PLASMA-ACTIVATED ELECTRON-BEAM DEPOSITION WITH DIFFUSE CATHODIC VACUUM-ARC DISCHARGE (SAD) - A TECHNIQUE FOR COATING STRIP STEEL

The diffuse cathodic vacuum are discharge is an efficient plasma sourc e suitable to activate the process of high-rate electron beam depositi on on large areas. With condensation rates of some microns per second, ion current densities of, say, 100 mA cm(-2) and more can be obtained on the substrate. The layout of equipment and process control offers many opportunities to match this coating process, termed SAD, to the s pecific requirement of the various layer materials and applications. P resented in this paper are the results of process development. The dep osited layers are characterized especially by their high density, duct ility and smooth surface. Exemplified by the coating of strip steel wi th titanium, the resulting effects on the properties of the coated pro duct are shown in detail. Of particular significance is the high corro sion protecting action that is maintained also after deformation of th e coated substrates. Finally, an outlook is given on practicable possi bilities of use.