Development of an ICME Approach for Aluminum Alloy Corrosion

Corrosion costs the United States over $1 trillion annually, yet is typically not analyzed at a detailed level during the product design phase. Our vision is to develop robust corrosion performance modeling tools that will ultimately enable us to predict corrosion behavior and generate composition-processing-structure-performance relationships that can be integrated into the product design standard work for product corrosion liability, and reduction of both the design cycle duration and cost. Our approach links modeling and experiments with verification and validation by coupling thermodynamic and kinetic modeling of alloy processing, phase-specific electrochemical characterization, and a multi-physics model description of the localized electrochemical properties such as corrosion current density. Material composition, processing conditions, and environmental exposure will serve as inputs to the predictive corrosion modeling. An initial application of this methodology on aluminum alloy will be presented and exemplary guidance on how the heterogeneity of the intermetallic (IM) particles within the alloy influence the alloy electrochemical response will be discussed. By understanding the phase-specific electrochemical response through measurements and density functional theory calculations, the impact of variations in alloy composition and processing can be related to the corrosion performance. Combining the intermetallic phase descriptions with the electrochemical response into a multi-physics model will then allow us to interrogate effects such as IM particles composition, size and distribution on the electrochemical response to guide alloy modification for corrosion risk mitigation.