CONTAINERLESS PROCESSING OF UNDERCOOLED MELTS - MEASUREMENTS OF SURFACE-TENSION AND VISCOSITY

Electromagnetic levitation is an elegant way of processing highly reac tive liquid metals. It avoids contact with any container walls and thu s protects the sample's surface from contamination. This is important not only for obtaining reliable surface tension data for the pure meta ls or alloys, but also for accessing the metastable. undercooled regim e. With electromagnetic levitation, the undercooled state can be maint ained for extended periods of time, allowing in situ diagnostics, i.e. non-contact measurements of thermophysical properties. The oscillatin g drop technique can be used to determine surface tension and viscosit y as a function of temperature. The frequencies of the oscillations of liquid drops are related to the restoring force, the surface tension. while the damping of the oscillations is related to the viscosity.