کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1448103 988664 2009 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A molecular dynamics study of self-diffusion in the cores of screw and edge dislocations in aluminum
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
A molecular dynamics study of self-diffusion in the cores of screw and edge dislocations in aluminum
چکیده انگلیسی

Self-diffusion along screw and edge dislocations in Al is studied by molecular dynamics simulations. Three types of simulations are performed: with pre-existing vacancies in the dislocation core, with pre-existing interstitials, and without any pre-existing defects (intrinsic diffusion). We find that diffusion along the screw dislocation is dominated by the intrinsic mechanism, whereas diffusion along the edge dislocation is dominated by the vacancy mechanism. Diffusion along the screw dislocation is found to be significantly faster than diffusion along the edge dislocation, and both diffusivities are in reasonable agreement with experimental data. The intrinsic diffusion mechanism can be associated with the formation of dynamic Frenkel pairs, possibly activated by thermal jogs and/or kinks. The simulations show that at high temperatures the dislocation core becomes an effective source/sink of point defects and the effect of pre-existing defects on the core diffusivity diminishes.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 57, Issue 18, October 2009, Pages 5531–5542
نویسندگان
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