Heat balance in levitation melting: The influence of sample cooling by heat conduction
Georg Lohöfer and Stephan Schneider
Electromagnetic levitation melting is a containerless processing technique for liquid metals requiring non-contact diagnostic tools. In order to properly perform such experiments, a precise knowledge of the temperature-time behaviour of the metal sample resulting from the heat balance between its heating and cooling during the processing is a prerequisite. In a preceding paper we provided the necessary theoretical background for the inductive heat input by the high frequency magnetic levitation field and the heat loss due to radiation and heat conduction through a surrounding gas and defined the set of experiments needed for obtaining the key parameters of the thermal model. In the present paper we improve the previous work – based on further experiments under microgravity – by investigating in detail the influence of the sample cooling by heat conduction in a surrounding Argon and Helium gas atmosphere.
Keywords: Levitation melting, containerless processing, electromagnetic levitation, heat balance, thermal conduction, microgravity