TY - CONF A1 - Grandel, Jonas T1 - Fine-tuning universal interatomic potentials for phonon properties without catastrophic forgetting N2 - Accurate phonon predictions are essential for evaluating material stability and thermal behavior. Traditional DFT-based methods are computationally intensive, driving interest in faster, machine-learning-based alternatives. In this work, we fine-tune the machine learning interatomic potential MACE-MP-0b3 (https://arxiv.org/abs/2401.00096) to improve the prediction of harmonic phonons and thermal properties. A key challenge is the need for highly accurate force calculations. While fine-tuning can enhance phonon accuracy, it may reduce generalizability to other properties. Despite this, our study shows that fine-tuned models can accurately predict phonon properties (including renormalization of imaginary phonons) at the same time as volume-dependent properties like the bulk modulus. We fine-tune the base model using small sets of rattled structures and introduce a novel fine-tuning method, benchmarking it against existing techniques. These results suggest that refined MACE-based universal potentials are a promising path for efficient and accurate phonon modeling. All implementations are included in the equitrain training code (https://github.com/BAMeScience/equitrain). T2 - Psi-k Konferenz CY - Lausanne, France DA - 25.08.2025 KW - Machine Learning KW - MACE KW - Phonon KW - Thermal properites PY - 2025 AN - OPUS4-64010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Walterbos, Luc T1 - Double trouble: exploring the chemical landscape of halide double perovskites N2 - Halide Double Perovskites (HDPs) are an emerging class of materials with chemical formula A2BB’X6 with possible applications in photovoltaics, X-ray detection, sensing, photocatalysis and spintronics.. However, with more than 40,000 potential HDP compositions, much of the chemical landscape remains unexplored. We have generated a database of spin-polarized, hybrid functional (HSE06) electronic structure data of all HPDs with A=Cs that are predicted to be stable based on a tolerance-factor analysis. Our high-throughput workflow also consists or a chemical bonding and orbital projection analysis based on LOBSTER (ww.cohp.de), leading to a comprehensivedatabase of electronic, magnetic and chemical bonding properties of >2700 HDP compositions, which can serve as a starting point for material design and discovery via interpretable machine learning techniques, which we use to identify unexpected trends and relations in the chemical landscape. T2 - Psi-k 2025 CY - Lausanne, Swiss DA - 25.08.2025 KW - Materials design KW - Halide perovskite KW - Halide double perovskite KW - High-throughput KW - Hybrid functional PY - 2025 AN - OPUS4-64009 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael T1 - Component-test for determination of welding residual stresses and their effect on stress relief cracking in thick-walled welds N2 - Controlling the residual stress level during welding of creep-resistant Cr-Mo-V steels is crucial to avoid so called stress relief cracking (SRC) during post weld heat treatment (PWHT) of large-scale components. In the present study, a laboratory scale test specimen (slotted sample with 400 mm width, 400 mm length and 25 mm thickness) was used to simulate thick-walled component welds made of 13CrMoV9-10. The aim was to identify the level and distribution of residual stresses to evaluate the suitability of the specimen for laboratory based SRC testing. High restraint was ensured by the specimen geometry with a narrow welding gap in the center. This gap was filled by multi-layer submerged arc welding. Two specimens were welded with identical parameters and compared in the as-welded state and after PWHT (705 °C for 10 h). Neutron diffraction was used to determine the residual stresses in the weld metal, the heat-affected zone (HAZ) and the base material at different depths longitudinal, transverse, and normal to the welding direction. The experiments were performed on the former instrument E3 of the research reactor BER II of Helmholtz-Zentrum Berlin (HZB), Germany. Complementarily, laboratory X-ray diffraction was applied to characterize the surface residual stresses. In the welded condition, especially in the weld metal and the adjacent HAZ, the longitudinal residual stresses reached values of up to 1,000 MPa to 1,200 MPa due to the increasing strength and hardness of the CrMoV-material during welding. The conducted welding experiments revealed that way higher residual stresses in the welded joint have to anticipated before the PWHT is performed than it was expected in advance. This demonstrated the necessity of suitable component-like welding tests as they must ensure realistic mechanical stiffness (hindered shrinkage of welding joint by slotted self-restraint sample) and heat dissipation conditions (definition of minimum welding joint thickness vs. welding process-specific heat input). T2 - FEMS Euromat 2025 - 18th European Congress and Exhibition on Advanced Materials and Processes CY - Granada, Spain DA - 15.09.2025 KW - Component test KW - Submerged arc welding KW - Post weld heat treatment KW - Residual stresses KW - Neutron diffraction PY - 2025 AN - OPUS4-64161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ryll, Tom William T1 - In-situ analysis of nucleation processes – case study: calciumsulfate N2 - In this project we investigate nucleation pathways by utilizing synchrotron-XRD and running a case-study on calcium sulfate and its polymorphs. To accomplish this, we developed a modular automation setup for reactions in solution to run synthesis and control reaction conditions. So far we successfully characterized the recycling process of gypsum (CaSO4*2H2O) and are now investigating the formation of anhydrite (CaSO4*0H2O) as well as possible applications for the automation setup and analysis. T2 - SALSA Make & Measure 2025 CY - Berlin, Germany DA - 10.09.2025 KW - Recycling KW - Gypsum KW - Synchrotron-X-ray-diffraction KW - Raman-spectroscopy KW - Automation PY - 2025 AN - OPUS4-64135 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Melzer, Michael T1 - The temperature DCC exposed N2 - The DAkkS-accredited calibration laboratory of the German Federal Institute for Materials Research and Testing (BAM) has established valid XML digital calibration certificates (DCCs) for calibrations of resistance thermometers within the scope of its accreditation. Hence, all necessary information according to ISO/IEC 17025 and the DKD-R 5-1 calibration rule is provided in a machine-readable and machine-interpretable form. Furthermore, we actively participate in the definition of general and community-specific good practice requirements for the DCC of temperature quantities as technical specifications, hosted by the German Calibration Service (DKD). In this contribution the entire XML source code of a DCC from a Pt 100 thermometer calibration will be exposed and discussed. The DCC was automatically generated using a self-implemented middleware that is compiling the metadata (i.e. customer-, order-, item- and method data) and combines it with the measured calibration data and influence conditions into a process- and lab-specific DCC template. Since it was issued as an accredited calibration certificate, the validated and authorized DCC is also equipped with the novel digital accreditation symbol to form an `eAttestation´. This advanced electronic seal with a qualified certificate was recently piloted with the German national accreditation body (DAkkS), and, after successful validation by the receiver, verifies the active accreditation status of the issuing body at the time of sealing (authorization). As it also provides all other functionalities of an electronic seal, (i.e. data integrity and authenticity), it can fully replace a digital signature on accredited DCCs. The presented temperature DCC architecture fully complies to the latest good practice definitions of the DKD and thus represents a level 4 DCC according to the utility model for machine interpretability of