scholarly journals Size Sensitive Transport Behavior of Liquid Metallic Mixtures

2015 ◽  
Vol 20 (2) ◽  
pp. 140-144
Author(s):  
Bhrigunandan Prasad Singh ◽  
Ishwar Koirala
Keyword(s):  
Size Effect ◽  
Transport Properties ◽  
Diffusion Coefficients ◽  
Liquid Alloys ◽  
Long Wavelength ◽  
Binary Liquid ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Gibb’S Free Energy ◽  
Limit Diffusion

We have used a formalism that connects thermodynamic and transport properties. The formalism has been used to calculate the Gibb’s free energy of mixing, concentration fluctuations in the long wavelength limit, diffusion coefficients and viscosity in Cu-Tl, Cu-Pb and Sn-Tl binary liquid alloys at 1573K, 1473K and 723K respectively with aid of size effect and no size effect. Our calculations show that appreciable size ratio has more effects on the transport properties as compared to thermodynamic properties of homo-coordinated liquid alloys Cu-Tl, Cu-Pb and Sn-Tl.Journal of Institute of Science and Technology, 2015, 20(2): 140-144  

scholarly journals Study of size mismatches effect on transport properties in Cu-Sb and Cu-Sn liquid alloys

BIBECHANA ◽  
2014 ◽  
Vol 12 ◽  
pp. 96-103
Author(s):  
B. P. Singh ◽  
B. K. Singh ◽  
I. S. Jha ◽  
G. K. Shrestha ◽  
I. Koirala ◽  
...  
Keyword(s):  
Size Effect ◽  
Transport Properties ◽  
Concentration Dependence ◽  
Liquid Alloys ◽  
Size Mismatch ◽  
Long Wavelength ◽  
Reasonable Degree ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
And Diffusion

We report a formalism that connects thermodynamics and transport properties such as viscosity and diffusion coefficient which has been used to calculate the concentration dependence of free energy of mixing, concentration-concentration fluctuations in the long wavelength limit and concentration dependence of diffusion and viscosity in Cu-Sb and Cu-Sn binary liquid alloys at 1190K and 1400K respectively with aid of size effect and no size effect. Our calculations show that a reasonable degree of chemical order exists in both alloys system. It can be concluded that size mismatch has more effects on the transport properties of Cu-Sb hetero-coordinated system with greater size ratio than Cu-Sn hetero-coordinated system.DOI: http://dx.doi.org/10.3126/bibechana.v12i0.11781BIBECHANA 12 (2015) 96-103

Quasi-Chemical Model for Liquid Li-Cd Alloys

1989 ◽  
Vol 44 (6) ◽  
pp. 529-532
Author(s):  
L. C. Prasad ◽  
R. N. Singh
Keyword(s):  
Order Parameter ◽  
Short Range ◽  
Short Range Order ◽  
Chemical Model ◽  
Liquid Alloys ◽  
Range Order Parameter ◽  
Long Wavelength ◽  
Pairwise Interactions ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

The quasi-chemical model based on pairwise interactions is used to study the concentration dependent thermodynamic properties of Li-Cd liquid alloys. Special attention is given to the concentration-concentration correlation function in the long wavelength limit [Scc(0)] and the chemical short-range order parameter (CSRO). The activity, free energy of mixing, Scc(0) and CSRO are computed as functions of temperature and concentration.

scholarly journals Energetics and local order in In-based liquid alloys

BIBECHANA ◽  
2015 ◽  
Vol 13 ◽  
pp. 60-71
Author(s):  
RP Koirala ◽  
BP Singh ◽  
IS Jha ◽  
D Adhikari
Keyword(s):  
Thermodynamic Properties ◽  
Local Order ◽  
Heat Of Mixing ◽  
Liquid Alloys ◽  
Association Model ◽  
Long Wavelength ◽  
Energy Of Mixing ◽  
Self Association ◽  
Free Energy Of Mixing ◽  
Solution Behaviour

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

scholarly journals Thermodynamic Properties of InNa Liquid Alloy

1970 ◽  
Vol 6 (6) ◽  
pp. 16-18
Author(s):  
SK Chakrabarti ◽  
IS Jha ◽  
BP Singh
Keyword(s):  
Thermodynamic Properties ◽  
Liquid Alloy ◽  
Heat Of Mixing ◽  
Liquid Alloys ◽  
Atomic Composition ◽  
Binary Liquid ◽  
Scientific World ◽  
Energy Of Mixing ◽  
Large Asymmetry ◽  
Free Energy Of Mixing

