Carbon in Modern Industries---pyrolytic graphite and pyrolytic carbon

Carbon is the source of life, the skeleton element of all living organisms on earth, and the most important element that constitutes the human body. Carbon in Modern Industries is mainly used as precision heaters, high-strength structures, new batteries, nuclear reactors, etc. in the form of pyrolytic graphite, pyrolytic carbon, and isostatic graphite.

Pyrolytic graphite

Pyrolytic graphite is a new type of carbon material. It is a pyrolytic carbon with high crystal orientation, which is deposited by chemical vapor deposition of high-purity hydrocarbon gas on a graphite matrix at 1800 ° C ~ 2000 ° C under a certain furnace pressure. It has high density. (2.20g/cm), high purity (impurity content (0.0002%) and thermal, electrical, magnetic and mechanical properties anisotropy. It can still maintain a vacuum of 10mmHg at about 1800 °C.

Main application

In the semiconductor industry, to drawn the silicon single crystal guide tube.

Graphite heater coatings for the semiconductor industry.

Coating of PBN/PG composite heater during wafer annealing process.

Pyrolytic graphite coating for atomic absorption tubes for analytical instruments.

E-beam crucible.

Pyrolytic carbon

Pyrolytic carbon and pyrolytic graphite are vapor-deposited carbons with special structure and properties.

According to their characteristics, pyrolytic carbon can be divided into dense pyrolytic carbon with high density, loose pyrolytic carbon with low density, and isotropic and anisotropic pyrolytic carbon. Its properties and structure depend on the pyrolysis temperature. Pyrolytic carbon is pyrolyzed below 800-1000 °C, and pyrolytic graphite is treated at 1400-2000 °C or higher. The property structure of pyrolytic carbon depends on its manufacturing conditions, among which the deposition temperature is the most important.

In terms of its reaction mechanism, the preparation of pyrolytic carbon has to go through two stages:

1. A carbonization process occurs, resulting in coke and separated volatile products.

2. The resulting product is degraded into pyrolytic carbon, water, and gas. .