کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5435835 1509545 2017 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Stress-assisted grain growth in nanocrystalline metals: Grain boundary mediated mechanisms and stabilization through alloying
ترجمه فارسی عنوان
رشد دانه با استرس در فلزات نانوکریستال: مکانیزم های مرزی دانه و تثبیت آن از طریق آلیاژ کردن
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
چکیده انگلیسی

The mechanisms of stress-assisted grain growth are explored using molecular dynamics simulations of nanoindentation in nanocrystalline Ni and Ni-1 at.% P as a function of grain size and deformation temperature. Grain coalescence is primarily confined to the high stress region beneath the simulated indentation zone in nanocrystalline Ni with a grain size of 3 nm. Grain orientation and atomic displacement vector mapping demonstrates that coalescence transpires through grain rotation and grain boundary migration, which are manifested in the grain interior and grain boundary components of the average microrotation. A doubling of the grain size to 6 nm and addition of 1 at.% P eliminates stress-assisted grain growth in Ni. In the absence of grain coalescence, deformation is accommodated by grain boundary-mediated dislocation plasticity and thermally activated in pure nanocrystalline Ni. By adding solute to the grain boundaries, the temperature-dependent deformation behavior observed in both the lattice and grain boundaries inverts, indicating that the individual processes of dislocation and grain boundary plasticity will exhibit different activity based on boundary chemistry and deformation temperature.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 131, 1 June 2017, Pages 39–47