A new non-contact optical method for determining the thermal conductivity of metals and carbides at their melting/freezing temperatures
| Autor: | Anatoliy I. Fisenko, Vladimir F. Lemberg |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Phase transition Materials science Mechanical Engineering Thermodynamics 02 engineering and technology 01 natural sciences Drude model Freezing point Carbide Zirconium carbide chemistry.chemical_compound Thermal conductivity 020401 chemical engineering chemistry Mechanics of Materials 0103 physical sciences Solid mechanics Emissivity General Materials Science 0204 chemical engineering |
| Zdroj: | Journal of Materials Science. 53:12534-12542 |
| ISSN: | 1573-4803 0022-2461 |
| Popis: | It is now recognized that the contact methods to measure a thermal conductivity of metals and carbides in liquid/solid phase transition are facing some difficulties. On the other side, the normal spectral emissivity for these materials at melting/freezing points can be measured with high degree of accuracy. Therefore, it is of considerable interest to develop a method that makes it possible to determine the thermal conductivity through the measured value of the normal spectral emissivity. A new optical non-contact method to determine the thermal conductivity of metals and carbides at their melting/freezing points is proposed. This method is based on the use of the Drude model, the Hagen–Rubens relation, and the Wiedemann–Franz law. To define the thermal conductivity of materials at melting/freezing points, the experimental measurements of the normal spectral emissivity in a specific far-infrared range are needed. The proposed method does not require to model the power balance of heat transport for calculating the thermal conductivity. The applicability of the proposed method was demonstrated on cobalt, nickel, and zirconium carbide. A good agreement with experimental data published in the literature is obtained. The gap between the thermal conductivity of the materials under study in the solid and liquid phases at their melting/freezing temperatures is calculated. The temperature dependence of the thermal conductivity of the “ideal” solar power emitter is obtained. |
| Databáze: | OpenAIRE |
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