کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1448530 988676 2008 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Tensile properties of nanocrystalline tantalum from molecular dynamics simulations
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Tensile properties of nanocrystalline tantalum from molecular dynamics simulations
چکیده انگلیسی

The tensile behaviors of nanocrystalline tantalum are studied using molecular dynamics simulations. The results show that the elastic modulus increases linearly with density. The flow stress decreases with decreased grain size, but increases with increased strain rate or decreased temperature. A strain rate sensitivity of ∼0.14 is derived from the simulations with a resultant activation volume of ∼1b3 associated with plastic deformation. Grain rotation, grain boundary sliding or migration, dislocation motion and intergranular activities are observed in the deformation process. Twinning is regarded to be a secondary mechanism. Stress-induced phase transitions from body-centered cubic to face-centered cubic (fcc) and hexagonal close-packed (hcp) structures take place locally, and the hcp structure is a derivative of the fcc structure. The higher the strain rate, the further delayed the phase transition. Such phase transitions are found to occur only at relatively low-temperatures and are reversible with respect to stress.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 56, Issue 14, August 2008, Pages 3470–3480
نویسندگان
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