Influences of Al, Ce on the Microstructure and Mechanical Properties of As-cast Mg-6Zn Alloy

摘要

The effects of minor Al and Ce on the microstructures, room-temperature and high-temperature mechanical properties of as-cast Mg-6Zn magnesium alloys were investigated. With the Al addition into Mg-6Zn alloy, the coarse eutectic Mg_(51)Zn_(20) phases were refined and distributed discontinuously. After adding 0.5wt.% Ce into Mg-6Zn-lAl alloy, a new needle-like Al_2CeZn_2 phase was observed. Meanwhile, the volume fraction of Mg_(51)Zn_(20) phase decreased and the semi-continuous Mg_(51)Zn_(20) phase became discontinuous globular morphology. It has been observed that the addition of Ce element coarsens the grains, and 1 wt.% Al addition enhanced the yield strength and ultimate strength from 86.35MPa, 229MPa to 90.7MPa, 238MPa, respectively. Moreover, the Ce addition can significantly increase the high-temperature mechanical properties of cast Mg-6Zn-1Al alloy.