scholarly journals Effect of temperature on mixing behavior and stability of liquid Al-Fe alloys

2021 ◽  
Vol 2070 (1) ◽  
pp. 012025
Author(s):  
I B Bhandari ◽  
N Panthi ◽  
S Gaire ◽  
Ishwar Koirala
Keyword(s):  
Free Energy ◽  
Surface Composition ◽  
Dynamic Properties ◽  
Enthalpy Of Mixing ◽  
Effect Of Temperature ◽  
Mixing Enthalpy ◽  
Energy Parameters ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Experimental Values

Abstract A theoretical model based on the assumption of compound formation in binary liquid alloy has been used to investigate the thermodynamic properties (free energy of mixing, enthalpy of mixing and entropy of mixing), microscopic properties (concentration fluctuation in long wavelength limit and chemical short range order parameter), surface properties (surface tension and surface composition) and dynamic properties ( viscosity and diffusion coefficient). All the properties of Al2Fe binary melt have been measured using the same energy parameters configured for experimental values of free energy of mixing. The energy parameters are detected as independent of concentration, but depend on temperature. The findings are well consistent with the experimental standards.

scholarly journals Thermodynamic and structural properties of Mg-Tl liquid alloy

BIBECHANA ◽  
2012 ◽  
Vol 8 ◽  
pp. 81-89 ◽  
Author(s):  
BP Singh ◽  
D Adhikari ◽  
IS Jha ◽  
BC Kumar ◽  
SK Chaudhary ◽  
...  
Keyword(s):  
Short Range ◽  
Enthalpy Of Mixing ◽  
Mixing Enthalpy ◽  
Mixing Properties ◽  
Long Wavelength ◽  
Energy Of Mixing ◽  
Chemical Complex ◽  
Free Energy Of Mixing ◽  
Associated Solution Model ◽  
Associated Solution

The concentration dependent asymmetry in mixing properties of Mg-Tl liquid alloys at 923 K has been investigated on the basis of regular associated solution model. The concentration of ApB type complex in a regular associated solution of Mg and Tl have been determined. We have then used the concentration of complex to calculate the free energy of mixing, enthalpy of mixing, entropy of mixing, activity, concentration fluctuations in long wavelength limit SCC(0) and the Warren Cowley short-range parameter 1 α .The analysis suggests that heterocoordination leading to the formation of chemical complex Mg2Tl is likely to exist in the melt. The analysis reveals that there is a tendency of unlike atom pairing (Mg-Tl) in Mg-Tl alloy whole range of concentration.Keywords: Mg-Tl alloy; microscopic structure; pairwise interaction energy; chemical short range orderDOI: http://dx.doi.org/10.3126/bibechana.v8i0.5692BIBECHANA 8 (2012) 81-89

scholarly journals Activity of Mercury in its Amalgams at Molten Stage

1970 ◽  
Vol 8 (8) ◽  
pp. 56-58
Author(s):  
SK Chakrabarti ◽  
BK Jha ◽  
IS Jha
Keyword(s):  
Free Energy ◽  
Successive Approximations ◽  
Method Of Successive Approximations ◽  
Size Factor ◽  
Thermodynamic Relation ◽  
Binary Liquid ◽  
Energy Of Mixing ◽  
Interchange Energy ◽  
Free Energy Of Mixing ◽  
Experimental Values

