TY - GEN A1 - Bauer, A. A1 - Neumeier, Steffen A1 - Pyczak, Florian A1 - Singer, Robert F. A1 - Göken, Mathias T1 - Creep properties of different γ'- strengthened Co-base superalloys T2 - Materials Science and Engineering A Y1 - 2012 SN - 1873-4936 IS - 550 SP - 333 EP - 341 ER - TY - CHAP A1 - Bauer, Alexander A1 - Neumeier, Steffen A1 - Pyczak, Florian A1 - Göken, Mathias ED - Huron, Eric S. ED - Reed, Roger C. ED - Hardy, Mark C. ED - Mills, Michael J. ED - Montero, Rick E. ED - Portella, Pedro D. ED - Telesmann, Jack T1 - Creep strength and microstructure of polycrystalline γ’–strengthened cobalt-base superalloys T2 - Superalloys 2012, proceedings of the 12th International Symposium on Superalloys, held September 9-13, 2012 at Seven Springs Mountain Resort, Seven Springs, PA Y1 - 2012 SN - 978-1-118-51643-0 SN - 978-0-470-94320-5 SP - 695 EP - 703 PB - Wiley [u.a.] CY - Hoboken, New Jersey ER - TY - GEN A1 - Schloffer, Martin A1 - Iqbal, Farasat A1 - Gabrisch, Heike A1 - Schwaighofer, Emanuel A1 - Schimansky, Frank-Peter A1 - Mayer, Svea A1 - Stark, Andreas A1 - Lippmann, Thomas A1 - Göken, Mathias A1 - Pyczak, Florian A1 - Clemens, Helmut T1 - Microstructure development and hardness of a powder metallurgical multi phase gamma-TiAl based alloy T2 - Intermetallics Y1 - 2012 U6 - https://doi.org/10.1016/j.intermet.2011.11.015 SN - 0966-9795 IS - 22 SP - 231 EP - 240 ER - TY - GEN A1 - Neumeier, Steffen A1 - Dinkel, Michael A1 - Pyczak, Florian A1 - Göken, Mathias T1 - Nanoindentation and XRD investigations of single crystalline Ni-Ge brazed nickel-base superalloys PWA 1483 and René N5 T2 - Materials Science and Engineering A Y1 - 2011 SN - 1873-4936 IS - 528 SP - 815 EP - 822 ER - TY - GEN A1 - Bauer, A. A1 - Neumeier, Steffen A1 - Pyczak, Florian A1 - Göken, Mathias T1 - Microstructure and creep strength of different γ/γ'- strengthened Co-base superalloy variants T2 - Scripta Materialia Y1 - 2010 SN - 1359-6462 VL - 63 IS - 12 SP - 1197 EP - 1200 ER - TY - GEN A1 - Pyczak, Florian A1 - Neumeier, Steffen A1 - Göken, Mathias T1 - Temperature Dependence of Element Partitioning in Rhenium and Ruthenium Bearing Nickel-Base Superalloys T2 - Materials Science and Engineering A Y1 - 2010 SN - 1873-4936 IS - 527 SP - 7939 EP - 7943 ER - TY - GEN A1 - Neumeier, Steffen A1 - Pyczak, Florian A1 - Göken, Mathias T1 - Influence of Rhenium and Ruthenium on Local Mechanical Properties of Nickel-Base Superalloys T2 - Philosophical Magazine A Y1 - 2011 SN - 1478-6443 VL - 91 IS - 33 SP - 4187 EP - 4199 ER - TY - GEN A1 - Gebhard, Susanne A1 - Pyczak, Florian A1 - Göken, Mathias T1 - Microstructural and Micromechanical Characterisation of TiAl Alloys Using Atomic Force Microscopy and Nanoindentation T2 - Materials Science and Engineering A Y1 - 2010 SN - 1873-4936 IS - 523 SP - 235 EP - 241 ER - TY - GEN A1 - Pyczak, Florian A1 - Neumeier, Steffen A1 - Göken, Mathias T1 - Change of Internal Stress and Strain States in Nickel-Base Superalloys during Creep Deformation T2 - Materials Science and Engineering A Y1 - 2009 SN - 1873-4936 IS - 510-511 SP - 295 EP - 300 ER - TY - GEN A1 - Rettig, Ralf