Additive manufacturing of an ultrastrong, deformable Al alloy with nanoscale intermetallics

• Published in: Nature communications 2024-06, Vol.15 (1), p.5122-12
• Main Authors: Shang, Anyu, Stegman, Benjamin, Choy, Kenyi, Niu, Tongjun, Shen, Chao, Shang, Zhongxia, Sheng, Xuanyu, Lopez, Jack, Hoppenrath, Luke, Zhang, Bohua Peter, Wang, Haiyan, Bellon, Pascal, Zhang, Xinghang
• Format: Article
• Language: English
• Subjects: 147/143; 639/166/988; 639/301/1023/1026; 639/301/1023/303; Additive manufacturing; Alloys; Aluminum; Aluminum base alloys; Compression; Compression tests; Compressive strength; Deformability; Deformation analysis; Dislocation; Entropy; Formability; High strength alloys; Humanities and Social Sciences; Industrial applications; Intermetallic compounds; Lamella; Laser beam melting; Manufacturing; multidisciplinary; Science; Science (multidisciplinary); Solidification; Stacking faults; Yield strength
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-48693-4

Light-weight, high-strength, aluminum (Al) alloys have widespread industrial applications. However, most commercially available high-strength Al alloys, like AA 7075, are not suitable for additive manufacturing due to their high susceptibility to solidification cracking. In this work, a custom Al alloy Al 92 Ti 2 Fe 2 Co 2 Ni 2 is fabricated by selective laser melting. Heterogeneous nanoscale medium-entropy intermetallic lamella form in the as-printed Al alloy. Macroscale compression tests reveal a combination of high strength, over 700 MPa, and prominent plastic deformability. Micropillar compression tests display significant back stress in all regions, and certain regions have flow stresses exceeding 900 MPa. Post-deformation analyses reveal that, in addition to abundant dislocation activities in Al matrix, complex dislocation structures and stacking faults form in monoclinic Al 9 Co 2 type brittle intermetallics. This study shows that proper introduction of heterogeneous microstructures and nanoscale medium entropy intermetallics offer an alternative solution to the design of ultrastrong, deformable Al alloys via additive manufacturing. Commercial high-strength Al alloys often suffer from cracking during additive manufacturing. Here, the authors present an additively manufactured, a strong and plastically deformable Al alloy with heterogeneous nanoscale intermetallics.