DCCs. This also includes basic and quantity-specific refType definitions that are linked to an online refType repository to harmonize these key semantic providing elements across other DCC-issuing laboratories. The paper and also its conference poster will not represent a general introduction and motivation for the DCC itself. It rather addresses more detailed aspects of good practice, especially for DCCs from temperature quantity calibrations and may stimulate in-depth discussions between DCC experts from the providing, utilizing and accrediting points of view. The work was performed within the national QI-Digital initiative of the German Federal Ministry for Economic Affairs and Climate Action, T2 - Global Industrie CY - Lyon, France DA - 11.03.2025 KW - Calibration KW - Digital Calibration Certificate KW - E-Attestation KW - Digital Metrology KW - QI-Digital PY - 2024 AN - OPUS4-64177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan T1 - Robot-assisted compositional screening in the System Na2O-Al2O3-B2O3-SiO2 N2 - The system Na2OB2O3SiO2 (NBS) is the basis of many industrial glass applications and therefore one of the most studied systems at all. Glass formation is possible over a wide compositional range, but the system also contains ranges of pronounced phase separation and crystallization tendency. Even small addition of Al2O3can change this behavior essentially. As the Na2OAl2O3B2O3SiO2 (NABS) system is also known as the basis for glasses in strength-relevant applications, the behavior during the transition from the NBS system to the NABS system is of interest. Therefore, some small step melt series in these systems were studied using the robotic glass melting system at the Federal Institute for Materials Research and Testing (BAM, Division Glasses). For these series the small step changes of glass transition temperature, crystallization behavior as well as glass density were studied. Additionally, experimental data were compared with their modeled counterparts. T2 - 98. Glastechnische Tagung CY - Goslar, Germany DA - 26.05.2025 KW - Sodium alumino boro silicate glasses KW - Glass transition temperature KW - Density KW - Robotic melting PY - 2025 AN - OPUS4-64076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Evans, Alexander T1 - AGIL Project - Microstructure development in additively manufactured metallic components: from powder to mechanical failure N2 - Overview of the concept of the AGIL Project, work packages and Prior published work from BAM on the subject T2 - Challenges in Additive Manufacturing: Innovative Materials and Quality Control CY - BAM, Berlin-Adlershof, Germany DA - 12.09.2018 KW - AGIL KW - Additive manufacturing PY - 2018 AN - OPUS4-46100 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Jonathan T1 - Near-real-time in-situ powder bed anomaly detection using machine learning algorithms for high-resolution image analysis in PBF-LB/M N2 - In-situ captured visual images of the laser powder bed fusion process (PBF-LB/M) provide valuable insights into process dynamics. Automatic analysis of after-recoating images using machine learning algorithms enables the detection of process deviations to reduce scrap production. However, current industrial monitoring systems for PBF-LB/M are limited by low image resolution. While higher resolutions enable the system’s ability to capture smaller features, they increase storage and computational demand. Edge devices offer a solution by enabling near-real-time, on-premises image analysis within the machine and company network. In this study, high-resolution after-recoating images, captured with a spatial resolution of 17 µm/pixel and an image size of 9344 x 7000 pixels, were processed on an Nvidia Jetson Orin NX16 edge device. The images were downscaled, and anomaly detection algorithms were used to identify regions of interest for segmentation and classification at full resolution. To address computational constraints, state-of-the-art anomaly detection algorithms were evaluated and an appropriate downscaling factor for the on-edge implementation was determined. The EfficientAD algorithm achieved promising results, detecting anomalies within an inference time of less than 10 seconds. The presented framework enables anomaly detection with a maximum delay of one layer. This lays the foundation for the future development of near-real-time intervention in the PBF-LB/M process. T2 - ISAM 2025 – 6th International Symposium on Additive Manufacturing CY - Dresden, Germany DA - 21.05.2025 KW - Additive manufacturing KW - Image processing KW - In-situ monitoring KW - Powder bed fusion PY - 2025 AN - OPUS4-63231 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Selleng, Christian T1 - Effect of 90°C thermal treatment on Ultra-High Performance Concrete N2 - Ultra High Performance Concrete (UHPC) is characterized by high strength and high durability. This is achieved by an optimized grain size distribution, especially within fine grains, and addition of superplasticizer, which allow the reduction of the water/cement ratio in the cement paste and thereby the increase of the density of UHPC. Thermal treatment, i.e. curing at elevated temperature and pressure, contributes to a further increase of compressive strength. The aim of the presented study was to analyze the effect of thermal treatment at 90 ◦C and atmospheric pressure on UHPC samples. Varying factors were the age of the samples when heat treatment started (initial storage time), the duration of heat treatment and the type of heat treatment. It was applied in three ways: 1. treated without any protection, 2. sealed in plastic foil and 3. treated in hot water. Afterwards the samples were analyzed with respect to their mechanical properties and their phase composition. Furthermore, the weight (water absorption) of the samples was observed over 28 days and was correlated with the strength test results. The development of strength depends on the combination of initial storage time and the duration of heat treatment and is also influenced by the type of thermal treatment. The highest compressive strengths have been observed by implementing the hot water treatment. Thereby the weight of the samples increase due to additional absorbed water. This enables an increased hydration of cement clinker inducing a higher strength. T2 - GeoBerlin 2015: Dynamic Earth - from Alfred Wegener to today and beyond CY - Berlin, FU Berlin DA - 04.10.2015 PY - 2015 AN - OPUS4-34504 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Redmer, Bernhard A1 - Weise, Frank A1 - Ewert, Uwe A1 - Patitz, G. T1 - Kombinierter Einsatz zerstörungsfreier Prüfverfahren zur Bauzustandsanalyse antiker Baudenkmäler im Pergamonmuseum Berlin N2 - Zur Planung und Durchführung umfangreicher Sanierungs- und Umbaumaßnahmen im Pergamon-Museum Berlin bestand die Erfordernis einer Bauzustandsanalyse an antiken Baudenkmälern. Bestandsunterlagen waren unvollständig vorhanden bzw. fehlten. Hieraus ergab sich die Notwendigkeit des kombinierten Einsatzes zerstörungsfreier Prüftechnik. T2 - Jahrestagung Zerstörungsfreie Materialprüfung 2004 CY - Salzburg, Austria DA - 17.05.2004 KW - Baudenkmal KW - Bauzustandsanalyse KW - Radar KW - Radiografie KW - Videoskopie KW - Zerstörungsfreie Prüfung PY - 2004 AN - OPUS4-35531 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Voigt, Marieke T1 - Thermally treated UHPC: a durability study N2 - Ultra high performance concrete (UHPC) is known for its high compressive strength of more than 150 MPa and its high durability. Thermal treatment at 90°C can accelerate the strength development so that the 28-days-strength can be achieved immediately after the treatment and an additional increase up to 30 % in some cases. The reason for the strength development is an accelerated hydration of the clinker minerals and an intensified pozzolanic reaction leading to a denser microstructure. In previous research inhomogeneities in form of a zonation after unprotected thermal treatment were observed and analysed in respect to changes in the microstructure. This zonation is defined by a different microstructure in the core compared to the outer zone in the matter of porosity, mineral phase composition and a significant change in the potassium and sulphur concentration of the zones is measurable. To isolate different transport mechanisms responsible for these element distributions UHPC samples were thermally treated at 90 °C and the microstructure was investigated under dry conditions and after immersion in water to investigate the influence of dehydration during and rehydration after the thermal treatment on the microstructure. Through durability testing via water absorption, water vapour diffusion, permeability testing and sulfuric acid resistance transport mechanisms like diffusion, migration, capillary suction are under investigation in correlation with the microstructure analysis. For the microstructure analysis measurements with µXRF, mercury intrusion porosity, XRD and SEM were conducted. T2 - HiPerMat 2020 CY - Kassel, Germany DA - 11.03.2020 KW - UHPC KW - Thermal treatment KW - Zonation KW - Transport mechanism KW - Durability PY - 2020 AN - OPUS4-52372 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kilinc, Sefine T1 - Grinding method and oxidative aging of tire wear microplastics affect the fitness of the nematode C. elegans N2 - This study gives a first insight in the toxicological relevance of tire wear MP on soil invertebrates. Both grinding technique and aging method had an effect on the results of the particle size distribution, particle properties and toxicity tests. This outcome highlights the importance of oxidative and mechanical aging of tire wear when investigating effects on soil biota. In particular the demonstrated differences due to grinding method of the pristine material questions scientific practice in common toxicity tests. It is essential to implement realistic refernce material as well as standardized aging and handling procedures. T2 - Tire Emissions Research Conference 2024 CY - Munich, Germany DA - 04.12.2024 KW - Nematode C. elegans KW - Oxidative aging KW - Tire wear KW - Microplastics PY - 2024 AN - OPUS4-62361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin T1 - Porenstruktur von Beton mit Recyclingzuschlägen N2 - Recyclingzuschläge (rezyklierte Gesteinskörnungen, Betonsplitt) werden großtechnisch aus dem Material, das beim Abbruch von Betonbauwerken anfällt, hergestellt. Sie bestehen zu mehr als 90% aus Altbeton. Die Wiederverwendung dieser Materialien zur Herstellung von neuen hochwertigen Beton erfordert umfangreiche Kenntnisse über ihre betontechnologischen und chemisch-physikalischen Eigenschaften. Zwei unterschiedliche Recyclingzuschläge und die damit hergestellten Betone wurden im Vergleich zu einem Referenzbeton mit natürlichen Zuschlägen gleicher Sieblinie untersucht. T2 - Tag der offenen Tür der BAM CY - Berlin, Germany DA - 19.06.2004 PY - 2004 AN - OPUS4-11432 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin T1 - Mikrostruktur von hochfestem Beton N2 - Hochfeste Betone werden durch die Zugabe puzzolanischer Zusatzstoffe (Microsilica, Flugasche) und die Reduzierung des Wasser-Zement-Wertes bei gleichzeitiger Verwendung eines Fließmittels hergestellt. Diese Modifizierungen des Betons beeinflußen die Zusammensetzung und die Mikrostruktur seiner Mörtelmatrix. T2 - Tag der offenen Tür der BAM CY - Berlin, Germany DA - 19.06.2004 PY - 2004 AN - OPUS4-11431 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ramge, Peter T1 - Einflüsse der Mischungszusammensetzung auf die Porenstruktur von Instandsetzungsmörteln N2 - Untersucht wurde der Einfluss der Applikationsart (konventionelle und gespritzte Herstellung, Wasserlagerung bis zur Prüfung), der Einfluss von Fasern (konventionelle Herstellung, Wasserlagerung bis zur Prüfung) und der Einfluss von Schwindreduzierern (konventionelle Herstellung, Luftlagerung bis zur Prüfung). T2 - XV. Workshop über die Charakterisierung von feinteiligen und porösen Festkörpern (Porotec-Workshop) CY - Bad Soden, Germany DA - 16.11.2010 PY - 2010 AN - OPUS4-22634 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank T1 - Influence of aggregate size on the damage potential of alkal-silica-reaction N2 - The poster shows new results on Alkali-Silica-Reaction (a damage mechanism of concrete). The influence of the aggregate size in the sand fraction is investigated, revealing that different types of aggregate behave in a different way. T2 - 15th International Conference of Alkali Aggregate Reaction in Concrete (ICAAR 2016) CY - Sao Paulo, Brazil DA - 03.07.2016 KW - Alkali-silica-reaction KW - Building materials KW - Concrete KW - Durability PY - 2016 AN - OPUS4-36951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin T1 - Use of municipal solid waste incinerator bottom ash as aggregate concrete N2 - Modern municipal solid waste incinerator plants produce bottom ashes, which are used in building industry, especially as base course in road constructions. Because of a highly sophisticated reprocessing technique, the ashes Show a relatively stable composition, comparatively well defined properties and environmentally relevant Parameters below legal Limits. Due to its chemical and mineralogical characteristics, the bottom ash can in principle be used as Aggregate in the production of normal strength concrete. However, if the ash contains concrete damaging components Recycling becomes problematic. To assess the use of municipal solid waste incinerator bottom ash (MSWI bottom ash) as Aggregate in concrete, different additionally treated ashes were chemical and physical characterised. Furthermore, concrete specimens with bottom ash as aggregates were produced and their Engineering properties were studied. T2 - EGU 2007 European Geosciences Union General Assembly 2007, Symposium Energy, Resources and the Environment ERE8 "Aggregates - the most widely used geological material" CY - Vienna, Austria DA - 15.04.2007 PY - 2007 AN - OPUS4-18949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herbst, Tristan T1 - Nachhaltiges Bauen mit Beton - Einsatz sekundärer Gesteinskörnungen N2 - Im Hinblick auf eine nachhaltige Entwicklung sollen nach dem KrW/AbfG der Rohstoffeintrag und der Abfallaustrag in den Lebensphasen eines Bauwerks durch weitgehende Verwertung von Sekundärrohstoffen (Reststoffen) möglichst gering gehalten werden. Ein Einsatz von Reststoffen wie Hausmüllverbrennungsaschen (MV-Aschen) im Betonbau kann potenziell einen wesentlichen Beitrag zur nachhaltigen Entwicklung leisten. T2 - 17. IBAUSIL CY - Weimar, Germany DA - 23.09.2009 PY - 2009 AN - OPUS4-19731 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maultzsch, Matthias A1 - Kühne, Hans-Carsten T1 - Entwicklung von Betonen mit geringer Festigkeit für die Beurteilung von Instandsetzungssystemen im Wasserbau N2 - Die Regelwerke (RL SIB, ZTV-ING) setzen für die Instandsetzung mit Betoninstandsetzungssystemen vergleichsweise hochwertige Betonuntergründe voraus. Speziell bei älterenWasserbauwerken sind oftmals nur geringerfeste Betonuntergründe vorhanden für die es bis jetzt keine geeigneten und geprüften Instandsetzungssysteme gab. Grundlage für die Entwicklung solcher Systeme sind entsprechende Referenzbetone als Untergrundbeton für die Verbundkörperprüfung. T2 - Wissenschaftsrat CY - Berlin, Germany DA - 17.01.2006 PY - 2006 AN - OPUS4-12028 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kühne, Hans-Carsten T1 - Abschätzung der Druckfestigkeit von hochfestem Beton mit dem Rückprallhammer N2 - Ziel der Untersuchungen war es, herauszufinden ob die Druckfestigkeit hochfester Betone zerstörungsfrei mit dem Rückprallhammer PROCEQEQUOSCHMIDT durch Ermittlung des klassischen Rückprallwerts R in Kombination, mit einem aus der Untersuchung von Metallen bekannten neuen Messwert L mit ausreichender Sicherheit beschrieben werden kann. T2 - Wissenschaftsrat CY - Berlin, Germany DA - 17.02.2006 PY - 2006 AN - OPUS4-12029 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin T1 - Charakterisierung der Porenstruktur von ultrahochfestem Beton N2 - Ultrahochfeste Betone (UHPC) sind durch Druckfestigkeiten > 150 MPa und eine besonders hohe Dauerhaftigkeit