Effect of Ce content and rolling route on the microstructure and mechanical properties of high-Zn content Al-Zn-Ce alloys

In this study, Al-20 wt%Zn-x wt%Ce alloys (x = 0, 0.1, 0.5, and 1) were fabricated by casting, hot rolling, cold rolling, and solution treatment to investigate the effects of Ce content and rolling route on the microstructure and mechanical properties of high-Zn content Al-Zn-Ce alloys. Ce addition with weight ratio no higher than 0.5 % led to the formation of Al2CeZn2 phases in the Al-20Zn alloy, and the CeZn3 phases were obtained in this alloy when the Ce content increased to 1 %. Rolling effectively disrupted the Ce-containing phases, and the presence of these phases changed the grain structure of the Al-Zn-Ce alloys by affecting their deformation mode during rolling. Dynamic precipitation of Zn phases occurred in the Al-20Zn alloys during rolling. However, the Ce-containing phase consumed a large amount of Zn atoms, and then inhibited the dynamic precipitation of Zn phases in the studied alloys. The alloys with 0.5 wt%Ce addition exhibited the best mechanical properties, and the strengthening mechanism of the Al-Zn-Ce alloys were studied.