TY - CONF A1 - Üstündag, Ömer A1 - Gumenyuk, Andrey A1 - Gook, S. A1 - Rethmeier, Michael T1 - Investigation of the mechanical properties of single-pass hybrid laser-arc welded thick X120 pipeline steel plates N2 - High heat input leads to grain coarsening and softening in WM and HAZ; the tensile strength is reduced. Low heat input leads to inadmissible hardening in the WM; the impact strength is reduced. The proposed t8/5-time of 3 s to 15 s could be achieved through the reduced welding velocity. The concept of electromagnetic weld pool support system allowed single-pass welds in flat position without gravity drop-outs even for reduced welding speeds; in this way the heat input can be controlled. The adaptation of the electromagnetic weld pool support system to laser and laser hybrid welding process can dramatically increase the potential field of application of these technologies for real industrial implementation. T2 - 14th Pipeline Technology Conference 2019 CY - Berlin, Germany DA - 18.03.2019 KW - Toughness KW - Hybrid laser-arc welding KW - Pipeline steel X120 KW - Electromagnetic weld pool support KW - Mechanical properties PY - 2019 AN - OPUS4-49894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ö. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Single-pass Hybrid Laser Arc Welding of Thick Materials Using Electromagnetic Weld Pool Support N2 - Hybrid laser-arc welding process allows single-pass welding of thick materials, provides good quality formation of joints with minimal thermal deformations and a high productivity in comparison with arc-based welding processes. Nevertheless, thick-walled steels with a thickness of 20 mm or more are still multi-pass welded using arc welding processes, due to increased process instability by increasing laser power. One limitation factor is the inadmissible formation of gravity drop-outs at the root. To prevent this, an innovative concept of electromagnetic weld pool support is used in this study. With help of such system a stable welding process can be established for 25 mm thick steel plates and beyond. Sound welds could be obtained which are tolerant to gaps and misalignment of the welded parts. The adaptation of this system to laser and hybrid laser-arc welding process can dramatically increase the potential field of application of these technologies for real industrial implementation. T2 - Lasers in Manufacturing Conference 2019 CY - Munich, Germany DA - 24.06.2019 KW - Full Penetration KW - Hybrid Laser Arc Welding KW - Electromagnetic Weld Pool Support KW - Thick Materials PY - 2019 SP - 1 EP - 8 PB - WLT Wissenschaftliche Gesellschaft Lasertechnik e.V. AN - OPUS4-48971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Üstündag, Ö. A1 - Gook, S. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Mechanical Properties of Single-pass Hybrid Laser Arc Welded 25 mm Thick-walled Structures Made of Fine-grained Structural Steel N2 - The presented study deals with the performing and mechanical testing of single pass hybrid laser-arc welds (HLAW) on 25 mm thick plates made of steel grade S355J2. One of the challenges have to be solved at full penetration HLAW of thick plates is the drop formation occurring due to the disbalances of the forces acting in the keyhole and on the melt pool surface. Such irregularities mostly limit the use of high-power laser beam welding or HLAW of thick-walled constructions. To overcome this problem, an innovative concept of melt pool support based on generating Lorentz forces in the weld pool is used in this work. This method allows to perform high quality welds without sagging even for welding of 25 mm thick plates in flat position at a welding speed of 0.9 m min-1. For the obtain of full penetrated welds a laser beam power of 19 kW was needed. A high V-impact energy of up to 160 J could be achieved at the test temperature of 0 °C. Even at the most critical part in the weld root an impact energy of 60 J in average could be reached. The tensile strength of the weld reaches that of the base material. An introduce of the HLAW process with electromagnetic support of the melt pool in the industrial practice is an efficient alternative to the time- and cost-intensive arc-based multi-layer welding techniques which are established nowadays for joining of thick-walled constructions. KW - Mechanical Properties KW - Hybrid Laser Arc Welding KW - Thick-walled Structures KW - Fine-grained Steel PY - 2019 DO - https://doi.org/10.1016/j.promfg.2019.08.016 SN - 2351-9789 VL - 36 SP - 112 EP - 120 PB - Elsevier B.V. AN - OPUS4-48969 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ö. A1 - Gook, S. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Investigation of the mechanical properties of single-pass hybrid laser-arc welded thick X120 pipeline steel plates N2 - With global increases in clean energy demand, the natural gas is gaining in importance. Pipelines are the safest and most cost-effective way of transporting natural gas. Due to high transport volume and resulting high operation pressure, the demand for ultra-high strength steel grades such as X120 is very strong. As a result of the fact that these steels are produced by thermo-mechanical controlled processing, the welding process must be selected accordingly. Based on investigations, a high heat input such as by submerged arc welding process leads to softening in the weld metal and loss of strength whereas pure laser beam welding results in high cooling rates and deteriorate toughness of the weld metal. The objective of this research is to investigate the influence of heat input to mechanical properties of hybrid laser-arc welded pipeline steels of grade X120. Test specimens with a thickness of 20 mm could be welded without preheating in a single-pass with different welding velocities to observe the largest possible parameter window of the heat input. The achieved V-notch impact energy for hybrid laser-arc welded samples was 144±37 J at a testing temperature of -40 °C. With a tensile strength of 930±4 MPa the requirements of API 5L was achieved. To prevent gravity drop-outs at the slow welding speeds, an electromagnetic weld pool support system was used, which works contactless and is based on generating Lorentz forces. It was therefore possible to control the cooling rate in order to meet the requirements of the mechanical properties. By adapting the electromagnetic weld pool support to the laser and laser hybrid welding process, the application potential of these technologies for industrial implementation can be drastically increased. T2 - 14th Pipeline Technology Conference CY - Berlin, Germany DA - 18.03.2019 KW - Mechanical properties KW - Hybrid laser arc welding KW - Pipeline steel X120 PY - 2019 UR - https://www.pipeline-conference.com/conferences/14th-pipeline-technology-conference-2019 SN - 2510-6716 SP - 1 EP - 10 AN - OPUS4-48970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Üstündag, Ö. A1 - Avilov, V. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Improvement of Filler Wire Dilution Using External Oscillating Magnetic Field at Full Penetration Hybrid Laser-Arc Welding of Thick Materials N2 - Hybrid laser-arc welding offers many advantages, such as deep penetration, good gap bridge-ability, and low distortion due to reduced heat input. The filler wire which is supplied to the process is used to influence the microstructure and mechanical properties of the weld seam. A typical problem in deep penetration high-power laser beam welding with filler wire and hybrid laser-arc welding is an insufficient mixing of filler material in the weld pool, leading to a non-uniform element distribution in the seam. In this study, oscillating magnetic fields were used to form a non-conservative component of the Lorentz force in the weld pool to improve the element Distribution over the entire thickness of the material. Full penetration hybrid laser-arc welds were performed on 20-mm-thick S355J2 steel plates with a nickel-based wire for different arrangements of the oscillating magnetic field. The Energy-dispersive X-ray spectroscopy (EDS) data for the distribution of two tracing elements (Ni and Cr) were used to analyze the homogeneity of dilution of the filler wire. With a 30° turn of the magnetic field to the welding direction, a radical improvement in the filler material distribution was demonstrated. This would lead to an improvement of the mechanical properties with the use of a suitable filler wire. KW - Thick materials KW - Hybrid laser-arc welding KW - Oscillating magnetic field KW - Electromagnetic stirring KW - Full penetration PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-489644 DO - https://doi.org/10.3390/met9050594 SN - 2075-4701 VL - 9 IS - 5 SP - 594 PB - Multidisciplinary Digital Publishing Institute CY - Basel AN - OPUS4-48964 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem A1 - Wurzler, Nina A1 - Hampel, Marco A1 - Witt, Julia A1 - Schenderlein, Matthias T1 - In situ imaging of corrosion processes N2 - The presentation summarizes our recent results on the coupled electrochemical methods for high resolution corrosion studies. The combination of Scanning Electrochemical Microscopy (SECM) and multielectrode (MMA) based real-time corrosion monitoring was presented as a new method for achieving high time resolution in local electrochemical analysis. Correlative imaging by means of Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) was demonstrated as a tool for the investigation of local corrosion processes initiated by the intermetallic particles (IMPs) on AA2024-T3 aluminium alloy. T2 - BAM-IfW Workshop CY - Dresden, Germany DA - 28.03.2019 KW - MIC KW - Atomic Force Microscopy (AFM) KW - Corrosion monitoring KW - Corrosion PY - 2019 AN - OPUS4-50291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem A1 - Wurzler, Nina A1 - Hampel, Marco A1 - Sobol, Oded A1 - Schütter, Jan David T1 - Effekt der Vorkonditionierung und Umweltparameter auf die Anheftung und Biofilmbildung N2 - Aktuelle Ergebnisse des Fachbereiches auf dem Gebiet MIC. T2 - Treffen der GfKORR/DECHEMA Fachgruppe MikroMatz CY - Berlin, Germany DA - 09.04.2019 KW - MIC KW - Korrosion KW - Korrosionsüberwachung KW - Biofilmbildung PY - 2019 AN - OPUS4-50292 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia A1 - Almalla, Ahed T1 - Application of atomic force microscopy (AFM) for in situ corrosion studies of thin film covered AA2024 T3 aluminium alloy surface N2 - The performance of functional coatings and adhesively joined hybrid components relies strongly on the stability of the polymer-metal interface. With the increasing utilization of multi-material structures in the automotive and aerospace industry, it is of great scientific and technical interest to understand the processes leading to interface degradation and to develop novel strategies to increase corrosion and delamination resistance. The aim of this project is to develop thin epoxy-based films and their carbon nanofiller loaded composites on aluminium alloy AA2024-T3 as a model system and to investigate their interfacial stability under corrosive and coupled corrosive-mechanical load. Spin coating was used for the layer-by-layer deposition of poly[(o-cresyl glycidyl ether)-co-formaldehyde] and poly-(ethylenimine) bi-layers. Atomic force microscopy (AFM) results indicate a very homogeneous and dense film with low surface roughness. Carbon nanofillers were introduced either by mixing into the coating components or in between individual layers to control the separation between the carbon nanofillers and alloy surface. The film chemistry and barrier properties were characterized by means of spectroscopic and electrochemical methods, respectively. The degradation and delamination behavior of the epoxy-based films was characterized by means of in situ AFM corrosion experiments. The quantitative imaging (QI) mode allowed the observation of hydrogen-generation induced blister formation during exposure to corrosive electrolyte and how the local corrosion processes evolved with exposure time. Complementary energy dispersive X-ray spectroscopy (EDX) analysis was performed to correlate the corrosion behavior with the different intermetallic particle chemistries and distributions. The presentation will summarize our results on the effect of interface chemistry and carbon nanofiller – alloy separation on the initiation of local corrosion processes on thin film covered AA2024-T3 aluminium alloys. T2 - EuroCorr2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Corrosion KW - Atomic Force Microscopy (AFM) PY - 2019 AN - OPUS4-50293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia A1 - Fernandes Jamar, Marina A1 - Stepien, Daniel T1 - In situ atomic force microscopy (AFM) analysis of materials under combined corrosive and mechanical load N2 - In service, most materials are operated under simultaneous corrosive and mechanical load and there are very few methods capable for testing material degradation under these conditions, especially when it comes to high resolution analysis. For this purpose, in this work, a tensile module capable of uniaxial stretching and compression with up to 5 kN force was integrated into an AFM stage. The elimination of the need for sample unmounting and remounting and the resulting possibility of keeping the sample under constant mechanical load during AFM measurements not only enables a precise positioning of the area of interest but also allows for the analysis of processes in the elastic deformation regime. This methodology was demonstrated for two case studies. Scanning Kelvin Probe Force Microscopy (SKPFM) was used as the main tool to characterize the deformation behavior. Moreover, a flexible electrochemical measurement cell was used to enable electrochemical analysis by means of electrochemical impedance spectroscopy (EIS) and Linear Sweep Voltammetry (LSV) during AFM measurements at different levels of strain. The in situ AFM results are complemented by microstructure analysis by means of electron backscatter diffraction (EBSD). In the first case study, the deformation induced delamination of a thin organic coating on AA2024 T3 aluminium alloy was investigated as a function of alloy surface treatment. The formation of cracks in the insulating passive film enabled an early detection of deformation processes by means of SKPFM. The second case study focused on the comparison of corrosion and deformation behavior of conventional and additively manufactured 316 stainless steels. In comparison to the conventional 316 stainless steel, the effect of processing was clearly detectable on the additively manufactured material as zones of inhomogeneous potential, which also affected the initiation of local corrosion processes. The contribution will provide detailed information on the new AFM setup and summarize our results from both case studies. T2 - EuroCorr2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Corrosion KW - Coupled corrosive and mechanial load KW - Atomic Force Microscopy (AFM) PY - 2019 AN - OPUS4-50294 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia A1 - Schenderlein, Matthias A1 - Hampel, Marco A1 - Almalla, Ahed T1 - Coupled electrochemical, microscopic and spectroscopic techniques for the analysis of local corrosion and mic processes N2 - Summary of the research topics of the division 6.2 and recent results T2 - HZDR-IRE Institutscolloquium CY - Dresden, Germany DA - 24.09.2019 KW - MIC KW - Localised corrosion KW - Corrosion monitoring KW - Biofilmbildung KW - Atomic Force Microscopy (AFM) PY - 2019 AN - OPUS4-50295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia A1 - Almalla, Ahed A1 - Fernandes Jamar, Marina A1 - Stepien, Daniel T1 - Untersuchung lokaler Korrosionsprozesse mittels kombinierter elektrochemischer und mikroskopischer Methoden N2 - Aktuelle Forschungsergebnisse - Korrosionseigenschaften von AA 2024-T3 und AM-316 unter gekoppelter korrosiv/mechanischer Beanspruchung. T2 - MPIE Düsseldorf, Sitzung der GfKORR Arbeitskreise Grundlagen und Simulation und Korrosionsuntersuchung und überwachung CY - Dusseldorf, Germany DA - 20.11.2019 KW - Corrosion KW - Atomic Force Microscopy (AFM) KW - Coupled corrosive/mechanical load PY - 2019 AN - OPUS4-50296 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zutta Villate, J. M. A1 - Hahn, Marc Benjamin T1 - Radioactive gold nanoparticles for cancer treatment N2 - Dose enhancement by gold nanoparticles (AuNP) was shown to increase the biological effectiveness of radiation damage in biomolecules and tissue. Most of the current studies focus on external beam therapy on combination with AuNP. Here we present a Monte-Carlo study (Geant4) to characterise radioactive AuNP. Radioactive 198 Au emits beta and gamma rays and is considered for applications with solid tumours. To effectively apply 198 AuNP their energy deposit characteristics have to be determined in terms of intrinsic and extrinsic properties e.g. AuNP diameter, AuNP density, and their clustering behaviour. After each decay process, the energy deposit, inelastic scattering events, kinetic energy spectrum of secondary particles within the AuNP themselves and in a spherical target volume of water up to 1 μm radius were determined. Simulations were performed for AuNP radii ranging from 2.5 nm to 20 nm radius, different cluster sizes and densities. The results show an increase of the energy deposit in the vicinity of the AuNP up to 150 nm. This effect nearly vanishes for distances up to one micron. For the case of AuNP clusters and the same activity, the enhancement of the energy deposit increases with the relative gold mass percentage and therefore can be adjusted by changing AuNP radius or clustering behaviour. KW - Gold KW - Nanoparticle KW - Cancer KW - Monte-Carlo KW - Simulation KW - Cluster PY - 2019 DO - https://doi.org/10.1140/epjd/e2019-90707-x SN - 1434-6060 SN - 1434-6079 VL - 73 IS - 95 SP - 1 EP - 7 PB - Springer CY - Berlin AN - OPUS4-47964 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zocca, Andrea A1 - Lüchtenborg, Jörg A1 - Mühler, T. A1 - Wilbig, Janka A1 - Mohr, Gunther A1 - Villatte, T. A1 - Léonard, Fabien A1 - Nolze, Gert A1 - Sparenberg, M. A1 - Melcher, J. A1 - Hilgenberg, Kai A1 - Günster, Jens T1 - Enabling the 3D Printing of Metal Components in μ-Gravity N2 - As humanity contemplates manned missions to Mars, strategies need to be developed for the design and operation of hospitable environments to safely work in space for years. The supply of spare parts for repair and replacement of lost equipment will be one key need, but in-space manufacturing remains the only option for a timely supply. With high flexibility in design and the ability to manufacture ready-to-use components directly from a computeraided model, additive manufacturing (AM) technologies appear extremely attractive. For the manufacturing of metal parts, laser-beam melting is the most widely used AM process. However, the handling of metal powders in the absence of gravity is one prerequisite for its successful application in space. A gas flow throughout the powder bed is successfully applied to compensate for missing gravitational forces in microgravity experiments. This so-called gas-flow-assisted powder deposition is based on a porous Building platform acting as a filter for the fixation of metal particles in a gas flow driven by a pressure difference maintained by a vacuum pump. KW - Additive manufacturing KW - µ-gravity KW - Laser beam melting KW - Parabolic flight KW - 3D printing PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-492190 DO - https://doi.org/10.1002/admt.201900506 SP - 1900506 PB - WILEY-VCH Verlag GmbH AN - OPUS4-49219 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zocca, Andrea A1 - Lüchtenborg, Jörg A1 - Lima, P. A1 - Diener, S. A1 - Katsikis, N. A1 - Günster, Jens T1 - Additive Manufacturing of Silicon Carbide by LSD-print N2 - The layerwise slurry deposition (LSD) has been established in the recent years as a method for the deposition of ceramic powder layers. The LSD consists in the layer-by-layer deposition of a ceramic slurry by means of a doctor blade; each layer is sequentially deposited and dried to achieve a highly packed powder layer. The combination of binder jetting and LSD was introduced as a novel technology named LSD-print. The LSD-print takes advantage of the speed of binder jetting to print large areas, parallel to the flexibility of the LSD, which allows the