gekennzeichnet. Ihre Herstellung gelingt durch die Optimierung der Mischungszusammensetzung, des Mischprozesses und der Nachbehandlung. Maßnahmen dazu bestehen in der Verwendung feinstgemahlener Zemente, puzzolanischer und inerter Feinststoffe, dem Einsatz gezielt ausgewählter grober und feiner Gesteinskörnungen, der Reduktion des Wasser/Bindemittel-Wertes bei Zugabe von Fließmitteln auf Polycarboxylat-Basis sowie einer Wärmebehandlung der Betone. Das Ziel dabei ist es, eine möglichst hohe Packungsdichte in der Bindemittelmatrix bei Ausbildung einer sehr gleichmäßigen und extrem dichten Gefügestruktur mit einem hohen Anteil an Calciumsilicathydrat-Phasen zu erreichen. Deshalb sind Untersuchungen zur Porosität und Porenstruktur ein wichtiger Bestandteil zur Materialcharakterisierung im Rahmen der Mischungsoptimierung. Die Ergebnisse der Mikrostrukturuntersuchungen werden im Vergleich zu denen an einem hochfesten Beton und einem Normalbeton betrachtet. T2 - XIII. Workshop über die Charakterisierung von feinteiligen und porösen Festkörpern CY - Bad Soden, Germany DA - 14.11.2006 PY - 2006 AN - OPUS4-14010 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Osterhus, Lennart T1 - Kieselsäurehaltiger Filterrückstand aus industrieller Abwasserbehandlung für den Einsatz als hydraulisches Bindemittel N2 - - 5.000 bis 10.000 t wasserhaltiger Filterrückstand (FR) entstehen jährlich pro Produzent bei der Neutralisation der Abwässer aus der Silicon- oder Kieselsäureherstellung - Anfall als fester, feuchter, schollenartiger Filterkuchen - Verwertung heute: Deponierung, Tagebauverfüllung -> ungenutzte Sekundärrohstoffquelle - Untersuchung der Einsatzmöglichkeiten der aufbereiteten Filterrückstände zur Eigenschaftsverbesserung zementgebundener Baustoffe analog der wohlbekannten Anwendung von hochdisperser Kieselsäure und Silicastaub T2 - GDCh-Tagung Bauchemie CY - Hamburg, Germany DA - 06.10.2011 PY - 2011 AN - OPUS4-24819 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herbst, Tristan T1 - Integrated and holistic suitability assessment of recycling options for masonry rubble N2 - Behandelt den Bausektor und die Verarbeitsungsqualität T2 - European Geosciences Union (EGU) General Assembly 2012 CY - Vienna, Austria DA - 22.04.2012 PY - 2012 AN - OPUS4-25868 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herbst, Tristan T1 - Verwertung kieselsäurehaltiger Filterrückstände in mineralischen Baustoffen N2 - - jährlicher Anfall von 5.000 bzw. 10.000 Tonnen wasserhaltiger Filterrückstände (FR) pro Produzent bei der Abwasser-Neutralisation aus der Kieselsäure- bzw. Chlorsilanherstellung (FR1, FR2) - heute: Deponierung, Tagebauverfüllung - ungenutzte Sekundärrohstoffquelle - Untersuchung möglicher Anwendungsbereiche für FR T2 - GDCh Tagung Bauchemie CY - Dübendorf, Switzerland DA - 11.10.2012 PY - 2012 AN - OPUS4-26673 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Makris, Ruben T1 - Crack Luminescence as innovative method for detection of fatigue damage N2 - Conventional methods of crack detection only provide a snapshot of the fatigue evolution at a specific location and in the moment of examination. The crack luminescence method realizes a clear visibility of the occurring cracks in loaded components during ongoing operation. Several different experiments show that due to the sensitive coating even the early stage of the crack formation can be detected what makes the crack luminescence helpful to determine the incipient crack opening behavior depending on load alternation. Due to the emitting of light under UV-radiation the crack gets clearly visible what makes continuous monitoring and automated crack detection possible. This can reduce costs and time needed for maintenance and inspection. T2 - Sensor +Test 2017 CY - Nuremberg, Germany DA - 30.05.2017 KW - Fatigue damage KW - Crack KW - Luminescence KW - Detection PY - 2017 AN - OPUS4-41839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kruschwitz, Sabine T1 - Junior Research Group Materials Characterization and Informatics for Sustainability in Civil Engeneering (CE) N2 - Vorstellung der Themen der Nachwuchsgruppe "Materialcharakterisierung und -informatik für die Nachhaltigkeit im Bauwesen" von Prof. Sabine Kruschwitz (TU Berlin und BAM) T2 - Themenkonferenz Nachhaltiges Bauen CY - Berlin, Germany DA - 08.12.2022 KW - Recycling KW - NMR KW - Materialcharakterisierung KW - Data Science PY - 2022 AN - OPUS4-56648 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hirsch, T. T1 - Impact of autoclaving on the phase assemblage of Portland cement: Experiment and thermodynamic modelling N2 - Even after autoclaving for 2 weeks in the temperature range of 120 to 200 °C, CEM I paste with a water-to-cement ratio of 0.5 still contains some low-crystalline C-S-H. The conversion of low-crystalline C-S-H to crystalline is faster with increasing temperature. The observed low-crystalline and crystalline C-S-H phases (reinhardbraunsite, jaffeite) indicate that the samples have not reached equilibrium yet under these experimental conditions. However, there is a good agreement between experiment and thermodynamic modelling for the other solids indicating that the used datasets are suitable for this application. T2 - 16th International Congress on the Chemistry of cement 2023 - ICCC2023 CY - Bangkok, Thailand DA - 18.09.2023 KW - Zement KW - Thermodynamik KW - Phasenzusammensetzung KW - Mineralogie KW - Modellierung PY - 2023 UR - https://iccc2023.org AN - OPUS4-58967 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Error margins in the Determination of Molar Mass and Oligomer Content of Polymers N2 - Size exclusion chromatography (SEC) is still the method of choice for determining the molar mass and molar mass distribution of macromolecules. It is a liquid chromatographic technique that separates molecules based on their size, respectively their hydrodynamic volume using a porous stationary phase that allows smaller molecules to pass through the pores while excluding larger molecules. The chromatogram from the size separation can be calibrated using polymers of known molar mass resulting in a relative molar mass distribution curve. From this distribution curve molar mass averages and the oligomer content (percentage of peak area smaller than 1000 g/mol and 500 g/mol) of polymers can be derived. The determination of oligomer content is important, because it is often used in regulatory contexts as a measure of small, mobile and potentially more toxic parts of the polymer. Polymer regulations are of increasing political and social importance. Regulations often set very narrow limits. SEC has rather large error margins of 10-20% for the molar mass determination performed in different laboratories or on different instruments. These variances are well known to all experts and users and have been investigated in several round robin tests in the past. These resulted in DIN and ISO standards which, in our opinion, no longer meet today's requirements. As far as we know, the margins of error in determining oligomer content have not yet been investigated. It is expected that the variation will be rather high. This is because it depends on many factors related to the experimental conditions (column sets used, solvent, temperatures, sample preparation) on the one hand, and the data evaluation mechanisms (choice of baseline and peak limits) on the other. In order to actually measure the error margins and to support this with actual data a round robin test has been performed from June to November 2024 with approx. 