TY - CONF A1 - Wachtendorf, Volker A1 - Barthel, Anne Kathrin A1 - Meyer-Plath, Asmus A1 - Sturm, Heinz A1 - Kalbe, Ute A1 - Bandow, Nicole A1 - Krüger, Oliver T1 - Maßgeschneiderte künstliche Bewitterungstests zur Untersuchung der alterungsbedingten Freisetzung von Produkten in die Umwelt N2 - Genormte künstliche Bewitterungstests sind häufig nicht spezifisch für die Anwendungssituation oder das Material. Das macht die Entwicklung spezifischer Tests erforderlich. Für deren Entwicklung müssen Maximalparameter der Anwendungssituation bekannt sein, womit dann der künstliche Test formuliert wird und dessen Bedingungen werden dann solange optimiert, bis die Korrelation der Effekte von natürlichem und künstlichem Test ausreichend ist. Für Untersuchungen der Freisetzung kann der verbleibende Rest in der Probe und/oder die freigesetzte Menge in Luft, Boden, Wasser bestimmt werden. Im ersten Beispiel der Witterungswirkung wurde die Freisetzung von Kohlenstoff-Nanoröhrchen (CNT) aus Polymer-Kompositen untersucht (unter Verwendung von empfindlich-nachweisbarer radioaktiver 14C-Markierung für einzelne CNT-Partikel), in einem zweiten die Freisetzung von anorganischen und organischen Bestandteilen aus elastomeren Bestandteilen von Sportböden (Bahnen und Kunstrasen) in Wasser. T2 - SKZ-Tagung: Bewitterung van Kunststoffen CY - Würzburg, Germany DA - 06.07.2022 KW - Künstliche Bewitterung KW - UV KW - Degradation KW - Freisetzung KW - CNT KW - Carbo-Nanotubes KW - Composite KW - Nano-Partikel KW - 14C-Markierung KW - Sportböden KW - Kunstrasen KW - Grundwasser PY - 2022 AN - OPUS4-55219 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pirskawetz, Stephan A1 - Weise, Frank A1 - Rieffel, Y. A1 - Gorbushina, Anna T1 - Die Schlossbrücke Berlin - Schutz der Göttinnen N2 - Vielleicht nannten es die Berliner „Puppen putzen“, wenn in den 1880er Jahren die Marmorstatuen auf der Schlossbrücke vor dem Berliner Stadtschloss mit Bürste, Wasser und Seife von Staub, Ruß und Taubendreck befreit wurden. Soviel Pflege wurde diesen Göttinnen aus der griechischen Mythologie nicht immer zuteil. So haben Klima, Luftverschmutzung und der 2. Weltkrieg, wie bei anderen Kunstwerken auch, tiefe Spuren hinterlassen. Der Erhalt dieser zwischen 1847 und 1857 aufgestellten Skulpturen und vieler vergleichbarer Objekte im Stadtbild ist durch die auch heute weiter fortschreitende Schädigung des Marmors gefährdet. In den Jahren 2006 bis 2010 förderte die Deutsche Bundesstiftung Umwelt (DBU) ein Projekt zur „Entwicklung und Überprüfung von Einhausungssystemen zur Reduzierung umweltbedingter Schädigungen von außenexponierten Marmorobjekten mit dem Ziel des langfristigen Erhalts in situ an einem national bedeutenden Objektkomplex, den Schlossbrückenfiguren unter den Linden, Berlin“. Geleitet und restauratorisch betreut wurde das Projekt durch das Landesdenkmalamt (LDA) Berlin. Durch die Abteilung Strukturgeologie und Geodynamik (GZG) der Georg-August Universität Göttinnen wurden die Verwitterungsmechanismen des Marmors untersucht und auf dieser Basis Anforderungen an das Schutzsystem formuliert. Anhand von numerischen Simulationen des Instituts für Bauklimatik der Technischen Universität Dresden (TUD) wurde das bauphysikalische Konzept des Einhausungssystems optimiert. Die konstruktive Gestaltung eines Prototyps und des finalen Entwurfs erfolgte durch das Fachgebiet Konstruktives Entwerfen und Tragwerkslehre der Universität der Künste Berlin. Durch den Fachbereich Baustoffe der BAM erfolgten die Realisierung des Prototyps der Einhausung sowie ein umfangreiches Klimamonitoring an den Skulpturen. Anhand dieses interdisziplinären Projektes und ergänzt durch weitere Messungen wird gezeigt, mit welchen Methoden die für die Degradation von Marmor relevanten Mechanismen untersucht werden können. Die Erkenntnisse aus dem Projekt sind die Grundlage für die Entwicklung nachhaltiger Pflege- und Schutzkonzepte für die kulturhistorisch wertvollen Skulpturen. Nur mit solchen modernen konservatorischen Programmen können die Originalskulpturen im Berliner Stadtraum erlebbar bleiben. T2 - Workshop Kulturerhaltung - Vom Dampfkessel zu Nanomaterialien CY - Berlin, Germany DA - 17.11.2021 KW - Baustoffe KW - Marmor KW - Verwitterung KW - Kulturelles Erbe KW - Wintereinhausungen KW - Klima KW - Zerstörungsfreie Prüfung KW - Building materials KW - Marble KW - Degradation KW - Cultural heritage KW - Winter shelters KW - Climate KW - Nondestructive testing PY - 2021 SN - 2567-1251 VL - 3 SP - 87 EP - 96 PB - Druckerei G. Bohm CY - Berlin AN - OPUS4-54637 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Aging of elastomer O-rings and PE neutron shielding materials for radioactive waste containers N2 - Our institution BAM in Berlin, Germany is concerned with research and testing of materials in the context of safety in chemistry and technology. Our working group is involved in the licensing procedures of casks for radioactive waste. Besides, we’re doing research on aging and lifetime prediction of elastomer O-rings and investigate degradation and thermal expansion of PE neutron shielding materials. T2 - Polymers in nuclear applications CY - Online meeting DA - 01.12.2021 KW - Rubber KW - Polyethylene KW - Thermal expansion KW - Lifetime KW - Degradation PY - 2021 UR - https://energiforsk.se/media/30631/bam_material_aging_analysis.pdf AN - OPUS4-54191 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Mente, Tobias T1 - Hydrogen embrittlement of steels N2 - Hydrogen assisted cracking of metals is a serious issue in the safety of components, espcially in case of welding. The current presentation gives an overview on specialized testing procedures at Department 9 including the quantitative determination of hydrogen. T2 - HYDROGENIUS BAM Joint Hydrogen Symposium CY - Online meeting DA - 06.07.2021 KW - Hydrogen KW - Embrittlement KW - Degradation KW - Carrier gas hot extraction KW - Welding PY - 2021 AN - OPUS4-53049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skrotzki, Birgit T1 - Aging processes in precipitation hardened aluminum alloys N2 - The mechanical strength of wrought high-strength aluminum alloys is essentially based on precipitation hardening, possibly in combination with prior forming, e. g. by stretching. Important parameters for achieving an optimum combination of hardness, strength, ductility, toughness, and further properties such as corrosion resistance are age-hardening temperature and time. During thermal (mechanical) treatment, nucleation and growth of precipitates takes place, leading to the desired degree of hardening. In aluminum alloys, precipitation sequences are usually passed through, i. e. a sequence of metastable precipitates is formed before the stable phase can precipitate. The optimum combination of properties is therefore based on a certain (optimum) microstructure, which can, however, change during the use of a component, since the microstructure is not stable. This happens in particular when the operating temperatures are close to the aging temperature and/or the operating times are sufficiently long. An external mechanical load may accelerate the processes. The presentation gives some examples for this. T2 - Materials Science and Engineering Congress MSE 2022 CY - Darmstadt, Germany DA - 27.9.2022 KW - Aluminium alloy KW - Precipitation hardening KW - Aging KW - Degradation PY - 2022 AN - OPUS4-55877 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Richter, Tim A1 - Rhode, Michael A1 - Nietzke, Jonathan A1 - Mente, Tobias A1 - Mayr, P. A1 - Nitsche, A. T1 - Hydrogen embrittlement and mechanical properties of 9 % Cr P92 steel and P91 weld metal N2 - Martensitic 9 %-Cr steels like P91 and P92 can show an increased susceptibility to delayed hydrogen assisted cracking. The focus of this study was the microstructure and heat treatment effect on the mechanical properties of P92 base material and P91 multi-layer weld metal in both as-welded and post weld heat treated (PWHT) condition. Tensile tests with hydrogen free reference samples and electrochemically hydrogen charged samples were carried out, the mechanical properties were assessed and supported by dedicated fractographic analysis. In addition, hydrogen and microstructure dependent fracture criteria were calculated. All investigated microstructures showed a hydrogen influenced degradation of the mechanical properties compared to the hydrogen free reference samples. In that connection, the as welded martensitic P91 weld metal had the highest degree of degradation in presence of hydrogen. The P91 PWHT weld metal and the P92 base material had comparable properties. From that point of view, a significantly increased risk for hydrogen assisted cold cracking during welding fabrication of P91 weld joints must be considered before any heat treatment is conducted. T2 - IIW Annual Assembly, Meeting of Commission IX-C CY - Tokyo, Japan DA - 21.07.2022 KW - Creep-resistant steel KW - Mechanical properties KW - Hydrogen assisted cracking KW - Weld joint KW - Degradation PY - 2022 AN - OPUS4-55462 