TY - JOUR
A1 - Zia, Ghezal Ahmad Jan
A1 - Hanke, Thomas
A1 - Skrotzki, Birgit
A1 - Völker, Christoph
A1 - Bayerlein, Bernd
T1 - Enhancing Reproducibility in Precipitate Analysis: A FAIR Approach with Automated Dark-Field Transmission Electron Microscope Image Processing
N2 - AbstractHigh-strength aluminum alloys used in aerospace and automotive applications obtain their strength through precipitation hardening. Achieving the desired mechanical properties requires precise control over the nanometer-sized precipitates. However, the microstructure of these alloys changes over time due to aging, leading to a deterioration in strength. Typically, the size, number, and distribution of precipitates for a quantitative assessment of microstructural changes are determined by manual analysis, which is subjective and time-consuming. In our work, we introduce a progressive and automatable approach that enables a more efficient, objective, and reproducible analysis of precipitates. The method involves several sequential steps using an image repository containing dark-field transmission electron microscopy (DF-TEM) images depicting various aging states of an aluminum alloy. During the process, precipitation contours are generated and quantitatively evaluated, and the results are comprehensibly transferred into semantic data structures. The use and deployment of Jupyter Notebooks, along with the beneficial implementation of Semantic Web technologies, significantly enhances the reproducibility and comparability of the findings. This work serves as an exemplar of FAIR image and research data management.
KW - Industrial and Manufacturing Engineering
KW - General Materials Science
KW - Automated image analysis
KW - FAIR research data management
KW - Reproducibility
KW - microstructural changes
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593905
DO - https://doi.org/10.1007/s40192-023-00331-5
SN - 2193-9772
SP - 1
EP - 15
PB - Springer Science and Business Media LLC
CY - Heidelberg
AN - OPUS4-59390
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Madia, Mauro
A1 - Baer, Wolfram
A1 - Wagener, Rainer
A1 - Kiyak, Yusuf
T1 - Betriebsfestigkeit und Bruchverhalten von bainitischen Schmiedestählen
N2 - Die neue Generation von bainitischen Schmiedestählen bietet auf der einen Seite ein erhebliches Festigkeitspotenzial, das es im Sinne des Leichtbaus auch für zyklisch belastete Sicherheitsbauteile zu heben gilt. Auf der anderen Seite geht mit dieser Festigkeitssteigerung im Vergleich zu Vergütungsstählen ein Verlust an Duktilität und Zähigkeit einher. Am Beispiel des Demonstratorbauteils Achsschenkel ging das Forschungsvorhaben der Frage nach, wie ein Freigabeprozess zu gestalten ist, damit das Festigkeitspotenzial der neuen Stähle zuverlässig ausgenutzt werden kann. Als Ergebnis wird eine Vorgehensweise dargestellt, die den Eigenschaften der neuen Generation von Schmiedestählen Rechnung trägt, um den sicheren Betrieb der Komponenten zu gewährleisten.
KW - Bainitischer Schmiedestahl
KW - Bruchmechanik
KW - Sicherheit
KW - Betriebsfestigkeit
KW - Bauteilauslegung
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594296
SN - 2366-5106
SP - 50
EP - 54
PB - Industrieverband Massivumformung e. V
CY - Hagen
AN - OPUS4-59429
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zuffa, Caterina
A1 - Cappuccino, Chiara
A1 - Casali, Lucia
A1 - Emmerling, Franziska
A1 - Maini, Lucia
T1 - Liquid reagents are not enough for liquid assisted grinding in the synthesis of (AgBr)(n-pica) n
N2 - This study investigates the mechanochemical reactions between AgBr 3-picolylamine and 4-picolylamine. The use of different stoichiometry ratios of the reagents allows [(AgBr)(n-pica)]n and [(AgBr)2(n-pica)]n to be obtained, and we report the new structures of [(AgBr)2(3-pica)]n and [(AgBr)2(4-pica)]n which are characterized by the presence of the following: (a) infinite inorganic chains, (b) silver atom coordinated only by bromide atoms and (c) argentophilic interactions. Furthermore, we studied the interconversion of [(AgBr)(n-pica)]n/[(AgBr)2(n-pica)]n by mechanochemical and thermal properties. The in situ experiments suggest that [(AgBr)(3-pica)]n is kinetically favoured while [(AgBr)2(3-pica)]n is converted into [(AgBr)(3-pica)]n only with a high excess of the ligand. Finally, the liquid nature of the ligands is not sufficient to assist the grinding process, and the complete reaction is observed with the addition of a small quantity of acetonitrile.
KW - Mechanochemistry
KW - Complex
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594755
DO - https://doi.org/10.1039/d3cp04791a
SN - 1463-9076
SP - 1
EP - 10
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59475
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schwarz, I.
A1 - Rieck, Arielle
A1 - Mehmood, Asad
A1 - Bublitz, R.
