Predictive modeling of localized corrosion: An application to aluminum alloys

Corrosion prevention in light-weight alloys is currently an area of major research for civilian, aerospace, and defense applications. In order to understand thoroughly the complex corrosion system and hence develop effective and “green” corrosion prevention strategies, predictive modeling is believed to be an essential tool. This work presents a new finite element method (FEM)-based corrosion model, specifically tailored for localized pitting corrosion of aluminum alloys. The model distinguishes itself from existing ones by its strong predictive power and high generality. By resorting to this methodology, not only corrosion rate but also pit stability can be quantitatively evaluated for a wide range of systems involving heterogeneous alloy microstructure, complex pit morphology, and versatile solution chemistry. Moreover, the knowledge discovered can shed light on the control of pit repassivation, which will eventually lead to effective corrosion inhibition approaches. A thorough investigation of pitting corrosion of aircraft aluminum alloys is presented in order to demonstrate the efficacy and attractiveness of our method.

► Al corrosion around intermetallic particles.
► Pit growth dynamics correlated to corrosion rates.
► Changes in corrosion rates with pit morphology.
► 3D potential–pH diagrams with corrosion rate axis.
► Predictive modeling of corrosion rates for Al alloys.