Ceramic component gradient modified C / C composite component and preparation method and application thereof

Abstract

The application discloses a kind of ceramic component gradient modification C / C composite material components and its preparation method and application, it is related to carbon material technical field.The method includes that C / C composite material is processed into the component of specific shape;Ceramic infiltration powder is pressed into ceramic sheet;Ceramic sheet is placed in the specified position of component, and both are placed in selectively open graphite mould, vacuum extraction is 0.1~500Pa, subsequently in inert atmosphere, at 1200~2100 DEG C, 0.5~10h is kept, obtains ceramic component gradient modification C / C composite material component.The application realizes the one-step efficient preparation of ceramic component gradient modification C / C composite material component by optimizing reaction infiltration (RMI) process.

Description

Technical Field

[0001] This invention relates to the field of carbon materials technology, specifically to a ceramic component gradient modified C / C composite material component, its preparation method, and its application. Background Technology

[0002] When hypersonic vehicles glide, cruise, or re-enter the atmosphere at high Mach numbers, their thermal protection components, such as nose wings and leading edges, must withstand prolonged, extremely high-temperature, and intensely erosive aerodynamic thermal environments. Therefore, thermal protection materials possessing both high thermal conductivity and ablation resistance are crucial for the long-term stable operation of hypersonic vehicles under ultra-high temperature and complex thermodynamic conditions. Carbon / carbon (C / C) composites possess excellent high-temperature mechanical and thermophysical properties and are currently used to manufacture hot-end components such as engine nozzles, missile nose cones, aircraft brake discs, and aircraft wing leading edges. However, the high high-temperature oxidation sensitivity and insufficient ablation resistance of C / C composites severely restrict their widespread application and development. Currently, introducing ablation-resistant ultra-high temperature ceramics (UHTCs) into the C / C composite matrix is ​​an effective means to improve its oxidation and ablation resistance. Meanwhile, SiC, due to its moderate coefficient of thermal expansion, can alleviate the thermal expansion mismatch between UHTCs and C / C and is often introduced into the C / C matrix as a synergistic modifier. However, existing matrix modification processes generally suffer from problems such as blind modification leading to C / C weight reduction and weakened thermal conductivity, as well as difficulty in fully utilizing the anti-oxidation / ablation properties of each ceramic component.

[0003] In existing technologies, the proportion of the modified component (ZrC-SiC) is continuously reduced radially from the center to the edge of the preform by controlling the process, resulting in a gradient change in the properties of the C / C composite material. The prepared composite material has a high ZrC content at the ablation center to provide ablation resistance, while the ablation edge has a high SiC content to match the thermophysical properties of C / C. However, the chemical liquid phase vapor deposition method uses a lot of raw materials, has low precursor utilization, and leaves a large amount of organic waste residue, causing serious environmental pollution. In addition, this method is mainly for regular-shaped components and is difficult to achieve ceramic gradient modification of irregularly shaped C / C composite components. In actual service environments, irregularly shaped C / C components are widely used as high-temperature structural parts, and the shape of the component has a significant impact on the ablation behavior of the composite material. Taking a sharp C / C composite component as an example, during the ablation process, a significant temperature gradient is present inside, with a large amount of heat concentrated at the tip of the material, which is not conducive to the long-term service of the material. Therefore, optimizing the preparation process to achieve a gradient distribution of ceramic components in conventional and irregular C / C structures, so as to achieve a high ceramic content and ablation resistance at the front end and a low ceramic content and high thermal conductivity at the back end, is the key to further improving the long-term service stability of C / C-UHTCs composite components. Summary of the Invention

