Quench rate sensitivity of age-hardenable Al-Zn-Mg-Cu alloys with respect to the Zn/Mg ratio: An in situ SAXS and HEXRD study

Hot Deformation Behavior and Microstructure Evolution of a Novel Al-Zn-Mg-Li-Cu Alloy

“…As the long needle-like phase is too small, the phase distribution map by EBSD cannot be calibrated. By comparing the phases commonly found in Al-Zn-Mg alloys, this long needle phase could be the η-MgZn 2 phase [ 35 ]. Figure 3 shows the XRD pattern of the as-cast alloy.…”

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].…”

“…The effects of the first two factors are assumed to be similar for all present alloys, and the influences of the few Fe-or Si-enriched phases can be ignored compared to the above key factors. Furthermore, the quenching rate is very high ($100 °C/s) after solution treatment, which can inhibit the quench-induced precipitates [20,82]. The precipitation strengthening response as the dominant contribution to the strength of the Al-Zn-Mg-Cu alloy is greatly determined by the size, number density and volume fraction of the matrix precipitates (i.e., GP zone and g' phase), which mainly depends on the key alloying elements levels (i.e., Zn, Mg and Cu elements).…”

“…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]…”

Hot Deformation Behavior and Dynamic Softening Mechanism in 7B50 Aluminum Alloy

“…Compared with 7050 aluminum alloy, 7B50 aluminum alloy appropriately increases the content of Zn and Mg elements, and further reduces the content of impurity elements, such as Fe and Si, by improving the melting and casting processes. Related studies [ 19 , 20 , 21 ] have confirmed that increasing the content of Zn and Mg elements can simultaneously improve the strength of 7××× aluminum alloy. In addition, the decrease in Fe and Si impurity element content can reduce the formation of hard and brittle second phase and improve the plastic formability of 7××× aluminum alloy [ 22 ].…”