scholarly journals WITHDRAWN: Enthalpies of mixing of liquid alloys of aluminum–germanium–manganese

2006 ◽  
Author(s):  
Dmitry S. Kanibolotsky ◽  
Olena A. Bieloborodova ◽  
Vladyslav V. Lisnyak
Keyword(s):  
Liquid Alloys ◽  
Enthalpies Of Mixing

Enthalpies of mixing in liquid alloys of iron with the lanthanides

2013 ◽  
Vol 104 (9) ◽  
pp. 849-857 ◽  
Author(s):  
Michael Ivanov ◽  
Vadim Berezutski ◽  
Natalia Usenko ◽  
Natalia Kotova
Keyword(s):  
Liquid Alloys ◽  
Enthalpies Of Mixing

Enthalpies of mixing in ternary Al–Gd–Mn liquid alloys

2021 ◽  
Vol 112 (9) ◽  
pp. 735-742
Author(s):  
Michael Ivanov ◽  
Natalia Usenko ◽  
Natalia Kotova
Keyword(s):  
Binary System ◽  
Ternary System ◽  
Liquid Alloys ◽  
Enthalpies Of Mixing ◽  
Minimum Value ◽  
Isoperibolic Calorimetry ◽  
Wide Range ◽  
Constituent Binary

Abstract The enthalpies of mixing in liquid alloys of the ternary Al–Gd–Mn system were determined over a wide range of compositions by means of isoperibolic calorimetry at 1650 K. The measurements of the partial enthalpies of components were performed along five sections: for the ΔH̅ Al (sections with x Gd/x Mn = 0.30/0.70 and 0.65/0.35 for x Al changed from 0 up to 0.30); for the ΔH̅ Gd (x Al/x Mn = 0.80/ 0.20 and 0.50/0.50 for x Gd changed from 0 up to 0.30); for the ΔH̅ Mn (x Al/x Gd = 0.29/0.71 for x Mn changed from 0 up to 0.26). The enthalpies of mixing in the ternary system were found to be exothermic and steadily increasing in absolute values from the Mn corner towards the Al–Gd constituent binary system, reaching the minimum value of approximately – 37 kJ · mol–1 in the vicinity of the Al0.6Gd0.4 composition, evidently related to the formation of stable Al2Gd phase.

scholarly journals FEATURES OF COMPONENT INTERACTION IN LIQUID ALLOYS OF TERNARY Al-Ge-3d-Me (Me = Mn, Fe, Ni, Cu) SYSTEMS

2020 ◽  
pp. 34-40
Author(s):  
N. Kotova ◽  
N. Usenko ◽  
N. Golovata
Keyword(s):  
Thermodynamic Properties ◽  
Binary Systems ◽  
Ternary Systems ◽  
Pair Interaction ◽  
Joint Analysis ◽  
Alloy Formation ◽  
Liquid Alloys ◽  
Component Interaction ◽  
Enthalpies Of Mixing ◽  
Constituent Binary

The features of the component interaction in liquid alloys of ternary Al-Ge-3d-Me systems (Me = Mn, Fe, Ni, Cu) are described. A joint analysis of the concentration dependences of the enthalpies of mixing of liquid alloys previously obtained by the authors via high-temperature calorimetry, and also of the phase diagrams of the constituent binary systems was carried out. The relationship between the enthalpy values and the type of short-range ordering in liquid alloys of the studied systems was established. The visual similarity of the topology of the projections of ΔmH isolines of the Al-Ge-Fe (Ni, Cu) liquid alloys and a completely different course of the isolines of the enthalpies of mixing for the liquid Al-Ge-Mn alloys are established. The changes in the absolute values of the ΔmHmin from system to system are observed. The enthalpies are approximately the same for the Al-Ge-Mn and Al-Ge-Fe systems (about -20 kJ⋅mol-1), they increase significantly from Al-Ge-Fe to Al-Ge-Ni (-50 kJ⋅mol-1), and then decrease substantially towards the Al-Ge-Cu system (-15 kJ⋅mol-1). For the Al-Ge-Mn (Fe, Ni, Cu) liquid alloys the lines of extreme interaction are located near the 3d-corner of the concentration triangle. These lines connect the compositions of the most stable intermetallic compounds in binary Al(Ge)-Mn(Fe, Ni, Cu) systems. It has been shown that the thermodynamic properties of Al-Ge-Fe (Ni, Cu) liquid alloys are mainly determined by the pair interaction of the components of the constituent binary Al-Fe(Ni, Cu) and Ge-Fe(Ni, Cu) systems, the influence of Al-Fe(Ni, Cu) systems being prevailed. For the Al-Ge-Mn system, the interaction of components in the Ge-Mn binary system gives the main contribution to the thermodynamic properties of the ternary system. The Al-Ge-Mn (Fe, Cu) systems are characterized by significantly lower absolute values of the heats of alloy formation compared to the Al-Ge-Ni one. The specified characteristics of component interaction in the ternary systems under consideration and different values of the enthalpies of mixing are determined by the peculiarities and regular changes of the electronic structure of 3d metals across the 3d series from Mn to Cu.

