@misc{LiPyczakOehringetal., author = {Li, Yuzhi and Pyczak, Florian and Oehring, Michael and Wang, Li and Paul, Jonathan and Lorenz, Uwe and Yao, Zekun}, title = {Thermal Stability of gamma' phase in long-term aged Co-Al-W alloys}, series = {Journal of Alloys and Compounds}, volume = {729}, journal = {Journal of Alloys and Compounds}, issn = {0925-8388}, pages = {266 -- 276}, language = {en} } @misc{LiWangLiangetal., author = {Li, Longjun and Wang, Li and Liang, Zhida and He, Junyang and Qiu, Jingwen and Pyczak, Florian and Song, Min}, title = {Effects of Ni and Cr on the high-temperature oxidation behavior and mechanisms of Co- and CoNi-base superalloys}, series = {Materials and Design}, volume = {224}, journal = {Materials and Design}, issn = {1873-4197}, doi = {10.1016/j.matdes.2022.111291}, abstract = {The high-temperature oxidation behaviors of Co- and CoNi-base alloys with different Ni and Cr additions were investigated by isothermal oxidation in air at 900 and 1000 °C. The structure, composition, and element distribution in the three layers within the oxide scales in different alloys have been explored in detail by electron microscopy, especially with regard to the fine oxide particles in the intermediate layer. Based on the microstructure and phase constitution of the oxide scales, the synergetic effects of alloying elements on the oxidation mechanisms and resistance have been elucidated in detail with the aid of CALPHAD calculation.}, language = {en} } @misc{LiPyczakStarketal., author = {Li, Yuzhi and Pyczak, Florian and Stark, Andreas and Wang, Li and Oehring, Michael and Paul, Jonathan and Lorenz, Uwe}, title = {Temperature dependence of misfit in different Co-Al-W ternary alloys measured by synchrotron X-ray diffraction}, series = {Journal of Alloys and Compounds}, volume = {819}, journal = {Journal of Alloys and Compounds}, issn = {0925-8388}, pages = {9}, language = {en} } @misc{WangOehringLietal., author = {Wang, Li and Oehring, Michael and Li, Yuzhi and Song, Lin and Liu, Yon and Stark, Andreas and Lorenz, Uwe and Pyczak, Florian}, title = {Microstructure, phase stability and element partitioning of γ/γʹ Co-9Al-9W-2X alloys in different annealing conditions}, series = {Journal of Alloys and Compounds}, volume = {787}, journal = {Journal of Alloys and Compounds}, issn = {0925-8388}, pages = {594 -- 605}, language = {en} } @misc{WangPyczakZhangetal., author = {Wang, Li and Pyczak, Florian and Zhang, Jian and Lou, Langhong and Singer, Robert F.}, title = {Effect of eutectics on plastic deformation and subsequent recrystallization in the single crystal nickel base superalloy CMSX-4}, series = {Materials Science and Engineering A}, journal = {Materials Science and Engineering A}, number = {532}, issn = {1873-4936}, pages = {487 -- 492}, language = {en} } @misc{WangPyczakZhangetal., author = {Wang, Li and Pyczak, Florian and Zhang, Jian and Singer, Robert F.}, title = {On the role of eutectics during recrystallization in a single crystal nickel-base superalloy - CMSX-4}, series = {International Journal of Materials Research}, volume = {100}, journal = {International Journal of Materials Research}, number = {8}, issn = {2195-8556}, pages = {1046 -- 1051}, language = {en} } @inproceedings{WangPyczakGabrischetal., author = {Wang, Li and Pyczak, Florian and Gabrisch, Heike and Lorenz, Uwe and M{\"u}nch, Mathias and Schimansky, Frank-Peter and Schreyer, Andreas and Stark, Andreas}, title = {Effects of Carbon Content, Annealing Condition and Internal Defects on the nucleation, growth and coarsening of P-type Carbides in High Niobium Containing TiAl Alloys}, series = {Advanced structural and functional intermetallic-based alloys, November 30 - December 5, 2014, Boston, Massachusetts, USA}, booktitle = {Advanced structural and functional intermetallic-based alloys, November 30 - December 5, 2014, Boston, Massachusetts, USA}, publisher = {Curran}, address = {Red Hook, NY}, isbn = {978-1-5108-0634-4}, pages = {61 -- 66}, language = {en} } @misc{WangGabrischLorenzetal., author = {Wang, Li and Gabrisch, Heike and Lorenz, Uwe and Schimansky, Frank-Peter and Schreyer, Andreas and Stark, Andreas and Pyczak, Florian}, title = {Nucleation and thermal stability of carbide precipitates in high Nb containing TiAl alloys}, series = {Intermetallics}, volume = {66}, journal = {Intermetallics}, issn = {0966-9795}, doi = {10.1016/j.intermet.2015.07.001}, pages = {111 -- 119}, language = {en} } @misc{ZangLinLietal., author = {Zang, Yufeng and Lin, Nanying and Li, Yaping and Wang, Xiadon and Kang, Junyong and Wilks, Regan G. and B{\"a}r, Marcus and Mu, Rui}, title = {The isotype ZnO/SiC heterojunction prepared by molecular beam epitaxy - A chemical inert interface with significant band discontinuities}, series = {Scientific reports}, volume = {6}, journal = {Scientific reports}, issn = {2045-2322}, doi = {10.1038/srep23106}, pages = {23106}, language = {en} } @misc{WangLorenzMuenchetal., author = {Wang, Li and Lorenz, Uwe and M{\"u}nch, Mathias and Stark, Andreas and Pyczak, Florian}, title = {Influence of alloy composition and thermal history on carbide precipitation in γ-based TiAl alloys}, series = {Intermetallics}, volume = {89}, journal = {Intermetallics}, issn = {0966-9795}, pages = {32 -- 39}, language = {en} } @misc{WangZenkStarketal., author = {Wang, Li and Zenk, Carolin and Stark, Andreas and Felfer, Peter and Gabrisch, Heike and G{\"o}ken, Mathias and Lorenz, Uwe and Pyczak, Florian}, title = {Morphology evolution of Ti3AlC carbide precipitates in high Nb containing TiAl alloys}, series = {Acta Materialia}, journal = {Acta Materialia}, number = {137}, issn = {1359-6454}, pages = {36 -- 44}, language = {en} } @misc{WangLiEuler, author = {Wang, Jian and Li, Zheng and Euler, Mathias}, title = {Investigation on shear buckling of steel welded I-section beams with reinforced web openings}, series = {ce/papers}, volume = {6}, journal = {ce/papers}, number = {3-4}, doi = {10.1002/cepa.2361}, pages = {1754 -- 1760}, language = {en} } @misc{WangLiPasternaketal., author = {Wang, Jian and Li, Zheng and Pasternak, Hartmut and Euler, Mathias}, title = {Querkrafttragf{\"a}higkeit von Wellstegtr{\"a}gern mit versteiften quadratischen Steg{\"o}ffnungen}, series = {Bauingenieur}, volume = {98}, journal = {Bauingenieur}, number = {11}, issn = {0005-6650}, doi = {10.37544/0005-6650-2023-11-31}, pages = {343 -- 353}, abstract = {Die Ergebnisse aus drei Traglastversuchen und einer umfangreichen numerischen Parameterstudie (FE-Berechnungen) zum Tragverhalten von Wellstegtr{\"a}gern mit quadratischen Steg{\"o}ffnungen werden vorgestellt. Es werden versteifte Steg{\"o}ffnungen mit einem umlaufenden Versteifungskranz betrachtet. In der Parameterstudie werden die Einfl{\"u}sse der Steg{\"o}ffnungsgeometrie, der Tr{\"a}gergeometrie und der Position der Steg{\"o}ffnung auf die Querkrafttragf{\"a}higkeit der Wellstegtr{\"a}ger untersucht.}, language = {de} } @misc{SongAppelWangetal., author = {Song, Lin and Appel, Fritz and Wang, Li and Oehring, Michael and Hu, Xingguo and Stark, Andreas and He, Junyang and Lorenz, Uwe and Zhang, Tiebang and Lin, Junpin and Pyczak, Florian}, title = {New insights into high-temperature deformation and phase transformation mechanisms of lamellar structures in high Nb-containing TiAl alloys}, series = {Acta Materialia}, volume = {186}, journal = {Acta Materialia}, issn = {1873-2453}, doi = {10.1016/j.actamat.2020.01.021}, pages = {575 -- 586}, language = {en} } @misc{WangKongOehringetal., author = {Wang, Li and Kong, Yi and Oehring, Michael and Song, Min and Pyczak, Florian}, title = {Atomic site occupancy of alloying elements and Laves phase stability in γ-γ′ Co-base superalloys}, series = {Journal of Alloys and Compounds}, volume = {906}, journal = {Journal of Alloys and Compounds}, issn = {1873-4669}, doi = {10.1016/j.jallcom.2022.164261}, abstract = {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.