TY - GEN A1 - Pirskawetz, Stephan A1 - Bösche, Thomas A1 - Carstens, Ole A1 - Hille, Falk A1 - Holst, Ralph A1 - Käding, Max A1 - Kaplan, Felix A1 - Löhr, Manuel A1 - Richter, Walter A1 - Saloga, Katrin A1 - Schmidt, Sebastian A1 - Sodeikat, Christian A1 - Thenikl, Thomas T1 - Detektion von Spanndrahtbrüchen mit Schallemissionsanalyse N2 - Dieses Dokument beschreibt das Verfahren Schallemissionsanalyse zur Detektion von Spanndrahtbrüchen in Spannbetonbrücken im Rahmen einer kontinuierlichen Überwachung. Die Überwachung mit Schallemission liefert eine Aussage über die Anzahl von Spanndrahtbrüchen innerhalb des Überwachungszeitraumes und innerhalb der Reichweite der installierten Sensoren. Mit dem Verfahren können die Spanndrahtbrüche lokalisiert werden. Auf Basis einer weitgehend automatisierten Datenanalyse stehen Informationen über Drahtbrüche kurzfristig nach dem Ereignis zur Verfügung. Der Anwendungsbereich des Dokuments umfasst Brücken- und Ingenieurbauwerke mit Spanndrähten mit sofortigem oder nachträglichem Verbund. Spannsysteme ohne Verbund fallen nicht in den Anwendungsbereich. Die beschriebenen Verfahren können auf Spannsysteme ohne Verbund übertragen werden. Mit dem Verfahren Schallemissionsanalyse ist es nicht möglich, Spanndrahtbrüche zu finden, die vor dem Beginn der Überwachung entstanden sind. Das Dokument richtet sich an Baulastträger, Anbieter und Betreiber von Monitoringsystemen auf Basis der Schallemissionsanalyse sowie Ingenieurbüros, welche die Ergebnisse der Überwachung bewerten und Maßnahmen daraus ableiten. Es gibt Hinweise zur Planung, Ausschreibung, Installation und zum Betrieb von Monitoringsystemen zur Detektion von Spanndrahtbrüchen mit Schallemission sowie zur Überprüfung der Funktion installierter Systeme. Zur Funktionskontrolle werden Signale mit der Referenzquelle am Bauwerk ausgelöst. Diese Signale sind zu detektieren, innerhalb der vorgegebenen Genauigkeit zu lokalisieren und die vorgegebene Alarmkette muss angestoßen werden. KW - Schallemission KW - Brücke KW - Spannbeton KW - Spannstahlbruch PY - 2024 SN - 978-3-947971-34-3 VL - Richtlinie SE 05 SP - 1 EP - 33 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin ET - Ausgabe Mai 2024 AN - OPUS4-60679 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vollmer, Malte A1 - Degener, Sebastian A1 - Bolender, Artjom A1 - Bauer, Andre A1 - Liehr, Alexander A1 - Stark, Andreas A1 - Schell, Norbert A1 - Barriobero-Vila, Pere A1 - Requena, Guillermo A1 - Niendorf, Thomas T1 - Time resolved insights into abnormal grain growth by in situ synchrotron measurements N2 - Large oligo-crystalline or single-crystalline metallic materials are of great interest for numerous applications, and a recently developed strategy for promoting abnormal grain growth induced by a cyclic heat treatment opens up new opportunities to manufacture single crystals with a size of several centimeters. So far, the entire available knowledge on this kind of abnormal grain growth has been elaborated based on time discrete observations and, thus, detailed insights into the interplay of elementary mechanisms are still lacking in open literature. The present study reveals time resolved insights into this kind of abnormal grain growth for the first time. It was possible to break down the influence of the individual heat treatment phases by in situ synchrotron high energy X-ray diffraction analysis during cyclic heat reatment. The results obtained not only help to gain a deep understanding of the abnormal grain growth mechanisms, they will also be the basis for an adjustment of the cyclic heat treatment process to improve its efficiency and to eventually obtain even larger single crystals. KW - Single crystals KW - Grain growth method KW - Synchrotron diffraction KW - High-energy X-ray diffraction KW - Grain boundary migration PY - 2023 DO - https://doi.org/10.1016/j.actamat.2023.119168 SN - 1359-6454 VL - 257 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-62188 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Alexander A1 - Dingel, Kristina A1 - Kottke, Daniel A1 - Degener, Sebastian A1 - Meier, David A1 - Sick, Bernhard A1 - Niendorf, Thomas T1 - Data selection strategies for minimizing measurement time in materials characterization N2 - Every new material needs to be assessed and qualified for an envisaged application. A steadily increasing number of new alloys, designed to address challenges in terms of reliability and sustainability, poses significant demands on