Density and surface tension measurements of molten Al-Si based alloys

This study is part of a series of studies aimed at measuring the thermophysical properties of molten phase change material-type metallic thermal energy storage mate-rials near 873 K (600 degrees C). The target material is Al-Si based alloys. First, as a feasibility study, density measurements of the molten state of three Al-Si binary alloys (Al-12.2Si, Al-50Si and Al-90Si in atomic%) were performed. A highly accurate non-contact density measurement method based on the static magnetic field superposition electromagnetic levitation (EML) method was employed as the density mea-surement method. The validity of this experimental method was confirmed, and density of molten Al-Si base alloys (ADC12 and Al-5.9mass%Si-1.6mass%Fe) were measured as a function of temperature with an expanded uncertainty of 1.2%. In addition, the surface tension of the alloys was measured by the droplet oscillation method using the EML technique. The surface tension was successfully obtained as a function of temperature with expanded uncertainty of 2.3%.