A1 - Bongers, L.
A1 - Weuster-Botz, D.
A1 - Fellinger, Tim-Patrick
T1 - PEM Electrolysis in a Stirred-Tank Bioreactor Enables Autotrophic Growth of Clostridium ragsdalei with CO2 and Electrons
N2 - Acetogenic bacteria produce CO2-based chemicals in aqueous media by hydrogenotrophic conversion of CO2, but CO is the preferred carbon and electron source. Consequently, coupling CO2 electrolysis with bacterial fermentation within an integrated bio-electrocatalytical system (BES) is promising, if CO2 reduction catalysts are available for the generation of CO in the complex biotic electrolyte. A standard stirred-tank bioreactor was coupled to a zero-gap PEM electrolysis cell for CO2 conversion, allowing voltage control and separation of the anode in one single cell. The cathodic CO2 reduction and the competing hydrogen evolution enabled in-situ feeding of C. ragsdalei with CO and H2. Proof-of-concept was demonstrated in first batch processes with continuous CO2 gassing, as autotrophic growth and acetate formation was observed in the stirred BES in a voltage range of −2.4 to −3.0 V. The setup is suitable also for other bioelectrocatalytic reactions. Increased currents and lower overvoltages are however required. Atomically-dispersed M−N−C catalysts show promise, if degradation throughout autoclaving can be omitted. The development of selective and autoclavable catalysts resistant to contamination and electrode design for the complex electrolyte will enable efficient bioelectrocatalytic power-to-X systems based on the introduced BES.
KW - Energy Conversion
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594766
DO - https://doi.org/10.1002/celc.202300344
SN - 2196-0216
SP - 1
EP - 10
PB - Wiley VHC-Verlag
AN - OPUS4-59476
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zaytsev, D.
A1 - Funk, Alexander
T1 - On the crack evolutional in human dentin under uniaxial compression imaged by high resolution tomography
N2 - An observation of the fracture process in front of the crack tip inside a dentin sample by means of ex-situ X-ray computed tomography after uniaxial compression at different deformation values was carried out in this work. This ex-situ approach allowed the microstructure and fracturing process of human dentin to be observed during loading. No cracks are observed up to the middle part of the irreversible deformation in the samples at least visible at 0.4μm resolution. First cracks appeared before the mechanical stress reached the compression strength. The growth of the cracks is realized by connecting the main cracks with satellite cracks that lie ahead of the main crack tip and parallel its trajectory. When under the stress load the deformation in the sample exceeds the deformation at the compression strength of dentin, an appearance of micro-cracks in front of the main cracks is observed. The micro-cracks are inclined (~60°) to the trajectory of the main cracks. The further growth of the main cracks is not realized due to the junction with the micro-cracks; we assume that the micro-cracks dissipate the energy of the main crack and suppressed its growth. These micro-cracks serve as additional stress accommodations, therefore the samples do not break apart after the compression test, as it is usually observed under bending and tension tests.
KW - Dentin
KW - Crack evolution
KW - Compression strength
KW - Mechanical properties
KW - Microstructure
KW - Ex-situ X-ray computed tomography
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594810
DO - https://doi.org/10.18149/MPM.5152023_5
SN - 1605-8119
VL - 51
IS - 5
SP - 38
EP - 51
PB - Advanced Study Center
CY - St. Petersburg
AN - OPUS4-59481
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Jordan, T.
A1 - Askar, Enis
A1 - Holtappels, Kai
A1 - Deeg, S.
A1 - Jopen, M.
A1 - Stoll, U.
A1 - Reinecke, E.-A.
A1 - Krause, U.
A1 - Beyer, M.
A1 - Markus, D.
T1 - Stand der Kenntnisse und Technik bezüglich Wasserstoffsicherheit
N2 - Die Einführung von Wasserstoff als sicherer Energieträger braucht eine robuste Wissensbasis, darauf aufgebaute Werkzeuge zur Auslegung und Sicherheitsbewertung von Wasserstofftechnologien und ein international harmonisiertes Regelwerk. Viele der innovativen Technologien implizieren Wasserstoff bei hohen Drücken und/oder kryogenen Temperaturen, mit denen in verteilten Anwendungen erstmalig private Nutzer in Kontakt kommen. Um überkonservative, teure Sicherheitslösungen zu vermeiden, gleichzeitig aber die Einsetzbarkeit und Sicherheit von Wasserstoffanwendungen zu demonstrieren und die Akzeptanz für die Technologie aufrecht zu halten, muss auch die Sicherheitsforschung mit den Trends der technologischen Entwicklung Schritt halten, oder sie besser noch antizipieren. So beschreibt dieser Überblicksartikel nicht nur den gegenwärtigen Stand der Kenntnisse und Technik bezüglich Wasserstoffsicherheit, sondern auch ihre Weiterentwicklung.