well-known analysis methods in terms of their efficiency, e.g., in X-ray diffraction analysis. Particularly in laboratory measurements, where the intensities in diffraction experiments tend to be low, a possibility to adapt the exposure time to the prevailing boundary conditions, i.e., the investigated microstructure, is seen to be a very effective approach. The counting time is decisive for, e.g., complex texture, phase, and residual stress measurements. Traditionally, more measurement points and, thus, longer data collection times lead to more accurate information. Here, too short counting times result in poor signal-to-background ratios and dominant signal noise, respectively, rendering subsequent evaluation more difficult or even impossible. Then, it is necessary to repeat experiments with adjusted, usually significantly longer counting time. To prevent redundant measurements, it is state-of-the-art to always consider the entire measurement range, regardless of whether the investigated points are relevant and contribute to the subsequent materials characterization, respectively. Obviously, this kind of approach is extremely time-consuming and, eventually, not efficient. The present study highlights that specific selection strategies, taking into account the prevailing microstructure of the alloy in focus, can decrease counting times in X-ray energy dispersive diffraction experiments without any detrimental effect on data quality for the subsequent analysis. All relevant data, including the code, are carefully assessed and will be the basis for a widely adapted strategy enabling efficient measurements not only in lab environments but also in large-scale facilities. KW - Materials characterization KW - Machine learning KW - X-ray diffraction KW - Measurement optimization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630831 DO - https://doi.org/10.1038/s41598-025-96221-1 SN - 2045-2322 VL - 15 IS - 1 SP - 1 EP - 12 PB - Springer Science and Business Media LLC AN - OPUS4-63083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lauhoff, Christian A1 - Degener, Sebastian A1 - Bolender, Artjom A1 - Liehr, Alexander A1 - Hübner, Leoni A1 - Frenck, Johanna-Maria A1 - Molotnikov, Andrey A1 - Niendorf, Thomas T1 - In Situ Synchrotron Diffraction Assessment of Reversibility of the Martensitic Transformation in Single-Crystalline Co–Ni–Ga Shape Memory Alloy Under Torsion N2 - AbstractHeusler-type Co–Ni–Ga shape memory alloys attracted significant attention due to their excellent functional properties in single-crystalline state under both compressive and tensile loading. The present study investigates the superelastic deformation behavior under torsion. Using a newly installed torsion testing setup, in situ synchrotron diffraction was carried out on single-crystalline material in order to investigate the martensitic phase transformation. Incremental deformation experiments reveal a fully reversible martensitic transformation under torsional loading at room temperature, leading to excellent strain recovery after deformation to 6.5% shear strain. Furthermore, relevant aspects towards the analysis of powder diffraction data obtained for single-crystalline material in transmission mode under torsional loading are presented and critically discussed. KW - Shape memory alloy KW - Pseudoelasticity KW - Martensitic transformation KW - Synchrotron diffraction KW - In situ testing KW - Torsion PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-621872 DO - https://doi.org/10.1007/s40830-024-00496-8 VL - 10 SP - 326 EP - 333 PB - Springer Science and Business Media LLC AN - OPUS4-62187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Recknagel, Sebastian A1 - Noack, Siegfried A1 - Steiger, Thomas A1 - Kipphardt, Heinrich A1 - Matschat, Ralf T1 - International comparability of determination of mass fractions of chromium, copper, iron, manganese and zinc in aluminium alloy: Comité consultatif pour la quantité de matière key comparison K42 N2 - The degree of equivalence within the participating national metrology institutes for the measurement results of the mass fractions of the analytes Cr, Cu, Fe, Mn and Zn in an aluminium alloy was assessed. This interlaboratory comité consultatif pour la quantité de matière key comparison (CCQM-K42) was organised as an activity of the Inorganic Analytical Working Group of CCQM. In total seven laboratories participated, six of them for all analytes. Measurands were the mass fractions of the analytes in a range of 0.05 and 0.2%. As an outcome the consistency of the results for all elements investigated was acceptable, hence satisfactory comparability was established. An aluminium based certified reference material—undisclosed to the analysts which one it was—was used as test sample. For the purpose of this study homogeneity was tested at BAM. Each laboratory was free to choose any analytical method they wanted to use for the analysis. Consequently various methods of measurement were employed: instrumental neutron activation analysis, X-ray fluorescence spectrometry (XRF) using fused cast-bead method combined with reconstitution technique, inductively coupled plasma optical emission spectrometry (ICP OES) and inductively coupled plasma mass spectrometry. Metrological traceability of the measurement results to the SI unit had to be demonstrated. Therefore, methods such as spark OES or XRF (without fused cast-bead technique)—both of them being most important methods for the analysis of metals and alloys in industrial laboratories—could not be used in the frame of the key comparison. KW - Aluminium alloy KW - International comparison KW - CCQM-K42 KW - Key comparison PY - 2010 DO - https://doi.org/10.1007/s00769-010-0641-5 SN - 0949-1775 SN - 1432-0517 VL - 15 IS - 7 SP - 401 EP - 407 PB - Springer CY - Berlin AN - OPUS4-21628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kipphardt, Heinrich A1 - Dudzus, Thomas A1 - Meier, Klaus A1 - Recknagel, Sebastian A1 - Hedrich, Martina A1 - Matschat, Ralf T1 - Measurement of oxygen and nitrogen in high purity metals used as national standards for elemental analysis in Germany by classical carrier gas hot extraction (HE) and HE after activation with photons N2 - The special importance of the analysis of non-metals in high purity metals, which will serve as national standards for elemental analysis in Germany, is illustrated for oxygen and nitrogen. The typical range of the mass fraction of oxygen and nitrogen in these materials is below 10.MU.g/g, often close to 1.MU.g/g. The two methods applied at BAM for these measurements are classical carrier gas hot extraction (HE) and carrier gas hot extraction after activation with photons (PAA-HE). The approach, the methods and their advantages and limitations are discussed. Comparative results from the measurement of oxygen and nitrogen in Cu, Fe, Ga, Pb, Sn and W are presented. (author abst.) T2 - 8th International Conference on Ultra-High Purity Base Metals (UHPM-2001) CY - Berlin, Germany DA - 2001-06-25 KW - Oxygen determination KW - Nitrogen determination KW - High purity metals KW - Carrier gas hot extraction KW - Photon activation analysis PY - 2002 DO - https://doi.org/10.2320/matertrans.43.98 SN - 1345-9678 SN - 1347-5320 VL - 43 IS - 2 SP - 98 EP - 100 PB - Japan Institute of Metals CY - Sendai AN - OPUS4-1361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kipphardt, Heinrich A1 - Dudzus, Thomas A1 - Meier, Klaus A1 - Recknagel, Sebastian A1 - Hedrich, Martina A1 - Matschat, Ralf T1 - The measurement of O and N by classical carrier gas hot extraction (HE) - Carrier gas hot extraction after activation with photons T2 - CENAM CY - Mexico City, Mexico DA - 2002-01-28 PY - 2002 AN - OPUS4-1610 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Merchel, Silke A1 - Dudzus, Thomas A1 - Ecker, Klaus A1 - Hedrich, Martina A1 - Kipphardt, Heinrich A1 - Recknagel, Sebastian T1 - Viele (BAM-) Wege führen zu den leichten Elementen T2 - 12. Jahrescolloquium "Analyse von Feststoffen unterschiedlicher Materialien aus Industrie und Umwelt" CY - Berlin, Deutschland DA - 2002-11-19 PY - 2002 SP - 1(?) AN - OPUS4-2024 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Frenck, Johanna-Maria A1 - Frenck, Georg A1 - Degener, Sebastian A1 - Vollmer, Malte A1 - Niendorf, Thomas T1 - Interrelationships of stress-induced martensitic phase transformation and pitting corrosion in iron-based shape memory alloys N2 - Orientation dependence of stress-induced martensitic transformation under compression and the influence of a corrosion attack on superelastic properties were investigated for Fe42.7Mn34.7Al13.4Ni7.7Cr1.5 (at.−%) single crystals. The results of incremental strain tests show that the crystallographic orientation has a considerable impact on the superelastic performance, eventually resulting from the formation of twinned or detwinned martensite to accommodate strain as well martensite variant interaction. In order to investigate the effect of a corrosive environment on the mechanical performance and martensitic transformation, compression specimens were immersed in a 5.0 wt.