The configurational entropy of mixing of metastable random solid solution in complex multicomponent alloys

2016 ◽  
Vol 120 (15) ◽  
pp. 154902 ◽  
Author(s):  
Q. F. He ◽  
Y. F. Ye ◽  
Y. Yang
Keyword(s):  
Solid Solution ◽  
Configurational Entropy ◽  
Multicomponent Alloys ◽  
Entropy Of Mixing

Modelling of solid solution strengthening in multicomponent alloys

2017 ◽  
Vol 700 ◽  
pp. 301-311 ◽  
Author(s):  
Martin Walbrühl ◽  
David Linder ◽  
John Ågren ◽  
Annika Borgenstam
Keyword(s):  
Solid Solution ◽  
Multicomponent Alloys ◽  
Solid Solution Strengthening ◽  
Solution Strengthening

Thermodynamic Properties of Actinide Oxide Solid Solutions

2008 ◽  
Vol 1125 ◽  
Author(s):  
Lindsay C. Shuller ◽  
Niravun Pavenayotin ◽  
Rodney C. Ewing ◽  
Udo Becker
Keyword(s):  
Solid Solution ◽  
Monte Carlo ◽  
Ab Initio ◽  
Density Functional ◽  
Configurational Entropy ◽  
Enthalpy Of Mixing ◽  
Fluorite Structure ◽  
Excess Gibbs Free Energy ◽  
Cation Ordering ◽  
End Members

ABSTRACTDensity functional theory and Monte(Carlo methods were used to investigate the solid( solution behavior of actinide dioxides (AcO2). The end(members of interest include: ZrO2, ThO2, UO2, NpO2, and PuO2; all have the isometric fluorite structure. Ab initio and subsequent Monte( Carlo simulations are used to calculate the excess enthalpy of mixing (ΔHexcess), excess Gibbs free energy of mixing (ΔGexcess), and excess configurational entropy (ΔSexcess) for the above solid(solution series. From ΔGexcess, phase diagrams are derived and miscibility gaps identified. All of the binaries of the aforementioned end(members were studied; however, this paper focuses on the U1(xZrxO2 and Np1(xUxO2 binaries. About 25 at.% Zr can be in solid solution with the UO2 matrix above 1500 K, while Np is completely miscible in the UO2 matrix. Partial cation ordering was observed at all temperatures for the U1(xZrxO2 binary. The Np1(xUxO2 binary approaches perfect cation disorder at high temperatures (2000 K). The cation ordering scheme is not identified in this study because the number of cation(cation interaction parameters was limited by the single unit cell from the ab initio calculations.

Mixing entropy and the nucleation of silicides: Ni–Pd–Si and Co–Mn–Si ternary systems

2003 ◽  
Vol 18 (7) ◽  
pp. 1668-1678 ◽  
Author(s):  
C. Detavernier ◽  
X. P. Qu ◽  
R. L. Van Meirhaeghe ◽  
B. Z. Li ◽  
K. Maex
Keyword(s):  
Solid Solution ◽  
Free Energy ◽  
Gibbs Free Energy ◽  
Ternary Systems ◽  
Nucleation Temperature ◽  
Alloying Element ◽  
Entropy Of Mixing ◽  
Mixing Entropy ◽  
Nucleation Barrier ◽  
The Difference

Nucleation can play an important role during the formation of silicides, especially when the difference in Gibbs free energy ΔG between the existing and newly formed phase is small. In this work, it is shown that the addition of elements that form a solid solution with either the existing or nucleating phase influences the entropy of mixing and thus changes ΔG. In this way, the height of the nucleation barrier may be controlled, thus controlling the nucleation temperature. The influence of mixing entropy on silicide nucleation is illustrated by experiments for two ternary systems: Co–Mn–Si and Ni–Pd–Si. It is shown that the nucleation temperature of CoSi2 is increased by the addition of Mn, the nucleation temperature of MnSi1.7 is increased by the presence of Co, the nucleation temperature of NiSi2 is increased by the addition of Pd, and the nucleation temperature of PdSi is decreased by the addition of Ni. In all four cases, the effect of the alloying element on the nucleation temperature can be explained by a model on the basis of the concept of mixing entropy.

scholarly journals Temperature-Dependent Configurational Entropy Calculations for Refractory High-Entropy Alloys

2021 ◽  
Author(s):  
Chiraag M Nataraj ◽  
Axel van de Walle ◽  
Amit Samanta
Keyword(s):  
Cluster Expansion ◽  
Configurational Entropy ◽  
Temperature Limit ◽  
Design Guidelines ◽  
Alloy Design ◽  
Solid Solution Alloy ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Entropy Of Mixing ◽  
The Ideal

AbstractThe cluster expansion formalism for alloys is used to construct surrogate models for three refractory high-entropy alloys (NbTiVZr, HfNbTaTiZr, and AlHfNbTaTiZr). These cluster expansion models are then used along with Monte Carlo methods and thermodynamic integration to calculate the configurational entropy of these refractory high-entropy alloys as a function of temperature. Many solid solution alloy design guidelines are based on the ideal entropy of mixing, which increases monotonically with $$N$$ N , the number of elements in the alloy. However, our results show that at low temperatures, the configurational entropy of these materials is largely independent of $$N$$ N , and the assumption described above only holds in the high-temperature limit. This suggests that alloy design guidelines based on the ideal entropy of mixing require further examination.

scholarly journals Thermodynamic Modelling of Hydrogen-Multicomponent Alloy Systems: Calculating Pressure-Composition-Temperature Diagrams

2021 ◽  
Author(s):  
Guilherme Zepon ◽  
Bruno Silva ◽  
Claudia Zlotea ◽  
Walter José Botta ◽  
Yannick Champion
Keyword(s):  
Hydrogen Storage ◽  
Configurational Entropy ◽  
Multicomponent Alloy ◽  
Multicomponent Alloys ◽  
High Entropy ◽  
Storage Media ◽  
First Approximation ◽  
Site Blocking ◽  
Simple Ideal ◽  
The Ideal

<p>The applicability of an alloy as a hydrogen storage media mostly relies on its pressure-composition-temperature (PCT) diagram. Since the PCT diagram is composition-dependent, the vast compositional filed of high entropy alloys, complex concentrated alloys or multicomponent alloys can be explored to design alloys with optimized properties for each application. In this work, we present a thermodynamic model to calculate PCT diagrams of body-centered (BCC) multicomponent alloys. The entropy of the phases is described using the ideal configurational entropy for interstitial solid solutions with site blocking effect. As a first approximation, it is assumed that the H partial molar enthalpy of a phase is constant, so the enthalpy of H mixing varies linearly with the H concentration. Moreover, the H partial enthalpy of a phase for a multicomponent alloy was approximated by a simple ideal mixture law of this quantity for the alloy’s components with the same structure. Experimental data and DFT calculations were used for parametrization of the enthalpy terms of eight elements (Ti, V, Cr, Ni, Zr, Nb, Hf, and Ta), which are the components of the alloys tested in this work. Experimental PCTs of six BCC multicomponent alloys of four different systems were compared against the calculated ones and the agreement was remarkable. The model and parameters presented here can be regarded as a basis for developing powerful alloy design tools for different hydrogen storage applications.</p>

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