TY - CONF A1 - Bonse, Jörn T1 - LIPSS for beginners N2 - This overview introduces to the phenomenon of Laser-Induced Periodic Surface Structures (LIPSS). Starting from a phenomenological introduction, the most relevant physical effects and theoretical models are discussed. Applications and future directions are outlined. T2 - Workshop “Ultrafast Structural Transformations in Condensed Matter – Bridging Theory and Experiment” CY - Wroclaw, Poland DA - 09.02.2026 KW - Laser-induced periodic surface structures (LIPSS) KW - Coherent optical scattering KW - Nanostructures KW - Matter reorganization PY - 2026 AN - OPUS4-65672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja T1 - Discussion on Weathering Reference Materials N2 - Weathering reference materials are used to characterize the harshness of an exposure, aiming on either reproducibility of a specific exposure or on the comparability between various kinds of weathering exposure. The materials that are used as weathering reference materials differ in their sensitivities (as well as in interactions and interferences of the latter), conditioned by the different processes which lead to the respective property change. It is also essential to take into account the necessary measurement equipment for the respective property change, in order to allow timely intervention. What are the key issues on choosing a weathering reference material? What can be learned from the weathering reference materials, investigated so far? Possibilities and limitations are discussed on the basis of existing weathering reference materials. Conclusions are drawn, for establishing new weathering reference materials. T2 - 9th European Weathering Symposium CY - Basel, Switzerland DA - 18.09.2019 KW - Plastic KW - Ageing KW - Fragmentation KW - Environment KW - Digital twin PY - 2019 AN - OPUS4-49713 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mrkwitschka, Paul A1 - Sahre, Mario A1 - Corrao, Elena A1 - Pellegrino, Francesco A1 - Alonso, Beatriz A1 - Zurutuza, Amaia A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - Standardized Elemental Composition Analysis of Graphene‐Related 2D Materials (GR2M) With SEM/EDS and XPS Works Reliably N2 - Reliable quantification of the chemical composition of graphene‐related 2D materials (GR2M) as powders and liquid suspensions is a challenging task. Analytical methods such as X‐ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICP‐MS), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) are recommended by standardization bodies. The specific parameters to be measured are also defined, e.g., the oxygen‐to‐carbon (O/C) atomic ratio, the trace metal impurities, or the functional groups. In this contribution, for the first time, results of a systematic study on the capability of energy‐dispersive X‐ray spectroscopy (EDS) at a scanning electron microscope (SEM) to reliably quantify the O/C ratio and impurities remained from the synthesis of selected GR2M are reported. The robustness of SEM/EDS analysis is verified for various measurement conditions (different excitations and EDS detectors) and the validity of the results is tested by comparison to the established XPS analysis. Moreover, an ionic liquid is used as a reference material for the quantification of the light elements such as C, N, O and F. The study clearly demonstrates the reliability of the fast and widely available SEM/EDS as a standard method for the quantification of the elemental composition of GR2M and generally of light materials. KW - Graphene oxide flakes KW - Impurities KW - O/C ratio KW - SEM/EDS KW - Standard KW - XPS PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656748 DO - https://doi.org/10.1002/smll.202511283 SN - 1613-6810 SP - 1 EP - 10 PB - Wiley-VHC GmbH AN - OPUS4-65674 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aliyah, K. A1 - Berger, A. A1 - Lazaridis, T. A1 - Appel, C. A1 - Prehal, C. A1 - Menzel, A. A1 - Guizar-Sicairos, M. A1 - Smales, Glen J. A1 - Pauw, Brian Richard A1 - Gasteiger, H. A. A1 - Gubler, L. A1 - Büchi, F. N. A1 - Eller, J. T1 - Impact of Microporous Layer Composition on the Water Content in the Membrane Electrode Assembly of Polymer Electrolyte Fuel Cells N2 - Polymer electrolyte fuel cells are paramount for future emission-free mobility. One of the vital challenges for prospering commercialization of PEFCs is water management in the cells. A microporous layer (MPL) is typically positioned between the gas Diffusion layer (GDL) and the catalyst layer (CL) to boost the cell performance and facilitate water management. In this study, three different MPLs were investigated, namely, carbon black-based MPLs with different PTFE binder contents (20 wt % PTFE as a base case and 40 wt % PTFE), as well as perforated MPLs with micron-sized pores coated on the same GDL- Substrate (Freudenberg H14). The water content in the membrane, catalyst layers (CL), and MPLs was explored using operando scanning small- and wide-angle X-ray scattering (S/WAXS). At Tcell = 80 °C, relative humidity = 100%, pabs = 3 bar, the MPL with larger pores exhibits slightly higher performance than the base case, while a considerably lower cathode CL and MPL saturation levels were observed for the MPL. In contrast, the MPL with higher amounts of PTFE binder shows lower performance than the base case, with considerably higher cathode CL and MPL saturation levels. 3D representations of how the pores could be filled in the cathode CLs were obtained from operando SAXS profiles using representative structure modeling for the different materials and operating conditions. KW - Polymer electrolyte fuel cell KW - Catalyst layer saturation KW - Microporous layer saturation KW - Membrane hydration KW - Small and wide-angle scattering KW - MOUSE KW - SAXS KW - X-ray scattering KW - Energy storage materials PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656691 DO - https://doi.org/10.1021/acsami.5c22540 SN - 1944-8244 SP - 1 EP - 17 PB - American Chemical Society (ACS) AN - OPUS4-65669 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Charlesworth, M. A1 - Lampronti, G. A1 - Belenguer, Ana M. A1 - Day, S. A1 - Saunders, L. A1 - Connolly, E. A1 - Midgley, P. A1 - Michalchuk, Adam A. L. T1 - Influence of Liquid on Crystallite Size Evolution During Ball Milling N2 - Liquid assisted grinding (LAG) is a commonly used mechanochemical procedure, especially for polymorphic conversions. However, it is not understood what effect liquid additives actually play in driving mechanochemical polymorphic conversions, precluding our ability to control solid form transformations under mechanochemical conditions. We here present a time-resolved in situ (TRIS) synchrotron powder Xray diffraction (PXRD) monitoring strategy that can track, with few nm resolution, the evolution of crystalline size under liquid assisted ball milling conditions. We apply this method to investigate the influence of liquid additives on the polymorphic conversion of the 1:1 co-crystal of theophylline and benzamide, with particular focus on the role that crystallite size plays in driving ball milling induced polymorphic transformations. We find that the crystallite sizes achieved by ball milling are highly sensitive to the amount of liquid added to the reaction mixture. Liquid additives generally lead to larger crystallite sizes as compared with neat grinding protocol, with our findings indicating that crystallite size reduction is not the main factor that causes polymorph conversion under liquid assisted grinding conditions. The data presented clearly indicates the presence of an induction period before phase transformation begins with a minimum value in the crystallite size of the starting polymorph indicating the end of that induction period. KW - Ball milling KW - In situ diffraction KW - Phase transformation KW - Liquid assisted grinding KW - Crystallite size PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656783 DO - https://doi.org/10.1021/acs.cgd.5c01662 SN - 1528-7483 SP - 1 EP - 7 PB - American Chemical Society (ACS) AN - OPUS4-65678 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yang, Chunliang A1 - Yang, Fan A1 - Meng, Xiangmeng A1 - Putra, Stephen Nugraha A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Phase-field simulation of the dendrite fragmentation by electromagnetic stirring in AA5754 aluminum alloy laser beam welding N2 - A phase-field model including magnetic field induced dendrite fragmentation was established and applied to the cases with different initial crystal nuclear positions for AA5754 aluminum alloy electromagnetic laser beam welding. Compare the calculated results that include dendrite fragmentation caused by the thermal electromagnetic Lorentz force with the results that consider only the thermal electromagnetic Lorentz force, without fragmentation, at the characteristic time instants. Both in the early and late stages, the small fragmentation at the dendrite tip promotes the number of higher-order branches and their growth, especially in the direction perpendicular to the solidification. The later stage fragmentation has the possibility of breaking one grain into several, which verifies the possibility of grain refinement caused by dendrite fragmentation. The fracture surface caused by fragmentation also makes more solid-liquid interfaces and their growth. In addition, the cases with different initial nuclear positions were compared. The grain growth in the low-temperature zone can be inhibited by the equiaxed grains' fragmentation at the high-temperature area (179.8 μm² and 14.7 % start at the center, 115.4 μm² and 9.4 % start at the high-temperature corner, 134.3 μm² and 10.9 % start at the low-temperature corner), which is another kind of grain refinement by the dendrite fragmentation. This kind of inhibition effect on grain growth in the low-temperature region will be enhanced with the increasing time interval between the two crystal nuclei’ appearance (179.8 μm² and 14.7 % when virtual grains appear at t = 4.3803 s and t = 4.3803 s, 134.3 μm² and 10.9 % at t = 4.0977 s and t = 3.9564 s, and 115.4 μm² and 9.4 % at t = 3.8151 s and t = 3.5325 s). KW - Laser beam welding KW - Electromagnetic KW - Aluminum alloys KW - Phase field method KW - Equiaxed grain KW - Dendrite fragmentation PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656610 DO - https://doi.org/10.1016/j.cwe.2025.100014 SN - 3117-4159 VL - 35 IS - 1 SP - 1 EP - 12 PB - Elsevier B.V. AN - OPUS4-65661 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meng, Xiangmeng A1 - Bachmann, Marcel A1 - Kising, Pascal A1 - Yang, Fan A1 - Rethmeier, Michael T1 - Prediction of weld pool and keyhole geometries in high-power laser beam welding through a physics-informed generative artificial intelligence approach N2 - The weld pool and keyhole geometries are critical characteristics in evaluating the stability of the high-power laser beam welding (LBW) process and determining the resultant weld quality. However, obtaining these data through experimental or numerical methods remains challenging due to the difficulties in experimental measurements and the high computational demands of numerical modelling. This paper presents a physics-informed generative approach for predicting weld pool and keyhole geometries in the LBW process. With the help of a well