Applications of Liquid Cell-TEM in Corrosion Research; Recent Trends and Advancements in Spectroscopic and Microscopic Techniques

A fundamental understanding of corrosion at the nanometer scale is needed to develop physics-based predictive models of the corrosion mechanisms. Recent advancements associated with in-situ Transmission Electron Microscopy (TEM) liquid cell experiments, also known as liquid phase experiments, in the last twenty years has permitted the real time nanoscale observation of mechanisms in a range of complex materials and liquid environments. In all of these experiments, caution and care must be taken to understand the impact of the liquid cell dimension and electron beam effects on the observed reactions. Despite these cautions, over the last seven years, in-situ TEM liquid cell experiments have been expanded to experiments exploring corrosion initiation. The early studies explored simple deposited high purity metal systems exposed to deionized water, brine, or acetic acid; however, the more recent studies have shown that experiments can be performed on complex environments like site-specific regions of pipeline steel in a range of tailored corrosive environments. During this time, the number and refinement of the analytical techniques utilized during the in-situ TEM corrosion experiment has also increased, providing insight into the evolving sample thickness, composition, crystallographic orientation, bonding structure, and much more. This chapter concludes with a discussion of the potential expansion of in-situ TEM corrosion to such complex degradation phenomena, such as stress corrosion cracking and biofouling.