TY - THES A1 - Schilling, Markus T1 - Environmental Stress Cracking (ESC) and Slow Crack Growth (SCG) of PE-HD induced by external fluids N2 - High-density polyethylene (PE-HD) is widely used as a packaging material. Typical applications are pipes and containers for storage and transport of dangerous goods. For these applications, the understanding of the craze-crack damage mechanisms slow crack growth (SCG) and environmental stress cracking (ESC) is of importance. Since these mechanisms are considered to be the major causes of failure, their understanding is essential for inspection and release of those materials. A well-established test method for the assessment of these damage mechanisms is the full-notch creep test (FNCT). It is used in this study for a detailed investigation of crack propagation phenomena in PE-HD container materials under the influence of different fluids such as air, water and aqueous detergent solutions (Arkopal N 100) as well as biodiesel and diesel. Based on the results of the FNCT, a classification scheme of different fluids is proposed, which allows for an assignment of the respective damage mechanisms. Hereby, it is differentiated between (i) inert, (ii) purely surface-active and (iii) additionally sorptive, bulk-active fluids with respect to SCG. If the test fluid changes the intrinsic properties (at the surface or in the bulk), the damage mechanism is addressed to ESC behavior. In FNCT investigations, stress, temperature and specimen geometry were varied systematically. In addition to the time to failure as common measure for the resistance of a PE-HD type against crack propagation, specimen elongation was considered in detail. Several imaging techniques were applied for fracture surface analysis of specimens tested in FNCT to gain novel information on SCG and ESC behavior. From height profiles obtained by laser scanning microscopy (LSM) and information on surface structures from scanning electron microscopy (SEM), indicators for the differentiation of the crack propagation mechanisms could be derived. Based on the LSM data, an algorithm for the distinction between ductile shear deformation and brittle crack growth as dominating failure mechanism was developed. Imaging techniques were also used for determination of crack propagation rates, which were related to time-resolved FNCT elongation data. From the time-resolved determination of crack lengths of partly damaged FNCT specimens, an increasing length of craze zone with a progressively propagating crack was revealed for the first time. This relation of crack and craze zones was specified by fracture mechanical considerations. N2 - Polyethylen hoher Dichte (PE-HD) wird als Werkstoff für Rohre und Behälter für den Transport und zur Lagerung von Gefahrgütern verwendet. Für die Beurteilung und technische Freigabe dieser Materialien ist das Verständnis der beiden Schädigungsmechanismen „langsames Risswachstum“ (engl.: „slow crack growth“, SCG) und „umgebungsbedingter Spannungsriss“ (engl.: „environmental stress cracking“, ESC) essentiell. Eine etablierte Prüfmethode zur Bewertung dieser Schädigungsmechanismen ist der Full-Notch Creep Test (FNCT), der in dieser Arbeit zur systematischen Untersuchung des Risswachstums in PE-HD Behältermaterialien unter Einwirkung von Luft, Wasser und wässrigen Netzmittellösungen (Arkopal N 100) sowie Biodiesel und Diesel verwendet wird. Aus den Ergebnissen des FNCT wird ein Klassifikationsschema für Fluide vorgeschlagen, welches ebenfalls eine Zuordnung zu den Schädigungsmechanismen erlaubt. Hierbei wird in (i) inerte, (ii) rein oberflächen-aktive und (iii) zusätzliche sorptive, volumen-aktive Fluide hinsichtlich des langsamen Risswachstums (SCG) unterschieden. Wenn ein Fluid lokal die intrinsischen Materialeigenschaften des Polymers verändert, wird der Schädigungsmechanismus dem umgebungsbedingten Spannungsriss (ESC) zugeordnet. Bei den FNCT-Untersuchungen wurden die mechanische Spannung, die Temperatur und die Prüfkörpergeometrie systematisch variiert. Zusätzlich zur Standzeit wurde die Prüfkörperdehnung zeitabhängig erfasst. Aus einer erweiterten Bruchflächenanalyse konnten neuartige Informationen über SCG und ESC erhalten werden. Hierzu wurden verschiedene Bildgebungsverfahren verwendet. Insbesondere wurden mit Laserscanningmikroskopie (LSM) Höhenprofile und mit Rasterelektronenmikroskopie (REM) Oberflächeninformationen zur Charakterisierung der Rissfortschrittsmechanismen erhalten. Auf Basis der LSM wurde unter Zuhilfenahme von Höhenprofildaten ein Algorithmus zur Unterscheidung zwischen duktiler Scherverformung und sprödem Risswachstum als dominierende Schädigungsmechanismen entwickelt. Die aus den bildgebenden Verfahren ermittelten Rissfortschrittsraten konnten mit den Daten der während des FNCT erfassten Dehnung der Prüfkörper in Beziehung gesetzt werden. Weiterhin wurde mithilfe von zeitaufgelösten Risslängendaten erstmals eine direkte Korrelation der Risslänge zu vorgeschädigten, fibrillierten Bereichen (Crazes) im PE-HD Prüfkörper während des FNCT nachgewiesen. Demnach vergrößert sich die Craze-Länge linear mit zunehmender Risslänge. Dieser Zusammenhang zwischen Riss- und Craze-Längen wurde auf mathematisch, bruchmechanischer Grundlage bestätigt. KW - High-density polyethylene (PE-HD) KW - Full-Notch Creep Test (FNCT) KW - Slow crack growth (SCG) KW - Environmental Stress Cracking (ESC) KW - Biodiesel KW - Diesel KW - Crack propagation analysis KW - Fracture Surface Analysis KW - Test Improvement KW - Imaging PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:tuda-tuprints-115443 DO - https://doi.org/10.25534/tuprints-00011544 SP - 1 EP - 212 CY - Darmstadt AN - OPUS4-50941 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghafafian, Carineh T1 - Localized repairs for wind turbine rotor blades N2 - The effect of localized repairs on the structural integrity and thus the lifespan of wind turbine rotor blade shells is examined. T2 - SAMPE Symposium 2020 CY - Kassel, Germany DA - 17.02.2020 KW - GFRP KW - Wind turbine blade shells KW - Scarf joint repairs KW - Sandwich PY - 2020 AN - OPUS4-50480 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stephan-Scherb, Christiane T1 - Applied Crystallography as a tool for a better understanding of Fundamental Questions of high temperature corrosion phenomena N2 - Corrosion Science Meets X-Rays, Neutrons and Electrons. The presentation gives an overview on current research activities applying in-situ X-ray diffraction and spectroscopy for a better understanding of fundamental mechanisms of high temperature corrosion. Additionally the knowledge gain by applying neutron powder diffraction and EBSD analysis is presented. T2 - Joint meeting of german and polish crystallographic association 2020 CY - Wroclaw, Poland DA - 24.02.2020 KW - Corrosion KW - Oxidation KW - In situ KW - Diffraction PY - 2020 AN - OPUS4-50483 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heuser, Lina A1 - Sobek, P. T1 - Sintering of silver-alkali zinc borate glass composites N2 - High conductive silver-glass-metallization-pastes are key components in photovoltaics and advanced microelectronics. However, the underlying mechanisms of liquid phase sintering as silver dissolution, diffusion and reprecipitation are poorly understood so far. In the current work, the influence of different network modifier in alkali-zinc-borate paste-glasses on liquid phase sintering of silver-glass-composites was studied. Therefore, silver-glass-composites containing 30 vol% glass were prepared, using low melting X2O-ZnO-B2O3 glasses with X = Na, Li, and Rb (NZB, LZB, and RZB). Glass transition temperature, viscosity, glass-silver wetting, crystallization and sintering behavior was studied by means of thermal analysis, dilatometry, heating microscopy and microscopy. Similar glass transition temperatures of 450 °C (RZB), 460 °C (LZB) and 465 °C (NZB) were found by means of thermal analysis for glasses under study. Also, all glasses have a similar crystallization onset at about 550 °C, even though exhibiting with a different degree of crystallization. Despite these similarities, however, the sintering behavior, measured in terms of area shrinkage, significantly differs for the composites. This finding indicates a different degree of silver dissolution. Assuming that dissolved silver reduces the viscosity, this effect could explain why glass crystallization starts at lower temperature in the composites. For example, the crystallization peak of LZB at 629 °C measured for pure glass powder compacts was decreased to 586 °C for the composite. Confirmatively, microstructure analyses indicate different degrees of silver dissolution, as e.g. revealed by different amount of silver precipitates within the residual glass phase, and reprecipitation. Best silver dissolution appeared for the RZB glass. Nevertheless, the final densification of RZB was retarded probably due to swelling and crystallization. T2 - XRM Workshop CY - Halle, Germany DA - 03.03.2020 KW - Silver-glass-metallization-paste KW - Sintering KW - Alkali ions PY - 2020 AN - OPUS4-51243 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker T1 - Composite materials - focus polymer matrix composites (PMC) N2 - Lecture about polymer matrix composites as part of the first trainings event GW4SHM, properties, production, basic theory, testing. T2 - 1. Training GW4SHM-Project CY - BAM, Berlin, Germany DA - 23.11.2020 KW - Polymer matrix composites KW - Composite testing KW - NDT PY - 2020 AN - OPUS4-51868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nolze, Gert T1 - Lattice parameter determination with EBSD. Is that possible? N2 - CALM is software for determining the Bravais lattice type and the resulting lattice parameters from a single Kikuchi pattern. It requires the definition of 4 bands and a single bandwidth from which all other band positions as well as bandwidths are derived. For band detection, it uses the Funk transform, which allows detection of twice as many bands as usual. CALM works for any symmetry and requires low-noise patterns of at least 320x240 pixels. The resulting errors are <2% even for such small patterns, assuming good quality. The relative errors are <0.5%. However, this requires a projection centre position best derived from a sample of a cubic phase in CALM. However, this must have been recorded under identical conditions. Hundreds of Kikuchi patterns of phases with different symmetries were examined. T2 - Institutskolloquium Kassel CY - Online meeting DA - 30.10.2020 KW - Phasenidentifikation KW - EBSD KW - Gitterkonstanten PY - 2020 AN - OPUS4-51813 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - Focused ion beam techniques beyond the ordinary - Methodological developments within ADVENT N2 - This poster presents the focused ion beam preparation methodologies developed within the framework of the EU funded EURAMET project ADVENT (Advanced Energy-Saving Technology). It summarises the key breakthroughs achieved for various in situ investigation techniques, e.g. in situ experiments at the Synchrotron facility BESSY II (IR-SNOM and XRS), TEM and SMM instrumentation. The created experimental devices from diverse thin-film semiconductor materials paved the way to dynamic structural studies bearing the potential to determine nanoscale correlations between strain and electric fields and, moreover, for the fundamental development of new in situ capabilities. N2 - Dieses Poster zeigt die FIB Präparationstechniquen, die im Rahmen des EU-finanzierten EURAMET-Projekts ADVENT (Advanced Energy Saving Technology) entwickelt wurden. Es fasst die wichtigsten Errungenschaften zusammen, die für verschiedene in situ Untersuchungstechniken erzielt wurden, z.B. situ-Experimente in dem Synchrotronring BESSY II (IR-SNOM und XRS), in situ TEM Experimente und für die SMM Technik. Die experimentellen Probenstrukturen, die aus verschiedenen Dünnschicht-Halbleitermaterialien erzeugt wurden, ebneten den Weg für dynamische Strukturstudien, die das Potenzial haben, nanoskalige Korrelationen zwischen Dehnung und elektrischen Feldern zu bestimmen und darüber hinaus neue in situ Messmethoden zu entwickeln. T2 - Final Meeting CY - Online Meeting DA - 30.06.2020 KW - FIB KW - Sample preparation KW - In situ KW - TEM KW - AFM PY - 2020 AN - OPUS4-51606 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - Innovations- Plattform Material Digital N2 - Mit der Initiative MaterialDigital fördert das BMBF seit dem letzten Jahr ein wichtiges Instrument zur Digitalisierung der Materialwissenschaft und Werkstofftechnik in Deutschland. In der ersten Phase dieser Initiative wird seit Juli 2019 die Plattform MaterialDigital von einem Konsortium aufgestellt. Ziel dieser Plattform ist der Aufbau eines virtuellen Materialdatenraums, um zusammen mit allen Interessenten die Systematisierung des Umgangs mit Werkstoffdaten voranzutreiben. In einer zweiten Phase werden akademische F&E-Projekte voraussichtlich Anfang 2021 gefördert. In jedem dieser Projekte wird an einer konkreten Fragestellung das Themenfeld „Digitalisierung der Materialwissenschaft und Werkstofftechnik“ adressiert und multidisziplinär bearbeitet. In einer dritten Phase werden im Rahmen industriegeführter vorwettbewerblicher Verbundprojekte mit der gleichen Zielsetzung gefördert. T2 - Workshop - “Datenmanagement in der Additiven Fertigung” CY - Online meeting DA - 27.10.2020 KW - Digitalisierung KW - Plattform Material Digital KW - Virtueller Materialdatenraum KW - Vernetzung KW - Ontologien PY - 2020 AN - OPUS4-51609 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Winkelmann, A. A1 - Nolze, Gert A1 - Cios, G. A1 - Tokarski, T. A1 - Bala, P. A1 - Hourahine, B. A1 - Trager-Cowan, C. T1 - Kikuchi pattern simulations of backscattered and transmitted electrons N2 - We discuss a refined simulation approach which treats Kikuchi diffraction patterns in electron backscatter diffraction (EBSD) and transmission Kikuchi diffraction (TKD). The model considers the result of two combined mechanisms: (a) the dynamical diffraction of electrons emitted coherently from point sources in a crystal and (b) diffraction effects on incoherent diffuse intensity distributions. Using suitable parameter settings, the refined simulation model allows to reproduce various thickness- and energy-dependent features which are observed in experimental Kikuchi diffraction patterns. Excess-deficiency features are treated by the effect of gradients in the incoherent background intensity. Based on the analytical two-beam approximation to dynamical electron diffraction, a phenomenological model of excess-deficiency features is derived, which can be used for pattern matching applications. The model allows to approximate the effect of the incident beam geometry as a correction signal for template patterns which can be reprojected from pre-calculated reference data. As an application, we find that the accuracy of fitted projection centre coordinates in EBSD and TKDcan be affected by changes in the order of 10−3–10−2 if excess-deficiency features are not considered in the theoreticalmodel underlying a best-fit pattern matching approach. Correspondingly, the absolute accuracy of simulation-based EBSD strain determination can suffer frombiases of a similar order of magnitude if excess-deficiency effects are neglected in the simulation model. KW - Electron diffraction KW - EBSD KW - Kikuchi diffraction KW - Pattern matching PY - 2021 DO - https://doi.org/10.1111/jmi.13051 VL - 284 IS - 2 SP - 157 EP - 184 PB - Wiley Online Library AN - OPUS4-53584 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Charmi, Amir T1 - Mechanical anisotropy of additively manufactured stainless steel 316l: an experimental and numerical study N2 - This work aims for a yield function description of additively manufactured (AM) parts of stainless steel 316L at the continuum-mechanical macro-scale by means of so-called virtual experiments using a crystal plasticity model at meso-scale. T2 - 1st Workshop on In-situ Monitoring and Microstructure Development in Additive Manufacturing CY - BAM, Berlin DA - 10.12.2020 KW - Anisotropy KW - Crystal plasticity KW - Additive manufacturing PY - 2020 AN - OPUS4-51941 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Optische Beobachtungen der Faser-Matrix-Trennung im Pull-out-Versuch N2 - Der Vortrag behandelt Rissentstehung und Ausbreitung an Faser-Matrix-Interfaces, untersucht mit dem optischen Mikroskop. T2 - Composites United, CU-Arbeitsgruppe/n Faser-Matrix-Haftung & Matrices CY - Online meeting DA - 02.12.2021 KW - Faser KW - Matrix KW - Pull-out KW - Interface PY - 2021 AN - OPUS4-53968 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmies, Lennart A1 - Sonntag, U. T1 - Quantitative Fraktographie unter Verwendung klassischer Verfahren, Topographie-Daten und Deep-Learning N2 - Die Analyse von Bruchflächen wird in der Schadensanalyse meist auf der Basis von Erfahrungswissen vorgenommen, welches aus vorliegenden Untersuchungen, eigenen Vergleichsversuchen und aus der Literatur stammt. Durch Vergleiche mit bereits vorliegenden Bildern werden qualitativ Bruchmechanismen ermittelt. Grundlage sind zumeist zweidimensionale Bilder aus licht- und elektronenoptischen Verfahren. Quantitative Aussagen beziehen sich bislang beispielsweise auf makroskopische Anteile von Bruchmechanismen oder die Ausmessung von Schwingstreifen. In jüngerer Zeit gibt es vermehrt Ansätze, Computer-Algorithmen einzusetzen, die in der Lage sind, unterschiedlich strukturierte Bruchmerkmale zu finden und zu klassifizieren. Im hier vorgestellten IGF-Vorhaben „iFrakto“, IGF Vorhaben Nr.: 21477 N, werden licht- und elektronen-optisch Topographie-Bilder erzeugt und die gewonnenen 3D-Informationen zusammen mit den klassischen 2D-Bildern ausgewertet. Analytische Algorithmen und Machine Learning werden eingesetzt, um Bruchmerkmale zu analysieren, zu bewerten und mit Informationen aus einer fraktographischen Datenbank zu verknüpfen. Ziel ist die Bereitstellung von Software zur Unterstützung der Fraktographie in der Schadensanalyse. In diesem Beitrag werden erste Ergebnisse des Vorhabens vorgestellt. T2 - 55. Metallographie-Tagung CY - Online meeting DA - 29.9.2021 KW - Fraktographie KW - Machine Learning KW - Datenbank KW - REM KW - Topographie PY - 2021 AN - OPUS4-53491 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Agea, Boris A1 - Walzel, S. T1 - 3D Druck unterstütz die Dekarbonisierung N2 - Suspensionsbasiertes Binder Jetting reduziert die Brennzeiten von technischer Keramik im Vergleich zu anderen 3d-druckverfahren signifikant. dabei wird nicht nur Energie beim Betrieb der Brennöfen gespart, sondern auch die Emission von Kohlendioxid beim Brennvorgang selbst gesenkt. KW - Schlickerdeposition PY - 2021 VL - 6 SP - 26 EP - 28 PB - Keramische Zeitschrift AN - OPUS4-53812 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Le, Quynh Hoa A1 - Balzer, B T1 - „Auffällige große Streifen“ im Schwingbruch N2 - Die „auffälligen großen Streifen“ sind von echten Schwingstreifen nur sehr schwer zu trennen, weil sie parallel zu den Schwingstreifen verlaufen und meistens ebenfalls nicht sehr groß sind. Die im Labor getesteten Proben zeigten, dass diese großen Streifen zusammen mit Verreibungen auftraten und „tire tracks“ („Reifenspuren“) verursachten. Dies wurde durch eine hochauflösende REM-Untersuchung bestätigt, die „tire tracks“ auf den „großen Streifen“ zeigte. Ein weiterer Hinweis ist die Änderung des R-Werts von -1 auf 0,1, was zu einer Bruchfläche ohne große Streifen und „tire tracks“ führt. T2 - Treffen der AG Fraktographie im Gemeinschaftsausschuss Rasterelektronenmikroskopie in der Materialprüfung CY - Online meeting DA - 19.11.2021 KW - Fractography KW - Fracture surface KW - SEM KW - REM KW - Fraktographie KW - Schwingstreifen KW - Fatigue PY - 2021 UR - https://dgm.inventum.de/widget/preview/45d8c33d-622b-43e2-8459-ba783394a723/611d133ebdac0611d133ebdac1 AN - OPUS4-53796 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghafafian, Carineh T1 - The effect of fiber orientation mismatch on scarf joint damage mechanisms under fatigue load N2 - Wind turbine rotor blades commonly fail before their projected 20-year lifespan largely due to defects that originate during manufacturing and are propagated by operational fatigue and environmental conditions. The cost-intensive replacement outcomes lead to a high loss of earnings, and are one of the inhibitors of wind turbine production. A potential repair alternative to restoring the mechanical properties of such lightweight fiber reinforced polymer (FRP) structures is to locally patch these areas with scarf joints. This type of repair allows for a smoother load distribution across the joint, and is favored especially on structures where minor aerodynamic contour changes are key. The effects of such repairs on the structural integrity, however, is still largely unknown. Building upon an understanding of the static load failure mechanism of GFRP scarf joints, presented at the ICCS23 Joint Event in 2020, the influence of the fiber orientation