scholarly journals Thermochemical properties of liquid alloys along xCu/xSb= 0.2/08 section of the ternary Cu-Sb-Ce system

2017 ◽  
Vol 5 (2) ◽  
pp. 24-29 ◽  
Author(s):  
Natalia Kotova ◽  
Michael Ivanov ◽  
Natalia Usenko
Keyword(s):  
Experimental Data ◽  
High Temperature ◽  
Cross Section ◽  
Analytical Method ◽  
Composition Dependence ◽  
Liquid Alloys ◽  
Thermochemical Properties ◽  
Enthalpies Of Mixing ◽  
The Cross ◽  
Toop Model

The enthalpies of mixing of liquid alloys of the ternary Cu–Sb–Ce system were studied by high-temperature calorimetry along the cross-section = 0.2/0.8. The composition dependence of these values were modelled using four "geometric" models and also the analytical method of Redlich–Kister–Muggianu. A comparison of the experimental data for the cross section = 0.2/0.8 and simulated values of the enthalpies of mixing showed that the most suitable for describing the properties of liquid alloys of ternary Cu–Sb–Ce system is the Toop model.

Enthalpies of mixing in ternary Ce–Cu–Sb liquid alloys

2019 ◽  
Vol 110 (11) ◽  
pp. 1058-1065
Author(s):  
Michael Ivanov ◽  
Natalia Usenko ◽  
Natalia Kotova ◽  
Natalia Golovataya
Keyword(s):  
Liquid Alloys ◽  
Enthalpies Of Mixing

scholarly journals MODELING OF THERMOCHEMICAL PROPERTIES AND GLASSFORMING TENDENCY OF THE MELTS OF TERNARY Mn–Al–Gd SYSTEM

2018 ◽  
pp. 46-50
Author(s):  
N. Kotova ◽  
N. Golovata ◽  
N. Usenko
Keyword(s):  
Ternary System ◽  
Binary Systems ◽  
Hard Spheres ◽  
Regular Solution Model ◽  
Ternary Systems ◽  
Ternary Alloys ◽  
Liquid Alloys ◽  
Thermochemical Properties ◽  
Ternary Compounds ◽  
Enthalpies Of Mixing

In the present work, the enthalpies of mixing of liquid alloys of the ternary Mn-Al-Gd system have been calculated using the regular solution model by the Redlich-Kister-Muggianu formula. Also a comparison was made of calculated values of enthalpies of mixing in this system with the experimentally determined thermochemical properties of liquid alloys of the Mn-In-Gd ternary system obtained previously. In general, we estimate that the values of the enthalpies of mixing in the Mn-Al-Gd ternary system should be more exothermic than in the Mn–In-Gd one. This fact can be explained taking into consideration the main features of the component interaction in the boundary binary systems, namely, such important characteristics as electronegativity of the components, their electron work functions and a large difference in size of atoms. It can be concluded that it is the binary Mn–Al system that makes a significant contribution to the formation energy of ternary alloys. An imaginary line drawn through the points of maximum curvature of the isoenthalpic lines is considerably shifted towards the binary Mn–Al boundary, thus expanding significantly the region of rather exothermic enthalpies of mixing in the corresponding ternary system. For the two indicated ternary systems the size mismatch entropy has been calculated within the framework of hard spheres model and the Sσ/kB parameter has been determined. On the basis of the comprehensive analysis carried out, the criteria for the probability of occurrence of regions of easy amorphization in these ternary systems are proposed. The determination of the topology of the mixing enthalpy surface and the Sσ/kB parameter for the melts of studied ternary systems together with the data on binary and ternary compounds existing in these systems allowed to reasonably assume the concentration regions where the investigated ternary alloys have tendency for easy amorphization while rapid cooling of the melt. The simultaneous realization of the following three conditions was taken as a criterion for the possible existence of a region of easy amorphization: the absolute value of the enthalpies of mixing is at least 6 kJ/mol, the Sσ/kB parameter is not less than 0.3–0.4 and a certain distance from the concentration region corresponding to the exact composition of binary or ternary compounds.

