Corrosion inhibition of Elektron WE43 magnesium alloy in NaCl solution

Abstract

Magnesium alloys have a wide range of applications but suffer low corrosion resistance. One of the most accessible ways to protect metals from corrosion, which can also be combined with other methods, is the use of corrosion inhibitors. The effect of 1,2,3-benzotriazole, 5-chloro-1,2,3-benzotriazole and sodium dioctyl phosphate on the corrosion of Elektron WE43 magnesium alloy in 0.05 M NaCl solution was studied using polarization and EIS measurements. Azoles do not exhibit the inhibitive action towards the WE43 alloy, but they slightly reduce the barrier effect of the film of corrosion products. Sodium dioctyl phosphate (DOP) is an effective inhibitor due to its anionic nature. It mainly inhibits the anodic dissolution of the alloy and has a slight effect on the cathodic process. DOP enhances the protective effect in time due to improvement of protective films. An increase in DOP concentration depresses the anodic dissolution of the alloy as well as the local depassivation, which is characterized by a displacement of the pitting potential in the positive direction. Scanning vibrating electrode technique (SVET) measurements confirmed the effectiveness of DOP as a corrosion inhibitor for Electron WE43 alloy.