Dumont, M.; Borbély, A.; Sander, P. M.; Kostka, A.; Kaysser-Pyzalla, A. R.: Crystallographic investigations of a growth series of Apatosaurus long bones: Implications for biomechanics. 71st SVP meeting, Las Vegas, NV, USA (2011)
Dumont, M.; Borbély, A.; Sander, P. M.; Kostka, A.; Kaysser-Pyzalla, A. R.: Texture and nanostructure of Sauropod bones: Implications for biomechanics. 1st International symposium on paleohistology, Barcelona, Spain (2011)
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)
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, Germany (2009)
Springer, H.; Kostka, A.: Verbinden von hochfestem Stahl mit einer Aluminiumlegierung durch Rührreibschweißen. 4. GKSS Workshop, Geesthacht, Germany (2009)
Kostka, A.: Microstructure of Dissimilar Al to Steel Friction Stir Welds. XIII International Conference on Electron Microscopy, Zakopane, Poland (2008)
Kostka, A.: Microstructure and Properties of Al to Steel Friction Stir Overlap Welds. 7th International Friction Stir Welding Symposium, Awaji Island, Japan (2008)
Kostka, A.: ESBD Microstructure and Material Flow Characterization of an AA6181-T4 Aluminium Alloy to DP600 High Steel Friction Stir Butt-joint Weld. 3rd FSW Modelling and Material Flow Seminar, Geesthacht, Germany (2008)
Coelho, R. S.; Kostka, A.; Sheikhi, S.; Kocak, M.; Dos Santos, J.; Pyzalla, A. R.: Charakterisierung der Mikrostruktur und Verformung in Mg-Mg-Laserschweißnähten und Al-Stahl-Reibrührschweißverbindungen. 54. Metallkunde-Kolloquium Werkstoffforschung, Lech / Österreich (2008)
Garcia, J.; Lammer, A.; Garcia, L. F.; Weber, S.; Kostka, A.; Pyzalla, A. R.: Investigations of Wear Mechanisms in Diamond Tools with Fe-Based Matrices Reinforced with WC-Co Particles. Intern. Symposium on Friction, Wear and Wear Protection, Aachen, Germany (2008)
Garcia, L. F.; Garcia, J.; Kostka, A.; Weber, S.; Lammer, A.: Wear Behaviour of Cooper-Iron-Cobalt Diamond Tool Bonding Matrices Reinforced with Hardmetal Granulates. 9th Intern. Conference on the Science of Hard Materials, Montego Bay, Jamaica (2008)
Coelho, R. S.; Kostka, A.; Sheikhi, S.; dos Santos, J.; Pyzalla, A. R.: Friction Stir Welding of ZStE340 High-strength Steel and AA6181-T4 Aluminium Alloy. SOLVSTIR - International Seminar on Friction Stir Welding of Steels, Geesthacht (2007)
Agudo, L.; Pinto, H.; Kostka, A.; Weber, S.; Wagner, J.; Arenholz, E.; Bruckner, J.; Pyzalla, A. R.: Study of Microstructure and Residual Stresses in Dissimilar Al/Steel Welds Produced by Cold Metal Transfer. MECASENS IV, Wien (2007)
Coelho, R. S.; Kostka, A.; Riekehr, S.; Kocak, M.; Pyzalla, A. R.: Microstructure and residual stress of Nd:YAG laser AZ31B butt welds. MECASENS IV, Wien, Austria (2007)
Agudo, L.; Kostka, A.; Weber, S.; Wagner, J.; Arenholz, E.; Bruckner, J.; Pyzalla, A. R.: Al/Steel welds: Fundamental investigation of intermetallic phases. 4th Discussion Meeting on the Development of Innovative Iron Aluminium Alloys, FeAl2007, Interlaken, Switzerland (2007)
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.
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.
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.
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.
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.
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…
We have studied a nanocrystalline AlCrCuFeNiZn high-entropy alloy synthesized by ball milling followed by hot compaction at 600°C for 15 min at 650 MPa. X-ray diffraction reveals that the mechanically alloyed powder consists of a solid-solution body-centered cubic (bcc) matrix containing 12 vol.% face-centered cubic (fcc) phase. After hot compaction, it consists of 60 vol.% bcc and 40 vol.% fcc. Composition analysis by atom probe tomography shows that the material is not a homogeneous fcc–bcc solid solution