In the present work we have considered two molten amalgams e.g. sodium amalgam and potassium amalgam. Efforts are made to compute the activity of mercury therein by applying Flory's model. This statistical mechanical model is based on the size factor of the ingredients of a binary liquid alloy. In case of each of the amalgams we have started with the expression for the free energy of mixing (GM) according to this model. After knowing the ratio of the atomic volumes of the constituent species of an amalgam the prime task becomes the determination of the interchange energy (ω) between them. For this purpose the experimental values of GM for different concentrations of the ingredients of the amalgam are collected. From these known values ω has been computed by using the expression for GM. A suitable value of ω is chosen from the set of values so obtained. Putting this value of ω the free energy of mixing is calculated for several concentrations and then compared with its observed values. Accordingly, a modified value of ω has been considered and the calculations are repeated. In this way by the method of successive approximations we have ascertained the value of the interchange energy. Thereafter, with the help of standard thermodynamic relation activity has been computed. The results explain the observed anomaly of the activity of mercury in the present molten amalgams. Keywords: Binary liquid alloys; Flory's model; Amalgams; Activity of mercury. DOI: 10.3126/sw.v8i8.3850 Scientific World Vol.8(8) 2010 pp.56-58

scholarly journals Thermodynamic and structural behaviour of Tl-Na liquid alloy

BIBECHANA ◽  
2014 ◽  
Vol 12 ◽  
pp. 20-29 ◽  
Author(s):  
S. K. Yadav ◽  
L. N. Jha ◽  
D. Adhikari
Keyword(s):  
Structural Properties ◽  
Liquid Alloy ◽  
Enthalpy Of Mixing ◽  
Heat Of Formation ◽  
Liquid System ◽  
Heat Of Mixing ◽  
Structural Behaviour ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Experimental Values

In this work we intend to study the thermodynamic and microscopic structural properties of Tl-Na liquid alloy at 673 K on the basis of regular associated solution model. We have estimated the mole fractions of the complex and the free monomers assuming the complex TlNα as energetically favoured in the initial melt. In thermodynamic properties, we have computed free energy of mixing (GM), enthalpy of mixing (GM), entropy of mixing (SM) and activities of the monomers (αTl and αNα). The compositional contributions of the heat of mixing and the heat of formation of the complex to the net enthalpy change have also been studied. The microscopic structural properties of the alloy have been studied by computing concentration fluctuation in the long wavelength limit (SCC(O)), chemical short range order parameter (α1) and the ratio of mutual to intrinsic diffusion coefficients (DM/Did). Both the theoretical and the experimental values of SCC(O) are found to be less than the ideal values at all compositions which indicates the ordering nature of Tl-Na liquid alloy at 673 K. All the interaction energy parameters are found to be negative and temperature dependent. The liquid system is found to be moderately interacting.DOI: http://dx.doi.org/10.3126/bibechana.v12i0.11784BIBECHANA 12 (2015) 20-29

scholarly journals Hetero-Coordination in Liquid Pb-K Alloys

2015 ◽  
Vol 5 ◽  
pp. 87-90
Author(s):  
B. P. Singh ◽  
I. S. Jha ◽  
I. Koirala
Keyword(s):  
Enthalpy Of Mixing ◽  
Chemical Activity ◽  
Mixing Enthalpy ◽  
Interaction Energies ◽  
Molten State ◽  
Energy Of Mixing ◽  
Frame Work ◽  
Free Energy Of Mixing ◽  
Constituent Atom ◽  
Good Agreement

The observed asymmetry in properties of mixing of Pb-K alloys in the molten state is successfully explained on the basis of the quasi-lattice model. The thermodynamic functions such as free energy of mixing, enthalpy of mixing, entropy of mixing and chemical activity of the constituent atom of the alloys have been computed within the frame work of presented model. Most of the computed values are in good agreement with the experimental data. The pair-wise interaction energies between the species of the melt are found to depend considerably on temperature. Theoretical analysis suggests that hetero-coordination leading to the formation of complex Pb2K is likely to exist but is of weakly interacting in nature. The Himalayan Physics Vol. 5, No. 5, Nov. 2014 Page: 82-86

Liquidus Curves of Eutectic NaK and NaCs Systems

1984 ◽  
Vol 39 (9) ◽  
pp. 842-845 ◽  
Author(s):  
L. J. Gallego ◽  
J. M. López ◽  
J. A. Alonso
Keyword(s):  
Free Energy ◽  
Cell Surface ◽  
Enthalpy Of Mixing ◽  
Semiempirical Model ◽  
Binary Liquid ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Modified Forms ◽  
Atomic Cell ◽  
Surface Area Concentration

