TY - CONF A1 - Plarre, Rüdiger T1 - Invasoren im Kleiderschrank N2 - Die Kleidermotte wird als invasive Art (Neozoon) beschrieben. T2 - Lange Nacht der Wissenschaften, FU Berlin, FB Biologie CY - Berlin, Germany DA - 11.06.16 KW - Kleidermotte KW - Invasive Arten KW - Neozoon PY - 2016 AN - OPUS4-36964 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fontana, Patrick A1 - Miccoli, Lorenzo A1 - Hoppe, Johannes T1 - Beton mit funktionalen Oberflächen N2 - Beton ist als Massenbaustoff vielseitig einsetzbar. Eine der neuesten Entwicklungen ist Ultrahochleistungsbeton (UHPC). Seine besonderen Eigenschaften ermöglichen eine zusätzliche Funktionalisierung der Oberflächen, da annähernd beliebige Mikrostrukturen exakt abgeformt werden können. So lassen sich beispielsweise Fassadenelemente aus UHPC bereits bei ihrer Herstellung im Betonfertigteilwerk mit selbstreinigenden Oberflächen ausrüsten. Eine andere Möglichkeit ist eine Anwendung als Datenspeicher. Wie das Beispiel der Schallplatte aus UHPC zeigt, lassen sich Muster, die hier die Schallinformationen enthalten, exakt von einer Matrize kopieren. T2 - Lange Nacht der Wissenschaften 2016 CY - Berlin, Germany DA - 11.06.2016 KW - UHPC KW - Selbstreinigung KW - Datenträger KW - Betonschallplatte PY - 2016 AN - OPUS4-36948 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Sebastian A1 - Meng, Birgit A1 - Selleng, Christian T1 - A new sample holder for fast xrd investigation on UHPC N2 - A new sample holder is described in this poster. It was developed in BAM for fast XRD investigation on UHPC (ultra high performance concrete). Results measuring solid, i.e. not pulverized, samples are shown. T2 - GeoBerlin 2015 CY - Berlin, Germany DA - 04.10.2015 KW - Building Materials KW - UHPC KW - X-ray diffractometry PY - 2015 AN - OPUS4-36949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank A1 - Meng, Birgit A1 - Werner, Daniel T1 - Influence of aggregate size on the damage potential of alkal-silica-reaction N2 - The poster shows new results on Alkali-Silica-Reaction (a damage mechanism of concrete). The influence of the aggregate size in the sand fraction is investigated, revealing that different types of aggregate behave in a different way. T2 - 15th International Conference of Alkali Aggregate Reaction in Concrete (ICAAR 2016) CY - Sao Paulo, Brazil DA - 03.07.2016 KW - Alkali-silica-reaction KW - Building materials KW - Concrete KW - Durability PY - 2016 AN - OPUS4-36951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epping, Ruben A1 - Falkenhagen, Jana T1 - Characterization of statistical EO-PO copolymers containing different end groups by UPLC/ESI-MS N2 - Commercial statistical ethylene oxide (EO) and propylene oxide (PO) copolymers of different monomer compositions and different average molar masses were studied by liquid chromatography under critical conditions (LCCC). Theoretical predictions of the existence of a critical adsorption point (CPA) for statistical copolymers with a given chemical and sequence distribution, could be studied and confirmed. An improved way to determine these critical conditions in a copolymer, alongside the inevitable chemical composition distribution (CCD), with the aid of mass spectrometric detection is described. Shift of the critical eluent composition with the monomer composition of the polymers could be observed. Due to the relatively low average molecular weight, broad molecular weight distribution (MWD) and the presumed existence of different end group functionalities as well as sequence distribution, gradient separation only by CCD was not possible. Therefore isocratic separations at the CPA of definite CCD’s were applied. Although the various present distributions partly superimposed the separation process the goal of separation by end group functionality could still be achieved on the basis of the additional dimension of ESI-MS. The existence of HO-H besides the desired AllylO-H end group functionalities could be confirmed and their amount could be estimated. T2 - International Symposium GPC/SEC and Related Techniques CY - Amsterdam, The Netherlands DA - 26.09.2016 KW - Polymers KW - UPLC KW - ESI-TOF-MS PY - 2016 AN - OPUS4-37632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schade, U. A1 - Ritter, E. A1 - Puskar, L. A1 - Aziz, E. F. A1 - Beckmann, Jörg T1 - Estimation of THz waveforms for material characterization of stratified objects N2 - The poster discusses theoretically and exemplarily the influence of the materials and experimentally selected situation on the shape and size deformation of a detected pulse signal previously reflected on a three layer sheet. T2 - 41st International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2016) CY - Copenhagen, Denmark DA - 25.09.2016 KW - THz spectroscopy KW - Pulse reflection KW - Pulse shape analysis KW - Optical layer model PY - 2016 AN - OPUS4-37639 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madkour, Sherif A1 - Penner, P. A1 - Zhang, X. A1 - Gölzhäuser, A. A1 - Schönhals, Andreas T1 - Dielectric investigations on carbon nanomembranes N2 - Multilayer carbon nanomembrances (CNMs) could pave the way for a new ultrathin functional conductive coatings with tunable electrical, optical, and chemical properties. Due to their molecular thickness, they can also be regarded as “interfaces without bulk” separating regions of different gaseous, liquid, or solid components and controlling the materials exchange between them, making them optimal materials for membranes applications. Furthermore, their physical and chemical properties depend strongly on their structure, molecular composition, and the surroundings of either sides, thus allowing for tailored properties. Here, nanolayers of Aromatic p-terphenylthiol (TPT) self-assembled into 2D carbon monolayers (thickness - 1.6 nm) were synthesized and further crosslinked by ion bombardment, forming CNMs. Here, though a recently developed multilayer nanosheets routine, stacks of 5, 10, 15 and 20 TPT sheets where transferred on top of each other forming a multilayered CNMs. However, this transfer routine could introduce some intrinsic defects to the sheets, which would alter the molecular composition and / or structure, thus consequently the CNMs properties. Therefore, it is essential to characterize defects in “pure” TPT nanomembranes, before tailoring the molecular compositions, e.g. adding functional groups. For this reason, broadband dielectric spectroscopy (BDS) was utilized to characterize any defects that could be rasied during preparation. Due the structure of pure TPT membranes, no dipole moment should exsist. However, the presence of other elements, e.g. water or sulphur, would result in a dipole moment that could be probed by BDS. As a main result, for all different stacked-layer numbers, a clear relaxation process is seen, which moves to higher frequencies with increasing the temperature. The temperature dependence of the relaxation rate of this process is independent of film thickness and can be well described by a common VFT function, hence a corporative motion. This relaxation process was assigned to intrinisic defects in the membranes, introduced during preparation, which was further confimed by a detailed anaylsis of the dielectric strength. This is the first BDS measurment on TPT CNMs. T2 - 9th International Conference on Broadband Dielectric Spectroscopy and its Applications CY - Pisa, Italy DA - 11.09.2016 KW - Carbon nanomembranes PY - 2016 AN - OPUS4-37527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Cheng-Chieh A1 - Weisbrich, S. A1 - Neitzel, F. T1 - Determination of an approximate anisotropic model for a given geometrical complex isotropic structure by means of finite element method and least-squares adjustment N2 - Many engineering structures are made of composite materials or metal foam. To simulate the deformational behaviour of these structures often requires a high number of discretisation elements. This in turn yields a very large system of linear equations that are extremely time and memory consuming or practically impossible to solve. It is therefore desirable to find an approach to overcome this obstacle. T2 - PhD Day 2016 CY - Berlin, Germany DA - 01.09.2016 KW - Least-Squares Adjustment KW - Inverse Analysis KW - Finite Element Method PY - 2016 AN - OPUS4-37521 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Cheng-Chieh A1 - Weisbrich, S. A1 - Neitzel, F. T1 - Approximate model for geometrical complex structures N2 - Many engineering structures are made of composite materials or metal foam. To simulate the deformational behaviour of these structures often requires a high number of discretisation elements. This in turn yields a very large system of linear equations that are extremely time and memory consuming or practically impossible to solve. It is therefore desirable to find an approach to overcome this obstacle. T2 - 33rd Danubia- Adria Symposium on Advances in Experimental Mechanics CY - Portorož, Slovenia DA - 20.09.2016 KW - Inverse analysis KW - Finite element method KW - Least-squares adjustment PY - 2016 AN - OPUS4-37523 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Sophie A1 - Mieller, Björn A1 - Rabe, Torsten T1 - Optimization of Solid-State-Reactions of Calcium Cobaltite Ca3Co4O9 N2 - Calcium cobaltite is a promising p-type oxide thermoelectric material for high temperature applications due to its high figure of merit between 600 °C and 900 °C in air. The solid-state-reaction is well known for large scale powder synthesis of functional materials. As a high temperature process, the powder synthesis consumes a lot of energy. In different studies, different synthesis conditions were used for the preparation of calcium cobaltite powder. This study showed that a higher energy input (elevated temperatures, longer dwell times, or repeated calcinations) during powder synthesis does not increase but decrease the Seebeck coefficient and the electrical conductivity. The same correlation was determined for the densification. As a higher energy input leads to a larger grain size and therefore to a reduced sinter activity, it can be concluded that the thermoelectric properties are correlated with the sinter activity of the powder. These results can be used to minimize the energy demand for the powder synthesis of Ca₃Co₄ O₉. T2 - 14th European Conference on Thermoelectrics CY - Lisbon, Portugal DA - 20.09.2016 KW - Thermoelectrics KW - Solid-State-Reaction KW - Calcium cobaltite PY - 2016 AN - OPUS4-37543 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Agea Blanco, Boris A1 - Müller, Ralf T1 - Sintering and bloating phenomena of barium disilicate glass powders T2 - 88. Glastechnische Tagung DGG - ACerS GOMD 2014 CY - Aachen, Germany DA - 26.05.2014 PY - 2014 AN - OPUS4-30810 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sojref, Regine A1 - Schreiber, R. A1 - Makrlik, A. A1 - Schadrack, Reinhard A1 - Müller, Ralf T1 - Fused Silica Containing Powders for Low Sintering (1650°C) Mullite-Zirconia Composites T2 - 23rd International Congress on Glass CY - Prague, Czech Republic DA - 01.07.2013 PY - 2013 AN - OPUS4-30851 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günther, Alexander A1 - Muschik, Bernd A1 - Gründer, Klaus-Peter T1 - Bi-spektrale Messung der Reflexionseigenschaften von fluoreszierenden Materialien N2 - Beim bispektralen Verfahrensprinzip (auch 2-Monochromatoren-Methode genannt) zur Charakterisierung fluoreszierender Reflexionsproben wird das Probenmaterial monochromatisch bestrahlt und für jede dieser anregenden Wellenlängen das emittierte Spektrum monochromatisch gemessen. Dies hat gegenüber einer polychromatischen Anregung (z. B. Normlichtart D65) den Vorteil, dass spektrale Materialfunktionen (Gesamt-, Reflexions- und Lumineszenz-Strahldichtefaktoren sowie das Lumineszenz-Anregungsspektrum) und diverse Farbmaßzahlen (Sicherheits- und Kontrastfarben; Referenzmaterial) für beliebige Anregungsspektren (Normlichtarten) bestimmt werden können. T2 - Licht 2010 (Gemeinschaftstagung der deutschen, niederländischen, schweizerischen und österreichischen lichttechnischen Verbände) CY - Vienna, Austria DA - 17.10.2010 PY - 2010 AN - OPUS4-22050 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin A1 - Haamkens, Frank A1 - Linde, O. T1 - Use of municipal solid waste incinerator bottom ash as aggregate concrete N2 - Modern municipal solid waste incinerator plants produce bottom ashes, which are used in building industry, especially as base course in road constructions. Because of a highly sophisticated reprocessing technique, the ashes Show a relatively stable composition, comparatively well defined properties and environmentally relevant Parameters below legal Limits. Due to its chemical and mineralogical characteristics, the bottom ash can in principle be used as Aggregate in the production of normal strength concrete. However, if the ash contains concrete damaging components Recycling becomes problematic. To assess the use of municipal solid waste incinerator bottom ash (MSWI bottom ash) as Aggregate in concrete, different additionally treated ashes were chemical and physical characterised. Furthermore, concrete specimens with bottom ash as aggregates were produced and their Engineering properties were studied. T2 - EGU 2007 European Geosciences Union General Assembly 2007, Symposium Energy, Resources and the Environment ERE8 "Aggregates - the most widely used geological material" CY - Vienna, Austria DA - 15.04.2007 PY - 2007 AN - OPUS4-18949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hünert, Daniela A1 - Schulz, Wencke A1 - Kranzmann, Axel T1 - Carburization and Oxidation of Power Plant Steels under Oxyfuel-Conditions N2 - Modern CO2-reduced power plants with Oxyfuel-Combustion operate with gas compositions of high CO2 partial pressure and steam (Boiler, Recycling). The corrosion process occurring under such service conditions is different from that under current conditions with air combustion. The effect of temperature, pressure, chromium content on the corrosion reaction of typical power plant steels in CO2 -H2O and CO-H2O-O2 was investigated. T2 - 3rd World Materials Research Institute Forum & Energy Symposium (WMRIF) CY - Gaithersburg, MD, USA DA - 21.06.2009 PY - 2009 AN - OPUS4-22625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dörfel, Ilona A1 - Rooch, Heidemarie A1 - Österle, Werner A1 - Kranzmann, Axel T1 - Vanadium and chromium containing precipitates in heat resistant steel T92 T2 - "Current Developments in TEM" (JEOL user meeting) CY - Freiberg, Germany DA - 10.03.2011 PY - 2011 AN - OPUS4-22678 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ramge, Peter A1 - Rübner, Katrin A1 - Kühne, Hans-Carsten T1 - Einflüsse der Mischungszusammensetzung auf die Porenstruktur von Instandsetzungsmörteln N2 - Untersucht wurde der Einfluss der Applikationsart (konventionelle und gespritzte Herstellung, Wasserlagerung bis zur Prüfung), der Einfluss von Fasern (konventionelle Herstellung, Wasserlagerung bis zur Prüfung) und der Einfluss von Schwindreduzierern (konventionelle Herstellung, Luftlagerung bis zur Prüfung). T2 - XV. Workshop über die Charakterisierung von feinteiligen und porösen Festkörpern (Porotec-Workshop) CY - Bad Soden, Germany DA - 16.11.2010 PY - 2010 AN - OPUS4-22634 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Heidmann, G. T1 - Monitoring von Hochspannungskabel-Muffen und -Endverschlüssen N2 - - Zunehmender Energiebedarf erfordert höhere Übertragungskapazitäten - Dezentrale ökologische Energiegewinnung, z. B. Offshore, erfordert Übertragung großer