TY - CONF A1 - Jaunich, Matthias T1 - Elastomerdichtungen für Wasserstoffanwendungen - Vergleich des Alterungsverhaltens in Luft und Wasserstoff N2 - In diesem Beitrag soll ein Fokus auf das Alterungsverhalten von Elastomerdichtungen unter Wasserstoff gelegt werden. Hierfür wurden Untersuchungen bei einem mittleren Wasserstoffdruck über Alterungszeiten von bis zu 100 Tagen durchgeführt. Das Alterungsverhalten wird im Vergleich der Alterungseffekte unter thermooxidativen Bedingungen betrachtet und bewertet. Die Annahme, dass der Alterungseffekt unter Wasserstoff stets weniger ausgeprägt ist als an Luft bestätigt sich nicht durch die Ergebnisse. T2 - 4. O-Ring-Forum der Firma ISGATEC CY - Bad Schönborn, Germany DA - 15.05.2025 KW - Wasserstoff KW - Dichtung KW - Thermische Alterung KW - Elastomer PY - 2025 AN - OPUS4-63135 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abel, Andreas A1 - Zapala, P. T1 - Materials Applications FeAl (WAFEAL) N2 - The increasing importance of resource availability and closed-loop material cycles are driving materials research to reduce alloying content in conventional materials or even substitute them with more sustainable alternatives. Intermetallic iron aluminide alloys (FeAl) present a potential alternative. Many alloy concepts for improved high-temperature properties or ductility have already been successfully implemented in casting technologies on a laboratory scale. However, successful testing of FeAl alloys on an industrial scale was still pending at the beginning of the project. Therefore, the aim of the project was to develop simulation-based casting concepts for industrial casting processes using the base alloy Fe-26Al-4Mo-0.5Ti-1B and to narrow down process limits by means of hot cracking tests. Findings were transferred into practice-oriented guidelines for casting of iron aluminides, which is accessible to future applicants in SMEs. The focus was placed on centrifugal casting combined with investment casting or die casting. In addition to numerous design and casting process parameters, heat treatments and alloying additions (Al, Mo, B) were varied to determine the influence of alloying elements on castability, microstructure and mechanical properties. Data from microstructure analyses (microscopic imaging, determination of grain sizes as well as phase compositions and volume fractions, fractography), mechanical tests (hardness measurements, compression tests, ambient and high-temperature tensile tests, creep tests) as well as measurements of thermophysical properties could be generated on the base alloy. Correlations of materials data with process variables allowed conclusions to be drawn on strengthening mechanisms and ductility of the alloy and how they can be controlled in terms of processing and component design. Successful casting of highly complex components with thin wall thicknesses and optimised alloy compositions points out prospects for new fields of application. T2 - FVV Transfer + Netzwerktreffen | Informationstagung – Frühjahr 2023 CY - Würzburg, Germany DA - 29.03.2023 KW - Fe-Al alloys KW - Intermetallics KW - Iron aluminides KW - Microstructure-property-correlation KW - High temperature mechanical properties KW - Creep data KW - Tensile data KW - Fractography KW - Casting PY - 2023 AN - OPUS4-57248 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Framework for Curation and Distribution of Reference Datasets on the Example of Creep Data of Ni- Based Superalloys N2 - This presentation introduces our current effort to develop a best practice framework for generating and distributing MSE reference datasets using creep data of Ni-based superalloys as an example, building on previous approaches. Such reference datasets can be used in the verification of testing equipment or to compare experimental or simulation results among different laboratories or collaborative centers. Our framework concept, for reference data, includes the generation of the data along with an agreement on the necessary metadata, considering the intended usage, and the integration into an easily accessible digital infrastructure to annotate and discover/distribute the datasets using a metadata schema accordingly aligned to a domain ontology. T2 - International Materials Science and Engineering Congress - MSE 2024 CY - Darmstadt, Germany DA - 24.09.2024 KW - Referenzdaten KW - Digitalisierung KW - Data schema KW - NFDI-MatWerk KW - Datenschema KW - FAIR PY - 2024 AN - OPUS4-61175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skrotzki, Birgit T1 - Fatigue Behavior at Elevated Temperature of Alloy EN AW-2618A N2 - The influence of test temperature and frequency on the fatigue life of the alloy EN AW-2618A (2618A) was characterized. The overaged condition (T61 followed by 1000 h/230 °C) was investigated in load-controlled tests with a stress ratio of R = -1 and two test frequencies (0.2 Hz, 20 Hz) at room temperature and at 230°C, respectively. An increase in the test temperature reduces fatigue life, whereby this effect is more pronounced at lower stress amplitudes. Decreasing the test frequency in tests at high temperatures further reduces the service life. T2 - ICAA19 International Conference on Aluminum Alloys CY - Atlanta, GA, USA DA - 23.06.2024 KW - Aluminium alloy KW - EN AW 2618A KW - Fatigue KW - Overaging KW - Damage behavior PY - 2024 AN - OPUS4-60426 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Skrotzki, Birgit T1 - Brinell-Hardness (HBW 2.5/62.5) of Al-alloy EN AW-2618A after different aging times and temperatures N2 - The dataset contains data from Brinell hardness measurements of Al-alloy EN AW-2618A after aging for different times and temperatures. Aging was either load free or with applied tensile load (creep). KW - Aluminium alloy KW - EN AW-2618A KW - Brinell hardness KW - Aging KW - Creep PY - 2022 UR - https://doi.org/10.5281/zenodo.6787085 UR - https://doi.org/10.5281/zenodo.10396823 DO - https://doi.org/10.5281/zenodo.6787084 PB - Zenodo CY - Geneva AN - OPUS4-55158 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - Adopting FAIR data practices in materials science: Semantic representation of a quantitative precipitation analysis N2 - Many metallic materials gain better mechanical properties through controlled heat treatments. For example, in age-hardenable aluminium alloys, the strengthening mechanism is based on the controlled formation of nanometre-sized precipitates, which represent obstacles to dislocation movement and consequently increase the strength. Precise tuning of the material microstructure is thus crucial for optimal mechanical behaviour under service condition of a component. Therefore, analysis of the microstructure, especially the precipitates, is essential to determine the optimum parameters for the interplay of material and heat treatment. Transmission electron microscopy (TEM) is utilized to identify precipitate types and orientations in the first step. Dark-field imaging (DF-TEM) is often used to image the precipitates and thereafter quantify their relevant dimensions. Often, these evaluations are still performed by manual image analysis, which is very time-consuming and to some extent also poses reproducibility problems. Our work aims at a semantic representation of an automatable digital approach for this material specific characterization method under adaption of FAIR data practices. Based on DF-TEM images of different precipitation states of a wrought aluminium alloy, the modularizable, digital workflow of quantitative analysis of precipitate dimensions is described. The integration of this workflow into a data pipeline concept will also be discussed. Using ontologies, the raw image data, their respective contextual information, and the resulting output data of the quantitative image analysis can be linked in a triplestore. Publishing the digital workflow and the ontologies will ensure data reproducibility. In addition, the semantic structure enables data sharing and reuse for other applications and purposes, demonstrating interoperability. T2 - FEMS EUROMAT 2023 CY - Frankfurt a. M., Germany DA - 03.09.2023 KW - Semantic Representation KW - FAIR data management KW - Quantitative Precipitation Analysis KW - Knowledge graph and ontologies PY - 2023 AN - OPUS4-58199 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Olbricht, Jürgen T1 - Einfluss von Haltezeiten auf die TMF-Lebensdauer von P92 bei mittleren und geringen Dehnungsamplituden N2 - Results of an extended TMF test program on grade P92 steel in the temperature range of 620 ◦C–300 ◦C, comprising in-phase (IP) and out-of-phase (OP) tests, partly performed with symmetric dwells at Tmax/Tmin, are presented. In contrast to previous studies, the low-strain regime is also illuminated, which approaches flexible operation in a power plant with start/stop cycles. At all strain amplitudes, the material performance is characterized by continuous cyclic softening, which is retarded in tests at lower strains but reaches similar magnitudes in the course of testing. In the investigated temperature range, the phase angle does not affect fatigue life in continuous experiments, whereas the IP condition is more detrimental in tests with dwells. Fractographic analyses indicate creep-dominated and fatigue-dominated damage for IP and OP, respectively. Analyses of the (micro)hardness distribution in the tested specimens suggest an enhanced microstructural softening in tests with dwell times for the low- but not for the high-strain regime. To rationalize the obtained fatigue data, the fracturemechanics-based DTMF concept, which was developed for TMF life assessment of ductile alloys, was applied. It is found that the DTMF parameter correlates well with the measured fatigue lives, suggesting that subcritical growth of cracks (with sizes from a few microns to a few millimeters) governs failure in the investigated range of strain amplitudes. T2 - DVM-Arbeitskreis Bauteilverhalten bei thermomechanischer Ermüdung - Workshop 2023 CY - Berlin, Germany DA - 20.09.2023 KW - 9–12%Cr steel KW - Thermomechanical fatigue KW - Symmetric dwell periods KW - Parametric modeling PY - 2023 AN - OPUS4-58431 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Bachmann, Marcel A1 - Rethmeier, Michael A1 - Meng, Xiangmeng T1 - Project title: Multi-physical simulation of the influence of an auxiliary magnetic field on the process porosity formation during high-power laser beam welding N2 - In this project, a multiphysically coupled numerical model will be developed to quantitatively describe porosity reduction in high-power laser beam welding of up to 10 mm thick AlMg3 using an oscillating magnetic field. The aim is to gain fundamental insights into the physical dependencies of the introduced electromagnetic forces on the melt pool behavior and the reduction of porosity. With the help of the numerical model, the transient, multi-coupled, three-dimensional problem of heat transfer, liquid flow, free surface deformation, and magnetic induction is to be solved, taking into account temperature-dependent material properties. The numerical modelling of the heat source will integrate all relevant physical mechanisms, for instance, multiple reflections of the laser radiation by an advanced ray tracing model, as well as local Fresnel absorption at the keyhole wall. This allows an analysis of the keyhole fluctuations, which have a dominant influence on the formation of process spores during deep penetration welding, based on physical principles. In addition, further physical factors such as the ablation pressure of the evaporating metal, the Laplace pressure, and Marangoni shear stresses are also to be integrated into the model. To evaluate the pore formation and reduction by means of the electromagnetic forces introduced in the molten pool, suitable models for describing the movement of the pores in the melt are to be developed. For the process pores, their movement can be implemented by tracking their surface under consideration of their internal pressure and temperature. With the help of the simulation model, all key factors for the formation of process pores during laser beam welding of the used aluminum alloy, as well as their avoidance, can be decoupled and analyzed. Accompanying welding tests are planned at BAM on a 20 kW fiber laser and a 16 kW disk laser. The magnetic flux density will be up to 500 mT at a maximum frequency of 5 kHz. The experimental results, in particular temperature measurements, weld cross sections, computer tomography, and X-ray examinations, will be used to verify the multiphysical model and its calibration. Moreover, the models will be validated and quantified by in situ high-speed imaging of the keyhole dynamics in a metal/quartz glass configuration with keyhole illumination by a diode laser coaxial to the processing laser. On the basis of the numerical and experimental results, the dependencies between applied magnetic field, melt pool behavior, and porosity formation will be revealed in this project. KW - Laser beam welding KW - Electromagnetic weld pool control KW - Numerical simulation KW - Process porosity PY - 2026 DO - https://doi.org/10.34657/27669 SP - 1 EP - 14 AN - OPUS4-65335 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Quackatz, Lukas A1 - Griesche, Axel A1 - Kannengießer, Thomas T1 - Rapid solidification during welding of duplex stainless steels – in situ measurement of the chemical concentration by Laser-Induced Breakdown Spectroscopy (LIBS) N2 - Duplex stainless steels (DSS) are frequently used, especially in applications requiring high strength combined with high corrosion resistance in aggressive media. Examples include power plant components and maritime structures. During welding of these steels, local variations in chemical composition can occur. This results in ferritization of the material and negatively affects the mechanical properties of the components. In this work, tungsten inert gas (TIG) welding experiments were performed with DSS. Chemical composition analysis was realized in situ by using Laser Induced Breakdown Spectroscopy (LIBS). The aim of the work is to quantitatively measure the chemical composition in the weld seam of various DSS and to identify possible influences of welding parameters on the microstructure of the material. The chemical concentrations of the main alloying elements Cr, Ni, Mn on the surface of the sample during the welding process and the cooling process were measured. Mn and Ni are austenite stabilizers and their content increases during welding by using certain high alloyed filler material. Spectra were recorded every 1.3 s at a spacing of approximately 2 mm. During the cooling process the location of the measurement was not changed. The LIBS method is proofed to be suitable for the quantitative representation of the chemical compositions during the welding process. T2 - ICASP-6 CY - Le Bischenberg, France DA - 20.06.2022 KW - LIBS KW - In situ measurement KW - Duplex stainless steel KW - TIG welding KW - Evaporation PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571308 DO - https://doi.org/10.1088/1757-899X/1274/1/012018 VL - 1274 SP - 1 EP - 8 PB - IOP Publishing CY - Bristol AN - OPUS4-57130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Maack, Stefan A1 - Bertovic, Marija A1 - Radtke, Martin A1 - et al., ED - Wahlster, W. ED - Winterhalter, C. T1 - Deutsche Normungsroadmap künstliche Intelligenz N2 - Rund ein Jahr haben DIN und DKE in einem gemeinsamen Projekt mit dem Bundesministerium für Wirtschaft und Energie und zusammen mit ca. 300 Fachleuten aus Wirtschaft, Wissenschaft, öffentlicher Hand und Zivilgesellschaft an der Normungsroadmap Künstliche Intelligenz gearbeitet. Eine hochrangige Steuerungsgruppe unter dem Vorsitz von Prof. Wolfgang Wahlster hat die Erarbeitung koordiniert und begleitet. Ziel der Roadmap ist die frühzeitige Entwicklung eines Handlungsrahmens für die Normung und Standardisierung, der die internationale Wettbewerbsfähigkeit der deutschen Wirtschaft unterstützt und europäische Wertmaßstäbe auf die internationale Ebene hebt. KW - Künstliche Intelligenz KW - Normung KW - Roadmap PY - 2020 UR - https://www.din.de/resource/blob/772438/ecb20518d982843c3f8b0cd106f13881/normungsroadmap-ki-data.pdf VL - 2020 SP - 1 EP - 232 PB - Deutsches Institut für Normung (DIN) CY - Berlin ET - 1. AN - OPUS4-51733 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira Guilherme Buzanich, Ana T1 - The versatility of X-ray absorption spectroscopy (XAS) for exploring new materials in collaborative research N2 - With increasing demand and environmental concerns, researchers are exploring new materials that can perform as well or better than traditional materials while reducing environmental impact. X-ray absorption spectroscopy (XAS) enables unique atom-specific tool to probe the electronic structure of materials. The BAM plays a central role in this highly collaborative research. The BAMline, a real-life sample materials research beamline, at the Berlin Synchrotron BESSY-II, provides unique insights into materials’ electronic and chemical structure at different time and length scales. This enables real-time optimization of material properties and performance for various applications, such as energy storage and conversion, catalysis, and corrosion resistance. This talk provides an overview of the analytical methods and sample environments of the BAMline and addresses its potential for further advances in sustainable materials research. T2 - International symposium of radiation physics (ISRP-16) CY - Lisbon, Portugal DA - 01.09.2024 KW - XAS KW - Time-resolved studies KW - Operando KW - Corrosion KW - Electrochemistry PY - 2024 AN - OPUS4-60996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Su, C. A1 - Shi, J. A1 - Durlo Tambara, Luís Urbano A1 - Yang, Y. A1 - Liu, B. A1 - Revilla-Cuesta, V. T1 - Improving the mechanical properties and durability of steam-cured concrete by incorporating recycled clay bricks aggregates from C&D waste N2 - The output of C&D waste is increasing year by year, among which low-quality recycled brick aggregates (RBAs) have not been well utilized and brought environmental burden. The durability of steam-cured concrete (HCC) is often compromised due to the detrimental effects of this curing regime on the long-term performance and microstructure development of the concrete material. To address this issue, this study investigates the potential of incorporating RBAs to improve the long-term durability of HCC. The results demonstrate that the incorporation of a small amount of RBA (10–20%) not only enhances the 28-d strength of HCC by 2.5–11.3%, but also improves its impermeability by mitigating heat damage effects. The combined application of fine and coarse RBA was found to effectively balance the negative effects of coarse RBA on the performance of HCC. Furthermore, the utilization of RBA in HCC was shown to have economic and environmental benefits. The results of this study demonstrate a simple and effective approach to improve the long-term durability of HCC while promoting the high-value utilization of solid waste. KW - Steam-cured concrete KW - C&D waste KW - Durability KW - Recycled aggregate KW - Environmental benefits PY - 2024 DO - https://doi.org/10.1016/j.powtec.2024.119571 VL - 438 SP - 1 EP - 14 PB - Elsevier B.V. AN - OPUS4-59799 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Durlo Tambara, Luís Urbano T1 - Early hydration reactions of calcium sulfoaluminate cement in water and alkaline media N2 - This study investigates the early hydration of calcium sulfoaluminate (CSA) cement in water (CSAH) and 2M NaOH (CSA2M), both with a liquid/solid ratio of 0.5. Hydration kinetics were assessed using in situ X-ray diffraction, isothermal conduction calorimetry, ultrasonic pulse velocity (UPV) and mechanical strength measurements. The results indicate that in the CSA2M system, the maximum heat release occurs earlier, and UPV measurements reveal a more rapid increase in mechanical stiffness (Figure 1a). The presence of alkalis accelerates the dissolution of ye’elimite and anhydrite, leading to a shorter induction period and faster precipitation of ettringite (Figure 1b-d). The phase refinement confirmed a higher dissolution rate of anhydrite in the alkaline environment, while the formation of ettringite stabilizes within 10 hours. Initial dissolution (0–40 min) increases ion concentration, followed by accelerated ettringite formation (0.6–2.5 h) with rising heat flow and UPV. A secondary acceleration (2.5–4.3 h) occurs only in CSAH. Deceleration (2.5–10 h) leads to further stabilization, with reactions proceeding at a slower rate. At 25 h, CSAH reached 58.3% ettringite and CSA2M 48.2%. These findings contribute to a deeper understanding of the early hydration mechanisms of CSA cement and the impact of alkalis on phase evolution. T2 - 3rd International Workshop on Calcium Sulfoaluminate Cements CY - Leeds, UK DA - 23.06.2025 KW - Calcium sulfoaluminate cement KW - Ultrasonic pulse velocity KW - Early hydration KW - Alkali KW - In situ XRD PY - 2025 AN - OPUS4-63758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bruna, F. G. A1 - Prokop, M. A1 - Bystron, T. A1 - Loukrakpam, R. A1 - Melke, J. A1 - Lobo, C. M. S. A1 - Fink, M. A1 - Zhu, M. A1 - Voloshina, E. A1 - Kutter, M. A1 - Hoffmann, H. A1 - Yusenko, Kirill A1 - de Oliveira Guilherme Buzanich, Ana A1 - Röder, B. A1 - Bouzek, K. A1 - Paulus, B. A1 - Roth, C. T1 - Following adsorbed intermediates on a platinum gas diffusion electrode in H3PO3‑containing electrolytes using in situ X‑ray absorption spectroscopy N2 - One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalyst with H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate proton conductivity in the temperature range of 120−200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR). The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4 −. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4 −, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt−P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition. KW - H3PO4 life cycle KW - XAS KW - In situ coupling KW - High-temperature fuel cells KW - Δμ XANES KW - H3PO3 PY - 2022 DO - https://doi.org/10.1021/acscatal.2c02630 SN - 2155-5435 VL - 12 IS - 18 SP - 11472 EP - 11484 PB - ACS CY - Washington, DC AN - OPUS4-55815 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grengg, C. A1 - Koraimann, G. A1 - Ukrainczyk, N. A1 - Rudic, O. A1 - Luschnig, S. A1 - Gluth, Gregor A1 - Radtke, Martin A1 - Dietzel, M. A1 - Mittermayr, F. T1 - Cu- and Zn-doped alkali activated mortar – Properties and durability in (bio)chemically aggressive wastewater environments N2 - Metakaolin-based alkali activated mortars (AAM) - with and without CuSO4·5H2O and ZnO addition (mass ratio Mn+/solid binder 0.08% to 1.7%) - were casted and exposed within an extensive long-term field campaign over the period of 20 months to a sewer basin, strongly affected by biogenic acid corrosion. (Un-)exposed AAM were tested regarding their physicochemical and microstructural properties, bioreceptivity and overall durability. Metal addition led to a retarding effect during alkali-activation reaction, as well as to an increase in open porosity of up to 3.0% and corresponding lower compressive strength of up to 10.9%. Reduced microbial colonization and diversity were observed on AAM with Cu, while Zn addition led to increased biodiversity. We propose that the observed higher durability of Cu-doped AAM is due to antibacterial effects and associated reduction of biogenic acid production, superseding overall negative effects of metal-dosage on physical material properties. Observed lower durability of Zn-doped AAM was related to combined negative physicochemical and microbial effects. KW - Microbially induced corrosion KW - Alkali-activated materials KW - Biogenic acid corrosion KW - Biogene Schwefelsäurekorrosion KW - MIC PY - 2021 DO - https://doi.org/10.1016/j.cemconres.2021.106541 SN - 0008-8846 VL - 149 SP - 1 EP - 15 PB - Elsevier CY - Oxford AN - OPUS4-53070 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Durlo Tambara, Luís Urbano A1 - Dehn, F. A1 - Gluth, Gregor T1 - Effect of alkali-activated concrete composition on carbonation rate under accelerated and natural conditions N2 - While alkali-activated binders offer certain advantages over traditional Portland cement binders, particu¬larly in terms of resistance against chemical attacks and potentially environmental footprint, their degradation mechanisms remain incompletely understood at present, specifically carbonation. Thus, this study investigates the impact of natural and accelerated carbonation (1% and 4% CO2) on three different compositions of alkali-activated concretes: 100% calcined clay (C100) binder, 100% ground blast furnace slag (S100) binder, and a 40% calcined clay and 60% blast furnace slag blend (C40S60). C100 concretes exhibit faster carbonation kinetics, with five times greater natural carbonation depths than S100. This difference diminishes under accelerated carbonation, showing a 1.5 times difference for 1% CO2 and complete carbonation for 4% CO2 at 90 days. The results thus confirm that accelerated carbonation testing of low-Ca alkali-activated concretes yields results that are not representative of natural carbonation. The C40S60 sample demonstrates a carbonation profile similar to a CEM I concrete, i.e., a high carbonation resistance. Microstructure analysis indicates the formation of three polymorphs of calcium carbonate for S100 (calcite, vaterite, and aragonite), with a higher CO2 concentration favouring aragonite over vaterite. C100 exhibits no calcium carbonates; instead, sodium carbonates form, including trona for 4% CO2 and natrite for both accelerated tests. C40S60 shows calcium and sodium carbonates, although to a lesser extent, containing predominantly calcite and minor signals of natrite. Suitable compositions, like C40S60, prove as effective during natural or accelerated carbonation tests as conventional Portland cement concrete. T2 - RILEM Spring Convention 2024 CY - Milan, Italy DA - 10.04.2024 KW - Alkali-activated concrete KW - Carbonation KW - Calcined clay KW - Slag KW - Durability PY - 2024 AN - OPUS4-59915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Ballach, F. A1 - Bartscher, M. A1 - Bellon, Carsten A1 - Borges de Oliveira, F. A1 - Braun, M. A1 - Dennerlein, F. A1 - Flessner, M. A1 - Fuchs, P. A1 - Günnewig, O. A1 - Hausotte, T. A1 - Hess, J. A1 - Kasperl, S. A1 - Kirschbaum, K. A1 - Li, K. A1 - Maass, N. A1 - Mayer, T. A1 - Orth, Anthony A1 - Reuter, T. A1 - Suppes, A. A1 - von Schmid, M. A1 - Weiß, D. T1 - Realistische Simulation realer Röntgencomputertomografie-Systeme mit basisqualifizierter Simulationssoftware – CTSimU2 BT - Abschlussbericht N2 - Das Förderprojekt CTSimU2 baute auf den Ergebnissen des Projektes CTSimU auf. Dieses Vorprojekt erarbeitete ein (Basis-)Qualifizierungsframework für Simulationssoftwares zur Anwendung bei der Röntgen-CT für dimensionelle Messungen. Dabei stand die ausreichende physikalische Korrektheit der Durchstrahlungssimulation im Vordergrund. Für die realitätsnahe Simulation einer CT-Anlage in einer Simulationssoftware (Digitales Modell) ist jedoch nicht nur die Korrektheit der Simulationssoftware selbst, sondern auch die Güte der Parametrisierung des realen CT-Systems in der Simulationssoftware entscheidend – dies stellte den Ausgangspunkt dar. Die Parametrisierung eines CT-Systems in einer Simulationssoftware lässt sich in vier Schritte unterteilen: nach der Datenaufnahme am realen CT-System folgt die Auswertung der aufgenommenen Daten für die Generierung allgemeiner Parameterangaben. Als letztes folgte die Übertragung der Parameter in die spezifischen Simulationssoftwares und die Validierung der resultierenden Simulationsparameter. Die Methodik der Datenaufnahme am CT und die Auswertung der Daten wurde in einem Werkzeugkasten allgemein beschrieben. Der dritte Schritt, die Umsetzung der Parameter, war softwarespezifisch und wurde beispielhaft mit den vorhandenen Simulationssoftwares durchgeführt. Die Validierung der Parameter war standardisierbar und konnte durch den entwickelten Test geleistet werden, auf dessen Basis die ausreichend korrekte Simulation einer realen Anlage beurteilt werden konnte. Endresultat des Projektes war ein Richtlinienentwurf (z. B. VDI/VDE 2630) zu diesem Test, der einen informativen Annex zum Stand der Technik bezüglich der Möglichkeiten zur Parameterbestimmung enthält. Mit einer Simulationssoftware, die die Basisqualifizierung aus CTSimU bestanden hat und einen Parameterdatensatz für ein reales CT-System enthält, der den Test aus CTSimU2 bestanden hat, können realistische Simulationen dieses CT-Systems möglich sein. KW - Computertomografie KW - Simulation KW - Dimensionelles Messen PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641719 DO - https://doi.org/10.34657/21602 N1 - Dieses Projekt wurde durch die Förderrichtlinie WIPANO gefördert und durch das Bundesministerium für Wirtschaft und Klimaschutz (2022 -2025) finanziert. Der Projektträger Jülich verwaltet die Projekte der Förderrichtlinie WIPANO. SP - 1 EP - 22 PB - TIB Technische Informationsbibliothek CY - Hannover AN - OPUS4-64171 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winckelmann, Alexander T1 - Investigation of degradation of the aluminum current collector in lithium-ion batteries by glow-discharge optical emission spectroscopy N2 - Lithium-ion batteries (LIBs) are one technology to overcome the challenges of climate and energy crisis. They are widely used in electric vehicles, consumer electronics, or as storage for renewable energy sources. However, despite innovations in batteries' components like cathode and anode materials, separators, and electrolytes, the aging mechanism related to metallic aluminum current collector degradation causes a significant drop in their performance and prevents the durable use of LIBs. Glow-discharge optical emission spectroscopy (GD-OES) is a powerful method for depth-profiling of batteries' electrode materials. This work investigates aging-induced aluminum deposition on commercial lithium cobalt oxide (LCO) batteries' cathodes. The results illustrate the depth-resolved elemental distribution from the cathode surface to the current collector. An accumulation of aluminum is found on the cathode surface by GD-OES, consistent with results from energy-dispersive X-ray spectroscopy (EDX) combined with focused ion beam (FIB) cutting. In comparison to FIB-EDX, GD-OES allows a fast and manageable depth-profiling. Results from different positions on an aged cathode indicate an inhomogeneous aluminum film growth on the surface. The conclusions from these experiments can lead to a better understanding of the degradation of the aluminum current collector, thus leading to higher lifetimes of LIBs. T2 - Adlershofer Forschungsforum 2022 CY - Berlin, Germany DA - 11.11.2022 KW - Lithium Ion Batteries KW - GD-OES KW - FIB KW - SEM KW - EDX PY - 2022 AN - OPUS4-56246 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schilling, Markus A1 - Marschall, Niklas A1 - Niebergall, Ute A1 - Wachtendorf, Volker A1 - Böhning, Martin T1 - Unveiling Effects of Biodiesel and Diesel on Environmental Stress Cracking of PE-HD N2 - The behavior of high‐density polyethylene with respect to resistance against environmental stress cracking (ESC) is usually regarded as an inherent material property being specific for respective types of PE‐HD and tested using standardized methods, conditions, and also standard testing liquids (usually aqueous surfactant solutions). On the other hand, for practical applications the ESC behavior of those polymeric materials, commonly used for pipes or containers, in contact with other liquids (e.g., fuels) is often of relevant interest, but for a reasonable assessment, where consistent benchmark data for a direct comparison are often missing, it is essential to determine the actually prevailing failure mode and classify it related to crack propagation or other mechanisms. Using the well‐established Full Notch Creep Test, which favorably allows for a detailed microscopic fracture surface analysis after failure, the behavior of two typical PE‐HD types for container applications is investigated in biodiesel and diesel and compared to a standard surfactant solution. This enables a clear identification of characteristic features of the interaction of biodiesel and diesel as sorptive fuels in contact with the polymer, revealing the complex interplay of sorption and plasticization as well as ESC inducing effects on PE‐HD, which could be clearly shown for both fuels. KW - Biodiesel KW - Confocal laser scanning microscopy (LSM) KW - Diesel KW - Full notch creep test (FNCT) KW - Plasticization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650525 DO - https://doi.org/10.1002/pen.70239 SN - 0032-3888 SP - 1 EP - 16 PB - Wiley CY - Hoboken (NJ) AN - OPUS4-65052 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF 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 (CVAE) model is employed to generate realistic 2D weld pool and keyhole geometries from the welding parameters. We utilize a β-VAE model with the Evidence Lower Bound (ELBO) 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. T2 - International Congress of Applications of Lasers & Electro-Optics 2025 CY - Orlando, USA DA - 12.10.2025 KW - Laser beam welding KW - Generative artificial intelligence KW - Machine learning KW - numerical simulation PY - 2025 SP - 1 EP - 10 AN - OPUS4-65075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winckelmann, Alexander T1 - Investigation of degradation of the aluminum current collector in lithium-ion batteries by glow-discharge optical emission spectroscopy N2 - Lithium-ion batteries (LIBs) are one technology to overcome the challenges of climate and energy crisis. They are widely used in electric vehicles, consumer electronics, or as storage for renewable energy sources. However, despite innovations in batteries' components like cathode and anode materials, separators, and electrolytes, the aging mechanism related to metallic aluminum current collector degradation causes a significant drop in their performance and prevents the durable use of LIBs.[1] Glow-discharge optical emission spectroscopy (GD-OES) is a powerful method for depth-profiling of batteries' electrode materials. This work investigates aging-induced aluminum deposition on commercial lithium cobalt oxide (LCO) batteries' cathodes. The results illustrate the depth-resolved elemental distribution from the cathode surface to the current collector. An accumulation of aluminum is found on the cathode surface by GD-OES, consistent with results from energy-dispersive X-ray spectroscopy (EDX) combined with focused ion beam (FIB) cutting. In comparison to FIB-EDX, GD-OES allows a fast and manageable depth-profiling. Results from different positions on an aged cathode indicate an inhomogeneous aluminum film growth on the surface. The conclusions from these experiments can lead to a better understanding of the degradation of the aluminum current collector, thus leading to higher lifetimes of LIBs. T2 - European Winter Conference on Plasma Spectrochemistry (EWCPS 2023) CY - Ljubljana, Slovenia DA - 29.01.2023 KW - Lithium-ion batteries KW - Aging mechanisms KW - Depth-profiling PY - 2023 AN - OPUS4-56992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winckelmann, Alexander T1 - Investigation of degradation of the aluminum current collector in lithium-ion batteries by GD-OES N2 - Lithium-ion batteries (LIBs) are one technology to overcome the challenges of climate and energy crisis. They are widely used in electric vehicles, consumer electronics, or as storage for renewable energy sources. However, despite innovations in batteries' components like cathode and anode materials, separators, and electrolytes, the aging mechanism related to metallic aluminum current collector degradation causes a significant drop in their performance and prevents the durable use of LIBs. Glow-discharge optical emission spectroscopy (GD-OES) is a powerful method for depth-profiling of batteries' electrode materials. This work investigates aging-induced aluminum deposition on commercial lithium cobalt oxide (LCO) batteries' cathodes. The results illustrate the depth-resolved elemental distribution from the cathode surface to the current collector. An accumulation of aluminum is found on the cathode surface by GD-OES, consistent with results from energy-dispersive X-ray spectroscopy (EDX) combined with focused ion beam (FIB) cutting. In comparison to FIB-EDX, GD-OES allows a fast and manageable depth-profiling. Results from different positions on an aged cathode indicate an inhomogeneous aluminum film growth on the surface. The conclusions from these experiments can lead to a better understanding of the degradation of the aluminum current collector, thus leading to higher lifetimes of LIBs. T2 - Empa Group Meeting CY - Dübendorf, Switzerland DA - 22.11.2022 KW - Lithium Ion Batteries KW - GD-OES KW - FIB KW - SEM KW - EDX PY - 2022 AN - OPUS4-56584 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Huo, Wenjie A1 - Schmies, Lennart A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael A1 - Wolter, Katinka T1 - An illumination based backdoor attack against crack detection systems in laser beam welding N2 - Deep neural networks (DNNs) have been wildly used in engineering and have achieved state-of-the-art performance in prediction and measurement tasks. A solidification crack is a serious fault during laser beam welding and it has been proven to be successfully detected using DNNs. Recently, research on the security of DNNs is receiving increasing attention because it is necessary to explore the reliability of DNNs to avoid potential security risks. The backdoor attack is a serious threat, where attackers aim to inject an inconspicuous pattern referred to as trigger into a small portion of training data, resulting in incorrect predictions in the reference phase whenever the input contains the trigger. In this work, we first generate experimental data containing actual cracks in the welding laboratory for training a crack detection model. Then, targeting this scenario, we design a new type of backdoor attack to induce the model to predict the crack as a normal state. Considering the stealthiness of the attack, a common phenomenon during the welding process, illumination, is used as the backdoor trigger. Experimental results demonstrate that the proposed method can successfully attack the crack detection system and achieve over 90% attack success rate on the test set. T2 - 8th ML4CPS 2025 – Machine Learning for Cyber-Physical Systems CY - Berlin, Germany DA - 06.03,2025 KW - System security KW - Welding crack detection KW - Backdoor attack KW - Deep neural networks PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651357 DO - https://doi.org/10.24405/20021 VL - 2025 SP - 12 EP - 21 PB - Universitätsbibliothek der HSU/UniBw H CY - Hamburg AN - OPUS4-65135 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nikoonasab, Ali A1 - Licht, M. A1 - Weiler, L. A1 - Achenbach, R. A1 - Raupach, M. A1 - Gluth, Gregor T1 - Pore Solution composition of GGBFS-containing cement pastes N2 - Ground Granulated Blast-Furnace Slag (GGBFS), a by-product of the iron-making process, has gained significant attention as a supplementary cementitious material and has become increasingly popular in recent years due to its remarkable properties. GGBFS can significantly reduce the environmental impact of cement production when it comes to building concrete structures. GGBFS can either be blended with ordinary Portland cement (OPC) (up to a 90% replacement), or it can be used in the production of alkali-activated materials (AAMs). However, a comprehensive understanding of the pore solution composition is necessary for understanding various aspects of cementitious materials and their durability, including corrosion behavior, passivation of steel, and resistance to deteriorative processes. In the present work, the pore solutions of seven different GGBFS-containing cements (alkali-activated slag, alkali-activated slag/fly ash blends, a hybrid alkaline cement, CEM III/C, and CEM III/B) were extracted and analysed by inductively coupled plasma-optical emission spectroscopy, ion chromatography, pH, redox potential, and conductivity measurements. For comparison, a Portland cement pore solution was analysed similarly. The Concentrations of reduced sulfur were noteworthy in all GGBFS-containing cements, particularly in alkali-activated cements, where concentrations were notably higher compared to standard cements. The redox potentials of the pore solutions were primarily dictated by the concentrations of reduced sulfur, although other factors may contribute. Additionally, sulfur species in the pore solutions had an impact on pH, electrical conductivity, and other properties pertinent to the corrosion of reinforcements. T2 - RILEM Spring Convention 2024 & Conference on Advanced Construction Materials and Processes for a Carbon Neutral Society CY - Milan, Italy DA - 10.04.2024 KW - GGBFS KW - AAM KW - Sulfide KW - Pore solution composition KW - Redox potential PY - 2024 AN - OPUS4-59960 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Soni, Akshar T1 - Simulation of functional ageing towards failure prediction of dental restorations - Investigating the Crown-Cement-Tooth Complex (CCTC) N2 - Dental crown restorations are the most common type of indirect restoration in Germany, with over 5 million crowns placed annually. Clinical complications such as debonding and crown fractures cannot yet be adequately correlated with cement ageing processes. The SimuCrown project systematically investigates the ageing mechanisms of the crown–cement–tooth complex (CCTC) while also validating the in vitro methodology itself. This interdisciplinary cooperation combines experimental ageing simulation (Charité), computer-aided finite element method based simulation (TU Berlin), and high-resolution structural analysis using synchrotron-based X-ray refraction radiography (SXRR) on BAMline at BESSY II (BAM). T2 - 17th BESSY@HZB User Meeting CY - Berlin, Germany DA - 03.12.2025 KW - X-ray refraction KW - Synchrotron radiation KW - Dental Materials KW - Crown-cement-tooth complex (CCTC) KW - Crack evolution PY - 2025 AN - OPUS4-65166 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröpfer, Dirk T1 - Wear resistance of modified Ni based claddings in relation to the resulting machinability via ultrasonic-assisted milling N2 - In the field of plastics processing, extruder screws are subjected to significant wear stresses. The extruder screw is the main wear component in those production machines and is usually coated with intermetallic wear protection alloys composed of Ni-based alloys, specifically Colmonoy C56 PTA (NiMoCrSi). There is a growing demand for providing an economic machinability of these alloys to achieve defined contours with a sufficient surface integrity. Recent investigations exhibit promising results applying ultrasonic milling for such hard-to-cut materials. The Colmonoy C56 is modified by various alloying additions Ti, Nb, Mo, Hf, and Al, and then cladded on a steel S355 via Plasma Transferred Arc process. The effect of alloying additions on the microstructure is analyzed regarding their resistance to abrasive and adhesive wear. With Miller test ASTM G75 the influence of alloying elements on resistance to abrasive wear for two abrasive materials is investigated (high-grade corundum F220 and quartz powder). The wear loss is not increased for additions of Nb and Ti compared to the base material C56. Modifications with Hf or Al reduces the resistance to abrasive wear and significantly increases material loss. The extruder screw is also subject to adhesive wear, which can be quantified by means of the pin-roll test. It is demonstrated that the addition of Hf, for example, contributes to a reduction in wear loss. Aim of the investigations is to find suitable modifications for the wear claddings of C56 for a sufficient machineability, without compemising the wear resistant. The machinability is considerably affected by the alloy additions, and is determined using ultrasonic-assisted milling. The addition of hafnium reduces machinability, i.e. significantly increases cutting forces. The incorporation of Nb exhibits a significant reduction of cutting forces, and results in reduced tool wear and an enhanced of surface integrity (roughness, density of defects, residual stresses). T2 - Wear of Materials 2025 CY - Sitges, Spain DA - 13.04.2025 KW - Abrasive wear KW - Adhesive wear KW - Colmonoy C56 KW - PTA welding KW - Service life and efficiency KW - Substitution of critical raw materials KW - Surface integrity KW - Ultrasonic-assisted milling process PY - 2025 AN - OPUS4-65189 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sonntag, Nadja T1 - Dwell-Fatigue and Cyclic Softening of Grade P92 Steel under LCF and TMF Conditions N2 - Tempered martensite-ferritic steels, such as the grade P92 steel studied in this contribution, exhibit pronounced macroscopic cyclic softening under isothermal low-cycle fatigue (LCF) and non-isothermal thermomechanical fatigue (TMF) conditions, which is considered to be the predominant degradation mechanism in high-temperature fatigue in this and other material groups. However, such softening processes are highly complex since microscopic (e.g., recovery) and macroscopic (e.g., crack initiation and growth), as well as global and local effects superimpose, especially under creep-fatigue conditions. In this contribution, we discuss the cyclic deformation and softening behavior of P92 in strain-controlled LCF, in-phase (IP) TMF, and out-of-phase (OP) TMF tests with and without dwell times in the temperature range from 300 °C to 620°C. EBSD-based dislocation analysis on various fatigued material states confirms the continuous redistribution and annihilation of geometrically necessary dislocations in all studied states, which can be quantitatively correlated with macroscopic softening despite different damage mechanisms for different test types. Deviations from this correlation are observed for OP TMF and LCF with dwell times, i.e., for conditions where optical microscopy reveals pronounced crack-oxidation interactions at the specimen surfaces. T2 - LCF9 - Ninth International Conference on Low Cycle Fatigue CY - Berlin, Germany DA - 21.06.2022 KW - LCF KW - TMF KW - EBSD PY - 2022 DO - https://doi.org/10.48447/LCF9-2022-111 AN - OPUS4-55128 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drexler, A.