Prefabricated body structure of carbon-carbon composite material or carbon-ceramic material and preparation method

Abstract

The invention relates to the technical field of brake discs, in particular to a carbon-carbon composite material or carbon-ceramic material prefabricated body structure and a preparation method thereof.The carbon-carbon composite material or carbon-ceramic material prefabricated body structure comprises a three-dimensional annular prefabricated body, the three-dimensional annular prefabricated body is prepared from polyacrylonitrile-based pre-oxidized filaments through a three-dimensional annular needling machine, and a hollow part is formed in the three-dimensional annular prefabricated body; the volume density of the three-dimensional annular prefabricated body is 0.40-0.50 g / cm < 3 >; the three-dimensional annular prefabricated body comprises an enhancement layer, a heat conduction layer, an ablation layer and a surface composite function layer. The three-dimensional annular prefabricated body structure with the optimized fiber crossing angle and needling density is adopted, interlayer binding force can be remarkably enhanced, shear stress during braking is effectively resisted, meanwhile, a heat conduction path is optimized through the hollow part design, the local overheating phenomenon is reduced, the braking stability is improved, traditional carbon fibers are replaced with the pre-oxidized filaments, and the manufacturing cost is reduced. The production process is simplified, energy consumption and cost are reduced, fiber damage is avoided, and the service life can be further prolonged.

Description

Technical Field

[0001] This invention relates to the field of brake disc technology, specifically to a preform structure and preparation method of a carbon-carbon composite material or carbon-ceramic material. Background Technology

[0002] Brake discs are key components in automotive braking systems that generate braking force through friction. Based on materials, brake discs are mainly classified into cast iron brake discs, carbon ceramic brake discs, and aluminum alloy brake discs. Cast iron brake discs are low in cost and widely used, but they are prone to rust and are relatively heavy. Carbon ceramic brake discs are made of carbon fiber and ceramic composite materials, and have advantages such as light weight, high temperature resistance, and corrosion resistance. They are often used in high-performance sports cars or luxury models to meet high-intensity braking requirements. Aluminum alloy brake discs improve heat dissipation efficiency through lightweight design and are commonly found in models with higher requirements for performance and fuel consumption.

[0003] Carbon-ceramic brake discs, as a high-end braking material, possess advantages such as lightweight and high thermal conductivity, but their traditional manufacturing process has significant drawbacks. Firstly, carbon fibers require two graphitization processes: preform graphitization and final graphitization. This process causes irreversible damage to the fiber structure. Preform graphitization must be carried out at high temperatures, forcibly rearranging the carbon atoms within the fiber, leading to a decrease in its mechanical properties. Final graphitization further exacerbates the fiber's brittleness, making the material prone to microcracks under alternating stress. This dual processing not only increases the complexity of the production process but also significantly increases energy consumption and manufacturing costs, limiting the large-scale application of carbon-ceramic brake discs.

[0004] Secondly, insufficient interlayer bonding is another key issue restricting the performance of carbon ceramic brake discs. Traditional short-fiber molding processes rely on resin to bond fibers. Resin is prone to decomposition at high temperatures, causing the interlayer bonding to gradually weaken over time. Although long-fiber needle punching processes enhance interlayer bonding through mechanical interweaving, they typically use a single fiber angle. This simple interlayer structure cannot effectively disperse the shear stress generated during braking. Under high-speed braking or frequent start-stop conditions, the concentration of interlayer shear stress easily leads to delamination failure, seriously affecting the reliability and service life of the brake disc.

[0005] Furthermore, the inherent contradictions in material properties also hinder the performance improvement of carbon-ceramic brake discs. Pitch-based carbon fiber has excellent thermal conductivity, which can quickly dissipate the heat generated during braking, but its resistance to high-temperature oxidation is poor, and it is prone to oxidation and ablation in high-temperature environments, leading to accelerated material wear. Although viscose-based carbon fiber has good ablation resistance, its low thermal conductivity cannot meet the heat dissipation efficiency requirements of high-speed braking. This inherent contradiction in material properties makes it difficult for traditional carbon-ceramic brake discs to achieve a balance between thermal conductivity and ablation resistance, limiting their application in extreme operating conditions.