[0004] To address the shortcomings of the aforementioned background technology, this invention primarily solves the problem of the difficulty in achieving ceramic gradient modification of irregularly shaped C / C composite components in existing technologies. This invention provides a ceramic component gradient-modified C / C composite component, its preparation method, and its application. This method optimizes the reactive melt infiltration (RMI) process and utilizes a designed selectively porous graphite mold to achieve a one-step, highly efficient preparation of ceramic component gradient-modified C / C composite components. Compared to traditional methods, this invention achieves a gradient distribution of the modified component UHTCs-SiC in the C / C preform by pressing the melt infiltration powder into tablets and precisely controlling the infiltration temperature and duration. This not only simplifies the process and improves preparation efficiency but is also applicable to C / C composite components of different shapes and sizes. Furthermore, the selectively porous graphite mold can guide the directional extraction of airflow during negative pressure RMI, thereby inducing the directional flow of the molten metal and facilitating the gradient distribution of the ceramic component. This technology enables a gradient change in the UHTCs / SiC ratio from the front to the back end of the component, as well as a gradual decrease in the ceramic phase content and a gradual increase in the carbon content along the penetration direction, thus providing a new technology and method for constructing high thermal conductivity and ablation-resistant ceramic-modified C / C composite materials.

[0005] The first objective of this invention is to provide a method for preparing C / C composite material components with ceramic component gradient modification, comprising the following steps:

[0006] Processing C / C composite materials into components of specific shapes;

[0007] The ceramic infiltration powder is pressed into ceramic sheets;

[0008] Ceramic sheets are placed at designated positions on the component, and both are placed in a selectively perforated graphite mold. The vacuum is then evacuated to 0.1–500 Pa, and the component is then kept at 1200–2100 °C for 0.5–10 h in an inert atmosphere to obtain a ceramic component gradient modified C / C composite component.

[0009] Preferably, the ceramic infiltration powder is one or more of Zr, Hf, Ta, Si, Al2O3, ZrSi, ZrSi2, HfSi2, TaSi2, ZrCu, HfCu, Zr2Cu, Cu5Si, (Zr,Hf)Si2, and (Zr,Hf,Ta)Si2.

[0010] Preferably, the ceramic sheet is obtained by the following steps: ball milling and mixing different types of ceramic melting powder in a certain proportion and drying them, and pressing them into ceramic sheets under a pressure of 30 to 180 MPa.

[0011] Preferably, in an inert atmosphere, the heating rate is 5–10 °C / min.

[0012] Preferably, the inert atmosphere is a flowing argon atmosphere with a flow rate of 50-100 mL / min.

[0013] Preferably, the density of the C / C composite material is 1.15–1.45 g / cm³. 3 .

[0014] More preferably, after the C / C composite material is processed into a component of a specific shape, it is ultrasonically cleaned with anhydrous ethanol and deionized water for 10 to 70 minutes, and then kept at 60 to 100°C for 5 to 24 hours until it is dried.

[0015] The second objective of this invention is to provide a ceramic component gradient modified C / C composite material component.

[0016] Preferably, the component is in the shape of a disk, a wedge-shaped leading edge, a spherical head, or a cuboid.

[0017] The third objective of this invention is to provide an application of ceramic component gradient modified C / C composite material components in thermal protection.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This invention provides a ceramic component gradient-modified C / C composite material component, its preparation method, and its application. The method first utilizes the pressure applied during ceramic sheet pressing to effectively shorten the distance between infiltrated particles, thereby forming a stable molten pool on the ceramic sheet during the infiltration process. Next, the infiltration temperature and duration are precisely controlled based on the melting point of the infiltrated powder to adjust the relative concentration change of the melt during the infiltration process, achieving a gradient change in the ceramic phase content within the preform. Furthermore, a selectively perforated graphite mold is designed to guide the directional extraction of airflow during negative pressure RMI, thereby inducing the directional flow of the molten metal and contributing to the gradient distribution of ceramic components. The method also includes adjusting parameters such as RMI reaction temperature, heating rate, reaction time, gas flow rate, raw material mass, furnace pressure, ceramic sheet placement, infiltrated powder composition, and graphite mold structure to further regulate the infiltration behavior of the melt within the C / C preform under capillary action, optimizing the densification effect of the modified C / C composite material. This technology ensures a high content of UHTCs components at the C / C service front end, effectively suppressing the formation of rapid oxidation channels and cracking of the carbon matrix during oxidation or ablation. From the service front to the back end, this method achieves a gradient structure with a gradually decreasing UHTCs / SiC ratio and overall ceramic content, while the carbon content gradually increases. This method not only optimizes the thermal conductivity of the C / C composite material, ensuring rapid heat dissipation during ablation, but also significantly improves the material's fabrication efficiency and versatility, making it suitable for fabricating components of various shapes and sizes. In summary, this method based on the gradient distribution of ceramic components achieves a harmonious match between ceramic and C / C, providing an innovative solution for integrated high thermal conductivity and ablation functionality. Attached Figure Description

