 |
| Quantity: | |
|---|---|
Product Description
Carbon-carbon composite materials (C/C composites)are a type of pure carbon multiphase structural material composed of carbon fibers or their fabrics as the reinforcing phase and carbonaceous materials such as pyrolytic carbon, resin carbon, or pitch carbon as the matrix.
It has a "carbon matrix + carbon fiber" structure. It possesses characteristics such as high strength, high rigidity, low expansion, high temperature resistance, corrosion resistance, wear resistance, and stable thermal shock resistance, making it particularly suitable for use as heating elements, fasteners, transmission components, support plates, and other high-temperature structural components under vacuum and high-temperature conditions.
In addition to its successful application in the aerospace field, it is also widely used in vacuum metallurgy, new chemical materials, atomic energy, semiconductors, and electronic new energy fields.
Manufacturing Process
The preparation of carbon-carbon composite materials mainly involves three key steps: preform molding, densification treatment, and graphitization treatment, with the densification process being the core step. The specific process is detailed below:
1. Preform Molding
This is the foundation for preparing carbon-carbon composite materials, requiring the carbon fibers to be molded into a preform with a specific structure and shape in a specific manner. Common methods include:
1) Short fiber molding: Carbon fibers are cut, dispersed, filtered, dried, cured, and carbonized to form the preform, but the mechanical properties are relatively low.
2) Long fiber fabric lamination: Carbon fiber cloth/felt is cut, arranged, clamped, cured, and carbonized to form the preform, but the interlaminar shear strength is low.
3) Multidimensional weaving/piercing: Based on long fiber fabric lamination, the fiber content and distribution in the Z-axis direction are increased to improve interlaminar performance, but the cost is higher.
2. Preform Densification
This is a critical step in the preparation of carbon-carbon composite materials. Only carbon-carbon composite materials reaching a certain density can possess good mechanical properties. The densification process mainly includes:
1) Liquid phase impregnation-carbonization (LIC) process: The preform is impregnated with resin or asphalt, followed by carbonization treatment. Carbonization after impregnation with liquid organic matter allows for control of material properties by adjusting parameters.
2) Chemical vapor infiltration (CVI) process: Carbon is deposited in the voids of the preform using chemical vapor deposition. Gaseous substances react on the fiber surface to produce pyrolytic carbon, resulting in good densification but a longer cycle time.
3) Liquid phase vaporization deposition (CLVI) process: Combining liquid phase and gas phase deposition techniques.
4) CVI and LIC composite process: Combining chemical vapor infiltration and liquid phase impregnation carbonization processes.
3. Graphitization Treatment
High-temperature treatment at 1800~2800ºC converts the carbon structure in the carbon-carbon composite material into a graphite structure, improving the material's electrical and thermal conductivity.
Characteristics
1. Mechanical Properties
1) High Strength: The tensile strength, elastic modulus, and flexural strength of carbon-carbon composite materials are higher than those of general carbon materials, and the reinforcing effect of carbon fibers is significant. Three-dimensional orthogonal finely woven carbon-carbon composite materials have a tensile strength greater than 10 MPa and a tensile modulus greater than (4~6) × 10MPa.
2) High-Temperature Strength Retention: It can maintain its room-temperature strength even at temperatures as high as 1627ºC, and may even show an increase in strength. It is currently the only engineering material that can maintain this characteristic.
3) Pseudoplastic Effect: The stress-strain curve shows a linear relationship in the initial stage of loading, but later becomes bilinear. Cracks do not propagate further, resulting in higher reliability.
2. Thermophysical Properties
1) Low Thermal Expansion Coefficient: Only 1/(5~10) of that of metal materials, resulting in low thermal stress at high temperatures.
2) High Thermal Conductivity: Approximately 1.59~1.88 W/(m·K) at room temperature, decreasing to 0.43 W/(m·K) at 1650ºC, and can be adjusted by controlling carbon deposition and processing techniques.
3) High Specific Heat Capacity: Approximately 1.26 kJ/(kg·ºC) at room temperature and 2.1 kJ/(kg·ºC) at 1930ºC, enabling it to store a large amount of thermal energy.
4) Thermal Shock Resistance: Insensitive to thermal stress, and does not experience sudden catastrophic failure like ceramic materials and general graphite.