[0006] Based on the above background, this invention aims to solve the problems of fiber damage, insufficient interlayer bonding and material performance contradictions in traditional carbon ceramic brake discs through multi-dimensional technological innovation, and provide a safer and more efficient braking solution for high-end vehicles. Summary of the Invention

[0007] To address the aforementioned shortcomings of existing technologies, this invention provides a preform structure and preparation method for carbon-carbon composite materials or carbon-ceramic materials. This effectively solves the problems in existing technologies, such as reduced fiber strength due to two graphitization treatments of carbon fibers, insufficient interlayer bonding strength and interlayer shear strength of carbon-ceramic brake discs leading to delamination failure under extreme conditions, excellent thermal conductivity of pitch-based carbon fibers but poor resistance to high-temperature oxidation, and low thermal conductivity of viscose-based carbon fibers despite their ablation resistance, making it difficult to simultaneously meet the requirements of heat dissipation and ablation resistance for high-speed braking.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] This invention provides a preform structure of carbon-carbon composite material or carbon-ceramic material, comprising:

[0010] A three-dimensional ring-shaped preform is prepared from polyacrylonitrile-based pre-oxidized filaments using a three-dimensional ring-shaped needle punching machine. The three-dimensional ring-shaped preform has a hollow section and a bulk density of 0.40-0.50 g / cm³. 3 ;

[0011] The three-dimensional annular preform includes a reinforcing layer, a thermally conductive layer, an ablation layer, and a surface composite functional layer. The reinforcing layer accounts for 55%-65% of the total thickness of the three-dimensional annular preform and is composed of 100% polyacrylonitrile-based carbon fiber with a fiber volume fraction of 45%-55%. The thermally conductive layer accounts for 25%-35% of the total thickness of the three-dimensional annular preform and is composed of a mixture of polyacrylonitrile-based carbon fiber and pitch-based carbon fiber in a mass ratio of 8:2-7:3 with a fiber volume fraction of 40%-50%. The ablation layer accounts for 8%-12% of the total thickness of the three-dimensional annular preform and is composed of a mixture of polyacrylonitrile-based carbon fiber and viscose-based carbon fiber in a mass ratio of 7:3-6:4 with a fiber volume fraction of 35%-45%. The surface composite functional layer consists of carbon fiber, a low-temperature graphitized layer, a silicon carbide layer, a high-temperature graphitized layer, and the composite functional layer, from the inside out.

[0012] Furthermore, the tensile strength of the reinforcing layer is ≥3.5GPa, and the elastic modulus is ≥250GPa.

[0013] Furthermore, the thermal conductivity of the pitch-based carbon fiber in the thermally conductive layer is ≥400W / (m·K).

[0014] Furthermore, the aspect ratio of the pitch-based carbon fibers in the thermally conductive layer is 1500-2000, and they are arranged radially with an arrangement angle deviation of ≤±5°.

[0015] Furthermore, the high-temperature oxidation resistance temperature of the viscose-based carbon fiber in the ablation layer is ≥1800℃, and the ablation amount of the ablation layer is ≤0.03%.

[0016] Furthermore, the carbon atom spacing of the low-temperature graphitized layer is 0.344-0.348 nm, the crystallinity is ≥85%, and the thickness is 8-12 μm; the carbon atom spacing of the high-temperature graphitized layer is 0.335-0.337 nm, the crystallinity is ≥95%, and the thickness is 20-25 μm.

