کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5435988 1509542 2017 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Stacking fault energies of face-centered cubic concentrated solid solution alloys
ترجمه فارسی عنوان
انباشته شدن انرژی خطا از آلیاژهای محلول جامد مکعبی صورت محور
کلمات کلیدی
آلیاژهای جامد محلول جامد، انرژی گسل پشته شدن، محاسبات اولیه اصول، آنتروپی ارتعاشی،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
چکیده انگلیسی

We report the stacking fault energy (SFE) for a series of face-centered cubic (fcc) equiatomic concentrated solid solution alloys (CSAs) derived as subsystems from the NiCoFeCrMn and NiCoFeCrPd high entropy alloys based on ab initio calculations. At low temperatures, these CSAs display very low even negative SFEs, indicating that hexagonal close-pack (hcp) is more energy favorable than fcc structure. The temperature dependence of SFE for some CSAs is studied. With increasing temperature, a hcp-to-fcc transition is revealed for those CSAs with negative SFEs, which can be attributed to the role of intrinsic vibrational entropy. The analysis of the vibrational modes suggests that the vibrational entropy arises from the high frequency states in the hcp structure that originate from local vibrational mode. Our results underscore the importance of vibrational entropy in determining the temperature dependence of SFE for CSAs.

Both supercell and axial interaction model indicate that some concentrated solid solutions exhibit negative stacking fault energies, which suggest hexagonal close-pack (hcp) is more energy favorable than face-centered cubic (fcc) structure. A hcp-to-fcc transition is revealed for these CSAs at finite temperature, which is attributed to the intrinsic vibrational entropy originated from local lattice relaxations.162

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 134, 1 August 2017, Pages 334-345
نویسندگان
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