Shot noise and statistical parameters for the estimation of corrosion mechanisms

In this paper, electrochemical noise measurements on aluminium AA2014 are reported. Samples were exposed to a range of solutions to promote different corrosion rates and mechanisms. Subsequently, statistical parameters (electrochemical noise resistance, coefficient of variation of current and localization index) and parameters derived from shot noise theory (the low frequency limit of the amplitude of the noise impedance, Zn,f→0, the average charge in each event, q, and the frequency of events, fn) were obtained and related with the type and rate of corrosion. Finally, pairs of shot noise parameters were represented in maps to relate their values with the corresponding corrosion rates and mechanisms.