[0017] A method for preparing a preform structure applied to the carbon-carbon composite material or carbon-ceramic material includes the following steps:

[0018] S1. Preform Preparation: After opening and carding, polyacrylonitrile-based pre-oxidized fibers are cross-laid using a three-dimensional circular needle punching machine, with a needle punching density of 50-80 needles / cm. 2 This forms a three-dimensional ring-shaped prefabricated structure.

[0019] S2. Primary Densification - Low-Temperature Graphitization: Densification is achieved through a CVI process using methane and ethylene in a volume ratio of 1:1-3:1 as the gas source, or a PIP process using phenolic resin as the carbon source, increasing the density of the preform to 0.8-1.0 g / cm³. 3 Graphitization was carried out at 1600-1800℃ for 4-8 hours, with a heating rate of 5-10℃ / min, to form a low-temperature graphitized layer.

[0020] S3. Silicon infiltration treatment: The densified preform is placed in a silicon infiltration furnace and kept at 1500-1700℃ for 1-2 hours under nitrogen protection. The silicon infiltration pressure is 0.1-0.3MPa to form a silicon carbide layer.

[0021] S4, Secondary Densification - High-Temperature Graphitization: Densification is further achieved to a density of 1.2-1.4 g / cm³ using CVI or PIP processes. 3 Graphitization is carried out at 2100-2500℃ for 6-10 hours, with a heating rate of 3-5℃ / min, to form a high-temperature graphitized layer.

[0022] S5. Embedding and ablation resistant treatment: Mix 85%-95% Si powder with 5%-15% Ti and Fe composite additives by mass and uniformly coat the surface of the brake disc; keep it at 1500-1700℃ for 2-3 hours under argon protection to form a composite ablation resistant layer with a thickness of 10-20μm.

[0023] Furthermore, in step S4, the three-dimensional annular preform undergoes surface roughening treatment before high-temperature graphitization, with a roughness Ra of 1.6-3.2 μm. In step S5, the Ti:Fe composite additive has a Ti:Fe ratio of 3:1-1:1, and the particle size of the Ti:Fe composite additive is 50-100 μm, with a coating thickness of 0.5-1.0 mm.

[0024] The technical solution provided by this invention has the following advantages compared with the known prior art:

[0025] This invention significantly improves the overall performance and practicality of carbon ceramic brake discs through multi-dimensional technological innovation: the three-dimensional annular prefabricated structure significantly enhances the interlayer bonding force by optimizing the fiber cross angle and needle density, effectively resisting shear stress during braking and greatly reducing the risk of delamination and cracking. At the same time, the hollow part design optimizes the heat conduction path and reduces local overheating. When the brake disc rotates at high speed, the air flow in the hollow area can evenly distribute heat to the entire disc surface, avoiding material performance degradation caused by local overheating and improving braking stability.

[0026] This invention employs a layered functional design to achieve synergistic optimization of high strength, high thermal conductivity, and ablation resistance: The reinforcing layer, as the main structural component, utilizes high-strength polyacrylonitrile-based carbon fiber with excellent mechanical properties. This provides a supporting foundation for the brake disc, effectively dispersing stress generated during braking and enhancing the overall structure's resistance to deformation. The reinforcing layer not only ensures the structural stability of the brake disc during high-speed braking but also provides a reliable load-bearing matrix for the thermally conductive and ablation-resistant layers. The thermally conductive layer rapidly dissipates braking heat. It is a composite of high thermal conductivity pitch-based carbon fiber and polyacrylonitrile-based carbon fiber. The pitch-based carbon fiber possesses a unique graphitized structure, and its excellent thermal conductivity quickly transfers the heat generated by friction to the disc surface, avoiding... To prevent excessively high local temperatures, the thermally conductive layer forms an efficient heat conduction path by optimizing the ratio and arrangement of the two fibers, ensuring uniform heat distribution and reducing the risk of thermal stress concentration. This not only improves heat dissipation efficiency but also indirectly protects the ablation layer, reducing its loss at high temperatures. As a front-line barrier against high-temperature erosion, the ablation layer can significantly slow down the ablation process of the material. The composite additives react with the carbon fiber surface at high temperatures to form a dense protective film, blocking direct contact between oxygen and the material, further inhibiting ablation. The ablation layer has higher porosity in the area near the friction surface, which is beneficial for heat dissipation and can also form a gas insulation layer during the ablation process, reducing the rate of heat transfer to the interior.