mismatch between parent and repair materials of 1:50 scarf joints on the failure mechanism of monolithic glass FRP specimens under cyclic fatigue load were examined in this study. Specimens with various layups were produced with the vacuum-assisted resin infusion (VARI) process using biaxial E-glass non-crimp fabric (NCF). The patch layers were then joined directly to the parent structure with the VARI using biaxial E-glass NCF with half the areal weight of the parent side to allow for better drapability. This mimics the soft-to-hard patch style utilized in wind turbine blade shell field repairs. The specimens were tested under uniaxial fatigue load, during which they were periodically monitored for damage onset. A comparison of the +45/-45° and 0/90° layups allowed for an understanding of the role of a highly mismatching fiber orientation in the transition zone between parent and patch material on the failure mechanism of the scarf joint. In addition to the tensile strength and stiffness property recovery assessment, a grayscale analysis using in-situ camera images determined the damage state leading to failure in each region across the scarf joint, which varied in the parent material versus scarf joint region, providing insight to the critical regions in this composite structure under cyclic loading. T2 - ICCS24 - 24th International Conference on Composite Structures CY - Online meeting DA - 14.06.2021 KW - Glass fiber reinforced polymers KW - Scarf repairs KW - Damage mechanisms PY - 2021 AN - OPUS4-52817 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Sophie T1 - Entwicklung thermoelektrischer Multilayergeneratoren auf der Basis von Calciumcobaltit N2 - Thermoelectric generators can be used as energy harvesters for sensor applications. Multilayer thermoelectric generators (ML-TEGs) are a promising alternative to conventional π-type generators due to their high filling factor, high capability of automated production and the texturing potential during the production process. Calcium cobaltite is a promising thermoelectric oxide (p-type) with highly anisotropic properties. The following study shows the development of a textured unileg ML-TEG using ceramic multilayer technology. Tape-casting and pressure assisted sintering are applied to fabricate textured calcium cobaltite. Compared to conventional sintering, pressure assisted sintering increases the strength by the factor 10. Thermoelectric properties can be tuned either towards maximum power factor or towards maximum figure of merit depending on the pressure level. As electrical insulation material, a screen-printable glass-ceramic with high resistivity and adapted coefficient of thermal expansion is developed. From various commercial pastes a metallization with low contact resistance is chosen. The unileg ML-TEG is co-fired in one single step. The demonstrators reach 80% of the simulated output power and the power output is highly reproducible between the different demonstrators (99%). These results provide the first proof-of-concept for fabricating co-fired multilayer generators based on textured calcium cobaltite with high power factor, high density, and high strength. N2 - Thermoelektrische Generatoren können zum „Energy harvesting“ für den autarken Betrieb von bspw. Sensoren eingesetzt werden. Eine interessante Alternative zu den herkömmlichen π-Typ Generatoren sind auf Grund der höheren Leistungsdichte und der guten Automatisierbarkeit thermoelektrische Multilayergeneratoren. Calciumcobaltit ist ein vielsprechendes oxidisches Thermoelektrika (p-Typ) mit stark anisotropen Eigenschaften. Die hier vorgestellte Studie zeigt die Entwicklung von texturierten Unileg-Multilayer-Generatoren mittels keramischer Multilayertechnologie. Calciumcobaltit wird durch Foliengießen und druckunterstützte Sinterung texturiert. Im Vergleich zur konventionellen Sinterung verbessert sich die Festigkeit um den Faktor 10. Die thermoelektrischen Eigenschaften können je nach verwendetem Druckniveau hinsichtlich maximalem Power Factor oder hinsichtlich maximalem Gütefaktor optimiert werden. Ein Glaskeramikkomposit wird als Isolationsmaterial mit hohem Volumenwiderstand und angepasstem Wärmeausdehnungskoeffizienten entwickelt. Der Unileg-Multilayer-Generator wird in einem Schritt co-gesintert. Die hergestellten Demonstratoren erreichen 80% der simulierten Output-Leistung. Diese Ergebnisse stellen den ersten Machbarkeitsnachweis für die Herstellung von co-gesinterten Multilayer-Generatoren aus texturiertem Calciumcobaltit mit hohem Power Factor und hoher Festigkeit dar. T2 - Seminar des Lehrstuhls für Funktionsmaterialien, Universität Bayreuth CY - Online meeting DA - 18.06.2021 KW - Thermoelektrischer Generator KW - Multilayertechnik KW - Energy harvesting PY - 2021 AN - OPUS4-52834 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Rabe, Torsten A1 - Eichler, J. A1 - Picht, G. A1 - Rossner, W. A1 - Stelter, M. A1 - Voigt, I. T1 - Digitalisierung der keramischen Fertigung - Herausforderungen und Chancen N2 - Dieses Strategiepapier zielt darauf ab, Akteuren und Entscheidungsträgern den Status der Digitalisierung in der keramischen Fertigung, erfolgreiche Best-Practice-Beispiele aber auch die Herausforderungen nahezubringen, die es nun anzugehen gilt. Es ist die Vision, die Keramikfertigung durchgehend zu digitalisieren und alle Schritte des Produktkreislaufs lückenlos über die gesamte Wertschöpfungs- und Nutzungskette zu vernetzen: also eine Keramikindustrie 4.0 zu etablieren. Das Strategiepapier erfasst zunächst die Spezifität der keramischen Fertigung und nimmt eine Analyse des gegenwärtigen Standes der Digitalisierung in der keramischen Industrie vor, auch anhand einiger ausgewählter Beispiele aus der industriellen Praxis. Auf Basis der wesentlichen Bausteine für eine Fertigungsdigitalisierung werden schließlich die Chancen für Keramikproduzenten sowie der erforderliche Forschungs- und Entwicklungsbedarf aufgezeigt. KW - Datenmanagement KW - Digitalisierung KW - Fertigungsprozess KW - Keramik KW - Sensorik PY - 2021 SP - 1 EP - 39 PB - Deutsche Gesellschaft für Materialkunde (DGM) und Deutsche Keramische Gesellschaft (DKG) CY - Köln ET - 1000 AN - OPUS4-52708 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kraus, David A1 - Trappe, Volker T1 - Transverse damage in glass fiber reinforced polymer under thermo-mechanical loading N2 - In this study, the thermomechanical damage behavior of a glass fiber reinforced polymer material is investigated. The coefficients of thermal expansion of the composite as well as the matrix are measured in a wide temperature range. Quasi-static experiments with neat resin, unidirectional and multidirectional laminates are performed as well as fatigue experiments in a temperature range from 213 K to 343 K. This study focusses on the matrix damage due to fiber-parallel loading. A correlation between matrix effort, the dilatational strain energy of the matrix and the damage state of the specimen is demonstrated. It is shown that a fatigue life assessment can be performed with the aid of a temperature-independent master fatigue curve. KW - Composite KW - Glass fiber reinforced polymer KW - Thermo-mechanics KW - Fatigue KW - Damage KW - Temperature PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527462 DO - https://doi.org/10.1016/j.jcomc.2021.100147 SN - 2666-6820 VL - 5 SP - 100147 PB - Elsevier B.V. AN - OPUS4-52746 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghafafian, Carineh T1 - Restoring lightweight strength - Effect of localized repairs on the mechanical properties of composites sandwich structures N2 - As a type of high-performance composite material, glass-fiber reinforced plastics (GFRP) are favored for the construction of wind turbine rotor blades due to their high specific strength and stiffness properties (Grasse et al, 2010). During the blade manufacturing process, however, imperfections are often introduced, then further propagated due to harsh environmental conditions and a variety of loads (Caminero et al, 2013; Trappe et al, 2018). This leads to failure significantly before their designed lifespan. Since replacement of entire blades can be a costly potential outcome, localized repairs of the damaged region to restore structural integrity and thus lengthen its lifespan can executed in the field by technicians accessing the blades directly by suspended roping. These methods involve replacing the lost load path with a new material that is joined to the parent structure. In recent years, considerable studies have been conducted to investigate the influence of different repair parameters on the stress distribution, ultimate strength, impact behavior, and residual stresses of bonded repaired structures [Caminero et al, 2013; Trappe et al, 2018; Shufeng et al, 2014; Harman and Rider, 2011; Ahn and Springer, 2000; Lekou and Vionis, 2002). However, there currently do not exist any standardized repair procedures for wind turbine rotor blades. Namely, there is a lack of understanding about the effects of the layup of various repair methods, especially on the damage mechanism and fatigue life of the shells of rotor blades (Caminero et al, 2013; Trappe et al, 2018). This work therefore aims to begin to enrich this knowledge gap by testing the influence of different variables among repair patches on the mechanical properties of sandwich composite structures. Manufactured with the vacuum-assisted resin infusion (VARI) process, the test specimens are produced as a GFRP structure to represent the outer shell portion of a wind turbine blade, then repaired with a scarf joint. Scarf repairs are favored as the most efficient of the common structural joints, as the removal of the damaged area with angled walls leads to a nearly uniform shear stress distribution along the bond surface and no eccentricity in the load distribution (Caminero et al, 2013; Lekou and Vionis, 2002; Siener, 1992). The performance of specific layup methods of repair patches, namely a large-to-small versus small-to-large scheme of repair layers, is studied with static and load-controlled fatigue testing, then compared to pristine test specimens as well as to each other in terms of mechanical property restoration. The transition layer between repair and parent material is especially of interest in the performance of the structure. Damage onset, crack development and eventual failure are monitored in-situ with non-destructive testing methods, including thermography with an infrared camera system and a 3D deformation analysis system, to develop a more robust understanding of the effects of these repair concept variables on wind turbine blade shell structures. T2 - Wind Energy Science Conference CY - Online Meeting DA - 25.05.2021 KW - Glass fiber reinforced polymers KW - Wind turbine blade shell structures KW - Scarf joint repair PY - 2021 AN - OPUS4-52687 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Höhne, Patrick T1 - Limits of computer tomography aided characterization of different types of porous ceramic materials N2 - Ceramics with open porosity are attractive materials in many fields of applications covering medicine, catalysis, and filtration. Manifold technologies to produce porous ceramics are available, e.g. foaming and replica processes, resulting in various microstructures. Development and manufacturing of new materials is accelerating, while crucial characterization is becoming increasingly difficult and conventional measurements lack the desired speed. Computed tomography (CT) offers the possibility to three-dimensionally characterize entire samples with minimal sample preparation, while its main advantage is that it is non-destructive. Still, the assessment of quantitative results from CT measurements is not trivial. The poster presents CT characterizations of newly developed as well as commercially available openly porous ceramic samples. Properties such as porosity, permeability or pore characteristics were measured conventionally and compared to results calculated from CT-measurements using the commercial software VG StudioMax. The determined differences between measured and calculated values are presented and application areas as well as limits of the CT characterization are evaluated. T2 - Jahrestagung der Deutschen keramischen Gesellschaft 2021 CY - Online Meeting DA - 19.04.2021 KW - Ceramic KW - Porosity PY - 2021 AN - OPUS4-52724 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nolze, Gert T1 - CALM down: Identifying unknown phases N2 - CALM is software for determining the Bravais lattice type and the resulting lattice parameters from a single Kikuchi pattern. It requires the definition of 4 bands and a single bandwidth from which all other band positions as well as bandwidths are derived. For band detection, it uses the Funk transform, which allows detection of twice as many bands as usual. CALM works for any symmetry and requires low-noise patterns of at least 320x240 pixels. The resulting errors are <2% even for such small patterns, assuming good quality. The relative errors are <0.5%. However, this requires a projection centre position best derived from a sample of a cubic phase in CALM. However, this must have been recorded under identical conditions. Hundreds of Kikuchi patterns of phases with different symmetries were examined. T2 - Chemnitz MTEX Workshop 2021 CY - Online meeting DA - 08.03.2021 KW - EBSD KW - Gitterkonstanten KW - Phasenidentifikation PY - 2021 AN - OPUS4-52345 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Tensile Test: From Standard to PMD Application Ontology N2 - Data analysis methods play an important role in both the experimental and simulation-based digital description of materials but have so far been poorly structured. The platform Material Digital (PMD) should contribute to a standardized description of data processing methods in materials research. The goal is the quality assurance of the processes and the output data, the acquisition and definition of their accuracy as well as the interoperability between applications. Therefore, application ontologies are created to explicitly describe processes and test methods. In this presentation, the first efforts in creating a tensile test application ontology in accordance with the ISO standard 6892-1:2019-11 are shown. Especially, the path of ontology development to be pursued based on standards was focused. T2 - Onboarding Workshop der Plattform Material Digital (PMD) CY - Online meeting DA - 13.04.2021 KW - Ontology KW - Platform MaterialDigital KW - PMD KW - Tensile Test KW - Normung KW - Standardization PY - 2021 AN - OPUS4-52425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stargardt, Patrick T1 - Modeling of the cooling behavior of thermoelectric multilayers N2 - Multilayered designs are an attractive approach towards cost-effective manufacturing of thermoelectric generators. Therefore, efforts are being made to co-fire two promising thermoelectric oxides, namely calcium cobaltite and calcium manganate. In this study, ceramic tapes, multilayer technology, and pressure-assisted sintering (PAS) were used. A major challenge for the PAS of low-sintered calcium manganate was cracking during cooling. A relationship between the properties of the release tape used during PAS and the cracking behavior was experimentally observed. To understand the origin of failure, reaction layers in the multilayer were analyzed and thermal stresses during cooling were estimated by finite element (FE) simulations. Thermal expansion, elastic properties, and biaxial strength of the thermoelectric oxides and selected reaction layers were determined on separately prepared bulk samples. The analysis showed that the reaction layers were not the cause for cracking of calcium manganate. Using the FE model, thermal stresses in different manganate multilayer designs with varying properties of the release tape were studied. The FEM study indicated, and a validation experiment proved that the thickness of the release tape has the main effect on thermal stresses during cooling in separately sintered calcium manganate. T2 - Keramik 2021 / Ceramics 2021 CY - Online Meeting DA - 19.04.2021 KW - Fem KW - Thermoelectric KW - Pressure assisted sintering PY - 2021 AN - OPUS4-52489 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Charmi, Amir T1 - Mechanical anisotropy of LPBF 316L: a modeling approach N2 - The underlying cause of mechanical anisotropy in additively manufactured (AM) parts is not yet fully understood and has been attributed to several different factors like microstructural defects, residual stresses, melt pool boundaries, crystallographic and morphological textures. To better understand the main contributing factor to the mechanical anisotropy of AM stainless steel 316L, bulk specimens were fabricated via laser powder bed fusion (LPBF). Tensile specimens were machined from these AM bulk materials for three different inclinations relative to the build plate. Dynamic Young's modulus measurements and tensile tests were used to determine the mechanical anisotropy. Some tensile specimens were also subjected to residual stress measurement via neutron diffraction, porosity determination with X-ray micro-computed tomography, and texture analysis with electron backscatter diffraction (EBSD). A crystal plasticity model was used to analyze the elastic anisotropy and the anisotropic yield behavior of the AM specimens, and it was able to capture and predict the experimental behavior accurately. Overall, it was shown that the mechanical anisotropy of the tested specimens was mainly influenced by the crystallographic texture. T2 - 2. Online-Workshop "In-situ Monitoring and Microstructure Development in Additive Manufactured Alloys " CY - Online meeting DA - 20.04.2021 KW - Anisotropy KW - Crystal plasticity KW - Additive manufacturing PY - 2021 AN - OPUS4-52603 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Portella, Pedro Dolabella A1 - Trappe, Volker T1 - Non-destructive characterization methods for polymer matrix composites N2 - The mechanical behavior of fiber reinforced composites with polymer matrix is governed by several mechanisms operating at different length scales. In this contribution we describe first non-destructive techniques which are adequate for the characterization of the fiber-matrix interphase at a microscopic level. In a second step we describe on a mesoscopic level the influence of manufacturing related elements on the mechanical properties of rotor blades for wind turbines. We concentrate on thermography, laminography and ultrasound in connection with mechanical testing systems. Finally we present methods for monitoring rotor blades by using embedded optical fibers. T2 - Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ, Brasilien CY - Online meeting DA - 26.11.2020 KW - Polymer matrix composites PY - 2020 AN - OPUS4-52043 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Portella, Pedro Dolabella T1 - Charakterisierung metallischer Werkstoffe für Anwendungen bei hohen Temperaturen N2 - In diesem Beitrag werden am Beispiel von Gasturbinen Verfahren zur Charakterisierung des werkstoff-mechanischen Verhaltens sowie der Gefügeentwicklung von Bauteilen für Anwendungen bei hohen Temperaturen aufgezeigt. Gasturbinen sind technisch gesehen sehr interessante Systeme, die in der Energietechnik und in der Luftfahrt von hoher wirtschaftlicher Relevanz sind. Seit Jahrzehnten gelten Gasturbinen als klassische Innovationstreiber, für ihre Entwicklung wurden bereits maßgebliche Erneuerungen im Bereich der Aerodynamik und der Werkstofftechnik hervorgebracht. T2 - Deutsche Physikalische Gesellschaft Senior Expert Netzwerk CY - Online meeting DA - 20.01.2021 KW - Superlegierungen KW - Gasturbinen PY - 2020 AN - OPUS4-52045 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Portella, Pedro Dolabella A1 - Krebber, Katerina T1 - Fiber Optic Sensors for SHM - From Laboratory to Industrial N2 - The paper highlights the research activities in Germany and Europe in the development of distributed fiber optic sensor for structural health monitoring (SHM) like the monitoring of geotechnical and civil infrastructures and presents selected results achieved within these projects. T2 - Conaendi & IEV 2021 CY - Online meeting DA - 09.03.2021 KW - Fiber KW - Optic KW - SHM PY - 2021 AN - OPUS4-52254 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sandoval Saldias, Janina 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 - CHAP A1 - Stephan-Scherb, Christiane ED - Schorr, S. ED - Weidenthaler, C. T1 - Crystallographic challenges in corrosion research N2 - High-temperature corrosion is a widespread problem in various industries. As soon as a hot and reactive gas (CO2, O2, H2O, SO2, NOx, etc.) is in contact with a solid, physico-chemical processes at the surface and interfaces lead to material degradation. The processes are dynamic and controlled by thermodynamic and kinetic boundary conditions. Whether a reaction product is protective or not depends on various factors, such as chemical