Researchers from RWTH Aachen University, Aachen, Germany, recently published an open-access paper focusing on the use of Al-Cu-Li alloys and their place in Additive Manufacturing.
The high strength and lightweight benefits of Al-Cu-Li alloys are said to make them attractive for aerospace applications. The major strength-contributing phase is the T1(Al2CuLi) phase. While extensive reporting has been done on its nucleation behaviour and structure in conventional T1 microstructures, little has been done in regard to T1 as it pertains to Additive Manufacturing.
‘Characterisation of T1(Al2CuLi) Precipitates in Conventional (2099-T83) and Laser Additive Manufactured (PBF-LB/M, DED-LB/M) Microstructures’ focuses on the comparative characterisation of the T1 phase (structure, nucleation behaviour) in conventional (2099-T83) Laser Beam Powder Bed Fusion (PBF/LB) and laser-based Directed Energy Deposition (DED) AA2099 microstructures.
The paper reported that the use different Additive Manufacturing technologies and heat treatments allows the achievement of different T1 microstructures. After 3% cold work and artificial aging (150°C), intragranular T1 plates that nucleated on dislocations were characterised in AA2099-T83. In DED single track with in-situ preheating, characterised microstructures showed grain boundary T1.
In room-temperature, cladded DED single tracks, intragranular T1 plates were formed after the application of T6 heat treatment. For In-situ-preheated (500°C) PBF-LB, the T1 plates were found to nucleate on intermetallic phase.
‘Characterisation of T1(Al2CuLi) Precipitates in Conventional (2099-T83) and Laser Additive Manufactured (PBF-LB/M, DED-LB/M) Microstructures’ was originally presented as part of the 44th Risø International Symposium on Materials Science (RISO 2024), Roskilde, Denmark, and has been published as part of the IOP Conference Series: Materials Science and Engineering series.
The full paper is available here.
