Metallic Melts 2 - Electrical Resistivity Measurement of High Temperature Metallic Melts - 2
Our pulse heating method is especially suitable to measure the liquid phase. It can be operated without any crucible or levitation device. High heating rates of approx. 10 8 K/s and the short experimental duration (generally 50 μs) simply prevent a divergence or drop down of the liquid sample. The liquid state is of great interest for the metal-working industry.
In comparison to highly alloyed steels, binary alloys are more suitable for a research project like ours. Properties of the alloy can be traced back to the properties of the pure ingredients. Nevertheless, alloys of industrial relevance were chosen for investigation. For example, the so-called "resistance alloy" constantan consists of copper and nickel (Cu55Ni45 mass %).
This system was investigated at five different compositions. Results were compared to pure copper and pure nickel. The roughly ‘constant’ resistivity throughout the liquid phase makes this material a candidate for calibration measurements with the levitation setup aboard ISS.
There is a good congruence between the results for electrical resistivity in the liquid phase at 1750 K and the results from the levitation setup measured on Earth. Two models, calculated from pure copper and pure nickel, were also taken into consideration. This work is a nice demonstration for the interaction of basic research, applied physics, and theory, driven by the challenge of space exploration.
CuNi samples were cast at the Austrian Foundry Research Institute (ÖGI) in Leoben. The pictures show some impressions of casting and the correlated phenomena.
Graz University of Technology, Institute of Experimental Physics - Prof. Gernot Pottlacher
German Aerospace Center (DLR), Institute of Materials Physics in Space, Cologne - Georg Lohöfer
Graz University of Technology - Institute of Experimental Physics
Prof. Gernot Pottlacher
Tel.: +43 (316) 873 8149