TY - GEN A1 - Wang, Li A1 - Lorenz, Uwe A1 - Münch, Mathias A1 - Stark, Andreas A1 - Pyczak, Florian T1 - Influence of alloy composition and thermal history on carbide precipitation in γ-based TiAl alloys T2 - Intermetallics Y1 - 2017 SN - 0966-9795 VL - 89 SP - 32 EP - 39 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 - Wang, Li A1 - Pyczak, Florian A1 - Paul, Jonathan A1 - Oehring, Michael A1 - Lorenz, Uwe A1 - Yao, Zekun A1 - Ning, Yongquan T1 - Rafting of γ′ precipitates in a Co-9Al-9W superalloy during compressive creep T2 - Materials Science and Engineering Y1 - 2018 U6 - https://doi.org/10.1016/j.msea.2018.02.017 SN - 0921-5093 VL - 719 SP - 43 EP - 48 ER - TY - GEN A1 - Wang, Li A1 - Oehring, Michael A1 - Lorenz, Uwe A1 - Stark, Andreas A1 - Pyczak, Florian T1 - New insights into perovskite-Ti3AlC precipitate splitting in a Ti-45Al-5Nb-0.75C alloy by transmission electron microscopy T2 - Intermetallics Y1 - 2018 U6 - https://doi.org/10.1016/j.intermet.2018.06.006 SN - 0966-9795 VL - 100 SP - 70 EP - 76 ER - TY - GEN A1 - Wang, Li A1 - Oehring, Michael A1 - Lorenz, Uwe A1 - Yang, Junjie A1 - Pyczak, Florian T1 - Influence of alloying additions on L1₂ decomposition in γ-γʹ Co-9Al-9W-2X quaternary alloys T2 - Scripta Materialia Y1 - 2018 SN - 1359-6462 VL - 154 SP - 176 EP - 181 ER - TY - GEN A1 - Song, Lin A1 - Wang, Li A1 - Oehring, Michael A1 - Hu, Xingguo A1 - Appel, Fritz A1 - Pyczak, Florian A1 - Zhang, Tiebang T1 - Evidence for deformation twinning of the D019-α2 phase in a high Nb containing TiAl alloy T2 - Intermetallics Y1 - 2019 U6 - https://doi.org/10.1016/j.intermet.2019.03.014 SN - 0966-9795 VL - 109 SP - 91 EP - 96 ER - TY - GEN A1 - Wang, Li A1 - Song, Lin A1 - Stark, Andreas A1 - Liu, Yong A1 - Oehring, Michael A1 - Lorenz, Uwe A1 - Pyczak, Florian T1 - Identification of Laves phases in a Zr or Hf containing γ-γ′ Co-base superalloy T2 - Journal of Alloys and Compounds Y1 - 2019 SN - 0925-8388 VL - 805 SP - 880 EP - 886 ER - TY - GEN A1 - Song, Lin A1 - Hu, Xingguo A1 - Wang, Li A1 - Stark, Andreas A1 - Lazurenko, Daria V. A1 - Lorenz, Uwe A1 - Lin, Junpin A1 - Pyczak, Florian A1 - Zhang, Tiebang T1 - Microstructure evolution and enhanced creep property of a high Nb containing TiAl alloy with carbon addition T2 - Journal of Alloys and Compounds Y1 - 2019 U6 - https://doi.org/10.1016/j.jallcom.2019.151649 SN - 0925-8388 VL - 807 ER - TY - GEN A1 - Han, Liuliu A1 - Xu, Xiandong A1 - Wang, Li A1 - Pyczak, Florian A1 - Zhou, Rui A1 - Liu, Yong T1 - A eutectic high-entropy alloy with good high-temperature strength-plasticity balance T2 - Materials Research Letters Y1 - 2019 SN - 2166-3831 VL - 7 IS - 11 SP - 460 EP - 466 ER - TY - GEN A1 - Wang, Li A1 - Oehring, Michael A1 - Liu, Yuzhi A1 - Lorenz, Uwe A1 - Pyczak, Florian T1 - Site occupancy of alloying elements in the L12 structure determined by channeling enhanced microanalysis in γ/γ’ Co-9Al-9W-2X alloys T2 - Acta Materialia Y1 - 2019 SN - 1359-6454 VL - 162 SP - 176 EP - 188 ER - TY - GEN A1 - Song, Lin A1 - Wang, Li A1 - Zhang, Tiebang A1 - Lin, Junpin A1 - Pyczak, Florian T1 - Microstructure and phase transformations of omega_o-Ti4Al3Nb based alloys after quenching and subsequent aging at intermediate temperatures T2 - Journal of Alloys and Compounds Y1 - 2020 SN - 0925-8388 VL - 821 ER - TY - GEN A1 - Song, Lin A1 - Appel, Fritz A1 - Wang, Li A1 - Oehring, Michael A1 - Hu, Xingguo A1 - Stark, Andreas A1 - He, Junyang A1 - Lorenz, Uwe A1 - Zhang, Tiebang A1 - Lin, Junpin A1 - Pyczak, Florian T1 - New insights into high-temperature deformation and phase transformation mechanisms of lamellar structures in high Nb-containing TiAl alloys T2 - Acta Materialia Y1 - 2020 U6 - https://doi.org/10.1016/j.actamat.2020.01.021 SN - 1873-2453 SN - 1359-6454 VL - 186 SP - 575 EP - 586 ER - TY - GEN A1 - Wang, Li A1 - Kong, Yi A1 - Oehring, Michael A1 - Song, Min A1 - Pyczak, Florian T1 - Atomic site occupancy of alloying elements and Laves phase stability in γ-γ′ Co-base superalloys T2 - Journal of Alloys and Compounds N2 - The atomic site occupancy of alloying elements in the ZrCo2 and HfCo2 based Laves phases formed