Chemical approach to inhibit dezincification of Cu‐based alloys Available to Purchase

The inhibition effect and mechanism of benzotriazole 2‐mercaptobenzothiazole with and without the addition of thiourea on dezincification of Cu‐based alloys have been studied. The measurement were carried out in the solution of 3.5% NaCl with 0.025% Na2SO44 at pH adjusted to 3.53 and at 29° and 60°C. Electrical measurements were conducted galvanostatically (2.14 mA/cm2) and potentiostatically (−200 mV vs. SCE) for 3 hr in the test solution. The performance of the inhibitor were assessed in terms of (1) dissolution of Cu/Zn during polarization and (2) electric charge measurement. The inhibition efficiency calculated from electric charge was in good conformity with the results of chemical analysis of Cu/Zn dissolution during polarization in the test solution. The results were discussed in the light of adsorption theory.