Evaluation of inhibition effect on microbiologically influenced corrosion of Ti-5Cu alloy against marine Bacillus vietnamensis biofilm

Titanium is highly susceptible to biofouling due to the poor toxicity and excellent biocompatibility. Microbiologically influenced corrosion of cp-Ti induced by Bacillus vietnamensis and the inhibition effect of Ti-5Cu alloy were evaluated using various electrochemical techniques and surface analyses. Electrochemical results revealed that, cp-Ti and Ti-5Cu alloy exhibited excellent passivation in the sterile medium. In biotic medium, however, attachment of B. vietnamensis biofilm to surface of cp-Ti accelerated the active dissolution and poisons repassivation. In contrast, cells adhered preferentially as a form of discrete colonies on Ti₂Cu intermetallic phases. Release of Cu²⁺ ions induced damage in morphology of B. vietnamensis cells resulting in relative resistance to pitting corrosion estimated by 3.1 ± 0.6 µm and 2.0 ± 0.4 µm for cp-Ti and Ti-5Cu alloy, respectively.