Phase composition and mechanical properties of wrought aluminum alloys of the system Al-Cu-Mg-Ag-Xi

Microstructure and Properties of an АА 2139 Alloy Welded Joint Produced by Linear Friction Welding

“…Different phases can be found in it depending on treatment. The phases are Ω, θ″, θ′(Al2Cu), S′(Al 2 CuMg) and T(Al 6 CuAgMg 4 ) [10,11]. During LFW metal heating combined with plastic deformation can lead to change in the phase composition at the expense of dissolution or precipitation of different phases.…”

Low-cyclic fatigue behaviour of an Al–Cu–Mg–Ag alloy under T6 and T840 conditions

“…[1][2][3][4][5][6][7][8] Thus, these alloys are traditionally subjected to a T8 temper that involves small strains (<10%) prior to ageing. 1,3,[5][6][7][8] In Al-Cu-Mg-Ag alloys in the T8 process, the cold working has resulted in a high density of dislocations and significantly increased the number density of the θ ′ -phase, which forms rectangular or octagonal plates that are parallel and semi-coherent to the {100} α planes on lattice dislocations at the expense of the Ω-phase.…”

“…Age-hardenable aluminium alloys that belong to the Al-Cu-Mg-Ag system (2XXX series) are used in the aerospace industry because of their attractive combination of high specific strength, good fracture toughness and superior creep resistance, which can be attributed to the highly efficient strengthening by the Ω-phase. [1][2][3][4][5][6] This precipitate forms as a uniform dispersion of thin, hexagonal plates with large aspect ratios (diameter/thickness) on {111} α habit planes and has a coherent structure of broad faces. [3][4][5][6] Several structures for the Ω-phase have been proposed, although the most widely accepted structure is orthorhombic (Fmmm, a = 0.496 nm, b = 0.859 nm, c = 0.848 nm), which has very small differences in its atomic coordinates compared with the equilibrium θ-phase (Al 2 Cu, body-centred tetragonal lattice, I4/ mcm, a = b = 0.6066 nm, c = 0.495 nm) in Al-Cu alloys.…”

“…[1][2][3][4][5][6] This precipitate forms as a uniform dispersion of thin, hexagonal plates with large aspect ratios (diameter/thickness) on {111} α habit planes and has a coherent structure of broad faces. [3][4][5][6] Several structures for the Ω-phase have been proposed, although the most widely accepted structure is orthorhombic (Fmmm, a = 0.496 nm, b = 0.859 nm, c = 0.848 nm), which has very small differences in its atomic coordinates compared with the equilibrium θ-phase (Al 2 Cu, body-centred tetragonal lattice, I4/ mcm, a = b = 0.6066 nm, c = 0.495 nm) in Al-Cu alloys. 1,2,[4][5][6][7] It has been established that the Ag and Mg atoms segregate on the board interfaces of the Ωphase plate and provide a coherence structure of current boundaries.…”

“…[3][4][5][6] Several structures for the Ω-phase have been proposed, although the most widely accepted structure is orthorhombic (Fmmm, a = 0.496 nm, b = 0.859 nm, c = 0.848 nm), which has very small differences in its atomic coordinates compared with the equilibrium θ-phase (Al 2 Cu, body-centred tetragonal lattice, I4/ mcm, a = b = 0.6066 nm, c = 0.495 nm) in Al-Cu alloys. 1,2,[4][5][6][7] It has been established that the Ag and Mg atoms segregate on the board interfaces of the Ωphase plate and provide a coherence structure of current boundaries. 1,2,[4][5][6][7] The edges of the Ω plates can lose coherency through thickening of the plates during ageing.…”