-K. A1 - Konert, Florian A1 - Nietzke, Jonathan A1 - Hodžić, E. A1 - Pastore, S. A1 - Domitner, J. A1 - Rhode, Michael A1 - Sommitsch, C. A1 - Böllinghaus, Thomas T1 - Effect of Tensile Loading and Temperature on the Hydrogen Solubility of Steels at High Gas Pressure N2 - The hydrogen solubility in ferritic and martensitic steels is affected by hydrostatic stress, pressure, and temperature. In general, compressive stresses decrease but tensile stresses increase the hydrogen solubility. This important aspect must be considered when qualifying materials for high‐pressure hydrogen applications (e.g., for pipelines or tanks) by using autoclave systems. In this work, a pressure equivalent for compensating the effect of compressive stresses on the hydrogen solubility inside of closed autoclaves is proposed to achieve solubilities that are equivalent to those in pipelines and tanks subjected to tensile stresses. Moreover, it is shown that the temperature effect becomes critical at low temperatures (e.g., under cryogenic conditions for storing liquid hydrogen). Trapping of hydrogen in the microstructure can increase the hydrogen solubility with decreasing temperature, having a solubility minimum at about room temperature. To demonstrate this effect, the generalized law of the hydrogen solubility is parameterized for different steels using measured contents of gaseous hydrogen. The constant parameter sets are verified and critically discussed with respect to the high‐pressure hydrogen experiments. KW - Hydrogen KW - Solubility KW - Temperature KW - Tensile loading KW - Analytical calculation PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-586701 DO - https://doi.org/10.1002/srin.202300493 SN - 1611-3683 SP - 1 EP - 9 PB - Wiley AN - OPUS4-58670 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Fedelich, Bernard ED - Cailletaud, G. ED - Cormier, J. ED - Eggeler, G. ED - Maurel, V. ED - Nazé, L. T1 - Crystal orientation and elastic properties N2 - The elastic constants are the most basic mechanical properties of a material and are needed for any structural analysis of a component. For example, they have a major influence on the eigenfrequencies of vibrating parts. Single crystals of Ni-base superalloys are strongly anisotropic, which means that the observed properties are orientation dependent. Tensor algebra is then required to mathematically formulate the elastic properties and their relations to the crystal orientation. Hence, this chapter first summarizes some basic definitions and calculation rules for Rotation matrices, including the definition of the Euler angles, which are most commonly used to define the relative orientations of the crystal and the component. Parts of this chapter closely follow the lines of the excellent exposition of the topic by Olschewski. KW - Nickel-base superalloys KW - Elasticity PY - 2022 SN - 978-0-12-819357-0 SP - 41 EP - 67 PB - Elsevier Inc. AN - OPUS4-53435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epishin, A. A1 - Camin, B. A1 - Hansen, L. A1 - Heuser, M. A1 - Lopez-Galilea, I. A1 - Ruttert, B. A1 - Theisen, W. A1 - Fedelich, Bernard T1 - Refinement and Experimental Validation of a Vacancy Model of Pore Annihilation in Single-Crystal Nickel-Base Superalloys during Hot Isostatic Pressing N2 - Initially, as-cast and homogenized single crystals of nickel-base superalloy CMSX-4 are subjected to hot isostatic pressing at 1288 °C. Two series of experiments are conducted: under the same pressure of 103 MPa but with different durations, between 0.5 and 6 h, and under different pressures, between 15 and 150 MPa, but for the same time of 0.5 h. The porosity annihilation is investigated metallographically and by high-resolution synchrotron X-ray tomography. The obtained experimental results are compared with the predictions of the vacancy model proposed recently in the group. Herein, the model is further refined by coupling with X-ray tomography. The model describes the evolution of the pore arrays enclosed in the 3D synchrotron tomograms during hot isostatic pressing and properly predicts the time and stress dependences of the pore annihilation kinetics. The validated model and the obtained experimental results are used for selecting the optimal technological parameters such as applied pressure and processing time KW - Superalloys KW - HIP KW - Single-Crystal KW - Diffusion PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-526859 DO - https://doi.org/10.1002/adem.202100211 VL - 23 IS - 7 SP - 211 AN - OPUS4-52685 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drexler, A A1 - Konert, Florian A1 - Sobol, Oded A1 - Rhode, Michael A1 - Domitner, J A1 - Sommitsch, C A1 - Böllinghaus, Thomas T1 - Enhanced gaseous hydrogen solubility in ferritic and martensitic steels at low temperatures N2 - Metals that are exposed to high pressure hydrogen gas may undergo detrimental failure by embrittlement. Understanding the mechanisms and driving forces of hydrogen absorption on the surface of metals is crucial for avoiding hydrogen embrittlement. In this study, the effect of stress-enhanced gaseous hydrogen uptake in bulk metals is investigated in detail. For that purpose, a generalized form of Sievert's law is derived from thermodynamic potentials considering the effect of microstructural trapping sites and multiaxial stresses. This new equation is parametrized and verified using experimental data for carbon steels, which were charged under gaseous hydrogen atmosphere at pressures up to 1000 bar. The role of microstructural trapping sites on the parameter identification is critically discussed. KW - Hydrogen KW - Thermodynamic modelling KW - Pressure-dependent solubility KW - Steel KW - Trapping PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559307 DO - https://doi.org/10.1016/j.ijhydene.2022.09.109 SN - 0360-3199 VL - 47 IS - 93 SP - 39639 EP - 39653 PB - Elsevier Ltd. AN - OPUS4-55930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ahmadian, A. A1 - Scheiber, D. A1 - Zhou, X. A1 - Gault, B. A1 - Darvishi Kamachali, Reza A1 - Romaner, L. A1 - Ecker, W. A1 - Dehm, G. A1 - Liebscher, C. H. T1 - Interstitial segregation has the potential to mitigate liquid metal embrittlement in iron N2 - The embrittlement of metallic alloys by liquid metals leads to catastrophic material failure and severely impacts their structural integrity. The weakening of grain boundaries by the ingress of liquid metal and preceding segregation in the solid are thought to promote early fracture. However, the potential of balancing between the segregation of cohesion-enhancing interstitial solutes and embrittling elements inducing grain boundary decohesion is not understood. Here, we unveil the mechanisms of how boron segregation mitigates the detrimental effects of the prime embrittler, zinc, in a Σ5 [0 0 1] tilt grain boundary in α −Fe (4 at.% Al). Zinc forms nanoscale segregation patterns inducing structurally and compositionally complex grain boundary states. Ab-initio simulations reveal that boron hinders zinc segregation and compensates for the zinc induced loss in grain boundary cohesion. Our work sheds new light on how interstitial solutes intimately modify grain boundaries, thereby opening pathways to use them as dopants for preventing disastrous material failure. KW - Materials Modelling KW - Liquid Metal Embrittlement KW - Alloy Safety KW - CALPHAD KW - Microstructure Design PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-573576 DO - https://doi.org/10.1002/adma.202211796 SN - 0935-9648 IS - e2211796 PB - Wiley online library AN - OPUS4-57357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gesell, Stephan T1 - Numerical calculation of ΔCTOD for thermomechanical fatigue crack growth N2 - The cyclic crack tip opening displacement ΔCTOD is a promising loading Parameter to quantify the crack propagation under thermomechanical fatigue (TMF). In this work, suitable techniques are investigated and compared for an accurate calculation of ΔCTOD under TMF loading using a viscoplastic temperature dependent material model. It turned out that collapsed special crack tip elements give the best results. An efficient FEM-technique is developed to simulate the incremental crack growth by successive remeshing, whereby the deformations and internal state variables are mapped from the old mesh onto the new one. The developed techniques are demonstrated and discussed for two-dimensional examples like TMF-specimens. Recommendations are made regarding important numerical control parameters like optimal size of crack tip elements, length of crack growth increment in relation to plastic zone size and ΔCTOD value. T2 - ESIS Technical Meeting on Numerical Methods (TC8) CY - Online meeting DA - 06.04.2021 KW - Crack tip opening displacement KW - Thermomechanical fatigue KW - Crack growth PY - 2021 AN - OPUS4-52410 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ganesh, Rahul A1 - Gesell, Stephan A1 - Kuna, M. A1 - Fedelich, Bernard A1 - Kiefer, B. T1 - Numerical calculation of ΔCTOD for thermomechanical fatigue crack growth N2 - The cyclic crack tip opening displacement ΔCTOD is a promising loading Parameter to quantify the crack propagation under thermomechanical fatigue (TMF). In this work, suitable techniques are investigated and compared for an accurate calculation of ΔCTOD under TMF loading using a viscoplastic temperature dependent material model. It turned out that collapsed special crack tip elements give the best results. An efficient FEM-technique is developed to simulate the incremental crack growth by successive remeshing, whereby the deformations and internal state variables are mapped from the old mesh onto the new one. The developed techniques are demonstrated and discussed for two-dimensional examples like TMF-specimens. Recommendations are made regarding important numerical control parameters like optimal size of crack tip elements, length of crack growth increment in relation to plastic zone size and ΔCTOD value. N2 - Zur Bewertung des Rissfortschritts unter thermomechanischer Ermüdung (TMF) ist die zyklische Rissöffnungsverschiebung ΔCTOD ein aussichtsreicher bruchmechanischer Beanspruchungsparameter. In dieser Arbeit werden unter Anwendung eines viskoplastischen, temperaturabhängigen Materialmodells geeignete FEM-Techniken für die akkurate Berechnung des ΔCTOD bei TMF erprobt und verglichen. Als beste Technik hat sich die Verwendung kollabierter Rissspitzenelemente erwiesen. Es wurde ein effizienter FEM-Algorithmus zur Simulation der Rissausbreitung mit inkrementeller Neuvernetzung entwickelt, bei dem die Verformungen und inelastischen Zustandsvariablen jeweils vom alten auf das neue Netz übertragen werden. Die erarbeiteten Techniken werden am Beispiel von zweidimensionalen Strukturen und TMF-Proben vorgestellt und diskutiert. Dabei werden wesentliche Kontrollparameter der Simulation wie optimale Grösse der Rissspitzenelemente, Länge des Rissinkrementes in Relation zur plastischen Zone und dem ΔCTOD-Wert empfohlen. T2 - 53. Tagung des Arbeitskreises "Bruchmechanik und Bauteilsicherheit" CY - Online meeting DA - 18.02.2021 KW - Crack tip opening displacement KW - Thermomechanical fatigue KW - Crack growth PY - 2021 SP - 1 EP - 10 PB - DVM (Deutscher Verband für Materialforschung und -prüfung) CY - Berlin AN - OPUS4-52519 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ganesh, R. A1 - Gesell, Stephan A1 - Fedelich, Bernard A1 - Kuna, Meinhard A1 - Kiefer, B. T1 - Procrackplast: Eine Software zur Simulation des 3D-Risswachstums unter großen plastischen Deformationen T1 - Procrackplast: A software for simulating 3D crack growth under large plastic deformation N2 - The finite element software ProCrackPlast is developed for the automated simulation of fatigue crack growth in arbitrarily loaded three-dimensional components with large scale plastic deformations, in particular under cyclic thermomechanical (TMF) loading. ProCrackPlast is developed by extending the software Procrack, created at TU Freiberg for linear-elastic crack growth simulations. The pre-processing, FEM analysis, and the post-processing in ProCrackPlast are done by the commercial software ABAQUS. ProCrackPlast resorts to a crack growth procedure which adaptively updates the crack in finite increments based on the fracture-mechanical parameter, cyclic crack tip opening displacement ΔCTOD . Features of this software along with two application examples of fatigue crack growth in a typical cast steel, Ni-Resist, are presented in this paper to show its capability and performance. N2 - Es wird die Finite-Element-Software ProCrackPlast vorgestellt, die eine automatische Simulation der Ermüdungsrissausbreitung in beliebig belasteten dreidimensionalen Bauteilen mit größeren plastisch verformten Bereichen ermöglicht, insbesondere bei thermomechanischer Wechselbelastung (TMF). ProCrackPlast entstand durch Erweiterung des Programs ProCrack, das an der TU Freiberg für linear-elastische inkrementelle Rissfortschrittsanalysen entwickelt wurde. Das Pre-Processing, die FEM Analyse und das Post-Processing werden mit Hilfe der kommerziellen FE-Software ABAQUS durchgeführt. ProCrackPlast beruht auf einem Algorithmus, mit dem der Rissfortschritt adaptiv in endlichen Inkrementen unter Verwendung des bruchmechanischen Parameters der zyklischen Rissöffnungsverschiebung ΔCTOD gesteuert wird. Die Funktionseigenschaften dieser Software werden anhand von zwei Anwendungsbeispielen zum Ermüdungsrisswachstum für einen typischen Stahlguss, Ni-Resist, exemplarisch dargestellt, um die Möglichkeiten und Leistungsfähigkeit von ProCrackPlast zu demonstrieren. T2 - 54. Tagung des Arbeitskreises "Bruchmechanik und Bauteilsicherheit" CY - Online meeting DA - 22.02.2021 KW - Automated finite element analysis KW - Automatische Finite Element Simulation KW - Thermomechanical fatigue KW - Crack growth KW - Thermomechanische Ermüdung KW - Rissausbreitung PY - 2022 SP - 205 EP - 214 PB - Deutscher Verband für Materialforschung und -prüfung e.V. AN - OPUS4-54435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ruffini, A. A1 - Le Bouar, Y. A1 - Finel, A. A1 - Epishin, A. I. A1 - Fedelich, Bernard A1 - Feldmann, Titus A1 - Viguier, B. A1 - Poquillon, D. T1 - Dislocations interacting with a pore in an elastically anisotropic single crystal nickel-base superalloy during hot isostatic pressing N2 - The formation of pores in CMSX-4 nickel based superalloys is detrimental to the service life of the material. A way to avoid the problem is to treat the superalloys under Hot Isostatic Pressing (HIP), which enables a large volume fraction of pores to be annihilated. This paper aims to understand the contribution of plastic activity related to the gliding of dislocations on the pore annihilation. Simulations based on a phase-field model of dislocation are performed and make it possible to consider the strong anisotropy of the CMSX-4 under HIP conditions in conjunction to the strong elastic heterogeneity introduced by the pore. For pores with a radius of few micrometers, it is shown that edge parts of dislocation lines that present an extra half atomic plane oriented towards the pore are stacked above and under it in the direction which is perpendicular to their slip-planes, causing an increase of the number of dislocation along the four octahedral directions of the FCC single crystal which intersect the pore center. Results are streamlined within the isotropic elastic theory of dislocations. Effects of elastic anisotropy and dislocation reactions are also investigated in order to specify what would be the dislocation configuration around a pore in CMSX-4 under HIP conditions. Notably, the elastic anisotropy is shown to significantly modify the arrangement of dislocations close to the pore equator. Simulations also allow for the characterization of pore/dislocation interactions when dislocations are involved in Low Angle Boundaries as experimentally observed. KW - HIP KW - Superalloys KW - Dislocation KW - Pore KW - Phase-field PY - 2022 DO - https://doi.org/10.1016/j.commatsci.2021.111118 SN - 0927-0256 VL - 204 SP - 1 EP - 14 PB - Elsevier CY - Amsterdam AN - OPUS4-54220 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bachmann, Marcel A1 - Putra, Stephen Nugraha A1 - Yang, Fan A1 - Meng, Xiangmeng A1 - Pusbatzkies, Pablo A1 - Rethmeier, Michael T1 - Elucidation of the laser beam energy attenuation by the vapor plume formation during high-power laser beam welding N2 - In high-power laser beam welding, a common phenomenon is the formation of a keyhole caused by the rapid evaporation of the material. Under atmospheric pressure, this evaporation generates a vapor plume that interacts with the laser beam, leading to energy attenuation and scattering of the laser radiation along its path. These interactions affect the stability of the process and the overall weld quality. This study investigates the influence of the vapor plume on the weld pool and keyhole dynamics during high-power laser beam welding of AlMg3 aluminum alloy through experimental and numerical approaches. The primary goal is to identify key vapor plume characteristics, particularly its length fluctuations, and to improve the accuracy of the numerical models. To achieve this, an algorithm was developed for the automated measurement of the vapor plume length using high-speed imaging and advanced data processing techniques. The measured plume length is then used to estimate additional vapor heating and laser energy attenuation using the Beer–Lambert law. A refined numerical CFD model, incorporating 3D transient heat transfer, fluid flow, and ray tracing, was developed to evaluate the vapor plume’s impact. Results show that already the time-averaged plume length effectively captures its transient influence and aligns well with experimental weld seam geometries. Additionally, energy scattering and absorption caused by the vapor plume led to a wider weld pool at the top surface. The study also shows an increased percentage of keyhole collapses due to the reduced laser power absorption at the keyhole bottom, further highlighting the importance of accurately modeling vapor plume effects. T2 - International Congress of Applications of Lasers & Electro-Optics 2025 CY - Orlando, USA DA - 12.10.2025 KW - Laser beam welding KW - Vapor plume formation KW - Weld pool KW - Keyhole dynamics KW - Numerical modeling PY - 2026 DO - https://doi.org/10.2351/7.0001863 SN - 1938-1387 IS - 38 SP - 012001-1 EP - 012001-9 PB - Laser Institute of America AN - OPUS4-64949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kromm, Arne T1 - Werkstoffsichere Dickblechschweißung und KI N2 - Der Vortrag zeigt, welche Herausforderungen beim Schweißen sogenannter Dickblechverbindungen bestehen und welche Strategien zur Lösung genutzt werden können. Ansätze zur Fehlerprävention werden vorgestellt. Es wird dargestellt, wie KI-basierte Methoden die Fehlererkennung erleichtern. Letztlich werden Potentiale zur effizienten Fehlerbeseitigung aufgezeigt und der Anwendernutzen herausgestellt. T2 - Mitgliederversammlung der Forschungsvereinigung Stahlanwendung e. V. CY - Essen, Germany DA - 17.12.2025 KW - UP-Schweißen KW - Eigenspannungen KW - Künstliche Intelligenz KW - Reparatur PY - 2025 AN - OPUS4-65210 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Chaurasia, Prashant Kumar A1 - Fabry, Çağtay A1 - Pittner, Andreas A1 - Rethmeier, Michael T1 - Tandem-GMAW: advanced pulsed and short cicuiting process mode experimental data N2 - This dataset consists of raw recordings for 5 Tandem gas metal arc welding experiments (Tandem-GMAW / T-GMAW). KW - T-GMAW KW - High power welding KW - Deposition efficiency KW - Life Cycle Assessment PY - 2025 DO - https://doi.org/10.5281/zenodo.17951724 PB - Zenodo CY - Geneva AN - OPUS4-65206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröpfer, Dirk T1 - Comparative residual stress analysis on a DED-Arc manufactured high-strength steel component using the contour method and XRD N2 - Lightweight construction is a vital approach for reducing CO₂ emissions. It contributes to the development of more energy-efficient structures and supports the overall goal of achieving carbon neutrality in the transition to sustainable manufacturing. Thus, a topology-optimized design often leads to complex geometries. Additive manufacturing (AM) processes such as direct energy deposition with arc (DED-Arc) offers a great design freedom due to the build-up of components in layers. Furthermore, they enable efficient production due to the high deposition rate, process reliability and good automation capability. Further efficiency can be achieved through weight optimization, enabled by high-strength steels. However, a major challenge is the process induced residual stresses (RS) in the component. High tensile residual stresses are detrimental as they increase the risk of cold cracking. Knowledge of residual stress distribution is crucial for predicting service life of the component and structural integrity assessment, especially for safety critical applications. Therefore, this study focuses on the use of Contour method (CM) to analyse the full field longitudinal residual stresses in an open hollow cuboid component (dimensions: 120 x 50 x 30 mm3) manufactured by DED-Arc (yield strength > 730 MPa). In the contour method, the component is cut along a desired plane of interest and the contour of deformed cut surface is measured. A finite element model is used to reconstruct the residual stresses field in the 2-dimensional plane of cut. In this paper a modified cutting strategy was employed, post cutting the deformed cut surfaces were measured utilizing two surface measurement techniques i.e., coordinate measuring machine (CMM) and a 3D Scanner. The accuracy of the contour method was validated against surface stresses measured using X-ray diffraction. Additionally, a comparison of neutron diffraction experiments was conducted. The residual stresses were further correlated with hardness measurements. The results from surface measurement techniques showed good agreement regarding the measured displacement contours and the contour method results revealed peak stresses in the DED-Arc walls, bending deformation in substrate induces tensile stresses at the bottom of the substrate plate and compressive stresses in the middle top region. The residual stresses obtained from diffraction and contour method showed a good agreement and correlated qualitatively with the hardness measurements. T2 - 78th IIW Annual Assembly and International Conference on Welding and Joining CY - Genoa, Italy DA - 22.06.2025 KW - Residual stress KW - Contour method KW - DED-Arc/M KW - High-strength steel KW - Filler metals KW - XRD KW - Neutron diffraction PY - 2025 AN - OPUS4-65215 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröpfer, Dirk T1 - Residual stress evaluation using the contour method of an additive manufactured high-strength steel solid cuboid N2 - Direct Energy Deposition with Arc (DED-Arc) enables the weight-optimized and near-net-shape manufacturing of complex structures. Lightweight construction principles allow a reduction of CO2 emissions by saving time, costs, and resources. Further optimisations can be achieved by using high-strength steel. This allows for a reduction in wall thickness and optimisation of weight. However, manufacturing intricate geometries using high-strength steels poses challenges in managing residual stresses (RS), which are essential for ensuring the structural integrity of welded components. High residual stresses can increase the risk of cold cracking, arising from the complex interactions between material properties, process conditions, and component design. Despite the availability of suitable filler metals, the lack of comprehensive knowledge and guidelines on residual stress formation limits the industrial application. Therefore, in the present study, the contour method (CM) was used to analyse the full field longitudinal residual stresses in an solid cuboid component (dimensions: 120 × 50 × 35 mm³) manufactured by DED-Arc. The CM enables the analysis of the two-dimensional map of residual stresses normal to a cutting plane using a finite element model. For this purpose, a solid cuboid component was welded fully automatically with a high-strength solid wire specially adapted for DED-Arc (yield strength > 790 MPa) onto conventionally manufactured substrates made of S690QL. The residual stresses from CM in the volume are compared with residual stress analyses using X-Ray diffraction on the surface. Additionally, comparative data from previous studies on hollow cuboid structures was included in order to identify similarities and differences in the resulting stress state, and to complement and validate the CM results. These results demonstrate the significant influence of the geometry on the residual stress profiles within the solid cuboid in relation to the open hollow. T2 - 4th International Conference on Advanced Joining Processes 2026 CY - Coimbra, Portugal DA - 16.10.2025 KW - Residual stress KW - Contour method KW - DED-Arc/M KW - High-strength steel KW - Filler metals KW - Neutron diffraction PY - 2025 AN - OPUS4-65209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nikoonasab, Ali T1 - Electrochemical study of steel reinforcement in the synthetic pore solution of alkali-activated binders: Pore solution composition N2 - It is well known that cement manufacture, including CaCO3 calcination and clinker formation, is associated with substantial energy consumption and significant greenhouse gas emissions. Alkali-activated binders (AAB) and concretes made from them can significantly contribute to reducing CO2 emissions caused by the construction industry. However, to what extent and for how long concretes made from AAB can protect the steel in reinforced concrete components from corrosion is still unclear. Unlike PC-based binders, AABs are made by reacting alkaline solutions with solid precursors such as fly ash and ground granulated blast furnace slag (GGBFS). Therefore, steel reinforcement corrosion mechanisms in AAMs differ from PC-based binders. The present study aims to evaluate the corrosion behavior of steel rebar in alkali-activated materials (AAMs) synthetic pore solution with different chemical concentrations representing different GGBFS and Flay Ash based binders by performing electrochemical tests to measure the corrosion rate and corrosion potential of steel rebar. This information can be used to improve the design of AAMs in order to ensure a longer service life for these materials. T2 - Eurocorr2023 CY - Brussels, Belgium DA - 27.08.2023 KW - GGBFS KW - AAM KW - Sulfide KW - Pore solution composition KW - Redox potential KW - Corrosion PY - 2023 AN - OPUS4-59090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Graebner, Maraike A1 - Giese, Marcel A1 - Lorenz, Svenja A1 - Treutler, Kai A1 - Schröpfer, Dirk A1 - Wesling, Volker A1 - Kannengießer, Thomas T1 - Wear resistance of modified NiMoCrSi claddings in relation to the resulting surface machinability via ultrasonic-assisted milling N2 - In the field of plastics processing, extruder screws are subjected to significant wear stresses. The extruder screw is the main wear component in those production machines and is usually coated with intermetallic wear protection alloys composed of Ni-based alloys, specifically Colmonoy C56 PTA (NiMoCrSi). There is a growing demand for providing an economic machinability of these alloys to achieve defined contours with a sufficient surface integrity. Recent investigations exhibit promising results applying ultrasonic milling for such hard-to-cut materials. The Colmonoy C56 is modified by various alloying additions Ti, Nb, Mo, Hf, and Al, and then cladded on a steel S355 via Plasma Transferred Arc process. The effect of alloying additions on the microstructure is analyzed regarding their resistance to abrasive and adhesive wear. With Miller test ASTM G75 the influence of alloying elements on resistance to abrasive wear for two abrasive materials is investigated (high-grade corundum F220 and quartz powder). The wear loss is not increased for additions of Nb and Ti compared to the base material C56. Modifications with Hf or Al reduces the resistance to abrasive wear and significantly increases material loss. The extruder screw is also subject to adhesive wear, which can be quantified by means of the pin-roll test. It is demonstrated that the addition of Hf, for example, contributes to a reduction in wear loss. Aim of the investigations is to find suitable modifications for the wear claddings of C56 for a sufficient machineability, without compemising the wear resistant. The machinability is considerably affected by the alloy additions, and is determined using ultrasonic-assisted milling. The addition of hafnium reduces machinability, i.e. significantly increases cutting forces. The incorporation of Nb exhibits a significant reduction of cutting forces, and results in reduced tool wear and an enhanced of surface integrity (roughness, density of defects, residual stresses). KW - Colmonoy C56 KW - PTA welding KW - Adhesive wear KW - Abrasive wear KW - Ultrasonic-assisted milling process KW - Surface integrity KW - Service life and efficiency KW - Substitution of critical raw materials PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651530 DO - https://doi.org/10.1016/j.wear.2025.205830 SN - 0043-1648 VL - 571 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-65153 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - An, Biwen Annie A1 - Deland, Eric A1 - Sobol, Oded A1 - Yao, Jizheng A1 - Skovhus, T. L. A1 - Koerdt, Andrea T1 - The differences in the corrosion product compositions of Methanogen-induced microbiologically influenced corrosion (Mi-MIC) between static and dynamic growth conditions N2 - Currently, corrosion rates (CR) and/or corrosion products (CP) obtained for methanogen-induced microbiologically influenced corrosion (Mi-MIC) on carbon steel are mainly analyzed from static-incubations. By using a multiport-flow-column, much higher CRs (0.72 mm/yr) were observed, indicating static-incubations are not suitable for determining the corrosive potential of Mi-MIC. With the combination of various analytical methods (ToF-SIMS/SEM-EDS/SEM-FIB) and contrary to previously published data, we observed that CPs contained phosphorus, oxygen, magnesium, calcium and iron but lacked carbon-related species (e.g. siderite). Overall, siderite nucleation is disrupted by methanogens, as they convert aqueous bicarbonate into carbon dioxide for methanogenesis resulting in increased localized corrosion. KW - Carbon steel KW - Modelling studies KW - SIMS KW - SEM KW - Reactor conditions KW - Microbiologically influenced corrosion PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517632 DO - https://doi.org/10.1016/j.corsci.2020.109179 SN - 0010-938X VL - 180 SP - 9179 PB - Elsevier AN - OPUS4-51763 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Falk, Florian A1 - Sobol, Oded A1 - Stephan-Scherb, Christiane T1 - The impact of the microstructure of Fe-16Cr-0.2C on high-temperature oxidation – sulphidation in SO2 N2 - This study elucidates the impact of the microstructure of Fe-16Cr-0.2C on oxide layer formation at 650 ◦C in Ar-0.5 % SO2. A cold-rolled and two heat-treated states of the alloy were exposed for up to 1000 h. The samples were characterised in detail from microstructural and chemical perspectives using scanning electron microscopy (SEM), X-ray diffraction (XRD) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The microstructural modification of the alloy by heat-treatment was advantageous. It was found that Cr-carbides support chromia formation and reduce sulphidation when their area fraction is low and diameter is small. KW - Steel KW - Iron KW - SIMS KW - SEM KW - High temperature corrosion KW - Oxidation KW - Sulphidation PY - 2021 DO - https://doi.org/10.1016/j.corsci.2021.109618 VL - 190 SP - 109618 PB - Elsevier Ltd. AN - OPUS4-53001 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Darvishi Kamachali, Reza T1 - Melting upon Coalescence of Solid Nanoparticles N2 - The large surface-to-volume ratio of nanoparticles is understood to be the source of many interesting phenomena. The melting temperature of nanoparticles is shown to dramatically reduce compared to bulk material. Yet, at temperatures below this reduced melting point, a liquid-like atomic arrangement on the surface of nanoparticles is still anticipated to influence its properties. To understand such surface effects, here, we study the coalescence of Au nanoparticles of various sizes using molecular dynamics simulations. Analysis of the potential energy and Lindemann index distribution across the nanoparticles reveals that high-energy, high-mobility surface atoms can enable the coalescence of nanoparticles at temperatures much lower than their corresponding melting point. The smaller the nanoparticles, the larger the difference between their melting and coalescence temperatures. For small enough particles and/or elevated enough temperatures, we found that the coalescence leads to a melting transition of the two nominally solid nanoparticles, here discussed in relation to the heat released due to the surface reduction upon the coalescence and the size dependence of latent heat. Such discontinuous melting transitions can lead to abrupt changes in the properties of nanoparticles, important for their applications at intermediate temperatures. KW - Nanoparticles KW - Molecular Dynamics KW - Surface-induced Melting PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552183 DO - https://doi.org/10.3390/solids3020025 VL - 3 IS - 2 SP - 361 EP - 373 PB - MDPI AN - OPUS4-55218 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhou, X. A1 - Wei, Y. A1 - Kühbach, M. A1 - Zhao, H. A1 - Vogel, F. A1 - Darvishi Kamachali, Reza A1 - Thompson, G. B. A1 - Raabe, D. A1 - Gault, B. T1 - Revealing in-plane grain boundary composition features through machine learning from atom probe tomography data N2 - Grain boundaries (GBs) are planar lattice defects that govern the properties of many types of polycrystalline materials. Hence, their structures have been investigated in great detail. However, much less is known about their chemical features, owing to the experimental difficulties to probe these features at the atomic length scale inside bulk material specimens. Atom probe tomography (APT) is a tool capable of accomplishing this task, with an ability to quantify chemical characteristics at near-atomic scale. Using APT data sets, we present here a machine-learning-based approach for the automated quantification of chemical features of GBs. We trained a convolutional neural network (CNN) using twenty thousand synthesized images of grain interiors, GBs, or triple junctions. Such a trained CNN automatically detects the locations of GBs from APT data. Those GBs are then subjected to compositional mapping and analysis, including revealing their in-plane chemical decoration patterns. We applied this approach to experimentally obtained APT data sets pertaining to three case studies, namely, Ni-P, Pt-Au, and Al-Zn-Mg-Cu alloys. In the first case, we extracted GB specific segregation features as a function of misorientation and coincidence site lattice character. Secondly, we revealed interfacial excesses and in-plane chemical features that could not have been found by standard compositional analyses. Lastly, we tracked the temporal evolution of chemical decoration from early-stage solute GB segregation in the dilute limit to interfacial phase separation, characterized by the evolution of complex composition patterns. This machine-learning-based approach provides quantitative, unbiased, and automated access to GB chemical analyses, serving as an enabling tool for new discoveries related to interface thermodynamics, kinetics, and the associated chemistry-structure-property relations. KW - Machine learning KW - Digitalization KW - Alloy microstructure PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543049 DO - https://doi.org/10.1016/j.actamat.2022.117633 SN - 1359-6454 VL - 226 SP - 1 EP - 15 PB - Elsevier CY - Amsterdam AN - OPUS4-54304 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Darvishi Kamachali, Reza T1 - On the origin of embrittlement in Mn containing and Zn-coated steels N2 - Grain boundary embrittlement in medium-Mn steels and liquid metal embrittlement (LME) in Zn-coated high strength steels are among key challenges on the way of safe application of sustainable steels for automotive industry. Using a novel density-based model for grain boundaries, we reveal that the affinity of a grain boundary to attract Mn and Zn atoms result in a segregation transition accompanied by interfacial structural changes. In case of the Zn, the simulations show that the amount of segregation abruptly increases with decreasing temperature, while the Zn content in the alloy, required for triggering the segregation transition, decreases. The results are discussed in the context of CALPHAD-integrated density-based grain boundary phase diagrams. T2 - DPG 2024 CY - Berlin, Germany DA - 17.03.2024 KW - Phase-Field Simulation KW - CALPHAD KW - Steels KW - Density-based Thermodynamics PY - 2024 AN - OPUS4-60743 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Röhsler, Andreas A1 - Sobol, Oded A1 - Hänninen, H. A1 - Böllinghaus, Thomas T1 - In-situ ToF-SIMS analyses of deuterium re-distribution in austenitic steel AISI 304L under mechanical load N2 - Hydrocarbons fuel our economy. Furthermore, intermediate goods and consumer products are often hydrocarbon-based. Beside all the progress they made possible, hydrogen-containing substances can have severe detrimental effects on materials exposed to them. Hydrogen-assisted failure of iron alloys has been recognised more than a century ago. The present study aims to providing further insight into the degradation of the austenitic stainless steel AISI 304L (EN 1.4307) exposed to hydrogen. To this end, samples were electrochemically charged with the hydrogen isotope deuterium (2H, D) and analysed by scanning electron microscopy (SEM), electron back-scatter diffraction (EBSD) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). It was found that deuterium caused a phase transformation from the original γ austenite into ε- and α’-martensite. Despite their low solubility for hydrogen, viz. deuterium, the newly formed phases showed high deuterium concentration which was attributed to the increased density of traps. Information about the behaviour of deuterium in the material subjected to external mechanical load was gathered. A four-point-bending device was developed for this purpose. This allowed to analyse in-situ pre-charged samples in the ToF-SIMS during the application of external mechanical load. The results indicate a movement of deuterium towards the regions of highest stress. KW - ToF-SIMS KW - Hydrogen KW - Deuterium KW - AISI 304L KW - EBSD PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505142 DO - https://doi.org/10.1038/s41598-020-60370-2 VL - 10 IS - 1 SP - 3611 PB - Nature AN - OPUS4-50514 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schaupp, Thomas A1 - Rhode, Michael A1 - Yahyaoui, Hamza A1 - Kannengießer, Thomas ED - Lippold, J. ED - Böllinghaus, Thomas ED - Norrish, J. ED - Scotti, A. T1 - Hydrogen-assisted cracking in GMA welding of high-strength structural steels using the modified spray arc process N2 - High-strength structural steels are used in machine, steel, and crane construction with yield strength up to 960 MPa. However, welding of these steels requires profound knowledge of three factors in terms of avoidance of hydrogen-assisted cracking (HAC): the interaction of microstructure, local stress/strain, and local hydrogen concentration. In addition to the three main factors, the used arc process is also important for the performance of the welded joint. In the past, the conventional transitional arc process (Conv. A) was mainly used for welding of high-strength steel grades. In the past decade, the so-called modified spray arc process (Mod. SA) has been increasingly used for welding production. This modified process enables reduced seam opening angles with increased deposition rates compared with the Conv. A. Economic benefits of using this arc type are a reduction of necessary weld beads and required filler material. In the present study, the susceptibility to HAC in the heat-affected zone (HAZ) of the high-strength structural steel S960QL was investigated with the externally loaded implant test. For that purpose, both Conv. A and Mod. SA were used with same heat input at different deposition rates. Both conducted test series showed same embrittlement index “EI” of 0.21 at diffusible hydrogen concentrations of 1.3 to 1.6 ml/100 g of arc weld metal. The fracture occurred in the HAZ or in the weld metal (WM). However, the test series withMod. SA showed a significant extension of the time to failure of several hours compared with tests carried out with Conv. A. KW - High-strength steel KW - GMA welding KW - Diffusible hydrogen KW - Implant test KW - Fractography PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515330 DO - https://doi.org/10.1007/s40194-020-00978-0 SN - 1878-6669 SN - 0043-2288 VL - 64 IS - 12 SP - 1997 EP - 2009 PB - Springer CY - Berlin Heidelberg AN - OPUS4-51533 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Böllinghaus, Thomas A1 - Cross, Carl T1 - Obituary: Prof. Dr.-Ing. Hans Hoffmeister N2 - On November 3, 2023, our dear colleague, Prof. Dr.