Microstructure and mechanical properties of high speed indirect-extruded Mg-5Sn-(1,2,4)Zn alloys

Abstract

The microstructural evolution and mechanical properties of high speed indirect-extruded Mg-5%Sn-(1, 2, 4) Zn (mass fraction, %) alloys were investigated by optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis (DTA) and a static tension tester. All the studied alloys can be extruded successfully at a high speed of 10 m/min. The grain size, area fraction of particles and tensile properties are found to be greatly affected by the extrusion speed and Zn content, resulting in tensile properties showing lower strength and ductility as the extrusion speed increases and Zn content decreases. The dependence of grain size and tensile properties on the second phase particles is also discussed.