Influence of Al Addition on the Microstructure and Mechanical Properties of Mg-Zn-Sn-Mn-Ca Alloys

Abstract

The effects of Al addition on the microstructure and mechanical properties of Mg-Zn-Sn-Mn-Ca alloys are studied in this paper. It was found that the Mg-6Sn-4Zn-1Mn-0.2Ca-xAl (ZTM641-0.2Ca-xAl, x = 0, 0.5, 1, 2 wt.%; hereafter, all compositions are in weight percent unless stated otherwise) alloys have α-Mg, Mg2Sn, Mg7Zn3, MgZn, α-Mn, CaMgSn, AlMn, Mg32(Al,Zn)49 phases. The grain is also refined when the Al element is added, and the angular-block AlMn phases are formed in the alloys. For the ZTM641-0.2Ca-xAl alloy, the higher Al content is beneficial to elongation, and the double-aged ZTM641-0.2Ca-2Al alloy has the highest elongation, which is 13.2%. The higher Al content enhances the high-temperature strength for the as-extruded ZTM641-0.2Ca alloy; overall, the as-extruded ZTM641-0.2Ca-2Al alloy has the best performance; that is, the tensile strength and yield strength of the ZTM641-0.2Ca-2Al alloy are 159 MPa and 132 MPa at 150 °C, and 103 MPa and 90 MPa at 200 °C, respectively.

Study on the Microstructure of Mg-4Zn-4Sn-1Mn-xAl As-Cast Alloys

“…In order to further increase the strength of the Mg-Sn-Zn alloys at elevated temperatures, researchers have focused on the Zn/Sn mass ratio and micro-alloying in Mg-Sn-Zn alloys. Zn/Sn mass ratio can change the type of the Zn-rich and Sn-rich phases while micro-alloying elements can form new second phases [16][17][18][19][20][21][22][23][24][25][26][27]. Mg-Zn-Sn alloys with the Zn/Sn mass ratio of 1:1, and Mg-Sn-Zn-Mn alloys have excellent strength at elevated temperatures [28][29][30].…”