TY - CONF A1 - Zakel, S. A1 - Schröder, Volkmar A1 - Gabel, D. A1 - Hirsch, W. A1 - Kleinert, J. A1 - Krause, U. A1 - Krietsch, Arne A1 - Meistes, J. A1 - Sachtleben, A. A1 - Schmidt, Martin A1 - Askar, Enis T1 - Safety characteristics of hybrid mixtures for explosion protection N2 - In this joint project, standardized measurement methods for hybrid mixtures are developed, which serve to determine safety characteristics for explosion protection. A hybrid mixture is a multi-phase System consisting of fuel gas or vapor, as well as air and flammable dust. This combination can occur for instance in drying processes or during heterogenous reaction processes. T2 - 27th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS) CY - Beijing, VR China DA - 28.07.2019 KW - Explosionsschutz KW - Gas-Staub-Gemische KW - Hybride Gemische KW - Sicherheitstechnische Kenngrößen PY - 2019 AN - OPUS4-48992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rockenhäuser, Christian A1 - Häusler, I. A1 - Piesker, B. A1 - Skrotzki, Birgit T1 - Influence of prestraining on the aging response of an Al-Cu-Li alloy N2 - The influence of prestraining on the aging response of an Al-Cu-Li alloy is investigated by preparation of different strain states (3 %, 4 %, 6 %) of the initial aging state. The Brinell hardness of the subsequently aged samples (up to 60 h aging time) was measured and it was found that the increasing dislocation concentration in the 3 different initial states leads to faster hardness increases and slightly higher maximum hardness. T2 - Microscopy Conference 2019 (MC2019) CY - Berlin, Germany DA - 01.09.2019 KW - Al-Cu-Li alloys KW - Degradation KW - Hardness PY - 2019 AN - OPUS4-48953 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rockenhäuser, Christian A1 - von Hartrott, P. A1 - Metzger, M. A1 - Skrotzki, Birgit T1 - Digital material representation of alloy 2618A for the lifetime assessment of radial compressor wheels N2 - The concept of digital material representation is introduced and the aluminium alloy 2618A is discussed as an example of this concept regarding the simulation of material ageing based on nanoscaled precipitates. T2 - Microscopy Conference 2019 (MC2019) CY - Berlin, Germany DA - 01.09.2019 KW - Alloy 2618A KW - Degradation KW - Coarsening KW - Transmission electron microscopy KW - Digital material representation PY - 2019 AN - OPUS4-48954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Taparli, Ugur Alp A1 - Griesche, Axel A1 - Michalik, K. A1 - Mory, D. A1 - Kannengießer, Thomas T1 - In situ Tungsten inert gas welding monitoring by LIBS N2 - TIG welding process was monitored using LIBS for the in situ measurement of chemical compositions in austenitic stainless steels. This research aims to prototype a real-time chemical composition analysis system for welding applications and prove the feasibility of such a quality control loop. The chemical compositions of the weld pool, considering the welding metallurgy, is the most critical parameter for any occurring weld defects, e.g. hot cracking. Hence, controlling the weld pool chemical composition allows governing of the weld pool solidification behavior by monitoring and adjusting the respective welding parameters, e.g. welding current. LIBS measurements were conducted during a TIG-welding process. The effect of the welding plasma on the LIBS signal was thoroughly investigated by varying various LIBS settings, e.g. delay and exposure time. Quantification of the main alloying elements Cr and Ni in the weld pool during welding was achieved by univariate calibration procedure. T2 - 10th Euro-Mediterranean Symposium on Laser-Induced Breakdown Spectroscopy CY - Brünn, Czech Republic DA - 08.09.2019 KW - LIBS TIG welding KW - Austenitic stainless steels KW - Chemical composition KW - In situ measurement, PY - 2019 AN - OPUS4-48996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hennersdorf, Felix A1 - Weltschev, Margit A1 - Hertwig, Andreas T1 - ATR Investigations into the effect of ageing on HD-PE heating oil storage tanks after a service life of more than 30 years N2 - Heating oil storage tanks made of polyethylene grades have been on the market in Germany since the early 1970s. To ensure safety, their replacement is recommended by tank manufacturers after a period of 30 years. Polyethylene is subject to ageing by alteration of the properties during its life cycle. The degree of degradation and the nature of the process mainly depend on the chemical alteration of the polyethylene, the wall thickness of the tank and the environmental conditions. There are no data available on the long-term behaviour of the polyethylene grades, especially after a service life of more than 30 years. The aim of this investigation was to find a suitable test method to determine the factual degree of damage in comparison to the uncontaminated polyethylene grades. Material data of the used polyethylene grades are available because the BAM was the competent authority for the tests and expert reports for the approval of these tanks until the middle of the 1990s. Therefore, tank sections from the bottom, the shell and the roof of 22 individual storage tanks produced of polyethylene grades A and B have been examined by Melt Flow Rate (MFR) and Attenuated Total Reflectance (ATR). Their service life was in the range between 20 and 41 years. The MFR measurements of the tank sections showed differences in the values depending on the weight which was used (5 kg or 21.6 kg). An increase of the MFR was determined for the samples of polyethylene grade A, whereas a reduction of the MFR values was measured for most samples of polyethylene grade B. This grade is mainly subject to the internal ageing by cross-linkages, increased degree of branched molecules and loss of the plasticizer. ATR analysis exhibits an absorption band at 909 cm‒1 predominantly in samples of polyethylene grade A indicating chain scission and concomitantly formed terminal vinyl groups. This absorption band can be used for the characterization of the ageing of the polyethylene grades. T2 - EUROCORR 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Heating oil tanks KW - Polyethylene KW - Ageing KW - Service life PY - 2019 AN - OPUS4-49000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Torge, Manfred A1 - Seneschal-Merz, Karine A1 - Feldmann, Ines A1 - Bücker, Michael A1 - Oleszczuk, S. T1 - EDX-Analysis on medieval glasses and innovative protection of stained glass panels N2 - The church of Koszewko (Poland) is a brick building edified in the 15th century built on cobblestone foundations. There are five windows in the sanctuary. Three of them enclose heraldic panels from the Küssow’s family from the 15th century which are surrounded with Goethe glass from the 18th century to complete the windows. The colored heraldic panels are strongly damaged and corroded with massive paint layer losses, glass- and leadbreakages. Those medieval glass fragments have been shortly discovered and are of particular interest for Poland since only few medieval glazing have been conserved. The damages as well as the glass compositions have been investigated with ESEM/EDX. Two categories of medieval glass compositions have been identified. The blue glass is particularly sensible to corrosion because of his high content in K2O. The colorless and the red glass samples belong to a stable glass type. Due to the thickness of the gel layer, it is easy to see that the degradation is strongly proceeded. The protection of those medieval stained-glass panels is absolute necessary. The medieval panels have been restored and surrounded from a copper frame. Then they have been fixed on the wood frame in the church. The exterior glazing has been closed with a panel of Goethe glass. The gap between the Goethe- and the medieval glass is about 3 cm. The Goethe glass panel has been stabilized with a film based on polyester to protect the medieval glasses against any damages. In this way, a low cost protective glazing has been installed for a long-term conservation of each medieval stained-glass panels. The climate measurements over the period of one year on the restored windows are in process. The temperature and the relative humidity are recorded in the church interior, in the gap between the original and the Goethe glass and outdoors. T2 - 93rd Annual Meeting of DGG and Annual Meeting of USTV CY - Nuremberg, Germany DA - 13.05.2019 KW - Medieval glasses KW - Stained glasses KW - EDX Analysis KW - Corrosion PY - 2019 AN - OPUS4-48025 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröder, Volkmar A1 - Zakel, S. T1 - Sicherheitstechnische Kenngrößen des Explosionsschutzes für hybride Stoffgemische - Das Verbundvorhaben "NEX-HYS" N2 - Sicherheitstechnische Kenngrößen des Explosionsschutzes für hybride Stoffgemische – Das Verbundvorhaben „NEX-HYS“ Im Rahmen des WIPANO-Programms (Wissens- und Technologietransfer durch Patente und Normen), gefördert vom BMWi, ist ein Verbundvorhaben zur Bestimmung sicherheitstechnischer Kenngrößen hybrider Gemische begonnen worden. Teilnehmer sind die OvGU Magdeburg (Koordination), die BAM, die PTB, die INBUREX GmbH und das DIN. Hybride Gemische, z.B. Staub-Brenngas-Luft-Gemische, spielen in der Prozesstechnik bei Trocknungs- und Transportprozessen eine wichtige Rolle. Für diese Gemische lassen sich die sicherheitstechnischen Kenngrößen nach den vorhandenen Normen nicht bestimmen. Aus bisherigen Forschungsarbeiten ist allerdings bekannt, dass hybride Gemische teilweise zündempfindlicher sind, erweiterte Explosionsbereiche aufweisen und die Auswirkungen von Explosionen heftiger ausfallen können als bei Brennstoffen, die nur in einem Aggregatzustand vorliegen. Ziel des Verbundprojektes ist es, labortechnische Verfahren zur Bestimmung sicherheitstechnischer Kenngrößen (STK) für hybride Gemische bis zur