composition of the solid and the reactive media, surface treatment as well as diffusion and transport paths of cations and anions. Resulting chemical and structural inhomogeneities with the corrosion layers are characterized by off stoichiometry within cationic and anionic sub lattices. The competitive processes can be studied by various techniques of applied crystallography. This chapter gives an overview on the challenges of chemical-structural Analysis of reaction products by crystallographic methods such as X-ray diffraction and X-ray near-edge structure spectroscopy and scanning electron microscopy electron backscatter diffraction (SEM-EBSD) for corrosion science. KW - High-temperature corrosion KW - Oxidation KW - Diffraction KW - Spectroscopy KW - Oxides PY - 2021 DO - https://doi.org/10.1515/9783110674910-009 SP - 291 PB - De Gruyter ET - 1 AN - OPUS4-52903 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker T1 - Thermo-mechanical fatigue of glass fiber reinforced polymer N2 - Glass fiber reinforced polymer (GFRP) materials in practical applications have to endure cyclic mechanical loading in a wide temperature range (e.g. aircraft applications, automotive, wind turbine blades). In this study the static strength and fatigue behavior of GFRP was investigated in a temperature range from 213 K to 343 K. Therefor the coefficients of thermal expansion of the composite as well as the matrix are measured in this temperature interval. The inverse laminate theory was extended and used to calculate the inter fiber-failure effort for a virtual UD-layer according to the layer wise strength approach. The experimentally determined results are compared with the micro-mechanical model according to Krimmer, which has been enhanced to include the effect of temperature and fiber-perpendicular failure modes. A correlation between matrix effort, the dilatational strain energy of the matrix and the damage state of the specimen is demonstrated. It is shown that a fatigue life assessment can be performed with the aid of a temperature-independent master fatigue curve, as it was similar done for the fatigue behavior of CFRP and GFRP to very high load cycles at room temperature. T2 - ICFC8 - The 8th International Conference on the Fatigue of Composites CY - Online meeting DA - 23.06.2021 KW - Glass fibre reinforced plastics KW - Fatigue KW - Thermo-mechanical-loading PY - 2021 AN - OPUS4-52910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Agea Blanco, Boris A1 - Walzel, S. A1 - Chi, J. A1 - Lüchtenborg, J. T1 - Making Binder Jetting Really Work for Technical Ceramics - Additive Manufacturing of Technical Ceramics N2 - As an alternative shaping method to the traditionally used processes, additive manufacturing (AM) can produce economical ceramic components in small lot sizes and/or with complex geometries. Powder-based additive manufacturing processes like binder jetting are popular in the field of metal AM. One reason is the increased productivity compared to other AM technologies. For ceramic materials, powder-based AM technologies result in porous ceramic parts, provided they are not infiltrated. CerAMing GmbH unites the advantages of powder-based processes with the production of dense ceramic by means of the Layerwise Slurry Deposition. By using a suspension, a high packing density of the powder bed is achieved which leads to high green body densities. Due to this advantage the approach overcomes the problems of other powder-based AM technologies. Furthermore, a very economical debinding time allows the production of parts with high wall thicknesses. KW - Additive Manufacturing KW - Binder Jetting KW - Layerwise Slurry Deposition KW - Lithography-based technologies KW - Technical Ceramics PY - 2021 SP - 49 EP - 52 PB - Göller Verlag CY - Baden-Baden AN - OPUS4-52948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Tensile Test Ontology used in Platform Material Digital (PMD) N2 - Data analysis methods play an important role in both the experimental and simulation-based digital description of materials but have so far been poorly structured. The platform Material Digital (PMD) is supposed to contribute to a standardized description of data processing methods in materials research. The goal is the quality assurance of the processes and the output data, the acquisition and definition of their accuracy as well as the interoperability between applications. Therefore, application ontologies are created to explicitly describe processes and test methods. In this presentation, the first efforts within the joint project PMD in creating a tensile test application ontology in accordance with the ISO standard 6892-1:2019-11 are shown. Especially, the path of ontology development to be pursued based on standards was focused. Furthermore, the presentation includes a live demonstration of queries possibly performed to query data that was uploaded in the PMD triple store. T2 - Online Workshop: An introduction to the semantic web and ontologies CY - Online meeting DA - 23.04.2021 KW - Ontology KW - Tensile Test KW - Platform Material Digital KW - PMD KW - Knowledge Graphs KW - Semantic Web PY - 2021 AN - OPUS4-52949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk A1 - Le, Quynh-Hoa T1 - Entwicklung einer fraktographischen Symbolik N2 - Bei der Untersuchung von Bruchflächen werden zunächst Beobachtungen gemacht, d.h. makroskopische und mikroskopische Merkmale analysiert und in Bildern dokumentiert. Im zweiten Schritt werden anhand der gefundenen Merkmale Rissverlauf und Bruchmechanismen ermittelt. Abschließend sollen diese Ergebnisse in einem Bericht oder Gutachten zusammengefasst werden. Hierbei ist eine skizzenhafte Darstellung der fraktographischen Befunde hilfreich für das Verständnis des Lesers. Ein vorgefertigter fraktographischer Symbolsatz würde dies erheblich vereinfachen. Skizzen von fraktographischen Befunden sind in der Literatur recht häufig zu finden, z.B. in der VDI 3822 oder dem ASM Handbook Fractography, allerdings gibt es hierzu keine umfassende Systematik, wie sie z.B. aus der Meteorologie (Wetterkarten), Geographie (Landkarten, Seekarten) oder Geologie (Bodenkarten) seit langer Zeit bekannt sind. Deshalb wird hier der Versuch unternommen, einen Symbolsatz zu entwickeln und zur Verfügung zu stellen, mit dessen Hilfe fraktographische Befunde in eindeutiger und übersichtlicher Weise veranschaulicht werden können. Der fraktographische Symbolsatz ("Fracto Graphics") befindet sich in Entwicklung, ist offen zur Diskussion sowie für Verbesserungen. T2 - 55. Metallographie-Tagung CY - Online meeting DA - 29.9.2021 KW - Fraktographie KW - Symbolik KW - Schadensanalyse PY - 2021 AN - OPUS4-53433 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, Anja A1 - Wolf, Marcus A1 - Kranzmann, Axel T1 - Corrosion and corrosion fatigue of steels in downhole CCS environment - A summary N2 - Static immersion tests of potential injection pipe steels 42CrMo4, X20Cr13, X46Cr13, X35CrMo4, and X5CrNiCuNb16-4 at T = 60 °C and ambient pressure, as well as p = 100 bar were performed for 700–8000 h in a CO₂-saturated synthetic aquifer environment similar to CCS sites in the Northern German Basin (NGB). Corrosion rates at 100 bar are generally lower than at ambient pressure. The main corrosion products are FeCO₃ and FeOOH with surface and local corrosion phenomena directly related to the alloy composition and microstructure. The appropriate heat treatment enhances corrosion resistance. The lifetime reduction of X46Cr13, X5CrNiCuNb16-4, and duplex stainless steel X2CrNiMoN22-5-3 in a CCS environment is demonstrated in the in situ corrosion fatigue CF experiments (axial push-pull and rotation bending load, 60 °C, brine: Stuttgart Aquifer and NGB, flowing CO₂: 30 L/h, +/- applied potential). Insulating the test setup is necessary to gain reliable data. S-N plots, micrographic-, phase-, fractographic-, and surface analysis prove that the life expectancy of X2CrNiMoN22-5-3 in the axial cyclic load to failure is clearly related to the surface finish, applied stress amplitude, and stress mode. The horizontal grain attack within corrosion pit cavities, multiple fatigue cracks, and preferable deterioration of austenitic phase mainly cause fatigue failure. The CF life range increases significantly when a protective potential is applied. KW - Steel KW - High alloyed steel KW - Corrosion KW - Corrosion fatigue KW - Carbon capture and storage PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531391 DO - https://doi.org/10.3390/pr9040594 SN - 2227-9717 VL - 9 IS - 4 SP - 1 EP - 33 PB - MDPI CY - Basel AN - OPUS4-53139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, Anja A1 - Kranzmann, Axel T1 - Effects of saline aquifer water on the corrosion behaviour of martensitic stainless steels during exposure to CO2 environment N2 - Immersion tests of potential injection pipe steels 42CrMo4, X20Cr13, X46Cr13, X35CrMo4 and X5CrNiCuNb16-4 at T=60 °C and ambient pressure and p=100 bar were performed for 700 h - 8000 h in a CO₂-saturated synthetic aquifer environment similar to CCS-sites in the Northern-German-Basin. Main corrosion products are FeCO₃ and FeOOH. Highest surface corrosion rates at ambient pressure are 0.8 mm/year for 42CrMo4 and lowest 0.01 mm/year for X5CrNiCuNb16-4. Corrosion rates at 100 bar (max. 0.01 mm/year for 42CrMo4, X20Cr13, X46Cr13) are generally lower than at ambient pressure (<0.01 mm/year for X35CrMo4, X5CrNiCuNb16-4). Heat treatment to martensitic microstructure offers good corrosion resistance. T2 - 15th International Conference on Greenhouse Gas Control Technologies, GHGT-15 CY - Abu Dhabi, United Arab Emirates DA - 15.03.2021 KW - CCS KW - Corrosion KW - High alloyed steels PY - 2021 DO - https://doi.org/10.2139/ssrn.3812248 SP - 1 EP - 12 PB - SSRN CY - Rochester, NY AN - OPUS4-53140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, Anja A1 - Wolf, Marcus A1 - Kranzmann, Axel T1 - Evaluating corrosion and corrosion fatigue behavior via laboratory testing techniques in highly corrosive CCS-environment N2 - In CCS environment (carbon capture and storage) pipes are loaded statically and/or cyclically and at the same time exposed constantly to the highly corrosive hot thermal water. Experimental procedures such as ambient pressure immersions tests, in-situ corrosion fatigue experiments using a flexibly designed corrosion chamber at ambient pressure and a specially designed corrosion chamber at high pressure. Experimental set-ups for push/pull and rotation bending load are introduced. The corrosion behavior and lifetime reduction of high alloyed steels (X46Cr13, 1.4043), (X5CrNiCuNb16-4, 1.4542) and (X2CrNiMoN22-5-3, 1.4462) is demonstrated (T=60 °C, geothermal brine: Stuttgart Aquifer flow rate: 9 l/h, CO₂). T2 - 15th International Conference on Greenhouse Gas Control Technologies, GHGT-15 CY - Abu Dhabi, United Arab Emirates DA - 15.03.2021 KW - Steel KW - Supercritical CO2 KW - Pipeline KW - Corrosion KW - CO2-storage PY - 2021 DO - https://doi.org/10.2139/ssrn.3812193 SP - 1 EP - 11 PB - SSRN CY - Rochester, NY AN - OPUS4-53142 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werner, Tiago T1 - Comparison of the fatigue behavior of wrought and additively manufactured AISI 316L N2 - Additively Manufactured (AM) parts are still far from being used in safety-relevant applications, mainly due to a lack of understanding of the feedstock-process-propertiesperformance relationship. This work aims at providing a characterization of the fatigue behavior of the additively manufactured AISI 316L austenitic stainless steel and a direct comparison with the fatigue performance of the wrought steel. A set of specimens has been produced by laser powder bed fusion (L-PBF) and a second set of specimens has been machined out of hot-rolled plates. The L-PBF material shows a higher fatigue limit and better finite life performance compared to the wrought material, accompanied by an extensive amount of cyclic softening. T2 - Fatigue Design 2021 CY - Online meeting DA - 17.11.2021 KW - Additive Manufacturing KW - AM KW - 316L KW - Fatigue KW - High Cycle Fatigue KW - Low Cycle Fatigue PY - 2021 AN - OPUS4-53780 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, Anja T1 - Vom Blended Learning zum Full Online – so einfach geht es nicht – Praxiserfahrungen zum Einsatz von Lehrfilmen N2 - Mit Beginn der Covid-19 Pandemie und dem damit verbundenen ausschließlichen Lehren im online-Format war die Hoffnung verbunden ein Blended Learning Lehrformat für die Studieeingangsphase ohne viel konzeptionelle Änderungen übertragen zu können. Der Kurs Werkstofftechnik als Grundlagenfach für den Maschinenbau baut sich auf inverted classroom Lehrszenarien auf, deren Lerngrundlage hierfür eigens produzierte und auf das Lernziel abgestimmte Lehrfilme und Lightboard-Vorlesungen darstellen. Im Kontext der Studieneingangsphase bieten audiovisuell stimulierende Lehrfilme umfassende Lernmedien, wenn sie analog der Lerninhalte einem technischen und didaktischen Qualitätsanspruch genügen. In der Praxis des SS2020 und WS2020/21 hat sich gezeigt, dass die Moderation und Durchführung eines online-Kurses sich deutlich von dem eins blended learning-Kurses unterscheidet. Um denselben Lernerfolg bei Studierenden zu erzielen, müs-sen Anforderungen viel genauer und detaillierter verfasst werden, Studierende enger und persönlicher begleitet werden und Lehrfilme und Lernmedien in einen Gesamtzusammenhang gestellt werden. Im Folgenden werden aus persönlicher Erfahrung heraus niederschwellige, zum Teil ungewöhnliche praktische Erfahrungen zur erfolgreichen Umsetzung von Lehrfilm-basierten inverted classroom Lehrszenarien zusammengefasst und im Hinblick auf die online-Lehre bewertet. T2 - 19. Fachtagung Bildungstechnologien (DELFI) CY - Bonn, Germany DA - 13.09.2021 KW - Inverted classroom KW - Lehrfilm KW - Lehrfilmformate KW - Online KW - Covid-19 PY - 2021 SP - 289 EP - 295 AN - OPUS4-54154 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, Anja T1 - Improving Learning Outcome for GSL (German as a Second Language) Students in a Blended Learning Cumulative Assessment Material Science Course N2 - First year students especially with migration background and language deficiencies rate material science in mechanical engineering as one of the fundamental courses with high work load and necessity of language skills due to the descriptive nature of the course. Therefore a blended learning course structure using based on inverted classroom teaching scenarios was established. Heart of the self-study period are visualizing peer-to-peer lecture films supported by micro-lectures along with various online teaching materials. Although students with migration background generally scored lower in tests due to the lack of language skills improved learning outcomes are demonstrated in high quality class discussions and in overall understanding. This paper introduces the learning structure and graded activities, evaluates the course and compares results of native German-speaking students to those of students with migration background. KW - Portfolio KW - Diversity KW - Blended learning KW - Inverted classroom KW - Lecture films PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-541557 DO - https://doi.org/10.17706/ijeeee.2021.11.3.93-100 SN - 2010-3654 VL - 11 IS - 3 SP - 93 EP - 100 AN - OPUS4-54155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, Anja T1 - How flipped classroom teaching methods in first year studying succeed N2 - Flipping the classroom is a method to let students study on their own and then take time to discuss their questions and do extended hands-on lectures or exercises in class – or in the case of the covid-19 pandemic during plenary online sessions. First year mechanical engineering students use different teaching materials (mainly lecture videos, lightboard videos and micromodule lectures) to study from a distance and comprehend the principle underlying science in theory. Then the online plenary lectures offer the opportunity to apply their knowledge and transfer different scientific aspects of the course to get the bigger picture. Exercises, worked solutions, selfassessed tests and peer-instruction during present time help students to check on their learning progress. However, the self-study periods and (online) plenary sessions need to be guided carefully. To meet the course learning outcome and overcome the diversity of a first year class various practical leads have to be fulfilled to turn flipped classroom teaching into success. T2 - 7th International Conference on Higher Education Advances (HEAd’21) CY - Valencia, Spain DA - 20.06.2021 KW - Inverted classroom KW - Flipped classroom KW - Online teaching KW - Lecture videos KW - First year students PY - 2021 DO - https://doi.org/10.4995/HEAd21.2021.12792 SP - 1211 EP - 1219 AN - OPUS4-54156 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, Anja A1 - Wolf, M. A1 - Kranzmann, Axel T1 - Corrosion and Corrosion Fatigue of Steels in Downhole CCS Environment—A Summary N2 - Static immersion tests of potential injection pipe steels 42CrMo4, X20Cr13, X46Cr13, X35CrMo4, and X5CrNiCuNb16-4 at T = 60 °C and ambient pressure, as well as p = 100 bar were performed for 700–8000 h in a CO2-saturated synthetic aquifer environment similar to CCS sites in the Northern German Basin (NGB). Corrosion rates at 100 bar are generally lower than at ambient pressure. The main corrosion products are FeCO3 and FeOOH with surface and local corrosion phenomena directly related to the alloy composition and microstructure. The appropriate heat treatment enhances corrosion resistance. The lifetime reduction of X46Cr13, X5CrNiCuNb16-4, and duplex stainless steel X2CrNiMoN22-5-3 in a CCS environment is demonstrated in the in situ corrosion fatigue CF experiments (axial push-pull and rotation bending load, 60 °C, brine: Stuttgart Aquifer and NGB, flowing CO2: 30 L/h, +/− applied potential). Insulating the test setup is necessary to gain reliable data. S-N plots, micrographic-, phase-, fractographic-, and surface analysis prove that the life expectancy of X2CrNiMoN22-5-3 in the axial cyclic load to failure is clearly related to the surface finish, applied stress amplitude, and stress mode. The horizontal grain attack within corrosion pit cavities, multiple fatigue cracks, and preferable deterioration of austenitic phase mainly cause fatigue failure. The CF life range increases significantly when a protective potential is applied. KW - Steel KW - High alloyed steel KW - Corrosion fatigue KW - Cabon capture and storage KW - CCS PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-541626 DO - https://doi.org/10.3390/pr9040594 VL - 9 IS - 4 SP - 594 PB - MDPI AN - OPUS4-54162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blaeß, Carsten T1 - Viskose Rissschließung in Gläsern und Glasmatrixkompositen N2 - Um die Langzeitbeständigkeit von Hochtemperatur-Festoxidbrennstoffzellen (SOFC) sicherzustellen, ist das grundlegende Verständnis der viskosen Schließung oder Heilung von Rissen, als Folge wechselnder thermischer oder mechanischer Belastung, in Gläsern und teilkristallinen Materialien ein entscheidender Faktor. In Glas ist die Rissheilung hauptsächlich durch viskoses Fließen bestimmt. In teilkristallinen Schmelzen bewirkt der kristalline Volumenanteil die Erhöhung der effektiven Viskosität. Um die Auswirkungen des kristallinen Volumenanteils auf die Rissheilung zu ergründen, wurden Glasmatrixkomposite mit variierten inerten kristallinen Fülleranteilen, die während der Wärme-behandlung konstant blieben, hergestellt. Verwendet wurde ein kristallisationsträges Natrium-Calcium-Silicatglas und ZrO2 als inerter Füller. Komplexe, reproduzierbare Rissstrukturen wurden durch Vickers-Eindrücke erzeugt und die viskose Rissschließung während isothermer Wärmebehandlungs-schritte mittels Laser-Scanning-Mikroskopie verfolgt. Die Untersuchungen zeigen, dass, verglichen zum füllerfreien Glas, der kristalline Phasenanteil die effektive Viskosität erhöht und dadurch großräumiges Fließen verlangsamt. Dies verzögert das Aufweiten der Risse. Dieser Effekt erschwert die Rissverkürzung und führt oftmals zu großen gerundeten Kavitäten und dadurch zu einer verzögerten Rissschließung. Wird dieses Aufweiten verringert, ist zunächst ein lokales viskoses Fließen der Restglasphase weiterhin gegeben, sodass sich die Risse sogar schneller schließen. Für kristalline Anteile > 27 Vol% bildet sich dann ein stabiles Perkolationsgerüst aus, das die weitere Rissschließung auch lokal unterbindet. Nur innerhalb größerer glasiger Bereiche ist hierbei noch eine Rissschließung zu beobachten. Ein Optimum der Risslängenverkürzung konnte bei 17 Vol% beobachtet werden. T2 - 94. Glastechnische Tagung CY - Online meeting DA - 10.05.2021 KW - Glas KW - Hochtemperaturbrennstoffzelle KW - Glasmatrixkomposit KW - Rissheilung PY - 2021 AN - OPUS4-54245 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, A. A1 - Kranzmann, Axel T1 - Understanding the Anomalous Corrosion Behaviour of 17% Chromium Martensitic Stainless Steel