Anodic behavior in AlCl3-EMIC ionic liquid of Ti6Al4V alloy and its application for enhancing the adhesion strength of aluminum coatings

In this paper, we studied the anodic behavior of Ti6Al4V electrode samples in 2:1 acidic AlCl3-1-ethyl-3methyl-imidazolium chloride (AlCl3-EMIC) ionic liquid. Linear sweep voltammetry, chronoamperometry and galvanostatic polarization were carried under different conditions and the electrodes surfaces were analyzed with SEM and EDS. The passivation layers observed on the electrode were also analyzed through Raman spectroscopy. On the basis of these anodic behavior results, the electrodeposition of protective Al coating on Ti6Al4V alloys was performed after different electrolytic etching pretreatments and the results were discussed. The etching pretreatments resulted in the complete removal of surface oxides and an irregular surface morphology, which consequently increased the adhesion strength of the protective coatings to the substrates.