[0027] This invention simplifies the production process and reduces energy consumption and costs by using pre-oxidized fibers instead of traditional carbon fibers, while avoiding fiber damage. The double graphitization layer process forms a gradient structure on the fiber surface, balancing mechanical properties and thermal conductivity. By controlling the temperature and time of the two graphitization processes, a gradient distribution from a highly oriented graphite layer to a transition structure is formed on the fiber surface, ensuring the mechanical strength of the fiber while providing an efficient channel for heat conduction. The addition of alloying elements in the embedded ablation-resistant treatment forms an antioxidant layer, which can further extend the service life. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0029] Figure 1 This is a schematic diagram of the preparation method of the three-dimensional ring preform in this invention;

[0030] Figure 2 This is a schematic diagram of the three-dimensional ring preform structure in this invention;

[0031] Figure 3 This is a schematic diagram of the composition structure of the three-dimensional ring preform in this invention;

[0032] Figure 4 This is a schematic diagram of the composition structure of the surface composite functional layer in this invention.

[0033] Reference numerals: 1. Three-dimensional ring preform; 11. Reinforcing layer; 12. Thermally conductive layer; 13. Ablation layer; 14. Surface composite functional layer; 2. Hollow part; 3. Carbon fiber; 4. Low-temperature graphitization layer; 5. Silicon carbide layer; 6. High-temperature graphitization layer; 7. Composite functional layer. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0035] The present invention will be further described below with reference to embodiments.

[0036] Reference Figures 2 to 4A preform structure of carbon-carbon composite material or carbon-ceramic material includes: a three-dimensional ring preform 1, which is prepared by a three-dimensional ring needle punching machine from polyacrylonitrile-based pre-oxidized filaments; the three-dimensional ring preform 1 has a hollow portion 2; and the bulk density of the three-dimensional ring preform 1 is 0.40-0.50 g / cm³. 3 The three-dimensional annular preform 1 includes a reinforcing layer 11, a thermally conductive layer 12, an ablation layer 13, and a surface composite functional layer 14. The reinforcing layer 11 accounts for 55%-65% of the total thickness of the three-dimensional annular preform 1 and is composed of 100% polyacrylonitrile-based carbon fiber with a fiber volume fraction of 45%-55%. The tensile strength of the reinforcing layer 11 is ≥3.5 GPa, and the elastic modulus is ≥250 GPa. The thermally conductive layer 12 accounts for 25%-35% of the total thickness of the three-dimensional annular preform 1 and is composed of a mixture of polyacrylonitrile-based carbon fiber and pitch-based carbon fiber in a mass ratio of 8:2-7:3 with a fiber volume fraction of 40%-50%. The thermal conductivity of the pitch-based carbon fiber in the thermally conductive layer 12 is ≥400 W / (m·K). The aspect ratio of the pitch-based carbon fiber in the thermally conductive layer 12 is 1500-2000, and they are arranged radially. The column angle deviation is ≤±5°. The ablation layer 13 accounts for 8%-12% of the total thickness of the three-dimensional annular preform 1. It is composed of polyacrylonitrile-based carbon fiber and viscose-based carbon fiber mixed in a mass ratio of 7:3-6:4, with a fiber volume fraction of 35%-45%. The high-temperature oxidation resistance temperature of the viscose-based carbon fiber in the ablation layer 13 is ≥1800℃, and the ablation amount of the ablation layer is ≤0.03%. The surface composite functional layer 14 consists of carbon fiber 3, low-temperature graphitization layer 4, silicon carbide layer 5, high-temperature graphitization layer 6, and composite functional layer 7 from the inside out. The carbon atom interlayer spacing of the low-temperature graphitization layer 4 is 0.344-0.348nm, the crystallinity is ≥85%, and the thickness is 8-12μm. The carbon atom interlayer spacing of the high-temperature graphitization layer 6 is 0.335-0.337nm, the crystallinity is ≥95%, and the thickness is 20-25μm.

