Thermal Conductivity Measurement of Molten Al-Si Alloy by Hot-Disk Method with Minimal Influence of Thermal Convection

Abstract

  A technique for measuring the thermal conductivity of molten metals using the hot disk method with minimal influence of thermal convection was developed. First, the thermal conductivity of molten Bi, Sn, and Al was measured by employing a measurement time of less than 0.8 s for molten Sn and Bi, 0.5 s for molten Al. The measured results were in good agreement with the recommended values by Assael et al. and Touloukian et al., and those measured in microgravity. Next, the thermal conductivity of molten Al-Si alloys was measured. The thermal conductivity of molten Al-Si alloys was significantly lower than that of solid Al-Si alloys, and increased with increasing temperature. This tendency can be explained by the Wiedemann-Franz law. Moreover, the thermal conductivity of molten Al-Si alloys was found to decrease with increasing Si content.