Improved tensile properties of Mg-8Sn-1Zn alloy induced by minor Ti addition

In this study, the influence of minor titanium (Ti) addition on the microstructure and tensile properties of Mg-8Sn-1Zn based alloys were investigated by means of optical microscopy, X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry, and tensile tests. The results showed that Ti can decrease the secondary dendrite arm spacing (SDAS). The tensile strength of the Mg-8Sn-1Zn-Ti alloys is initially increased by increasing the Ti content up to 0.09wt.%, but subsequently decreased for further increase of Ti content. The improved tensile properties are attributed to the decreased SDAS and refined Mg2Sn phases, as well as the increased fraction of tin (Sn) segregated regions. The tensile fracture surface of the studied alloys shows mixed characteristics of cleavage and quasi-cleavage fracture. Adding Ti does not significantly change the fracture mode of the studied alloys.