The Effect of Zn on the Properties of Mg-10Al-6Ca-1Sn Alloy

In this study, Mg-10Al-6Ca-1Sn and Mg-17Al-4Zn-3Ca-1Sn composite alloys were prepared. They were prepared by melting them in argon atmosphere on a water-cooled copper hearth. The sample were then analyse to determine the microstructure and mechanical properties using scanning electron microscope (SEM) and hardness testing, respectively. Moreover, a few of tests had been done to observe and determine microstructure and mechanical properties of the alloys. Mg-17Al-4Zn-3Ca-1Sn alloy, the microstructure of Mg-17Al-4Zn-3Ca-1Sn alloy distinctly portrays fine grains, resulting abundant of grain boundaries, which consist of eutectic phase, surround of primary magnesium grains. In contrast, the Mg-10Al-6Ca-1Sn alloy exhibits large differences in grain size. As a control, the sample without the addition of Zn element portrays large particles and creating very small amount of grain boundaries in the captured area of 30 mu m. In perspective of mechanical properties, Mg-17Al-4Zn-3Ca-1Sn composite alloy showed higher Vickers hardness value with average of 81.8 Hv compared to Mg-10Al-6Ca-1Sn composite alloy, which was 70.5 Hv. In conclusion, the addition of Zn has effectively improved the hardness of the Mg alloy. This is supported by XRD analysis, which confirms the phase of new alloys that composed of Zinc element.