Microbiologically influenced corrosion of copper and its alloys: A review

Copper and its alloys are indispensable engineering materials, prized for their exceptional electrical and thermal conductivity. However, their long-term performance is increasingly threatened by microbiologically influenced corrosion (MIC), an issue that has garnered significant scientific attention in recent years. This review comprehensively synthesizes the current state of knowledge on this critical topic. This review begins by outlining the historical context of research into the MIC of copper and its alloys, and illustrates the issue with case studies from a variety of service environments. Then, the underlying mechanisms by which microorganisms facilitate corrosion are elucidated, and the key factors modulating corrosion behavior, encompassing environmental conditions (e.g., pH value, nutrients, gas-liquid partitioning, and electron shuttles), material characteristics (alloy composition and microstructure), and the role of stress are critically examined in the review. After that, the current protective strategies, including cathodic protection, green corrosion inhibitors, and biocides, are evaluated. Finally, the critical knowledge gaps and proposed priority directions for future research are identified. This work aims to provide a fundamental theoretical framework for understanding the MIC of copper and its alloys and to inform the development of effective mitigation strategies for both scientific investigation and engineering practice.