Effect of Sr/Al Ratio on Microstructure and Properties of Mg-Al-Sr Alloy

Abstract The effect of the Sr/Al mass ratio on the microstructure and properties of Mg-Al-Sr alloys was studied using optical microscopy, scanning electron microscopy and energy dispersive spectroscopy, transmission electron microscopy, and a universal tensile testing machine. The results show that the constituents of the alloys vary with the Sr/Al mass ratio. The major second phase includes Al 4 Sr and Al 2 Sr, but the amount and morphology of these compounds are different in the alloys. Moreover, the mechanical properties of the alloys at 175 °C vary with the ratio. The tensile strength of the alloys reaches a maximum when the ratio is 0.25.