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Thermophysical properties of molten refractory metals have been measured using an electrostatic levitation furnace. The developed levitation furnace could stably levitate molten samples at temperatures exceeding 3,000 C. In addition, non-contact thermophysical properties measurement techniques have been implemented. Properties such as density, heat capacity, heat of fusion, surface tension, and viscosity have been measured over wide temperature ranges, including the undercooled region., 資料番号: AA0046917081

The electrostatic levitation system, including its history and development, and techniques for non-contact thermophysical property measurements (density, surface tension, and viscosity) are reviewed. Thermophysical properties of refractory metals whose melting temperatures are over 2,000 K have been measured with an electrostatic levitator. The experimental results for vanadium, zirconium, niobium, molybdenum, rhodium, ruthenium, iridium, tantalum, rhenium, tungsten, and rhenium are presented. Comparison between theoretical calculations based on hard sphere model and measured data, as well as the necessity of microgravity conditions for this research are also discussed., 資料番号: AA0048136000, レポート番号: JAXA-RR-04-024E

The use of an hybrid pressurized electrostatic-aerodynamic levitation furnace and procedures developed by the Japan Aerospace Exploration Agency overcame the contamination problems associated with the processing of ceramics under extreme temperature conditions. This made possible property measurements over wide temperature ranges that cover the superheated as well as the supercooled states. In this study, samples of various ceramics were levitated and their densities were found as a function of temperature by extracting the area from images of a UV backlit axi-symmetric sample of known mass. In addition, the work function of each molten material was estimated using the Richardson-Dushman equation., 資料番号: AA0048452000, レポート番号: JAXA-RR-04-023E