Surface Tension and Density of Liquid Metallic Alloys Measured by Electromagnetic Levitation

Abstract

Reliable thermophysical data form the basis of any accurate solidification simulation. For the liquid phase of high-temperature metallic alloys, such data are scarce. In recent years, containerless methods, in particular electromagnetic levitation, have paved the way for noncontact measurement methods allowing precise determination of crucial thermophysical properties such as density, thermal expansion, and surface tension for this class of materials. Systematic investigations of the thermophysical properties of copper-based, nickel-based, and aluminum-based alloys have been carried out by the authors. This paper reviews the noncontact methodology used and provides a listing of the results obtained so far. Densities are discussed in terms of molar and excess volumes, whereas surface segregation is the key to understanding surface tensions of alloys.