2015年6月14日星期日

The Introductions of Wide variety and Characteristic of Graphite



Graphite is definitely an allotrope of carbon, and its every single carbon atom is connecting three other carbon atoms so that the arrangement can be a hexagon beehive type. There is a weak Van der Waals force between every single layer. Since each and every carbon atom emits an electron, and also the electrons can move freely, to ensure that the graphite belongs to the conductor. Graphite is the softest mineral in the planet, opaque and feels greasy. Its color is from black to steel grey, and also the shape is numerous, for example crystalline, sheet shaped, squamous, striped and so on. It constantly distribute in metamorphic rocks, and its chemical properties are usually not active, with corrosion resistance.
Graphite is broadly applied in just about each market. Various crystalline graphite minerals have distinctive industrial worth and use. In accordance with the diverse crystalline morphology, all-natural graphite points into Graphite Block, flake graphite and hidden high quality graphite; in line with its forming way, it may be divided into Isostatic Graphite, mole pressing graphite, extruded graphite. As outlined by the granularity of graphite, additionally, it might be divided into detail structure graphite, middle graphite and electrode graphite. In addition, using the development in the science and technologies, now there are some new kinds of graphite in the industry, including Artificial Graphite, photovoltaic graphite and so on.
The graphite has so unique structure that it has some special characteristics distinct from other materials.
The graphite has high temperature resistance. The melting point of graphite is 3850 degrees, as well as the boiling point of it truly is 42.5 degrees. In order that its loss in weight was quite small even it is fired by the ultra high temperature arc, and also the coefficient of thermal expansion is quite smaller, too. The graphite strength will enhance together with the temperature, and also reached to double when the temperature is at 2000 degrees.
The graphite has incredibly excellent electric conduction and thermal conductivity. The electric conductivity of graphite is 1 hundred times greater than common nonmetal mineral. The thermal conductivity of graphite is over greater than steel, iron, lead and other metal components. The thermal conductivity of it's decreased with the enhance of temperature, even it will be insulator when it was in really high temperature.
The lubrication functionality of graphite depends on the size of graphite flake. The flake is larger, the friction coefficient is smaller sized as well as the lubrication overall performance is better. The graphite also has fantastic chemical stability at room temperature, and it is actually in a position to bear acid, alkali and other organic solvent.
Meanwhile, the graphite has incredibly excellent toughness and may be milled into thin slices. The graphite can withstand the temperature adjustments with out failure. When the temperature is changed, the volume of graphite won't alter, and no crack will be produced.

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