Multiscale simulations of electrochemical corrosion at metal-solution interfaces

Corrosion and chemical degradation of metals in the presence of water carry significant cost burdens, both for structural applications and for components in functional devices. The earliest stages of degradation are often difficult to characterize, making computational methods imperative for assessing structure-property relations if the large range of spatiotemporal scales can be spanned. Moreover, the governing processes occur at solid-liquid interfaces that are dynamically and compositionally complex, involving a surface oxide that ultimately determines passivity. Our team has been developing and applying multiscale approaches, combined with detailed characterization, to understand early-stage metal degradation in complex chemical and electrochemical environments. I will showcase examples of how first-principles simulations are being combined with kinetic Monte Carlo approaches, advanced statistical sampling, and microstructure-level simulations to better understand the factors that govern loss of metal passivity at solid-liquid interfaces. The role of dynamically evolving surface oxide compositions will be discussed, as well as microstructural factors that control interfacial dissolution and reprecipitation kinetics. The examples will focus on degradation of Al- and NiCr-based alloys.

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.