Study of excess free energy of mixing and heat of mixing of liquid ternary Al–Li–Zn alloy by assessing the thermodynamic properties of sub-binary alloys

2021 ◽  
Vol 610 ◽  
pp. 412941
Author(s):  
R.K. Gohivar ◽  
S.K. Yadav ◽  
R.P. Koirala ◽  
D. Adhikari
BIBECHANA ◽  
1970 ◽  
Vol 8 ◽  
pp. 90-95
Author(s):  
D Adhikari

Flory’s model has been used for the study of thermodynamic properties of Cd-Bi liquid alloys. Free energy of mixing, heat of mixing, entropy of mixing and activity of Cd have been determined. All of these computed quantities have been found to be in a good agreement with observed values.Keywords: Flory’s model; thermodynamic properties; Cd-Bi liquid alloy; weakly interacting system; interaction energy parameter  DOI: http://dx.doi.org/10.3126/bibechana.v8i0.5693  BIBECHANA 8 (2012) 90-95


1997 ◽  
Vol 11 (02n03) ◽  
pp. 93-106 ◽  
Author(s):  
O. Akinlade

The recently introduced four atom cluster model is used to obtain higher order conditional probabilities that describe the atomic correlations in some molten binary alloys. Although the excess free energy of mixing for all the systems studied are almost symmetrical about the equiatomic composition, most other thermodynamic quantities are not and thus, the study enables us to explain the subtle differences in their physical characteristics required to describe the mechanism of the observed strong heterocoordination in Au–Zn or homocoordination in Cu–Ni within the same framework. More importantly, we obtain all calculated quantities for the whole concentration range thus complimenting experimental evidence.


2011 ◽  
Vol 391-392 ◽  
pp. 1017-1021
Author(s):  
Ru Zhang ◽  
Yan Fen Wu ◽  
Ping Hu

Six binary silane systems were chosen to calculate the activity coefficients (γ) and free energies of mixing (ΔGm). These systems included: methyldichlorosilane + methyltrichlorosilane, methyldichlorosilane + methylvinyldichlorosilane, methyldichlorosilane + toluene, methyltrichlorosilane + methylvinyldichlorosilane, methyltrichlorosilane + toluene, methylvinyldichlorosilane + toluene. Based on the Antoine constants, critical parameters of the pure components and Wilson model parameters, γ and ΔGmwere calculated. The influence factors of these thermodynamic properties were also discussed.


2021 ◽  
Vol 14 (2) ◽  
pp. 111-116

Abstract: The thermodynamic model based on clustering of two atoms is considered with the view to obtain the concentration-concentration fluctuation, Scc(0) and the darken stability function. The thermodynamic properties of these alloys were evaluated based on clustering of two atoms (A & B) or (B & A). Each system has the view of obtaining concentration-concentration fluctuation, Scc(0) enumerating the low-order atomic correlation in the nearest neighbour shell of liquid binary alloys. The highlights of reciprocals of Scc(0) of these alloys were noted . The values of Scc(0) for Al-In alloy throughout the entire concentration were positive and higher for activity ratio and lower than the ideal solution values for free energy of mixing at specific Al composition. The values of darken stability function of Al-In alloy fall below the ideal darken stability function for activity ratio and free energy of mixing . The indication of the reciprocal of Scc(0) for all the alloys is in support of homocoordination / heterocoordination in the nearest neighbour shell. The Scc(0) and darken stability function of Bi-Zn binary alloys were noted with fluctuations. Keywords: Concentration-concentration fluctuation, Darken stability function, Ordering energy.


BIBECHANA ◽  
2017 ◽  
Vol 15 ◽  
pp. 11-23
Author(s):  
G K Shrestha ◽  
I S Jha ◽  
B K Singh

The thermodynamic properties, i.e. free energy of mixing (GM), heat of mixing (HM), entropy of mixing (SM) and activity (ai) of the component i (i , and structural property i.e. concentration fluctuations in long wave-length limit [Scc(0)] of In-Tl binary liquid alloy at a specified temperature have been investigated in the framework of quasi-lattice model on assuming the coupled effect of size ratio and entropic (or energetic) as well as enthalpic effect. These properties of In-Tl liquid alloy at 723 K have been computed theoretically by estimating the best fit value of order energy parameter (W) and size ratio () over the entire range of concentration in order to match their experimental values. The best fit value of  W at 723 K has been used to determine the values of W at different temperatures with the help of temperature derivative of W which are then used for the optimization procedure in order to calculate the corresponding values of excess free energy of mixing, partial excess free energy of mixing and activity of the components involved in the alloy at different temperatures. These parameters have been used to investigate the concentration fluctuations in long wavelength limit {Scc(0)} of In-Tl binary liquid alloy at different temperatures over the entire range of concentration which have been used to predict the various other structural properties like excess stability function (EXS), diffusion coefficient ratio (Dm/Did), short range order parameter (α1) at different temperatures.BIBECHANA 15 (2018) 11-23


