TY - CONF A1 - Agudo Jácome, Leonardo A1 - Jürgens, Maria A1 - Sonntag, Nadja A1 - Olbricht, Jürgen A1 - Skrotzki, Birgit T1 - Cyclic operation performance of 9 -12% cr ferritic martensitic steels part 1: cyclic mechanical behavior under fatigue and creep fatigue loading N2 - 9-12% Cr ferritic-martensitic stainless steels are widely used as high temperature construction materials in fossil fueled power plants due to their excellent creep and oxidation resistance, but changes in electricity markets during the last two decades have considerably changed the typical working conditions of these facilities. The growing share of renewable energy sources in power generation forces most of these plants into flexible operation with frequent load shifts or shutdowns. These cyclic operation profiles constitute a major lifetime issue, raising the question which fundamental processes govern the reaction of ferritic-martensitic steels to cyclic load and temperature variations. The present contribution reports on current findings obtained in a multidisciplinary project funded by German Ministry of Education and Research (BMBF) which combines cyclic mechanical and cyclic oxidation testing of different 9-12% Cr grades with detailed microstructural analyses and related micromechanical modeling. In the present first part of our contribution, an overview will be given on the results obtained in the mechanical testing programme of the project. Mechanical analyses were carried out on P91 and (mainly) P92 steel grades, particularly looking at softening phenomena and lifetimes obtained in isothermal cyclic loading (low cycle fatigue, LCF), non-isothermal cyclic loading (thermo-mechanical fatigue, TMF), and service-like combinations of creep and fatigue periods. For this purpose, cylindrical specimens were extracted from thick-walled steam pipes, orthogonal to the pipe axis, and subjected to strain controlled cyclic loading (± 0.2 to ±0.5 % mechanical strain) to different degrees of softening at temperatures up to 620 °C. The test results will be presented and discussed with a focus on the impact of hold periods (i.e. combined creep-fatigue conditions) on mechanical softening, lifetime and crack formation. Details on the microstructural evolution and their representation in a micromechanical model will be given in a second, complementary contribution to this conference. T2 - 45. MPA-Seminar CY - Stuttgart, Germany DA - 01.10.2019 KW - Tempered Martensite Ferritic Steels KW - Low Cycle Fatigue KW - Creep-Fatigue KW - Thermo-Mechanical Fatigue KW - P92 PY - 2019 AN - OPUS4-50050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria A1 - Mohring, W. A1 - Karafiludis, Stephanos A1 - Schneider, M. A1 - Haas, S. A1 - Hagen, S. A1 - Glatzel, U. A1 - Laplanche, G. A1 - Stephan-Scherb, C. T1 - Corrosion in the Co-Cr-Fe-Ni high entropy alloy family N2 - While a lage amount of research on high entropy alloys is oriented towards mechanical properties and the microstructural improvement it is also necessary to keep an eye on the environment that potential application materials will be submitted to. The Co-Cr-Fe-Ni based high entropy family has shown great potential over the years of high entropy research and some candidate alloys are chosen for an insight into their corrosion behaviour. Several atmospheres are studied, i.e. O2, H2O, SO2 and a mix thereof in argon as well as synthetic air. Just as for classic alloys, the chromium is the most important element in terms of protection agains further corrosion. The addition of manganese, as in case of the “Cantor alloy” CrMnFeCoNi, overpasses Cr when it comes to oxygen affinity and thus counteracts the layer formation of Cr2O3. Even without Mn, a temperature chosen too high will also affect the formation of the chromium oxide layer and spall it off, annulling its protective potential. We can also observe how trace elements influence the layer formation. These effects and their mechanisms will be discussed for the alloys CrFeNi, CoCrNi, CrMnFeCoNi and variations of Al10Co25Cr8Fe15Ni36Ti6 using a combination of electron microscopy, thermodynamic calculations and x-ray diffraction. T2 - MRS-T International Conference CY - Hsinchu, Taiwan DA - 17.11.2023 KW - Corrosion KW - Scanning electron microscopy KW - Mixed gas atmosphere PY - 2023 AN - OPUS4-58980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sandoval Saldias, Janina A1 - Blank, Robin A1 - Stephan-Scherb, Christiane T1 - Chloridische