40 participating laboratories. Three different solvents were selected, namely THF, DMAc or DMF and water. The samples were selected together with all the experts, taking into account a wide range of practical aspects far from narrowly distributed standards: e.g higher distribution range, reduced solubility, included side components, copolymers and dispersions with gel content. In this contribution we will present the detailed concept of this round robin test and first results. T2 - SETAC Europe 35th Annual Meeting CY - Vienna, Austria DA - 11.05.2025 KW - Size exclusion chromatography KW - REACH KW - Polymers KW - Round Robin Tests PY - 2025 AN - OPUS4-63307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Limitations of SEC: Strategies for Improved Regulatory Polymer Analysis N2 - Polymers, composed of repeating units called monomers, exhibit a diverse range of properties, with molecular weight distribution (MWD) being particularly important for regulatory risk assessments. Size exclusion chromatography (SEC), or gel permeation chromatography (GPC), is the primary technique for MWD characterization, as detailed in OECD guidelines 118 and 119, along with DIN and ISO standards. However, SEC faces significant shortcomings that complicate the accurate determination of MWD and oligomer content. These limitations include the insolubility of certain polymers, crosslinking, and ultra-high molecular weight characteristics, which can exceed SEC's separation capabilities. The presence of salts or modifiers can further interfere with oligomer content determination, and the availability of appropriate SEC columns and calibration standards limits comparability across laboratories. To enhance SEC's reliability and applicability within regulatory frameworks, innovative methods and strategies are essential. Proposed solutions involve new sample preparation techniques, advanced data interpretation methods, and the establishment of standardized methodologies to promote harmonization. This is especially crucial in light of the expected Polymer REACh (PREACh) legislation, which aims to regulate polymer registration and risk assessment within the European market. Given the anticipated complexity of the registration process, which requires extensive data generation, proactive strategies are needed to address SEC's challenges. Currently, there are no viable alternatives for oligomer content determination, and the unique properties of polymers often necessitate tailored analytical approaches. Without new methodologies and guidelines, the polymer registration process could become burdensome and costly, jeopardizing important products and markets in the EU. Key areas for improvement include extending existing norms to cover a broader range of solvents, addressing high error margins in oligomer content determination, establishing harmonized approaches for dealing with side components, and providing clarity on measuring partially soluble polymers. In conclusion, addressing SEC's limitations through the development of comprehensive guidelines and harmonization is critical for ensuring accurate and efficient polymer analysis, ultimately facilitating smoother registration processes. T2 - SETAC Europe 35th Annual Meeting CY - Vienna, Austria DA - 11.05.2025 KW - Size exclusion chromatography KW - Polymers KW - REACH PY - 2025 AN - OPUS4-63309 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epperlein, Nadja T1 - Influence of femtosecond laser produced nanostructures on biofilm growth on steel N2 - Large area periodic surface structures were generated on steel surfaces using 30-fs laser pulses at 790 nm wavelength. Two types of steel exhibiting a different corrosion resistance were used, i.e. a plain structural steel (corrodible) and a stainless steel (resistant to corrosion). Homogeneous fields of laser-induced periodic surface structures (LIPSS) were realized utilizing laser fluences close to the ablation threshold while scanning the sample under the focused laser beam in a multi-pulse regime. The nanostructures were characterized with optical and scanning electron microscopy. For each type of steel, more than ten dentical samples were laser-processed. These samples were subjected to microbial adhesion tests, investigating bacterial adhesion behavior on the laser structures in comparison to polished reference surfaces. Short term experiments (<24h) were carried out to determine initial biofilm development. E. coli as a typical bacterium representing pathogenic bacteria and Shewanella putrefaciens as metal corrosive bacterium were used for biofilm development analyses. Bacterial cell adhesion was determined microscopically after DAPI cell staining (DNA staining). Comparison of the coverage areas between nanostructured and polished surfaces revealed differences in cell adhesion behavior and biofilm structure. T2 - E-MRS 2016 Spring Meeting, Symposium C: "Laser-material interactions for tailoring future applications" CY - Lille, France DA - 02.05.2016 KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Biofilms KW - Steel PY - 2016 AN - OPUS4-36045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stroj, S. T1 - Laser-generated high wetting contrast surfaces for microbiological applications N2 - We demonstrate a 2D platform based on high contrast wetting patterns suitable for miniaturized microbiological assays. In principal, superhydrophilic spots are surrounded by a superhydrophobic surface area. The special structure of the superhydrophilic functional surface ensures that liquids, e.g. bacterial suspensions or biocide solutions, spread immediately and evenly on this surface without passing the wetting boundary. This feature allows a homogenous distribution of bacteria or chemical substances on well defined lateral dimensions. The superhydrophilic spots may also serve as substrate for bacterial biofilms. Due to the high wetting contrast and the fabrication process, it is possible to minimize the test areas as well as their distance to each other. We demonstrate the fabrication process of the high wetting contrast platform and also present a microbiological assay as an application example. Advantages of this platform are the use of low volumes and its potential of automated analysis. T2 - Biointerfaces International Conference CY - Zürich, Austria DA - 14.08.2018 KW - Biofilm KW - Bacterial growth KW - Laser structuring KW - Superhydrophobic surface KW - Superhydrophilic surface PY - 2018 AN - OPUS4-45863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zekhnini, Khalid T1 - Corrosion at metallic offshore constructions – Bundesanstalt für Materialforschung und -prüfung (BAM) N2 - In the maritime context of offshore operation, corrosion, in combination with the materials used, poses a particular challenge to ensure safe operation over long indefinite periods and to minimise susceptibility to failure. Until today, only a few corrosion protection systems have proven themselves for the interaction of efficiency, installation, and maintenance in the offshore sector. In addition, available corrosion test methods sometimes have major deficits about conclusions of the durability. Therefore, there is more research and development needed. The flagship project H2Mare of the Federal Ministry of Education and Research aims to enable the production of green hydrogen and PtX products at high seas. Research is being driven forward by the partners in four individual projects, where BAM is involved in two. In PtX-Wind, major kinds of corrosion attacks at offshore constructions are characterized and investigated, and suitable corrosion protection measures determined. In TransferWind, attention focusses on transferring scientific results into standardization. This poster at the H2Mare Conference 2023 presents an overview of the investigation methods and contribution of the department “Corrosion and Corrosion Protection”. T2 - H2Mare Conference 2023 CY - Frankfurt/Main, Germany DA - 12.06.2023 KW - Atmospheric Corrosion KW - Sea Water KW - Corrosion Testing KW - Offshore KW - Laboratory Container KW - Corrosion protecting system PY - 2023 AN - OPUS4-57838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Rüden, H. T1 - Röntgen-Computertomographie (CT) für die Kulturguterhaltung N2 - Als bildgebendes und zerstörungsfreies Verfahren eignet sich die Röntgen-Computertomographie (CT) insbesondere bei der Untersuchung von Kunst- und Kulturgütern. Die für Werkstoffprüfung und Materialanalyse konzipierten CT-Anlagen bieten dank hoher Röntgenleistung die Möglichkeit zusätzlich zu Holz, Keramiken und Kunststoffen auch stark schwächende Materialien, wie bspw. Metalle, zu durchdringen. Für eine