Narrow Results

Microstructure and tensile properties of squeeze cast Mg-Al-Ca alloys with different levels of calcium addition (AMC50X) were studied. The microstructural analysis by optical and scanning electron microscopy (SEM) shows that the squzeeze cast Mg-Al-Ca alloys contain primary α-Mg, (Al, Mg)₂Ca and Mn-Al intermetallic while the base alloy AM50 contains primary α-Mg, β-Mg₁₂Al₁₇ and Mn-Al intermetallic. The addition of calcium varying from 1 to 4 wt.% increases the fraction area of Ca-containing secondary phases from 9.5% to 19.5%. The experimental observation confirms also that the calcium has a grain refining effect on the base alloy AM50A. The tensile testing results indicate that, as the calcium content of AMC50X alloys increases from 0 to 4%, the ultimate tensile strength (UTS) and elongation (E_f) decrease dramatically at room temperature as their yield strengths (YS) improves slightly. At 150°C, however, both the UTS and YS of the alloys increase with increasing the Ca content.