BIBECHANA ◽  
2015 ◽  
Vol 13 ◽  
pp. 60-71
Author(s):  
RP Koirala ◽  
BP Singh ◽  
IS Jha ◽  
D Adhikari

A comparative study has been carried out to understand the concentration dependence of thermodynamic properties such as, free energy of mixing, heat of mixing, entropy of mixing, activity  and microscopic properties, such as concentration fluctuation in long wavelength limit  and Warren-Cowley short range order parameter  of  In-based three liquid alloys (In-Pb , In-Tl and In-Zn) on the basis of self-association model. The analysis reveals that self-association model successfully explains the observed properties of the liquid alloys.  Positive deviation of the thermodynamic properties of the alloys from the Raoultian solution behaviour indicates that the alloys are weakly segregating in nature. The comparative assessment of the interaction energy and the microscopic properties suggests that the degree of segregation is greatest in In-Zn alloy and comparable in In-Pb and In-Tl alloys.BIBECHANA 13 (2016) 60-71


1970 ◽  
Vol 48 (22) ◽  
pp. 3483-3486 ◽  
Author(s):  
A. D. Pelton ◽  
S. N. Flengas

The phase diagram of the RbCl–NaCl system has been measured by the method of cooling curves. By combining these data with available thermochemical data for the system, the integral molar excess free energy of mixing at 800 °C has been calculated as ΔGE = −632XRbClXNaCl cal/mole; and the integral molar excess entropy of mixing has been calculated as ΔSE = −0.208XRbClXNaCl cal/°K mole. Estimated precisions are ±50 cal for ΔGE and ±0.05 cal/°K mole for ΔSE at XRbCl = XNaCl = 0.5.


This paper describes a new statistical approach to the theory of multicomponent systems. A ‘conformal solution’ is defined as one satisfying the following conditions: (i) The mutual potential energy of a molecule of species L r and one of species L s at a distance ρ is given by the expression u rs (ρ) = f rs u 00 ( g rs ρ ), where u 00 is the mutual potential energy of two molecules of some reference species L 0 at a distance ρ , and f rs and g rs are constants depending only on the chemical nature of L r and L s . (ii) If L 0 is taken to be one of the components of the solution, then f rs and g rs are close to unity for every pair of components. (iii) The constant g rs equals ½( g rr + g ss ). From these assumptions it is possible to calculate rigorously the thermodynamic properties of a conformal solution in terms of those of the components and their interaction constants. The non-ideal free energy of mixing is given by the equation ∆* G = E 0 ƩƩ rs x r x s d rs , where E 0 equals RT minus the latent heat of vaporization of L 0 , x r is the mole fraction of L r and d rs denotes 2 f rs — f rr — f ss . This equation resembles that defining a regular solution, with the important difference that E 0 is a measurable function of T and p , which makes it possible to relate the free energy, entropy, heat and volume of mixing to the thermodynamic properties of the reference species; and the predicted relationships between these quantities agree well with available data on non-polar solutions. The theory makes no appeal to a lattice model or any other model of the liquid state, and can therefore be applied both to liquids and to imperfect gases, and to two-phase two-component systems near the critical point.


1970 ◽  
Vol 6 (6) ◽  
pp. 16-18
Author(s):  
SK Chakrabarti ◽  
IS Jha ◽  
BP Singh

The large asymmetry observed in the properties of mixing of indium-sodium liquid alloy is discussed on the basis of quasi-lattice chemical model. A special attention is given to the concentration dependence of free energy of mixing, entropy of mixing and heat of mixing. The results explain the observed asymmetry in the properties of mixing of InNa liquid alloys around equi-atomic composition. Key words: Complex forming alloys; Binary liquid alloys; Quasi-lattice model; Thermodynamic properties. DOI: 10.3126/sw.v6i6.2627 Scientific World, Vol. 6, No. 6, July 2008 16-18


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