TY - CONF A1 - Sojref, Regine A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Schulz, Wencke A1 - Wollschläger, Nicole A1 - Kranzmann, Axel T1 - Thin and porous sol-gel alumina coatings on a 9% Cr steel as a protection against high-temperature corrosion in power plants N2 - In order to reduce CO2 emissions fossil fuelled power stations with high combustion efficiency are being developed. The increase of the operating temperature, a common way to improve combustion efficiency, leads to enhanced corrosion of heat exchange steel tubes in the power plants. Within the framework of the European project “Production of Coatings for New Efficient and Clean Coal Power Plant Materials” (POEMA)", high temperature corrosion protection coatings are now under investigation. Thin porous sol-gel alumina films are promising candidate coating materials. Coatings were prepared by applying boehmite sols on grinded steel P92 and subsequent heat treatments at temperatures up to 650 °C. Thus a porous layer of worm-like particles was formed consisting of nano-crystallites and amorphous alumina. A dense interface with satisfying adhesion resulted from diffusion of chromium and iron ions out of the steel into the porous coating. However, the film locally exhibited some cracks caused by steep edges in the grinded steel surface. An appropriate substrate pretreatment should avoid this problem. The protection of the steel relies on the barrier function of the alumina coating and the formation of a dense chromia layer at the steel surface. T2 - ICC6 6th International Congress on Ceramics CY - Dresden, Germany DA - 21.08.2016 KW - High-temperature corrosion KW - Alumina KW - Chromium PY - 2016 AN - OPUS4-38354 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shashev, Yury A1 - Kupsch, Andreas A1 - Lange, A. A1 - Bruno, Giovanni A1 - Müller, Bernd R. A1 - Hentschel, M.P. A1 - Britzke, Ralf T1 - Optimizing visibility of phase gratings for Talbot-Lau X-ray imaging N2 - We investigated the efficiency of phase gratings, i.e., the visibility upon variation of different parameters. Rotating around an axis parallel to the grid lines of the phase grating changes the grating’s shape and thereby the initial distribution of phase shifts. This yields high visibilities for shorter propagation distances than derived from box shapes. Tilting the grating in the scattering plane allows continuous tuning of the grating’s height that corresponds to an ideal phase shift for a particular photon energy. This opens the way for tuning the design energy suitable for the material under investigation. Our study included simulations for monochromatic sources with the sampling procedure for rectangular and triangular phase gratings. T2 - HZB - 8th joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 07.12.16 KW - Phase grating KW - X-ray interferometry KW - X-ray imaging PY - 2016 AN - OPUS4-38823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Ben T1 - Aging of composite pressure cylinder (COD-AGE) N2 - Subject, Aim and methods within the Project COD-AGE. Test methods and condition monitoring for Composite-cylinders T2 - Follow-up Workshop on statistical safety assessment CY - Berlin, Germany DA - 05.10.2016 KW - Aging KW - Composite cylinder KW - Non destructive testing PY - 2016 AN - OPUS4-39087 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Ben A1 - Munzke, Dorit A1 - Schukar, Marcus T1 - Zustandsüberwachung von Composite-Druckgefäßen mit faseroptischer Sensorik N2 - Einsatz der Faseroptik zur Zustandsüberwachung von Composite-Druckgefäßen. Aufbau, Integration, Messergebnisse. T2 - Follow-up Workshop on Statistical Safety Assessment of Composite Cylinders CY - Berlin, Germany DA - 05.10.2016 KW - Faseroptik KW - Zustandsüberwachung KW - Composite-Druckgefäße PY - 2016 AN - OPUS4-39088 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Laquai, René A1 - Müller, Bernd R. A1 - Kupsch, Andreas A1 - Nellesen, J. A1 - Tillmann, W. T1 - Characterizing damage evolution in metal matrix composites with X-ray refraction topography and in situ tensile loading N2 - In this study a metal-matrix-composite with aluminum matrix and Al2O3 particles was investigated with x-ray refraction topography and in-situ tensile loading. It could be observed that after reaching a certain load the specific surface increased steadily. However, the classical radiographs taken for comparison show no damage in the sample. T2 - 8th Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 07.12.2016 KW - X-ray refraction KW - Metal matrix composites KW - In-situ loading KW - Synchrotron PY - 2016 AN - OPUS4-39113 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Bruno, Giovanni A1 - Müller, Bernd R. A1 - Hentschel, Manfred A1 - Britzke, Ralf T1 - Optimizing visibility of phase gratings for Talbot-Lau X-ray imaging N2 - We investigated the efficiency of phase gratings, i.e., the visibility upon variation of different parameters. Rotating around an axis parallel to the grid lines of the phase grating changes the grating’s shape and thereby the initial distribution of phase shifts. This yields high visibilities for shorter propagation distances than derived from box shapes. Tilting the grating in the scattering plane allows continuous tuning of the grating’s height that corresponds to an ideal phase shift for a particular photon energy. This opens the way for tuning the design energy suitable for the material under investigation. Our study included simulations for monochromatic sources with the sampling procedure for rectangular and triangular phase gratings. T2 - User-Meeting CY - Berlin, Germany DA - 8.12.2016 KW - Talbot-Lau interferomerty KW - Phase grating KW - Synchrotron radiation PY - 2016 AN - OPUS4-39096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Munzke, Dorit A1 - Becker, Ben A1 - Schukar, Macus T1 - Zustandsüberwachung von Composite-Druckgefäßen mit faseroptischer Sensorik N2 - Funktionsweise, Integration und Messergebnisse von opt. Fasern zur Zustandsüberwachung von Composite-Druckgefäßen. T2 - 3. Workshop Themenfeld Material CY - Berlin, Germany DA - 12.10.2016 KW - Faseroptik KW - Zustandsüberwachung KW - Composite-Druckgefäße PY - 2016 AN - OPUS4-39097 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Armatys, Kamila A1 - Adamczyk, Burkart A1 - Adam, Christian A1 - Galetz, M.C. A1 - Pflumm, R. T1 - Corrosion and abrasion resistant protective coatings for biomass combustion N2 - One of the alternative renewable fuels is biomass but it is a difficult fuel because of its diversity and complexity. It can contain high percentages of K and Cl responsible for corrosion together with sand that have additionally an abrasive effect during combustion. Because of permanently extending the surface reaction due to abrasion the corrosion of the materials increases. In particular in power plants, the superheater tubes are exposed to a corrosive abrasive attack that is one of the main sources of concern. The development of new alloys for multilayer surface, which combines corrosive and abrasive resistance is therefore of high importance. Those new technical approaches must be at the same time cost-effective to be an alternative to conventional materials. The aim of the presented investigation methods is to test and develop suitable alloys for coatings for the super heater tubes of biomass power plants. First results of abrasion investigations show improved abrasion resistance compared to the multi-component reference material Alloy 625. T2 - Young Researchers Conference: Energy Efficiency & Biomass CY - Wels, Austria DA - 24.02.2016 KW - Coatings KW - Corrosion PY - 2016 AN - OPUS4-35713 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Harald Rune A1 - Hoffmann, Katrin A1 - Schwibbert, Karin A1 - Sameith, Janin A1 - Toepel, Jörg A1 - Resch-Genger, Ute T1 - Imaging of local pH in biofilm using polymeric sensors: towards the elucidation of microbial induced corrosion N2 - Microbial induced corrosion (MIC) is a crucial problem in many technical plants as well as fuel tanks, leading to considerable damage and huge financial losses. Successful prevention of MIC requires the localization of first signs of corrosion as well as the identification