Microstructures and mechanical properties of extruded Mg-1Mn-3.5Y and Mg-1Mn-1Y-2.5Nd alloys

Both Mg-1Mn-3.5Y and Mg-1Mn-1Y-2.5Nd alloys (mass fraction, %) were extruded at 380 °C. Most of the (100) crystal planes in the Mg-1Mn-3.5Y alloy are parallel to the normal direction, while most of the (101) crystal planes in the Mg-1Mn-1Y-2.5Nd alloy are parallel to the normal direction. The tensile tests at room temperature, 100 °C and 200 °C show that the Mg-1Mn-3.5Y alloy exhibits higher yield strength, but lower elongation to failure as compared with the Mg-1Mn-1Y-2.5Nd alloy. These differences in the tensile mechanical properties between the two alloys are mainly attributed to their different texture types and amount and distribution of the Mg24Y5 precipitates. The serration flow behavior is observed in the Mg-1Mn-1Y-2.5Nd alloy at 200 °C, but does not occur in the Mg-1Mn-3.5Y alloy. The Mg-1Mn-3.5Y alloy shows the cleavage fracture mode, while the Mg-1Mn-1Y-2.5Nd alloy exhibits the dimple fracture mode.