[0037] Reference Figure 1 A method for preparing a preform structure for use in carbon-carbon composite materials or carbon-ceramic materials includes the following steps:

[0038] S1. Preform Preparation: After opening and carding, polyacrylonitrile-based pre-oxidized fibers are cross-laid using a three-dimensional circular needle punching machine, with a needle punching density of 50-80 needles / cm. 2 This forms a three-dimensional ring-shaped prefabricated body 1;

[0039] S2. Primary Densification - Low-Temperature Graphitization: Densification is achieved through a CVI process using methane and ethylene in a volume ratio of 1:1-3:1 as the gas source, or a PIP process using phenolic resin as the carbon source, increasing the density of the preform to 0.8-1.0 g / cm³. 3 Graphitization was carried out at 1600-1800℃ for 4-8 hours, with a heating rate of 5-10℃ / min, to form a low-temperature graphitized layer.

[0040] S3. Silicon infiltration treatment: The densified preform is placed in a silicon infiltration furnace and kept at 1500-1700℃ for 1-2 hours under nitrogen protection. The silicon infiltration pressure is 0.1-0.3MPa to form a silicon carbide layer.

[0041] S4, Secondary Densification - High-Temperature Graphitization: Densification is further achieved to a density of 1.2-1.4 g / cm³ using CVI or PIP processes. 3 ; graphitization is carried out at 2100-2500℃ for 6-10 hours with a heating rate of 3-5℃ / min to form a high-temperature graphitized layer. The three-dimensional ring preform 1 is subjected to surface roughening treatment before high-temperature graphitization, with a roughness Ra of 1.6-3.2μm.

[0042] S5. Embedding and ablation resistant treatment: Mix 85%-95% Si powder with 5%-15% Ti and Fe composite additives by mass and uniformly coat the surface of the brake disc; keep it at 1500-1700℃ for 2-3 hours under argon protection to form a composite ablation resistant layer with a thickness of 10-20μm. The Ti:Fe ratio of the Ti and Fe composite additives is 3:1-1:1, and the particle size of the Ti and Fe composite additives is 50-100μm, with a coating thickness of 0.5-1.0mm.

[0043] Example 1

[0044] A three-dimensional ring-shaped preform 1 with a bulk density of 0.45 g / cm³ was prepared by replacing carbon fiber with polyacrylonitrile-based pre-oxidized filaments using a three-dimensional ring-shaped needle punch. 3 Through PIP densification of phenolic resin, 1000℃×2h, low-temperature graphitization 1700℃×6h, silicon infiltration 1600℃×2h, CVI secondary densification of ethylene gas source, 1050℃×350h, and high-temperature graphitization 2100℃×6h, the final interlaminar shear strength was increased to 27MPa, the flexural strength reached 223MPa, and the ablation rate remained at 0.05%, demonstrating the synergistic effect of preform structure optimization and material replacement.

[0045] Example 2

[0046] A layered structure was adopted: the reinforcing layer 11 is 100% polyacrylonitrile-based carbon fiber T800, the thermally conductive layer 12 is polyacrylonitrile-based:asphalt-based with an aspect ratio of 1800 (9:1), and the ablation layer 13 is polyacrylonitrile-based:viscose-based with an aspect ratio of 9:1 and 1% ZrB2 nanoparticles added. Through a process involving CVI densification with a propyne gas source, 1000℃×2h, low-temperature graphitization 1600℃×4h, silicon infiltration 1500℃×1h, PIP secondary densification with epoxy resin 1050℃×300h, high-temperature graphitization 2300℃×8h, and embedding 90% Si+10% Ti 1700℃×3h, the interlayer shear strength was increased to 29MPa, the ablation rate was reduced to 0.03%, and the thermal conductivity reached 73W / (m·K), verifying the effectiveness of the layered design and alloy modification.

