Synergistic effect of chloride ion and Shewanella algae accelerates the corrosion of Ti-6Al-4V alloy

摘要

The increasing utilization of titanium alloys in marine environments makes their microbiologically influenced corrosion study a timely matter.This work demonstrated that the corrosion ofTi-6 Al-4 V alloy was accelerated by a marine bacterium Shewanella algae in 2216 E medium with different Cl-level.Various electrochemical,pitting morphology and passive film analyses demonstrated that S.algae weakened the passive film,which made Cl-more aggressive.The synergy of those two factors caused considerable corrosion acceleration of the titanium alloy,leading to a maximum pit depth of 3.2μm and corrosion current density of 26.5 nA cm_(-2) in 2216 E medium with 3.50%(w/w)Cl^(-).