Solidification - microstructure relationships of model ferro-silicon alloy by means of thermodynamic calculations of ternary (Al, Fe, Si) and (Ca, Fe, Si) phase diagrams

1993 ◽  
Vol 90 ◽  
pp. 409-419 ◽  
Author(s):  
C Gueneau ◽  
C Servant ◽  
I Ansara
Keyword(s):  
Phase Diagrams ◽  
Solidification Microstructure ◽  
Thermodynamic Calculations ◽  
Silicon Alloy ◽  
Ferro Silicon

scholarly journals Calculation of dopant solubilities and phase diagrams of X–Pb–Se (X = Br, Na) limited to defects with localized charge

2016 ◽  
Vol 4 (9) ◽  
pp. 1769-1775 ◽  
Author(s):  
Saurabh Bajaj ◽  
Heng Wang ◽  
Jeff W. Doak ◽  
Chris Wolverton ◽  
G. Jeffrey Snyder
Keyword(s):  
Phase Diagrams ◽  
Accurate Prediction ◽  
Thermodynamic Calculations ◽  
Charge States

Performing thermodynamic calculations using only the expected charge states, excluding others, enables accurate prediction of experimentally measured doping efficiencies and phase diagrams.

scholarly journals Thermodynamic calculations in alloys Ti-Al, Ti-Fe, Al-Fe and Ti-Al-Fe

2008 ◽  
Vol 44 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Ana Kostov ◽  
B. Friedrich ◽  
D. Zivkovic
Keyword(s):  
Phase Diagrams ◽  
Ternary Alloy ◽  
Ternary Systems ◽  
Thermodynamic Calculations ◽  
Calculated Phase ◽  
Gibbs Energies ◽  
Different Temperatures ◽  
Binary And Ternary Systems ◽  
Thermodynamic Determination

Thermodynamic calculations of three binary Ti-based alloys: Ti-Al, Ti-Fe, and Al-Fe, as well as ternary alloy Ti-Al-Fe, is shown in this paper. Thermodynamic calculations involved thermodynamic determination of activities, coefficient of activities, partial and integral values for enthalpies and Gibbs energies of mixing and excess energies at different temperatures: 1873K, 2000K and 2073K, as well as calculated phase diagrams for the investigated binary and ternary systems. The FactSage is used for all thermodynamic calculations.

Thermodynamic Calculations as the Basis for CVD Production of Silicide Coatings

MRS Bulletin ◽  
1999 ◽  
Vol 24 (4) ◽  
pp. 27-31 ◽  
Author(s):  
Claude Bernard ◽  
Michel Pons ◽  
Elisabeth Blanquet ◽  
Roland Madar
Keyword(s):  
Phase Diagrams ◽  
Integrated Circuit ◽  
Materials Science ◽  
Semiconductor Industry ◽  
Chemical Vapor ◽  
Ternary Systems ◽  
Thin Layers ◽  
Thermodynamic Calculations ◽  
Experimental Conditions ◽  
Scale Integration

The exponential increase in computing power realized over the past three decades has required devices of ever-decreasing dimensions. With these reductions in feature size, each generation of circuit technology creates a new set of materials-science challenges, as exemplified by the use of silicide-based diffusion barriers.The use of transition-metal silicides in the semiconductor industry began in the early 1980s with (in retrospect) fairly thick films, simple compositions, and minimal microstructural requirements. The implementation of thin-film binary silicides in integrated circuit (IC) applications required the development of appropriate modeling techniques to select the deposited metal, its gaseous precursor, and the Silicon precursor. These vectors were used to define experimental conditions to yield desired films. Chemical-vapor-deposition (CVD) experiments were simulated and CVD phase diagrams were used to describe the changing film properties with different thermodynamic conditions.In the early 1990s, research began to focus on CVD of ternary Systems (Ta-Si-N, Ti-Si-N). Modeling these complex Systems required optimization of the thermodynamic data and careful evaluation of the ternary phase diagrams.Current-generation materials are deposited in extremely thin layers (ULSI, or ultralarge-scale integration), composed of multiple elements from a variety of gas sources, an d have tailored micro-structures. As described in this article, early thermodynamic modeis helped develop deposition techniques for early-generation silicides. As the technological requirements increased, the modeling method s evolved in parallel, yielding continued insight into the relevant processes. Current work on CVD modeling couples thermodynamic calculations with heat and mass transfer. Incorporating both kinetic and thermodynamic effects, these methods provide a more realistic description of the CVD reactor.