[0020] Figure 1 Schematic diagrams showing the geometric dimensions and ablation directions of C / C composite components of different shapes (unit: mm);

[0021] Figure 2 This is a schematic diagram illustrating different placement methods of the ceramic sheet and different opening designs of the graphite mold during the RMI process of this invention;

[0022] Figure 3 The image shows the XRD pattern of the ZrC-SiC gradient modified wedge-shaped C / C composite material prepared according to Example 3 of the present invention.

[0023] Figure 4 The microstructure of the ZrC-SiC gradient modified wedge-shaped C / C composite material prepared according to Example 3 of the present invention;

[0024] Figure 5 Comparison of the linear ablation rate of the ZrC-SiC ceramic uniformly modified C / C composite component and the gradient modified component prepared in Example 3 of this invention. Detailed Implementation

[0025] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the present invention.

[0026] This invention provides a method for preparing C / C composite material components modified with ceramic component gradient, comprising the following steps:

[0027] Processing C / C composite materials into components of specific shapes; pressing ceramic melt-infiltrating powder into ceramic sheets;

[0028] Ceramic sheets are placed at designated positions on the component, and both are placed in a selectively perforated graphite mold. The vacuum is then evacuated to 0.1–500 Pa, and the component is then kept at 1200–2100 °C for 0.5–10 h in an inert atmosphere to obtain a ceramic component gradient modified C / C composite component.

[0029] This invention achieves a gradient distribution of the modified component ratio (UHTCs / SiC) in C / C composite materials by finely adjusting the ceramic pressing parameters and reasonably controlling the melting and infiltration temperature and time, and ensures that the ceramic phase content gradually decreases while the carbon content gradually increases from the front end to the back end of service.

[0030] The ceramic infiltration powder is one or more of Zr, Hf, Ta, Si, Al2O3, ZrSi, ZrSi2, HfSi2, TaSi2, ZrCu, HfCu, Zr2Cu, Cu5Si, (Zr,Hf)Si2, and (Zr,Hf,Ta)Si2.

[0031] Specifically, the ceramic sheet is obtained by the following steps: ball milling and mixing different types of ceramic melting powder in a certain proportion and drying them, and pressing them into ceramic sheets under a pressure of 30 to 180 MPa.

[0032] In an inert atmosphere, the heating rate is 5–10 °C / min. The inert atmosphere is a flowing argon atmosphere with a flow rate of 50–100 mL / min.

[0033] According to the present invention, the density of the C / C composite material is 1.15 to 1.45 g / cm³. 3 After the C / C composite material is processed into components of a specific shape, it is ultrasonically cleaned with anhydrous ethanol and deionized water for 10–70 min, and then kept at 60–100 °C for 5–24 h until dried.

[0034] In one embodiment, the method for constructing a C / C composite material component with high thermal conductivity and ablation resistance based on the gradient distribution of ceramic components is as follows:

[0035] Step 1: C / C composite material treatment: Take a density of 1.15~1.45g / cm³. 3 The C / C composite material is processed into C / C composite component of a specific shape. It is ultrasonically cleaned with anhydrous ethanol and deionized water for 10–70 min, and then placed in an oven at 60–100℃ for 5–24 h until dried.

[0036] Step 2, Melt-infiltrating powder pressing: A certain proportion of different ceramic melt-infiltrating powders are ball-milled, mixed, and dried, and then pressed into ceramic sheets with a diameter of 10-50mm and a diameter of 5-30mm under a pressure of 30-180MPa.

[0037] Step 3: Introduction of Ceramic Component Gradient Distribution: Using a zoned / selective introduction process, ceramic sheets of different components prepared in Step 2 are placed at designated locations on the C / C composite component. Both are then placed within a selectively perforated graphite mold, which is placed in the high-temperature reaction chamber of a heat treatment furnace. A vacuum of 0.1–500 Pa is then applied, and the temperature is raised to 1200–2100 °C at a rate of 5–10 °C / min in an inert atmosphere. This temperature is maintained for 0.5–10 h, the power is turned off, and the sample is allowed to cool naturally to room temperature before being removed. The placement of the ceramic sheets, the location and size of the perforations in the graphite mold, and the composition and content of the melt-infiltrating powder used in each pressing are optimized to ultimately achieve a gradient distribution of the ceramic components within the C / C matrix.

