Electrochemical Investigations of the Activation Mechanism of Aluminum

The aim of this work was to study the activation mechanism of pure aluminum in the absence and presence of indium ions in a chloride-containing medium using the electrochemical noise technique. A correlation was obtained between the noise response and the type of corrosion morphology observed by scanning electron microscopy (SEM). Noise measurements were compared with electrochemical impedance data for an aluminum-zinc-indium alloy (Al-5Zn-0.5ln) in a chloride solution. Polarizing conditions when indium ions are present promote chloride adsorption, which is responsible for the initiation of the activation process.