Thermophysical Properties Measurement of Al–22.5 wt pctCu in Reduced Gravity Using the ISS-EML

A hypoeutectic Al–22.5 wt pctCu sample was processed using the Electro-Magnetic Levitator on board of the International Space Station within the frame of the European Space Agency projects NEQUISOL and THERMOLAB. In total, 21 cycles of melting and cooling were carried out, with the last cycle yielding a primary undercooling of 20 K and a eutectic undercooling of 35 K. The density, surface tension, and viscosity of the liquid sample were measured using the oscillating drop method and a high-speed camera. The evolution of the temperature was recorded with a pyrometer. The oscillations of the drop appear modulated, indicative of a nonlinear behavior caused by rotation, precession, nutation of the sample, and high initial deformation. Nevertheless, the measurements are in line with previous experimental results for alloys of similar composition and with theoretical predictions. These results highlight the potential of the method to build an extensive and reliable database of the thermophysical properties of pure metals and alloys.