KW - Alternative Energieträger
KW - Explosionsschutz
KW - Flüssigwasserstoff
KW - Unfallszenarien
KW - Wasserstoffspeicherung
KW - Sicherheitsbewertung
KW - Regelsetzung
KW - Gefährdungs- und Risikobeurteilung
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593629
DO - https://doi.org/10.1002/cite.202300141
SN - 0009-286X
VL - 96
IS - 1-2
SP - 1
EP - 20
PB - Wiley-VCH
AN - OPUS4-59362
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Quackatz, Lukas
A1 - Griesche, Axel
A1 - Nietzke, Jonathan
A1 - Kannengießer, Thomas
T1 - In situ measurement of hydrogen concentration in steel using laser‑induced breakdown spectroscopy (LIBS)
N2 - The ISO 3690 standard “Determination of hydrogen content in arc weld metal” requires a thermal activation of the diffusible hydrogen in a piece of weld metal for the subsequent ex situ concentration measurement by carrier gas hot extraction CGHE or thermal desorption spectroscopy (TCD). Laser-induced breakdown spectroscopy (LIBS) offers a time and spatially resolved, almost non-destructive, in situ measurement of hydrogen at surfaces without sample preparation. We measured hydrogen in steels, which were charged either electrochemically or by high-pressure hydrogen gas, and compared the results. Further, the feasibility of quantitative hydrogen line scan measurements with LIBS was demonstrated by measuring hydrogen at water jet cut surfaces. The hydrogen concentrations measured with the help of LIBS were compared with CGHE measurements. It was observed that hydrogen can be reliably measured with LIBS for concentrations larger than 2 wt.-ppm. The maximum hydrogen concentration achieved using electrochemical charging was 85.1 ppm. The results show that LIBS is a promising technique for time- and spatially resolved measurements of hydrogen in steels.
T2 - IIW Annual Assembly 2023
CY - Singapore
KW - LIBS
KW - Hydrogen measurement
KW - Welding
KW - Stainless steel
KW - Diffusible hydrogen
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593664
DO - https://doi.org/10.1007/s40194-023-01677-2
SP - 1
EP - 9
PB - Springer
AN - OPUS4-59366
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Licht, M.
A1 - Nikoonasab, Ali
A1 - Gluth, Gregor
A1 - Raupach, M.
ED - Claßen, M.
ED - Hegger, J.
ED - Matschei, T.
ED - Raupach, M.
T1 - Alkali-aktivierte Hüttensandbetone – CO2-reduzierte Bindemittel mit hohem Korrosionsschutzpotential
N2 - Durch den Ersatz von Portlandzement können alkali-aktivierte Bindemittel einen bedeutenden Beitrag zur Verringerung der durch die Zementklinkerherstellung verursachten CO2-Emissionen leisten. Für die Verwendung von alkali-aktivierten Bindemitteln in Stahlbetonkonstruktionen, die Chloriden oder Carbonatisierung ausgesetzt sind, ist die Fähigkeit des Stahls, den passiven Zustand zu erreichen und aufrechtzuerhalten, von großer Bedeutung. Die Prozesse der Deckschichtbildung von Stahl in alkali-aktivierten Materialien unterscheiden sich jedoch zum Teil grundlegend von denen in Portlandzementen. Alkali-aktivierte Hüttensandbetone weisen gute technische Eigenschaften auf, bisher fehlen jedoch grundlegende Kenntnisse bzgl. ihrer schützenden Wirkung bei korrosiven Angriffen. Dies ist vor allem auf ihre sulfidhaltige Porenlösung zurückzuführen, welche die elektrochemischen Eigenschaften der Stahloberfläche beeinflusst und die Verwendung herkömmlicher Bewertungsmaßstäbe erschwert. Es werden erste Ergebnisse eines DFG-Forschungsprojektes vorgestellt, in dem das Passivierungsverhalten von Stahl in alkali-aktivierten Hüttensandmörteln unterschiedlicher Zusammensetzungen sowie in Mörteln auf Basis hüttensandhaltiger Normzemente untersucht wird. Über einen Zeitraum von mindestens 28 Tagen werden an Zylinderprüfkörpern im 3-Elektroden-Aufbau das Ruhepotential sowie die Polarisationswiderstände der Stahlelektroden ermittelt.
T2 - 10. DAfStb-Jahrestagung mit 62. Forschungskolloquium
CY - Aachen, Germany
DA - 26.09.2023
KW - Bewehrung
KW - Stahlkorrosion
KW - Hüttensandmehl
KW - Sulfid
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593775
DO - https://doi.org/10.18154/RWTH-2023-06676
SP - 233
EP - 238
PB - RWTH Aachen
CY - Aachen
AN - OPUS4-59377
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Böllinghaus, Thomas
A1 - Cross, Carl
T1 - Obituary: Prof. Dr.-Ing. Hans Hoffmeister
N2 - On November 3, 2023, our dear colleague, Prof. Dr.-Ing. Hans Hoffmeister, born in 1932 in Kassel, Germany, passed away in Ahrensburg, near Hamburg, Germany.