3. Ablation Performance
1) Ablation Resistance: When exposed to high temperatures and rapid heating environments, the surface indentation is shallow, and the ablation is uniform and symmetrical, making it widely used as a heat-resistant material.
2) High Sublimation Temperature: The sublimation temperature of carbon is as high as 3000ºC or more, resulting in a high surface ablation temperature.
4. Chemical Stability
1) Corrosion Resistance: Does not react with general acid, alkali, and salt solutions, is insoluble in organic solvents, and only reacts with concentrated oxidizing acid solutions.
2) Poor oxidation resistance: Oxidation reactions occur in an oxygen-containing environment at temperatures above 400ºC, leading to a sharp decline in material performance. Oxidation protection measures are required.
5. Application Characteristics
1) Integral molding: It can be integrally molded, reducing the number of parts and increasing service life.
2) Good friction performance: It is wear-resistant and corrosion-resistant, and is among the best of various wear-resistant materials.
Applications
1. Aerospace Field
1) Rocket Engines: Used to manufacture ablation-resistant components, such as nozzle throat liners, capable of withstanding high temperatures of 3500°C and high-speed gas erosion, improving thrust stability.
2) Spacecraft Heat Shields: Used in critical parts of space shuttles, such as nose cones and wing leading edges, since the 1970s.
3) Aircraft Brake Discs: Account for 63%-81% of material applications, reducing weight by 20% compared to metal brake discs, and supporting 500-5000 landings and takeoffs without repair.
2. Automotive Industry
Brake Pads: Used in high-performance cars and racing cars, providing excellent friction performance and thermal shock resistance.
3. New Energy Field
1) Photovoltaic Single Crystal Furnace Hot Zone: Replaces graphite materials and is used in crystalline silicon growth equipment.
2) Semiconductor Manufacturing: Applied in high-temperature equipment such as ingot furnaces.
4. Medical Field
Biomedical Materials: Used as implants such as artificial bones and joints, possessing good biocompatibility.
5. Other Fields
1) Metallurgy and Chemical Industry: Used in heating elements, support frames, corrosion-resistant pipes, etc.
2) High-End Machinery Manufacturing: Applied in heat exchangers, mechanical fasteners, etc.
Product Parameters
Product Description
Carbon-carbon composite materials (C/C composites)are a type of pure carbon multiphase structural material composed of carbon fibers or their fabrics as the reinforcing phase and carbonaceous materials such as pyrolytic carbon, resin carbon, or pitch carbon as the matrix.
It has a "carbon matrix + carbon fiber" structure. It possesses characteristics such as high strength, high rigidity, low expansion, high temperature resistance, corrosion resistance, wear resistance, and stable thermal shock resistance, making it particularly suitable for use as heating elements, fasteners, transmission components, support plates, and other high-temperature structural components under vacuum and high-temperature conditions.
In addition to its successful application in the aerospace field, it is also widely used in vacuum metallurgy, new chemical materials, atomic energy, semiconductors, and electronic new energy fields.
Manufacturing Process
The preparation of carbon-carbon composite materials mainly involves three key steps: preform molding, densification treatment, and graphitization treatment, with the densification process being the core step. The specific process is detailed below:
1. Preform Molding
This is the foundation for preparing carbon-carbon composite materials, requiring the carbon fibers to be molded into a preform with a specific structure and shape in a specific manner. Common methods include:
1) Short fiber molding: Carbon fibers are cut, dispersed, filtered, dried, cured, and carbonized to form the preform, but the mechanical properties are relatively low.
2) Long fiber fabric lamination: Carbon fiber cloth/felt is cut, arranged, clamped, cured, and carbonized to form the preform, but the interlaminar shear strength is low.
3) Multidimensional weaving/piercing: Based on long fiber fabric lamination, the fiber content and distribution in the Z-axis direction are increased to improve interlaminar performance, but the cost is higher.
2. Preform Densification
This is a critical step in the preparation of carbon-carbon composite materials. Only carbon-carbon composite materials reaching a certain density can possess good mechanical properties. The densification process mainly includes:
1) Liquid phase impregnation-carbonization (LIC) process: The preform is impregnated with resin or asphalt, followed by carbonization treatment. Carbonization after impregnation with liquid organic matter allows for control of material properties by adjusting parameters.