Energiemengen in die Ballungszentren (Nord-Süd-Trassen) - Hohe Auslastung der Netze erfordert Beherrschbarkeit der im Fehlerfall auftretenden Risiken für Menschen, Umwelt und energietechnische Anlagen - Etwa 90 % der Anlagenausfälle sind verursacht durch Teilentladungen (TE) in Endverschlüssen und Muffen mit modernen polymeren Isoliersystemen - Etablierte elektrische Verfahren erlauben nur externe Schadensdetektion. T2 - Expertenforum Strukturmonitoring auf der Sensor+Test-Messe CY - Nuremberg, Germany DA - 08.06.2011 PY - 2011 AN - OPUS4-24054 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ried, Peter A1 - Gaber, Martin A1 - Müller, Ralf A1 - Holtappels, Kai A1 - Schmidtchen, Ulrich A1 - Deubener, J. T1 - Wasserstoffpermeations-messung an Gläsern T2 - Glastechn. Tagung, HVG-DGG CY - Saarbrücken, Germany DA - 30.05.2011 PY - 2011 AN - OPUS4-24012 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Basedau, Frank T1 - Langzeitmonitoring der Ederstaumauer N2 - Die Fixierung der Stahlanker im Felsfundament zur Stabilisierung der Schwergewichtsmauer werden mit integrierten faseroptischen Dehnungssensoren überwacht. In die Glasfaser sind Reflektoren eingebaut; zwei Reflektoren bilden jeweils eine Messstrecke, die Auskunft über die Fixierung geben. Am Ankerkopf wird der Zustand der Messstrecken abgefragt. T2 - Expertenforum Strukturmonitoring auf der Sensor+Test-Messe CY - Nuremberg, Germany DA - 08.06.2011 PY - 2011 AN - OPUS4-24047 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herbst, Tristan A1 - Rübner, Katrin A1 - Meng, Birgit A1 - Hauer, B. T1 - Einsatzpotenzial und nachhaltige Verwertung von Hausmüllverbrennungsaschen als Gesteinskörnungen im Beton N2 - Im Hinblick auf eine nachhaltige Entwicklung sollen nach dem KrW/AbfG der Rohstoffeintrag und der Abfallaustrag in den Lebensphasen eines Bauwerks durch weitgehende Verwertung von Sekundärrohstoffen (Reststoffen) möglichst gering gehalten werden. Ein Einsatz von Reststoffen wie Hausmüllverbrennungsaschen (MV-Aschen) im Betonbau kann potenziell einen wesentlichen Beitrag zur nachhaltigen Entwicklung leisten. T2 - Tagung Bauchemie CY - Freiberg, Germany DA - 08.10.2009 PY - 2009 AN - OPUS4-22966 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Keserović, Amela A1 - Sobetzki, Joana A1 - Sarmiento Klapper, Helmuth A1 - Dimper, Matthias T1 - Evaluation of metallic materials for geothermal applications N2 - Since geothermal wells are a feasible energy source to replace fossil fuel supply, many technologies have been developed to take advantage of geothermal energy. Nevertheless, service conditions in geothermal facilities are due to the chemical composition of hydrothermal fluids and temperatures, in many cases, extreme in terms of corrosion. Therefore, materials selection based on preliminary material qualification is essential to guarantee a secure and reliable operation of the facilities. The corrosion behavior of different high-alloyed metals including Duplex and austenitic stainless steels as well as a nickel alloy have been evaluated in artificial geothermal fluids simulating the conditions in some locations with geothermal potential in Germany as well as two sites in Indonesia. The suitability of carbon steel 25CrMo4, stainless steels X2CrNiMo17-12-2, X2CrNiMo-22-5, X2CrNiMoCuWN25-7-4 and super austenitic steel X1CrNiMoCu32-28-7 in these geothermal fluids obtained by electrochemical measurements and exposure tests is limited. The nickel alloy NiCr23Mo16Al shows an excellent corrosion resistance against pitting corrosion. Excluding its high cost, it is a very good alternative to be used in the construction of geothermal facilities having highly saline brines. Stainless and Duplex steels exhibit a limited corrosion resistance concerning pitting and crevice corrosion. Beside of the higher alloyed materials, also the lowalloyed steel 25CrMo4 could be employed as a constructional material for the geothermal power plant in stagnant highly acidic non Saline environments, as long as the wall thickness of the material vs. corrosion rate is taken into account. T2 - European Geothermal Congress CY - Strasbourg, France DA - 19.09.2016 KW - Localized corrosion KW - Stainless steel KW - Ni-based alloy KW - Geothermal energy PY - 2016 AN - OPUS4-37751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Yevtushenko, Oleksandra A1 - Bettge, Dirk A1 - Le, Quynh Hoa A1 - Carrillo Salgado, I. T1 - Korrosion von Rohrleitungswerkstoffen durch Kondensationseffekte infolge von SO2- und NO2-Begleitstoffen in CO2 N2 - Derzeit wird der Einsatz metallener Werkstoffe in CCU-/CCS-Anlagen hinsichtlich deren Korrosionsbeständigkeit und eine eventuell daraus resultierende Herausforderung diskutiert. Während des CO₂-Transportes vom Abscheide- zum Injektionsort kann es aufgrund der den CO₂-Strom begleitenden Beimengungen, wie Wasser, O₂, SOₓ , NOₓ , Temperaturschwankungen durchaus zu Kondensationseffekten und daraus resultierenden Schäden kommen. Es konnte gezeigt werden, dass die sich möglicherweise innerhalb einer CO₂-Rohrleitung bildenden Kondensate infolge von Begleitstoffen wie SO2 und NO2 eine viel korrosivere Wirkung auf Rohrleitungswerkstoffe entfalten, als in reinem CO₂. T2 - 48. Kraftwerkstechnisches Kolloquium CY - Dresden, Germany DA - 18.10.2016 KW - CO2-Korrosion KW - Edelstahl KW - Chromstahl KW - CCUS KW - Kondensation PY - 2016 AN - OPUS4-37753 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Yevtushenko, Oleksandra A1 - Oelrich, Gerhard A1 - Hattendorf, H. T1 - Hochlegierte metallene Werkstoffe in Salzschmelzen N2 - In letzter Zeit kommen immer mehr alternative Energiequellen als Ersatz fossiler Brennstoffe zum Einsatz, so auch die Solarthermie. Jedoch sind die Betriebsbedingungen aufgrund der chemischen Zusammensetzung der Wärmeträgermedien und herrschenden Temperaturen extrem hinsichtlich Korrosion. Da die Kraftwerke bei maximaler Lebensdauer ökonomisch vertretbar sein müssen, ist eine Werkstoffauswahl basierend auf Voruntersuchungen notwendig, um einen sicheren und verlässlichen Betrieb dieser Anlagen zu gewährleisten. Die Werkstoffauswahl hängt von der Betriebstemperatur eines Kraftwerks bzw. der chemischen Zusammensetzung des Wärmeträgermediums ab. In hochkorrosiven Umgebungen werden aufgrund ihrer sehr guten Korrosionsbeständigkeit Nickelbasislegierungen nicht nur für stark korrosiv beanspruchte Bauteile als die Lösung angesehen. Jedoch kann es durchaus beständigkeitsbedingte Einschränkungen für den Einsatz geben, wofür die hier vorgestellten Ergebnisse dienen sollen. In diesem Beitrag wird die Beständigkeit ausgewählter hochlegierter Werkstoffe (inklusive einer neuentwickelten Legierung in einer Nitrat-Salzschmelze (60 % NaNO3/40 % KNO3) vorgestellt, die mittels elektrochemischer Messungen und Auslagerungsversuchen ermittelt wurde. T2 - 48. Kraftwerkstechnisches Kolloquium CY - Dresden, Germany DA - 18.10.2016 KW - Örtliche Korrosion KW - Nickelbasislegierungen KW - Solarenergie KW - Erneuerbare Energien KW - Elektrochemische Charakterisierung PY - 2016 AN - OPUS4-37754 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Konnertz, Nora A1 - Böhning, Martin T1 - QCM System for the Characterization of Gas Sorption and Physical Aging of Membrane Polymers for Gas Separation Applications N2 - Polymers are favorable materials for gas separation membranes. In general, gas transport experiments are performed with films in the range of 100 µm thickness. However, in large-scale processes very thin selective polymer layers in the range of 100 nm to 1 µm are used. Moreover, it was shown that thin films behave different compared to thick films with respect to gas transport properties and physical aging as well. Thus, for fundamental research it is important to realize gas transport experiments with thin films. The Quartz Crystal Microbalance (QCM) is a very sensitive method to detect mass changes in the range of nanograms. Therefore, this method enables sorption experiments with thin films or layers attached to the QCM crystal (100 nm up to 1 µm). Here, we present the experimental set-up for using the QCM technique for characterizing the gas sorption behavior of thin polymer films in a temperature controlled pressurized environment (up to 50 bar) - also quartz crystals and crystal holders were optimized. The study aims for the characterization of long-term behavior and physical aging of high-performance polymers for gas separation membranes - such as polyimides and polymers of intrinsic microporosity (PIMs) and respective nanocomposites. Especially the differences of the behavior of thin films compared to films with thicknesses up to 100 µm as well as nanofiller induced-effects are adressed. T2 - Polydays 2016 CY - Potsdam, Germany DA - 28.09.2016 KW - Quartz Crystal Microbalance QCM KW - Thin Films; KW - Gas Sorption KW - High Pressure PY - 2016 AN - OPUS4-37911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Konnertz, Nora A1 - Ding, Y. A1 - Schönhals, Andreas A1 - Böhning, Martin T1 - Enhanced gas separation performance of nanocomposites based on a polymer with intrinsic microporosity PIM-1 and phenethyl-POSS N2 - In times of the energy revolution, the need for energy efficient separation processes promotes the advancement of new high performance materials for use as highly selective separation membranes. Most promising materials in this field, especially for gas separation, are polymers with intrinsic microporosity (PIMs) which were firstly introduced by Budd and McKeown. In this study the permeability of PIM-1 was increased by 439 % by formation of nanocomposites with only 1 wt% of polyhedral oligomeric phenethyl-silsesquioxane (PhE-POSS) within the polymer matrix. As the CO2/CH4 selectivity is fully retained, this leads to a shift in the Robeson plot towards the upper bound. The Robeson plot describes the current state of the art trade-off relation between selectivity and permeability of all known membrane polymers. As molecular mobility is a key factor for gas transport as well as the often observed physical aging of such polymers, our study also includes for the first time, molecular dynamics and conductivity of pure PIM-1 and PIM-1 nanocomposites as investigated by broadband dielectric spectroscopy (BDS). T2 - Polydays 2016 CY - Potsdam, Germany DA - 28.09.2016 KW - PIM-1 KW - POSS KW - Broadband dielectric spectroscopy KW - Permeation PY - 2016 AN - OPUS4-37701 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marzok, Ulrich A1 - Müller, Ralf A1 - Reetz, R. A1 - Trunkhardt, M. T1 - High-temperature laser profilometry N2 - Advanced methods for 3D green density characterization like computed tomography and 3D FE sinter modeling can be utilized for increasing the reliability of sintered components. The experimental in situ observation of sintering, however, is currently restricted to silhouette methods, i.e. heating microscopy. For complex shaped samples, in situ shape screening during shrinkage would allow much better validation of 3D sinter simulation models. Further, by revealing temporary sinter warpage, 3D high-temperature shape screening would allow to locate potential defects of complex sintered components. Against this background, BAM developed a testing device for in situ 3D high-temperature shape screening for ceramic and glass-ceramic tapes up to 1000°C. Current work is focused on dropping this restriction in sample shape and temperature. The poster illustrates the current state of this work and possible applications of the method e.g. in detecting sinter warpage of metallized glass-ceramic LTCC tapes. T2 - ICC6, 6th International Congress on Ceramics CY - Dresden, Germany DA - 21.08.2016 KW - Laser profilometry KW - 3D High-temperature shape screening KW - Sintering PY - 2016 AN - OPUS4-37708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Steger, Jörg A1 - Böllinghaus, Thomas A1 - Hoffmeister, H. A1 - Münster, C. A1 - Kannengießer, Thomas T1 - Hydrogen in Welded Microstructures of T24 Steel: Effect on Mechanical Properties and Corresponding Hydrogen Diffusion N2 - Low-alloyed CrMoV steels, such as T24, are widely used for welded components in fossil power stations due to their excellent creep-strength. Spectacular failure cases in the recent years exhibited severe cracking in T24 welds. The results showed that hydrogen-assisted cracking (HAC) occurring up to 200 degree Celsius cannot be excluded. Hence, a basic understanding is necessary on how hydrogen affects the material properties of welded microstructures. In this regard, each weld microstructure (HAZ and weld metal) has influence on the HAC susceptibility and respective hydrogen diffusion. Thus, the present contribution summarizes different results obtained from experiments with grades T24 (CrMoV alloy) and T22 (CrMo) and thermally simulated HAZ. Tensile tests were conducted with hydrogen charged specimens and compared to hydrogen-assisted stress corrosion cracking results obtained from slow strain rate tests (SSRT) up to 200 degree Celsius. Electrochemical permeation and degassing experiments were performed to identify a particular weld microstructure influence on hydrogen diffusion and trapping (especially in the HAZ). The results showed that T24 base material has improved resistance to hydrogen-assisted degradation/cracking. In contrast, the as-welded HAZ had remarkably increased susceptibility (tesnile tests at hydrogen concentration of 1 to 2 ppm). SSRT experiments confirmed this at elevated temperatures for both the T24 and the T22. Hence, the evaluation of a particular degradation of the mechanical properties should be performed independently for each weld microstructure. In addition, the HAZ showed decreased diffusion coefficients (at room temperature) of approximately one magnitude compared to the base materials. Trapped hydrogen was determined in the T24 at temperatures up to 120 degree Celsius compared to 75 degree Celsius in the T22. This has to be considered in case of changing operational temperatures, e.g. in the case of start-up and shutdown processes of boiler components. T2 - 10th Conference on Trends in Welding Research CY - Tokyo, Japan DA - 11.10.2016 KW - Degradation of Mechanical Properties KW - Hydrogen KW - Creep-resistant Steel KW - Weld Joint KW - Diffusion PY - 2016 AN - OPUS4-37827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rockenhäuser, Christian A1 - Schriever, Sina A1 - Piesker, Benjamin A1 - Skrotzki, Birgit T1 - Microstructure evolution in aluminium alloy 2618 A during ageing and creep N2 - The Microstructure Evolution in Aluminium Alloy 2618 A during Ageing and Creep was presented and discussed. T2 - Microscopy & Microanalysis 2016 CY - Columbus, OH, USA DA - 24.07.2016 KW - Aluminium alloys KW - Coarsening KW - Transmission electron microscopy PY - 2016 AN - OPUS4-38268 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf A1 - Behrens, H. A1 - Deubener, J. T1 - Impact of structure and relaxation on fatigue and micromechanical properties of oxide glasses: the role of volatiles and bonding state N2 - As subcritical crack growth (SCCG) can reduce tensile strength of glasses by many orders of magnitude, the potential for improvement of fatigue behaviour is most intriguing in developing ultra-strong glasses. An essential bottleneck is the basic understanding of the numerous interplaying pressure-, temperature- and water-affected relaxation phenomena at the crack tip and related toughening strategies. Therefore, the present project aims to advance the basic understanding of structural relaxation effects and local properties caused by increased water concentration and tensile stresses at the