in Laboratory CCS-Environment—A Descriptive Approach N2 - To mitigate carbon dioxide emissions CO2 is compressed and sequestrated into deep geological layers (Carbon Capture and Storage CCS). The corrosion of injection pipe steels is induced when the metal is in contact with CO2 and at the same time the geological saline formation water. Stainless steels X35CrMo17 and X5CrNiCuNb16-4 with approximately 17% Cr show potential as injection pipes to engineer the Northern German Basin geological onshore CCS-site. Static laboratory experiments (T = 60 ◦C, p = 100 bar, 700–8000 h exposure time, aquifer water, CO2-flow rate of 9 L/h) were conducted to evaluate corrosion kinetics. The anomalous surface corrosion phenomena were found to be independent of heat treatment prior to exposure. The corrosion process is described as a function of the atmosphere and diffusion process of ionic species to explain the precipitation mechanism and better estimate the reliability of these particular steels in a downhole CCS environment. KW - Corrosion KW - Steel KW - High alloyed steel KW - Corrosion mechanism KW - CCS PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545700 DO - https://doi.org/10.3390/cleantechnol4020014 VL - 4 IS - 2 SP - 239 EP - 257 PB - MDPI AN - OPUS4-54570 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk T1 - MGA Round Robin Test on Al-AM Fatigue Testing - Fractographic Results N2 - Presentation of results of an investigation of fracture mechanisms and crack start sites of an additive manufactured aluminium alloy after fatigue testing. Collaboration within the MGA initiative (Mobility Goes Additive). T2 - MGA Mid Term Meeting 2022 CY - Berlin, Germany DA - 05.07.2022 KW - Aluminium Alloy KW - Fractography KW - Additive Manufacturing PY - 2022 AN - OPUS4-55192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker T1 - Dynamic mechanical analysis of epoxy-matrix cross linking measured in-situ using an elastomer container N2 - A new patented dynamic mechanical analysis (DMA) is presented, where the tensile, bending- or torsional stiffness of a media can be characterized in-situ during the phase transition from liquid to solid. An epoxy system, e.g. Hexion L285/H287, is filled into an elastomer container, such as a silicone tube. This can be mounted into a conventional DMA and, based on a linear viscoelastic approach, the storage modulus (E’;G’), the loss modulus (E’’;G’’) and the loss angle tan(delta) can be measured at constant temperature as a function of time in order to investigate the liquid to sol-gel to solid transition. With this new method, the stiffness increase as a result of the cure process can be directly measured more precisely than with a rheometer in a shear plate set-up, because using an elastomer container gives a defined cross section for calculating the Young’s modulus. T2 - 20th European Conference on Composite Materials, ECCM20 CY - Lausanne, Switzerland DA - 26.06.2022 KW - Dynamic mechanical analysis (DMA) KW - Thermoset polymers KW - Cure process KW - Cross linking PY - 2022 AN - OPUS4-55213 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Suárez Ocano, Patricia T1 - I n situ monitoring of growing oxidation of the chemically complex alloy AlMo 0.5 NbTa 0.5 TiZr in the high temperature regime using synchrotron radiation Preliminary results N2 - The chemically complex alloys (CCAs) that contain mostly refractory elements (rCCAs), may be highly resistant to heat and load, which makes them attractive candidates for use at extremely high temperatures associated with many technological applications, e.g. aeroengine turbines. However, the field of CCAs, especially their resistance in harsh (oxidative) and hot environment is still young and not much experimental evidence for the understanding mechanisms in this regime is available, which the proposed study addresses. For safe use in structural applications, in addition to their mechanical performance, the environmental resistance of this alloy is also critical. Surface degradation can significantly decrease the mechanical resistance during high temperature exposure, leading to premature failure. The AlMo0.5NbTa0.5TiZr rCCA only contains Al as a protection candidate and it is composed of a coherent B2/bcc nanoscopic cube-on-cube interweave and an hexagonal phase. The evaluation of the oxidation process in the AlMo0.5NbTa0.5TiZr rCCA in the heat-treated state has not been assessed yet. The proposed study focusses on a deeper understanding of the formation mechanism and growth kinetics of oxides at high temperature in the AlMo0.5NbTa0.5TiZr rCCA using synchrotron radiation. Due to the envisaged high temperature structural applications, the alloy is evaluated in an oxidation environment specifically between 800°C and 1000°C. T2 - Large scale facility-based techniques SPP meeting CY - Online meeting DA - 02.11.2021 KW - Refractory chemically complex alloys KW - Oxidation behavior KW - Microstructural analysis KW - Synchrotron radiation PY - 2021 AN - OPUS4-54383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuchenbecker, Petra T1 - Bestimmung der Partikelgrößenverteilung mittels Zentrifugen-Sedimentationsverfahren nach ISO 13318-2 (Küvette) N2 - Im Vortrag werden das Messprinzip des Zentrifugen-Sedimentationsverfahrens erläutert und die Anforderungen der zugrundeliegenden Normen diskutiert. Es schließen sich umfangreiche Ausführungen zur praktischen Durchführung der Messung, insbesondere auch zu den vorbereitenden Arbeiten, sowie zur Auswertung der Rohdaten an. Gezeigt werden die Validierung sowie ein Beispiel zur regelmäßigen Verifizierung des Verfahrens. Nach Beispielen und Vergleichen zu Ergebnissen mit anderen Messverfahren, wird das Verfahren in einer Zusammenfassung bewertet. T2 - Seminar Rheologie und Stabilität von dispersen Systemen CY - Potsdam, Germany DA - 09.05.2022 KW - Nano powder KW - Cetrifugal Liquid Sedimentation CLS KW - Particle size determination PY - 2022 AN - OPUS4-54863 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghafafian, Carineh T1 - Fully-reversed fatigue behavior of scarf joint repairs for wind turbine blade shell applications N2 - Due to manufacturing imperfections which can propagate to damage under in-service loads, wind turbine rotor blades, made primarily of glass fiber reinforced polymers (GFRP), often fail significantly before their design life. To enable a quick and cost-effective return to service, localized repairs can be executed by technicians in the field, directly accessing the blades by suspended roping. Scarf joint repairs, shown to be highly efficient with a smooth load transition across angled joint walls and a restored aerodynamic profile, are the focus of this study. The damage mechanisms of these structures were examined under fully-reversed mechanical cyclic loading with a load ratio R = -1, which was made possible on the coupon scale by a custom designed anti-buckling support. The number of cycles to failure were compared across load levels. While the scarf joint ratio was held constant at 1:50, known from industry and literature to be a good compromise between restored mechanical properties and repair size, the layup sequence was varied between small-to-large and large-to-small. Hereby the effect of the presence of resin pockets and fiber orientation mismatch between the parent and repair structure on the failure mechanism as well as fatigue strength of ±45° GFRP scarf joint repair structures was studied. Strain development across the joint length was measured to assess stiffness degradation in addition to the fatigue strength recovery of scarf joint structures with respect to pristine reference specimens. Grayscale analysis was used to monitor the damage state leading to fracture across the specimens. Post-mortem fractography analysis with light microscopy described the global failure mechanisms as well as local damage distribution within the structure, all of which provided insight to critical variables in scarf joint GFRP structures under fully-reversed mechanical cyclic loading, allowing for the tailoring of such repairs on wind turbine blade shells for maximum restoration of service life. T2 - 20th European Conference on Composite Materials (ECCM20) CY - Lausanne, Switzerland DA - 26.06.2022 KW - Glass fiber reinforced polymers KW - Scarf repairs KW - Fatigue PY - 2022 AN - OPUS4-55638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönauer-Kamin, Daniela T1 - Powder-Aerosol deposited (PAD) calcium manganate as n-type thermoelectric material N2 - Currently, calcium manganate CaMnO3 and calcium cobaltite Ca3Co4O9 are being investigated as n-type resp. p-type semiconducting materials as oxidation- and temperature-resistant thermoelectric materials for oxide multilayer thermoelectric generators (TEGs). In order to manufacture multilayer TEGs, pressure-assisted sintering processes at high temperatures are necessary to achieve optimal thermoelectric material properties. To realize TEGs in planar film technology, another method to obtain dense ceramic layers directly from the synthesized starting powders without a subsequent high temperature step is emerging recently: the powder aerosol deposition (PAD) method. In the present work, it is investigated whether PAD is suitable to produce dense ceramic films from Sm-doped CaMnO3 and Ca3Co4O9 powders. The resulting thermoelectric properties are characterized as a function of temperature. CaMnO3 powder could successfully be processed by PAD with resulting layer thicknesses of 5- 6 µm without any high-temperature sintering steps of the films. The electrical conductivity and the Seebeck coefficient of the films were determined in-plane from room temperature to 600 °C in air. The results show a Seebeck coefficient of around -200 µV/K, which is comparable to results of pressed and sintered bars. At 400 °C, the electrical conductivity corresponds to the conductivity of the bar. At higher temperatures the conductivity is better than with the reference. Below 400°C, the electrical conductivity is somewhat lower than that of the reference sample, a mild thermal treatment of the PAD layer improves it. It is expected that the thermal conductivity of the PAD film will be lower compared to the bars due to the nano-crystalline film morphology. This should result in a significantly increased ZT value for the PAD layers and a higher efficiency of the TEG. The work shows that both CaMnO3 and Ca3Co4O9 can be successfully processed by PAD, and the PAD films show comparable thermoelectric properties. T2 - 18th European Conference on Thermoelectrics CY - Barcelona, Spanien DA - 14.09.2022 KW - Film depositition KW - Calcium cobaltite PY - 2022 AN - OPUS4-55771 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Junge, P. A1 - Stargardt, Patrick A1 - Kober, D. A1 - Greinacher, M. A1 - Rupprecht, C. T1 - Thermally Sprayed Al2O3 Ceramic Coatings for Electrical Insulation Applications N2 - Thermal spraying enables a fast and propelling way to additively deposit various ceramics as electric insulators, which are used in conditions where polymers are not suitable. Alumina (Al2O3) is among the most employed materials in the coating industry since it exhibits good dielectric properties, high hardness, high melting point while still being cost-effective. Various parameters (e.g. feedstock type, plasma gas mixture, plasma power) significantly influence the resulting coating in terms of microstructure, porosity, crystallinity, and degree of un-or molten particles. As a consequence, these parameters need to be investigated to estimate the impact on the electrical insulating properties of thermally sprayed alumina. This study focuses on the development of a novel electric insulation coating from Al2O3 feedstock powders deposited via atmospheric plasma spray (APS). The microstructure, porosity, and corresponding crystallographic phases have been analyzed with optical microscopy, XRD, and SEM images. To achieve an understanding of the parameters influencing the electrical insulation performance of the manufactured coatings, an in-depth analysis of the fundamental dielectric parameters e.g., DC resistance, breakdown strength, dielectric loss tangent, permittivity is presented. T2 - International Thermal Spray Conference and Exposition 2022 CY - Vienna, Austria DA - 04.05.2022 KW - Thermal Spray KW - Alumina KW - Dielectric properties PY - 2022 SP - 1 EP - 8 AN - OPUS4-55821 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Sophie T1 - Oxidkeramische Werkstoffe und Folien für thermoelektrische Multilayergeneratoren N2 - Thermoelektrische Effekte beschreiben die direkte Verknüpfung von thermischer Energie und elektrischer Energie in Festkörpern. Durch Thermodiffusionsströme entsteht direkt, ohne beweg¬liche Teile, ein elektrisches Feld als Folge einer Temperaturdifferenz. Diese Material-eigenschaft wird durch den Seebeckkoeffizienten beschrieben. Je nach Art der Ladungs¬träger sind die indu¬zierte Spannung und der Seebeckkoeffizient positiv (p-Typ) oder negativ (n-Typ). Thermo¬elek¬trische Effekte lassen sich beispielsweise in Thermo¬elementen zur Temperatur-messung, in Pel¬tierelementen zum Kühlen oder Heizen und in thermo¬elektrischen Generatoren zur Umwandlung von thermischer Energie in elektrische Energie nutzen. In thermoelektrischen Generatoren werden Schenkel aus p-Typ- und n-Typ-Materialien elek-trisch in Reihe und thermisch parallel verschaltet. Konventionell werden einzelne Schenkel aus Bismut¬tellurid auf ein metallisiertes Substrat gelötet. Man spricht vom π-Typ-Design. Aufgrund auf¬wendiger Fertigung und nicht optimaler Flächennutzung stellt dieses Design nicht die best-mög¬liche Lösung dar. Neben Telluriden gibt es noch andere vielversprechende thermoelektrische Material¬systeme wie die oxidischen Thermoelektrika. Im Temperatur¬bereich oberhalb von 700 °C können oxidische thermoelektrische Materialien mit nichtoxidischen konkurrieren. Zudem sind sie oxidationsbeständig und können aus weniger toxischen und besser verfügbaren Rohstoffen her¬ge¬stellt werden. Da es sich um keramische Materialien handelt, können unter Nutzung der Multi¬layer¬technologie (auch Vielschicht- oder Mehrlagentechnik) Generatoren im Multilayer¬design hergestellt werden. Keramische Multi¬layer¬generatoren sind aufgrund der höheren Leis¬tungs¬dichte, der Möglichkeit der gezielten Texturierung und des hohen möglichen Auto¬mati¬sierungs¬grades des Herstellungs¬prozesses eine viel¬versprechende Alternative zu konven¬tionellen π-Typ-Generatoren. Alle Lagen werden in einem Schritt co-gesintert. Die beiden zum jetzigen Zeit¬punkt wohl viel¬versprechendsten oxi¬dischen Thermoelektrika sind Calcium-cobaltit Ca3Co4O9 als p-Typ und Calciummanganat CaMnO3 als n-Typ. Die Sinter¬tem¬peratur von Ca3Co4O9 ist durch eine Phasenumwandlung bei 926 °C beschränkt. Texturiertes, dichtes Ca3Co4O9 mit einer hohen Festigkeit kann nur über Hei߬pressen hergestellt werden. Das Co-Sintern von Ca3Co4O9 und CaMnO3 war wegen der Tem¬pera¬tur¬differenz von 350 K zwischen den jeweiligen Sinterintervallen bisher nicht möglich. Ziel dieser Arbeit war deshalb die Ent¬wick¬lung von kompatiblen oxidkeramischen Werkstoffen und Folien für thermoelektrische Multilayer-generatoren auf der Basis von Ca3Co4O9 und CaMnO3. Daraus resultieren vier wesentliche Arbeitspakete. Zunächst die Materialentwicklungen von Ca3Co4O9 (p-Typ) und CaMnO3 (n-Typ) für ein Co-Sintern bei 900 °C mit akzeptablen thermoelek¬trischen Eigenschaften, dann die Entwicklung der weiteren im Generator benötigten Kompo¬nenten wie der Isolationsschicht und abschließend die Fertigung und Bewertung von Demonstra¬toren im Multi¬layer¬design. Foliengießen und druckunterstütztes Sintern ermöglichen die Herstellung von dichtem, tex-turier¬tem Ca3Co4O9 mit hoher Festigkeit und hohem Leistungsfaktor. Letzterer ist das Produkt der elek¬trischen Leitfähigkeit und dem Quadrat des Seebeckkoeffizienten. Für die elektrische Leit¬fähigkeit zeigte sich in dieser Arbeit ein kombinierter Einfluss von Sinterdichte und Textur. Die thermo¬elektrischen Eigen¬schaften lassen sich somit über die Einstellung der Mikrostruktur gezielt steuern. Durch die Optimierung der Pulversynthese, die Einführung des Sinteradditives CuO und die Kombi¬nation mit dem druckunterstützten Sintern (7,5 MPa) konnte die Sintertemperatur des CaMnO3 bei gleichbleibendem Leistungsfaktor von 1250 °C auf 950 °C gesenkt werden. Druck-unter¬stütztes Sintern von CaMnO3 ist bei 900 °C möglich, führt aber zu einem Werkstoff mit geringerem Leistungsfaktor, geringerer Dichte und ungenügender Festigkeit. Zur elektrischen Isolation der beiden thermoelektrischen Materialien wurde ein Glas-Keramik-Kompo¬sit mit hohem Volumenwiderstand und angepasstem Wärmeausdehnungs¬koef¬fizienten ent¬wickelt. Aus den zu Folien vergossenen thermoelektrischen Materialien, der siebgedruckten Iso¬lations-schicht und der siebgedruckten Metallisierung wurden mittels Multilayertech¬nologie De¬mons-tratoren hergestellt. Neben dem pn-Generator aus Ca3Co4O9 und CaMnO3 wurden auch Unileg-generatoren aus Ca3Co4O9 gefertigt. Bei Unileggeneratoren wird die Komplexität des Aufbaus durch die Verwendung von nur einem thermoelektrischen Material verringert. Die Simulation der Demonstratoren zeigte, dass der pn-Generator aus Ca3Co4O9 und CaMnO3 keine höheren Leis-tungsdichten erbringt als der aus nur Ca3Co4O9 bestehende Unileg¬generator. Auf¬grund des ge-ringen Leistungsfaktors und der geringen Festigkeit des bei 900 °C gesinterten CaMnO3 er¬scheint die Fertigung von pn-Multilayer¬generatoren aus Ca3Co4O9 und CaMnO3 derzeit nicht sinn¬voll. Die Unileg¬generatoren aus Ca3Co4O9 erreichen mit sehr hoher Reproduzier¬barkeit 2 mW/cm² bei einer Temperaturdifferenz von 230 K, dies entspricht 80 % der simulierten elektrischen Leistung. Es handelt sich hierbei um den ersten Machbarkeits¬nachweis zur Herstellung von Multilayer-generatoren auf Basis von texturiertem Ca3Co4O9 mit hohem thermoelektrischem Leistungsfaktor, hoher Dichte und hoher Festigkeit. Solch thermoelektrische Multilayergeneratoren könnten zukünftig Systeme mit geringen elek-trischen Leistungsanforderungen wie Sensoren autark und nachhaltig mit elektrischer Energie ver¬sorgen. T2 - Promotionskolloquium CY - Bayreuth, Germany DA - 25.04.2022 KW - Calciumcobaltit KW - Calciummanganat KW - Foliengießen KW - Sintertemperatur PY - 2022 AN - OPUS4-54726 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker T1 - Scarf-joint repairs under fatigue loading investigated for sandwich shell applications N2 - Wind turbine rotor blades are produced as aerodynamic, three-dimensionally formed sandwich shell structures using mainly glass fiber reinforced plastics (GFRP). The GFRP used today have the potential to withstand the harsh operating conditions of rotor blades over the projected service life of 20 years. Premature damages that occur can be traced primarily back to design and/or manufacturing imperfections, as well as unusually high load scenarios (for instance lightning strikes, or strong winds combined with system control errors). Therefore, rotor blades have to be repaired several times (on average 2-3 times) during their projected service life. Approximately 70% of these are repairs of small- to medium-sized sandwich shells, carried out by technicians directly accessing the blade by suspended roping at the wind turbine location. The goal is to execute repairs that will last over the remaining service life, i.e. be sustainable. Within the framework of a research project carried out at BAM, Division 5.3 Polymer Matrix Composites, Department 5 for Materials Engineering, not only was the geometric shape (round vs. square in relation to the top view) varied, but also the layup of the scarf repair structure, variables that have not been studied systematically to-date. Sub-component scale sandwich shell specimens with representative repairs were used in this work in addition to coupon-scale specimens that are more commonly seen in literature. These sub-component shell specimens were tested using a unique shell test bench under loading conditions representative of wind turbine blade shell operating conditions with respect to fatigue strength. Using non-destructive testing methods (field strain measurement and thermography), damage development and distribution was monitored and analyzed in-situ. As a result, a concept was developed in which the repaired areas showed at least equivalent if not higher fatigue strength than the reference shells that were not repaired. T2 - ICFC9 - The 9th International Conference on the Fatigue of Composites CY - Vicenza, Italy DA - 21.06.2023 KW - Repair of sandwich shell structures KW - Non-destructive testing KW - Wind turbine blades PY - 2023 AN - OPUS4-57929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schilling, Markus T1 - Tensile Test Ontology (TTO) N2 - This is the stable version 2.0.1 of the PMD ontology module of the tensile test (Tensile Test Ontology - TTO) as developed on the basis of the 2019 standard ISO 6892-1: Metallic materials - Tensile Testing - Part 1: Method of test at room