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stockmann, Jörg M. A1 - Hertwig, Andreas A1 - Beck, Uwe T1 - Visualization of low-contrast surface modifications: thin films, printed pattern, laser-induced changes, imperfections, impurities, and degradation N2 - Industrial quality control (QC) nowadays requires the visualization of surface modifications from the macro-scopic to the microscopic or even nanoscopic scale. This is a prerequisite to the evaluation of functionality and reliability, the detection of defects and their separation of artefacts. The diversity of applications ranges from low-E glazings and solar panels, micro- and optoelectronics, micro- and smart devices to sensor-on-chip and lab-on-chip systems [1]. Optical microcopy (light, confocal laser scanning, white light interference) as established QC-tool is operated at normal incidence, i.e. p- and s-polarization are undistinguishable. Either light-intensity in terms of grey scale and colour or intensity-correlated effects of phase shifts are used. In case of ellipsometry, operated at oblique incidence, p- and s-polarization matter, and amplitude ratios and phase shifts upon reflection are measured. Hence, information content must be much higher. The visualization of surface modifications may be very challenging for coating/substrate systems of either al-most identical optical constants, e.g. transparent films on substrates of the same material, or minor film thick-ness, substance quantity and affected area, e.g. ultra-thin or island films. Ellipsometry gives access to the con-trast of intensity (I), amplitude ratio (Ψ), and phase shift (Δ) with nanometer-scaled vertical and micrometer-scaled lateral sensitivity, one is able to identify tiny changes within an unmodified surface. As both mapping ellipsometry (ME) and imaging ellipsometry (IE) are operated in the optical far-field, surface inspection is also possible on the macroscopic scale. Near the Brewster-angle of the bare, undamaged, clean, and fresh substrate, the contrast to add-on and sub-off features is superior. Fig. 1 shows three examples of ellipsometric imaging, i.e. a thin SnO:Ni film on SiO2/Si (Fig. 1a), a dried stain of an anti-body solution on cyclo-olefin-polymer (COP) shown in Fig. 1b, and a polyimide film residue on SiO2/Si (Fig. 1c). For all of these examples, ellipsometry provides much better contrast between substrate and surface modification than optical microscopy, sometimes primarily caused by the oblique incidence (Figs. 1a and 1c), in other cases related to the phase sensitivity of ellipsometry (Fig. 1b). Other examples are laser surface modifications and the corrosion of glass. In these cases, optical microscopy and IE yield to similar results, how-ever only ellipsometry gives access to modelling. Further investigated coating/substrate systems are 100Cr6 steel, native oxide on silicon, borosilicate glass, and the polymer polycarbonate with deposited films of graphene and ta-C:H, printed and dried pattern of liquids such as water, cleaning agents, and dissolved silicone. Besides imaging ellipsometry, referenced spectral ellipsometry (RSE) has been applied, combining the advantages of both optical microscopy (fast measurement) and ellipsometry (high sensitivity to tiny modifications). T2 - International Conference on Spectroscopic Ellipsometry (ICSE-7) CY - Berlin, Germany DA - 06.06.2016 KW - Ellipsometry KW - Thin films KW - Impurities KW - Degradation PY - 2016 AN - OPUS4-37068 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erdmann, Maren A1 - Niebergall, Ute A1 - Toepel, Jörg A1 - Böhning, Martin T1 - Diesel and biodiesel induced degradation of polyethylene N2 - Renewable resources become more and more relevant to maintain energy demands for an increasing global population. Biosynthetic fuels like biodiesel might replace conventional petrochemical fuels, such as diesel. However, more research is needed to characterize the interaction between the different fuels and the polymeric material, especially with respect to ageing and degradation. The poster will present several interaction and degradation phenomena of high density polyethylene (PE-HD) induced by diesel and biodiesel 1-3. Also the possible influence of microbial growth (fungi and bacteria) is considered. The chosen PE-HDs are typical thermoplastic resins for container and storage tank applications. Degradation of PE-HD will be investigated by changes of the mechanical properties – with main emphasis on the Charpy impact strength 2. Furthermore, with