Determining Thermophysical Properties of Normal and Metastable Liquid Zr-Fe Alloys by Electrostatic Levitation Method

The thermophysical properties of liquid Zr-Fe alloys were experimentally measured by an electrostatic levitation technique. A series of undercoolings from 45 K to 410 K were achieved for these liquid alloys in the natural radiation cooling process. Since the experiments were conducted in high-vacuum and containerless conditions, the ratio of the specific heat to the hemispherical emissivity was deduced and showed a quadratic relationship with temperature. For the eutectic Zr₇₆Fe₂₄ alloy, the hypercooling of 306 K and hemispherical emissivity were derived theoretically due to its low liquidus temperature and scarce volatilization. Through digital image processing, the alloy densities were measured, and the results depended linearly on temperature over a wide temperature range covering both superheated and undercooled liquid states. The absolute value of the temperature coefficient tended to increase with increasing Fe contents, indicating that the liquid density sensitivity increased with increasing Fe contents. The surface tension and viscosity were also determined by a drop oscillation method under the electrostatic levitation condition.