Effects of Y on Elevated Temperature Mechanical Properties of Mg-8Al-2Sr Alloy

The effects of Y on mechanical properties of Mg-8AI-2Sr-xY alloys at elevated-temperature were investigated by optical microscopy(OM),scanning electron microscopy(SEM) and energy dispersive spectroscopy(EDS),high resolution transmission electron microscopy(HRTEM),X-ray diffraction(XRD) and tensile testing.Results show that adequate Y addition can refine the grains of Mg- 8AI-2Sr alloy distinctly,change phase composing,restraineβ-Mg_(17)Al_(12) effectively and heat-resistant Al_2Y and Al_2Sr came forth as a result and improve the elevated temperature mechanical properties.But superabundant Y addition results in uneven microstructure and composition and the decrease of the mechanical properties.