A study of the initial stages of pitting formation on aluminum in alkaline chloride media using optical in situ microscopy and computer vision methods

The process of local corrosion of the aluminum surface in solutions of 0.1 M NaCl (pH 10–11.4) was studied. Data on the rates of local partial processes were obtained based on processing a series of images using computer vision methods. It is shown that the places of localization of defects are determined at the very beginning of the process and their location can be estimated in the first 10 min of the experiment. Based on changes in the diameter of hydrogen bubbles during the cathode process, the mass of aluminum dissolved during the anode process is calculated. The mass–time dependence is linear in semi-logarithmic coordinates and has the form m ~ tα. It is established that α changes during the process: for small times, α > 1; for large times, α < 1.