temperature. The TTO was developed in the frame of the PMD project. The TTO provides conceptualizations valid for the description of tensile test and corresponding data in accordance with the respective standard. By using TTO for storing tensile test data, all data will be well structured and based on a common vocabulary agreed on by an expert group (generation of FAIR data) which will lead to enhanced data interoperability. This comprises several data categories such as primary data, secondary data and metadata. Data will be human and machine readable. The usage of TTO facilitates data retrieval and downstream usage. Due to a close connection to the mid-level PMD core ontology (PMDco), the interoperability of tensile test data is enhanced and data querying in combination with other aspects and data within the broad field of material science and engineering (MSE) is facilitated. The TTO class structure forms a comprehensible and semantic layer for unified storage of data generated in a tensile test including the possibility to record data from analysis, re-evaluation and re-use. Furthermore, extensive metadata allows to assess data quality and reproduce experiments. Following the open world assumption, object properties are deliberately low restrictive and sparse. KW - Ontology KW - Tensile Test KW - Digitalization KW - Plattform MaterialDigital KW - Structured Data PY - 2023 UR - https://github.com/MarkusSchilling/application-ontologies/blob/479311832819af695a2c64fa8eb772f2da398061/tensile_test_ontology_TTO/pmd_tto.ttl UR - https://github.com/materialdigital/core-ontology/blob/59f5727b0437ceea5e3d9fcb8fcd0ac211e92cc3/pmd_tto.ttl PB - GitHub CY - San Francisco, CA, USA AN - OPUS4-57935 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heuser, Lina A1 - Nofz, Marianne T1 - Alkali and alkaline earth zinc and lead borate glasses: Structure and properties N2 - Low melting Li2O-PbO-B2O3, Me2O-ZnO-B2O3, Me = Li, Na, K, Rb and CaO-ZnO-B2O3 glasses were studied with Raman and infrared spectroscopies to advance the structural understanding of zinc borate glasses as potential candidates for substitution of lead containing glasses. Although the effect of type of alkali ions on the number (N4) of fourfold coordinated boron (B4) in the glasses is small, the alkali ions direct the type of borate groups, i.e., pentaborate in lithium, sodium, and calcium zinc borate glasses, as well as diborate in potassium and rubidium containing ones. Both groups were simultaneously found in Li2O-PbO-B2O3. Alkali ions are mainly responsible for the formation of B4-units and metaborate. Zinc ions favorably compensate non-bridging oxygen and partially form ZnO4. With decreasing N4 and field strength of the alkali ions the atomic packing density, glass transition temper ature and Young’s Modulus also decrease. The coefficient of thermal expansion increases with decreasing N4. KW - Raman spectroscopy KW - IR spectroscopy KW - Alkali zinc borate glasses KW - Lead borate glasses KW - Physical properties KW - Young’s Modulus PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-556109 DO - https://doi.org/10.1016/j.nocx.2022.100109 SN - 2590-1591 VL - 15 SP - 1 EP - 12 PB - Elsevier CY - Amsterdam AN - OPUS4-55610 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker A1 - Kalinka, Gerhard A1 - Loose, Florian T1 - Carbon fibre composites exemplarily research at BAM N2 - Lightweighting as a cross-cutting technology contributes significantly to achieve the European Green Deal goals. Based on, but not limited to, advanced materials and production technologies, the demand for natural resources and CO2 emmissions are reduced by lightweighting during production, as well as use phase. Therefore, lightweighting is a crucial transformation technology assisting in decoupling economic growth from resource consumption. In this manner, lightweighting contributes significantly as a key technology of relevance for many industrial sectors such as energy, mobility, and infrastructure, towards resource efficiency, climate action and economic strength, as well as a resilient Europe. To strengthen international partnerships, addressing global issues of today at the edge of science with high performance lightweight material based on carbon fibers, an overview about the BAM expertise in carbon fiber reinforced materials is given. T2 - Meeting KCarbon CY - Berlin, Germany DA - 15.06.2023 KW - Lightweighting KW - Carbon Fibers KW - Recycling KW - Push-out Test KW - multi scale testing PY - 2023 AN - OPUS4-58094 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - PMD Workshop: Use and benefits of the PMDco N2 - This is an interactive workshop of the Plattform MaterialDigital (PMD) on Semantic Web technologies (SWT) where we delve into the world of ontology development and data structuring in the field of materials science and engineering (MSE). This workshop is designed to equip participants with essential skills in categorizing classes within ontologies, with a special emphasis on the PMD Core Ontology (PMDco). Discover the immense value of ontologies for MSE data reproducibility and reuse and harness the power of PMDco to foster your data management practices. In this workshop, you will explore the intricacies of class categorization when developing ontologies in the MSE domain. Through interactive discussions and hands-on exercises, you will learn effective techniques for structuring and organizing ontologies to enhance data retrieval and analysis. You will gain valuable insights into best practices and considerations for class categorization, aiming at optimal data organization and management within your MSE projects. One of the highlights of this workshop is the introduction to PMDco, a mid-level ontology in the field of MSE developed community-driven in the frame of the project PMD. Learn about PMDco, its underlying concepts, and its application in detail. Discover how PMDco provides a comprehensive framework for MSE data representation, enabling seamless integration and interoperability across different systems and platforms. In addition to exploring PMDco, this workshop will illustrate the benefits of data interoperability and SWT with respect to leveraging the full potential of MSE data. T2 - NFDI MatWerk Conference 2023 CY - Siegburg, Germany DA - 27.06.2023 KW - Workshop KW - Ontology KW - Plattform MaterialDigital KW - PMDco PY - 2023 AN - OPUS4-57802 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Plattform MaterialDigital in DIN NA 062-01-42 AA N2 - In dieser Präsentation werden die letzten Entwicklungen in der Plattform MaterialDigital (PMD) im DIN Normenausschuss 062-01-42 AA zur Zug- und Duktilitätsprüfung für Metalle vorgestellt. Dabei werden hauptsächlich die Entwicklungen und Neustrukturierung der PMD Core Ontology (PMDco) sowie die entsprechende Anpassung der Zugversuchsontologie (Tensile Test Ontology - TTO) inklusive des Datenmappings adressiert. Für das Datenmapping wurde ein speziell im Zusammenhang mit der PMD erstellter Zugversuchsdatensatz verwendet, welcher frei verfügbar in einem online Zenodo Repository veröffentlicht ist. Weiterhin wird die Weiterentwicklung der Norm in Verbindung mit ihrer folgenden Revision hinsichtlich der Integration von Aspekten zur Digitalisierung in der Materialwissenschaft und Werkstofftechnik sowie der Verwendung von semantischen Technologien, wie unter anderem ontologischen Repräsentationen von Materialien und Prozessen, diskutiert. T2 - DIN NA 062-01-42 AA Meeting CY - Berlin, Germany DA - 14.06.2023 KW - Ontologie KW - Semantic Web Technologies KW - Normung KW - DIN KW - Plattform MaterialDigital KW - Zugversuch KW - Tensile Test KW - Materialcharakterisierung PY - 2023 AN - OPUS4-57803 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk A1 - Klinger, Christian T1 - Schadensanalyse an Fahrradkomponenten - Fraktographie, Ursachen, Prävention N2 - Komponenten von Fahrrädern werden im Betrieb vorwiegend schwingend beansprucht. Typische Werkstoffe sind Stahl, Aluminiumlegierungen, Messing, CFK und thermoplastische Kunststoffe. Da es sich, unabhängig von der Preiskategorie, um konstruktiven Leichtbau handelt, werden einige Bauteile betriebsfest mehr oder weniger weit oberhalb der Dauerfestigkeit ausgelegt. Die im normalen Betrieb auftretenden Schäden sind daher weit überwiegend Schwingbrüche. Andere Schadensmechanismen wie z.B. Korrosion spielen quantitativ eine untergeordnete Rolle. Schwingbrüche treten nach einer Periode unbemerkten Risswachstums oft ohne Vorwarnung und ohne makroskopische Verformung auf. Im Falle von sicherheitsrelevanten Komponenten wie Rahmen, Gabeln, Lenkern, Sattelstützen, Kurbelarmen oder Pedalen kann dies zu erheblichen Personenschäden führen, die den Wert des ursächlichen Bauteilschadens weit überschreiten. Über einen langjährigen Zeitraum wurden gebrochene Komponenten aus dem Alltag und aus Gerichtsverfahren analysiert. Das Hauptaugenmerk lag hierbei auf der fraktographischen Analyse, teilweise wurden die zu Grunde liegenden Schadensursachen ermittelt. Einflussfaktoren sind beispielsweise konstruktive Kerben an ungünstigen Stellen, aber auch Werkstoffwahl und Fertigungsqualität spielen eine Rolle. In den meisten Fällen wurde jedoch die konstruktive Lebensdauer überschritten. Diese wird praktisch nie mitgeteilt, und eine wiederkehrende Prüfung sicherheitsrelevanter Bauteile findet nicht statt. Im Sinne der Vermeidung von Schäden und Unfällen könnte darauf hingewirkt werden, für sicherheitsrelevante Komponenten Lebensdauern besser abzuschätzen und von der Laufleistung abhängige Sichtprüfungen zu empfehlen. T2 - Werkstoffprüfung 2022 CY - Dresden, Germany DA - 27.10.2022 KW - Fahrrad KW - Fraktographie KW - Lebensdauer KW - Schadensanalyse KW - Schadensprävention KW - Öffentliche Sicherheit PY - 2023 UR - https://dgm.de/fileadmin/DGM/Veranstaltungen/2022/Werkstoffpruefung/Tagungsband/WP2022-Tagungsband-online.pdf SN - 978-3-88355-430-3 SP - 73 EP - 78 PB - DGM - Deutsche Gesellschaft für Materialkunde e.V CY - Sankt Augustin AN - OPUS4-56832 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönauer-Kamin, D. T1 - Powder Aerosol deposited (PAD) calcium cobaltite as textured p type thermoelectric material N2 - Oxide thermoelectric semiconducting materials like p-type calcium cobaltite Ca3Co4O9 are investigated as oxidation- and temperature-resistant thermoelectric materials for thermoelectric generators (TEGs). To realize TEGs in planar film technology, the powder aerosol deposition (PAD) method is emerging recently. PAD is a method to obtain dense ceramic films directly from the synthesized starting powders without a subsequent high temperature step. In the present work, Ca3Co4O9 (CCO) powders are processed by PAD to ceramic films at room temperature. The thermoelectric properties of the films (film thickness 10 – 20 µm) are characterized from room temperature to 900°C. Additionally, the layer morphology and texture of the films will be investigated. As result, the Seebeck coefficient of the CCO-PAD film is comparable to pressed and sintered CCO-bulk materials during the 1st heating cycle to 900°C. The morphology of the films after the thermal treatment shows strong aligned crystallites resulting in a strong texture of the films. The electrical conductivity increases strongly during the 1st heating cycle to 900°C and stays almost constant afterwards. Compared to CCO-bulks, the films provide higher electrical conductivity which could be explained by the oriented crystal growth in-plane direction of the film. The relationship between thermoelectric properties and layer morphology as a function of thermal annealing parameters will be further investigated. T2 - KERAMIK 2023 / 98. DKG-Jahrestagung CY - Jena, Germany DA - 27.03.2023 KW - Layer depostion KW - Texture KW - Heat treatment PY - 2023 AN - OPUS4-57285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schilling, Markus T1 - Full-Notch Creep Test Ontology (ontoFNCT) N2 - This is the stable version of the full-notch creep test ontology (OntoFNCT) that ontologically represents the full-notch creep test. OntoFNCT has been developed in accordance with the corresponding test standard ISO 16770:2019-09 Plastics - Determination of environmental stress cracking (ESC) of polyethylene - Full-notch creep test (FNCT). The OntoFNCT provides conceptualizations that are supposed to be valid for the description of full-notch creep tests and associated data in accordance with the corresponding test standard. By using OntoFNCT for storing full-notch creep test data, all data will be well structured and based on a common vocabulary agreed on by an expert group (generation of FAIR data) which is meant to lead to enhanced data interoperability. This comprises several data categories such as primary data, secondary data and metadata. Data will be human and machine readable. The usage of OntoFNCT facilitates data retrieval and downstream usage. Due to a close connection to the mid-level PMD core ontology (PMDco), the interoperability of full-notch creep test data is enhanced and querying in combination with other aspects and data within the broad field of materials science and engineering (MSE) is facilitated. The class structure of OntoFNCT forms a comprehensible and semantic layer for unified storage of data generated in a full-notch creep test including the possibility to record data from analysis and re-evaluation. Furthermore, extensive metadata allows to assess data quality and reliability. Following the open world assumption, object properties are deliberately low restrictive and sparse. KW - Ontology KW - Full-Notch Creep Test KW - FNCT KW - Knowledge Representation KW - Semantic Web Technologies KW - Data Structures KW - Data Management PY - 2024 UR - https://github.com/MarkusSchilling/ontoFNCT/blob/4abce82852190a5e444d302da077aa7404f433f0/ontoFNCT.ttl UR - https://raw.githubusercontent.com/MarkusSchilling/ontoFNCT/main/ontoFNCT.ttl PB - GitHub CY - San Francisco, CA, USA AN - OPUS4-59815 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Birkholz, H. A1 - Bayerlein, Bernd T1 - PMD Core Ontology: A Community Driven Mid-Level Ontology in the MSE Domain N2 - Knowledge representation in the materials science and engineering (MSE) domain is a vast and multi-faceted challenge: Overlap, ambiguity, and inconsistency in terminology are common. Invariant and variant knowledge are difficult to align cross-domain. Generic top-level semantic terminology often is too abstract, while MSE domain terminology often is too specific. In this presentation, an approach how to maintain a comprehensive and intuitive MSE-centric terminology composing a mid-level ontology–the PMD core ontology (PMDco)–via MSE community-based curation procedures is shown. The PMDco is designed in direct support of the FAIR principles to address immediate needs of the global experts community and their requirements. The illustrated findings show how the PMDco bridges semantic gaps between high-level, MSE-specific, and other science domain semantics, how the PMDco lowers development and integration thresholds, and how to fuel it from real-world data sources ranging from manually conducted experiments and simulations as well as continuously automated industrial applications. T2 - FEMS EUROMAT 2023 CY - Frankfurt a. M., Germany DA - 03.09.2023 KW - Knowledge Representation KW - Semantic Interioerability KW - Mid-Level Ontology for MSE KW - FAIR Data Management PY - 2023 AN - OPUS4-58201 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lemiasheuski, Anton A1 - Bajer, Evgenia A1 - Oder, Gabriele A1 - Göbel, Artur A1 - Hesse, Rene A1 - Bettge, Dirk T1 - Development of an Automated 3D Metallography System (RASI) and its Application in Microstructure Analysis N2 - Many microstructural features exhibit non-trivial geometries, which can only be derived to a limited extent from two-dimensional images. E.g., graphite arrangements in lamellar gray cast iron have complex geometries, and the same is true for additively manufactured materials and three-dimensional conductive path structures. Some can be visualized using tomographic methods, but some cannot be due to weak contrast and/or lack of resolution when analyzing macroscopic objects. Classic metallography can help but must be expanded to the third dimension. The method of reconstructing three-dimensional structures from serial metallographic sections surely is not new. However, the effort required to manually assemble many individual sections into image stacks is very high and stands in the way of frequent application. For this reason, an automated, robot-supported 3D metallography system is being developed at BAM, which carries out the steps of repeated preparation and image acquisition on polished specimen. Preparation includes grinding, polishing and optionally etching of the polished surface. Image acquisition comprises autofocused light microscopic imaging at several magnification levels. The image stacks obtained are then pre-processed, segmented, and converted into 3D models, which in the result appear like microtomographic models, but with high resolution at large volume. Contrasting by classical chemical etching reveals structures that cannot be resolved using tomographic methods. The integration of further imaging and measuring methods into this system is underway. Some examples will be discussed in the presentation. T2 - Euromat 2023 CY - Frankfurt a. M., Germany DA - 04.07.2023 KW - Metallography KW - 3D Reconstruction KW - Roboter KW - Automation KW - Microstructure PY - 2023 AN - OPUS4-58202 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - PMDco - Platform MaterialDigital Core Ontology N2 - The PMD Core Ontology (PMDco) is a comprehensive set of building blocks produced via consensus building. The ontological building blocks provide a framework representing knowledge about fundamental concepts used in Materials Science and Engineering (MSE) today. The PMDco is a mid-level ontology that establishes connections between narrower MSE application ontologies and domain neutral concepts used in already established broader (top-level) ontologies. The primary goal of the PMDco design is to enable interoperability between various other MSE-related ontologies and other common ontologies. PMDco’s class structure is both comprehensive and extensible, rendering it an efficient tool to structure MSE knowledge. The PMDco serves as a semantic middle-layer unifying common MSE concepts via semantic mapping to other semantic representations using well-known key terms used in the MSE domain. The PMDco enables straight-forward documentation and tracking of science data generation and in consequence enables high-quality FAIR data that allows for precise reproducibility of scientific experiments. The design of PMDco is based on the W3C Provenance Ontology (PROV-O), which provides a standard framework for capturing the production, derivation, and attribution of resources. Via this foundation, the PMDco enables the integration of data from various data origins and the representation of complex workflows. In summary, the PMDco is a valuable advancement for researchers and practitioners in MSE domains. It provides a common MSE vocabulary to represent and share knowledge, allowing for efficient collaboration and promoting interoperability between diverse domains. Its design allows for the systematic integration of data and metadata, enabling seamless tracing of science data. Overall, the PMDco is a crucial step towards a unified and comprehensive understanding of the MSE domain in general. T2 - FEMS EUROMAT 2023 CY - Frankfurt a. M., Germany DA - 03.09.2023 KW - Knowledge Representation KW - Ontology KW - Semantic Interoperability KW - FAIR KW - Automation PY - 2023 AN - OPUS4-58197 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Suárez Ocano, Patricia T1 - Thermodynamic and microstructural stabilities at high temperatures and their effects on mechanical properties in an AlMo0.5NbTa0.5TiZr refractory high entropy superalloy N2 - Today’s industrial demands challenge the research and development sector to make advances in the design and properties of materials that can withstand harsh environments. The AlMo0.5NbTa0.5TiZr refractory high-entropy superalloy (RSA), with a remarkable morphological similarity to the γ/γ' microstructure of Ni-based superalloys and promising high-temperature compressive properties, has been considered as a candidate for structural applications. However, additional properties need to be investigated in order to assess the suitability of this alloy for high temperature applications. Therefore, this work investigates the thermodynamic and microstructural stabilities of the RSA at room temperature and between 900 and 1100 °C, and their influence on the mechanical properties. Although it is possible to improve the mechanical properties at 20 °C by tuning the cooling rate, long-term high temperature exposures lead to phase instabilities that negatively influence the creep behavior. N2 - Die heutigen industriellen Anforderungen erfordern Fortschritte bei Werkstoffdesign und -entwicklung, insbesondere für raue Umgebungen. Die hochentropische Refraktärsuperlegierung (RSA) AlMo0.5NbTa0.5TiZr, die eine bemerkenswerte morphologische Ähnlichkeit mit der γ/γ'-Mikrostruktur von Ni-Basis-Superlegierungen und vielversprechende Hochtemperatur-Druckeigenschaften aufweist, wurde als Kandidat für strukturelle Anwendungen erwägt. Weitere Eigenschaften müssen untersucht werden, um die Eignung dieser Legierung für Hochtemperaturanwendungen zu beurteilen. In dieser Arbeit werden die thermodynamischen und mikrostrukturellen Stabilitäten von RSA bei Raumtemperatur und zwischen 900 und 1100°C sowie deren Einfluss auf die mechanischen Eigenschaften untersucht. Obwohl es möglich ist, die mechanischen Eigenschaften bei 20 °C durch Abstimmung der Abkühlrate zu verbessern, führen langfristige Hochtemperaturexpositionen zu Phaseninstabilitäten, die das Kriechverhalten negativ beeinflussen. KW - Hochentropielegierung KW - Gefüge (Werkstoffkunde) KW - Mikrostruktur KW - Kriechen KW - Thermodynamische Stabilität KW - High entropy alloys KW - Microstructure KW - Creep KW - Thermodynamic stability PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:hbz:294-108415 DO - https://doi.org/10.13154/294-10841 SP - 1 EP - 170 CY - Bochum AN - OPUS4-59929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - FAIR Data in Platform MaterialDigital (PMD) - Ontologies , Semantic Data Integration and Data Exchange N2 - Following the new paradigm of materials development, design, and optimization, digitalization is the main goal in materials sciences and engineering (MSE) which imposes a huge challenge. In this respect, the quality assurance of processes and output data as well as the interoperability between applications following FAIR principles are to be ensured. For storage, processing, and querying of data in contextualized form, Semantic Web technologies (SWT) are used since they allow for machine-actionable and human-readable knowledge representations needed for data management, retrieval, and (re)use. The project ‘platform MaterialDigital’ (PMD, https://materialdigital.de) aims to bring together and support interested parties from both industrial and academic sectors in a sustainable manner in solving digitalization tasks and implementing digital solutions. Therefore, the establishment of a virtual material data space and the systematization of the handling of hierarchical, process-dependent material data are focused. Core points to be dealt with are the development of agreements on data structures and interfaces implemented in distinct software tools and to offer users specific support in their projects. Furthermore, the platform contributes to a standardized description of data processing methods in materials research. In this respect, selected MSE methods are semantically represented which are supposed to serve as best practice examples with respect to knowledge representation and the creation of knowledge graphs used for material data. Accordingly, this presentation shows the efforts taken within the PMD project towards the digitalization in MSE such as the development of the mid-level PMD core ontology (PMDco, https://github.com/materialdigital/core-ontology). Furthermore, selected results of a PMD partner project use case addressing data and knowledge management from synthesis, production, and characterization of materials are shown. T2 - 1st VMAP User Meeting 2024 CY - Sankt Augustin, Germany DA - 14.02.2024 KW - Ontology KW - Semantic Web Technologies KW - Plattform MaterialDigital KW - Data Interoperability KW - Data Exchange KW - Data Structures PY - 2024 AN - OPUS4-59567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schilling, Markus A1 - Bayerlein, Bernd A1 - Birkholz, H. A1 - Fliegener, S. A1 - Grundmann, J. A1 - Hanke, T. A1 - von Hartrott, P. A1 - Waitelonis, J. T1 - PMD Core Ontology (PMDco) N2 - The PMD Core Ontology (PMDco) is a comprehensive framework for representing knowledge that encompasses fundamental concepts from the domains of materials science and engineering (MSE). The PMDco has been designed as a mid-level ontology to establish a connection between specific MSE application ontologies and the domain neutral concepts found in established top-level ontologies. The primary goal of the PMDco is to promote interoperability between diverse domains. PMDco's class structure is both understandable and extensible, making it an efficient tool for organizing MSE knowledge. It serves as a semantic intermediate layer that unifies MSE knowledge representations, enabling data and metadata to be systematically integrated on key terms within the MSE domain. With PMDco, it is possible to seamlessly trace data generation. The design of PMDco is based on the W3C Provenance Ontology (PROV-O), which provides a standard framework for capturing the generation, derivation, and attribution of resources. By building on this foundation, PMDco facilitates the integration of data from various sources and the creation of complex workflows. In summary, PMDco is a valuable tool for researchers and practitioners in the MSE domains. It provides a common language for representing and sharing knowledge, allowing for efficient collaboration and promoting interoperability between diverse domains. Its design allows for the systematic integration of data and metadata, enabling seamless traceability of data generation. Overall, PMDco is a crucial step towards a unified and comprehensive understanding of the MSE domain. PMDco at GitHub: https://github.com/materialdigital/core-ontology KW - Ontology KW - Semantic Web technologies KW - Digitalization KW - Data Interoperability KW - PMD Core Ontology PY - 2023 UR - https://github.com/materialdigital/core-ontology/blob/f2bd420348b276583fad6fa0fb4225f17b893c78/pmd_core.ttl PB - GitHub CY - San Francisco, CA, USA AN - OPUS4-59352 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina T1 - Electron-beam induced particle synthesis: Phenomenological study of the physical mechanisms N2 - Several studies have shown that the electron beam (e-beam) can be used to create nanomaterials from microparticles in situ in a TEM. However, attempts to produce gold nanoparticles (NPs) on silicon oxide substrate remained to be accomplished. Here, we show that the production of gold NPs is possible by using the e-beam in a SEM, under a set of parameters. To understand the physical mechanisms leading to the gold NPs, the mechanisms of e-beam induced charging as well as e-beam induced heating of the MPs were discussed. Several hints point to heating as the driving mechanism. T2 - IFW Dresden, Seminar CY - Dresden, Germany DA - 06.12.2023 KW - Electron-beam-induced modification KW - Nanoparticle synthesis KW - Scanning electron microscopy KW - Driving physical mechanism KW - Negative charged microparticle KW - Temperature driven process PY - 2023 AN - OPUS4-59081 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Hochwertige, verlässliche und FAIRe Daten erstellen: Von Ontologien und elektronischen Laborbüchern zu Datenmanagement und Wissenstransfer N2 - Das hochaktuelle Thema der Integration und Wiederverwendung von Wissen und Daten aus Herstellung, Bearbeitung und Charakterisierung von Materialien wird im Zuge der digitalen Transformation in der Materialwissenschaft und Werkstofftechnologie in verschiedenen Projekten adressiert. Dabei stehen die Interoperabilität von nach FAIR-Prinzipien erstellten und veröffentlichten Daten und Anwendungen im Vordergrund. Zur Umsetzung eines komplexen Datenmanagements sowie der Digitalisierung im Bereich der Materialwissenschaften etablieren sich Ontologien zunehmend als belastbares Werkzeug. Sie ermöglichen sowohl menschenlesbare als auch maschinenverständliche und -interpretierbare Wissensrepräsentationen durch semantische Konzeptualisierungen. Im Rahmen des Projektes Plattform MaterialDigital (PMD, materialdigital.de) werden Ontologien verschiedener Ebenen entwickelt (verbindende mid-level sowie Domänen-Ontologien). Die PMD-Kernontologie (PMD Core Ontology - PMDco) ist eine Ontologie der mittleren Ebene), die Verbindungen zwischen spezifischeren MSE-Anwendungsontologien und domänenneutralen Konzepten herstellt, die in bereits etablierten Ontologien höherer Ebenen (top-level Ontology) verwendet werden. Sie stellt somit einen umfassenden Satz von durch Konsensbildung in der Gemeinschaft (geteiltes Vokabular) entstanden Bausteinen grundlegender Konzepte aus der Materialwissenschaft und Werkstofftechnik (MSE) dar. Das primäre Ziel des PMDco-Designs ist es, die Interoperabilität zwischen verschiedenen MSE-bezogenen und anderen Ontologien zu ermöglichen. Die PMDco dient als umfassend ausgelegte und erweiterbare semantische Zwischenschicht, die gemeinsame MSE-Konzepte durch semantisches Mapping auf andere Darstellungen vereinheitlicht, was sie zu einem effizienten Werkzeug zur Strukturierung von MSE-Wissen macht. In dieser Präsentation wird die Version 2.0 der PMDco vorgestellt. Weiterhin wird eine auf die PMDco bezogene normenkonforme ontologische Repräsentation zur Speicherung und Weiterverarbeitung von Zugversuchsdaten präsentiert, die in enger Zusammenarbeit mit Standardisierungsgremien erstellt wurde. Dies umfasst den Weg von der Entwicklung einer Ontologie nach Norm, der Konvertierung von Daten aus Standardtests in das interoperable RDF-Format bis hin zur Verbindung von Ontologie und Daten. Letztendlich können die entsprechenden Daten in einem Triple Store abgelegt und abgefragt werden. Auf Basis dieser Zugversuchsontologie wurde im Folgenden unter Verwendung eines elektronischen Laborbuches (electonic lab notebook – ELN) zur Datenaufnahme eine Praktikumsreihe von Universitätsstudierenden digitalisiert. Dadurch wurde eine vollständig digital integrierte Versuchsführung ermöglicht, die auf andere Versuchsreihen und Experimente übertragbar ist und ebenfalls vorgestellt werden soll. Neben einer erleichterten Aufnahme, Analyse und (Wieder-)Verwendbarkeit von Daten wird damit eine Sensibilisierung von Studierenden für Datenstrukturierung sowie semantische Technologien im Sinne der Aus- und Weiterbildung erreicht. T2 - DVM-Tagung Werkstoffprüfung CY - Berlin, Germany DA - 23.11.2023 KW - Ontologie KW - Semantic Web Technologies KW - Plattform MaterialDigital KW - PMDco KW - Zugversuchsontologie KW - Zugversuch KW - Elektronisches Laborbuch (ELN) PY - 2023 AN - OPUS4-59030 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - PMDco: Achieving High-Quality & Reliable FAIR Data N2 - Knowledge representation in the materials science and engineering (MSE) domain is a vast and multi-faceted challenge: Overlap, ambiguity, and inconsistency in terminology are common. Invariant and variant knowledge are difficult to align cross-domain. Generic top-level semantic terminology often is too abstract, while MSE domain terminology often is too specific. In this presentation, an approach how to maintain a comprehensive and intuitive MSE-centric terminology composing a mid-level ontology–the PMD core ontology (PMDco)–via MSE community-based curation procedures is shown. The PMDco is designed in direct support of the FAIR principles to address immediate needs of the global experts community and their requirements. The illustrated findings show how the PMDco bridges semantic gaps between high-level, MSE-specific, and other science domain semantics, how the PMDco lowers development and integration thresholds, and how to fuel it from real-world data sources ranging from manually conducted experiments and simulations as well as continuously automated industrial applications. T2 - Kupfer-Symposium CY - Jena, Germany DA - 29.11.2023 KW - Ontology KW - Semantic Web Technologies KW - Plattform MaterialDigital KW - PMDco PY - 2023 AN - OPUS4-59031 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina T1 - Electron-beam-induced production of gold nanoparticles N2 - Several studies have shown that the electron beam (e-beam) can be used to create nanomaterials from microparticles in situ in a TEM. However, attempts to produce gold nanoparticles (NPs) on silicon oxide substrate remained to be accomplished. Here, we show that the production of gold NPs is possible by using the e-beam in a SEM, under a set of parameters. The NPs produced present a size gradient along the radial direction. A parameter study shows that the microparticles may: 1) flicker away without producing NPs, 2) fragment to form NPs and/or 3) react with the silicon oxide substrate, depending on the applied current. A hypothesis regarding the driving physical phenomena that lead the microparticles to fragment into NPs is discussed. Fabrication of gold NPs in the SEM provides a more cost-effective option as compared to the established method in the TEM. T2 - PhD Seminar CY - Berlin, Germany DA - 26.11.2023 KW - Electron-beam-induced modification KW - Gold nanoparticles KW - Fabrication method KW - Scanning electron microscope KW - Nano-assemblies PY - 2023 AN - OPUS4-59080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - PMDco - Platform MaterialDigital Core Ontology: Achieving High-Quality & Reliable FAIR Data N2 - Knowledge representation in the materials science and engineering (MSE) domain is a vast and multi-faceted challenge: Overlap, ambiguity, and inconsistency in terminology are common. Invariant and variant knowledge are difficult to align cross-domain. Generic top-level semantic terminology often is too abstract, while MSE domain terminology often is too specific. In this poster presentation, an approach how to maintain a comprehensive and intuitive MSE-centric terminology composing a mid-level ontology–the PMD core ontology (PMDco)–via MSE community-based curation procedures is shown. The PMDco is designed in direct support of the FAIR principles to address immediate needs of the global experts community and their requirements. The illustrated findings show how the PMDco bridges semantic gaps between high-level, MSE-specific, and other science domain semantics, how the PMDco lowers development and integration thresholds, and how to fuel it from real-world data sources ranging from manually conducted experiments and simulations as well as continuously automated industrial applications. T2 - DVM Arbeitskreis Betriebsfestigkeit - Potenziale der Betriebsfestigkeit in Zeiten des technologischen und gesellschaftlichen Wandels CY - Munich, Germany DA - 11.10.2023 KW - Digitalization KW - Semantic Web Technologies KW - FAIR KW - Data Interoperability KW - PMD Core Ontology PY - 2023 AN - OPUS4-58602 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - Platform MaterialDigital Core Ontology (PMDco): A Community Driven Mid-Level Ontology in the MSE Domain N2 - Knowledge representation in the materials science and engineering (MSE) domain is a vast and multi-faceted challenge: Overlap, ambiguity, and inconsistency in terminology are common. Invariant and variant knowledge are difficult to align cross-domain. Generic top-level semantic terminology often is too abstract, while MSE domain terminology often is too specific. The PMDco is designed in direct support of the FAIR principles to address immediate needs of the global experts community and their requirements. The illustrated findings show how the PMDco bridges semantic gaps between high-level, MSE-specific, and other science domain semantics, how the PMDco lowers development and integration thresholds, and how to fuel it from real-world data sources ranging from manually conducted experiments and simulations as well as continuously automated industrial applications. T2 - Patents4Science CY - Berlin, Germany DA - 05.10.2023 KW - Knowledge Representation KW - Semantic Interoperability KW - FAIR data management KW - Knowledge graph and ontologies KW - PMD Core Ontology PY - 2023 AN - OPUS4-58507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - News from the working area - Semantic Interoperability N2 - This presentation provides a comprehensive overview of recent developments and the current status within the Semantic Interoperability work area, with a particular emphasis on the advancements related to the Platform MaterialDigital Core Ontology (PMDco). The presentation will delve into the collaborative and community-supported curation process that has been instrumental in shaping PMDco. Additionally, we will introduce the innovative Ontology Playground, showcasing its role in fostering experimentation and exploration within the realm of ontology development. T2 - MaterialDigital Vollversammlung CY - Karlsruhe, Germany DA - 21.09.2023 KW - Semantic Representation KW - FAIR data management KW - Semantic Interoperability KW - Knowledge graph and ontologies KW - PMD Core Ontology KW - MaterialDigital PY - 2023 AN - OPUS4-58422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk A1 - Schmies, Lennart T1 - Die Fraktographische Online-Datenbank der AG Fraktographie – Entwicklungsstand und weitere Planung N2 - Vortrag zum aktuellen Stand der fraktographischen online-Datenbank. Darstellung des AGM/DVM Gemeinschaftsausschusses REM in der Materialforschung und seiner Arbeitsgruppen Fraktographie, EBSD und 2D/3D-Prüfung. Ziele und Inhalte der fraktographischen Datenbank, Aufruf zum Mitmachen. Durchführung von Vergleichsversuchen, Entwicklung einer fraktographischen Symbolik, Ringversuch, Vorhaben iFrakto mit Entwicklung einer KI-gestützten Bruchflächenanalyse. T2 - Metallographietagung 2023 CY - Leoben, Austria DA - 13.09.2023 KW - Fraktographie KW - Machine Learning KW - Datenbank PY - 2023 AN - OPUS4-58467 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghafafian, Carineh A1 - Trappe, Volker ED - Vassilopoulos, A. P. ED - Michaud, V. T1 - Fully-reversed fatigue behavior of scarf joint repairs for wind turbine blade shell applications N2 - To enable a quick and cost-effective return to service for wind turbine blades, localized repairs can be executed by technicians in the field. Scarf repairs, shown to be highly efficient with a smooth load transition across angled joint walls and a restored aerodynamic profile, are the focus of this work. The failure mechanisms of these structures were examined under quasi-static tensile and fully-reversed cyclic loading. While the scarf ratio was held constant at 1:50, the repair layup was varied between large-to-small and small-to-large. The effect of the presence of resin pockets and the fiber orientation mismatch between parent and repair material on the restored strength of BIAX ±45° glass fiber reinforced polymer scarf joint structures was studied. T2 - 20th European Conference on Composite Materials CY - Lausanne, Switzerland DA - 26.06.2022 KW - Fatigue KW - Scarf repairs KW - Glass fiber reinforced polymers PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569646 UR - https://infoscience.epfl.ch/record/298799 SN - 978-2-9701614-0-0 VL - Vol. 5 - Applications and structures SP - 195 EP - 201 PB - Composite Construction Laboratory (CCLab) CY - Lausanne AN - OPUS4-56964 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cysne Barbosa, Ana Paula A1 - Azevedo do Nascimento, Allana A1 - Pavasarytė, Lina A1 - Trappe, Volker A1 - Melo, D. T1 - Effect of addition of thermoplastic self-healing agent on fracture toughness of epoxy N2 - Self-healing agents have the potential to restore mechanical properties and extend service life of composite materials. Thermoplastic healing agents have been extensively investigated for this purpose in epoxy matrix composites due to their strong adhesion to epoxy and their ability to fill in microcracks. One of the most investigated thermoplastic additives for this purpose is poly(ethylene-co-methacrylic acid) (EMAA). Despite the ability of thermoplastic healing agents to restore mechanical properties, it is important to assess how the addition of thermoplastic healing agents affect properties of the original epoxy material. In this work, EMAA was added to epoxy resin and the effect of the additive on fracture toughness of epoxy was evaluated. Results indicate that although added in low concentrations, EMAA can affect fracture toughness. T2 - 6th Brazilian Conference on Composite Materials CY - Tiradentes, Minas Gerais, Brazil DA - 14.08.2022 KW - Epoxy KW - Self-healing KW - Thermoplastic KW - Fracture PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572707 SN - 978-65-00-49386-3 DO - https://doi.org/10.29327/566492 SN - 2316-1337 SP - 219 EP - 222 AN - OPUS4-57270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker A1 - Sachs, Patrick ED - Vassilopoulos, A. P. ED - Michaud, V. T1 - Dynamic mechanical analysis of epoxy-matrix cross linking measured in-situ using an elastomer container N2 - A new patented dynamic mechanical analysis (DMA) is presented, where the tensile, bending- or torsional stiffness of a media can be characterized in-situ during the phase transition from liquid to solid. An epoxy system, e.g. Hexion L285/H287, is filled into an elastomer container, such as a silicone tube. This can be mounted into a conventional OMA and, based on a linear viscoelastic approach, the storage modulus (E';G'), the loss modulus (E'';G'') and the loss angle tan(δ) can be measured at constant temperature as a function of time in order to investigate the liquid to sol-gel to solid transition. With this new method, the stiffness increase as a result of the cure process can be directly measured more precisely than with a rheometer in a shear plate set-up, because using an elastomer container gives a defined cross section for calculating the Young's modulus. T2 - 20th European Conference on Composite Materials CY - Lausanne, Switzerland DA - 26.06.2022 KW - Cross linking KW - Dynamic mechanical analysis (DMA) KW - Thermoset polymers KW - Cure process PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569651 UR - https://infoscience.epfl.ch/record/298799 SN - 978-2-9701614-0-0 VL - Vol. 5 - Applications and structures SP - 181 EP - 186 PB - Composite Construction Laboratory (CCLab) CY - Lausanne AN - OPUS4-56965 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maaß, Robert T1 - Transitions from scale-free to scale-dependent fluctuations in plasticity N2 - Plastic deformation in crystals is mediated by the motion of line defects known as dislocations. For decades, dislocation activity has been treated as a homogeneous, smooth continuous process that relies on well-average quantities. However, it is now recognized that plasticity can be determined by long-range correlated and intermittent collective dislocation activity, known as avalanches. These abrupt plastic fluctuations often exhibit pure power-law scaling or truncated power-law scaling, which indicates at least some degree of scale-free dislocation behavior. Intriguingly, such statistical signatures can persist across scales exceeding those of the material’s microstructure, raising the question of what relationship there may be between structure and long-range correlated dislocation activity that underlie power-law scaling. In this talk, we address this question by highlighting examples in which a transition from scale-free to scale-dependent plastic deformation is observed either due to changing external testing conditions (stress-state or temperature) or by tuning the microstructure. In particular, we will focus on the details of the temperature-driven change, that demonstrates how scale-free intermittent flow in body-centered cubic Nb is progressively quenched out with decreasing temperature. The plastic response of Nb is shown to be bimodal across the studied temperature regime, with conventional thermally-activated smooth plastic flow coexisting with sporadic bursts controlled by athermal screw dislocation activity, thereby violating the classical notion of temperature-dependent screw dislocation motion at low temperatures. An abrupt increase of the athermal avalanche component is identified at the critical temperature of the material. We combine the experimental observations with 3D dislocation dynamics simulations, identify a possible origin to athermal screw activity, and discuss the co-existence scale-free and scale-dependent plasticity. T2 - Cairo Symposium on The Physics of Metal Plasticity CY - Cairo, Egypt DA - 05.09.2023 KW - Plastic deformation KW - Dislocations KW - Avalanches PY - 2023 AN - OPUS4-60648 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Glauer, M. A1 - Schilling, Markus A1 - Stappel, M. T1 - A practical ontology development guide N2 - Knowledge representation is becoming increasingly important in view of the large amounts of data that are handled in the modern scientific landscape. Many of the domains that have most readily realised this problem and worked on potential solutions have been the domain of biochemistry. And although the developments sought here were not accompanied by philosophers, this process organically led to the development of formal and structured representations of certain domains. While the resulting structures were not the first formal ontologies, they are ones that are still in wide use to this day. These approaches have led to major advances in the organisation, structuring and communication of scientific results. Since then, a variety of other domains have tried to adapt a similar process and develop their own ontologies. However, the development of ontologies from the domain of biochemistry was the result of a years-long process that also involved a large number of errors and course corrections. One of the greatest challenges is also one of the greatest strengths of ontologies: Interoperability with other ontologies. To ensure this interoperability, ontologies must follow certain principles. In the field of biochemistry, the OBO Foundry has established itself, which offers functionalities for a rich network of ontologies from the domain, but at the same time also defines rules. The purpose of this document is to define a similar set of rules for open ontology development, but which addresses a broader domain and at the same time lowers the barrier of entry for new ontology developers. To this end, we will outline a workflow that can be used to build new ontologies more efficiently. This workflow is based not only on our own years of experience in ontology development, but also on the rules of external experts such as the OBO Foundry. KW - Ontology KW - Data integration KW - Ontologie KW - Data interoperability PY - 2024 UR - https://scientific-ontology-network.github.io/ UR - https://github.com/scientific-ontology-network/ontology-development-guide/releases/download/v0.1.0/ontology-guide.pdf SP - 1 EP - 27 PB - GitHub CY - San Francisco ET - Version 0.1 AN - OPUS4-61140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Birkholz, Henk A1 - Bayerlein, Bernd T1 - Evolution of the PMD Core Ontology (PMDco) Towards ISO/IEC 21838-2:2021 Basic Formal Ontology (BFO) N2 - Knowledge representation in the materials science and engineering (MSE) domain is a vast and multi-faceted challenge: Overlap, ambiguity, and inconsistency in terminology are common. Invariant and variant knowledge are difficult to align cross-domain. Generic top-level semantic terminology often is too abstract, while MSE domain terminology often is too specific. In this presentation, an approach how to maintain a comprehensive and intuitive MSE-centric terminology composing a mid-level ontology–the PMD Core Ontology (PMDco)–via MSE community-based curation procedures is shown. The PMDco is designed in direct support of the FAIR principles to address immediate needs of the global experts community and their requirements. The illustrated findings show how the PMDco bridges semantic gaps between high-level, MSE-specific, and other science domain semantics, how the PMDco lowers development and integration thresholds, and how to fuel it from real-world data sources ranging from manually conducted experiments and simulations as well as continuously automated industrial applications. T2 - MSE Congress 2024 - Materials Science and Engineering CY - Darmstadt, Germany DA - 24.09.2024 KW - Ontology KW - Semantic Interoperability KW - Knowledge representation KW - FAIR Data Management KW - PMD Core Ontology PY - 2024 AN - OPUS4-61141 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisenbart, Miriam T1 - Digitalization of a high-throughput alloy development process N2 - Digitalization is nowadays the central key in developing pharmaceutical products, but it also becomes increasingly important in computer aided material development. In this work it is presented how a collaborative ontology development for the alloy development process is approached and a workflow for chemical optimization of copper alloys is introduced. This is done by employing a combination of a high-throughput alloy development method [1] with the calculation of the corresponding phase compositions. The work presented here is part of the publicly funded project KupferDigital. The project is associated with the innovation platform MaterialDigital (PMD) and focusses on the digitalization of processes as well as knowledge representation along the life-cycle of copper and copper alloys. One part of this life cycle is the alloy development of copper alloys, in this case the alloy development employing a high throughput method based on diffusion couples. The alloy development process can be further broken down into several typical material processing steps such as casting, diffusion welding and annealing. As part of the copper life cycle, the constitution and the properties of an alloy play an important role for processes further down the road during product manufacturing and service life and are also crucial for the recycling properties of the alloy. It is therefore important to, on the one hand, communicate data concerning properties, process history and constitution to the following stations of the life cycle, on the other hand, it is also elementary for the material scientist to be aware of the recycling properties of the alloys constituents. This motivates sharing of data along the life cycle and the development of ontology based data spaces, where life-cycle information can be linked across all involved domains. As part of the alloy development process, it is presented how experimental data created at fem are shared using linked data and ontologies with an example based on the digital representation of the chemical composition of copper alloys further processed by CALculation of PHAse Diagrams (CALPHAD) at the Fraunhofer IWM. The calculation results are used to correlate measured hardness data with the equilibrium phases of the alloys. Selected Compositions are cast and heat treated and subjected to mechanical testing at BAM and the resulting mechanical property-data are again linked to the measured and simulated data from the alloy development process. T2 - MSE2024 CY - Darmstadt, Germany DA - 24.09.2024 KW - Digitalization KW - Alloy development PY - 2024 AN - OPUS4-61150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Höhne, Patrick T1 - Optimized spray granules for dry pressing by means of slurry destabilization and ultrasonic atomization N2 - The homogeneous introduction of organic additives is a prerequisite for good processability of ceramic powders during dry pressing. The addition of organic additives by wet route via ceramic slurries offers advantages over dry processing. The organic content can be reduced and a more homogeneous distribution of the additives on the particle surface is achieved. In addition to the measurements of zeta potential and viscosity, sedimentation analysis by optical centrifugation was also tested and successfully used to characterize the ceramic slurries and accurately evaluate of the suitability of different types, amounts, and compositions of organic additives. Spray drying of well-stabilized slurries usually results in mostly hollow granules with a hard shell leading to sintered bodies with defects and reduced strength and density. By purposefully degrading the slurry stability after dispersion of the ceramic powder, the drying behavior of the granules in the spray drying process and thus the granule properties can be influenced. Destabilization of the slurry and thus partial flocculation was quantified by optical centrifugation. Spray drying of the destabilized alumina slurries resulted in "non-hollow" granules without the detrimental hard shell and thus improved granule properties. Further improvement of the granules was achieved by installing ultrasonic atomization in the spray dryer. A narrower granule size distribution was achieved, which had a positive effect on, among other things, the flowability of the granules. Specimens produced from this granules had fewer defects of smaller size, leading to better results for the density and strength of the sintered bodies. The observations made for alumina could be transferred to zirconia and as well to ZTA with 20 wt% zirconia. T2 - Ceramics in Europe 2022 CY - Krakau, Poland DA - 10.07.2022 KW - Ultrasound KW - Spray drying KW - Slurry PY - 2022 AN - OPUS4-56171 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk A1 - Klinger, Christian T1 - Schadensanalyse an Fahrradkomponenten - Fraktographie, Ursachen, Prävention N2 - Komponenten von Fahrrädern werden im Betrieb vorwiegend schwingend beansprucht. Typische Werkstoffe sind Stahl, Aluminiumlegierungen, Messing, CFK und thermoplastische Kunststoffe. Da es sich, unabhängig von der Preiskategorie, um konstruktiven Leichtbau handelt, werden einige Bauteile betriebsfest mehr oder weniger weit oberhalb der Dauerfestigkeit ausgelegt. Die im normalen Betrieb auftretenden Schäden sind daher weit überwiegend Schwingbrüche. Andere Schadensmechanismen wie z.B. Korrosion spielen quantitativ eine untergeordnete Rolle. Schwingbrüche treten nach einer Periode unbemerkten Risswachstums oft ohne Vorwarnung und ohne makroskopische Verformung auf. Im Falle von sicherheitsrelevanten Komponenten wie Rahmen, Gabeln, Lenkern, Sattelstützen, Kurbelarmen oder Pedalen kann dies zu erheblichen Personenschäden führen, die den Wert des ursächlichen Bauteilschadens weit überschreiten. Über einen langjährigen Zeitraum wurden gebrochene Komponenten aus dem Alltag und aus Gerichtsverfahren analysiert. Das Hauptaugenmerk lag hierbei auf der fraktographischen Analyse, teilweise wurden die zu Grunde liegenden Schadensursachen ermittelt. Einflussfaktoren sind beispielsweise konstruktive Kerben an ungünstigen Stellen, aber auch Werkstoffwahl und Fertigungsqualität spielen eine Rolle. In den meisten Fällen wurde jedoch die konstruktive Lebensdauer überschritten. Diese wird praktisch nie mitgeteilt, und eine wiederkehrende Prüfung sicherheitsrelevanter Bauteile findet nicht statt. Im Sinne der Vermeidung von Schäden und Unfällen könnte darauf hingewirkt werden, für sicherheitsrelevante Komponenten Lebensdauern besser abzuschätzen und von der Laufleistung abhängige Sichtprüfungen zu empfehlen. T2 - DGM Tagung Werkstoffprüfung CY - Dresden, Germany DA - 26.10.2022 KW - Fraktographie KW - Fahrrad KW - Lebensdauer KW - Öffentliche Sicherheit KW - Schadensanalyse KW - Schadensprävention PY - 2022 AN - OPUS4-56122 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf T1 - GLAS DIGITAL - Datengetriebener Workflow für die beschleunigte Entwicklung von Glas N2 - Aktuelle Ergebnisse des Projektes GlasDigital werden kurz zusammenfassend und allgemein verständlich vorgestellt. T2 - MatFo 2022 CY - Cologne, Germany DA - 14.11.2022 KW - Oxidglas KW - robotische Glasschmelzanlage KW - Ontologie KW - ML KW - Digitaler Zwilling KW - Bildanalyse PY - 2022 AN - OPUS4-56492 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina T1 - Glas Digital Datengetriebener Workflow für die beschleunigte Entwicklung von Glas N2 - Der aktuelle Stand des Projektes GlasDigital wird in Kurzform präsentiert. T2 - PMD Vollversammlung CY - Online meeting DA - 17.03.2022 KW - Oxidglas KW - robotische Glasschmelzanlage KW - Ontologie KW - ML KW - Digitaler Zwilling KW - Bildanalyse PY - 2022 AN - OPUS4-56493 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hemmleb, M. T1 - Integrated topographic SEM imaging for software assisted fractography N2 - The aim of a fractographic investigation is the evaluation of macroscopic and microscopic fracture surface characteristics and, as a result, the determination of the fracture mechanism of a component from a failure case. The basis for such evaluations of fracture characteristics comes from actual comparative mechanical testing and from the literature. A fractographic analysis can be very complex and, in any case, requires considerable experience. Machine learning methods enables the quantitative determination of fracture characteristics and fracture mechanisms utilizing digitized expert knowledge [1]. Although the application of SE images provides promising results, additional information is required to obtain reliable solutions. As expected, BSE and 3D information helps to improve the classification (Fig. 1). But only a fast, widely integrated, and automated topography measurement can provide the required amount of referenced surface data for the application of machine learning methods. To fulfil these requirements, topographical data are obtained from a BSE detector with four symmetric segments (4Q-BSE) using shape-from-shading technology [2]. Surface height calculation is performed live during image acquisition and provides immediate feedback in three dimensions. All available signals (SE, BSE and more if applicable) are recorded simultaneously together with the surface topography and stored in a multichannel data file. This guaranties the same geometrical reference for all data, which is required for further analysis (Fig. 2). When applying machine learning methods to topographic data together with SEM images, topographic information must be provided as depth image. Consequently, a unique height scale is required for all applied data with different magnifications. This requires a calibrated height measurement, which is ensured with the integrated 3D calibration of the topographic acquisition and a dedicated calibration sample. Thus, a large number of data sets from different fracture samples was generated and used as training data for machine learning. T2 - 16th Multinational Congress on Microscopy CY - Brno, Czech Republic DA - 04.09.2022 KW - Fractography KW - Machine Learning KW - Topography PY - 2022 AN - OPUS4-55937 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmies, Lennart T1 - Using Machine Learning and Topographic SEM Imaging for Software Assisted Fractography N2 - The aim of a fractographic investigation is the evaluation of macroscopic and microscopic fracture surface characteristics and, as a result, the determination of the fracture mechanism of a component from a failure case. The basis for such evaluations of fracture characteristics comes from actual comparative mechanical testing and from the literature. A fractographic analysis can be very complex and, in any case, requires considerable experience. In the IGF project "iFrakto", software is being developed that quantitatively determines fracture characteristics and fracture mechanisms utilizing digitized expert knowledge, machine learning, and standard 2D and topographical data from SEM imaging. Topographical data are obtained from 4QBSE detector using shape-from-shading technology. In the medium term, a software tool should provide knowledge-based suggestions for the evaluation of fracture surfaces in real time during SEM work or at subsequent evaluation. As a basis for this, round robins were carried out among fractographers in order to create a knowledge base, to query the practice-relevant requirements for such tools and to carry out first practical tests. Actual results are presented and the relevance of the evaluation strategy is evaluated. T2 - Material Science and Engineering 2022 CY - Darmstadt, Germany DA - 27.9.2022 KW - Fractography KW - Machine Learning KW - Topography PY - 2022 AN - OPUS4-55938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sonntag, U. T1 - Softwaregestützte Bestimmung von Bruchmechanismen und Bruchflächenmerkmalen mittels Machine Learning und Topographie-Informationen N2 - Ziel von fraktographischen Untersuchungen ist die Auswertung von makroskopischen und mikroskopischen Bruchflächenmerkmalen und daraus resultierend die Bestimmung des Bruchmechanismus eines Bauteils aus einem Schadensfall. Die Grundlage für die Bewertung von Bruchmerkmalen stammt dabei aus zuvor durchgeführten eigenen Vergleichsversuchen und aus der Literatur. Eine fraktographische Analyse kann sehr aufwändig sein und setzt in jedem Fall erhebliches Erfahrungswissen voraus. Im IGF-Vorhaben „iFrakto“ wird Software entwickelt, die auf Basis von digitalisiertem Expertenwissen, Machine Learning und unter Zuhilfenahme von Topographie-Daten anhand von REM-Aufnahmen Bruchmerkmale und Bruchmechanismen quantitativ bestimmt, s. Abbildung. Solche Software soll mittelfristig direkt am REM oder bei der nachfolgenden Auswertung wissensbasierte Vorschläge für die Bewertung von Bruchflächen liefern. Als Grundlage hierfür wurden Ringversuche unter Fraktograph/inn/en durchgeführt, um die Wissensbasis zu schaffen, die praxisrelevanten Anforderungen an solche Software abzufragen und erste Praxistests durchzuführen. Die bisherigen Ergebnisse werden vorgestellt und die Relevanz der Auswertestrategie und unterschiedlicher Sensordaten bewertet. T2 - 56. Metallographie-Tagung CY - Saarbrücken, Germany DA - 21.9.2022 KW - Fraktographie KW - Machine Learning KW - Topographie PY - 2022 AN - OPUS4-55939 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meyer, Lena T1 - Additive Fertigung unter Mikrogravitationsbedingungen für Anwendungen im Weltraum N2 - Präsentation der Aktivitäten an der BAM im Bereich Additive Fertigung unter Mikrogravitationsbedingungen für Anwendungen im Weltraum beim Arbeitsgruppentreffen der AG Werkstoffe & Prozesse vom Netzwerk Space2Motion. T2 - Arbeitsgruppentreffen beim Netzwerk Space2Motion CY - Online meeting DA - 09.11.2022 KW - Additive Fertigung KW - Mikrogravitation PY - 2022 AN - OPUS4-56353 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf T1 - GlasDigital - Datengetriebener Workflow für die beschleunigte Entwicklung von Glas N2 - Das Projekt GlasDigital im Rahmen der BMBF Initiative MaterialDigital wird vorgestellt. T2 - MatFo22 CY - Berlin, Germany DA - 14.11.2022 KW - Material Digital PY - 2022 AN - OPUS4-56282 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Langer, Carlotta A1 - Georgie, Yasmin Kim A1 - Porohovoj, Ilja A1 - Hafner, Verena Vanessa A1 - Ay, Nihat T1 - Analyzing Multimodal Integration in the Variational Autoencoder from an Information-Theoretic Perspective N2 - Human perception is inherently multimodal. We integrate, for instance, visual, proprioceptive and tactile information into one experience. Hence, multimodal learning is of importance for building robotic systems that aim at robustly interacting with the real world. One potential model that has been proposed for multimodal integration is the multimodal variational autoencoder. A variational autoencoder (VAE) consists of two networks, an encoder that maps the data to a stochastic latent space and a decoder that reconstruct this data from an element of this latent space. The multimodal VAE integrates inputs from different modalities at two points in time in the latent space and can thereby be used as a controller for a robotic agent. Here we use this architecture and introduce information-theoretic measures in order to analyze how important the integration of the different modalities are for the reconstruction of the input data. Therefore we calculate two different types of measures, the first type is called single modality error and assesses how important the information from a single modality is for the reconstruction of this modality or all modalities. Secondly, the measures named loss of precision calculate the impact that missing information from only one modality has on the reconstruction of this modality or the whole vector. The VAE is trained via the evidence lower bound, which can be written as a sum of two different terms, namely the reconstruction and the latent loss. The impact of the latent loss can be weighted via an additional variable, which has been introduced to combat posterior collapse. Here we train networks with four different weighting schedules and analyze them with respect to their capabilities for multimodal integration. KW - Multimodal Integration KW - Variational Autoencoder KW - Information Theory KW - Posterior Collapse PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-616420 DO - https://doi.org/10.48550/arXiv.2411.00522 SP - 1 EP - 17 PB - Cornell University CY - Ithaca, NY AN - OPUS4-61642 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Interoperabilität und Wiederverwendung von Materialdaten: Der Weg zu Daten- und Wissensrepräsentationen in der PMD N2 - Die Integration und Wiederverwendung von Wissen und Daten aus der Herstellung, Bearbeitung und Charakterisierung von Materialien wird im Zuge der digitalen Transformation in der Materialwissenschaft und Werkstofftechnologie in verschiedenen Projekten behandelt. Dabei liegt der Fokus auf der Interoperabilität von Daten und Anwendungen, die nach den FAIR-Prinzipien erstellt und veröffentlicht werden. Zur Umsetzung eines komplexen Datenmanagements und der Digitalisierung im Bereich der Materialwissenschaften gewinnen Ontologien zunehmend an Bedeutung. Sie ermöglichen sowohl menschenlesbare als auch maschinenverständliche und -interpretierbare Wissensrepräsentationen durch semantische Konzeptualisierungen. Im Rahmen des Projektes Plattform MaterialDigital (PMD, materialdigital.de), welches in dieser Präsentation vorgestellt wird, werden Ontologien verschiedener Ebenen entwickelt (verbindende mid-level sowie Domänen-Ontologien). Die PMD-Kernontologie (PMD Core Ontology - PMDco) ist eine Ontologie der mittleren Ebene, die Verbindungen zwischen spezifischeren MSE-Anwendungsontologien und domänenneutralen Konzepten herstellt, die in bereits etablierten Ontologien höherer Ebenen (top-level Ontology) verwendet werden. Sie stellt somit einen umfassenden Satz von durch Konsensbildung in der Gemeinschaft (geteiltes Vokabular) entstanden Bausteinen grundlegender Konzepte aus der Materialwissenschaft und Werkstofftechnik (MSE) dar. In dieser Präsentation wird die PMDco adressiert. Weiterhin wird eine auf die PMDco bezogene normenkonforme ontologische Repräsentation zur Speicherung und Weiterverarbeitung von Zugversuchsdaten – die Tensile Test Ontology (TTO) – präsentiert, die in enger Zusammenarbeit mit dem zugehörigen DIN-Standardisierungsgremium NA 062-01-42 AA erstellt wurde. Dies umfasst den Weg von der Entwicklung einer Ontologie nach Norm, der Konvertierung von Daten aus Standardtests in das interoperable RDF-Format bis hin zur Verbindung von Ontologie und Daten. Auf Grundlage der dabei entwickelten Struktur und Vorgehensweise können weitere Materialcharakterisierungsmethoden semantisch beschrieben werden, woraus sich in diesem Zusammenhang Kooperationsmöglichkeiten ergeben. T2 - 20. Sitzung des NA 062-01-43 AA CY - Online meeting DA - 28.05.2024 KW - Semantische Daten KW - Plattform Material Digital KW - Ontologie KW - Normung KW - Wissensrepräsentation PY - 2024 AN - OPUS4-60178 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Digital Transformation in Materials Science: Insights from Platform MaterialDigital (PMD), Tensile Test Ontology (TTO), Electronic Lab Notebooks (ELN) N2 - The digital era has led to a significant increase in innovation in scientific research across diverse fields and sectors. Evolution of data-driven methodologies lead to a number of paradigm shifts how data, information, and knowledge is produced, understood, and analyzed. High profile paradigm shifts in the field of materials science (MS) include exploitative usage of computational tools, machine learning algorithms, and high-performance computing, which unlock novel avenues for investigating materials. In these presentations, we highlight prototype solutions developed in the context of the Platform MaterialDigital (PMD) project that addresses digitalization challenges. As part of the Material Digital Initiative, the PMD supports the establishment of a virtual materials data space and a systematic handling of hierarchical processes and materials data using a developed ontological framework as high priority work items. In particular, the mid-level ontology PMDco and its augmentation through application-specific ontologies are illustrated. As part of the conclusion, a discussion encompasses the evolutionary path of the ontological framework, taking into account standardization efforts and the integration of modern AI methodologies such as natural language processing (NLP). Moreover, demonstrators illustrated in these presentations highlight: The integration and interconnection of tools, such as digital workflows and ontologies, Semantic integration of diverse data as proof of concept for semantic interoperability, Improved reproducibility in image processing and analysis, and Seamless data acquisition pipelines supported by an ontological framework. In this context, concepts regarding the application of modern research data management tools, such as electronic laboratory notebooks (ELN) and laboratory information management systems (LIMS), are presented and elaborated on. Furthermore, the growing relevance of a standardized adoption of such technologies in the future landscape of digital initiatives is addressed. This is supposed to provide an additional basis for discussion with respect to possible collaborations. T2 - NIST Seminar Series CY - Gaithersburg, MD, USA DA - 11.06.2024 KW - Semantic Data KW - Plattform Material Digital KW - Digitalization KW - Data Interoperability KW - NIST KW - Tensile Test Ontology KW - Elctronic Lab Notebook PY - 2024 AN - OPUS4-60392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Structure-property correlations in RE-doped fluoride-phosphate glasses sought by NMR, EPR & PL N2 - As the development of optimized glass compositions by traditional trial-and-error methods is laborious, expensive, and time consuming, it is desirable to gather fundamental understanding of structure and to develop structure-property relation models, which allow best and faster choices. Particularly, when it comes to optical applications of glasses doped with emissive trivalent rare earth ions (RE), the chemical environmental around the ions will have a direct influence on the radiative/non-radiative emission probabilities. The vibrational environment and the chemical nature of the bonds in the first coordination sphere of the ions can be tailored, to some extent, based on structural information given by magnetic resonance (NMR and EPR) techniques associated to Raman and photophysical characterization. For the past 5 years, one of the interests of my research group at the University of São Paulo, in Brazil, has been the development of high-density fluoride-phosphate glasses as promising UV and X-ray scintillator materials. The targeted glasses offer a lower vibrational energy, less hygroscopic fluoride environment for the RE ions whereas the phosphate network provides improved mechanical and chemical stability than a purely fluoride glass matrix. Different sets of glasses, based on the compositional system (Ba/Sr)F2-M(PO3)3-MF3-(Sc/Y)F3 where M = Al, In, Ga, and the phosphate component is substituted by the fluoride analogue in 10-30 mol%, were investigated, using Sc3+, Y3+, and the Eu3+ and Yb3+ dopants, as structural probes. Overall, results show that the desired RE coordination by F, at a given F/P ratio, is proportional to the atomic mass of M (In> Ga> Al) and that the Ga- and In- based systems differ from the Al- one by near absence of P-O-P network linkages i.e, the network structures are dominated by Ga-O-P or In-O-P linkages as evidenced by 31P MAS-NMR and Raman. These results are nicely corroborated by observation of decreased intensity in the vibronic band of Eu3+ and significant increase in the excited state lifetime values. Radioluminescence studies were carried out for a series of In-based glasses doped with Ce3+ and Tb3+ yielding intense emissions in the blue and green, respectively, compatible to the spectral region of highest sensitivity of radiation sensor detectors. The aim of the presentation is to show how powerful the combination of NMR, EPR, Raman and PLE spectroscopies can be to provide structural information and to present the perspectives for their introduction in the research agenda of Division 5.6 – Glass, which I now lead, at the Federal Institute for Materials Research and Testing (BAM) in Berlin, Germany. T2 - GOMD 2024 - Glass and Optical Division Meeting, ACerS CY - Las Vegas, NV, USA DA - 19.05.2024 KW - Glass Digital KW - Glasses KW - Robotic melting PY - 2024 AN - OPUS4-60357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Galleani, Gustavo A1 - Lodi, Thiago A. A1 - Conner, Robin L. A1 - Jacobsohn, Luiz G. A1 - de Camargo, Andrea Simone Stucchi T1 - Photoluminescence and X-ray induced scintillation in Gd3+-Tb3+ co-doped fluoride-phosphate glasses, and derived glass-ceramics containing NaGdF4 nanocrystals N2 - The glass system (50NaPO3–20BaF2–10CaF2–20GdF3)-xTbCl3 with x = 0.3, 1, 3, 5, and 10 wt % was investigated. We successfully produced transparent glass ceramic (GC) scintillators with x = 1 through a melt-quenching process followed by thermal treatment. The luminescence and crystallization characteristics of these materials were thoroughly examined using various analytical methods. The nanocrystallization of Tb3+-doped Na5Gd9F32 within the doped fluoride-phosphate glasses resulted in enhanced photoluminescence (PL) and radioluminescence (RL) of the Tb3+ ions. The GC exhibited an internal PL quantum yield of 33 % and the integrated RL intensity across the UV-visible range was 36 % of that reported for the commercial BGO powder scintillator. This research showcases that Tb-doped fluoridephosphate GCs containing nanocrystalline Na5Gd9F32 have the potential to serve as efficient scintillators while having lower melting temperature compared to traditional silicate and germanate glasses. KW - Glass scintillator KW - Fluoride phosphate glasses KW - Gd3+ KW - Tb3+ PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603588 DO - https://doi.org/10.1016/j.omx.2023.100288 VL - 21 SP - 1 EP - 9 PB - Elsevier B.V. AN - OPUS4-60358 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Structure-property correlations in RE-doped fluoride-phosphate glasses for scintillation N2 - As the development of optimized glass compositions by traditional trial-and-error methods is laborious, time consuming, and expensive, it is desirable to develop glass compositions based on a fundamental understanding of the glass structure and to establish structure-property relation models. Particularly, when it comes to optical applications of glasses doped with emissive trivalent rare earth ions (RE), the chemical environmental around the ions will have a direct influence on the radiative/non-radiative emission probabilities. The local vibrational environment and the chemical nature of the bonds in the first coordination sphere of the ions can be tailored, to good extent, based on structural information given by magnetic resonance techniques (NMR and EPR), associated to Raman and photophysical characterization. For the past 5 years, while still employed at the University of São Paulo, in Brazil, one of the interests of my research group has been the development of high-density fluoride-phosphate glasses as promising UV and X-ray scintillator materials. The targeted glasses offer a lower vibrational energy, less hygroscopic fluoride environment for the RE ions whereas the phosphate network provides better mechanical and chemical stability than a purely fluoride glass matrix. Different sets of glasses, based on the compositional system (Ba/Sr)F2-M(PO3)3-MF3-(Sc/Y)F3 where M = Al, In, Ga, and the phosphate component is substituted by the fluoride analogue in 10 - 30 mol%, were investigated, using Sc3+, Y3+, and the Eu3+ and Yb3+ dopants, as structural probes. Overall, results show that the desired RE coordination by fluorine, at a given F/P ratio, is proportional to the atomic mass of M (In> Ga> Al) and that the Ga- and In- based systems differ from the Al- one by near absence of P-O-P network linkages. That is, the network structures are dominated by Ga-O-P or In-O-P linkages, as evidenced by 31P MAS-NMR and Raman. These results are nicely corroborated by observation of decreased intensity of the vibronic band in Eu3+-doped glasses and marked increase in excited state lifetime values. Radioluminescence studies were carried out for a series of In-based glasses doped with Ce3+ and Tb3+, yielding intense emissions in the blue and green, respectively, compatible to the spectral region of the highest sensitivity of radiation sensor detectors. The aim of the presentation is to show how powerful the NMR and EPR techniques can be to provide decisive structural information, and to present the research perspectives in my new role as the Head of Division 5.6 – Glass at BAM. T2 - Fachausschusses I „Physik und Chemie des Glases“, DGG CY - Jena, Germany DA - 02.11.2023 KW - Structure-property correlation KW - Fluoride phosphate glasses KW - Scintillators KW - High energy radiation PY - 2024 AN - OPUS4-60360 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Galleani, Gustavo A1 - Lodi, Thiago A1 - Merízio, Leonnam A1 - de Jesus, Vinícius A1 - de Camargo, Andrea Simone Stucchi T1 - Scintillators, persistent luminescent and white light emitters: Progresses on UV and X-ray converting glasses and composites N2 - Recently, detection and conversion of high energy radiation such as ultraviolet and X-rays has gained renewed attention. In part, technological applications in radioimaging and tomography have developed considerably as to allow lower dosages and higher resolutions, which require optimized scintillators and dosimeters. On the other hand, the increasing effort to reduce carbon footprint in energy production has triggered an intensive search for materials that can be excited with sunlight, ranging from photocatalysts to solar concentrators. At LEMAF – Laboratory of Spectroscopy of Functional Materials at IFSC/USP, we have been developing bulk glasses, polycrystalline and composite materials designed to target both challenges and, in this work an overview of recent progresses and of the state of art of these materials will be given. For instance, the few available comercial scintillators are crystalline materials with costly and time consuming growth which hinders the development of new compositions. Glasses and glass ceramics, such as the NaPGaW composition developed in our lab, present high density, very good optical properties and high chemical stability which allow them radioluminescent response when doped with low concentrations of Ce3+, Eu3+ and Tb3+ offering a promise as alternatives to crystal scintillators. On the other hand, phosphor in glass (PiG) composites based on the persistent luminescent polycrystalline material Sr2MgSi2O7:Eu2+,Dy3+ (SMSO) embedded into NaPGa glasses offer interesting perspectives for the of UV light into visible, useful for white light generation (lighting), improved harvesting and conversion of solar light when coupled to c-Si PV cells and photocatalysis. These and other examples will be discussed. The glasses are prepared through the conventional melt quenching technique, followed by controlled heating when glass ceramics are desired. The persistent luminescent phosphor is prepared by the microwave assisted technique (MAS) much faster and with considerable energy consumption reduction than in the usual solid state synthesis. The materials are characterized from the structural, morphological and spectroscopic (optical – UV-Vis, PL, PLE, and structural – NMR, EPR) points of view such that structure-property correlations are constantly sought to feedback synthesis and processing. Fig. 1, illustrates two examples of scintillator glasses doped with Tb3+ and PiG composites doped with Eu2+ and Dy3+. T2 - 11th International Conference on f Elements (ICFE-11) CY - Strasbourg, France DA - 22.08.2023 KW - Scintillators KW - Persistent luminescence KW - White light emitters PY - 2023 AN - OPUS4-60361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Optical properties of dental ceramics: Characterization via UV-Vis and photoluminescence spectroscopies N2 - When it comes to dental treatments, success is not only measured by attained functionality but, to a large extent, the associated aesthetics. This can become challenging for certain restorations and implants due to the complex optical characteristic of a tooth, which reflects, absorbs, diffuses, transmits, and even emits light. Thus, to get acceptable aesthetic results, favourable shade matching of ceramic restorations and implants should be achieved by strict control of optical response, which translates into a materials design question. Optical response is affected by several factors such as the composition, crystalline content, porosity, additives, grain size and the angle of incidence of light on the dental ceramics. The properties to be characterized are colour (and its stability), translucency, opalescence, refractive index, and fluorescence. Several techniques can be applied for the characterization of these properties and in this presentation, an overview will be given. Moreover, particular emphasis will be given on the capacitation of less familiarized public to UV-Vis absorption and photoluminescence (PLE) spectroscopies that are versatile and widely employed for functional and structural characterization of glasses and glass ceramic materials. T2 - 2nd BAYLAT Workshop of CERTEV - FAU CY - Nuremberg, Germany DA - 04.12.2023 KW - Optical properties KW - Dental ceramics KW - Optical spectroscopy PY - 2023 AN - OPUS4-60364 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Glass Digitalization: Contributions from BAM N2 - An overview of the Glass Digitalization efforts at BAM, within the framework of the Glass Digital consortium, was given. From the development of the robotic melting device to the ML capabilities, a description of the different stages of the developments and roles of project partner was presented. T2 - GlaCerHub Melting Day CY - Oponice, Slovakia DA - 12.06.2024 KW - Glass Digital KW - Robotic glass melting KW - Digitalization PY - 2024 AN - OPUS4-60365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Gender equality in Sciences: Let´s teach our girls to be brave! N2 - A panorama of the global gender gap scenario in sciences, specially STEM, was given to illustrate the need for urgent actions (and suggestions of them) to correct biased treatment and promote females in their scientific careers. T2 - FunGlass School CY - Oponice, Slovakia DA - 10.06.2024 KW - Gender gap KW - Women in science KW - Female noble prize winners PY - 2024 AN - OPUS4-60366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -