Additive manufacturing of AlCrFeNi alloys: Correlation between composition, formability, and corrosion resistance in lead-bismuth eutectic

To ensure the long-term reliability of pressure vessels in lead-cooled fast reactors (LFRs) exposed to lead–bismuth eutectic (LBE) environments, developing corrosion-resistant materials with superior formability and LBE compatibility has become a critical research priority. In this study, 30 AlCrFeNi alloys with varying Al and Cr contents were prepared using directed energy deposition (DED) from elemental powders. The effects of alloy composition on formability, microstructure, and corrosion resistance were investigated. The results indicated that the FCC phase exhibited a preferential tendency toward corrosion, whereas the intergranular distribution of BCC/B2 phases can suppress dissolution within the FCC. The designed Al_17.825Cr₁₇FeNi alloy exhibited a relatively thin oxide layer, with a dense Al₂O₃–Cr₂O₃ passive layer formed on its surface. This work demonstrated a synergistic optimization of composition and properties in AlCrFeNi alloys, while additive manufacturing allows an effective increase in the thickness of corrosion-resistant layer, highlighting its potential for advanced nuclear structural materials.