crack tip as they are a key for structural toughening designs to develop SCCG-free glasses and glass surfaces. Our first studies give clear evidence that glass structure and dynamics is strongly modified upon hydration of glasses. These changes are highly related to the nature of network formers but are affected as well by the counter ions (network modifier). Results of the 1st project part suggest that structural relaxation below glass transition temperature, i.e. overlapping of short-range (beta) and long-range (alpha) interactions can contribute to SCCG in water-free environments and that structurally dissolved water in the glasses can have decisive impact on this effect. In the 2nd project stage specific glasses compositions will be investigated to gain an improved understanding on the relation of sub-Tg relaxation and inert SCCG as well as to shed light to the related effects of dissolved water and its speciation. These glasses cover a broader range of different glass topologies and binding partners, whereby the coupling of alpha and beta relaxations is varied systematically by alkali-, alkaline earth ions and water species concentrations. Preparation of hydrous glasses (up to 8 wt% water) will be performed by high pressure syntheses. Structure will be resolved by NMR, Raman and IR spectroscopy while structural relaxation is accessed in the temperature and frequency domain using dynamic mechanical spectroscopy and ultrasonic damping. We will focus on measurements of inert SCCG (region III) conducting experiments in vacuum and dry gas atmospheres using indentation techniques and stressing of glass specimens in DCB geometry. Experimental data on SCCG will be provided to SPP groups, which deals with fatigue in metallic glasses and vice versa we will test theoretical predictions of ab-initio simulations of partner within SPP 1594 in order to quantify the effect of water on the crack tip. In summa topological factors controlling the subcritical crack growth with respect to water will be identified from which structural toughening designs for highly fatigue resistant-glasses can be derived. N2 - Subkritisches Risswachstum (SCCG) kann die Zugfestigkeit von Glas um viele Größenordnungen erniedrigen. Deshalb birgt die Verbesserung des Ermüdungsverhaltens ein hohes Potential für das topologische Design hochfester Gläser. Ein diesbezüglicher Engpass ist das Verständnis der zahlreichen interagierenden druck-, temperatur- und wasserbeeinflussten Relaxationsphänomene an der Rissspitze und hieraus abgeleitete Verstärkungsstrategien. Ziel des Projekts ist es daher, das grundlegende Verständnis der Effekte, die infolge erhöhter Wasserkonzentrationen und Zugspannungen an der Rissspitze entstehen, zu vertiefen, da sie als ein Schlüssel für künftige strukturelle Designprinzipien zur Entwicklung schadenstoleranter Gläser und Glasoberflächen gelten. Unsere ersten Studien zeigen, dass die Struktur und Dynamik von Gläsern nach einer Hydration stark verändert sind. Diese Modifikationen sind mit der Art der Netzwerkbildner stark verknüpft, aber auch von ihren Gegenionen (Netzwerkwandler) abhängig. Die Ergebnisse des ersten Projektabschnitts legen nahe, dass strukturelle Relaxation unterhalb der Glasübergangstemperatur, d. h. ein Überlappen von kurz-reichweitigen (beta) und lang-reichweitigen (alpha) Wechselwirkungen, zum subkritisches Risswachstum in wasserfreien Umgebungen beitragen kann und, dass strukturell gelöstes Wasser in Gläsern sich entscheidend auf diese Effekt auswirken kann. Im zweiten Projektabschnitt werden daher spezielle Glaszusammensetzungen untersucht, die zu einem besseren Verständnis der Verbindung zwischen sub-Tg Relaxation und SCCG führen aber auch den Einfluss von gelöstem Wasser und dessen Speziation näher beleuchten. Diese Gläser weisen eine großen Breite an verschiedenen Topologien und Bindungspartnern auf, wobei die Kopplung von alpha und beta Relaxation durch Veränderungen in den Gehalten von Alkali-, Erdalkalionen und der Wasserspezies systematisch variiert wird. Die Präparation hydratisierter Gläser (bis zu 8 Ma.%) erfolgt mittels Hochdrucksynthesen. Die Glasstruktur wird durch NMR, Raman und IR Spektroskopie aufgeklärt während die Strukturrelaxation anhand dynamische mechanische Spektroskopie und Ultraschalldämpfung im Temperatur- und Frequenzraum erfasst wird. Im Fokus werden Messungen des inerten subkritischen Risswachstums (Region III) stehen, die Indenter-Experimente im Vakuum und trockenen Gasatmosphären sowie Verspannen von Glasproben in DCB Geometrie beinhalten. Experimentelle SCCG Daten werden Gruppen im Schwerpunktprogramm zur Verfügung stellen, die sich mit Ermüdung in metallischen Gläsern beschäftigen und im Gegenzug werden wir theoretische Vorhersagen aus ab initio Simulationen der Partner im SPP 1594 testen, um den Einfluss von Wasser auf die mechanischen Eigenschaften an der Rissspitze und deren Einfluss auf SCCG zu quantifizieren. In summa werden topologische Faktoren bezüglich Wasser, die SCCG kontrollieren, identifiziert, um daraus Designprinzipien für hoch ermüdungsresistente Gläser abzuleiten. T2 - Kolloquium des DFG-PP 1594 CY - Jena, Germany DA - 17.9.2015 KW - Glass KW - Fatigue PY - 2015 AN - OPUS4-38334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinemann, Steffi A1 - Babutzka, Martin A1 - Lehmann, Jens A1 - Burkert, Andreas T1 - Untersuchung des Einflusses industrieller Korundschleifprozesse auf die Korrosionsbeständigkeit nichtrostender Stähle mittels KorroPads N2 - Das Poster stellt aktuelle Eregbnisse des AiF-Vorhabens 18823 N/1 zum Einfluss von Schleifprozessen auf die Korrosionsbeständigkeit nichtrostender Stähle vor. T2 - Jahrestagung 2016 der GfKORR CY - Frankfurt/Main, Germany DA - 15.11.2016 KW - Korrosion KW - Corrosion KW - Korundschleifen KW - Corundum grinding KW - Nichtrostende Stähle KW - Stainless steels PY - 2016 AN - OPUS4-38299 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blaeß, Carsten A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Groh, D. A1 - Döhler, F. A1 - Brauer, D. S. T1 - Sintering and crystallization of new bioactive glasses N2 - Bioglass® 45S5 is mainly used clinically as powders, granules or pastes instead of sintered compacts. This is due to the inherent problem of crystallization during the sintering, which results in poor mechanical properties and reduced bioactivity. Recently, new bioactive glasses with improved crystallization stability have been developed as promising candidates for manufacturing of sintered powder compacts for bone regeneration, which combine improved sintering behavior with bioactivity. Compared with the well-known Bioglass® 45S5 (SiO2-P2O5-CaO-Na2O) the calcium/alkali oxide ratio was increased, sodium oxide was partially replaced by potassium oxide and up to 3 mol% calcium fluoride were added, in order to stabilize the glass against crystallization. The aim of this study was to investigate the sintering and crystallization behavior of these new bioactive glasses. Sintering and crystallization were characterized by heating microscopy, XRD, FTIR, SEM, and DTA. The results show that a sintered density of 88-99 % is achieved in contrast to only 57-67% for Bioglass® 45S5. In addition, FTIR and XRD analyses show that Bioglass® 45S5 crystallized during sintering while for the new glasses no crystalline phases are detected. The thermal properties of all glasses were studied by DTA measurements, and the influence of grain size was characterized. These studies showed that full densification can be attained for particle size < 32 µm, whereas coarser particles progressively increase residual porosity. Observed foaming phenomena, are strongly retarded by crystallization of beta-HAp. T2 - ICG 2016 CY - Shanghai, China DA - 07.04.2016 KW - Bioactive KW - Glass KW - Crystallization KW - Sintering PY - 2015 AN - OPUS4-38304 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blaeß, Carsten A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Groh, D. A1 - Döhler, F. A1 - Brauer, D. S. T1 - New bioactive glasses with improved sintering behavior N2 - Nowadays, the use of bioactive glasses is established for bone regeneration; however glasses are used mostly as powders, granules or in a paste. Sintered scaffolds are not used clinically, because of the in inherent problem of crystallization during the sintering process, resulting in poor mechanical properties and reduced bioactivity. The aim of this study was therefore to design new bioactive glasses, which combine improved processing and sintering with bioactivity. Compared with the well-known Bioglass® 45S5 (SiO2-P2O5-CaO-Na2O) the calcium/alkalioxide ratio was increased, sodiumoxide was partially replaced by potassiumoxide and up to 8 mol% calciumflorid were added, in order to stabilize the glass against crystallization. The sintering behavior of the new glasses was characterized by heating microscopy and compared to Bioglass® 45S5. The results showed that the new glasses achieved a sintered density of 88-99 % in contrast to only 57-67% for Bioglass® 45S5. In addition FTIR and XRD analyses showed that Bioglass® 45S5 crystallized during sintering while for the new glasses no crystalline phases were detected. The thermal properties of all glasses were studied by DTA and DSC measures, and the influence of grain size and heating rate were characterized. These studies showed a shift of start and end temperature of sintering process as well as the final density. The structure of sintered specimens during and after sintering was examined using light and electron microscopy (REM). T2 - Crystallization 2015 CY - Nagaoka, Japan DA - 11.10.2015 KW - Bioactive KW - Glass KW - Crystallization KW - Sintering PY - 2015 AN - OPUS4-38308 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blaeß, Carsten A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Brauer, D. S. T1 - Sintering and crystallization of new bioactive glasses N2 - Bioglass® 45S5 is mainly used clinically as powders, granules or pastes instead of sintered compacts. This is due to the inherent problem of crystallization during sintering. Recently, new bioactive glasses with improved crys-tallization stability have been developed as promising candidates for manufacturing of sintered powder compacts for bone regeneration, which combine improved sintering behavior with bioactivity. Compared with the well-known Bioglass® 45S5 (SiO2-P2O5-CaO-Na2O) the calcium/alkali oxide ratio was increased, sodium oxide was partially replaced by potassium oxide and up to 3 mol% calcium fluoride were added, in order to stabilize the glass against crystallization. Sintering and crystallization were characterized by heating microscopy, XRD, FTIR, SEM, and DTA. The results show that a sintered density of 88-99 % is achieved in contrast to only 57-67% for Bioglass® 45S5. Whereas Bioglass® 45S5 powder compacts crystallize during sintering, for the new glasses no crystalline phases were detected. Additionally the influence of grain size was characterized. These studies showed that full densification can be attained for particle size < 32 µm, whereas coarser particles pro-gressively increase residual porosity. Observed foaming phenomena, are strongly retarded by crystallization. T2 - 90. Glastechnische Tagung (Deutsche Glastechnische Gesellschaft e.V.) CY - Goslar, Germany DA - 06.06.2016 KW - Bioactive KW - Glass KW - Crystallization KW - Sintering PY - 2016 AN - OPUS4-38311 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Laquai, René A1 - Schaupp, Thomas A1 - Müller, Bernd R. A1 - Griesche, Axel A1 - Bruno, Giovanni A1 - Kannengießer, Thomas T1 - 3D imaging of hydrogen assisted cracking using analyser-based imaging N2 - To better understand the mechanism of hydrogen assisted cracking (HAC), it is important to investigate the 3D structure of the cracks non-destructively. Since, cracks introduced by HAC are usually very small, conventional x-ray imaging methods often lack the required spatial resolution. However, the detection of those cracks can be enhanced by taking advantage of refraction at interfaces within the sample. To image this refractive deflection we employ analyser based imaging (ABI). In this work we aim at proving the enhanced crack detection of ABI by investigating an alluminum alloy weld. T2 - BESSY User Meeting 2015 CY - Berlin, Germany DA - 09.12.2015 KW - X-ray refraction KW - Synchrotron KW - Analyser-based imaging KW - Hydrogen assisted cracking KW - Welding PY - 2015 AN - OPUS4-38278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Babutzka, Martin A1 - Burkert, Andreas A1 - Heyn, A. T1 - Bestimmung von Korrosionsabträgen an Zink mittels gelartiger Elektrolyte N2 - Das Poster zeigt eine Methode zur Bestimmung von Korrosionsraten und Korrosionsabträgen an Zink durch Verwendung von gelartigen Elektrolyten. T2 - Jahrestagung 2016 der GfKORR CY - Frankfurt/Main, Germany DA - 15.11.2016 KW - Gelartige Elektrolyte KW - Gel-type electrolytes KW - Verzinkungen KW - Zinc coatings KW - Korrosionsabtrag KW - Corrosion loss PY - 2016 AN - OPUS4-38298 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nützmann, Kathrin A1 - Schulz, Wencke A1 - Saliwan Neumann, Romeo A1 - Wollschläger, Nicole A1 - Stephan, Christiane A1 - Kranzmann, Axel T1 - The influence of sulfur on initial high temperature corrosion of Fe-Cr model alloys N2 - Ferritic steels with Cr-contents up to 13 wt. % are used as heat exchanger or boiler tube materials in combustion based power plants. These materials are subject to aggressive corrosion caused by the reaction of the steel with highly corrosive gases under high temperatures up to 650°C. The early stages of corrosion and sulfidation especially and the influence of the Cr-content in the alloy are thereby not understood but of fundamental interest. Our work shows corrosion mechanisms and presents corrosion models for Fe and different Fe-Cr-alloys under pure SO2 und SO2+O2 atmospheres for different time scales. Modell alloys of high purity are used to focus on the reaction of the intended elements: Fe, Cr, S, and O. Long-time experiments (≥12h) took place in tube furnaces and short-time experiments (≥5min) in a special designed light furnace. Heating and cooling took place under inert atmosphere. The reactive gases were added not until the experimental temperature was reached. Samples were analyzed using high resolution synchrotron X-ray diffraction using a micro focus setup and electron microscopy including FIB. Many earlier studies on corrosion and sulfidation on iron based alloys show a higher corrosion rate and material loss when sulfur was present in the atmosphere. In contrast, later studies propose an inhibiting effect of sulfur containing atmospheres. On the one side, most likely due to the formation of a protective layer of Mx(SO4)y -phases at the scale-gas interface. On the other side, a very recent study proposes the theory that MxSy-phases limit the further diffusion of elements. Up to now, no Mx(SO4)y –phases were detected in our samples, but sulfide phases nucleated within the oxide phases. For pure Fe our samples show FeS at the scale-metal interface working as a diffusion barrier for Fe-Cations from the base material in to the oxide scale. The above lying spalled off oxide-sulfide scale shows a wide area of small voids and accumulations of FeS-Crystals at the bottom. Under the main oxide scale a second generation of oxide-sulfide scale starts to form. For the Fe-Cr-alloys the inner oxide scale only shows FeS- and CrS-phases surrounded by hollow space. The here presented study will explain and discuss a new growth model for the shown