Normungsreife zu entwickeln und mittelfristig eine europäische Normung für hybride Gemische im CEN TC305 zu initiieren. Folgende, technisch wichtige Kenngrößen sollen bearbeitet werden: Untere Explosionsgrenze, Sauerstoffgrenzkonzentration, maximaler Explosionsdruck, maximaler zeitlicher Druckanstieg und Mindestzündtemperatur. Um eine schnelle allgemeine Verfügbarkeit der Ergebnisse zu gewährleisten, ist im Rahmen des Vorhabens die Erstellung einer DIN SPEC (Vornorm) geplant. Im Poster wird das Verbundvorhaben mit den einzelnen Arbeitspaketen dargestellt und diskutiert. T2 - 15. BAM-PTB-Kolloquium 2019 CY - Braunschweig, Germany DA - 21.05.2019 KW - Gas-Staub-Gemische KW - Explosionsschutz KW - Sicherheitstechnische Kenngrößen KW - Hybride Gemische PY - 2019 AN - OPUS4-48536 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Li, Wei T1 - Crack propagation in filled and unfilled polymers: Separation of surface energy and irreversible deformation energy N2 - Fiber-reinforced-polymers (FRPs) are in current research focus in the lightweight construction industry, because of their extraordinary characteristics (stiffness and strength-to-density relation). The structure of polymer matrix and the interaction with reinforcement are crucial for optimization of the mechanical and thermal properties of FRPs. Due to the macromolecular chain structure, the mechanical properties of a polymer strongly vary with temperature: Below the glass transition, the chain segments of a polymer are “frozen”. Regarding fracture, the total changed energy during fracture if only dissipates for the generation of the new surfaces. However, in the region of the glass transition, the polymer chain segments start to get “unfrozen”, and the energy is not only required for generating new surfaces, but also for irreversibly deformation. This irreversible deformation is affected by the global temperature and the local temperature near the crack tip, which is affected by the local strain rate and crack propagation velocity. Hence, in this research project, the irreversible deformation of neat and reinforced polymers will be controlled by changing the global temperature as well as the local temperature. With using different fracture experiments, the amount of energy required for creating new surfaces and for the irreversible deformation will be separated. The fracture tests include the conventional tensile test, the macroscopic peel test and the single fiber peel – off test. T2 - PhD Day 2018 of BAM CY - Berlin, Germany DA - 31.05.2018 KW - Crack Propagation KW - Polymer PY - 2018 AN - OPUS4-48471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Li, Wei T1 - Crack propagation in polymers: Separation of surface energy and irreversible deformation energy N2 - Fiber-reinforced-polymers (FRPs) are in current research focus in the lightweight construction industry, because of their extraordinary characteristics (stiffness and strength-to-density relation). The structure of polymer matrix and the interaction with reinforcement are crucial for optimization of the mechanical and thermal properties of FRPs. Due to the macromolecular chain structure, the mechanical properties of a polymer strongly vary with temperature: Below the glass transition, the chain segments of a polymer are “frozen”. Regarding fracture, the total changed energy during fracture if only dissipates for the generation of the new surfaces. However, in the region of the glass transition, the polymer chain segments start to get “unfrozen”, and the energy is not only required for generating new surfaces, but also for irreversibly deformation. This irreversible deformation is affected by the global temperature and the local temperature near the crack tip, which is affected by the local strain rate and crack propagation velocity. Hence, in this research project, the irreversible deformation of neat and reinforced polymers will be controlled by changing the global temperature as well as the local temperature. With using different fracture experiments, the amount of energy required for creating new surfaces and for the irreversible deformation will be separated. This poster is the summary of the first part of the whole project. In the first part, the basic crack propagation theory for neat polymers is established and the special fracture experiment sample is prepared and tested at room temperature. In addition, the fracture experiment at room temperature is validated numerically. T2 - PhD Day 2019 of BAM CY - Berlin, Germany DA - 22.05.2019 KW - Crack Propagation KW - Polymer PY - 2019 AN - OPUS4-48472 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas A1 - Erdmann, Maren A1 - Müller, Bernd R. A1 - Hentschel, M.P. A1 - Niebergall, Ute A1 - Böhning, Martin A1 - Bruno, Giovanni T1 - Warum wird zugbelastetes HD-Polyethylen in Dieselumgebung transparent? N2 - Behälter aus hochdichtem Polyethylen (PE-HD) werden zur Lagerung und für den Transport von Kraftstoffen eingesetzt. Beim Kontakt beider Medien diffundiert der Kraftstoff in das Polymer, erhöht dessen Volumen und Duktilität und ändert damit das Fließverhalten des Polymers unter Zugbelastung. Zudem weist PE-HD in Luft im verstreckten Bereich das sogenannte strain-whitening (Lichtstreuung) auf, während in Diesel gelagertes PE-HD optisch transparent wird. Zur Untersuchung dieses Phänomens wurden ortsaufgelöste Röntgenrefraktion und –diffraktion (Topographie) eingesetzt. Aus Sicht der molekularen Struktur (Diffraktion) weisen die beiden Probentypen keine Unterschiede auf: im verstreckten Bereich liegt eine „Fasertextur“ der Polymerketten in Belastungsrichtung vor, im unverstreckten Bereich nahezu ideale Isotropie. Die für mikroskopische Strukturen empfindliche Röntgenrefraktion zeigt außerdem für die Probe in Luft im verstreckten Bereich eine ausgeprägte Orientierung von Grenzflächen in Zugrichtung, während die in Diesel gelagerte Probe keine Grenzflächen zeigt. In Analogie zum optischen Verhalten bewirken die ähnlichen Brechungsindizes beider Medien im Röntgenbereich, dass eindiffundierter Diesel als Immersionsflüssigkeit die Brechungseigenschaften herabsetzt. T2 - DACH-Jahrestagung 2019 CY - Friedrichshafen, Germany DA - 27.05.2019 KW - Diesel KW - HDPE Sorption KW - Röntgenrefraktion KW - Röntgenbeugung KW - Mikrostruktur KW - Kavitation PY - 2019 AN - OPUS4-48311 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ermilova, Elena A1 - Hertwig, Andreas A1 - Beck, Uwe A1 - Schneider, S. A1 - Peters, S. T1 - Standardization of spectroscopic ellipsometry as GUM-compliant accredited measurement method N2 - Ellipsometry has become a powerful measurement tool in semiconductor industry since the sixties of the last century. Early standardization activities focused exclusively on SiO2/Si (ASTM F 576-01, SEMI 3624). The first generic standard dealing with ellipsometry is DIN 50989-1:2018 Ellipsometry – Part 1: Principles. Standardization is a prerequisite for accreditation according to DIN EN ISO/IEC 17025 and the evaluation of uncertainty budgets. T2 - 8th International conference on spectroscopic CY - Barcelona, Spain DA - 26.05.2019 KW - Standardization of Ellipsometry KW - GUM-compliance KW - Uncertainty budgets KW - Bulk material PY - 2019 AN - OPUS4-48348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kiefer, P. A1 - Deubener, J. A1 - Waurischk, Tina A1 - Balzer, R. A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Behrens, H. T1 - Subcritical crack growth in water bearing soda-aluminosilicate glasses N2 - The subcritical crack growth in water bearing soda-aluminosilicate glasses is compared to the crack growth in a commercial soda-lime silicate glass. The water speciation is shown for comparison of water species in the material. Differences will be discussed in the poster session. T2 - Glastechnische Tagung 2019 CY - Nürnberg, Germany DA - 13.05.2019 KW - Glass KW - Crack growth KW - Vickers KW - Water speciation PY - 2019 AN - OPUS4-48343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bärmann, F A1 - Dittmann, Daniel A1 - Braun, Ulrike A1 - Jonas, U. A1 - Fuchs, S. T1 - Degradation analysis of polypropylene in the presence of phosphorus and sulfur containing additives - TGA-FTIR N2 - Polyolefins as polypropylene are widely used in packaging, automotive, consumer goods, construction, infrastructure, agricultural film and other film and sheet applications. Due to their molecular structure, polyolefins inherently burn well. The wide and growing usage implements that fire retardancy of polyolefin products is necessary and gains more attention. Sulfurous additives with synergistic flame retarding effects were shown in polymers like polystyrene and polyolefins by Bellin et al. and Fuchs et al. earlier. For polystyrene compounds, Braun et al. revealed that thermal degradation in the presence of phosphorus and sulfurous additives changes massively. The total release, the composition, and the onset temperature of evolved decomposition products changes. For polypropylene, mixtures containing triphenyl phosphate (TPP), sulfur (S8) and poly(tertbutylphenol) disulphide (PBDS) (Table 1) were prepared and investigated via thermogravimetric analysis coupled to Fourier transformed infrared spectroscopy (TGA-FTIR). T2 - FRPM 2019 CY - Turku, Finland DA - 26.06.2019 KW - TGA-FTIR KW - Polypropylene KW - Phosphorus KW - Sulfur PY - 2019 AN - OPUS4-49391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heilmann, Maria A1 - Kulla, Hannes A1 - Prinz, Carsten A1 - Bienert, Ralf A1 - Marquardt, Julien A1 - de Oliveira Guilherme Buzanich, Ana A1 - Emmerling, Franziska T1 - Synthesis of Bimetallic Nickel Nanoparticles as Catalysts for the Sabatier Reaction N2 - Nanoparticles (NP) have become important materials for a variety of chemical technologies. The enhance surface-area-to-volume ratio of NPs is very high, making them excellent for use