KW - Metals and Alloys
KW - Mechanical Engineering
KW - Mechanics of Materials
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594160
DO - https://doi.org/10.1007/s40194-023-01675-4
SP - 1
EP - 2
PB - Springer Science and Business Media LLC
AN - OPUS4-59416
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schnell, A.
A1 - Rübner, Katrin
A1 - Seher, Julia
A1 - Müller, A.
A1 - Liebezeit, S.
A1 - Fenner, J.
A1 - Martin, F.
A1 - Pniok, N.
T1 - REALight ‐ Leichtgranulate und REA‐Gips aus feinkörnigen sulfatbelasteten Bau‐ und Abbruchabfällen
N2 - Ziel des Projekts REALight ist die Entwicklung einer Referenzanlage zur Herstellung von Leichtgranulaten (leichte Gesteinskörnungen) aus Bau‐ und Abbruchabfällen und zur Gipsrückgewinnung. Als Rohstoffe werden bisher ungenutzte oder auf niedrigem Niveau eingesetzte Bau‐ und Abbruchabfälle und industrielle Nebenprodukte verwendet. Als Produkte werden leichte Gesteinskörnungen hergestellt. Die Sulfatabtrennung durch eine thermische Zersetzung bildet die Grundlage für die zusätzliche Gewinnung von Rauchgasentschwefelungs‐Gips (REA‐Gips). Das Projekt wird im Rahmen der Fördermaßnahme „Ressourceneffiziente Kreislaufwirtschaft – Bauen und Mineralische Stoffkreisläufe (ReMin)” gefördert. ReMin ist eine Maßnahme zur Umsetzung des BMBF‐Forschungskonzepts „Ressourceneffiziente Kreislaufwirtschaft” als Teil der BMBF Strategie „Forschung für nachhaltige Entwicklung – FONA”. Ziel der Förderung ist es, den Ausbau der Kreislaufwirtschaft voranzutreiben. Im Mittelpunkt steht dabei die Bauwirtschaft mit ihrer hohen Nachfrage nach Rohstoffen und gleichzeitig großen Mengen an anfallenden mineralischen Abfällen. Am Projekt REALight sind 12 Partner aus verschiedenen Bereichen der Baustoffherstellung und ‐anwendung, Abfallaufbereitung, Verfahrenstechnik sowie Forschung und Entwicklung beteiligt.
T2 - 21. Internationale Baustofftagung (ibausil)
CY - Weimar, Germany
DA - 13.09.2023
KW - Baustoffrecycling
KW - Leichtgranulate
KW - Gips
KW - Leichte Gesteinskörnungen
KW - Drehrohrofen
KW - Recycling
KW - Mauerwerkbruch
KW - Infraleichtbeton
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-591708
DO - https://doi.org/10.1002/cepa.2840
SN - 2509-7075
VL - 6
IS - 6
SP - 530
EP - 536
PB - Ernst & Sohn
CY - Berlin
AN - OPUS4-59170
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Jablonka, Kevin Maik
A1 - Ai, Qianxiang
A1 - Al-Feghali, Alexander
A1 - Badhwar, Shruti
A1 - Bocarsly, Joshua D.
A1 - Bran, Andres M.
A1 - Bringuier, Stefan
A1 - Brinson, L. Catherine
A1 - Choudhary, Kamal
A1 - Circi, Defne
A1 - Cox, Sam
A1 - de Jong, Wibe A.
A1 - Evans, Matthew L.
A1 - Gastellu, Nicolas
A1 - Genzling, Jerome
A1 - Gil, María Victoria
A1 - Gupta, Ankur K.
A1 - Hong, Zhi
A1 - Imran, Alishba
A1 - Kruschwitz, Sabine
A1 - Labarre, Anne
A1 - Lála, Jakub
A1 - Liu, Tao
A1 - Ma, Steven
A1 - Majumdar, Sauradeep
A1 - Merz, Garrett W.
A1 - Moitessier, Nicolas
A1 - Moubarak, Elias
A1 - Mouriño, Beatriz
A1 - Pelkie, Brenden
A1 - Pieler, Michael
A1 - Ramos, Mayk Caldas
A1 - Ranković, Bojana
A1 - Rodriques, Samuel G.
A1 - Sanders, Jacob N.
A1 - Schwaller, Philippe
A1 - Schwarting, Marcus
A1 - Shi, Jiale
A1 - Smit, Berend
A1 - Smith, Ben E.
A1 - Van Herck, Joren
A1 - Völker, Christoph
A1 - Ward, Logan
A1 - Warren, Sean
A1 - Weiser, Benjamin
A1 - Zhang, Sylvester
A1 - Zhang, Xiaoqi
A1 - Zia, Ghezal Ahmad
A1 - Scourtas, Aristana
A1 - Schmidt, K. J.
