کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1580565 1514832 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Computational study of the impurity induced reduction of grain boundary energies in nano- and bi-crystalline Al–Pb alloys
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
Computational study of the impurity induced reduction of grain boundary energies in nano- and bi-crystalline Al–Pb alloys
چکیده انگلیسی

Segregation of impurities with limited solubilities to grain boundaries can slow or even eliminate grain growth in nanocrystalline materials. Due to a very limited miscibility Pb is a potential candidate for thermodynamically stabilizing nanocrystalline Al. To investigate this we have used atomic modeling to characterize the structure and energy of substitutional Pb defects in bulk Al, in Al bi-crystals and in an Al nanocrystal. Monte Carlo simulations using a modified embedded-atom method (MEAM) potential fit to the results of density functional theory (DFT) calculations predict the formation of Pb clusters, in agreement with prior experiments. In addition, the simulations show strong segregation of Pb atoms to grain boundaries, a result that supports prior suggestions that Pb is distributed along grain boundaries in nanocrystals created by ball milling. Analysis of the enthalpies for Pb defects using MEAM and DFT calculations suggests that Pb impurities can help stabilize nanocrystalline Al against grain growth.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volume 527, Issues 7–8, 25 March 2010, Pages 1769–1775
نویسندگان
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