phenomenon. T2 - 9th High Temperature Corrosion and Protection of Materials CY - Ile des Embiez, France DA - 15.05.2016 KW - Sulfidation KW - Diffusion barrier KW - Fe-Cr alloys PY - 2016 AN - OPUS4-38250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blaeß, Carsten A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Brauer, D. S. T1 - Sintering and crystallization of new bioactive glasses N2 - Bioglass® 45S5 is mainly used clinically as powders, granules or pastes instead of sintered compacts. This is due to the inherent problem of crystallization during the sintering, which results in poor mechanical properties and reduced bioactivity. Recently, new bioactive glasses with improved crystallization stability have been developed as promising candidates for manufacturing of sintered powder compacts for bone regeneration, which combine improved sintering behavior with bioactivity. Compared with the well-known Bioglass® 45S5 (SiO2-P2O5-CaO-Na2O) the calcium/alkali oxide ratio was increased, sodium oxide was partially replaced by potassium oxide and up to 3 mol% calcium fluoride were added, in order to stabilize the glass against crystallization. The aim of this study was to investigate the sintering and crystallization behavior of these new bioactive glasses. Sintering and crystallization were characterized by heating microscopy, XRD, FTIR, SEM, and DTA. The results show that a sintered density of 88-99 % is achieved in contrast to only 57-67% for Bioglass® 45S5. In addition, FTIR and XRD analyses show that Bioglass® 45S5 crystallized during sintering while for the new glasses no crystalline phases are detected. The thermal properties of all glasses were studied by DTA measurements, and the influence of grain size was characterized. These studies showed that full densification can be attained for particle size < 32 µm, whereas coarser particles progressively increase residual porosity. Observed foaming phenomena, are strongly retarded by crystallization of beta-HAp. T2 - SGT Centenary Conference CY - Sheffield, UK DA - 04.09.2016 KW - Bioactive KW - Glass KW - Crystallization KW - Sintering PY - 2016 AN - OPUS4-38317 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf A1 - Marzok, Ulrich A1 - Reetz, R. A1 - Trunkhardt, M. T1 - High-temperature laser profilometry N2 - Advanced methods for 3D green density characterization like computed tomography and 3D FE sinter modeling can be utilized for increasing the reliability of sintered components. The experimental in situ observation of sintering, however, is currently restricted to silhouette methods, i.e. heating microscopy. For complex shaped samples, in situ shape screening during shrinkage would allow much better validation of 3D sinter simulation models. Further, by revealing temporary sinter warpage, 3D high-temperature shape screening allows to locate potential defects of complex sintered components. Against this background, BAM developed a testing device for in situ 3D high-temperature shape screening for ceramic and glass-ceramic tapes up to 1000°C [1-3]. Current work is focused on dropping this restriction in sample shape and temperature. The poster illustrates the current state of this work and possible applications of the method e.g. in detecting sinter warpage of metallized glass-ceramic LTCC tapes. T2 - SGT Centenary Conference, & ESG 2016 CY - Sheffield, UK DA - 04. 09. 2016 KW - Laser profilometry KW - 3D High-temperature shape screening KW - Sintering PY - 2016 AN - OPUS4-38320 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shashev, Yury A1 - Kupsch, Andreas A1 - Lange, Alex A1 - Bruno, Giovanni A1 - Müller, Bernd R. A1 - Hentschel, Manfred P. A1 - Britzke, Ralf T1 - Improving 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 T2 - PhD Day 2016 CY - Berlin, Germany DA - 2.09.2016 KW - Phase grating PY - 2016 AN - OPUS4-38323 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shashev, Yuri A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Britzke, Ralf A1 - Bruno, Giovanni A1 - Müller, Bernd R. A1 - Hentschel, Manfred P. T1 - Optimizing the performance of phase gratings for better visibility in Talbot- Lau interferometry 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. T2 - PhD Day 2015 CY - Berlin, Germany DA - 14.7.2015 KW - Talbot-Lau interferometry PY - 2015 AN - OPUS4-38325 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erdmann, Maren A1 - Niebergall, Ute A1 - Böhning, Martin T1 - Mechanical characterization of high-density polyethylene in contact with diesel and biodiesel fuels N2 - Renewable resources become more and more relevant to maintain energy demands for an increasing global population. Biosynthetic fuels like biodiesel might replace conventional petrochemical fuels, such as diesel. However, more research is needed to characterize the interaction between the different fuels and polymeric materials widely used in the fuel infrastructure as well as for automotive parts. Especially changes in the structural properties and mechanical behavior of the polyethylene (PE-HD) have to be addressed. The presented work comprises the direct interaction of high density polyethylene (PE-HD) with diesel and biodiesel, resulting in swelling and plasticization. Also long-term degradation phenomena will be discussed. The chosen PE-HD types are typical thermoplastic resins for container and storage tank applications. The impact of diesel and biodiesel in PE-HD is investigated by changes in the mechanical properties with emphasis on the Charpy impact strength. Furthermore, structural and dynamic influences on the polymeric material induced by diesel and biodiesel are proven in Dynamic Mechanical Analysis (DMA). Both methods, Charpy impact strength and DMA, reveal softening effects due to the migration of diesel and biodiesel into the amorphous regions of PE-HD. Since biodiesel is more prone to oxidative degradation compared to diesel, the fuel/air/polymer-interaction is studied for partly immersed tensile test specimens. Main focus of the evaluation is the co-oxidation. Here, the accelerated deterioration of PE caused by the sorption of the facile oxidation of biodiesel into the solid polymer might be a major degradation mechanism in this context. T2 - POLYDAYS 2016 CY - Potsdam, Germany DA - 28.09.2016 KW - PE-HD KW - Diesel KW - Biodiesel KW - Oxidation PY - 2016 AN - OPUS4-37677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Menzel, Friederike A1 - Menzel, Friederike A1 - Conradi, Bianca A1 - Rodenacker, K. A1 - Gorbushina, Anna A1 - Schwibbert, Karin T1 - Semi-automated statistical quantification of initial colonization of bacteria on different materials under standardized conditions N2 - The formation of biofilms on different materials provokes high costs in industrial processes, as well as in medical applications. Therefore, the interest in development of new materials with improved surfaces to reduce bacterial colonization rises. In order to evaluate the quality and safety of these new materials, it is highly important to ensure world-wide comparable tests that are relying on statistical evidence. The only way to reach this statistical safety is through a high-throughput Screening under standardized test conditions. We developed a flow through system for cultivation of biofilm-forming bacteria under controlled conditions with a total capacity for testing up to 32 samples in parallel. Quantification of the surface colonization was done by staining the bacterial cells with a fluorescence marker, followed by epifluorescence microscopy. More than 100 images of each sample were automatically taken and the surface coverage was estimated with the free open source software gmic (http://gmic.eu), followed by a precise statistical evaluation. Overview images of all gathered pictures of the whole material coupon were generated to illuminate the colonization characteristics of the selected bacteria on certain materials. With this method, differences in bacterial colonization on different materials can be quantified in a statistically validated manner. The innovative and solid test procedure will support the design of improved materials for medical and industrial applications such as implants, ship hulls, pipelines, heat exchangers, aquaculture equipments, photovoltaic-panels and fundaments of wind power plants. T2 - Vereinigung für Allgemeine und Angewandte Mikrobiologie - Jahrestagung 2016 CY - Jena, Germany DA - 13.03.2016 KW - Biofilm cultivation KW - Image analysis KW - Microscopy PY - 2016 AN - OPUS4-37724 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yildirim, Arda A1 - Sentker, K. A1 - Kityk, A. V. A1 - Huber, P. A1 - Schönhals, Andreas T1 - Structure and dynamics of 2,3,6,7,10,11-hexakis[hexyloxy] triphenylene in nanoporous anodic aluminum oxide membranes N2 - Due to their chemical structure, a rigid disk-like aromatic core and flexible alkyl chains attached to the core, discotic liquid crystals (DLCs) can organize and stack themselves into columns in a hexagonal columnar mesophase, a mesophase in between the plastic crystalline and isotropicphase. The overlap of the π orbitals of the aromatic core in the hexagonal columnar mesophase leads to a high charge-carrier mobilitie along the column axis – these columns can be considered as “moleculer nanowires” making liquid crystals a promising class of materials for electronic applications. Previous studies on DLCs showed that the phase behavior of DLCs is susceptible to nano confinement. Here in this study, the thermotropic collective orientational order of 2,3,6,7,10,11 hexakis[hexyloxy] triphenylene (HAT6), a triphenylene based DLC, and the effects of nano confinment on of its phase behavior were investigated by broadband dielectric spectroscopy (BDS) and differential scanning calorimetry (DSC). HAT6 was embedded into nanoporous anodic aluminum oxide membranes by melt infiltration in the isotropic phase under argon atmosphere. The filled membranes have the thickness of 80 µm and the diameter of 15mm and parallel aligned tubular nanopores having the pore diameters of 25, 40, 80 and 180 nm. The filling degree for each sample was checked by thermogravimetric analysis (TGA) in order to ensure complete filling. The bulk HAT6 forms, a hexagonal columnar phase between the isotropic phase above 371 K, and the plastic crystalline phase below 340 K. Unlike the bulk, the confined HAT6 forms two peaks in the heat flow during the plastic crystalline-to-hexagonal columnar phase transition, which might be the evidence of two different phase structures close to the wall and in the pore center. Moreover, the isotropic-to-columnar transition of the confined HAT6 shifts with decreasing pore diameter to lower temperatures. T2 - 9th International Conference on Broadband Dielectric Spectroscopy and its Applications CY - Pisa, Italy DA - 11.09.2016 KW - Discotic liquid crystals PY - 2016 AN - OPUS4-37712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus A1 - Niebergall, Ute A1 - Böhning, Martin A1 - Alig, I. A1 - Oehler, H. T1 - Degradation of PE-HD induced by liquid media - FNCT testing N2 - The Full-Notch Creep Test (FNCT) is widely used to characterize the slow crack growth (SCG) behavior of polyolefin materials in “inert” media as well as effects of environmental stress cracking (ESC) in which the medium has decisive influence on damage mechanism and time to failure tf*. Usually the FNCT is applied as a standardized testing method (ISO 16770) using a few universal liquid media, such as solutions of Arkopal N 100 (detergent). Selected relevant PE-HD materials are investigated also in real media and influences of temperature and geometry of specimen and notch are explicitly addressed. The investigations comprise also the ESC behavior of PE-HD in media that are sorbed to a significant extent – such as Diesel and Biodiesel – based on comparison with samples previously saturated with those media. T2 - PolyDays 2016 CY - Potsdam, Germany DA - 28.09.2016 KW - Sorption KW - Environmental stress cracking KW - Slow crack growth KW - PE-HD KW - FNCT PY - 2016 AN - OPUS4-37716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mishurova, Tatiana A1 - Cabeza, Sandra A1 - Bruno, Giovanni T1 - The role of reinforcement orientation on the damage evolution of short fibre reinforced metal matrix composite under compression N2 - In the present study, internal damage to an AlSi12CuMgNi alloy reinforced with planar random Al2O3 short fibres was investigated after compression testing. Due to the alloy composition, this composite contains a second reinforcement phase in the form of eutectic Si, which builds interpenetrated networks in the volume and increases the creep resistance and load-bearing capacity of the material. Materials with their fibre plane parallel and transversal to the load direction were characterized in order to investigate the dependence of load partition and damage on fibre plane orientation. In-situ compression testing during neutron diffraction measurements showed that internal damage is strongly influenced by the load partition between matrix and reinforcement. Moreover, micro-computed tomography was performed in the same material after ex-situ compression for damage analysis. In the case of a fibre plane perpendicular to the applied load, breakage and interconnected cracks appeared in a significantly higher volume fraction than with a fibre plane parallel to load. T2 - RACIRI Summer School CY - Repino, Russia DA - 22.08.2016 KW - Metal matrix composite KW - Computed tomography KW - Neutron diffraction KW - Load transfer PY - 2016 AN - OPUS4-38107 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosu, Dana-Maria A1 - Hertwig, Andreas A1 - Beck, Uwe T1 - The accuracy and reproducibility in thickness determination of thin films using SE N2 - Maintaining a consistent product quality is critical for the thin film industry. Therefore, the development of highly accurate protocols able to detect variations and nonidealities in manufactured thin film devices is essential and helps improve production quality and decrease manufacturing costs. The present work will discuss the accuracy and reproducibility in the determination of the thickness of thin films relevant for optoelectronic industry using spectroscopic ellipsometry, starting with the importance of set-up calibration, the need for very well defined calibration standards suitable for real devices and not least, the importance of accurate data analysis. As ellipsometry is an indirect method and theoretical modelling is needed to obtain the desired information regarding the investigated samples (e.g. thickness, roughness, optical constants), the model uncertainty has to be discussed and taken into account. If for ideal samples consisting of single layers with well-known optical constants the determination of thickness and roughness is straight forward and pretty accurate, for real samples, more complex theoretical models are needed and extracting accurate information regarding the samples can be very challenging. With careful calibration and a multidisciplinary approach, a combined measurement methodology can be developed enabling reliability, comparability, and accuracy. For production-relevant operation, maintaining the ease of use and scalability of ellipsometry as a technique can also be retained. T2 - EOSAM (European Optical Society Annual Meeting) CY - Berlin, Germany DA - 26.09.2016 KW - Spectroscopic ellipsometry KW - Thin films KW - Film thickness determination KW - Uncertainty PY - 2016 AN - OPUS4-38109 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wurzler, Nina