Thermophysical Properties of Molten Fe–Cu Alloy Measured Using the Electrostatic Levitation Furnace Aboard the International Space Station (ISS-ELF) under Microgravity Conditions

The thermophysical properties of molten Fe–Cu alloys, including density, surface tension, and viscosity, were measured using the electrostatic levitation furnace aboard the International Space Station (ISS-ELF) under microgravity conditions, which provided an environment that facilitated accurate measurements. The densities of the molten Fe–25at%Cu and Fe–50at%Cu alloys decreased linearly with increasing temperature, and higher copper compositions resulted in increased density. The surface tension of the molten alloys exhibited a unique up-convex temperature dependence curve that initially increased and then decreased as the temperature increased. Viscosity measurements indicated that the viscosity of the molten Fe–Cu alloys decreased with increasing temperature, following a quadratic curve, and that an increase in the copper composition resulted in lower viscosity.