1. Marija Riđošić, Faculty of Technology - University of East Sarajevo,
Republic of Srpska, Bosnia and Herzegovina
2. Aleksandra Josipović, Faculty of Technology - University of East Sarajevo, Republic of Srpska, Bosnia and Herzegovina
3. Milorad Tomić, Republic of Srpska, Bosnia and Herzegovina
4. Miomir Pavlović, Faculty of Technology - University of East Sarajevo, Republic of Srpska, Bosnia and Herzegovina
Development of the alternative processes for the „dirty” technology in all industrial areas is an essential task nowadays. Among the technologies that are most hazardous for environment and which has to be replaced by “green” processes are galvanic and decorative coatings. It is well-known that electroplating of finishes, like hard chromium, cadmium or nickel in metal finishing is recognized as a source of pollution which is very dangerous for environment and humans. Good alternative for the deposition of the coatings from standard plating baths could be physical vapour deposition (PVD), plasma-assisted chemical vapour deposition, and chemical vapour deposition (CVD) or thermal spraying. In this work the Nb coatings will be deposited on steel by PVD process. After deposition, the anodic oxidation on different potentials will be applied to obtain different colouring of the coating which is very important decorative factor today in many manufacturing areas. Two different solutions for anodic oxidation will be used and compared with commercial solution for this purpose. The colour and morphology of the obtained coatings was examined by bench-top spectrophotometer and optical microscopy. The corrosion stability of the obtained coatings was determined in 3,5wt% NaCl by electrochemical techniques. Namely, the potentiodynamic polarization and electrochemical impedance spectroscopy was used to study the corrosion processes of the coatings in saline environment. Obtained results shows that coatings anodised at 140 V had the best corrosion performance from all solutions. Coatings anodised in prepared solution 3 showed advanced properties than those obtained from commercial solution. The corrosion rate was 0.018µm/year in 3 wt% NaCl.
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