2) Chemical vapor infiltration (CVI) process: Carbon is deposited in the voids of the preform using chemical vapor deposition. Gaseous substances react on the fiber surface to produce pyrolytic carbon, resulting in good densification but a longer cycle time.
3) Liquid phase vaporization deposition (CLVI) process: Combining liquid phase and gas phase deposition techniques.
4) CVI and LIC composite process: Combining chemical vapor infiltration and liquid phase impregnation carbonization processes.
3. Graphitization Treatment
High-temperature treatment at 1800~2800ºC converts the carbon structure in the carbon-carbon composite material into a graphite structure, improving the material's electrical and thermal conductivity.
Characteristics
1. Mechanical Properties
1) High Strength: The tensile strength, elastic modulus, and flexural strength of carbon-carbon composite materials are higher than those of general carbon materials, and the reinforcing effect of carbon fibers is significant. Three-dimensional orthogonal finely woven carbon-carbon composite materials have a tensile strength greater than 10 MPa and a tensile modulus greater than (4~6) × 10MPa.
2) High-Temperature Strength Retention: It can maintain its room-temperature strength even at temperatures as high as 1627ºC, and may even show an increase in strength. It is currently the only engineering material that can maintain this characteristic.
3) Pseudoplastic Effect: The stress-strain curve shows a linear relationship in the initial stage of loading, but later becomes bilinear. Cracks do not propagate further, resulting in higher reliability.
2. Thermophysical Properties
1) Low Thermal Expansion Coefficient: Only 1/(5~10) of that of metal materials, resulting in low thermal stress at high temperatures.
2) High Thermal Conductivity: Approximately 1.59~1.88 W/(m·K) at room temperature, decreasing to 0.43 W/(m·K) at 1650ºC, and can be adjusted by controlling carbon deposition and processing techniques.
3) High Specific Heat Capacity: Approximately 1.26 kJ/(kg·ºC) at room temperature and 2.1 kJ/(kg·ºC) at 1930ºC, enabling it to store a large amount of thermal energy.
4) Thermal Shock Resistance: Insensitive to thermal stress, and does not experience sudden catastrophic failure like ceramic materials and general graphite.
3. Ablation Performance
1) Ablation Resistance: When exposed to high temperatures and rapid heating environments, the surface indentation is shallow, and the ablation is uniform and symmetrical, making it widely used as a heat-resistant material.
2) High Sublimation Temperature: The sublimation temperature of carbon is as high as 3000ºC or more, resulting in a high surface ablation temperature.
4. Chemical Stability
1) Corrosion Resistance: Does not react with general acid, alkali, and salt solutions, is insoluble in organic solvents, and only reacts with concentrated oxidizing acid solutions.
2) Poor oxidation resistance: Oxidation reactions occur in an oxygen-containing environment at temperatures above 400ºC, leading to a sharp decline in material performance. Oxidation protection measures are required.
5. Application Characteristics
1) Integral molding: It can be integrally molded, reducing the number of parts and increasing service life.
2) Good friction performance: It is wear-resistant and corrosion-resistant, and is among the best of various wear-resistant materials.
Applications
1. Aerospace Field
1) Rocket Engines: Used to manufacture ablation-resistant components, such as nozzle throat liners, capable of withstanding high temperatures of 3500°C and high-speed gas erosion, improving thrust stability.
2) Spacecraft Heat Shields: Used in critical parts of space shuttles, such as nose cones and wing leading edges, since the 1970s.
3) Aircraft Brake Discs: Account for 63%-81% of material applications, reducing weight by 20% compared to metal brake discs, and supporting 500-5000 landings and takeoffs without repair.
2. Automotive Industry
Brake Pads: Used in high-performance cars and racing cars, providing excellent friction performance and thermal shock resistance.
3. New Energy Field
1) Photovoltaic Single Crystal Furnace Hot Zone: Replaces graphite materials and is used in crystalline silicon growth equipment.
2) Semiconductor Manufacturing: Applied in high-temperature equipment such as ingot furnaces.
4. Medical Field
Biomedical Materials: Used as implants such as artificial bones and joints, possessing good biocompatibility.
5. Other Fields
1) Metallurgy and Chemical Industry: Used in heating elements, support frames, corrosion-resistant pipes, etc.
2) High-End Machinery Manufacturing: Applied in heat exchangers, mechanical fasteners, etc.
Product Parameters
