کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1446875 988627 2011 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Microstructural stability of nanostructured Cu–Nb–W alloys during high-temperature annealing and irradiation
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Microstructural stability of nanostructured Cu–Nb–W alloys during high-temperature annealing and irradiation
چکیده انگلیسی

The microstructural evolution of dilute Cu-based ternary Cu–Nb alloys during high-temperature annealing was investigated using a combination of transmission electron microscopy, X-ray diffraction and kinetic Monte Carlo (KMC) simulations. The experiments showed that, during annealing, the Cu90Nb10 binary alloy undergoes extensive coarsening at 600 °C, with precipitate sizes increasing to >40 nm. Additions of just 1.5 at.% W to this alloy, however, dramatically suppresses the growth; the average precipitate size in the ternary alloy now increases to only ∼10 nm at 600 °C, and only to 18 nm at 700 °C. On annealing at still higher temperatures, the precipitate size then, surprisingly, decreases. The precipitate size distribution at the higher temperatures, moreover, is bimodal. It is also observed that irradiation has no effect on the microstructure of the ternary alloys above 600 °C. KMC simulations indicate that the saturation of the average precipitate size, followed by its decrease as the annealing temperature is increased and the development of a bimodal size distribution can be explained by competition between thermodynamic and kinetic effects during precipitation in this ternary alloy.


► Alloying Cu-Nb with W yields nanostructures stable at very high temperature and under irradiation.
► Competition between thermodynamics and kinetics lead to bimodal precipitate size distribution and apparent inverse coarsening.
► Atomistic kinetic Monte Carlo simulations offer rationalization of observed experimental effects.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 59, Issue 13, August 2011, Pages 5332–5341
نویسندگان
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