A1 - Heckl, Astrid A1 - Neumeier, Steffen A1 - Pyczak, Florian A1 - Göken, Mathias A1 - Singer, Robert F. T1 - Verification of a commercial CALPHAD database for Re and Ru containing nickel-base superalloys T2 - Defect and Diffusion Forum Y1 - 2009 SN - 1662-9507 IS - 289-292 SP - 101 EP - 108 ER - TY - GEN A1 - Dinkel, Michael A1 - Pyczak, Florian A1 - May, Johannes A1 - Höppel, Heinz Werner A1 - Göken, Mathias T1 - XRD profile analysis characterization of ultrafine grained Al-Mg alloys T2 - Journal of Materials Science Y1 - 2008 SN - 1573-4803 VL - 43 IS - 23-24 SP - 7481 EP - 7487 ER - TY - CHAP A1 - Heinz, Paul A1 - Volek, Andreas A1 - Singer, Robert F. A1 - Dinkel, Michael A1 - Pyczak, Florian A1 - Göken, Mathias A1 - Ott, Michael A1 - Affeldt, Ernst A1 - Vossberg, Andreas ED - Öchsner, Andreas ED - Murch, Graeme E. T1 - Diffusion brazing of single crystalline nickel base superalloys using boron free nickel base braze alloys T2 - Diffusion in Solids and Liquids III, 3rd International Conference on Diffusion in Solids and Liquids, Liege Konferenz Y1 - 2008 SN - 978-3-908451-51-8 SP - 294 EP - 299 PB - Trans Tech Publ. CY - Stafa-Zurich [u.a.] ER - TY - CHAP A1 - Durst, K. A1 - Pyczak, Florian A1 - Biermann, H. A1 - Göken, Mathias A1 - Mughrabi, Hael A1 - Vehoff, H. T1 - Microstructural and micromechanical characterisation of nickel-base superalloys by CBED and nanoindentation investigations T2 - Proceedings, Materials Week 2002 Y1 - 2002 SN - 3-88355-314-X PB - Werkstoffinformationsgesellschaft mbH CY - Frankfurt am Main ER - TY - GEN A1 - Bauer, Alexander A1 - Neumeier, Steffen A1 - Pyczak, Florian A1 - Göken, Mathias T1 - Influence of Iridium on the Properties of γ′-Strengthened Co-Base Superalloys T2 - Advanced Engineering Materials Y1 - 2015 SN - 1527-2648 VL - 17 IS - 6 SP - 748 EP - 754 ER - TY - GEN A1 - Wang, Li A1 - Zenk, Carolin A1 - Stark, Andreas A1 - Felfer, Peter A1 - Gabrisch, Heike A1 - Göken, Mathias A1 - Lorenz, Uwe A1 - Pyczak, Florian T1 - Morphology evolution of Ti3AlC carbide precipitates in high Nb containing TiAl alloys T2 - Acta Materialia Y1 - 2017 SN - 1359-6454 IS - 137 SP - 36 EP - 44 ER - TY - GEN A1 - Kolb, M. A1 - Wheeler, Jeffrey M. A1 - Mathur, H. N. A1 - Neumeier, Steffen A1 - Korte-Kerzel, Sandra A1 - Pyczak, Florian A1 - Michler, Johann A1 - Göken, Mathias T1 - Local mechanical properties of the (β0+ω0) composite in multiphase titanium aluminides studied with nanoindentation at room and high temperatures T2 - Materials Science and Engineering A Y1 - 2016 U6 - https://doi.org/10.1016/j.msea.2016.04.026 SN - 0921-5093 VL - 665 SP - 135 EP - 140 ER - TY - GEN A1 - Iqbal, Farasat A1 - Pyczak, Florian A1 - Neumeier, Steffen A1 - Göken, Mathias T1 - Crack nucleation and elastic / plastic deformation of TiAl alloys investigated by in-situ loaded atomic force microscopy T2 - Materials Science and Engineering : A, Structural materials Y1 - 2017 SN - 0921-5093 SN - 1873-4936 VL - 689 SP - 11 EP - 16 ER - TY - GEN A1 - Pyczak, Florian A1 - Bauer, Alexander A1 - Göken, Mathias A1 - Lorenz, Uwe A1 - Neumeier, Steffen A1 - Oehring, Michael A1 - Paul, Jonathan A1 - Schell, Norbert A1 - Schreyer, Andreas A1 - Symanzik, Felix T1 - The effect of tungsten content on the properties of L12-hardened Co-Al-W alloys T2 - Journal of Alloys and Compounds Y1 - 2015 SN - 0925-8388 IS - 632 SP - 110 EP - 115 ER - TY - CHAP A1 - Neumeier, Steffen A1 - Pyczak, Florian A1 - Göken, Mathias ED - Reed, Roger C. ED - Green, Kenneth A. ED - Caron, Pierre ED - Gabb, Timothy P. ED - Fahrmann, Michael G. ED - Huron, Eric S. ED - Woodard, Shiela R. T1 - The Influence of Ruthenium and Rhenium on the local Properties of the gamma- and gamma'-Phase in Nickel-Base Superalloys and their Consequences for Alloy Behaviour T2 - Superalloys 2008, proceedings of the Eleventh International Symposium on Superalloys, held September 14 - 18, 2008, Pennsylvania, USA Y1 - 2008 SN - 978-0-87339-728-5 SP - 109 EP - 119 PB - TMS CY - Warrendale, Pa. ER - TY - CHAP A1 - Dinkel, Michael A1 - Pyczak, Florian A1 - Göken, Mathias A1 - Heinz, Paul A1 - Volek, Andreas A1 - Singer, Robert F. A1 - Ott, Michael A1 - Affeldt, Ernst A1 - Vossberg, Andreas ED - Lecomte-Beckers, Jacqueline ED - Carton, M. ED - Schubert, F. ED - Ennis, P. J. T1 - Nanoindentation and Orientation Measurements in Single Crystalline Brazing Joints of Nickel-Base Superalloys T2 - Materials for advanced power engineering 2006, proceedings of the 8th Liege Conference, Bd. 2 Y1 - 2006 SN - 3-89336-436-6 SP - 633 EP - 642 PB - Forschungszentrum CY - Jülich ER - TY - GEN A1 - Liang, Zhida A1 - Paul, Jonathan A1 - Stark, Andreas A1 - Bezold, Andreas A1 - Neumeier, Steffen A1 - Göken, Mathias A1 - Pyczak, Florian T1 - High-Temperature CoNi-Based Superalloys Strengthened by γ′-(Ni,Co)3(Cr,Al,Ti,X): The Effect of Refractory Elements T2 - Metallurgical and materials transactions. A, Physical metallurgy and materials science N2 - Recent research on Co-based and CoNi-based alloys revealed that the Co–Al–W-system provides interesting properties, however, the high content of W addition triggers high mass density of alloys which limits its industrial application. Therefore, new high temperature superalloys based on the Co–Ni–Al–Ti-system with high content Cr and strengthened by γ′-(Ni,Co)3(Cr,Al,Ti) precipitates, have been developed, and the effect of different refractory element additions was investigated. STEM-EDS and HEXRD were employed to determine the elemental partitioning behavior and the lattice misfit between the γ and γ′ phases. Ta and Nb strongly concentrate within the γ′ phase, whereas Mo weakly partitions to the γ phase. W distributes equally between the γ and γ′ phases. These new superalloys have an unexpectedly high positive misfit compared with some conventional Ni-based superalloys and Co-based superalloys. Nb and Ta additions increase the lattice misfit further, while Mo and W decrease the lattice misfit. The effect of refractory elements alloying on the yield stress at room temperature was evaluated by analyzing the contributions of different strengthening mechanisms. Alloying with Nb or Ta significantly improves precipitation strengthening by increasing the antiphase boundary energy. Mo has the highest solid solution strengthening effect in the γ phase, followed by W. Compared with some conventional Ni-based superalloys, the investigated new CoNi-based superalloys exhibited better mechanical properties at high temperature, which indicates that these compositionally complex alloys are possible candidates for high temperature applications. Y1 - 2022 U6 - https://doi.org/10.1007/s11661-022-06795-y SN - 1543-1940 VL - 54 (2023) IS - 5 SP - 1620 EP - 1634 ER - TY - GEN A1 - Liang, Zhida A1 - Neumeier, Steffen A1 - Rao, Ziyuan A1 - Göken, Mathias A1 - Pyczak, Florian T1 - CALPHAD informed design of multicomponent CoNiCr-based superalloys exhibiting large lattice misfit and high yield stress T2 - Materials Science and Engineering: A, Structural materials N2 - Usually, Co-based superalloys contain a high fraction of W and/or Mo. The refractory elements stabilize the precipitate phase, but cause a high density. In this work, new L12-phase hardened, low-density CoNiCr-based superalloys were developed with the assistance of CALPHAD calculations. Several alloys were studied experimentally and their microstructures, elemental distributions, lattice parameters and the lattice misfit between the γ and γ′ phases were evaluated using scanning electron microscopy, transmission electron microscopy, atom probe tomography and high energy X-ray diffraction. The alloys exhibit a very high misfit, good phase stability and excellent mechanical strength. It was found by hardness tests that a two-step heat treatment improves the strength of the new alloys even further. In comparison with conventional Co-based superalloys, Co–Al–W based superalloys and Co–Ti based superalloys, as well as Ni-based superalloys, i.e. Udimet 720Li, they have a low mass density and high yield stress. They also overcome the problem of a generally low lattice misfit of previous L12-phase hardened CoNiCr-based superalloys with high Ni and Cr contents. As a result, they show cuboidal-shaped precipitates similar to Co–Al–W and Co–Al–Mo based superalloys. Y1 - 2022 U6 - https://doi.org/10.1016/j.msea.2022.143798 SN - 1873-4936 SN - 0921-5093 VL - 854 ER - TY - GEN A1 - Pyczak, Florian A1 - Bauer, A. A1 - Göken, Mathias A1 - Neumeier, Steffen A1 - Lorenz, U. A1 - Oehring, Michael A1 - Schell, N. A1 - Schreyer, Andreas A1 - Stark, Andreas A1 - Szymanzik, F. T1 - Plastic Deformation Mechanisms in a Crept L12 hardened Co-Base Superalloy T2 - Materials Science and Engineering A Y1 - 2013 SN - 1873-4936 IS - 571 SP - 13 EP - 18 ER - TY - GEN A1 - Neumeier, Steffen A1 - Pyczak, Florian A1 - Göken, Mathias T1 - The temperature dependent lattice misfit of rhenium and ruthenium containing nickel-base superalloys–experiment and modelling T2 - Materials and Design Y1 - 2020 SN - 0264-1275 VL - 198 ER - TY - GEN A1 - Bresler, Johannes A1 - Neumeier, Steffen A1 - Ziener, Marco A1 - Pyczak, Florian A1 - Göken, Mathias T1 - The influence of niobium, tantalum and zirconium on the microstructure and creep strength of fully lamellar γ/α2 titanium aluminides T2 - Materials Science and Engineering Y1 - 2019 U6 - https://doi.org/10.1016/j.msea.2018.11.152 SN - 0921-5093 VL - 744 SP - 46 EP - 53 ER - TY - GEN A1 - Freund, Lisa P. A1 - Stark, Andreas A1 - Pyczak, Florian A1 - Schell, Norbert A1 - Göken, Mathias A1 - Neumeier, Steffen T1 - The grain boundary pinning effect of the µ phase in an advanced polycrystalline γ/γʹ Co-base superalloy T2 - Journal of Alloys and Compounds Y1 - 2018 U6 - https://doi.org/10.1016/j.jallcom.2018.04.204 SN - 0925-8388 VL - 753 SP - 333 EP - 342 ER - TY - GEN A1 - Freund, Lisa P. A1 - Stark, Andreas A1 - Kirchmayer, Andreas A1 - Schell, Norbert A1 - Pyczak, Florian A1 - Göken, Mathias A1 - Neumeier, Steffen T1 - The Effect of a Grain Boundary Pinning B2 Phase on Polycrystalline Co-Based Superalloys with Reduced Density T2 - Metallurgical and Materials Transactions A Y1 - 2018 U6 - https://doi.org/10.1007/s11661-018-4757-2 SN - 1543-1940 SN - 1073-5623 VL - 49 IS - 9 SP - 4070 EP - 4078 ER - TY - GEN A1 - Dinkel, Michael A1 - Heinz, Paul A1 - Pyczak, Florian A1 - Volek, Andreas A1 - Ott, Michael A1 - Affeldt, Ernst A1 - Vossberg, Andreas A1 - Göken, Mathias A1 - Singer, Robert F. ED - Reed, Roger C. ED - Green, Kenneth A. ED - Caron, Pierre ED - Gabb, Timothy P. ED - Fahrmann, Michael G. ED - Huron, Eric S. ED - Woodard, Shiela R. T1 - New Boron and Silicon Free Single Crystal-Diffusion Brazing Alloys T2 - Superalloys 2008, proceedings of the Eleventh International Symposium on Superalloys, held September 14 - 18, 2008, Pennsylvania, USA Y1 - 2008 SN - 978-0-87339-728-5 SP - 211 EP - 220 PB - TMS CY - Warrendale, Pa. ER - TY - GEN A1 - Haußmann, Lukas A1 - Neumeier, Steffen A1 - Bresler, Johannes A1 - Keim, Simon A1 - Pyczak, Florian A1 - Göken, Mathias T1 - Influence of Nb, Ta and Zr on the Interdiffusion Coefficients and Solid Solution Strengthening of γ-TiAl Single Phase Alloys T2 - Metals N2 - The alloying elements Nb, Ta and Zr improve the creep properties of fully lamellar γ/α2 titanium aluminides significantly. Since high temperature deformation mainly occurs in the γ-phase of γ/α2 titanium aluminides, the diffusivity and the solid solution hardening effect of these three elements in the γ-phase is studied by analyzing the concentration gradients of the alloying elements and the resulting hardness across the interdiffusion zone of diffusion couples by energy dispersive X-ray diffraction and nanoindentation. The results reveal that Zr has the highest interdiffusion coefficient but also the largest solid solution hardening coefficient. The mechanical properties of single γ-phase Ti-54Al-5X alloys were investigated by strain rate jump tests. The addition of 5 at.% Nb or Ta lead to an increased strength compared to a binary γ-Ti-54Al alloy. The Zr-containing γ-TiAl alloy reveals the highest strength at 750°C and 900°C, which is discussed to be due to the strong solid solution hardening effect of Zr. However, in comparison to the other alloys, Ti-54Al-5Zr shows quite brittle behavior up to 900°C. The lower diffusivity of Ta compared to Nb leads to a higher strength of the Ta-modified alloy at 900◦C. Y1 - 2022 U6 - https://doi.org/10.3390/met12050752 SN - 2075-4701 VL - 12 IS - 5 ER -