Abstract: Additive manufacturing provides an opportunity to efficiently produce the structure- performance integrated forming of aluminum alloy components, which has long been a primary objective in the aerospace and automobile industries. However, achieving nearly fully dense additive manufacturing of high-strength aluminum alloys remains a major challenge because of their high cracking sensitivity. In this study, an Al-Fe-V-Si-Sc alloy was designed and prepared by laser powder bed fusion (LPBF). The extremely high cooling rate and thermal gradient during the LPBF process facilitate the formation of a unique hierarchical heterostructure. The amorphous/crystal composite structure, located at the molten pool center, along with various nanoscale precipitates present at the molten pool boundary, can provide strengthening effects to this alloy, thereby conferring ultrahigh strength on the alloy at both room temperature and elevated temperatures. These findings offer valuable insights into the design of additively manufactured aluminum alloys, holding great promise for the advancement of aerospace components.

Key words: Laser powder bed fusion, Al-Fe-V-Si-Sc alloy, Microstructure, Mechanical properties