Graphite powder soft, black gray; greasy feeling, can pollute the paper. Hardness of 1 ~ 2, along the vertical direction with the increase of impurities in its hardness can be increased to 5 ~ 3. Proportion of 1.9 to 2.3. Under the condition of isolated oxygen, its melting point is above 3000 degrees Celsius, it is one of the most temperature resistant minerals. At room temperature the chemical properties of graphite is relatively stable, insoluble in water, dilute acid, dilute alkali and organic solvent; material has high temperature resistant conductive performance, do refractory materials, conductive materials, wear-resistant lubricating material.
Material profile
Graphite powder soft, black gray; greasy feeling, can pollute the paper. Hardness of 1 ~ 2, along the vertical direction with the increase of impurities in its hardness can be increased to 5 ~ 3. Proportion of 1.9 to 2.3. Under the condition of isolated oxygen, its melting point is above 3000 degrees Celsius, it is one of the most temperature resistant minerals. Under normal temperature chemical properties of graphite is relatively stable, insoluble in water, dilute acid, dilute alkali and organic solvent; reacts with oxygen under different temperature, generated carbon dioxide or carbon monoxide; in halogen only fluorine can and elemental carbon direct reaction; in the heating, graphite powder is easy to be acid oxidation; at high temperature, but also with many metal reaction to generate metal carbides, at high temperatures can be metal smelting.
Material characteristics
Graphite powder is a chemical reaction is very sensitive material, in the different environment inside his resistivity will change, his resistance values will change, but is not the, graphite powder is one of non metal conductive material is very good, as long as the insulating objects ensure graphite powder uninterrupted, like a thin line that will electrify, however, resistance value is how much, this numerical didn't an accurate number, because the thickness of the graphite powder, used in different materials and environmental graphite resistor values will be different. Because of its special structure, graphite has the following special properties:
1) high temperature resistant: Graphite melting point of 3850 + 50 DEG C, the boiling point of 42.5 DEG C, even the ultra high temperature arc ignition, weight loss is very small, coefficient of thermal expansion is also very small. Graphite strength increases with the increase of temperature, and the strength of graphite is doubled at 2000 C.
2) conductive and thermal conductivity: the conductivity of graphite is one hundred times higher than that of general non metal mine. Thermal conductivity of steel, iron, lead and other metal materials. The thermal conductivity decreases with the increase of temperature, even in high temperature, graphite as insulator.
3) the lubrication performance of graphite depends on the size of graphite flake, the bigger the scale, the smaller the coefficient of friction, the better the performance of the lubrication.
4) chemical stability: graphite has good chemical stability at room temperature, acid and alkali corrosion resistance to organic solvents.
5) plasticity: the toughness of graphite is good, can connect a very thin sheet.
6) thermal shock resistance: graphite at room temperature when used to withstand the severe changes in temperature without damage, temperature change, the volume of graphite change is not large, will not produce cracks.
Application case
1, as a refractory material: graphite and its products have properties of high - strength, high temperature resistance, mainly used to produce graphite crucible in the metallurgical industry, in steelmaking in graphite is usually used for the protection of steel ingot agent, metallurgical furnace lining.
2, as the conductive material: used for manufacturing electrode, carbon brush, carbon rod, carbon nanotubes, mercury is the cathode in electrical industry, graphite gaskets, telephone parts, TV picture tube coating.
3, as wear-resistant lubricating material: Graphite in the mechanical industry as a lubricant. Lubricating oil can not be used in high speed, high temperature and high pressure conditions, and graphite wear resistant material can be in a high sliding speed at 200~2000. Many of the devices that transport corrosive media are widely used in the piston cup, seal rings and bearings, which are widely used in graphite materials. Shi Moru is one of many metal processing (drawing, drawing) the good lubricant.