Salzschmelzen als latente Wärmespeicher N2 - Latente Wärmspeicher auf der Basis von NaCl-KCl-MgCl2 Mischungen stellen eine kostengünstige Option für die Energiespeicherung von Prozesswärme dar. Der Beitrag gibt einen Überblick über die materialwissenschaftlichen Herausforderungen im System Salz-Legierung, welche gelöst werden müssen, um diese Speichertechnologie industriell zu etablieren. T2 - DMG Sektionstreffen Angewandte Mineralogie und Kristallographie CY - Online Meeting DA - 25.02.2021 KW - Wärmespeicher KW - Korrosion KW - Salzschmelzen PY - 2021 AN - OPUS4-52234 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina A1 - Gonzalez-Martinez, I. A1 - Agudo Jacome, Leonardo T1 - Damage induced by electric field of microparticles in the electron microscope N2 - Damage induced by electric field (DIEF) that happens in the transmission electron microscope (TEM) when converging the electron beam (e-beam) on microparticles (MPs) can be used to synthesis new nanomaterial and nanomaterial compositions. The research questions are to clarify the limits and possibilities of the method regarding materials that can be produced, systems to which it is applicable and working beam parameters. Synthesis of nano-objects from microparticles using DIEF in TEM could be shown for different materials. Additionally, DIEF using the e-beam in a scanning electron microscope (SEM) can also be used to synthesis nano-objects. A deeper material analysis of this nano-objects was done using TEM and shows that the material of the nanoparticles (NPs) can be gold or/and silicon. Furthermore, the size of the NPs depends on the distance to the center of DIEF whereby the larger NPs are closer to the center. The areas of gold NPs are promising candidates for plasmonic or photonic devices for energy storage or transport. T2 - PhD-Day 2022 CY - Berlin, Germany DA - 06.09.2022 KW - Electron microscopy KW - Electron beam induced modification KW - Gold nanoparticles PY - 2022 AN - OPUS4-58264 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria A1 - Yesilcicek, Yasemin A1 - Haas, S. A1 - Glatzel, U. T1 - Über das Zusammenspiel von Gitterfehlpassung, Kriecheigenschaften und γ'-Würfelform in Hf-W-modifizierten Al10Co25Cr8Fe15Ni36Ti6—Legierungen N2 - Spurenelemente spielen eine wichtige Rolle bei der Verfeinerung der Eigenschaften von komplexen Materialien. Diese Arbeit zeigt die Korrelation zwischen der Mikrostruktur, der Gitterfehlpassung und den Kriecheigenschaften. Die Legierung Al10Co25Cr8Fe15Ni36Ti6 (in at. %) mit komplexer Zusammensetzung wurde mit den Elementen Hf und W verstärkt. Die Zugabe von Hf bewirkt eine eckigere Form der würfelförmigen gamma'-Ausscheidungen und einen erhöhten Anteil der Heusler-Phase. Die Zugabe von W wiederum formt die Würfelchen rundlicher und löst die Heusler-Phase auf. Eine Mischung der beiden Spurenelemente zeigt einen Übergang zwischen den beiden Extremen, sowohl in Hinsicht auf die Form der Ausscheidungen als auch in Bezug auf die Gitterfehlpassung und die Kriecheigenschaften. T2 - 11. Metals and Alloys Seminar CY - Cala Santanyi, Spain DA - 20.06.2022 KW - Hochentropie-Legierung KW - Kriechversuche KW - Gitterfehlpassung KW - Transmissionselektronenmikroskopie PY - 2022 AN - OPUS4-55396 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker A1 - Altmann, Korinna A1 - Marzik, Julian T1 - Roving-Alterung und mechanische Eigenschaften N2 - Im statistischen Mittel steht eine Windkraftanlage (WKA) in Deutschland alle 6 Jahre wegen eines Schadens an den Rotorblättern und verursacht Kosten von 20k€-40k€ infolge Ertragsausfall und Reparaturkosten. Bei über 30.000 WKA in Deutschland verursacht dies jährlichen Kosten von 100-200 Mio. €. Zu 70% sind die Ursachen Fertigungsfehler. Diesem Themenkomplex widmet sich FB-5.3 in Kooperation mit FBs der Zerstörungsfreien Prüfung (Abt. 8) schon seit Jahren. Im aktuellen Projekt geht es um einen vorzeitigen Verschleiß der Rotorblätter infolge der Verwendung gealterter Glasfaser-Rovings. (GF). Die Entwicklung moderner Windkraftanlagen hatte in Europa seinen Ursprung in den 90er Jahren. OEMs und GF-Hersteller waren dicht beisammen. Die Globalisierung des Marktes führt heute zu einer weltweiten Verschiffung der GF in feucht-warmen Containern. Je nach Beschaffenheit (Chemie) der Schlichten (Oberflächenbehandlung) von GF können diese stark altern (Hydrolyse-Effekte) und die Festigkeit kann im Bauteil um bis zu 50% abgemindert sein. In einer Kooperation mit der Rotorblattallianz, einem Zusammenschluss der OEMs, Halbzeugherstellern und Forschungsinstituten, wurden schon vor 5 Jahren in einem Forschungsprojekt (FB-5.3; VH 5538) die chemischen Mechanismen der Alterung exemplarisch für eine Glasfaser-Roving-Type aufgeklärt. Im aktuellen Projekt (FB-5.3; VH 5304) wird ein beschleunigtes Alterungsverfahren (erhöhte Temperatur und Feuchte) am Roving im un-impregnierten Zustand entwickelt und die Festigkeit nachfolgend nach Einbettung in eine Epoxid-Harz-Matrix bestimmt. Je nach Alterungszustand zeigt sich eine Abnahme der Zwischenfaserbruchfestigkeit von bis zu 50%. Nicht alle Glasfaser-Roving-Typen zeigen diesen Effekt. Es ist gelungen für OEMs und Halbzeughersteller ein handhabbares Verfahren zur innerbetrieblichen Qualitätssicherung zu entwickeln, da die wenigsten Firmen über komplexe Analyseverfahren, wie an der BAM, verfügen. T2 - Composite United - AG Faserverbund in der Windenergie CY - Braunschweig, Germany DA - 09.05.2023 KW - Faserkunststoffverbunde KW - Windenergie KW - Alterung PY - 2023 AN - OPUS4-58409 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Goedecke, Caroline A1 - Altmann, Korinna A1 - Bannick, C. G. A1 - Kober, E. A1 - Ricking, M. A1 - Schmitt, T. A1 - Braun, Ulrike T1 - Detection of polymers in treated waste water using TED-GC-MS N2 - The presence of large quantities of plastic waste and its fragmentation in various environmental compartments are an important subject of current research. In the environment, (photo ) oxidation processes and mechanical abrasion lead to the formation of microplastics. However, until now, there are no established quality assurance concepts for the analysis of microplastic (<5 mm) in environmental compartments, including sampling, processing and analysis. The aim of the present work is the development of suitable examination methods and protocols (sampling, sample preparation and detection) to qualify and quantify microplastic in urbane water management systems. At first a fractional filtration system for sampling and the analytical tool, the so-called TED-GC-MS (thermal desorption gas chromatography mass spectrometry) were developed. The TED-GC-MS method is a two-step analytical procedure which consists of a thermal extraction where the sample is annealed and characteristic decomposition products of the polymers are collected on a solid phase. Afterwards these products are analysed using GC-MS. The developed fractional filtration for sampling and the TED-GC-MS for detection were used for quantitative analysis to screen the waste water influent and effluent of a Berlin waste water treatment plant for the most relevant polymers, polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET) and polyamide (PA). The results of the study revealed that the polymeres PE, PS and PP were detected in the effluent, and PE and PS were find in the raw waste water of the sewage treatment plant in Ruhleben, Berlin. Differences in polymer types and amounts were detected at different sampling dates and within different sieve fractions. Much higher amounts of polymers were observed in the raw waste water. The peak areas of the decomposition products, used for quantification of the polymers, were adjusted using so-called response factors since the TED-GC-MS method is more sensitive for PP and PS than for PE. It has been shown that PE is the most dominant polymer in the samples. Comparing the masses of polymers in the effluent and in the raw sewage, a removal of 99 % of the polymers in the water treatment plant can be assumed. These results are consistent with the literature where removal rates between 98-99 % were described. T2 - SETAC Europe CY - Rom, Italy DA - 13.05.2018 KW - Microplastics KW - Thermogravimetry KW - Waste water KW - Chromatography PY - 2018 AN - OPUS4-44968 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna A1 - Goedecke, Caroline A1 - Bannick, C.G. A1 - Ricking, M. A1 - Kober, E. A1 - Schmitt, T. A1 - Braun, Ulrike T1 - Detektion von Polymeren im Abwasser eines Klärwerks mittels TED-GC_MS N2 - In den Umweltmedien Wasser, Boden und Luft wird Mikroplastik (MP) gefunden. Mögliche Eintragspfade, besonders Einträge über den Klarlauf kommunaler Klärwerke, sind unklar. Dazu wurde das Klärwerk Ruhleben in Berlin an jeweils vier Tagen im Sommer- und Winterbetrieb beprobt. Es wurde jeweils 1 m3 Klarlauf fraktioniert filtriert (500, 100 und 50 µm Siebe). Weiterhin wurde Rohabwasser exemplarisch untersucht. Als Analyse-methoden wurden die TED-GC-MS und die FTIR Mikroskopie verwendet. Bei der TED-GC-MS wird die Probe zunächst thermisch extrahiert, bevor die charakteristischen Zersetzungsgase mittels einer GC-Säule getrennt und im MS detektiert werden [1,2]. Es ist hier erstmals gelungen, nicht nur das MP zu identi-fizieren, sondern auch eine Massenbilanz zu erstellen und so eine quantitative Auswertung vorzunehmen. Es wurde PE, PS ganzjährig und PP im Sommer gefunden. Das Klärwerk Ruhleben hat einen Rückhalt an MP von 99%. T2 - Wasser 2018 CY - Papenburg, Germany DA - 07.05.2018 KW - Mikroplastik KW - Abwasser KW - TED-GC-MS KW - Bilanzierung PY - 2018 AN - OPUS4-44889 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günster, Jens A1 - Zocca, Andrea T1 - Dense Powder Beds for the Additive Manufacturing of Ceramics N2 - Regarding feedstocks for the additive manufacturing (AM) of ceramics, two features are most critical in classical powder based AM processes: a high particle packing density (typically >50% TD) must be achieved with very fine particles (typically submicron) in order to ensure sufficient sintering activity. Three innovative approaches will be introduced to overcome this problem: 1. Layer wise slurry deposition: The use of water based ceramic slurries as feedstock for the additive manufacture of ceramics has many advantages which are not fully exploit yet. In the layerwise slurry deposition (LSD) process a slurry with no or low organic content is repetitively spread as thin layers on each other by means of a doctor blade. During the deposition, the ceramic particles settle on the previously deposited and dried material to form thin layers with a high packing density (55-60%). The LSD therefore shares aspects both of tape casting and slip casting. The LSD differentiates from the classical powder-based AM layer deposition, which typically achieves with a flowable coarse grained powder a low packing density (35-50%) only, consequently hindering the ability of sintering ceramic parts to full density. The LSD is coupled with the principles of selective laser sintering (SLS) or binder jetting, to generate novel processes which take advantage of the possibility of achieving a highly dense powder-bed. 2. Laser induced slip casting: Contrary to the LSD process, which requires drying of each individual layer, the direct interaction of ceramic slurries with intense laser radiation, for the laser induced slip casting (LIS), is a promising approach for the additive manufacture of voluminous parts. 3. Gas flow assisted powder deposition: By the application of a vacuum pump a gas flow is realized throughout the powder bed. This gas flow stabilizes the powder bed and results into an enhanced flowability and packing density of the powder during layer deposition. The presentation will provide a detailed discussion of potentialities and issues connected to the mentioned technologies and will describe the most recent developments in their application to technical ceramics. T2 - SmatMade 2022 CY - Osaka, Japan DA - 25.10.2022 KW - Additive Manufacturing KW - Advanced ceramics PY - 2022 AN - OPUS4-59886 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günster, Jens T1 - Binder Jetting of Advanced Ceramics N2 - The Binder Jetting BJ process is one of the most versatile additive manufacturing technologies in use. In this process a binder is locally jetted into a powder bed for the consolidation of a 3D structure, layer by layer. Basically, all materials which can be provided as a flowable powder and, thus, spreadable to a thin layer, can be processed. Metals, ceramics and polymers are processable, but also materials from nature, such as sand, wood sawdust and insect frass. Moreover, the BJ technology is adapted to large building volumes of some cubic meters easily. Besides these striking advantages, the manufacture of ceramic parts by BJ is still challenging, as the packing density of the powder bed is generally too low and the particle size of a flowable powder too large for a successful densification of printed parts in a subsequent sintering step to an advanced ceramic product. After an introduction of binder jetting in general and highlighting some examples, strategies for obtaining dense ceramic parts by BJ will be introduced. T2 - yCAM 2022 CY - Barcelona, Spain DA - 08.11.2022 KW - Additive Manufacturing KW - Ceramics PY - 2022 AN - OPUS4-59887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -