Tantalum carbide coating, preparation method thereof and tantalum carbide coating product

Abstract

The invention discloses a tantalum carbide coating, a preparation method thereof and a tantalum carbide coating product, and the preparation method of the tantalum carbide coating comprises the following steps: carrying out chemical vapor deposition by taking a solid tantalum source and gas containing halogen elements and carbon elements as raw materials to obtain the tantalum carbide coating; the saturated vapor pressure of the solid tantalum source at 2000 DEG C is 10 Pa or less. The solid tantalum source which is not prone to volatilization and the gas containing the halogen element and the carbon element serve as precursors for preparing the tantalum carbide coating, the tantalum halide can be generated in situ through the solid tantalum source and the gas containing the halogen element and the carbon element, and then preparation of the tantalum carbide coating is achieved. The preparation process and equipment of the existing tantalum carbide coating are simplified, the production cost is reduced, the preparation efficiency and safety of the tantalum carbide coating are improved, and the defects in the prior art are overcome.

Description

Technical Field

[0001] This application belongs to the field of tantalum carbide coatings, specifically relating to a tantalum carbide coating and its preparation method, as well as tantalum carbide coated products. Background Technology

[0002] Tantalum carbide (TaC) coatings, due to their high hardness, high melting point, excellent chemical stability, and good electrical and thermal conductivity, have shown broad application prospects in numerous fields such as aerospace, electronic devices, and cutting tools. For example, in the aerospace field, tantalum carbide coatings can be used to protect critical components such as engine turbine blades, ensuring stable performance under extreme environments of high temperature, high pressure, and strong corrosion, thus extending component lifespan. In the field of electronic devices, tantalum carbide coatings can act as a diffusion barrier layer, effectively preventing the diffusion of metal atoms and improving the reliability and stability of devices. In the field of cutting tools, tantalum carbide coatings can significantly improve tool wear resistance and cutting performance, while reducing processing costs.

[0003] Currently, the main methods for preparing tantalum carbide coatings include chemical vapor deposition (CVD) and physical vapor deposition (PVD). Among them, CVD technology has become the mainstream method for preparing tantalum carbide coatings due to its advantages such as the ability to deposit uniform and dense coatings on the surface of substrates with complex shapes and strong adhesion between the coating and the substrate. However, existing CVD processes for preparing tantalum carbide coatings have problems such as process complexity and high cost, which limits the further widespread application of tantalum carbide coating products. Summary of the Invention

[0004] This application aims to at least partially address one of the technical problems in related technologies. Therefore, the purpose of this application is to provide a tantalum carbide coating, its preparation method, and tantalum carbide coated products. This application utilizes a non-volatile solid tantalum source, such as flakes, and a gas containing halogen and carbon elements as precursors for preparing the tantalum carbide coating. These precursors can generate tantalum halides in situ, thereby achieving the preparation of the tantalum carbide coating. This not only simplifies the existing tantalum carbide coating preparation process and equipment, reducing production costs, but also improves the efficiency and safety of tantalum carbide coating preparation.

[0005] The first aspect of this application discloses a method for preparing a tantalum carbide coating. According to embodiments of this application, the method for preparing the tantalum carbide coating includes the following steps:

[0006] Tantalum carbide coatings were obtained by chemical vapor deposition using solid tantalum source and gas containing halogen and carbon elements as raw materials.

[0007] The solid tantalum source has a saturated vapor pressure of less than 10 Pa at 2000℃.

[0008] The method for preparing tantalum carbide coatings according to the above embodiments of this application uses a non-volatile solid tantalum source, such as a sheet, and a gas containing halogen and carbon elements as precursors for preparing the tantalum carbide coating. Because the solid tantalum source has an extremely low saturated vapor pressure, it can exist stably on its own at high temperatures. When the gas containing halogen and carbon elements is introduced, the saturated vapor pressure of the solid tantalum source is increased, promoting its volatilization. This allows for the in-situ formation of tantalum halides, thereby achieving the preparation of the tantalum carbide coating. This avoids problems such as pre-reaction of the precursor materials and improves the uniformity of the tantalum carbide coating surface. This not only simplifies the existing tantalum carbide coating preparation process and equipment, reducing production costs, but also improves the efficiency and safety of tantalum carbide coating preparation.

[0009] In addition, the method for preparing the tantalum carbide coating according to the above embodiments of this application may also have the following additional technical features:

[0010] In some embodiments of this application, the solid tantalum source includes at least one of metallic tantalum and tantalum pentoxide, and the shape of the solid tantalum source includes at least one of sheet-like and disc-like shapes.

[0011] In some embodiments of this application, the halogen-containing and carbon-containing gas includes at least one of halogenated hydrocarbon compounds and a mixture of halogen elements and hydrocarbon compounds.

[0012] In some embodiments of this application, the haloalkanes include at least one of CCl4, CBr4, CHCl3, CH2Cl2, CH3Cl, CHBr3, CH2Br2, CH3Br, CHF3, CH2F2, CH3F, and CF4;

[0013] And / or, the halogen element includes at least one of Cl2 and Br2;

[0014] And / or, the hydrocarbon compound includes at least one of gaseous alkanes and gaseous olefins, wherein the gaseous alkanes include at least one of methane, ethane, and propane, and the gaseous olefins include at least one of ethylene and propylene;

[0015] And / or, the volume ratio of the halogen element to the hydrocarbon compound is (10-30):1.

[0016] In some embodiments of this application, the chemical vapor deposition step using a solid tantalum source and a gas containing halogen and carbon elements as raw materials includes the following processes:

[0017] The substrate is placed between two solid tantalum sources, and a first chemical vapor deposition is performed in the gas atmosphere containing halogen and carbon elements.

[0018] Alternatively, the substrate is placed between two solid tantalum sources, and a second chemical vapor deposition is performed in an atmosphere of halogen-containing and carbon-containing gases and a reducing gas.

[0019] In some embodiments of this application, the operating condition parameters for the first chemical vapor deposition include:

[0020] The temperature is 1800℃~2100℃;

[0021] Pressure ranges from 1000 Pa to 90000 Pa;

[0022] The time is 1 hour to 10 hours;

[0023] The flow rate of the gas containing halogen and carbon elements is 50 sccm to 1500 sccm.

[0024] The carrier gas flow rate is 1 slm to 30 slm;

[0025] The carrier gas is an inert gas, which includes at least one of argon and helium.

[0026] In some embodiments of this application, the operating condition parameters for the second chemical vapor deposition include:

[0027] The temperature ranges from 1200℃ to 1800℃.

