The Influence of Benzotriazole on the Electrochemical Behavior of the AgCu50 Alloy in a Chloride Medium

摘要

The effect of benzotriazole (BTA) on the electrochemical behavior of the alloy AgCu50 (50 wt % Ag + 50 wt % Cu) in 0.5 M NaCl solution was investigated. Electrochemical behavior of pure copper, pure silver, as well as AgCu50 alloy, were studied under the same conditions for comparative analysis. The effect was studied by measuring the open circuit potentials as well as by using anodic potentiodynamic polarization and potentiostatic method. The value of open circuit potential for the alloy AgCu50 is between the potentials for pure silver and pure copper. SEM and EDS analyses were performed after potentiostatic treatment. Five current peaks were detected on the anodic polarization curve for alloy in 0.5 M NaCl. The addition of BTA in concentrations above 0.005 M decreases the current in investigated potential range and almost completely passivates the AgCu50 alloy. The results of potentiostatic investigations indicate that the mechanism of inhibiting effect depends on the benzotriazole concentration in electrolyte. Better effect of inhibition is achieved with the higher concentration of BTA. The results obtained by SEM and EDS analyzes show that in the presence of BTA amount of corrosion products decreases.