Effect of Micro-alloyed Ce on the Microstructure and Mechanical Properties of Mg-Gd-Zr Alloy

The effect of the microalloying element Ce on the microstructure and tensile mechanical properties of a Mg-10Gd-0.5Zr alloy was investigated in this work. The results indicated that adding a small amount of Ce to the Mg-10Gd-0.5Zr alloy refined the grain size and formed the Mg 5 (Gd, Ce) eutectic phase. In addition, micro-alloyed Ce promoted the age-hardening response, shortened the peak-aging time, improved the density of the β' strengthening phase, and enhanced the aspect ratio of the phase. Adding 0.6 wt.% Ce to the alloy improved the yield strength and ultimate tensile strength from 141 to 182 MPa and 210 to 275 MPa, respectively. The improved mechanical properties were related to grain refinement, a high-density β' strengthening phase and a larger aspect ratio of the strengthening phase.