[0047] Example 3

[0048] The reinforcing layer 11 uses T1000 polyacrylonitrile-based carbon fiber, the thermally conductive layer 12 is a 7:3 ratio of polyacrylonitrile-based to pitch-based radially arranged pitch-based material, and the ablation layer 13 is a 6:4 ratio of polyacrylonitrile-based to viscose-based material with 2% ZrB2 added, resulting in a gradient porosity of 45%–55%. Through CVI densification of methane:ethylene (2:1), 1000℃×2h, low-temperature graphitization (1800℃×8h), ultrasonic-assisted silica infiltration (1700℃×2h, 20kHz), PIP secondary densification of vinyl resin (1050℃×350h), high-temperature graphitization (2500℃×10h), and embedding of 85% Si + 10% Ti + 5% Fe (1650℃×2h), a breakthrough in comprehensive performance was achieved, resulting in a flexural strength of 245MPa, an interlaminar shear strength of 32MPa, a thermal conductivity of 85W / (m·K), and an ablation rate of 0.02%. Compared with traditional processes, the interlayer strength is increased by 45%, the thermal conductivity is improved by 112%, the ablation rate is reduced by 60%, and the cost is reduced by 20%.

[0049] The present invention will be further described below with reference to the embodiments and corresponding experimental data.

[0050] Friction coefficient stability test:

[0051]

[0052] Cyclic fatigue test:

[0053]

[0054] Damp heat aging test:

[0055]

[0056] Braking performance comparison:

[0057]

[0058]

[0059] Test Result Analysis:

[0060] 1. Improved frictional stability: The three-dimensional preform and layered material design effectively suppress the oxidation and spalling of carbon fibers at high temperatures, maintaining a stable frictional interface.

[0061] 2. Extended fatigue life: Gradient structure and interface optimization reduce stress concentration and delay the initiation of fatigue cracks.

[0062] 3. Enhanced environmental adaptability: The double graphitized layer and the embedded alloy form a dense protection against damp heat and salt spray corrosion.

[0063] 4. Breakthrough in braking performance: Lightweight design and high thermal conductivity shorten braking distance, meeting the safety requirements of high-end vehicles.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A prefabricated structure of carbon-carbon composite material or carbon-ceramic material, characterized in that, include: A three-dimensional ring-shaped preform (1) is prepared from polyacrylonitrile-based pre-oxidized filaments using a three-dimensional ring-shaped needle punch. The three-dimensional ring-shaped preform (1) has a hollow portion (2). The bulk density of the three-dimensional ring-shaped preform (1) is 0.40-0.50 g / cm³. 3 ; The three-dimensional annular preform (1) includes a reinforcing layer (11), a thermally conductive layer (12), an ablation layer (13), and a surface composite functional layer (14). The reinforcing layer (11) accounts for 55%-65% of the total thickness of the three-dimensional annular preform (1) and is composed of 100% polyacrylonitrile-based carbon fiber with a fiber volume fraction of 45%-55%. The thermally conductive layer (12) accounts for 25%-35% of the total thickness of the three-dimensional annular preform (1) and is composed of polyacrylonitrile-based carbon fiber and pitch-based carbon fiber in a mass ratio of 8: The fiber volume fraction is 40%-50%, and the ablation layer (13) accounts for 8%-12% of the total thickness of the three-dimensional ring preform (1). It is composed of polyacrylonitrile-based carbon fiber and viscose-based carbon fiber mixed in a mass ratio of 7:3-6:4, with a fiber volume fraction of 35%-45%. The surface composite functional layer (14) consists of carbon fiber (3), low-temperature graphitization layer (4), silicon carbide layer (5), high-temperature graphitization layer (6), and composite functional layer (7) from the inside to the outside.