deposition of highly packed powder layers with a variety of ceramic materials. The working principle and history of the LSD technology will be shortly discussed. A theoretical background will be also discussed, highlighting advantages and drawbacks of the LSD compared to the deposition of a dry powder. The last part of the talk will be dedicated to highlight recent results on the LSD-print of SiSiC of geometrically complex components, in collaboration between BAM and HC Starck Ceramics GmbH. Density, microstructure and mechanical properties of LSD-printed and isostatic pressed samples will be discussed and compared. T2 - XVI ECerS CONFERENCE CY - Torino, Italy DA - 16.06.2019 KW - Additive Manufacturing KW - Silicon Carbide KW - 3D printing KW - Layerwise Slurry Deposition PY - 2019 AN - OPUS4-49220 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zocca, Andrea A1 - Mühler, T. A1 - Lima, P. A1 - Günster, Jens A1 - Lüchtenborg, Jörg T1 - Advanced ceramics by powder bed 3D printing N2 - Powder bed -based technologies are amongst the most successful Additive Manufacturing (AM) techniques. "Selective laser sintering/melting" (SLS/SLM) and "binder jetting 3D printing" (3DP) especially are leading AM technologies for metals and polymers, thanks to their high productivity and scalability. However, the flowability of the powder used in these processes is essential to achieve defect-free and densely packed powder layers. For standard powder bed AM technologies, this limits the use of many raw materials which are too fine or too cohesive. This presentation will discuss the possibilities to either optimize the powder raw material to adapt it to the specific AM process, or to develop novel AM technologies which are able to process powders in a wider range of conditions. In this context, the "layerwise slurry deposition" (LSD) has been developed as a layer deposition method which enables the use of very fine ceramic particles. T2 - Smart Made CY - Osaka, Japan DA - 01.09.2019 KW - Additive Manufacturing KW - Ceramic KW - Powder KW - Layerwise slurry deposition KW - 3D printing PY - 2019 AN - OPUS4-49221 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zocca, Andrea A1 - Lüchtenborg, Jörg A1 - Günster, Jens A1 - Diener, S. A1 - Lima, P. A1 - Katsikis, N. T1 - Layerwise Slurry Deposition for the Additive Manufacturing of Ceramics N2 - In powder bed Additive Manufacturing (AM) technologies, a part is produced by depositing and piling up thin powder layers. In each layer, the cross section of the object to build is defined by locally consolidating the powder, by sintering/melting the material (powder bed fusion technologies) or by ink jetting a binder (binder jetting technologies). These are already leading AM technologies for metals and polymers, thanks to their high productivity and scalability. The application of these techniques to most ceramics has been challenging so far, because of the challenges related to the deposition of homogeneous powder layers when using fine powders. In this context, the "layerwise slurry deposition" (LSD) has been developed as a layer deposition method which enables the use of SLS/SLM and 3DP technologies for advanced ceramic materials. LSD consists in the layer-by-layer deposition of a ceramic slurry by means of a doctor blade. Each layer is deposited and dried to achieve a highly packed powder layer. The LSD offers high flexibility in the ceramic feedstock used, especially concerning material and particle size, and enables the production of parts with physical and mechanical properties comparable to pressed or slip-casted parts. In this presentation, the LSD technique will be introduced and several examples of application to porcelain, SiC and alumina products will be reported. T2 - ICACC 2019 - 43rd International Conference and Exposition on Advanced Ceramics and Composites CY - Daytona Beach, FL, USA DA - 27.01.2019 KW - Additive Manufacturing KW - Ceramic KW - Layerwise KW - Slurry PY - 2019 AN - OPUS4-47865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zocca, Andrea A1 - Lima, P. A1 - Lüchtenborg, Jörg A1 - Mühler, T. A1 - Günster, Jens T1 - Advanced ceramics by powder bed 3D printing N2 - Powder bed -based technologies are amongst the most successful Additive Manufacturing (AM) techniques. "Selective laser sintering/melting" (SLS/SLM) and "binder jetting 3D printing" (3DP) especially are leading AM technologies for metals and polymers, thanks to their high productivity and scalability. However, the flowability of the powder used in these processes is essential to achieve defect-free and densely packed powder layers. For standard powder bed AM technologies, this limits the use of many raw materials which are too fine or too cohesive. This presentation will discuss the possibilities to either optimize the powder raw material to adapt it to the specific AM process, or to develop novel AM technologies which are able to process powders in a wider range of conditions. In this context, the "layerwise slurry deposition" (LSD) has been developed as a layer deposition method which enables the use of very fine ceramic particles. Another technology, the Gas Flow Assisted Powder Deposition, can increase the stability of the powder bed and the packing density, even in extreme conditions such as in absence of gravitational forces. T2 - yCAM 2019 - young Ceramists Additive Manufacturing Forum CY - Mons, Belgium DA - 03.04.2019 KW - Additive Manufacturing KW - Flowability KW - Ceramic KW - Powder PY - 2019 AN - OPUS4-47867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zocca, Andrea A1 - Lüchtenborg, Jörg A1 - Lima, P. A1 - Günster, Jens T1 - Additive Manufacturing of Ceramic Materials N2 - Powder bed -based technologies are amongst the most successful Additive Manufacturing (AM) techniques. "Selective laser sintering/melting" (SLS/SLM) and "binder jetting 3D printing" (3DP) especially are leading AM technologies for metals and polymers, thanks to their high productivity and scalability. In this context, the "layerwise slurry deposition" (LSD) has been developed as a layer deposition method which enables the use of SLS/SLM and 3DP technologies for advanced ceramic materials. LSD consists in the layer-by-layer deposition of a ceramic slurry by means of a doctor blade. Each layer is deposited and dried to achieve a highly packed powder layer, which can be used for SLM or for 3DP. This technique offers high flexibility in the ceramic feedstock used, especially concerning material and particle size, and is capable of producing parts with physical and mechanical properties comparable to traditionally shaped parts. In this presentation, the LSD technique will be introduced and several examples of application to porcelain, SiC and alumina products will be reported. T2 - First Sino-German Workshop on 3D Printing in Space CY - Beijin, China DA - 20.02.2019 KW - Additive Manufacturing KW - Ceramic KW - Layerwise PY - 2019 AN - OPUS4-47868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zirnstein, Benjamin A1 - Schulze, Dietmar A1 - Schartel, Bernhard T1 - The impact of polyaniline in phosphorus flame retardant ethylene-propylene-diene-rubber (EPDM) N2 - Usually elastomers are loaded with high amounts of flame retardants to fulfill fire safety requirements. In this study the potential char precursor polyaniline (PANI) and the established fire retardant pentaerythritol (PER) were implemented in ethylene-propylene-diene monomer rubber (EPDM). PANI and PER were used in low loadings (7 phr) and combined with two phosphorous flame retardants, Ammonium polyphosphate (APP) and a piperazine-pyrophosphate/phosphoric acid compound (FP), to boost their performance. A comprehensive study is presented, explaining the impact of PANI on curing and mechanical properties, including compensation for the plasticizer-like effect of APP in EPDM, and improved flame retardancy. In the cone calorimeter test, the combination of EPDM/FP/PANI reduced the effective heat of combustion by 20%. All nine EPDM rubber compounds were investigated with the LOI and UL 94 tests, cone calorimeter, FMVSS 302 and glow wire testing to quantify fire performance. The PANI containing EPDM rubbers, EPDM/APP/PANI and EPDM/FP/PANI outperformed the corresponding PER containing, EPDM/APP/PER and EPDM/FP/PER rubbers in various tests. Moreover, the study investigated the impact of PANI and PER on the mode of action of the phosphorus species and showed that the addition of PANI increased the amount of phosphorus in the condensed phase. To receive a broader understanding of the flame retardant mode of action of PANI in combination with APP and FP, calculations were carried out to estimate the impact of PANI on the protective layer effect. KW - EPDM KW - Rubber KW - Flame retardant KW - Polyaniline KW - Pentaerythritol PY - 2019 DO - https://doi.org/10.1016/j.tca.2019.01.019 SN - 0040-6031 VL - 673 SP - 92 EP - 104 PB - Elsevier B.V. AN - OPUS4-47503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ziemann, M. A. A1 - Sigmund, Sandra A1 - Simon, Sebastian A1 - Meng, Birgit T1 - Insight into Concrete Deterioration with Raman Spectroscopy N2 - Alkali-silica reaction (ASR) is a serious Problem concerning the deterioration of concrete. This leads to significant maintenance and reconstruction costs for concrete infrastructures all over the world. The geographical regions, which play a major role in concrete deterioration, are for example coastal Areas or in general, areas with a high air humidity/salinity due to closeness of rivers or lakes. These exemplary results show, the application of Raman spectroscopy establishes a valuable approach for characterizing the chemical and structural composition of ASR-products. The results prove the potential to trace the kind of reaction products, developing in dependence on the aggregate and to follow up its local alteration from origin of the gel. T2 - 10th International Congress on the Application of Raman Spectroscopy in Art and Archaeology (RAA2019) CY - Potsdam, Germany DA - 03.09.2019 KW - Building Materials KW - Alkali-silica-reaction KW - ASR KW - Raman Spectroscopy PY - 2019 AN - OPUS4-49471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhang, R. A1 - Qian, M. A1 - Waske, Anja A1 - Shen, H. A1 - Zhang, X. T1 - Investigating the microstructure and magnetic properties of La-Fe-Si microwires during fabrication and heat treatment process N2 - In this study, the optimized fabrication and evolution of the microstructure and magnetic Transition behavior of the melt-extraction LaFe11.2Si1.8 microwires have been studied. After the optimization of extraction technique (heating power 22 KW, feeding rate 30-50 mm/s, rotation velocity 1700 r/min), the content of La Fe,Si)13 phase in the as-extracted microwires was 54 wt% due to the high solidification velocity, which was increased to 85 wt% via annealing at 1373 K for 20 min. The amount of La(Fe,Si)13 phase was increased and the composition of La(Fe,Si)13 phase became more homogenized through peritectic reaction and short-distance diffusion in the microwires during annealing process. The coexistence of the nanocrystalline and amorphous structures contributed to the broad magnetic Transition temperature range of the as-extracted and annealed microwires. The annealed microwires exhibited a second-order magnetic transformation behavior and showed a maximum magnetic entropy Change jDSMjmax of 6.2 J/kgK and working temperature interval of 36.0 K under a magnetic field of 20 kOe. KW - Magnetocaloric effect KW - Melt-extraction technique KW - La(Fe,Si)13 phase KW - Peritectic reaction KW - Short-distance diffusion PY - 2019 DO - https://doi.org/10.1016/j.jallcom.2019.04.196 SN - 0925-8388 SN - 1873-4669 VL - 794 SP - 153 EP - 162 PB - Elsevier B.V. AN - OPUS4-48095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Vormwald, M. T1 - Applying fracture mechanics to fatigue strength determination - some basic considerations N2 - A discussion is provided on demands that must be met in order to apply fracture mechanics to the determination of overall fatigue lifetime and strength, i.e., S-N curves and fatigue limits. These comprise the determination of the cyclic crack driving force for all stages of fatigue crack propagation, in particular for the short crack stage where the crack driving force has to be determined for elastic-plastic deformation and the gradual build-up of the crack closure phenomenon. Special emphasis is put on a fatigue damage relevant specification of the initial crack size. Different approaches in the literature are discussed. Another important aspect is the adequate treatment of multiple crack propagation. Finally, the discussion is illustrated by an example of a butt weld made of a medium strength steel. KW - Multiple cracks KW - Fatigue strength KW - Fracture mechanics KW - Fatigue crack propagation KW - Initial crack size PY - 2019 DO - https://doi.org/10.1016/j.ijfatigue.2019.05.009 SN - 0142-1123 VL - 126 SP - 188 EP - 201 PB - Elsevier Ltd. AN - OPUS4-48091 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - BOOK A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Schork, B. A1 - Hensel, J. A1 - Kucharczyk, P. A1 - Ngoula, D. A1 - Tchuindjang, D. A1 - Bernhard, J. A1 - Beckmann, C. T1 - The IBESS approach for the determination of the fatigue life and strength of weldments by fracture mechanics analysis N2 - This book provides a comprehensive and thorough guide to those readers who are lost in the often-confusing context of weld fatigue. It presents straightforward information on the fracture mechanics and material background of weld fatigue, starting with fatigue crack initiation and short cracks, before moving on to long cracks, crack closure, crack growth and threshold, residual stress, stress concentration, the stress intensity factor, J-integral, multiple cracks, weld geometries and defects, microstructural parameters including HAZ, and cyclic stress-strain behavior. The book treats all of these essential and mutually interacting parameters using a unique form of analysis. KW - Fatigue crack propagation KW - Cyclic J-integral KW - Cyclic R-curve analysis KW - Fatigue S-N curve KW - HAZ PY - 2019 SN - 978-3-030-04072-7 SN - 978-3-030-04073-4 DO - https://doi.org/10.1007/978-3-030-04073-4 SP - 1 EP - 130 PB - Springer CY - Cham AN - OPUS4-47576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Klinger, Christian A1 - Bettge, Dirk A1 - Murakami, Y. T1 - Defects as a root cause of fatigue failure of metallic components. III: Cavities, dents, corrosion pits, scratches N2 - This third part of the review on defects as root cause of fatigue failure addresses cavities (pores, micro-shrinkages, unmelted regions), defective microstructures and microcracks as material defects and defects due to local damage during manufacturing, service and maintenance such as dents, scratches and localized corrosion. In addition, damage due to contact fatigue and the effect of surface roughness are discussed in the context of fatigue failure. Also addressed is the competition between different kinds of defects in controlling the initiation and early growth of fatigue cracks. KW - Pores KW - Micro-shrinkages KW - Impact damage KW - Contact fatigue KW - Corrosion pits KW - Scratches PY - 2019 DO - https://doi.org/10.1016/j.engfailanal.2019.01.034 SN - 1350-6307 VL - 97 SP - 759 EP - 776 PB - Pergamon-Elsevier Science Ltd CY - Oxford, England AN - OPUS4-47373 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Klinger, Christian A1 - Bettge, Dirk A1 - Murakami, Y. T1 - Defects as a root cause of fatigue failure of metallic components. I: Basic aspects N2 - According to the definition of the ASM handbook [1,3], a defect is "an imperfection. that can be shown to cause failure by a quantitative analysis and that would not have occurred in the absence of the imperfection". The topic of the present three-part review is a discussion of defects which can cause failure in cyclically loaded structures. The features discussed comprise material defects such as non-metallic inclusions, pores or micro-shrinkages, etc. and geometric defects such as surface roughness and secondary notches which have their origin in manufacturing, and defects such as surface damage due to scratches, impact events or contact fatigue as well as corrosion pits which arise in service. In this first part, the discussion is prefaced by an introduction to basic aspects which are essential for a deeper understanding of the characteristics and mechanisms how the defects influence fatigue crack initiation and propagation. These include the life cycle of a fatigue crack from initiation up to fracture, crack arrest, multiple crack initiation and coalescence, and the material and geometrical properties affecting these. KW - Defects KW - Fatigue crack propagation stages KW - Crack arrest KW - Multiple cracks PY - 2019 DO - https://doi.org/10.1016/j.engfailanal.2019.01.055 SN - 1350-6307 VL - 97 SP - 777 EP - 792 PB - Pergamon-Elsevier Science Ltd CY - Oxford, England AN - OPUS4-47372 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Klinger, Christian A1 - Bettge, Dirk A1 - Murakami, Y. T1 - Defects as a root cause of fatigue failure of metallic components. II: Non-metallic inclusions N2 - This second part of the review on defects as root cause of fatigue failure comprises the origin, the nature and the effects of non-metallic inclusions. Topics addressed are the different kinds of inclusions formed during the manufacturing process, various types of mis-match causing local stresses and, as a consequence, fatigue crack initiation, and effects of characteristics such as size, morphology, localization, spatial distribution and orientation of the defects on the fatigue behavior. Methods for inclusion counting and sizing are discussed along with statistical aspects necessary to be considered when evaluating structural components. KW - Non-metallic inclusions KW - Mis-match KW - Inclusion size KW - Inclusion cluster KW - Statistics PY - 2019 DO - https://doi.org/10.1016/j.engfailanal.2019.01.054 SN - 1350-6307 VL - 98 SP - 228 EP - 239 PB - Elsevier Ltd. AN - OPUS4-47459 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Klinger, Christian T1 - Material defects as cause for the fatigue failure of metallic components N2 - The paper provides an overview on material defects which may serve as fatigue crack initiation sites and can cause final fatigue failure of a component. These comprise nonmetallic inclusions in Steel and aluminum alloys, cavities such as pores, micro-shrinkages and un-welded regions in cast, sinter and additively manufactured alloys, graphite nodules, shrinkages and other items in modular cast iron, regions of defective microstructure, microcracks and secondary notches such as undercuts and surface roughness. Besides their origin, the effect and mechanisms on fatigue crack initiation and propagation are discussed. The considerations are proceeded and accompanied by a Brief discussion of some Basic aspects such as the stages of crack propagation along their length scale, the overcoming of crack arrest and the question when a secondary notch can be treated as a crack. KW - Material defects KW - Fatigue strength and life KW - Non-metallic inclusions KW - Pores KW - Shrinkages KW - Graphite modules KW - Surface roughness PY - 2019 DO - https://doi.org/10.1016/j.ijfatigue.2019.06.024 SN - 0142-1123 SN - 1879-3452 VL - 127 SP - 312 EP - 323 PB - Elsevier AN - OPUS4-49127 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zerbst, Uwe T1 - Schwingfestigkeit und Bruchmechanik N2 - Der Vortrag behandelt in grundsätzlicher weise die Anwendung bruchmechanischer Methoden auf die rechnerische Ermittlung der Wöhlerkurve. Dabei werden die Besonderheiten des Kurzrisswachstums (Notwendigkeit der elastisch-plastischen Beschreibung der zyklischen Rissspitzenbelastung, gradueller Aufbau des Rissschlißphänomens) ebenso diskutiert wie das Problem des Mehrfachrissewachstums und Rissarrest. Die Ausführungen werden an einem Beispiel illustriert. T2 - Sitzung des FKM - Fachkreises "Bauteilfestigkeitä2 CY - Frankfurt/M., Germany DA - 05.09.2019 KW - Schwingfestigkeit KW - Bruchmechanik KW - Rissarrest KW - Kurzrisswachstum PY - 2019 AN - OPUS4-49085 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Hildenberg, Kai A1 - Hrabe, N. T1 - Thoughts on damage tolerance and safe life design in metallic AM structures N2 - Der Vortrag bietet eine Diskussion zur Abschätzung des