}, language = {en} } @misc{WangLiPasternaketal., author = {Wang, Jian and Li, Zheng and Pasternak, Hartmut and Euler, Mathias}, title = {Shear Buckling Behavior of Tapered Steel Plate Girders with Sinusoidally Corrugated Webs}, series = {ce/papers}, volume = {6}, journal = {ce/papers}, number = {3-4}, issn = {2509-7075}, doi = {10.1002/cepa.2534}, pages = {1787 -- 1792}, language = {en} } @misc{WangEulerPasternaketal., author = {Wang, Jian and Euler, Mathias and Pasternak, Hartmut and Li, Zheng and Krausche, Thomas and Launert, Benjamin}, title = {Bending capacity of single and double-sided welded I-section girders: Part 1: Experimental investigations}, series = {Current Perspectives and New Directions in Mechanics, Modelling and Design of Structural Systems : Proceedings of The Eighth International Conference on Structural Engineering, Mechanics and Computation, 5-7 September 2022, Cape Town, South Africa}, journal = {Current Perspectives and New Directions in Mechanics, Modelling and Design of Structural Systems : Proceedings of The Eighth International Conference on Structural Engineering, Mechanics and Computation, 5-7 September 2022, Cape Town, South Africa}, publisher = {CRC Press}, address = {Boca Raton}, isbn = {978-1-00-334845-0}, doi = {10.1201/9781003348443-159}, pages = {975 -- 980}, abstract = {The lateral-torsional buckling resistance of welded steel girders is affected by their residual stresses and geo-metric imperfections. Generally, both influences are mainly controlled by the manufacturing process, in partic-ular the welding of the girder. This paper presents experimental investigations on four laterally unbraced welded steel girders with thin-walled I-sections, whose flange-to-web junctions are welded from one or two sides to evaluate the fabrication influence. The investigations include lateral-torsional buckling tests under combined bending and torsion loading caused by three-point bending due to an eccentric vertical single force. The geometric imperfections of the welded test girders are determined by 3D laser scanning. The test results show that the influence of the geometric imperfections and the residual stresses on the lateral-torsional buck-ling resistance is limited for the tested girders.}, language = {en} } @misc{GabrischStarkSchimanskyetal., author = {Gabrisch, Heike and Stark, Andreas and Schimansky, Frank-Peter and Wang, Li and Schell, Norbert and Pyczak, Florian}, title = {Carbides in Ti-45Al-5Nb alloys with different carbon contents}, series = {Intermetallics}, journal = {Intermetallics}, number = {33}, issn = {0966-9795}, pages = {44 -- 53}, language = {en} } @misc{SongWangZhangetal., author = {Song, Lin and Wang, Li and Zhang, Tiebang and Lin, Junpin and Pyczak, Florian}, title = {Microstructure and phase transformations of omega_o-Ti4Al3Nb based alloys after quenching and subsequent aging at intermediate temperatures}, series = {Journal of Alloys and Compounds}, volume = {821}, journal = {Journal of Alloys and Compounds}, issn = {0925-8388}, pages = {11}, language = {en} } @misc{WangSongStarketal., author = {Wang, Li and Song, Lin and Stark, Andreas and Liu, Yong and Oehring, Michael and Lorenz, Uwe and Pyczak, Florian}, title = {Identification of Laves phases in a Zr or Hf containing γ-γ′ Co-base superalloy}, series = {Journal of Alloys and Compounds}, volume = {805}, journal = {Journal of Alloys and Compounds}, issn = {0925-8388}, pages = {880 -- 886}, language = {en} } @misc{HanXuWangetal., author = {Han, Liuliu and Xu, Xiandong and Wang, Li and Pyczak, Florian and Zhou, Rui and Liu, Yong}, title = {A eutectic high-entropy alloy with good high-temperature strength-plasticity balance}, series = {Materials Research Letters}, volume = {7}, journal = {Materials Research Letters}, number = {11}, issn = {2166-3831}, pages = {460 -- 466}, language = {en} } @misc{WangOehringLiuetal., author = {Wang, Li and Oehring, Michael and Liu, Yuzhi and Lorenz, Uwe and Pyczak, Florian}, title = {Site occupancy of alloying elements in the L12 structure determined by channeling enhanced microanalysis in γ/γ' Co-9Al-9W-2X alloys}, series = {Acta Materialia}, volume = {162}, journal = {Acta Materialia}, isbn = {1359-6454}, pages = {176 -- 188}, language = {en} } @misc{SongHuWangetal., author = {Song, Lin and Hu, Xingguo and Wang, Li and Stark, Andreas and Lazurenko, Daria V. and Lorenz, Uwe and Lin, Junpin and Pyczak, Florian and Zhang, Tiebang}, title = {Microstructure evolution and enhanced creep property of a high Nb containing TiAl alloy with carbon addition}, series = {Journal of Alloys and Compounds}, volume = {807}, journal = {Journal of Alloys and Compounds}, issn = {0925-8388}, doi = {10.1016/j.jallcom.2019.151649}, pages = {11}, language = {en} } @misc{SongWangOehringetal., author = {Song, Lin and Wang, Li and Oehring, Michael and Hu, Xingguo and Appel, Fritz and Pyczak, Florian and Zhang, Tiebang}, title = {Evidence for deformation twinning of the D019-α2 phase in a high Nb containing TiAl alloy}, series = {Intermetallics}, volume = {109}, journal = {Intermetallics}, issn = {0966-9795}, doi = {10.1016/j.intermet.2019.03.014}, pages = {91 -- 96}, language = {en} } @misc{WangOehringLorenzetal., author = {Wang, Li and Oehring, Michael and Lorenz, Uwe and Stark, Andreas and Pyczak, Florian}, title = {New insights into perovskite-Ti3AlC precipitate splitting in a Ti-45Al-5Nb-0.75C alloy by transmission electron microscopy}, series = {Intermetallics}, volume = {100}, journal = {Intermetallics}, issn = {0966-9795}, doi = {10.1016/j.intermet.2018.06.006}, pages = {70 -- 76}, language = {en} } @misc{WangPyczakPauletal., author = {Wang, Li and Pyczak, Florian and Paul, Jonathan and Oehring, Michael and Lorenz, Uwe and Yao, Zekun and Ning, Yongquan}, title = {Rafting of γ′ precipitates in a Co-9Al-9W superalloy during compressive creep}, series = {Materials Science and Engineering}, volume = {719}, journal = {Materials Science and Engineering}, issn = {0921-5093}, doi = {10.1016/j.msea.2018.02.017}, pages = {43 -- 48}, language = {en} } @misc{WangOehringLorenzetal., author = {Wang, Li and Oehring, Michael and Lorenz, Uwe and Yang, Junjie and Pyczak, Florian}, title = {Influence of alloying additions on L1₂ decomposition in γ-γʹ Co-9Al-9W-2X quaternary alloys}, series = {Scripta Materialia}, volume = {154}, journal = {Scripta Materialia}, issn = {1359-6462}, pages = {176 -- 181}, language = {en} } @phdthesis{Wang, author = {Wang, Li}, title = {Millimeter-wave Integrated Circuits in SiGe:C Technology}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-5993}, language = {en} } @misc{LiXuGeissleretal., author = {Li, Zheng and Xu, Siying and Geißler, Karsten and Wang, Jian and Pasternak, Hartmut}, title = {Developed numerical Analysis of Residual Stress caused by Welding and Cutting in Steel Structures}, series = {ce/papers}, volume = {6}, journal = {ce/papers}, number = {3-4}, issn = {2509-7075}, doi = {10.1002/cepa.2601}, pages = {1507 -- 1512}, abstract = {The welding and flame-cutting process in the steel construction are commonly used, especially for the bridge structure. Some experiments about welding and cutting have been done separately by some researchers. The results from the experiments were also compared with the results from the numerical simulation under 3D or 2D models. The agreements between those results are as good as they predicted. Therefore, the numerical simulation is a better way to analyze the quality of the steel construction after welding and cutting without time-consuming and a large amount of cost. But there are only a few research about the numerical simulation and the some of them are aimed to verify the experiments. In this study, the calculation about the residual stresses after welding and thermo-cutting are considered from 3D-model into 2D-Model. The heat source model is simply regarded as curves of time and welding energy with the algorithm methods. And no matter the change of the parameters of the model and the heat source, the heat transfer and the residual stresses can be calculated with the 2D models as fast as possible. By the means of the finite element software Abaqus, the I-profiles are easy to receive the job results with the input parameters. The influence of the welding and cutting process are visual and direct.