TY - GEN A1 - Zaghdoudi, M. A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar ED - Altenbach, H. ED - Hitzler, L. ED - Johlitz, M. ED - Merkel, M. ED - Öchsner, A. T1 - Analysis of Heterogeneous Ageing of HNBR O-Rings N2 - Abstract Hydrogenated nitrile butadiene rubber (HNBR) elastomer was thermo-oxidatively aged at different temperatures up to 150 °C. Fourier transform infrared spectroscopy (FTIR), compression stress relaxation (CSR) and international rubber hardness degree (IRHD) microhardness were used to characterise the chemo-mechanical changes of HNBR O-rings during thermo-oxidative ageing. FTIR shows the development of carbonyl, methyl and ester groups but the nitrile content was not affected by ageing. The effect of sample geometry during CSR was investigated. CSR data were converted through integrated kinetic laws. The conversion has proven its sensibility to detect heterogeneous ageing. This was confirmed by the IRHD measure-ments across the section of O-rings. The influence of compression during ageing was assessed through IRHD measurements across the section of compressed and uncom-pressed aged O-rings. The DLO effect was more pronounced in compressed O-rings. By applying the model of Wise et al., theoretical IRHD and oxidation profiles were determined on the basis of IRHD experimental data of compressed O-rings. Good agreements between the experimental and the theoretical IRHD profiles in the core region were obtained. However, near the edge, the theoretical IRHD values were overestimated. KW - Ageing KW - Rubber seals KW - Stress relaxation KW - Modelling PY - 2024 SN - 978-3-031-49042-2 DO - https://doi.org/10.1007/978-3-031-49043-9 SN - 1869-8433 SP - 331 EP - 348 PB - Springer Nature CY - Cham, Switzerland AN - OPUS4-59769 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wiederholt, Wilhelm ED - Rabald, E. ED - Behrens, D. T1 - Metallüberzüge (Allgemein) N2 - In der Technik müssen Werkstoffe vielfach aus Gründen der Wirtschaftlichkeit und ihrer mechanischen bzw. sonstigen speziellen Eigenschaften eingesetzt werden, obwohl sie den chemischen Beanspruchungen nicht gewachsen sind. Will und kann man unter derartigen Bedingungen auf ihren Einsatz nicht verzichten, so bietet sich die Möglichkeit, die chemischen Beanspruchungen auf den Werkstoff dadurch auszuschalten, daß der Werkstoff von seiner Umgebung durch Schutzschichten, Überzüge, Folien, dickere Beläge oder dgl. vollständig und dauernd abgeschirmt wird. Diese Trennung muß in jedem Falle so gut und vollständig sein, daß das angreifende Mittel nicht mehr an den Grundwerkstoff gelangen kann. Die Abwehr gegen den chemischen Angriff übernimmt dann 100%ig die Abschirmung. KW - Metallüberzug KW - Schutzschicht KW - chemische Beanspruchung PY - 1968 VL - DWT-Werkstoff-Gruppe 99, Met.., Dezember 1968 SP - 1 EP - 14 PB - DECHEMA CY - Frankfurt a.M. AN - OPUS4-60293 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wiederholt, Wilhelm ED - Rabald, E. ED - Behrens, D. T1 - Metallüberzüge: Cr N2 - Chrom ist ein verhältnismäßig hartes, sprödes Metall mit einem hohen Schmelzpunkt. Durch diese Eigenschaften werden die Herstellungsmöglichkeiten der Überzüge dieses Metalles in der Weise eingeschränkt, daß im technischen Maßstabe Chrom auf anderen metallischen Werkstoffen nur aus wäßrigen Lösungen oder bei höheren Temperaturen aus Chromverbindungen über die Gasphase abgeschieden werden kann. Aus den genannten Gründen kommen Überzüge nur in geringen Dicken in Betracht, da sie andernfalls vom Untergrund abplatzen würden. Die Chromüberzüge zeichnen sich je nach den Herstellungsbedingungen durch blankes bzw. hochglänzendes Aussehen, eine gute Korrosionsbeständigkeit gegen zahlreiche angreifende Mittel, durch ihre fettabweisende Wirkung, durch hohe Härte und durch gute Widerstandsfähigkeit gegen gleitende bzw. reibende Beanspruchungen aus. Je nach den gewünschten Eigenschaften wird man das Verfahren als dekorative bzw. Glanzverchromung, Hartverchromung