chloride (purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.) was added. The CVD growth reaction was carried out at 1100℃ and 10 kPa for 10 min. The carbon nanostructure diameter was 30 nm and the coating thickness was 8 μm.

[0085] Step c): Tantalum chloride is vaporized and mixed with methane, hydrogen, argon, etc. in a molar ratio of 1:0.2:10:100. The tantalum chloride is introduced at a rate of 120 g / min. The mixture is reacted at 1500℃ and 3 kPa for 150 min to obtain a dense TaC composite coating (fine grain layer thickness 3 μm, coarse grain layer thickness 12 μm), with a TaC composite coating thickness of 15 μm.

[0086] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0087] Example 2

[0088] The method of Example 1 is followed, except that the carbon source for the first vapor deposition is C2H4 and the carbon source for the second vapor deposition is C2H4, thus preparing a TaC composite coating.

[0089] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0090] Example 3

[0091] The method of Example 1 is followed, except that the carbon source for the first vapor deposition is CH4 and the carbon source for the second vapor deposition is C2H4, thus preparing a TaC composite coating.

[0092] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0093] Example 4

[0094] The preparation method of Example 1 is the same, except that the carbon source for the first vapor deposition is C2H4 and the carbon source for the second vapor deposition is CH4, thus obtaining a TaC composite coating.

[0095] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0096] Example 5

[0097] The TaC composite coating was prepared according to the preparation method of Example 1, except that the pressure of the first vapor deposition was 10 kPa and the pressure of the second vapor deposition was 5 kPa.

[0098] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0099] Example 6

[0100] The TaC composite coating was prepared according to the preparation method of Example 1, except that the pressure of the first vapor deposition was 20 kPa and the pressure of the second vapor deposition was 3 kPa.

[0101] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0102] Example 7

[0103] The preparation method of Example 1 is different in that the gas ratio in the second vapor deposition is changed, and the molar ratio of the tantalum source, the carbon source gas, the reactant gas and the carrier gas is 1:0.2:5:20, so that a TaC composite coating is prepared.

[0104] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0105] Example 8

[0106] The preparation method of Example 1 is different in that the gas ratio in the second vapor deposition is changed, and the molar ratio of the tantalum source, the carbon source gas, the reactant gas and the carrier gas is 1:0.4:10:100, so that a TaC composite coating is prepared.

[0107] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0108] Example 9

[0109] The preparation method of Example 1 is different in that the gas ratio in the second vapor deposition is changed. The molar ratio of the tantalum source, the carbon source gas, the reactant gas and the carrier gas is 1:0.2:10:150, and a TaC composite coating is prepared.

[0110] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0111] Example 10

[0112] The TaC composite coating was prepared according to the preparation method of Example 1, except that the amount of metal salt catalyst consumed was changed and the amount of ferric chloride consumed was adjusted to 0.1 mol.

[0113] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0114] Example 11

[0115] The TaC composite coating was prepared according to the preparation method of Example 1, except that the amount of metal salt catalyst consumed was changed and the amount of ferric chloride consumed was adjusted to 1 mol.

[0116] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0117] Comparative Example 1

[0118] The TaC composite coating was prepared according to the preparation method of Example 1, except that no etching treatment was performed in the pretreatment stage.

[0119] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0120] Comparative Example 2

[0121] The TaC composite coating was prepared according to the preparation method of Example 1, except that no metal salt catalyst was added in the first vapor deposition.

[0122] Comparative Example 3

[0123] The preparation method of Example 1 is followed, except that tantalum chloride and methane are interchanged. Specifically, in step b), tantalum chloride is introduced at a rate of 3 L / min, and in step c), the ratio of tantalum chloride, methane, hydrogen, and argon is adjusted from 1:0.2:10:100 to 0.2:1:10:100, while other parameters remain unchanged. This process yields a TaC composite coating.

[0124] The dense TaC composite coating obtained above was tested, and the experimental results are shown in Table 1.

[0125] Table 1 Performance test results of the comparative examples.

[0126]

[0127] As can be seen from the data of Examples 1-11 and Comparative Examples 1-2 above, the TaC composite coating provided by the present invention improves the thermal shock resistance of the coating and the bonding strength with the substrate.

[0128] The experimental results of Examples 1-4 show that, in the TaC composite coating process provided in this application, appropriately adjusting the types of carbon sources in the first vapor deposition and the second vapor deposition has little impact on the seismic performance of the TaC composite coating and its bonding strength with the substrate.

[0129] The experimental results of Examples 1, 5-6 show that, in the TaC composite coating process provided in this application, appropriately adjusting the pressure of the first vapor deposition and the second vapor deposition has little effect on the seismic performance of the TaC composite coating and its bonding strength with the substrate.

[0130] The experimental results of Examples 1 and 7-9 show that, in the TaC composite coating process provided in this application, appropriately adjusting the molar ratio of tantalum source gas, carbon source gas, reactive gas and carrier gas in the second vapor deposition has little effect on the seismic performance of the TaC composite coating and its bonding strength with the substrate.

[0131] The experimental results of Examples 1 and 10-11 show that, in the TaC composite coating process provided in this application, appropriately adjusting the consumption of metal salt catalyst has little impact on the shock resistance performance of the TaC composite coating and its bonding strength with the substrate.

[0132] The experimental results of Example 1 and Comparative Example 1 show that without etching treatment on the graphite substrate, the seismic performance and bonding strength with the substrate of the final TaC composite coating are significantly reduced.

[0133] The experimental results of Example 1 and Comparative Example 2 show that when no metal salt catalyst is added in the first vapor deposition process, i.e., no transition layer of carbon nanostructure is formed, the shock resistance and bonding strength with the substrate of the final TaC composite coating are significantly reduced.

[0134] The experimental results of Example 1 and Comparative Example 3 show that when tantalum chloride and methane are mixed, the tantalum coating is deposited first. The tantalum coating is relatively dense. The efficiency of preparing tantalum carbide coating by secondary carburizing is low. Under the same conditions, the degree of carburizing is not as complete as that of tantalum carburizing. The composite coating prepared in Comparative Example 3 has a large difference in thermal expansion. Although the bonding strength only decreases slightly, the thermal shock performance is significantly reduced.

[0135] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0136] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the aforementioned specific details.

[0137] In the foregoing description of this specification, references to terms such as "one embodiment," "another embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples, without contradiction. Additionally, it should be noted that in this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0138] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for carbon nanostructure transition layer based TaC composite coating, characterized in that, Includes the following steps: a) Pretreatment of the substrate surface to form grooves; b) Carbon source gas is introduced and carbon nanoparticles are grown by first chemical vapor deposition under the action of metal salt catalyst. The substrate pretreated in step a) is deposited to obtain a transition layer substrate. c) After the tantalum source is vaporized, it is mixed with carbon source gas, reaction gas and carrier gas to perform a second chemical vapor deposition. A fine grain layer is formed inside the transition layer deposition substrate, and then a coarse grain layer is formed on the surface of the transition layer deposition substrate to finally obtain a TaC composite coating. Both the fine-grained particle layer and the coarse-grained particle layer are composed of TaC. The metal salt catalyst includes at least one of nickel chloride, ferric chloride, cobalt chloride, ferric nitrate, and nickel nitrate. The carbon source gas includes at least one of methane, ethane, propane, ethylene, and acetylene; The carbon source gas is introduced at a rate of 1 L / min to 10 L / min; The amount of the metal salt catalyst consumed is 0.1 mol to 0.5 mol; The reaction temperature of the first chemical vapor deposition reaction is 1000℃~1200℃, the reaction time is 5min~60min, and the reaction pressure is 1kPa~20kPa; The tantalum source is introduced at a rate of 100 g / min to 250 g / min; The molar ratio of the tantalum source, the carbon source gas, the reactant gas, and the carrier gas is 1:0.1~0.4:5~20:20~150; The reaction temperature of the second chemical vapor deposition reaction is 1300℃~1800℃, the reaction time is 100min~300min, and the reaction pressure is 0.5kPa~5kPa; The reacting gas includes hydrogen.

2. The TaC composite coating process according to claim 1, characterized in that, In step a): The substrate includes at least one of graphite, carbon fiber reinforced composite material, silicon carbide, silicon nitride, and alloy material; And / or, the pretreatment includes at least one of oxidation etching, oxidation etching, laser etching, electrochemical etching, wet chemical etching, and plasma dry etching; And / or, the depth of the trench is 1μm~5μm.

3. The TaC composite coating process of claim 1, wherein, In step b): the diameter of the carbon nanoparticles is between 20 nm and 100 nm; And / or, the thickness of the transition layer deposition substrate is 0.5 μm to 5 μm.

4. The TaC composite coating process of claim 1, wherein, In step c): The tantalum source includes at least one of tantalum pentachloride, tantalum pentafluoride, tantalum pentabromide, tantalum trichloride, and metallic tantalum vapor.

5. The TaC composite coating process of claim 1, wherein, In step c): the carrier gas includes at least one of argon, helium, and neon.

6. The TaC composite coating process of claim 1, wherein, In step c): the thickness of the TaC composite coating is 10μm~40μm.

7. The TaC composite coating process of claim 1, wherein, In step c): the fine-grained particle layer includes fine-grained particles with a particle size of 0.5 μm to 1.5 μm; And / or, the thickness of the fine-grained particle layer is 0.5 μm to 5 μm; And / or, the coarse-grained particle layer includes coarse-grained particles with a particle size of 5μm to 30μm; And / or, the thickness of the coarse-grained particle layer is 10μm~30μm.

8. A TaC coating material, characterized by, The TaC coating material comprises a substrate and a TaC composite coating prepared by the TaC composite coating process according to any one of claims 1-7.

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