Corrosion behavior of high-strength aluminum alloys produced by laser powder bed fusion: A critical review

Laser powder bed fusion (LPBF) enables the fabrication of complex geometries that consist of microstructures distinct from those produced by conventional processing routes. In LPBF, the microstructure, processing-induced defects, and resulting properties (e.g. corrosion behavior) are governed by alloy composition and processing parameters. This review critically examines the current literature on the corrosion of aluminum alloys produced by LPBF, with a primary focus on moderate- to high-strength alloys. Emphasis is placed on the role of microstructural heterogeneity and how features such as secondary phase characteristics, grain structure, anisotropy, and post-processing heat treatments contribute to localized corrosion mechanisms. While some studies report enhanced corrosion resistance relative to conventional counterparts, others demonstrate increased susceptibility, highlighting the difficulty in isolating the effects of individual microstructural features. In evaluating recent findings, this review highlights the complexity and variability in the corrosion behavior of LPBF aluminum alloys and identifies key limitations in current experimental approaches. It also outlines critical knowledge gaps, including the need to evaluate service-relevant failure modes under application-relevant corrosive environments, that must be addressed to enable the reliable design of corrosion-resistant aluminum alloys for LPBF applications.