Comparison of the influence of chromium and zirconium on the quench sensitivity of Al-Zn-Mg-Cu alloys

Effect of Homogenization and Aging Treatment on Mechanical Properties and Stress-Corrosion Cracking of 7050 Alloys

“…In the lower right region of Figure 10(a), i.e., the recrystallized region, the heterogeneous precipitation g phase is found to occur at the interfaces of the incoherent Al 3 Zr dispersoids, due to high interfacial energy. [28] Figure 10(b) also shows that this phenomenon evidently occurred inside the recrystallized grains. On the contrary, the Al 3 Zr dispersoids are still coherent in the unrecrystallized region, so their interfaces cannot serve as heterogeneous nucleation sites, due to low interfacial energy.…”

“…[27,28] Consequently, the Al 3 Zr dispersoids become incoherent with the matrix in the recrystallized region. In the lower right region of Figure 10(a), i.e., the recrystallized region, the heterogeneous precipitation g phase is found to occur at the interfaces of the incoherent Al 3 Zr dispersoids, due to high interfacial energy.…”

Influence of Mg content on quench sensitivity of Al–Zn–Mg–Cu aluminum alloys

“…As a result, Alcoa Company developed the 7050 and 7150 alloys, in which quench sensitivities are lower than those of 7075 alloy, and used them in the Boeing 757, 767, and 777 aircrafts [9,10]. The quench sensitivities of various Al alloys and addition of trace elements (e.g., Cr, Zr) have been reported in many papers [4,[11][12][13][14]. In 2003, Alcoa Company developed 7085 Al alloy, which has high strength and toughness and low quench sensitivity; this alloy has been used in the advanced aircrafts such as A380 [11].…”

Field ion microscopy and 3-D atom probe analysis of Al3Zr particles in 7050 Al alloy

“…Zr is an important trace alloy element in high strength 7xxx series Al alloys, which is often added to optimise properties, and has effects such as refining grain size, inhibiting recrystallisation, and improving stress corrosion cracking resistance [1] and quench sensitivity [2]. In addition, it has been reported recently that Zr addition also has a significant influence on early stage ageing behaviour of a 7xxx series Al alloy [3].…”