Carbon-carbon composite materials were first discovered in 1958. American researchers were attempting to determine the carbon fiber content in carbon fiber-reinforced phenolic resin-based composite materials. Due to an error in the experimental process, the phenolic resin matrix was not oxidized but instead pyrolyzed, unexpectedly yielding a carbon matrix. Through analysis of the carbonized material, researchers discovered and developed a new type of carbon fiber-reinforced carbon matrix composite material, known as carbon-carbon composite material. This material exhibits a series of outstanding physical and high-temperature properties, representing a novel structural composite material. From this point onward, carbon-carbon composite materials became part of the composite materials family. Upon its discovery, the material immediately garnered widespread attention from materials science and engineering researchers, and its development accelerated rapidly in response to the demands of the aerospace industry.
Carbon-carbon composite materials are fully carbon-based composites made using carbon fibers and their fabrics as reinforcing materials, with carbon (or graphite) as the matrix, through densification and graphitization processes.
As an important member of the carbon fiber composite materials family, carbon-carbon composites possess many of the advantages of carbon and graphite materials. For example, they have low density (theoretical density less than 2.2 g/cm³), high thermal conductivity [up to 400 W/(m·K)], and a low thermal expansion coefficient [(1–5) × 10^(−6)/°C]. Additionally, as a new type of structural material, carbon-carbon composites feature high strength, excellent thermal shock resistance, good corrosion resistance, wear resistance, and corrosion resistance. Carbon-carbon composite materials can withstand temperatures exceeding 3000°C. Especially, the unique property of carbon-carbon composite materials, where their strength increases rather than decreases with rising temperature, gives them an unmatched advantage over other materials when selected for aircraft thermal protection systems and engine hot-end components. Therefore, carbon-carbon composite materials are considered one of the most promising high-temperature materials.
The inherent performance advantages of carbon-carbon composite materials make them suitable for use in a wide range of applications. Due to their low density, high-temperature resistance, excellent wear resistance, and ability to absorb large amounts of braking energy, they serve as an excellent friction material. When applied to aircraft brake discs, they can reduce weight by 40%, enhance high-temperature friction stability during braking, and prevent issues such as thermal warping and surface cracking, thereby extending the service life of the brake discs. Due to their high-temperature resistance and ablation resistance, they can be used as nozzle materials for solid rocket engines. Their low density, ablation resistance, good thermal conductivity, and thermal shock resistance make them the ideal material for missile nose cones. Their excellent load-bearing capacity at high temperatures enables their application in high-temperature thermal protection components, high-temperature fasteners, and high-temperature heating elements.