[0028] Pressure ranges from 1000 Pa to 90000 Pa;

[0029] The time is 1 hour to 10 hours;

[0030] The flow rate of the gas containing halogen and carbon elements is 50 sccm to 1500 sccm.

[0031] The flow rate of the reducing gas is 50 sccm to 5000 sccm;

[0032] The carrier gas flow rate is 1 slm to 30 slm;

[0033] The carrier gas is an inert gas, including at least one of argon and helium; the reducing gas includes hydrogen.

[0034] In some embodiments of this application, the projected area S1 of the solid tantalum source in the same plane as the substrate surface to be plated and the area S2 of the substrate surface to be plated satisfy the following relationship: S1≥S2;

[0035] And / or, several reaction chamber units are arranged in the same reaction chamber, and tantalum carbide coatings are prepared simultaneously in the reaction chamber units.

[0036] A second aspect of this application discloses a tantalum carbide coating. According to an embodiment of this application, the tantalum carbide coating is prepared using the tantalum carbide coating preparation method described in any one of the first aspects.

[0037] The tantalum carbide coating of the above embodiments of this application is prepared by the method for preparing tantalum carbide coating as described in any one of the first aspects. Therefore, this tantalum carbide coating has the advantages of simple preparation process, low equipment requirements, low preparation cost, and high preparation efficiency, making it more suitable for industrial-scale production.

[0038] A third aspect of this application discloses a tantalum carbide coated article. According to embodiments of this application, the tantalum carbide coated article comprises a tantalum carbide coating prepared by the method described in any one of the first aspects or a tantalum carbide coating described in any one of the second aspects. This effectively reduces the production cost of the tantalum carbide coated article.

[0039] Additional aspects and advantages of this application 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 this application. Attached Figure Description

[0040] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0041] Figure 1 This is a schematic diagram showing the positions of various materials in the small crucible during the preparation method of the tantalum carbide coating in this application.

[0042] Figure 2 This is a macroscopic morphological diagram of the tantalum carbide coating obtained in Example 1 of this application.

[0043] Figure 3 This is a scanning electron microscope image of the tantalum carbide coating obtained in Example 1 of this application.

[0044] Figure 4 This is a macroscopic morphological diagram of the tantalum carbide coating obtained in Example 15 of this application.

[0045] Figure 5 This is a scanning electron microscope image of the tantalum carbide coating obtained in Example 15 of this application.

[0046] Figure 6 This is a macroscopic morphology diagram of the tantalum carbide coating obtained in Comparative Example 1 of this application.

[0047] Figure 7 This is a scanning electron microscope image of the tantalum carbide coating obtained in Comparative Example 1 of this application.

[0048] Figure 8 This is a macroscopic morphology diagram of the tantalum carbide coating obtained in Comparative Example 2 of this application.

[0049] Figure 9 This is a scanning electron microscope image of the tantalum carbide coating obtained in Comparative Example 2 of this application.

[0050] Explanation of reference numerals in the attached figures:

[0051] 1-Top of the small crucible in the reaction chamber, 2-Bottom of the small crucible in the reaction chamber, 3-Substrate, 4-Solid tantalum source. Detailed Implementation

[0052] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0053] The first aspect of this application discloses a method for preparing a tantalum carbide coating. According to embodiments of this application, the method for preparing the tantalum carbide coating includes the following steps:

[0054] Tantalum carbide coatings were obtained by chemical vapor deposition using solid tantalum source and gas containing halogen and carbon elements as raw materials.

[0055] The solid tantalum source has a saturated vapor pressure of less than 10 Pa at 2000℃.

[0056] Currently, existing chemical vapor deposition (CVD) processes for preparing tantalum carbide coatings typically use volatile tantalum halides (such as tantalum pentachloride and tantalum pentafluoride) that readily react with air, water vapor, and alcohols as the tantalum source, along with carbon-containing gases (such as methane, acetylene, and olefins) as precursors. These gases are then introduced into a reaction chamber and deposited under specific temperature and pressure conditions to form a tantalum carbide coating on the substrate surface. However, this existing CVD process for preparing tantalum carbide coatings has several drawbacks:

[0057] 1. High raw material cost: The synthesis of tantalum sources such as tantalum pentachloride requires high temperature, high pressure and specific catalysts, and the purification process requires multiple steps, resulting in high price; at the same time, tantalum pentachloride has a low tantalum content (about 50%, the rest is chlorine), and the tantalum source utilization efficiency is low, which further increases the cost of preparing tantalum carbide coating.

[0058] 2. Complex preparation process: Since tantalum pentachloride is a solid, a specific solid feed device is required. Moreover, tantalum sources with certain volatility, such as tantalum pentachloride, are continuously fed into the reaction chamber along with carbon-containing gases as precursors for deposition. In order to prevent the precursor from pre-reacting and the tantalum source from condensing before entering the reaction chamber, precise temperature control of the conveying pipeline is required. The addition of a quantitative and controllable solid source feed device increases the difficulty and complexity of process control, and also places higher demands on the design and manufacturing of process equipment, thus increasing equipment investment.

[0059] 3. Poor safety: Tantalum pentachloride reacts readily with water vapor to generate highly corrosive hydrochloric acid mist, posing a threat to the health of operators and the safety of equipment. In the event of a large-scale leak, it will not only pollute the environment but may also cause safety accidents.

[0060] The method for preparing tantalum carbide coatings described in the above embodiments of this application utilizes a non-volatile solid tantalum source, such as a sheet-like form, and a gas containing halogen and carbon elements as precursors for preparing the tantalum carbide coating. Because the solid tantalum source has an extremely low saturated vapor pressure at 2000°C, it can exist stably on its own at high temperatures. Introducing the gas containing halogen and carbon elements increases the saturated vapor pressure of the solid tantalum source, promoting its volatilization and enabling the in-situ formation of tantalum halides, thereby achieving the preparation of the tantalum carbide coating. This avoids problems such as pre-reaction of the precursor materials and improves the uniformity of the tantalum carbide coating surface. This not only simplifies the existing tantalum carbide coating preparation process and equipment, reducing production costs, but also improves the efficiency and safety of tantalum carbide coating preparation. Specifically:

[0061] In this application, the solid tantalum source has a saturated vapor pressure below 10 Pa at 2000°C, making its tantalum source contribution due to volatilization negligible when it exists alone at high temperatures. Simultaneously, in the presence of halogen- and carbon-containing gases, the non-volatile solid tantalum source can be converted into a more volatile tantalum source through an in-situ reaction, increasing the tantalum source concentration in the process area. Under these conditions, the reaction between the solid tantalum source and the halogen- and carbon-containing gases creates a uniformly distributed and relatively enriched tantalum halide atmosphere, which is beneficial for the preparation of tantalum carbide coatings. Since this reaction occurs in a closed reaction chamber and only at relatively high temperatures, the tantalum halide significantly improves the efficiency and safety of tantalum carbide coating preparation.

[0062] It should be noted that the saturated vapor pressure of the aforementioned solid tantalum source can be determined using existing methods such as the static method (at the measurement temperature, the solid sample is placed in a sealed container to reach equilibrium with the gas phase, and the pressure of the gas phase at this point is directly measured, which is the saturated vapor pressure at that temperature), the saturated gas flow method (at a certain temperature and pressure, a certain volume of gas flow saturated with the vapor of the solid sample to be tested is passed through the gas flow, and a certain substance is used to completely absorb the vapor in the gas flow. The increase in weight of the absorbed substance is then weighed, and the partial pressure of the vapor can be calculated, which is the saturated vapor pressure of the solid sample to be tested at that temperature), the dynamic boiling point method (by adjusting the external pressure of the system to make the solid tantalum source sample boil, measuring the relationship between boiling temperature and pressure, and calculating the saturated vapor pressure using the Clausius-Clapeyron equation), and thermogravimetric analysis (based on the relationship between the mass change of the sample and time when it is heated under controlled temperature conditions. As the temperature rises, the volatile components in the sample gradually escape, resulting in a decrease in sample mass, and the pressure of the escaped substance is the measured saturated vapor pressure), etc.

[0063] In the embodiments of this application, the gas containing halogen elements and carbon elements can be a single gas or a mixture of gases; at the same time, the components contained in the gas containing halogen elements and carbon elements can be in a gaseous state or a liquid state at room temperature and pressure. If the components contained in the gas containing halogen elements and carbon elements are in a non-gaseous state such as a liquid at room temperature and pressure, they can be pre-vaporized.

[0064] According to further specific embodiments of this application, the solid tantalum source includes at least one of metallic tantalum and tantalum pentoxide, and the shape of the solid tantalum source includes at least one of sheet-like and disc-like forms. Compared to existing tantalum sources (which are generally in the form of powder particles and require heating to present an unstable gaseous state), this application uses materials such as metallic tantalum (which, according to existing records, has a vapor pressure of <1.3 Pa at 537.2°C) and tantalum pentoxide (which, according to existing records, has a vapor pressure of 10 Pa at 1920°C). -2 Using non-volatile solid tantalum sources such as tantalum pentoxide (TP) is beneficial for the uniform distribution of tantalum sources in the reaction space and their relative enrichment near the process area. This improves uniformity and significantly increases the utilization efficiency of tantalum sources, reducing the waste of tantalum sources in non-process areas. Furthermore, the preparation of solid tantalum sources, such as sheet-like sources, can generally be achieved using processes like pressing. Specifically, sheet-like solid tantalum sources, such as metallic tantalum sheets and tantalum pentoxide sheets, involve the following processes: metal forming methods such as die casting or powder forming methods such as extrusion. Compared to existing tantalum sources such as tantalum pentachloride, the solid tantalum sources selected in this application, such as metallic tantalum and tantalum pentoxide, have the advantages of low raw material cost and high tantalum content.

[0065] According to some specific embodiments of this application, the halohydrocarbon compound includes at least one selected from CCl4, CBr4, CHCl3, CH2Cl2, CH3Cl, CHBr3, CH2Br2, CH3Br, CHF3, CH2F2, CH3F, and CF4;

[0066] And / or, the halogen element includes at least one of Cl2 and Br2;

[0067] And / or, the hydrocarbon compound includes at least one of gaseous alkanes and gaseous olefins, wherein the gaseous alkanes include at least one of methane, ethane, and propane, and the gaseous olefins include at least one of ethylene and propylene;

[0068] And / or, the volume ratio of the halogen element to the hydrocarbon compound is (10-30):1, for example, 10:1, 15:1, 20:1, 25:1, 30:1, etc.

[0069] According to some specific embodiments of this application, the steps of chemical vapor deposition using a solid tantalum source and a gas containing halogen and carbon elements as raw materials include the following processes:

[0070] The substrate is placed between two solid tantalum sources, and a first chemical vapor deposition is performed in the gas atmosphere containing halogen and carbon elements.

[0071] Alternatively, the substrate is placed between two solid tantalum sources, and a second chemical vapor deposition is performed in an atmosphere of halogen-containing and carbon-containing gases and a reducing gas.

[0072] Compared to the continuous feeding method in existing chemical vapor deposition processes for preparing tantalum carbide coatings, this application significantly simplifies equipment design, reduces operational difficulty, and improves operational safety by placing the substrate between two solid tantalum sources and pre-positioning both the solid tantalum sources and the substrate in the reaction chamber. The reaction is carried out in a gaseous atmosphere containing halogen and carbon elements to obtain gaseous tantalum halides. Specifically, in the embodiments of this application, the reaction chamber can be located in a device such as a reactor. Several reaction chamber units can also be set up within the same reactor chamber, where tantalum carbide coatings are prepared simultaneously. For example, several small crucibles can be used. These small crucibles are relatively enclosed spaces within the reaction chamber where samples are directly placed. Their size can be customized according to the sample. Based on the size of the small crucibles and the volume of the reaction chamber, and because the process conditions within each small crucible are relatively independent, this design is highly scalable. Multiple samples can be placed in a single furnace without affecting the coating effect, which significantly reduces the process cost per product. Meanwhile, since each crucible is a relatively independent reaction system, multiple crucibles can be set in one reactor, thereby increasing the capacity and preparation efficiency of a single reactor. Furthermore, because the distribution of the solid tantalum source can be controlled by the size of the solid tantalum source itself (generally, the larger the size of the sheet-like solid tantalum source, the better the in-situ generation of gaseous tantalum source, ensuring uniform distribution of the gaseous tantalum source on the sample surface), it has excellent scalability, making it particularly suitable for coating multiple samples in one furnace, significantly reducing the production cost per unit by increasing equipment utilization. In addition, placing the substrate between two solid tantalum sources ensures that both the upper and lower sides of the substrate surface to be coated are equipped with solid tantalum sources, allowing the substrate to be fully exposed to the tantalum source atmosphere, improving the uniformity and quality of the tantalum carbide coating. Specifically, a schematic diagram of the positions of the materials in the small crucibles within the reaction chamber in the tantalum carbide coating preparation method of this application is shown below. Figure 1 As shown, Figure 1 In the middle: 1-top of the small crucible in the reaction chamber, 2-bottom of the small crucible in the reaction chamber, 3-substrate, 4-solid tantalum source.

[0073] According to some further specific embodiments of this application, the operating condition parameters for the first chemical vapor deposition include:

[0074] The temperature is between 1800℃ and 2100℃, for example, it can be 1800℃, 1810℃, 1820℃, 1830℃, 1840℃, 1850℃, 1860℃, 1870℃, 1880℃, 1890℃, 1900℃, 1910℃, 1920℃, 1930℃, 1940℃, 1950℃, 1960℃, 1970℃, 1980℃, 1990℃, 2000℃, 2010℃, 2020℃, 2030℃, 2040℃, 2050℃, 2060℃, 2070℃, 2080℃, 2090℃, 2100℃, etc. In this application, controlling the temperature of the first chemical vapor deposition to the above parameters is beneficial to a higher reaction temperature to accelerate the deposition rate, preferably 2100℃;

[0075] The pressure ranges from 1000 Pa to 90000 Pa, for example, it can be 1000 Pa, 2000 Pa, 3000 Pa, 4000 Pa, 5000 Pa, 6000 Pa, 7000 Pa, 8000 Pa, 9000 Pa, 10000 Pa, 11000 Pa, 12000 Pa, 13000 Pa, 14000 Pa, 15000 Pa, 16000 Pa, 17000 Pa, 18000 Pa, 19000 Pa, 20000 Pa, 21000 Pa, 22000 Pa, 23000 Pa, 24000 Pa, 25000 Pa, 26000 Pa, 27000 Pa, 28000 Pa, 29000 Pa, 30 000Pa, 31000Pa, 32000Pa, 33000Pa, 34000Pa, 35000Pa, 36000Pa, 37000Pa, 38000Pa, 39000Pa, 40000Pa, 41000Pa, 42000Pa, 43000Pa, 44000Pa, 45000Pa, 46000Pa, 47000Pa, 48000Pa, 49000Pa, 50000Pa, 60000Pa, 70000Pa, 80000Pa, 90000Pa, etc. In this application, controlling the pressure of the first chemical vapor deposition to the above parameters is beneficial to increasing the residence time in the reaction chamber, preferably 50000Pa;

[0076] The time ranges from 1 hour to 10 hours, for example, it can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, 8.5 hours, 9 hours, 9.5 hours, 10 hours, etc. In this application, there is no special limitation on the time of the first chemical vapor deposition, and the process time can be selected according to the target coating thickness.

[0077] The flow rate of the gas containing halogen and carbon elements is 50 sccm to 1500 sccm, for example, it can be 50 sccm, 100 sccm, 150 sccm, 200 sccm, 250 sccm, 300 sccm, 350 sccm, 400 sccm, 450 sccm, 500 sccm, 550 sccm, 600 sccm, 650 sccm, 700 sccm, 750 sccm, 800 sccm, 850 sccm. ccm, 900sccm, 950sccm, 1000sccm, 1050sccm, 1100sccm, 1150sccm, 1200sccm, 1250sccm, 1300sccm, 1350sccm, 1400sccm, 1450sccm, 1500sccm, etc. In this application, the flow rate of the gas containing halogen elements and carbon elements in the first chemical vapor deposition is not specifically limited, and can be selected according to the specific parameters such as equipment size;

[0078] The flow rate of the carrier gas is 1 slm to 30 slm, for example, it can be 1 slm, 2 slm, 3 slm, 4 slm, 5 slm, 6 slm, 7 slm, 8 slm, 9 slm, 10 slm, 11 slm, 12 slm, 13 slm, 14 slm, 15 slm, 16 slm, 17 slm, 18 slm, 19 slm, 20 slm, 21 slm, 22 slm, 23 slm, 24 slm, 25 slm, 26 slm, 27 slm, 28 slm, 29 slm, 30 slm, etc. In this application, the flow rate of the carrier gas in the first chemical vapor deposition is not specifically limited and can be selected according to parameters such as equipment size; wherein, the carrier gas is an inert gas, and the inert gas includes at least one of argon and helium.

[0079] According to further specific embodiments of this application, the operating condition parameters for the second chemical vapor deposition include:

[0080] The temperature is 1200℃~1800℃, for example, it can be 1200℃, 1250℃, 1300℃, 1350℃, 1400℃, 1450℃, 1500℃, 1550℃, 1600℃, 1650℃, 1700℃, 1750℃, 1800℃, etc. When the temperature of the second chemical vapor deposition is controlled to the above parameters in this application, it is beneficial to not destroy the solid properties of tantalum pentoxide, which has a melting point of about 1800℃, and at the same time, a higher temperature helps to accelerate the deposition rate, preferably 1700℃;

[0081] The pressure ranges from 1000 Pa to 90000 Pa, for example, it can be 1000 Pa, 2000 Pa, 3000 Pa, 4000 Pa, 5000 Pa, 6000 Pa, 7000 Pa, 8000 Pa, 9000 Pa, 10000 Pa, 11000 Pa, 12000 Pa, 13000 Pa, 14000 Pa, 15000 Pa, 16000 Pa, 17000 Pa, 18000 Pa, 19000 Pa, 20000 Pa, 21000 Pa, 22000 Pa, 23000 Pa, 24000 Pa, 25000 Pa, 26000 Pa, 27000 Pa, 28000 Pa, 29000 Pa. In this application, controlling the pressure for the second chemical vapor deposition to the above parameters is beneficial to accelerating the deposition rate, and 50,000 Pa is preferred.

[0082] The time ranges from 1 hour to 10 hours, for example, it can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, 8.5 hours, 9 hours, 9.5 hours, 10 hours, etc. In this application, there is no special limitation on the time of the second chemical vapor deposition, and the process time can be selected according to the target coating thickness.

[0083] The flow rate of the gas containing halogen and carbon elements is 50 sccm to 1500 sccm, for example, it can be 50 sccm, 100 sccm, 150 sccm, 200 sccm, 250 sccm, 300 sccm, 350 sccm, 400 sccm, 450 sccm, 500 sccm, 550 sccm, 600 sccm, 650 sccm, 700 sccm, 750 sccm, 800 sccm, 850 sccm. ccm, 900sccm, 950sccm, 1000sccm, 1050sccm, 1100sccm, 1150sccm, 1200sccm, 1250sccm, 1300sccm, 1350sccm, 1400sccm, 1450sccm, 1500sccm, etc. In this application, the flow rate of the gas containing halogen elements and carbon elements in the second chemical vapor deposition is not specifically limited, and can be selected according to the specific parameters such as equipment size;

[0084] The carrier gas flow rate is 1 slm to 30 slm, for example, it can be 1 slm, 2 slm, 3 slm, 4 slm, 5 slm, 6 slm, 7 slm, 8 slm, 9 slm, 10 slm, 11 slm, 12 slm, 13 slm, 14 slm, 15 slm, 16 slm, 17 slm, 18 slm, 19 slm, 20 slm, 21 slm, 22 slm, 23 slm, 24 slm, 25 slm, 26 slm, 27 slm, 28 slm, 29 slm, 30 slm, etc., wherein the carrier gas is an inert gas, and the inert gas includes at least one of argon and helium. In this application, there is no special limitation on the carrier gas flow rate in the second chemical vapor deposition, and it can be selected according to the specific parameters such as equipment size;

[0085] The flow rate of the reducing gas ranges from 50 sccm to 5000 sccm, for example, it can be 50 sccm, 150 sccm, 250 sccm, 350 sccm, 450 sccm, 550 sccm, 650 sccm, 750 sccm, 850 sccm, 950 sccm, 1050 sccm, 1150 sccm, 1250 sccm, 1350 sccm, 1450 sccm, 1550 sccm, 1650 sccm, 1750 sccm, 1850 sccm, 1950 sccm, 2050 sccm, 2150 sccm, 2250 sccm, 2350 sccm, 2450 sccm, 2550 sccm, 2650 sccm, 2750 sccm. The flow rates of reducing gas in the second chemical vapor deposition process in this application are 2850 sccm, 2950 sccm, 3050 sccm, 3150 sccm, 3250 sccm, 3350 sccm, 3450 sccm, 3550 sccm, 3650 sccm, 3750 sccm, 3850 sccm, 3950 sccm, 4050 sccm, 4150 sccm, 4250 sccm, 4350 sccm, 4450 sccm, 4550 sccm, 4650 sccm, 4750 sccm, 4850 sccm, and 4950 sccm, etc. There is no specific limitation on the flow rate of reducing gas in the second chemical vapor deposition process; it can be specifically selected according to parameters such as equipment size and coating thickness. The reducing gas includes hydrogen.

[0086] According to some specific embodiments of this application, the projected area S1 of the solid tantalum source in the same plane as the substrate surface to be plated and the area S2 of the substrate surface to be plated satisfy the following relationship: S1≥S2;

[0087] And / or, several reaction chamber units are arranged in the same reaction chamber, and tantalum carbide coatings are prepared simultaneously in the reaction chamber units.

[0088] In this embodiment, by setting the projected area S1 of the solid tantalum source in the same plane as the substrate surface to be plated to be no less than the area of ​​the substrate surface to be plated, the substrate can be fully exposed to the precursor atmosphere, which is beneficial to the preparation of tantalum carbide coating. Meanwhile, in this embodiment, the reaction chamber can be located in a device such as a reactor. Several reaction chamber units can also be set within the same reactor chamber, where tantalum carbide coating can be prepared simultaneously. For example, several small crucibles can be used. These small crucibles are relatively enclosed small spaces within the reaction chamber where samples are directly placed. Their size can be customized according to the sample. Based on the size of the small crucibles and the volume of the reaction chamber, since the process conditions within a single small crucible are relatively independent, this design is highly scalable. Multiple samples can be placed in a single furnace without affecting the coating effect, which significantly reduces the process cost of a single product. A detailed cost comparison analysis is as follows:

[0089] 1. Among various tantalum precursors, tantalum pentachloride contains only 50% tantalum, tantalum pentoxide contains 82% tantalum, while tantalum metal contains as much as 100% tantalum. It is worth noting that chlorine does not contribute to the coating deposition process. In terms of market price, the order of these three precursors is: tantalum pentachloride > tantalum pentoxide > tantalum metal.

[0090] 2. In traditional processes, the concentration of tantalum pentachloride is dispersed throughout the reaction chamber, resulting in a large amount of tantalum source deposited on the reactor wall, leading to extremely low precursor utilization efficiency. In contrast, the new process can directionally form a tantalum source enrichment zone near the sample to be coated, significantly improving the utilization efficiency of the tantalum source and thus greatly reducing the amount of precursor consumed when depositing a coating of the same thickness.

[0091] 3. Compared to traditional processes, the new process provided in this application is less affected by the external environment of the small crucible in terms of deposition effect, which is beneficial for capacity expansion. By increasing the output per furnace, the new process can further reduce the cost per unit product. Traditional processes, on the other hand, are strictly limited in terms of output per furnace due to the need to prevent excessive product stacking from disrupting the gas flow field. It is estimated that the output per furnace of the new process can be increased by 2 to 3 times compared to the traditional process.

[0092] 4. Traditional processes have high requirements for the gas flow field within the reaction chamber, and their solid-source continuous quantitative controllable feeding equipment is complex in design, containing multiple moving parts, resulting in a higher failure rate and correspondingly higher fixed investment costs. In contrast, the new process has lower requirements for equipment, and its fixed asset depreciation costs are also relatively lower.

[0093] 5. Tantalum pentachloride is unstable in air and reacts violently with moisture to form acid mist, thus requiring higher safety standards for related operations. In contrast, tantalum metal and tantalum pentoxide are stable in air and require no additional safety measures.

[0094] A second aspect of this application discloses a tantalum carbide coating. According to an embodiment of this application, the tantalum carbide coating is prepared using the tantalum carbide coating preparation method described in any one of the first aspects.

[0095] The tantalum carbide coating of the above embodiments of this application is prepared by the method for preparing tantalum carbide coating as described in any one of the first aspects. Therefore, this tantalum carbide coating has the advantages of simple preparation process, low equipment requirements, low preparation cost, and high preparation efficiency, making it more suitable for industrial-scale production.

[0096] A third aspect of this application discloses a tantalum carbide coated article. According to embodiments of this application, the tantalum carbide coated article comprises a tantalum carbide coating prepared by the method described in any one of the first aspects or a tantalum carbide coating described in any one of the second aspects. This effectively reduces the production cost of the tantalum carbide coated article.

[0097] In the embodiments of this application, the aforementioned tantalum carbide coated product may specifically be a product containing a tantalum carbide coating, such as an engine nozzle, a heat shield, or a cutting tool.

[0098] The embodiments of this application are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known methods. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0099] Example 1

[0100] This embodiment provides a method for preparing a tantalum carbide coating, wherein the tantalum carbide coating precursor in the preparation method includes:

[0101] The solid tantalum source is specifically a sheet-like tantalum pentoxide with a cross-sectional area of ​​700 cm². 2 ;

[0102] Gases containing halogens and carbon, specifically carbon tetrachloride (CFCs have CAS number 56-23-5);

[0103] The carrier gas, specifically argon;

[0104] Reducing gas, specifically hydrogen;

[0105] Specifically, the following steps are included:

[0106] The substrate to be coated (specifically isostatically pressed graphite with a surface area of ​​435 cm²) is cleaned and dried. 2The crucible is placed horizontally in a graphite crucible that is ventilated on the sides and pre-coated (the pre-coating component is TaC). A horizontally placed tantalum pentoxide sheet is fixed at the top and bottom of the graphite crucible. The tantalum pentoxide sheet weighs 50g. After confirming that the airtightness of the reaction chamber meets the standard (the airtightness requirement is that the pressure rise rate is less than 20pa / h), the temperature is raised. After the temperature of the reaction chamber reaches the target temperature of 1600℃, the pressure condition in the reaction chamber is adjusted to 20000pa.

[0107] After the reaction chamber temperature and pressure reach the target conditions, argon, chlorofluorocarbon (CFC) gas, and hydrogen are introduced, with a CFC gas flow rate of 50 sccm, an argon gas flow rate of 1 slm, and a hydrogen gas flow rate of 200 sccm; the temperature and pressure are maintained for 3 hours.

[0108] After the process is completed and the temperature is lowered to below 50°C, the furnace is opened and the product is removed to obtain a tantalum carbide coating.

[0109] Example 2

[0110] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that:

[0111] (1) The temperature of the reaction chamber is 1200℃;

[0112] (2) The pressure in the reaction chamber is 1000 Pa;

[0113] (3) The heat preservation and pressure holding time is 1 hour;

[0114] Example 3

[0115] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that: (1) the reaction chamber temperature is 1200℃;

[0116] (2) The pressure in the reaction chamber is 1000 Pa;

[0117] (3) The heat preservation and pressure holding time is 1 hour;

[0118] (4) The flow rate of chlorofluorocarbon gas is 1500 sccm.

[0119] Example 4

[0120] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that: (1) the reaction chamber temperature is 1200℃;

[0121] (2) The pressure in the reaction chamber is 1000 Pa;

[0122] (3) The heat preservation and pressure holding time is 1 hour;

[0123] (4) The argon flow rate is 30 slm.

[0124] Example 5

[0125] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that: (1) the reaction chamber temperature is 1200℃;

[0126] (2) The pressure in the reaction chamber is 1000 Pa;

[0127] (3) The heat preservation and pressure holding time is 1 hour;

[0128] (4) The argon flow rate is 30 slm;

[0129] (5) The flow rate of chlorofluorocarbon gas is 1500 sccm.

[0130] Example 6

[0131] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that: (1) the reaction chamber temperature is 1200℃;

[0132] (2) The pressure in the reaction chamber is 1000 Pa;

[0133] (3) The flow rate of chlorofluorocarbon gas is 1500 sccm.

[0134] Example 7

[0135] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that: (1) the reaction chamber temperature is 1200℃;

[0136] (2) The pressure in the reaction chamber is 1000 Pa;

[0137] (3) The flow rate of chlorofluorocarbon gas is 1500 sccm;

[0138] (4) The argon flow rate is 30 slm.

[0139] Example 8

[0140] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that: (1) the reaction chamber temperature is 1800℃;

[0141] (2) The pressure in the reaction chamber is 1000 Pa;

[0142] (3) The heat preservation and pressure preservation time is 1 hour.

[0143] Example 9

[0144] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that: (1) the reaction chamber temperature is 1800℃;

[0145] (2) The pressure in the reaction chamber is 1000 Pa;

[0146] (3) The heat preservation and pressure holding time is 1 hour;

[0147] (4) The flow rate of chlorofluorocarbon gas is 1500 sccm.

[0148] Example 10

[0149] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that: (1) the reaction chamber temperature is 1800℃;

[0150] (2) The pressure in the reaction chamber is 1000 Pa;

[0151] (3) The heat preservation and pressure holding time is 1 hour;

[0152] (4) The argon flow rate is 30 slm.

[0153] Example 11

[0154] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that: (1) the reaction chamber temperature is 1800℃;

[0155] (2) The pressure in the reaction chamber is 1000 Pa;

[0156] (3) The heat preservation and pressure holding time is 1 hour;

[0157] (4) The argon flow rate is 30 slm;

[0158] (5) The flow rate of chlorofluorocarbon gas is 1500 sccm.

[0159] Example 12

[0160] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that: (1) the reaction chamber temperature is 1800℃;

[0161] (2) The pressure in the reaction chamber is 1000 Pa;

[0162] (3) The flow rate of chlorofluorocarbon gas is 1500 sccm.

[0163] Example 13

[0164] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that: (1) the reaction chamber temperature is 1800℃;

[0165] (2) The pressure in the reaction chamber is 1000 Pa;

[0166] (3) The flow rate of chlorofluorocarbon gas is 1500 sccm;

[0167] (4) The argon flow rate is 30 slm.

[0168] Example 14

[0169] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that:

[0170] (1) The temperature of the reaction chamber is 1800℃;

[0171] (2) The pressure in the reaction chamber is 50,000 Pa;

[0172] (3) The flow rate of chlorofluorocarbon gas is 1500 sccm;

[0173] (4) The argon flow rate is 30 slm.

[0174] Example 15

[0175] This embodiment provides a tantalum carbide coating precursor, the tantalum carbide coating precursor comprising:

[0176] The solid tantalum source is specifically a sheet-like metallic tantalum plate with a surface area of ​​700 cm². 2 ;

[0177] Gases containing halogens and carbon, specifically carbon tetrachloride (CFCs have CAS number 56-23-5);

[0178] The carrier gas is argon.

[0179] This embodiment applies the above-mentioned tantalum carbide coating precursor to the preparation of tantalum carbide coating, specifically including the following steps:

[0180] The substrate to be coated (specifically isostatically pressed graphite with a surface area of ​​435 cm²) is cleaned and dried. 2 The material is placed horizontally into a graphite crucible that is ventilated on the sides and pre-coated (the pre-coating component is TaC). A horizontally placed tantalum sheet weighing 50g is fixed at the top and bottom of the graphite crucible. After confirming that the airtightness of the reaction chamber meets the standard (the airtightness requirement is a pressure rise rate of <20Pa / h), the temperature is raised. After the temperature of the reaction chamber reaches the target temperature of 2100℃, the pressure conditions in the reaction chamber are adjusted to 20000pa.

[0181] After the reaction chamber temperature and pressure reach the target conditions, argon, chlorofluorocarbon gas and hydrogen are introduced, with a chlorofluorocarbon gas flow rate of 50 sccm and an argon gas flow rate of 1 slm; the temperature and pressure are maintained for 3 hours.

