TY - JOUR
T1 - Mechanistic origin and prediction of enhanced ductility in magnesium alloys
AU - Wu, Zhaoxuan
AU - Ahmad, Rasool
AU - Yin, Binglun
AU - Sandlöbes, Stefanie
AU - Curtin, W. A.
PY - 2018/1/26
Y1 - 2018/1/26
N2 - Pure magnesium exhibits poor ductility owing to pyramidal {c + a} dislocation transformations to immobile structures, making this lowest-density structural metal unusable for many applications where it could enhance energy efficiency. We show why magnesium can be made ductile by specific dilute solute additions, which increase the {c + a} cross-slip and multiplication rates to levels much faster than the deleterious {c + a} transformation, enabling both favorable texture during processing and continued plastic straining during deformation. A quantitative theory establishes the conditions for ductility as a function of alloy composition in very good agreement with experiments on many existing magnesium alloys, and the solute-enhanced cross-slip mechanism is confirmed by transmission electron microscopy observations in magnesium-yttrium. The mechanistic theory can quickly screen for alloy compositions favoring conditions for high ductility and may help in the development of high-formability magnesium alloys.
AB - Pure magnesium exhibits poor ductility owing to pyramidal {c + a} dislocation transformations to immobile structures, making this lowest-density structural metal unusable for many applications where it could enhance energy efficiency. We show why magnesium can be made ductile by specific dilute solute additions, which increase the {c + a} cross-slip and multiplication rates to levels much faster than the deleterious {c + a} transformation, enabling both favorable texture during processing and continued plastic straining during deformation. A quantitative theory establishes the conditions for ductility as a function of alloy composition in very good agreement with experiments on many existing magnesium alloys, and the solute-enhanced cross-slip mechanism is confirmed by transmission electron microscopy observations in magnesium-yttrium. The mechanistic theory can quickly screen for alloy compositions favoring conditions for high ductility and may help in the development of high-formability magnesium alloys.
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U2 - 10.1126/science.aap8716
DO - 10.1126/science.aap8716
M3 - RGC 21 - Publication in refereed journal
SN - 0036-8075
VL - 359
JO - Science
JF - Science
IS - 6374
M1 - A36
ER -