@misc{LauhoffAroldBolenderetal., author = {Lauhoff, Christian and Arold, Tizian and Bolender, Artjom and Rackel, Marcus W. and Pyczak, Florian and Weinmann, Markus and Xu, Wenzheng and Molotnikov, Andrey and Niendorf, Thomas}, title = {Microstructure of an additively manufactured Ti-Ta-Al alloy using novel pre-alloyed powder feedstock material}, series = {Additive Manufacturing Letters}, volume = {Vol. 6}, journal = {Additive Manufacturing Letters}, issn = {2772-3690}, doi = {10.1016/j.addlet.2023.100144}, language = {en} } @misc{GuoSongLiuetal., author = {Guo, Xiang and Song, Lin and Liu, Xu and Stark, Andreas and Pyczak, Florian and Zhang, Tiebang}, title = {In-situ synchrotron HEXRD study on the phase transformation mechanisms of the ω-related phases in a Ti4Al3Nb alloy}, series = {Materials Characterization}, volume = {Vol. 200}, journal = {Materials Characterization}, issn = {1873-4189}, doi = {10.1016/j.matchar.2023.112901}, language = {en} } @misc{PyczakLiangNeumeieretal., author = {Pyczak, Florian and Liang, Zhida and Neumeier, Steffen and Rao, Ziyuan}, title = {Stability and Physical Properties of the L12-γ′ Phase in the CoNiAlTi-System}, series = {Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science}, volume = {54}, journal = {Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science}, number = {5}, issn = {1073-5623}, doi = {10.1007/s11661-022-06949-y}, pages = {1661 -- 1670}, language = {en} } @misc{VolpatoPereiraLemosetal., author = {Volpato, G. M. and Pereira, A. S. P. and Lemos, G. and Schmitt, M. and Pyczak, Florian and Tetzlaff, Ulrich and Fredel, M{\´a}rcio C.}, title = {Out-of-Equilibrium Formation of Ni3Ti η-Phase in Inconel X-750 Produced via Laser Powder Bed Fusion and Spark Plasma Sintering}, series = {Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science}, volume = {54}, journal = {Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science}, number = {5}, issn = {1073-5623}, doi = {10.1007/s11661-022-06946-1}, pages = {1924 -- 1936}, language = {en} } @misc{ZhangWangPyczaketal., author = {Zhang, Haoyin and Wang, C. P. and Pyczak, Florian and Ebel, Thomas and Liu, X. J.}, title = {A New Kind of Biomedical Ti-Mn-Nb Alloy}, series = {Physica Status Solidi. A, Applications and Materials Science}, volume = {220}, journal = {Physica Status Solidi. A, Applications and Materials Science}, number = {7}, issn = {1862-6300}, doi = {10.1002/pssa.202200348}, language = {en} } @misc{LiuSongStarketal., author = {Liu, Xu and Song, Lin and Stark, Andreas and Pyczak, Florian and Zhang, Tiebang}, title = {In-situ synchrotron high energy X-ray diffraction study on the deformation mechanisms of D019-α2 phase during high-temperature compression in a TiAl alloy}, series = {Journal of Materials Research and Technology}, volume = {33}, journal = {Journal of Materials Research and Technology}, publisher = {Elsevier BV}, issn = {2238-7854}, doi = {10.1016/j.jmrt.2024.10.231}, pages = {5850 -- 5862}, language = {en} } @misc{CaoWangTaoetal., author = {Cao, Xianli and Wang, Li and Tao, Hui and He, Weiwei and Liang, Xiaopeng and Liu, Bin and Oehring, Michael and Paul, Jonathan and Pyczak, Florian and Liu, Yong}, title = {Morphology evolution of P-Ti3AlC carbides and their influence on creep properties in a crept Ti-45Al-5Nb-0.75C alloy}, series = {Journal of Materials Research and Technology}, volume = {29}, journal = {Journal of Materials Research and Technology}, publisher = {Elsevier BV}, issn = {2238-7854}, doi = {10.1016/j.jmrt.2024.02.146}, pages = {4181 -- 4190}, language = {en} } @misc{WangWangPyczaketal., author = {Wang, Li and Wang, Yihao and Pyczak, Florian and Oehring, Michael and Song, Min and Liu, Yong}, title = {Revealing complex planar defects and their interactions at atomic resolution in a Laves phase containing Co-base superalloy}, series = {Acta Materialia}, volume = {264}, journal = {Acta Materialia}, publisher = {Elsevier BV}, issn = {1359-6454}, doi = {10.1016/j.actamat.2023.119568}, pages = {1 -- 20}, language = {en} } @misc{TangLiLuetal., author = {Tang, Yingchun and Li, Changle and Lu, Song and Li, Wei and Vitos, Levente and Pyczak, Florian}, title = {Magneto-chemical effects in the elastic properties of Co3Al-based compounds}, series = {Materials Today Communications}, volume = {41}, journal = {Materials Today Communications}, publisher = {Elsevier BV}, issn = {2352-4928}, doi = {10.1016/j.mtcomm.2024.110507}, pages = {1 -- 11}, language = {en} } @misc{HeidariPebdaniJanischPyczak, author = {Heidari Pebdani, Zeinab and Janisch, Rebecca and Pyczak, Florian}, title = {Effect of V-VIB group ternary elements on the properties of Ti2AlM-type O-phases: A first-principles study}, series = {Computational Condensed Matter}, volume = {40}, journal = {Computational Condensed Matter}, publisher = {Elsevier BV}, issn = {2352-2143}, doi = {10.1016/j.cocom.2024.e00945}, pages = {10}, language = {en} } @misc{GuptaPaulSchmittetal., author = {Gupta, Vipul and Paul, Jonathan David Heaton and Schmitt, Ingo and Pyczak, Florian}, title = {SciLitMiner : an intelligent system for scientific literature mining and knowledge discovery}, series = {Advanced intelligent systems}, journal = {Advanced intelligent systems}, publisher = {Wiley}, address = {Weinheim}, issn = {2640-4567}, doi = {10.1002/aisy.202501235}, pages = {1 -- 20}, abstract = {Recent advances in data mining have enabled automation in literature-based discovery (LBD), allowing synergistic evaluation of experimental findings reported in scientific publications. However, existing tools and digital libraries fall short in generating relevant literature collections and evaluating them for highly specific questions. This article presents SciLitMiner, an intelligent system to address this gap. SciLitMiner enables federated ingestion of literature from digital libraries; applies advanced retrieval techniques, including dataset-aware retrieval from visual elements, to identify relevant studies; and leverages retrieval-augmented generation (RAG) tailored to domain-specific knowledge reasoning. The system is applied in materials science to study the creep behavior of γ-TiAl alloys, revealing the intricate interplay between material, process, microstructure, and creep rate, represented through knowledge graphs. Two domain experts rate responses from the knowledge reasoning workflow with OpenAI large language models (LLMs) as the backbone above "good" (3 on a 5-point Likert scale) in over 90\% across qualitative criteria, indicating strong performance. In a case study, the workflow also outperforms gpt-4.5-turbo with web search and other leading tools in reliability. A second case study benchmarks open-source LLMs as drop-in replacements for proprietary models, demonstrating comparable-to-superior performance. The system's flexibility enables its use in automated LBD across diverse research domains.}, language = {en} } @misc{LiuSongPyczaketal., author = {Liu, Xu and Song, Lin and Pyczak, Florian and Stark, Andreas and Wang, Li and Guo, Xiang and Zhang, Tiebang}, title = {Stress-induced orthorhombic O phase in TiAl alloys}, series = {Acta materialia}, volume = {286}, journal = {Acta materialia}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {1359-6454}, doi = {10.1016/j.actamat.2025.120751}, pages = {1 -- 13}, abstract = {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.}, language = {en} } @misc{StarkRackelPyczak, author = {Stark, Andreas and Rackel, Marcus W. and Pyczak, Florian}, title = {How rapid heating and quenching cycles affect phase evolution in advanced γ-TiAl alloys : an in situ synchrotron radiation study}, series = {MRS communications}, volume = {15}, journal = {MRS communications}, number = {4}, publisher = {Springer Science and Business Media LLC}, address = {Berlin}, issn = {2159-6867}, doi = {10.1557/s43579-025-00756-3}, pages = {790 -- 795}, abstract = {Additive manufacturing (AM) processes are increasingly considered as an alternative manufacturing route to produce complex aircraft components out of γ-TiAl-based alloys. Due to the process-related high and short-time energy input, extremely fast heating and cooling rates occur which can result in thermodynamic and chemical disequilibrium. We studied the effect of rapid heating and quenching cycles in a Ti-48Al-2Nb-2Cr (in at.\%) alloy by carrying out in situ high-energy X-ray diffraction experiments in which AM-related heating cycles were simulated. These in situ experiments allow to determine the influence of cooling rate and a chosen powder bed temperature on phase evolution.}, language = {en} } @misc{StarkLottPyczak, author = {Stark, Andreas and Lott, Dieter and Pyczak, Florian}, title = {A dilatometer and in situ synchrotron X-ray diffraction study : α-quenching and reheating of a Nb-rich titanium aluminide alloy}, series = {MRS advances}, volume = {10}, journal = {MRS advances}, number = {14}, publisher = {Springer Science and Business Media LLC}, address = {Cham}, issn = {2731-5894}, doi = {10.1557/s43580-025-01382-w}, pages = {1767 -- 1772}, abstract = {Intermetallic γ-TiAl-based alloys are currently used as structural materials for turbine blades in aero engines. Additive manufacturing is increasingly considered as an additional manufacturing route for components consisting of γ titanium aluminides; however, the high heating and cooling rates result in chemical and thermodynamical disequilibrated