Analysis of the role and use of graphite rods

- Aug 07, 2018 -

Graphite rod, Graphite plate J structure: A typical layered structure, carbon atoms arranged into six-square mesh layer, the carbon atoms on the mesh node relative to the center of the upper and lower adjacent grid. The repeating layer is 2 graphite 2H, which is a six-square crystal system, that is, the graphite rod and graphite plate which are usually referred to, and if the repeating layer is 3, the graphite is 3R-shaped, is a tri-square crystal system, but in the natural graphite structure, can not separate out. In graphite crystal structure, the coordination number of carbon atoms in the layer is 3, with covalent metal bond, spacing 0.142nm, layer and layer are connected by molecular bond, spacing is 0.340nm,

This kind of special crystal structure and chemical bonding make graphite have some special process properties. Because the carbon atoms are arranged tightly in the atomic layer of the graphite crystalline lattice and the thermal vibration is difficult, the graphite rod and the graphite plate are capable of high temperature and special thermal properties. The melting point of graphite is 3,850 ℃, the boiling point is 4,250 ℃, the heat absorbing 6.9036x107j/kg, the low temperature arc burning weight loss At 2,500 ℃, its strength is 1 time times higher than normal temperature, the coefficient of thermal expansion is small (1.2x10-6), and its volume changes little when the temperature is abrupt. Because of the existence of an easily-flowing electron in graphite crystals, the conductivity and thermal conductivity are no less than that of metal. At very high temperature tends to not heat conduction state. Graphite rod, graphite plate chemical stability is good, not affected by acid, alkali and organic solvents. The lubrication property of graphite is similar to that of molybdenum disulfide and PTFE, the coefficient of friction is less than 0.1 in the lubrication medium, especially the lubrication of flake graphite is better. In addition, graphite is also coated and malleable, The coating is applied to the surface of solid body, which can form a strong adhesion of the film to protect the solid, and can be made into any complex shape products.