کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1558990 1513824 2012 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
First-principles calculations and thermodynamic re-modeling of the Hf–W system
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
First-principles calculations and thermodynamic re-modeling of the Hf–W system
چکیده انگلیسی

An integrative approach coupling first-principles calculations and the CALculation of PHAse Diagram (CALPHAD) method provides a more thermodynamically accurate model of the Hf–W system when compared to previous models. A two-sublattice model is used for describing the solid solubility of the HfW2 Laves phase. The modeling of the Laves phase includes input from first-principles total energy calculations and predictions of finite temperature properties from the Debye–Grüneisen model. In addition, first-principles calculations performed on hcp and bcc special quasirandom structures (SQS) predicted a positive enthalpy of mixing in both solid solution phases. Predicting the finite temperature properties of bcc SQS with the Debye–Grüneisen model was necessary to balance the positive, asymmetric enthalpy of mixing found in the bcc solid solution. The model produced by the coupling of CALPHAD modeling with first-principles calculations agrees well with experimental data. It also reproduces the Hf–W phase diagram with fewer parameters than previous models, which were created without the aid of first-principles calculations.


► The Hf–W system was reassessed to incorporate calculated thermodynamic properties.
► Thermodynamic properties were obtained via first-principles calculations.
► Enthalpy of formation of HfW2 and enthalpies of mixing were calculated.
► Finite temperature properties were also calculated using the Debye–Grüneisen model.
► Using this data produced a thermodynamically accurate model of the Hf–W system.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Calphad - Volume 38, September 2012, Pages 92–99
نویسندگان
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