Effect of plasma surface treatment on mechanical and corrosion protection properties of UV-curable sol-gel based GPTS-ZrO2 coatings on mild steel

✍ Scribed by P. Kiruthika; R. Subasri; A. Jyothirmayi; K. Sarvani; N.Y. Hebalkar

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 510 KB
• Volume: 204
• Category: Article
• ISSN: 0257-8972
• DOI: 10.1016/j.surfcoat.2009.10.017

✦ Synopsis

Hybrid sol-gel based nanocomposite coatings derived from hydrolysis and condensation of a photopolymerizable silane precursor 3-Glycidoxypropyltrimethoxy silane in combination with zirconium-n-propoxide were deposited on mild steel substrates by a dip coating technique. In some cases, substrates were subjected to an atmospheric air-plasma surface pre-treatment prior to coating deposition. The coatings were subsequently densified by exposure to ultraviolet radiation followed by a thermal treatment at 250 °C. Characterization of the coatings with respect to thickness, water contact angle, pencil scratch hardness, adhesion and abrasion resistance was carried out. Corrosion testing was carried out on the coatings for a 1 h exposure to a 3.5% NaCl solution by electrochemical polarization and impedance measurements. The hybrid sol-gel coatings were found to improve the mechanical properties and corrosion resistance of mild steel. Plasma surface pre-treatment was found to improve the adhesion of coatings significantly and decreased the corrosion rate from 0.2652 mpy obtained for coatings without any surface pre-treatment to 0.0015 mpy, which was nearly 600 times lower than that of bare mild steel.