The surface tension of liquid metals and alloys was measured for the first time in microgravity using the oscillating drop technique. Data for pure gold, a congruently melting gold-copper alloy, and an eutectic zirconium-nickel alloy are presented. We find excellent agreement with available results obtained on Earth by the same technique, but only if the latter are corrected to account for gravity effects. This not only shows the necessity for the correction of the surface tension data derived from Earth-bound oscillating drop experiments, but also proves its correctness.

The results of surface tension measurements on liquid metals and alloys, performed in microgravity, are presented. Using electromagnetic levitation and the oscillating drop technique, the surface tension of gold, gold-copper, and zirconium-nickel was measured. We find excellent agreement with available results obtained on earth by the same technique, but only if the latter are corrected to account for gravity effects. This not only shows the necessity for the correction of surface tension data derived from earthbound oscillating drop experiments but also proves its correctness.

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We present the results of analytical and numerical calculations of the free-surface shape and temperature distribution produced in liquid metal droplets processed in the TEMPUS electromagnetic levitation facility. The mathematical models were developed to predict the behavior of liquid metal droplets in containerless experiments used to measure thermophysical properties aboard the Space Shuttle Columbia during the IML-2 mission in July 1994. A normal stress balance model was used to numerically calculate the equilibrium free-surface shapes for various samples produced by a number of induction coil voltages. Analytical and numerical calculations were performed to model the heat transfer in the liquid metal droplets during and following the heating coil pulses. The work illustrates the use of mathematical modeling in the design of microgravity experiments and is applicable to industrial processes such as casting and skull melting.