Enthalpies of mixing in binary Cu–Eu and ternary Al–Cu–Eu liquid alloys

2020 ◽  
Vol 111 (4) ◽  
pp. 273-282
Author(s):  
Natalia Usenko ◽  
Michael Ivanov ◽  
Natalia Kotova
Keyword(s):  
Ternary System ◽  
Enthalpy Of Mixing ◽  
Integral Enthalpy ◽  
Liquid Alloys ◽  
Temperature Range ◽  
Enthalpies Of Mixing ◽  
Minimum Value ◽  
Isoperibolic Calorimetry ◽  
Wide Range ◽  
Binary Constituent

Abstract The enthalpies of mixing in liquid alloys of the binary Cu-Eu and ternary Al-Cu-Eu systems were determined over a wide range of compositions by means of isoperibolic calorimetry in the temperature range 1 300 - 1450 K. The enthalpies of mixing in the Cu-Eu system demonstrate small exothermic effects (ΔHmin = -4.1 ± 0.5 kJ · mol-1at xCu = 0.70). The measurements for the liquid ternary Al- Cu-Eu alloys were performed along five sections (xCu/ xEu = 0.70/0.30; 0.50/0.50 and 0.27/0.73 for xAl changed from 0 up to 0.30 and xAl/xEu = 0.20/0.80 and 0.47/0.53 for xCu changed from 0 up to 0.30). The enthalpies of mixing in the ternary system were found to be exothermic and increasing in absolute values from the Al corner towards the Al0.40Cu0.60-Al0.60Eu0.40section and from the constituent binary Cu-Eu system towards the same section. The minimum value of the integral enthalpy of mixing is expected in the vicinity of the Al0.6Eu0.4composition of the binary constituent Al-Eu system (about -23.00 kJ · mol-1).

Partial and integral enthalpies of mixing of Ag–Ga–Sn liquid alloys

2011 ◽  
Vol 523 (1-2) ◽  
pp. 51-62 ◽  
Author(s):  
D. Li ◽  
S. Delsante ◽  
W.Gong ◽  
G. Borzone
Keyword(s):  
Liquid Alloys ◽  
Enthalpies Of Mixing

scholarly journals MODELING OF THERMODYNAMIC PROPERTIES OF THE MELTS OF TERNARY Ge-Mn-Gd SYSTEM

2019 ◽  
pp. 18-22
Author(s):  
N. Golovata ◽  
N. Kotova ◽  
N. Usenko
Keyword(s):  
Thermodynamic Properties ◽  
Gibbs Energy ◽  
Ternary System ◽  
Binary Systems ◽  
Thermodynamic Characteristics ◽  
Published Data ◽  
Liquid Alloys ◽  
Model Calculations ◽  
Enthalpies Of Mixing ◽  
Gibbs Energies

In the present work, the Gibbs energies of mixing of liquid alloys of the Ge-Mn-Gd ternary system were determined, which was made on the basis of an analysis of published data on the thermodynamic properties of liquid alloys of boundary binary systems that form the ternary Ge-Mn-Gd, as well as on the basis of the model calculations in these binary systems. To determine the activities of the components, the Gibbs energies of mixing, and the enthalpies of mixing of liquid alloys of the Ge-Mn(Gd) systems, for which alloying process is accompanied by significant heat release, an ideal associated solution model was applied. For the melts of the Mn-Gd system, which are characterized by rather insignificant exothermic effects, a model of regular solutions was used. The surface of the Gibbs energy of mixing for the alloys of the Ge-Mn-Gd ternary system has been determined on the basis of the concentration dependences of the Gibbs energies of mixing obtained for constituent binary systems under the assumption of additivity of pair interactions using the Redlich-Kister-Muggianu method. The obtained topology of the Gibbs energy isolines projections is compared with the thermochemical properties of liquid alloys of this system that we have determined earlier. A comparative analysis of the topology of these surfaces in the Ge-Mn-Gd system led to the conclusion that the surfaces of ΔG and ΔmH monotonically decrease from the manganese-rich angle of the diagram towards the Ge-Gd side of the concentration triangle. The minimum value of the thermodynamic characteristics of mixing of the ternary liquid alloys corresponds to the composition, which coincides with the composition of the most stable intermetallic compound in the Ge-Gd system. From the course of isolines of free energies and integral enthalpies of mixing, one can also conclude about the influence of a short-range order, existed in the Ge-Mn system near the composition with a mole fraction of mangan greater than 0.7, on the properties of ternary alloys in the vicinity of this composition. Thus, the topology of isolines and the large exothermic values of the obtained thermodynamic properties allow us to make a reasonable conclusion that the strong interaction between unlike components inherent in the Ge-Gd system in the solid state is also maintained for liquid alloys of the Ge-Mn-Gd system.

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