ELECTRON BEAM-PVD ENHANCED SURFACE-PROPERTIES ON METALLIC STRIPS AND SHEETS

PVD layers represent a great potential to improve the surface properti es of metallic strips and sheets. The development of low cost PVD proc esses is a basic requirement for using such layers for the surface imp rovement of large area substrates. Electron beam evaporation is theref ore an obvious choice because it can achieve high-rate and large area deposition. The advantages of this environmentally protective process include the huge number of suitable layer materials (metals, alloys an d compounds) and the possibility of making tailor-made layer systems f or special applications. Additionally the layer properties can be impr oved by different kinds of plasma activation of the electron beam depo sition process. Thin layers and layer systems were deposited on steel, zinc coated steel and aluminum by high-rate electron beam evaporation . The investigations were focused on such systems, which are not or no t economically available by means of other processes. One topic is to substitute chemical chromating and phosphating of zinc coated steel by thin silicon or aluminum oxide PVD-layers. Our results show that this process fulfills the main requirements of chromating and phosphating concerning temporary corrosion protection and improvement of lacquer a dhesion. The fundamental knowledge is applicable to other substrates s uch as steel, tin plated steel or aluminum. (C) 1997 Elsevier Science S.A.