hohe räumliche Auflösung im unteren Mikrometerbereich (2-200µm) sorgen entsprechend ausgelegte CT-Anlagen. In der Bundesanstalt für Materialforschung und -prüfung (BAM) stehen mehrere solcher CT-Anlagen für unterschiedliche Fragestellungen sowie Probengrößen und - materialien zur Verfügung. Einige Beispiele aus den vergangenen Arbeiten der BAM veranschaulichen das große Potential dieser Untersuchungsmethode. Da bei einer CT-Messung in der Regel das gesamte Untersuchungsobjekt erfasst und in ein digitales Volumenmodell überführt wird, eröffnet sich für Archäologen und Restoratoren die Möglichkeit Untersuchungen hinsichtlich Materialzusammensetzung, Erhaltungszustand und Herstellungstechnik am virtuellen Objekt vorzunehmen, ohne die Originalsubstanz zu beeinträchtigen. Gegenüber der klassischen Radiografie, bei der nur eine zweidimensionale Abbildung erreicht wird, bietet die CT-Untersuchung die Möglichkeit innenliegende Strukturen dreidimensional zu erfassen. Die notwendige Bestimmung der Objektoberfläche erlaubt zudem die Erstellung eines Oberflächenmodells des untersuchten Gegenstandes. Damit lassen sich unter anderem mechanische Simulationen (Belastung, Durchbiegung, Durchströmung) durchführen. Der erzeugte Datensatz kann somit auch zur Herstellung eines Replikats im 3D-Druckverfahren genutzt werden. Anhand der Untersuchung der Mandoline von Smorsone wird gezeigt, wie eine CT-Messung durchgeführt wird und wie in dem anschließend rekonstruierten 3D-Datensatz mittels Koordinatenmesstechnik Maße (Abstände, Wandstärken, Winkel) exakt ermittelt werden können. T2 - Jahrestagung der Gesellschaft für Musikforschung CY - Berlin, Germany DA - 28.09.2022 KW - Mikro-CT KW - Bildverarbeitung KW - Holz KW - Bronze KW - ZfP PY - 2022 AN - OPUS4-56412 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ulbricht, Alexander T1 - Do Microbes like Additively Manufactured Aluminium? First Details of a Corrosion Test using Sulphate-Reducing Bacteria N2 - Additively manufactured metals become relevant for industrial application. Although many studies on wet corrosion of these metals have been conducted, to the authors knowledge no study seems to contain microbiological corrosion (MIC). In the presented study an experiment was conducted on PBF-LB/AlSi10Mg to test this material's susceptibility for MIC. The tested specimen were analysed using Computed Tomography before and after the MIC experiment to enable a detailed characterisation the damage on the specimens' global and local level. A global reduction of material was observed. In addition, localised damage along process inherent features of the materials microstructure was observed. T2 - Beiratssitzung TF Umwelt CY - Berlin, Germany DA - 17.03.2025 KW - Computed Tomography KW - Additive Manufacturing KW - Biocorrosion KW - Sulphate-reducing Bacteria KW - Microbially influenced corrosion PY - 2025 AN - OPUS4-62772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Merz, Benjamin T1 - Precise Position Detection for Repair of Gas Turbine Blades using PBF-LB/M N2 - Additive manufacturing (AM) technologies are becoming increasingly important, not only for the manufacture of parts, but also as repair technology that complement existing production technologies. Powder bed fusion of metals by laser beam (PBF-LB/M) combines the freedom in design with high achievable accuracy, making it ideal as a repair approach. However, there are still challenges in adapting process for repair applications. When mounting parts inside PBF-LB/M machines, their real position within the build volume is unknown. One goal of a repair process is to minimize the offset between the base component and the additively manufactured structure to reduce additional rework. For a minimum offset between component and additively manufactured structure, the actual position of the component has to be identified with high precision within the machine coordinate system (MCS). In this work a process setup is presented that allows the actual position of a gas turbine blade to be detected inside a PBF-LB/M machine. A high resolution camera with 65 megapixel is used for this purpose. The presented setup is implemented on a SLM 280 HL PBF-LB/M machine. In addition to the setup, a novel repair workflow using PBF-LB/M is presented. The developed setup and workflow consider inaccuracies in the component and camera mounting, as well as process inaccuracies. This includes keystone distortion correction by homography. The machine setup and workflow are used to repair a real gas turbine blade. Subsequently the offset between the turbine blade and the additivley manufactured structure is validated by 3D scanning the repaired part. The maximum offset is 160 µm. The presented approach can be extended to other geometries and PBF-LB/M machine manufacturers. The high-resolution camera approach is platform independent, which facilates the market penetration of PBF-LB/M repair processes. T2 - International Symposium Additive Manufacturing 2023 (ISAM 2023) CY - Dresden, Germany DA - 30.11.2023 KW - additive manufacturing KW - powder bed fusion of metals utilizing a laser beam KW - PBF-LB/M KW - hybrid repair KW - position detection KW - high-resolution camera PY - 2023 AN - OPUS4-59193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - A unique authenticator for additively manufactured parts derived from 3D microstructural information N2 - Additive manufacturing (AM) is rapidly emerging from rapid prototyping to industrial production [1]. Thus, providing AM parts with a tagging feature that allows identification, like a fingerprint, can be crucial for logistics, certification, and anti-counterfeiting purposes since nearly any geometry can be produced by AM with stolen data or reverse engineering of an original product. However, the mechanical and functional properties of the replicated part may not be identical to the original ones and pose a safety risk [2]. Several methods are already available, which range from encasing a detector to leveraging the stochastic defects of AM parts for the identification, authentication, and traceability of AM components. The most prevailing solution consists of local process manipulation, such as printing a quick response (QR) code [3] or a set of blind holes on the surface of the internal cavity of hollow components. Local manipulation of components may alter the properties. The external tagging features can be altered or even removed by post-processing treatments. Integrating electronic systems [4] in AM parts can be used to identify and authenticate components with complex or customized geometries. However, metal-based AM, especially in powder bed fusion (PBF-LB/M) techniques, has a strong shielding effect that interferes with the communication between the reader and the transponder. Our work suggests a methodology for the identification, authentication, and traceability of AM components using microstructural features in AM components. We will show a workflow that includes analysing 3D micro computed tomography data and selecting a set number of voids that fulfil the identification criteria. We will show the results this workflow produces for a series of 20 Al-based cuboid samples with identical processing parameters and discuss their prospects and limitations. The workflow can help to establish a non-tamperable connection between an additively manufactured part and its digital data and hence link the physical and the digital world. T2 - MSE Konferenz CY - Darmstadt, Germany DA - 24.09.2024 KW - Additive Manufacturing KW - Fingerprint KW - Computed tomography PY - 2024 AN - OPUS4-62288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seifert, Lando T1 - Das Meerwasserlabor am Eidersperrwerk N2 - Das Meerwasserlabor (Laborcontainer) ist eine Remote-fähiges Elektrochemie-Labor mit entfeuchtungsfähiger Klimatisierung in dem eine Vielfalt an experimentellen Möglichkeiten besteht. Das Alleinstellungsmerkmal ist der Meerwasser-Bypass, durch den eine Besiedlung und Erhalt von Salzwasser- bzw. Brackwasserbewuchs (Bakterien, Algen, Tiere, Pilze, etc.) möglich ist. Der jährliche Verlauf der Meeresumwelt wird dadurch abgebildet. T2 - Leitprojekt H2Mare Verbundtreffen PtX-Wind & TransferWind CY - Frankfurt am Main, Germany DA - 05.12.2024 KW - Offshore Corrosion KW - Marine Corrosion KW - Corrosion KW - Green Hydrogen PY - 2024 AN - OPUS4-62054 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fayet, G. T1 - First models to predict thermal decomposition properties of possible self-reactive substances based on industrial datasets N2 - Self-reactive substances are unstable chemical substances which can easily decompose and may lead to explosion. For this reason, their thermal stability properties are required within regulatory frameworks related to chemicals in order to assess their hazardous properties. Due to the fast development and availability of computers, predictive approaches like QSPR models are increasingly used in the evaluation process of hazardous substances complementary to experiments. In that context, the HAZPRED project (2015-2018) aimed to develop QSPR models to predict physical hazards of substances to fill the lack of knowledge on these hazardous substances quickly. An experimental campaign, based on 50 samples provided by Industrial producers, was carried out on potential self-reactive substances, for which no QSPR model already existed. Their heats of decomposition were characterized using differential scanning calorimetry in homogeneous experimental conditions. QSPR models were derived using the GA-MLR method (using a genetic algorithm and multi-linear regressions) using molecular descriptors calculated by Dragon software based on both 3D molecular structures from density functional theory (DFT) optimizations, to access three-dimensional descriptors, and SMILES codes, favoring the access to simpler models, requiring no preliminary quantum chemical calculations. All models respected the OECD validation guidelines for regulatory acceptability of QSPR models. They were tested by internal and external validation tests and their applicability domains were defined and analyzed. If improved models should be expected with larger database (and a better ratio between size and chemical diversity), these first models already represent a screening tool capable to access early reactive hazards. T2 - 19th International Workshop on Quantitative Structure-Activity Relationships in Environmental and Health Sciences CY - Online meeting DA - 07.06.2021 KW - QSPR KW - Self-reactive substances KW - Thermal decomposition PY - 2021 AN - OPUS4-53178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Oster, Simon T1 - Multispectral in-situ monitoring of a L-PBF manufacturing process using three thermographic camera systems N2 - The manufacturing of metal parts for the use in safety-relevant applications by Laser Powder Bed Fusion (L-PBF) demands a quality assurance of both part and process. Thermography is a nondestructive testing method that allows the in-situ determination of the thermal history of the produced part which is connected to the mechanical properties and the formation of defects [1]. A wide range of commercial thermographic camera systems working in different spectral ranges is available on the market. The understanding of the applicability of these cameras for qualitative and quantitative in-situ measurements in L-PBF is of vital importance [2]. In this study, the building process of a cylindrical specimen (Inconel 718) is monitored by three camera systems simultaniously. These camera systems are sensitive in various spectral bandwidths providing information in different temperature ranges. The performance of each camera system is explored in the context of the extraction of image features for the detection of defects. It is shown that the high temporal and thermal process dynamics are limiting factors on this matter. The combination of different spectral camera systems promises the potential of an improved defect detection by data fusion. T2 - LASER SYMPOSIUM & ISAM 2021 CY - Online meeting DA - 07.12.2021 KW - Laser Powder Bed Fusion KW - Thermography KW - In-situ Monitoring KW - Defect detection PY - 2021 AN - OPUS4-54141 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Taparli, Ugur Alp T1 - Time- and space-resolved in situ LIBS measurements of chemical compositions during TIG-welding N2 - An in situ monitoring of chemical compositions in the weld pool and the heat affected zone (HAZ) can enable the control of the welding process through the regulation of the welding parameters, and thus can prevent possible weld defects. The most critical parameter for hot cracking -from a metallurgical point of view- is the chemical composition of the weld pool. Chemical composition can be measured and quantified during the welding process with the LIBS technique having the appropriate calibration measurements. T2 - ICWAM 2017 CY - Metz, France DA - 17.05.2017 KW - Chemical compositions KW - TIG-welding KW - In situ measurement KW - LIBS PY - 2017 AN - OPUS4-40313 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmitt, Johannes T1 - Data acquisition system for single particle inductively coupled plasma mass spectrometry (spICP-MS) with nanosecond time resolution N2 - This study presents our data acquisition system prototype for single particle inductively coupled plasma mass spectrometry (spICP-MS) with nanosecond time resolution (nanoDAQ) and a matching data processing approach for time-resolved data in the nanosecond range. The system continuously samples the secondary electron multiplier (SEM) detector signal with a dwell time of approximately 2 ns and enables detection of gold nanoparticles (AuNP) as small as 7.5 nm with a commercial single quadrupole ICP-MS instrument. [1] Analysis of acquired transient data is based on the temporal distance between detector events and a derived ion event density. It was shown that the inverse logarithm of the distance between detector events is proportional to particle size. Also, the number of detector events per particle can be used to calibrate and determine the particle number concentration (PNC) of a nanoparticle dispersion. Particle-by-particle-based analysis of ion event density and other parameters derived from nanosecond time resolution show promising results. High data acquisition frequency of the systems allows recording of a statistically significant number of data points in 60 s or less, which leaves only the sample uptake and rinsing steps as remaining factors for limiting the total measurement time. T2 - 20th European Winter Conference on Plasma Spectrochemistry CY - Berlin, Germany DA - 02.03.2025 KW - ICP-MS KW - Instrumentation KW - Nano KW - Nanoparticle Characterization PY - 2025 AN - OPUS4-63599 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael T1 - Component test for the assessment of hydrogen assisted cracking susceptibility of thick-walled submerged arc welded offshore steels N2 - Offshore wind turbines (OWT) are a key factor of the sustainable energy generation of tomorrow. The continuously increasing installation depths and weight of the OWTs require suitable foundation concepts like monopiles or tripods. Typically, mild steels like the S420ML are used with plate thicknesses up to several hundreds of mm causing high restraints in the weld joints. Due to the large plate thickness, submerged arc welding (SAW) with multiple wires is the state-of-the-art welding procedure. As a result of the very high stiffness of the construction, a certain susceptibility for time-delayed hydrogen-assisted cracking (HAC) may occur. The evaluation of crack susceptibility is very complex due to the component size and stiffness of real offshore structures. For this purpose, a near-component test geometry was developed to transfer the real stiffness conditions to laboratory (i.e., workshop) scale. The investigated mock-up, weighing 350 kg, comprised heavy plates (thickness 50 mm, seam length 1,000 m) joined by a 22-pass submerged arc weld. Additional stiffeners simulated the effect of high restraint or shrinkage restraint of the weld. Extreme scenarios of hydrogen absorption during welding were simulated via the use of