Schadenstoleranzverhaltens metallischer AM - Komponenten. Im Fokus stehen Probleme bei der Ermittlung repräsentativer Materialdaten, der Einfluss von Materialdefekten und Eigenspannungen. Ausgehend von derzeitigem Stand auf dem Gebiet werden Möglichkeiten der Schadenstoleranten Bauteileauslegung von AM diskutiert. N2 - The presentation provides a discussion and damage tolerant assessment of metallic AM components. In the focus are problems of the determination of representative material data, the effect of material defects and residual stresses. Starting with the actual state-of-the-art in the field, options and possibilities of a damage tolerant design for AM are discussed. T2 - BAM/NIST-Workshop on Fatigue of Additive Manufactured Metallic Components CY - Berlin, Germany DA - 16.05.2019 KW - Schadenstolerante Bauteilauslegung KW - Repräsentative Werkstoffeigenschaften KW - Defekte Eigenspannung KW - Damage tolerant component design KW - Representative material properties KW - Residual stresses PY - 2019 AN - OPUS4-48810 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Hensel, J. A1 - Nitschke-Pagel, T. T1 - Schweißeigenspannungen und Bauteilintegrität aus bruchmechanischer Sicht N2 - Der Vortrag thematisiert die Behandlung von Schweißeigenspannungen bei der Auslegung geschweißter Bauteile. Ausgehend von Fragen der Klassifizierung unterschiedlicher Typen von Eigenspannungen wird auf Fragen der Behandlung von Primär- und Sekundärspannungen, der Ermittlung und Aussagefähigkeit von Eigenspannungs-Tiefen-Profilen und der Stabilität der Eigenspannungen bei zyklischer Beanspruchung eingegangen. Neben der Auslegung auf Bruch wird die Beschreibung der Ermüdungsrissausbreitung bei Vorhandensein von Eigenspannungen diskutiert, wobei neben der klassischen Langrissbruchmechanik auch Besonderheiten der Kurzrissbruchmechanik angesprochen werden. T2 - DVM - Workshop "Eigenspannungen in der industriellen Praxis" CY - Berlin, Germany DA - 05.11.2019 KW - Schweißeigenspannungen KW - Primär- und Sekundärspannungen KW - Schweißeigenspannungs-Tiefen-Profile KW - Stabilität von Eigenspannungen KW - Kurz- und Langriss-Ermüdungsbruchmechanik PY - 2019 AN - OPUS4-49498 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zemke, F. A1 - Schölch, V. A1 - Bekheet, M.F. A1 - Schmidt, Franziska T1 - Surfactant-assisted sol–gel synthesis of mesoporous bioactive glass microspheres N2 - Spherical mesoporous bioactive glasses in the silicon dioxide (SiO2)-phosphorus pentoxide (P2O5)–calcium oxide (CaO) system with a high specific surface area of up to 300m2/g and a medium pore radius of 4 nm were synthesized by using a simple one-pot surfactant-assisted sol–gel synthesis method followed by calcination at 500–700°C. The authors were able to control the particle properties by varying synthesis parameters to achieve microscale powders with spherical morphology and a particle size of around 5–10 mm by employing one structure-directing agent. Due to a high Calcium oxide content of 33·6mol% and a phosphorus pentoxide content of 4·0mol%, the powder showed very good bioactivity up to 7 d of immersion in simulated Body fluid. The resulting microspheres are promising materials for a variety of life science applications, as further processing – for example, granulation – is unnecessary. Microspheres can be applied as materials for powder-based additive manufacturing or in stable suspensions for drug release, in bone cements or fillers. KW - bioactive KW - biomaterials KW - bone PY - 2019 DO - https://doi.org/10.1680/jnaen.18.00020 SN - 2045-9831 SN - 2045-984X VL - 8 IS - 2 SP - 126 EP - 134 PB - ICE Publishing CY - London AN - OPUS4-50148 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zakel, S. A1 - Schröder, Volkmar A1 - Askar, Enis A1 - Gabel, D. A1 - Hirsch, W. A1 - Kleinert, J. A1 - Krause, U. A1 - Krietsch, Arne A1 - Meistes, J. A1 - Sachtleben, A. A1 - Schmidt, Martin T1 - Sicherheitstechnische Kenngrößen des Explosionsschutzes von hybriden Stoffgemischen - Normungsfähige Bestimmungsverfahren N2 - In diesem Verbundvorhaben werden standardisierte Messverfahren für hybride Gemische erarbeitet, die der Bestimmung sicherheitstechnischer Kenngrößen des Explosionsschutzes dienen. Unter einem hybriden Gemisch wird dabei ein mehrphasiges System aus Brenngas oder brennbarem Dampf, sowie Luft und brennbarem Staub verstanden. Die Veröffentlichung der Ergebnisse erfolgt in einem Abschlussbericht und als DIN-Spezifikation (DIN SPEC). Diese DIN SPEC versetzt Prüfinstitute und Industrie in die Lage, Explosionsgefahren beim Betrieb technischer Anlagen mit hybriden Gemischen einzuschätzen und damit Prozesse sowohl sicherer als auch effizienter zu steuern. Dieses Projekt wird im Rahmen des WIPANOProgramms (Wissens- und Technologietransfer durch Patente und Normen) vom BMWi gefördert. T2 - 14. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 07.11.2019 KW - Explosionsschutz KW - Sicherheitstechnische Kenngrößen KW - Hybride Gemische KW - Normung PY - 2019 SN - 978-3-89746-220-5 SP - 73 CY - Frankfurt am Main AN - OPUS4-49954 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zakel, S. A1 - Schröder, Volkmar A1 - Gabel, D. A1 - Hirsch, W. A1 - Kleinert, J. A1 - Krause, U. A1 - Krietsch, Arne A1 - Meistes, J. A1 - Sachtleben, A. A1 - Schmidt, Martin A1 - Askar, Enis T1 - Safety characteristics of hybrid mixtures for explosion protection N2 - In this joint project, standardized measurement methods for hybrid mixtures are developed, which serve to determine safety characteristics for explosion protection. A hybrid mixture is a multi-phase System consisting of fuel gas or vapor, as well as air and flammable dust. This combination can occur for instance in drying processes or during heterogenous reaction processes. T2 - 27th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS) CY - Beijing, VR China DA - 28.07.2019 KW - Explosionsschutz KW - Gas-Staub-Gemische KW - Hybride Gemische KW - Sicherheitstechnische Kenngrößen PY - 2019 AN - OPUS4-48992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zakel, S. A1 - Schröder, Volkmar A1 - Askar, Enis A1 - Gabel, D. A1 - Hirsch, W. A1 - Kleinert, J. A1 - Krietsch, Arne A1 - Meistes, J. A1 - Sachtleben, A. A1 - Schmidt, Martin A1 - Krause, U. T1 - Entwicklung von normungsfähigen Bestimmungsverfahren für sicherheitstechnische Kenngrößen des Explosionsschutzes von hybriden Stoffgemischen N2 - In diesem Verbundvorhaben werden standardisierte Messverfahren für hybride Gemische erarbeitet, die der Bestimmung sicherheitstechnischer Kenngrößen des Explosionsschutzes dienen. Unter einem hybriden Gemisch wird dabei ein mehrphasiges System aus Brenngas oder brennbarem Dampf, sowie Luft und brennbarem Staub verstanden. Die Veröffentlichung der Ergebnisse erfolgt in einem Abschlussbericht und als DIN-Spezifikation (DIN SPEC). Diese DIN SPEC versetzt Prüfinstitute und Industrie in die Lage, Explosionsgefahren beim Betrieb technischer Anlagen mit hybriden Gemischen einzuschätzen und damit Prozesse sowohl sicherer als auch effizienter zu steuern. Dieses Projekt wird im Rahmen des WIPANOProgramms (Wissens- und Technologietransfer durch Patente und Normen) vom BMWi gefördert. T2 - 14. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 07.11.2019 KW - Explosionsschutz KW - Sicherheitstechnische Kenngrößen KW - Hybride Gemische KW - Normung PY - 2019 AN - OPUS4-49953 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yusenko, Kirill A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Emmerling, Franziska T1 - BAMline 2.0 – further technical developments for a broader multipurpose hard X-ray beamline at BESSY II N2 - We show further development of our beamline in the contexst of further itermational collaboration. T2 - PACC and AfSC CY - Accra, Ghana DA - 28.01.2019 KW - Synchrotron radiation PY - 2019 AN - OPUS4-47317 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yin, Huajie A1 - Chapala, P. A1 - Bermeshev, M. A1 - Pauw, Brian Richard A1 - Schönhals, Andreas A1 - Böhning, Martin T1 - Influence of Trimethylsilyl Side Groups on the Molecular Mobility and Charge Transport in Highly Permeable Glassy Polynorbornenes N2 - Superglassy polymers with a large fractional free volume have emerged as novel materials with a broad range of applications, especially in the field of membrane separations. Highly permeable addition-type substituted polynorbornenes with high thermal resistance and chemical stability are among the most promising materials. The major obstacle for extending the practical membrane application is their strong tendency to physical aging, leading to a partial decline in their superior transport performance over time. In the present study, broadband dielectric spectroscopy with complementary X-ray scattering techniques were employed to reveal changes in microporous structure, molecular mobility, and conductivity by systematic comparison of two polynorbornenes with different numbers of trimethylsilyl side groups. Their response upon heating (aging) was compared in terms of structure, dynamics, and charge transport behavior. Furthermore, a detailed analysis of the observed Maxwell−Wagner−Sillars polarization at internal interfaces provides unique information about the microporous structure in the solid films. The knowledge obtained from the experiments will guide and unlock potential in synthesizing addition-type polynorbornenes with versatile properties. KW - Dielectric spectroscopy KW - Molecular mobility KW - Electrical conductivity KW - Gas separation membranes PY - 2019 DO - https://doi.org/10.1021/acsapm.9b00092 SN - 2637-6105 VL - 1 IS - 4 SP - 844 EP - 855 PB - ACS CY - Washington DC AN - OPUS4-47838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yin, Huajie A1 - B, Yang A1 - Chua, Y. Z. A1 - Szymoniak, Paulina A1 - Carta, M A1 - Malpass-Evans, R A1 - McKeown, N A1 - Harrison, W A1 - Budd, P A1 - Schick, C A1 - Böhning, Martin A1 - Schönhals, Andreas T1 - Effect of backbone rigidity on the glass transition of polymers of in-trinsic microporosity probed by fast scanning calorimetry N2 - Polymers of Intrinsic Microporosity (PIMs) of high performance have developed as materials with a wide application range in gas separation and other energy-related fields. Further optimization and long-term behavior of devices with PIMs require an understanding of the structure-property relationships including physical aging. In this context the glass transi-tion plays a central role, but with conventional thermal analysis a glass transition is usually not detectable for PIMs be-fore their thermal decomposition. Fast scanning calorimetry provides evidence of the glass transition for a series of PIMs, as the time scales responsible for thermal degradation and for the glass transition are decoupled by employing ultrafast heating rates of tens of thousands K s-1. The investigated PIMs were chosen considering the chain rigidity. The estimated glass transition temperatures follow the order of the rigidity of the backbone of the PIMs. KW - Polymers of intrinsic microporosity KW - Fast scanning calormetry PY - 2019 DO - https://doi.org/10.1021/acsmacrolett.9b00482 SN - 2161-1653 VL - 8 IS - 8 SP - 1022 EP - 1028 PB - ACS Publications AN - OPUS4-48617 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yin, Huajie A1 - Schönhals, Andreas A1 - Böhning, Martin T1 - Molecular Mobility and Charge Transport in Polymers of Intrinsic Microporosity (PIMs) as Revealed by Dielectric Spectroscopy N2 - Polymeric membranes represent a low-cost, energy efficient solution for gas separation. Recently polymers of intrinsic microporosity (PIMs) have emerged as prestigious membrane materials featuring a large concentration of pores smaller than 1 nm, a BET surface area larger than 700 m2/g and high gas permeability and selectivity. Unusual chain structure combining rigid segments with sites of contortion gives rise to the intrinsic microporosity. However, this novel class of glassy polymers are prone to pronounced physical aging. The initial microporous structures approach a denser state via local small scale fluctuataions, leading to a dramatic reduction in the gas permeabilities. For the first time, dielectric relaxation spectroscopy with state-of-the-art high-resolution analyzers was employed to investigate three representative PIMs with a systematic change in chain rigidity: PIM-EA-TB 〉 PIM-1 〉 PIM-MDPH-TB. The molecular mobility, the charge transport and their response upon heating (aging) in the polymers were measured in a broad temperature range through isothermal frequency scans during different heating / cooling cycles. Multiple dielectric processes following Arrhenius behavior were observed for the investigated polymers. Local fluctuations, Maxwell-Wagner-Sillars (MWS) polarization and structural relaxation phenomena were discussed and attempted to be correlated with the structural features of PIMs. Moreover, all PIMs showed conductivity in the glassy state. The significant increase in the conductivity with increasing temperature far below the glass transition temperature of PIMs is explained in terms of the loosely packed microporous structure and the formation of local intermolecular agglomerates due to interaction of π-electrons in aromatic moieties of the polymer backbone. T2 - American Chemical Society (ACS) National Meeting & Expo 2019 CY - Orlando, FL, USA DA - 31.03.2019 KW - Dielectric spectroscopy KW - Polymeric membrane KW - Polymers of intrinsic microporosity PY - 2019 AN - OPUS4-47805 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yin, Huajie A1 - Chua, Y. Z. A1 - Yang, B. A1 - Schick, C. A1 - Böhning, Martin A1 - Schönhals, Andreas T1 - Probing the glass transition temperature of polymers of intrinsic microporosity (PIMs) by fast scanning calorimeter N2 - High performance polymers of intrinsic microporosity (PIMs) have emerged as novel materials with broad applications from gas separation to electronic devices. Sufficiently rigid, even contorted polymer chains show only limited molecular mobility, therefore undergo inefficient packing and give rise to intrinsic microporosity with pore size generally smaller than 1 nm and BET surface areas larger than 700 m2/g. Further performance optimization and long-term stability of devices incorporating PIMs rely on our understanding of structure-processing-property relationships and physical aging, in which glass transition plays a key role. Up to now no glass transition temperature (Tg) of PIMs could be detected with conventional thermal analysis techniques before degradation. Decoupling the time scales responsible for the glass transition and the thermal decomposition is a reliable strategy to overcome this. This was achieved by employing fast scanning calorimetry (FSC) based on a chip sensor, which is capable to heat and cool a small sample (ng-range) with ultrafast rates of several ten thousand K/s. FSC provides definitive evidence of glass transition of a series of PIMs with a special consideration on the chain rigidity. The determined glass transition temperature of these PIMs follows the order of the rigidity of their backbone structures. FSC provides the first clear-cut experimental evidence of the glass transition of PIM-EA-TB with a Tg of 663 K, PIM-1 of 644 K and PIM-DMDPH-TB of 630 K at a heating rate of 1Χ104 K/s. Local fluctuations are featured in glass transition of highly rigid PIMs. As conformational changes are prevented by the backbone rigidity, the glass transition must rather be assigned to local small scale fluctuations. T2 - American Chemical Society (ACS) National Meeting & Expo 2019 CY - Orlando, FL, USA DA - 31.03.2019 KW - Glass transition KW - Polymers of intrinsic microporosity KW - Fast scanning calorimeter PY - 2019 AN - OPUS4-47806 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yildirim, Arda A1 - Sentker, K. A1 - Smales, Glen Jacob A1 - Pauw, Brian Richard A1 - Huber, P. A1 - Schönhals, Andreas T1 - Collective orientational order and phase behavior of a discotic liquid crystal under nanoscale confinement N2 - The phase behavior and molecular ordering of hexakishexyloxy triphenylene (HAT6) DLC under cylindrical nanoconfinement is studied utilizing differential scanning calorimetry (DSC) and dielectric spectroscopy (DS), where cylindrical nanoconfinement is established through embedding HAT6 into the nanopores of anodic aluminum oxide membranes (AAO), and a silica membrane with pore diameters ranging from 161 nm down to 12 nm. Both unmodified and modified pore walls were considered, and in the latter case the pore walls of AAO membranes were chemical treated with n octadecylphosphonic acid (ODPA) resulting in the formation of a 2.2 nm thick layer of grafted alkyl chains. Phase transition enthalpies decrease with decreasing pore size, indicating that a large proportion of the HAT6 molecules within the pores has a disordered structure, which increases with decreasing pore size for both pore walls. In the case of the ODPA modification the amount of ordered HAT6 is increased compared to the unmodified case. The pore size dependencies of the phase transition temperatures were approximated using the Gibbs Thomson equation, where the estimated surface tension is dependent on the molecular ordering of HAT6 molecules within the pores and upon their surface. DS was employed to investigate the molecular ordering of HAT6 within the nanopores. These investigations revealed that with a pore size of around 38 nm, for the samples with the unmodified pore walls, the molecular ordering changes from planar axial to homeotropic radial. However, the planar axial configuration, which is suitable for electronic applications, can be successfully preserved through ODPA modification for most of the pore sizes. KW - Discotic Liquid Crystals KW - Nanoconfinement PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-475222 DO - https://doi.org/10.1039/c8na00308d SN - 2516-0230 VL - 1 IS - 3 SP - 1104 EP - 1116 PB - RSC AN - OPUS4-47522 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yildirim, Arda A1 - Bühlmeyer, A. A1 - Hayash, S A1 - Haenle, J. C. A1 - Sentker, K. A1 - Krause, Christina A1 - Huber, Patrick A1 - Laschat, Sabine A1 - Schönhals, Andreas T1 - Multiple glassy dynamics in dipole functionalized triphenylene-based discotic liquid crystals revealed by broadband dielectric spectroscopy and advanced calorimetry – assessment of the molecular origin N2 - A selected series of dipole functionalized triphenylene-based discotic liquid crystals (DLCs) was synthesized and investigated in a systematic way to reveal the phase behavior and molecular dynamics. The later point is of particular importance to understand the charge transport in such systems which is the key property for their applications such as organic field-effect transistors, solar cells or as nanowires in molecular electronics, and also to tune the properties of DLCs. The mesomorphic properties were studied by polarizing optical microscopy, X-ray diffraction, and differential scanning calorimetry, which were compared to the corresponding unfunctionalized DLC. The molecular dynamics were investigated by a combination of state-of-the-art broadband dielectric spectroscopy (BDS) and advanced calorimetry such as fast scanning calorimetry (FSC) and specific heat spectroscopy (SHS). Besides localized fluctuations, surprisingly multiple glassy dynamics were detected for all materials for the first time. Glassy dynamics were proven for both processes unambiguously due to the extraordinary broad frequency range covered. The a1-process is attributed to fluctuations of the alky chains in the intercolumnar space because a polyethylene-like glassy dynamics is observed. This corresponds to a glass transition in a confined three-dimensional space. The a2-process found at temperatures lower than a1-process, is assigned to small scale rotational and/or translational in plane fluctuations of the triphenylene core inside distorted columns. This can be considered as a glass transition in a one-dimensional fluid. Therefore, obtained results are of general importance to understand the glass transition, which is an unsolved problem of condensed matter science. KW - Discotic Liquid Crystals KW - Broadband dielectric spectroscopy KW - Flash DSC KW - Specific heat spectroscopy PY - 2019 DO - https://doi.org/10.1039/c9cp03499d SN - 1463-9076 VL - 21 IS - 33 SP - 18265 EP - 18277 PB - RSC AN - OPUS4-48739 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yildirim, Arda A1 - Bühlmeyer, A. A1 - Hayashi, S. A1 - Haenle, J. C. A1 - Sentker, K. A1 - Huber, P. A1 - Laschat, S. A1 - Schönhals, Andreas T1 - Molecular Dynamics of Dipole Functionalized Triphenylene-based Discotics N2 - In this study, the molecular dynamics of a series of dipole functionalized triphenylene-based discotics, forming a columnar mesophase, were investigated by broadband dielectric spectroscopy (BDS). In addition to conductivity and localized dynamics, glassy dynamics were also observed. At higher temperatures an α1-processes and at low temperatures an α2 processes were detected having a completely different temperature dependence of its relaxation times. Different molecular assignments of α1- and α2-processes are suggested. The phase behavior of the material was explored under helium purge down to 100 K by differential scanning calorimetry (DSC). Besides the phase transition temperatures and enthalpies, one or two thermal glass transitions were found for all the materials. Moreover, the glassy dynamics were further investigated by Flash DSC, which is a chip-based calorimetry technique allowing for fast heating and cooling rates as high as 10000K/s. T2 - Spring Meeting of German Physical Society CY - Regensburg, Germany DA - 01.04.2019 KW - Liquid Crystals PY - 2019 AN - OPUS4-47827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Würth, Christian A1 - Radunz, Sebastian A1 - Frenzel, Florian A1 - Resch-Genger, Ute T1 - Understanding Nucleation and Optical Properties of Upconverting Nanoparticles N2 - Non-linear optical emitters are promising materials for energy applications and biotechnologies. Solid-state multi-band emitters like lanthanide doped up-conversion nanoparticles (UCNPs) show excellent photostability, are excitable in the near infrared (NIR), and show emission bands from the UV to SWIR spectral regions. The optical properties of these materials strongly depend on the excitation power density, i.e., the number of photons absorbed per time interval. The upconversion (ΦUC) and downshifting quantum efficiencies (ΦDS) of these materials, the excitation power dependent population, and the deactivation dynamics are influenced by nanoparticle architecture, doping concentration, and the microenvironment. We studied the fundamental changes of the luminescence properties of ß-NaYF4 UCNPs doped with Yb3+ and Er3+ depending on size, different surroundings such as aqueous and organic media, and different surface chemistries. We obtained further insights into shelling procedures, FRET optimization, influence of doping concentration, and advantages of different sensitizer ions. T2 - NaNaX CY - Hamburg, Germany DA - 16.09.2019 KW - UpConversion KW - Optical properties KW - Nanoparticle KW - Nanomaterial PY - 2019 AN - OPUS4-49700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Sato, K. A1 - Brandt, Guido A1 - Schmid, Thomas A1 - Sasaki, S. A1 - Woydt, Mathias T1 - Wear behaviour of MgO stabilized zirconia in hot steam environment up to 400°C N2 - Self-mated magnesia stabilized zirconia (Mg-PSZ) ceramic sliding couples have been investigated at 100 N load (P0max= 1324 MPa) in oscillating sliding conditions in different humidity conditions in air and in hot steam. Temperatures have been varied up to 400 °C and pressures up to 6 bars. The results show that the wear behavior of MgO-ZrO2 under high Hertzian contact pressures is strongly dependent on temperature and is similar for both dry oscillating and oscillating in hot steam. However, although the evolution in wear rates on temperature is similar and the wear rates of MgO-ZrO2 plunged above 300 °C in hot steam and air by nearly three orders of magnitude, SEM micrographs revealed in hot steam at 400 °C smooth wear tracks. In contrast, hot steam enhanced the tribochemistry of self-mated alumina couples and reduced wear rates. Hot steam decreased the coefficients of friction of MgO-ZrO2 with increasing temperature, but not the wear rates. KW - Hot steam KW - Zirconia KW - Friction KW - Wear KW - Tribofilm KW - Raman spectroscopy PY - 2019 DO - https://doi.org/10.1016/j.wear.2019.01.047 VL - 426-427 SP - 428 EP - 432 PB - Elsevier B.V. AN - OPUS4-47873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wurzler, Nina A1 - Wagner, Ralph A1 - Schutter, Jan David A1 - Das, Chayanika A1 - Dimper, Matthias A1 - An, Biwen A1 - Koerdt, Andrea A1 - Lützenkirchen-Hecht, Dirk A1 - Özcan Sandikcioglu, Özlem T1 - Effect of cultivation conditions on the electrochemical activity of metal reducing bacteria (mrb) on stainless steel surfaces N2 - Investigation of the electrochemical activity of two cultures grown with and without abundance of Fe(III) and their different ability to reduce and therefore dissolve iron oxides in steel and model iron thin films. T2 - Eurocorr2019 CY - Sevilla, Spain DA - 09.09.2019 KW - X-ray spectroscopic techniques KW - Microbiologically influenced corrosion KW - MIC KW - XANES KW - Metal reducing bacteria KW - In situ PY - 2019 AN - OPUS4-49692 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Cheng-Chieh A1 - Weisbrich, S. A1 - Neitzel, F. A1 - Kadoke, Daniel A1 - Fischer, Michael A1 - Kohlhoff, Harald ED - Pastramă, Ştefan Dan ED - Constantinescu, Dan Mihai T1 - A Small-Scale Test Bridge for Measurement and Model-based Structural Analysis N2 - The Measurement- and Model-based Structural Analysis (MeMoS) integrates a finite element model into least squares adjustment and thus allows to evaluate a mechanical model and measurements in a combined analysis. To examine the capability to detect and localise damage using this integrated analysis MeMoS, a small-scale truss bridge made of aluminium profiles is built as a test specimen for this purpose. T2 - 35th Danubia Adria Symposium on Advances in Experimental Mechanics CY - Sinaia, Romania DA - 25.09.2018 KW - Structural analysis KW - Damage detection and localisation KW - Finite element method KW - Photogrammetry KW - Adjustment calculation PY - 2019 UR - http://www.sciencedirect.com/science/article/pii/S2214785319304894 DO - https://doi.org/10.1016/j.matpr.2019.03.130 SN - 2214-7853 VL - 12 IS - 2 SP - 319 EP - 328 PB - Elsevier Ltd. AN - OPUS4-48053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Cheng-Chieh A1 - Weisbrich, S. A1 - Burger, M. A1 - Neitzel, F. T1 - A Four-Point Bending Test Apparatus for Measurement- and Model-based Structural Analysis N2 - By means of a small-scale truss bridge, the ability of the Measurement- and Model-based Structural Analysis to detect and localize damage was examined. Although there was no noteworthy difficulty in detecting damage, it turned out that damage localization responds sensitively to systematic influences, i.e. non-modelled properties of the mechanical model. Therefore, another experiment is being conducted to re-examine the Measurement- and Model-based Structural Analysis. For this purpose, the bending test is carried out as it has been already theoretically respectively numerically discussed. In this attempt, the systematic influences such as residual stress are kept as low as possible. T2 - 36th Danubia Adria Symposium on Advances in Experimental Mechanics CY - Pilsen, Czech Republic DA - 24.09.2019 KW - Damage detection KW - Adjustment calculation KW - Finite element method PY - 2019 SN - 978-80-261-0876-4 SP - 63 EP - 64 CY - Pilsen, Czech Republic AN - OPUS4-49290 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Wu, Cheng-Chieh T1 - The measurement- and model-based structural analysis for damage detection N2 - Die vorliegende Arbeit soll einen Beitrag zur Überwachung von Ingenieurbauwerken leisten. Die Detektion von Schäden an Bauwerken basiert auf der Auswertung von räumlich und zeitlich verteilten Hybridmessungen. Die erfassten Daten können rein geometrisch oder physikalisch ausgewertet werden. Letzteres ist vorzuziehen, da die Schadensursache mittels geometrisch-physikalischer Gesetze ermittelt werden kann, um rechtzeitig eingreifen und die weitere Nutzung der Bauwerke sicherstellen zu können. Aus diesem Grund werden die kontinuumsmechanischen Feldgleichungen in Verbindung mit der Finite-Elemente-Methode und Hybridmessungen durch die Ausgleichungsrechnung zu einer einzigen Auswertemethode kombiniert. Dabei ergeben sich zwei Aufgabenstellungen. Die erste Aufgabe beschäftigt sich mit der Beziehung zwischen der Finite-Elemente-Methode und der Ausgleichungsrechnung. Die Finite-Elemente-Methode löst bestimmte Problemklassen, die durch ein System elliptischer partieller Differentialgleichungen beschrieben werden. Während die Methode der kleinsten Quadrate eine weitere Klasse von Problemen löst, die als ein überdeterminiertes Gleichungssystem formuliert ist. Die auffallende Ähnlichkeit zwischen den beiden Methoden ist seit vielen Jahrzehnten bekannt. Es bleibt jedoch ungeklärt, warum diese Ähnlichkeit besteht. Der Beitrag soll dies klären, indem die Variationsrechnung im Hinblick auf ihr methodisches Vorgehen untersucht wird. Obwohl das bekannte Gauß-Markov-Modell innerhalb der Methode der kleinsten Quadrate und die Finite-Elemente-Methode inhärent unterschiedliche Problemklassen lösen, wird gezeigt, dass beide Methoden durch die gleichen methodischen Schritte der Variationsrechnung abgeleitet werden können. Aus methodischer Sicht bedeutet dies, dass beide Methoden nicht nur ähnlich, sondern sogar gleich sind. Außerdem wird darauf hingewiesen, wo eine mögliche Querverbindung zu anderen Methoden besteht. Die zweite Aufgabenstellung stellt eine Messungs- und Modellbasierte Strukturanalyse (MeMoS) durch die Integration der Finite-Elemente-Methode in die Ausgleichungsrechnung vor. In numerischen Untersuchungen wird gezeigt, wie diese integrierte Analyse zur Parameteridentifikation sowohl einfacher als auch beliebig geformter Strukturbauteile eingesetzt werden kann. Darauf aufbauend wird untersucht, mit welchen Beobachtungstypen, mit welcher Genauigkeit und an welcher Stelle der Struktur diese Messungen durchgeführt werden müssen, um die Materialparameter möglichst genau zu bestimmen. Dies dient der Ermittlung eines optimalen und wirtschaftlichen Messaufbaus. Mit dieser integrierten Analyse kann auch ein Ersatzmodell einer geometrisch komplexen Struktur ermittelt werden. Die Frage der Erkennung und Lokalisierung von Schäden innerhalb einer Struktur wird mit Hilfe dieser Strukturanalyse behandelt. Die Messungs- und Modellbasierte Strukturanalyse wird mit zwei verschiedenen Testaufbauten, einer Aluminium-Modellbrücke und einem Biegebalken, validiert. N2 - The present work is intended to make a contribution to the monitoring of civil engineering structures. The detection of damage to structures is based on the evaluation of spatially and temporally distributed hybrid measurements. The acquired data can be evaluated purely geometrically or physically. It is preferable to do the latter, since the cause of damage can be determined by means of geometrical-physical laws in order to be able to intervene in time and ensure the further use of the structures. For this reason, the continuum mechanical field equations in conjunction with the finite element method and hybrid measurements are combined into a single evaluation method by the adjustment calculation. This results in two challenges. The first task deals with the relationship between the finite element method and the method of least squares. The finite element method solves certain problem classes, which are described by a system of elliptical partial differential equations. Whereas the method of least squares solves another class of problems, which is formulated as an overdetermined system of equations. The striking similarity between both methods is known since many decades. However, it remains unresolved why this resemblance exists. The contribution is to clarify this by examining the variational calculus, especially with regard to its methodological procedure. Although the well-known Gauss-Markov model within the method of least squares and the finite element method solve inherently different problem classes, it is shown that both methods can be derived by following the same methodological steps of the variational calculus. From a methodical viewpoint, this implies that both methods are not only similar, but actually the same. In addition, it is pointed out where a possible cross-connection to other methods exists. The second task introduces a Measurement- and Model-based Structural Analysis (MeMoS) by integrating the finite element method into the adjustment calculation. It is shown in numerical examinations how this integrated analysis can be used for parameter identification of simple as well as arbitrarily shaped structural components. Based on this, it is examined with which observation types, with which precision and at which location of the structure these measurements must be carried out in order to determine the material parameters as precisely as possible. This serves to determine an optimal and economic measurement set-up. With this integrated analysis, a substitute model of a geometrically complex structure can also be determined. The issue of the detection and localisation of damage within a structure is studied by means of this structural analysis. The Measurement and Model-based Structural Analysis is validated using two different test setups, an aluminum model bridge and a bending beam. T3 - BAM Dissertationsreihe - 166 KW - Ausgleichungsrechnung KW - Finite-Elemente-Methode KW - Integrierte Analyse KW - Kontinuumsmechanik KW - Schadenserkennung KW - Variationsrechnung KW - Adjustment calculation KW - Continuum mechanics KW - Damage detection KW - Finite element method KW - Integrated analysis KW - Variational calculus PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-501977 SN - 1613-4249 VL - 166 SP - 1 EP - 184 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-50197 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Wu, Cheng-Chieh T1 - The measurement- and model-based structural analysis for damage detection T1 - Schadensfrüherkennung mittels messungs- und modellbasierter Strukturanalyse N2 - The present work is intended to make a contribution to the monitoring of civil engineering structures. The detection of damage to structures is based on the evaluation of spatially and temporally distributed hybrid measurements. The acquired data can be evaluated purely geometrically or physically. It is preferable to do the latter, since the cause of damage can be determined by means of geometrical-physical laws in order to be able to intervene in time and ensure the further use of the structures. For this reason, the continuum mechanical field equations in conjunction with the finite element method and hybrid measurements are combined into a single evaluation method by the adjustment calculation. This results in two challenges. The first task deals with the relationship between the finite element method and the method of least squares. The finite element method solves certain problem classes, which are described by a system of elliptical partial differential equations. Whereas the method of least squares solves another class of problems, which is formulated as an overdetermined system of equations. The striking similarity between both methods is known since many decades. However, it remains unresolved why this resemblance exists. The contribution is to clarify this by examining the variational calculus, especially with regard to its methodological procedure. Although the well-known Gauss-Markov model within the method of least squares and the finite element method solve inherently different problem classes, it is shown that both methods can be derived by following the same methodological steps of the variational calculus. From a methodical viewpoint, this implies that both methods are not only similar, but actually the same. In addition, it is pointed out where a possible cross-connection to other methods exists. The second task introduces a Measurement- and Model-based Structural Analysis (MeMoS) by integrating the finite element method into the adjustment calculation. It is shown in numerical examinations how this integrated analysis can be used for parameter identification of simple as well as arbitrarily shaped structural components. Based on this, it is examined with which observation types, with which precision and at which location of the structure these measurements must be carried out in order to determine the material parameters as precisely as possible. This serves to determine an optimal and economic measurement set-up. With this integrated analysis, a substitute model of a geometrically complex structure can also be determined. The issue of the detection and localisation of damage within a structure is studied by means of this structural analysis. The Measurement and Model-based Structural Analysis is validated using two different test setups, an aluminum model bridge and a bending beam. N2 - Die vorliegende Arbeit soll einen Beitrag zur Überwachung von Ingenieurbauwerken leisten. Die Detektion von Schäden an Bauwerken basiert auf der Auswertung von räumlich und zeitlich verteilten Hybridmessungen. Die erfassten Daten können rein geometrisch oder physikalisch ausgewertet werden. Letzteres ist vorzuziehen, da die Schadensursache mittels geometrisch-physikalischer Gesetze ermittelt werden kann, um rechtzeitig eingreifen und die weitere Nutzung der Bauwerke sicherstellen zu können. Aus diesem Grund werden die kontinuumsmechanischen Feldgleichungen in Verbindung mit der Finite-Elemente-Methode und Hybridmessungen durch die Ausgleichungsrechnung zu einer einzigen Auswertemethode kombiniert. Dabei ergeben sich zwei Aufgabenstellungen. Die erste Aufgabe beschäftigt sich mit der Beziehung zwischen der Finite-Elemente-Methode und der Ausgleichungsrechnung. Die Finite-Elemente-Methode löst bestimmte Problemklassen, die durch ein System elliptischer partieller Differentialgleichungen beschrieben werden. Während die Methode der kleinsten Quadrate eine weitere Klasse von Problemen löst, die als ein überdeterminiertes Gleichungssystem formuliert ist. Die auffallende Ähnlichkeit zwischen den beiden Methoden ist seit vielen Jahrzehnten bekannt. Es bleibt jedoch ungeklärt, warum diese Ähnlichkeit besteht. Der Beitrag soll dies klären, indem die Variationsrechnung im Hinblick auf ihr methodisches Vorgehen untersucht wird. Obwohl das bekannte Gauß-Markov-Modell innerhalb der Methode der kleinsten Quadrate und die Finite-Elemente-Methode inhärent unterschiedliche Problemklassen lösen, wird gezeigt, dass beide Methoden durch die gleichen methodischen Schritte der Variationsrechnung abgeleitet werden können. Aus methodischer Sicht bedeutet dies, dass beide Methoden nicht nur ähnlich, sondern sogar gleich sind. Außerdem wird darauf hingewiesen, wo eine mögliche Querverbindung zu anderen Methoden besteht. Die zweite Aufgabenstellung stellt eine Messungs- und Modellbasierte Strukturanalyse (MeMoS) durch die Integration der Finite-Elemente-Methode in die Ausgleichungsrechnung vor. In numerischen Untersuchungen wird gezeigt, wie diese integrierte Analyse zur Parameteridentifikation sowohl einfacher als auch beliebig geformter Strukturbauteile eingesetzt werden kann. Darauf aufbauend wird untersucht, mit welchen Beobachtungstypen, mit welcher Genauigkeit und an welcher Stelle der Struktur diese Messungen durchgeführt werden müssen, um die Materialparameter möglichst genau zu bestimmen. Dies dient der Ermittlung eines optimalen und wirtschaftlichen Messaufbaus. Mit dieser integrierten Analyse kann auch ein Ersatzmodell einer geometrisch komplexen Struktur ermittelt werden. Die Frage der Erkennung und Lokalisierung von Schäden innerhalb einer Struktur wird mit Hilfe dieser Strukturanalyse behandelt. Die Messungs- und Modellbasierte Strukturanalyse wird mit zwei verschiedenen Testaufbauten, einer Aluminium-Modellbrücke und einem Biegebalken, validiert. KW - Damage detection KW - Continuum mechanics KW - Adjustment calculation KW - Finite element method KW - Variational calculus KW - Integrated analysis KW - Schadenserkennung KW - Kontinuumsmechanik KW - Ausgleichungsrechnung KW - Finite-Elemente-Methode KW - Variationsrechnung KW - Integrierte Analyse PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:101:1-2019100201583156925935 DO - https://doi.org/10.14279/depositonce-8845 SP - 1 EP - 169 PB - Technische Universität Berlin CY - Berlin AN - OPUS4-49288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Woydt, Mathias T1 - Sub-stoichiometric oxides for wear