Atomic layer deposition of TiO<sub>2</sub> and Al<sub>2</sub>O<sub>3</sub> thin films for the electrochemical study of corrosion protection in aluminum alloy cans used in beverage
V M Dias, William Chiappim, Mariana Amorim Fraga, Homero Santiago Maciel, Fernanda Roberta Marciano, Rodrigo Sávio Pessoa
Abstract
Abstract Titanium dioxide (TiO 2 ) and aluminum oxide (Al 2 O 3 ) thin films, with thicknesses around 100 nm, were grown on commercial pure- and resin-coated Al substrates using the atomic layer deposition (ALD). A comprehensive and comparative study of corrosion protection was carried out by linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) measurements for a set of six samples: two reference samples (Al-bare and Al-resin), and four ALD coated samples ( Al-TiO 2 , Al-Al 2 O 3 , Al-resin-TiO 2 , and Al-resin-Al 2 O 3 ). The LSV and EIS results display good mutual agreement, indicating a higher protection efficiency of all ALD-coated samples after immersion in NaCl. When compared to Al-bare, all ALD coated samples (TiO 2 or Al 2 O 3 ) showed a corrosion inhibition enhancement factor of 99%. Besides, our results demonstrated that Al-resin+Al 2 O 3 has 24.95% and 33.40% more corrosion inhibition than Al-Al 2 O 3 and Al-resin, respectively. EIS data were fitted by an equivalent electric circuit (EEC). The Nyquist and Bode plots from the experiments showed that ALD films are a potential candidate for altering/improving commercial resin-coated Al cans.