Modulated electromagnetic induction calorimetry of reactive metallic liquids

A method for the non-contact measurement of the specific heat capacity, the enthalpy of fusion and thermal transport properties of electromagnetically levitated liquid metallic alloys is described. The method is based on the separation of heating and positioning fields, modulation of the inductive heating power input and pyrometric temperature measurement making highly reactive or undercooled metallic liquids amenable to calorimetric investigation. A heat flow model based on coupled reservoirs is developed from which conditions for the accurate measurement of the specific heat capacity and of the thermal relaxation times are derived. Calibration procedures for the quantification of the modulated heating power input are described from which the specific heat capacity is obtained. Experimental results to demonstrate the principles of the method and some application results from the IML-2 and MSL-1 Spacelab missions are presented.