oder Schwarzverchromug auf elektrolytischem Wege oder als Diffusionsverchromung durchführen. KW - Chromüberzug KW - Schutzschicht KW - chemische Beanspruchung PY - 1968 VL - DWT-Werkstoff-Gruppe 14, Met.., Dezember 1968 SP - 1 EP - 3 PB - DECHEMA CY - Frankfurt a.M. AN - OPUS4-60296 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wiederholt, Wilhelm ED - Rabald, E. ED - Behrens, D. T1 - Metallüberzüge: Ni N2 - Die gute Korrosionsbeständigkeit von Nickel gegen die Atmosphäre, Alkalien u. dgl. sowie seine speziellen mechanischen Eigenschaften - vor allem gute Temperaturbeständigkeit, genügende Härte und Verschleißfestigkeit - wird auch in Form von Überzügen zum Schutz von mechanisch und chemisch weniger widerstandsfähigen Metallen ausgenutzt. Die Überzüge können durch fremdstromlose, elektrolytische, Diffusions-, Spritz-, Vakuumaufdampf-, Plattier- und Aufschweißverfahren hergestellt werden. Je nach den gewählten Verfahren und den jeweiligen Arbeitsbedingungen erhält man Überzüge mit speziellen Eigenschaften, so daß je nach den Beanspruchungsbedingungen Überzüge mit den jeweils zweckentsprechenden Eigenschaften hergestellt werden können. Bei der Auswahl der Verfahren sind neben den Kosten allerdings u. a. auch Art und Form der zu überziehenden Werkstoffe und Werkstücke zu berücksichtigen. KW - Nickelüberzug KW - Schutzschicht KW - chemische Beanspruchung PY - 1968 VL - DWT-Werkstoff-Gruppe 39, Met.., Dezember 1968 SP - 1 EP - 8 PB - DECHEMA CY - Frankfurt a.M. AN - OPUS4-60297 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Vladár, A. E. A1 - Hodoroaba, Vasile-Dan ED - Hodoroaba, Vasile-Dan ED - Unger, Wolfgang ED - Shard, A. G. T1 - Characterization of nanoparticles by scanning electron microscopy N2 - In this chapter sample preparation, image acquisition, and nanoparticle size and shape characterization methods using the scanning electron microscope (SEM) in reflective and transmitted working modes are described. These help in obtaining reliable, highly repeatable results. The best solutions vary case-by-case and depend on the raw (powdered or suspension) nanoparticle material, the required measurement uncertainty and on the performance of the SEM. KW - Nanoparticles KW - Sample preparation KW - Electron microscopy KW - SEM KW - Size measurement KW - Shape KW - Threshold PY - 2020 SN - 978-0-12-814182-3 DO - https://doi.org/10.1016/B978-0-12-814182-3.00002-X SP - 7 EP - 27 PB - Elsevier CY - Amsterdam AN - OPUS4-50120 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Unger, Wolfgang A1 - Wirth, Thomas A1 - Hodoroaba, Vasile-Dan ED - Hodoroaba, Vasile-Dan ED - Unger, Wolfgang ED - Shard, A. G. T1 - Auger electron spectroscopy N2 - An introduction in the application of Auger Electron Spectroscopy to surface chemical analysis of nanoparticles is given. Auger Electron Spectroscopy is a mature method in the field of surface chemical analysis. The chapter addresses the physical basis of the method, the principal design of recent instruments together with modes of operation and options for the presentation of spectra, as well as different approaches for qualitative (including identification of chemical species) and quantitative surface analysis of elements. An application paragraph on surface chemical analysis of nanoparticles by AES or SAM introduces the different measurement approaches and sample preparation strategies applied by analysts. The analysis of nanoparticle ensembles, the so-called selected point analysis where a narrow primary electron beam is centered on an individual nanoparticle, and chemical mapping of individual nanoparticles (or a line scan across) are addressed. Existing literature is reviewed and informative case studies presented. Limitations and pitfalls in the application of AES in surface chemical analysis of nanoparticles are also addressed. KW - Auger Electron Spectroscopy KW - Surface chemical analysis KW - Imaging surface chemical analysis KW - Nanoparticles KW - Nanotechnology