کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5436288 1509548 2017 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Triple junction drag effects during topological changes in the evolution of polycrystalline microstructures
ترجمه فارسی عنوان
سهولت اتصال باعث افزایش اثرات تغییرات توپولوژیکی در تکامل میکرو سازه های پلی کریستالی می شود
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
چکیده انگلیسی

Experiments, theory and atomistic simulations show that finite triple junction mobility results in non-equilibrium triple junction angles in evolving polycrystalline systems. These angles have been predicted and verified for cases where grain boundary migration is steady-state. Yet, steady-state never occurs during the evolution of polycrystalline microstructures as a result of changing grain size and topological events (e.g., grain face/edge switching - “T1T1” process, or grain disappearance “T2T2” or “T3T3” processes). We examine the non-steady evolution of the triple junction angle in the vicinity of topological events and show that large deviations from equilibrium and/or steady-state angles occur. We analyze $∖tau$ the characteristic relaxation time of triple junction angles τ by consideration of a pair of topological events, beginning from steady-state migration. Using numerical results and theoretical analysis we predict how the triple junction angle varies with time and how τ varies with triple junction mobility. We argue that it is precisely those cases where grain boundaries are moving quickly (e.g., topological process in nanocrystalline materials), that the classical steady-state prediction of the triple junction angle about finite triple junction mobility is inapplicable and may only be applied qualitatively.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 128, 15 April 2017, Pages 345–350