The Conformal Solution and Flory's expressions for the free energy of mixing ΔGM of a binary liquid alloy have been modified by using a form for the enthalpy of mixing ΔHM which incorporates the concentration dependence given by Miedema's semiempirical model. This model emphasizes the importance of the atomic cell-surface area concentration in evaluating ΔHM. The modified forms of ΔGM have been used to construct the liquidus curves of NaCs and NaK.

scholarly journals Free energy of mixing and activity of indium-tin alloy

BIBECHANA ◽  
1970 ◽  
Vol 7 ◽  
pp. 26-29 ◽  
Author(s):  
IS Jha ◽  
Arun K Khan ◽  
BC Kumar
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Liquid Alloy ◽  
Reasonable Agreement ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Experimental Values

Flory's model has been used to calculate the free energy of mixing and activity of In in InSn liquid alloy at 700 K. The values of these thermodynamic parameters obtained from this model are compared with corresponding experimental values. The computed values are in reasonable agreement with the observed values. Keywords: Flory's model; Activity; Indium-tin alloy DOI: 10.3126/bibechana.v7i0.4040BIBECHANA 7 (2011) 26-29

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 STUDY OF SEGREGATING NATURE IN LIQUID Al-Ga ALLOYS

2015 ◽  
Vol 12 (12) ◽  
pp. 14-20 ◽  
Author(s):  
I Koirala ◽  
B P Singh ◽  
I S Jha
Keyword(s):  
Surface Properties ◽  
Surface Segregation ◽  
Input Parameter ◽  
Enthalpy Of Mixing ◽  
Mixing Enthalpy ◽  
Temperature Dependent ◽  
Long Wavelength ◽  
Structural Functions ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

We report energetic of mixing behavior of liquid Al-Ga alloys, using simple statistical theory through concentration dependence thermodynamic, structural, transport and surface properties at 1023K. The concentration dependent thermodynamic functions (free energy of mixing, enthalpy of mixing, entropy of mixing and activity coefficient of the component), structural functions (concentration fluctuation in the long wavelength limit and chemical short range order parameter), transport properties (diffusivity and viscosity) and surface properties (surface segregation and surface tension) have got special attention to show a tendency of homo-coordination of atom in the mixture. The theoretical analysis reveals that input parameter, order energy is temperature dependent and Al-Ga alloys is of weakly interacting system.Scientific World, Vol. 12, No. 12, September 2014, page 14-20    

scholarly journals Thermodynamic properties of liquid InNa alloys

BIBECHANA ◽  
2012 ◽  
Vol 9 ◽  
pp. 165-174
Author(s):  
AK Mishra ◽  
M Milanarun
Keyword(s):  
Thermodynamic Properties ◽  
Theoretical Study ◽  
Stoichiometric Composition ◽  
Enthalpy Of Mixing ◽  
Mixing Enthalpy ◽  
Size Difference ◽  
Formation Model ◽  
Energy Of Mixing ◽  
Asymmetric Behaviour ◽  
Free Energy Of Mixing

Concept of complex formation model has been applied to account for the thermodynamic properties of liquid InNa alloy. The theoretical study reveals that the intermetallic compound In3Na2 exists at stoichiometric composition. Our expressions reproduce successfully the asymmetric behaviour of free energy of mixing, enthalpy of mixing, s-type entropy of mixing, CSRO and phase separation in liquid In- Na alloy. It is found that Na atoms segregate on the surface. The study reveals that various factors such as size difference and electronegative factor are not sufficient to account for the asymmetry in the system. The low value of order energy suggests that In-Na is a weak interacting system DOI: http://dx.doi.org/10.3126/bibechana.v9i0.7192 BIBECHANA 9 (2013) 165-174

Sign in / Sign up

Export Citation Format

Share Document