- Revelation of mechanisms controlling the ductility and crack growth resistance in such microstructures with respect to strength, ductility and toughness in these types of materials.
With these goals in mind the project should contribute to develop a methodology allowing the prediction of the required SPD production steps to generate a desired nanostructured bulk material or nanocomposite. As target groups for these new materials magnetic, electrical and even medical applications can be considered.
In order to persue this ambitious long-term vision different alloy systems were investigated ranging from very classical materials such as perlitic steels to novel materials such as high entropy alloys.
The lastest outcome of the project can be found here:
B. Schuh, R. Pippan, A. Hohenwarter, Tailoring bimodal grain size structures in nanocrystalline compositionally complex alloys to improve ductility, Mater. Sci. Eng. A, 748 (2019), 379-385.
B. Schuh, B. Völker, J. Todt, K. S. Kormout, Norbert Schell, A. Hohenwarter, Influence of Annealing on Microstructure and Mechanical Properties of a Nanocrystalline CrCoNi Medium-Entropy Alloy, Materials 2018, 11(5), 662.
B. Schuh, B. Völker, J. Todt, N. Schell, L. Perrière, J. Li, et al., Thermodynamic instability of a nanocrystalline, single-phase TiZrNbHfTa alloy and its impact on the mechanical properties, Acta Mater. 142 (2018) 201–212.
B. Schuh, B. Völker, V. Maier-Kiener, J. Todt, J. Li, A. Hohenwarter, Phase Decomposition of a Single-Phase AlTiVNb High-Entropy Alloy after Severe Plastic Deformation and Annealing, Adv. Eng. Mater. 19 (2017).
V. Maier-Kiener, B. Schuh, E. P. George, H. Clemens, A. Hohenwarter, Nanoindentation testing as a powerful screening tool for assessing phase stability of nanocrystalline high-entropy alloys, Mater. Design 115 (2017) 479-485.
B. Völker, N. Jäger, M. Calin, M. Zehetbauer, J. Eckert, A. Hohenwarter, Influence of testing orientation on mechanical properties of Ti45Nb deformed by high pressure torsion, Mater. Design 114 (2017) 40-46.
A. Hohenwarter, B. Völker, M.W. Kapp, Y. Li, S. Goto, D. Raabe, et al., Ultra-strong and damage tolerant metallic bulk materials: A lesson from nanostructured pearlitic steel wires, Sci. Rep. 6 (2016).
R. Pippan, A. Hohenwarter, The importance of fracture toughness
in ultrafine and nanocrystalline bulk materials, Mater. Res. Lett. (2016), 4:3, 127-136.
B. Schuh, F. Mendez-Martin, B. Völker, E.P. George, H. Clemens, R. Pippan, et al., Mechanical properties, microstructure and thermal stability of a nanocrystalline CoCrFeMnNi high-entropy alloy after severe plastic deformation, Acta Mater. 96 (2015) 258–268.
A. Hohenwarter, R. Pippan, Fracture and fracture toughness of nanopolycrystalline metals produced by severe plastic deformation Subject Areas :, Philos. Trans. R. Soc. A Math. Phys. Eng. Sci. 373 (2015) Article number 20140366.
A. Hohenwarter, Incremental high pressure torsion as a novel severe plastic deformation process: Processing features and application to copper, Mater. Sci. Eng. A. 626 (2015) 80–85.
B. Schuh, Thermodynamic stability and mechanical properties of
nanocrystalline high-entropy alloys, PhD-thesis, Montanuniversität Leoben (link to pdf)