Localized corrosion of 2024 T351 aluminium alloy in chloride media

The corrosion behaviour of 2024 T351 alloy was investigated in 1M NaCl solution, the purpose being to understand the susceptibility of the alloy towards intergranular corrosion and other localised corrosion from potentiokinetic polarization curves. Tests on the alloy specimens consisted of potentiokinetic polarization of the samples from the cathodic potential of -900mV/SCE to the highest potential of -400mV/SCE. After polarization, the specimens were firstly examined by optical microscopy, then by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Energy dispersed spectrometry (EDS) analysis was performed during SEM and TEM to study intermetallic particle composition and to determine the composition of intergranular and other small precipitates. The polarization curve obtained showed two breakdown potentials. (Abstract quotes from original text)