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Dilute Mg alloys based upon earth-abundant elements, e.g., Al, Ca, and Zn have attractive combinations of strength, ductility, and workability. Even higher strength can be obtained in work-hardened material without the heat treatments required to induce Guinier-Preston zone strengthening of previously studied versions of these alloys. This stems from a slightly stronger crystallographic texture than is present after solutionizing, a high dislocation density, and to a lesser degree, a fine distribution of globular Zn-rich precipitates. The anisotropic plastic response of sheet material is described using an elasto-viscoplastic self-consistent (EVPSC) polycrystal model. Strain partitioning between grains during rolling-induced strain hardening is held responsible for the yield strength, ductility, and especially, strain hardening anisotropy. Texture-induced plastic anisotropy is well- known, but the effect of strong partitioning of strain between variously oriented grains is critical to explain what may be classified as a sort of strain path change (generalized Bauschinger) effect. 

Textured Mg alloy sheet samples were tensile tested parallel to the transverse direction, at Zener–Hollomon parameter values ranging from Z ~ 50 at room temperature and 10−3 s−1 down to Z ~ 18 at 350 °C and 10−5 s−1. At high Z, the samples exhibit strong texture evolution indicative of significant prismatic slip of dislocations with  Burgers vectors. Correspondingly, the plastic anisotropy is high, r ~ 4. At low Z, the texture evolution is minimal and the response is nearly isotropic, r ~ 1. Previously, it has been asserted that the high ductility and low plastic anisotropy observed at low Z conditions is due to enhanced activity of non-basal slip modes, including prismatic slip of  dislocations and pyramidal slip of  and  dislocations. The present results call this understanding into question and suggest that the enhanced ductility is more closely associated with the climb of  dislocations.