A magnesium alloy containing Al₂Y particles was successfully fabricated by changing the content of Al in the Mg-6Y alloy melt. Its microstructure and mechanical properties were subsequently characterized. The results show that two types of Al₂Y particles were discovered in the Mg-6Y-xAl (x = 0.5⁻5) alloys, which are namely the polygonal particles in the pre-precipitated phase and the discontinuous network of particles in the eutectic phase. With an increase in Al content, the amount of pre-precipitated Al₂Y increases and the eutectic decreases gradually. When the Al content is 5 wt %, Al₂Y particles are almost all in the pre-precipitated phase in the Mg-6Y alloy. After hot extrusion, the YA65 alloy could be regarded as the Mg master alloy that contains Al₂Y particles with heterogeneous nucleation capability or Al₂Y particle-reinforced magnesium matrix composites. The tensile strength of the as-extruded magnesium alloy is significantly improved at ambient temperatures.
Keywords: Al2Y; Mg-Y alloys; heterogenous nucleation; microstructure.