[0182] After the process is completed and the temperature is lowered to below 50°C, the furnace is opened and the product is removed to obtain a tantalum carbide coating.

[0183] Example 16

[0184] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that:

[0185] (1) The temperature of the reaction chamber is 1800℃;

[0186] (2) The pressure in the reaction chamber is 1000 Pa;

[0187] (3) The heat preservation and pressure preservation time is 1 hour.

[0188] Example 17

[0189] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that:

[0190] (1) The temperature of the reaction chamber is 1800℃;

[0191] (2) The pressure in the reaction chamber is 1000 Pa;

[0192] (3) The flow rate of chlorofluorocarbon gas is 1500 sccm;

[0193] (4) The heat preservation and pressure preservation time is 1 hour.

[0194] Example 18

[0195] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that: (1) the reaction chamber temperature is 1800℃;

[0196] (2) The pressure in the reaction chamber is 1000 Pa;

[0197] (3) The argon flow rate is 30 slm;

[0198] (4) The heat preservation and pressure preservation time is 1 hour.

[0199] Example 19

[0200] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that: (1) the reaction chamber temperature is 1800℃;

[0201] (2) The pressure in the reaction chamber is 1000 Pa;

[0202] (3) The argon flow rate is 30 slm;

[0203] (4) The flow rate of chlorofluorocarbon gas is 1500 sccm;

[0204] (5) The heat preservation and pressure preservation time is 1 hour.

[0205] Example 20

[0206] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that: (1) the reaction chamber temperature is 1800℃;

[0207] (2) The pressure in the reaction chamber is 1000 Pa;

[0208] (3) The flow rate of chlorofluorocarbon gas is 1500 sccm.

[0209] Example 21

[0210] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that: (1) the reaction chamber temperature is 1800℃;

[0211] (2) The pressure in the reaction chamber is 1000 Pa;

[0212] (3) The flow rate of chlorofluorocarbon gas is 1500 sccm;

[0213] (4) The argon flow rate is 30 slm.

[0214] Example 22

[0215] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that: (1) the reaction chamber temperature is 2300℃;

[0216] (2) The pressure in the reaction chamber is 1000 Pa;

[0217] (3) The heat preservation and pressure preservation time is 1 hour.

[0218] Example 23

[0219] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that: (1) the reaction chamber temperature is 2300℃;

[0220] (2) The pressure in the reaction chamber is 1000 Pa;

[0221] (3) The heat preservation and pressure holding time is 1 hour;

[0222] (4) The flow rate of chlorofluorocarbon gas is 1500 sccm.

[0223] Example 24

[0224] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that: (1) the reaction chamber temperature is 2300℃;

[0225] (2) The pressure in the reaction chamber is 1000 Pa;

[0226] (3) The heat preservation and pressure holding time is 1 hour;

[0227] (4) The argon flow rate is 30 slm.

[0228] Example 25

[0229] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that: (1) the reaction chamber temperature is 2300℃;

[0230] (2) The pressure in the reaction chamber is 1000 Pa;

[0231] (3) The heat preservation and pressure holding time is 1 hour;

[0232] (4) The argon flow rate is 30 slm;

[0233] (5) The flow rate of chlorofluorocarbon gas is 1500 sccm;

[0234] Example 26

[0235] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that: (1) the reaction chamber temperature is 2300℃;

[0236] (2) The pressure in the reaction chamber is 1000 Pa;

[0237] (3) The flow rate of chlorofluorocarbon gas is 1500 sccm.

[0238] Example 27

[0239] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that: (1) the reaction chamber temperature is 2300℃;

[0240] (2) The pressure in the reaction chamber is 1000 Pa;

[0241] (3) The flow rate of chlorofluorocarbon gas is 1500 sccm;

[0242] (4) The argon flow rate is 30 slm.

[0243] Example 28

[0244] This embodiment provides a method for preparing a tantalum carbide coating, which differs from Example 15 only in that: (1) the reaction chamber temperature is 2300℃;

[0245] (2) The pressure in the reaction chamber is 50,000 Pa;

[0246] (3) The flow rate of chlorofluorocarbon gas is 1500 sccm;

[0247] (4) The argon flow rate is 30 slm.

[0248] Comparative Example 1

[0249] This comparative example provides a conventional chemical vapor deposition process for preparing tantalum carbide coatings, including the following steps:

[0250] The substrate to be coated (specifically isostatically pressed graphite with a surface area of ​​435 cm²) is cleaned and dried. 2 The crucible is placed horizontally into a graphite crucible that is ventilated on the side and pre-coated (the pre-coating component is TaC). After confirming that the airtightness of the reaction chamber meets the standard (the airtightness requirement is a pressure rise rate of <20pa / h), the temperature is raised. Once the temperature of the reaction chamber reaches the target temperature of 1800℃, the pressure conditions in the reaction chamber are adjusted to 50000pa.

[0251] After the reaction chamber temperature and pressure reach the target conditions, C3H6, H2, TaCl5 (the solid source of tantalum pentachloride is converted into gaseous form and carried into the process system by the carrier gas) and Ar are introduced. The flow rate of C3H6 is 50 sccm, the flow rate of hydrogen is 1 slm, the flow rate of argon is 30 slm, and the feeding rate of TaCl5 is 10 g / min. The temperature and pressure are maintained for 2 hours.

[0252] After the process is completed and the temperature is lowered to below 50°C, the furnace is opened and the product is removed to obtain a tantalum carbide coating.

[0253] Comparative Example 2

[0254] This comparative example provides a method for preparing a tantalum carbide coating, which differs from Example 1 only in that:

[0255] (1) No chlorofluorocarbon gas (i.e., carbon tetrachloride gas in Example 1) was introduced.

[0256] The preparation of the tantalum carbide coating specifically includes the following process: The substrate to be coated (specifically isostatically pressed graphite with a surface area of ​​435 cm²) is cleaned and dried. 2 The crucible is placed horizontally in a graphite crucible that is ventilated on the sides and pre-coated (the pre-coating component is TaC). A horizontally placed tantalum pentoxide sheet is fixed at the top and bottom of the graphite crucible. The tantalum pentoxide sheet weighs 50g. After confirming that the airtightness of the reaction chamber meets the standard (the airtightness requirement is that the pressure rise rate is less than 20pa / h), the temperature is raised. After the temperature of the reaction chamber reaches the target temperature of 1600℃, the pressure condition in the reaction chamber is adjusted to 20000pa.

[0257] After the reaction chamber temperature and pressure reach the target conditions, argon and hydrogen are introduced, with an argon flow rate of 1 slm and a hydrogen flow rate of 200 sccm; the temperature and pressure are maintained for 3 hours.

