Microstructure and Tensile Properties of Mg–5Zn Alloy Containing Ca.

The present study aimed at investigating the effect of Ca (0–3 wt%) on the microstructure and tensile properties of as-cast and as-extruded Mg–Zn alloy, in which tensile tests, X-ray diffraction, SEM, EDX and texture analysis were used to evaluate these features. Based on the results obtained, it is shown that the average grain size decreased from 305 to 84 μm by adding 3 wt% Ca to the as-cast Mg–Zn alloy. XRD and SEM results reveal that the dominant second phase in the presence of Ca is Ca₂Mg₆Zn₃ which is formed continuously between dendrite arms spacing. It has been observed that the addition of 0.1 wt% Ca, significantly enhanced both UTS and elongation of as-cast alloy. It is found that the size of DRXed grains decreases with the increase of Ca (4 μm with 3 wt% Ca addition) after hot-extrusion. Further, it has been observed that Ultimate tensile strength (UTS) and elongation values of extruded alloys containing Ca are enhanced and the best result is obtained for Mg–5Zn–0.1Ca sample. Ultimate tensile strength (UTS) of 351 MPa and elongation percentage of 24% are obtained for Mg–5Zn–0.1Ca extruded alloy. [ABSTRACT FROM AUTHOR]