of factors influencing the corrosion process. In this respect, also the determination of corrosion rates can be of interest for the possible prevention of MIC. Hence, there is a growing need for sensitive and preferably inexpensive tools that enable the early detection of MIC. Of special interest are methods, which provide spatially and time-resolved information and allow the study of changes on metal surfaces as prerequisites for a more detailed analysis of ongoing corrosion processes at a MIC-affected site. Biofilm formation can lead to changes in pH, oxygen and chloride concentration as well as to the release of certain metal ions like Fe(II) and Mn(II) depending on the type of metal surface involved. Hence, optical methods enabling the detection of these analytes at very low concentration and monitoring of their changes can be used for MIC detection. Here, we propose to utilize polymeric nanosensors for MIC detection via the determination of the local pH value changes in different biofilms. Such nanosensors are known to have several advantages in imaging applications such as intracellular pH measurements including the ease of doping or labeling with a multitude of analyte-responsive and inert dye molecules for the realization of a high analyte sensitivity and ratiometric sensing. Moreover, they can be surface functionalized with target-specific ligands e.g., lectins, for the specific binding to the outer surface of certain types of bacteria. In this respect, different polymer architectures will be studied to identify an optimal candidate in terms of imaging performance in conjunction with several classes of pH-responsive fluorescent dyes like cyanines, aza-BODIPYs, and xanthenes, utilizing different mechanism of signal generation such as photo-induced electron transfer or protonation-induced changes in the spectral position of absorption and emission spectra. T2 - Europtrode CY - Graz, Austria DA - 20.03.2016 KW - Nanosensor KW - Microbial induced corrosion KW - Imaging KW - Nanosensor KW - Mikrobiell induzierte Korrosion KW - Bildgebung PY - 2016 AN - OPUS4-35628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steinborn, Gabriele A1 - Woydt, Mathias A1 - Gemeinert, Marion T1 - Stable aqeous niobium carbide suspensions for production of homogeneous hard materials N2 - Hard materials consist of a hard phase embedded in a metallic binder. In order to achieve high toughness and strength, it is necessary to have a perfect mixing of hard phase and binder, which is mainly achieved by ball milling. Niobium carbide (NbC) has a high potential to substitute tungsten carbide as hard material. The publication presents the development of stable homogeneous and de-agglomerated NbC-dispersions. To prevent agglomeration of the powder, stable suspensions were achieved by surface treatments with the dispersants (PD and HD), which resulted in a charge reversal from a negative to a positive zeta potential. This surface-modified powder guaranteed a stable re-dispersion in the binder suspension. Nickel powder was added as metallic binder. This suspension was suited for 3D-printing. The green samples could be sintered in vacuum or Argon atmosphere. T2 - 91. Jahrestagung der deutschen keramischen Gesellschaft CY - Freiberg, Germany DA - 07.03.2016 KW - Niobium carbide powder KW - Stable suspensions KW - Reduction of agglomerates PY - 2016 AN - OPUS4-35636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Taabache, Soraya A1 - Bertin, Annabelle A1 - Maskos, M. T1 - Microfluidic-Assisted Self-Assembly of Dendritic Amphiphiles N2 - The controlled production of supramolecular aggregates formed by the self-assembly of dendritic amphiphiles is of great interest owing to their potential application in the fields of nanotechnology and nanomedicine. Dendritic amphiphiles as building blocks offer the advantage that their structure and size can be precisely tuned through organic synthesis. This synthetic flexibility enables the fine-tuning of the hydrophobic to hydrophilic ratio of the dendritic segments, which mainly controls the morphology of the self-assembled structures. A promising method for the controlled preparation of supramolecular assemblies is based on the use of micromixers.[5,6] Due to their mixing times in the range of milliseconds at the microscale level, the application of such microfluidic systems benefits from a high mixing efficiency, a low mixing time and a reproducible synthesis compared to conventional batch-based techniques such as the solvent injection method or the film hydration method. Herein, we report on the microfluidic-assisted self-assembly of several dendritic amphiphiles and the impact of the mixing parameters on the self-assembly process. T2 - Makromolekulares Kolloquium 2016 CY - Freiburg im Breisgau, Germany DA - 24.02.2016 KW - Dendritic amphiphiles KW - Self-assembly KW - Dendrimersomes KW - Micromixer KW - Microfluidic PY - 2016 AN - OPUS4-35477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Oesch, Tyler T1 - In-situ CT investigation of pull-out failure for reinforcing bars embedded in conventional and high-performance concretes N2 - The use of high-performance concretes holds great promise for many structural applications. This paper investigates the performance of these materials when used in combination with traditional reinforcing bars. An improved understanding of failure during reinforcing bar pull-out from high-performance concretes is needed in order to better predict the embedment length required to develop full reinforcing bar pull-out strength and the required thickness of reinforcing bar cover for adequate corrosion protection. The cracking structures surrounding the reinforcing bars were analyzed using x-ray computed tomography (CT) in order to determine the stress states causing failure. This was accomplished by conducting in-situ reinforcing bar pull-out experiments during CT scanning. A conventional concrete, a high-strength concrete, and a high-strength fiber reinforced concrete were all tested during the experiments. The results of these experiments showed that the levels of brittleness of the different concrete materials had a major impact on the failure mechanisms that they experienced during reinforcing bar pull-out. It was also clear that the specimen geometry and the casting method had a major impact on fiber orientation. The inclusion of fibers within concrete was also found to significantly improve strength and corrosion protection during reinforcing bar pull-out. T2 - 6th Conference on Industrial Computed Tomography CY - Wels, Austria DA - 09.02.2016 KW - Fiber KW - Reinforcing Bar KW - Computed Tomography KW - In-Situ KW - High-Performance Concrete PY - 2016 AN - OPUS4-35521 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lauer, Franziska A1 - Kneipp, Janina A1 - Weidner, Steffen A1 - Seifert, Stephan T1 - Multivariate statistics applied to MALDI-TOF MS data of pollen samples N2 - Current pollen screening information networks are based on time-consuming, microscopic determination of the genus-specific pollen morphology. Additionally, the given information relies on prediction of plant growth, wind direction and seasonal information. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was introduced for rapid analysis of complex biological samples. MALDI-TOF provides the possibility to measure species-specific mass peak patterns of pollen and offers a powerful tool for investigation of taxonomic relations. Our objective is to develop a fast, reliable, routine method for detecting single pollen grains in pollen mixtures. The obtained spectra are analyzed by multivariate statistics. T2 - 49. Jahrestagung der Deutschen Gesellschaft für Massenspektrometrie CY - Hamburg DA - 28.02.2016 KW - Pollen KW - Datenanalyse KW - Hauptkomponentenanalyse PY - 2016 AN - OPUS4-35523 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fischer, Franziska A1 - Joester, Maike A1 - Rademann, K. A1 - Emmerling, Franziska T1 - Survival of the fittest - Competetive cocrystal reactions in the ball mill N2 - Mechanochemistry is increasingly used for synthesizing various materials including cocrystals and metal organic compounds. Although this synthesis approach offers a fast and pure synthesis in high yields there is a lack in understanding the mechanisms of milling reactions. The driving forces triggering the formation of cocrystals under milling conditions were investigated using a set of multi-component competitive milling reactions. In these reactions, different active pharmaceutical ingredients were ground together with a further compound acting as coformer. The study was based on new cocrystals including the coformer anthranilic acid. The results of the competitive milling reactions indicate that the formation of cocrystals driven by intermolecular recognition are influenced and inhibited by kinetic aspects including the formation of intermediates and the stability of the reactants. T2 - Berliner Chemie Symposium CY - Berlin, Germany DA - 12.04.2016 KW - milling KW - cocrystal KW - mechanochemistry PY - 2016 AN - OPUS4-35862 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Greiser, Sebastian A1 - Sturm, Patrick A1 - Gluth, Gregor A1 - Hunger, M. A1 - Jäger, Christian T1 - 29Si-27Al NMR to verify and distinguish Qn(mAl) sites in zeolites and geopolymers N2 - One-part-geopolymers, produced by addition of water to a mixture of solid silica and sodium alumi-nate, are a less exhaustively studied approach to form geopolymeric binders. Depending on the silica source, the reaction products show significant amounts of zeolite Na-A besides amorphous compounds. Previously, 29Si MAS NMR has been used to analyze the chemical structure of such one-part geopolymers, having crystalline structures and amorphous phases (Q2, Q3, Q4). In this work, pure zeolites and three different one-part-geopolymers cured for 1 day were investigated by 29Si-27Al TRAPDOR NMR. It was used to identify aluminum phases in overlapping silicon sites. Zeolites Na-X (Si/Al=1.4) and Na-Y (Si/Al=2.7) served as model systems to measure the TRAPDOR effect of the structural units Q4(mAl). Both materials show several Q4(mAl) signals, which are all separated by their chemical shifts. The more aluminum surrounds the silicon tetrahedron the higher are the normalized TRAPDOR difference signals (S0/∆S). The intensity ratios between Q4(mAl) to Q4({m-1}Al) of these signals is fixed but vary slightly between both zeolites. These results are transferred to the complex geopolymer structure. T2 - 57th Experimental nuclear magnetic resonance conference CY - Pittsburgh, PA, USA DA - 10.04.2016 KW - NMR KW - 29Si-27Al TRAPDOR MAS KW - Geopolymer KW - One-part formulation KW - Rice husk ash PY - 2016 AN - OPUS4-35864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nguyen, Thi Yen A1 - Bernardes, C. A1 - Minas da Piedade, M. E. A1 - Rademann, K. A1 - Emmerling, Franziska T1 - Direct evidence of polyamorphism in paracetamol N2 - While polymorphism is a common phenomenon in the crystallization processes of organic compounds, polyamorphism has gained importance only recently. Using sophisticated sample environments and applying in situ scattering methods and vibrational spectroscopy, the complete crystallization process of organic compounds from solution can be traced and characterized. Diffuse scattering from amorphous intermediates can be investigated by analyzing the atomic pair Distribution function (PDF) to gain further insights into molecular pre-orientation. The crystallization behavior of Paracetamol was studied exemplarily under defined, surface-free conditions. Based on the choice of the solvent, the formation of different polymorphs is promoted. The thermodynamically stable form I and the metastable orthorhombic form II could be isolated in pure form directly from solution. For both polymorphs, the crystallization from solution proceeds via a distinct amorphous precursor phase. PDF analyses of these different amorphous states indicate a specific pre-orientation of the analyte molecules introduced by the solvent. The resulting crystalline polymorph is already imprinted in these proto-crystalline precursors. Direct experimental evidence for the polyamorphism of paracetamol is provided. T2 - Annual CM1402 crystallize COST meeting CY - Coimbra, Portugal DA - 06.04.2016 KW - Paracetamol KW - Crystallization KW - In situ analysis KW - Active pharmaceutical ingredient (API) PY - 2016 AN - OPUS4-35873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wallau, Wilma A1 - Pirskawetz, Stephan A1 - Meng, Birgit T1 - Alkali-Kieselsäure-Reaktion in Beton - Entwicklung eines Prognoseverfahrens N2 - Zur Vermeidung der schädigenden Alkali-Kieselsäure-Reaktion in Betonbauwerken wird die Alkalireaktivität von Gesteinskörnungen im Vorhinein getestet. Der 60°C-Betonversuch ermöglicht eine vergleichsweise schnelle Einschätzung nach fünf-monatiger Testzeit. Dazu wird die Dehnung von Betonprüfkörpern, die mit der zu testenden Gesteinskörnung hergestellt wurden, manuell alle 28 Tage gemessen. Ein alternatives, an der BAM in den vergangen Jahren entwickeltes Verfahren setzt Dehnungssensoren ein, um kontinuierlich und online zu messen. Die Dehnungskurven sind eine gute Grundlage sowohl für die Prognose vom Expansionsverhalten während des Tests als auch für die Validierung von Expansionsmodellen. T2 - 3. Workshop im Themenfeld Material zu den Schwerpunktthemen "Laufende Projekte und neue Aktivitäten" CY - Berlin, Germany DA - 12.10.2016 KW - Baustoffe KW - Alkali-Kieselsäure-Reaktion PY - 2016 AN - OPUS4-40156 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, Paul A1 - Baumann, O. A1 - Müller, C. A1 - Gottwald, W.-R. A1 - Modersohn, W. T1 - Einfluss der Oberflächennachbearbeitung auf die Korrosionsbeständigkeit von Schweiß-nähten des Duplexstahls 1.4062 N2 - Die Korrosionsbeständigkeit geschweißter Konstruktionen aus nichtrostenden Duplexstählen wird von den Schweißparametern und der Nachbehandlung der Oberflächen bestimmt. Eine etablierte Methode der Schweißnahtnachbehandlung ist das Strahlen der Oberfläche mit Glasperlen. Diese Methode soll aus wirtschaftlichen Gründen durch das Strahlen mit Korund ersetzt werden, welches deutliche Zeit- und Kostenvorteile bietet. Besonders bei der Lochkorrosionsbeständigkeit hat sich das Schleifen mit Korund bereits als nachteilig erwiesen, weshalb diese Umstellung auch beim Stahlen kritisch hinterfragt wird. Daher wurden Probeschweißungen bei der Firma Modersohn hergestellt und mit verschiedenen Oberflächenbearbeitungsmethoden (Glasperlenstrahlen, Korundstrahlen, Beizen, Elektropolieren, Schleifen) nachbehandelt. Diese verschiedenen Oberflächenzustände wurden analytisch (REM, Rauheit) charakterisiert und hinsichtlich ihrer Lochkorrosionsbeständigkeit vergleichend untersucht werden, um die Eignung des Strahlens mit Korund zu beurteilen. T2 - GfKORR-Jahrestagung 'Duplex-Stähle – Nische oder Zukunft ?' CY - Frankfurt/M., Germany DA - 15.11.2016 KW - Korrosionsbeständigkeit KW - Schweißnähte KW - Duplexstahl PY - 2016 AN - OPUS4-39470 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, Paul A1 - Kauss, Norman A1 - Heyn, A. T1 - Einfluss des Schwefelgehalts auf die Korrosionsbeständigkeit des nichtrostenden Stahls 1.4404 N2 - Die Korrosionsbeständigkeit nichtrostender Stähle wird maßgeblich von ihrer chemischen Zusammensetzung bestimmt. Der tendenzielle Einfluss ist für die Hauptlegierungselemente in der wissenschaftlichen Fachliteratur beschrieben. Bei Begleitelement Schwefel gibt es dagegen keine konkreten Untersuchungen die belegen, ab welchem Gehalt mit einer Verringerung der Korrosionsbeständigkeit zu rechnen ist. Im Lichtbogenschmelzofen wurden verschiedene Legierungen mit abgestuftem Schwefelgehalten hergestellt, um den Einfluss dieses Begleitelementes auf die Korrosionsbeständigkeit systematisch zu untersuchen. Die KorroPad-Prüfung und die Bestimmung kritischer Lochkorrosionspotentiale wurden zur Charakterisierung der Legierungen genutzt. Beide Methoden belegen eine zunehmende Verringerung der Lochkorrosionsbeständigkeit mit dem Schwefelgehalt. T2 - GfKORR-Jahrestagung 'Duplex-Stähle – Nische oder Zukunft ? CY - Frankfurt/M., Germany DA - 15.11.2016 KW - Schwefelgehalt KW - Korrosionsbeständigkeit KW - Nichtrostender Stahl PY - 2016 AN - OPUS4-39472 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, C. A1 - Rosemann, Paul A1 - Diehl, V. A1 - Halle, T. T1 - Einfluss der Abkühlgeschwindigkeit auf die Korrosionsbeständigkeit martensitischer nichtrostender Stähle N2 - Martensitische nichtrostende Stähle werden in verschiedenen technischen Bereichen eingesetzt, bei denen eine optimale Kombination aus hoher mechanischer Festigkeit und guter korrosiver Beständigkeit gefordert wird. Beide Eigenschaften werden in der Industrie primär durch die Wärmebehandlung gesteuert. Die Korrosionseigenschaften sind dabei stark von der diffusionsbedingten Bildung und Auflösung von Chromkarbiden abhängig. In vergangenen wissenschaftlichen Arbeiten konnte nachgewiesen werden, dass die Abkühlgeschwindigkeit nach dem Austenitisieren einen großen Einfluss auf die Bildung solcher Karbide hat. Der Einfluss der Abkühlgeschwindigkeit auf die Lochkorrosionsbeständigkeit wurde an den Stählen 1.4108 und 1.4116 systematisch untersucht. Mit Hilfe des Stirnabschreckversuches wurde dabei die Abkühlgeschwindigkeiten variiert und anschließend die Veränderung von Gefüge, Lochkorrosionsbeständigkeit und Härte untersucht. Als Ergebnis konnten kritische Abkühlgeschwindigkeiten ermittelt werden, bei denen eine kritische Verringerung der Korrosionsbeständigkeit einsetzt. T2 - GfKORR-Jahrestagung 'Duplex-Stähle – Nische oder Zukunft ?' CY - Frankfurt/M., Germany DA - 15.11.2016 KW - Korrosionsbeständigkeit KW - Martensitische nichtrostende Stähle KW - Abkühlgeschwindigkeit PY - 2016 AN - OPUS4-39473 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kabelitz, Anke A1 - Dinh, Hoang An A1 - Emmerling, Franziska T1 - Time resolved WAXS studies on the crystallization of Al13 keggin clusters N2 - We report on the in situ investigation of the Al13 sulfate synthesis by WAXS. Al13 sulfates were crystallized by precipitating hydrolyzed aluminum solutions by the addition of sodium sulfate. The measurements were performed using an acoustic levitator. The study provides information about the intermediates during the crystallization process. T2 - Eighth Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 07.12.2016 KW - In situ KW - Crystallization KW - WAXS PY - 2016 AN - OPUS4-39365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien A1 - Tammas-Williams, S. A1 - Todd, I. T1 - CT for additive manufacturing process characterisation: assessment of melt strategies on defect population N2 - Selective Electron Beam Melting (SEBM) is a promising powder bed Additive Manufacturing (AM) technique for near net-shape manufacturing of high-value titanium components. However, as with every emerging technique, the manufacturing processes can still be greatly improved and optimised. In particular, the links between AM settings and the resulting sample porosity is of great interest, as the fatigue life of SEBM parts is currently dominated by the presence of porosity. In this study, the size, volume fraction, and spatial distribution of the pores in model samples have been characterised in 3D, using X-ray Computed Tomography (CT), and correlated to the SEBM process variables. A strong relationship was found with the different beam strategies used to contour, and infill by hatching, a part section. The majority of pores were found to be small spherical gas pores, concentrated in the infill hatched region. Rarer irregular shaped pores were mostly located in the contour region and have been attributed to a lack of fusion between powder particles. T2 - Conference on Industrial Computed Tomography iCT2016 CY - Wels, Austria DA - 09.02.2016 KW - Titanium KW - Additive Manufacture KW - Selective Electron Beam Melting KW - Pores KW - Defects KW - X-ray Computed Tomography PY - 2016 AN - OPUS4-39186 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - Rosu, Dana-Maria A1 - Ortel, Erik A1 - Hodoroaba, Vasile-Dan A1 - Krähnert, R. T1 - Measurement of porous TiO2 layers with spectroscopic ellipsometry - a multi-method study N2 - By means of an effective medium (EMA) based approach, it is possible to use spectroscopic ellipsometry to determine the mixing ratios between air and material in porous dielectrics and calculate a quantitative value of the porosity for these materials. As this method is model-based, it is very difficult to provide a quantitative measure for the accuracy of porosity values determined by this method. Valuable additional information can often be obtained by combining ellipsometry with other complementary methods. In the present study, the ellipsometry results were validated by Electron Probe Microanalysis (EPMA) with the option of layer analysis (by the socalled “STRATAGem” approach), gravimetry, and electron microscopy. We analysed porous TiO2 thin layers synthesised by means of a template synthesis Approach (evaporation induced self assembly). Ellipsometry measurements on porous samples are difficult to analyse due to the complexity of the models necessary. Often it is difficult to decide if the measured data contains enough information to successfully determine the target quantities (mixing ratio, dielectric function of the matrix material). One method to decrease the complexity of the fit and therefore use the measurement data most efficiently is a multi-sample analysis. In the present case, multi-sample analysis was used for determining the porosity factors of the individual layers while using one common set of dielectric function values for the matrix in all cases. While the results of the fit analysis in this case can be used to show the feasibility and also the limitations of the multi-method approach, the porosity values themselves show a promising agreement between the Independent methods. It can therefore be concluded that determining porosity values with ellipsometry is in accordance to other methods to the level of accuracy provided by the complementary methodologies. T2 - ICSE-7, 7th International Conference on Spectroscopic Ellipsometry CY - Berlin, Germany DA - 5.6.2016 KW - Spectroscopic ellipsometry KW - Electrolysis KW - Catalysis KW - Thin film metrology KW - Porous materials PY - 2016 AN - OPUS4-39940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rizzo, F. A1 - Agudo Jácome, Leonardo A1 - Mosquera Feijoo, Maria A1 - Nolze, Gert A1 - Kranzmann, Axel A1 - Costa e Silva, A. T1 - Evaluation of nano-sized internal oxidation in a Fe-13Cr alloy exposed to water vapor atmosphere N2 - The topotactic formation of nano-sized precipitates immediately under the internal oxide layer in a Fe-13Cr alloy exposed to oxidizing water vapor atmosphere was recently reported. The precipitates were identified as lath-shaped Fe-Cr spinel exhibiting a crystallographic orientation relationship with the ferritic matrix. The authors proposed that these precipitates could act as a precursor to the formation of the spinel layer observed in the adjacent part of the oxide scale.The occurrence of internal oxidation in Fe–Cr alloys subjected to similar conditions had been previously identified and directly correlated to the presence of water vapor. In the present work, we attempt to rationalize the processes occurring during the oxidation of this alloy through thermodynamic and kinetic analyses based on the CALPHAD approach, using the geometrical representation of phase equilibria and concepts developed to describe internal oxidation. The influence of water vapor on the mechanism and kinetics of formation of the nano-sized precipitates and its role in the overall oxidation process is also considered. T2 - CALPHAD XLV The forty-fifth International Conference on CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) CY - Awaji Island, Hyogo, Japan DA - 29.05.2016 KW - Precipitation KW - Internal oxidation KW - CALPHAD KW - Topotactic transformation KW - Microscopy PY - 2016 AN - OPUS4-42156 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sieber, Sarah A1 - Niederleithinger, Ernst A1 - Grohmann, Maria T1 - Image denoising of ultrasonic echo data acquired on concrete N2 - Ultrasonic echo testing has become a common method in civil engineering for the investigation of concrete structures. The detection of inhomogeneities, reinforcing elements and the geometry of the object is required for quality assurance and Inspection. This assessment depends on the quality of ultrasonic images which can be improved by using Reverse Time Migration (RTM) rather than the standard method, Synthetic Aperture Focusing Technique (SAFT). Although RTM provides a better mapping of circular objects and (dipping) reflectors, the image is corrupted by migration noise. To suppress the image noise, we have tested various filter methods in the spatial domain, frequency domain as well as in the curvelet domain on ultrasonic RTM images. We found that either a spatial edge detection filter in combination with a lowpass filter (Laplacian of Gaussian filter) or two lowpass filter with different filter parameters (Difference of Gaussian filter) removed artefacts. An additional smoothing was obtained by applying the first generation curvelet transform after downsampling the image matrix and adding Gaussian noise. The proposed filter scheme is able to suppress RTM noise and enhance the image quality such that the objective interpretation of ultrasonic images for Quality assessment of concrete specimen is simplified. T2 - 76. Jahrestagung der Deutschen Geophysikalischen Gesellschaft CY - Münster, Germany DA - 14.03.2016 KW - Ultrasonic echo technique KW - Reverse-time migration KW - Image Denoising KW - Curvelet Transform PY - 2016 AN - OPUS4-35839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - John, Sebastian T1 - Lebensdauerabschätzung von Composite-Druckgefäßen / COD-AGE N2 - Ermittlung von Kennwerten und Modelbildung zur Lebensdauerabschätzung von Composite-Druckgefäßen. T2 - 3. Workshop Themenfeld Material CY - Berlin, Germany DA - 12.10.2016 KW - Composite-Druckgefäße KW - Lebensdauer KW - FEM KW - Bruchmechanik PY - 2016 AN - OPUS4-39090 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheuerlein, C. A1 - Rehmer, Birgit A1 - Finn, Monika A1 - Uhlemann, Patrick A1 - Savary, F. A1 - Lackner, F. T1 - Mechanical properties of the HL-LHC 11 Tesla Nb3Sn magnet constituent materials N2 - A test campaign was launched to determine the mechanical properties of the HL-LHC 11 T Nb₃Sn magnet components in order to accurately model the mechanical properties in Finite Element simulations that predict the stress and strain distribution in these magnets. Static and dynamic test methods have been applied for determining elastic materials behavior, and highly accurate Young’s moduli are obtained with the dynamic methods resonance and impulse excitation. These non-destructive methods also enable temperature dependent modulus measurements during in situ heat cycles. T2 - Applied Superconductivity Conference CY - Denver, USA DA - 04.09.2016 KW - Young´s modulus KW - Tensile KW - Compression KW - Temperature dependence PY - 2016 AN - OPUS4-37922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kathan, Michael A1 - Kovanicek, Petr A1 - Jurissek, Christoph A1 - Senf, Antti A1 - Dallmann, Andre A1 - Thünemann, Andreas A1 - Hecht, Stefan T1 - Photocontrolling imine exchange kinetics to modulate inherent characteristics of self-healing polysiloxane networks N2 - Materials that respond to the environment by changing their properties are critical for developing autonomously adaptive systems. However, to reversibly influence a material's inherent characteristics, such as its ability to self-heal, from distance without continuously expending energy, remains a challenging task. Herein, we report on the modul at ion of imine exchange kinetics by light, manifested in a remote controllable dynamic covalent polymer network. Simple mixing of a commercially available amino-functionalized polysiloxane with small amounts of a photoswitchable diarylethene cross-linker, carrying two aldehyde groups, yields a rubbery material. Its viscoelastic and self-healing properties can be reversibly tuned with everyday light sources, such as sunlight. Our two-component system offers the unique advantage that self-healing takes place continuously without any additives at ambient conditions and is neither dependent on continuous illumination nor does it require recent damage. Overall, our approach allows for the local amplification of intrinsic material properties in a permanent yet reversible fashion. The availability of the inexpensive sta1ting materials on a multi-gram scale, the easy synthesis of the polymer network, and its convenient handling paired with high versatility make our Approach highly applicable to create custom-tailored adaptive materials. T2 - POLYDAYS 2016 CY - Potsdam, Germany DA - 28.09.2016 KW - Self-healing KW - Polymer PY - 2016 AN - OPUS4-37623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fuhrmann, A. A1 - Göstl, R. A1 - Wendt, R. A1 - Kötteritzsch, J. A1 - Hager, M. D. A1 - Schubert, U. S. A1 - Brademann-Jock, Kerstin A1 - Thünemann, Andreas A1 - Nöchel, U. A1 - Behl, M. A1 - Hecht, S. T1 - Conditional repair by locally switching the thermal healing ability of dynamic covalent polymers ON and OFF with light N2 - Healable materials are able to repair inflicted damages, herin often applied: dynamic covalent polymer networks. We have shown in this study that light of different colors shift the Diels-Alder and retro Diels-Alder crosslinking and decrosslinking equilibrium. This effect was utilized for self-healing of a polymer film. Small-angle X-ray scattering was used to quantifiy the polymeric mesh size on a nanoscale. T2 - Polydays 2016 CY - Potsdam, Germany DA - 28.09.2016 KW - Polymer KW - Small-angle X-ray scattering KW - SAXS KW - Self-healing PY - 2016 AN - OPUS4-37570 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thünemann, Andreas T1 - Characterization of silver nanoparticles in cell culture medium containing fetal bovine serum N2 - Nanoparticles are being increasingly used in consumer products worldwide, and their toxicological effects are currently being intensely debated. In vitro tests play a significant role in nanoparticle risk assessment, but reliable particle characterization in the cell culture medium with added fetal bovine serum (CCM) used in these tests is not available. As a step toward filling this gap, we report on silver ion release by silver nanoparticles, and changes in the particle radii and in their protein corona when incubated in CCM. Particles of a certified reference material (CRM), p1, and particles of a commercial silver nanoparticle material, p2, were investigated. The colloidal stability of p1 is provided by the surfactants polyethylene glycole-25 glyceryl trioleate and polyethylene glycole-20 sorbitan monolaurate, whereas p2 is stabilized by polyvinylpyrrolidone (PVP). Dialysis of p1 and p2 reveal that their silver ion release rates in CCM are much larger than in water. Particle characterization was performed with asymmetrical flow field-flow fractionation (FFF), small-angle X-ray scattering (SAXS), dynamic light scattering (DLS) and electron microscopy. p1 and p2 have similar hydrodynamic radii of 15 nm and 16 nm, respectively. The silver core radii are 9.2 and 10.2 nm. Gel electrophoresis and subsequent peptide identification reveal that albumin is the main corona component of p1 and p2 after incubation in CCM, which consists of Dulbeccos Modified Eagle Medium with 10% fetal bovine serum added. T2 - 6th International Colloids Conference CY - Berlin, Germany DA - 19.06.2016 KW - SAXS KW - Nanoparticle KW - Silver KW - Albumin PY - 2016 AN - OPUS4-36639 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mull, Birte A1 - Sauerwald, T. A1 - Richter, Matthias A1 - Horn, Wolfgang A1 - Brödner, Doris A1 - Schultealbert, C. T1 - Development of a reproducibly emitting reference material for volatile organic compounds N2 - Volatile organic compounds (VOC) are ubiquitous in the indoor air, since they emit from materials used indoors. Investigations of these materials are mostly carried out in test chambers under controlled climatic conditions. Quality control of these test chamber measurements is important but there is a lack of commercially available homogenous reference materials. The approach of this study is to dope a supporting material with VOCs, which are then reproducibly released in measurable chamber air concentrations between 30 to 300 µg m ³. From several tested supporting materials vacuum grease (APIEZON M) was selected because of its very low own