Dresden 2006 – wissenschaftliches Programm
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MM: Metall- und Materialphysik
MM 13: Symposium Modern Metallic Materials Design III
MM 13.10: Vortrag
Dienstag, 28. März 2006, 13:00–13:15, IFW B
Undercooling and unidirectional solidification of Ni-Cu melts by electromagnetic levitation facility — •Qiang Wang1, Riping Liu1, Q. Jing1, M. Z. Ma1, Christian Panofen2, and Dieter M. Herlach2 — 1Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, Hebei, P. R. China — 2Institute of Space Simulation, German Aerospace Center DLR, D-51170 Koeln, Germany
Deep undercooling of metallic melt is a widely used method for investigation of nucleation and crystal growth during solidification. To obtain deep undercooling, electromagnetic levitation has been proved to be one of the most important techniques. A great deal of research has been given to nucleation, crystal growth, metastable phase formation (including metallic glass formation), thermal and physical properties of the undercooled melts, etc. Usually, the melt samples treated by this technique are spherical influenced by the gravity and the surface tension.
In this experiment, we report a new way to produce cylindrical undercooled melt samples with temperature gradients at different levels, and to investigate rapid unidirectional solidification of the undercooled melts. The cylindrical sample of Ni-Cu alloy, 5mm in diameter and 50 mm in height, was wrapped in dehydrated B2O3 flux in a quartz tube, and then heated by a gradient RF coil in an electromagnetic levitation facility. Treated by several cycles of heating and cooling, undercooling and directional solidification of the sample were obtained.