Static and Dynamic Precipitation Behavior of the Al–20wt.%Zn Alloy

The static and dynamic precipitation behavior of solution-treated binary Al–20 wt.% Zn alloy is investigated via artificial aging, cold rolling and artificial aging combined with cold rolling. The solution-treated Al–Zn alloy exhibits high thermal stability during aging, and low densities of nano-sized Zn particles are precipitated along with Al grain boundaries after aging at 200^\circ\!C for 13 h. Compared with static precipitation, dynamic precipitation occurs more easily in the Al–Zn alloy. Zn clusters are obtained after cold rolling at an equivalent plastic strain of 0.6, and the size of the Zn phase reaches hundreds of nanometers when the strain is increased to 12.1. The results show that the speed of static precipitation can be significantly enhanced after the application of 2.9 rolling strain. Grain refinement and defects induced by cold rolling are considered to promote Zn precipitation. The hardness of Al–Zn alloy is also affected by static and dynamic precipitations.