A comparison of microstructure and mechanical properties of Mg-9Al-1Zn sheets rolled from as-cast, cast-rolling and as-extruded alloys

The effects of different initial microstructures of Mg-9Al-1Zn alloy on microstructure and mechanical properties after rolled were investigated in this study. Three original Mg-9Al-1Zn alloys involving as-cast, cast-rolling and as-extruded conditions present different initial grain sizes and initial textures. After a rolling process, all the corresponding rolled sheets show a fine-grained recrystallized microstructure (2.7-3.6 mu m) and a strong basal (0002) texture. The tensile tests of the three rolled sheets show that the as-extruded alloy after rolled exhibits the highest yield strength (-248 MPa) and the highest tensile strength (similar to 382 MPa) at room temperature, and has the greatest ultimate elongation (similar to 697%) at 300 degrees C. Therefore, the Mg-9Al-1Zn alloy sheet via a combination of extrusion and rolling possesses the best integrated performance in service at room temperature and presents the most excellent superplastic capacity at elevated temperature among all the three sheets. The results in this study would be of high industrial or scientific interest in industrial applications and superplastic preprocessing on magnesium alloys. (C) 2015 Elsevier Ltd. All rights reserved.