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Metallic glasses are metastable materials characterised by special atomic arrangement and properties. They are generally harder, more corrosion resistant and stronger than ordinary metals. Their amorphous structure is formed when natural crystallisation is prevented. This can be achieved, for example, by rapidly cooling the melt so that the atoms are deprived of mobility before they can adopt the crystal arrangement. The reverse process - rapid heating of metallic glasses - gives access and control of the non-equilibrium states and structures with unique physical and mechanical properties, which cannot be obtained by conventional methods. However, due to the fast transformation kinetics, on the millisecond time-scale, in situ studies have always been challenging for materials scientists and physicists. Researchers have now succeeded in observing the phase transformations with high temporal resolution over the entire temperature range of the supercooled liquid's existence.
In a recent paper published in Nature Communications, researchers report that they applied a combination of different and complementary techniques to study the phase transformations during rapid heating (annealing) of a copper-zirconium-aluminium glass. The structural studies have been carried out using in situ X-ray diffraction at PETRA III synchrotron source (DESY Hamburg) with the experimental setups for electromagnetic levitation and flash-annealing both constructed at IFW Dresden, and transmission electron microscopy at the University of Cambridge (UK). The local microstructure was analyzed by atom probe tomography at MPIE Düsseldorf, and the surface chemistry was studied by Auger and X-ray photoelectron spectroscopy at IFW Dresden. Such a unique combination of experimental techniques provided hitherto inaccessible insight into the phase-transformation mechanism and its kinetics with high temporal resolution over the entire temperature range of the existence of the supercooled liquid. For the first time, the conditions under which the glass can form structures with beneficial materials properties are defined in situ. This approach can also be applied to map phase transformations in other metallic-glass-forming systems.
This work was financially supported by the Deutsche Forschungsgemeinschaft (DFG) under grants KA 3209/9-1 (I. Kaban, IFW Dresden) and HE 7225/1-1 (M. Herbig, MPIE Düsseldorf).
Original publication: J. Orava, S. Balachandran, X. Han, O. Shuleshova, E. Nurouzi, I. Soldatov, S. Oswald, O. Gutowski, O. Ivashko, A.-C. Dippel, M. v. Zimmermann, Y.P. Ivanov, A.L. Greer, D. Raabe, M. Herbig & I. Kaban, In situ correlation between metastable phase transformation mechanism and kinetics in a metallic glass, Nature Commun., 2021, Vol. 12, Article No. 2839; DOI: https://doi.org/10.1038/s41467-021-23028-9
The paper is featured as Editor’s Highlights in Materials Science and Chemistry (listing the top 50 papers published recently in Nature Communications) https://www.nature.com/collections/eecgdgijhh
Dr. Ivan Kaban
Phone: +49 (0) 351 4659-252
Tailoring biocompatible Ti-Zr-Nb-Hf-Si metallic glasses based on high-entropy alloys design approach
Mariana Calin, Jithin Vishnu, Pramote Thirathipviwat, Monica Popa, Maria Krautz, Geetha Manivasagam, Annett Gebert
Materials Science & Engineering C, 121 (2021) 111733
For more information see here:
Laser Powder Bed Fusion Processing of Fe-Mn-Al-Ni Shape Memory Alloy—On the Effect of Elevated Platform Temperatures
1Institute of Materials Engineering—Metallic Alloys, University of Kassel, 34125 Kassel, Germany
2Leibniz IFW Dresden, Institute for Complex Materials, 01069 Dresden, Germany
*Author to whom correspondence should be addressed.
For more information see here:
In a recent contribution to “The World Scientific Reference of Amorphous Materials” by Orava (IFW Dresden), Lee, Elliott, and Greer, the authors discuss and critically evaluate the emerging experimental techniques and computer simulations that have significantly enhanced our understanding of fast, ~10-100 ns, switching in phase-change memory – commercialized as Intel Optane.
Angelo F. Andreoli' was awarded 1st prize in a contest: XIX MetMat Metallurgy and Materials Photomicrograph. Organized by the Polytechnical School of the University of São Paulo and GERDAU.
Here is the website: https://www.metmat.org/
This cover image represents a promising approach on the processing of biodegradable stent structures out of a novel developed FeMnCS alloy by selective laser melting. Thereby, significant changes in the microstructure ‐ in comparison to the as‐cast counterpart ‐ can be observed, as displayed by electron backscatter diffraction mappings. Further details can be found in the article by Julia Hufenbach, Jan Sander, Fabian Kochta, Stefan Pilz, Andrea Voss, Uta Kühn, and Annett Gebert.
BIOREMIA Workshop entitled “Research methodology, characterisation techniques, and reporting scientific results” was held on 1.10. - 2.10.2020, as an online event with more than 50 participants from 13 countries.
It aimed at introducing the PhD fellows to the whole Consortium members and so to integrate them into the BIOREMIA community. The workshop provided outstanding interdisciplinary training for the researchers involved, with lectures on structural and mechanical characterisation techniques of biomaterials, biomechanics of skeleton, basics of microbial diversity, introduction to biomaterial-associated infection, biofilms and ethical issues.
BIOREMIA ("BIOfilm-REsistant Materials for hard tissue Implant Applications") is a 4-year project funded by the European Commission under Horizon 2020 Marie Skłodowska Curie Actions (European Network Training, GA No. 861046). The key idea behind this project is to tackle the implant-associated infections problem by proposing innovative material-based solutions with enhanced antibacterial and antifouling functionality for bone-related applications (orthopedics and dentistry).
Two BIOREMIA PhD students are hosted by our institute (IKM / Chemistry of Functional Materials):
Der Posterpreis wurde im Rahmen der Fachtagung "Werkstoffe und Additive Fertigung" von der Bundesvereinigung-GRAT „Gesellschaft für Ressourceneffizienz und Additive Technologien“ e. V. verliehen. Die Fachtagung vom wurde in diesem Jahr als Web-Konferenz durchgeführt.