[0038] Preferably, the shape of the C / C composite material component described in step one is one of, but not limited to: a disk, a wedge-shaped leading edge, a spherical head, or a cuboid.

[0039] It should be noted that, see Figure 2 As shown, the selectively perforated graphite mold includes: a graphite mold with a cavity, and through holes on the top and / or sidewalls of the graphite mold to facilitate the directional extraction of gas; wherein, when the sidewalls are perforated, symmetrical through holes can be opened on opposite sidewalls of the graphite mold; in addition, during the negative pressure RMI process, the components and ceramic sheets are located in the inner cavity of the graphite mold.

[0040] This invention provides a ceramic component gradient modified C / C composite material component.

[0041] The present invention also provides an application of ceramic component gradient modified C / C composite material components in thermal protection.

[0042] It should be noted that, unless otherwise specified, the experimental methods used in this invention are all conventional methods; and the reagents and materials used, unless otherwise specified, are all commercially available.

[0043] Example 1

[0044] I. C / C Composite Material Treatment: A density of 1.20 g / cm³ is used. 3 The C / C composite material was processed into a disc component with dimensions of Φ30mm×5mm. It was ultrasonically cleaned with anhydrous ethanol and deionized water for 50 minutes, and then placed in an oven at 70℃ for 20 hours until completely dried.

[0045] II. Melt-infiltrating powder pressing: Take 15g of ZrSi2 powder and 4g of Si powder, and press them into cylindrical ceramic sheets with a diameter of 15mm using a hydraulic press at 30MPa. Remove and dry.

[0046] III. Introduction of Gradient Distribution of Ceramic Components: The ZrSi2 and Si ceramic sheets prepared in step II were placed at the top and bottom of the C / C disk component, respectively. The ceramic sheets and the C / C composite component were then placed in a graphite mold with an opening at the top. The graphite mold was placed in the high-temperature reaction chamber of a heat treatment furnace. The furnace was then evacuated to 2 Pa and heated to 1900 °C at a rate of 5 °C / min under a flowing argon atmosphere (flow rate 50 mL / min). The temperature was held for 0.5 h, the power was turned off, and the sample was allowed to cool naturally to room temperature before being removed. Finally, a gradient distribution structure was obtained in the C / C matrix, showing a gradual decrease in ZrC content and a gradual increase in SiC content from the front to the rear of the service path.

[0047] Example 2

[0048] I. C / C composite material treatment: A density of 1.28 g / cm³ is used. 3 The C / C composite material was processed into a disc component with dimensions of Φ30mm×5mm. It was ultrasonically cleaned with anhydrous ethanol and deionized water for 20 minutes, and then placed in an oven at 70℃ for 20 hours until completely dried.

[0049] II. Molten Infiltration Powder Compression: Take 20g each of ZrSi powder and Si and Al2O3 ceramic powder in a mass ratio of 10:1, and press them into cylindrical ceramic sheets with a diameter of 15mm using a hydraulic press at 150MPa. These are labeled as 1 and 2. Remove and dry.

[0050] III. Introduction of Gradient Distribution of Ceramic Components: Ceramic sheets 1 and 2 prepared in step II were placed at the top and bottom of the C / C disk component, respectively. The ceramic sheets and the C / C composite component were placed in a graphite mold with an opening at the top. The graphite mold was then placed in the high-temperature reaction chamber of a heat treatment furnace. A vacuum of 20 Pa was then applied, and under the protection of a flowing argon atmosphere (flow rate of 50 mL / min), the temperature was increased to 1900 °C at a rate of 8 °C / min and held for 1 hour. The power was then turned off, and the sample was allowed to cool naturally to room temperature before being removed. Finally, a gradient distribution structure was obtained in the C / C matrix, showing a gradual decrease in ZrC content and a gradual increase in SiC content from the front to the rear end of the service path.

