ISS Science Project Office, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)
ISS Science Project Office, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)
Space Development Division, Advanced Engineering Services Co. Ltd.
ISS Science Project Office, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)
ISS Science Project Office, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)
出版者
宇宙航空研究開発機構宇宙科学研究本部
出版者(英)
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)
雑誌名
宇宙利用シンポジウム
雑誌名(英)
Space Utilization Research: Proceedings of Space Utilization Symposium
The Twenty-fifth Space Utilization Symposium (January 14-15, 2009: ISAS/JAXA Sagamihara, Japan)
抄録(英)
The supercooling of liquid phase is important to understand and to control the solidification of casting materials. However, no significant advances have been given for its study since the period of Turnbull. This is derived from the difficulty of realization of ideal homogeneous nucleation experiment. However, at present, an ideal supercooling experiment is possible due to the advance of experimental containerless (levitation) techniques, which are now very popular experimental tools in the microgravity experiments. The supercooling is very sensitive to the concentration fluctuation of liquids. Recently by one of present authors from the electrical resistivity measurements the large concentration fluctuation has been found for the homogeneous liquid phase of many eutectic systems. This concentration fluctuation corresponds to the presolidification phenomena. In this study the supercooling experiment is performed for the Ni-Nb system with eutectic points by using the electrostatic levitation technique. It is found that the supercooling and the relative supercooling are smallest at the eutectic point. This fact strongly supports the existence of concentration fluctuation in the homogeneous liquid phase of eutectic alloy systems.