resistance N2 - In the present work it was shown that the tribologcal profiles of special model oxides under dry unidirectional sliding have shown, that sub-oxides have a contribution to the tribological behavior of carbides and cermets, when they are tribo-oxidatively formed, because their tribological profiles as monolithic materials are homologous in part or totally, or compete with hardmetals or cermets, depending from the operating conditions regarded. KW - Sub-oxide KW - Friction KW - Wear KW - Carbide KW - Hardmetal PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-498154 DO - https://doi.org/10.1016/j.wear.2019.203104 SN - 0043-1648 N1 - Eine identische Version zu diesem Artikel wurde publiziert unter: Wear 438-439 (2019) 102735, https://doi.org/10.1016/j.wear.2019.01.066 - An identical version to this article was published under: Wear 438-439 (2019) 102735, https://doi.org/10.1016/j.wear.2019.01.066 VL - 440-441 SP - 203104-1 EP - 203104-7 PB - Elsevier CY - Amsterdam AN - OPUS4-49815 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Winkelmann, A. A1 - Britton, T. B. A1 - Nolze, Gert T1 - EBSD Kikuchi Pattern Analysis, Silicon 15kV N2 - Supplementary data and images for Si EBSD pattern analysis as presented in: A. Winkelmann, T.B. Britton, G. Nolze "Constraints on the effective electron energy spectrum in backscatter Kikuchi diffraction", Physical Review B (2019). KW - EBSD KW - Electron energy KW - Energy distribution KW - Kikuchi pattern KW - Simulation PY - 2019 DO - https://doi.org/10.5281/zenodo.2565061 PB - Zenodo CY - Geneva AN - OPUS4-51907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilrich, Cordula T1 - Brennbar oder explosiv? Strategien zur Einstufung physikalischer Gefahren N2 - Das Seminar gibt einen detaillierten Einblick in die physikalischen Gefahrenklassen nach der CLP-Verordnung und stellt Strategien bei der Einstufung vor. Möglichkeiten zum Waiving und Screening werden erläutert und Berechnungsmethoden für Gemische werden in kurzen Aufgaben für die Seminarteilnehmer durchexerziert. T2 - Veranstaltung "Gemische im Fokus: Herausforderungen durch Einstufung und Giftinformation meistern" des Helpdesks REACH-CLP-Biozid bei der BAuA CY - Dortmund, Germany DA - 20.05.2019 KW - Chemikalienrecht KW - UN-GHS KW - Einstufung KW - Gefährliche Stoffe KW - CLP-Verordnung KW - Physikalische Gefahren PY - 2019 AN - OPUS4-48060 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilrich, Cordula T1 - Chemikalienrecht ‒ eine Einführung • Grundzüge & Prinzipien • Wo gibt es Informationen & Hilfestellungen N2 - Der Vortrag gibt einen Überblick über das Chemikalienrecht, stellt die wichtigsten Regelungen sowie ihre Schnittstellen vor und gibt Informationen zu verfügbaren Hilfestellungen. Besprochen werden • das UN-GHS (Globally Harmonized System of Classification and Labelling of Chemicals) • REACH (EU-Verordnung zur Registrierung, Bewertung, Zulassung und Beschränkung chemischer Stoffe) • CLP (EU-Verordnung über die Einstufung, Kennzeichnung und Verpackung von Stoffen und Gemischen) • Gefahrstoffverordnung T2 - Vortrag im Rahmen der Ringvorlesung für den Studiengang "Sicherheit und Gefahrenabwehr" der Hochschule Magdeburg-Stendal in Zusammenarbeit mit der Otto von Guericke Universität Magdeburg und dem Institut für Brand- und Katastrophenschutz Heyrothsberge CY - Magdeburg, Germany DA - 24.01.2019 KW - Chemikalienrecht KW - UN-GHS KW - Gefährliche Stoffe KW - CLP-Verordnung KW - REACH KW - Sicherheitsdatenblatt KW - Gefahrstoffverordnung PY - 2019 AN - OPUS4-47270 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wilke, Olaf A1 - Jann, Oliver A1 - Plehn, W. A1 - Brozowski, F. T1 - Untersuchungen zur Etablierung der DIN EN 16516 als neuer Referenznorm für die Prüfung von Formaldehydemissionen aus Holzwerkstoffen gemäß Chemikalien-Verbotsverordnung T1 - Investigations to establish DIN EN 16516 as new reference standard for testing of formaldehyde emissions from wood-based panels under the Chemikalien-Verbotsverordnung N2 - Im Januar 2018 wurde die DIN EN 16516 „Bauprodukte: Bewertung der Freisetzung gefährlicher Stoffe – Bestimmung von Emissionen in die Innenraumluft“ als harmonisierte europäische Prüfnorm veröffentlicht. Für die Etablierung der DIN EN 16516 als neue Referenznorm wurden verschiedene Emissionsprüfungen mit dem Ziel durchgeführt, ein neues Prüfverfahren für Formaldehydemissionen aus Holzwerkstoffen zu erarbeiten. Das übergeordnete Ziel ist die Minimierung des Risikos von Überschreitungen des Innenraumrichtwertes für Formaldehyd. Die Untersuchungen ergaben teilweise hohe Formaldehydemissionen, insbesondere bei höheren Beladungsfaktoren und Temperaturen, sowie bei niedrigen Luftwechselraten. Eine getestete Spanplatte hätte aufgrund ihrer hohen Formaldehydemission nicht auf den deutschen Markt gebracht werden dürfen. Durch vergleichende Untersuchungen konnte ein Umrechnungsfaktor in Höhe von 2,0 für die Umrechnung von Prüfwerten nach DIN EN 717-1 zu DIN EN 16516 abgeleitet werden. N2 - DIN EN 16516 "Construction products: Assessment of release of dangerous substances - Determination of emissions into indoor air" was published as a harmonized European standard in January 2018. For the establishment of DIN EN 16516 as the new reference standard various emission tests were carried out with the aim to develop a new test procedure for the measurement of formaldehyde emissions from wood-based panels. The superior aim is to minimize the risk of exceeding the indoor air reference value for formaldehyde. The investigations showed some particularly high formaldehyde emissions, especially at higher loading and temperature and at low air change rates. One of the tested particle boards exceeded the formaldehyde limit value and should not have been sold in Germany. For the conversion of test values from DIN EN 717-1 to DIN EN 16516 a conversion factor of 2.0 was derived from the comparative investigations. KW - Formaldehyd KW - DIN EN 16516 KW - Innenraumluft KW - Emissionsprüfung PY - 2019 SN - 0949-8036 VL - 79 IS - 3 SP - 79 EP - 85 PB - VDI Fachmedien CY - Düsseldorf AN - OPUS4-47666 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilke, Olaf A1 - Jann, Oliver T1 - Formaldehydmessungen an Holzwerkstoffplatten N2 - Die von der BAM eingekauften Holzwerkstoffplatten (Verlegespanplatten, OSB, Multiplexplatten) verschiedener Hersteller zeigten teilweise hohe Formaldehyd-emissionen unter den Prüfbedingungen nach EN 16516, eine Spanplatte hielt den Grenzwert von 0,1 ppm selbst bei Prüfung nach DIN EN 717-1 nicht ein, dürfte also in Deutschland gar nicht in den Verkauf gelangen. Holzwerkstoffe, die unter den Prüfbedingungen der DIN EN 717-1 die Formaldehydklasse E1 einhalten, können insbesondere bei großflächigem Einsatz im Innenraum zu Überschreitungen des Richtwertes für die Innenraumluft führen. Zusätzlich zur Anpassung des Luftwechsels ist auch der Parameter Beladung bei einer Überarbeitung der Norm anzupassen. In der DIN EN 16516 werden produktspezifische (am Einsatz der Produkte orientierte) Beladungsfaktoren vorgegeben. Für den Einsatz von Holzwerkstoffplatten ergäben sich Beladungen von 0,4 (Boden oder Decke), 1,0 (Wände), 1,4 (Wände plus Boden oder Decke) und 1,8 m²/m³ (Wände, Boden und Decke). Um die realen Bedingungen in modernen Gebäuden abzubilden, ist deshalb eine Beladung von 1,8 m²/m³ für die Prüfkammermessung erforderlich. Hierbei ist darauf hinzuweisen, dass für die Beladung im Referenzraum Möbel nicht berücksichtigt wurden. Damit soll sichergestellt werden, dass die Einhaltung des Schutzniveaus bei realen Innenraumbedingungen auch unter den Randbedingungen eines niedrigen Luftwechsels sowie bei sommerlichen Bedingungen und heutigem Lüftungsverhalten der Menschen soweit wie möglich gewährleistet ist. T2 - 26. WaBoLu-Innenraumtage CY - Berlin, Germany DA - 20.05.2019 KW - Formaldehyd KW - Emissionsprüfkammer KW - DIN EN 16516 KW - DIN EN 717-1 PY - 2019 AN - OPUS4-48065 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilbig, Janka A1 - Borges de Oliveira, F. A1 - Schwentenwein, M. A1 - Günster, Jens T1 - Quality Aspects of Additively Manufactured Medical Implants - Defect Detection in Lattice Parts N2 - Additive Manufacturing technologies are developing fast to enable a rapid and flexible production of parts. Tailoring products to individual needs is a big advantage of this technology, which makes it of special interest for the medical device industry and the direct manufacturing of final products. Due to the fast development, standards to assure reliability of the AM process and quality of the printed products are often lacking. The EU project Metrology for Additively Manufactured Medical Implants (MetAMMI) is aiming to fill this gap by investigating alternative and cost efficient non-destructive measurement methods. T2 - yCAM Forum CY - Mons, Belgium DA - 03.03.2019 KW - Additive Manufacturing KW - Metrology PY - 2019 AN - OPUS4-49141 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiesholler, L. M. A1 - Frenzel, Florian A1 - Grauel, Bettina A1 - Würth, Christian A1 - Resch-Genger, Ute A1 - Hirsch, T. ED - Resch-Genger, Ute ED - Hirsch, Thomas T1 - Yb,Nd,Er-doped upconversion nanoparticles: 980 nm versus 808 nm excitation N2 - Yb,Nd,Er-doped upconversion nanoparticles (UCNPs) have attracted considerable interest as luminescent reporters for bioimaging, sensing, energy conversion/shaping, and anticounterfeiting due to their capability to convert multiple near-infrared (NIR) photons into shorter wavelength ultraviolet, visible or NIR luminescence by successive absorption of two or more NIR photons. This enables optical measurements in complex media with very little background and high penetration depths for bioimaging. The use of Nd3+ as substitute for the commonly employed sensitizer Yb3+ or in combination with Yb3+ shifts the excitation wavelength from about 980 nm, where the absorption of water can weaken upconversion luminescence, to about 800 nm, and laser-induced local overheating effects in cells, tissue, and live animal studies can be minimized. To systematically investigate the potential of Nd3+ doping, we assessed the performance of a set of similarly sized Yb3+,Nd3+,Er3+-doped core- and core–shell UCNPs of different particle architecture in water at broadly varied excitation power densities (P) with steady state and time-resolved fluorometry for excitation at 980 nm and 808 nm. As a measure for UCNPs performance, the P-dependent upconversion quantum yield (Φ) and its saturation behavior were used as well as particle brightness (B). Based upon spectroscopic measurements at both excitation wavelengths in water and in a lipid phantom and B-based calculations of signal size at different penetration depths, conditions under which excitation at 808 nm is advantageous are derived and parameters for the further optimization of triple-doped UCNPs are given. KW - Lanthanide KW - Upconversion KW - Nanoparticle KW - Photoluminescence KW - Quantum yield KW - Lifetime KW - Brightness KW - Nd excitation KW - Excitation power density KW - Modelling KW - NIR PY - 2019 DO - https://doi.org/10.1039/C9NR03127H SN - 2040-3372 SN - 2040-3364 VL - 11 IS - 28 SP - 13440 EP - 13449 PB - Royal Society of Chemistry CY - London AN - OPUS4-48608 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werner, Tiago A1 - Madia, Mauro A1 - Zerbst, Uwe A1 - Sprengel, Maximilian A1 - Ulbricht, Alexander A1 - Evans, Alexander T1 - Experimental investigation on cyclic R-curves for additively manufactured 316L steel N2 - The present study deals with the experimental characterization of short crack propagation in SLM (selective-laser-melting) manufactured stainless steel. More specifically, the determination of cyclic R-curves is discussed. This describes the dependency of the crack propagation threshold on crack growth during the short crack propagation stage. For metals, the threshold, starting at a material-intrinsic value, increases until it reaches a value independent of the crack length due to crack closure phenomena which build up at that stage. The cyclic R-curve, when used in the frame of a cyclic R curve analysis, characterizes the resistance of a material to fatigue crack growth and the ability to arrest a physically short crack. Thus, it is the link between classical fatigue and fracture mechanics. In the high-cycle-fatigue range, the short crack propagation stage dominates the overall lifetime, i.e., the number of cycles until failure. Below the fatigue limit crack arrest of hitherto propagable micro-cracks will occur. The effort for the experimental characterization of the short fatigue crack propagation behavior and the cyclic R-curve is very high compared to experiments on long crack propagation. A very exact measurement of crack extension is required, since small increments need to be depicted. Pre-cracking must leave a closure free initial crack, since closure must be build up only by the cyclic R-curve. The closure-free status is achieved by compression pre-cracking. The aim of the present study is an insight into the influence of an AM process on the short crack propagation threshold. Cyclic R-curves are experimentally determined at different load-ratios for 316L austenitic steel specimens produced by SLM and conventional manufacturing. Residual stresses are measured in the crack plane and their influence on the cyclic R-curve is discussed. T2 - ESIAM19 CY - Trondheim, Norway DA - 09.09.2019 KW - fatigue crack growth KW - Additive Manufacturing KW - 316L KW - Cyclic R-curve KW - Laser Powder Bed Fusion KW - AM KW - L-PBF PY - 2019 AN - OPUS4-49412 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werner, Tiago ED - Madia, Mauro ED - Zerbst, Uwe T1 - Experimental investigation on cyclic R-curves for additively manufactured 316L steel N2 - The present study deals with the experimental characterization of short crack propagation in SLM (selective-laser-melting) manufactured stainless steel. More specifically, the determination of cyclic R-curves is discussed. This describes the dependency of the crack propagation threshold on crack growth during the short crack propagation stage. For metals, the threshold, starting at a material-intrinsic value, increases until it reaches a value independent of the crack length due to crack closure phenomena which build up at that stage. The cyclic R-curve, when used in the frame of a cyclic R curve analysis, characterizes the resistance of a material to fatigue crack growth and the ability to arrest a physically short crack. Thus, it is the link between classical fatigue and fracture mechanics. In the high-cycle-fatigue range, the short crack propagation stage dominates the overall lifetime, i.e., the number of cycles until failure. Below the fatigue limit crack arrest of hitherto propagable micro-cracks will occur. The effort for the experimental characterization of the short fatigue crack propagation behavior and the cyclic R-curve is very high compared to experiments on long crack propagation. A very exact measurement of crack extension is required, since small increments need to be depicted. Pre-cracking must leave a closure free initial crack, since closure must be build up only by the cyclic R-curve. The closure-free status is achieved by compression pre-cracking. The aim of the present study is an insight into the influence of an AM process on the short crack propagation threshold. Cyclic R-curves are experimentally determined at different load-ratios for 316L austenitic steel specimens produced by SLM and conventional manufacturing. Residual stresses are measured in the crack plane and their influence on the cyclic R-curve is discussed. T2 - ESIAM19 CY - Trondheim, Norway DA - 09.09.2019 KW - Fatigue crack growth KW - Additive Manufacturing KW - 316L KW - Cyclic R-curve KW - Laser Powder Bed Fusion KW - AM KW - L-PBF PY - 2019 SP - 1 EP - 8 AN - OPUS4-49416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werner, Tiago A1 - Madia, Mauro A1 - Zerbst, Uwe T1 - Investigation on short crack propagation in additive manufactured steel N2 - The assessment of high cycle fatigue in additive manufactured (AM) components is a challenge due to complex microstructure, anisotropic material behavior, residual stresses and porosity / lack-of-fusion defects. Due to the statistical distribution of defects, a high scatter band of S-N-curves is expected. The fracture mechanics-based fatigue assessment of additive manufactured components must consider the propagation of short cracks emanating from defects. In this work, the fatigue crack propagation resistance in the short and large crack regimes of additive and conventionally manufactured AISI 316L stainless steel is examined experimentally based on the cyclic R-curve. However, remaining residual stresses in the AM specimen lead to unexpected and dramatic crack-growth during the pre-cracking procedure. T2 - Workshop on Additive Manufacturing CY - BAM Berlin, Germany DA - 13.05.2019 KW - Fatigue crack growth KW - Additive Manufacturing KW - 316L KW - Cyclic R-curve KW - Laser Powder Bed Fusion KW - AM KW - L-PBF PY - 2019 AN - OPUS4-49419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit A1 - Pötzsch, Sina A1 - Bäßler, Ralph T1 - Entwicklung einer Prüfmethode zur Bewertung der Materialbeständigkeit von Bauteilen in Mitteldestillatanwendungen N2 - Für Bauteile (Komponenten) von Versorgungsanlagen für flüssige Brenn- und Kraftstoffe muss die Beständigkeit der metallenen Werkstoffe und Polymere nachgewiesen werden. Im Anwendungsfall von Heizöl mit 20 % biogenen Anteilen in Form von Rapsölfettsäuremethylester (FAME, Biodiesel) ist es für eine konservative Beurteilung des Korrosionssystems Werkstoff/Medium/Umgebung wichtig, die Alterungs­effekte des Mediums einzubeziehen. Entwicklung eines Prüfverfahrens für die Untersuchung der Beständigkeit von metallenen Werkstoffen und Polymeren in Heizöl und Heizöl-FAME-Blends, das für eine Vorauswahl der Werkstoffe und zum Nachweis der Beständigkeit im Hinblick auf die bauaufsichtlichen Zulassungsverfahren geeignet ist. Ein Schwerpunkt wird bei den metallenen Werkstoffen auf der Erprobung von Messmethoden liegen, mit denen sich in kurzer Versuchszeit ein Korrosionsangriff detektieren lässt. Metallene Werkstoffe: Weder örtliche Korrosion noch erhöhte Flächenkorrosion (Korrosionsrate:< 0,1 m/Jahr) sind bei den bisher geprüften Werkstoffen: Aluminium, C-Stahl 1.0037, austenitischer CrNi-Stahl 1.4301, Kupfer und Messing in Heizöl und B20 (Heizöl mit 20% Biodiesel) aufgetreten. Diese Werkstoffe sind in den Prüfmedien Heizöl und B20 als beständig zu bewerten. Es wurde keine signifikante Veränderung des pH-Wertes der Prüfmedien gemessen. Polymere: Massebestimmung: Die Prüfkörper der Elastomere ACM, HNBR und PUR sowie in geringerem Maße PE neigten zur Quellung in Heizöl und B20 nach 42 d und 84 d Auslagerung; für PA 6, POM und PVC wurde keine Masseänderung gemessen. Die Masseänderung der Prüfkörper in Heizöl und B20 ist mit Ausnahme von PUR vergleichbar. Bei PE traten Verfärbungen durch die Brennstoffe auf. Zugeigenschaften: ACM, HNBR, PE und PVC sind in Heizöl und B20 beständig, da die Änderung der Zugfestigkeit und der Reißdehnung < 15 % beträgt. PA und POM sind bedingt beständig, da die Änderung der Zugfestigkeit und der Reißdehnung < 30% beträgt. T2 - DGMK-Projekttreffen CY - Rostock, Germany DA - 28.03.2019 KW - Beständigkeitsbewertung KW - Metallene Werkstoffe KW - Polymere KW - Heizöl KW - Heizöl-FAME-Blends PY - 2019 AN - OPUS4-47841 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit A1 - Pötzsch, Sina A1 - Rehfeldt, Rainer T1 - Compatibility of polymeric materials with heating oil/biodiesel blends at different temperatures N2 - Materials compatibility is a major concern whenever the fuel composition is changed. The question arises of whether polymeric materials are resistant to heating oil with admixtures of 10 % biodiesel (B10) and 20 % biodiesel (B20). The polarity of biodiesel increases its solvency and facilitates permeation and extrac-tion. Solvation, swelling and/or extraction lead to changes in the physical properties and chemical changes of polymeric materials. The objective of this research was to determine the resistance of frequently used sealing materials such as FKM, EPDM, CR, CSM, NBR, IIR, VMQ, FVMQ, PA and PUR in up to four-year aged B10 for 84 days at 20 °C, 40 °C and 70 °C. The polymeric materials: ACM, FKM, HNBR, PA, PE; POM, PUR and PVC were ex-posed to B20 for 84 days at 40°C and 70°C in another research project. Mass, tensile strength, breaking elongation and Shore hardness A (D) of the test specimens were determined before and after the exposure for 84 (42) days in the heating oil blends B10 and B20. There is not determined a threshold for the reduction in tensile properties and Shore hardness in the international standards. Therefore, a threshold of 15 % was deter-mined for the evaluation of the compatibility. Measurements of the variations in mass, tensile properties and Shore hardness after exposure of the polymers in non-aged and aged heating oil B10 showed clearly that FKM, FVMQ and PA were the most resistant materials in B10. The elastomers CR, CSM, EPDM, IIR, NBR and VMQ were generally not resistant to B10. Damage to the materials increased with higher test temperatures and the age of B10. FKM, POM and PVC showed high compatibility in B20 at 40°C and 70 °C. ACM, HNBR and PA were evaluated as resistant in B20 at 40 °C but not at 70°C. T2 - Corrosion 2019 CY - Warsaw, Poland DA - 27.09.2019 KW - Polymers KW - Compatibility evaluations KW - Heating oil with 10% biodiesel KW - Heating oil with 20% biodiesel KW - Tensile properties KW - Shore hardness PY - 2019 AN - OPUS4-48146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weltschev, Margit T1 - Compatibility of sealing materials with biofuels and biodiesel heating oil blends at different temperatures N2 - Biofuels including ethanol and biodiesel (fatty acid methyl ester, FAME) represent an important renewable fuel alternative to petroleum-derived transport fuels. Increasing biofuels use would bring some benefits, such as a reduction in oil demands and greenhouse gas emissions, and an improvement in air quality. Materials compatibility is a major concern whenever the fuel composition is changed in a fuel system. The objective of this research was to determine the resistance of frequently used sealing materials such as CR (chloroprene rubber), CSM (chlorosulfonated polyethylene), EPDM (ethylene-propylene-diene rubber), FKM (fluorocarbon rubber), FVMQ (methyl-fluorosilicone rubber), IIR (butyl rubber), NBR (acrylonitrile-butadiene rubber), PA (polyamides), PUR (polyester urethane rubber) and VMQ (methyl-vinyl-silicone rubber), in heating oil with admixtures of biogenic sources such as E10 (fuel with max. 10 % ethanol), E85 (fuel with 85 % ethanol), non-aged and aged biodiesel, diesel fuel with 5 % biodiesel, non-aged and aged B10 (heating oil with 10 % biodiesel) at 20 °C, 40 °C and 70 °C. Mass, tensile strength and breaking elongation of the test specimens were determined before and after the exposure for 84 days in the fuels. The visual examination of some elastomer test specimens clearly showed the great volume increase until break or partial dissolution. Shore hardness A and D (for PA) were determined before and after exposure of the test specimens in the biofuels for 42 days. There is not determined a threshold for the reduction in tensile properties and Shore hardness in the international standards. Therefore, a threshold of 15 % was set for the evaluation of the compatibility. The sealing materials CR, CSM, EPDM, IIR and NBR were generally not resistant to biodiesel and B10. In summary, it can be therefore stated that the chemical resistance of the fluoropolymers FKM and FVMQ in fuels and biofuels is the best one. KW - Compatibility evaluation KW - Polymers KW - FAME KW - Heating oil with 10 % FAME PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-479722 DO - https://doi.org/10.15344/2456-351X/2019/165 SN - 2456-351X VL - 4 IS - 165 SP - 4 EP - 9 PB - Graphyonline Publications Pvt. Ltd. CY - Bangalore, Karnataka, Indien AN - OPUS4-47972 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit T1 - Bewertung der Beständigkeit von metallischen und polymeren Werkstoffen für Behälter zur Lagerung und Beförderung von Chemikalien N2 - In der Bundesrepublik Deutschland werden über 400 Mio.t Gefahrgüter jährlich in Tankfahrzeugen, Aufsetztanks, Batteriefahrzeugen, Eisenbahnkesselwagen und Tankcontainern befördert, davon etwa 150 Millionen Tonnen im Straßengüterverkehr. Zu den Hauptschadensursachen zählt die Korrosion, wobei die gleichmäßige und ungleichmäßige Flächenkorrosion die Korrosionsart ist, die beim Chemikalientransport in Tanks am häufigsten auftritt. Viele Schäden durch Lochkorrosion entstehen beim Transport von chloridhaltigen Medien bei Anwesenheit von Feuchtigkeit. Die BAM-Liste - Anforderungen an Tanks für die Beförderung gefährlicher Güter - ist Grundlage für die stoffbezogenen Baumusterzulassungen für Tankcontainer und ortsbewegliche Tanks zur Beförderung gefährlicher Güter durch die BAM seit der Herausgabe der 1. Auflage 1989. In die BAM-Liste wurden vorrangig solche gefährlichen Güter aufgenommen, die potenziell in Tanks befördert werden können. Die Beständigkeitsbewertungen gebräuchlicher metallischer Tankwerkstoffe und polymerer Dichtungs-, Beschichtungs- und Auskleidungswerkstoffe werden auch bei der Zulassung von Kesselwagen und Tankfahrzeugen als Erkenntnisquelle verwendet. Diese Daten sind aber unter sorgfältiger Überprüfung der Übertragbarkeit auch für andere praktische Anwendungen und unter Berücksichtigung der jeweiligen Praxisbedingungen auch als Ratgeber für Verpackungen, IBC, Lagerbehälter, Rohrleitungen usw. aus metallischen Werkstoffen anwendbar. In den internationalen Gefahrgutverordnungen ADR, RID und IMDG-Code wird nach einer vorgegebenen Prüffrist eine innere Besichtigung der Tanks gefordert. Bei Tankcontainern beträgt diese Prüffrist im ADR/RID, Kap. 6.8 , fünf Jahre (bei der Beförderung von ortsbeweglichen Tanks nach ADR/RID, Kap. 6.7, und nach dem IMDG-Code 2½ Jahre) und bei Tankfahrzeugen sechs Jahre. Im RID wird für Eisenbahnkesselwagen eine Prüffrist von acht Jahren für die Innenbesichtigung vorgeschrieben. Für die Dauer der Prüfintervalle muss die Werkstoffbeständigkeit der Tankwerkstoffe gewährleistet sein. T2 - 28. Fachtagung BUKO, Workshop: DD/Ex/AwSV CY - Berlin, Kiwa GmbH, Germany DA - 04.10.2019 KW - Korrosionsschäden KW - Beständigkeitsbewertungen KW - BAM-Liste KW - Transport und Lagerung von Chemikalien PY - 2019 AN - OPUS4-49206 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit A1 - Pötzsch, Sina T1 - Compatibility of polymeric sealing materials with biodiesel heating oil blends at different temperatures N2 - Biodiesel is subject to degradation processes like oil and grease. The oxidative degradation products of vegetable oil esters in biodiesel particularly lead to enhanced sedimentation in blended fuels. The polarity of biodiesel increases its solvency and facilitates permeation and extraction. Solvation, swelling and/or extraction lead to changes in the physical properties and chemical changes of polymeric materials. It also accelerates the degradation (hydrolysis and oxidation) of these materials with the loss of additives and stabilizers. The objective of this research was to determine the resistance of frequently used polymeric materials such as ACM, EPDM, FKM, FVMQ, CR, CSM, IIR, HNBR, NBR, PA, PE; POM, PUR, PVC and VMQ in biodiesel and heating oil with 10 %/20 % biodiesel (B10/B20) at 40°C and 70°C. Mass, tensile strength and breaking elongation of the test specimens were determined before and after the exposure for 84 days in the biodiesel heating oil blends. The visual examination of some elastomer test specimens clearly showed the great volume increase until break or partial dissolution. Shore hardness A and D were determined before and after exposure of the test specimens in the biofuels for 42 days. The elastomers CR, CSM, EPDM, IIR, NBR and VMQ were generally not resistant to biodiesel and B10 at 40°C and 70°C. FKM, ACM, HNBR, PA, PE, POM, and PVC showed high compatibility in B10/B20 at 40°C. A lower compatibility was determined for ACM in biodiesel. ACM and HNBR were not resistant in B20 at 70°C. T2 - Biofuels & Bioenergy CY - Rome, Italy DA - 14.10.2019 KW - Heating oil-Biodiesel-Blend KW - Compatibility evaluations KW - Tensile properties KW - Shore hardness PY - 2019 AN - OPUS4-49306 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit A1 - Pötzsch, Sina A1 - Bäßler, Ralph T1 - Compatibility of polymers with heating oil with 20 % biodiesel at different temperatures under static and compressed conditions N2 - Biodiesel is viewed as a major source of energy. In areas such as the European Union, where 80 % of the oil-based fuel is imported, there is also the desire to reduce dependence on external oil supplies. Materials compatibility is a major concern whenever the fuel composition is changed. The question arises of whether polymeric materials are resistant to heating oil with 20 % biodiesel (B20) in comparison to pure heating oil. The polarity of biodiesel increases its solvency and facilitates permeation and extraction. Solvation, swelling and/or extraction lead to changes in the physical properties. Extraction alters the fuel chemistry. These chemical changes could also accelerate the degradation (hydrolysis and oxidation) of the polymeric material with the loss of additives and stabilizers. The objective of this research was to determine the resistance of frequently used materials for components in middle distillate facilities such as ACM, FKM, HNBR, PA, PE, POM, PUR and PVC in heating oil and heating oil blend B20 for 84 days at 40 °C, and FKM, HNBR, PA, POM, PUR and PVC at 70 °C. Mass, tensile strength, breaking elongation and Shore hardness A (D) of the test specimens were determined before and after exposure for 84 (42) days in the test fuels under static conditions. For the investigations under compressed conditions, the mass and the compression set of FKM test specimens were determined before and after exposure for 3, 7, 14, 28, 56 and 90 days in B20 at 40 °C and 70 °C according to ISO 815-1 “Rubber, vul-canized or thermoplastic - determination of compression set – Part 1: At ambient or elevated temperatures”. There is not determined a threshold for the reduction in tensile properties and Shore hardness in the international standards. Therefore, a threshold of 15 % was determined for the evaluation of the compatibility. The change of tensile strength and breaking elongation of test specimens made of ACM, FKM, HNBR, PA, PE, POM, PUR and PVC exposed to heating oil and the blend B20 was less than 15 % at 40 °C. A maximum reduction in Shore hardness A of 14 % was determined for ACM at 40 °C and for HNBR of 15 % at 70 °C. It can be concluded that ACM, FKM, HNBR, PA, PE, POM, PVC and PUR were resistant in B20 at 40°C. FKM, PA, POM and PVC were evaluated as resistant in heat-ing oil and B20 at 70 °C, HNBR and PUR were not resistant in these fuels at 70°C. Based on the mass increase and compression set values of FKM test specimens it can be stated that FKM is resistant in B20 under compressed conditions at 40 °C and 70 °C. T2 - EUROCORR 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Heating oil - biodiesel - blend KW - Polymeric materials KW - Compatibility KW - Tensile properties KW - Shore Hardness PY - 2019 AN - OPUS4-49002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit T1 - Beständigkeit von Fluorkautschuk in Kraftstoffen und Heizöl mit biogenen Anteilen unter Druckbeanspruchung N2 - Die Bewertung der Werkstoffbeständigkeit ist von großer Bedeutung bei Änderung der Zusammensetzung der Kraftstoffe und des Heizöls, insbesondere die Frage nach der Beständigkeit der Dichtungswerkstoffe bei Zusätzen von Bioethanol und Biodiesel (Rapsölfettsäuremethylester). Vorhergehende Untersuchungen (Messungen der Veränderungen der Masse, der Zugeigenschaften und der Härte) bezogen sich auf die Bewertung der Beständigkeit häufig verwendeter Dichtungswerkstoffe wie FKM, FVMQ, VMQ, EPDM, CR, CSM, IIR, PA, NBR und PUR in Kraftstoffen und Heizöl mit 10 % Biodiesel (nicht gealtert und bis zu 5 Jahre gealtert) unter statischen Bedingungen. Ziel der Untersuchungen war die Bewertung der Beständigkeit von Fluorkautschuk unter verpressten Bedingungen in Analogie zu den Einsatzbedingungen in der Praxis. Die Masse und der Druckverformungsrest von Prüfkörpern aus FKM wurden vor und nach der Auslagerung über einen Zeitraum von 3, 7, 14, 28, 56 und 90 Tagen in E10 (Kraftstoff mit max. 10 % Ethanol), E85 (Kraftstoff mit 85 % Ethanol), Biodiesel (Rapsölfettsäuremethylester), Super (Kraftstoff mit max. 5 % Ethanol), Dieselkraftstoff mit max. 5 % Biodiesel, Super Plus (Kraftstoff ohne Ethanolzusatz) und Heizöl mit 10 % Biodiesel (B10) bei 40 °C gemäß ISO 815-1 bestimmt. Die Druckverformungsrestprüfung zählt neben der Messung der Härte, der Dichte und der Zugeigenschaften zu den wichtigsten Grundprüfverfahren der Elastomerindustrie. Nach Ende der Auslagerung in den Kraftstoffen und der Aufhebung der Verpressung wur-de der Druckverformungsrest der Prüfkörper in regelmäßigen Zeitabständen bis zu einer Rücktrocknung > 90 Tage bestimmt. Zum Vergleich wurden Prüfkörper aus FKM ohne Kraftstoff oder Heizöl unter Verpressung bei 40 °C ausgelagert. Die Masseänderung der Prüfkörper aus FKM betrug nach 90 Tagen Auslagerung in E10 9 %, in Super 8 %, in E85 4% und 0,6 % in Biodiesel. Die Erhöhung der Masse und die damit verbundene Quellung der Prüfkörper in E10 und Super mit 5 – 10% Ethanolzusatz hatte einen Einfluss auf den Druckverformungsrest, der sprunghaften Veränderungen unterlag im Vergleich zu den Werten nach Auslagerung in Biodiesel, Dieselkraftstoff und Heizöl B10 bei 40 °C. Zum Vergleich, unter statischen Bedingungen verringerte sich die Zugfestigkeit der Prüfkörper aus FKM nach Auslagerung in E10 bei 40 °C um 31 % und die Reißdehnung um 18 %. T2 - Gastvortrag im Rahmen des Seminars: Ausgewählte Kapitel der Werkstofftechnik an der Bergischen Universität Wuppertal CY - Wuppertal, Germany DA - 11.01.2019 KW - Dichtungswerkstoffe KW - Beständigkeit in Biokraftstoffen KW - Biodiesel KW - Heizöl mit 10% Biodiesel KW - E10 (Kraftstoff mit bis zu 10% Ethanol) PY - 2019 AN - OPUS4-47222 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit A1 - Pötzsch, Sina A1 - Bäßler, Ralph T1 - DGMK-Projekt 780: Entwicklung einer Prüfmethode zur Bewertung der Materialbeständigkeit von Bauteilen in Mitteldestillatanwendungen N2 - Für Bauteile (Komponenten) von Versorgungsanlagen für flüssige Brenn- und Kraftstoffe muss die Beständigkeit der metallenen Werkstoffe und Polymere nachgewiesen werden. Im Anwendungsfall von Heizöl mit 20 % biogenen Anteilen in Form von Rapsölfettsäuremethylester (FAME, Biodiesel) ist es für eine konservative Beurteilung des Korrosionssystems Werkstoff/Medium/Umgebung wichtig, die Alterungseffekte des Mediums einzubeziehen. Entwicklung eines Prüfverfahrens für die Untersuchung der Beständigkeit von metallenen Werkstoffen und Polymeren in Heizöl und Heizöl-FAME-Blends, das für eine Vorauswahl der Werkstoffe und zum Nachweis der Beständigkeit im Hinblick auf die bauaufsichtlichen Zulassungsverfahren geeignet ist. Ein Schwerpunkt wird bei den metallenen Werkstoffen auf der Erprobung von Messmethoden liegen, mit denen sich in kurzer Versuchszeit ein Korrosionsangriff detektieren lässt. Die untersuchten Werkstoffe Aluminium, Stahl 1.0037, 1.4301, Kupfer, Messing (CuZn40Pb) und Zink (ZP0410) sind in B0, B20, B100 und in 6 Jahre altem B100 beständig. Auch in einem Jahr alten B20 und in einem Jahr alten B100 sind die Werkstoffe beständig. Bei Kupfer blieb die Korrosionsrate in der Flüssigphase sowohl in B20 (0 μ m/ a) als auch in B100 (4 μ m/ a) nach einem Jahr unverändert. Für das 6 Jahre alte B100 stieg die Korrosionsrate des Kupfers an (16 μ m/a). Im Gegensatz dazu sank bei Messing die Korrosionsrate in der Flüssigphase mit dem Alter des Brennstoffs, nach einem Jahr für B20 von 4 μ m/ a auf 1 μ m/a und für B100 von 36 μ m/ a auf 6 μ m/ a, im 6 Jahre alten B100 lag die Korrosionsrate des Messings bei 0 μ m/ a. In 8 Jahre altem B10 trat bei Zink in der Flüssigphase Flächenkorrosion auf, es ist in dem Medium demnach nicht beständig. Messing zeigte örtliche Korrosion in der Gasphase, es ist folglich unbeständig und für den Einsatz in stark gealterten B10 nicht geeignet. Aluminium, 1.0037, 1.4301 und Kupfer sind in dem 8 Jahre alten B10 beständig. Die Änderung der Zugfestigkeit und der Reißdehnung von ACM, HNBR und FKM in Heizöl, B20 und gealterten B10 beträgt < 15 %. Diese Werkstoffe sind in Heizöl, B20 und in gealterten B10 unter Berücksichtigung des von der BAM zur Beurteilung der Beständigkeit festgelegten Grenzwertes von 15 % bei 40 °C als beständig zu bewerten. PUR ist bei 40 °C nicht beständig in B20 und in gealtertem B10. Bei 70 °C ist HNBR nicht in B20 beständig aufgrund der Verringerung der Zugfestigkeit (40 %) und der Reißdehnung (50 %). FKM ist bei 70 °C in Heizöl und in B20 beständig. T2 - Sitzung AK Prüfstellen CY - Berlin, Germany DA - 18.09.2019 KW - Heizöl mit 20% Biodiesel (B20) KW - Beständigkeit KW - Metallene Werkstoffe KW - Polymere Werkstoffe KW - Zugeigenschaften KW - Shore-Härte PY - 2019 AN - OPUS4-50188 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Welter, T. A1 - Marzok, Ulrich A1 - Deubener, J. A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Hydrogen diffusivity in sodium aluminosilicate glasses N2 - Hydrogen gas diffusivity of fourteen glasses of the Na2O-Al2O3-SiO2 system are studied along the joins quartzalbite-jadeite-nepheline (Qz-Ab-Jd-Np, fully polymerized) and albite-sodium disilicate (Ab-Ds, depolymerized). Density measurements show that ionic porosity decreases from 54.4% (Qz) to 51.5% (Np) and from 52.4% (Ab) to 50.2% (Ds). Hydrogen diffusivity D follows similar trends but at another scale. D at 523 K decreases from 4×10−12 to 3×10−14m2 s−1 (Qz-Np) and from 4×10−13 to 3×10−15m2 s−1 (Ab-Ds). Charge compensating Na+ acting as a filling agent in fully polymerized network structures leads to up to one order of Magnitude higher diffusivities as depolymerized glass structures of the same SiO2 content where Na+ takes the role of a modifier ion. Temperature dependence of the diffusivity indicates that both the activation energy involved with the moving H2 molecule as well as the accessible volume in the structure contribute to this compositional trend. KW - Aluminosilicate glasses KW - Hydrogen diffusivity KW - Ionic porosity PY - 2019 DO - https://doi.org/10.1016/j.jnoncrysol.2019.119502 VL - 521 SP - 119502 PB - Elsevier B.V. AN - OPUS4-50392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Matthias A1 - Hertwig, Andreas A1 - Beck, Uwe T1 - Scanning White Light Interference Microscopy - Measurement of Topometry and Layer Thickness N2 - 3D coherence scanning interferometry (CSI) is anoptical, non-contact and rapide measurement technique using a defined bandwidth of white light at normal incidence. White light interference microscopy (WLIM) providest here-dimensional surface topometry data up to a resolution of 0.4 µm lateral and 0.1 nm vertical. Three operating modi, surface, films and advanced films, enable measurements of step heights, roughness, wear volume, cone angle, surface pattern and layer thickness. Traceability to SI system is ensured by certified standards (PTB/NIST) within a DAkkS DIN EN ISO/IEC 17025:2018 accredited lab. T2 - EFDS, V2019, Vakuum und Plasma, WS 4, Beschichtungen für Werkzeuge & Bauteile CY - Dresden, Germany DA - 08.10.2019 KW - DIN EN ISO/IEC 17025:2018 KW - Certified standards KW - White light interference microscopy(WLIM) KW - 3D coherence scanning interferometry (CSI) KW - Topometry PY - 2019 AN - OPUS4-49323 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank A1 - Fladt, Matthias T1 - Innenhydrophobierung - neuartige AKR-Vermeidungsstrategie bei Betonfahrbahndecken N2 - Verstärkt auftretende Schäden in Betonfahrbahndecken des Bundesfernstraßennetzes, die mit einer Alkali-Kieselsäure-Reaktion (AKR) in Verbindung gebracht werden, haben zu einer massiven Verschärfung der Prüfvorschriften zur Bewertung der Alkaliempfindlichkeit von Ge-steinskörnungen geführt. Die damit verbundene Einschränkung potenziell für den Straßenbau einsetzbarer Gesteinskörnungen ruft eine verstärkte Ressourcenknappheit und ein erhöhtes Transport- und damit einhergehendes Kostenaufkommen hervor. Vor diesem Hintergrund wird nach neuartigen AKR-Vermeidungsstrategien gesucht, die auch eine Verwendung grenzwertig alkaliempfindlich eingestufter Gesteinskörnungen erlaubt. Einen möglichen Lösungsansatz stellt in diesem Kontext die Innenhydrophobierung des Fahrbahndeckenbetons dar. Es soll so durch die Behinderung des Feuchte- und Tausalzeintrags in den Beton der AKR-Schädigungs-prozess signifikant