Self-assembly molecules (SAM - Self Assembly Monolayer) are corrosion inhibitors, due to their capacity to organize on surfaces, forming thin films. SAM presents a high affinity to aluminum oxide. However, the interactions between the oxide layer and SAM are not always satisfactory; therefore the oxide formed on the surface presents heterogeneities that hinder SAM film formation. The aim of this work was to study the corrosion protection of aluminum AA 2024-T3 associated with SAM, after treatment with alkaline degreasing. The electrochemical characterization was carried out by electrochemical impedance spectroscopy and anodic potentiodynamic polarization in Na2SO4 0,5 mol.L-1 in pH 4,0. The superficial morphology was investigated by optic microscopy. The results showed that SAM promoted greater aluminum protection when this was pretreated with degreasing.
Aluminum alloy; self-assembly monolayers; corrosion