**2. Materials and methods**

## **2.1 Materials**

Mg-Zn-Ca alloys were prepared from high purity Mg (99.99 %), Purity Zn (99.8 %), and an Mg-26.9 wt. % Ca master alloy. Melting and alloying operations were carried out in a steel crucible under the protection of a mixed gas atmosphere of SF6 (0.3 vol. %) and CO2 (Bal.). Purity Zn and master alloy were added into the pure Mg melts at 720 oC. The melts were kept for 10min at 720oC to ensure that all the required alloying elements were dissolved in the melt alloy, and then the melts were cooled down to 700 oC and poured into a steel mold which had been pre-heated to 200 oC.
