Corrosion Kinetics of Aluminum in Trichloracetic Acid

The methods of weight-loss, polarization curve and kinetic analysis were used to investigate the corrosion behavior of aluminum in trichloracetic acid (TCA) solutions. The influences of the concentration and temperature of TCA on the corrosion rate of aluminum were analyzed. The corrosion kinetic equation was formulated and the corresponding kinetic parameters were calculated. The corrosion potential and corrosion current density were tested. The mechanism of the anodic dissolution and cathodic hydrogen evolution on aluminum were discussed. The results indicated that the corrosion of aluminum showed an even rate and activation control in the studied concentration range. The relationship between corrosion temperature and rate followed Arrhenius formula, and the relationship between TCA concentration and corrosion rate followed Mathur formula. The theoretical and experimental kinetic equations of cathodic reaction and anodic reaction were consistent. The results of the polarization curves were in concordance with those of weight-loss tests. These results showed that there was no passivation layer on aluminum surface.