A New Finite Element Simulation Methodology for Analyzing the Mechano-Electrochemical Effects of Al Alloys

A new finite element simulation methodology for analyzing the mechano-electrochemical effects of Al alloys with intermittent measurement and reconstructed boundary conditions is proposed. It enables the simulation of the coupled mechano-electrochemical effects within the entire elastoplastic range of Al alloys. The model's accuracy was verified through measurements of galvanic current, coupled potential, and corrosion morphology. This study indicates that the non-uniform stress distribution on a metal surface results in inconsistent electrochemical properties, leading to the spontaneous formation of anodes and cathodes and facilitating galvanic corrosion. Regions with stress concentration act as anodes in the corrosion reaction, while other areas serve as cathodes. The electrolyte domain is approximately polarized to the same potential, but there are also minor differences between different regions. As the stress concentration gradually increases, the mixed potential decreases, leading to greater polarization and an accelerated corrosion reaction rate. The galvanic current and the coupled potential calculated by the model differ from the measured values by less than 15%. Moreover, the observed corrosion morphology is consistent with the calculated results, indicating that the model provides good predictions of coupled mechano-electrochemistry.