as catalyst, in analytical assays, and for antimicrobial applications. Nickel NPs have exhibited immense potential as important catalyst for the Sabatier reaction, i.e. converting waste to energy via transformation of CO2 into CH4, and could replace the rare earth elements such as Ru, PT, or Rh. In this work we describe the solvothermal synthesis of monometallic and bimetallic nickel nanoparticles. Monodisperse monometallic Ni nanoparticles were synthesized using Oleylamin as solvent and reducing agent. The nanoparticles were investigated using small angle scattering (SAXS), scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDX), showing that the catalytically active sites are accessible. However, Ni has a high propensity to undergo oxidation, and becoming deactivated by coke formation. Hence, we further explore the preparation of bimetallic NPs, where a second metal is added to stabilize the Ni. Bimetallic Cu-Ni NPs were synthesized by simultaneous solvothermal reduction. These bimetallic NPs exhibit excellent catalytic properties are promising candidates to be used as catalysts for efficient energy storage. T2 - Joint Polish-German Crystallographic Meeting CY - Wroclaw, Poland DA - 24.02.2020 KW - Nanoparticles KW - Synthesis KW - Catalysis PY - 2020 AN - OPUS4-51663 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Serrano Munoz, Itziar A1 - Mishurova, Tatiana A1 - Fritsch, Tobias A1 - Ulbricht, Alexander A1 - Evans, Alexander A1 - Hofmann, Michael A1 - Bruno, Giovanni T1 - Influence of the scanning strategy on the residual stress state in IN718 additive manufactured parts N2 - Laser Powder Bed Fusion (L-PBF) is an additive manufacturing technique enabling the design of complex geometries that are unrivalled by conventional production technologies. Nevertheless, L-PBF process is known to induce a high amount of residual stresses (RS) due to the high temperature gradients present during powder melting by laser. High tensile residual stresses are to be found the edges whereas the bulk material shows balancing compressive RS. Literature shows that the RS is highly sensitive to the process parameters. In particular, this study presents the characterization of the RS state in two L-PBF parts produced with a rastering scan vector that undergoes 90° or 67° rotation between subsequent layers. T2 - MLZ User Meeting 2020 CY - Online meeting DA - 08.12.2020 KW - Laser Powder Bed Fusion KW - IN718 KW - EBSD analysis KW - Residual stress state PY - 2020 AN - OPUS4-51821 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas A1 - Trappe, Volker A1 - Müller, Bernd R. A1 - Bruno, Giovanni T1 - Evolution of CFRP stress cracks observed by in situ X-ray refractive imaging N2 - Modern air-liners and wind turbine rotor blades are made up primarily of fiber reinforced plastics. Failure of these materials heavily impairs the serviceability and the operational safety. Consequently, knowledge of the failure behavior under static and cyclic loads is of great interest to estimate the operational strength and to compare the performance of different materials. Ideally, the damage evolution under operational load is determined with in-situ non-destructive testing techniques. Here, we report in-situ synchrotron X-ray imaging of tensile stress induced cracks in carbon fiber reinforced plastics due to inter-fiber failure. An inhouse designed compact tensile testing machine with a load range up to 15 kN was integrated into the beamline. Since conventional radiographs do not reveal sufficient contrast to distinguish cracks due to inter-fiber failure and micro cracking from fiber bundles, the Diffraction Enhanced Imaging (DEI) technique is applied in order to separate primary and scattered (refracted) radiation by means of an analyzer crystal. This technique allows fast measurements over large fields-of-view and is ideal for in-situ investigations. T2 - 12th BESSY@HZB User Meeting 2020 CY - Online meeting DA - 10.12.2020 KW - Carbon Fiber Reinforced Plastics KW - Crack evolution KW - Diffraction Enhanced Imaging KW - In situ tensile test KW - X-ray refraction PY - 2020 AN - OPUS4-51802 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mrkwitschka, Paul A1 - Abram, Sarah-Luise A1 - Kuchenbecker, Petra A1 - Würth, Christian A1 - Rühle, Bastian A1 - Resch-Genger, Ute A1 - Hodoroaba, Vasile-Dan T1 - Fine iron oxide nanoparticles as a candidate reference material for reliable measurement of particle size N2 - Background, Motivation and Objective Nanomaterials are at the core of some of the 21st century’s most promising technologies. In order to utilize and rationally design materials at the nanoscale the reliable characterization of their physico-chemical properties is highly important. Furthermore, the European Commission has taken measures via the REACH Regulations to control the classification of nanomaterials. REACH Annexes which entered into force in January 2020 require manufacturers to register nanomaterials that are traded in larger quantities (at least 1 ton). Every powder or dispersion where 50% (number distribution) of the constituent particles have sizes ≤ 100 nm in at least one dimension are defined as a nanomaterial. This creates a need for both industrial manufacturers and research and analytical service facilities to reliably characterize potential nanomaterials. Currently, BAM is working on developing reference nanoparticles, which shall expand the scarce list of worldwide available nano reference materials certified for particle size distribution, but also targeting other key parameters such as shape, structure (including porosity) and functional properties. Thus, candidate materials are considered to complement the already available spherical and monodisperse silica, Au and polystyrene reference nanoparticles, e.g. iron oxide and titanium oxide, with an average atomic number between those of silica and gold. Particularly for the imaging by electron microscopies, new nanoparticles of well-defined size in the range of 10 nm are decisive for the accurate particle segmentation by setting precise thresholds. Statement of Contribution/Methods Synthesis: Highly monodisperse iron oxide nanoparticles can be synthesized in large quantities by thermal decomposition of iron oleate or iron acetylacetonate precursors in high boiling solvents such as octadecene or dioctyl ether in the presence of oleic acid and oleylamine as capping agents. Scanning Electron Microscope: An SEM of type Supra 40 from Zeiss has been used including the dedicated measurement mode transmission in SEM (STEM-in-SEM) with a superior material contrast for the nanoparticle analysis. The software package ImageJ has been used for the analysis of the STEM-in-SEM images and to determine the particle size distribution. Dynamic Light scattering (DLS): Particles in suspension were measured in comparison by means of Zetasizer Nano (Malvern Panalytical; cumulants analysis) and NanoFlex (Microtrac; frequency power spectrum). Results/Discussion In this study iron oxide nanoparticles synthesized at BAM and pre-characterized by DLS, SEM (including the transmission mode STEM-in-SEM) are presented. The particles are spherical and highly monodisperse with sizes slightly larger than 10 nm. T2 - Nanosafe 2020 CY - Online meeting DA - 16.11.2020 KW - Reference nanomaterials KW - Imaging techniques KW - Size and size distribution KW - Reliable characterization KW - Iron oxide nanoparticles PY - 2020 AN - OPUS4-51767 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dittmann, Daniel A1 - Lucke, T A1 - Hermann, M A1 - Ruhl, A. S. A1 - Winzenbacher, R A1 - Jekel, M A1 - Braun, Ulrike T1 - Aktivkohlecharakterisierung von GAK-Filtern bei unterschiedlichen Laufzeiten N2 - Eine umfangreich ausgestaltete Trinkwasseraufbereitung als Multibarrieren-System ist notwendig, wenn das Rohwasser direkt aus Fließgewässern entnommen wird (z. B. für das Mülheimer Verfahren). Eine der Barrieren wird, als gezielte Behandlungs- oder Sicherheitsstufe, oft als Filter mit granulierter Aktivkohle (GAK-Filter) realisiert. Ihre Standzeit kann bei geringer Wasserbelastung (DOC < 2 mg/L), z. B. bei der Landeswasserversorgung Langenau, bis zu 5 Jahre betragen. Bei Rohwasser mit höherem Organikgehalt (DOC > 7 mg/L), wie bei der Nordwasser in Rostock, wird hingegen mindestens alle drei Jahre die GAK in den Filterkolonnen ausgetauscht. Die Rest-Adsorptionskapazität der GAK kann durch verschiedene Verfahren abgeschätzt werden, ist aber nach wie vor Gegenstand aktueller Forschung. Die weitergehende Charakterisierung der beladenen GAK kann hierbei helfen. Auf dem Poster sollen erste Ergebnisse zu den in Langenau und Rostock eingesetzten Aktivkohlen präsentiert werden. Hierzu wurden die frischen und nach unterschiedlichen Laufzeiten beladenen GAK untersucht. Die Zusammensetzung der Anorganik und der adsorbierten Organik, welche mittels Zersetzungs¬gasanalyse charakterisiert wurde, zeigt deutliche Unterschiede. Bspw. nimmt der Calcium-Gehalt der GAK in Langenau kontinuierlich zu, wohingegen dieser in den Proben aus Rostock mit zunehmender Laufzeit zurückgeht. Umgekehrt verhält es sich mit der Organik: Die GAK aus Rostock zeigen Hinweise auf biologische Besiedelung, während diese in Langenau trotz längerer Filterlaufzeit auszubleiben scheint. T2 - 4. Mülheimer Wasseranalytisches Seminar (MWAS2020) CY - Mülheim an der Ruhr, Germany DA - 16.09.2020 KW - Thermogravimetrie KW - Trinkwasser KW - Wasseraufbereitung KW - Aktivkohle PY - 2020 AN - OPUS4-51433 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Raedel, Martina A1 - Bücker, Michael A1 - Feldmann, Ines A1 - Reimann, M. T1 - Conservation of damaged architectural aluminum elements N2 - Aluminum is an often-used building material in modern architecture. In recent years buildings from the 1950th and 1960th are increasingly subject of conservation works including the aluminum parts. Typical surface damages are signs of corrosion caused by weathering processes or scratches in the anodized layer due to extensive wear. To repair damaged aluminum surfaces, there are usually two options: smaller areas are repaired by using a touch-up pen, for larger damages it is necessary to remove the anodized layer completely. Both possibilities are disadvantageous for the objects; the touch-up pen often does not match the color together with an insufficient corrosion protection, while newly anodized layers often differ in color and gloss from the original surface. For this reason, a research project was initiated to develop a mobile method to repair anodized aluminum parts. The first step focusses on the mobile anodization process by using the electrolyte with a gel substrate. Different cathodic materials are to be tested together with appropriate cooling material. The anodized area should be isolated to protect undamaged areas. Examinations of the produced layers are conducted by using Keyence microscope, eddy current testing and ESEM analysis. Further steps are to transform the coloring and sealing process for mobile application. Color could be applied by using a brush or by spray while the sealing process could be performed with water vapor. An heatable putty knife could be used, if heating up the area will be necessary. Once the application process is developed, the anodization will be tested on samples with artificial damages, fixed in horizontal and vertical positions. The stability of the anodized surface will be examined by accelerated ageing in a climate chamber and outdoor weathering. The electrolyte (diluted sulfuric acid) was combined with a gel binder to enable a mobile application. Several thickening agents were tested concerning their conductivity and stability in acid systems. Anodization tests with different cathodic material and shapes were conducted. The temperature during anodization was controlled and adjusted if necessary. The anodized area was restricted by using either a lacquer, an adhesive or a removable silicon barrier. The fist results show the feasibility of the method on enclosed areas. The achieved thickness was measured by eddy current testing and the structure was controlled by ESEM analysis. The examinations show a connection between thickness and porosity of the anodized layers and the temperature during the application process. Next steps are testing mobile coloring and sealing methods followed by mobile anodization on artificial damaged areas. T2 - Metal 2019 CY - Neuchâtel, Switzerland DA - 02.09.2019 KW - Mobile anodisation KW - Aluminium KW - Conservation KW - Damage repair PY - 2020 UR - https://www.lulu.com/shop/claudia-chemello-and-laura-brambilla-and-edith-joseph/metal-2019-proceedings-of-the-interim-meeting-of-the-icom-cc-metals-working-group-september-2-6-2019-neuch%C3%A2tel-switzerland-ebook/ebook/product-24517161.html AN - OPUS4-51479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feldkamp, Martin A1 - Erenberg, Marina A1 - Nehrig, Marko A1 - Bletzer, Claus A1 - Musolff, André A1 - Wille, Frank T1 - Heat Flux from Wood Filled Impact Limiter under Fire Conditions N2 - Packages for the transport of high-level radioactive material must withstand severe hypothetical accidents. Regulatory test conditions shall cover these severe accident conditions and consist of mechanical tests and a following thermal test. To withstand the mechanical tests heavy weight packages are often designed with impact limiters consisting of wood encapsulated in steel sheets. The thermal test is defined precisely in the IAEA-regulations as a 30 minute fully engulfing 800 °C fire. After the fire phase a pre-damaged impact limiter might continue burning or smouldering and influence the cask thermal behaviour with its energy release. The energy transferred from the impact limiter to the cask is of importance for the safety of transport packages. A full-scale fire test with an impact limiter of 2.3 m in diameter and filled with spruce wood was designed and performed. The impact limiter continued burning for 3 days. Energy transfer and temperature measurements were performed. T2 - 9th International Scientific Conference - wood & fire safety 2020 CY - Online meeting DA - 02.11.2020 KW - Fre KW - Smouldering KW - Wood PY - 2020 AN - OPUS4-51517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Schade, U. A1 - Pulskar, L. A1 - Ritter, E. T1 - Novel Technique for On-Line Monitoring of the Curing Process of Fiber Reinforced Polymer Composites N2 - A specially designed experimental set up has been integrated into a commercially available FT IR Spectrometer for ATR experiments on Epoxy Systems. Representative data of far infrared spectra measured during the curing process at different temperatures of an epoxy system will be presented in dependency of the curing situation. The experiments and the selected set up are discussed to demonstrate its potential for future monitoring and ageing control applications during a manufacturing process of polymer composites. T2 - 45. International Confercene on infrared, milimeter and terahertz waves CY - Online meeting DA - 08.11.2020 KW - Far-infrared spectroscopy KW - Curing Monitoring PY - 2020 UR - https://live-irmmwthz.pantheonsite.io/technical-program AN - OPUS4-51649 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bennet, Francesca A1 - Burr, L. A1 - Schmid, D. A1 - Hodoroaba, Vasile-Dan T1 - Towards a method for quantitative evaluation of nanoparticles in suspension via Microprinting and SEM analysis N2 - A series of different nanoparticle suspensions (Gold, Latex, and SiO2 in varying concentrations) were microprinted onto TEM grids in a 4 x 4 array in the concentration range 7x10^8 to 1x10^11 NP/mL and imaged with SEM and TSEM. Concentrations and printing conditions (temperature, relative humidity) were varied in order to minimize the coffee ring effect. T2 - nanoSAFE 2020 CY - Online meeting DA - 16.11.2020 KW - Nanoparticles KW - Microprinting KW - Image analysis PY - 2020 AN - OPUS4-51699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lüth, Peter A1 - Frost, K. A1 - Kurth, Lutz A1 - Malow, Marcus A1 - Schmidt, Martin A1 - Michael-Schulz, Heike A1 - Uhlig, S. A1 - Zakel, S. T1 - CEQAT-DGHS Ringversuchsprogramm für die Chemikaliensicherheit - Schlussfolgerungen N2 - Die Ursachen für Chemikalienunfälle können vielfältig sein. Prävention beginnt bereits im Prüflabor, wenn Chemikalien auf ihre gefährlichen Eigenschaften getestet werden. Dazu sind Prüfmethoden entwickelt und veröffentlicht worden, die heute weltweit Anwendung finden. Auf die Validität der Prüfmethode und richtige Durchführung der Prüfung im Laboratorium müssen sich Sicherheitsfachkräfte, Transporteure oder Händler verlassen können. Anhand der in den letzten 10 Jahren im Rahmen des CEQAT-DGHS von BAM und PTB durchgeführten Ringversuche (RV) wird gezeigt, dass bei allen bisher untersuchten Prüfmethoden ein Verbesserungsbedarf besteht. Die RV müssen daher zunächst auf die Methodenverbesserung und -validierung abzielen und nicht auf Leistungstests. Das Labormanagement und die praktische Durchführung der Prüfung sind in vielen Laboratorien verbesserungsbedürftig. Der Begriff „Erfahrung der Prüfer“ ist kritisch zu sehen: Eine „lange Erfahrung mit vielen Prüfungen“ ist nicht unbedingt ein Garant für richtige Ergebnisse. T2 - 15. BAM-PTB-Kolloquium zur chemischen und physikalischen Sicherheitstechnik CY - Braunschweig, Germany DA - 21.05.2019 KW - Gefahrgut KW - Gefahrstoff KW - Ringversuch KW - Prüfmethode KW - Validierung KW - Qualitätssicherung PY - 2019 AN - OPUS4-49486 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schaupp, Thomas A1 - Yahyaoui, Hamza A1 - Schröder, Nina A1 - Kannengießer, Thomas T1 - Kaltrissprüfung hochfester Feinkornbaustähle beim Schweißen mit modifiziertem Sprühlichtbogen N2 - Sind in Stahlkonstruktionen hohe Tragfähigkeiten bei geringem Eigengewicht gefordert, finden hochfeste Feinkornbaustähle mit Streckgrenzen ≥ 960 MPa Anwendung. In der Vergangenheit wurde der konventionelle Übergangslichtbogen (Konv. LB) zur schweißtechnischen Fertigung von hochfesten Stählen eingesetzt. In den letzten Jahren wurde der modifizierte Sprühlichtbogen (Mod. SLB) entwickelt, welcher reduzierte Nahtöffnungswinkel bei erhöhter Abschmelzleistung ermöglicht. Jedoch treten höhere Wasserstoffkonzentrationen verbunden mit Mikro-(Kalt-)rissen unter reduziertem Nahtöffnungswinkel mit Mod. SLB auf. In diesem Beitrag wird die Kaltrissempfindlichkeit des hochfesten Feinkornbaustahles S960QL mit artgleichem Schweißzusatzwerkstoff untersucht. T2 - Tagung Werkstoffprüfung CY - Neu-Ulm, Germany DA - 03.12.2019 KW - Hochfester Feinkornbaustahl KW - Kaltrissprüfung KW - TEKKEN-Test KW - Implant-Test KW - Eigenspannungen PY - 2019 AN - OPUS4-49925 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Bär, Sylke A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Puskar, L. A1 - Schade, U. T1 - Photolytically and Thermally Initiated Destruction N2 - Casks for storage and transportation of used fuel rods of radioactive material are equipped with polyethylene (PE) for improved neutron flux shielding. The embedded PE structures are additionally exposed to gamma radiation and heat flow due to the specific high activity of the fission products. 60Co γ-radiation and heat load experiments at 125°C has been performed to evaluate PE degradation during the ageing process. FAR-FTIR-experiments were subsequently performed at differently aged PE test samples to characterize the oxidation process and morphological changes in the samples during the ageing at 125°C. T2 - 11'th Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 04.12.2019 KW - FTIR KW - High Molecular Polyethylene KW - Ageing PY - 2019 AN - OPUS4-49988 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Backes, Sebastian A1 - Fahrbach, M. A1 - Cappella, Brunero A1 - Peiner, E. T1 - Scanning characterization of polymer coating layers using contact resonance with piezoresistive microprobes N2 - The motivation and the measurement setup for large fast-scanning piezoresistive cantilevers are presented. The theory behind the measurements of mechanical properties through contact resonance is explained. Results of such measurements on two kinds of polymer are compared to results from force distance curves. Noise, time-dependency and dependency of the results on the vibration mode are identified as challenges of contact resonance. T2 - 19th International Conference and Exhibition (European Society for Precision engineering and Nanotechnology/EUSPEN) CY - Bilbao, Spain DA - 03.06.2019 KW - Force distance curves KW - Contact resonance KW - Lubricants KW - Photoresist PY - 2019 AN - OPUS4-49903 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meierhofer, F. A1 - Dissinger, F. A1 - Weigert, Florian A1 - Resch-Genger, Ute A1 - Waldvogel, S. R. A1 - Voss, T. T1 - Citric-Acid-Based Carbon Dots with Luminescence Quantum Yields > 50%: spectral tuning of the luminescence by ligand exchange and pH adjustment N2 - We report the synthesis and characterization of carbon nanodots (CDs) with high quantum yield (>50%) and tailored optical absorption as well as emission properties. A well-described protocol with polyethyleneimine (PEI) as amine precursor is used as a reference to a new CD system which is stabilized by aromatic 2,3-diaminopyridine (DAP) molecules instead. The DAP stabilizer is installed in order to red-shift the absorption peak of the n-π* electron transition allowing efficient radiative recombination and light emission. Size, shape, and chemical composition of the samples are determined by (HR)TEM, EDX and FTIR-spectroscopy. Optical parameters are investigated using UV-VIS, PL and QY measurements. Several parameters such as concentration, excitation wavelength and pH are studied. Zeta-potential analysis indicate that pH-induced (de-)protonation processes of functional moieties directly affect the n-π* energy bands. This results in unique pH-dependent absorption and emission characteristics which are discussed on the specific chemical composition of each CD system. T2 - MRS 2019 CY - Boston, MA, USA DA - 03.12.2019 KW - Nanoparticle KW - Carbon dot KW - Surface chemistry KW - Fluorescence KW - PH KW - Ligand KW - FTIR KW - Synthesis KW - Characterization PY - 2019 AN - OPUS4-49968 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bakir, Nasim A1 - Üstündag, Ömer A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Numerical and Experimental Observation of the melt pool behaviour for laser beam welded thick plates in partial penetration mode N2 - The geometry of the melt pool in laser beam welding plays a major role to understand the dynamics of the melt and its solidification behavior. In this study, a butt configuration of 20 mm thick structural steel and transparent quartz glass was used to observe the weld pool geometry in the partial penetration mode by means of a high-speed camera. The observations show that the dimensions of the weld pool vary depending on the depth. The areas close to the weld pool surface take a teardrop-shape. A bulge-region and its temporal evolution were observed approximately in the weld pool root. Additionally, a 3D transient thermal-fluid numerical simulation was performed to obtain the weld pool shape and to understand the formation mechanism of the observed bulging effect. The model considers the local temperature field, the effects of phase transition, thermo-capillary convection, natural convection and temperature-dependent material properties. The numerical results showed good accordance and were furthermore used to improve the understanding of the experimentally observed bulging effect. T2 - 5th International Symposium on Visualization in Joining & Welding Science through Advanced Measurements and Simulation CY - Osaka, Japan DA - 21.11.2019 KW - Partial penetration KW - Laser beam welding KW - Melt pool behaviour PY - 2019 AN - OPUS4-49896 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten T1 - Radiographic Simulator aRTist - Computer simulation for industrial Tomography N2 - aRTist is an easy-to-use and practical simulation tool to generate realistic radiographic images from CAD objects. A dedicated add-on module makes CT simulation easy (virtual computer tomography). Just choose the number of projections. Unlike in the practice, simulation can separately image the primary and scatter radiation. This allows studying the scattering artefacts in CT (gray-level variations in regions of homogeneous material). T2 - 5. Jenaer μCT-Workshop CY - Jena, Germany DA - 20.11.2019 KW - Vitual computer tomography simulation PY - 2019 AN - OPUS4-49826 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lüth, Peter A1 - Frost, K. A1 - Kurth, Lutz A1 - Malow, Marcus A1 - Michael-Schulz, Heike A1 - Schmidt, Martin A1 - Uhlig, S. A1 - Zakel, S. T1 - CEQAT-DGHS Interlaboratory tests for method validation and measurement uncertainty determination N2 - An explosion in a chemical plant or a fire on a dangerous goods vessel - the reason for such accidents can be numerous. Prevention starts in the laboratory where chemicals are tested for their hazardous properties in order to be able to assess the risks involved in their handling. For this purpose, test methods have been developed and published. They are applied globally nowadays. Safety experts, manufacturers, suppliers, importers, employers or consumers must be able to rely on the validity of safety-related test methods and on correct test results and assessments in the laboratory. Interlaboratory tests play a decisive role in assessing the reliability of test results. Participation in interlaboratory tests is not only a crucial element of the quality assurance of laboratories; as such it is explicitly recommended in DIN EN ISO/IEC 17025. In addition, interlaboratory tests are also used to develop and validate test methods and can be used for the determination of the measurement uncertainty. Interlaboratory tests on different test methods have been performed by Bundesanstalt für Materialforschung und –prüfung (BAM) and Physikalisch-Technische Bundesanstalt (PTB) in collaboration with the QuoData GmbH during the last 10 years. Significant differences between the results of the participating laboratories were observed in all interlaboratory tests. The deviations of the test results were not caused only by laboratory faults but also by deficiencies of the test method (see interlaboratory test reports of the CEQAT-DGHS Centre for quality assurance for testing of dangerous goods and hazardous substances: www.ceqat-dghs.bam.de). In view of the interlaboratory test results the following conclusions can be drawn: • To avoid any discrepancy on classification and labelling of chemicals it should become state of the art to use validated test methods and the results accompanied by the measurement uncertainty. • A need for improvement is demonstrated for all examined test methods. Thus, interlaboratory tests shall initially aim at the development, improvement and validation of the test methods (including the determination of the measurement uncertainty) and not on proficiency tests. • The laboratory management and the practical execution of the tests need to be improved in many laboratories. • The term "experience of the examiner" must be seen critically: A "long experience with many tests" is not necessarily a guarantee for correct results. T2 - Eurachem International Workshop Uncertainty from sampling and analysis for accredited laboratories CY - Berlin, Germany DA - 19.11.2019 KW - Gefahrgut KW - Gefahrstoff KW - Ringversuch KW - Prüfmethode KW - Validierung KW - Qualitätssicherung KW - Messunsicherheit KW - Dangerous goods KW - Hazardous substances KW - Interlaboratory comparison KW - Quality assurance KW - Round robin test KW - Test method KW - Validation KW - Measurement uncertainty PY - 2019 UR - https://www.eurachem.org/index.php/events/completed/277-wks-mu2019#posters AN - OPUS4-49832 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Hartrott, P. A1 - Rockenhäuser, Christian A1 - Metzger, M. A1 - Skrotzki, Birgit T1 - Assessment of EN AW-2618A for high temperature applications considering aging effects N2 - The alloy EN AW-2618A was assessed regarding its properties for high temperature applications considering aging effects. T2 - BAM TMF-Workshop 2019 CY - Berlin, Germany DA - 13.11.2019 KW - Alloy 2618A KW - Degradation KW - Coarsening KW - Transmission electron microscopy KW - Dark-field transmission electron microscopy (DFTEM) PY - 2019 AN - OPUS4-49808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Das, Chayanika A1 - Witt, Julia A1 - Kastanias, Eleni A1 - Özcan Sandikcioglu, Özlem T1 - Graphene-polymer nanocomposite coatings for corrosion protection of Mg-alloys N2 - Mg is a very promising material for lightweight construction and biomedical applications. However, the applicability of Mg and its alloys is hindered by its high corrosion susceptibility. Moreover, due to the toxicity of most inorganic conversion coating systems, the development of novel pre-treatment strategies for technical alloys are of vital importance. The aim of this study is to develop polymeric bilayer thin films for corrosion protection of Mg-alloys. As polymer matrix, poly(4-vinyl pyridine) (P4VP) was selected due to its semiconducting properties and protonic conductivity. In contrast to ICPs with electronic conductivity, the pH-dependant, reversible protonation/de-protonation capability of the P4VP has been utilized to synthesize environment-responsive coatings. Polyacrylicacid (PAA) was tested as crosslinking layers to improve interfacial