experimentally validated numerical model considering the underlying physics in the LBW, the geometries of the weld pool and keyhole under various welding conditions are calculated, serving as the dataset of the generative model. A conditional variational autoencoder model is employed to generate realistic 2D weld pool and keyhole geometries from the welding parameters. We utilize a β-variational autoencoder model with the evidence lower bound loss function and include Kullback–Leibler divergence annealing to better optimize model performance and stability during training. The generated results show a good agreement with the ground truth from the numerical simulation. The proposed approach exhibits the potential of physics-informed generative models for a rapid and accurate prediction of the weld pool geometries across a diverse range of process parameters, offering a computationally efficient alternative to full numerical simulations for process optimization and control in laser beam welding processes. KW - Laser beam welding KW - Generative artificial intelligence KW - Machine learning KW - Numerical simulation KW - Weld pool KW - Keyhole dynamics PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656621 DO - https://doi.org/10.2351/7.0001862 SN - 1042-346X VL - 38 IS - 1 SP - 1 EP - 8 PB - Laser Institute of America AN - OPUS4-65662 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - El Abbassi, Abdelouahad A1 - Krenzer, Julius A1 - Petrov, Eugene P. A1 - Biesen, Lukas A1 - Vasylyeva, Vera A1 - Merzenich, Sarah A1 - Resch-Genger, Ute A1 - Müller, Thomas J. J. T1 - Aroyl-S,N-ketene acetal-triarylamine bichromophores – intramolecular energy transfer and dual emission upon induced aggregation and encapsulation N2 - Aroyl-S,N-ketene acetal-based bichromophores are synthesized by a catalytic aryl amination and their photophysics are studied in the solid state, in ethanol–water mixtures inducing aggregation, and after encapsulation in polystyrene nanoparticles. The dye substitution pattern controls aggregation-induced emission and intramolecular energy transfer efficiency, resulting in single-band or dual fluorescence and a strong increase in fluorescence quantum yield upon particle encapsulation. KW - Fluorescence KW - Dye KW - Aggregation KW - Photophysics KW - Enhancement KW - White light emission KW - Energy transfer KW - Quantum yield PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656700 DO - https://doi.org/10.1039/d5ra09361a SN - 2046-2069 VL - 16 IS - 11 SP - 10255 EP - 10260 PB - Royal Society of Chemistry (RSC) AN - OPUS4-65670 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hilberg, Alec T1 - Untersuchung und Kompensation des Size-of-Source Effektes der Thermografie zur Prozessüberwachung in der metallischen additiven Fertigung N2 - Der Einsatz der Thermografie zur Prozessüberwachung in der additiven Fertigung von Metallen ist aktueller Schwerpunkt diverser Forschungsprojekte. Prozessbedingt können im Bauteil Risse, innere Spannungen und sonstige interne Fehlerstellen auftreten, deren Entstehung durch wichtige thermische Größen wie Phasenumwandlungstemperaturen, Abkühlgeschwindigkeiten und thermische Gradienten beeinflusst wird. Um diese Einflüsse zu untersuchen, ist eine möglichst genaue Messung dieser Parameter notwendig. Neben den häufig betrachteten Einflüssen des Emissionsgrades, der Umgebungstemperatur und der atmosphärischen Absorption besteht ein weiterer Einfluss, hervorgerufen durch das optische System. Der Kameraaufbau, das verwendete Objektiv und Teilchen im Strahlengang können zur Beugung, Streuung, Reflektion und Aberration der elektromagnetischen Strahlung führen, wodurch die thermografische Messung verfälscht wird. Dies ist ein in der Pyrometrie intensiv erforschter Effekt und wird, aufgrund der Abhängigkeit zur betrachteten Objektgröße, als Size-of-Source Effekt bezeichnet und in dieser Arbeit untersucht. Im Laser-Pulver-Auftragsschweißen (LPA) wird mittels eines Lasers auf einer Substratplatte ein Schmelzbad erzeugt und durch Einblasen von Metallpulver die lagenweise Fertigung von komplexen Bauteilen ermöglicht. Dabei können, je nach geometrischer Auflösung der Kamera, Größen des Schmelzbades im Bereich weniger Prozente der gesamten Bildfläche auftreten. Aus durchgeführten Referenzmessungen an Schwarzkörperstrahlern kann in der gleichen Größenordnung eine Abweichung der Strahlungswerte im zweistelligen Prozentbereich festgestellt werden. Daher ist in diesem Anwendungsfall der dadurch verursachte Fehler nicht zu vernachlässigen, weshalb auf Basis der Referenzmessungen eine Methode entwickelt wurde, um in Abhängigkeit der Größe des Objektes einen Faktor zur Kompensation des Size-of-Source Effektes zu berechnen. In diesem Beitrag werden erste Ergebnisse dieser im Rahmen des DFG Projektes QT-LPA (Nr. 516965606) durchgeführten Arbeiten präsentiert. T2 - DGZfP Jahrestagung 2025 CY - Berlin, Germany DA - 26.05.2025 KW - SSE KW - Thermografie KW - Size of source Effect PY - 2025 AN - OPUS4-65651 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hilberg, Alec T1 - Multispektrale Thermografie zur quantitativen Temperaturbestimmung im DED-LB/M Prozess N2 - Additive Fertigungsverfahren bieten konstruktive Freiheiten, die mit konventionellen Herstellungsverfahren nur schwer zu realisieren sind. Durch die Möglichkeit hochkomplexe Bauteile aus Metall fertigen zu können, stellt die additive Fertigung in vielen Industriezweigen eine vielversprechende Fertigungsalternative da. Allerdings treten prozessbedingt hohe Temperaturgradienten und schnelle Phasenumwandlungen auf, die maßgeblich entscheidend für die Mikrostruktur und die Bildung von internen Spannungen, Rissen und weiteren Defekten sind. Diese Effekte wirken sich direkt auf die mechanischen Eigenschaften der gefertigten Bauteile aus und verdeutlichen die Notwendigkeit einer zuverlässigen Bauteilprüfung. Dabei sind nachgelagerte Verfahren in der Regel zeit- und kostenaufwändig, weshalb die Anwendung von in-situ Verfahren zur Qualitätssicherung im Fokus diverser Forschungsprojekte steht. Die Thermografie erlaubt die orts- und zeitaufgelöste Messung der im Prozess auftretenden Temperaturfelder. Allerdings müssen die tatsächlich gemessenen digitalen Sensorwerte mittels geeigneter radiometrischer Modelle in Temperaturen umgewandelt werden. Da diese Modelle in der Regel auf Basis von Messungen an Schwarzkörperstrahlern kalibriert werden, kann dieses Vorgehen nur zufriedenstellende Werte liefern, sofern der Emissionsgrad des zu messenden Objektes bekannt ist. Während in statischen Anwendungen häufig ein konstanter Materialreferenzwert hinreichend befriedigende Ergebnisse liefert, ist man in der additiven Fertigung mit dem Problem konfrontiert, dass der Emissionsgrad lokal in kürzester Zeit starke Änderungen durchläuft. Beeinflusst wird dieser Effekt unter anderem durch Temperatur, Phasenzustand und Oberflächenzustand. Das hier vorgestellte Verfahren nutzt Referenzmessungen des Emissionsgrades in Abhängigkeit von Temperatur, Winkel und Phasenzustand, um in einem DED-LB/M-Prozess (auch Laser-Pulver-Auftragschweißen, LPA) sowohl den Emissionsgrad als auch die tatsächliche Temperatur orts- und zeitaufgelöst zu bestimmen. Grundlage hierfür sind multispektrale thermografische Messungen, bei denen (quasi-) synchron in acht unterschiedlichen Wellenlängenbereichen gemessen wird. In diesem Beitrag werden Ergebnisse der im Rahmen des DFG-Projektes QT-LPA (Nr. 516965606) durchgeführten Arbeiten präsentiert. T2 - Thermo25 CY - Garching bei München, Germany DA - 11.11.2025 KW - Thermografie KW - TES KW - Multispektral KW - DED-LB/M KW - Laserpulverauftragschweißen PY - 2025 AN - OPUS4-65652 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ziegler, Mathias A1 - Strobach, L. T1 - Infrarotreflektographie und Blitzthermographie zur Sichtbarmachung von historischen Farbschichten am Flugzeug Bücker Bü 181 Bestmann N2 - Die Geschichte eines Flugzeuges ist häufig von unterschiedlichen Nutzungsphasen geprägt. Zum Beispiel ist der Wechsel des Eigentümers eines Flugzeuges häufig mit umfassenden Veränderungen der Farbgebung und Kennzeichnung verbunden. Wenn ein Flugzeug in die Sammlung eines Museums aufgenommen wird, zeigt es entweder den letzten Einsatzzustand oder andere zu späteren Zeiten durchgeführte Reparaturen auf seiner Oberfläche. Oft befinden sich unterhalb dieser letzten äußeren Schicht, ältere Spuren der Nutzung. Um diese verdeckt liegenden Lackierungen sichtbar zu machen, können die Verfahren der Infrarotreflektographie und der aktiven Thermographie eingesetzt werden. Die Infrarotreflektographie wird häufig in der Gemälderestaurierung eingesetzt, um zum Beispiel Vorzeichnungen sichtbar zu machen. Die aus der industriellen zerstörungsfreien Prüfung bekannten Verfahren der aktiven Thermographie fanden bisher überwiegend im Bereich der Bauwerksuntersuchungen Anwendung. Erste Ergebnisse zu Farbuntersuchungen an historischen Flugzeugen mit den beiden Verfahren fanden am Deutschen Museum München in Zusammenarbeit mit der TU-München statt. Ein Projekt der HTW-Berlin mit der Bundesanstalt für Materialforschung und –prüfung (BAM) und dem Militärhistorischen Museum Flugplatz Berlin-Gatow greift diese Anwendungsidee auf und vergleicht beide Verfahren. Am Beispiel des Flugzeuges Bücker Bü 181 Bestmann können die Möglichkeiten, Grenzen und Potentiale der Technologien zum gegenwärtigen Entwicklungsstand verdeutlicht werden. T2 - Material Truth CY - Magdeburg, Germany DA - 04.03.2026 KW - Aktive Thermographie KW - Flugzeuggeschichte KW - Zerstörungsfreie Prüfung (ZfP) KW - Infrarotreflektographie PY - 2026 AN - OPUS4-65658 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja T1 - Quantitative Auswertemöglichkeiten bei der spektralen Bestrahlung – Berechnung des Wirkungsspektrums N2 - Für die Bewertung des Wellenlängeneinflusses auf die Alterungsvorgänge bei der Bestrahlung UV- oder lichtempfindlicher Materialien kann die Methode der spektralen Bestrahlung angewendet werden. Im Prinzip wird dabei das linear dispergierte Spektrum einer Strahlenquelle mit kontinuierlichem Spektrum (z.B. Xe-Lampe) auf eine Probenoberfläche abgebildet, so dass Ort einer Materialänderung und Wellenlänge der Bestrahlung einander zugeordnet werden können. Nachfolgende lokal-auflösende Analysemethoden ermitteln eine Eigenschaftsänderung an einem spezifischen Ort der Probe, aus dem sich dann die Bestrahlungswellenlänge ergibt. Der verwendete Aufbau wird beschrieben. Es wird an einem ausgewählten Beispiel gezeigt, wie durch geeignete Anbindung eines Messsystems zur Bestimmung der spektralen Bestrahlungsstärke und ortsaufgelöste Messungen der Eigenschaftsänderungen eine quantitative Auswertung realisiert werden kann. Der Einfluss nichtlinearer Alterungsverläufe wird diskutiert. Grenzen der Methode werden aufgezeigt und Erweiterungsmöglichkeiten dargestellt. T2 - 46. Jahrestagung der GUS CY - Stutensee-Blankenloch, Germany DA - 22.03.2017 KW - UV-Bestrahlung PY - 2017 AN - OPUS4-42577 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - BOOK A1 - Geburtig, Anja A1 - Manier, G. A1 - Cäsar, J. A1 - Herlyn, J. A1 - Hülsmann, Ph. A1 - Köhl, M. A1 - Reichert, Th. A1 - Ruoss, H. A1 - Rüther, N. A1 - Schönlein, A. T1 - Wasser und Materialeigenschaften N2 - In der Gesellschaft für Umweltsimulation GUS e.V. erarbeiten Fachleute aus Wissenschaft und Industrie