AN ULTRAHIGH VACUUM STUDY OF WETTING IN LIQUID METAL – SOLID METAL SYSTEMS

摘要

Surface tensions of pure bismuth, lead, and lead-bismuth eutectic were determined as functions of temperature under ultrahigh vacuum conditions. The correlations were all non¬linear, surface tension increasing slightly just above the Belting point, going through a maximum, and then decreasing with further increases in temperature. The non-linear behav¬ior could be explained in terms of entropy generation caused by drop evaporation.nAdditions of zirconium to lead-blsmuth eutectic were found to increase the surface tension, when measured under UHV conditions (10 -9 torr), but to lower it when the system pressure was increased to 10-6 torr. Oxidation of the zircon-luo was found to be the cause of this as the oxide concen-trated on the surface of the drop.