Abstract
Aluminum and its alloys are widely used in so many applications owing to their important characteristics. The use of aluminum gets limited due to its corrosion when exposed to aggressive environments, especially those containing chloride ions. In this work, the effects of 3-amino-1,2,4-triazole-5-thiol (ATAT) on the inhibition of unalloyed aluminum of corrosion in aerated stagnant 3.5 wt.% NaCl solution as a corrosion inhibitor was studied. Cyclic potentiodynamic polarization (CPP), potentiostatic current-time (CCT), and electrochemical impedance spectroscopy (EIS) were employed. CPP measurements showed that Al in 3.5 wt.% NaCl suffers both uniform and pitting corrosion; the presence of ATAT and the increase of its concentrations inhibit this corrosion by decreasing the corrosion current and corrosion rate and increasing the polarization resistance of Al. The CCT experiments at -680 mV vs. Ag/AgCl indicated that ATAT decreases the absolute current values for Al. EIS data concluded that the surface and charge transfer resistances for Al increase by the addition and upon the increase of ATAT concentration.