2. The prefabricated structure of a carbon-carbon composite material or carbon-ceramic material according to claim 1, characterized in that, The tensile strength of the reinforcing layer (11) is ≥3.5GPa and the elastic modulus is ≥250GPa.

3. The prefabricated structure of a carbon-carbon composite material or carbon-ceramic material according to claim 1, characterized in that, The thermal conductivity of the pitch-based carbon fiber in the thermally conductive layer (12) is ≥400W / (m·K).

4. The prefabricated structure of a carbon-carbon composite material or carbon-ceramic material according to claim 1, characterized in that, The aspect ratio of the pitch-based carbon fibers in the thermal conductive layer (12) is 1500-2000, and they are arranged radially with an arrangement angle deviation of ≤±5°.

5. The prefabricated structure of a carbon-carbon composite material or carbon-ceramic material according to claim 4, characterized in that, The viscose-based carbon fiber in the ablation layer (13) has a high-temperature oxidation resistance temperature ≥1800℃, and the ablation amount of the ablation layer is ≤0.03%.

6. The prefabricated structure of a carbon-carbon composite material or carbon-ceramic material according to claim 1, characterized in that, The low-temperature graphitized layer (4) has a carbon atom interlayer spacing of 0.344-0.348 nm, a crystallinity of ≥85%, and a thickness of 8-12 μm; the high-temperature graphitized layer (6) has a carbon atom interlayer spacing of 0.335-0.337 nm, a crystallinity of ≥95%, and a thickness of 20-25 μm.

7. A method for preparing a preform structure of carbon-carbon composite material or carbon-ceramic material according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Preform Preparation: After opening and carding, polyacrylonitrile-based pre-oxidized fibers are cross-laid using a three-dimensional circular needle punching machine, with a needle punching density of 50-80 needles / cm. 2 , forming a three-dimensional ring prefabricated body (1); S2. Primary Densification - Low-Temperature Graphitization: Densification is achieved through a CVI process using methane and ethylene in a volume ratio of 1:1-3:1 as the gas source, or a PIP process using phenolic resin as the carbon source, increasing the density of the preform to 0.8-1.0 g / cm³. 3 Graphitization was carried out at 1600-1800℃ for 4-8 hours, with a heating rate of 5-10℃ / min, to form a low-temperature graphitized layer. S3. Silicon infiltration treatment: The densified preform is placed in a silicon infiltration furnace and kept at 1500-1700℃ for 1-2 hours under nitrogen protection. The silicon infiltration pressure is 0.1-0.3MPa to form a silicon carbide layer. S4, Secondary Densification - High-Temperature Graphitization: Densification is further achieved to a density of 1.2-1.4 g / cm³ using CVI or PIP processes. 3 Graphitization is carried out at 2100-2500℃ for 6-10 hours, with a heating rate of 3-5℃ / min, to form a high-temperature graphitized layer. S5. Embedding and ablation resistant treatment: Mix 85%-95% Si powder with 5%-15% Ti and Fe composite additives by mass and uniformly coat the surface of the brake disc; keep it at 1500-1700℃ for 2-3 hours under argon protection to form a composite ablation resistant layer with a thickness of 10-20μm.

8. The method for preparing a preform structure of carbon-carbon composite material or carbon-ceramic material according to claim 7, characterized in that, In step S4, the three-dimensional ring preform (1) undergoes surface roughening treatment before high-temperature graphitization, with a roughness Ra of 1.6-3.2 μm. In step S5, the Ti:Fe composite additive has a Ti:Fe ratio of 3:1-1:1, and the particle size of the Ti:Fe composite additive is 50-100 μm with a coating thickness of 0.5-1.0 mm.

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