Physics based modeling to understand and predict atmospheric and galvanic corrosion in aerospace components (RIP2026-00071)

Ganesh Arumugam, Venkat Kamavaram, Suthee Wiri, Christopher Ong

Oceanit, Applied Research Associates (ARA), Applied Research Associates Inc

Galvanic corrosion is a critical challenge in aerospace design, particularly for aircraft operating in harsh marine environments. Currently, methods for assessing galvanic compatibility rely on immersion testing or simplified models that fail to capture the complexities of three-dimensional geometries, occluded regions, and thin-film atmospheric conditions. The absence of computational tools tailored to aerospace-relevant materials and geometries limits the ability of engineers to make informed design choices early in the development process, potentially leading to costly redesigns and retrofitting efforts. In this presentation a physics-based model for predicting atmospheric and galvanic corrosion using dynamic electrolyte film corrosion (DEFC) model will be presented. DEFC model simulates thin film electrolyte thickness evolution under dynamic atmospheric conditions such as relative humidity (%RH), temperature, salt content to estimate corrosion rates and mass loss. The model was validated using published data and accelerated corrosion testing was used to simulate long term weathering as per ASTM B117 Salt fog and GMW 14872 cyclic corrosion testing. Evaluation was focused on atmospheric, pitting and galvanic corrosion on aluminum alloy 2024-T3, 7075 with steel A286 and titanium Ti64 fasteners. Environmental data from test sites, chloride concentration, relative humidity etc., were plugged in to the model to achieve excellent corrosion rate predictions matching the published corrosion data from various test sites. Accelerated corrosion testing parameters were also used to predict mass loss which matched the actual mass loss measured from corrosion test coupons. Based on the DEFC model a strong correlation between environmental factors in the outdoor and accelerated testing has been demonstrated. Details on the model development and correlations between outdoor, accelerated testing and predicted mass loss from corrosion will be presented.