TU Graz Physicists Study Steel Behaviour on Board ISS
For many years, the Institute of Experimental Physics at Graz University of Technology in Styria in Austria and the Styrian industrial company Böhler Edelstahl have been conducting joint research on the surface tension and temperature dependence of different types of steel. Steel in particular is the focus of interest here, because it will be needed in metallic laser 3-D printing to produce steel components using this new remelting technology in the future. Conventional examination methods only work up to a certain upper temperature limit. At higher temperatures, problems can occur with the sample container, such as interactions between the container and the sample, and this would falsify the measuring results. This is why physicist Gernot Pottlacher and his research group use the method of levitation, which is used to study such materials. Mr Pottlacher said "This data is of great importance for both science and industry. It demonstrates how the material behaves when it is heated and cooled, that is, how it changes from the solid to the liquid phase and back again. We let the samples hover electromagnetically or electrostatically and thus avoid contact with the sample container. On Earth, gravity is not an insignificant component altogether, influencing the measuring results, but in space, this influence vanishes, allowing more accurate measurements to be made.”
For the experiments, the Styrian team works together with Japanese and American researchers and uses the Electrostatic Levitation Furnacet. ELF is an experimental setup of the Japanese Aerospace Exploration Agency JAXA in the Japanese experiment module Kibo at the International Space Station. The sample is fed into the experimental unit and positioned accordingly. A laser then heats and melts the floating steel sample. Subsequently, various sensors measure the density, surface tension and viscosity of the molten material. When the material cools down again, the researchers can observe and measure this process closely, too. The experiment is controlled from Earth, where G Pottlacher and his team follow the event live while the data obtained is passed on directly via downlink.
The L331 ELF experiment is a collaboration of various researchers and research institutions, in which in addition to the working group at Graz University of Technology, the following scientists are involved: Douglas Matson of Tufts University, Robert W Hyers of University of Massachusetts, Michael P Sansoucie of NASA Marshall Space Flight Center, Hirohisa Oda of Japan Aerospace Exploration Agency, Jannatun Nawer of Tufts University, Hideki Saruwatari of Japan Aerospace Exploration Agency, Chihiro Koyama of Japan Aerospace Exploration Agency, Wolfgang Schützenhöfer of voestalpine BÖHLER Edelstahl GmbH & Co KG and Siegfried Kleber of BÖHLER Edelstahl GmbH & Co KG.
Source : Strategic Research Institute