Duarte, M. J.; Fang, X.; Rao, J.; Krieger, W.; Brinckmann, S.; Dehm, G.: In situ nanoindentation during electrochemical hydrogen charging: a comparison between front-side and a novel back-side charging approach. Journal of Materials Science 56 (14), pp. 8732 - 8744 (2021)
An, D.; Krieger, W.; Zaefferer, S.: Unravelling the effect of hydrogenon microstructure evolution under low-cycle fatigue in a high-manganese austenitic TWIP steel. International Journal of Plasticity 126, 102625 (2020)
Sun, B.; Krieger, W.; Rohwerder, M.; Ponge, D.; Raabe, D.: Dependence of hydrogen embrittlement mechanisms on microstructure-driven hydrogen distribution in medium Mn steels. Acta Materialia 183, pp. 313 - 328 (2020)
Wu, C.-H.; Krieger, W.; Rohwerder, M.: On the robustness of the Kelvin probe based potentiometric hydrogen electrode method and its application in characterizing effective hydrogen activity in metal: 5 wt. % Ni cold-rolled ferritic steel as an example. Science and Technology of Advanced Materials 20 (1), pp. 1073 - 1089 (2019)
Krieger, W.; Merzlikin, S. V.; Bashir, A.; Springer, H.; Rohwerder, M.: Influence of strengthening mechanisms and environmental conditions on the performance of ferritic steels. In: EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion. Joint European Corrosion Congress 2017, EUROCORR 2017 and 20th International Corrosion Congress and Process Safety Congress 2017, Prague, Czech Republic, September 03, 2017 - September 07, 2017. (2017)
Altin, A.; Wohletz, S.; Krieger, W.; Groche, P.; Erbe, A.: Effect of surface condition on the bond strength between aluminum and steel joint in cold welding. CETAS 2015, Düsseldorf, Germany (2015)
Altin, A.; Wohletz, S.; Krieger, W.; Kostka, A.; Groche, P.; Erbe, A.: Nanoscale understanding of bond formation during cold welding of aluminum and steel. 6th International Conference on Tribology in Manufacturing Processes & Joining by Plastic Deformation, Darmstadt, Germany (2014)
Krieger, W.: Charakterisierung von Wasserstofffallen und deren Einfluss auf die Wasserstoffversprödung in ferritischen Stählen. Dissertation, Ruhr University Bochum, Bochum, Germany (2018)
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
Magnetic properties of magnetocaloric materials is of utmost importance for their functional applications. In this project, we study the magnetic properties of different materials with the final goal to discover new magnetocaloric materials more suited for practical applications.
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…
This study investigates the mechanical properties of liquid-encapsulated metallic microstructures created using a localized electrodeposition method. By encapsulating liquid within the complex metal microstructures, we explore how the liquid influences compressive and vibrational characteristics, particularly under varying temperatures and strain…
In this project we pursue recent developments in the field of austenitic steels with up to 18% reduced mass density. The alloys are based on the Fe-Mn-Al-C system.
Local lattice distortion is one of the core effects in complex concentrated alloys (CCAs). It has been expected that the strength CCAs can be improved by inducing larger local lattice distortions. In collaboration with experimentalists, we demonstrated that VCoNi has larger local lattice distortions and indeed has much better strength than the…
Laser Powder Bed Fusion (LPBF) is the most commonly used Additive Manufacturing processes. One of its biggest advantages it offers is to exploit its inherent specific process characteristics, namely the decoupling the solidification rate from the parts´volume, for novel materials with superior physical and mechanical properties. One prominet…
The aim of the current study is to investigate electrochemical corrosion mechanisms by examining the metal-liquid nanointerfaces. To achieve this, corrosive fluids will be strategically trapped within metal structures using novel additive micro fabrication techniques. Subsequently, the nanointerfaces will be analyzed using cryo-atom probe…