Mechanistic origin and prediction of enhanced ductility in magnesium alloys.
Science
; 359(6374): 447-452, 2018 Jan 26.
Article
em En
| MEDLINE
| ID: mdl-29371467
ABSTRACT
Pure magnesium exhibits poor ductility owing to pyramidal [Formula see text] 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 [Formula see text] cross-slip and multiplication rates to levels much faster than the deleterious [Formula see text] 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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Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article