microstructures. In our study, in situ synchrotron X-ray diffraction was applied to follow the formation of the disequilibrium microstructure during quenching and to study its re-equilibration during a subsequent annealing treatment in a Nb-rich γ-TiAl-based alloy. The quenched sample showed an incomplete massive transformation, with large remaining α2 grains. During reheating, the analysis of the collected data showed that equilibration of the quenched microstructure takes place in several reordering and transformation steps, e.g., orthorhombic distortion of the hexagonal α2 phase (around 550 °C), almost complete transformation of the supersaturated quenched α2 to γ (around 850 °C), and retransformation of γ to new α2 (around 1050 °C).}, language = {en} } @misc{LiuLiuWuetal., author = {Liu, Shen and Liu, Xu and Wu, Qiaohan and Li, Yixuan and Shi, Qiuyi and Song, Lin and Pyczak, Florian and Stark, Andreas and Li, Xiaobing and Zhang, Tiebang}, title = {In-situ synchrotron high energy X-ray diffraction study on the internal strain evolution of an extruded Ti-45Al-8Nb-0.2C alloy during high-temperature compression}, series = {Materials characterization}, volume = {230}, journal = {Materials characterization}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {1044-5803}, doi = {10.1016/j.matchar.2025.115746}, pages = {1 -- 12}, abstract = {Due to their exceptional properties, γ-TiAl based alloys present substantial prospect for aerospace and automotive applications. However, the significant disparity in plasticity between the D019-α2 and L10-γ phases greatly affects TiAl alloys' service behavior. This study investigates the internal strain accumulation in the α2 and γ phases of an extruded Ti-45Al-8Nb-0.2C alloy during compression at 900 °C and the subsequent stress relaxation behavior during annealing at 850 °C, using in situ synchrotron high-energy X-ray diffraction (HEXRD). During compression, the γ phase starts to yield plastically at approximately 410 MPa true stress, progressively shifting the load to the α2 phase and generating high residual stress in the α2 phase after deformation. However, annealing at 850 °C for 30 min only partially relieves the residual stress in the α2 phase, with the relaxation rate decreasing substantially after the first 10 min. Furthermore, when the true stress reaches 790 MPa during compression, the α2 phase undergoes rigid-body rotation to accommodate the plastic deformation of the adjacent γ phase, initiating texture evolution that ultimately forms a distinct fiber texture.}, language = {en} } @misc{WangWangLiangetal., author = {Wang, Li and Wang, Yihao and Liang, Xiaopeng and Liu, Bin and He, Junyang and Oehring, Michael and Pyczak, Florian and Liu, Yong}, title = {Revealing the unique evolution and splitting behavior of carbides at atomic-scale in TiAl alloys : the role of elastic interactions and chemical fluctuations}, series = {Acta materialia}, volume = {296}, journal = {Acta materialia}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {1359-6454}, doi = {10.1016/j.actamat.2025.121277}, pages = {1 -- 17}, abstract = {Cubic perovskite-Ti3AlC carbides are essential strengthening particles in TiAl alloys, especially for application above 800 °C where coarsening is expected to occur. However, these carbides can decompose into small sub-particles upon extended annealing, and the underlying atomic-scale mechanisms, especially structural and compositional changes, driving this unique splitting remain unclear. This study revisits this behavior in a Ti-45Al-5Nb-0.75C alloy utilizing probe-corrected transmission electron microscopy, atom probe tomography and first-principle calculations. The results reveal that the elastic interactions significantly influence carbide evolution. While needle-like carbides transform to intact plates during aging, those in high-density regions tend to coalesce or align along elastically softest γ-matrix directions, forming low-energy plate-like carbide conglomerates. With extended annealing, periodic chemical fluctuations driven by lattice misfit, especially along the needles induce splitting. Simultaneously, a γi-phase with a larger tetragonality and a 90°-rotated c-axis relative to the γ matrix emerges between the sub-particles, which exhibits near-zero lattice mismatch with carbides along [001], combined with mass-center shifts of carbides, further stabilizing the split configurations. This study provides atomic-scale insights into the evolution and stability of strengthening precipitates in systems with tetragonal misfit, and offers new strategies for improving creep properties of TiAl alloys by tailoring carbide configurations.}, language = {en} }