in freiwilliger Selbstverantwortung Leitfäden und Bücher zur, Umweltsimulation und zur Wirkungssimulation von Umwelteinflüssen. Diese beschreiben den Stand der Technik bzw. Stand der Wissenschaft und dienen als Anleitung für Umweltingenieure und Personen, die sich in die Arbeitsgebiete Produktqualifikation und Umweltsimulation einarbeiten und einiesen wollen. Folgende Themenschwerpunkte werden in diesem Leitfaden behandelt: Wasser und seine Eigenschaften, Phasenübergänge, Transportvorgänge, Änderung von Materialeigenschaften durch Wasser, Messmethoden. KW - Wasser KW - Materialien PY - 2019 SN - 978-3-9818507-4-1 N1 - Belegexemplar liegt bei Frau Geburtig. SP - 1 EP - 445 PB - Stober GmbH CY - Eggenstein AN - OPUS4-48325 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Engelking, Lorenz A1 - Eissel, A. A1 - Madia, Mauro A1 - Schröpfer, Dirk A1 - Treutler, K. A1 - Kruse, Julius A1 - Kannengießer, Thomas A1 - Wesling, V. T1 - Influence of ultrasonic-assisted milling on surface integrity of additively manufactured components using MSG processes N2 - Additive manufacturing (AM) is increasingly used for producing complex metallic components. Subsequent machining is essential to achieve final geometries and surface conditions. The resulting surface integrity, particularly the near-surface residual stress state, plays a crucial role in component performance and fatigue life. This study investigates the potential of ultrasonic-assisted milling (USAM), a hybrid machining process, to improve surface integrity and machinability compared to conventional milling (CM). Three materials were investigated, two difficult-to-cut materials CoCr26Ni9Mo5W and FeNi36 and a low-alloy steel S355J2C. The CoCr26Ni9Mo5W and FeNi36 were additively manufactured via Directed Energy Deposition (DED)-Arc and then machined with varying cutting speeds and feed rates within a Design of Experiments. USAM exhibited enhanced machinability and surface integrity, particularly at low cutting speeds, by reducing cutting forces up to 40% and shifting near-surface residual stresses from tensile to compressive. For S355J2C, USAM reduced cutting forces by approximately 45% and induced near-surface compressive residual stresses up to approximately −700 MPa. Rotating bending tests (DIN50100) show that USAM increases the technical fatigue limit from 307 MPa (CM) to 341 MPa (USAM), i.e., by ∼11%. These findings highlight the advantages of ultrasonic assistance in post-AM machining, offering enhanced fatigue performance and surface quality for various metallic materials. T2 - 4th International Conference on Advanced Joining Processes 2025 CY - Coimbra, Portugal DA - 16.10.2025 KW - Ultrasonic-assisted milling KW - Residual stress KW - Surface integrity PY - 2026 DO - https://doi.org/10.1177/14644207261416395 SP - 1 EP - 12 PB - Sage Journals AN - OPUS4-65682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jesus, Vinicius D. A1 - Merizio, Leonnam G. A1 - Galleani, Gustavo A1 - Raffy, Guillaume A1 - Carpentier, Mathis A1 - Petit, Yannick A1 - Cardinal, Thierry A1 - de Camargo, Andrea S. S. T1 - Energy transfer from Ag species to Nd 3+ in Ga–fluoride–phosphate glasses: near-infrared emission enhancement via controlled heat treatment and femtosecond laser inscription N2 - Gallium fluoride–phosphate glasses are promising materials with wide optical transmission window, high volumetric density, and the ability to accommodate high concentrations of rare earth dopant ions within a tailored fluoride-rich coordination environment, resulting in high emission cross sections. In this work, the compositional system 25Ga(PO3)3–20ZnF2–30BaF2–(25–x–y)SrF2–xAgNO3–yNdF3 (x = 0–10 mol%, y = 0 or 1 mol%) was studied to understand how silver species affect the near-infrared (NIR) emission of Nd3+ ions, when the glasses are subjected to controlled heat treatment and to femtosecond direct laser writing (DLW). The glasses were obtained via the melt-quenching technique and characterized by DSC, XRD, UV-Vis-NIR absorption, and PL spectroscopy. The as-prepared glasses show broad UV-Vis excitation and emission bands arising from the coexistence of Ag+ ions and ionic Ag pairs. In samples with 10 mol% Ag+, brownish coloration and modified emission profiles indicated Ag nanoparticle formation at the surface. Heat treatment promoted the conversion of isolated Ag+ into ionic pairs, producing broadband emissions tunable by excitation wavelength and Ag+ concentration. In co-doped samples, Nd3+ introduced absorption dips in the Ag-related UV-Vis bands, consistent with energy transfer, which was further confirmed by shortened Ag excited-state lifetimes and increased Nd3+ NIR emission under UVVis excitation. In order to control the spatial distribution and size of Ag aggregates (nanoclusters, NCs) and to increase the energy transfer efficiency to Nd3+, femtosecond direct laser writing (DLW) was employed to co-doped glasses with 3 and 5 mol% Ag+. This approach enabled three-dimensional localized growth of Ag NCs with sub-micron spatial control. In the laser processed regions, the NIR emissions of Nd3+ at 900 and 1060 nm were significantly enhanced, clearly evidencing enhanced energy transfer from the localized laserinduced Ag-NCs to the Nd3+ ions. These findings suggest the possibility of tailoring high optical contrast near-IR emissions in glasses, enabling progress in advanced photonic applications. KW - Neodymium KW - Silver KW - Fluoride phosphate glasses KW - Direct laser writing PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656888 DO - https://doi.org/10.1039/d5ma01430a SN - 2633-5409 SP - 1 EP - 14 PB - Royal Society of Chemistry (RSC) AN - OPUS4-65688 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scharf-Wildenhain, R. A1 - Engelking, Lorenz A1 - Hälsig, A. A1 - Schröpfer, Dirk A1 - Kannengießer, Thomas A1 - Hensel, J. T1 - Influence of build‑up height on residual stresses in additive repair and modification using DED‑Arc with high‑strength filler metals N2 - Directed energy deposition (DED)-Arc is suitable for the hybrid additive manufacturing, modification and repair of large metal components with high deposition rates. Residual stresses and distortion are of central importance when characterizing the manufactured components and the sensitive transition area between additive manufactured (AM) component and semifinished product. Residual stresses caused by the thermal cycles during the manufacturing process can impair the mechanical properties of the manufactured parts and can lead to component failure, especially for high-strength steels. Therefore, understanding and controlling residual stresses, when combining different base and feedstock materials, is critical to improve the quality and efficiency of the hybrid DED-Arc process. This article deals with the influence of the build-up height on the residual stress distribution of additively manufactured components with a selected base and feedstock material from commercial high-strength steels. Using a robot-assisted DED-system and a controlled short arc, AM welding experiments were carried out with close to the application parameters at working temperature (200 °C) and heat input (650 kJ/m). Five hybrid AM specimens (AM wall on upright structural steel plate) were produced using a one bead per layer strategy and selected AM-wall heights between 15 and 300 mm. The influence of the AM build height on the longitudinal residual stress in the whole hybrid AM specimen (in welding direction) was analyzed and discussed. All experiments exhibit comparable stress distributions in the area of the substrate plate up to the heat-affected zone (HAZ) and the transition zone, regardless of the building height. The height significantly influences the residual stress distribution of the deposited AM-component. Tensile residual stresses with a maximum range between 300and 400 MPa were always found in the last approx. 18 component layers (upper 40 mm). This is due to restraint of the shrinking of the top layers by the layers below. The lower layers show homogeneous residual stress distributions characterized by low compressive stresses due to the process-related tempering during the deposition of each layer on top of each other. As a result, the significant difference between the various AM build-up heights of the hybrid AM specimens is the extent (or height) of this tempered zone with low compressive stresses. These correlations contribute to the understanding of residual stress development with increasing structure height or ratio of component heights of substrate semi-finished product and AM component in hybrid additive manufacturing. T2 - 78th IIW Annual Assembly and International Conference CY - Genoa, Italy DA - 22.06.2025 KW - DED-Arc KW - Residual stress KW - Heat control PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656793 DO - https://doi.org/10.1007/s40194-026-02417-y SN - 1878-6669 SP - 1 EP - 12 PB - Spriner AN - OPUS4-65679 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fabry, Çağtay A1 - Pittner, Andreas A1 - Kaplan, Alexander A1 - Rethmeier, Michael T1 - Digitalisation and Carbon Footprint Evaluation of Gas Metal Arc Welding and Wire-Arc Directed Energy Deposition N2 - This paper showcases how a holistic approach to digitalisation enables data-driven welding applications, exemplarily for a gas metal arc welding (GMAW) laboratory. The workflow integrates advanced process monitoring, synchronised multi-sensor data acquisition and tools for data analytics. A welding domain-specific data exchange format weldx is presented that unifies and aggregates the data sets acquired during process monitoring with final component quality metrics, supporting reuse, traceability, and reproducibility. Two case studies illustrate the approach. First, GMAW parameters are adaptively adjusted according to local seam geometry to compensate joint-preparation deviations from nominal values typical for large-scale steel fabrication. Second, the seamless data aggregation along the welding production chain enables an automatic life-cycle assessment (LCA), quantifying the environmental impacts of additive manufacturing with DED Arc/M and attributing the dominant contributors to the carbon footprint. Collectively, the results indicate that a fully integrated experimental set-up together with standardised data structures and scalable analytics can couple monitoring, control, and sustainability, thereby realising the potential of digitalisation for high-quality and environmentally informed welding production. KW - Digitalisation KW - Arc welding KW - DED-arc KW - Life Cycle Assessment PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656812 DO - https://doi.org/10.1088/1757-899X/1342/1/012067 SN - 1757-8981 VL - 1342 IS - 1 SP - 1 EP - 15 PB - IOP Publishing AN - OPUS4-65681 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja T1 - Messung der effektiven UV-Bestrahlung bei der Bewitterung von Polymeren N2 - Bei der Bestrahlung und Bewitterung von polymeren Werkstoffen wird die Degradation durch eine Absorption von Strahlung initiiert und meistens durch weitere Klimagrößen, wie z.B. Wärme, Feuchte und atmosphärische Gase beeinflusst. Die Messung einer effektiven Bestrahlungsstärke und ihre zeitliche Integration sind deshalb von großer Bedeutung. Photochemische Prozesse werden beim Sehen oder