[0051] Example 3

[0052] I. C / C Composite Material Treatment: A density of 1.40 g / cm³ is used. 3 The C / C composite material was processed into a wedge-shaped leading edge component with a curvature radius of 1.5 mm. It was ultrasonically cleaned with anhydrous ethanol and deionized water for 60 min, and then placed in an oven at 80 °C for 10 h until it was dried.

[0053] II. Melt-infiltrating powder pressing: Take 20g of ZrSi2 and ZrO2 ceramic powders with a mass ratio of 1:0.5 and ball-mill them together. Then, use a hydraulic press to press out cylindrical ceramic sheets with a diameter of 25mm under a pressure of 120MPa. Remove and dry.

[0054] III. Introduction of Gradient Distribution of Ceramic Components: The cylindrical ceramic sheet prepared in step II was placed on the top of the wedge-shaped leading edge component. The ceramic sheet and the C / C composite component were placed in a graphite mold with an opening at the top. The graphite mold was then placed in the high-temperature reaction chamber of a heat treatment furnace. The furnace was then evacuated to 150 Pa and heated to 2100 °C at a rate of 6 °C / min under a flowing argon atmosphere (flow rate 100 mL / min). The temperature was held for 2 hours, the power was turned off, and the sample was allowed to cool naturally to room temperature before being removed. Finally, a gradient distribution structure was obtained in the C / C matrix, showing a gradual decrease in ZrC content and a gradual increase in SiC content from the front to the rear of the service path.

[0055] Example 4

[0056] I. C / C composite material treatment: A density of 1.18 g / cm³ is used. 3 The C / C composite material was processed into a wedge-shaped leading edge component with a curvature radius of 1.5 mm. It was ultrasonically cleaned with anhydrous ethanol and deionized water for 20 min, and then placed in an oven at 70 °C for 6 h until completely dried.

[0057] II. Molten Infiltration Powder Pressing: Take 30g of HfSi2 ceramic powder and 15g of Si powder, and press them into cylindrical ceramic sheets with a diameter of 25mm using a hydraulic press under a pressure of 100MPa. Remove and dry.

[0058] III. Introduction of Gradient Distribution of Ceramic Components: Cylindrical ceramic sheets of HfSi2 and Si prepared in step II were placed at the top and bottom of the wedge-shaped leading edge component, respectively. The ceramic sheets and the C / C composite component were placed in a graphite mold with through holes on both sides. The graphite mold was placed in the high-temperature reaction chamber of a heat treatment furnace. Then, the vacuum was evacuated to 0.1 Pa, and under the protection of a flowing argon atmosphere (flow rate of 50 mL / min), the temperature was increased to 1800℃ at a heating rate of 6℃ / min and held for 1.5 h. The power was then turned off, and the sample was allowed to cool naturally to room temperature before being removed. Finally, a gradient distribution structure was obtained in the C / C matrix, showing a gradual decrease in HfC content and a gradual increase in SiC content from the front end to the rear end.

[0059] Example 5

[0060] I. C / C composite material treatment: A density of 1.22 g / cm³ is used. 3 The C / C composite material was processed into a cuboid component with dimensions of 30mm × 10mm × 8mm. It was ultrasonically cleaned with anhydrous ethanol and deionized water for 50 minutes, and then placed in an oven at 70℃ for 10 hours until completely dried.

[0061] II. Melt-infiltrating powder pressing: Take 15g of ZrSi2 and Si ceramic powders with a mass ratio of 1:0.38 and ball-mill them together. Then, use a hydraulic press to press out cylindrical ceramic sheets with a diameter of 20mm under a pressure of 60MPa. Remove and dry.

[0062] III. Introduction of Gradient Distribution of Ceramic Components: The ceramic sheet prepared in step II was placed on the left side of the C / C cuboid component. Both were then placed inside a graphite mold with perforated sidewalls. The graphite mold was placed in the high-temperature reaction chamber of a heat treatment furnace. A vacuum of 400 Pa was then applied, and under a flowing argon atmosphere (flow rate of 100 mL / min), the temperature was increased to 2100 °C at a rate of 6 °C / min and held for 3 hours. The power was then turned off, and the sample was allowed to cool naturally to room temperature before being removed. Ultimately, a gradient distribution structure was obtained in the C / C matrix, exhibiting a gradual decrease in ZrC content and a gradual increase in SiC content from the front to the rear of the service path.

[0063] Example 6

[0064] I. C / C composite material treatment: A density of 1.42 g / cm³ was used. 3 The C / C composite material was processed into a wedge-shaped leading edge component with a curvature radius of 1.5 mm. It was ultrasonically cleaned with anhydrous ethanol and deionized water for 45 min, and then placed in an oven at 80 °C for 10 h until it was dried.

[0065] II. Molten Infiltration Powder Pressing: Take 20g each of ZrSi2 and Si ceramic powder with a mass percentage of 1:0.38 and ZrSi2 and ZrO2 ceramic powder with a mass percentage of 1:0.5, and press them into cylindrical ceramic sheets with a diameter of 30mm using a hydraulic press under a pressure of 80MPa. These are labeled as 1 and 2.

[0066] III. Introduction of Gradient Distribution of Ceramic Components: Ceramic sheets 1 and 2 prepared in step II were placed at the bottom and top of the wedge-shaped leading edge component, respectively. The ceramic sheets and the C / C composite component were placed in a graphite mold with through holes on both sides. The graphite mold was placed in the high-temperature reaction chamber of a heat treatment furnace. Then, the vacuum was evacuated to 50 Pa, and under the protection of a flowing argon atmosphere (flow rate of 100 mL / min), the temperature was increased to 1800 °C at a rate of 5 °C / min, held for 2 h, the power was turned off, and the sample was allowed to cool naturally to room temperature before being removed. Finally, a gradient distribution structure was obtained in the C / C matrix, showing a gradual decrease in ZrC content and a gradual increase in SiC content from the front end to the rear end.

[0067] Example 7

[0068] I. C / C Composite Material Treatment: A density of 1.40 g / cm³ is used. 3 The C / C composite material was processed into a wedge-shaped leading edge component with a curvature radius of 1.5 mm. It was ultrasonically cleaned with anhydrous ethanol and deionized water for 30 min, and then placed in an oven at 80 °C for 22 h until it was dried.

[0069] II. Molten Infiltration Powder Pressing: Take 30g of (Zr,Hf)Si2 and 10g of Si ceramic powder. Use a hydraulic press to press out cylindrical ceramic sheets with a diameter of 15mm under a pressure of 180MPa. Remove and dry.

[0070] III. Introduction of Gradient Distribution of Ceramic Components: The (Zr,Hf)Si2 and Si ceramic sheets prepared in step II were placed at the top and bottom of the wedge-shaped leading edge component, respectively. The ceramic sheets and the C / C composite component were placed in a graphite mold with an opening at the top, and the graphite mold was placed in the high-temperature reaction chamber of a heat treatment furnace. Then, the vacuum was evacuated to 500 Pa, and under the protection of a flowing argon atmosphere (flow rate of 80 mL / min), the temperature was increased to 1950 °C at a rate of 8 °C / min, held for 3 h, the power was turned off, and the sample was allowed to cool naturally to room temperature before being removed. Finally, a gradient distribution structure was obtained in the C / C matrix, showing a gradual decrease in UHTCs content and a gradual increase in SiC content from the front end to the rear end.

[0071] Example 8

[0072] I. C / C composite material treatment: A density of 1.28 g / cm³ is used. 3The C / C composite material was processed into a wedge-shaped leading edge component with a curvature radius of 1.5 mm. It was ultrasonically cleaned with anhydrous ethanol and deionized water for 20 min, and then placed in an oven at 70 °C for 10 h until it was dried.

[0073] II. Molten Infiltration Powder Compression: Take 30g of (Zr, Hf, Ta)Si2 and 10g of Si ceramic powder. Use a hydraulic press to compress them into cylindrical ceramic sheets with a diameter of 30mm under a pressure of 120MPa. Remove and dry.

