The mechanism of comprehensive properties enhancement in Al–Zn–Mg–Cu alloy via novel thermomechanical treatment

Tuning homogenization of high-strength aluminum alloys through thermodynamic alloying approach

“…Thus, it can be considered that the S phase may transform into the V or T (non-equilibrium) phase during the solidification. Some earlier studies showed mainly MgZn 2 and Al 2 Mg 3 Zn 3 phases or their isomorphous phases in the as-cast state without the S phase [36,49 54,61], and Cu sublattices in the S structure partially replaced by Zn atoms, thus forming the stoichiometric Al 2 -Cu X MgZn 1-X phase ((50-58)Al-(14-17)Zn- (19)(20)(21)(22)(23)Mg-(9-13)Cu, at.%) [19]. In addition, some Zn sublattices in the MgZn 2 structure can be replaced by Al and Cu atoms, thus forming the M phase (eventually forming AlCuMg phase), which also occurs in the Al 2 -Mg 3 Zn 3 structure to form Mg 3 (AlCuZn) 2 phase (eventually in the form of Al 6 CuMg 4 ) [14,53].…”

“…AA7075, AA7050, AA7055, AA7085, are commonly applied in the transportation industry [1][2][3] with long-term objective of better integrated properties such as high strength and fracture toughness, good corrosion resistance and high fatigue resistance [4][5][6][7][8][9][10][11][12][13][14][15]. These properties are highly impacted by the strengthening precipitates, dispersoids and coarse constituents, i. e., insoluble Cu-/Fe-rich intermetallics and the partially soluble S (Al 2 CuMg) phase [7][8][9], as well as serious macro-/micro-segregation [12][13][14][15][16], all of which highly depend on the composition and processing [17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Specifically, the soluble g (MgZn 2 ) phase or its precursors such as metastable g' and GP zones are mainly responsible for the alloy strength [7], while the workability and fracture behavior are highly affected by the soluble T (Al 2 Mg 3 Zn 3 or Al 6 Mg 11 Zn 11 ) phase, partially soluble S phase, insoluble Al 7 Cu 2 Fe and Mg 2 Si phases [8,14,[31][32]…”

Effect of Cold Pressing and Aging on Reduction and Evolution of Quenched Residual Stress for Al-Zn-Mg-Cu T-Type Rib

“…A thermo-mechanical treatment [5,6] was adopted to decrease the quenched residual stress by applying cold deformation between the solution and aging process. Meanwhile, the cold deformation also increased the dislocation density of the material, which contributed to the precipitation of strengthening phases and the strength increase in the aging stage [7,8].…”

Progress in dispersoids distribution precipitating during homogenising Zr-containing Al–Cu–Li and Al–Zn–Mg alloys

“…High-strength Al alloys including 7xxx Al-Zn-Mg and third-generation Al-Cu-Li alloys have been widely used for manufacturing structural components in the aerospace industry [1][2][3]. The comprehensive properties such as high yield strength and good fracture toughness can be ensured by optimising the complex thermo-mechanical processing [4][5][6][7]. Before thermomechanical processing, a homogenisation annealing treatment is usually carried out directly after casting with the primary purpose of removing the microsegregation of solutes and dissolving brittle eutectic intermetallic particles [8,9].…”