Effects of small additions of Zr and Sr on as cast microstructure and tensile properties of Mg–4Y–1·2Mn–0·9Sc (wt-) alloy

Abstract

The effects of small additions of Zr and Sr on the as cast microstructure and tensile properties of the Mg–4Y–1·2Mn–0·9Sc (wt-) magnesium alloy were investigated. The results indicate that small additions of Zr and/or Sr to the Mg–4Y–1·2Mn–0·9Sc alloy do not cause an obvious change in the morphology and size of the secondary phases. However, the grains of the Zr and/or Sr containing alloys are effectively refined. Among the Zr and/or Sr containing alloys, the grains of the alloy with addition of 0·5 wt-Zr+0·1 wt-Sr are found to be the finest, followed by the alloys with additions of 0·5 wt-Zr and 0·1 wt-Sr respectively. Furthermore, the tensile properties of the Mg–4Y–1·2Mn–0·9Sc alloy, especially the room temperature ductility, are improved by small additions of Zr and/or Sr. Among the Zr and/or Sr containing alloys, the alloy with addition of 0·5 wt-Zr+0·1 wt-Sr obtains the optimum tensile properties at room temperature and 300°C, and the tensile properties of the alloys with additions of 0·5 wt-Zr and 0·1 wt-Sr are similar.

Effects of Al addition on the microstructure and mechanical properties of Mg–4Y alloys

“…The high solid solubility of Y can effectively improve the mechanical properties of magnesium alloys at room and elevated temperatures [8][9][10][11]. Therefore, a series of highperformance RE magnesium alloys based on Mg-Y have been developed, including Mg-4Y-3Nd-0.5Zr (WE43) [12,13], Mg-5Y-4Gd-0.4Zr (WE54) [14], and Mg-4Y-1Mn-1Sc [15]. The additions of alloying elements in Mg-Y alloys significantly reduce the solubility of Y in Mg but can remarkably increase the volume fraction of the precipitated phase, thus further improving the mechanical properties [2,6,16].…”