vermindert werden. Für die Bewertung der Leistungsfähigkeit der Innen-hydrophobierung zur Vermeidung einer schädigenden AKR in Betonfahrbahndecken wird zur-zeit im Auftrage der BASt an der BAM ein Forschungsvorhaben bearbeitet. Im Rahmen dieses Beitrags werden erste ausgewählte Ergebnisse dieses Forschungsvorhabens vorgestellt. So wird exemplarisch an einem Oberbeton (0/8) mit einer alkaliempfindlichen Gesteinskörnung der Einfluss eines Hydrophobierungsmittels auf die Frisch- und Festbetoneigenschaften ganz-heitlich aufgezeigt und bewertet. Bei Letzteren stehen zunächst die mechanischen und hygri-schen Parameter sowie der Frost-Tausalzwiderstand im Vordergrund. In einem weiteren Schritt wird der Einfluss der Innenhydrophobierung auf die schädigende AKR mittels verschie-denartiger AKR-Performanceprüfungen beleuchtet. T2 - Betonstraßentagung 2019 CY - Aschaffenburg, Germany DA - 26.09.2019 KW - Alkali-Kieselsäure-Reaktion KW - AKR KW - Innenhydrophobierung PY - 2019 SN - 978-3-86446-260-3 SP - 1 EP - 15 AN - OPUS4-49484 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank T1 - AKR an Betonfahrbahndecken - ausgewählte Einflussgrößen und neuartige AKR-Vermeidungsstrategie N2 - In den letzten Jahren sind im deutschen Bundesautobahnnetz vermehrt Schäden an vor 2005 hergestellten Betonfahrbahndecken aufgetreten, die mit einer Alkali-Kieselsäure-Reaktion(AKR) in Verbindung gebracht werden. Vor diesem Hintergrund werden in diesem Beitrag zunächst die Voraussetzungen und ausgewählte Einflussgrößen für eine schädigende AKR aufgezeigt. Besondere Aufmerksamkeit wird dabei der Rolle des Tausalzeintrags durch den Winterdienst bei Betonfahrbahndecken geschenkt. So wird mit Löseversuchen in 1 M KOH-Lösung zweier Gesteinskörnungen bei 80 °C gezeigt, dass mit zunehmender NaCI-Zugabe die Löslichkeit von SiÖ2 zunimmt und die von AI2O3 eine Verminderung erfährt. Basierend auf dem so exemplarisch erbrachten Nachweis für die Verstärkung der schädigenden AKR durch das Tausalz wird die Notwendigkeit und Richtigkeit der Durchführung von AKR-Betonversuchen mit Alkalizufuhr im ARS 04/2013 zur zukünftigen Vermeidung von AKR-Schäden an Betonfahrbahndecken im Rahmen von Neubau- und Erneuerungsmaßnahmen im Bundesfernstraßennetz belegt. Zusätzlich durchgeführte WS-Grundprüfungen nach dem ARS 04/2013 mit den beiden Gesteinskörnungen der Löse versuche veranschaulichen, dass die nach der Alkali-Richtlinie des DAfStb als unbedenklich eingestuften Gesteinskörnungen bei den Betonversuchen mit Alkalizufuhr durchaus als alkaliempfindlich bewertet werden können. Dies wiederum führt zu einer Verminderung der für den Betonstraßenbau verfügbaren Gesteinskörnungen. Vor diesem Hintergrund wird nach neuartigen AKR-Vermeidungsstrategien gesucht, die auch eine Verwendung der als grenzwertig alkaliempfindlich eingestuften Gesteinskörnungen erlaubt. Einen möglichen Lösungsansatz stellt in diesem Kontext die Innenhydrophobierung des Fahrbahndeckenbetons dar. Es soll so durch die Behinderung des Feuchte- und Tausalzeintrags in den Beton der AKR-Schädigungsprozess signifikant vermindert werden. Für die Bewertung der Leistungsfähigkeit der Innenhydrophobierung zur Vermeidung bzw. Verminderung einer schädigenden AKR in Betonfahrbahndecken wird zurzeit im Aufträge der BASt an der BAM ein Forschungsvorhaben bearbeitet. Im Rahmen dieses Beitrags werden erste Ergebnisse dieses Projekts vorgestellt. So wird exemplarisch an einem Oberbeton (D > 8)/Unterbeton und einem Oberbeton 0/8 mit einer alkaliempfindlichen Gesteinskörnung der Einfluss zweier Hydrophobierungsmittel auf die Frisch- und Festbetoneigenschaften ganzheitlich aufgezeigt und bewertet. Bei Letzteren stehen zunächst die mechanischen und hygrischen Parameter sowie der Frost-Tausalzwiderstand im Vordergrund. In einem weiteren Schritt wird der Einfluss beider Hydrophobierungsmittel auf die schädigende AKR mittels AKR-Betonversuchen mit Alkalizufuhr beleuchtet. Dabei gelangen ergänzend zur Beurteilung des Tausalzeintrags die Laser-Induced Breakdown Spectroscopy (LIBS) und zur Bewertung der Ausprägung der AKR und sekundären Ettringitbildung (SEB) die Dünnschliffmikroskopie zum Einsatz. T2 - 9. Betonfachtagung 2019 CY - Berlin, Germany DA - 12.11.2019 KW - AKR KW - Betonfahrbahn KW - Innenhydrophobierung KW - Tausalzeintrag KW - AKR-Betonversuche PY - 2019 AN - OPUS4-50218 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank T1 - AKR an Betonfahrbahndecken - ausgewählte Einflussgrößen und neuartige AKR-Vermeidungsstrategie N2 - In den letzten Jahren sind im deutschen Bundesautobahnnetz vermehrt Schäden an vor 2005 hergestellten Betonfahrbahndecken aufgetreten, die mit einer Alkali-Kieselsäure-Reaktion (AKR) in Verbindung gebracht werden. Vor diesem Hintergrund werden in diesem Beitrag zunächst die Voraussetzungen und ausgewählte Einflussgrößen für eine schädigende AKR aufgezeigt. Besondere Aufmerksamkeit wird dabei der Rolle des Tausalzeintrags durch den Winterdienst bei Betonfahrbahndecken geschenkt. So wird mit Löseversuchen in 1 M KOH-Lösung zweier Gesteinskörnungen bei 80 °C gezeigt, dass mit zunehmender NaCI-Zugabe die Löslichkeit von SiÖ2 zunimmt und die von AI2O3 eine Verminderung erfährt. Basierend auf dem so exemplarisch erbrachten Nachweis für die Verstärkung der schädigenden AKR durch das Tausalz wird die Notwendigkeit und Richtigkeit der Durchführung von AKR-Betonversuchen mit Alkalizufuhr im ARS 04/2013 zur zukünftigen Vermeidung von AKR-Schäden an Betonfahrbahndecken im Rahmen von Neubau- und Erneuerungsmaßnahmen im Bundesfernstraßennetz belegt. Zusätzlich durchgeführte WS-Grundprüfungen nach dem ARS 04/2013 mit den beiden Gesteinskörnungen der Löse versuche veranschaulichen, dass die nach der Alkali- Richtlinie des DAfStb als unbedenklich eingestuften Gesteinskörnungen bei den Betonversuchen mit Alkalizufuhr durchaus als alkaliempfindlich bewertet werden können. Dies wiederum führt zu einer Verminderung der für den Betonstraßenbau verfügbaren Gesteinskörnungen. Vor diesem Hintergrund wird nach neuartigen AKR-Vermeidungsstrategien gesucht, die auch eine Verwendung der als grenzwertig alkaliempfindlich eingestuften Gesteinskörnungen erlaubt. Einen möglichen Lösungsansatz stellt in diesem Kontext die Innenhydrophobierung des Fahrbahndeckenbetons dar. Es soll so durch die Behinderung des Feuchte- und Tausalzeintrags in den Beton der AKR-Schädigungsprozess signifikant vermindert werden. Für die Bewertung der Leistungsfähigkeit der Innenhydrophobierung zur Vermeidung bzw. Verminderung einer schädigenden AKR in Betonfahrbahndecken wird zurzeit im Aufträge der BASt an der BAM ein Forschungsvorhaben bearbeitet. Im Rahmen dieses Beitrags werden erste Ergebnisse dieses Projekts vorgestellt. So wird exemplarisch an einem Oberbeton (D > 8)/Unterbeton und einem Oberbeton 0/8 mit einer alkaliempfindlichen Gesteinskörnung der Einfluss zweier Hydrophobierungsmittel auf die Frisch- und Festbetoneigenschaften ganzheitlich aufgezeigt und bewertet. Bei Letzteren stehen zunächst die mechanischen und hygrischen Parameter sowie der Frost-Tausalzwiderstand im Vordergrund. In einem weiteren Schritt wird der Einfluss beider Hydrophobierungsmittel auf die schädigende AKR mittels AKR-Betonversuchen mit Alkalizufuhr beleuchtet. Dabei gelangen ergänzend zur Beurteilung des Tausalzeintrags die Laser-Induced Breakdown Spectroscopy (LIBS) und zur Bewertung der Ausprägung der AKR und sekundären Ettringitbildung (SEB) die Dünnschliffmikroskopie zum Einsatz. T2 - 9. Betonfachtagung 2019 CY - Berlin, Germany DA - 12.11.2019 KW - AKR KW - Betonfahrbahn KW - Innenhydrophobierung KW - Tausalzeintrag KW - AKR-Betonversuche PY - 2019 SN - 978-3-7640-0633-4 SP - 159 EP - 176 AN - OPUS4-50056 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank T1 - AKR an Betonfahrbahndecken – ausgewählte Einflussgrößen und neuartige AKR-Vermeidungsstrategie N2 - In den letzten Jahren sind im deutschen Bundesautobahnnetz vermehrt Schäden an vor 2005 hergestellten Betonfahrbahndecken aufgetreten, die mit einer Alkali-Kieselsäure-Reaktion (AKR) in Verbindung gebracht werden. Vor diesem Hintergrund werden in diesem Beitrag zunächst die Voraussetzungen und ausgewählte Einflussgrößen für eine schädigende AKR aufgezeigt. Besondere Aufmerksamkeit wird dabei der Rolle des Tausalzeintrags durch den Winterdienst bei Betonfahrbahndecken geschenkt. So wird mit Löseversuchen in 1 M KOH-Lösung zweier Gesteinskörnungen bei 80 °C gezeigt, dass mit zunehmender NaCl-Zugabe die Löslichkeit von SiO2 zunimmt und die von Al2O3 eine Verminderung erfährt. Basierend auf dem so exemplarisch erbrachten Nachweis für die Verstärkung der schädigenden AKR durch das Tausalz wird die Notwendigkeit und Richtigkeit der Durchführung von AKR-Betonversuchen mit Alkalizufuhr im ARS 04/2013 zur zukünftigen Vermeidung von AKR-Schäden an Betonfahrbahndecken im Rahmen von Neubau- und Erneuerungsmaßnahmen im Bundesfernstraßennetz belegt. Zusätzlich durchgeführte WS-Grundprüfungen nach dem ARS 04/2013 mit den beiden Gesteinskörnungen der Löseversuche veranschaulichen, dass die nach der Alkali-Richtlinie des DAfStb als unbedenklich eingestuften Gesteinskörnungen bei den Betonversuchen mit Alkalizufuhr durchaus als alkaliempfindlich bewertet werden können. Dies wiederum führt zu einer Verminderung der für den Betonstraßenbau verfügba-ren Gesteinskörnungen. Vor diesem Hintergrund wird nach neuartigen AKR-Vermeidungsstrategien gesucht, die auch eine Verwendung der als grenzwertig alkaliemp-findlich eingestuften Gesteinskörnungen erlaubt. Einen möglichen Lösungsansatz stellt in diesem Kontext die Innenhydrophobierung des Fahrbahndeckenbetons dar. Es soll so durch die Behinderung des Feuchte- und Tausalzeintrags in den Beton der AKR-Schädigungsprozess signifikant vermindert werden. Für die Bewertung der Leistungsfähigkeit der Innenhydrophobierung zur Vermeidung bzw. Verminderung einer schädigenden AKR in Betonfahrbahndecken wird zurzeit im Auftrage der BASt an der BAM ein Forschungsvorha-ben bearbeitet. Im Rahmen dieses Beitrags werden erste Ergebnisse dieses Projekts vorge-stellt. So wird exemplarisch an einem Oberbeton (D > 8)/Unterbeton und einem Oberbeton 0/8 mit einer alkaliempfindlichen Gesteinskörnung der Einfluss zweier Hydrophobierungsmit-tel auf die Frisch- und Festbetoneigenschaften ganzheitlich aufgezeigt und bewertet. Bei Letz-teren stehen zunächst die mechanischen und hygrischen Parameter sowie der Frost-Tausalzwiderstand im Vordergrund. In einem weiteren Schritt wird der Einfluss beider Hydro-phobierungsmittel auf die schädigende AKR mittels AKR-Betonversuchen mit Alkalizufuhr beleuchtet. Dabei gelangen ergänzend zur Beurteilung des Tausalzeintrags die Laser-Induced Breakdown Spectroscopy (LIBS) und zur Bewertung der Ausprägung der AKR und sekundä-ren Ettringitbildung (SEB) die Dünnschliffmikroskopie zum Einsatz. T2 - 9. Betonfachtagung CY - Berlin, Germany DA - 12.11.2019 KW - AKR, Betonfahrbahndecke, Tausalzeintrag, Innenhydrophobierung PY - 2019 SN - 978-3-7640-0633-4 SP - 159 EP - 175 PB - Verlag Bau + Technik GmbH CY - Erkrath AN - OPUS4-51563 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank A1 - Fladt, Matthias T1 - Innenhydrophobierung - neuartige AKR-Vermeidungsstrategie N2 - Verstärkt auftretende Schäden in Betonfahrbahndecken des Bundesfernstraßennetzes, die mit einer Alkali-Kieselsäure-Reaktion (AKR) in Verbindung gebracht werden, haben zu einer massiven Verschärfung der Prüfvorschriften zur Bewertung der Alkaliempfindlichkeit von Ge-steinskörnungen geführt. Die damit verbundene Einschränkung potenziell für den Straßenbau einsetzbarer Gesteinskörnungen ruft eine verstärkte Ressourcenknappheit und ein erhöhtes Transport- und damit einhergehendes Kostenaufkommen hervor. Vor diesem Hintergrund wird nach neuartigen AKR-Vermeidungsstrategien gesucht, die auch eine Verwendung grenzwertig alkaliempfindlich eingestufter Gesteinskörnungen erlaubt. Einen möglichen Lösungsansatz stellt in diesem Kontext die Innenhydrophobierung des Fahrbahndeckenbetons dar. Es soll so durch die Behinderung des Feuchte- und Tausalzeintrags in den Beton der AKR-Schädigungs-prozess signifikant vermindert werden. Für die Bewertung der Leistungsfähigkeit der Innen-hydrophobierung zur Vermeidung einer schädigenden AKR in Betonfahrbahndecken wird zur-zeit im Auftrage der BASt an der BAM ein Forschungsvorhaben bearbeitet. Im Rahmen dieses Beitrags werden erste ausgewählte Ergebnisse dieses Forschungsvorhabens vorgestellt. So wird exemplarisch an einem Oberbeton (0/8) mit einer alkaliempfindlichen Gesteinskörnung der Einfluss eines Hydrophobierungsmittels auf die Frisch- und Festbetoneigenschaften ganzheitlich aufgezeigt und bewertet. Bei Letzteren stehen zunächst die mechanischen und hygrischen Parameter sowie der Frost-Tausalzwiderstand im Vordergrund. In einem weiteren Schritt wird der Einfluss der Innenhydrophobierung auf die schädigende AKR mittels verschiedenartiger AKR-Performanceprüfungen beleuchtet. T2 - Betonstraßentagung 2019 CY - Aschaffenburg, Germany DA - 26.09.2019 KW - Alkali-Kieselsäure Reaktion KW - AKR KW - Innenhydrophobierung PY - 2019 AN - OPUS4-49475 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wegner, Karl David A1 - Moros, M. A1 - Castillo-Michel, H. A1 - Materra, L. A1 - Onorato, G. A1 - Ling, W. L. A1 - Reiss, P. A1 - Tortiglione, C. T1 - In Vivo Biotransformations of Indium Phosphide Quantum Dots Revealed by X‑Ray Microspectroscopy N2 - Many attempts have been made to synthesize cadmium-free quantum dots (QDs), using nontoxic materials, while preserving their unique optical properties. Despite impressive advances, gaps in knowledge of their intracellular fate, persistence, and excretion from the targeted cell or organism still exist, precluding clinical applications. In this study, we used a simple model organism (Hydra vulgaris) presenting a tissue grade of organization to determine the biodistribution of indium phosphide (InP)-based QDs by X-ray fluorescence imaging. By complementing elemental imaging with In L-edge X-ray absorption near edge structure, unique information on in situ chemical speciation was obtained. Unexpectedly, spectral profiles indicated the appearance of In−O species within the first hour post-treatment, suggesting a fast degradation of the InP QD core in vivo, induced mainly by carboxylate groups. Moreover, no significant difference in the behavior of bare core QDs and QDs capped with an inorganic Zn(Se,S) gradient shell was observed. The results paralleled those achieved by treating animals with an equivalent dose of indium salts, confirming the preferred bonding type of In3+ ions in Hydra tissues. In conclusion, by focusing on the chemical identity of indium along a 48 h long journey of QDs in Hydra, we describe a fast degradation process, in the absence of evident toxicity. These data pave the way to new paradigms to be considered in the biocompatibility assessment of QD-based biomedical applications, with greater emphasis on the dynamics of in vivo biotransformations, and suggest strategies to drive the design of future applied materials for nanotechnology-based diagnosis and therapeutics. KW - Indium phosphide KW - Quantum dots KW - Cytotoxicity KW - X-ray microspectroscopy PY - 2019 DO - https://doi.org/10.1021/acsami.9b15433 VL - 11 IS - 39 SP - 35630 EP - 35640 PB - ACS Publications AN - OPUS4-49425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wegner, Karl David A1 - Dussert, F. A1 - Truffier-Boutry, D. A1 - Benayad, A. A1 - Beal, D. A1 - Mattera, L. A1 - Ling, W. L. A1 - Carrière, M. A1 - Reiss, P. T1 - Influence of the Core/Shell Structure of Indium Phosphide Based Quantum Dots on Their Photostability and Cytotoxicity N2 - With the goal to improve their photostability, InP-based QDs are passivated with three types of inorganic shells, namely (i) a gradient ZnSexS1−x shell, (ii) an additional ZnS shell on top of the gradient shell with two different thicknesses (core/shell/shell, CSS), (iii) an alumina coating on top of ZnS. All three systems have photoluminescence Quantum yields (PLQY) > 50%and similar PL decay times (64–67 ns). To assess their photostability they are incorporated into a transparent poly (methyl methacrylate) (PMMA) matrix and exposed to continuous irradiation with simulated sunlight in a climate chamber. The alumina coated core/shell system exhibits the highest stability in terms of PLQY Retention as well as the lowest shift of the PL maximum and lowest increase of the PL linewidth, followed by the CSS QDs and finally the gradient shell system. By means of XPS studies we identify the degradation of the ZnS outer layer and concomitant xidation of the emissive InZnP core as the main origins of degradation in the gradient structure. These modifications do not occur in the case of the alumina-capped sample, which exhibits excellent chemical stability. The gradient shell and CSS systems could be transferred to the aqueous phase using surface ligand exchange with penicillamine. Cytotoxicity studies on human primary keratinocytes revealed that exposure for 24 h to 6.25–100 nM of QDs did not affect cell viability. However, a trend toward reduced cell proliferation is observed for higher concentrations of gradient shell and CSS QDs with a thin ZnS shell, while CSS QDs with a thicker ZnS shell do not exhibit any impact. KW - Indium phosphide KW - Quantum dots KW - Cytotoxicity KW - Photostability PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-494249 DO - https://doi.org/10.3389/fchem.2019.00466 VL - 7 SP - Article Number: 466 PB - Frontiers Media SA AN - OPUS4-49424 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wegner, Karl David A1 - Carrière, M. A1 - Reiss, P. T1 - Tuning the photoluminescence of inp quantum dots with gallium N2 - Semiconductor nanocrystals (quantum dots, QDs) are well known for their superior photophysical properties and enabled advancements in several key technologies of the 21st century and numerous technological applications. However, the most studied II-VI semiconductor nanocrystals contain the toxic heavy metal element cadmium, which is limiting their utilization in commercial applications. This has drawn the interest to alternative materials with less toxicity but having similar photophysical features. The newest generation of TV screens based on QDs have shown that there is a promising environmentally friendly alternative with similar optoelectronic properties, namely indium phosphide (InP) QDs. InP QDs possess a bulk band gap of 1.35 eV with an exciton Bohr radius of ca. 10 nm and thus allow to tune their photoluminescence (PL) from the visible to the near-infrared. Tuning the size and shape of InP QDs and thus tailor their optoelectronic properties can be achieved by different strategies, which range from different types and concentrations of precursors, synthesis temperature or post-synthetic manipulations like etching. The incorporation of other elements like Gallium within the InP core synthesis is another possibility. Using a GaP intermediate layer before growing a ZnS shell has been shown to increase the PL quantum yield, which has been attributed to reduced lattice strain and the removal of phosphor vacancies. Different Ga precursors were investigated but a thorough investigation in terms of their reactivity, localization in the QD and influence on the photophysical properties is lacking to date. In this contribution we will present the detailed investigation of the presence of two different Ga precursors within the InP core synthesis. Photophysical characterizations (steady-state and PL life-time measurements), transmission electron microscopy, XRD and EDX gave insights into the reactivity of the Ga precursors, the Ga localization in the InP core and influences on the photophysical properties. The variation of the precursor and surfactant concentration and the utilization of different ligands for the Ga precursor allowed tuning the PL emission towards the blue or the red. Depending on the used precursor type we observed the formation of larger-sized InP/GaP core/shell nanocrystals or the formation of InGaP alloy structures enabling to assess the blue range of emission (475 nm). T2 - Zsigmondy Colloquium CY - Dresden, Germany DA - 10.07.2019 KW - Indium phosphide KW - Quantum dots KW - Gallium doping PY - 2019 AN - OPUS4-49426 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weber, Kathrin A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Stephan-Scherb, Christiane T1 - A µ‐XANES study of the combined oxidation/sulfidation