The United States invented the base metal mesophase pitch for textile pitch-based carbon fibers. After the precursor was stabilized and carbonized, the tensile strength of the carbon fiber was 3.5 GPa and the modulus was 252 GPa. France developed heat and high conductivity. Mesophase pitch-based carbon fiber; Poland developed a new method for coating metal-coated carbon fibers. For example, copper-coated pitch-based carbon fibers are prepared by a mixing method. First, a copper salt is mixed with an isotropic coal pitch to perform centrifugal spinning. Stabilized in air and treated in high temperature hydrogen to obtain carbon fibers of alloy copper. The world's asphalt-based carbon fiber production capacity is relatively small, and the research and development of domestic pitch-based carbon fiber is earlier, but there is a big gap in development, production and application compared with foreign countries.
Carbon fiber is classified into aerospace grade and industrial grade according to product specifications, also known as small tow and large tow. Carbon fibers above 48K are usually referred to as large tow carbon fibers, including 360K and 480K. The aerospace-grade carbon fiber was mainly developed at 3K and gradually developed into 12K and 24K. It is mainly used in defense military and high-tech, as well as sports and leisure products, such as airplanes, missiles, rockets, satellites and fishing rods, and golf clubs. Industrial grade carbon fiber is used in various civil industries, including: textiles, medical and health, electromechanical, civil engineering, transportation and energy.