Mechanistic origin and prediction of enhanced ductility in magnesium alloys

    loading  Checking for direct PDF access through Ovid


Pure magnesium exhibits poor ductility owing to pyramidal 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 cross-slip and multiplication rates to levels much faster than the deleterious 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.

    loading  Loading Related Articles