Sažetak
In the present work the corrosion protection of aluminium alloy AA2024-T3 has been studied in NaCl solution, with and without the addition of cerium (III) chloride heptahydrate. The corrosion inhibitor efficiency after immersion into 10 mM NaCl, with or without 3 mM of CeCl3·7H2O at 20 °C, 40 °C and 60 °C were investigated. Performed quantitative tests include electrochemical techniques, such as method of quasi-potentiostatic polarization (Tafel extrapolation), Cyclic polarization and Electrochemical Impedance Spectroscopy (EIS) to determine corrosion rate (vcorr), inhibition efficiency (η %), protective ability (γ), degree of coverage (ϑ) and pitting nucleation resistance. The samples were analyzed with Scanning Electronic Microscopy (SEM) and Energy Dispersive X-Ray Analysis (EDX) to evaluate and characterize formed precipitates on the surface of aluminium samples and to determine dominate type of corrosion. The formation of Ce3+ precipitates occurred on cathodic intermetallic (IMC) sites and the surface in general resulted in improved corrosion resistance. Tested cerium (III) chloride heptahydrate proved to be an effective inorganic corrosion inhibitor for AA2024-T3 in chloride solution, which by the action of cerium ions, reduced corrosion on the surface of the studied aluminum alloy.
Ključne riječi
Aluminium alloy ; Chloride solution ; Cerium (III) chloride heptahydrate ; Electrochemical techniques ; Pitting corrosion