Controlled-atmosphere and vacuum induction heating - Graphitization furnaces.
Vacuum or control-atmosphere high-temperature induction heating is used in "infiltration" processes (graphitization) for parts that may be made of carbon-carbon composite materials. The standard graphitization process entails heating up a carbon part (porous or nonporous) to between 1,000°C and 2,800°C and infusing it with a humidified gas. The parts undergo long treatments and pressure matrix cycles (vacuum and gas pressure). The treatment is done in a reducing atmosphere (nitrogen or argon atmosphere at atmospheric pressure, reduced pressure or in a vacuum).
A graphite susceptor is induction-heated and then transfers the energy to the parts by radiation. The inductor and the susceptor are placed in a chamber where the required pressure cycle takes place. The startup powers for more modern systems exceed 1,000 kW.
The CELES IS generator technology distributes and modulates the susceptor's injected power at several different zones, which keeps the temperature inside the chamber consistent for a high-quality treatment.