Microstructure, texture and mechanical properties of extruded Mg–5Al–2Nd–0.2Mn alloy

Abstract

The microstructure, texture and mechanical properties of extruded Mg–5Al–2Nd–0.2Mn alloy were investigated in the present work. The extruded alloy demonstrated a near-completely recrystallized grain structure with average grain size of about 20 μm. Intermetallic phases Al11Nd3 and Al2Nd were fragmented to small particles and a small amount of Mg17Al12 phase was precipitated during extrusion, which promoted grain refinement during dynamic recrystallization. A strong basal texture was formed with the basal plane parallel to the extrusion direction (ED) of the plate. The tensile strength was obviously improved after extrusion, and the difference in tensile strength of the extruded alloy in ED and transverse direction (TD) was obscure. However, the elongation in ED was higher than that in TD at both room temperature and 150 °C. It was resulted from the distribution of secondary phases along ED and basal plane texture tilting toward ED in the extruded alloy. The significant improvement in strength of the extruded alloy, compared with that of the as-cast alloy, was due to the grain refinement, the fragment of Al–Nd intermetallics, the increased interaction between the Al–Nd intermetallics and grain boundaries as well as dislocations, solid solution strengthening and texture strengthening.