[0074] III. Introduction of Gradient Distribution of Ceramic Components: The (Zr,Hf,Ta)Si2 and Si ceramic sheets prepared in step II were placed at the top and bottom of the wedge-shaped leading edge component, respectively. The ceramic sheets and the C / C composite component were placed in a graphite mold with an opening at the top, and the graphite mold was placed in the high-temperature reaction chamber of a heat treatment furnace. Then, the vacuum was evacuated to 50 Pa, and under the protection of a flowing argon atmosphere (flow rate of 80 mL / min), the temperature was increased to 1850 °C at a rate of 8 °C / min, held for 2 h, the power was turned off, and the sample was allowed to cool naturally to room temperature before being removed. Finally, a gradient distribution structure was obtained in the C / C matrix, showing a gradual decrease in UHTCs content and a gradual increase in SiC content from the front end to the rear end.

[0075] Example 9

[0076] I. C / C composite material treatment: A density of 1.34 g / cm³ is used. 3 The C / C composite material was processed into a wedge-shaped leading edge component with a curvature radius of 1.5 mm. It was ultrasonically cleaned with anhydrous ethanol and deionized water for 25 min, and then placed in an oven at 70 °C for 18 h until it was dried.

[0077] II. Molten Infiltration Powder Compression: Take 30g of ZrSi2, HfSi2, and TaSi2 ceramic powders with a mass percentage ratio of 1:1.59:1.61, and 15g of Si ceramic powder. Use a hydraulic press to compress them into cylindrical ceramic sheets with a diameter of 30mm under a pressure of 80MPa, and name them 1 and 2. Remove and dry.

[0078] III. Introduction of Gradient Distribution of Ceramic Components: Ceramic sheets 1 and 2 prepared in step II were placed at the top and bottom of the wedge-shaped leading edge component, respectively. The ceramic sheets and the C / C composite component were placed in a graphite mold with an opening at the top. The graphite mold was then placed in the high-temperature reaction chamber of a heat treatment furnace. A vacuum of 2 Pa was then applied, and under the protection of a flowing argon atmosphere (flow rate of 80 mL / min), the temperature was increased to 1900℃ at a rate of 10℃ / min and held for 2 hours. The power was then turned off, and the sample was allowed to cool naturally to room temperature before being removed. Finally, a gradient distribution structure was obtained in the C / C matrix, showing a gradual decrease in UHTCs content and a gradual increase in SiC content from the front to the rear of the service path.

[0079] Example 10

[0080] I. C / C composite material treatment: A density of 1.25 g / cm³ is used. 3 The C / C composite material was processed into a cuboid component with dimensions of 30mm × 10mm × 8mm. It was ultrasonically cleaned with anhydrous ethanol and deionized water for 10 minutes, and then placed in an oven at 70℃ for 10 hours until completely dried.

[0081] II. Melting and Infiltrating Powder Pressing: Take 25g of ZrCu ceramic powder and press it into cylindrical ceramic sheets with a diameter of 30mm using a hydraulic press at a pressure of 180MPa.

[0082] III. Introduction of Gradient Distribution of Ceramic Components: The ceramic sheet prepared in step II was placed at the left end of the cuboid component. The ceramic sheet and the C / C composite component were placed in a graphite mold with perforated sidewalls. The graphite mold was then placed in the high-temperature reaction chamber of a heat treatment furnace. A vacuum of 250 Pa was then applied, and under a flowing argon atmosphere (flow rate of 100 mL / min), the temperature was increased to 1350 °C at a rate of 10 °C / min and held for 1.5 h. The power was then turned off, and the sample was allowed to cool naturally to room temperature before being removed. Finally, a gradient distribution structure with a gradually decreasing ZrC ceramic phase content from the front end to the rear end was obtained in the C / C matrix.

[0083] This invention employs an optimized RMI process to provide an efficient method for preparing ceramic component gradient-modified C / C composite material components. The technical solution provided by this invention ensures that the prepared modified C / C composite material possesses strong structural and thermal stability. Furthermore, addressing the issues of localized overheating and stress concentration caused by component size, shape, and large temperature gradients, this invention effectively designs a ceramic gradient-modified C / C matrix, providing a new technology and method for achieving a harmonious match between ceramic and C / C, and realizing better integrated thermal conductivity and ablation properties.

