Specific Heat and Thermal Transport of Liquid Metallic Specimen by
Contactless ac-Calorimetry
Non contact electromagnetic modulation calorimetry was applied for the measurement of the specific heat of metallic specimen in the stable and undercooled melt under conditions of reduced gravity. With these data the thermodynamic functions and thus the stability of the undercooled liquid with regard to homogenous nucleation can be inferred. Furthermore, by variation of the modulation frequency an effective thermal conductivity in the liquid can be obtained. Modulation calorimetry was also applied in the two phase region allowing determination of the solid - liquid fraction. These properties are of considerable interest to the foundry industry for modelling of casting processes while corresponding data for high melting point reactive alloys are very scarce. In order to take full advantage of this method for example for determination of the intrinsic thermal conductivity in the liquid and two phase region detailed numerical modelling of the fluid and thermal flows in the specimen is required.