Metallic Melts 2 - Electrical Resistivity Measurement of High Temperature Metallic Melts - 2

This project has directly continued the research done in the frame of its preceding project "Electrical Resistivity Measurement of High Temperature Metallic Melts". Unlike its predecessor, it focuses on the measurements of alloys. The pulse heating setup at TU Graz serves as a benchmark for the results obtained from the levitation setup of DLR. The latter is designed to be carried out in microgravity environment. At this stage, parabolic flights with prototypes prepare for a future mission aboard the ISS.

Short Description

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.

Project Partners

Coordinator

Graz University of Technology, Institute of Experimental Physics - Prof. Gernot Pottlacher

Partners

German Aerospace Center (DLR), Institute of Materials Physics in Space, Cologne - Georg Lohöfer

Contact Address

Graz University of Technology - Institute of Experimental Physics
Prof. Gernot Pottlacher
Petersgasse 16
A-8010 Graz
Tel.: +43 (316) 873 8149
E-mail: pottlacher@tugraz.at
Web: www.tugraz.at