High-modulus graphite fiber and preparation method thereof

Abstract

The invention discloses a high-modulus graphite fiber with the tension-resistant modulus being 270-650GPa, and the high-modulus graphite fiber is in multiple crystallization structures, and the thicknesses (Lc) of the crystallization structures are 20-70 angstrom. The preparation method of the high-modulus graphite fiber comprises the following steps of carrying out ultra-fast high-temperature graphitization preparation on a carbon fiber as a raw material in a microwave focusing mode, increasing the temperature of the carbon fiber at a heating speed of 10-100 DEG C per minute to the graphitization temperature of 1400-3000 DEG C, and carrying out fast graphitization preparation within 0.5-10 minutes, so as form the graphite fiber with the high-modulus property.

Description

technical field [0001] The present invention relates to a high-modulus graphite fiber and its manufacturing method, aiming to provide a manufacturing method that can greatly improve the efficiency of graphitization and reduce the manufacturing process cost. Background technique [0002] Carbon fiber has a series of excellent characteristics such as low specific gravity, high tensile strength, high modulus, high electrical conductivity, high thermal conductivity, etc., and also has the advantages of flexible and weavable fibers. Among them, special carbon fibers with high strength and high modulus are widely used in new reinforced composite materials for construction, aviation and military. There are many types of carbon fiber raw materials, such as rayon, polyvinyl alcohol, vinylidene chloride, polyacrylonitrile (PAN), pitch, etc. The current mainstream carbon fiber uses polyacrylonitrile (PAN) as the raw material. The carbon fiber has excellent mechanical properties such a...

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Problems solved by technology

Disadvantages: This technology requires a long-term (>4 hours) pre-carbonization process in a traditional high-temperature furnace. Pre-carbonized fibers are formed before microwave carbonization, which increases the difficulty of the process. In addition, the precursor is low-carbon content. It is impossible to form high-strength and high-modulus materials by rapid carbonization

The patent US6372192B1 is for Oak ridge lab to use microwave plasma to carbonize polyacrylonitrile fiber (PAN). Carbonization of pre-oxidized PAN fibers in the environment, the microwave energy is mainly used to generate gas plasma, the main heating area is the fiber surface, the heat capacity is difficult to quantify the production of large bundles of fibers, and the highest strength is only 2.3GPa, the modulus is only 192GPa, no Capable of high modulus specifications

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