What are the special properties of graphite?
Due to its special structure, graphite has the following special properties:
(1) High temperature resistance
The melting point of graphite is 3850±50°C. Even if burned by ultra-high temperature arc, the weight loss is very small and the thermal expansion coefficient is very small. The strength of graphite increases with the increase of temperature. At 2000°C, the strength of graphite doubles.
(2) Electrical and thermal conductivity
The conductivity of graphite is one hundred times higher than that of general non-metallic minerals. Thermal conductivity exceeds that of metal materials such as steel, iron, and lead. The thermal conductivity decreases with increasing temperature, and even at extremely high temperatures, graphite becomes an insulator. Graphite can conduct electricity because each carbon atom in graphite only forms 3 covalent bonds with other carbon atoms, and each carbon atom still retains 1 free electron to transfer charge. To
The lubricating performance of graphite depends on the size of the graphite flakes. The larger the flakes, the smaller the friction coefficient and the better the lubricating performance. To
(4) Chemical stability
Graphite has good chemical stability at room temperature, and is resistant to acid, alkali and organic solvent corrosion. To
Graphite has good toughness and can be rolled into very thin flakes.
(6) Thermal shock resistance
Graphite can withstand drastic changes in temperature without being damaged when used at room temperature. When the temperature changes suddenly, the volume of graphite will not change much and no cracks will occur.