interactions between the polymeric layers. The macroscopic corrosion properties of the bilayer coatings were investigated by means of electrochemical methods such as linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in corrosive media simulating technical and biomedical applications. The presentation summarizes our recent results on the synthesis and characterization of this novel coating system with a special focus on their interfacial stability and corrosion protection properties. T2 - E-MRS 2019 Spring Meeting CY - Nice, France DA - 27.05.2019 KW - Polymer bilayer coatings KW - Graphene polymer nanocomposite KW - Corrosion inhibition KW - Magnesium alloy PY - 2019 AN - OPUS4-49848 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Das, Chayanika A1 - Witt, Julia A1 - Kastanias, Eleni A1 - Özcan Sandikcioglu, Özlem T1 - Graphene polymer nanocomposite coatings for corrosion inhibition of mg alloys N2 - Mg is a very promising material for lightweight construction and biomedical applications. However, the applicability of Mg and its alloys is hindered by its high corrosion susceptibility. Moreover, due to the toxicity of most inorganic conversion coating systems, the development of novel pre-treatment strategies for technical alloys are of vital importance. Recently, the application of intrinsically conducting polymers (ICPs) have been introduced as an alternative approach for corrosion protection of Mg alloys. ICPs with electronic conductivity are known to be able to passivate small defects, however they fail in the presence of large defects due to fast coating reduction and increased cation transport if macroscopically extended percolation networks exist. The aim of this study is to develop graphene-polymer nanocomposite thin films for corrosion protection of Mg-alloys. As polymer matrix, poly(4-vinyl pyridine) (P4VP) was selected due to its semiconducting properties and protonic conductivity. In contrast to ICPs with electronic conductivity, the pH-dependant, reversible protonation/de-protonation capability of the P4VP has been utilized to synthesize environment-responsive coatings. The presentation summarizes our recent results on the synthesis and characterization of this novel coating system with a special focus on their interfacial stability and corrosion protection properties. T2 - Eurocorr 2019 CY - Seville, Spain DA - 09.09.2019 KW - Polymer bilayer coatings KW - Ggraphene polymer nanocomposite KW - Corrosion inhibition KW - Magnesium alloy PY - 2019 AN - OPUS4-49849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sprengel, Maximilian A1 - Kromm, Arne A1 - Evans, Alexander A1 - Bruno, Giovanni A1 - Kannengießer, Thomas T1 - Heat treatment induced residual stress relaxation in additively manufactured L-PBF 316L stainless steel N2 - Residual stress relaxation as a function of heat treatment strategies in laser based powder bed fused 316l samples. T2 - Eleventh Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 04.12.2019 KW - Additive Manufacturing KW - Residual Stress KW - Neutron Diffraction KW - 316L PY - 2019 AN - OPUS4-49851 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Bernd R. A1 - Mack, D.E. A1 - Laquai, René A1 - Helle, O. A1 - Sebold, D. A1 - Vaßen, R. A1 - Bruno, Giovanni T1 - Evolution of porosity, crack density, and CMAS penetration in thermal barrier coatings subjected to burner rig testing N2 - Degradation of thermal barrier coatings (TBCs) in gas‐turbine engines due to calcium–magnesium–aluminosilicate (CMAS) glassy deposits from various sources has been a persistent issue since many years. In this study, state of the art electron microscopy was correlated with X‐ray refraction techniques to elucidate the intrusion of CMAS into the porous structure of atmospheric plasma sprayed (APS) TBCs and the formation and growth of cracks under thermal cycling in a burner rig. Results indicate that the sparse nature of the infiltration as well as kinetics in the burner rig are majorly influenced by the wetting behavior of the CMAS. Despite the obvious attack of CMAS on grain boundaries, the interaction of yttria‐stabilized zirconia (YSZ) with intruded CMAS has no immediate impact on structure and density of internal surfaces. At a later stage the formation of horizontal cracks is observed in a wider zone of the TBC layer. T2 - Eleventh Joint BER II and BESSY II User Meeting CY - Wilhelm-Conrad-Roentgen-Campus, Berlin-Adlershof, Germany DA - 04.12.2019 KW - Characterization KW - CMAS KW - Synchrotron X-ray refraction radiography KW - Thermal arrier coatings PY - 2019 AN - OPUS4-49857 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina A1 - Müller, Ralf A1 - Balzer, R. A1 - Kiefer, P. A1 - Reinsch, Stefan A1 - Behrens, H. A1 - Deubener, J. T1 - Subcritical crack growth in hydrous soda-lime silicate glass N2 - Glass strength and fatigue is limited by surface cracks. As subcritical crack growth (SCCG) is governed by ambient humidity, stress corrosion at the crack tip is widely accepted to be the underlying mechanism. However, as water is known to have decisive effect on glass properties and can rapidly enter the crack tip near glass region, SCCG could be affected by such water related phenomena. We tried to mimic these effects studying water dissolution and speciation, mechanical properties, and SCCG in water-bearing glasses. For this purpose, glasses up to 8 wt% water have been prepared by means of high-pressure melting of glass powder - water mixtures. As part of this effort, SCCG in dry and hydrous commercial micros¬cope slide glass (CW = 6 wt%) was studied in double cantilever beam (DCB) geometry and sub-Tg relaxation was measured by Dynamic Mechanical Analysis (DMA). For SCCG in ambient air (24% r.h.), SCCG was promoted by the presence of 6wt% bulk water with respect to the dry glass. On the other hand, stress intensity values, KI, required to cause slow crack growth (v < 10-6 ms-1) resemble literature findings for float glass of similar composition in liquid water, which might represent the maximum possible promoting effect of ambient water on SCCG. For SCCG in vacuum (10-3 mbar), dissolved bulk water causes even more pronounced effects. Most strikingly, it strongly decreases the slope of the log v(KI)-curve, which is a measure of dissipated energy during fracture. A strong increase of sub-Tg relaxation with increasing water content was confirmed by DMA. As a consequence, slow crack growth occurs at KI values as measured in the dry glass whereas fast crack growth occurs at much larger KI than that of the dry glass. Kinks and shoulders shown by the inert log v(KI)-curve indicate that bulk water does not simply affect bulk mechanical properties. T2 - 9th Otto Schott Colloquium CY - Jena, Germany DA - 09.09.2019 KW - Internal friction KW - Soda-lime silicate glass KW - Crack growth KW - Water content KW - DCB PY - 2019 AN - OPUS4-49534 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rühle, Bastian A1 - Nirmalananthan-Budau, Nithiya A1 - Roloff, Alexander A1 - Resch-Genger, Ute T1 - Surface Functional Group Quantification on Micro- and Nanoparticles N2 - Organic and inorganic micro- and nanoparticles are increasingly used as drug carriers, fluorescent sensors, and multimodal labels in the life and material sciences. Typically, these applications require further functionalization of the particles with, e.g., antifouling ligands, targeting bioligands, stimuli-responjsive caps, or sensor molecules. Besides serving as an anchor point for subsequent functionalization, the surface chemistry of these particles also fundamentally influences their interaction with the surrounding medium and can have a significant effect on colloidal stability, particle uptake, biodistribution, and particle toxicity in biological systems. Moreover, functional groups enable size control and tuning of the surface during the synthesis of particle systems. For these reasons, a precise knowledge of the chemical nature, the total number of surface groups, and the number of groups on the particle surface that are accessible for further functionalization is highly important. In this contribution, we will will discuss the advantages and limitiations of different approaches to quantify the amount of commonly used surface functional groups such as amino,[1,2] carboxy,[1,2] and aldehyde groups.[3] Preferably, the quantification is carried out using sensitive and fast photometric or fluorometric assays, which can be read out with simple, inexpensive instrumentation and can be validated by complimentary analytic techniques such as ICP-OES and quantitative NMR. T2 - NANAX Hamburg CY - Hamburg, Germany DA - 16.09.2019 KW - Microparticles KW - Nanoparticles KW - Quantitative Analysis KW - Surface KW - Funtional Groups PY - 2019 AN - OPUS4-49616 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gräf, S. A1 - Kunz, C. A1 - Büttner, T.N. A1 - Naumann, B. A1 - Boehm, A.V. A1 - Gnecco, E. A1 - Bonse, Jörn A1 - Neumann, C. A1 - Turchanin, A. A1 - Müller, F.A. T1 - Large-area fabrication of low- and high-spatial-frequency laser-induced periodic surface structures on carbon fibers N2 - The properties of fiber-reinforced polymers (CFRP) or concretes (ECC) strongly depend on the interface between the fiber and the surrounding matrix. Different methods such as plasma oxidation, chemical or electrolytic etching and chemical vapor deposition have been investigated to increase, for example, the bonding strength. The present study deals with the functionalization of the fiber surface based on laser-induced periodic surface structures (LIPSS). They can be characterized as a modulation of the surface topography on the nano- and microscale that results from the irradiation of the surface with linearly polarized laser radiation close to the ablation threshold. According to their spatial period, LIPSS are classified into low-spatial frequency LIPSS (LSFL) and high-spatial frequency LIPSS (HSFL). The great potential of both types of LIPSS structures regarding functional surface properties was demonstrated in numerous investigations. The objective of the present study was the homogenous manufacturing of both types of LIPSS on large areas of carbon fiber arrangements without damage. The results are discussed based on a detailed analysis of the topographic and chemical surface properties. T2 - 15th International Conference on Laser Ablation (COLA 2019) CY - Hawaii, USA DA - 08.09.2019 KW - Laser-induced periodic surface structures (LIPSS) KW - Carbon fibers KW - Femtosecond laser ablation KW - Surface functionalization PY - 2019 AN - OPUS4-49676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska T1 - Acoustic Emission Monitoring of materials, production processes, infrastructures N2 - Acoustic Emission testing is a usable tool for failure Analysis of materials as well as to monitor infrastructurs or production processes. T2 - 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures CY - Potsdam, Germany DA - 27.08.2019 KW - Acoustic Emission (AE) KW - Laser Metal Deposition (LMD) KW - Pipeline KW - NDT Monitoring PY - 2019 AN - OPUS4-49696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Würth, Christian A1 - Radunz, Sebastian A1 - Frenzel, Florian A1 - Resch-Genger, Ute T1 - Understanding Nucleation and Optical Properties of Upconverting Nanoparticles N2 - Non-linear optical emitters are promising materials for energy applications and biotechnologies. Solid-state multi-band emitters like lanthanide doped up-conversion nanoparticles (UCNPs) show excellent photostability, are excitable in the near infrared (NIR), and show emission bands from the UV to SWIR spectral regions. The optical properties of these materials strongly depend on the excitation power density, i.e., the number of photons absorbed per time interval. The upconversion (ΦUC) and downshifting quantum efficiencies (ΦDS) of these materials, the excitation power dependent population, and the deactivation dynamics are influenced by nanoparticle architecture, doping concentration, and the microenvironment. We studied the fundamental changes of the luminescence properties of ß-NaYF4 UCNPs doped with Yb3+ and Er3+ depending on size, different surroundings such as aqueous and organic media, and different surface chemistries. We obtained further insights into shelling procedures, FRET optimization, influence of doping concentration, and advantages of different sensitizer ions. T2 - NaNaX CY - Hamburg, Germany DA - 16.09.2019 KW - UpConversion KW - Optical properties KW - Nanoparticle KW - Nanomaterial PY - 2019 AN - OPUS4-49700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja T1 - Possibilities on prediction of plastic’s fragmentation time - Digital twins for decomposing-time predictions N2 - Depending on the specific plastic’s ageing sensitivities, the durations which plastic components remain in the environment can be very long. As, in the past, the advantages in ageing resistance and durability were highly evaluated, we now face the problem of quite stable plastic waste within the environment. However, there is only little knowledge on the real timescales until macroscopic fragmentation for the different kinds of plastic under various environmental conditions. Here, weathering methods are presented, which have been used for the failure prediction in specific outdoor conditions. Issues of uncertainty, reproducibility, or validation are discussed. For the prediction of the plastic’s fragmentation, much longer time scales have to be considered. To do this within a limited project life span, various processes as well as their acceleration potential have to be evaluated separately, such as temperature increase or spectral shift. The possibilities and limitations of such controlled acceleration will be discussed. T2 - 29th IAPRI Symposium on Packaging CY - Twente, Enschede, The Netherlands DA - 11.06.2019 KW - Plastic KW - Ageing KW - Environment KW - Fragmentation KW - Digital twin PY - 2019 AN - OPUS4-49714 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hübner, Oskar A1 - Resch-Genger, Ute T1 - Spectral and Lifetime Encoding of Polymer Particles with Cd-free Ternary Semiconductor Nanocrystals for Flow Cytometry with Time Resolved Fluorescence Detection N2 - Multiplexed encoding schemes of nano- and micrometer sized particles with fluorescent dyes or quantum dots (QDs) and their optical detection, are of increasing interest for applications in the life sciences, for example in flow cytometry. Almost all strategies utilizing fluorescence focus on spectrally distinguishable emission bands or colors and different intensity levels as fluorescence codes. The fluorescence parameter lifetime has been, however, barely exploited. In this work the goal is to perform multiplexing with encoding fluorophores with different fluorescence lifetimes (LTs). In comparison to the spectral multiplexing strategies this has the advantage, that the different fluorescence LT codes can be measured with the excitation and emission wavelength, thus reducing instrument costs. Moreover, LTs should not depend on emitter concentration. Unlike organic dyes, the LTs of which are typically < 10 ns, the fluorescence LTs of ternary semiconductor QDs that represent a “green” alternative to conventional Cd-containing QDs are in the range of several hundred ns, independent of oxygen concentration, and can be tuned to a certain extent by chemical composition and surface chemistry. This present a time region that can be barely covered by other emitters that have either much shorter or longer lifetimes. In this project, different encoding strategies will be assessed and the encoded particles will be then used for fluorescence assays for the analysis of several targets in parallel. Therefor the encoded particles will be functionalized with different target-specific bioligands and read out with a specifically designed flow cytometer enabling time-resolved fluorescence detection. With this instrument, the particles will be discriminated by their fluorescence LTs In one detection channel while the analytes will be quantified by fluorescence labels in a second channel in the intensity domain. T2 - Bad Honnef Physics School Exciting nanostructures: Characterizing advanced confined systems CY - Bad Honnef, Germany DA - 21.07.2019 KW - Multiplexing KW - Lifetime KW - Bead KW - Flow cytometry KW - Fluorescence KW - Quantum dot KW - InP KW - AIS KW - Dye KW - Encoding KW - Barcoding KW - Assay KW - Method PY - 2019 AN - OPUS4-49723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heckel, Thomas A1 - Bertovic, Marija A1 - Rosenthal, Martina A1 - Pavlovic, M. A1 - Bartsch, L. A1 - Muhs, V. A1 - Holstein, R. T1 - Zuverlässigkeitsbetrachtungen bei der Ultraschallprüfung von Radsatzwellen im Ausbildungsbetrieb N2 - Im Rahmen des UT1 E W im Ausbildungszentrum Wittenberge der DGZfPwurden statistische Untersuchungen am Beispiel der Radsatzwellenprüfung mit Testradsatzwellen durchgeführt. Diese Untersuchungen hatten zum Ziel, die wesentlichen Einflussparameter bei der Handprüfung auf das Prüfergebnis zu evaluieren. Im Rahmen der Zuverlässigkeitsbetrachtung wurden die ProbabilityofDetection(POD) und die Nachweisgrenzen ermittelt.Die durchgeführte Studie zeigt, dass die Bewertung der gesamten Zuverlässigkeit der ZfP komplex ist. Dieses verlangt eine detaillierte Versuchsplanung und die Einbeziehung von unterschiedlichen Faktoren, von den Anwendungsparametern bis hin zu den komplexen menschlichen und organisatorischen Faktoren. Die im Rahmen der Studie ermittelten Ergebnisse lassen aufgrund der geringen Anzahl an Testreflektoren keine allgemeingültige Übertragung auf beliebige Korbbogen-geometrienund Reflektorgeometrienzu. T2 - DGZfP DACH Tagung 2019 CY - Friedrichshafen, Germany DA - 27.05.2019 KW - Ausbildung KW - Wellenprüfung KW - Ultraschall KW - Zuverlässigkeit KW - POD PY - 2019 AN - OPUS4-49683 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Haferkamp, Sebastian A1 - Emmerling, Franziska A1 - Akhmetova, Irina A1 - Kulla, H. A1 - Rademann, K. T1 - Insights into mechanochemical Knoevenagel condensations N2 - Mechanochemistry paves the way to simple, fast, and green syntheses. Despite considerable effort, there is a lack in understanding of the underlying mechanisms. In situ investigations help to understand these mechanisms, which occur during a mechanochemical reaction. Here we present a universal strategy for simultaneous real-time in situ analysis, combining X-ray diffraction, Raman spectroscopy, and thermography. The potential of of our approach is shown for diffrent model reactions. T2 - Adlershofer Forschungsforum 2019 CY - Berlin, Germany DA - 11.11.2019 KW - Mechanochemistry KW - In situ KW - Knoevenagel condensation PY - 2019 AN - OPUS4-49694 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Evsevleev, Sergei A1 - Mishurova, Tatiana A1 - Garces, G. A1 - Sevostianov, I. A1 - Hofmann, M. A1 - Bruno, Giovanni T1 - Micromechanical response of multi-phase Al-alloy matrix composites under uniaxial compression N2 - Aluminum alloys are extensively used in the automotive industry. Particularly, squeeze casting production of Al-Si alloys is employed in the conception of metal matrix composites (MMC) for combustion engines. Such materials are of a high interest since they allow combining improved mechanical properties and reduced weight and hence improve efficiency. Being a multiphase material, most MMCs show complex micromechanical behavior under different load conditions. In this work we investigated the micromechanical behavior of two MMCs, both consisting of a near-eutectic cast AlSi12CuMgNi alloy, one reinforced with 15%vol. Al2O3 short fibers and the other with 7%vol. Al2O3 short fibers + 15%vol. SiC particles. Both MMCs have complex 3D microstructure consisting of four and five phases: Al-alloy matrix, eutectic Si, intermetallics, Al2O3 fibers and SiC particles. The in-situ neutron diffraction compression experiments were carried out on the Stress-Spec beamline and disclosed the evolution of internal phase-specific stresses in both composites. In combination with the damage mechanism revealed by synchrotron X-ray computed tomography (SXCT) on plastically pre-strained samples, this allowed understanding the role of every composite’s phase in the stress partitioning mechanism. Finally, based on the Maxwell scheme, a micromechanical model was utilized. The model perfectly rationalizes the experimental data and predicts the evolution of principal stresses in each phase. T2 - MLZ User Meeting 2020 CY - Online meeting DA - 09.12.2020 KW - Metal matrix composite KW - Neutron diffraction KW - Damage mechanism KW - Load transfer KW - Computed tomography PY - 2020 AN - OPUS4-52032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ciornii, Dmitri A1 - Drobne, D. A1 - Novak, S. A1 - Kranjc, E. A1 - Bohmer, N. A1 - Hodoroaba, Vasile-Dan T1 - Knowledge Readiness Level (KaRL) approach for nanorisk governance and beyond N2 - Regulatory decisions require reliable data and knowledge derived from this. Among stakeholders in nanotechnology, however, there is often uncertainty about the quality of data for regulatory purposes. In addition, the general public often finds itself excluded from nanoregulation and policy decisions. This creates uncertainty in the nanotechnology field and also in other branches of technology and leads to concerns among the society. To address these issues, NANORIGO elaborates a framework to support decision making as well as data, information and knowledge sharing and use. We refer to “reliability” of data and knowledge as a degree of readiness or maturity. According to these criteria we worked out a 9-level scale in analogy to TRL (technology readiness level), the KaRL system (Knowledge, Data and Information Readiness Level). KaRL allows assessment of knowledge readiness for decision making by applying defined quality criteria for each level. It also provides guidance on how to enhance the readiness level by the help of available tools and procedures. KaRL addresses SEIN[1] principles, circular economy and thus involves the public concerns in regulation. A specialized nanorisk governance council (being under development in NANORIGO) is suggested to perform quality check of an actionable document, thus, aiding in consensus on the reliability (maturity) of knowledge for decision making. Moreover, KaRL facilitates traceability of knowledge before its use in decision making. This enables the transparency demanded by all stakeholders. T2 - EuroNanoForum 2021 CY - Online meeting DA - 05.05.2021 KW - Knowledge Readiness Level KW - Nanorisk KW - Nanomaterials KW - Data PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524725 AN - OPUS4-52472 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Voigt, Marieke A1 - von Werder, Julia A1 - Meng, Birgit T1 - Thermally treated UHPC: a durability study N2 - Ultra high performance concrete (UHPC) is known for its high compressive strength of more than 150 MPa and its high durability. Thermal treatment at 90°C can accelerate the strength development so that the 28-days-strength can be achieved immediately after the treatment and an additional increase up to 30 % in some cases. The reason for the strength development is an accelerated hydration of the clinker minerals and an intensified pozzolanic reaction leading to a denser microstructure. In previous research inhomogeneities in form of a zonation after unprotected thermal treatment were observed and analysed in respect to changes in the microstructure. This zonation is defined by a different microstructure in the core compared to the outer zone in the matter of porosity, mineral phase composition and a significant change in the potassium and sulphur concentration of the zones is measurable. To isolate different transport mechanisms responsible for these element distributions UHPC samples were thermally treated at 90 °C and the microstructure was investigated under dry conditions and after immersion in water to investigate the influence of dehydration during and rehydration after the thermal treatment on the microstructure. Through durability testing via water absorption, water vapour diffusion, permeability testing and sulfuric acid resistance transport mechanisms like diffusion, migration, capillary suction are under investigation in correlation with the microstructure analysis. For the microstructure analysis measurements with µXRF, mercury intrusion porosity, XRD and SEM were conducted. T2 - HiPerMat 2020 CY - Kassel, Germany DA - 11.03.2020 KW - UHPC KW - Thermal treatment KW - Zonation KW - Transport mechanism KW - Durability PY - 2020 AN - OPUS4-52372 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Höhne, Patrick A1 - Kuchenbecker, Petra A1 - Lindemann, Franziska A1 - Güther, Wolfgang A1 - Rabe, Torsten T1 - Utilization of an ultra sound atomizer for spray granulation of oxide ceramic fine powder N2 - Spray drying based granulation processes aim for flowable granules neither containing voids nor hard shells thus leading to a homogenous microstructure in the green and sinter bodies without strength reducing large pores. The increase of the specific surface area due to the utilization of finer powders as raw materials makes the production of granules of demanded quality more sophisticated. Innovations regarding additives as well as process engineering are therefore required. While conventional spray granulation processes of ceramic materials are based on rotational, one stream or two stream nozzles for nebulization, the investigations in the ZIM project concentrate on the applicability of an ultra sound atomizer unit. A spray dryer comprised of the aforementioned ultra sound atomization unit implemented in a commercial spray dryer (Niro, Denmark) was used as test system. Potential advantages of the ultra sound nebulization are investigated for model systems of alumina, zirconia and a ZTA composite while focusing on solids content, yield, pressability and granule properties (size, size distribution, flowability, shape and microstructure) as well as the final sinter body properties (density, microstructure and flexural strength). First ultra sound spray drying experiments yielded granules with excellent processability. Spray drying of identical slurries, as before tested and optimized for a two stream nozzle atomization process, resulted in a more suitable size distribution for dry pressing (less particles below 20 µm) and a higher yield. Furthermore, sinter bodies produced of ultra sound granules seem to have less large pores and a more homogenous microstructure T2 - 92. Jahrestagung der deutschen keramischen Gesellschaft CY - Berlin, Germany DA - 20.03.2017 KW - Ceramics KW - Spray drying KW - Ultra sound KW - Atomization KW - Microstructure PY - 2017 AN - OPUS4-39588 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Otremba, Frank A1 - Sklorz, Christian T1 - Testing of pressurized vessels N2 - The results are based on data1. Figure 3 displays temperatures of the tank wall and of the gas phase over testing time. It can be seen that a complete coating strongly delayed the heating of tank wall and gas phase, whereas the partly coated tanks only had a minor influence on temperature development. There was no significant difference between a half coated and a thirdly coated tank measurable. Figure 4 shows the internal pressure of tanks over testing time. Only the fully coated tank enabled a low pressure over 90 min testing time. Hence, a complete coating is necessary to guarantee the fire safety of hazmat tanks and a partly coating is not sufficient. T2 - Annual Conference on Engineering and Information Technology CY - Nagoya - Japan DA - 29.03.2017 KW - Fire KW - Testing KW - Vessels KW - Dangerous goods PY - 2017 AN - OPUS4-39843 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Tschiche, Harald Rune A1 - Resch-Genger, Ute T1 - Fluorescence microscopic and spectroscopic monitoring of degradation processes upon polymer ageing N2 - The majority of all routinely used methods to assess polymer aging are based on destructive tests and methods. Early indicators for the deterioration of polymer materials are e.g., physical or mechanical properties like tensile strength, adhesion, brittleness, and color. It is well-known, however, that predominantly chemical changes are the underlying process of the physical changes that occur in organic materials upon aging over time. Typical initial steps during polymer degradation are crosslinking or chain breaking, alteration of autofluorescence, “yellowing” or bleaching caused by the formation of new functional groups. A straightforward strategy towards the sensitive detection and monitoring of chemical changes in the course of polymer aging is based on non-destructive optical measurements. Luminescence techniques, one of the most sensitive spectroscopic methods are the method of choice. Here, we present first results of luminescence-based monitoring of polymer degradation induced by different environmentally relevant weathering factors (e.g. humidity and UV exposure). Our studies include fluorescence spectroscopy as well as spectral scanning confocal fluorescence microscopy and clearly demonstrate the possibility to follow accelerate-aging processes by luminescence detection. T2 - Focus on Microscopy 2017 CY - Bordeaux, France DA - 09.04.2017 KW - Polymer aging KW - Confocal fluorescence microscopy KW - Fluorescence spectroscopy KW - Surface functionalities PY - 2017 AN - OPUS4-40274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -