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[Display omitted] • A novel Al-Cu-Li-Mg-Ag-Sc alloy was fabricated by direct energy deposition. • Dual-phase strengthening of Al 3 Sc and T 1 phases can be achieved with a single-stage T6 heat treatment. • The excellent compressive yield strengths achieved 512, 345 and 227 MPa at 20, 200 and 300 °C, respectively. • Al 3 Sc and T 1 phases can maintain strong pinning effects on dislocations. In this work, precipitation and deformation behavior of a novel Al-Cu-Li-Mg-Ag-Sc alloy fabricated by direct energy deposition (DED) were investigated in detail. Dual-phase strengthening of Al 3 Sc and T 1 (Al 2 CuLi) phases can be achieved with a single-stage T6 heat treatment compared to normal double-aging. The excellent compressive yield strengths achieved 512, 345 and 227 MPa at 20, 200 and 300 °C, respectively. Al 3 Sc and T 1 phases can maintain strong pinning effects on dislocations, suggesting a good work hardening ability during deformation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Quasi-crystalline T 2 phase precipitates for 2A97 Al-Li alloy produced by laser additive manufacturing. • Under influence of thermal cycle, T 2 phase transforms into face-centered cubic Y phase. • T 2 phase turns into O phase with orthorhombic at 515 °C for 1.5 h during solution treatment. Precipitated phases of 2A97 Al-Li alloy fabricated by laser additive manufacturing with thermal input are mainly composed of quasicrystal T 2 phase gathered around grain boundary and T B phase in grain interior. Diffraction patterns of quasi-crystalline T 2 phase show two-fold, three-fold and five-fold symmetry, respectively. Under condition of thermal cycling, T 2 phase transforms into a face-centered cubic Y phase with a lattice constant of 2 nm. Y phase can grow into twins, and the twin plane is (1 1 1). After solution treatment at 515 °C for 1.5 h, δ' phase, T 1 phase and T B phase are completely dissolved in matrix, while quasi-crystalline T 2 phase transforms into orthorhombic O phase. The size of O phase is similar to that of T 2 , with length of about 400 nm and rougher surface. [ABSTRACT FROM AUTHOR]