Measurement of Surface Tension of Molten Metal under Reducing Gas Atmosphere in Microgravity Condition during Parabolic Flight: Attempt to Control Oxygen Partial Pressure

Abstract

In order to establish technology for precise measurement of surface tension of molten metals under microgravity condition during the parabolic flight of an airplane, copper was selected as the sample from the viewpoints of its oxidization tendency, oxygen partial pressure dependence of surface tension of the molten sample, and ease of heating with electromagnetic levitation. The non-combustibility of the Ar-3vol. %H2 gas that can reduce the oxygen partial pressure of the measurement atmosphere was experimentally confirmed as stipulated in the civil aeronautics law in order to employ it in the parabolic flight experiment. The surface tension of molten copper was successfully measured under the reducing gas atmosphere in microgravity during a parabolic flight experiment for the first time.