A1 - Foster, Ian
A1 - White, Andrew D.
A1 - Blaiszik, Ben
T1 - 14 examples of how LLMs can transform materials science and chemistry: a reflection on a large language model hackathon
N2 - Large-language models (LLMs) such as GPT-4 caught the interest of many scientists. Recent studies suggested that these models could be useful in chemistry and materials science. To explore these possibilities, we organized a hackathon. This article chronicles the projects built as part of this hackathon. Participants employed LLMs for various applications, including predicting properties of molecules and materials, designing novel interfaces for tools, extracting knowledge from unstructured data, and developing new educational applications. The diverse topics and the fact that working prototypes could be generated in less than two days highlight that LLMs will profoundly impact the future of our fields. The rich collection of ideas and projects also indicates that the applications of LLMs are not limited to materials science and chemistry but offer potential benefits to a wide range of scientific disciplines.
KW - Large Language model
KW - Hackathon
KW - Concrete
KW - Prediction
KW - Inverse Design
KW - Orchestration
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-589961
DO - https://doi.org/10.1039/d3dd00113j
VL - 2
IS - 5
SP - 1233
EP - 1250
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-58996
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rhode, Michael
A1 - Kromm, Arne
A1 - Mente, Tobias
A1 - Brackrock, Daniel
A1 - Czeskleba, Denis
A1 - Kannengießer, Thomas
T1 - Component test for the assessment of delayed hydrogen-assisted cracking in thick-walled SAW joints for offshore applications
N2 - Offshore wind turbines continuously increase in size and weight and demand adequate offshore foundations concepts like monopiles, tripods, or jackets. These components are typically constructed using submerged arc welding (SAW) with high-strength thick steel plates like the S420ML. During welding, the occurrence of delayed hydrogen-assisted cracking (HAC) must be anticipated. HAC is a critical combination of the local hydrogen concentration within a susceptible microstructure under certain mechanical load, i.e., the occurring (welding) residual stresses. The welding sequence of the thick-walled plates complicates the residual stress distribution due to the necessary repeated thermal cycling, i.e., welding seam/layer deposition to fill the joint. For that purpose, SAW with two-wire-technique was used to weld a specially designed and prototype-like mock-up of a real component with a thickness of 50 mm, filled with over 20 passes and a seam length of 1000 mm. Additional welded stiffeners simulated the effect of a high restraint, to achieve critical HAC conditions. The necessity of a minimum waiting time (MWT) before the NDT can be conducted (to exclude HAC) was critically verified by the application of ultrasonic testing of the welded joint at different time-steps of the NDT of up to 48 h after the completion welding. The residual stresses were determined by a robot XRD goniometer. Tensile residual stresses up to the yield limit are found both in the weld metal and in the heat-affected zone. Numerical modeling allowed the qualitative estimation of the hydrogen diffusion in the weld. No noticeable HAC occurrence was identified and confirms the high cracking resistance of the investigated material. Finally, the applicability of the MWT concept should be critically discussed.
KW - Hydrogen
KW - Cold cracking
KW - Minimum Waiting Time
KW - Offshore steel grade
KW - Component test
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-591981
DO - https://doi.org/10.1007/s40194-023-01658-5
SP - 1
EP - 15
PB - Springer Science and Business Media LLC
AN - OPUS4-59198
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bayerlein, Bernd
A1 - Schilling, Markus
A1 - Birkholz, Henk
A1 - Jung, Matthias
A1 - Waitelonis, Jörg
A1 - Mädler, Lutz
A1 - Sack, Harald
T1 - PMD Core Ontology: Achieving semantic interoperability in materials science
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 (consistent) and variant (context-specific) 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 paper, an approach how to maintain a comprehensive MSE-centric terminology composing a mid-level ontology–the Platform MaterialDigital Core Ontology (PMDco)–via MSE community-based curation procedures is presented. The illustrated findings show how the PMDco bridges semantic gaps between high-level, MSE-specific, and other science domain semantics. Additionally, it demonstrates how the PMDco lowers development and integration thresholds. Moreover, the research highlights how to fuel it with real-world data sources ranging from manually conducted experiments and simulations with continuously automated industrial applications.
