کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1446724 988624 2012 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
First-principles study on the mobility of screw dislocations in bcc iron
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
First-principles study on the mobility of screw dislocations in bcc iron
چکیده انگلیسی

The fully two-dimensional Peierls barrier map of screw dislocations in body-centered cubic (bcc) iron has been calculated using the first-principles method to identify the migration path of a dislocation core. An efficient method to correct the effect of the finite size cell used in the first-principles method on the energy of a lattice defect was devised to determine the accurate barrier profile. We find that the migration path is close to a straight line that is confined in a {1 1 0} plane and the Peierls barrier profile is single humped. This result clarifies why the existing empirical potentials of bcc iron fail to predict the correct mobility path. A line tension model incorporating these first-principles calculation results is used to predict the kink activation energy to be 0.73 eV in agreement with experiment.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 60, Issue 9, May 2012, Pages 3698–3710
نویسندگان
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