Effect of 2-mercaptobenzothiazole on the corrosion inhibition of Cu-10Ni alloy in 3 wt% NaCl solution

2-Mercaptobenzothiazole (MBT), a heterocyclic compound, is a remarkable corrosion inhibitor for pure Cu. Among different copper-based alloys, Cu-Ni alloys are used in a wide range of applications in industries that are exposed to the corrosive environment and making them prone to corrosion. In the current study, the effect of 2-Mercaptobenzothiazole (MBT) concentration on the corrosion inhibition of Cu-10Ni alloy in 3 wt% NaCl solution was studied using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and weight loss methods. SEM and XPS were also used for surface characterization. Results of different methods were in good agreement and showed that MBT enhances the corrosion resistance of the alloy at concentrations of 60 and 80 ppm. At the concentration of 40 ppm, MBT deteriorates the corrosion resistance. Maximum inhibition of about 92% was achieved for the concentration of 80 ppm. MBT acts as a mixed-type inhibitor, and the N atom and exocyclic S atom of the MBT are involved in the molecule adsorption. The role of MBT in corrosion inhibition was attributed to the role of adsorbed inhibitor film, which hinders the Ni Dealloying.

Automated summary

This study found that 2-Mercaptobenzothiazole (MBT) can enhance the corrosion resistance of Cu-10Ni alloy at certain concentrations, but deteriorate it at others. The maximum inhibition rate achieved was around 92%.