Dresden 2006 – wissenschaftliches Programm
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MM: Metall- und Materialphysik
MM 13: Symposium Modern Metallic Materials Design III
MM 13.3: Vortrag
Dienstag, 28. März 2006, 10:45–11:00, IFW B
Local amorphization/nanocrystallization in a bulk Ni45Cu5Ti33Zr16Si1 alloy during solidification — •K. B. Kim1, S. Yi2, H. Choi-Yim3, J. Das1,4, W. Xu1, W. L. Johnson5, and J. Eckert1,4 — 1FG Physikalische Metallkunde, FB 11 Material- und Geowissenschaften, Technische Universität Darmstadt, Petersenstraße 23, D-64287 Darmstadt, Germany — 2Department of Materials Sciences and Metallurgy, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701, Korea — 3Department of Physics, Sookmyung Women*s University, Seoul 140-742, Korea — 4IFW Dresden, Institute für Metallische Werkstoffe, Postfach 270016, D-01171 Dresden, Germany — 5Keck Laboratory of Engineering Materials, California Institute of Technology, Pasadena, California 91125, USA
A local amorphization/nanocrystallization at the interfaces between B2 ordered Ni(Ti,Zr) phase and NiTiZr phase with P63/mmc has been investigated in a multicomponent Ni45Cu5Ti33Zr16Si1 alloy during solidification. So far there are several well-known mechanisms for interfacial amorphization in the solid state but no interfacial instability-driven amorphization/nanocrystallization during transition from liquid to solid state has ever been reported. The curvature of the interfacial area of the ordered Ni(Ti,Zr) phase is locally negative accompanying reverse atomic diffusion. This results in the frustration of the strong ordering tendency of the Ni(Ti,Zr) phase, and induces local amorphization/nanocrystallization.