The inhibition efficiency of different species on AA2024/graphite galvanic coupling models depicted by SVET

The inhibition efficiency of several species on the corrosion of AA2024-T3/graphite galvanic coupling was determined in NaCl electrolyte. Two distinct galvanic coupling models with different anode/cathode area ratios were elaborated making use of a graphite rod or of a graphite foil. SVET was applied in order to directly measure the current densities related to galvanic corrosion processes. Inhibition efficiency rankings were established by calculating the average total currents from SVET data and by the galvanic currents provided by ZRA. The quantitative results together with optical analysis revealed that the most effective inhibitor system is the benzotriazole + 2-mercaptobenzothiazole + Tween-80.