Fabrication of excellent mechanical properties AZ31 magnesium alloy sheets by conventional rolling and subsequent annealing

AZ31 magnesium alloy sheets were produced by conventional rolling at a temperature range of 433-523 K and subsequent annealing. The process could be optimized to produce sheets with grains as fine as 2.8 μm in average size. Obvious dynamic recrystallization was found to occur during rolling at temperature above 473 K. For the sheets rolled at temperature below 473 K, a subsequent annealing was needed to obtain a fine fully recrystallized microstructure, which gives rise to a significant increase in ductility as compared with the as-rolled state. The sheets produced by the processing route in the present study exhibit excellent mechanical properties, with the yield strength and tensile elongation achieving as high as 350 MPa and 35%, respectively. Their mechanical properties and the Hall-Petch relationship were compared with those magnesium alloys processed by other deformation methods. The results show that the present process offers a cost-effective way to produce high-performance Mg alloy thin sheets.