scholarly journals Thermophysical properties of some liquid binary Mg-based alloys

2017 ◽  
Vol 53 (3) ◽  
pp. 279-284
Author(s):  
Y. Plevachuk ◽  
V. Sklyarchuk ◽  
G. Pottlacher ◽  
A. Yakymovych ◽  
O. Tkach
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Thermoelectric Power ◽  
Thermophysical Properties ◽  
Point Contact ◽  
Calculated Data ◽  
Contact Method ◽  
Concentric Cylinder ◽  
Cast Alloys ◽  
Cylinder Method

In this study, some structure-sensitive thermophysical properties, namely, electrical conductivity, thermal conductivity and thermoelectric power of liquid binary alloys Al33.3Mg66.7, Mg47.6Zn52.4 and Mg33.3Zn66.7 (all in wt.%), as the most promising cast alloys to fabricate components for cars, aircraft and other complex engineering products, were investigated. The electrical conductivity and thermoelectric power were measured in a wide temperature range by the four-point contact method. The thermal conductivity was measured by the steady-state concentric cylinder method. The obtained results are compared with literature experimental and calculated data.

scholarly journals The liquid AlCu4TiMg alloy: thermophysical and thermodynamic properties

2020 ◽  
Vol 49 (1-2) ◽  
pp. 61-73
Author(s):  
YURIY PLEVACHUK ◽  
VASYL SKLYARCHUK ◽  
GERNOT POTTLACHER ◽  
THOMAS LEITNER ◽  
PETER ŠVEC SR. ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Surface Tension ◽  
Thermoelectric Power ◽  
Pure Aluminum ◽  
Point Contact ◽  
Calculated Data ◽  
Electromagnetic Levitation ◽  
Contact Method ◽  
Concentric Cylinder ◽  
Cylinder Method

In this study, some structure-sensitive thermophysical properties, namely, thermal conductivity, thermoelectric power, density and surface tension of liquid AlCu4TiMg alloy, as one of the most promising cast alloys to fabricate components for cars, aircraft and other complex engineering products, were investigated. Thermoelectric power was measured in a wide temperature range by the four-point contact method. Thermal conductivity was investigated by the steady-state concentric cylinder method. The oscillating drop technique combined with electromagnetic levitation was used for density and surface tension studies. The results obtained are compared with experimental and calculated data from literature for pure aluminum.

scholarly journals The influence of Li on the thermophysical properties of liquid Ga–Sn–Zn eutectic alloys

2019 ◽  
Vol 30 (20) ◽  
pp. 18970-18980 ◽  
Author(s):  
A. Dobosz ◽  
Yu. Plevachuk ◽  
V. Sklyarchuk ◽  
B. Sokoliuk ◽  
T. Gancarz
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Surface Tension ◽  
Thermoelectric Power ◽  
Thermophysical Properties ◽  
Eutectic Alloys ◽  
Negative Electrodes ◽  
Density Surface ◽  
Li Ion ◽  
Li Content

Abstract The Ga–Li system is very attractive for the development of microelectronic and Li-ion cell applications as negative electrodes. In this study, thermophysical properties such as density, surface tension, viscosity, thermal and electrical conductivity, and thermoelectric power were investigated. Taking into account the intermetallic compounds occurring in Ga–Li, the measurements were conducted in a temperature range of 323–773 K. The experimentally obtained results revealed lower density and surface tension with increasing Li additions. The viscosity, electrical conductivity and thermoelectric power slightly reduced with the addition of Li content to eutectic Ga–Sn–Zn. The opposite was true of thermal conductivity, which increased slightly. The performed Nusselt number and Peclet number calculations for eutectic Ga–Sn–Zn with Li additions show similar dependency as found in literature data for Ga and Ga–In alloys.