-Ing. Hans Hoffmeister, born in 1932 in Kassel, Germany, passed away in Ahrensburg, near Hamburg, Germany. KW - Metals and Alloys KW - Mechanical Engineering KW - Mechanics of Materials PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594160 DO - https://doi.org/10.1007/s40194-023-01675-4 SP - 1 EP - 2 PB - Springer Science and Business Media LLC AN - OPUS4-59416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feldmann, Titus A1 - Fedelich, Bernard A1 - Epishin, A. T1 - Simulation of Hot Isostatic Pressing in a Single-Crystal Ni Base Superalloy with the Theory of Continuously Distributed Dislocations Combined with Vacancy Diffusion N2 - Single-crystal components made of nickel base superalloys contain pores after casting and homogenization heat treatment. Hot isostatic pressing (HIP), which is carried above the γ' -solvus temperature of the alloy, is industrially applied to reduce porosity. A modeling of HIP based on continuously distributed dislocations is developed in a 2D setting. Glide and climb of straight-edge dislocations, as well as vacancy diffusion, are the deformation mechanisms taken into account. Thereby, dislocation glide is controlled by dragging a cloud of large atoms, and climb is controlled by vacancy diffusion. Relying on previous investigations of the creep behavior at HIP temperatures, it is assumed that new dislocations are nucleated at low-angle boundaries (LAB) and move through subgrains until they either reach the opposite LABs or react with other dislocations and annihilate. Vacancies are created at the pore surface and diffuse through the alloy until they are either consumed by climbing dislocations or disappear at the LABs. The field equations are solved by finite elements. It is shown that pore shrinking is mostly controlled by vacancy diffusion as the shear stresses at the LABs are too low to nucleate a sufficient amount of dislocations. KW - Nickel-base superalloys KW - HIP KW - Dislocation KW - Creep KW - Model PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542309 DO - https://doi.org/10.1002/adem.202101341 VL - 2022 PB - Wiley AN - OPUS4-54230 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holzwarth, M. A1 - Baer, Wolfram A1 - Mayer, U. A1 - Weihe, S. T1 - Untersuchung des Master Curve-Konzepts für ferritisches Gusseisen mit Kugelgraphit N2 - Das Master Curve (MC) Konzept nach ASTM E1921 wird momentan u.a. in der Kerntechnik für die bruchmechanische Sicherheitsbewertung ferritischer Stähle eingesetzt. Für ferritisches Gusseisen mit Kugelgraphit (GJS) fehlt jedoch eine Validierung dieser Methode und ggf. eine systematische Überprüfung möglicher Modifikationen grundlegender Ansätze des MC-Konzepts. Aus diesem Grund soll in einem kürzlich gestarteten BMUV-Verbundprojekt zwischen der MPA Stuttgart und der BAM Berlin die Anwendbarkeit des MC-Konzepts auf GJS bei dynamischer Beanspruchung untersucht werden. Ziel ist es, eine effektive und effiziente Methodik bereitzustellen, mit der mittels einer vergleichsweise kleinen Stichprobe bruchmechanischer Kleinproben eine Referenztemperatur T0 zur werkstoffspezifischen Temperaturjustierung der MC ermittelt werden kann. T2 - 55. Jahrestagung des DVM-Arbeitskreises "Bruchmechanik und Bauteilsicherheit" CY - Darmstadt, Germany DA - 14.02.2023 KW - Dynamische Beanspruchung KW - Bruchmechanik KW - Master Curve-Konzept KW - Gusseisen mit Kugelgraphit PY - 2023 DO - https://doi.org/10.48447/Br-2023-BB SP - 101 EP - 108 PB - DVM Berlin CY - Berlin AN - OPUS4-57024 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holzwarth, M. A1 - Baer, Wolfram T1 - Untersuchung des Master Curve-Konzeptes für ferritisches Gusseisen mit Kugelgraphit N2 - Das Master Curve (MC) Konzept nach ASTM E1921 wird momentan u.a. in der Kerntechnik für die bruchmechanische Sicherheitsbewertung ferritischer Stähle eingesetzt. Für ferritisches Gusseisen mit Kugelgraphit (GJS) fehlt jedoch eine Validierung dieser Methode und ggf. eine systematische Überprüfung möglicher Modifikationen grundlegender Ansätze des MC-Konzepts. Aus diesem Grund soll in einem kürzlich gestarteten BMUV-Verbundprojekt zwischen der MPA Stuttgart und der BAM Berlin die Anwendbarkeit des MC-Konzepts auf GJS bei dynamischer Beanspruchung untersucht werden. Ziel ist es, eine effektive und effiziente Methodik bereitzustellen, mit der mittels einer vergleichsweise kleinen Stichprobe bruchmechanischer Kleinproben eine Referenztemperatur T0 zur werkstoffspezifischen Temperaturjustierung der MC ermittelt werden kann. T2 - 55. Jahrestagung des DVM-Arbeitskreises Bruchmechanik und Bauteilsicherheit CY - Darmstadt, Germany DA - 14.02.2023 KW - Bruchmechanik KW - Master Curve-Konzept KW - Dynamische Beanspruchung KW - Gusseisen mit Kugelgraphit PY - 2023 AN - OPUS4-57025 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Madia, Mauro A1 - Baer, Wolfram A1 - Wagener, Rainer A1 - Kiyak, Yusuf T1 - Betriebsfestigkeit und Bruchverhalten von bainitischen Schmiedestählen N2 - Die neue Generation von bainitischen Schmiedestählen bietet auf der einen Seite ein erhebliches Festigkeitspotenzial, das es im Sinne des Leichtbaus auch für zyklisch belastete Sicherheitsbauteile zu heben gilt. Auf der anderen Seite geht mit dieser Festigkeitssteigerung im Vergleich zu Vergütungsstählen ein Verlust an Duktilität und Zähigkeit einher. Am Beispiel des Demonstratorbauteils Achsschenkel ging das Forschungsvorhaben der Frage nach, wie ein Freigabeprozess zu gestalten ist, damit das Festigkeitspotenzial der neuen Stähle zuverlässig ausgenutzt werden kann. Als Ergebnis wird eine Vorgehensweise dargestellt, die den Eigenschaften der neuen Generation von Schmiedestählen Rechnung trägt, um den sicheren Betrieb der Komponenten zu gewährleisten. KW - Bainitischer Schmiedestahl KW - Bruchmechanik KW - Sicherheit KW - Betriebsfestigkeit KW - Bauteilauslegung PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594296 SN - 2366-5106 SP - 50 EP - 54 PB - Industrieverband Massivumformung e. V CY - Hagen AN - OPUS4-59429 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wallin, Kim A1 - Baer, Wolfram T1 - Evaluation of Charpy-V transition curve fitting based on distribution-free statistical assessment N2 - A non-parametric, distribution-free, statistical assessment of 5 large Charpy transition curve data sets is used for the optimum fitting equations for smaller data sets. The assessment makes use of a combination of rank probability and binomial probability analysis of the data. The original non-parametric assessment method is improved by combining upper and lower bound binomial estimates, thus removing a bias that exists in the original method. The non-parametric assessment is not suitable as a standard method because it requires too many data points to give a reliable result. It is, however, ideal as a research tool to examine transition curve shape and scatter. Based on the assessment several recommendations for transition curve fitting can be made. KW - Mechanical Engineering KW - Mechanics of Materials KW - General Materials Science KW - Charpy Impact Test KW - Charpy Transition Curve PY - 2023 DO - https://doi.org/10.1016/j.ijpvp.2023.105079 SN - 0308-0161 VL - 206 SP - 1 EP - 13 PB - Elsevier B.V. AN - OPUS4-58635 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baer, Wolfram T1 - Chunky Graphite - Recognition, Quantification, and Impact on Properties of Spheroidal Graphite Cast Iron N2 - Since there is a continuously growing demand for complex, frequently heavy-sectioned spheroidal graphite cast iron (SGI) castings it is worth paying attention to the chunky graphite (CHG) degeneration which may occur under certain technological circumstances. Although a reference line for preventive actions in terms of general metallurgical and process measures could be drawn to avoid CHG in heavy-sectioned ferritic SGI castings, a broad majority of experts claim the avoidance of CHG in heavy sections cannot yet be rated a hundred percent process safe. A major reason may be seen in the fact that a universal, generally accepted explanation of CHG formation and growth has not yet been established, although several theories have been proposed. Nevertheless, metallurgical aspects are not in the focus of this paper. This paper is about the current state of methods to detect CHG in SGI on the laboratory and component scales. Capabilities and limits of different metallographic, fractographic and non-destructive computer tomographic methods to recognize and quantify CHG are discussed. With respect to the characteristic fili-gree three-dimensional string-like, multi-branched CHG structure, which is non-isometric and non-dispersed, serious implications on the possibility to quantitatively characterize the amount of CHG must be considered. In contrary to the metallurgical aspects, the knowledge about the impact of CHG on the materials and com-ponents properties is still surprisingly limited. Therefore, special emphasis of this paper is on the impact of CHG degeneration on the properties of ferritic SGI. Experimental results are reviewed to illustrate the effect of CHG on mechanical strength and ductility properties as well as fracture mechanics properties in terms of crack resistance and fracture toughness. The present situation is characterized by discussions and uncertainty about the acceptance or rejection of SGI components containing CHG. Addressing this, conclusions from the materials engineering point of view are drawn for quality control, a safe operational strategy in the foundry and component safety. T2 - InCeight Casting 2023 CY - Darmstadt, Germany DA - 06.03.2023 KW - Chunky graphite KW - Structure KW - Recognition KW - Quantification KW - Tensile properties KW - Fracture toughness KW - Ferritic spheroidal KW - Graphite cast iron PY - 2023 AN - OPUS4-57121 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baer, Wolfram T1 - Detection and understanding of the chunky graphite degeneration in ferritic spheroidal graphite cast iron materials with respect to fatigue N2 - CHG is very different compared to other graphite degenerations or defects; Filigree, multi-branched string-like, 3d interconnected structure; Morphology and volumetric amount of CHG cannot be accessed by stereological interpretation of 2d section data; Field-tested, technically established method to quantify CHG in components not available; Fatigue: CHG causes substantial reduction in fatigue limit and significant increase in crack growth rate; Therefore: Avoid or exclude CHG! T2 - 4th International Symposium on Fatigue Design and Material Defects CY - Online meeting DA - 26.05.2020 KW - Ductile cast iron KW - Chunky graphite degeneration KW - Fatigue KW - Correlation microstructure to properties PY - 2020 AN - OPUS4-54409 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baer, Wolfram A1 - Breidung, Marc A1 - Kiyak, Yusuf A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Küppers, M. T1 - Aspekte der analytischen bruchmechanischen Bauteilbewertung N2 - Am Beispiel eines abgesetzten zylindrischen Bauteils (Achsschenkel) werden Probleme der analytischen bruchmechanischen Bauteilbewertung diskutiert. Als Basis-philosophie wird ein Fail Safe-Kriterium (kontrolliertes Versagen) angesetzt. Die Forderung ist, dass sich der Achsschenkel, bevor er bricht, in einem Ausmaß plastisch verformen kann, bei dem der Fahrer bemerkt, dass mit seinem Fahrzeug etwas nicht in Ordnung ist. Um das zu gewährleisten, muss der Werkstoff einen bestimmten Riss-widerstand aufweisen. Dazu werden im hier vorgestellten ersten Teil des Projektes mittels FEM Rissspitzenbeanspruchungen in Abhängigkeit von der Auslenkung des Zylinders und angenommener Rissgrößen ermittelt. Diese finden als Zielgrößen in der weiteren Analyse Anwendung. Da eine einfach umzusetzende Lösung angestrebt wird, werden zusätzlich analytische Rechnungen an Ersatzgeometrien (halbunendliche Platte und Vollzylinder), aber mit den realen Spannungen am Bauteil durchgeführt. Es zeigt sich, dass die Ergebnisse wegen des Steifigkeitsunterschieds zwischen Bauteil und Ersatzgeometrie unvertretbar konservativ sind. Alternativ wird ein hybrides Konzept vorgestellt, für das die Modellparameter mittels FEM bestimmt werden. Es liefert sehr genaue Ergebnisse. Im Rahmen der analytischen Rechenvorschrift können die Lösungen auf andere Werkstoffe übertragen werden, ohne dass zusätzliche FEM-Analysen notwendig sind. T2 - 54. Tagung des DVM-Arbeitskreises Bruchmechanik und Bauteilsicherheit CY - Online meeting DA - 22.02.2022 KW - FEM KW - Bauteilbewertung KW - Fail-safe KW - Analytisches Modell PY - 2022 DO - https://doi.org/10.48447/Br-2022-BB VL - 254 SP - 1 EP - 11 PB - DVM CY - Berlin AN - OPUS4-54406 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baer, Wolfram A1 - Holzwarth, M. A1 - Mayer, U. T1 - Investigation of the Master Curve Concept for ferritic Ductile Cast Iron N2 - Based on state-of-the-art research and regulations, the application of the fracture mechanics master curve (MC) concept to ferritic ductile cast iron (DCI) is being investigated in a recently started German joint research project between BAM Berlin and MPA Stuttgart. This paper outlines the research approach and the planned investigations and provides first results. According to the IAEA guidelines SSG 26, the safety assessment of DCI containers for transport as well as interim and final storage of radioactive materials is based on the fracture mechanics criterion of general crack initiation exclusion. Within this context, the focus of the current research project is on the further development of brittle fracture safety assessment methods under dynamic loading conditions. Within fracture mechanics safety assessments for steels in nuclear technology, the probabilistic MC concept according to ASTM E1921 is currently used for quasi-static loading conditions as a supplement to the established deterministic ASME reference curve concept. The MC concept allows for an effective statistical consideration of the scatter of the material toughness in the transition regime. Furthermore, the MC can also be used for elevated loading rates as they occur in accident or crash scenarios. However, for DCI, a systematic review of potential modifications to the MC assumptions and procedure according to ASTM E1921 and an associated validation are still lacking. Therefore, a corresponding methodology shall be established to determine and assess dynamic fracture toughness values of DCI in the ductile-to-brittle transition regime, using samples extracted from a component. For the experimental program, a DCI material was produced as it is generally used for transport and storage containers. A basic mechanical-technological material characterization consisting of tensile, Charpy, and Pellini tests is planned. A comprehensive fracture mechanics test program was compiled covering dynamic testing of DC(T)9, C(T)25, C(T)50, SE(B)10, SE(B)25, and SE(B)140 specimens. Moreover, numerical analyses of different specimen geometries and test setups are planned to investigate the influences of stress triaxiality and loading rate. Throughout the experimental program, the microstructure-property relationship will be investigated based on quantitative metallographic and fractographic analyses. Finally, different MC assessment strategies will be considered, and modifications will be made if necessary. T2 - PATRAM22 Conference CY - Juans-les-Pins, France DA - 11.06.2023 KW - Master Curve KW - Ductile cast iron KW - Dynamic fracture toughness PY - 2023 SP - 1 EP - 9 PB - World Nuclear Transport Institute AN - OPUS4-57765 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baer, Wolfram ED - Bleicher, C. ED - Kaufmann, H. ED - Pittel, C. T1 - Chunky Graphite - Recognition, Quantification, and Impact on Properties of Spheroidal Graphite Cast Iron N2 - Since there is a continuously growing demand for complex, frequently heavy-sectioned spheroidal graphite cast iron (SGI) castings it is worth paying attention to the chunky graphite (CHG) degeneration which may occur under certain technological circumstances. Although a reference line for preventive actions in terms of general metallurgical and process measures could be drawn to avoid CHG in heavy-sectioned ferritic SGI castings, a broad majority of experts claim the avoidance of CHG in heavy sections cannot yet be rated a hundred percent process safe. A major reason may be seen in the fact that a universal, generally accepted explanation of CHG formation and growth has not yet been established, although several theories have been proposed. Nevertheless, metallurgical aspects are not in the focus of this paper. This paper is about the current state of methods to detect CHG in SGI on the laboratory and component scales. Capabilities and limits of different metallographic, fractographic and non-destructive computer tomographic methods to recognize and quantify CHG are discussed. With respect to the characteristic fili-gree three-dimensional string-like, multi-branched CHG structure, which is non-isometric and non-dispersed, serious implications on the possibility to quantitatively characterize the amount of CHG must be considered. In contrary to the metallurgical aspects, the knowledge about the impact of CHG on the materials and com-ponents properties is still surprisingly limited. Therefore, special emphasis of this paper is on the impact of CHG degeneration on the properties of ferritic SGI. Experimental results are reviewed to illustrate the effect of CHG on mechanical strength and ductility properties as well as fracture mechanics properties in terms of crack resistance and fracture toughness. The present situation is characterized by discussions and uncertainty about the acceptance or rejection of SGI components containing CHG. Addressing this, conclusions from the materials engineering point of view are drawn for quality control, a safe operational strategy in the foundry and component safety. T2 - InCeight Casting Conference 2023 CY - Darmstadt, Germany DA - 06.03.2023 KW - Fracture toughness KW - Chunky graphite KW - Structure KW - Recognition KW - Quantification KW - Ferritic spheroidal graphite cast iron KW - Tensile properties PY - 2023 SN - 978-3-8396-1892-9 SP - 1 EP - 11 PB - Fraunhofer Verlag AN - OPUS4-57120 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rua-Ibarz, Ana A1 - Nakadi, Flávio V. A1 - Bolea-Fernandez, Eduardo A1 - Bazo, Antonio A1 - Battistella, Beatrice A1 - Matiushkina, Anna A1 - Resch-Genger, Ute A1 - Abad Andrade, Carlos Enrique A1 - Resano, Martín T1 - Discrete entity analysis via microwave-induced nitrogen plasma–mass spectrometry in single-event mode N2 - In this work, single-event microwave-induced nitrogen plasma–mass spectrometry (single-event MINP-MS) was evaluated for the first time for the analysis of discrete entities such as nanoparticles, biological cells, and microplastics. Nitrogen (N2) effectively overcomes Ar-based polyatomic interferences, enabling (ultra)trace element determination of Fe and Se using their most abundant isotopes, 56Fe (91.66%) and 80Se (49.82%). Iron oxide nanoparticles (Fe2O3 NPs) ranging from 20 to 70 nm were accurately characterized, with excellent agreement with established sizing techniques, such as transmission electron microscopy (TEM) and dynamic light scattering (DLS). A limit of detection (LoD) of 8.6 ag for Fe─equivalent to an LoDsize of 19 nm for Fe2O3─was achieved, which is significantly lower than recent values reported for high-end quadrupole-based ICP-MS. Selenium nanoparticles (SeNPs) of 150 and 250 nm were also accurately characterized, without the N2-based plasma experiencing issues handling relatively large metallic NPs (linearity, R2 = 0.9994). Se-enriched yeast cells (SELM-1 certified reference material) were successfully analyzed via single-cell MINP-MS using external calibration based on SeNPs and a transport efficiency-independent approach. In addition, 2–3 μm polystyrene (PS) and polytetrafluoroethylene (PTFE) were accurately sized by monitoring 12C+, confirming the method’s suitability for handling micrometer-sized polymeric materials (microplastics). The average duration of individual events (680 ± 160 μs) suggests that the digestion of individual entities in N2-based plasmas is comparable to that in Ar-based plasmas. These results open new avenues for this instrumentation as an alternative to ICP ionization sources, also in the context of discrete entity analysis. KW - Microwave-Induced Nitrogen Plasma KW - Discrete entity analysis KW - Particle/droplet event counting KW - Comparison to SP-ICP-MS methodologies KW - Nitrogen plasma vs. argon ICP trade-offs KW - Trace elemental quantification at the single-entity level KW - Time-resolved mass spectrometry for discrete entities PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643825 DO - https://doi.org/10.1021/acs.analchem.5c04341 SN - 0003-2700 SP - 1 EP - 8 PB - American Chemical Society (ACS) AN - OPUS4-64382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deland, Eric T1 - Environmental conditions affect the corrosion product composition of Methanogen induced microbiologically influenced corrosion (Mi-MIC) N2 - Corrosion is a very expensive and serious problem in the different industry sectors, eg. Petroleum-, On- and off-shore, infrastructure. It is estimated that 20% of all corrosion damage is caused by microorganisms or microbiologically influenced corrosion (MIC). Several microorganisms are known to cause corrosion, including sulfate-reducing bacteria, nitrate-reducing bacteria, methanogens etc. For several years, methanogens were regarded as a mild corroder (~0.065 mm/yr), largely due to a lack of detailed investigation on the corrosion mechanism under real-environment simulated conditions. Resulting in the common belief that siderite, a non-conductive compound, is the sole corrosion product (CP) of methanogen-induced MIC (Mi-MIC). To simulate natural environmental conditions, we developed and introduced the multiport flow column system (MFC), a multi-sectional corrosion flow-cell. Using the MFC, we obtained ten times higher corrosion rates than previously reported. With a combination of several analytical techniques, such as ToF-SIMS, SEM-EDS and FIB-SEM, we found strong indication that siderite is not the sole corrosion product of Mi-MIC. The corrosion layers contained phosphorus, oxygen, magnesium, calcium and iron. The differences in the CP between static and dynamic environments demonstrated the impact of testing procedures on the corrosive potential of methanogens. To further verify and deepen our understanding of Mi-MIC, we are currently studying the influence of additional environmental parameters (e.g. pH, salinity, flow rate) on Mi-MIC. Overall, results of this study will expand the current understanding of MIC from both analytical and mechanistic points of view, thus aiding the development of different mitigation strategies for various industry sectors. T2 - ISMOS-8 CY - Online meeting DA - 08.06.2021 KW - Methanogen-induced microbiologically influenced corrosion KW - Carbon steel KW - ToF-SIMS KW - Modelling studies PY - 2021 AN - OPUS4-54041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deland, Eric T1 - Environmental conditions impact the corrosion layer composition of Methanogen induced microbiologically influenced corrosion (Mi-MIC) N2 - Microbiologically influenced corrosion (MIC) is a now well-known challenge and affects industry, society and infrastructure. For a long time, the impact of methanogen-induced MIC (Mi-MIC) was underestimated. This was mainly due to the rather low published corrosion rates and the presumed corrosion product siderite, which is not electrically conductive. In our laboratory, we were able to show that this trivialization or underestimation of Mi-MIC was due to the nature of the testing. The static systems used so far do not provide environmentally relevant information about the corrosion rate and the corrosion product, especially for methanogens To further illustrate the importance of the environment on the MIC process, we established a multiport flow column (MFC), to simulate the natural environment. With this method, and in contrast to published results using the static conditions, we obtained ten times higher corrosion rates. We analyzed the corrosion products with a combination of techniques, like ToF-SIMS, SEM-EDS and FIB-SEM, and found strong evidence that siderite is not the sole corrosion product of Mi-MIC. The corrosion layers contain phosphorus, oxygen, magnesium, calcium and iron and lacked on carbon-related species. It is hypothesized that methanogens may have influenced the nucleation process of siderite, converting bicarbonate into carbon dioxide for methanogenesis. This results in increased localized corrosion and reduced siderite formation. To verify and deepen our understanding of Mi-MIC, we are currently studying the influence of additional environmental parameters (e.g. pH, salinity, flow rate etc.) on Mi-MIC and the subsequent impacts on corrosion rates and the corrosion products. Overall, results of this study will expand the current understanding of MIC from both analytical and mechanistic points of view, thus aiding the development of different mitigation strategies for various industry sectors. T2 - Eurocorr 2021 CY - Online meeting DA - 20.09.2021 KW - Methanogen-induced microbiologically influenced corrosion KW - Carbon steel KW - SEM-EDS KW - Modelling studies PY - 2021 AN - OPUS4-54043 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - The impact and potential of halophilic microorganisms on alternative fuels N2 - As more industrial interests focusing on using salt caverns and repurposed gas or petroleum reservoirs for alternative fuel storage, i.e. CO2/H2, the question raises whether microorganisms may impact the infrastructure, gas purity and storage condition over time. Environments with high salinity (> 1.5 Meq of NaCl) are resided by halophiles (salt-loving microorganisms). To compensate for the intensive osmotic stress, they have resorted to two main adaptation strategies: 1) production of compatible solutes and 2) accumulation of intracellular KCl. Microbial community analysis of several high salinity environments revealed a number