allgemeiner bei Farbstoffen schon durch sichtbare (VIS) Strahlung, dagegen bei der Erythembildung der Haut und der Photodegradation von Polymeren erst durch die energiereicheren Photonen der ultravioletten (UV) Strahlung initiiert. Die spektrale Empfindlichkeit des Auges und die Erythembildung sind im VIS- bzw. UV-Bereich sehr stark wellenlängenabhängig, was durch die Angabe der mit der spektralen Hellempfindlichkeit V() des Auges bewerteten VIS-Strahlung in Lux (lx) bzw. die mit der Erythem-Wirkfunktion bewertete UV Strahlung als dimensionsloser UV-Index berücksichtigt wird. Spektrale Empfindlichkeiten. Die Photodegradation von Polymeren ist im UV-Bereich ebenfalls stark wellenlängenab-hängig, was bisher nicht berücksichtigt wurde. Seit Mitte der 70er Jahre, als die lx- bzw lxh- Messung bei der Strahlungsbeanspruchung langsam durch die Ermittlung der radiometrischen UV-Bestrahlungsstärke bzw. der UV-Bestrahlung im gesamten UV-Bereich abgelöst wurde, gab es hier bei der Bewitterungsprüfung keine weiteren Fortschritte auf dem Gebiet der Charakterisierung der Strahlungsbeanspruchung im UV-Bereich. Seit Jahren liegen zahlreiche Ergebnisse über die spektrale Empfindlichkeit von Photo-degradationsprozessen vor, die zeigen, dass die spektrale Empfindlichkeit im Bereich der Globalstrahlung bei ca. 300 nm, am größten ist und im langwelligen UV-Bereich bei ca. 400 nm gegen Null geht. Die Messungen der radiometrischen Größen UV-Gesamt-bestrahlungsstärke und UV-Gesamtbestrahlung erfasst deshalb über weite Wellen-längenbereiche Strahlungsanteile, die für die Photodegradation bedeutungslos sind und mittelt über potenziell bedeutsame Änderungen im kurzwelligen UV-Bereich hinweg. Es wird das Konzept eines neuen UV-Radiometers vorgestellt, dessen spektrale Empfindlichkeit einer mittleren spektralen Empfindlichkeit der Photodegradation von Polymeren entspricht. Die effektive UV-Bestrahlungsstärke und UV-Bestrahlung kann dadurch wesentlich genauer erfasst werden. T2 - 48. Jahrestagung der GUS 2019 CY - Stutensee, Germany DA - 27.03.2019 KW - UV-Bestrahlungsstärke PY - 2019 AN - OPUS4-49712 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja T1 - Evaluation of Outdoor Exposures by means of Exposure Response Functions N2 - Outdoor exposure tests are a common tool to evaluate the weathering resistance of a polymeric material or component. However, they have only a limited validity, mainly due to the limited reproducibility of the weather as well as of the bad adaptability to other exposure sites. Typically, an outdoor exposure is characterized by the measured radiant exposure; sometimes averaged temperature data are added. These can be – separately – related to long-term annual means, to get an idea on the severity of the exposure. However, as for polymeric ageing, irradiance and temperature act simultaneously, such severity of an outdoor exposure could be better described by a computed property change of a similar material, which is calculated from the hourly irradiance and temperature values on the base of established exposure response functions. In this way, various outdoor exposures are evaluated. For several exposure sites, annual deviations of the ageing amount are related to annual mean values, to evaluate the weathering reproducibility at the exposure site. Additionally, correlations to relevant weather parameters are illuminated. Also some specific exposure conditions, such as tilt angle, are tested. Compared to the use of weathering reference materials, this procedure unfavourably depends on the availability of a suited control as well as on the quality of the established exposure response function. In contrast, it enables a later exposure evaluation, on the base of documented weather data, if for instance no reference material was exposed. T2 - 8th European Weathering Symposium CY - Vienna, Austria DA - 20.09.2017 KW - Photodegradation KW - Weathering KW - Service life prediction PY - 2017 AN - OPUS4-42576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker A1 - Barthel, Anne-Kathrin A1 - Geburtig, Anja A1 - Trubiroha, P. ED - Reichert, T. T1 - Low-Temperature Irradiation Experiments for PE, PA, and PC Matrices N2 - In this paper, we demonstrate the effects of radiation exposures of polymeric materials with UV-A 340 nm lamps (ISO 4892-3, Type 1A) at -10 °C in comparison to an irradiation at +50 °C using a Global UV Test 200 fluorescent lamp device from Weiss Umwelttechnik GmbH, which incorporates an active cooling appliance. While the effects at -10 °C actually are lower than at + 50°C their extent was clearly beyond expectations. T2 - 8th European Weathering Symposium CY - Vienna, Austria DA - 20.09.2017 KW - Artificial weathering KW - Irradiation KW - Low-temperature KW - Photo-oxidation KW - Polyamide KW - Polycarbonate KW - Polyethylene PY - 2017 SN - 978-3-9818507-1-0 VL - 18 SP - Paper 22, 319 EP - 329 PB - Thomas Würtz Grafik Design CY - Karlsruhe AN - OPUS4-42130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalbe, Ute A1 - Krüger, Oliver A1 - Bandow, Nicole A1 - Geburtig, Anja ED - Reichert, Thomas T1 - Laboratory Weathering Test for Simulating the Leaching from Artificial Sporting Grounds N2 - In order to estimating the amount and kind of emissions from polymeric sporting tracks a laboratory test was developed in BAM that combines artificial weathering and subsequent batch and column tests [1, 2, 3]. The goal consisted in nvestigating a possible change of emissions into soil and groundwater of a new sporting ground as a function of ageing and egradation of the system. At various stages of the weathering, the samples were removed and subjected to especially designed column extraction tests for the solid samples. Both these extracts and the accumulated rainwater run-off of the weathering device were subjected to analytical tests of their ingredients. The overall aim of the test consisted in developing ontrollable, reproducible, and standardisable conditions and methods of investigation that would allow an estimation of the emissions in the course of outdoor application of about five years. T2 - 7th European Weathering Symposium. Natural and Artificial Ageing of Polymers CY - Naples, Italy DA - 16.09.2015 KW - artificial weathering KW - emission KW - leaching KW - sporting track KW - degradation KW - ageing KW - rubber KW - extraction PY - 2015 SN - 978-3-9816286-6-1 VL - CEES 17 SP - 195 EP - 208 PB - Thomas Würtz CY - Karlsruhe, Germany AN - OPUS4-35401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja T1 - Testing of HDPE containers for dangerous goods after outdoor exposure N2 - Focus areas of BAM as well as testing results of HDPE containers for dangerous goods after outdoor exposure of were presented. T2 - 70th CEEES Meeting CY - Hørsholm, Danmark DA - 13.11.2018 KW - HDPE KW - Dangerous goods KW - Chemical resistance PY - 2018 AN - OPUS4-47032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, P. T1 - Quantitative Auswertemöglichkeiten bei der spektralen Bestrahlung – Berechnung des Wirkungsspektrums N2 - Für die Bewertung des Wellenlängeneinflusses auf die Alterungsvorgänge bei der Bestrahlung UV- oder lichtempfindlicher Materialien kann die Methode der spektralen Bestrahlung angewendet werden. Im Prinzip wird dabei das linear dispergierte Spektrum einer Strahlenquelle mit kontinuierlichem Spektrum (z.B. Xe-Lampe) auf eine Probenoberfläche abgebildet, so dass Ort einer Materialänderung und Wellenlänge der Bestrahlung einander zugeordnet werden können. Nachfolgende lokal-auflösende Analysemethoden ermitteln eine Eigenschaftsänderung an einem spezifischen Ort der Probe, aus dem sich dann die Bestrahlungswellenlänge ergibt. Der verwendete Aufbau wird beschrieben. Es wird an einem ausgewählten Beispiel gezeigt, wie durch geeignete Anbindung eines Messsystems zur Bestimmung der spektralen Bestrahlungsstärke und ortsaufgelöste Messungen der Eigenschaftsänderungen eine quantitative Auswertung realisiert werden kann. Der Einfluss nichtlinearer Alterungsverläufe wird diskutiert. Grenzen der Methode werden aufgezeigt und Erweiterungsmöglichkeiten dargestellt. T2 - 46. Jahrestagung der GUS CY - Stutensee-Blankenloch, Germany DA - 22.03.2017 KW - Bewitterung KW - Spektrale Bestrahlung KW - Kunststoffe PY - 2017 SN - 978-3-9816286-9-2 SP - 91 EP - 99 AN - OPUS4-39595 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oliveira Menezes, Letícia Gonçalves A1 - Trajano Silveira, Beatriz Aiub A1 - de Castro Raucci, Larissa Moreira Spinola A1 - Martorano, Antônio Secco A1 - de Oliveira, Paulo Tambasco A1 - Arai, Marylyn Setsuko A1 - de Camargo, Andréa Simone Stucchi A1 - Hannig, Christian A1 - Sterzenbach, Torsten A1 - Brighenti, Fernanda Lourenção A1 - de Oliveira, Analú Barros A1 - Moraes, João Carlos Silos A1 - Danelon, Marcelle T1 - Functional glass ionomer cement modified with phosphate and zinc oxide nanoparticles: in vitro insights into physicomechanical behavior, cytotoxicity and antimicrobial activity N2 - Objectives: To evaluate the effect of incorporating zinc oxide nanoparticles (ZnONPs) and sodium trimetaphosphate microparticles (TMP) into resin-modified glass ionomer cement (RMGIC) on its physicomechanical, microbiological, and cytotoxic properties. Methods: Six groups were prepared: 1) RMGIC (Fuji II LC); 2) RMGIC-1.0 %ZnONPs; 3) RMGIC-2.0 %ZnONPs; 4) RMGIC-14.0 %TMP; 5) RMGIC-1.0 %ZnONPs-14.0 %TMP; and 6) RMGIC-2.0 %ZnONPs-14.0 %TMP. Tensile/diametral compressive strengths (TS, DCS), surface hardness (SH) and degree of monomer conversion (%DC) were evaluated in 24 h and 7 days. Fluoride (F) release was assessed over 15 days using alternating demineralizing/remineralizing solutions. Antimicrobial/antibiofilm activity against S. mutans (UA159) was assessed through adhesion, biofilm growth measurements, and XTT assays. Cytotoxicity was tested on MDPC23 odontoblasts using the resazurin assay. Results: The DCS for the RMGIC-2.0 %ZnONPs group was 22.5 % higher when compared to RMGIC after 24 h (p <0.05); after 7 days, RMGIC-2.0 %ZnONPS-14.0 %TMP group was 23.4 % higher than RMGIC (p < 0.05). For TS after 7 days, the RMGIC-2.0 %ZnONPs-14.0 % TMP group showed the highest values (37 % and 55.4 %) than RMGIC and RMGIC-14.0 % TMP, respectively (p < 0.05). At 24 h, the RMGIC-2.0 %ZnONPs-14.0 %TMP Group showed the highest SH among all groups (p < 0.05). The greatest effect on reducing bacterial viability was observed for the RMGIC-2.0 %ZnONPs-14.0 %TMP group (p < 0.05). For cytotoxicity analysis, at 24 h, the RMGIC-1.0 %ZnONPs-14.0 %TMP group showed the highest cytocompatibility (p < 0.05). At 48 and 72 h, RMGIC-1.0 %ZnONPs, RMGIC-2.0 %ZnONPs, RMGIC-1.0 %ZnONPs-14.0 %TMP and RMGIC-2.0 %ZnONPs-14.0 %TMP groups showed the lowest cytotoxicity (p < 0.05) KW - Phosphate and zinc oxide nanoparticles KW - Glass ionomer PY - 2026 DO - https://doi.org/10.1016/j.jdent.2025.106307 SN - 0300-5712 VL - 165 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-65692 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ghadamyari, Marzieh A1 - Ebrahim Hosseini, Hossein A1 - Michálková, Monika A1 - de Camargo, Andréa Simone Stucchi A1 - Cao, Jiangkun A1 - Galusek, Dušan A1 - Chukova, Oksana A1 - Wondraczek, Lothar A1 - Jacobsohn, Luiz Gustavo A1 - Klement, Róbert T1 - Broadband visible emission in undoped K2ZnGeO4 by near UV and X-ray excitation N2 - Self-activated phosphors (SAP) have attracted significant attention for a wide range of applications, including lighting, displays, scintillators, lasers, luminescence-based sensors, bioimaging, drug delivery, and luminescent security inks. In this work, we report a new white emitting SAP, α-K2ZnGeO4, synthesized by high-temperature solid-state reaction. The phosphor crystallizes in a single-phase orthorhombic structure and consists of irregularly shaped particles. Under ultraviolet (UV) and X-ray excitation the sample exhibits broad yellowish-white emission spanning the 350–800 nm spectral range, with a long-wavelength tail extending into the near-infrared region, overlapping the biological window. Average lifetime values of 20.4 and 22.6 μs were determined from the fluorescence decay curves monitored at the centre of the band (550 nm), upon excitation at 272 and 377 nm, respectively. Additionally, the decay curve of a distinct spectral feature, peaked at 385 nm, was studied upon 272 nm excitation, yielding a lifetime of 2.3 μs. The role of structural defects (donors: VO and Zni; acceptors: VZn, VGe, and Oi) in the luminescence of α-K2ZnGeO4 was also investigated. Photoluminescence spectra recorded under 366 nm and 377 nm excitation yielded CIE 1931 chromaticity coordinates of (x, y) = (0.40213, 0.46943) and (0.39326, 0.47611), respectively. The values are almost identical and correspond to yellowish-white emission, highlighting the suitability of the material as a yellowish-white phosphor in white light-emitting diodes (wLEDs). KW - Broadband emitter KW - K2ZnGeO4 KW - X-ray excitation PY - 2026 DO - https://doi.org/10.1016/j.ceramint.2026.01.063 SN - 0272-8842 VL - 52 IS - 7 SP - 8658 EP - 8669 PB - Elsevier Ltd. AN - OPUS4-65691 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rex, Tobias A1 - Vilela, Raquel R. C. A1 - Bauer, Nadine A1 - Hepp, Alexander A1 - de Camargo, Andrea S. S. A1 - Kiefer, Friedemann A1 - Strassert, Cristian A. T1 - Host–Guest Nanoparticles Incorporating a Fluorophore-Conjugated Pt(II) Complex: A Ratiometric Dual Emitter Performing as a Self-Referenced Oxygen Reporter N2 - Ratiometric optical sensors, which provide real-time measurements by comparing the intensities of two spectrally separated emission bands, are highly effective for monitoring oxygen levels. By combining oxygen-independent and oxygensensitive emission characteristics, they offer accurate quantification, distinguishing them from other sensor types. In this work, we designed a ratiometric optical sensor concept based on a biscyclometalated platinum(II) complex coupled with an organic naphthalonitrile-based fluorophore and incorporated it into mesoporous silica nanoparticles. This encapsulation strategy significantly improved the stability and water-dispersibility of the otherwise hydrophobic coordination compound while preventing aggregation and enhancing its photophysical properties. Both the free molecule and its nanoparticle-encapsulated form were characterized, revealing high sensitivity to oxygen variations with the unique feature of self-referenced ratiometric readout. The sensor’s response was effectively measured at the single-particle level using photoluminescence microscopy, providing temporally and spatially resolved oxygen readouts. The versatility of the system was demonstrated across different experimental setups, including suspensions, solids, and agarose-embedded forms, highlighting is adaptability to a wide range of applications. This system holds significant promise for advanced oxygen monitoring, offering a reliable tool for high-resolution detection in complex environments with multiple orthogonal readouts. KW - Oxygen sensing KW - Ratiometric luminescence KW - Platinum (II) complex KW - Dual emitter probe KW - Mesoporous silica nanoprticles PY - 2026 DO - https://doi.org/10.1021/acsaom.5c00262 SN - 2771-9855 VL - 4 IS - 2 SP - 332 EP - 342 PB - American Chemical Society (ACS) AN - OPUS4-65689 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Saeed, A. M. A1 - Saied, M. A. A1 - Szymoniak, Paulina A1 - Altmann, Korinna A1 - Schönhals, Andreas A1 - Fahmy, Alaa T1 - High performance novel polyelectrolyte membrane consisting of polyvinyl alcohol-phenylsilanol-polypyrrole N2 - The synthesis of composite membranes based on PVA, PPy, and sulfonated–hydrolyzed TMPS was investigated for application in proton–exchange membrane fuel cells. FT–IR confirmed the hydrolysis of TMPS through the appearance of Si–OH vibrations, disappearance of Si–O–CH3 bands, reduced CH3 stretching intensity (2840 cm− 1), and successful sulfonation of the phenyl ring (1030 cm− 1). XPS verified the introduction of sulfonic acid groups by identifying S2p peaks between 166–170 eV. Scanning electron microscopy (SEM) showed an incorporation of PPy and that the membrane morphology altered by silanol leading to an increased surface roughness and inducing phase separation in comparison to pure PVA. The PVA–PPy–Si membrane which did not undergo phase separation demonstrated improved mechanical stability (maximum stress 5.91 MPa), reduced methanol uptake (22%, lower than Nafion’s 30%), and enhanced thermal resistance compared to PVA–PPy and PVA–Si. It also exhibited a high ion–exchange capacity (1.5mmol g− 1, exceeding Nafion® at 0.9mmol g− 1 ) and a proton conductivity of 0.036 S/cm, twice that of Nafion 117. These combined properties identify the PVA–PPy–Si composite as a promising high–performance polyelectrolyte membrane for fuel cell applications. KW - Polyelectrolyte membrane PY - 2026 DO - https://doi.org/10.1016/j.apsusc.2026.166495 SN - 1873-5584 VL - 731 SP - 1 EP - 11 PB - Elsevier B.V. AN - OPUS4-65627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Suarez Ocano, Patricia T1 - Influence of heat-treatment-induced microstructural evolution on the Low Cycle Fatigue behavior of 316L stainless steel fabricated by Laser Powder Bed Fusion N2 - Additive manufacturing, particularly the laser powder bed fusion (PBF-LB/M) process, has gained significant attention in recent years due to its ability to produce complex geometries with enhanced mechanical properties. Among the various materials used, 316L stainless steel is highly favored for cyclically loaded components due to its exceptional mechanical strength, high-temperature performance, and corrosion resistance, making it widely applicable across various industries. 316L SS fabricated by PBF-LB/M (PBF-LB/M/316L) exhibits a unique hierarchical microstructure, with high density of low-angle grain boundaries (LAGBs), nano-dispersed silicates, chemical micro-segregations, and solidification-induced cellular structures. Particularly, the submicron-sized cellular features enriched with chromium (Cr) and molybdenum (Mo), along with high dislocation densities, contribute to a superior strength-ductility balance compared to conventionally manufactured 316L SS. The dispersed silicate particles act also as a strengthening phase, impeding dislocation movement and enhancing plastic deformation resistance. This study explores the effect of heat treatments on the low-cycle fatigue (LCF) behavior of PBF-LB/M/316L at room temperature (RT) and 600 °C. First, three heat treatment conditions were applied to the as-built material: 450 °C for 4 hours (HT450/4), 800 °C for 3 hours (HT800/3), and 900 °C for 1 hour (HT900/1) to investigate their influence on microstructural evolution. Microstructural analysis revealed that the HT450/4 condition preserved the cellular structure with high dislocation density, while the HT800/3 condition showed partial dissolution of cells together with reduction in segregated elements along the cell walls and a reduced dislocation density. The HT900/1 condition resulted in complete segregation and cellular structure dissolution with comparable dislocation density to HT800/3 while maintaining the crystallographic texture and grain morphology. Intermetallic χ phase was mostly observed at the grain boundaries in HT800/3, but not in HT900/1. Fully reversed LCF tests were conducted under strain-controlled conditions with a strain amplitude of 0.8 %. Tests were interrupted at specific intervals to analyze the interaction between hierarchical microstructural features and deformation mechanisms in the three heat-treated conditions. Due to the pronounced dislocation cell structures and elemental segregation, the microstructure of the HT450/4 condition significantly impact deformation and damage mechanisms during cyclic loading, which in turn, differ from the conventional produced counterparts. The results provide insights into the relationship between microstructural features and fatigue performance, highlighting key deformation and failure mechanisms under cyclic loading. T2 - FEMS 2025 EUROMAT 18th European Congress and Exhibition on Advanced Materials and Processes CY - Granada, Spain DA - 14.09.2025 KW - Additive manufacturing KW - 316L stainless steel KW - Heat treatments KW - Low Cycle Fatigue KW - Microstructure PY - 2025 AN - OPUS4-64238 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo T1 - Low-Cycle Fatigue Behavior of Laser Powder Bed Fused Inconel 718 at Room and High Temperature N2 - The nickel-base superalloy Inconel 718 (IN718) is one of the most commonly used Ni-based superalloys for high temperature structural applications for its remarkable strength, as well as creep, fatigue, and corrosion resistance up to 650 °C. While IN718 has traditionally been employed as cast or wrought material, it is difficult to machine because of its high strength and toughness. The additive manufacturing of IN718 components made by metal AM has thus gained extensive attention to produce expensive near-net shaped components of high-temperature alloys such as IN718, for it saves material and costs in processing and machining steps. Among all metal additive manufacturing (AM) technologies, laser powder bed fusion (PBF-LB/M) is the most widespread, IN718 being one of the most common alloys produced with it. However, high cooling rates associated to the PBF-LB/M process, hinders the primary strengthening phases γ’’ and γ’ to form, as these cooling rates induce a dislocation cellular substructure, at which walls primary Laves phases bind segregating Nb, Ti and Mo. Many of the therefore needed heat-treatment strategies can then promote Laves-phase transformation into the stable δ phase along the cell and grain boundaries. Laves and δ phases, as well as grain-boundary primary carbides may have adverse effects on mechanical properties. The mostly needle-shaped δ phase was namely found to have a detrimental effect on creep rupture life while no direct effect on LCF fatigue life was evident. In this work room- and high-temperature (650 °C) low-cycle fatigue behavior of PBF-LB/M IN718 is investigated in the four-step heat-treated state and compared to wrought IN718. The microstructure of both materials is characterized across length scales via microscopy methods. The fatigue life at room temperature of the PBF-LB/M IN718 material is slightly lower than that for the wrought material, which is reversed at 650 °C. The cyclic stress response for both materials is marked by cyclic softening that is more pronounced at higher test temperatures. Multiple secondary cracks form at high strain amplitudes, at both room and high temperatures. High testing temperatures enhance specially