Dynamic and Static Precipitation Behaviors and Resultant Mechanical Properties of Al–15Zn–0.5Mg–0.5Sc Alloy

Cold rolling and aging were performed on the solid solution state Al–15Zn–0.5Mg–0.5Sc alloy to study the precipitation behavior of the Al–Zn base alloys. Cold rolling with a low deformation degree could lead to the formation of dislocations and promote the dynamic precipitation of the Zn phases and the static precipitation of η phases during subsequent aging. Natural and artificial aging could lead to the static precipitation of Zn-Mg phases with sizes of approximately 1 nm in the solution-treated Al–15Zn–0.5Mg–0.5Sc alloy with or without cold rolling. The Al–15Zn–0.5Mg–0.5Sc alloy subjected to solution treatment, cold rolling, and nature aging exhibited satisfactory mechanical properties. The sample had fine grain, dislocation, solution, and precipitation strengthening effects. An effective strategy to improve the mechanical properties of the Al–Zn base alloy through the combination of its dynamic precipitation during deformation and static precipitation during aging was presented.