MICROGRAVITY CONDITIONS AND ELECTRICAL-RESISTIVITY OF LIQUID ALLOYS WITH CRITICAL MIXING

The phenomena of two-liquid phase separations are significantly influe nced by the gravity on the ground because of the difference in the den sities of the constituent components, particularly, in the case of liq uid alloys with critical mixing. In this paper, experimental technique s and results are reported for the measurements of the electrical resi stivity for typical liquid alloys with critical mixing, such as Bi-Ga, under microgravity by the use of a rocket S520-19 belonging to ISAS ( Institute of Space and Astronautical Science, Japan), It was found tha t the temperature coefficient of the electrical resistivity, on coolin g of the homogeneous liquid phase, increases with the approach to the critical temperature. This trend under microgravity by the rocket expe riment is more pronounced compared to the trend of the reference exper iment on the ground. In addition, the supercooling of homogeneous liqu ids under microgravity is larger than that on the ground. These differ ences are explained by the difference in;he degree of the growth of co ncentration fluctuations; the concentration fluctuations are far great er under microgravity than on the ground. Therefore, it is found to be very important to study the process and the critical phenomena of two -liquid phase separations under microgravity. Measurement of electrica l resistivity is an effective method to obtain informations about the process, the critical phenomena, and the supercooling of two-liquid ph ase separations in liquid alloys with critical mixing.