alternating sorption and desorption cycles in combination with oven ageing the co-oxidation 3 of PE-HD in contact with biodiesel will be addressed. T2 - MoDeSt 2016 CY - Cracow, Poland DA - 04.09.2016 KW - Impact strength KW - PE-HD KW - Diesel KW - Biodiesel KW - Degradation PY - 2016 AN - OPUS4-37320 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Ageing of HNBR, EPDM and FKM O-rings N2 - HNBR, EPDM and FKM O-rings were aged uncompressed and compressed at 75 °C, 100 °C, 125 °C and 150 °C for up to 1 year. HNBR exhibited the strongest ageing effects with high increases of hardness and glass transition temperature. Furthermore, heterogeneous ageing caused by diffusion-limited oxidation effects had a significant influence for HNBR at ageing temperatures of 125 °C and 150 °C. EPDM showed similar property changes as HNBR, but less pronounced. FKM displayed only minor ageing effects. O-rings aged in compression exhibited considerable compression set (CS). CS data was used for a time-temperature shift and resulting master curve construction. Leakage rate measurements showed that O-rings can remain leak tight under static conditions even if material properties have already deteriorated strongly. N2 - HNBR-, EPDM- und FKM-O-Ringe wurden unverpresst und verpresst für bis zu 1 Jahr bei 75 °C, 100 °C, 125 °C und 150 °C gealtert. HNBR wies mit hohen Anstiegen von Härte und Glasübergangstemperatur die stärksten Alterungseffekte auf. Weiterhin hatte heterogene Alterung aufgrund von diffusionsbegrenzten Oxidationseffekten einen wesentlichen Einfluss auf HNBR bei Alterungstemperaturen von 125 °C und 150 °C. EPDM zeigte ähnliche Eigenschaftsänderungen wie HNBR, allerdings schwächer ausgeprägt. FKM wies nur geringfügige Alterungseffekte auf. O-Ringe, die verpresst gealtert wurden, hatten eine starke bleibende Verformung (DVR). Die gemessenen DVRWerte wurden für eine Zeit-Temperatur-Verschiebung und die Konstruktion einer Masterkurve genutzt. Leckageratenmessungen zeigten, dass O-Ringe unter statischen Bedingungen dicht bleiben können, auch wenn die Materialeigenschaften schon stark degradiert sind. KW - Aging KW - Degradation KW - Leakage KW - Compression KW - Seal PY - 2016 SN - 0022-9520 SN - 0948-3276 VL - 69 IS - 4 SP - 36 EP - 42 PB - Hüthig CY - Heidelberg, Germany AN - OPUS4-36336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Influence of ageing on sealability of HNBR, EPDM and FKM O-rings N2 - At BAM, which is a federal institute for materials research and testing in Germany, it is our responsibility to evaluate the safety of casks designed for transport and/or storage of radio-active material. This includes assessment of the elastomeric seals applied in the containers. Besides examining the low-temperature behaviour of elastomeric seals, it is our goal to evaluate the service lifetime of the seals with regard to the requirements for long-term safety (40 years and more) of the containers. Therefore, we started an ageing programme with selected rubbers (HNBR, EPDM and FKM) which are oven-aged at four different temperatures (75 °C, 100 °C, 125 °C and 150 °C) up to 1.5 years. In order to assess sealability, O-rings are aged in compression by 25 % (corresponding to the compression during service) between plates as well as in flanges that allow leakage rate measurements. For comparison, uncompressed O-rings are aged as well. Further methods characterising seal performance are compression stress relaxation (CSR) reflecting the loss of sealing force of a compressed seal over time, and compression set (CS) which represents the recovery behaviour of a seal after release from compression. Many other properties, e.g. hardness or glass transition temperature, are influenced in opposite directions by crosslinking and chain scission reactions during ageing. By contrast, CSR and CS are influenced additively by each reaction type, as crosslinking leads to the formation of network chains that are in equilibrium with the compressed geometry, and broken chains lose their recovery potential and their contribution to the sealing force. The experimental results indicate that while CSR and CS show considerable degradation effects, the leakage rate stays constant or even decreases until shrinkage and the loss of resilience of the aged sample leads to the formation of a leak path. T2 - PolyMerTec 2016 CY - Merseburg, Germany DA - 15.07.2016 KW - Degradation KW - Elastomer KW - Seal KW - Compression PY - 2016 AN - OPUS4-36993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -