Correlation between electrophoretic clearcoats properties and electrochemical characteristics of noble substrates
- 作者：Caterina Zanella ; caterina.zanella@ing.unitn.it ; Michele Fedel ; Flavio Deflorian
- 关键词：Electrophoresis ; Clearcoats ; Precious metals substrate
- 刊名：Progress in Organic Coatings
- 出版年：2012
- 期刊代码：70_03009440
- 类别：ce
- 出版时间：June, 2012
- 卷：74
- 期：2
- 页码：349-355
- 文件大小：902 K
摘要
The use of transparent organic coatings as protection for noble metal layers has a wide application especially in the costume jewellery and glass frames industry. The role of a clearcoat is to protect the noble substrate from scratches, tarnishing, and changes in gloss due to the interaction with the environment and human body. In this study electrodeposited organic coatings have been considered for this purpose. The application of clearcoats by electrophoresis usually assures a good adhesion to the substrate and the formation of a compact and protective layer. Electrophoresis has been developed especially under cathodic deposition and was mainly optimized for corrosion protection of active metals, but in this work both anodic and cathodic e-coats have been applied and analyzed. Since the substrates were noble metals, the surface could show a different reactivity during the application of the deposition voltage. The relationship between electrochemical behaviour of the substrate and the final properties of the clear coatings was investigated with electrochemical tests such as polarization curves, and electrochemical impedance spectroscopy. The correlation between deposition parameters and coatings properties as thickness and presence of defects was discussed according to the electrochemical results.