[0258] After the process is completed and the temperature is lowered to below 50°C, the furnace is opened and the product is removed to obtain a tantalum carbide coating.

[0259] Test Example 1

[0260] This test example characterizes the tantalum carbide coatings obtained in Examples 1, 15, 1, and 2 above.

[0261] The test results are shown below:

[0262] The macroscopic morphology and microscopic scanning electron microscope (SEM) images of Example 1 are as follows: Figure 2 and Figure 3 As shown, the macroscopic morphology and microscopic scanning electron microscope (SEM) images of Example 15 are as follows: Figure 4 and Figure 5 As shown, the macroscopic morphology and microscopic scanning electron microscope (SEM) images of Comparative Example 1 are as follows: Figure 6 and Figure 7 As shown, the macroscopic morphology and microscopic scanning electron microscope (SEM) images of Comparative Example 2 are as follows: Figure 8 and Figure 9 As shown.

[0263] The test results above show that:

[0264] 1) As shown in the test results of Comparative Example 1, Example 1, and Example 15, this application provides a new process for preparing tantalum carbide coatings by using a non-volatile solid tantalum source, such as flake form, and a gas containing halogen and carbon elements as precursors. The two can generate tantalum halides in situ, providing a novel process for preparing tantalum carbide coatings. Furthermore, the tantalum carbide coating obtained using this new process has superior thickness and density compared to the tantalum carbide coating obtained using conventional processes.

[0265] 2) The test results of Comparative Example 2, Example 1, and Example 15 show that when no chlorofluorocarbons are involved, tantalum pentoxide itself has very poor volatility, the coating is very thin under the same conditions, and the surface uniformity is significantly poor. In addition, tantalum pentachloride has a very low volatilization temperature (boiling point less than 300°C; that is, its volatility is high compared to solid tantalum sources such as tantalum pentoxide), and it volatilizes completely during the heating and vacuuming process. Moreover, since the temperature cannot produce tantalum carbide when volatilization occurs, a coating cannot be formed. Therefore, traditional volatile tantalum sources such as tantalum pentachloride are not applicable to this application.

[0266] Meanwhile, this test example performs performance tests on the tantalum carbide coatings obtained in Examples 1, 15, Comparative Example 1, and Comparative Example 2, and the test results are shown in Table 1.

[0267] Table 1

[0268] Test sample Hardness (HV) Example 1 2000 Example 15 1950 Comparative Example 1 1980 Comparative Example 2 1850

[0269] As shown in Table 1, there is no significant difference in hardness between the tantalum carbide coating obtained by the new process of this application and the tantalum carbide coating obtained by the traditional process, and the hardness of the tantalum carbide coating obtained in Example 1 is slightly better.

[0270] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example 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, without contradiction, 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.

[0271] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for preparing a tantalum carbide coating, characterized in that, Includes the following steps: Tantalum carbide coatings were obtained by chemical vapor deposition using solid tantalum source and gas containing halogen and carbon elements as raw materials. The solid tantalum source has a saturated vapor pressure of less than 10 Pa at 2000℃.

2. The method for preparing tantalum carbide coating according to claim 1, characterized in that, The solid tantalum source includes at least one of metallic tantalum and tantalum pentoxide, and the shape of the solid tantalum source includes at least one of sheet-like and disc-like shapes.

3. The method for preparing tantalum carbide coating according to claim 1, characterized in that, The halogen- and carbon-containing gas includes at least one of halogenated hydrocarbon compounds and mixtures of halogen elements and hydrocarbon compounds.

4. The method for preparing tantalum carbide coating according to claim 3, characterized in that, The halohydrocarbon compounds include at least one of CCl4, CBr4, CHCl3, CH2Cl2, CH3Cl, CHBr3, CH2Br2, CH3Br, CHF3, CH2F2, CH3F, and CF4; And / or, the halogen element includes at least one of Cl2 and Br2; And / or, the hydrocarbon compound includes at least one of gaseous alkanes and gaseous olefins, wherein the gaseous alkanes include at least one of methane, ethane, and propane, and the gaseous olefins include at least one of ethylene and propylene; And / or, the volume ratio of the halogen element to the hydrocarbon compound is (10-30):

1.

5. The method for preparing the tantalum carbide coating according to any one of claims 1 to 4, characterized in that, The steps for chemical vapor deposition using a solid tantalum source and a gas containing halogen and carbon elements as raw materials include the following processes: The substrate is placed between two solid tantalum sources, and a first chemical vapor deposition is performed in the gas atmosphere containing halogen and carbon elements. Alternatively, the substrate is placed between two solid tantalum sources, and a second chemical vapor deposition is performed in an atmosphere of halogen-containing and carbon-containing gases and a reducing gas.

6. The method for preparing tantalum carbide coating according to claim 5, characterized in that, The operating conditions for the first chemical vapor deposition include: The temperature is 1800℃~2100℃; Pressure ranges from 1000 Pa to 90000 Pa; The time is 1 hour to 10 hours; The flow rate of the gas containing halogen and carbon elements is 50 sccm to 1500 sccm. The carrier gas flow rate is 1 slm to 30 slm; The carrier gas is an inert gas, which includes at least one of argon and helium.

7. The method for preparing tantalum carbide coating according to claim 5, characterized in that, The operating conditions for the second chemical vapor deposition include: The temperature ranges from 1200℃ to 1800℃. Pressure ranges from 1000 Pa to 90000 Pa; The time is 1 hour to 10 hours; The flow rate of the gas containing halogen and carbon elements is 50 sccm to 1500 sccm. The flow rate of the reducing gas is 50 sccm to 5000 sccm; The carrier gas flow rate is 1 slm to 30 slm; The carrier gas is an inert gas, including at least one of argon and helium; the reducing gas includes hydrogen.

8. The method for preparing tantalum carbide coating according to claim 5, characterized in that, The projected area S1 of the solid tantalum source in the same plane as the substrate surface to be plated and the area S2 of the substrate surface to be plated satisfy the following relationship: S1≥S2; And / or, several reaction chamber units are arranged in the same reaction chamber, and tantalum carbide coatings are prepared simultaneously in the reaction chamber units.

9. A tantalum carbide coating, characterized in that, The tantalum carbide coating is prepared by the method for preparing tantalum carbide coating according to any one of claims 1 to 8.

10. A tantalum carbide coated product, characterized in that, The tantalum carbide coated product includes a tantalum carbide coating prepared by the method of any one of claims 1 to 8 or the tantalum carbide coating of claim 9.

Images