PY - 2020 SN - 978-0-12-814182-3 DO - https://doi.org/10.1016/B978-0-12-814182-3.00020-1 SP - 373 EP - 395 PB - Elsevier CY - Amsterdam AN - OPUS4-50119 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Thuy, Maximilian A1 - Brauch, N. A1 - Niebergall, Ute A1 - Alig, I. A1 - Oehler, H. A1 - Böhning, Martin T1 - Environmental Stress Cracking of PE-HD Induced by Liquid Test Media Representing Crop Protection Formulations N2 - Packaging containers for dangerous goods that include aggressive liquids require that any packaging material that is based on high-density polyethylene has a high degree of stability and durability. This work is focused on testing the environmental stress cracking of the high-density polyethylenes used for such containers in contact with crop protection formulations, in particular, two model liquids established in Germany as standardized test media representatives for crop protection formulations containing the various admixtures typical for such products. One of the liquids is water-based and contains mostly surface-active ingredients, while the other is solvent-based and includes some emulsifiers. Originally established for pin impression tests, these model liquids and their individual components were here used for the first time as environmental media in the Full Notch Creep Test, which addresses the resistance against environmental stress cracking. The Full Notch Creep Test was carried out on five high-density polyethylene types with both model liquids, and also on one selected material with its components. The evaluation was focused on the fracture surface structures, which were visualized by a scanning electron microscope and by optical in situ imaging of the notch opening. While the water-based model liquid and its surface-active individual components induced environmental stress cracking with the characteristic pattern for a craze-crack mechanism and so-called brittle fracture on the surface, the solvent-based model liquid and its soluble ingredients exhibited rather ductile failure behavior, caused by the plasticizing effect on the polymer that reduced the yield stress of the high-density polyethylene. For both cases, fracture surface analysis, together with side views of the crack opening, showed a clear relation between surface pattern, notch deformation (e.g., by blunting), or crack opening due to crack growth with time to failure and the solubility of the liquids in high-density polyethylene. KW - Environmental stress cracking KW - Fracture surface KW - Full Notch Creep Test KW - Crop protection formulations KW - High-density polyethylene PY - 2023 DO - https://doi.org/10.1520/STP164320210095 SP - 317 EP - 341 PB - ASTM International CY - West Conshohocken, PA (USA) AN - OPUS4-57459 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Shard, A. G. A1 - Hodoroaba, Vasile-Dan A1 - Unger, Wolfgang ED - Hodoroaba, Vasile-Dan ED - Unger, Wolfgang ED - Shard, A. G. T1 - Introduction N2 - The purpose of this book is to provide a comprehensive collection of analytical methods that are commonly used to measure nanoparticles, providing information on one, or more, property of importance. The chapters provide up-to-date information and guidance on the use of these techniques, detailing the manner in which they may be reliably employed. Within this chapter, we detail the rationale and context of the whole book, which is driven by the observation of a low level of reproducibility in nanoparticle research. The aim of the book is to encourage awareness of both the strengths and weaknesses of the various methods used to measure nanoparticles and raise awareness of the range of methods that are available. The editors of the book have, for many years, been engaged in European projects and standardization activities concerned with nanoparticle analysis and have identified authors who are experts in the various methods included within the book. This has produced a book that can be used as a definitive