New coating systems for steel strips by physical vapor deposition

Coatings deposited by PVD (Physical Vapor Deposition) are a promising alternative for the corrosion protection of strip steels. Conventionally coating systems have deficits regarding environmental compatibility and some application properties. PVD is an environment-friendly technology and is famous for the nearly unlimited material and process variety. EBHD (Electron Beam High-rate Deposition) with deposition rates up to some micrometers per second is one of the most powerful PVD technologies for low cost coating. The combination of evaporation with powerful plasma is an efficient possibility to improve the layer properties of compounds and high-melting metals. In the paper an overview about such emergent PVD technologies are presented. The paper presents some examples of new layer stacks onto steel sheets and onto galvanized steel sheets. Zinc-alloy coatings, coatings of high-melting metals and oxide coatings were deposited and investigated. The coatings were produced under the conditions of a very high deposition rate (more than 100 nm/s) within an in-line vacuum coater for metallic strips and sheets. The influence of the process and plasma parameters on the layer properties was investigated and are demonstrated for some special applications.