Al₁₁Ce₃ nano-network regulating micro-galvanic corrosion in Al–Ce-Mg alloy fabricated by laser powder bed fusion

Localized corrosion in multiphase aluminum alloys is governed by micro-galvanic coupling between intermetallic phases and the Al matrix. Here, an Al-Ce-Mg alloy containing an in-situ Al₁₁Ce₃ nano-network was fabricated via laser powder bed fusion to clarify the role of intermetallic morphology in corrosion behavior. Electrochemical measurements show that the as-built alloy exhibits an order-of-magnitude lower corrosion current density and higher polarization resistance than the heat-treated alloy. Scanning Kelvin probe force microscopy reveals that the nano-network reduces the potential difference between Al₁₁Ce₃ and the Al matrix from ∼111 mV to ∼26 mV. Meanwhile, XPS and TEM analyses reveal the formation of a compact CeO₂-rich passive film that suppresses micro-galvanic corrosion and enhances corrosion resistance.