Carbon fiber: the "small material" that supports the heavy equipment

A few days ago, the National Aeronautics and Space Administration and the US Air Force Research Laboratory have jointly developed a new technology for 3D printing high temperature polymers, which is expected to be applied to aerospace engines in the future. The material used in this technology is carbon fiber. The rapid development of modern warfare weapons and equipment is toward low energy consumption, large payload, stealth, and high mobility, and higher requirements are placed on the materials used to manufacture weapons. Carbon fiber composite materials, known as "black gold", are widely used in national defense and military industries due to their excellent material properties. The use of carbon fiber materials to create better weapons and equipment has long become a new battlefield where military powers compete.

The fascinating "black gold"

Remember the robot "Big White" in the animated movie Big Hero 6? The prototype of this medical robot that has touched countless people is made of carbon fiber materials. This allows him to withstand crushing and beating. In fact, even the F-35 fighter jet, which was previously troubled by the overweight problem, finally achieved its dream of flying by using up to 35% carbon fiber composite materials. Carbon fiber, known as "black gold", has long been widely used in the field of national defense and military. It is an indispensable basic material for rockets, satellites, missiles, fighter jets, and ships.

The origin of carbon fiber can be traced back to 1860. The Englishman Joseph Swan invented and patented carbon fiber when he made the filament of an electric light. Carbon fiber really ushered in the "blowout" stage of research and application, or something after the 1950s. In 1958, American researchers discovered high-performance carbon fiber for the first time, followed by Japanese and British researchers to improve and upgrade the performance of carbon fiber. By the 1970s, carbon fiber materials began to emerge in the structural parts of fighter aircraft. Carbon fiber materials can be seen on fighter aircraft such as F-15, B-1, F-16 and F-18. In addition to the extensive use of carbon fiber composite materials in the US Air Force’s F-22 and F-35 fighter jets, the X-47B, Global Hawk and other equipment also use carbon fiber materials to achieve a substantial increase in payload, endurance and survivability.

It is no exaggeration to describe carbon fiber materials as "rock solid and tough as hair". Regardless of whether carbon fiber materials are as soft and processable as textile fibers, they are a new generation of high-performance materials with greater strength than steel, corrosion resistance, high temperature resistance, and good electrical and thermal conductivity. The carbon fiber material bicycles that people usually come into contact with most often take advantage of the lack of plastic deformation of carbon fiber materials, which not only reduces the weight of the body, but also greatly increases the life of the bicycle.

At present, the characteristics of carbon fiber composite materials still have huge room for improvement. In the resin field where carbon fiber materials are focused on, the application of carbon fiber will further increase the service life of various parts of weapon equipment, and will significantly improve weapon equipment's impact resistance, fatigue resistance, processability, and heat and humidity resistance. The 3D printing achieved by the National Aeronautics and Space Administration and the US Air Force Research Laboratory will further improve the reliability of processing large-size and complex parts.

The "king of new materials" in the competition between big powers

The rapid development of modern warfare weapons and equipment toward low energy consumption, large payload, stealth, and high mobility has put forward new and higher requirements for the new material technology of manufacturing weapons and equipment. Looking back at history, it is not difficult to find that every time a major research progress is made in carbon fiber materials, it is accompanied by a strong pull of relevant military needs. In the 1950s, in order to solve key technical problems such as high temperature resistance and corrosion resistance of missile nozzles and warheads, the United States took the lead in developing viscose-based carbon fibers. Since then, with the emergence of higher performance and more varieties of carbon fiber materials, seemingly soft fibers have become the "king of new materials" in competition among major powers.

Carbon fiber is a new type of high-performance fiber with a carbon content of more than 95%, and its manufacturing technology is difficult. It is an important indicator of the advanced performance of weapon equipment systems. The manufacturing process of carbon fiber materials is very complex, involving chemical, textile, materials, precision machinery and other fields. It is a system engineering integrating multi-disciplinary, refined, and high-end technology. Since the entire production process is related to the high-precision control of thousands of parameters such as humidity, concentration, viscosity, and flow rate, a little carelessness will seriously affect the performance and quality stability of carbon fiber materials. Therefore, only a few countries can stably produce high-performance carbon fiber materials.

In fact, carbon fiber materials, especially high-strength carbon fiber precursors, can be used for the development of high-performance weapons and equipment, and thus have reached an embargo level on the export list of some countries on par with nuclear weapons technology. Therefore, the development of a new generation of carbon fiber materials and higher-performance weapons and equipment has become the "highlight" of various military powers competing for cutting-edge strength. At present, various military powers have set their sights on the field of "carbon fiber materials" and are racing to launch related plans for the development of carbon fiber materials, which may trigger a "competition" in the development of carbon fiber materials. The Advanced Research Projects Agency of the US Department of Defense has previously invested heavily in projects to improve the strength of carbon fiber materials, and the National Aeronautics and Space Administration has also actively invested in research on new carbon fiber thermal protection systems.

"Up to the world under the sea" has broad prospects for development

With the increasing maturity of related technologies and the increasing demand for weapons and equipment, the application of carbon fiber materials is also becoming more and more perfect. Carbon fiber materials, which have many advantages such as light weight, high strength, and chemical resistance, are bound to enter the field of weaponry and equipment in an all-round way, and achieve "the world under the sea", with broad development prospects.

In the field of aviation manufacturing, the application of carbon fiber materials has long been indispensable. The main body of the F-35 fighter flight helmet uses high-performance carbon fiber materials, which can project airspeed, heading, altitude, target information and radar warnings directly onto the helmet's visor, providing pilots with unprecedented situational awareness. The “Solar Impulse 2” solar-powered aircraft that started its global flight journey in 2015 uses carbon fiber materials as a “warm jacket” for 80% of the overall structure, which saves more power during the flight. In addition to meeting the body's weight reduction and special performance requirements, the carbon fiber material that can effectively absorb radar waves also puts a "stealth coat" on the fighter. The fuselage of the American B-2 bomber and the F-117A fighter also use carbon fiber absorbing materials.

In the field of drones, carbon fiber materials have become the irreplaceable "best shell." In order to ensure the carrying capacity and endurance, the UAV shell needs special materials with strong structure and light weight. Compared with aluminum alloys and engineering plastics that have been widely used before, carbon fiber materials are light in weight, high in strength, and have better electromagnetic shielding and stealth characteristics, and they are more convenient to be integrated and formed. In the future, they are bound to become the main material for UAV shells. . In particular, the micro-unmanned aerial vehicle made of carbon fiber and weighing only 106 milligrams can enter the squeezed narrow space to search for information, and has a wide range of application prospects in the military and civilian fields.

Carbon fiber materials can not only go to the sky, but also go to the sea. The US "Ford" aircraft carrier uses a large number of carbon fiber materials to "slim down". The Royal Swedish Navy "Visby"-class stealth frigate uses carbon fiber materials, which not only has high strength and durability, but also has excellent impact resistance. The Indian Navy also specially imported carbon fiber materials from Sweden when manufacturing the "Giltan" and "Kavalati" frigates.

In addition, carbon fiber materials are also widely used in satellites, missiles and rocket engines. Especially when satellites face "ice and fire" when flying in space, carbon fiber materials with almost negligible thermal expansion coefficient are precisely the "saviors" of satellites. Researchers even introduced a carbon fiber barrel, which can greatly improve the shooting accuracy, durability and barrel life of the firearm. A "big show" belonging to the military application of carbon fiber has just begun.

Drawing: Chen Chen

Source: People's Liberation Army Daily