Microstructure and mechanical properties of hot-rolled Mg-Zn-Nd-Zr alloys

Extruded Mg-5Zn-xNd-0.4Zr (x = 0, 1, 2 wt.%) plates 10 mm in thickness were hot-rolled at 673 K to 4 mm. Stable Mg-Zn-Nd particles are formed along the grain boundaries of the as-prepared material. The volume fraction of these particles increases with increasing Nd content while the solid solubility of Zn in matrix decreases. The particles are broken up and dispersed along the rolling direction. Mg-5Zn-1Nd-0.4Zr has the best ultimate and yield strengths at room temperature. At high temperatures after rolling, Mg-Zn-Nd-Zr alloys have much better tensile strength than the Mg-Zn-Zr alloy. The ultimate tensile strength of all alloys decreases with increasing the test temperature, while the ductility increases. (C) 2007 Elsevier B.V. All rights reserved.