Strip Hollow Cathode Plasmas: PECVD and Thermochemical Treatment
ByKrasimir Nikolov, Claus-Peter Klages
Pages 13

Low-pressure glow discharges are of great interest for the development of new technologies for surface modification of metal strips for different applications. The major challenge for the implementation of novel high-performance plasma deposition processes into existing schemes of continuous coating processes is the requirement of a very high deposition rate combined with minimal loss due to parasitic coating. Regarding these requirements, a strip hollow-cathode (SHC) is designed for plasma-enhanced chemical vapor deposition on large-area metal strips in a continuous technological process. The method is based on a hollow-cathode glow discharge between two parallel strip sections where the strip itself plays the role of a cathode. The SHC method has been further developed and applied for thermochemical treatment, primarily plasma nitriding, using a new concept for surface modification of metal strips by means of thin diffusion layer. The principle of the method and setup of the device for stationary treatment operation are described. Investigations of deposition of amorphous hydrogenated carbon films on highly grain-oriented electrical steel sheets and amorphous hydrogenated silicon-containing carbon coatings on zinc–magnesium-alloy-coated steel sheets as well as plasma nitriding of austenitic stainless steel sheets are presented. Several feasible applications show that the SCH method is very promising for realizing advanced industrial technologies.