[0084] Figure 1 This flowchart illustrates the geometric dimensions and ablation direction of C / C composite components of different shapes. It clearly shows that the functional requirements of C / C composite components, whether they are disk-shaped, wedge-shaped, or cuboid, vary from the front end to the back end of service. Gradient-modified C / C components can meet the requirements of ablation and thermal conductivity, as well as alleviate stress concentration, and are a solution to improve the long-term stable service of C / C-UHTCs composite components.

[0085] Figure 2This diagram illustrates different placement methods of the ceramic sheet and different opening designs of the graphite mold during the RMI process of this invention. The diagram clearly demonstrates that the negative pressure RMI method of this invention has high material preparation efficiency, enabling one-step efficient preparation of C / C composite material components with ceramic component gradient modification. Furthermore, this method is versatile and applicable to the preparation of C / C composite material components of various shapes and sizes, such as disks, wedge-shaped leading edges, spherical heads, and cuboids.

[0086] Figure 3 The image shows the XRD pattern of the ZrC-SiC gradient-modified wedge-shaped C / C composite material prepared in Example 3 of this invention. Figure 3 The results show that the prepared composite material components have a higher ZrC content at the front end of service, while the SiC and C content is even higher at the back end. This demonstrates that the process can effectively control the content of ceramic components in different regions according to service requirements.

[0087] Figure 4 The image shows the microstructure of the ZrC-SiC gradient-modified wedge-shaped C / C composite material prepared in Example 3 of this invention. Figure 4 As can be seen in (a), the composite material is dense overall, and the ceramic phase exhibits a gradient change from the front to the rear of the service path. Figure 4 As can be seen from (b), the white ZrC phase at the service front is the main component. Figure 4 As shown in (c), the gray SiC and black C phases are mainly distributed at the rear end of the service area, which is consistent with the XRD results.

[0088] Figure 5 A comparison of the linear ablation rates of ZrC-SiC ceramic-modified C / C composite components and the gradient-modified components prepared in Example 3 of this invention. Figure 5 It can be seen that, compared with ZrC-SiC ceramic-modified C / C composites, the composite material with ceramic gradient design exhibits better performance in an oxyacetylene environment (flow rate of 2.38 MW / m³). 2 The ablation rate decreased by more than 30% after 60 seconds of ablation.

[0089] This invention describes preferred embodiments and their effects. However, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to include both the preferred embodiments and all changes and modifications falling within the scope of this invention.

[0090] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a C / C composite material component with ceramic component gradient modification, characterized in that, Includes the following steps: Processing C / C composite materials into components of specific shapes; The ceramic infiltration powder is pressed into ceramic sheets; Ceramic sheets are placed at designated positions on the component, and both are placed in a selectively perforated graphite mold. The vacuum is evacuated to 0.1~500 Pa, and then kept at 1200~2100℃ for 0.5~10 h in an inert atmosphere to obtain a ceramic component gradient modified C / C composite component. The ceramic melting powder is one or more of Zr, Hf, Ta, Si, Al2O3, ZrSi2, HfSi2, TaSi2, Cu5Si, (Zr, Hf)Si2, and (Zr, Hf, Ta)Si2; The ceramic sheet is obtained by the following steps: ball milling and mixing different types of ceramic melting powder in a certain proportion and drying them, and pressing them into ceramic sheets under a pressure of 30~180 MPa; The shape of the component is a disk, a wedge-shaped leading edge, a spherical head, or a cuboid; The density of the C / C composite material is 1.15~1.45 g / cm³. 3 .

2. The method for preparing ceramic component gradient modified C / C composite material components according to claim 1, characterized in that, In an inert atmosphere, the heating rate is 5~10℃ / min.

3. The method for preparing ceramic component gradient modified C / C composite material components according to claim 1, characterized in that, The inert atmosphere is a flowing argon atmosphere with a flow rate of 50-100 mL / min.

4. The method for preparing ceramic component gradient modified C / C composite material components according to claim 1, characterized in that, After the C / C composite material is processed into components of a specific shape, it is ultrasonically cleaned with anhydrous ethanol and deionized water for 10-70 min respectively, and then kept at 60-100℃ for 5-24 h until dried.

5. A ceramic component gradient modified C / C composite material component prepared by the method of any one of claims 1 to 4.

6. The application of the ceramic component gradient modified C / C composite material component as described in claim 5 in thermal protection.

Images