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

scholarly journals Thermodynamic, structural, surface and transport properties of Au-Ni liquid alloy at 1150 K

BIBECHANA ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 184-192
Author(s):  
S K Yadav ◽  
N Chaudhary ◽  
D Adhikari
Keyword(s):  
Free Energy ◽  
Transport Properties ◽  
Gibbs Free Energy ◽  
Liquid Alloy ◽  
Concentration Fluctuation ◽  
Excess Gibbs Free Energy ◽  
Long Wavelength ◽  
Energy Of Mixing ◽  
Structural Surface ◽  
Free Energy Of Mixing

Thermodynamic, structural, surface, and transport properties of Au-Ni liquid alloy at 1150 K were computed using different theoretical approaches. The thermodynamic properties, such as excess Gibbs free energy of mixing, enthalpy of mixing, activity and excess entropy of mixing, and structural properties, such as concentration fluctuation in long-wavelength limit and Warren-Cowley short-range order parameter were computed in the framework of Flory’s model. The effect of positive and negative values of the interchange energy parameter on the excess Gibbs free energy of mixing and concentration fluctuation in the long-wavelength limit was also observed. The surface tension and surface concentration of the system were calculated using Butler’s model. In the transport property, the viscosity of the system was calculated using Kaptay and Budai-Benko-Kaptay (BBK) models. BIBECHANA 18 (2021) 184-192

scholarly journals Heat of Mixing of some Binary Liquid Alloys

1970 ◽  
Vol 7 (7) ◽  
pp. 96-99
Author(s):  
BK Kanth ◽  
SK Chakrabarti
Keyword(s):  
Free Energy ◽  
Successive Approximation ◽  
Chemical Model ◽  
Heat Of Mixing ◽  
Liquid Alloys ◽  
Atomic Composition ◽  
Entropy Of Mixing ◽  
Binary Liquid ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

There are a large number of binary liquid alloys the thermodynamic properties of mixing of which are not symmetrical about the equi-atomic composition-deviating maximally from those of the ideal alloys. Here we have considered three such alloys-indium-sodium, cadmium-sodium and copper-tin-and tried to calculate their heat of mixing at different concentrations of the ingredients. The liquidus lines of these alloys reveal that the constituent species form complexes. So, we have considered a quasi-lattice chemical model for computation of the thermodynamic entities. It is a statistical model in which grand partition function is used assuming that the energy of a given nearest neighbour bond is different if it belongs to the complex than if it does not. For each alloy we have started with the expression for excess free energy of mixing according to this model and computed the free energy of mixing for different concentrations of the metals within it by deriving the value of interaction parameters through successive approximation method. Thereafter, the expression for excess entropy of mixing is taken into account and the entropy of mixing is computed for different concentrations after finding out the temperature derivative of interaction parameters by the method of successive approximation. Finally the heat of mixing is calculated from these free energy of mixing and entropy of mixing on using the standard thermodynamic relation. The results explain the observed asymmetry in the heat of mixing of the said binary liquid alloys around equi-atomic composition. Key words : Binary liquid alloy; Quasi-lattice chemical model; Heat of mixing DOI: 10.3126/sw.v7i7.3836 Scientific World Vol.7(7) 2009 pp.96-99

scholarly journals Theoretical assessment for the mixing properties of AlMg liquid alloys at 1073K

2021 ◽  
Vol 2070 (1) ◽  
pp. 012074
Author(s):  
Shayista Ahmad ◽  
M P Sah ◽  
R P Chaudhary ◽  
I S Jha ◽  
J Mandal
Keyword(s):  
Free Energy ◽  
Short Range ◽  
Short Range Order ◽  
Liquid Alloys ◽  
Mixing Properties ◽  
Long Wavelength ◽  
Entropy Of Mixing ◽  
Mixing Energy ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

Abstract The alloying behavior of AlMg alloy in the liquid form at 1073 K has been theoretically investigated in the framework of four-parameter model which is based on Maclaurin series. The analytical expressions for thermodynamic functions such as excess free mixing energy, free mixing energy, enthalpy of mixing and entropy of mixing and microscopic functions such as concentration fluctuations at the long wavelength limit and Warren-Cowley chemical short range order parameter have been derived. These expressions have been used to compute the excess Gibbs free energy of mixing, Gibbs free energy of mixing, activity, enthalpy(heat) of mixing, excess entropy of mixing, entropy of mixing, concentration fluctuations in long wavelength limit and Warren-Cowley short range order parameters of AlMg liquid alloys at 1073 K. The investigation shows the excellent concurrence between the experimental and theoretical measurements of the mixing properties of AlMg liquid alloys at 1073 K. Interaction parameters of energy depends on temperature.

