High purity graphite: graphite content of more than 99.9% of graphite called high pure graphite. Is an ideal inorganic non metal crucible boat, crystal furnace heater, EDM graphite, sintering mold, tube anode, metal coating, semiconductor technology with graphite crucible, electron tube, thyratron and mercury arc rectifier with graphite anode, grid etc..
High purity graphite has the advantages of small resistance coefficient, high temperature resistance, corrosion resistance, oxidation resistance, good thermal shock resistance, electrical conductivity, thermal conductivity, small coefficient of expansion, self lubrication, easy machining precision and so on.
1) high temperature resistant graphite melting point of 3850 - 50 DEG C, the boiling point of 4250 DEG C, even after the ultra high temperature arc ignition, the weight loss is very small, the thermal expansion coefficient is small. The graphite strength increases with the increase of temperature, and at 2000 DEG C, the graphite strength is doubled.
2) conductivity, thermal conductivity: the conductivity of graphite is one hundred times higher than the general non-metallic minerals. 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. Graphite is able to conduct electricity because each carbon atom in graphite has only
3 covalent bonds with other carbon atoms, and each carbon atom retains 1 free electrons to transfer the charge.
3 lubrication: graphite lubrication performance depends on the size of the graphite flake, the larger the size, the smaller the friction coefficient, the better the lubrication performance.
4) chemical stability: graphite has good chemical stability at room temperature, acid and alkali corrosion resistance to organic solvents.