Accelerated development of Ti-6Al-4V microbial corrosion triggered by electroactive sulfate-reducing Desulfovibrio ferrophilus biofilm in enriched artificial seawater containing soluble electron shuttle

In this work, microbial corrosion behavior of Ti-6Al-4V (TC4) alloy caused by electroactive Desulfovibrio ferrophilus biofilm in enriched artificial seawater containing soluble electron shuttle was investigated. The addition of riboflavin-shuttle did not significantly change the planktonic and sessile cell counts but accelerated the microbiologically influenced corrosion of TC4 alloy. The Hilbert-Huang transform revealed the evolution of corrosion pits and the maximum pit depth enhanced with the increase of electron shuttle concentration. Electrochemical measurements proved that riboflavin-shuttle decreased the shuttled electron barrier and increased the anodic dissolution rate. Phase, organization and grain size of alloy were influenced by the MIC.