KW - Ontology
KW - Materials science and engineering
KW - Knowledge representation
KW - Reproducibility
KW - Semantic interoperability
KW - Semantic data integration
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-592948
DO - https://doi.org/10.1016/j.matdes.2023.112603
SN - 0264-1275
VL - 237
SP - 1
EP - 12
PB - Elsevier
CY - Amsterdam
AN - OPUS4-59294
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Klimek, André
A1 - Stelzner, Ludwig
A1 - Hothan, Sascha
A1 - Zehfuß, Jochen
T1 - Influence of thermal strain on concrete spalling
N2 - Understanding the susceptibility to spalling of concrete members in case of fire is important to evaluate the residual load-bearing capacity. The investigations of the spalling phenomenon of a concrete mixture using real scale members are necessary but expensive to carry out. Reducing the specimen size leads to an increase of boundary effects that can result in a reduced spalling or absence of spalling. In this study, fire tests were carried out on unrestrained, single-sided exposed, cuboid shaped specimens (0.6 m x 0.6 m x 0.29 m) as well as unrestrained and steel ring restrained cylindrical specimens (Ø = 0.47 m, h = 0.29 m), which induce different boundary conditions. These fire tests were carried out on two ordinary concrete mixtures. The two mixtures differ only in the type of aggregates (quartz gravel and basalt grit) and were used to investigate the influence of the thermal expansion of the aggregate on the spalling behaviour of the concrete. The results show a significant increase of
the spalling depth due to the restrained thermal expansion achieved by the applied steel rings. Additionally, the type of aggregate has a direct influence on the spalling behaviour of a concrete mixture. The reduction of the boundary effects by the steel rings recreate the test conditions in the centre of a large concrete member. Thus, this type of specimen is suitable to determine the susceptibility to spalling of a material (screening-tests) as preliminary investigations to full scale fire tests.
KW - Spalling
KW - Concrete
KW - Fire test
KW - Restraint
KW - Screening test
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593350
DO - https://doi.org/10.1617/s11527-023-02274-x
VL - 57
SP - 1
EP - 14
PB - Springer
AN - OPUS4-59335
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Heinekamp, Christian
A1 - Kneiske, Sönke
A1 - Guilherme Buzanich, Ana
A1 - Ahrens, Mike
A1 - Braun, Thomas
A1 - Emmerling, Franziska
T1 - A fluorolytic sol-gel route to access an amorphous Zr fluoride catalyst: A useful tool for C-F bond activation
N2 - A route to a ZrF4 catalyst active in room temperature Friedel–Crafts and dehydrofluorination reactions was developed via a fluorolytic sol–gel route, which was followed by a postfluorination step using a stream of CHClF2. The behaviour of different Zr(IV) precursors in a sol–gel reaction with anhydrous isopropanol/HF solution was investigated. The subsequent post-fluorination step was optimised in its temperature ramp and confirmed the necessity of a fluorination of the generated xerogels to obtain catalytic activity. The process is discussed in the context of the analysis of the materials using Brunauer–Emmett–Teller analysis (BET), powder X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The local structure of the amorphous catalyst was elucidated by extended X-ray absorption fine structure spectroscopy (EXAFS).
KW - Catalysis
KW - Heterogeneous catalysis
KW - C-F bond activation
KW - Postfluorination
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593433
DO - https://doi.org/10.1039/D3CY01439H
SN - 2044-4761
SP - 1
EP - 8
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59343
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Seher, Julia
A1 - Rübner, Katrin
A1 - Schnell, A.
A1 - Hahn, A.
A1 - Bruch, I.
A1 - Alewell, U.
A1 - Vöge, M.
A1 - Shafiei, K.
A1 - Schumann, G.
ED - Pfaff, G.
ED - Mertzsch, N.
ED - Jeremias, E.-P.
T1 - Hydrothermalgranulate – Eine Verwertungsmöglichkeit für Mauerwerkbruch
N2 - Im Jahr 2020 fielen in Deutschland rund 220 Millionen Tonnen mineralische Bau- und Abbruchabfälle an, die als Sekundärrohstoffquelle genutzt werden können. Trotz hoher Recyclingquoten wird ein Teil der mineralischen Bau- und Abbruchabfälle immer noch deponiert oder in Anwendungen mit geringen Qualitätsanforderungen eingesetzt, da ein effektives Recycling dieser heterogenen Abfälle recht kompliziert ist. Bauschutt ist ein heterogener, SiO2-reicher Sekundärrohstoff, der sich aus einem Gemisch verschiedener abgebrochener Baumaterialien wie Ziegel, Betonfertigteile, Leichtbeton, Porenbeton, Kalksandsteine, Natursteine, Gips und Mörtel zusammensetzt. Die genaue Zusammensetzung hängt von der Abbruchstelle, der Vorsortierung und der Wiederaufbereitung in der Recyclinganlage ab. Eine direkte Wiederverwendung als rezyklierte Gesteinskörnung ist aufgrund der uneinheitlichen Zusammensetzung und des bis zu 50 %igen Feinanteils nach der mechanischen Aufbereitung nicht zulässig. Eine Möglichkeit, Mauerwerksschutt effektiv zu recyceln, ist die rohstoffliche Verwertung über ein chemisch-hydrothermales Umwandlungsverfahren, das poröse Granulate erzeugt. Durch die Porenstruktur dieser hydrothermal gehärteten Granulate ergeben sich Anwendungsmöglichkeiten als Filter- oder Wasserspeichermaterial, die über den Bausektor hinausgehen. Diese neuartigen Granulate können leichte Gesteinskörnungen natürlichen Ursprungs (z. B. Lavasand, Bimsstein) oder Körner aus natürlichen Rohstoffen (z. B. Blähton) ersetzen. Die neue Recyclingstrategie spart natürliche Ressourcen. Im Vergleich zur Herstellung von Blähton ist der Energieverbrauch wesentlich geringer. Ziel des Verbundprojektes HYTEGRA war die Entwicklung eines Verfahrens zur Herstellung von leichten Gesteinskörnungen aus SiO2- und CaO-reichen Sekundärrohstoffen. Als Rohstoffe wurden Mauerwerksschutt als SiO2-Quelle und Papierasche aus der energetischen Verwertung von Reststoffen der Altpapierverwertung als CaO-Quelle eingesetzt. Der komplette Prozess von der mechanisch-physikalischen Aufbereitung über die Bildung des Grüngranulats bis zur hydrothermalen Härtung wurde entwickelt und im Labormaßstab getestet. Die Anwendungen des hydrothermal gehärteten Granulats als Wasserspeichermaterial für die innere Nachbehandlung von hochfestem Beton, Pflanzensubstrat und Filtermaterial in Bodenfiltern zur Abwasserreinigung wurden untersucht. Der Beitrag gibt einen Überblick über die wichtigsten Ergebnisse des erfolgreich abgeschlossenen Verbundforschungsprojekts HYTEGRA.
T2 - Kolloquium des Arbeitskreises “Energie, Mensch und Zivilisation” - Die Energiewende 2.0 Im Fokus: Die Stoffwirtschaft
CY - Potsdam, Germany
DA - 09.06.2023
KW - Rohstoffliches Recycling
KW - Mauerwerkbruch
KW - Papierasche
KW - leichte Gesteinskörnung
KW - poröse Granulate
KW - hydrothermale Behandlung
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593445
UR - https://leibnizsozietaet.de/wp-content/uploads/2023/12/01_SB158-0.pdf
SN - 978-3-86464-252-4
DO - https://doi.org/10.53201/SITZUNGSBERICHTE158
SN - 0947-5850
VL - 158
SP - 79
EP - 94
PB - trafo Wissenschaftsverlag
CY - Berlin
AN - OPUS4-59344
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wandtke, Karsten
ED - Becker, Amadeus
ED - Schröpfer, Dirk
ED - Kromm, Arne
ED - Kannengießer, Thomas
ED - Scharf-Wildenhain, R.
ED - Hälsig, A.
ED - Hensel, J.
T1 - Residual Stress Evolution during Slot Milling for Repair Welding and Wire Arc Additive Manufacturing of High-Strength Steel Components
N2 - High-strength steels offer potential for weight optimization due to reduced wall thicknesses in modern constructions. Additive manufacturing processes such as Wire Arc Additive Manufacturing (WAAM) enable the resource-efficient production of structures. In the case of defects occurring in weld seams orWAAM components due to unstable process conditions, the economical solution is local gouging or machining and repair welding. It is important to understand the effects of machining steps on the multiaxial stress state in conjunction with the design-related shrinkage restraints. Research into how welding and slot milling of welds andWAAM structures affects residual stresses is still lacking. For this reason, component-related investigations with high-strength steels with yield strengths ≥790 MPa are carried out in our research. In-situ digital image correlation (DIC) and ex-situ X-ray diffraction (XRD) were used to analyze the stresses and strains induced on specimens during and after milling. The systematic analyses revealed a significant interaction of the stiffness and microstructure of the specimens with the initial residual stresses induced by welding. Subsequent repair welds can result in significantly higher residual stresses.
KW - High strength steels
KW - Additive manufacturing
KW - Residual stress
KW - Repair welding
KW - Ditigtal image correlation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593515
DO - https://doi.org/10.3390/met14010082
VL - 14
IS - 1
SP - 1
EP - 11
PB - MDPI
CY - Basel
AN - OPUS4-59351
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ginés-Palomares, J.-C.
A1 - Fateri, M.
A1 - Schubert, T.
A1 - de Peindray d’Ambelle, L.
A1 - Simon, Sebastian
A1 - Gluth, Gregor
A1 - Günster, Jens
A1 - Zocca, Andrea
T1 - Material aspects of sintering of EAC-1A lunar regolith simulant
N2 - Future lunar exploration will be based on in-situ resource utilization (ISRU) techniques. The most abundant raw material on the Moon is lunar regolith, which, however, is very scarce on Earth, making the study of simulants a necessity. The objective of this study is to characterize and investigate the sintering behavior of EAC-1A lunar regolith simulant. The characterization of the simulant included the determination of the phase assemblage, characteristic temperatures determination and water content analysis. The results are discussed in the context of sintering experiments of EAC-1A simulant, which showed that the material can be sintered to a relative density close to 90%, but only within a very narrow range of temperatures (20–30 °C). Sintering experiments were performed for sieved and unsieved, as well as for dried and non-dried specimens of EAC-1A. In addition, an analysis of the densification and mechanical properties of the sintered specimens was done. The sintering experiments at different temperatures showed that the finest fraction of sieved simulant can reach a higher maximum sintering temperature, and consequently a higher densification and biaxial strength. The non-dried powder exhibited higher densification and biaxial strength after sintering compared to the dried specimen. This difference was explained with a higher green density of the non-dried powder during pressing, rather than due to an actual influence on the sintering mechanism. Nevertheless, drying the powder prior to sintering is important to avoid the overestimation of the strength of specimens to be fabricated on the Moon.
KW - Lunar regolith
KW - Ceramics
KW - Microstructure
KW - Sintering
KW - Softening temperature
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-592668
DO - https://doi.org/10.1038/s41598-023-50391-y
SN - 2045-2322
VL - 13
SP - 1
EP - 14
PB - Springer Nature
AN - OPUS4-59266
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Böllinghaus, Thomas
A1 - Lüders, V.
A1 - Nolze, Gert
T1 - Microstructural insights into natural silver wires
N2 - Due to the increasing global demand for pure silver, native wire silver aggregates in very high purities are gaining more industrial attention. Up to the present, no substantial metallurgical Investigation of natural wire silver exists in the accessible literature. To convey urgently needed cross-disciplinary fundamental knowledge for geoscientists and metallurgical engineers, twenty natural wire silver specimens from eight different ore deposits have been investigated in detail for the first time by EBSD (Electron Back Scattering Diffraction), supported by light microscopy and micro-probe analyses. The improved understanding of the natural silver wire microstructure provides additional Information regarding the growth of natural silver aggregates in comparison to undesired artificial growth on electronic devices. Clear evidence is provided that natural silver curls and hairs exhibit a polycrystalline face-centered cubic microstructure associated with significant twinning. Although the investigated natural wire silver samples have relatively high purity (Ag > 99.7 wt.-%), they contain a variety of trace elements such as, S, Cu, Mn, Ni, Zn, Co and Bi, As and Sb. Additionally, Vickers micro-hardness measurements are provided for the first time which revealed that natural silver wires and curls are softer than it might be expected from conversion of the general Mohs hardness of 2.7.
KW - Natural silver wires
PY - 2018
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-451655
UR - http://www.nature.com/articles/s41598-018-27159-w
DO - https://doi.org/10.1038/s41598-018-27159-w
SN - 2045-2322
VL - 8
IS - 1
SP - Article 9053, 1
EP - 9
PB - nature publishing group
CY - London, United Kingdom
AN - OPUS4-45165
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zare Pakzad, S.
A1 - Nasr Esfahani, M.
A1 - Tasdemir, Z.
A1 - Wollschläger, Nicole
A1 - Li, T.
A1 - Li, X.
A1 - Yilmaz, M.
A1 - Leblebici, Y.
A1 - Erdem Alaca, B.
T1 - Nanomechanical Modeling of the Bending Response of Silicon Nanowires
N2 - Understanding the mechanical behavior of silicon nanowires is essential for the implementation of advanced nanoscale devices. Although bending tests are predominantly used for this purpose, their findings should be properly interpreted through modeling. Various modeling approaches tend to ignore parts of the effective parameter set involved in the rather complex bending response. This oversimplification is the main reason behind the spread of the modulus of elasticity and strength data in the literature. Addressing this challenge, a surface-based nanomechanical model is introduced in this study. The proposed model considers two important factors that have so far remained neglected despite their significance: (i) intrinsic stresses composed of the initial residual stress and surface-induced residual stress and (ii) anisotropic implementation of surface stress and elasticity. The modeling study is consolidated with molecular dynamics-based study of the native oxide surface through reactive force fields and a series of nanoscale characterization work through in situ threepoint bending test and Raman spectroscopy. The treatment of the test data through a series of models with increasing complexity demonstrates a spread of 85 GPa for the modulus of elasticity and points to the origins of ambiguity regarding silicon nanowire properties, which are some of the most commonly employed nanoscale building blocks. A similar conclusion is reached for strength with variations of up to 3 GPa estimated by the aforementioned nanomechanical models. Precise consideration of the nanowire surface state is thus critical to comprehending the mechanical behavior of silicon nanowires accurately. Overall, this study highlights the need for a multiscale theoretical framework to fully understand the size-dependent mechanical behavior of silicon nanowires, with fortifying effects on the design and reliability assessment of future nanoelectromechanical systems.
KW - Silicon nanowires
KW - Native oxide
KW - Surface stress
KW - Surface elasticity
KW - Mechanical behavior
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581676
DO - https://doi.org/10.1021/acsanm.3c02077
SP - 1
EP - 14
PB - ACS Publications
AN - OPUS4-58167
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -