Kostka, A.; Tak, K.-G.; Eggeler, G.: On the effect of equal-channel angular pressing on creep of tempered martensite ferritic steels. Euromat 2007, Nürnberg (2007)
Coelho, R. S.; Kostka, A.; Riekehr, S.; Kocak, M.; Pyzalla, A. R.: Microstructure and Properties of AZ31B Magnesium Alloy Laser Beam Welds. Euromat 2007, Nürnberg, Germany (2007)
Coelho, R.; Kostka, A.; Pinto, H.; Kocak, M.; Pyzalla, A. R.: Mikrostruktur, Textur und Eigenspannungen in Schweißverbindungen aus AZ 31. FA 13 Eigenspannungen der AWT, Forschungsgemeinschaft Werkzeuge und Werkstoffe e.V., Remscheid (2007)
Coelho, R. S.; Kostka, A.; Riekehr, S.; Zettler, R.; Sheikhi, S.; Dos Santos, J.; Pyzalla, A. R.: Joining of light-weight materials by laser beam welding and friction stir welding. 2nd Alban Conference, Grenoble, France (2007)
Wang, M.; Tasan, C. C.; Ponge, D.; Kostka, A.; Raabe, D.: Size effects on mechanical stability of metastable austenite. GDRi CNRS MECANO General Meeting on the Mechanics of Nano-Objects, MPIE, Düsseldorf, Germany (2013)
Dumont, M.; Kostka, A.; Sander, M.; Borbély, A.; Pyzalla, A. R.: Comparison of apatite crystallite sizes in sauropod and mammal fossil bones. 6th Bone diagenesis meeting, Poppelsdorfer Schloss, University of Bonn, Bonn, Deutschland (2009)
Kostka, A.; Song, J.; Raabe, D.; Veehmayer, M.: Microstructure and properties of interfaces formed by explosion cladding of Ti-Steel. XXI Conference on Applied Crystallography, Zakopane, Poland (2009)
Springer, H.; Kostka, A.: Verbinden von hochfestem Stahl mit einer Aluminiumlegierung durch Rührreibschweißen. 4. GKSS Workshop, Geesthacht, Germany (2009)
Coelho, R. S.; Kostka, A.; Pinto, H.; dos Santos, J.; Pyzalla, A. R.: Microstructure and residual stresses of high-strength steel to aluminium alloy friction stir welds. ICRS-8, Denver, USA (2008)
Coelho, R. S.; Kostka, A.; dos Santos, J.; Pyzalla, A. R.: Friction stir welding of aluminum alloy to steel. Part I: Mechanical properties. VI-PNAM Symposium, Berlin, Germany (2008)
Coelho, R. S.; Kostka, A.; dos Santos, J.; Pyzalla, A. R.: Friction stir welding of aluminum alloy to steel. Part II: Microstructure. VI-PNAM Symposium, Berlin, Germany (2008)
Coelho, R. S.; Kostka, A.; dos Santos, J.; Pyzalla, A. R.: Friction stir welding of aluminum alloy to steel. Part III: Material flow. VI-PNAM Symposium, Berlin, Germany (2008)
Coelho, R. S.; Kostka, A.; Zettler, R.; dos Santos, J.; Pyzalla, A. R.: On the microstructure and residual stresses in friction-stir dissimilar AA6040 aluminium alloy to AZ31 magnesium alloy weld. MECASENS IV, Wien (2007)
Kostka, A.; Coelho, R.; dos Santos, J.; Pyzalla, A. R.: Microstructure and Mechanical Properties of Aluminium - Steel Friction Stir Welds. Small Scale Plasticity Workshop, Braunwald, Switzerland (2007)
Kostka, A.; Coelho, R.; Zettler, R.; dos Santos, J.; Pyzalla, A. R.: Microstructure and Residual Stresses in an AA6040-T4/AZ31B Friction-Stir Weld. Euromat 2007, Nürnberg, Germany (2007)
Oxides find broad applications as catalysts or in electronic components, however are generally brittle materials where dislocations are difficult to activate in the covalent rigid lattice. Here, the link between plasticity and fracture is critical for wide-scale application of functional oxide materials.
In this project we conduct together with Dr. Sandlöbes at RWTH Aachen and the department of Prof. Neugebauer ab initio calculations for designing new Mg – Li alloys. Ab initio calculations can accurately predict basic structural, mechanical, and functional properties using only the atomic composition as a basis.
The wide tunability of the fundamental electronic bandgap by size control is a key attribute of semiconductor nanocrystals, enabling applications spanning from biomedical imaging to optoelectronic devices. At finite temperature, exciton-phonon interactions are shown to exhibit a strong impact on this fundamental property.
Enabling a ‘hydrogen economy’ requires developing fuel cells satisfying economic constraints, reasonable operating costs and long-term stability. The fuel cell is an electrochemical device that converts chemical energy into electricity by recombining water from H2 and O2, allowing to generate environmentally-friendly power for e.g. cars or houses…
The project Hydrogen Embrittlement Protection Coating (HEPCO) addresses the critical aspects of hydrogen permeation and embrittlement by developing novel strategies for coating and characterizing hydrogen permeation barrier layers for valves and pumps used for hydrogen storage and transport applications.
In this project we study - together with the department of Prof. Neugebauer and Dr. Sandlöbes at RWTH Aachen - the underlying mechanisms that are responsible for the improved room-temperature ductility in Mg–Y alloys compared to pure Mg.
Efficient harvesting of sunlight and (photo-)electrochemical conversion into solar fuels is an emerging energy technology with enormous promise. Such emerging technologies depend critically on materials systems, in which the integration of dissimilar components and the internal interfaces that arise between them determine the functionality.
In this project, we work on a generic solution to design advanced high-entropy alloys (HEAs) with enhanced magnetic properties. By overturning the concept of stabilizing solid solutions in HEAs, we propose to render the massive solid solutions metastable and trigger spinodal decomposition. The motivation for starting from the HEA for this approach…