Microstructural characterisation and mechanical properties of Mg-xSn-5Al-1Zn alloys

In this study, the microstructure and mechanical properties of as cast Mg-xSn-5Al-1Zn alloys were investigated. The microstructures of the alloys were characterised by the presence of Mg2Sn and Mg17Al12 precipitates. The greatest tensile strength and elongation were obtained at the alloy containing 5 wt-%Sn at room temperature. Microhardness of the alloys and volume fraction of the Mg2Sn precipitates increased with increasing Sn content. Fractographic analysis demonstrated that dimple and cleavage facet were dominant mechanisms of these alloys tested at room and elevated temperature. The portion of cleavage facet was increased with the increment of Sn at the room and elevated temperatures.