Microstructure and mechanical property of high strength Mg-Sn-Zn-Al alloys

This paper aims to reveal the microstructure and mechanical properties of as-cast and hot-rolled Mg-Sn-Zn-Al based alloys. Three alloys, Mg-5Sn-2Zn (TZ52), Mg-5Sn-2Zn-2Al (TAZ522) and Mg-5Sn-5Al-1Zn-0.2Mn (TAZM5510) alloys were studied. The results revealed that the as-cast alloys showed fine dendritic structures. The TAZM5510 alloys exhibited moderate yield strength of 98 MPa with good elongation of similar to 15%, which was comparable to several commercially used Mg die-castings. Mechanical properties were significantly improved after multi-pass rolling. The TZ52 sheet showed a high yield strength of 277 MPa with excellent ductility exceeding 30%, and the TAZM5510 sheet exhibited the highest tensile strength of 386 MPa while keeping desirable elongation of 16.6%. These sheets are termed as strong and ductile Mg-Sn-Zn-Al wrought alloys.