Aging behavior of high zinc Al-Zn-Mg-Cu alloy prepared by spray forming

The microstructure and mechanical properties of high Zn Al-Zn-Mg-Cu aluminum alloys prepared by spray forming technology with different aging treatments were investigated. The results showed that strengthening phases precipitated from grain boundary during natural aging treatment, and with the prolong action of aging time the precipitate phases of single aging alloys grew up gradually. The precipitate phases of double aging alloys got coarsened and the precipitate phases of grain boundary were intermittence. The regression-reaging treated alloys possessed fine grain-interior precipitate phases and the discontinuous grain-boundary phases as the same as those of two-step aging alloys. Compared with peak aging alloys, the ultimate tensile strength (UTS) of two-step aging alloys reduced by about 13%, but UTS of regression-reaging treated alloys excelled that of peak aging alloys.