emissions. First tests were conducted with styrene. For the estimation of the initial emission and the emission over time FEM (finite element methods) modelling was used. Based on this, five samples with a surface of 7 cm2 and a thickness of 12 mm with a content of 1 ‰ styrene were investigated at (23 ± 2) °C and (50 ± 5) % relative humidity in the µ-chamber (3 samples) and 24 L test chambers (2 samples) for 28 days. Air samples were taken after 24 hours, 3, 7, 14, 21 and 28 days on Tenax TA® sorption tubes and analyzed by TD-GC-MS. The area specific emission rate (SERa) was calculated to compare the results from both chamber types. After 24 hours SERa was between 0.8 0.9 µg cm 2 h 1 (3800 4000 µg m 3) for the µ-chamber samples and between 0.9 1.1 µg cm 2 h 1 (300-370 µg m 3) for the 24 L test chamber samples. After 28 days the SERa was at 0.2 µg cm 2 h 1 for all samples. The relative standard deviation of the SERa was between 1 26 %. These results show the applicability of vacuum grease as supporting material and the favored starting concentration range could be achieved in the 24 L test chambers. T2 - Indoor Air 2016, the 14th international conference of Indoor Air Quality and Climate CY - Ghent, Belgium DA - 03.07.2016 KW - Emission test chamber KW - Indoor air KW - Quality assurance KW - Quality control PY - 2016 AN - OPUS4-36823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hübert, Thomas A1 - Kemnitz, Erhard A1 - Usmani, Shirin A1 - Schlischka, Jörg A1 - Klutzny, Kerstin A1 - de Laval, Yvonne A1 - Plarre, Rüdiger A1 - Krahl, Thoralf A1 - Stephan, Ina T1 - Wood protection with nanoparticles: MgF2 and CaF2 N2 - The potential of alkaline earth metal Fluoride nanoparticles was tested for protection of wood against fungi and termites. These nanoparticles are ideal for wood protection. T2 - School of Analytical Sciences Poster Session CY - Berlin, Germany DA - 06.12.2016 KW - Wood preservation KW - Fluorides KW - Nanoparticles PY - 2016 AN - OPUS4-39141 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin A1 - Meyer, Susan A1 - Solomun, Tihomir A1 - Kunte, Hans-Jörg A1 - Sturm, Heinz T1 - Electron irradiation of biomolecules under physiological conditions: Experimental realization and microdosimetric calculations N2 - In the last years, secondary low-energy electrons (LEE) emerged as important, if not predominant, reductive pathway in ionizing damage of biomolecules. These electrons are created in copious amount as result of inelastic scattering of high energy radiation at water. Until now, all experiments the quantification of the effects of LEEs on the biomolecular damage was either performed in vacuum with LEE sources or with DNA on surfaces in humid atmosphere. We present a new experimental setup to irradiate biomolecules with electrons under physiological conditions. In combination with monte carlo simulations this setup makes it possible to determine microdosimetric quantities for biomolecules in liquid environment under electron irradiation. This opens up new possibilities in radiation research to access the LEE damage under well defined physiological condition, for more complex systems, such as DNA-Protein complexes and even living cells. T2 - 14th International Congress of the International Radiation Protection Association CY - Cape Town, South Africa DA - 09.05.2016 KW - DNA KW - Dosimetry KW - Microdosimetry KW - Geant4 KW - Low energy electrons KW - Radicals KW - Radiation damage KW - Polymers PY - 2016 AN - OPUS4-36399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Veliz Montes, Cinthya A1 - Bottari, G. A1 - Trukina, O. A1 - Torres, Tomás A1 - Schneider, Rudolf T1 - Unsubstituted, covalently-linked phthalocyanine-C60 fullerene dyads N2 - Were prepared four unsubstituted Pc - C60 fullerene systems, using two different synthetic strategies, via Prato (1,3 - dipolar cycloaddition) or Bingel reactions. The precursor Pcs 1 and 2 were successfully synthesized by cyclotetramerization reaction between TBDPS - protected and unsubstituted phthalonitriles. The surface studies are currently ongoing. T2 - PcsTT2016 Symposium CY - Elche, Spain DA - 27.01.2016 KW - Fullerene KW - Phthalocyanine PY - 2016 AN - OPUS4-38556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cabeza, Sandra A1 - Thiede, Tobias A1 - Mishurova, Tatiana A1 - Nadammal, Naresh A1 - Kromm, Arne A1 - Bruno, Giovanni T1 - Development of residual stresses in IN718 parts obtained by SLM N2 - Additive Manufacturing by Selective Laser Melting (SLM) offers ample scope for producing geometrically complex parts as compared to the traditional subtractive manufacturing strategies. However, the residual stresses (RS) developed during the processing can reduce the load bearing capacity as well as induce unwanted distortion, limiting the application of SLM parts. In the present work, residual stresses in additivly manufactured IN718 part were analised by means of neutron diffraction and synchrotron X-ray diffraction. T2 - ISAM 2017 CY - Dresden, Germany DA - 07.02.2017 KW - Additive manufacturing KW - Residual stress KW - Inconel 718 KW - Netron diffraction KW - Microstructure PY - 2017 AN - OPUS4-39139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koclega, D. A1 - Radziszewska, A. A1 - Kranzmann, Axel A1 - Huebner, J. A1 - Kac, S. T1 - High temperature corrosion resistance of Inconel 686 coatings in aggresive environments N2 - The work presents the microstructure, chemical composition and mechanical properties of Inconel 686 coatings after high - temperature corrosion in environment of aggressive gases. To produce the Ni - base weld overlays the QS Nd:YAG laser beam was used. The substrates were 13Mo4-5 boilers plate steel. Ni - base alloys characterize the excellent high temperature corrosion resistance, good strength and good ability to work in aggressive environments. Applied overlays had a proper combination of the metal substrate in particular small amount of Fe. This could be achieved by the reduction of the melting of the substrate and its dissolution into the overlays. The microstructure, chemical composition of the obtained overlays were investigated by means of a light microscope, a scanning electron microscope (SEM) equipped with the EDS detector. The overlays had cellular-dendritic structure. The variations of the chemical composition (especially Mo, Ni and W ) in the interdendritic and dendritic regions were observed. The interdendritic regions were enriched during solidifications in Mo and W and had lower content of Ni. T2 - EUROCORR 2017 CY - Prague, Czech Republic DA - 03.09.2017 KW - Inconel 686 KW - Corrosion resistance KW - Laser cladding PY - 2017 AN - OPUS4-44197 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koclega, D. A1 - Radziszewska, A. A1 - Kranzmann, Axel A1 - Dymek, S. A1 - KĄc, S. T1 - The microstructure of weld overlay Ni - base alloy deposited on carbon steel by laser QS-Nd:YAG N2 - Ni- base alloys are used as a one of the most important coating material and can be applied in a different environments and elements of devices having various applications. To protect the surface of the material from aggressive gases at high temperature, there are use different kinds of the Ni- base alloys. One of such alloy is Ni-Cr-Mo-W called commercial Inconel 686. This alloy based on NiCr22Mo9Nb (Inconel 625), in which content of molybdenum increased and niobium was replaced with the addition of tungsten, in order to counteract the strong segregation in the microstructure, which results in homogeneity of the chemical composition of the structure. Inconel 686 is also characterized by greater resistance to high temperature corrosion and heat resistance than Inconel 625. The Inconel 686 alloy was deposited on 13CrMo4-5 steel by laser QS - Nd:YAG. In the poster the microstructure (SEM) and chemical composition (EDS) of obtained weld overlays were investigated. T2 - EUROMAT 2017 CY - Thessaloniki, Greece DA - 17.09.2017 KW - Nickel based alloy KW - Laser cludding KW - High temperature corrosion resistance PY - 2017 AN - OPUS4-44195 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Patzig, C. T1 - Surface-initiated microstructure formation in glass ceramics N2 - Up to now, the mechanisms