This research project aims to get a complete fundamental understanding of metastable coupled peritectic pattern formation under purely diffusive conditions including of specific transient growth modes. The European Space Agency (ESA) has supported the corresponding METCOMP project and performed during March-Aril 2021 fifteen different solidification experiments onboard of the International Space Station (ISS) using the transparent peritectic TRIS-NPG system as metall-like solidifiying model alloy. Starting from 04.10. 2023 until 17.10. 2023 there are going to be further experiments onboard the ISS. At the moment the around 70.000 pictures showing the evolution of isothermal peritectic growth (IPCG) recorded during the µg-mission are under evaluation.

The primary aims and objectives of this research field are:

• To understand the formation of isothermal peritectic coupled growth (IPCG) and the impact convection might have on the occurrence of this metastable growth mode;
• To define a suitable process window for the occurrence of IPCG;
• To perform solidification experiments with the transparent peritectic model alloy TRIS-NPG under micro-gravity conditions on board of the International Space Station (ISS), and compare the observation with its equivalent terrestrial experiments;
• To investigate the transition from lateral bands to IPCG and to identify transient and steady growth modes;
• To perform phase field simulation of IPCG and suggest a theoretic framework for the physical processes that favour this metastable growth form;

Examples of oscillatory peritectic coupled growth is shown in the above figure. Further details on that research field can be found in:

• Ludwig A., Mogeritsch J., Barati H., Wu M., Kharicha A.: Journal of Crystal Growth 644 (2024) 127824 DOI: doi.org/10.1016/j.jcrysgro.2024.127824
  “Explanation for the linear solid/liquid interface recoil observed during directional solidification of a TRIS-NPG alloy under microgravity conditions”
• Ludwig A., Mogertisch J.: Scripta Materialia 239 (2024) DOI: doi.org/10.1016/j.scriptamat.2023.115802
  "Observations of the occurrence and disappearance of peritectic couple growth performed under microgravity conditions"
• Ludwig A., Mogeritsch J.: Metallurgical and Materials Transactions A (2023) DOI: doi.org/10.1007/s11661-023-07052-6
  "In Situ Study of Peritectic Coupled Growth Under Purely Diffusive Conditions"
• Ludwig A., Mogeritsch J., Witusiewicz V.T.: J. Crystal Growth 604 (2023) DOI: doi.org/10.1016/j.jcrysgro.2022.127052
  "Hypo-peritectic TRIS-NPG in a stationary temperature gradient: Thermodynamics, grain boundary migration and phase identification"
• Mogeritsch J. Sillekens W., Ludwig A.: TMS 2022 151st Annual Meeting & Exhibition Supplemental Proceedings (2022) 1429-1441. DOI: doi.org/10.1007/978-3-030-92381-5_136
  "In-situ Observation of Coupled Growth Morphologies in Organic Peritecitcs under Pure Diffusion Conditions"
• Ludwig A., Mogeritsch J., Rettenmayr M.: Scripta Materialia 214 (2022). DOI: doi.org/10.1016/j.scriptamat.2022.114683
  "On/off directional solidification of near peritectic TRIS-NPG with a planar but tilted solid/liquid interface under microgravity conditions"
• Mogeritsch J.P., Pfeifer T., Ludwig A.: 5th Int. Conf. Adv. Solid. Proc. (ICASP-5) combined with 5th Int. Symp. Cutting Edge of Comp. Sim. of Solid., Cast. and Refining,Salzburg, Austria, IOP Conf. Series: Mater. Sci. & Eng., 529 (2019) 012025.
  "Formation of micro-plumes at a planar solid liquid interface in a temperature gradient"
• Mogeritsch J., Ludwig A.: Res. & Dev. Materials Sci. 4 (2018) 1-3. DOI:10.31031/RDMS.2018.04.000580
  "Investigation on Peritectic Layered Structures by Using the Binary Organic Components TRIS-NPG as Model Substances for Metal-Like Solidification"
• Mogeritsch J.P., Ludwig A.: 7th Int. Conf. Solidification and Gravity (SG 2018), Miskolc, Hungary, pp. 330-335.DOI: 10.31031/RDMS.2018.,4.000580
  "Investigation on the Binary Organic Components TRIS-NPG as Suitable Model Substances for Metal-Like Solidification"
• Mogeritsch J.P., Pfeifer T., Stefan-Kharicha M., Ludwig A.: 7th Int. Conf. Solidification and Gravity (SG 2018), Miskolc, Hungary, pp. 319-324.
  "Investigation on the Liquid Flow ahead of the Solidification Front During the Formation of Peritectic Layered Solidification Structures"
• Ludwig A., Mogeritsch J., Pfeifer T.: Acta Mater. 126 (2017) 329-35.
  "In-situ observation of coupled peritectic growth in a binary organic model alloy"
• Ludwig A., Mogeritsch J.: J. Crystal Growth 455 (2016) 99–104.
  "Compact seaweed growth of peritectic phase on confined, flat properitectic dendrites"
• Mogeritsch J.P., Ludwig A.: MCWASP XIV (14th Modeling of Casting, Welding and Adv. Solidification Processes) Awaji island, Hyogo, Japan, 21-26 June (2015), Ed.: H. Yasuda, IOP Conf. Series: Materials Science and Engineering 84 (2015) 012055.
  "In-situ observation of the dynamic of peritectic coupled growth using the binary organic system TRIS-NPG"
• Ludwig A., Mogeritsch J.: Mater. Sci. Forum, 790-791 (2014) 317-322.
  "Recurring instability of cellular growth in a near peritectic transparent NPG-TRIS alloy system"
• Ludwig A., Mogeritsch J., Kolbe M., Gerhard Z., Sturz L., Bergeon N., Faivre G., Billia B., Akamatsu S., Bottin-Rousseau S., Voss D.: JOM 64 (2012) 1097-101.
  "Adv. Solidification Studies on Transparent Alloy Systems: A New European Solidification Insert for Material Science Glovebox on Board the Int. Space Station"

see also our Topic Related Publications