ELECTROCHEMICAL EVALUATION OF THIN-FILMS AND COATINGS DEPOSITED WITH ION-BEAM-ASSISTED DEPOSITION (IBAD) USING SCANNING ELECTROCHEMICAL MICROELECTRODE

In this contribution the application of a modern technique-scanning el ectrochemical microelectrode - for the evaluation of thin film which w ere deposited for corrosion protection by ion beam assisted deposition (IBAD) is illustrated. New tendencies in the development of thin film s with anticorrosive purpose lead to the development of multi-layer sy stems acting similar to those commonly applied in the industry, howeve r, being much thinner. Imperfections and defects are commonly introduc ed in the coating during the deposition process, and these affect the anticorrosive properties of the film. In order to make a local electro chemical study of these multi-layer systems we have developed equipmen t in order to perform electrochemical surface-scans (potential and cur rent density) on the basis of a micro-electrode with a good lateral re solution (approximately 20 mu m). Al-Al2O3 multilayers on steel substr ates with differently designed interfaces were investigated to show th e variation of uniform and local electrochmecal information obtained i n dependence on the coating deposition parameters.