Melting and Solidification of Al-Pb-Bi Alloy in Short Durational Microgravity by Utilizing Airplane

Abstract

Al-Pb-Bi system is a typical system with immiscible two liquid solutions. Above the monotectic reaction temperature, Al-rich liquid solution and (Pb, Bi)-rich liquid solution coexist in the equilibrium. In this molten state, (Pb, Bi)-rich liquid drops can easily segregate gravitationally because of a large deference in density between two liquid solutions. On the other hand, in microgravity, there is no gravitational segregation and uniform dispersion of (Pb, Bi)-rich particles can be expected. In this paper, microstructural study on AI-Pb-Bi alloy molten and solidified in microgravity environment and in the terrestrial one is reported. Microgravity experiment was carried out by utilizing a parabolic flight of airplane (Mitsubishi, MU-300). In this flight experiment, microgravity environment of about 20 seconds was obtained. Furthermore, another objective of this study is to establish a basic technique for high temperature and short durational experiment in microgravity.