welding fluxes in dry (HD < 5 ml/100g Fe) and moisture condition (HD > 15 ml/100g Fe). The residual stresses were determined by a robot X-ray diffractometer. Areas of critical tensile residual stress (at the level of the yield strength) were found in the weld metal and heat affected zone. To identify possible delayed cracking, the welds were tested by phased array ultrasonic testing (PAUT) after 48 h. Summarized, no significant occurrence of HAC was detected, indicating the high crack resistance of the welded joint, i.e., a suitable combination of base material, welding consumable and welding parameters. T2 - AJP 2023: 3rd International Conference on Advanced Joining Processes 2023 CY - Braga, Portugal DA - 19.10.2023 KW - Hydrogen assisted cracking KW - Submerged arc welding KW - Component test KW - NDT KW - Waiting time PY - 2023 AN - OPUS4-58672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit T1 - A Preliminary Study on the Scaling of RC Structures under Blasting Loading N2 - Current capabilities for full-scale field blast testing are highly resource intensive. Reliable small-scale experiments are an effective alternative. Characterization of the dynamic response and damage of RC elements to scaled blast loads was investigated in scaled-down field experiments. Spatially resolved information on the dynamic structural response to blast loading was obtained using distributed fiber optic acoustic sensing (DAS), acceleration sensors as well as piezoelectric pressure sensors. T2 - 46. Informationstagung Sprengtechnik CY - Siegen, Germany DA - 25.04.2025 KW - Explosives KW - Blast and scaling effects KW - Concrete PY - 2025 AN - OPUS4-62994 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ryll, Tom William T1 - Researching automation of gypsum recycling N2 - This poster illustrates the recent work on a setup for automated in-situ analysis of gypsum recycling processes. Analysis in synchrotron X-rays, Raman- and UV-vis spectroscopy are made possible with this compact and mobile setup. First results from Raman spectroscopy on the conversion of gypsum to bassanite in hypersaline solutions are presented and future plans on optimization are formulated. T2 - ANAKON 2025 CY - Leipzig, Germany DA - 10.03.2025 KW - Recycling KW - Automation KW - Synchrotron-X-ray-diffraction KW - Raman-spectroscopy KW - Gypsum PY - 2025 AN - OPUS4-62706 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ryll, Tom William T1 - Researching automation of gypsum recycling N2 - This poster illustrates first successful experiments of recycling gypsum in hypersaline solutions with quantification via Raman-spectroscopy. To furhter enhancements include an automation setup, that was developed to gain in-situ measurements and open a pathway for batch-conversions and upscaling. T2 - BESSY@HZB User Meeting CY - Berlin, Germany DA - 12.12.2024 KW - Recycling KW - Gypsum KW - Raman-spectroscopy KW - Automation PY - 2024 AN - OPUS4-62292 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stawski, Tomasz T1 - Processing of calcium sulfate in brines N2 - Calcium sulfate hemihydrate (CaSO4·0.5H2O), also known as bassanite or "plaster of Paris", serves as a precursor for the production of gypsum (dihydrate, CaSO4·2H2O), widely used in construction. Currently, ~200 MT of calcium sulfate are consumed annually. Bassanite is obtained from gypsum through a solid-state thermal treatment in kilns at temperature ranging from 150 °C to 200 °C. We introduce a more efficient and sustainable method (T < 100 ºC) that enables the direct, rapid, and reversible conversion of gypsum to bassanite using reusable high salinity aqueous solutions (brines with c[NaCl] > 4 M). These transformations are controlled by the properties of the solution, offering extensive opportunities for precise manipulation of crystal formation and recycling of gypsum waste. T2 - BESSY User Meeting 2024 CY - Berlin, Germany DA - 12.12.2024 KW - Gypsum PY - 2024 AN - OPUS4-62095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tielemann, Christopher T1 - Oriented Surface Crystallization N2 - Up to now, oriented surface crystallization phenomena are discussed controversially, and related studies are restricted to few glasses. For silicate glasses we found a good correlation between the calculated surface energy of crystal faces and oriented surface nucleation. Surface energies were estimated assuming that crystal surfaces resemble minimum energy crack paths along the given crystal plane. This concept was successfully applied by Rouxel in calculating fracture surface energies of glasses. Several oriented nucleation phenomena can be herby explained assuming that high energy crystal surfaces tend to be wetted by the melt. This would minimize the total interfacial energy of the nucleus. Furthermore, we will discuss the evolution of the microstructure and its effect on the preferred crystal orientation. T2 - 26th International Congress on Glass CY - Berlin, Germany DA - 03.07.2022 KW - Glass KW - Surface energy KW - Crystal orientation PY - 2022 AN - OPUS4-56074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Chen, Y.-F. A1 - Contreras Jaimes, A. T1 - Datengetriebener Workflow für die beschleunigte Entwicklung von Glas (GlasDigital) N2 - Das Projekt GlasDigital wurde im allgemeinen vorgestellt, sowie die einzelnen Zwischenstände der verschiedenen Arbeitspakete aller Projektpartner präsentiert. Die allgemeine Porjektvorstellung ist auf deutsch. Die Zwischenstände der Arbeitsinhalte sind auf englisch. T2 - PMD Vollversammlung CY - Berlin, Germany DA - 03.11.2022 KW - Oxidglas KW - Robotische Glasschmelzanlage KW - ML KW - Ontologie KW - Digitaler Zwilling KW - Bildanalyse PY - 2022 AN - OPUS4-56491 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina T1 - Data-driven Workflow for Accelerated Glass Development (GlasDigital) N2 - As part of a joint project involving the Fraunhofer Institute for Silicate Research (ISC), the Friedrich Schiller University of Jena, the Clausthal University of Technology and the Federal Institute for Materials Research and Testing (BAM), digital tools are to be created for the development of new types of glass materials. Current processes for the production of glasses with improved properties are usually very cost- and energy-intensive due to the low degree of automation and are subject to long development cycles. The use of robotic synthesis processes in combination with self-learning machines is intended to overcome these problems in the long term. The development of new types of glass can then not only be accelerated considerably, but also be achieved with much less effort. In this talk, data generation via a robotic high-throughput glass melting system is presented, which should be the experimental basis for the ontology developed within the project GlasDigital. T2 - Materials Science and Engineering Congress (MSE 2022) CY - Darmstadt, Germany DA - 27.09.2022 KW - Oxidglas KW - Robotische Glasschmelzanlage PY - 2022 AN - OPUS4-56489 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - May, Anastasia T1 - Thermomechanochemical Synthesis of Pimelic Acid Cocrystals N2 - Milling temperature is a critical factor in mechanochemistry, affecting the kinetics and outcomes of reactions. In the context of cocrystallization, the influence of milling temperature on the process has been investigated for cocrystal systems pyrazinamide:pimelic acid (PZA:PA) and 4,4'-bipyridine:pimelic acid (BPY:PA). By means of temperature-controlled milling, stabilization of metastable polymorph of PZA:PA was achieved, thereby decelerating the aging process of the polymorph. This was accomplished through controlled heated milling of PZA and PA. Furthermore, we have successfully synthesized all three BPY:PA polymorphs by mechanochemistry involving controlled cooled and heated milling. In previous studies, only the most stable polymorph was obtained by mechanochemistry. T2 - 10th European Crystallography School CY - Ohrid, North Macedonia DA - 23.06.2025 KW - Mechanochemistry KW - Cocrystal PY - 2025 AN - OPUS4-63797 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -