A phase-field modeling for viscoplastic corrosion fracture of SAC305 solder alloy

Corrosion-assisted fracture is a dominant degradation mechanism in lead-free solder alloys and poses a serious risk to the reliability of electronic packaging systems. Despite its importance, the interaction between corrosion damage, viscoplastic deformation, and fracture remains insufficiently addressed. This study examines the coupled corrosion-fracture response of SAC305 solder alloy under low strain-rate loading at ambient conditions using combined experimental and numerical approaches. A unified phase-field formulation is implemented in ABAQUS through user-defined UEL and UMAT subroutines, enabling direct coupling between corrosion pit evolution and fracture processes. Numerical results are compared with tensile tests on pre-corroded specimens, showing close correspondence in pit morphology and associated strength reduction. The findings elucidate the combined roles of localized corrosion and viscoplastic flow in ductile failure and quantify the influence of strain rate on corrosion-induced mechanical degradation. The proposed framework enables quantitative assessment of solder joint integrity following corrosive degradation under subsequent mechanical loading.