METTRANS - Metastable Solidification of Composites: Novel Peritectic Structures - Studies with Transparent Model Alloys

Transparent model systems of peritectics are quite attractive for furthering our understanding of solidification of metastable in situ composites. Such systems offer the advantage that both the morphology and the dynamics of solidification can be investigated by using optical diagnostic means.

The comparison of experiments both on Earth and in Space gives access to determine directly the effect of gravitational phenomena as natural convection on the growth morphology and dynamics of peritectic solidification. In cooperation with the ESA-MAP project METCOMP, the present project is intended to directly observe morphological changes of the solid/liquid interface for the transparent metal-like solidifying peritectic model system Neopentylglycol - Tris(hydroxyl-methyl)aminoethan.

It is planned to perform systematic studies of the peritectic solidification phenomena, which occur at the limit of constitutional undercooling around the peritectic point.

As known in literature, a number of different morphologies are possible:

• oscillatory morphologies (bands),
• coupled growth (lamellar, island), etc.

So far our observations indicate an unexpected unsteady seaweed- like morphology which is highly dependent on time. As all these morphologies are strongly influenced by the presence of convection, it is planned to perform experimental investigations under reduced gravity conditions using the DIRSOL facility on board the International Space Station/ISS in 2008.

Coordinator

University of Leoben, Chair for Simulation and Modelling of Metallurgical
Processes, Department of Metallurgy - Univ. Prof. Dr. rer.nat. Dipl. Phys. habil. Andreas LUDWIG

Partners

• All members of the associated ESA-MAP Project METCOMP
• Dr. Matthias Kolbe, German Aerospace Center, DLR, D
• Prof. Dr. G. Eggeler, Ruhr-University Bochum, D
• Prof. Dr. Lászlo Gránásy, Brunel University (RISSPO), UK
• Prof. Dr. Dieter M. Herlach, German Aerospace Center,
• DLR, D
• Prof. Dr. Michel Rappaz, EPFL Lausanne, CH
• Dr. René Duursma, Corus Technology BV, NL
• Dr.-Ing. Jürgen Jestrabek, Schwermetall Halbzeug-Werk
• GmbH&Co.KG, D
• Dr. Claudio Penna, Swissmetal SA, CH
• Dr. Jürgen Stahl, Thyssen Krupp Steel AG, D
• Dr.-Ing. Hans-Achim Kuhn, Wieland-Werke AG, D

Chair for Simulation and Modelling of Metallurgical Processes, Department of Metallurgy - University of Leoben

Univ. Prof. Dr. rer.nat. Dipl. Phys. habil. Andreas LUDWIG
Franz-Josef-Str. 18
A-8700 Leoben
E-mail: ludwig@unileoben.ac.at