−% NaCl solution for 24 h before tested in incremental strain tests. The immersion of the compression specimens revealed a partial surface corrosion attack including localized pitting corrosion. The localized corrosion attack increased the number of active martensite plates, most probably due to an induced multiaxial stress state. Further investigations on specimens subjected to −6% compressive strain revealed that areas with retransformed martensite serve as nucleation zones for corrosion damage. Stress-induced corrosion cracks developed, which eventually deteriorate functional response. KW - Shape memory alloy (SMA) KW - In situ characterization KW - Corrosion KW - Austenite-to-martensite phase transformation PY - 2024 DO - https://doi.org/10.1016/j.mtla.2023.102001 VL - 33 SP - 1 EP - 11 PB - Elsevier BV AN - OPUS4-61283 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Erxleben, Kjell A1 - Kaiser, Sebastian A1 - Rhode, Michael A1 - Kannengiesser, Thomas A1 - Kromm, Arne T1 - In-service and repair welding of pressurized hydrogen pipelines–a review on current challenges and strategies N2 - Hydrogen is the energy carrier for a sustainable future without fossil fuels. As this requires a reliable transportation infrastructure, the conversion of existing natural gas (NG) grids is an essential part of the worldwide individual national hydrogen strategies, in addition to newly erected pipelines. In view of the known effect of hydrogen embrittlement, the compatibility of the materials already in use (typically low-alloy steels in a wide range of strengths and thicknesses) must be investigated. Initial comprehensive studies on the hydrogen compatibility of pipeline materials indicate that these materials can be used to a certain extent. Nevertheless, the material compatibility for hydrogen service is currently of great importance. However, pipelines require frequent maintenance and repair work. In some cases, it is necessary to carry out welding work on pipelines while they are under pressure, e.g., the well-known tapping of NG grids. This in-service welding brings additional challenges for hydrogen operations in terms of additional hydrogen absorption during welding and material compatibility. The challenge can be roughly divided into two parts: (1) the possible austenitization of the inner piping material exposed to hydrogen, which can lead to additional hydrogen absorption, and (2) the welding itself causes an increased temperature range. Both lead to a significantly increased hydrogen solubility in the respective materials compared to room temperature. In that connection, the knowledge on hot tapping on hydrogen pipelines is rare so far due to the missing service experiences. Fundamental experimental investigations are required to investigate the possible transferability of the state-of-the-art concepts from NG to hydrogen pipeline grids. This is necessary to ensure that no critical material degradation occurs due to the potentially increased hydrogen uptake. For this reason, the paper introduces the state of the art in pipeline hot tapping, encompassing current research projects and their individual solution strategies for the problems that may arise for future hydrogen service. Methods of material testing, their limitations, and possible solutions will be presented and discussed. KW - In-service KW - Welding KW - Hydrogen pipeline KW - Review PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-638847 DO - https://doi.org/10.1007/s40194-025-02127-x SN - 0043-2288 SP - 1 EP - 24 PB - Springer Science and Business Media LLC AN - OPUS4-63884 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Matschat, Ralf A1 - Dudzus, Thomas A1 - Meier, Klaus A1 - Recknagel, Sebastian A1 - Kipphardt, Heinrich A1 - Hedrich, Martina ED - Hirschfeld, D. T1 - Messung von Sauerstoff und Stickstoff mit klassischer Trägergasheißextraktion und Trägergasheißextraktion nach Aktivierung mit Photonen für die nationalen primären Kalibriernormale T2 - 8. Symposium Nichtmetalle in Metallen - NIM ; 8. Tagung des Gemeinschaftsausschusses "Nichtmetalle in Metallen" der GDMB CY - Münster, Deutschland DA - 2000-03-16 PY - 2000 SN - 3-9806913-1-4 SP - 19 EP - 27 PB - GDMB, Ges. für Bergbau, Metallurgie, Rohstoff- und Umwelttechnik CY - Clausthal-Zellerfeld AN - OPUS4-915 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -