(Corrosion Division H. H. Uhlig Award) A Journey From Ice-Breakers to Biomedical Implants: Multifacets of Corrosion

Abstract

Understanding of corrosion mechanisms enables safe, durable and sustainable application of metallic materials in various fields. The presentation will shortly summarize a personal selection of most important lessons learned in the last 30 years of corrosion research, and then highlights some recent developments for methodologies to study atmospheric and immersion corrosion by respirometry. The approach is based on monitoring the rate of cathodic reactions with help of different types of sensors; this enables a real-time, simultaneous quantification of the rate of the O2 reduction reaction (OER) and the H2 evolution reaction (HER). The respirometric setups can be coupled with electrochemistry, enlarging the corrosion cases to be studied from open-circuit conditions to potential-controlled systems. Examples will be presented, to illustrate the potential of these techniques to reveal insights on corrosion mechanisms of active (e.g. Mg and Zn) and passive metals and alloys (e.g. stainless steels). For passive metals and alloys, special focus in this presentation will be on transpassive dissolution. In essence, three processes can take place in this potential regime: metal dissolution, oxide film formation, and oxygen evolution from water oxidation. In this case, respirometric determination of the oxygen evolution reaction (ORR) helps to distinguish the current (charge) consumed for metal oxidation reactions vs. water oxidation. Most recent developments to enable high-resolution respirometric measurements – and hence to study corrosion in the passive state and its localized breakdown – will be presented.