A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Emmerling, Franziska A1 - Kunte, Hans-Jörg A1 - Özcan Sandikcioglu, Özlem T1 - Investigation of the mechanisms of microbially induced corrosion on Fe/steel surfaces N2 - The role of metal reducing bacteria (MRB) in corrosion is being controversially discussed in the literature. They can utilize metals including iron, uranium and manganese as well as many organic compounds as electron acceptors. The reduction of Fe(III) compounds to soluble Fe(II) species leads to the destruction of passive films on steel, resulting in acceleration of general and local corrosion processes. Recent research shows that the secretion of electron shuttles like riboflavins also contribute to the extracellular electron transfer (EET). The aim of this project is to understand the chemical and electrochemical interaction mechanisms of MRB with steel surfaces by means of combined in situ techniques. An electrochemical XANES (x-ray absorption near edge spectroscopy) cell has been designed to study the changes of passive film chemistry in the presence of biomolecules and MRB. Electrochemical quartz crystal microbalance (eQCM) is used for studying the kinetics of bacterial cell attachment and diffusion of biomolecules in model biofilms. In situ investigations are complemented by ex situ spectroscopic and microscopic analysis to investigate the biofilm structure, composition and cell viability. Via the combination of electrochemical methods with spectroscopic techniques and QCM we are able to follow biological processes and resulting degradation of steel surfaces in a non-destructive manner. The selection of model systems and a defined biological medium allows the identification of the effects of individual surface and environmental parameters. The fundamental understanding of bacterial attachment mechanisms and initial steps of biofilm formation will contribute to the development of new antifouling strategies. T2 - Electrochemistry 2016 CY - Goslar, Germany DA - 26.09.2016 KW - MIC KW - Microbiologically influenced corrosion KW - XANES KW - Electrochemistry PY - 2016 AN - OPUS4-38199 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madkour, Sherif A1 - Szymoniak, Paulina A1 - Schönhals, Andreas T1 - Evidence of a three-layred structure in ultrathin PVME and PVME-PS blend films by nanosized relaxation spectroscopy N2 - In the course of miniaturizing modern technology down to the molecular scale, much remain unknown about the materials behavior and the deviations from the bulk that might arises from confinement effects. Here, a combination of nano-sized relaxation spectroscopies (Broadband dielectric spectroscopy (BDS) and Specific heat spectroscopy (SHS); employing AC nanochip calorimetry) were utilized to investigate the glassy dynamics of ultra-thin films of Poly (vinyl methyl ether) (PVME) and of blends PVME / Polystyrene (PS) 50:50 wt-%,, which are miscible in bulk (thicknesses: ca. 8 nm – 160 nm, film thickness was controlled by ellipsometry, film topography by AFM). Both methods are sensitive to different probes; where SHS senses entropy fluctuations while BDS measures dipole fluctuations. For BDS measurements, a recently developed nano-structured electrode sample arrangement is employed, where ultra-thin films are spin-coated on an ultra-flat highly conductive silicon wafer, sandwiched between a wafer with nanostructured SiO2 nano-spacers with heights between 35 nm and 70 nm. For PVME films, two thickness independent processes were observed and interpreted to be the α-processes of a bulk-like layer and a process due to an absorbed layer to the substrate. This adsorbed layer further undergoes a confinement effect that results in the localization of the segmental dynamics, which results in an Arrhenius-like temperature dependence. A detailed analysis of the dielectric strengths of both processes reveals that the thickness of the adsorbed layer decreases with increasing temperature, while that of the bulk-like layer increases. For the blend system, by measuring the dynamic Tg in dependence of the film thickness, SHS showed that the Tg of the whole film was strongly influenced by a nanometer-thick surface layer at the polymer/air interface due to a self-assembling process. The dynamic Tg obtained from the SHS measurements decreased with decreasing film thickness. On the other hand, BDS measurements showed a completely different behavior. At high temperatures, the temperature dependence of the relaxation times of the films follows that of bulk-like PS/PVME; obeying the VFT-law. With decreasing temperature, the temperature dependence deviates from the VFT to an Arrhenius law; where the apparent activation energy decreases with decreasing film thickness. This is the first example where confinement induced changes were observed by BDS for ultra-thin films. All results were analyzed in detail in a comprehensive discussion. T2 - Polydays 2016 CY - Potsdam, Germany DA - 28.09.2016 KW - Ultra-Thin films PY - 2016 AN - OPUS4-38188 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk A1 - Sonnenburg, Elke A1 - Klinger, Christian T1 - Metallographische Zielpräparation von Ungänzen im Zusammenspiel mit ZfP-Methoden N2 - Oft sind von außen nicht sichtbare „Ungänzen“ im Innern die Ursache für das Versagen von Bauteilen. In manchen Fällen genügt eine herkömmliche metallographische Präparation, um der Schadensursache auf die Spur zu kommen. In anderen Fällen aber sind die Ungänzen zu klein oder ihre Lage zu ungewiss, um sie mit zufälligen Schnitten zu treffen. Zudem würde man durch Fehlversuche das Bauteil zu stark schädigen und so wertvolle Spuren verlieren sowie die weitere Untersuchbarkeit einschränken. In solchen Fällen ist es im wahrsten Sinn des Wortes zielführend, die Ungänzen mit Hilfe eines räumlich abbildenden ZfP-Verfahrens zu lokalisieren und dann mit den erhaltenen Koordinaten eine metallographische Zielpräparation präzise durchzuführen. Als Methoden kommen z.B. Mikro-Computer-Tomographie (µCT) und Tauch-Ultraschall in Frage. Bauteile können kleine elektronische Komponenten sein, aber auch große Bauteile wie Wellen aus Fahrzeugen oder Anlagen. T2 - Metallographietagung 2016 CY - Berlin, Germany DA - 21.09.2016 KW - Metallographie KW - ZfP KW - Schadensanalyse PY - 2016 AN - OPUS4-38190 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk A1 - Sturm, Daniel A1 - Goldbeck, Hennig A1 - Ell, Matthias A1 - Klinger, Christian T1 - Metallographische Untersuchungen an gebrochenen Hüftprothesen mit Schaftadapter N2 - Modulare Hüftprothesen können individuell der Anatomie des Patienten angepasst werden und haben dadurch eine positive Auswirkung auf dessen Lebensqualität. Unter Betriebsbelastung sind in der zusätzlichen Konusverbindung zwischen Schaft und Kopfteil Relativbewegungen möglich. Selbst an Titan-Bauteilen bewirken diese durch Verletzung der Passivschicht Reibkorrosion und infolgedessen Spaltkorrosion. Verunreinigungen wie z.B. Knochenrückstände in der Konusverbindung bewirken eine erhöhte Relativbewegung und führen zusätzlich zu einer örtlichen Spannungsüberhöhung durch lokale Pressung. Die an der Mantelfläche des Schafts entstehenden Korrosionsdefekte reduzieren die Schwingfestigkeit des Schafts erheblich, so dass dort Schwingrisse initiiert werden können, welche dann durch die üblichen zyklischen Schwell-Biegebelastungen bis zum Restgewaltbruch wachsen. T2 - Metallographietagung 2016 CY - Berlin, Germany DA - 21.09.2016 KW - Metallographie KW - Fraktographie KW - Schadensanalyse PY - 2016 AN - OPUS4-38191 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weigert, Florian A1 - Resch-Genger, Ute A1 - Würth, Christian T1 - Ensemble and single particle studies of the fluorescence properties of core­shell CdSe nanocrystals with different shells and surface chemistries N2 - The optical properties of semiconductor nanocrystals (SCNC) are controlled by constituent material, particle size, and surface chemistry, specifically the number of dangling bonds favoring nonradiative deactivation, and hence also by particle synthesis. In this respect, the fluorescence properties of coreshell CdSe SCNCs with different shells and surface chemistries were studied on ensemble and single particle level, using steady state and timeresolved fluorometry and confocal microscopy with time correlated single photon counting detection. Special emphasis was dedicated to correlate ensemble photoluminescence (PL) quantum yields and decay kinetics with particle brightness, PL time traces, and the Ontime fraction of the single SCNCs. Additionally, the confocal PL images were correlated with AFM measurements in order to derive the amount of absorbing, yet nonemisssive ”dark” SCNCs, the presence of which leading to an underestimation of ensemble PL quantum yields. The results of this study can help to identify synthetic routes and surface modifications minimizing the fraction of dark SCNC, thereby closing the gap to the ultimate goal of colloidally and photochemically stable SCNCs with a PL quantum yield of close to unity. T2 - FQDots16 CY - Berlin, Germany DA - 05.09.2016 KW - Confocal KW - QY KW - QD KW - SCNC KW - Single molecule KW - AFM PY - 2016 AN - OPUS4-38119 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weigert, Florian A1 - Resch-Genger, Ute A1 - Würth, Christian T1 - Photoluminescence Properties of coreshell CdSe Nanocrystals with Different Shells and Surface Chemistries Derived from Ensemble and Single Particle Measurements N2 - The optical properties of semiconductor nanocrystals (SCNCs) depend on constituent material, particle size, and surface chemistry, with the size of the photoluminescence (PL) quantum yield (QY) and the PL decay kinetics being largely controlled by the number of dangling bonds, which have to be properly passivated for high quality materials. Hence, PL measurements can provide insight not only in SCNC photophysics, yet can be also used for quality control of SCNC synthesis and surface modification. In this respect, steady state and time-resolved fluorometry and confocal microscopy with time correlated single photon counting were used to study the PL properties of core-shell CdSe SCNCs with different shells and surface chemistries on ensemble and single particle level, thereby focusing on a correlation of ensemble PL QY and PL decay kinetics with particle brightness, PL time traces, and the On-time fraction of single SCNCs. Additionally, confocal PL images were correlated with AFM measurements in order to derive the amount of absorbing, yet non-emissive ”dark” SCNCs, the presence of which resulting in an underestimation of ensemble PL quantum yields. The results of this study can help to identify synthetic routes and surface modifications, which minimize the fraction of dark SCNCs. T2 - PicoQuant 22nd International Workshop on Single Molecule and Super-Resolution Microscopy in the Life Sciences CY - Berlin, Germany DA - 14.09.2016 KW - Single molecule KW - SCNC KW - QY KW - AFM KW - Confocal PY - 2016 AN - OPUS4-38121 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kömmling, Anja A1 - Chatzigiannakis, Emmanouil A1 - Wachtendorf, Volker A1 - von der Ehe, Kerstin A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Discoloration effects of high-dose γ-irradiation and long-term thermal ageing of (U)HMW-PE N2 - Two polyethylene types with ultra high (UHMWPE) and high molecular weight (HMWPE), which are used as neutron radiation shielding materials in storage casks for radioactive waste, were subjected to gamma irradiation doses up to 600 kGy and subsequent thermal ageing at 125 °C for up to one year. One material was a medical grade UHMWPE and the other a HMWPE containing an antioxidant. Degradation effects in the materials were characterized using colorimetry, UV-Vis spectroscopy, MIR and FTIR measurements, DSC and, in the case of HMWPE, insoluble content determination. Both materials exhibited a yellowing upon irradiation. The discoloration of UHMWPE disappeared again after thermal ageing, which is why it was attributed to annealable color centers in the form of free radicals entrapped in the crystalline regions of the polymer that recombine during thermal ageing. Furthermore, oxidation species were observed with MIR and FTIR spectroscopy. For HMWPE, the yellowing occurred during both irradiation and thermal ageing and was correlated to antioxidant decomposition. Additionally, black spots were observed after thermal ageing of HMWPE that were attributed to reaction products of antioxidant derivatives and catalyst residues. While only little evidence of oxidation species was found in the light material parts, oxidation is expected to concentrate in the black spots as the catalyst residue promotes hydroperoxide decomposition and thus radical formation that initiate polymer oxidation T2 - Ionizing Radiation and Polymers Conference CY - Giens, France DA - 25.09.2016 KW - Polyethylene KW - Gamma-irradiation KW - Yellowing KW - Degradation PY - 2016 AN - OPUS4-38001 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bradley, I. A1 - Otremba, Frank A1 - Birk, A. M. A1 - Bisby, L. T1 - Novel equipment for the study of pressure vessel response to fire N2 - Pressurisation of full-containment pressure vessels in fire is known to be driven by thermal stratification. The predominant mode of heat transfer to the contents (convection from the shell to the liquid phase) results in formation of „hot“ boundary layers. Sub-cooled boiling may also be present. The warm layer rises to the surface through buoyancy and bubble flow, increasing the surface of the liquid above that of the bulk temperature, and hence driving a pressure rise. For reliable prediction of the complex effects governing vessel pressurization a three-dimensional numerical model is required. Work is being undertaken on such a model by other institutions in cooperation with this project. T2 - ASME 2016 CY - Phoenix, Arizona, USA DA - 11.11.2016 KW - Vessels KW - Novel equipment PY - 2016 AN - OPUS4-38433 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Otremba, Frank A1 - Sklorz, Christian A1 - Simon, Sylvio T1 - A new tank design for Hazmat N2 - Initial studies have shown pre-deformed honeycomb structure pressure vessels to have comparable burst pressure to straight steel vessels. It was shown that honeycomp structured tanks have a higher energy absorption than straight steel tanks. Future studies will investigate optimization of the deformed plate, to determine if increased payloads or a reduced wall thickness can be achieved. T2 - ASME 2016 International Mechanical Engineering Congress and Exposition (ICME 2016) CY - Phoenix, Arizona, USA DA - 11.11.2016 KW - Hazmat KW - Tankdesign KW - Honeycomb structure PY - 2016 AN - OPUS4-38399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönfelder, Thorsten A1 - Otremba, Frank T1 - Temperature distribution during filling of a composite receptacle N2 - The arrangement of the measuring sensors allowed the capture of air flow induced temperatures and material temperatures on various points of the cylinder body. Four significant temperature levels could be observed: Inside the cylinder (far from the wall, close to the wall), inside the aluminium liner and outer surface. Figure 5 shows the temperature distribution after a regular filling process with a filling time of ten minutes. The temperature sensors T1 - T9 are marked with different colors. The corresponding measurement points are shown in Figure 4. Due to the high thermal conductivity of the aluminum liner the induced temperature peaks are quickly derived. A flow-induced exceeding of the maximum approval temperature is not expected. Regarding the safety assessement the results show that the pressure and temperature profilesmustbe taken into account. T2 - ASME 2016 International Mechanical Engineering Congress and Exposition (IMECE2016) CY - Phoenix, Arizona, USA DA - 11.11.2016 KW - Distribution during filling KW - Type III composite pressure receptacles PY - 2016 AN - OPUS4-38404 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cabeza, Sandra A1 - Garcés, G. A1 - Pérez, P. A1 - Andrade, C. A1 - Adeva, Paloma T1 - Low alloyed Mg-Y/RE-Zn alloys: mechanical and corrosion behaviour N2 - Mg-Y,RE-Zn systems present second phases with high thermal stability, promoting the increase of strength and creep resistance at high temperatures. Mg and its alloys have a potential application as biomaterials due to their biocompatibility and degradation behaviour. The dominant corrosion mechanism in those alloys is the microgalvanic corrosion through coupling of the more noble second phases with the Mg matrix, and therefore a low concentration of those was sought. T2 - Mg 2015 CY - Jeju, South Korea DA - 12.10.2015 KW - Magnesium KW - LPSO KW - Corrosion behaviour KW - Mechanichal behaviour PY - 2015 AN - OPUS4-38398 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Selleng, Christian A1 - Gröger, K. A1 - Fontana, Patrick A1 - Meng, Birgit A1 - Altenberger, U. T1 - Effect of 90°C thermal treatment on Ultra-High Performance Concrete N2 - Ultra High Performance Concrete (UHPC) is characterized by high strength and high durability. This is achieved by an optimized grain size distribution, especially within fine grains, and addition of superplasticizer, which allow the reduction of the water/cement ratio in the cement paste and thereby the increase of the density of UHPC. Thermal treatment, i.e. curing at elevated temperature and pressure, contributes to a further increase of compressive strength. The aim of the presented study was to analyze the effect of thermal treatment at 90 ◦C and atmospheric pressure on UHPC samples. Varying factors were the age of the samples when heat treatment started (initial storage time), the duration of heat treatment and the type of heat treatment. It was applied in three ways: 1. treated without any protection, 2. sealed in plastic foil and 3. treated in hot water. Afterwards the samples were analyzed with respect to their mechanical properties and their phase composition. Furthermore, the weight (water absorption) of the samples was observed over 28 days and was correlated with the strength test results. The development of strength depends on the combination of initial storage time and the duration of heat treatment and is also influenced by the type of thermal treatment. The highest compressive strengths have been observed by implementing the hot water treatment. Thereby the weight of the samples increase due to additional absorbed water. This enables an increased hydration of cement clinker inducing a higher strength. T2 - GeoBerlin 2015: Dynamic Earth - from Alfred Wegener to today and beyond CY - Berlin, FU Berlin DA - 04.10.2015 PY - 2015 AN - OPUS4-34504 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin A1 - Prinz, Carsten A1 - Zimathies, Annett A1 - Adolphs, Jürgen A1 - Hempel, Simone A1 - Schnell, Alexander T1 - Studies on the Pore Structure of Lightweight Recycling Granules N2 - Lightweight granules are mineral, spherical and porous particles with bulk density less than 2000 kg m . New types of lightweight granules are made from masonry -3 rubble as an alternative to the commonly used expanded clay and shale. They are produced in a multistage manufacturing process by thermal or hydrothermal treatment. Studies of the microstructure of the new lightweight granules are very important to optimise the engineering properties with regard to different applications from lightweight concrete to planting substrates and wastewater treatment. Here, the results of porosity and pore structure measurements are presented. Characteristic samples with different bulk densities of both thermally and hydrothermally hardened granules have been analysed by means of various methods. T2 - 27. Deutsche Zeolith-Tagung CY - Oldenburg, Germany DA - 25.02.2015 PY - 2015 AN - OPUS4-32835 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chatzigiannakis, Emmanouil A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Schulze, Dietmar A1 - Wolff, Dietmar T1 - Influence of composition on the thermal ageing behaviour of EPDM N2 - Ethylene-propylenene-diene copolymer rubbers (EPDM) are used in a wide range of sealing applications e.g. in automotive industry or in containers for dangerous goods. Investigations with regard to the ageing behavior and lifetime prediction of commercial EPDM rubber seals consisting of 48 % polypropylene (PP) and 4.1 % of 5-ethylidene-2-norbornene (ENB) were conducted [1]. However, structural parameters (monomer ratio, diene type, curing agent etc.) and additives (filler, plasticizer etc.) are known to affect the ageing behavior of rubber compounds [2, 3]. The aim of the current study was to elucidate the influence of each component on the overall deterioration of material properties after thermal ageing. Therefore, different EPDM mixtures were prepared at BAM, the reference being an EPDM with 48 % PP and 4.1 % ENB reinforced with Sillitin. Five more formulations were prepared in order to assess the effect of (i) filler type (carbon black or sillitin), (ii) curing agent (sulfur or peroxide), (iii) plasticizer, (iv) ethylene-propylene ratio and (v) ENB content. Initially, the properties of the unaged materials were investigated by tensile testing, hardness and density measurements, TGA, DSC and DMA. Sulfur vulcanization resulted in higher elongation at break due to the flexibility of the sulfidic crosslinks. Carbon black resulted in better reinforcement compared to Sillitin. A higher ethylene and ENB content lead to higher hardness due to higher crystallinity and higher crosslink density, respectively. Thermal ageing for up to 30 days (with 10 days intervals) took place in circulating hot air ovens at 125 °C. Pronounced crosslinking was found to take place in all peroxide-cured materials, as the unreacted double bonds of the ENB units acted as starting points for oxidation and crosslinking. Increasing the ethylene content resulted in an increase in the ageing resistance of EPDM. This improvement was attributed to the higher crystallinity that inhibits oxygen diffusion and to the smaller number of chain scissions which occur in the PP units. Although significant loss of the plasticizer was observed, the remaining plasticizer adequately improved the tensile properties of the material. The filler type did not significantly affect the ageing behavior of EPDM. Finally, the lower thermal stability of the sulfidic crosslinks resulted in desulfurization and, thus, in an increase in the crosslinking density. To sum up, it has been shown that the monomer composition, curing agent and additives used in EPDM formulations greatly influence the properties and ageing resistance of these materials. T2 - 12. Kautschuk Herbst Kolloquium CY - Hanover, Germany DA - 22.11.2016 KW - Degradation KW - Elastomer KW - Compound PY - 2016 AN - OPUS4-38484 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stegemann, Robert A1 - Cabeza, Sandra A1 - Lyamkin, Viktor A1 - Bruno, Giovanni A1 - Wimpory, Robert A1 - Boin, Mirko A1 - Pittner, Andreas A1 - Kuffel, Mareike A1 - Kreutzbruck, Marc T1 - Characterization of residual stress state by neutron diffraction and residual magnetic field mapping N2 - Based on the residual stress characterization of tungsten inert gas welded S235JRC+C plates by means of neutron diffraction, the evaluation of residual stress with high spatial resolution GMR (giant magneto resistance) sensors is discussed. The experiments performed indicate a correlation of residual stress changes and local residual magnetic stray fields. T2 - Eighth Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 07.12.2016 KW - Residual stress KW - Magnetic stray fields KW - GMR KW - Neutron diffraction PY - 2016 AN - OPUS4-38676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mishurova, Tatiana A1 - Cabeza, Sandra A1 - Bruno, Giovanni A1 - Artzt, Katia A1 - Haubrich, J. A1 - Requena, G. T1 - Surface residual stresses analysis in SLM Ti–6Al–4V bridges N2 - Selective Laser Melting (SLM) technique allows to produce parts with complex geometry. Due to the rapid solidification and heat gradient during production, SLM results in presence of residual stress. The present study shows the influence of manufacturing parameters on surface residual stress of Ti-6Al-4V SLM parts. High tensile stresses in the front surface are found. Heat Treatment conditions relax residual stresses almost to zero. High scanning speed during manufacturing results in higher tensile stresses in the surface. T2 - HZB User Meeting CY - BESSY II, Berlin, Germany DA - 08.12.2016 KW - Additive manufacturing KW - Residual stress KW - Selective laser melting PY - 2016 AN - OPUS4-38657 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cabeza, Sandra A1 - Mishurova, Tatiana A1 - Kromm, Arne A1 - Nadammal, Naresh A1 - Bruno, Giovanni T1 - Residual stress characterization of IN718 part obtained by selective laser melting N2 - Additive Manufacturing (AM) 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 developed during the processing can reduce the load bearing capacity as well as induce unwanted distortion, limiting the application of SLM parts. IN718 manufactured by SLM process can show high tensile residual stresses in the surface as high as the yield strength of the wrought alloy. On the other hand, residual stresses in the bulk Show considerably lower stress values, even in compression, indicating a stress re-distribution during deposition of the SLM layers. T2 - HZB User meeting CY - BESSY II, Berlin, Germany DA - 08.12.2016 KW - Additive manufacturing KW - Residual stress KW - Selective laser melting KW - Neintron diffraction PY - 2016 AN - OPUS4-38660 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fischer, Franziska A1 - Kulla, Hannes A1 - Emmerling, Franziska A1 - Rademann, K. T1 - In situ investigation of the mechanochemical formation of cocrystals unsing combined PXRD and Raman spectroscopy N2 - We present an in situ investigation of the mechanochemical formation of cocrystals using synchrotron XRD and Raman spectroscopy. This combination allows to study milling processes on the level of the molecular and crystalline structure thus obtaining reliable data for mechanistic studies. Thereby, mechanochemical syntheses can be optimized to isolate new crystal structures. T2 - Joint BER II and BESSY II User Meeting 2016 CY - Berlin, Germany DA - 07.12.2016 KW - Intermediate KW - Mechanochemistry KW - Cocrystal KW - In situ KW - Milling PY - 2016 AN - OPUS4-38722 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Akhmetova, Irina A1 - Wilke, Manuel A1 - Emmerling, Franziska A1 - Rademann, K. T1 - In situ investigation of mechanochemical syntheses of metal phosphonates N2 - We report on the in situ investigation of mechanochemical syntheses of metal phosphonates. The metal phosphonates are formed in milling reactions starting from a metal acetate and a phosphonic acid. The conversions are observed by synchrotron PXRD and Raman spectroscopy to shed light on the reaction mechanisms including possible intermediates. T2 - 8th HZB User Meeting CY - Berlin, Germany DA - 07.12.2016 KW - Mechanochemistry KW - In situ KW - Metal phosphonates KW - XRD KW - Raman spectroscopy PY - 2016 AN - OPUS4-38780 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Naghib-zadeh, Hamid A1 - Güther, Wolfgang A1 - Rabe, Torsten T1 - High-strength and gas-tight ceramic-ceramic joints by RAB composite tapes N2 - Ceramic components with complex shape cannot be produced frequently by usual ceramic forming and sintering processes. Therefore, numerous joining methods were developed and introduced in industrial scale. Nowadays, multi-stage Mo-Mn-process and active brazing are preferentially used, if temperature-stable and gastight joints are required. Unfortunately, both processes involve cost-intensive thermal processes: hydrogenous atmosphere is essential for metallization in Mo-Mn-process and active brazing takes place under vacuum. Thermal processes can be drastically simplified by using Reactive Air Brazing (RAB). Joining under air atmosphere is an interesting alternative, especially to join oxide ceramic components among themselves. So far, main disadvantage of RAB is low strength of join connections. Aim of this investigation was the development of high-strength, thermal shock resistant and gastight ceramic-ceramic joints by RAB. Therefore, - commercial, silver and copper oxide containing RAB soldering composition was modified by addition of ceramic particles with low thermal expansion coefficients (TEC). Hence, thermal misfit between TEC of solder and ceramic components was significantly reduced. - RAB soldering paste was replaced with newly developed RAB composite tapes, produced by ceramic “doctor blade” technology. Thereby, improved potential exist to tailor the brazing layer relating to composition, thickness and thickness uniformity. Gastight alumina-alumina, alumina-zirconia and zirconia-zirconia joints with strongly improved strength were produced by novel composite tapes. No strength degradation of joints was observed after thermal cycling up to 700°C. T2 - Jahrestagung der Deutschen Keramischen Gesellschaft (DKG) 2016 CY - Freiberg, Germany DA - 07.03.2016 KW - Brazing KW - Compsite tapes KW - Ceramic-ceramc joints PY - 2016 AN - OPUS4-36114 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Derra, U. A1 - Mescheder, H. A1 - Winands, K. A1 - Emonts, C. A1 - Comanns, P. A1 - Krüger, Jörg A1 - Kirner, Sabrina A1 - Skoulas, E. A1 - Tsibidis, G.D. A1 - Stratakis, E. T1 - Mimicking lizard-like surface structures upon ultrashort laser pulse irradiation of inorganic materials N2 - The wetting behavior of material surfaces can be controlled by surface structures. We functionalized inorganic material surfaces, such as steel, titanium alloy and silicon, to modify the wetting behavior using ultrashort laser pulses (fs- to ps-range). The laser processing was performed by scanning the laser beam across the surface of initially polished flat sample material. A combined experimental and theoretical study of the laser processing parameters (peak fluence, scan velocity, line overlap) allowed the identification of different regimes associated with characteristic surface morphologies (laser-induced periodic surface structures, grooves, micro cones, dimples, etc.). Analyses of the surface using optical as well as scanning electron microscopy allowed the identification of morphologies providing the optimum similarity to the natural skin of lizards. For mimicking skin structures of moisture-harvesting lizards towards an optimization of the surface wetting behavior, additionally, a two-step laser processing strategy was established for realizing hierarchical micro- and nanostructures. In this approach, a laser-generated regular array of small dimples was superimposed (step 2) to the micron-scaled capillaries processed before (step 1). Optical focus variation imaging measurements finally revealed the three dimensional topography of the laser processed surfaces derived from lizard skin structures. The functionality of these surfaces was analyzed in view of wetting properties. T2 - E-MRS 2016 Spring