crack formation at the transitions of regions between elongated grains and columns of stacked grains with ripple patterns in the PBF-LB/M material. Additional to this behavior, pronounced crack branching and deflection indicate that the cracks are controlled by sharp micromechanical gradients. T2 - EUROMAT 2025 CY - Granada, Spain DA - 14.09.2025 KW - Additive manufacturing KW - Low-cycle fatigue KW - Microstructural characterization KW - Ni-base superalloy PY - 2025 AN - OPUS4-64354 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Witte, Julien A1 - Treutler, Kai A1 - Schroepfer, Dirk A1 - Kannengiesser, Thomas A1 - Wesling, Volker T1 - Influence of microstructure on the machinability and surface integrity of additively manufactured iron aluminides N2 - The increasing global focus on energy and resource efficiency has stimulated a growing interest in additive manufacturing. AM offers economic advantages and enables an efficient use of materials. However, AM components often require subsequent mechanical post-processing, such as machining (e.g., milling), to achieve the final contours or surfaces. This is a particular challenge due to the heterogeneous and anisotropic nature of AM structures, which affect machining and the resulting component properties. High-performance materials such as iron aluminide represent a promising alternative to conventional high-temperature materials with a significant economic advantage. However, the strength and hardness properties, which are advantageous for applications in highly stressed lightweight components, pose a challenge for economical machining in addition to the AM microstructure properties. The difficult-to-cut material causes accelerated tool wear and insufficient surface quality. This study shows that crack-free additive manufacturing of the three-component system of iron-nickel-aluminum is possible, and advantages in terms of machinability compared to FeAl-AM components are achieved. The more homogeneous microstructure leads to a reduction in cutting forces, with positive effects on the machinability and optimized surface integrity. Ultrasonic assisted milling (USAM) offers great potential to address the major challenges posed by difficult-to-cut materials and additively manufactured weld structures. Therefore, this study focuses on assessing the transferability of previous positive results by USAM to the selected iron aluminide alloys. The machinability of the aluminides is analyzed by varying significant influencing variables in finish milling experiments and evaluated in terms of the loads on the tool and the resulting surface integrity. KW - Iron aluminide KW - Additive manufacturing KW - Machinability KW - Surface integrity KW - Ultrasonic-assisted milling process PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656993 DO - https://doi.org/10.1007/s40194-026-02382-6 SN - 0043-2288 SP - 1 EP - 13 PB - Springer Science and Business Media LLC AN - OPUS4-65699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wachsmuth, Janne A1 - Malikoutsakis, M. A1 - Savaidis, G. A1 - Savaidis, A. A1 - Bohse, Jürgen T1 - Corrosion and fatigue crack monitoring by means of acoustic emission for application in transportation means N2 - Corrosion damages and fatigue cracks are the main causes of structural failures in vessels and transport products. Acoustic emission is suggested as an alternative to the conventional inspection processes enabling continuous health monitoring of the structures. Comprehensive finite element analyses have been performed on the example of a 3-compartment road tanker taking the corresponding ADR design loads into account. The numerical results reveal various weld joints as the structure’s failure-critical hot spots. Welded plates made of fine grain steel were stressed by corrosion and fatigue. Damage development in the material was measured and analyzed by acoustic emission testing. It is shown that the different degradation mechanisms, corrosion and fatigue crack growth in welded areas, can be reliably detected by acoustic emission. In addition, principal differences of the acoustic emission signals depending on the degradation mechanism are also explored. KW - Acoustic emission KW - Health monitoring KW - Fatigue crack growth KW - Corrosion KW - Finite elements KW - Welds PY - 2012 SN - 1943-3514 VL - 5 IS - 1 SP - 9 EP - 17 PB - Global Scientech CY - Basking Ridge, NJ, USA AN - OPUS4-27610 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fayis Kalady, Mohammed A1 - Schultz, Johannes A1 - Weinel, Kristina A1 - Wolf, Daniel A1 - Lubk, Axel T1 - Geometry-dependent localization of surface plasmons on random gold nanoparticle assemblies N2 - Assemblies of plasmonic nanoparticles (NPs) support hybridized modes of localized surface plasmons (LSPs), which delocalize in geometrically well-ordered arrangements. Here, the hybridization behavior of LSPs in geometrically completely disordered two-dimensional arrangements of Au NPs fabricated by an e-beam synthesis method is studied. Employing electron energy loss spectroscopy in a scanning transmission electron microscope and numerical simulations, the disorder-driven spatial and spectral localization of the coupled LSP modes that depends on the NP thickness is revealed. Below a NP thickness of 0.4 nm, localization increases toward higher hybridized LSP mode energies. In comparison, above 10 nm thickness, a decrease of localization toward higher mode energies is observed. In the intermediate thickness regime, a transition of the energy dependence of the localization between the two limiting cases, exhibiting a mode energy with minimal localization, is observed. It is shown that this behavior is mainly driven by the energy and thickness dependence of the polarizability of the individual NPs. KW - Gold Nanoparticles KW - Surface plasmons KW - Electron enerdy loss spectroscopy (EELS) KW - scanning transmission electron microscopy PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647230 DO - https://doi.org/10.1103/44nk-6bp2 SN - 2643-1564 VL - 7 IS - 043053 EP - 4 PB - American Physical Society AN - OPUS4-64723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hickel, Tilmann A1 - Waske, Anja A1 - Tehranchi, Ali A1 - Bhattacharya, Biswajit A1 - Stawski, Tomasz M. A1 - Fellinger, Tim-Patrick A1 - Mehmood, Asad A1 - Witt, Julia A1 - Ozcan, Ozlem A1 - Guilherme Buzanich, Ana A1 - Kumar, Sourabh A1 - Mishra, Rajesh Kumar A1 - Holzer, Marco A1 - Stucchi de Camargo, Andrea Simone A1 - Agudo Jácome, Leonardo A1 - Manzoni, Anna A1 - Fantin, Andrea A1 - John, Elisabeth A1 - Hodoroaba, Vasile-Dan A1 - Bührig, Sophia A1 - Murugan, Jegatheesan A1 - Marschall, Niklas A1 - George, Janine A1 - Darvishi Kamachali, Reza A1 - Maaß, Robert A1 - Emmerling, Franziska T1 - Chemically complex materials enable sustainable high-performance materials N2 - Chemically complex materials (CCMats) 􀀀 including high-entropy alloys, oxides, and related multi-principal element systems 􀀀 offer a paradigm shift in materials design by leveraging chemical diversity to simultaneously optimize functional, structural, and sustainability criteria. The vastness of the compositional and structural space in CCMats propels the field into an expanding exploratory state. To reconcile functional and structural performance across this immense parameter space remains an open challenge. This Perspective evaluates the opportunities and challenges associated with harnessing chemical complexity across a broad spectrum of applications, such as hydrogen storage, ionic conductors, catalysis, magnetics, dielectrics, semiconductors, optical materials, and multifunctional structural systems. It is delineated how three central design strategies: targeted substitution (SUB), defect engineering (DEF), and diversity management (DIV) enable the reconciliation of high functional performance with long-term structural stability and environmental responsibility. Advances in computational thermodynamics, microstructure simulations, machine learning, and multimodal characterization are accelerating the exploration and optimization of CCMats, while robust data infrastructures and automated synthesis workflows are emerging as essential tools for navigating their complex compositional space. By fostering cross-disciplinary knowledge transfer and embracing data-driven design, CCMats are poised to deliver next-generation materials solutions that address urgent technological, energy, and environmental demands. KW - Chemically complex materials KW - Structural stability KW - Functional performance KW - Design strategies KW - Sustainability PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655598 UR - https://www.sciencedirect.com/science/article/pii/S1359028626000033?via%3Dihub DO - https://doi.org/10.1016/j.cossms.2026.101256 SN - 1359-0286 VL - 42 SP - 1 EP - 26 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-65559 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Altmann, Korinna A1 - Abusafia, A A1 - Bannick, C-G A1 - Braun, U A1 - Crasselt, Claudia A1 - Dittmar, S A1 - Fuchs, M A1 - Gehde, M A1 - Hagendorf, C A1 - Heller, C A1 - Herper, D A1 - Heymann, S A1 - Kerndorff, A A1 - Knefel, M A1 - Jekel, M A1 - Lelonek, M A1 - Lunkenbein, T A1 - Obermaier, N A1 - Manhart, M A1 - Meurer, Maren A1 - Miclea, P-T A1 - Paul, A A1 - Richter, S A1 - Ricking, M A1 - Rohner, C A1 - Ruhl, A A1 - Sakai, Y A1 - Saravia Arzabe, C A1 - Scheid, C A1 - Schmitt, M A1 - Schnarr, M A1 - Schwertfirm, F A1 - Steinmetz, H A1 - Wander, Lukas A1 - Wiesner, Yosri A1 - Zechmeister, L T1 - RUSEKU - Repräsentative Untersuchungsstrategien für ein integratives Systemverständnis von spezifischen Einträgen von Kunststoffen in die Umwelt : Abschlussbericht N2 - Im Verbundprojekt RUSEKU wurde die Probenahme von Wasserproben entscheidend weiterentwickelt. Wichtig ist hierbei zu gewährleisten, dass genügend Merkmalsträger in jeder Probe untersucht werden. Es muss daher eine für den Probenahmeort repräsentative Beprobung hinsichtlich des Wasservolumens in Abhängigkeit der Partikelanzahl gewährleistet sein. Das Hauptaugenmerk lag im vorliegenden Projekt auf einer praxisnahen Beprobungsstrategie. Es wurden verschiedene Konzepte ausprobiert. • Grundsätzlich hat sich gezeigt, dass eine Stichprobe eine Momentaufnahme des MP-Massengehaltes zeigt. Es wird eine hohe Statistik, also eine Vielzahl an Messungen am gleichen Probenahmeort, benötigt, um eine valide Aussage über den MP-Gehalt zu machen. • Es zeigt sich, dass eine integrale Probenahme über mehrere Wochen mit dem SK routinemäßig möglich ist. Die erfassten MP-Massen sind reproduzierbar und robust. • Die DFZ ist für Stichproben geeignet. Partikel < 50 µm werden eventuell unterschätzt • Die fraktionierte Filtration kann für Stich- und Mischproben direkt im Feld genutzt werden. Fraktionen von 10 und 5 µm werden später im Labor Vakuum filtriert. Es erfolgt eine Fraktionierung der Probe mit Siebmaschenweiten von 1000, 500, 100, 50, 10 und 5 µm. • Die fraktionierte Filtration kann auch anschließend an die Beprobung mit dem SK zur Anwendung kommen. Wird die mit dem SK gewonnene Wasserprobe fraktioniert filtriert, kann neben einem MP-Gesamtgehalt auch eine Einschätzung über die Partikelgrößen gewonnen werden. • Für Wässer mit geringen Partikelzahlen wurde ein Messfiltertiegel entwickelt. Dieser hat eine Maschenweite