guide to current best practice in nanoparticle measurement. KW - Nanoparticles KW - Size distribution KW - Shape KW - Chemistry KW - Coating KW - Concentration KW - Standards KW - Charge KW - Characterisation PY - 2020 SN - 978-0-12-814182-3 DO - https://doi.org/10.1016/B978-0-12-814182-3.00001-8 SP - 1 EP - 6 PB - Elsevier CY - Amsterdam AN - OPUS4-50166 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schaepe, Kaija A1 - Jungnickel, H. A1 - Heinrich, Thomas A1 - Tentschert, J. A1 - Luch, A. A1 - Unger, Wolfgang ED - Hodoroaba, Vasile-Dan ED - Unger, Wolfgang ED - Shard, A. G. T1 - Secondary ion mass spectrometry N2 - This chapter provides an introduction in secondary ion mass spectrometry as one of the leading surface chemical analysis and imaging techniques with molecular specificity in the field of material sciences. The physical basics of the technique are explained along with a description of the typical instrumental setups and their modes of operation. The application paragraph specifically focuses on nanoparticle analysis by SIMS in terms of surface spectrometry, imaging, analysis in organic and complex media, and depth profiling. A review of the existing literature is provided, and selected studies are showcased. Limitations and pitfalls as well as current technical developments of SIMS application in nanoparticle surface chemical analysis are equally discussed. KW - Time-of-flight secondary ion mass spectrometry KW - Surface chemical analysis KW - Imaging KW - Nanomaterials KW - Nanoparticles KW - Core-shell PY - 2020 SN - 978-0-12-814182-3 DO - https://doi.org/10.1016/B978-0-12-814182-3.00025-0 SP - 481 EP - 509 PB - Elsevier CY - Amsterdam AN - OPUS4-50187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Rhode, Michael A1 - Mente, Tobias A1 - Kannengießer, Thomas A1 - Czeskleba, Denis T1 - Simulation of hydrogen distribution in submerged arc welded heavy plates as tool for evaluating cold cracking sensitivity for offshore structures N2 - Foundation structures for offshore wind turbines are typically made of heavy plate struc-tural steels, such as S420ML, welded by submerged arc welding. Due to the welding process conditions, higher amounts of hydrogen can be introduced. In this context, large plate thicknesses result in long diffusion paths and a prolonged diffusion time for hydrogen at ambient temperature and possible delayed hydrogen-assisted cold cracking. As a result, hydrogen can accumulate in areas of high mechanical stress and strain. Due to the delayed diffusion, a minimum waiting time of up to 48 h must be observed before non-destructive testing can be performed. In addition, the assessment of possible cold crack locations is very complex. For this reason, a numerical model of a component-like weld test was developed to simulate the temperature field during welding and subsequent cooling. A hydrogen diffusion model based on the temporal-local temperature distribution was established. It was applied to simulate the change of hydrogen distribution as a function of temperature cycle during multi-layer welding and further for the entire waiting time interval ≤ 48 h. As a result, crack critical areas could be evaluated in terms of accu-mulated hydrogen. An advantage of the diffusion model is the simulation of a normalized concentration, i.e. between "0" (no hydrogen) and "1" (max. concentration), which can be scaled to experimentally determined hydrogen concentrations. Finally, selected results for increased real hydrogen ingress are presented, which confirm the relatively high crack resistance of the S420 submerged arc welded joint. KW - Hydrogen assisted cracking KW - Diffusion KW - Numerical simulation KW - Offshore steel PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-632416 DO - https://doi.org/10.21268/20250507-6 SP - 1 EP - 12 PB - Technische Universität Clausthal CY - Clausthal-Zellerfeld, Deutschland AN - OPUS4-63241 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -