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In the present study, Mg-6Zn-1Zr (ZK60) alloy with a homogeneous fine-grained structure (~5 µm) was produced by hot extrusion. The influence of temperature on tensile properties anisotropy and the associated change in deformation mechanisms in the range of 25–275 °C of the fine-grained ZK60 alloy were investigated. Under room temperature, the fine-grained ZK60 alloy exhibited a high tensile strength of ~269–327 MPa and high ductility of ~15–39% when tested at three different directions, indicating a high anisotropy. With increasing testing temperature to 150 °C and further to 275 °C, the alloy showed a gradual decrease in anisotropy. Especially, the fine-grained ZK60 alloy exhibited superplasticity of ~376–434% when tested at 275 °C, which should be due to the increasing role of grain boundary sliding (GBS), as the strong basal texture associated with room temperature deformation became almost random at elevated temperatures. Moreover, the abrupt decrease in tensile anisotropy and associated change in texture with increasing temperature correlates closely to the transformation of deformation mode from a dislocation-dominated behavior to a GBS-mediated one. [ABSTRACT FROM AUTHOR]

We report a new rolling route combining one pass of hard-plate rolling and two passes of conventional rolling. This route is efficient in achieving near-spherical Mg 17 Al 12 phase (~0.5 µm) and uniform fine-grained structure (~3 µm) featuring a weakened texture in AZ91-0.4Sn plates after a total thickness reduction of ~86.4% via 3 rolling passes. Moreover, the processed alloy exhibited superplasticity-like fracture strain of ~96% at 200 °C, owing to fine α-Mg grains distributed with a high volume fraction of Mg 17 Al 12 . This new route significantly reduces rolling passes and hence has a great potential for industrial production. [ABSTRACT FROM AUTHOR]

Abstract: A first-principles method was performed to calculate generalized stacking fault (GSF) energies in Mg alloys with Sn, Pb and Sn+Pb dopings for acting as references of designing Mg–Sn–Pb alloys. We clarify the effect of Sn is dominated than Pb atom on reduced unstable stacking fault energy ( ), especially in basal and pyramidal slip systems. Such a reduction of non-basal slip GSF energy is in favor of improving the ductility of Mg matrix. [Copyright &y& Elsevier]

Generalized stacking fault energies of magnesium without and with Al and Sn dopings were studied using first-principles calculations to investigate mechanisms of improved ductility for a new Mg–3Al–3Sn alloy. Reduced unstable stacking fault energy (γus ) results in the improved activity of and the activation of the and slip systems. Moreover, the lower γus of than of leads to the replacement of the latter by the former to be the second primary slip system. [ABSTRACT FROM AUTHOR]