of recurring genera, including Halomonas and Halanaerobium. However, the impact of halophiles on the overall integrity and stability of the storage facilities remain largely unknown. To evaluate the suitability and stability of saline storage facilities, several model halophilic microorganisms, such as members of Halomonas, will be selected as testing subjects. First, the impact of halophiles on the infrastructure will be determined using an integrative approach by combining a number of techniques, including electrochemistry, TOF-SIMS, SEM/FIB/EDS and FIB-TEM. Second, the abilities of halophiles to alter the fuel composition (i.e. increase/decrease the fractions of H2) will be monitored using gas chromatography by growing them under high pressure. As a result of climate change and the accompanying mandatory shift to renewable energy resources, microorganisms will continue to play an important role in the energy sector, both to their benefit and detriment. Thus, it is important to achieve a certain level of understanding regarding the activities and mechanisms of halophiles prior to large-scaled excursions. T2 - ISMOS-8 CY - Online meeting DA - 07.06.2021 KW - Microbiologically influenced corrosion KW - Hydrogen KW - Gas storage KW - Contamination PY - 2021 AN - OPUS4-52891 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deland, Eric A1 - Kleinbub, Sherin T1 - Is Methanogen-induced microbiologically influenced corrosion (Mi-MIC) underestimated? N2 - The role of methanogens in microbiologically influenced corrosion (Mi-MIC) is often neglected, due to 1) low reported corrosion rates and 2) the suspected corrosion product siderite, which is electrically non-conductive. Typically, MIC corrosion studies are carried out using batch cultures, which did not represent the dynamic conditions, i.e. pipeline and provide insufficient information on the overall corrosion potential. We established a unique approach, a multiport flow column (MFC), to simulate pipeline conditions and obtained 10-times higher corrosion rates than previously published. Our result showed that testing procedures have a large impact on the corrosive potential of methanogens. We found strong indications with a combination of ToF-SIMS, SEM-EDS and FIB-SEM analyses that siderite is not the sole corrosion product. The corrosion layers contain phosphorus, oxygen, magnesium, calcium and iron. To verify and deepen our understanding of Mi-MIC, we are currently studying the influence of other environmental parameters (e.g. pH) on Mi-MIC. T2 - VAAM 2021 CY - Online meeting DA - 18.03.2021 KW - Methanogen-induced microbiologically influenced corrosion KW - Carbon steel KW - MIC Island PY - 2021 AN - OPUS4-54042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bevilacqua, Tommaso A1 - Gumenyuk, Andrey A1 - Habibi, Niloufar A1 - Hartwig, Philipp A1 - Klawonn, Axel A1 - Lanser, Martin A1 - Rethmeier, Michael A1 - Scheunemann, Lisa A1 - Schröeder, Jöerg T1 - Large-scale thermo-mechanical simulation of laser beam welding using high-performance computing: A qualitative reproduction of experimental results N2 - Laser beam welding (LBW) is a non-contact joining technique that has gained significant importance in modern industrial manufacturing. One potential problem, however, is the formation of solidification cracks, which particularly affects alloys with a pronounced melting range. The aim of the present work is the development of computational methods and software tools to numerically simulate LBW. In order to obtain a sufficiently accurate solution, a large number of finite elements has to be used. Therefore, a highly parallel scalable solver framework, based on the software library PETSc, was used to solve this computationally challenging problem on a high-performance computing architecture. Finally, the experimental results and the numerical simulations are compared. They are found to be in good qualitative agreement, which confirms the validity of the numerical simulations and allows for a better interpretation of the experimentally observed strain distribution. KW - Laser beam welding KW - Termo-mechanical processes KW - Solidification cracking KW - High-performance computing KW - Domain decomposition methods PY - 2025 DO - https://doi.org/10.1016/j.rineng.2025.108827 SN - 2590-1230 SP - 1 EP - 33 PB - Elsevier B.V. AN - OPUS4-65290 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kröll, Mirco T1 - Harmonising Tribotests of Polymers in Hydrogen N2 - This talk harmonised methods to investigate friction and wear of commercial and experimental polymer compounds in hydrogen using several tribometers. T2 - Surface Ventures - Symposium on Hydrogen Tribology CY - Online meeting DA - 31.07.2025 KW - Hydrogen KW - Polymers KW - Tribometer KW - Wear KW - Coefficient of Friction KW - Interlaboratory comparison KW - Comparability KW - Harmonisation KW - Standardisation KW - Tribology KW - Oil-coupled compounds KW - FAIR data KW - Database KW - i-TRIBOMAT PY - 2025 AN - OPUS4-63838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kröll, Mirco T1 - Tribological performance of polymer compounds in gaseous hydrogen N2 - In this study, friction and wear of conventional and alternative high performance polymer compounds, typically used for components of compressors, were investigated in gaseous hydrogen and nitrogen up to 80 bar of gas pressure. The compounds used were a commercial PEEK matrix with 10 wt.% each of PTFE, graphite, and short carbon fibres, a PPS matrix with 10 wt.% each of PTFE and graphite, and an experimental PA12 matrix with PTFE chemically coupled with an oleyl alcohol. Due to the cylindrical shape of the polymer samples, the contact area and pressure change if wear occurs. Therefore, experimental results of pre-screening tests have been used as input for FEM and an analytical model to determine the decreasing contact pressure over time. Afterwards, the outcome of the models was used to determine the duration of the experiments to reach typical contact pressures of seals in hydrogen compressors. T2 - ASMET TriboCorrosion International Conference 2025 CY - Vienna, Austria DA - 23.10.2025 KW - Hydrogen KW - Polymer KW - Tribometer KW - Comparability KW - Harmonisation KW - Oil-coupled compounds KW - Coefficient of Friction KW - Wear KW - FAIR data KW - Standardisation KW - Tribology KW - Database KW - i-TRIBOMAT PY - 2025 AN - OPUS4-64473 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grengg, C. A1 - Gluth, Gregor A1 - Mittermayr, F. A1 - Ukrainczyk, N. A1 - Bertmer, M. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Leis, A. A1 - Dietzel, M. T1 - Deterioration mechanism of alkali-activated materials in sulfuric acid and the influence of Cu: A micro-to-nano structural, elemental and stable isotopic multi-proxy study N2 - In this study, a multi-proxy approach combining 29Si, 27Al and 1H MAS-NMR, FEG-EPMA, XANES at the Cu K-edge and XRD analytics with hydrochemical tools such as ICP-OES analyses, oxygen-isotope signatures, and thermodynamic modelling was applied to K-silicate-activated metakaolin specimens - with and without CuSO4·5H2O addition - exposed to sulfuric acid at pH = 2 for 35 days. The results revealed a multistage deterioration mechanism governed by (i) acid diffusion, (ii) leaching of K-A-S-H, (iii) microstructural damage related to precipitation of expansive (K,Ca,Al)-sulfate-hydrate phases (iv) complete dissolution of the K-A-S-H framework, (v) and formation of silica gel in the outermost corroded regions. Copper ions were mainly located in layered spertiniite-chrysocolla-like phases in the as-cured materials. The results demonstrate an overall negative effect of Cu addition on chemical material durability, implying that the reported higher durability of Cu-doped AAM in biocorrosion environments can be best explained by bacteriostatic effects. KW - Alkali-activated materials KW - Acid resistance KW - Microbially induced corrosion KW - MIC PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520567 DO - https://doi.org/10.1016/j.cemconres.2021.106373 SN - 0008-8846 VL - 142 SP - 1 EP - 15 PB - Elsevier CY - Oxford AN - OPUS4-52056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gluth, Gregor A1 - Ebell, Gino A1 - Hlavacek, Petr A1 - Mietz, Jürgen T1 - Chloride‐induced steel corrosion in alkali‐activated fly ash mortar: Increased propensity for corrosion initiation at defects N2 - Chloride contents at the steel–mortar interface that initiate steel corrosion were determined for carbon steel in alkali‐activated fly ash mortar for three different exposure conditions: exposure to 1 M NaCl solution; leaching in deionized water and then exposure to 1 M NaCl solution; and leaching in deionized water, aging in air at 20°C and natural CO2 concentration, and then exposure to 1 M NaCl solution. For comparison, a Portland cement mortar, exposed to 1 M NaCl solution, was studied. The median values of the corrosion‐initiating chloride contents (average over the full length of the rebar) in the alkali‐activated fly ash mortar varied between 0.35 and 1.05 wt% Cl with respect to binder, consistently lower than what was obtained for the Portland cement mortar, but with no clear trend regarding the exposure conditions. For most of the alkali‐activated fly ash mortar specimens, preferential corrosion at the connection between the working electrode and the external measurement setup was observed, while preferential corrosion did not occur for the Portland cement mortar. Scanning electron microscopy and auxiliary experiments in synthetic solutions indicated that this behavior was caused by inhomogeneities at the steel–mortar interface in the alkali‐activated mortar, likely due to its peculiar rheological properties in the fresh state. KW - Alkali-activated materials KW - Steel corrosion KW - Critical chloride content KW - Steel-concrete interface PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507268 DO - https://doi.org/10.1002/maco.202011541 VL - 71 IS - 5 SP - 749 EP - 758 PB - Wiley-VCH AN - OPUS4-50726 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Kiyak, Yusuf A1 - Breidung, Marc A1 - Baer, Wolfram A1 - Küppers, M. ED - Madia, Mauro T1 - Stiffness/constraint effects in analytical flaw assessment - A technical note N2 - Using the case study of a fail-safe design criterion for a steering knuckle of a commercial vehicle, the effect of stiffness/constraint on the crack driving force in the component is discussed. The problem arises when assessment procedures such as R6, BS 7910 or SINTAP/FITNET are applied in conjunction with substitute geometries for determining the model parameters K-factor and limit load (or a substitute for the latter), as it is common practice. In the example, the conservatism was so pronounced that this procedure was in fact unusable. A way out could be the finite element-based determination of the model parameters and their use in the analytical framework. This procedure is useful and effective if the finite element-based calculations are used in parameter sensitivity analyses. KW - Fail-safe design KW - Fracture resistance KW - Fracture assessment KW - Stiffness KW - Constraint PY - 2022 DO - https://doi.org/10.1016/j.engfracmech.2022.108728 SN - 0013-7944 IS - 273 SP - 1 EP - 15 PB - Elsevier Science CY - Kidlington AN - OPUS4-55544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baer, Wolfram T1 - Was Sie schon immer über Chunky-Graphit wissen w(s)ollten, aber bisher nicht zu fragen wagten N2 - Duktile Gusseisenwerkstoffe mit Kugelgraphit (GJS) haben ein erhebliches technisches Potenzial und sind von wirtschaftlicher Bedeutung. Nicht zuletzt daher ist es ökonomisch sinnvoll, gesellschaftlich nachhaltig und wissenschaftlich interessant, ihren Herstellungsprozess zu optimieren. Eine maßgebliche Rolle kommt hierbei der Vermeidung von Qualitätsabweichungen in Form von Gefügefehlern zu. Dieser Beitrag befasst sich mit der – leider vielfach nicht richtig oder zu wenig verstandenen, aber insbesondere bei kostenintensi-ven dickwandigen Gussteilen relevanten - Graphitentartung Chunky-Graphit (CG). Die metallurgischen Ursachen von CG werden noch immer kontrovers diskutiert. Eine allgemein akzeptierte Theorie zur Bildung und dem Wachstumsmechanismus von CG existiert nicht, in der Gießereipraxis wird gleichwohl eine Fülle spezifischer technologischer Abhilfemaßnahmen praktiziert [1]. Der Schwerpunkt dieses Beitrages liegt jedoch nicht auf der metallurgischen Seite, sondern auf der Beschrei-bung der spezifischen Morphologie von CG (Bild 1), dessen Detektion im Werkstoff bzw. Bauteil sowie den Auswirkungen von CG auf die Werkstoffeigenschaften. Detailliert werden Möglichkeiten und Grenzen zer-störungsfreier und zerstörender Untersuchungsverfahren zur Identifikation und Quantifizierung von CG aufgezeigt. Ausgehend von der charakteristischen Morphologie von CG wird dessen Einfluss auf das Ver-formungs- und Bruchverhalten von GJS behandelt. Beispielhaft werden dabei die Eigenschaften Festigkeit, Verformbarkeit, das Risswachstumsverhalten und die Bruchzähigkeit diskutiert und Schlussfolgerungen für die Bewertung von mit CG behafteten GJS-Bauteilen abgeleitet. T2 - Ledebur-Kolloquium 2023 CY - Freiberg, Germany DA - 26.10.2023 KW - Gusseisen mit Kugelgraphit GJS KW - Chunky-Graphit KW - Graphitentartung KW - Duktiles Gusseisen PY - 2023 AN - OPUS4-58636 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baer, Wolfram T1 - Investigation of the Master Curve Concept for Ferritic Ductile Cast Iron (DCI) N2 - Based on state-of-the-art research and regulations, the application of the fracture mechanics master curve (MC) concept to ferritic ductile cast iron (DCI) is being investigated in a recently started German joint research project between BAM Berlin and MPA Stuttgart. This paper outlines the research approach and the planned investigations and provides first results. According to the IAEA guidelines SSG 26, the safety assessment of DCI containers for transport as well as interim and final storage of radioactive materials is based on the fracture mechanics criterion of general crack initiation exclusion. Within this context, the focus of the current research project is on the further development of brittle fracture safety assessment methods under dynamic loading conditions. Within fracture mechanics safety assessments for steels in nuclear technology, the probabilistic MC concept according to ASTM E1921 is currently used for quasi-static loading conditions as a supplement to the established deterministic ASME reference curve concept. The MC concept allows for an effective statistical consideration of the scatter of the material toughness in the transition regime. Furthermore, the MC can also be used for elevated loading rates as they occur in accident or crash scenarios. However, for DCI, a systematic review of potential modifications to the MC assumptions and procedure according to ASTM E1921 and an associated validation are still lacking. Therefore, a corresponding methodology shall be established to determine and assess dynamic fracture toughness values of DCI in the ductile-to-brittle transition regime, using samples extracted from a component. For the experimental program, a DCI material was produced as it is generally used for transport and storage containers. A basic mechanical-technological material characterization consisting of tensile, Charpy, and Pellini tests is planned. A comprehensive fracture mechanics test program was compiled covering dynamic testing of DC(T)9, C(T)25, C(T)50, SE(B)10, SE(B)25, and SE(B)140 specimens. Moreover, numerical analyses of different specimen geometries and test setups are planned to investigate the influences of stress triaxiality and loading rate. Throughout the experimental program, the microstructure-property relationship will be investigated based on quantitative metallographic and fractographic analyses. Finally, different MC assessment strategies will be considered, and modifications will be made if necessary. T2 - PATRAM22 Conference CY - Juans-les-Pins, France DA - 11.06.2023 KW - Dynamic Fracture Toughness KW - Ductile Cast Iron KW - Master Curve Method PY - 2023 AN - OPUS4-57766 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baer, Wolfram T1 - Aspekte der analytischen bruchmechanischen Bauteilbewertung N2 - Am Beispiel eines abgesetzten zylindrischen Bauteils (Achsschenkel) werden Probleme der analytischen bruchmechanischen Bauteilbewertung diskutiert. Als Basis-philosophie wird ein Fail Safe-Kriterium (kontrolliertes Versagen) angesetzt. Die Forderung ist, dass sich der Achsschenkel, bevor er bricht, in einem Ausmaß plastisch verformen kann, bei dem der Fahrer bemerkt, dass mit seinem Fahrzeug etwas nicht in Ordnung ist. Um das zu gewährleisten, muss der Werkstoff einen bestimmten Riss-widerstand aufweisen. Dazu werden im hier vorgestellten ersten Teil des Projektes mittels FEM Rissspitzenbeanspruchungen in Abhängigkeit von der Auslenkung des Zylinders und angenommener Rissgrößen ermittelt. Diese finden als Zielgrößen in der weiteren Analyse Anwendung. Da eine einfach umzusetzende Lösung angestrebt wird, werden zusätzlich analytische Rechnungen an Ersatzgeometrien (halbunendliche Platte und Vollzylinder), aber mit den realen Spannungen am Bauteil durchgeführt. Es zeigt sich, dass die Ergebnisse wegen des Steifigkeitsunterschieds zwischen Bauteil und Ersatzgeometrie unvertretbar konservativ sind. Alternativ wird ein hybrides Konzept vorgestellt, für das die Modellparameter mittels FEM bestimmt werden. Es liefert sehr genaue Ergebnisse. Im Rahmen der analytischen Rechenvorschrift können die Lösungen auf andere Werkstoffe übertragen werden, ohne dass zusätzliche FEM-Analysen notwendig sind. T2 - 54. Tagung des DVM-Arbeitskreises Bruchmechanik und Bauteilsicherheit CY - Online meeting DA - 22.02.2022 KW - Bauteilbewertung KW - Fail-safe KW - Analytisches Modell KW - FEM PY - 2022 AN - OPUS4-54408 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - WójciaK, K. A1 - Tokarski, T. A1 - Cios, G. A1 - Winkelmann, A. A1 - Chulist, R. A1 - Nolze, G. T1 - Unconventional Applications of Electron Backscattering Diffraction (EBSD) in Metallic Materials N2 - Electron backscattered diffraction is widely used for phase and orientation imaging of crystalline specimens. Despite the inherent complexity of diffraction images, current analysis methodologies typically focus on the position of Kikuchi bands or direct comparisons between experimental and simulated patterns. These approaches require prior knowledge of the phases to be analyzed, limiting their applicability in certain scenarios. This paper introduces an alternative methodology, crystallographic analysis of lattice metric, which extracts phase and orientation information directly from the registered diffraction pattern without requiring predefined standards. The paper outlines the methodology, discusses limitations, and demonstrates possible application in phase analysis, lattice parameter ratio mapping, and qualitative lattice distortion mapping. KW - EBSD KW - Virtual dark-field imaging KW - Lattice distortion PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656014 DO - https://doi.org/10.24425/amm.2025.156241 VL - 70 IS - 4 SP - 1619 EP - 1626 AN - OPUS4-65601 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Oliveira, P. F. M. A1 - Torresi, R. A1 - Emmerling, Franziska A1 - Carmago, P. T1 - Challenges and opportunities in the bottom-up mechanochemical synthesis of noble metal nanoparticles N2 - Mechanochemistry is a promising alternative to solution-based protocols across the chemical sciences, enabling different types of chemistries in solvent-free and environmentally benign conditions. The use of mechanical energy to promote physical and chemical transformations has reached a high level of refinement, allowing for the design of sophisticated molecules and nanostructured materials. Among them, the synthesis of noble metal nanoparticles deserves special attention due to their catalytic applications. In this review, we discuss the recent progress on the development of mechanochemical strategies for the controlled synthesis of noble metal nanostructures. We start by covering the fundamentals of different preparation routes, namely top-down and bottom-up approaches. Next, we focus on the key examples of the mechanochemical synthesis of non-supported and supported metal nanoparticles as well as hybrid nanomaterials containing noble metals. In these examples, in addition to the principles and synthesis mechanisms, their performances in catalysis are discussed. Finally, a perspective of the field is given, where we discuss the opportunities for future work and the challenges of mechanochemical synthesis to produce well-defined noble metal nanoparticles. KW - Mechanochemistry KW - Nanoparticles PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512080 DO - https://doi.org/10.1039/D0TA05183G VL - 8 IS - 32 SP - 16114 AN - OPUS4-51208 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wurzler, Nina A1 - Sobol, Oded A1 - Altmann, Korinna A1 - Radnik, Jörg A1 - Özcan Sandikcioglu, Özlem T1 - Preconditioning of AISI 304 stainless steel surfaces in the presence of flavins—Part I: Effect on surface chemistry and corrosion behavior N2 - Stainless steel AISI 304 surfaces were studied after a mild anodic polarization for oxide growth in the presence and absence of two derivatives of vitamin B2 (riboflavin and flavin mononucleotide) that can be secreted by metal‐reducing bacteria and act as a chelating agent for iron species. The alterations in oxide chemistry were studied by means of surface‐sensitive techniques such as X‐ray photoelectron spectroscopy and time‐of‐flight secondary ion mass spectrometry analysis. The complementary electrochemical characterization revealed a preferential growth of an oxide/hydroxide iron‐rich film that is responsible for an altered pit initiation and nucleation behavior. These findings suggest that as the corrosion behavior is determined by the interplay of the chemical and electronic properties, only a mild anodic polarization in the presence of redox‐active molecules is able to alter the chemical and electronic structure of the passive film formed on stainless steel AISI 304. This helps to achieve a profound understanding of the mechanisms of microbially influenced corrosion (MIC) and especially the possible effects of the redox‐active biomolecules, as they may play an important role in the corrosion susceptibility of stainless steel surfaces. KW - Corrosion KW - Stainless steel KW - Surface analysis PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-528117 DO - https://doi.org/10.1002/maco.202012191 VL - 72 IS - 6 SP - 974 EP - 982 PB - Wiley AN - OPUS4-52811 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Altmann, Korinna A1 - Goedecke, Caroline A1 - Bannick, C.-G. A1 - Abusafia, A. A1 - Scheid, C. A1 - Steinmetz, H. A1 - Paul, Andrea A1 - Beleites, C. A1 - Braun, U. T1 - Identification of microplastic pathways within a typical European urban wastewater system N2 - In recent years, thermoextraction/desorption-gas chromatography/mass spectrometry (TED-GC/MS) has been developed as a rapid detection method for the determination of microplastics (MP) mass contents in numerous environmentally relevant matrices and, in particular, for the measurement of polymers in water samples without time-consuming sample preparation. The TED-GC/MS method was applied to investigate a typical European municipal wastewater system for possible MP masses. Such investigations are important in view of the recent revision of the Urban Wastewater Treatment Directive. Four different representative sampling sites were selected: greywater (domestic wastewater without toilet), combined sewer, and influent and effluent of a wastewater treatment plant (WWTP). All samples were collected by fractional filtration. Filtration was carried out over mesh sizes of 500, 100, 50, and in some cases, 5 µm. Polyethylene (PE), polypropylene (PP), and polystyrene (PS) were detected in all samples, with the PE fraction dominating in all cases. Styrene-butadiene rubber which serves as an indication of tire abrasion, was only found in the influent of the WWTP. The highest MP mass contents were found in the combined sewer, so MP can become a source of pollution during heavy rain events when the capacity limits of the effluent are reached, and the polluted effluent is released uncontrolled into the environment. Based on the studies, MP retention from the WWTP could be estimated to be approximately 96%. Few trends in polymer type or mass contents were detected within the different fractions of the samples or when comparing samples to each other. KW - Microplastics KW - Microplastic analysis KW - TED-GC/MS KW - Microplastic pathways KW - Mass contents PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568289 DO - https://doi.org/doi.org/10.1002/appl.202200078 SP - 1 EP - 10 PB - Wiley-VCH CY - Weinheim AN - OPUS4-56828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Ciornii, Dmitri A1 - Hodoroaba, Vasile-Dan A1 - Benismail, Nizar A1 - Altmann, Korinna T1 - Project 2: Interlaboratory Comparison on detection and quantitative assessment of microplastics by use of spectroscopic and thermo-analytical methods N2 - Validated and standardized methods in microplastic analysis are indispensable for robust monitoring and regulation. Alongside also reference materials are urgently needed. An interlaboratory comparison (ILC) offers a powerful tool to address both these challenges. The present study aimed to compare the precision and accuracy of various methods for the detection and quantification of microplastic in a water-soluble matrix. Additionally, it evaluated the suitability of the test materials (containing environmentally relevant plastic polymers) to serve as reference materials for the microplastic analysis. In this ILC several most used thermo-analytical and spectroscopic methods have been addressed: Pyrolysis-Gas Chromatography Mass Spectrometry (Py-GC/MS), Thermal Extraction-Desorption Gas Chromatography Mass Spectrometry (TED-GC/MS), micro-Fourier Transform Infrared Spectroscopy (µ-FTIR), and micro-Raman Spectroscopy and Laser Direct Infrared Spectroscopy (LDIR). Microplastic powders of polyethylene (PE) and polyethylene terephthalate (PET) were used to assess suitability of the test materials (microplastic tablets) for method validation and use in the ILCs. The participants were guided with a SOP how to dissolve the test samples and, depending on their selected method, either quantify the number of particles (by the spectroscopic methods) or determine the mass fraction of microplastic particles per sample (by the thermo-analytical methods). KW - ILC KW - Microplastic KW - FTIR KW - Raman KW - TED-GC/MS KW - Py-GC/MS PY - 2024 SP - 1 EP - 16 AN - OPUS4-60612 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna A1 - Braun, U. T1 - Monitoring von Mikroplastik N2 - Der Vortrag gibt einen Überblick was bei der Analyse von Mikroplastik zu beachten ist und beschreibt die Vor- und Nachteile der TED-GC/MS. T2 - Abschlusstreffen MikroPlaTas CY - Online meeting DA - 23.06.2021 KW - Mikroplastik KW - TED-GC/MS KW - Mikroplastik-Analytik PY - 2021 AN - OPUS4-52916 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Micro and Nano Plastics in the Environment N2 - The VAMAS/TWA 45 Project 2 “Development of standardized methodologies for characterisation of microplastics with microscopy and spectroscopy methods” involving 85 participants around the world is primarily discussed with respect to the results received and a first data evaluation. Status of the Project "Guidelines for defining reference materials for plastic degradation in marine environment" is reported and two new project proposals are presented: "Development of standardized methodologies for characterisation of nanoplastics (starting soon, BAM as leader?) and "Development of analytical protocols for the identification and quantification of microplastics of fibrous shape (still in negotiation)". T2 - Versailles Project on Advanced Materials and Standards (VAMAS) 48th Steering Committee Meeting CY - New Delhi, India DA - 09.10.2023 KW - Microplastics KW - Nanoplastics KW - Interlaboratory comparison KW - VAMAS KW - Reference materials KW - ISO PY - 2023 UR - https://www.nplindia.org/index.php/amcsnzt_2023/ AN - OPUS4-58539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Kittner, Maria A1 - Altmann, Korinna A1 - Hamann, Sven A1 - Weyer, Rüdiger A1 - Kalbe, Ute T1 - Bewertung der Freisetzung von Mikroplastik aus Sportböden auf Kunststoffbasis - Abschlussbericht N2 - Die Europäische Kommission hat 2023 ein Verbot zum bewussten Austrag von Mikroplastik (MP) in die Umwelt beschlossen, das auch für die Verwendung von synthetischen Gummi-Granulaten (v. a. EPDM) in Sportböden gilt. In Deutschland gibt es laut DFB ca. 5100 Kunstrasenplätze. In der EU beläuft sich die Anzahl laut ECHA auf 13,000 Kunstrasen- und 47,000 Bolzplätze, Tendenz steigend. Das Hauptziel des Projektes war es daher, eine Massenbilanz für die Freisetzung von MP zu erstellen, um so eine Schätzung des MP-Austrags pro Kunstrasenplatz und Jahr zu ermöglichen. Dafür werden die MP-Emissionen von drei Kunstrasenszenarien in verschiedenen Zuständen (ungealtert, künstlich gealtert und in Echtzeit gealtert) verglichen: die Vergangenheit (Kunstrasen: fossilbasiert, EPDM-Füllung), die Gegenwart (der in Europa am häufigsten installierte Rasen) und die Zukunft (Rasen mit recycelten Grasfasern, keine synthetische Füllung sondern z.B. Quarzsand oder Korkschrott). Dazu werden fabrikneue Kunststoffrasen und EPDM-Granulat unter Laborbedingungen beschleunigt gealtert, um die Freiland-Beanspruchung eines Kunststoffrasens in circa 15 Jahren abzubilden. Die Verwendung spezieller Mikrofiltertiegel in Lysimeter-Experimenten ermöglicht die Abschätzung der Partikelgrößen des emittierten MP, was eine Grundbedingung für die Bewertung einer potenziellen Gesundheitsgefährdung für Menschen ist. Ergänzend wurden weitere umweltrelevante Schadstoffausträge aus den Kunststoffrasen quantifiziert. KW - Mikroplastik KW - Kunststoffrasen KW - Schadstoffe KW - Bewitterung KW - Lysimeter PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-633114 DO - https://doi.org/10.26272/opus4-63311 N1 - Das Projekt wurde gefördert vom Bundesinstitut für Bau-, Stadt- und Raumforschung (BBSR) im Auftrag des Bundesministeriums für Wohnen, Stadtentwicklung und Bauwesen (BMWSB) aus Mitteln des Innovationsprogramms Zukunft Bau. Aktenzeichen: FKZ 10.08.18.7-22.02. Projektlaufzeit: 09.2022 bis 03.2025. SP - 1 EP - 75 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-63311 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dorau, Kristof A1 - Rückamp, Daniel A1 - Weber, Christian A1 - Scheeder, Georg A1 - Reßing, Ronja A1 - Peth, Stephan A1 - Otto, Philipp A1 - Altmann, Korinna A1 - Fries, Elke A1 - Hoppe, Martin T1 - Characterization and spatial distribution of mesoplastics in an arable soil N2 - AbstractExtraction of plastic particles from soil is challenging and, thus, exceptionally little spatial information on plastic distribution at the field scale has been gathered. However, for environmental risk assessment, adequate sampling should complement coherent plastic profiling. In this study, we investigated the spatial distribution of mesoplastics (MePs; from 5 mm up to 130 mm) in arable soil (Haplic Cambisol) managed intensively by 12 years of compost application. Geo‐referenced samples (n = 128) and five different sampling designs (n = 45) of variable sampling volume (from 2 to 300 L) were collected at a three hectare study site in Northern Germany (0–30 cm soil depth). Soil properties such as pH and soil organic carbon (SOC) were measured to evaluate dispersion measures of these data. In total, we found 259 MePs with a predominance of transparent packaging foils made of polyethylene and coloured fibres of polypropylene. Average particle metrics were a projection area of 47 (3–400) mm2, a Feret diameter of 18.5 (5.4–130) mm and a mass of 1.89 (0.11–221) mg. Caution is advised when measuring the particle mass due to still strongly adhering soil material, especially for fibre bundles with 0.544 mg soil mg−1 particle. We recommend using a 0.1 mol L−1 tetrasodium pyrophosphate solution to purify MePs by removing attached soil before weighing for further environmental risk assessment. The MePs count with a median value of 0.50 (0–3.2) particles kg−1 and median mass of 2.26 (0–221) mg kg−1 featured the highest coefficient of variation (CV) with 103% and 187%, respectively. This is 10–20 times larger in comparison to the CV of SOC (9.2%) and even 50–93 times larger than CV of soil pH (2.2%). This leads to the need of larger sample numbers to delineate plastic metrics in comparison with soil properties to identify a reliable mean value of the field within a predefined allowable error. Mesoplastics in the soil were characterized by a pure nugget effect variogram (no spatial correlation), revealed no intrafield variability and the sample volume yielded inconclusive results. Sampling for plastics in soil should either (i) drastically increase the sample number for a single field or (ii) communicate transparently that the allowable error is by far enhanced in comparison with classical soil properties like pH and SOC. More systematic studies featuring geo‐spatial analysis of MePs and smaller‐sized plastics in soils are required to propose adequate sampling designs across multiple land uses and plastics fingerprints. A larger database would, thereupon, pave the way for best‐practice guides on how to treat ‘outliers’ and search for robust estimators for spatial mapping of plastics in soils. KW - Large microplastics KW - Microplastics PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-617772 DO - https://doi.org/10.1111/ejss.70016 VL - 75 IS - 6 SP - 1 EP - 16 PB - Wiley AN - OPUS4-61777 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wimmer, L A1 - Hoang, M V N A1 - Schwarzinger, J A1 - Jovanovic, V A1 - Adelkovic, B A1 - Velickovic, T C A1 - Meisel, T C A1 - Waniek, T A1 - Weimann, Christiane A1 - Altmann, Korinna A1 - Dailey, L A T1 - A quality-by-design inspired approach to develop PET and PP nanoplastic test materials for use in in vitro and in vivo biological assays N2 - Micro- and nanoplastics have become environmental pollutants of concern, receiving increased attention from consumers, scientists, and policymakers. The lack of knowledge about possible impacts on wildlife and human health requires further research, for which well-characterized testmaterials are needed. A quality-bydesign (QbD) driven approachwas used to produce sterile, endotoxinmonitored nanoplastics of polyethylene terephthalate (PET) and polypropylene (PP) with a size fraction of >90% below 1 μm and high yield of >90%. Glycerol was used as a versatile and biocompatible liquid storage medium which requires no further exogenous dispersing agent andmaintained colloidal stability, sterility (0 CFU mL−1), and low endotoxin levels (<0.1 EU mL−1) for more than one year of storage at room temperature. Further, the glycerol vehicle showed no biological effect on the tested human bronchial cell line Calu-3 up to 0.8% (w/v). Given the concentration of 40 mg g−1 nanoplastics in the glycerol stock, this corresponds to a nanoplastic concentration of 320 μg mL−1. The surfactant-free nanoplastics are dispersible in bio-relevant media from the glycerol stock without changing size characteristics and are suitable for in vitro and in vivo research. KW - Microplastics KW - Reference materials KW - Nanoplastics KW - Polymer 3R KW - Glycerol PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629934 DO - https://doi.org/10.1039/D4EN01186D SN - 2051-8161 VL - 12 IS - 5 SP - 2667 EP - 2686 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-62993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Visileanu, Emilia A1 - Catalin Grosu, Marian A1 - Tiberiu Miclea, Paul A1 - Altmann, Korinna A1 - Brossell, Dirk T1 - Methods for the collection and characterization of airborne particles in the textile industry N2 - Airborne particulate matter is one of the main air pollutants. Their impact on mortality, and the occurrence of pulmonary and cardiovascular complications, have been the subject of numerous studies. Airborne particles are complex mixtures of organic and inorganic substances from different sources of particle emissions. Particulate Matter (PM) particles are classified according to their aerodynamic diameter expressed in µm and can vary from coarse (PM 10) to fine (less than PM 2.5). These diameter considerations are fundamental because they condition the penetration of particles into the bronchopulmonary system and the body. In recent years, there has been an interest in so-called “ultra-fine” particles, with a diameter of 0.1 µm (or 100 nm), or PM 0.1. They are nanoparticles and their impact on human health is not yet clear.With more than 1.5 million employees, textiles and clothing is a diverse sector that plays an important role in the European manufacturing industry, producing a turnover of €162 billion.An important component of the solid particles that generate air pollution in the textile industry is microplastics (MP) and nano plastics (NP), which also include microfibers (<5mm) and nanofibers (<100 nm), respectively. The particles released into the air during fiber and yarn processing range from 1 µg/m3 to 50 µg/m3.The paper presents the results of the determination of indoor and outdoor air concentration levels in textile companies, to identify the areas with the highest concentration level, by using an online recording system such as the Laser Aerosol Spectrometer MINI LAS model 11-E. The total concentration level TSP (µg/m3), the fractions PM 10(µg/m3), PM 2.5(µg/m3), PM1(µg/m3), as well as the total number of particles TC (1/l), were shown. It was noted that TSP is approximately at the same level both indoors and outdoors, but the fractions of PM10, PM2.5, and PM1 have much higher values indoors than outdoors with possible consequences on workers' health.The next step was the collection of fibers, namely micro and nano plastic particles from the vicinity of the workplaces of polyester, polyamide, and polypropylene fibers processing units in the textile industry in Romania, to obtain a sufficient quantity for laboratory analysis to determine the size and shape of the particles as well as their chemical composition. Two types of pumps were used, differentiated by their operating parameters: TECORA SKYPOST with airflow of 38 l/min and GILAIRPLUS with airflow 2l/min. Filters made of different materials with different diameters and pore sizes were used, namely: quartz filters (ø 47 mm, and ø 37 mm) on a TECORA SKYPOST type pump, polycarbonate nucleopore coated with a gold membrane (ø 25 mm) and silica filter (ø 9 mm) on GILAIRPLUS type pump.Using descriptive statistics, the calculation of correlation coefficients highlighted a strong correlation between the variables: "Collected mass/ Air concentration" and "Collected mass/ Air volume" for all diameters of the filters.The highest collected particle volume, determined by weighing the filters before and after collection, was obtained with the quartz filters (ø 47 mm) at an airflow of 38 l/min. The particles collected (polyester, polyamide, polypropylene) in the first stage were analyzed by SEM and thermogravimetric and it was found that the quartz filters absorbed the particles inside, with very few remaining on the surface. Thus no known methods can be used to perform analysis for particles collected on quartz filters. The number of particles on the filters was insufficient for analysis either because of the collection parameters used or because of the loss of particles during transport. As a result, in the next step, the use of 9 mm Si filters using the GILAIRPLUS pump at an airflow rate of 2l/min was chosen.To improve the transport conditions and avoid the loss of the particles and keep them on the surface of the filters, two methods were applied:- after weighing the filters were reintroduced into the collection pump holder;- a filtration system for airborne micro-nano plastics was designed and manufactured to selectively collect and transport PM10 and PM1 particles collected on SI filters.In both cases, SEM, Raman mapping, and GS-MS microscopy were used for analysis.Several times more PM10 than PM1 (74.5µg compared to 12.5 µg) was found. In all cases, both particles and fibers showed the same Raman fingerprint.The GS-MS analyses showed some contamination of the workspaces with particles other than the processed fibers. The presence of non-notifiable substances was also observed.The most viable filters are Si filters with a pore size of 10 microns to 1 micron and the use of the selected collection and transport filter system. In the following a filter system will be applied for collection on Au membrane-coated polycarbonate filters. T2 - 5th International Conference on Human Systems Engineering and Design: Future Trends and Applications (IHSED 2023) KW - Microplastics KW - Textiles PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624442 DO - https://doi.org/10.54941/ahfe1004132 VL - 112 SP - 212 EP - 223 PB - AHFE International AN - OPUS4-62444 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Realitätsnahe Referenzmaterialien für die Mikroplastik-Analytik und Vergleichsuntersuchungen N2 - Zur Validierung und Harmonisierung von verschiedenen Methoden in der Mikroplastik-Analytik werden polymere Referenzmaterialien benötigt. In diesem Vortrag wird dargestellt, was bisher an der BAM zu Referenzmaterialien für die Mikroplastik-Analytik entwickelt wurde, wo es hingehen soll und ein Überblick über bisher gelaufene Vergleichsuntersuchungen gebracht. T2 - Kick-off Meeting "Mikroplastik in Lebensmitteln" CY - Online meeting DA - 03.12.2020 KW - Mikroplastik KW - Referenzmaterial KW - Vergleichsuntersuchungen KW - Ringversuche PY - 2020 AN - OPUS4-51743 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dittmar, Stefan A1 - Weyrauch, Steffen A1 - Reemtsma, Thorsten A1 - Eisentraut, Paul A1 - Altmann, Korinna A1 - Ruhl, Aki S. A1 - Jekel, Martin T1 - Settling Velocities of Tire and Road Wear Particles: Analyzing Finely Graded Density Fractions of Samples from a Road Simulator and a Highway Tunnel N2 - The terminal settling velocity is considered the most critical parameter determining the transport of tire and road wear particles (TRWP) in aquatic environments. Nonetheless, no respective empirical data has been reported so far. In this study, particle samples from a road simulator and a highway tunnel were investigated with a validated imaging method. Different density and size fractions of both samples were measured separately, acquiring sizes and settling velocities of more than 30,000 individual particles. In addition, tire marker polymers were analyzed for each fraction via thermal extraction desorption-gas chromatography/mass spectrometry. Finally, the acquired particle data was combined according to the fractions’ estimated tire contents in order to deduce detailed probability distributions of particle size and settling velocity for the actual TRWP from both samples. Weighted by TRWP-incorporated tire mass, median diameters of 54 and 44 μm as well as median settling velocities of 0.65 and 0.22 mm/s were found for TRWP from the road simulator and highway tunnel, respectively. This study thus provides the first ever empirical data on TRWP settling velocities in water, which can be highly valuable input for modeling the environmental transport of TRWP and for dimensioning TRWP retention systems. KW - Microplastics KW - TED-GC/MS KW - Sinking velocities KW - Transport PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635449 DO - https://doi.org/10.1021/acs.est.5c04165 SN - 0013-936X VL - 59 IS - 26 SP - 13434 EP - 13446 PB - American Chemical Society (ACS) AN - OPUS4-63544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dudziak, Mateusz A1 - Topolniak, Ievgeniia A1 - Silbernagl, Dorothee A1 - Altmann, Korinna A1 - Sturm, Heinz T1 - Long-time behavior of surface properties of microstructures fabricated by multiphoton lithography N2 - The multiphoton lithography (MPL) technique represents the future of 3D microprinting, enabling the production of complex microscale objects with high precision. Although the MPL fabrication parameters are widely evaluated and discussed, not much attention has been given to the microscopic properties of 3D objects with respect to their surface properties and time-dependent stability. These properties are of crucial importance when it comes to the safe and durable use of these structures in biomedical applications. In this work, we investigate the surface properties of the MPL-produced SZ2080 polymeric microstructures with regard to the physical aging processes during the post-production stage. The influence of aging on the polymeric microstructures was investigated by means of Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). As a result, a time-dependent change in Young’s Modulus, plastic deformation, and adhesion and their correlation to the development in chemical composition of the surface of MPL-microstructures are evaluated. The results presented here are valuable for the application of MPL-fabricated 3D objects in general, but especially in medical technology as they give detailed information of the physical and chemical time-dependent dynamic behavior of MPL-printed surfaces and thus their suitability and performance in biological systems. KW - Multiphoton lithography KW - Additive manufacturing KW - Microfabrication KW - SZ2080 negative photo-resist KW - Young´s modulus KW - Aging KW - Surface properties KW - X-ray photoelectron spectroscopy KW - Atomic force microscopy KW - Force-distance-curve PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542166 DO - https://doi.org/10.3390/nano11123285 SN - 2079-4991 VL - 11 IS - 12 SP - 1 EP - 12 PB - MDPI CY - Basel AN - OPUS4-54216 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Axel A1 - Altmann, Korinna A1 - Kocher, B. A1 - Braun, U. T1 - Determination of tire wear markers in soil samples and their distribution in a roadside soil N2 - Tire wear (TW) constitutes a significant source of microplastic in terrestrial ecosystems. It is known that particles emitted by roads can have an effect up to 100 m into adjacent areas. Here, we apply for the first-time thermal extraction desorption gas chromatography-mass spectrometry (TED-GC/MS) to determine TW in soil samples by detection of thermal decomposition products of styrene-butadiene rubber (SBR), without additional enrichment. Additionally, zinc contents were determined as an elemental marker for TW. Mixed soil samples were taken along three transects along a German motorway in 0.3, 2.0, and 5.0 m distance from the road. Sampling depths were 0–2, 2–5, 5–10, and 10–20 cm. Four fine fractions, 1 000–500, 500–100, 100–50, and <50 μm, were analyzed. TW contents based on SBR ranged from 155 to 15 898 mg kg−1. TW contents based on zinc were between 413 and 44 812 mg kg−1. Comparison of individual values of SBR and zinc reveals SBR as a more specific marker. Results confirm that most TW ends up in the topsoil within a 2 m distance. The sampling strategy resulted in representative data for a larger area. Standard deviations of quadruple TED-GC/MS determination of SBR were <10% for all grain size fractions. TED-GC/MS is a suitable analytical tool for determining TW in soil samples without the use of toxic chemicals, enrichment, or special sample preparation. KW - Microplastic KW - TED-GC/MS KW - Tire wear PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543344 DO - https://doi.org/10.1016/j.chemosphere.2022.133653 VL - 294 SP - 1 EP - 8 PB - Elsevier Ltd. AN - OPUS4-54334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abusafia, A. A1 - Scheid, C. A1 - Meurer, Maren A1 - Altmann, Korinna A1 - Dittmer, U. A1 - Steinmetz, H. T1 - Microplastic sampling strategies in urban drainage systems for quantification of urban emissions based on transport pathways N2 - Tracking waterborne microplastic (MP) in urban areas is a challenging task because of the various sources and transport pathways involved. Since MP occurs in low concentrations in most wastewater and stormwater streams, large sample volumes need to be captured, prepared, and carefully analyzed. The recent research in urban areas focused mainly on MP emissions at wastewater treatment plants (WWTPs), as obvious entry points into receiving waters. However, important transport pathways under wet-weather conditions are yet not been investigated thoroughly. In addition, the lack of comprehensive and comparable sampling strategies complicated the attempts for a deeper understanding of occurrence and sources. The goal of this paper is to (i) introduce and describe sampling strategies for MP at different locations in a municipal catchment area under dry and wet-weather conditions, (ii) quantify MP emissions from the entire catchment and two other smaller ones within the bigger catchment, and (iii) compare the emissions under dry and wet-weather conditions. WWTP has a high removal rate of MP (>96%), with an estimated emission rate of 189 kg/a or 0.94 g/[population equivalents (PEQ · a)], and polyethylene (PE) as the most abundant MP. The specific dry-weather emissions at a subcatchment were ≈30 g/(PEQ · a) higher than in the influent of WWTP with 23 g/(PEQ · a). Specific wet-weather emissions from large sub-catchment with higher traffic and population densities were 1952 g/(ha · a) higher than the emissions from smaller catchment (796 g/[ha · a]) with less population and traffic. The results suggest that wet-weather transport pathways are likely responsible for 2–4 times more MP emissions into receiving waters compared to dry-weather ones due to tire abrasion entered from streets through gullies. However, more investigations of wet-weather MP need to be carried out considering additional catchment attributes and storm event characteristics. KW - Combined sewer system KW - Large volume samplers KW - Microplastic pollution KW - Separate sewer system KW - Stormwater retention tank PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568271 DO - https://doi.org/10.1002/appl.202200056 SP - 1 EP - 12 PB - Wiley-VCH CY - Weinheim AN - OPUS4-56827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, S. A1 - Horstmann, J. A1 - Altmann, Korinna A1 - Braun, U. A1 - Hagendorf, C. T1 - A reference methodology for microplastic particle size distribution analysis: Sampling, filtration, and detection by optical microscopy and image processing N2 - Microplastic (MP) contamination in natural water circulation is a concern for environmental issues and human health. Various types of polymer materials have been identified and were detected in MP analytic test procedures. Beyond MP polymer type, particle size and form play a major role in water analysis due to possible negative toxicologic effects on flora and fauna. However, the correct quantitative measurement of MP size distribution over several orders of magnitude is strongly influenced by sample preparation, filtration materials and processes, and microanalytical techniques, as well as data acquisition and analysis. In this paper, a reference methodology is presented aiming at an improved quantitative analysis of MP particles. An MP analysis workflow is demonstrated including all steps from reference materials to sample preparation, filtration handling, and MP particle size distribution analysis. Background-corrected particle size distributions (1–1000 µm) have been determined for defined polyethylene (PE) and polyethylene terephthalate (PET) reference samples. Microscopically measured particle numbers and errors have been cross-checked with the total initial mass. In particular, defined reference MP samples (PE, PET) are initially characterized and applied to filtration experiments. Optical microscopy imaging on full-area Si filters with subsequent image analysis algorithms is used for statistical particle size distribution analysis. To quantify the effects of handling and filtration, several blind tests with distilled water are carried out to determine the particle background for data evaluation. Particle size distributions of PE and PET reference samples are qualitatively and quantitatively reproduced with respect to symmetry, and maximum and cut-off diameter of the distribution. It is shown that especially MP particles with a radius of >50 µm can be detected and retrieved with high reliability. For particle sizes <50 µm, a significant interference with background contamination is observed. Data from blank samples allows a correction of background contaminations. Furthermore, for enhanced sampling statistics, the recovery of the initial amount of MP will be qualitatively shown. The results are intended as an initial benchmark for MP analytics quality. This quality is based on statistical MP particle distributions and covers the complete analytic workflow starting from sample preparation to filtration and detection. Microscopic particle analysis provides an important supplement for the evaluation of established spectroscopic methods such as Fourier-transform infrared spectroscopy or Raman spectroscopy. KW - Drinking water KW - Filtration KW - Microplastics detection KW - Quality control KW - Statistical particle distribution PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567625 DO - https://doi.org/10.1002/appl.202200055 SN - 2702-4288 SP - 1 EP - 10 PB - Wiley-VCH CY - Weinheim AN - OPUS4-56762 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiesner, Yosri A1 - Hoffmann, Thomas A1 - Range, David A1 - Altmann, Korinna T1 - Microplastics in sediments of the river Rhine—A workflow for preparation and analysis of sediment samples from aquatic river systems for monitoring purposes N2 - AbstractMicroplastics (MP) can be detected in all environmental systems. Marine and terrestrial aquatic systems, especially the transported suspended solids, have often been the focus of scientific investigations in the past. Sediments of aquatic river systems, on the other hand, were often ignored due to the time‐consuming sample preparation and analysis procedures. Spectroscopic measurement methods counting particle numbers are hardly suitable as detection methods, because there are plenty of natural particles next to a small number of MP particles. Integral methods, such as thermoanalytical methods are determining the particle mass independently of the inorganic components.In this study, a workflow for sample preparation via density separation and subsequent analysis by thermal extraction desorption‐gas chromatography/mass spectrometry is presented, which leads to representative and homogeneous samples and allows fast and robust MP mass content measurements suitable for routine analysis. Polymers were identified and quantified in all samples. Polyethylene and styrene‐butadiene rubber are the dominant polymers, besides polypropylene and polystyrene. Overall, total polymer masses between 1.18 and 337.0 µg/g could be determined. Highest MP concentrations in riverbed sediment are found in sites characterized by low flow velocities in harbors and reservoirs, while MP concentrations in sandy/gravelly bed sediments with higher flow velocities are small. KW - Microplastics KW - Density separation KW - TED-GC/MS KW - NaI PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597335 DO - https://doi.org/10.1002/appl.202200125 VL - 3 IS - 2 SP - 1 EP - 10 PB - Wiley VHC-Verlag AN - OPUS4-59733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Seasonal microplastic concentrations along the rivers Rhine and Danube N2 - Over the last 20 years, many researchers, politicians and citizens have become increasingly aware of the growing plastic problem of our time. A lack of recycling concepts and plastic collection points as well as careless dumping lead to accumulation of plastic products in the environment. Natural weathering can cause these plastics to degrade and fractionate, meaning that microplastics (1 1,000 µm, ISO/TR 21960:2020) and nanoplastics (< 1 µm, ISO/TR 21960:2020) of various synthetic polymer materials can now be detected in all parts of the world. Whether microplastics or nanoplastics pose a toxicological hazard is being investigated in a variety of ways. Valid results are still pending. However, the EU precautionary principle applies to micro- and nanoplastics. Monitoring of microplastics is already required in the revision of the Drinking Water and Wastewater Framework Directive. Reliable monitoring of rivers can be carried out by sampling with sedimentation boxes and microplastic detection by using thermal extraction desorption gas chromatography/mass spectrometry (TED-GC/MS) in routine operation (Figure 1). The river Rhine was sampled for microplastic masses at three different sampling locations over a period of one year and in addition the Danube at randomized sampling locations The TED-GC/MS results showed that various synthetic polymers frequently produced in industry, such as polyethylene, polypropylene or polystyrene as well as the tire compound styrene-butadiene rubber were found. The work not only shows a possible workflow for monitoring concepts, but also provides information on environmentally relevant concentrations of microplastics and tire components in surface waters. This in turn is necessary for ecotoxicological studies. T2 - ESOPS CY - Berlin, Germany DA - 09.09.2024 KW - Microplastics KW - TED-GC/MS KW - Polymer 3R PY - 2024 AN - OPUS4-61016 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Béalu, Zoé A1 - Walther, Johanna A1 - Abusafia, Attaallah A1 - Altmann, Korinna A1 - Meurer, Maren A1 - Gretzschel, Oliver A1 - Schäfer, Michael A1 - Steinmetz, Heidrun T1 - Removal of Organic Micropollutants and Microplastics via Ozonation Followed by Granular Activated Carbon Filtration N2 - Discharge from Wastewater Treatment Plants (WWTPs) can result in the emission of organic micropollutants (OMPs) and microplastics (MPs) into the aquatic environment. To prevent this harmful release, a pilot plant consisting of an ozonation followed by a granular activated carbon (GAC) filter was operated at a WWTP in Germany, and its side-effects on the concentrations of nitrogen (N) and phosphorous (P) compounds were measured. Over 80% of OMPs and transformation products were removed during the operating time (around 6000 bed volumes) no matter the ozone dose (from around 0.1 to 0.5 mgO3/mgDOC), except for Diatrizoic acid, whose breakthrough appeared at 3500 BV. Formation of the oxidation by-product, NDMA, increased with higher ozone doses, but the concentration remained below 100 ng/L. Bromate was formed at a higher ozone dose (0.4 mgO3/mgDOC) but at a low concentration—below 10 µg/L. The MP particles detected in the inflow (PE, SBR, PP, and PS) were effectively eliminated to a high degree, with a removal rate of at least 92%. Carbon parameters (COD, DOC, and SAC254) were removed further by the pilot plant, but to different extents. As expected, nitrate was formed during ozonation, while nitrite’s concentration decreased. Further, nitrite decreased and nitrate increased within the GAC filter, while ammonium was eliminated by at least 90%. Total P concentration decreased after the pilot, but the concentration of PO4-P increased. KW - Microplastics KW - TED-GC/MS KW - Granular Activated Carbon Filtration KW - Removal of Organic Micropollutants KW - Wastewater treatment plant PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-615209 DO - https://doi.org/10.3390/environments11110241 VL - 11 IS - 11 SP - 1 EP - 38 PB - MDPI AG AN - OPUS4-61520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kittner, Maria A1 - Bauer, Vanessa A1 - Altmann, Korinna A1 - Kraft, Oliver A1 - Nordmann, Thomas A1 - Kalbe, Ute T1 - Mikroplastik-Austrage aus Kunststoffrasenplatzen ins Grundwasser N2 - Sportplätze aus Kunststoffrasen haben sich im Breitensport etabliert, weshalb ihre Anzahl jährlich zunimmt. Dabei werden Umwelt- und Gesundheitsrisiken, insbesondere durch Mikroplastik-Austräge, kontrovers diskutiert. Um die ungenügende Datenlage zur Menge des Austrages an Mikroplastik zu verbessern, haben sich zwei individuelle Studien mit dieser Forschungsfrage mit Fokus auf den Boden-Grundwasser-Pfad befasst, deren Ergebnisse hier erstmalig gemeinsam vorgestellt werden. Die erste Studie simulierte unter Laborbedingungen Mikroplastik-Emissionen von drei Kunststoffrasen-Szenarien in unterschiedlichen Alterungszuständen und analysierte thermoanalytisch. Die zweite Studie untersuchte Grundwasser-Proben von zwei Realsportplätzen, die 1 m unter dem Grundwasserspiegel entnommen und spektroskopisch untersucht wurden. Dies ermöglicht erstmalig einen Vergleich von Mikroplastik-Austrägen über das Sickerwasser in verschiedenen Bodentiefen. Die Labor-Ergebnisse ergaben je nach Alterungszustand des Kunststoffrasenplatzes Mikroplastik-Emissionen zwischen < 0,1 μg/L und 26,8 μg/L in 30 cm Bodentiefe. Wohingegen in den Grundwasser-Proben der Realsportplätze ab 4 m Bodentiefe keine Kunststoffrasen-Partikel detektiert wurden. Dies deutet darauf hin, dass vermehrt Mikroplastik durch Alterung aus Kunststoffrasen entsteht und im Sickerwasser ausgetragen wird, aber der Boden Mikroplastik- Partikel ≥ 5 μm durch Filtrationseffekte zurückhält, sodass diese im Grundwasser nicht nachweisbar waren. KW - Kunststoffrasen, Alterung, Mikroplastik, Elution, Schadstoffe PY - 2025 DO - https://doi.org/10.37307/j.1868-7741.2025.04.05 SN - 1868-7741 VL - 30 IS - 4 SP - 156 EP - 161 PB - Erich Schmidt Verlag GmbH & Co. KG AN - OPUS4-65098 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Welche Rolle spielen Textilien als Mikroplastik-Quelle im Abwasser? N2 - In diesem Vortrag wird die Rolle der Waschmaschine als Eintragspfad von Mikroplastik in das Abwasser diskutiert und eine experimentelle Annäherung an das Problem beschrieben. T2 - Wasserwirtschaftliches Kolloquium der TU Berlin CY - Berlin, Germany DA - 14.12.2023 KW - Mikroplastik KW - TED-GC/MS KW - Waschmaschine PY - 2023 AN - OPUS4-59278 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Systemverständnis und Untersuchungsstrategien von Kunststoffeinträgen in die Umwelt – Ergebnisse des RUSEKU-Forschungsprojektes N2 - Ziel des Vortrages ist die Vermittlung der Herausforderungen der Mikroplastik-Analytik sowie der Harmonisierung der Analytik und des Ergebnistransfers in die Normung. T2 - Jahresabschluss-Sitzung GA "Mensch und Umwelt" CY - Online meeting DA - 24.11.2021 KW - Mikroplastik KW - Mikroplastik-Analytik PY - 2021 AN - OPUS4-53830 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Microplastic occurrence in urban sewage systems: Identification of sources for pathways into the environment N2 - All over the world, microplastic (MP) particles (particle size: 1 - 1.000 µm) are found in water, soil, air, biota and even food products. But plenty of these discussed findings are based on a very low number of real datasets, which are extrapolated to general projections. Furthermore, most data are not comparable because the strategies for sampling, sample preparation and detection methods are not harmonised/ or standardised. This would require extensive proficiancy tests. Because of the ubiquity presence and the unclear risks, which might arise from those particles, various political and environmental organisations (i.e. OECD, UNEP, WHO) identify the reduction of plastic entry in the environment as a key challenge for now and the future. This challenge includes the identification of relevant entry pathways but also the demand of harmonised, meaningful and reliable analytical procedures. Regarding this task within the last few years, a fast practical solution for MP analysis has been developed, which includes the steps of representative sampling, adequate sample preparation and fast detection. Sampling is done by fractional filtration over sieves with mesh sizes of 500, 100, 50 and 5 µm [1]. The received samples are measured by ThermoExtraction/Desorption-Gas Chromatography-Mass Spectrometry (TED-GC-MS) [1,2]. for the most abundant polymers used in practice, which are polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyamide (PA) and acrylate as well as styrene-butadiene-rubber (SBR), a main component of tires. The present presentation will give first-time insight in a comprehensive dataset of microplastic analysis for an exemplary urban sewage system. MP mass contents of different waters at several days, such as greywater, stormwater retention tank, influent and effluent of a wastewater treatment plant (WWTP) within an urban sewage system in Germany are determined. Furthermore, the mass of the polymers found in dry weather and rain weather flow are compared. The use of these large datasets allows first expressive conclusions regarding the contribution of urban sewage system to the MP entry sources in the environments. We found PP and PS in all different waters. Furthermore, there is SBR in influent and also in effluent of the WWTP. Surprisingly, we could also detect hugh amounts of PE in the effluent of the WWTP. T2 - SETAC Europe 2020 CY - Online meeting DA - 03.05.2020 KW - Microplastic analysis KW - TED-GC/MS KW - Microplastic particles KW - Microplastic mass contents PY - 2020 AN - OPUS4-50795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Yusenko, Kirill A1 - Stawski, Tomasz A1 - Kulow, Anicó A1 - Cakir, Cafer Tufan A1 - Röder, Bettina A1 - Naese, Christoph A1 - Britzke, Ralf A1 - Sintschuk, Michael A1 - Emmerling, Franziska T1 - BAMline - A real-life sample materials research beamline N2 - With increasing demand and environmental concerns, researchers are exploring new materials that can perform as well or better than traditional materials while reducing environmental impact. The BAMline, a real-life sample materials research beamline, provides unique insights into materials’ electronic and chemical structure at different time and length scales. The beamline specializes in x-ray absorption spectroscopy, x-ray fluorescence spectroscopy, and tomography experiments. This enables real-time optimization of material properties and performance for various applications, such as energy transfer, energy storage, catalysis, and corrosion resistance. This paper gives an overview of the analytical methods and sample environments of the BAMline, which cover non-destructive testing experiments in materials science, chemistry, biology, medicine, and cultural heritage. We also present our own synthesis methods, processes, and equipment developed specifically for the BAMline, and we give examples of synthesized materials and their potential applications. Finally, this article discusses the future perspectives of the BAMline and its potential for further advances in sustainable materials research. KW - Extended X-ray absorption fine structure KW - Energy storage KW - Environmental impacts KW - Nondestructive testing techniques KW - X-ray fluorescence spectroscopy KW - Corrosion KW - Near edge X-ray absorption fine structure spectroscopy KW - X-ray absorption spectroscopy PY - 2023 DO - https://doi.org/10.1063/5.0157194 VL - 158 IS - 24 SP - 1 EP - 22 PB - AIP Publishing AN - OPUS4-57824 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Altmann, Korinna A1 - Heymann, S. A1 - Braun, U. A1 - Bannick, C.-G. A1 - Heller, C. A1 - Fuchs, M. A1 - Scheid, C. A1 - Abusafia, A. A1 - Steinmetz, H. A1 - Ricking, M. A1 - Kerndorff, A. T1 - Untersuchungsverfahren von Mikroplastikgehalten im Wasser für Praxis und Wissenschaft N2 - Zielsetzung des vom Bundesministerium für Bildung und Forschung geförderten Projektes RUSEKU war es, repräsentative Untersuchungsstrategien für die Detektion von Mikroplastik mittels TED GC/MS in wässerigen Medien zu ermitteln. Dabei wurden verschiedene Probenahmekonzepte und – verfahren für unterschiedliche Fallgestaltungen und Fragestellungen untersucht, sowie neue Filtersysteme entwickelt. Bei der Detektion der Partikel lag der Fokus auf der Anwendung und Weiterentwicklung der ThermoExtraktion/Desorption-Gaschromatographie-Massenspektrometrie (TED-GC/MS) zur Bestimmung von Mikroplastikgehalten. Anwendung fanden die Methoden bei der Beprobung von Flaschenwasser, Waschmaschinenabläufen, dem urbanen Abwassersystem der Stadt Kaiserslautern, sowie in Oberflächengewässer. KW - Mikroplastik KW - TED-GC/MS KW - Mikroplastik-Analytik KW - Probennahme PY - 2021 VL - 14. Jahrgang IS - 3 SP - 147 EP - 152 PB - Deutschen Vereinigung für Wasserwirtschaft, Abwasser und Abfall CY - Hennef AN - OPUS4-52260 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -