Analysis of electrochemical noise and physical model of corrosion process of Al–Zn–In series alloys in NaCl solutions

The corrosion process of Al–5Zn–0·02In–1Mg–0·05Ti (wt-) alloy was investigated by electrochemical noise. The corroded surfaces of the alloy were observed by scanning electron microscopy. The electrochemical noise data obtained from the corrosion process were analysed using shot noise theory. The pitting and uniform corrosions were confirmed by cumulative probability F [F = (fn)] versus the frequency of events fn. The Weibull probability plots show the three corrosion stages for the alloy: pitting, pitting and dissolution–precipitation and uniform corrosion. The physical model for the corrosion process has been developed.