Basis and application of carbon and graphite materials
carbon and graphite material
a class of non-metallic materials composed of carbon elements. There are three isomers of carbon element: one is amorphous carbon, such as charcoal, coke, carbon black, etc; The other two are crystalline carbon. 6. The laboratory where the experimental machine is located cannot have vibration, that is, graphite and diamond. Amorphous carbon can be transformed into graphite after high temperature treatment. Graphite can be converted into diamond under the action of catalyst, high pressure and high temperature. This is also the production method of artificial graphite and diamondThe spatial arrangement of atoms of the three isomers of carbon element is different. Graphite belongs to hexagonal system, and each layer is composed of hexagonal rings. The layers are parallel to each other, showing an orderly overlapping crystal structure (Fig. 1 [crystal structure of graphite]); Diamond belongs to tetrahedral structure of cubic crystal system (Fig. 2 [crystal structure of diamond]); Although amorphous carbon has microcrystals, it does not have the ordered arrangement like graphite| Mechnet | for more information, please visit the meaning of "innovation" understood by Chinese mechanical experts and plastic film blowing machine manufacturers.
classify carbon and graphite often used in mechanical engineering, which can be divided into carbon materials and graphite materials according to their organizational structure. Carbonaceous materials are made from petroleum coke and asphalt coke. Coal tar pitch is the binder, which is formed by kneading, pressing, heating and carbonization. Graphite can be divided into natural graphite and artificial graphite (including special graphite) according to its source. Natural graphite has two forms: scaly and earthy. Artificial graphite is made of carbonaceous materials by graphitizing at a high temperature above 2500 ℃. Special graphite is obtained from general graphite by hot pressing, or other organic raw materials and special processes. For example, glass carbon made of thermosetting resin through special heat treatment; Pyrolytic graphite formed by decomposition and deposition of hydrocarbons at high temperature; Flexible graphite, which is made of scaly natural graphite after acid treatment and then highly expanded at high temperature, and carbon fiber and graphite fiber made of synthetic fiber
characteristics and applications diamond is hard and wear-resistant, and is often used as abrasive, cutting tools and exploration bits. Carbonaceous materials and graphite materials have been widely used in mechanical, electrical, metallurgical, chemical, electronic, aerospace, rocket, atomic energy and other technical fields because of their different excellent properties. Generally, artificial graphite has good conductivity and heat resistance, and can be used to make electrodes for electric arc furnaces and EDM molds; Because of lubrication and wear resistance, it can be used to manufacture sealing rings, scrapers and high temperature bearings. The impermeable graphite impregnated with thermosetting resin can be used in heat exchangers, pipes and accessories in chemical equipment because of its excellent chemical corrosion resistance and good thermal conductivity. Flexible graphite is elastic and can be used to manufacture high-temperature sealing rings, fillers and gaskets
carbon fiber and graphite fiber have high strength and can be used as reinforcement of composites based on resin, metal, ceramics, carbon, etc. Porous graphite can resist high temperature and corrosion of gases and liquids, and can be used as high-temperature insulation materials and filter materials. High purity nuclear graphite without boron and rare earth elements is used in atomic reactors because it does not absorb neutrons and can decelerate neutrons. Pyrolytic graphite can be used as throat liner and nuclear fuel coating of rocket nozzle because of its large heat conduction anisotropy ratio; Because of the high degree of orientation, it can be used for the grid of high-power transmitting tubes. Artificial graphite can also be used as die casting die of copper and aluminum and sintering die of electronic components; Carbon brick and carbon block can be mainly considered by users as the tonnage of the experimental machine and the structure and control mode of the experimental machine, which can be used as the lining of iron smelting blast furnace and ferroalloy large electric furnace; Glassy carbon can be used to make auxiliary surfaces of rotary seals and electrodes in laser technology. As for natural graphite, due to its high content of impurities, it is generally only used for manufacturing crucibles and Sand Mold Coatings for smelting, or as raw materials, which are refined and used for liquid lubricants and flexible graphite
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