Wärmeleitfähigkeit, elektrische Leitfähigkeit, Hall-Effekt, Thermospannung und spezifische Wärme von Ag2Se

1962 ◽  
Vol 17 (10) ◽  
pp. 886-889 ◽  
Author(s):  
Y. Baer ◽  
G. Busch ◽  
C. Fröhlich ◽  
E. Steigmeier
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Low Temperature ◽  
Specific Heat ◽  
Thermoelectric Power ◽  
Hall Coefficient ◽  
A Value ◽  
Price Formula ◽  
Elektrische Leitfähigkeit ◽  
Increasing Temperature

The thermal conductivity, electrical conductivity. Hall coefficient und thermoelectric power of Ag2Se have been measured between 80 and 600°K. In the low temperature semiconductor phase the thermal conductivity increases with increasing temperature due to the high amount of carrier contribution. The latter has been calculated using the Price formula. Agreement with experiment is satisfactory. The specific heat has been measured between 30 and 200°C. For the latent heat a value of (5.7 ± 0.5) cal/gr was determined in agreement with measurements of Bellati and Lussana 4. In addition to the transition at 133 °C an unknown new transition has been found at about 90 °C.

Experimental Measurement of Thermophysical Properties of Alumina- MWCNTs/Salt–Water Hybrid Nanofluids

2020 ◽  
Vol 16 (5) ◽  
pp. 734-747 ◽  
Author(s):  
Amir Hossein Sharifi ◽  
Iman Zahmatkesh ◽  
Fatemeh F. Bamoharram ◽  
Amir Hossein Shokouhi Tabrizi ◽  
Safieh Fazel Razavi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Salt Concentration ◽  
Thermophysical Properties ◽  
Base Fluid ◽  
Volume Fraction ◽  
Ph Value ◽  
Nanoparticle Volume Fraction ◽  
Optimal Conditions ◽  
Hybrid Nanofluids

Background: Hybrid nanofluids are considered as an extension of conventional nanofluids which are prepared through suspending two or more nanoparticles in the base fluids. Previous studies on hybrid nanofluids have measured their thermal conductivity overlooking other thermophysical properties such as viscosity and electrical conductivity. Objective: An experimental investigation is undertaken to measure thermal conductivity, viscosity, and electrical conductivity of a hybrid nanofluid prepared through dispersing alumina nanoparticles and multiwall carbon nanotubes in saltwater. These properties are the main important factors that must be assessed before performance analysis for industrial applications. Methods: The experimental data were collected for different values of the nanoparticle volume fraction, temperature, salt concentration, and pH value. Attention was paid to explore the consequences of these parameters on the nanofluid’s properties and to find optimal conditions to achieve the highest value of the thermal conductivity and the lowest values of the electrical conductivity and the viscosity. Results: The results demonstrate that although the impacts of the pH value and the nanoparticle volume fraction on the nanofluid’s thermophysical properties are not monotonic, optimal conditions for each of the properties are reachable. It is found that the inclusion of the salt in the base fluid may not change the thermal conductivity noticeably. However, a considerable reduction in the viscosity and substantial elevation in the electrical conductivity occur with an increase in the salt concentration. Conclusion: With the addition of salt to a base fluid, the thermophysical properties of a nanofluid can be controlled.

On The Thermoelectric Power And Transport Properties Of Quasicrystals

1998 ◽  
Vol 553 ◽  
Author(s):  
F. Cyrot-Lackmann
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Fermi Surface ◽  
Physical Properties ◽  
Thermoelectric Power ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Phonon Drag ◽  
Crude Estimate

Stable quasicrystals exhibit specific and unusual physical properties, such as, diamagnetism, low electrical conductivity, low thermal conductivity, and large themoelectric power at room temperature. These properties can be understood with a Bragg's reflexions scheme due to their dense filled reciprocal space.This leads to small gaps on the Fermi surface (some tenths of eV), much narrower than the usual Hume-Rothery ones (of order of 0.5 eV) which explain their stability. These gaps lead to the existence of quasi Umklapp processes, crucial for the interpretation of thermoelectric power. In some cases, the positive phonon drag contribution due to Umklapp processes, add with the electronic one's and dominates at room temperature with a large positive thermoelectric power. A crude estimate of the figure of merit gives some hope for applications of some quasicrystals and high approximants as new thermoelectric materials.

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