Optimizing mechanical property of spray formed Al-Zn-Mg-Cu alloy by combination of homogenization and warm-rolling.

Effect of homogenization and warm-rolling on the mechanical properties of Al-11.38Zn-2.45Mg-1.1Cu-0.13Zr-0.1Fe (wt. %) alloy fabricated by spray forming technology was studied by scanning electron microscopy (SEM), electron back-scatter diffraction (EBSD), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The results indicate that the combination of homogenization and warm-rolling exhibit significantly potential for increasing the mechanical properties of the spray formed alloy. The introduction of two-step homogenization process can promote the precipitation of substantial amount of Al 3 Zr dispersoids, which provide the Orowan strengthening and inhibit recrystallization of the alloy. The warm-rolling at 200 °C produces a large number of dislocations, which not only provide strain hardening, but also promote the precipitation of η' phase during aging treatment. Besides, the relatively low temperature rolling combined with Al 3 Zr dispersoids can avoid dynamic recrystallization and thus maintain fibrous microstructure of the alloy. An ultrahigh strength (YS = 868.9 ± 1.6 MPa, UTS = 878.6 ± 2.8 MPa, respectively) is achieved for the alloy due to synergistic effect of homogenization and warm-rolling. [ABSTRACT FROM AUTHOR]