Meeting, Symposium C: "Laser-material interactions for tailoring future applications" CY - Lille, France DA - 02.05.2016 KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Steel KW - Lizard KW - Wetting PY - 2016 AN - OPUS4-36047 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Koter, Robert A1 - Hartelt, Manfred A1 - Spaltmann, Dirk A1 - Kirner, Sabrina A1 - Pentzien, Simone A1 - Höhm, S. A1 - Rosenfeld, A. A1 - Krüger, Jörg T1 - Tribological properties of femtosecond laserinduced periodic surface structures on metals N2 - Laser-induced periodic surface structures (LIPSS, ripples) were generated on steel and titanium surfaces upon irradiation with multiple linear polarized femtosecond laser pulses (pulse duration 30 fs, central wavelength 790 nm). The experimental conditions (laser fluence, spatial spot overlap) were optimized in a sample-scanning geometry for the processing of large surface areas covered homogeneously by the nanostructures. The irradiated surface regions were subjected to optical microscopy (OM), white light interference microscopy (WLIM) and scanning electron microscopy (SEM) revealing sub-wavelength spatial periods. The nanostructured surfaces were tribologically tested under reciprocal sliding conditions against a sphere of hardened 100Cr6 steel at 1 Hz using paraffin oil and engine oil as lubricants. After 1000 sliding cycles at a load of 1.0 N, the corresponding wear tracks were characterized by OM and SEM. For specific conditions the laser-generated nanostructures endured the tribological treatment. Simultaneously, a significant reduction of the friction coefficient was observed in the laser-irradiated (LIPSS-covered) areas when compared to the non-irradiated surface, indicating the potential benefit of laser surface structuring for tribological applications. T2 - SPIE Photonics West Conference, Symposium "Laser Applications in Microelectronic and Optoelectronic Manufacturing" (LAMOM) XXI CY - San Francisco, CA, USA DA - 13.02.2016 KW - Femtosecond laser ablation KW - Laser-induced periodic surface structures (LIPSS) KW - Tribology KW - Friction KW - Wear PY - 2016 AN - OPUS4-36041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kirner, Sabrina A1 - Bonse, Jörn A1 - Koter, Robert A1 - Spaltmann, Dirk A1 - Pentzien, Simone A1 - Krüger, Jörg T1 - Femtosecond laser-induced periodic surface structures on titanium nitride coatings for tribological applications N2 - Laser-induced periodic surface structures (LIPSS) were generated on titanium nitride (TiN) hardcoating surfaces (deposited on metallic substrates) upon irradiation with multiple linearly polarized femtosecond laser pulses in air (30 fs duration, 790 nm wavelength, 1 kHz pulse repetition rate). The conditions were optimized in a sample-scanning geometry for the processing of large surface areas (5 mm x 5 mm) covered homogeneously by nanostructures with sub-wavelength periods ranging between ~200 nm and 700 nm. For these nanostructures the coefficient of friction was characterized under reciprocating sliding condition against a ball of hardened steel at 1 Hz using different lubricants (regime of mixed friction). After 1000 cycles, the corresponding wear tracks were characterized by optical and scanning electron microscopy. High-resolution energy dispersive X-ray analyzes (EDX) allowed the visualization of chemical alterations within the wear tracks. For specific conditions, the nanostructures endured the tribological treatment. Our experiments provide a qualification of the tribological performance of the fs-LIPSS on TiN surfaces. T2 - E-MRS 2016 Spring Meeting, Symposium C: "Laser-material interactions for tailoring future applications" CY - Lille, France DA - 02.05.2016 KW - Femtosecond laser ablation KW - Laser-induced periodic surface structures (LIPSS) KW - Tribology KW - Friction KW - Wear KW - Titanium nitride PY - 2016 AN - OPUS4-36042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epperlein, Nadja A1 - Menzel, Friederike A1 - Schwibbert, Karin A1 - Koter, Robert A1 - Bonse, Jörn A1 - Sameith, Janin A1 - Krüger, Jörg A1 - Toepel, Jörg T1 - Influence of femtosecond laser produced nanostructures on biofilm growth on steel N2 - Large area periodic surface structures were generated on steel surfaces using 30-fs laser pulses at 790 nm wavelength. Two types of steel exhibiting a different corrosion resistance were used, i.e. a plain structural steel (corrodible) and a stainless steel (resistant to corrosion). Homogeneous fields of laser-induced periodic surface structures (LIPSS) were realized utilizing laser fluences close to the ablation threshold while scanning the sample under the focused laser beam in a multi-pulse regime. The nanostructures were characterized with optical and scanning electron microscopy. For each type of steel, more than ten dentical samples were laser-processed. These samples were subjected to microbial adhesion tests, investigating bacterial adhesion behavior on the laser structures in comparison to polished reference surfaces. Short term experiments (<24h) were carried out to determine initial biofilm development. E. coli as a typical bacterium representing pathogenic bacteria and Shewanella putrefaciens as metal corrosive bacterium were used for biofilm development analyses. Bacterial cell adhesion was determined microscopically after DAPI cell staining (DNA staining). Comparison of the coverage areas between nanostructured and polished surfaces revealed differences in cell adhesion behavior and biofilm structure. T2 - E-MRS 2016 Spring Meeting, Symposium C: "Laser-material interactions for tailoring future applications" CY - Lille, France DA - 02.05.2016 KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Biofilms KW - Steel PY - 2016 AN - OPUS4-36045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Walter, Astrid A1 - von Oertzen, Alexander T1 - EU-Projekt HOMER, home made explosives (HMEs) and recipes characterisation N2 - Das EU-Projekt HOMER befasst sich mit den sogenannten Home Made Explosives (HMEs) und frei verfügbaren Rezepten für deren Herstellung. Diese Selbstlaborate spielen in der heutigen Zeit vor allem im Zusammenhang mit terroristischen Aktivitäten eine bedeutende Rolle. Informationen zu HMEs und ihrer Herstellung werden einfacher denn je über das Internet verbreitet. Hier knüpft das im 7. EU‑Forschungsrahmenprogramm finanzierte Projekt an und bezweckt, die im Internet verfügbaren Quellen auszuwerten und so die Informationslage für Sicherheitskräfte und Ermittlungsbehörden zu verbessern. Im Rahmen des Projektes wird eine automatisierte Suche von Rezepten im Internet entwickelt. Die gefundenen sowie die im Projekt generierten Informationen über HMEs sollen im Endergebnis in Form einer Software (Knowledge Management Platform) informationstechnisch nutzbar gemacht werden. Diese Datenbank soll auch für mobile Geräte zur Verfügung stehen. Der Schwerpunkt der Projektbeteiligung des Fachbereichs 2.3 Explosivstoffe der BAM liegt in der Bewertung der Rezepturen und der auf ihrer Grundlage hergestellten Laborate. Es wurden HMEs entsprechend der vorgefundenen Rezepte und unter Beachtung aller notwendigen Sicherheitsvorkehrungen hergestellt und anschließend sicherheitstechnisch geprüft und bewertet. Dabei wurden sowohl Handhabungsparameter wie die Empfindlichkeiten gegen Schlag, Reibung und thermische Einflüsse ermittelt, als auch die Leistungsparameter wie Detonationsgeschwindigkeit und Luftstoßdruckwirkung gemessen. Die gewonnen Erkenntnisse fließen in die genannte Datenbank ein und sollen beispielsweise Einsatzkräften vor Ort helfen, angemessene Schutzabstände zu ermitteln. Auch das Personal in Laboren der Kriminalämter profitiert von der zusammengetragenen Information über HMEs bei der Analyse von unbekannten Explosivstoffspuren. T2 - 14. BAM-PTB-Kolloquium zur chemischen und physikalischen Sicherheitstechnik CY - Berlin, Germany DA - 14.06.2016 KW - Homemade explosives KW - Explosivstoffe KW - TATP KW - Ammoniumnitrat PY - 2016 AN - OPUS4-36594 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Welter, T. A1 - Deubener, J. A1 - Reinsch, Stefan A1 - Marzok, Ulrich A1 - Müller, Ralf T1 - Glasstrukturen mit geringer Helium- und Wasserstoffpermeation N2 - Wasserstoffbarrieren aus Glas erfahren zunehmend Bedeutung als Werkstoff in der Energietechnik. Trotz wachsender Anwendungen liegen überwiegend empirisch gewonnene Beziehungen zwischen Glaszusammensetzung und Wasserstoffpermeation vor, die im wesentlichen aus dem Verhalten von Kieselglas abgeleitet werden. In dieser Studie werden daher topologische Parameter der Glasstruktur identifiziert und mit thermodynamischen Parametern korreliert. Auf der Seite der Glastopologie steht das freie Volumen und der Vernetzungsgrad des Netzwerkes während auf der thermodynamischen Seite die Konfigurationsentropie bzw. die Konfigurationswärmekapazität Aufschluss über die Verteilung des freien Volumens geben kann. Dabei wird angenommen, dass für Temperaturen weit unterhalb der Glasübergangstemperatur die chemische Löslichkeit von H2 zu vernachlässigen ist. Um die eingeschränkte Datenlage für die Wasserstoffpermeation kompositionell zu erweitern, wurden zusätzlich Heliumpermeationsmessungen ausgewertet. Die Ergebnisse zeigen, dass für Silicatgläser ein charkteristisches Verhältnis von freiem Volumen zu Netzwerkaufspaltung herrschen muss, um permeationsstabile Gläser zu erhalten. T2 - 90. Glastechnische Tagung CY - Goslar, Germany DA - 06.06.2016 KW - Glasstruktur KW - Helium- und Wasserstoffpermeation KW - Alkalialumosilicatsysteme KW - Thermodynamik KW - Energietechnik PY - 2016 AN - OPUS4-36583 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kulla, Hannes A1 - Rademann, K. A1 - Emmerling, Franziska T1 - In situ investigation of mechanochemical reactions with PXRD and Raman spectroscopy - cocrystals of pyrazinamide with dicarboxylic acids N2 - - Cocrystal formation of pyrazinamide with dicarboxylic acids proceeds either directly or via a crystalline intermediate. - Two new crystal structures were discovered by in situ investigations. T2 - ICS 2016 CY - Granada, Spain DA - 30.05.2016 KW - In situ KW - Mechanochemie KW - XRD KW - Cocrystal PY - 2016 AN - OPUS4-36620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Münster, Christoph A1 - Mente, Tobias A1 - Steger, Jörg A1 - Böllinghaus, Thomas T1 - Influence of experimental conditions and calculation method on hydrogen diffusion coefficient evaluation at elevated temperatures N2 - Hydrogen-assisted cracking (HAC) represents a significant failure risk for (high strength) creep resistant low-alloyed steel components in fossil-fired power plant applications at temperatures of up to and above 200 °C. This particularly applies to respective start-up and shut-down processes associated with alternating service-conditions in terms of load flexible power plants. For quantitative determination of localized crack critical hydrogen concentrations, the temperature dependent hydrogen diffusion coefficients have to be determined as exactly as possible. However, available literature provides a wide range of hydrogen diffusion coefficients for low alloyed steels with similar microstructures. Additionally, the available diffusion data seem not to be very reliable and their scatter increases with decreasing temperature. One reason is that the experimental boundary conditions can have a major impact on the determination of respective effective diffusion coefficients. Hence, the scope of this study is to evaluate the influence of the experimental boundary conditions on the derived diffusion coefficients. In addition, different methods for calculating diffusion coefficients are discussed. To elucidate such influences and to draw a line to practical application, the diffusion and trapping behavior in the creep resistant steel 7CrMoVTiB10 10 has been studied. For such purpose, hydrogen charged specimens were isothermally degassed at different temperatures using carrier gas hot extraction (CGHE). Based on experimental data, a numerical model has been developed by which the hydrogen transport behavior and the respective hydrogen distribution during CGHE can be assessed. It is demonstrated that the specimen heating rate has a large influence on the calculated diffusion coefficients under assumption of isothermal degassing which elsewhere has been underestimated in the assessment of diffusion data in creep-resistant steels. The numerical results suggest that calculation methods for diffusion coefficients are limited if compared to experimental results. It also turned out that the sample preparation time before CGHE can enormously influence determined diffusion coefficients. Consequently, non-homogeneous hydrogen concentration profiles have to be anticipated in the simulations to arrive at characteristic effusion curves consistent to respective CGHE experiments. In turn, validated diffusion coefficients are now available for the low-alloyed Cr-Mo-V steel which might be helpful to calculate appropriate hydrogen removal heat treatment procedures, for instance. T2 - International Hydrogen Conference - Material Performance in Hydrogen Environments CY - Jackson Lake Lodge, Moran, Wyoming, USA DA - 11.09.2016 KW - Hydrogen diffusion KW - Elevated temperatures KW - Welding KW - Creep-resistant steel KW - Numerical modeling KW - Calculation PY - 2016 AN - OPUS4-37403 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Mente, Tobias A1 - Böllinghaus, Thomas T1 - Modeling of hydrogen-assisted cracking (HAC) in duplex stainless steels (DSS) N2 - Modeling of Hydrogen-Assisted Cracking (HAC) in Duplex Stainless Steels (DSS): - Hydrogen causes significant degradation in DSS and consequently HAC - Mechanisms of HAC have not been fully understood in two-phase microstructures - Mesoscale numerical modeling for HAC in DSS was created, coupled to the macroscale, enabling simulation of HAC in both phases independent from predefined crack paths T2 - International Hydrogen Conference - Material Performance in Hydrogen Environments CY - Jackson Lake Lodge, Moran, Wyoming, USA DA - 11.09.2016 KW - Hydrogen KW - Numerical modeling KW - Duplex stainless steel KW - Hydrogen assisted cracking PY - 2016 AN - OPUS4-37404 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Münster, Christoph A1 - Mente, Tobias A1 - Steger, Jörg A1 - Böllinghaus, Thomas T1 - Influence of Experimental Conditions and Calculation Method on Hydrogen Diffusion Coefficient Evaluation at Elevated Temperatures N2 - Hydrogen-assisted cracking (HAC) represents a significant failure risk for (high strength) creep resistant low-alloyed steel components in fossil-fired power plant applications at temperatures of up to and above 200 °C. This particularly applies to respective start-up and shut-down processes associated with alternating service-conditions in terms of load flexible power plants. For quantitative determination of localized crack critical hydrogen concentrations, the temperature dependent hydrogen diffusion coefficients have to be determined as exactly as possible. However, available literature provides a wide range of hydrogen diffusion coefficients for low alloyed steels with similar microstructures. Additionally, the available diffusion data seem not to be very reliable and their scatter increases with decreasing temperature. One reason is that the experimental boundary conditions can have a major impact on the determination of respective effective diffusion coefficients. Hence, the scope of this study is to evaluate the influence of the experimental boundary conditions on the derived diffusion coefficients. In addition, different