in the Co-9Al-9W-2Zr and Co-9Al-9W-2Hf alloys was experimentally determined by the combined techniques of energy-dispersive X-ray spectroscopy mapping with atomic resolution and the atom location by channeling enhanced microanalysis (ALCHEMI) method. The results show that both Al and W occupy the Zr site in the C15 and the Hf site in the C36 crystal structure. The atomic locations of Al and W were further confirmed by comparing calculated inelastic cross-sections with experimental ALCHEMI results. Using the determined atomic site occupancies of alloying elements, special quasirandom structure solid solution models with 192 atoms were constructed and employed in first-principles calculations. It is found theoretically that the energy of formation of the C15 structure is always lower than that of the C36 structure at 0 K in both ZrCo2 and HfCo2 phases, no matter whether Al and W are incorporated or not. However, further ab initio molecular dynamics simulations suggest that lattice vibration at finite temperature contributes significantly to the phase stability, stabilizing the C36 structure compared to the C15 type for the (Hf, Al, W)Co2 phase at finite temperature, which fits well with the experimental findings. Y1 - 2022 U6 - https://doi.org/10.1016/j.jallcom.2022.164261 SN - 1873-4669 SN - 0925-8388 VL - 906 ER - TY - GEN A1 - Wang, Li A1 - Liang, Xiaopeng A1 - Liu, Bin A1 - Oehring, Michael A1 - Paul, Jonathan David Heaton A1 - Liu, Jie A1 - Song, Min A1 - Pyczak, Florian A1 - Liu, Yong T1 - Stacking fault formation in perovskite Ti3AlC carbides in a TiAl based alloy during creep at 800°C T2 - Scripta Materialia Y1 - 2023 U6 - https://doi.org/10.1016/j.scriptamat.2022.115034 SN - 1872-8456 SN - 1359-6462 VL - Vol. 222 ER - TY - GEN A1 - Cao, Xianli A1 - Wang, Li A1 - Tao, Hui A1 - He, Weiwei A1 - Liang, Xiaopeng A1 - Liu, Bin A1 - Oehring, Michael A1 - Paul, Jonathan A1 - Pyczak, Florian A1 - Liu, Yong T1 - Morphology evolution of P-Ti3AlC carbides and their influence on creep properties in a crept Ti-45Al-5Nb-0.75C alloy T2 - Journal of Materials Research and Technology Y1 - 2024 U6 - https://doi.org/10.1016/j.jmrt.2024.02.146 SN - 2238-7854 VL - 29 SP - 4181 EP - 4190 PB - Elsevier BV ER - TY - GEN A1 - Liu, Xu A1 - Song, Lin A1 - Pyczak, Florian A1 - Stark, Andreas A1 - Wang, Li A1 - Guo, Xiang A1 - Zhang, Tiebang T1 - Stress-induced orthorhombic O phase in TiAl alloys T2 - Acta materialia N2 - The orthorhombic O phase precipitation within the D019-α2 phase has attracted increasing attention recently in high Nb containing TiAl (high Nb-TiAl) alloys since the precipitation temperature is close to the expected service temperature of the alloys. In this study, in-situ synchrotron high energy X-ray diffraction (HEXRD) reveals that the O phase precipitates at 550 °C while it dissolves into the α2 phase at 750 °C during heat treatments. However, under external stress the O phase unexpectedly precipitates from α2 phase at 800 °C and even 900 °C. The O phase formation proceeds further in the presence of a critical stress promoted by internal stress accumulation in the α2 phase, whereas the reverse O→α2 phase transformation takes place when the internal stresses are relaxed. Additionally, it has been revealed that the O phase preferentially precipitates from specifically oriented α2 grains with one of their <110> directions aligned perpendicular and their 〈0001〉 directions rotated by an angle of 120° out of the external load axis. This α2 phase orientation facilitates the α2→O crystal transition during uniaxial compression. Transmission electron microscopy (TEM) study shows that stress-induced α2→O transformation is governed by small atomic shifts in the α2 lattice. In addition, the selective growth of certain O variants via shuffling along an [110]α2 direction is found to accommodate the external strain component in this direction. KW - Titanium aluminides KW - Phase transformation KW - Strain accumulation KW - Variant selection KW - Hot compression Y1 - 2025 U6 - https://doi.org/10.1016/j.actamat.2025.120751 SN - 1359-6454 VL - 286 SP - 1 EP - 13 PB - Elsevier BV CY - Amsterdam ER -