ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
A high-temperature (〉 1500 K) containerless calorimeter is described and its usefulness demonstrated. The calorimeter uses the technique of omnidirectional electron bombardment of pendant drops to achieve an isothermal test environment. The small heat input into the sample (i.e., 15–50 W) can be controlled and measured. The apparatus can be used to determine the total hemispherical emissivity, specific heat, heat of fusion, surface tension, and equilibrium melting temperature of small molten drops in the temperature range of 1500 to 3500 K. The total hemispherical emissivity εT and specific heat Cp of pure niobium and two alloys of niobium–germanium have been measured in the temperature range of 1700 to 2400 K. As reported in the literature, εT varied as a function of temperature. However, Cp values for both the pure metal and alloys seem to be independent of temperature. Cp for the liquid alloy phase was also measured and compared to the solid phase.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1138318
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