scholarly journals Thermodynamic Prediction of the Free Energy of Mixing and Activities of some Goldbased Binary Liquid Alloys

2020 ◽  
Vol 9 (1) ◽  
pp. 11-16
Author(s):  
Y.A. Odusote ◽  
A.I Popoola
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Reasonable Agreement ◽  
Liquid Alloys ◽  
Approximation Model ◽  
Binary Liquid ◽  
Thermodynamic Prediction ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Experimental Values

The free energy of mixing and activities of gold in selected six Au-based binary liquid Au-Cu, Au-Zn, Au-Pb, Au-Ni, Au-Sn and Al-Au alloys at different working temperatures have been studied using the quasi-chemical approximation model (QCAM). The predicted free enegry of mixing and activities results were compared with available experimental values. The predicted results are in reasonable agreement with reported experimental data and confirms that the model is reliable and, thus should serve as an alternative for the prediction of thermodynamic properties of binary liquid alloys. Keywords: free energy of mixing, activities, Au, Binary liquid alloys, concentration

scholarly journals Free Energy of Mixing of some Binary Liquid Alloys

2016 ◽  
Vol 3 (1) ◽  
pp. 97
Author(s):  
S.K. Chakrabarti ◽  
J.P. Yadav ◽  
S.M. Rafique
Keyword(s):  
Free Energy ◽  
Theoretical Work ◽  
Heat Of Mixing ◽  
Size Factor ◽  
Liquid Alloys ◽  
Binary Liquid ◽  
Energy Of Mixing ◽  
Statistical Mechanical Model ◽  
Interchange Energy ◽  
Free Energy Of Mixing

<p>Binary liquid alloys often show interesting behaviour as regards their thermodynamic properties. The heat of mixing often bears a large negative value and the entropy of mixing an S-shape. The free energy of mixing becomes asymmetric around the equi-atomic composition especially in case of complex forming alloys. In the present theoretical work we have tried to compute the free energy of mixing of some binary alloys e.g. lithium-lead, potassium amalgam and magnesium-tin―all in liquid state near their respective melting points. All these alloys form strongly interacting systems. So, we have applied Flory’s model which is a statistical mechanical model considering the size factor of the constituent species of a binary liquid alloy. We have ignored the interaction between the complex and each ingredient within an alloy and amended the formula accordingly. In the light of observed activity of a metal within an alloy we have ascertained the interchange energy by the method of successive numerical approximations and then calculated the free energy of mixing according to the said model for different concentrations of the ingredients. Our results explain the observed anomaly in the free energy of mixing of the present liquid alloys.</p><p>Journal of Nepal Physical Society Vol.3(1) 2015: 97-101</p>

scholarly journals Free Energy of Mixing of the Binary Liquid Alloys of Sodium

2012 ◽  
Vol 3 ◽  
pp. 24-26
Author(s):  
S. K. Chakrabarti ◽  
J. Akhter ◽  
R. Sinha
Keyword(s):  
Free Energy ◽  
Liquid Alloy ◽  
Binary Alloys ◽  
Successive Approximations ◽  
Method Of Successive Approximations ◽  
Liquid Alloys ◽  
Binary Liquid ◽  
Energy Of Mixing ◽  
Interchange Energy ◽  
Free Energy Of Mixing

Sodium is a highly reactive alkali metal. Within a binary liquid alloy it generally forms complexes. Due to formation of such complexes the thermodynamic properties of the binary alloys of sodium often show anomaly-deviating maximally from that of the ideal alloys. In the present work we have confined our investigation into the free energy of mixing (GM) of two binary alloys of sodium in liquid phase-Na-Pb and Na-Hg-near the melting point. For this purpose we have used Flory’s model and started with the activity of sodium in the sodium-lead liquid alloy and that of mercury in the sodium amalgam at molten stage. By the method of successive approximations we have ascertained the value of interchange energy for each alloy in the light of the experimental values of activity and finally computed GM for different concentrations of the constituent species. Our computation explains the observed symmetry and anomaly in the free energy of mixing of the Na-Pb and Na-Hg liquid alloys respectively.The Himalayan PhysicsVol. 3, No. 32012Page : 24-26

Sign in / Sign up

Export Citation Format

Share Document