}, language = {en} } @misc{WangLiRobraetal., author = {Wang, Jian and Li, Zheng and Robra, J{\"o}rgen and Pasternak, Hartmut and Euler, Mathias}, title = {Investigation on Shear Buckling of Corrugated Web Beams with Reinforced Web Openings}, series = {ce/papers}, volume = {5}, journal = {ce/papers}, number = {4}, issn = {2509-7075}, doi = {10.1002/cepa.1800}, pages = {628 -- 634}, abstract = {Corrugated web beams are welded I-sections with thin-walled sinusoidal corrugated webs and flanges made of wide flat steel that have been developed as an alternative to steel girders with flat webs. In comparison with hot-rolled or welded I-beams with flat webs, corrugated web beams are connected with considerable material savings and fully automated production. Assuming the same load-bearing capacity, corrugated web beams are lighter than those with a flat web, since the corrugated web beams can often be loaded up to their plastic resistance without reinforcement of the web. The research on the load-bearing behavior of corrugated web beams without web openings is relatively mature. However, the resistance of corrugated web beams with reinforced web openings, as they are often used in buildings for installations, has not well experimentally been investigated, yet. This paper deals with the shear resistance of corrugated web beams with reinforced square web openings. Three specimens of different geometry with two square web openings were tested. The experiments are compared with a Finite Element Analysis by Abaqus® and with an analytical model allowing simplified calculation. Both models can relatively accurately calculate the shear resistance. The experimental and numerical results show that the increase of the shear resistance of perforated corrugated web beams depends on the wall-thickness and the steel grade of the web opening reinforcement.}, language = {en} } @misc{LiGaoWangetal., author = {Li, Bai and Gao, Jiarong and Wang, Xiuru and Ma, Lan and Cui, Qiang and Veste, Maik}, title = {Effects of biological soil crusts on water infiltration and evaporation Yanchi Ningxia, Maowusu Desert, China}, series = {International Journal of Sediment Research}, volume = {31}, journal = {International Journal of Sediment Research}, number = {4}, issn = {1001-6279}, doi = {10.1016/j.ijsrc.2016.05.005}, pages = {311 -- 323}, abstract = {Biological soil crusts serve as a vanguard for improving the ecological environment in arid, semi-arid desertification areas.It is a good indicator of the level of improvement which the local ecological evironment is undertaking. In desert areas, water condition is a key factor of improving the ecological environment. As a first layer protection, biological crusts play an important role in local vegetation succession due to their abilities to conserve and maintain moisture. Using Maowusu desert in Yanchi of Ningxia province as an example, after three years of research, this paper chooses three kinds of biological crusts including lichen, moss and cyanobacterial which are under the cover of Artemisia ordosicaas research objects. The results of this study indicate that, the closer biological crusts are to Artemisia ordosica vegetation, the thicker they become. In the same position of Artemisia ordosica vegetation, the thickness of moss crusts is the highest, followed by lichen crusts, and