of surface nucleation and surface-induced texture formation are far from being understood. Corresponding phenomena are discussed hypothetically or even controversial, and related studies are restricted to very few glasses. As a main drawback, the vast majority of previous work on oriented growth of surface crystals do not consider the possible effects of glass surface treatments (like polishing defects, adhered particles and cracks, …) or ambient annealing conditions (vacuum or atmospheric pressure) which both can influence crystal nucleation and growth. Moreover, very few observations of crystal orientation related to surface crystallization were focused on separately growing crystals. In conclusion, up to now, no systematic studies on initially oriented crystal growth or nucleation from defined active nucleation sites have been pursued. Therefore, the main objective of the proposed project is to gain a basic understanding of the mechanisms of surface-induced microstructure formation in glass ceramics. We shall answer the question whether preferred orientation of surface crystals is the result of oriented nucleation or caused by other orientation selection mechanisms acting during early crystal growth. In both cases, crystal orientation may be caused by the orientation of the glass surface itself or the anisotropy and orientation of active surface nucleation defects. New techniques of experimental characterization of surface-crystallized glasses shall be applied to find answers to the questions posed above. Based on a controlled preparation and annealing of the glass sample surfaces, that includes the defined creation of active nucleation defects, and followed by the microstructural characterization especially during the very early growth stages of separated surface crystals, the orientation relations between defect and initiated surface crystal will be analyzed. In order to gain new insights, a couple of entirely new microstructure diagnostics techniques, including chemically contrasted XRM, laser-based sample preparation for XRM, and 3D electron backscatter diffraction shall be developed or applied. This way, using X-ray microscopy as a pivotal technique for the non-destructive 3D characterization of relatively large samples at superior spatial resolution (but also complemented by other microstructure diagnostics techniques, e.g. TEM elemental mappings at cross-sectioned samples) unprecedented insights into the microstructure evolution upon surface crystallization of model glasses will be gained. T2 - DFG Begutachtungskolloquium (PAK 949/1 und PAK 950/1) CY - Bonn, Germany DA - 07.03.2017 KW - Oberflächenkeimbildung KW - Glaskeramik KW - Orientierung PY - 2017 AN - OPUS4-44221 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gollwitzer, Christian A1 - Cabeza, Sandra A1 - Garces, G. T1 - Synchrotron based absorption edge tomography for §D characterization of the microstructure of MG-Y-Zn alloys N2 - Absorption edge tomography is a method which exploits the sudden change of the attenuation coefficient, when the photon energy crosses the absorption edge of an element. The beamline BAMline at BESSY II, which is operated by the Federal Institute for Materials Research and Testing, can provide a monochromatized beam in a photon energy range from 5 keV up to 80 keV with a bandwidth of 2%. Together with the microtomography setup, this enables differential tomography sensitive to any element with N >= 24 (Cr) by using an appropriate K- or L-edge in this range. Here, absorption edge tomography at the Yttrium edge is employed to perform a non-destructive 3D characterization of the microstructure of a high strength Mg-Y-Zn alloy. The long period stacking ordered (LPSO) phase which forms fibres in this material was extracted based on the Yttrium content and the fibre length distribution was analysed. T2 - Ninth Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 13.12.2017 KW - Synchrotron KW - Computed Tomography KW - Absorption edge KW - BAMline PY - 2017 AN - OPUS4-43854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falk, Florian A1 - Menneken, Martina A1 - Stephan-Scherb, C. T1 - Early oxidation and sulfidation of high temprature alloys: An EDXRD in-situ study N2 - P92 is one of the important steels for super heater tubes used in combustion plants. However, in fossil fuel fired environments the formation of oxides and sulfides are challenging the material. To understand early corrosion mechanisms, which are important for process prediction, high temperature in-situ ageing experiments of Fe-Cr-Mn alloys in SO2 and SO2+H2O atmosphere were performed, applying energy dispersive X-ray diffraction (EDXRD) analysis. T2 - Bessy usermeeting CY - Berlin, Germany DA - 05.12.2017 KW - Corrosion KW - In-situ KW - EDXRD PY - 2017 AN - OPUS4-45368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wollschläger, N. A1 - Nützmann, Kathrin T1 - What happens during S-corrosion in Fe13Cr in the early stage? N2 - Ferritic alloys containing Cr form Cr5S6 precipitates along grain boundaries in hot SO2 environment. Grain boundary precipitates may influence the steel’s mechanical behavior. Cr5S6 precipitates were reconstructed three-dimensionally using FIB tomography analysis to determine the volume, number, and penetration depth. The volume growth of Cr5S6 precipitates increased only for the initial aging time of 3 h but became constant after 6 h. The number of precipitates increased linearly. T2 - Meeting on Focused Ion Beams in Berlin - FIBiB2017 CY - Berlin, HZB Wannsee Campus, Germany DA - 06.11.2017 KW - Grain boundary corrosion KW - 3D tomography KW - Sulfidation PY - 2017 AN - OPUS4-45061 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koclęga, Damian A1 - Dymek, S. A1 - Radziszewska, A. A1 - Huebner, J. T1 - Optimization of laser treatment parameters of Inconel 686 overlay weld on carbon steel 13Mo4-5 N2 - The work presents the effects of the change of the laser cladding parameters on microstructure, chemical composition and mechanical properties of Inconel 686 overlays (coatings). To obtain the best quality of these coatings the various parameters of laser cladding such as the power density of the laser beam, the laser beam velocity and overlapping ratio of the weld tracks were applied. The substrates were boilers plate made of the 13Mo4-5 steel. Ni - base alloys characterize by the excellent high-temperature corrosion resistance, good strength and good ability to work in aggressive environments. Applied overlays had a proper combination of the metal substrate in particular small amount of Fe. This could be achieved by the reduction of the substrate melting and its dissolution into the overlays. The microstructure, chemical composition of the obtained overlays were investigated by means of a light microscope, a scanning electron microscope (SEM) equipped with the EDS detector. The overlays had cellular-dendritic structure. The variations of the chemical composition (especially Mo, Ni and W ) in the interdendritic and dendritic regions were observed. The interdendritic regions were enriched during solidifications in Mo and W and had lower content of Ni. T2 - METAL 2017 CY - Brno, Czech Republic DA - 24.05.2017 KW - Laser cladding KW - Overlay KW - Chemical composition KW - Inconel 686 PY - 2017 AN - OPUS4-44464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kotaka, M. A1 - Honma, T. A1 - Shinozaki, K. A1 - Affatigato, M. A1 - Müller, Ralf A1 - Komatsu, T. T1 - Unique growth behavior of ferroelastic beta’-Gd2(MoO4)3 crystals in glasses N2 - An understanding on crystallization behavior and kinetics in glasses is one of the important topics in the glass science and technology. Tsukada et al.1) found an extremely unique and curious phenomenon in the crystallization of multiferroic (ferroelectric and ferroelastic properties) ’-Gd2(MoO4)3 crystals in Gd2O3-MoO3-B2O3 glasses. That is, crystals formed in the crystallization break into small pieces with a triangle prism or pyramidal shape having a length of 50-150 um spontaneously during the crystallization in the inside of an electric furnace, not during the cooling in air after the crystallization. They proposed to call this phenomenon “self-powdering phenomenon”. To the best of our knowledge, such a self-powdering phenomenon has not been observed in the crystallization of any other glasses. To investigate this phenomenon is very important for the glass science and for the preparation of bulk crystallized glasses with ferroelastic crystals. In this work, the preparation of crystallized glasses keeping the original shape is challenged, and the mechanism of self-powdering phenomenon is proposed. Glasses with the compositions of 21Gd2O3-63MoO3-(16-x)B2O3-xTeO2 (mol%) (x=0, 2, 4, 8) such as 21Gd2O3-63MoO3-16B2O3 (GM16B) and 21Gd2O3-63MoO3-8B2O3-8TeO2 (GM8T8B) were prepared using a conventional melt quenching technique. The quenched glasses were heat-treated at some temperatures, and the crystalline phase present in the crystallized samples was identified by X-ray diffraction (XRD) analyses, and the morphology and birefringence of crystals formed were observed using a polarized optical microscope (POM). The densities of GM16B and GM8T8B glasses are 4.76 g/cm3 and 4.91 g/cam3, respectively, and these values are higher than the density of ’-Gd2(MoO4)3 crystal, 4.555 g/cm3. These differences in the density might induce the large stresses in the inside of crystals during the crystal growth. The crystallized glasses of GM16B with ’-Gd2(MoO4)3 crystals do not keep the original glass shape, showing self-powdering phenomenon (breaking into small pieces). However, the crystallized glasses of GM8T8B keep the original glass shape without indicating any self-powdering. It is proposed that the stress at the interface between the glassy phase and ’-Gd2(MoO4)3 crystalline phase might be reduced in GM8T8B glasses containing TeO2 with weak Te-O bonds. T2 - Crystallization 2017 CY - Segovia, Spain DA - 10.09.2017 KW - Glass KW - Crystallization KW - Self-powdering PY - 2017 AN - OPUS4-44403 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stephan-Scherb, Christiane A1 - Nützmann, Kathrin T1 - Real time observation of crystallization and growth of corrosion products by energy dispersive X-ray diffraction N2 - Ferritic-martensitic high temperature alloys are widely used as boiler tube and heat exchanger materials in combustion based power plants. All technologies have in common that the applied materials are exposed to different temperatures, process pressures and reactive atmospheres which lead to a change of the material properties and a further degradation of the material. To date corrosion analytics mainly proceeds via the use of various microscopic techniques and the analysis of the corrosion products after the reaction is completed. Comprehensive efforts have been made to study high temperature corrosion by the use of environmental SEM’s or in-situ TEM technologies. The here presented work will show a different approach to study high temperature gas corrosion in a multiple gas atmosphere by energy dispersive X-ray diffraction (EDXRD). For this technique high energetic white X-ray radiation (10-100 keV) was used as radiation source instead of conventional monochromatic radiation. It enables us to study crystallization procedures on short and medium time scales (1 min < t < 24 h) and the collection of Bragg-Signals of the phases of interest as a function of process time. Their occurrence can directly be correlated with thermodynamic and kinetic parameters. A special designed corrosion reactor was used to combine high temperature gas corrosion experiments with the collection of diffraction patter. The crystallization and reaction paths for oxide and sulfide formation was followed in-situ on Fe-Cr and Fe-Cr-Mn model alloys in a hot SO2 containing (T=650 °C) atmosphere. T2 - Gordon Research Conference on High Temperature Corrosion and Protection of Materials CY - New London, NH, USA DA - 09.07.2017 KW - Corrosion KW - In situ diffraction KW - Crystallization PY - 2017 AN - OPUS4-44717 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 - Schlichting, S. A1 - Hönig, Gerald M. O. A1 - Wagner, M. R. A1 - Müßener, J. A1 - Hille, P. A1 - Teubert, J. A1 - Schörmann, J. A1 - Eickhoff, M. A1 - Hoffmann, A. A1 - Callsen, G. T1 - Tuning of the quantum-confined Stark effect in wurtzite [0001] nanostructures by the internal-field-guarded-active-region design N2 - In this work we eliminate the QCSE without having any special requirements on the growth procedure or the material. Hönig et al. developed the Internal-Field-Guarded-Active-Region Design (IFGARD), which we experimentally investigate in this work based on GaN/AlN nanodiscs (NDs). T2 - Compound Semiconductor Week 2017 CY - Berlin, Germany DA - 14.05.2017 KW - Halbleiterphysik KW - Nanophysik KW - Optoelektronik KW - Piezopolarisation KW - Spontane Polarisation PY - 2017 AN - OPUS4-40174 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 - TY - CONF A1 - Tschiche, Harald A1 - Hoffmann, Katrin A1 - Radunz, Sebastian A1 - Schwibbert, Karin A1 - Sameith, Janin A1 - Toepel, Jörg A1 - Resch-Genger, Ute T1 - A Polymeric Nanosensor for Sensing of Broad pH Changes in Biofilm as Tool for the Investigation of Microbial Induced Corrosion N2 - One of today’s major problems in many technical plants as well as fuel tanks is Microbial induced corrosion (MIC), leading to considerable damage and huge financial losses. Successful prevention of MIC requires the localization of first signs of corrosion as well as the identification of factors influencing the corrosion process. Hence, there is a growing need for sensitive and preferably inexpensive tools that enable the early detection of MIC. Of utmost importance are methods, which provide spatially and time-resolved information and allow the determination of corrosion rates at sites of interest for possible prevention of MIC. T2 - First European / 10th German BioSensor Symposium CY - Potsdam, Germany DA - 20.03.2017 KW - Nanoparticel based pH-probes KW - Microbial induced corrosion KW - Imaging PY - 2017 AN - OPUS4-40261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tschiche, Harald A1 - Hoffmann, Katrin A1 - Falkenhagen, Jana A1 - Weidner, Steffen A1 - Resch-Genger, Ute T1 - Determination of degradation products of thermoplastic polyurethane using fluorescent sensors in a model system N2 - Polyurethanes (PU) are formed by polyaddition reaction between diols and diisocyantes. They can be formed utilizing three building blocks, namely a polyol or long-chain diol, a chain extender or short-chain diol, and a diisocyanate. The derived multi-phase block copolymer has thermoplastic properties and is called thermoplastic PU (TPU). This modular approach allows for a variety of alternations yielding a broad range of structural properties and applications. TPUs are based on three main classes of polyols, i.e. polyethers, polyesters, and polycaprolactones. With these different polyols and the ability of changing the ratio of building blocks a variety of material properties can be obtained thus TPUs find numerous applications in e.g. lightweight construction1, insulation, flame retardants, lacquer and glue, as well as medicine. Linear, isocyanate terminated, polyurethane prepolymers prepared from non-equivalent amounts of diisocyanate such as methylene diphenyl diisocyanate (MDI) attached to a polyol are widely used as precursors of the correspondent polymers. Chain-extending reactions with low molecular weight compounds bearing different amounts of active hydrogens enable both linear and crosslinked polyurethane to be formed. Due to TPUs being used in a broad range of applications facing a variety of stress (e.g. mechanical, hydrolytic, thermal, radiative/UV, as well as its combinations) the complexity of possible degradation mechanism is high. A functional group derived from degradation of the bulk matrix can be detected utilizing a suited fluorogenic sensor molecule. There are several fluorogenic dyes known for the application as sensor for amine groups e.g. fluorescamine, pyrylium dyes, deriving a fluorescent signal upon reaction. T2 - ANAKON 2017 CY - Tübingen, Germany DA - 03.04.2017 KW - Bewitterung KW - Polyurethan KW - Functional group detection KW - Polyurethanes PY - 2017 AN - OPUS4-40262 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -