Cryogenic property in laser powder bed fusion - fabricated Sc/Zr-modified Al-Li Alloys

This study is the first to investigate the mechanical properties and strengthening mechanisms of Sc/Zr-modified Al-Li alloys fabricated by laser powder bed fusion (LPBF) in cryogenic environments. The results show that this alloy demonstrates a substantially higher cryogenic yield strength than nearly all aluminum alloys reported in the literature. Meanwhile, low-temperature produced a significant plasticizing effect on the 1.2Sc-0.6Zr alloy. However, the high brittleness caused by coarse Al₃(Li,Sc,Zr) phase in the 1.8Sc-0.9Zr alloy limits its plastic deformation, preventing improvement in plasticity. Therefore, a precise balance between the brittleness induced by microstructural features and the cryogenic ductility enhancement is essential.