von 6 µm. Seine Anwendung kann mögliche Verluste beim Transferieren vom Probenahmetool zum Messgefäß und mögliche Kontaminationen reduzieren. Die Optimierung der Probenahmestrategie wurde durch Modellversuche und Simulationen unterstützt. Modellversuche zum Sinkverhalten und Simulationen von MP in realen Gewässern verdeutlichten das komplexe Verhalten der Partikel. Es konnte gezeigt werden, dass Partikel ab einer bestimmten Größe (und kleiner) bei genügend starker Turbulenz sich in der Wassersäule unabhängig von ihrer Dichte verhalten und so auch MP mit kleiner Dichte (z.B. PE) in der gesamten Wassersäule zu finden sind. Es konnte mit dem TEM die Existenz von NP gezeigt werden. Ein wesentlicher Aspekt des RUSEKU Projektes war die Beprobung realer Kompartimente. Beprobt wurde neben Oberflächengewässern, das urbane Abwassersystem der Stadt Kaiserslautern, Waschmaschinenabwasser und Flaschenwasser. • In Oberflächengewässern wurde hauptsächlich PE gefunden. Je nach Probe und Gewässer konnten auch PP, PS, PET, PA, SBR und Acrylate nachgewiesen werden. • Im urbanen Abwassersystem der Stadt Kaiserslautern konnte an allen Probenahmestandorten MP nachgewiesen werden. Es wurde hauptsächlich PE, neben geringeren Mengen an PP, PS und SBR gefunden. Nach einem Regenereignis war der SBR Anteil deutlich erhöht. • Die Beprobung eines realen Wäschepostens, bestehend aus T-Shirts und Hemden mit PA/CO oder PES/CO Mischgewebe, zeigte einen PA- und PES-Austrag im Waschwasser. Der überwiegende Teil der detektierten Fasern ist aber auf Baumwolle zurückzuführen. Reine gravimetrische Messungen zur Detektion von MP führen zu einer starken Überschätzung. • In Flaschenwasser (PET-Flaschen) konnte MP detektiert werden. PET wurde nur im stillen Mineralwasser, nicht in Mineralwasser mit Kohlensäure gefunden werden. Teilweise wurde auch das MP-Material des Verschlusses im Wasser detektiert. • Für Luftproben konnte ein Aufbau zur größenselektiven Beprobung getestet werden. Neben der Probenahme hat das Projekt auch gezeigt, dass die TED-GC/MS geeignet für die MP-Detektion im Routinebetrieb ist. Die TED-GC/MS konnte weiter optimiert werden. Es wurden MP-Massen bestimmt. Im Projekt wurden erste realitätsnahe Referenzmaterialien für die MP Detektion hergestellt. Die Herstellung von realitätsnahen Polymeren in ausreichender Homogenität und Menge hat sich als große Herausforderung herausgestellt. KW - Mikroplastik KW - Probennahme KW - TED-GC/MS KW - Fraktionierte Filtration KW - Mikroplastikreferenzmaterial PY - 2022 SP - 1 EP - 201 AN - OPUS4-57800 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In situ studies of mechanochemistry: a force of synthesis N2 - Recent results in the field of mechanisms and kinetics of mechanochemical reactions. T2 - Seminar GFZ Potsdam CY - Postdam, Germany DA - 28.03.2018 KW - In situ KW - XRD KW - Rietveld PY - 2018 AN - OPUS4-46992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kabelitz, Anke T1 - In-situ characterisation of nucleation, growth, crystallisation and dissolution of nanoscaled iron oxides N2 - We present the synthesis of four mesoporous templated iron oxides: Ferrihydrite, Hematite, Maghemite, Magnetite/Maghemite and the influence of water on the crystallization mechanism and the kinetics. The absence of water stabilize the ferrihydrite structure. By monitoring the dissolution in situ by using a QCMB and ex situ microscopy we got details in the dissolution mechanism of ferrihydrite. T2 - Final Meeting of the CRC 1109 & Edith Flanigen Award Ceremony 2018 CY - Berlin, Germany DA - 10.10.2018 KW - Mesoporous KW - Iron oxide KW - Mechanism PY - 2018 AN - OPUS4-47010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yusenko, Kirill T1 - BAMline 2.0 – further technical developments for a broader multipurpose hard X-ray beamline at BESSY II N2 - We show further development of our beamline in the contexst of further itermational collaboration. T2 - PACC and AfSC CY - Accra, Ghana DA - 28.01.2019 KW - Synchrotron radiation PY - 2019 AN - OPUS4-47317 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - New insights in mechanochemical processes using real-time In situ investigations N2 - Mechanochemistry is a fast and efficient method applicable for the synthesis of new organic[1], metal-organic[2], and inorganic[3] compounds. The direct monitoring of milling reactions is still challenging. The underlying reaction mechanisms remain often unclear. In the last years, have established a tandem in situ approach for investigating mechanochemical reactions using time-resolved in situ XRD coupled with Raman spectroscopy.[4] Here, we present an in situ coupling of synchrotron XRD, Raman spectroscopy, and thermography allowing the observation of mechanochemical reactions in real time.[5] Information on the crystalline, molecular, and temperature state of the materials during grinding could be collected. The chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. Furthermore, the presented setup allows the detection of crystalline, amorphous, eutectic as well as liquid intermediates. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key for future optimization of mechanochemical syntheses. T2 - 5th International Conference "Fundamental Bases of Mechanochemical Technologies" CY - Novosibirsk, Russia DA - 25.06.2018 KW - Mechanochemistry KW - XRD KW - Kinetic KW - Coordination polymers PY - 2018 AN - OPUS4-46994 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Akhmetova, Irina T1 - Mechanochemical synthesis of metal phosphonates N2 - The exploration of metal phosphonates chemistry has gained great interest during the last decades, because of their structural diversity. Transition metal phosphonates are promising candidates for an application as electrocatalysts in oxygen evolution reactions (OER). Here, we present the in situ investigation of mechanochemical syntheses of different manganese phosphonates by synchrotron X-ray diffraction. Nitrilotri(methylenephosphonic acid) and N,N-Bis(phosphonomethyl)glycine were chosen as ligands. The liquid-assisted milling process can be divided into three steps, including an amorphous stage. One of the products has not been obtained by classical solution chemistry before. These metal phosphonates and/or their derivatives are considered to be active in electrochemical energy conversion. The verification of their applicability is one of the topics of our resent research. T2 - Fundamental Bases of Mechanochemical Technologies CY - Novosibirsk, Russia DA - 25.06.2018 KW - Metal phosphonates KW - Mechanochemistry KW - PXRD KW - Thermography PY - 2018 AN - OPUS4-46996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Akhmetova, Irina T1 - In situ investigation of milling reactions and structure determination of the products using X-ray diffraction N2 - Mechanochemistry is a versatile approach for green and fast synthesis of pure substances. By milling the reactants, various organic, inorganic, and metal-organic compounds can be obtained in high yields. Although mechanochemistry is widely used, the underlying mechanisms are not fully understood making mechanochemical reactions difficult to predict. Metal phosphonates are metal-organic compounds accessible by grinding. Because of their structural diversity, the exploration of the chemistry of metal phosphonates has gained considerable interest during the last decades. Transition metal phosphonates are promising candidates for an application as electrocatalysts in oxygen evolution reaction (OER). Here, we present the in situ investigation of the mechanochemical synthesis of a manganese(II)-phosphonate by synchrotron X-ray diffraction and thermography. The product has not been obtained by classical solution chemistry before and its crystal structure was determined from PXRD data. The milling process can be divided into different steps, with the product crystallization corresponding with the highest temperature rise. The activity of this metal phosphonate towards OER was measured and is presented here. T2 - International School of Crystallography - 52nd Course: Quantum Crystallography CY - Erice, Italy DA - 1.06.2018 KW - Metal phosphonates KW - Mechanochemistry KW - PXRD KW - OER KW - Thermography PY - 2018 AN - OPUS4-46998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kabelitz, Anke T1 - A02: In situ WAXS studies on the crystallization of Al 13 keggin clusters in water N2 - Polynuclear aluminium species (Al13 keggin cluster) find application in different areas like water purification [1], contaminant transport [2], and as pilling clays with high specific surface areas[3], due to their strong binding ability to aggregates and high positive charge. In the present contribution, we report on the in situ investigation of the Al13 sulfate synthesis by synchrotron wide-angle X-ray scattering (WAXS). Al13 cluster were crystallized by precipitating hydrolyzed aluminum solutions by the addition of sodium sulfate. The measurements were performed using a custom-made acoustic levitator as sample holder. The study provides information about the intermediates during the crystallization process. From the data, a mechanism was derived indicating the influence of the crystallization process. T2 - Final Meeting of the CRC 1109 & Edith Flanigen Award Ceremony 2018 CY - Berlin, Germany DA - 10.10.2018 KW - Crystallization KW - WAXS KW - Keggin Cluster PY - 2018 AN - OPUS4-47005 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Laboratory x-ray scattering instruments as agile test-beds towards holistic experimentation N2 - Laboratory sources offer a unique advantage compared to synchrotron sources, largely in terms of freedom of operation. This freedom from user obligations, technology and software stacks and legacy decisions make the laboratory a very flexible place to develop and explore new ideas. The unparalleled availability furthermore allows for iterative improvement of instrumentation, sample environments and measurement methodologies to maximise the quality of the data obtained. This talk will highlight the use of the laboratory as an agile test-bed and development space, by giving examples of some complete and incomplete investigations undertaken in our laboratory over the last years. Furthermore, it will introduce the concept of holistic experimentation, where the laboratory provides broad-ranging support for materials science investigations. This means that we assist in the experimental preparation, perform the measurements, correction and analysis, and follow-up with assistance in interpretation of our analyses in light of the results from other techniques applied to the investigation. T2 - Invited talk at Diamond Light Source CY - Didcot, UK DA - 22.05.2024 KW - X-ray scattering KW - Methodology development KW - Laboratory management KW - Holistic experimentation KW - Laboratory automation KW - Nanostructural analysis PY - 2024 AN - OPUS4-60582 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Glimpses of the Future : Oh my god it’s full of metadata! N2 - In this talk, the importance of metadata is underscored by real-world examples. Metadata is essential to alleviating the reproducibility crises in science. This imples that a wide range of metadata must be collected, with a heavy emphasis on the automated collection of such metadata. This must subsequently be organized in