کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1448972 988688 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
First-principles density functional theory study of phase transformations in NbCr2 and TaCr2
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
First-principles density functional theory study of phase transformations in NbCr2 and TaCr2
چکیده انگلیسی

Hexagonal to cubic phase transformations in the intermetallic Laves-phase compounds NbCr2 and TaCr2 have been studied systematically using the synchroshear deformation mechanism and first-principles density functional theory (DFT). The DFT results provide a quantitative description of the activation energy profiles during the deformation process. By means of these profiles we discuss several transformation possibilities and propose explanations for recent experimental data. In particular it is shown that the synchroshear deformation mechanism should prevail in the two Laves phases studied. Furthermore, the activation energy barriers for TaCr2 are about 17% larger than those for NbCr2. We discuss how this may lead to the experimentally observed, significantly slower transformation kinetics of TaCr2, compared to NbCr2. Both the observation of fine-scale twins and the origin for the twin formation can also be understood from the activation energy profiles.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 56, Issue 18, October 2008, Pages 4984–4992
نویسندگان
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