The Phase Stability in the Fe-B Binary System: Comparison between the Interstitial and Substitutional Models

2012 ◽  
Vol 322 ◽  
pp. 1-9 ◽  
Author(s):  
Z. Nait Abdellah ◽  
Redoune Chegroune ◽  
Mourad Keddam ◽  
B. Bouarour ◽  
L. Haddour ◽  
...  
Keyword(s):  
Binary System ◽  
Phase Diagrams ◽  
Solid Solutions ◽  
Phase Stability ◽  
Thermodynamic Stability ◽  
Thermodynamic Study ◽  
Thermodynamic Calculations ◽  
Chemical Potentials ◽  
Two Phases ◽  
Good Agreement

In the present work, a thermodynamic study was carried out in order to analyze the thermodynamic stability of the and phases in equilibrium with the phase using the calculation of phase diagrams (Calphad) formalism. The two phases and are modelled as substitutional and interstitial solid solutions of boron. The expressions of the chemical potentials ofBandFeare derived in both phases to perform the thermodynamic calculations. A comparison is made between the results provided by the substitutional and interstitial models and good agreement is observed between these two models.

A new and efficient computational thermodynamics approach for magmatic systems

2021 ◽  
Author(s):  
Nicolas Riel ◽  
Boris Kaus ◽  
Eleanor Green ◽  
Nicolas Berlie ◽  
Lisa Rummel
Keyword(s):  
Phase Diagrams ◽  
Adaptive Mesh Refinement ◽  
Plate Tectonics ◽  
Parallel Machines ◽  
Computational Cost ◽  
Stable Solution ◽  
Adaptive Mesh ◽  
Thermodynamic Calculations ◽  
Stable Phase ◽  
Rock Composition

<p>During the last decade, the development of numerical geodynamic tools helped the geosciences community to unravel complex thermo-mechanical processes at play during plate tectonics. Yet, the high computational cost of thermodynamic calculations, which simulates phase change, hampers our ability to integrate complex chemistry in such problems. This is particularly important for simulating magmatic processes, where the chemistry of differentiating melts can vary significantly from the mantle to the upper crust. The typical approach, currently used, is to precompute one or many phase diagrams and use them as look-up tables. For many geodynamic processes this is adequate but when the melt chemistry varies drastically it would be better to be able to do thermodynamic calculations on the fly, along with the geodynamic models.</p><p>For that, the thermodynamic computational approach must be sufficiently fast, should work fully automatically and be tuned for melting models of magmatic systems, for example by utilizing the recently developed thermodynamic melting model of Holland et al. (2018). Existing approaches do not fulfill all criteria, which is why we have developed a new computational library for this purpose. Our code is written in C, runs on massively parallel machines (MPI) and uses an adaptive mesh refinement strategy to compute phase diagrams. At the moment we have focused on the 'igneous set' of the Holland & Powell dataset (as defined in the thermocalc software) to calculate stable phase equilibria in the system K2O–Na2O–CaO–FeO–MgO–Al2O3–SiO2–H2O–TiO2–Fe2O3–Cr2O3 (KNCFMASHTOCr). The code uses pressure, temperature and bulk-rock composition as input and returns relevant petrological and geodynamic information such as (but not restricted to) stable assemblage, phase fractions and phase densities. Different than many of the existing approaches, our method can efficiently utilize initial guesses which naturally occur in geodynamic simulations where the changes in chemistry between timesteps are usually minor.</p><p>The methodology performs a Gibbs free energy minimization and involves two main steps. First, we use a combination of levelling methods (iterative change of base) to reduce the number of potential (pure and solution) phases and to bring the G-hyperplane close to solution. Second, we use a partitioning of Gibbs energy approach coupled with local minimization to satisfy the Gibbs-Duhem rule and to retrieve the final set of stable solution phases. To illustrate the efficiency of the library up to supra-solidus conditions we present a set of dry phase diagrams and compare results of our computations with thermocalc calculations.</p><p>Ongoing development includes the treatment of solvus to extend its applicability to complex wet systems involving solution phase such as amphibole.</p>

