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. Microbio-logically 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 repassi-vation. 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 mu m and 2.0 +/- 0.4 mu m for cp-Ti and Ti-5Cu alloy, respectively.