Microstructural refinement and tensile properties enhancement of the Mg-9Al-1Zn alloy after hot extrusion

The impact of hot extrusion process on the grain refinement and tensile properties for the rare earth elements (RE) and strontium (Sr)-containing Mg-9Al-1Zn alloys was studied. Based on the microstructural analysis, the grain size values reduced after the hot extrusion process, compared to the cast alloys. Moreover, the tensile properties of the extruded alloys were remarkably higher than the cast alloys. These extraordinary results were related to the grain refinement by the dynamic recrystallization phenomenon, and fragmentation and distribution of the intermetallics. Moreover, the RE/Sr additions improved the grain size reduction, owing to the presence of fragmented Al11RE3 intermetallics.