Thermodynamics on the Modification of Inclusions by Ca and Mg Treatment in GCr18Mo Bearing Steel

2018 ◽  
Vol 382 ◽  
pp. 73-79 ◽  
Author(s):  
Meng Ran Qiao ◽  
Shu Qiang Guo ◽  
Xin Su ◽  
Hong Yan Zheng ◽  
Li Bin Qin
Keyword(s):  
Phase Diagrams ◽  
Calcium Aluminate ◽  
Thermodynamic Calculation ◽  
Bearing Steel ◽  
Thermodynamic Calculations ◽  
Liquid Inclusion ◽  
Steel Smelting ◽  
Liquid Calcium ◽  
The Stability

The effect of Mg and Ca treatment on the modification of inclusions in GCr18Mo bearing steel at 1873K was studied by thermodynamic calculations. The stability phase diagrams among Mg, Ca, Al, and O were investigated to understand the fundamentals about the formation of inclusions. The calculated results showed that: (1) Both the alumina and spinel can be modified to MgO by Mg treatment in the case of the dissolved [Mg] = 5.9ppm ~ 40ppm, corresponding the dissolved [Al] ≤ 0.056%, which can control the [O] ≤ 3ppm. (2) The MgO·Al2O3spinel can be modified to 12CaO·7Al2O3liquid inclusion by Ca treatment in the case of the optimal [Al] = 0.07% ~ 0.31% and the dissolved [Mg] ≤ 5.2ppm, the [O] can be controlled at about 3ppm. (3) The alumina can be modified to liquid calcium aluminate inclusions by Ca treatment in the case of the dissolved [Al] = 0.03% ~ 0.29% and the dissolved [Ca] = 13ppm ~ 80ppm, correspondingly the equilibrium [O] is about 3ppm. These results of thermodynamic calculation will provide a detailed thermodynamic reference for GCr18Mo bearing steel smelting.

scholarly journals Thermodynamic predicting of Si-Me (Me = Ti, Al) binary systems

2007 ◽  
Vol 43 (1) ◽  
pp. 29-38 ◽  
Author(s):  
A. Kostov ◽  
D. Zivkovic ◽  
B. Friedrich
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Analysis ◽  
Binary Systems ◽  
Thermodynamic Calculations ◽  
Gibbs Energies ◽  
Different Temperatures ◽  
Thermodynamic Determination

Thermodynamic predicting analysis of Si-based binary systems - Ti-Si, and Al-Si, are shown in this paper. Thermodynamic analysis involved thermodynamic determination of activities, coefficient of activities, partial and integral values for enthalpies and Gibbs energies of mixing and excess energies at different temperatures: 2000K, 2400K and 2473K, as well as calculation of phase diagrams for the investigated binaries. The FactSage was used for all thermodynamic calculations. .

scholarly journals Thermodynamic study of Ti-V and Al-V systems using FactSage

2006 ◽  
Vol 42 (1) ◽  
pp. 57-65 ◽  
Author(s):  
A. Kostov ◽  
D. Zivkovic ◽  
B. Friedrich
Keyword(s):  
Phase Diagrams ◽  
Binary Systems ◽  
Thermodynamic Study ◽  
Thermodynamic Calculations ◽  
Calculated Phase ◽  
Gibbs Energies ◽  
Different Temperatures ◽  
Thermodynamic Determination

Thermodynamic study of Ti-V and Al-V binary systems is presented in this paper. Investigations included thermodynamic determination of activities, coefficient of activities, partial and integral values Gibbs energies of mixing and excess energies at four different temperatures: 2000K, 2073K, 2200K and 2273K, as well as calculated phase diagrams for the investigated systems. The FactSage program was used for all thermodynamic calculations.

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