Study on the Corrosion Resistance of Sn/Zr_(0.74)Y_(0.16)Ti_(0.10)O_(2-δ) Composite Coatings Electrodeposited on Carbon Steel in Acidic Medium

摘要

In this work the corrosion resistance of Sn/Zr_(0.74)Y_(0.16)Ti_(0.10)O_(2-δ) composite coatings electrochemically co-deposited from SnCl2solutions containing 4-amino'-N-(l,3-thiazole-2-yl) benzensulphonamide was evaluated and compared to the pure Sn coatings one. The corrosion resistance 0.1 M HCl solution was investigated using two electrochemical techniques: Tafel polarisation and electrochemical impedance spectroscopy (EIS). The surface morphology was examined using a metallographic microscope. Taf el polarisation showed that the insertion of Zr-based mixed oxide (Zr_(0.74)Y_(0.16)Ti_(0.10)O_(2-δ)) in solution disrupts the cathodic reaction and reduces in a significant manner the anodic reaction, leading to a considerable decrease of corrosion currents. The polarization resistance values obtained from Nyquist diagram confirm a much better protection of carbon steel in the presence of Zr-based mixed oxide. The microscopic images show the presence of distinct layers on carbon steel surface in the absence and presence of Zr based mixed oxide.