the thickness of cyanobacterial crusts is the lowest. Biological soil crusts coverage protects the natural water content of soil layers from 0 to 5cm. Also, it effects falling water to infiltrate deeper, and cannot prevent the surfacewater content from evaporating effectively. The effect of biological crusts blocking water infiltration decreases with the increase of rainfall. At the same rainfall level, moss crusts provide the strongest water infiltration blockage, followed by lichen crusts and cyanobacterial crusts. With the increase of rainfall, the depth of water infiltration increases.At the same rainfall level, the relationship of water infiltration depth is as follows: cyanobacterial crusts > lichen crusts > moss crusts. With the increase of biological crusts thickness, they blocking water infiltration capacity is stronger, and the depth of water infiltration is smaller. Analysis on the characteristic of simulated rainfall process on biological crusts shows that sandy land can be fixed by applying appropriate artificial biological crusts to build a sustainable forest protection system and to create a stable ecosystem in desertification area.}, language = {en} } @misc{LiZhangShietal., author = {Li, Zheng and Zhang, Qiulei and Shi, Fei and Wang, Jian and Pasternak, Hartmut}, title = {Geometric Properties of Steel Components with Stability and Fatigue Risks Using 3D-Laser-Scanning}, series = {Buildings}, volume = {14}, journal = {Buildings}, number = {1}, issn = {2075-5309}, doi = {10.3390/buildings14010168}, abstract = {Nowadays, 3D laser scanning technology is extensively employed in laboratory investigations of steel structural components, providing accurate geometric dimensions to reduce uncertainties caused by indeterminate geometry in experimental results. It is often used in conjunction with the Finite Element (FE) Method and analytical solutions, which are more accurate deterministic operators in the research on steel structures. However, establishing a common methodological framework for transferring or mapping 3D-scanned information into finite element models for complex steel structures with stability and fatigue risks remains an ongoing task. In light of this, this study has developed a 3D scanning platform capable of obtaining accurate geometric dimensions for various types of steel components. Different coordinate systems and point cloud mapping algorithms have been established for different types of components to construct actual finite element models with initial imperfections. The feasibility of the self-developed 3D scanning platform and finite element modelling has been validated through three experimental cases: weld details, steel girders, and cylindrical shells. The research findings demonstrate that the captured point cloud can be automatically processed and corrected using the developed algorithm. The scanned data can then be input into the numerical model using various mapping algorithms tailored to the specific geometric properties of the specimens. The differences between the experimental test results and the simulated results obtained from the 3D-scanned finite element models remain within a small range. The self-developed 3D scanning platform and finite element modelling technique effectively capture the actual dimensions of different steel components, enabling the prediction of their stability and fatigue risks through numerical simulations.}, language = {en} } @misc{WangLiangLiuetal., author = {Wang, Li and Liang, Xiaopeng and Liu, Bin and Oehring, Michael and Paul, Jonathan David Heaton and Liu, Jie and Song, Min and Pyczak, Florian and Liu, Yong}, title = {Stacking fault formation in perovskite Ti3AlC carbides in a TiAl based alloy during creep at 800°C}, series = {Scripta Materialia}, volume = {Vol. 222}, journal = {Scripta Materialia}, issn = {1872-8456}, doi = {10.1016/j.scriptamat.2022.115034}, language = {en} }