کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1449350 988700 2008 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of a tungsten addition on the morphological evolution, spatial correlations and temporal evolution of a model Ni–Al–Cr superalloy
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Effects of a tungsten addition on the morphological evolution, spatial correlations and temporal evolution of a model Ni–Al–Cr superalloy
چکیده انگلیسی

The effect of adding 2 at.% W to a model Ni–Al–Cr superalloy on the morphological evolution, spatial correlations and temporal evolution of γ′(L12)-precipitates at 1073 K is studied with scanning electron microscopy and atomic force microscopy. Adding W yields a larger microhardness, earlier onset of spheroidal-to-cuboidal precipitate morphological transition, larger volume fraction (from ∼20% to 30%), reduction in coarsening kinetics by one-third and a larger number density (Nv) of smaller mean radii (〈R〉) precipitates. The kinetics of 〈R〉 and interfacial area per unit volume obey t1/3 and t−1/3 relationships, respectively, which is consistent with coarsening driven by interfacial energy reduction. The Nv power-law dependencies deviate, however, from model predictions, indicating that a stationary state is not achieved. Quantitative analyses with precipitate size distributions, pair correlation functions and edge-to-edge interprecipitate distance distributions give insight into two-dimensional microstructural evolution, including the elastically driven transition from a uniform γ′-distribution to one-dimensional 〈0 0 1〉-strings to eventually clustered packs of γ′-precipitates in the less densely packed Ni–Al–Cr alloy.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 56, Issue 3, February 2008, Pages 448–463
نویسندگان
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