Normal spectral emittance of W-Re-HfC and W-Re-ThO2 alloys
| Autor: | N. O. Moraga, Mysore L. Ramalingam, Dean L. Jacobson, Bang-Hung Tsao |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Fluid Flow and Transfer Processes
Materials science Mechanical Engineering Aerospace Engineering chemistry.chemical_element Rhenium Tungsten Condensed Matter Physics law.invention Carbide Hafnium Condensed Matter::Materials Science chemistry Space and Planetary Science law Surface roughness Emissivity Physics::Accelerator Physics Thermal emittance Atomic physics Pyrometer |
| Zdroj: | Journal of Thermophysics and Heat Transfer. 6:680-684 |
| ISSN: | 1533-6808 0887-8722 1500-2500 |
| DOI: | 10.2514/3.11551 |
| Popis: | A photon counting pyrometer was used effectively in determining the normal spectral emittance of tungsten, rhenium alloys at 1500-2500 K. These tungsten, rhenium alloys were then compounded with thoria and hafnium carbide separately, and the normal spectral emittance for these combinations of alloying systems were generated in the same temperature regime. Although spectral emittance could be a strong function of several variables, such as surface roughness, wavelength of interference filters, in addition to alloying content, our investigation was centered around the effects of alloying thoria and hafnium carbide on the normal spectral emittance of tungsten, rhenium alloys. The normal spectral emittance of W-Re-ThO2 and W-Re-HfC decreased with respect to the temperature. Addition of HfC-ThO2 apparently raises the emittance compared to that obtained with the previous results for W-Re alloys. HfC exhibited a stronger dependence of emittance on temperature, compared to ThO2. Reproducible data were also generated with a maximum deviation of 1.5%. The effect of cavity size indicated that normal spectral emittance could be used between 1500 and 2500 K to correct the difference between the cavity and ideal blackbody temperatures when the length-to-diameter ratios were larger than eight. |
| Databáze: | OpenAIRE |
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