Enhanced mechanical properties in an Al-Cu-Mg-Ag alloy by duplex aging

► Duplex aging treatment (T8L6) was employed to improve the mechanical properties. ► The strength of T8L6 peak-aged temper was enhanced by 3-7%. ► The unfavorable effect of pre-strain on the precipitation of Ω phase was reduced. ► The precipitation of θ′ phase was restrained effectively at high aging temperature. ► More Ω precipitates were formed during secondary aging.