Effect of Zn on microstructure and mechanical property of Mg–3Sn–1Al alloys

The microstructure and mechanical properties of Mg–3Sn–xZn–1Al alloys were investigated. It was found that the grain size was basically similar, and the amount of fine Mg2Sn particle increases markedly as the Zn content increases. In the as-extruded state, the alloys show a much smaller grain size, in addition, the grain size decreases signally with Zn content increases. The better comprehensive mechanical property is attributed to the finer grains and an amount of fine Mg2Sn particles as a result of the recrystallization accompanied by dynamic precipitation, i.e. an ultimate tensile strength of 290 Mpa and an elongation of 12.2% at room temperature.