Thermophysical property measurements of liquid metals in microgravity

The thermophysical properties of liquid metals can be studied by electromagnetic levitation, a containerless technique. It avoids contamination of the melt and gives access to the undercooled regime allowing accurate measurements of thermophysical properties sensitive to surface contamination, like surface tension. Microgravity helps to reduce the undesirable side effects of the levitation field, such as heating, stirring and shape deformation. During the SpaceLab missions IML-2 and MSL-1, density, surface tension, viscosity and electrical conductivity of selected metals and alloys was measured in the TEMPUS levitation facility using non-contact, videographic and inductive methods. The results obtained from experiments in microgravity prove the feasibility of the approach of containerless processing and give an indication of the high quality that can be obtained. However, for parametric studies of complex alloys, as used in industrial applications, a systematic research program is necessary. In the space ...