an intelligible, archival structure, when possible with units and uncertainties. Such metadata can aid in improving the usage efficiency of instrumentation, as is demonstrated on the MOUSE instrument. This metadata can now be used to connect the various aspects of the holistic experimental procedure to gain better insights on the materials structure. A second example shows the extraction and organization of such metadata from an automated materials development platform, collected during the synthesis of 1200 samples. These metadata from the synthesis can then be linked to the results from the analysis of these samples, to find direct correlations between the synthesis parameters and the final structure of the materials. T2 - Helmholtz Incubator Summer Academy - Next Level Data Science CY - Online meeting DA - 18.09.2023 KW - Metadata KW - Lab automation KW - Data provenance KW - High-throughput KW - Correlative analysis KW - MOUSE KW - X-ray scattering KW - Robotics PY - 2023 AN - OPUS4-58463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Smales, Glen Jacob A1 - Pauw, Brian Richard T1 - DACHS/MOFs/AutoMOFs_4/Synthesis N2 - The DACHS (Database for Automation, Characterization and Holistic Synthesis) project aims to create completely traceable experimental data, covering syntheses, measurements, analyses, and interpretations. DACHS_MOFs focuses on the synthesis and characterisation of metal-organic frameworks, across multiple, automation-assisted experimental series (AutoMOFs), with the overall goal of producing reproducible MOF samples through tracking of the synthesis parameters. DACHS_MOFs is simultaneously used to test the DACHS principles. This upload contain synthesis data from AutoMOFs_4 in HDF5 format (.h5). Each .h5 file contains detailed information on the chemical, experimenal, and synthesis parameters used during the synthesis of a single AutoMOF sample. KW - Automation KW - Procedure KW - Synthesis KW - Traceability PY - 2024 DO - https://doi.org/10.5281/zenodo.11237899 PB - Zenodo CY - Geneva AN - OPUS4-61343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Smales, Glen Jacob A1 - Pauw, Brian Richard T1 - DACHS/MOFs/AutoMOFs_1/Synthesis N2 - The DACHS (Database for Automation, Characterization and Holistic Synthesis) project aims to create completely traceable experimental data, covering syntheses, measurements, analyses, and interpretations. DACHS_MOFs focuses on the synthesis and characterisation of metal-organic frameworks, across multiple, automation-assisted experimental series (AutoMOFs), with the overall goal of producing reproducible MOF samples through tracking of the synthesis parameters. DACHS_MOFs is simultaneously used to test the DACHS principles. This upload contain synthesis data from AutoMOFs_1 in HDF5 format (.h5). Each .h5 file contains detailed information on the chemical, experimenal, and synthesis parameters used during the synthesis of a single AutoMOF sample. KW - Synthesis KW - Automation KW - Traceability KW - Procedure PY - 2024 DO - https://doi.org/10.5281/zenodo.11236031 PB - Zenodo CY - Geneva AN - OPUS4-60243 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Hörmann, Anja A1 - Moeez, Abdul A1 - Breßler, Ingo T1 - BAMresearch/HDF5Translator: A Framework for translating and transforming data between HDF5 files N2 - HDF5Translator is a Python framework for translating and transforming data between HDF5 files. It supports operations like unit conversion, dimensionality adjustments, and subtree copying, making it suitable for managing and manipulating a wide range of scientific datasets. KW - Measurement data conversion KW - Data conversion KW - HDF5 KW - NeXus KW - NXsas KW - Framework KW - Python KW - Methodology PY - 2024 DO - https://doi.org/10.5281/zenodo.10927639 PB - Zenodo CY - Geneva AN - OPUS4-59797 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pauw, Brian Richard A1 - Laskina, Sofya A1 - Naik, Aakash A1 - Smales, Glen Jacob A1 - George, Janine A1 - Breßler, Ingo A1 - Benner, Philipp T1 - Jupyter notebook and VASP calculation details accompanying the manuscript: "Ultima Ratio: Simulating wide-range X-ray scattering and diffraction" N2 - Summary: This notebook and associated datasets (including VASP details) accompany a manuscript available on the ArXiv (https://doi.org/10.48550/arXiv.2303.13435) and hopefully soon in a journal as short communication as well. Most of the details needed to understand this notebook are explained in that paper with the same title as above. For convenience, the abstract is repeated here: Paper abstract: We demonstrate a strategy for simulating wide-range X-ray scattering patterns, which spans the small- and wide scattering angles as well as the scattering angles typically used for Pair Distribution Function (PDF) analysis. Such simulated patterns can be used to test holistic analysis models, and, since the diffraction intensity is presented coupled to the scattering intensity, may offer a novel pathway for determining the degree of crystallinity. The "Ultima Ratio" strategy is demonstrated on a 64-nm Metal Organic Framework (MOF) particle, calculated from $Q<0.01$\,$\mathrm{nm}^{-1}$ up to $Q\approx150$\,$\mathrm{nm}^{-1}$, with a resolution of 0.16\,\AA. The computations exploit a modified 3D Fast Fourier Transform (3D-FFT), whose modifications enable the transformations of matrices at least up to $8000^3$ voxels in size. Multiple of these modified 3D-FFTs are combined to improve the low-$Q$ behaviour. The resulting curve is compared to a wide-range scattering pattern measured on a polydisperse MOF powder. While computationally intensive, the approach is expected to be useful for simulating scattering from a wide range of realistic, complex structures, from (poly-)crystalline particles to hierarchical, multicomponent structures such as viruses and catalysts. KW - X-ray KW - Simulation KW - Scattering KW - MOUSE KW - Nanomaterials KW - XRD KW - SAXS KW - PDF KW - Total scattering KW - 3D Fourier transform KW - High resolution KW - FFT PY - 2023 DO - https://doi.org/10.5281/zenodo.7764044 PB - Zenodo CY - Geneva AN - OPUS4-57207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mehri Sofiani, F. A1 - Chaudhuri, Somsubhro A1 - Elahi, S. A. A1 - Wallaert, E. A1 - Depover, T. A1 - De Waele, W. T1 - Accelerated laboratory simulation of corrosion pit evolution in low-carbon steel using phase-field guided overpotential application N2 - This study is performed to replicate field data of pit geometry evolution in the laboratory by accelerating pit evolution through the application of relatively high overpotential on low-carbon steel. A phase-field model is used to reduce the number of trials and errors in the laboratory. The effect of overpotential on pitting corrosion is studied in low-carbon steel in the electrolyte representative of the North Sea. Based on the results obtained through the numerical model, potentiostatic polarisation tests are performed, and a comparison is made between such accelerated tests and steel coupons collected from the field. The results of this comparison suggest that the pitting corrosion acceleration mechanism effectively produces surface conditions closely resembling those of naturally pitted steel. Additionally, it enables the investigation of the electrochemical characteristics of a stable pit over long-term exposure, where direct probing is challenging. This framework strives to mitigate the excessive costs of time-consuming coupon experiments by correlating accelerated pitting corrosion in short periods of time with actual pitting corrosion observed over the long term. KW - Pitting corrosion KW - Corrosion acceleration KW - Potentiodynamic tests KW - Phase-field KW - S355 PY - 2025 DO - https://doi.org/10.1016/j.engfailanal.2025.110352 SN - 1350-6307 VL - 184 SP - 1 EP - 20 PB - Elsevier CY - Oxford AN - OPUS4-64805 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mohr, Gunther T1 - R&D insights into sustainable additive manufacturing for high-temperature applications (HTA) N2 - Im Rahmen des AM Forums Berlin 2026 wird durch diesen Vortrag ein Einblick in FuE-Aktivitäten der BAM auf dem Gebiet der additiven Fertigung für Hochtemperaturanwendungen gegeben. Es werden dabei insbesondere Aspekte der nachhaltigen Verwendung von Pulverausgangswerkstoff und der Einfluss von Sauerstoff im Pulverwerkstoff auf die Degradation resultierender mechanischer Eigenschaften von Probekörpern beleuchtet. Die präsentierten Arbeiten sind im Rahmen des Pro FIT Projektes HTA2.0 entstanden. T2 - 10. AM Forum 2026 CY - Berlin, Germany DA - 10.03.2026 KW - Additive Manufacturing KW - Sustainability KW - Powder recycling KW - Powder degradation PY - 2026 AN - OPUS4-65725 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hülagü, Deniz A1 - Hertwig, Andreas T1 - Correlative analysis of graphene: Advancing ellipsometry as a fast routine method N2 - Graphene (G) and graphene oxide (GO) are key materials for various applications, yet their structural and thickness inhomogeneities calls for rapid, reliable characterization. In this work, we performed a correlative analysis, combining spectroscopic (SE) and imaging ellipsometry (IE) with complementary microscopy techniques to investigate monolayer graphene and GO flakes on SiO₂/Si substrates. SEM, owing to its high resolution and excellent contrast, delivered a comprehensive overview of the monolayer graphene (Figure 1a) and enabled the clear identification of individual GO flakes (c). However, SEM does not provide layer-thickness information. In this case, SE served as a fast and non-destructive method capable of quantitative thickness determination through optical modeling, revealing a graphene layer thickness of 0.7 nm (b), corresponding to a monolayer. The GO flake identified by SEM was subsequently analyzed by AFM, a well-established technique providing nanoscale height profiles with high accuracy (d–f). AFM results further revealed flake thicknesses of a few monolayers. However, AFM is time-consuming, restricted to small scan areas, and does not offer a full overview of the sample. WLIM complemented these results by providing large-area imaging, enabling the visualization of multiple flakes simultaneously. Nevertheless, it is not able to quantify the exact thickness (e). In contrast, IE enabled non-destructive, substrate-independent thickness of GO flakes with single-atomic-layer precision and improved sensitivity, once the ellipsometer settings were optimized for material and thickness contrast and fixed during imaging, bridging the gap between overview imaging and quantitative nanoscale analysis (g–h). While SE provides non-destructive, quantitative thickness information for homogeneous monolayer graphene, GO flakes require imaging-based methods. Therefore, IE represents an attractive alternative, offering large-area maps of GO flakes together with local layer-thickness information. This correlative approach establishes a foundation for standardized, large-area quality assessment of such 2D materials. T2 - 13th Workshop on Spectroscopic Ellipsometry WSE 2026 CY - Genova, Italy DA - 09.02.2026 KW - Monolayer graphene KW - Graphene oxide KW - Correlative Analysis KW - SEM KW - Spectroscopic ellipsometry KW - Imaging ellipsometry KW - AFM PY - 2026 AN - OPUS4-65708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -