Materials Research in Reduced Gravity: Solidification II
Sponsored by: TMS Extraction and Processing Division, TMS Materials Processing and Manufacturing Division, TMS: Process Technology and Modeling Committee
Program Organizers: Robert Hyers, Worcester Polytechnic Institute; Douglas Matson, Tufts University; Michael Sansoucie, Nasa Marshall Space Flight Center; Shaun McFadden, Ulster University; Jonghyun Lee, Iowa State University; Wilhelmus Sillekens, European Space Agency; Takehiko Ishikawa, Japan Aerospace Exploration Agency
Thursday 2:00 PM
February 27, 2020
Room: 18
Location: San Diego Convention Ctr
Session Chair: Sonja Steinbach, DLR; Peter Galenko, University of Jena
2:00 PM
Dendrite Orientation Transition of fcc-Al in Bulk Al-Ge Alloys: Sonja Steinbach1; Matthias Kolbe1; Sebastian Wirth2; Laszlo Sturz3; Gerhard Zimmermann3; Florian Kargl1; Maike Becker4; 1DLR; 2RWTH Aachen; 3ACCESS e.V.; 4IM2NP
Recent studies with thin Al-Ge samples [M. Becker, 2019] and with Al-Zn alloys [T. Haxhimali, 2006] have shown a transition from the accepted growth direction of fcc-Al to a new direction with increasing solute content, a phenomenon that is called ‘Dendrite Orientation Transition’ (DOT) [F. Gonzales, 2006] and which is explained not only by the effect of composition on the anisotropy of the solid-liquid interfacial energy, but also by the containment of the sample. Therefore observations made on microstructures growing in thin-film samples are not necessarily transferable to 3D conditions. To shed light on this phenomena in 3D and to avoid strong segregation effects occurring in samples with high density differences of the alloy components on ground, Al-46wt%Ge samples were processed in a new furnace set-up for directional solidification experiments in microgravity and are compared to lab experiments.
2:20 PM
Comparison of Three-dimensional in situ Observations and Phase-field Simulations of Microstructure Formation during Directional Solidification of Transparent Alloys Aboard the ISS: Kaihua Ji1; Fatima Mota2; Younggil Song1; Jorge Pereda2; Trevor Lyons3; Louise Strutzenberg4; Rohit Trivedi3; Nathalie Bergeon2; Alain Karma1; 1Northeastern University; 2Aix-Marseille Université and CNRS; 3Iowa State University; 4Marshall Space Flight Center
Cellular/dendritic microstructures formed during solidification have a crucial influence on the mechanical properties of a wide range of structural alloys. By minimizing the amount of gravity-induced convection in the liquid, directional solidification experiments using transparent organic alloys conducted in the DECLIC-DSI onboard the International Space Station have provided unique 3D in situ observations of the spatiotemporal evolution of the solid-liquid interface during the formation of cellular and dendritic microstructures under purely diffusive growth conditions. Those observations have made it possible to perform benchmark quantitative comparisons with the predictions of state-of-the-art phase-field simulations of microstructure formation in 3D on experimentally relevant length and time scales. This talk will report quantitative comparisons between microgravity experiments and PF simulations in succinonitrile-camphor alloys of two different compositions that shed new light on the role of subgrain boundaries in the spatiotemporal evolution of the primary cellular spacing and the selection of dendritic array structures.
2:40 PM
Crystallizations Kinetics of Glass-forming ZrCu-based Alloys: Peter Galenko1; Stefanie Koch1; Markus Rettenmayr1; Vladimir Ankudinov2; Josef Slowik1; 1University of Jena; 2Udmurt State University
Experimental and theoretical results obtained in the MULTIPHAS-project are discussed regarding solidification kinetics of glass forming Zr50Cu50 and Zr50Cu30Ni20 alloy samples. The samples are investigated during solidification using a containerless technique. Applying elaborated methodologies for ground-based and microgravity experiments, the kinetics of dendritic solidification is quantitatively evaluated. The solidification kinetics is determined using a high-speed camera [1]. Experimental results on solidification kinetics are interpreted using theory of dendritic growth together with the analysis of the cluster structure behavior in glass-forming melts with the increase of undercooling [2]. The authors thank the German Space Center Space Management under contract no. 50WM1541. [1] P.K. Galenko, R. Hanke, P. Paul, S. Koch, M. Rettenmayr, J. Gegner, D.M. Herlach, W. Dreier, E.V. Kharanzhevski. IOP Conf. Ser.: Mat. Sci. Eng. 192, 2017, 012028-1-11. [2] P.K. Galenko, V. Ankudinov, K. Reuther, M. Rettenmayr, A. Salhoumi, E.V. Kharanzhevskiy, Phil. Trans. R. Soc. A 377, 2019, 20180205-1-24.
3:00 PM
The Enthalpy Method as an Alternative to Accurately Predicting Undercooled Solidification: Andrew Kao1; L V Toropova2; D V Alexandrov2; G Demange3; P K Galenko4; 1University of Greenwich; 2Ural Federal University; 3University of Rouen Normandy; 4Friedrich-Schiller-Universität-Jena
Traditional solidifcation methods for accurately predicting undercooled growth usually adopt a phase-field method. The phase field formulation strictly requires the cell size in the vacinity of the interface to be similar in size to the interfacial thickness. This requires a very fine mesh and the use of complex adaptive meshing techniques. On the other hand the Enthalpy method, has no such restrictions but instead suffers from narrow-band errors as the mesh becomes refined. However, by carefully selecting the mesh size to minimise this error we show that an excellent agreement can be found over a wide range of undercoolings from high 300 K down to 20 K against the sharp interface model. For the low undercooled regime the cell size is can be considerably larger than the interface thickness and utilising parallelisation capturing the entire solidification of microgravity droplets is becoming more feasible.
3:20 PM Break
3:50 PM Panel Discussion Community Discussion on Future Directions