methods for calculating diffusion coefficients are discussed. To elucidate such influences and to draw a line to practical application, the diffusion and trapping behavior in the creep resistant steel 7CrMoVTiB10 10 has been studied. For such purpose, hydrogen charged specimens were isothermally degassed at different temperatures using carrier gas hot extraction (CGHE). Based on experimental data, a numerical model has been developed by which the hydrogen transport behavior and the respective hydrogen distribution during CGHE can be assessed. It is demonstrated that the specimen heating rate has a large influence on the calculated diffusion coefficients under assumption of isothermal degassing which elsewhere has been underestimated in the assessment of diffusion data in creep-resistant steels. The numerical results suggest that calculation methods for diffusion coefficients are limited if compared to experimental results. It also turned out that the sample preparation time before CGHE can enormously influence determined diffusion coefficients. Consequently, non-homogeneous hydrogen concentration profiles have to be anticipated in the simulations to arrive at characteristic effusion curves consistent to respective CGHE experiments. In turn, validated diffusion coefficients are now available for the low-alloyed Cr-Mo-V steel, which can be helpful to calculate appropriate hydrogen removal heat treatment procedures. T2 - Project Meeting CAStLE CY - Colorado Springs, CO, USA DA - 07.09.2016 KW - Hydrogen KW - Diffusion Coefficient KW - Elevated Temperatures KW - Numerical Modeling KW - Carrier Gas Hot Extraction PY - 2016 AN - OPUS4-37408 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit A1 - Schwarzer, Stefanie A1 - Eiben, Mario T1 - Comparison of the environmental stress cracking behaviour of polyethylene and polyethylene terephthalate as materials for dangerous goods packagings N2 - The chemical industry has expressed great interest in using polyethylene terephthalate (PET) as material for packagings for the transport of dangerous goods. Due to the high strength and stiffness of PET, the wall thickness and weight of packagings can be reduced. This is a relevant cost factor. PET is a semi-crystalline thermoplast which is produced by polycondensation of terephthalic acid and ethylene glycol. According to the European dangerous goods regulations RID and ADR, samples of PET design types of packagings for dangerous goods must be pre-stored with the original filling good for six months at 23°C, before the design type tests can be carried out. For packagings made of polyethylene (PE) tests to prove the stress cracking resistance by using laboratory methods are possible to reduce time and costs. Therefore, standard liquids, simulating the different types of damaging effects on PE are defined in RID and ADR. However, there is no information and research available about the damaging mechanisms on PET in comparison to PE, especially regarding to stress cracking resistance and test methods. The aim of this work is to compare the stress cracking resistance of PE and PET with the Full Notch Creep Test (FNCT), which was developed by chemical industry and is described in the standards EN ISO 16101 and EN 15507. It was investigated whether testing specimens made of PE and PET with a full coplanar notch around the middle of the specimens show weakening after the impact of a tensile force in a wetting solution (Lutensol® FSA 10) at 50°C in a test device on the basis of the FNCT. The test results confirmed the suitability of the method for eight PE grades. Unfortunately, this method couldn’t be used for PET because the specimens broke during notching. In addition the molding of the sheets and the following temper process for twelve hours are very time-consuming, and the specimens broke during notching due to the high brittleness of PET. Another possibility to provide evidence of stress cracking resistance of PE packagings is laid down in BAM’s Dangerous Goods Rule BAM-GGR 015. This test was carried out with PE and PET bottles to compare both materials. Therefore 1l test bottles were filled with a 5% wetting solution and mounted with a clamping tool for 28 days at 40°C. Tensile test specimens were cut out afterwards from the middle of the bottles in the deformed areas. Tensile strength and breaking elongation of PE specimens were determined in comparison to the PET specimens. The tensile properties of the PET specimens couldn’t be determined due to the strength and the stiffness of the material. In conclusion the only way to provide information about the stress cracking resistance of PET was to perform stacking tests. 1l bottles made of PE and PET were filled with a 5% wetting solution and stored with a stacking load for 28 days at 40°C according to EN ISO 16495. Design types of PE and PET both passed the stacking tests. T2 - EUROCORR 2016 CY - Montpellier, France DA - 11.09.2016 KW - polyethylene terephthalate KW - stress cracking resistance KW - test methods KW - dangerous goods packagings PY - 2016 AN - OPUS4-37448 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holzweber, Markus A1 - Sobol, Oded A1 - Wirth, Thomas A1 - Böllinghaus, Thomas A1 - Unger, Wolfgang T1 - Deuterium permeation and cracking in duplex steels as viewed by ToF-SIMS and HR-SEM with data fusion N2 - Better understanding of hydrogen assisted degradation and trapping mecha-nisms requires sufficient imaging techniques for respective hydrogen-microstructure interaction studies, in particular with multi-phase metallic micro-structures [1]. The present work is focusing on the elucidation of deuterium be-havior in two austenitic-ferritic duplex stainless steels (DSS) under the assumption that deuterium behaves in many ways similarly to hydrogen [2]. For case studies standard 2205 and lean 2101 DSSs were chosen due to the extensive use of these steels in industry [3]. The analyses were conducted by using a novel in-situ permeation and Time-of-Flight secondary ion mass spectrometry (ToF-SIMS) imaging technique or by ex-situ ToF-SIMS imaging following electrochemical charging experiments. Another pioneering procedure was data fusion (including chemometry) of results of powerful laterally resolved chemical analysis and high resolution structural characterization techniques . Results for the ex-situ observations showed a different influence of deuterium loading on the two steel grades as well as different damage mechanisms in each phase. Formation of sub-surface blisters between the ferrite and austenite were obtained in both the standard and the lean DSS. In both steels, an increased deuterium concentration was observed around deformed regions such as cracks, confirming that they originate from the presence of deuterium [4]. The formation of parallel cracks was obtained only in the austenite within the standard duplex whereas in the lean duplex the highest intensity of deuterium was obtained in the austenite along the ferrite-austenite interphase. In comparison, application of the novel in-situ permeation technique enabled to register and record the deuterium permeation through the material and the respective saturation sequence of the two phases as well as the interfaces. Faster diffusion of the deuterium was observed in the ferrite and a direct proof for deuterium enrichment at the austenite-ferrite interface has been given [1]. The integration of the specified techniques gives a better insight into the processes leading to hydrogen induced failure. These two experimental techniques provide very valuable tools for elucidation of respective metallurgical failure mechanisms that can be used for the validation of respective numerical models for hydrogen assisted cracking (HAC). T2 - 19. Arbeitstagung Angewandte Oberflächenanalytik CY - Soest, Germany DA - 05.09.2016 KW - ToF-SIMS KW - Hydrogen assisted cracking KW - Data fusion KW - SEM PY - 2016 AN - OPUS4-37484 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheuerlein, A1 - Lackner, F. A1 - Savary, F. A1 - Rehmer, Birgit A1 - Finn, Monika A1 - Uhlemann, P. 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, Colorado, USA DA - 04.09.2016 KW - Young's modulus KW - Tensile test KW - Resonanz KW - Impact excitation PY - 2016 AN - OPUS4-37414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Babutzka, Martin A1 - Burkert, Andreas A1 - Heyn, A. T1 - Corrosion investigations by using gel-type electrolytes N2 - In the presentation different zinc coatings are presented and investigated. Their naturally formed protective layers are electrochemically characterized and corrosion relevant values are determined by using a gel pad based on polysaccharide. The corrosion relevant values allow the differentiation of various zinc coating systems and can describe the current protective effect provided by the coating. It is shown that gel-type electrolytes influence protective layers and coatings considerably less than corresponding bulk electrolytes. From the results it is evident that gel-type electrolytes represent a viable and promising field in corrosion research.zeige mehr T2 - EUROCORR European Corrosion Congress 2016 CY - Montpellier, France DA - 11.09.216 KW - Corrosion investigations KW - Gel-type electrolytes KW - Zinc coatings PY - 2016 AN - OPUS4-37496 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lüth, Peter A1 - Brandes, E. A1 - Frost, K. A1 - Kurth, Lutz A1 - Schmidt, Martin A1 - Michael-Schulz, Heike A1 - Uhlig, S. T1 - CEQAT-DGHS Ringversuchsprogramm der BAM in Kooperation mit QuoData und PTB N2 - Bei der Bewertung der Verlässlichkeit der im Labor gewonnenen Prüfergebnisse spielen Ringversuche eine entscheidende Rolle. Die Bundesanstalt für Materialforschung und -prüfung (BAM) unterstützt deshalb den weiteren Ausbau des Ringversuchsprogramms des im Jahr 2007 gegründeten Kompetenzzentrums zur Qualitätssicherung für Prüfungen von Gefahrgütern und Gefahrstoffen auf physikalische Gefahren (Centre for quality assurance for testing of dangerous goods and hazardous substances, CEQAT-DGHS). Bei allen bisher untersuchten Prüfmethoden besteht ein Verbesserungsbedarf. Die RV müssen daher zunächst auf die Methodenentwicklung, -verbesserung und -validierung abzielen und nicht auf Leistungstests. T2 - 14. Kolloquium zur chemischen und physikalischen Sicherheitstechnik (BAM-PTB-Kolloquium) CY - Berlin, Germany DA - 14.06.2016 KW - Gefahrgut KW - Gefahrstoff KW - Ringversuch KW - Prüfmethode KW - Validierung KW - Qualitätssicherung PY - 2016 AN - OPUS4-38465 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jürgens, Maria A1 - Olbricht, Jürgen A1 - Skrotzki, Birgit A1 - Fedelich, Bernard T1 - Ermüdungsverhalten, Lebensdauer und Schädigungsprozesse von P92 unter zyklischen Betriebsbedingungen N2 - Schnelle Lastwechsel mit hohen Temperaturgradienten führen zu thermischen und mechanischen Beanspruchungen v.a. in dickwandigen Bauteilen. Daraus ergibt sich ein komplexes Lastkollektiv, bei dem der Werkstoff sowohl durch Kriechermüdung als auch durch thermomechanische Ermüdung (TMF) geschädigt wird. Welche Auswirkungen hat eine gleichzeitige Änderung von Temperatur, mechanischer Beanspruchung und Arbeitsmedium auf die Schädigungsprozesse? T2 - KWT Dresden CY - Dresden, Germany DA - 18.10.2016 KW - LCF KW - P92 KW - TMF PY - 2016 AN - OPUS4-38587 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hemmleb, M. A1 - Bettge, Dirk A1 - Berger, D. A1 - Driehorst, I. T1 - 3D surface reconstruction with segmented BSE detector: New improvements and application for fracture analysis in SEM N2 - Application of 4Q-BSE detector and dedicated software enables 3D surface measurements of fracture samples in SEM. 3D surface measurement is independent from magnification and material invariant. Quantitative height measurements require careful detector adjustment and system calibration. Live 3D view allows a fast assessment of topographical features. In addition to SE and BSE imaging, 3D surface data help to analyse and interpret fracture samples. T2 - European Microscopy Congress 2016 CY - Lyon, France DA - 28.08.2016 KW - Topography KW - SEM KW - 3D analysis KW - Fractography PY - 2016 AN - OPUS4-38456 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - Maack, Stefan A1 - Kneib, G. T1 - Elastic wave propagation of ultrasound in bituminous road surfaces – simulations and measurements N2 - Maintenance costs of road infrastructure are increasing steadily. Adverse environmental impacts on infrastructure get more and more important as well. Therefore, it is important to determine how limited financial resources can be directed with an optimum pay-out. The present study takes first steps towards the usage of low-frequency ultrasound as a tool to evaluate the road condition. T2 - International Symposium Non-Destructive Testing in Civil Engineering 2015 CY - Berlin, Germany DA - 15.09.2015 KW - Wave propagation KW - Ultrasonic KW - NDT KW - Simulation PY - 2015 AN - OPUS4-38837 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 - 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 - Kulla, Hannes A1 - Becker, C. A1 - Paulus, B. A1 - Casati, N. A1 - Rademann, K. A1 - Emmerling, Franziska T1 - In situ investigations of a mechanochemical cocrystal formation by X-ray diffraction in two different milling jars N2 - We present an in situ PXRD investigation of the mechanochemical cocrystal formation of pyrazinamide with pimelic acid in two milling jar materials. DFT calculations of the two synthesized polymorphs suggest that the relative stability is based on a conformation change of pyrazinamide in the cocrystal. T2 - 3. BAM-BfR Workshop CY - Berlin, Adlershof, Germany DA - 15.02.2018 KW - Mechanochemistry KW - Cocrystal KW - Polymorph KW - In situ XRD KW - DFT PY - 2018 AN - OPUS4-44315 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 - Griesche, Axel T1 - Hydrogen in Iron visualized in 3D by neutron tomography N2 - Presented are neutron tomographies on hydrogen charged iron samples. T2 - RACIRI Summer School 2015 CY - Sellin, Rügen, Germany DA - 22.08.2015 KW - Tomographie KW - Wasserstoff KW - Neutronen KW - Hydrogen KW - Neutron KW - Tomography PY - 2014 AN - OPUS4-44838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hinsch, Alexandra A1 - Strelow, Christian A1 - Kipp, Tobias A1 - Würth, Christian A1 - Geißler, Daniel A1 - Resch-Genger, Ute A1 - Mews, Alf T1 - The influence of the individual Particles on the ensemble Quantum Yield of elongated CdSe/cds core/Shell nanoparticles N2 - Colloidal semiconductor nanoparticles with a spherical core and an elongated shell form bright emitters with a high absorption cross section. They show great potential for a multitude of optoelectronic applications such as LEDs or photovoltaic cells and can be used as gain material or as markers for bio imaging. For most of these applications high fluorescence quantum yields are a figure of merit for the emitter quality. In this work we investigate how the ensemble quantum yield is affected by the properties of the individual particles. In particular, we prove the role of non-emitting particles as well as the role of blinking. Using a combination of AFM and spatially resolved photoluminescence spectroscopy we measured hundreds of individual CdSe/CdS dot/rod particles of different shell lengths exciting with two different excitation wavelengths for shell or core excitation, respectively. T2 - SPIE Photonics West CY - San Francisco, CA, USA DA - 27.01.2018 KW - Exciton diffusion KW - Quantum Dot-Rod KW - Quantum Yield PY - 2018 AN - OPUS4-44759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -