Investigation on microstructures and mechanical properties of Mg–6Zn–0.5Ce–xMn (x = 0 and 1) wrought magnesium alloys

Abstract

The microstructure evolution and mechanical properties of Mg–6Zn–0.5Ce–xMn (x = 0 and 1 wt.%) wrought magnesium alloys were researched, and the morphologies and role of Mn element in the experimental alloys were analyzed. The research shows that all of Mn elements form the α-Mn pure phases, which do not participate in the formation of other phases, such as the τ-phases. The mechanical properties of Mn-containing alloys in as-extruded and aged states are superior to Mn-free alloys. During the hot extrusion process, the dispersed fine α-Mn particle phase hinders the migration of grain boundaries and inhibits dynamic recrystallization, which mainly takes effect of grain refining and dispersion hardening. During the aging treatments, the dispersed fine α-Mn particle phase not only hinders the growth of the solution-treated grains, but also becomes the nucleation cores of β1′ rod-like precipitate phase, which is conducive to increasing the nucleation rate of the precipitate phase. For the aged alloy, the Mn addition mainly takes effect of grain refining and promoting aging strengthening.

Keywords

• Mg–6Zn–0.5Ce alloy
• Microstructure evolution
• Mechanical property
• Mn element
• Aging precipitation