Predicting pitting corrosion behavior in additive manufacturing: electro-chemo-mechanical phase-field model

Abstract

Additive manufactured (AM) parts are usually subjected to residual stress and anisotropic microstructures, causing not only unique mechanical properties, but corrosion behaviors. In this study, an electro-chemo-mechanical phase-field model is employed to predict the pitting corrosion evolution in AM products, in which stress state and electrochemical reaction rates are intimately coupled. The anisotropic corrosion behavior is observed when the impact of grain orientations is considered. Residual tensile stress promotes anisotropic corrosion behaviors, generating a detrimental spike-like corrosion pit; however, residual compressive stress lessens the impact of microstructures, causing a corrosion pit more elliptical and symmetrical in shape.