Exciting gases until they transform into a plasma state is generally accomplished with an electric arc – but it can also be done with high-frequency electric fields.
This plasma can be used for various coating and surface finishing processes (even on workpieces which are not resistant to high temperatures). It also works on very large areas, which is where conventional high-energy arc plasma processes run up against their limitations. Process gases such as argon or oxygen are introduced into an evacuated tank. A high-performance high-frequency generator and an inductor adapted to the workpiece are used to excite the gas until it is transformed into a plasma state.
The gases or evaporated liquids introduced into the plasma react to various substances, which are deposited in the form of a thin layer on the workpiece. This allows items ranging from flat metal sheets to complex components to be coated with a SiO2 layer for corrosion protection.
High-frequency plasmas are also suitable for activating large surface areas for subsequent finishing processes or to harden special laquer with plasma-generated UV radiation.