Emissivities and Optical Constants of Electromagnetically Levitated Liquid Metals as Functions of Temperature and Wavelength

Krishnan, Shankar; Hansen, G. P.; Hauge, Robert H.; Margrave, John L.

doi:10.1007/978-1-4612-0481-7_11

Cited by 25 publications

(31 citation statements)

References 24 publications

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“…This is a good approximation for most metals; see Ref. 6. To measure the density based on the volume of the sample, it is of particular importance that the sample is fully visible from the side.…”

Section: Methodsmentioning

confidence: 99%

Density and Thermal Expansion of Liquid Au-Cu Alloys

Brillo

Egry

Giffard

et al. 2004

International Journal of Thermophysics

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The density of liquid Cu-Au alloys is measured using the technique of electromagnetic levitation, which entails producing a shadow image of the sample. The shadow is recorded by a digital CCD-camera, and the volume of the sample is calculated by an image processing algorithm. The density and thermal expansion of several alloys and the pure elements copper and gold are investigated at various temperatures above their melting points. In addition, the densities are also investigated as a function of the gold concentration at constant temperature. The measured values agree with literature data and with predictions obtained by molecular dynamics. It was found from data analysis that the ideal solution model applies.

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Section: Methodsmentioning

confidence: 99%

Density and Thermal Expansion of Liquid Au-Cu Alloys

Brillo

Egry

Giffard

et al. 2004

International Journal of Thermophysics

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“…Equation (8) is valid only if the sample emissivity at the operating wavelength of the pyrometer ε λ (T ) remains constant over the experimentally scanned range of temperature. This is a good approximation for most metals [16].…”

Section: Levitationmentioning

confidence: 97%

Density and Surface Tension of Liquid Ternary Ni–Cu–Fe Alloys

2006

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The density and surface tension of liquid Ni-Cu-Fe alloys have been measured over a wide temperature range, including the undercooled regime. A non-contact technique was used, consisting of an electromagnetic levitator equipped with facilities for optical densitometry and oscillating drop tensiometry. At temperatures above and below the liquidus point, the density and surface tension are linear functions of temperature. The concentration dependence of the density is significantly influenced by a third-order (ternary) parameter in the excess volume. The surface tensions are rather insensitive to substitution of the two transition metals Ni, Fe against each other and depend only on the copper concentration. By numerically solving the Butler equation, the surface tension of the ternary system can be derived from the thermodynamic potentials E G of the binary phases (Ni-Cu, Fe-Cu, Ni-Fe) alone.

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“…[7,8,9] One-color pyrometers, therefore, are applied to the temperature measurements for liquid metals at high temperatures. Many investigations have been attempted to determine spectral emissivities for liquid metals such as gold, [9][10][11][12][13] silver, [9,11,12,14,15] copper, [7,9,[11][12][13][14][15][16][17][18] nickel, [9,11,12,15,16,[19][20][21] iron, [11,12,15,16,19,[22][23][24] and so on [12,15,16,21,24] at their melting points, since these data can be used in practice as standard values of emissivities for their liquids.…”

Section: Introductionmentioning

confidence: 99%

Discontinuity in normal spectral emissivity of solid and liquid copper at the melting point

Watanabe

Susa

Nagata

1997

Metall Mater Trans A

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Normal spectral emissivities for solid (ε ,solid ) and liquid (ε ,liquid ) copper at the melting point have been determined, and the discontinuity in ε ,liquid and ε ,solid at the melting point has been discussed. The spectral emissivity was determined by comparing the spectral radiation intensity of the sample to that of the fixed-point blackbody over the wavelength range 550 to 750 nm. The samples and fixed-point blackbody were heated in the continuous casting type cold crucible. Values of ε ,liquid and ε ,solid at 650 nm were 0.167 and 0.108, respectively. The emissivity ratio of ε ,liquid /ε ,solid increased from approximately 1.2 to 1.8 as the wavelength increased in the range 550 to 750 nm. The discontinuity in ε ,liquid and ε ,solid at the melting point has been qualitatively explained by the optical absorption mechanism due to the intraband transition.

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Emissivities and Optical Constants of Electromagnetically Levitated Liquid Metals as Functions of Temperature and Wavelength

Cited by 25 publications

References 24 publications

Density and Thermal Expansion of Liquid Au-Cu Alloys

Density and Thermal Expansion of Liquid Au-Cu Alloys

Density and Surface Tension of Liquid Ternary Ni–Cu–Fe Alloys

Discontinuity in normal spectral emissivity of solid and liquid copper at the melting point

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