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)
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)
In this project, we employ a metastability-engineering strategy to design bulk high-entropy alloys (HEAs) with multiple compositionally equivalent high-entropy phases.
Low dimensional electronic systems, featuring charge density waves and collective excitations, are highly interesting from a fundamental point of view. These systems support novel types of interfaces, such as phase boundaries between metals and charge density waves.
About 90% of all mechanical service failures are caused by fatigue. Avoiding fatigue failure requires addressing the wide knowledge gap regarding the micromechanical processes governing damage under cyclic loading, which may be fundamentally different from that under static loading. This is particularly true for deformation-induced martensitic…
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.
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 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.