Fatigue damage evolution and failure mechanism in pre-corroded AlSi10Mg fabricated by laser powder bed fusion

Abstract

This study investigates the fatigue damage evolution and failure mechanisms of pre-corroded AlSi10Mg alloy fabricated by laser powder bed fusion (L-PBF) through comprehensive multi-source experimental analyses. Combining techniques including 3D surface measurement, digital image correlation (DIC), and scanning electron microscopy (SEM), related experimental data on corrosion morphology, strain field evolution, and fracture characteristics were captured and correlated. Statistical and machine learning analysis on experimental data revealed that key factors, including corrosion level, surface roughness, and pit volume, significantly influence the location of macro-crack initiation. Five distinct micro-crack initiation mechanisms were identified, driven by a combination of corrosion morphology, internal manufacturing defects, underlying microstructures, localized embrittlement, and applied loading conditions. These findings provide critical insights into the interplay between corrosion features and fatigue failure in L-PBF AlSi10Mg alloy, offering valuable guidance for improving its mechanical properties in service environments.