of Fe–Cr model alloys N2 - The precise analysis of cation diffusion profiles through corrosion scales is an important aspect to evaluate corrosion phenomena under multicomponent chemical load, as during high‐temperature corrosion under deposits and salts. The present study shows a comprehensive analysis of cation diffusion profiles by electron microprobe analysis and microbeam X‐ray absorption near edge structure (µ‐XANES) spectroscopy in mixed oxide/sulfide scales grown on Fe–Cr model alloys after exposing them to 0.5% SO2. The results presented here correspond to depth‐dependent phase identification of oxides and sulfides in the corrosion scales by µ‐XANES and the description of oxidation‐state‐dependent diffusion profiles. Scales grown on low‐ and high‐alloyed materials show both a well‐pronounced diffusion profile with a high concentration of Fe3+ at the gas and a high concentration of Fe2+ at the alloy interface. The distribution of the cations within a close‐packed oxide lattice is strongly influencing the lattice diffusion phenomena due to their different oxidation states and therefore different crystal‐field preference energies. This issue is discussed based on the results obtained by µ‐XANES analysis. KW - X-ray absorption spectroscopy KW - Oxidation KW - Sulfidation PY - 2019 DO - https://doi.org/10.1002/maco.201810644 VL - 70 IS - 8 SP - 1360 EP - 1370 PB - Wiley VCH-Verlag AN - OPUS4-47934 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Webb, A. A1 - Hofmann-Böllinghaus, Anja T1 - Changes in façade regulations N2 - Recent facade fires worldwide have driven change in regulations for façade fire safety in different parts of the world. The Grenfell Tower fire 2017 in London triggered a thorough investigation of many aspects of the fire. One investigation was about the UK building regulations from Dame Judith Hackett. This investigation compares the UK with the situation other parts of the world. Key findings of the review of building regulations by Judith Hackett are: T2 - Interflam 2019 CY - London, UK DA - 01.07.2019 KW - Facades PY - 2019 VL - 2019 SP - 213 EP - 228 PB - Interscience CY - London, UK AN - OPUS4-49893 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina A1 - Müller, Ralf A1 - Balzer, R. A1 - Kiefer, P. A1 - Reinsch, Stefan A1 - Behrens, H. A1 - Deubener, J. T1 - Subcritical crack growth in hydrous soda-lime silicate glass N2 - Glass strength and fatigue is limited by surface cracks. As subcritical crack growth (SCCG) is governed by ambient humidity, stress corrosion at the crack tip is widely accepted to be the underlying mechanism. However, as water is known to have decisive effect on glass properties and can rapidly enter the crack tip near glass region, SCCG could be affected by such water related phenomena. We tried to mimic these effects studying water dissolution and speciation, mechanical properties, and SCCG in water-bearing glasses. For this purpose, glasses up to 8 wt% water have been prepared by means of high-pressure melting of glass powder - water mixtures. As part of this effort, SCCG in dry and hydrous commercial micros¬cope slide glass (CW = 6 wt%) was studied in double cantilever beam (DCB) geometry and sub-Tg relaxation was measured by Dynamic Mechanical Analysis (DMA). For SCCG in ambient air (24% r.h.), SCCG was promoted by the presence of 6wt% bulk water with respect to the dry glass. On the other hand, stress intensity values, KI, required to cause slow crack growth (v < 10-6 ms-1) resemble literature findings for float glass of similar composition in liquid water, which might represent the maximum possible promoting effect of ambient water on SCCG. For SCCG in vacuum (10-3 mbar), dissolved bulk water causes even more pronounced effects. Most strikingly, it strongly decreases the slope of the log v(KI)-curve, which is a measure of dissipated energy during fracture. A strong increase of sub-Tg relaxation with increasing water content was confirmed by DMA. As a consequence, slow crack growth occurs at KI values as measured in the dry glass whereas fast crack growth occurs at much larger KI than that of the dry glass. Kinks and shoulders shown by the inert log v(KI)-curve indicate that bulk water does not simply affect bulk mechanical properties. T2 - 9th Otto Schott Colloquium CY - Jena, Germany DA - 09.09.2019 KW - Internal friction KW - Soda-lime silicate glass KW - Crack growth KW - Water content KW - DCB PY - 2019 AN - OPUS4-49534 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina A1 - Balzer, R. A1 - Kiefer, P. A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Behrens, H. A1 - Deubener, J. T1 - Subcritical crack growth in hydrous silicate glass N2 - Ambient water influences sub-critical crack growth (SCCG) from microscopic surface flaws, leading to stress corrosion at the crack tip. The complex influence of humidity accelerating slow crack propagation (region I) is well studied only for dry commercial NCS glass (< 1000 ppm water). To shed light on this influence, the effect of water is mimicked by studying SCCG water-bearing glasses. For this purpose, water-bearing silicate glasses of 8 wt% total water were synthesized at 0.5 GPa and compared to dry glasses. SCCG was measured in double cantilever beam geometry. For dry glasses, 3 trends in crack velocity vs. stress intensity, KI, curve were found. The slope in region I increases in the order NCS < NBS < BaCS < NZnS < NAS glass. The velocity range of region II, reflecting the transition between corrosion affected and inert crack growth (region III), varies within one order of magnitude among these glasses. The KI region of inert crack growth strongly scatters between 0.4 and 0.9 MPam0.5. For hydrous glasses, it is found that water strongly decreases Tg, form a new sub-Tg internal friction peak caused by molecular water, and makes the glasses more prone to SCCG. The observed trends will be discussed in terms of the effects of Youngs Modulus on the strain energy release rate and energy dissipation related to mechanical glass relaxation phenomena. T2 - 25th International Congress on Glass (ICG2019) CY - Boston, MA, USA DA - 09.06.2019 KW - Internal friction KW - Soda-lime silicate glass KW - Crack growth KW - Water content KW - DCB PY - 2019 AN - OPUS4-49536 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina A1 - Balzer, R. A1 - Kiefer, P. A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Behrens, H. A1 - Deubener, J. T1 - Sub-critical crack growth in hydrous silicate glasses N2 - Environmental conditions are known to influence sub-critical crack growth (SCCG) that starts from microscopic flaws at the glass surface, leading to stress corrosion phenomena at the crack tip. The processes at the crack tip are complex and water has been identified as a key component governing SCCG at low crack velocities (region I). In particular, the influence of humidity accelerating crack propagation is well studied for dry industrial soda-lime silicate glasses (< 1000 ppm water). To shed light on this influence, the effect of water is mimicked by studying SCCG in water-bearing glasses. For this purpose, water-bearing silicate glasses of up to 8 wt% total water were synthesized in an internally heated pressure vessel at 0.5 GPa and compared to dry glasses. SCCG was measured using the double cantilever beam technique. For dry glasses, three trends in the crack growth velocity versus stress intensity, KI, curve were found. The slope in region I, limited by environmental corrosion, increases in the order soda-lime silicate < sodium borosilicate < barium calcium silicate < sodium zinc silicate < sodium aluminosilicate glass. The velocity range of region II, reflecting the transition between corrosion affected and inert crack growth (region III), varies within one order of magnitude among these glasses. The KI region of inert crack growth strongly scatters between 0.4 and 0.9 MPam1/2. For hydrous glasses, it is found that water strongly decreases Tg, form a new sub-Tg relaxation peak caused by molecular water, and makes the glasses more prone to SCCG. The observed trends will be discussed in terms of the effects of Youngs Modulus on strain energy release rate and energy dissipation related to glass relaxation phenomena. T2 - Glastechnische Tagung CY - Nürnberg, Germany DA - 13.05.2019 KW - Glass KW - Crack growth KW - DCB KW - Water speciation PY - 2019 AN - OPUS4-48339 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wasmer, Paul A1 - Prager, Jens T1 - Eindimensionaler phononischer Kristall zur Schallisolierung in Stäben T1 - One-dimensional phononic crystal for sound insulation in rods N2 - Die Untersuchung von Schallausbreitung in periodischen Strukturen ist aktuell von großem Interesse für eine zielgerichtete Beeinflussung von Schallwellen in einem großen Frequenzbereich. Hierbei liegt der Fokus insbesondere auf den phononische Kristalle (PnK’s), einer periodischen Anordnung von Streuzentren in einer Matrix. PnK’s können neben anderen Anwendungen, wie der Sensoranwendung oder der Nutzung als effektiver Wellenleiter, als Schallisolator dienen. In dieser Arbeit wird ein neuartiger PnK aus einer periodischen Anordnung von Zylindern untersucht, welcher zur Schallisolation verwendet werden kann. Zunächst wird die Struktur simuliert, dabei wird ein achsensymmetrisches Modell mit einem 3D-Modell verglichen. Im Anschluss wird die simulierte Geometrie gefertigt und vermessen. N2 - The analysis of acoustic wave behavior in periodic structures is of great interest for the targeted manipulation of acoustic waves in a wide frequency range. In the focus are phononic crystals (PnC's), a periodic arrangement of scatterers in a host matrix. They can be used for various aspects, for example for sensor applications or as effectiv waveguides, but also for sound insulation. In this work, a new PnC consisting of a periodic arrangement of cylinders, which can be used for sound insulation, is investigated. To begin with, the geometry is simulated and an axisymmetric and a 3D-model are compared. The simulated geometry is fabricated and transmission behavior is measured. KW - Phononischer Kristall KW - Ultraschallmessung KW - Akustischer Isolator KW - Stabstruktur KW - Rod structure KW - Acoustic insulation KW - Phononic crystal KW - Ultrasonic measurement PY - 2019 DO - https://doi.org/10.1515/teme-2018-0065 SN - 0171-8096 VL - 86 IS - 2 SP - 66 EP - 72 PB - De Gruyter CY - Oldenbourg AN - OPUS4-47478 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wasmer, Paul A1 - Bulling, Jannis A1 - Prager, Jens T1 - Entwicklung eines Ultraschallrohrsensors auf Basis phononischer Kristalle N2 - Die Messung von Flüssigkeitskonzentrationen in Rohrsystemen ist von großem Interesse für viele unterschiedliche Anwendungen. Die meisten Messsysteme sind jedoch nicht in der Lage, die Flüssigkeit direkt im Rohr zu untersuchen und es muss eine zusätzliche Vorrichtung, wie z.B. einem Bypass, angebracht werden, welche den Kontakt zwischen Flüssigkeit und Sensor ermöglicht. Um den Einbauaufwand gering zu halten und die Strömungseigenschaften des Rohres nicht zu beeinflussen, wird ein neuartiges Messsystem entwickelt, welches als Teil der Rohrwand ausgeführt werden kann. Dieses neuartige System ist angelehnt an die Idee der phononischen Kristallen (PnK). PnK’s bestehen im Allgemeinen aus einem Matrixmaterial, in welchem Streuzentren periodisch angeordnet sind. Dies führt beim Eintreffen einer akustischen Welle in definierten Frequenz-bereichen, sogenannter Bandlücken, zu zunehmender destruktiven Interferenz. Wird innerhalb einer solchen Bandlücke durch Einbringen einer flüssigkeitsgefüllten Kavität ein Resonanzverhalten erzeugt, kann dies genutzt werden, um die Flüssigkeit zu analysieren. Im Rahmen von Voruntersuchung wird zunächst das akustische Verhalten des PnK’s, welcher für die Sensorentwicklung genutzt werden soll, unter Vernachlässigung der Flüssigkeit ausführlich untersucht. Hierbei werden zunächst die Bandlücken ermittelt und das Übertragungsverhalten betrachtet. Dieses wird im Anschluss experimentell überprüft. T2 - DAGA 2019 - 45. Jahrestagung für Akustik CY - Rostock, Germany DA - 18.03.2019 KW - Phononischer Kristall KW - Ultraschall KW - Flüssigkeitssensor KW - Scaled Boundary Finite Element Method PY - 2019 SP - 1030 EP - 1033 AN - OPUS4-47780 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wasmer, Paul A1 - Bulling, Jannis A1 - Prager, Jens T1 - Entwicklung eines Ultraschallrohrsensors auf Basis phononischer Kristalle N2 - Die Messung von Flüssigkeitskonzentrationen in Rohrsystemen ist von großem Interesse für viele unterschiedliche Anwendungen. Die meisten Messsysteme sind jedoch nicht in der Lage, die Flüssigkeit direkt im Rohr zu untersuchen und es muss eine zusätzliche Vorrichtung, wie z.B. einem Bypass, angebracht werden, welche den Kontakt zwischen Flüssigkeit und Sensor ermöglicht. Um den Einbauaufwand gering zu halten und die Strömungseigenschaften des Rohres nicht zu beeinflussen, wird ein neuartiges Messsystem entwickelt, welches als Teil der Rohrwand ausgeführt werden kann. Dieses neuartige System ist angelehnt an die Idee der phononischen Kristallen (PnK). PnK’s bestehen im Allgemeinen aus einem Matrixmaterial, in welchem Streuzentren periodisch angeordnet sind. Dies führt beim Eintreffen einer akustischen Welle in definierten Frequenz-bereichen, sogenannter Bandlücken, zu zunehmender destruktiven Interferenz. Wird innerhalb einer solchen Bandlücke durch Einbringen einer flüssigkeitsgefüllten Kavität ein Resonanzverhalten erzeugt, kann dies genutzt werden, um die Flüssigkeit zu analysieren. Im Rahmen von Voruntersuchung wird zunächst das akustische Verhalten des PnK’s, welcher für die Sensorentwicklung genutzt werden soll, unter Vernachlässigung der Flüssigkeit ausführlich untersucht. Hierbei werden zunächst die Bandlücken ermittelt und das Übertragungsverhalten betrachtet. Dieses wird im Anschluss experimentell überprüft. Hierzu werden neben herkömmlichen Fertigungsverfahren auch additive Verfahren zur Herstellung der Proben genutzt. T2 - DAGA 2019 CY - Rostock, Germany DA - 18.03.2019 KW - Ultraschallsensor KW - Phononische Kristalle PY - 2019 AN - OPUS4-47608 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Anwendungsaspekte magnetischer Funktionsmaterialien: Untersuchungen mit Computertomographie N2 - In diesem Vortrag wird am Beispiel magnetischer Werkstoffe zur Energiewandlung gezeigt, wie röntgentomographische Untersuchungen zur Strukturaufklärung in Kompositen und Massivproben beitragen können. Die Bauteile werden zerstörungsfrei geprüft, um Risse, Poren und andere Defekte und ihren Einfluss auf die funktionellen Eigenschaften dreidimensional und rechtzeitig im Lebenszyklus des Werkstoffs zu charakterisieren. Kombiniert man Mikrotomographie mit anderen Methoden der magnetischen Werkstoffcharakterisierung, lassen sich einzigartige Aussagen über den Aufbau und die funktionellen Eigenschaften treffen. T2 - Werkstoffwoche CY - Dresden, Germany DA - 18.09.2019 KW - X-Ray Imaging KW - Additive Manufacturing KW - Magnetocaloric KW - Material Science KW - Non-Destructive testing PY - 2019 AN - OPUS4-50175 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja A1 - Funk, Alexander A1 - Jaenisch, Gerd-Rüdiger A1 - Zscherpel, Uwe A1 - Grunwald, Marcel A1 - Moosavi, Robabeh A1 - Redmer, Bernhard A1 - Nazarzadehmoafi, Maryam T1 - X-ray non-destructive testing of materials and composites N2 - Using magnetic materials for energy conversion as an example, this lecture shows how X-ray tomography investigations can contribute to structure elucidation in composites and solid samples. The components are tested non-destructively in order to characterize cracks, pores and other defects and their influence on the functional properties three-dimensionally and in good time in the life cycle of the material. If you combine microtomography with other methods of magnetic material characterization, you can make unique statements about the structure and the functional properties. T2 - TU Chemnitz Vortrag CY - Chemnitz, Germany DA - 04.11.2019 KW - X-Ray Imaging KW - Additive Manufacturing KW - Materials Science KW - Non-destructiv testing PY - 2019 AN - OPUS4-50150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja A1 - Funk, Alexander A1 - Moosavi, Robabeh A1 - Redmer, Bernhard A1 - Nazarzadehmoafi, Maryam A1 - Jaenisch, Gerd-Rüdiger A1 - Zscherpel, Uwe T1 - X-ray non-destructive testing of materials and composites N2 - Using magnetic materials for energy conversion as an example, this lecture shows how X-ray tomography investigations can contribute to structure elucidation in composites and solid samples. The components are tested non-destructively in order to characterize cracks, pores and other defects and their influence on the functional properties three-dimensionally and in good time in the life cycle of the material. If you combine microtomography with other methods of magnetic material characterization, you can make unique statements about the structure and the functional properties. T2 - Dcms CY - Stockholm, Sweden DA - 28.08.2019 KW - X-Ray imaging KW - Additive Manufacturing KW - Magnetocoloric KW - Material Science KW - Non-destructive testing PY - 2019 AN - OPUS4-50151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja A1 - Dzekan, D. A1 - Stork, A. A1 - Sellschopp, K. A1 - Berger, D. A1 - Nielsch, K. A1 - Fähler, S. T1 - A thermomagnetic generator with novel magnetic field topology N2 - To date, there are only very few technologies available for the conversion of low temperature waste heat to electricity. In this talk, we first describe the principle of thermomagnetic generators. Then we focus on the impact of topology of the magnetic circuit within thermomagnetic generators. We demonstrate that the key operational parameters strongly depend on the genus, i.e. the number of holes within the magnetic circuit. T2 - 2019 Joint MMM-Intermag Conference CY - Washington, DC, USA DA - 14.01.2019 KW - Energy harvesting KW - Magnetocaloric KW - Materials Science KW - Non-destructiv testing PY - 2019 AN - OPUS4-50152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Energy harvesting using thermomagnetic generators with magnetocaloric materials N2 - To date, there are only very few technologies available for the conversion of low temperature waste heat to electricity. In this talk, we first describe the principle of thermomagnetic generators. Then we focus on the impact of topology of the magnetic circuit within thermomagnetic generators. We demonstrate that the key operational parameters strongly depend on the genus, i.e. the number of holes within the magnetic circuit. T2 - JEMS 2019 CY - Uppsala, Sweden DA - 26.08.2019 KW - Energy harvesting KW - Magnetocaloric KW - Materials science KW - Non-destructiv testing PY - 2019 AN - OPUS4-50153 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Cooling and energy harvesting using magnetic materials N2 - To date, there are very few technologies available for the conversion of low-temperature waste heat into electricity. Thermomagnetic generators are one approach proposed more than a century ago. Such devices are based on a cyclic change of magnetization with temperature. For thermomagnetic materials, we used a commercial magnetocaloric alloy with a transition temperature of 300 K. T2 - Summer School CY - Szczecin, Poland DA - 26.09.2019 KW - X-Ray Imaging KW - Energy harvesting KW - Magnetocaloric KW - Material Science KW - Non-destructive testing PY - 2019 AN - OPUS4-50155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Energy harvesting near room temperature using thermomagnetic materials N2 - To date, there are only very few technologies available for the conversion of low temperature waste heat to electricity. In this talk, we first describe the principle of thermomagnetic generators. Then we focus on the impact of topology of the magnetic circuit within thermomagnetic generators. We demonstrate that the key operational parameters strongly depend on the genus, i.e. the number of holes within the magnetic circuit. T2 - 8th WMRIF Symposium and General Assembly CY - Budapest, Hungary DA - 17.06.2019 KW - Energy harvesting KW - Magnetocaloric KW - Material Science KW - Non-Destructive testing PY - 2019 AN - OPUS4-50176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Properties of powder-in-tube formed magnetocaloric materials N2 - This talk gives an overview of the shaping options for magnetocaloric materials. We have shown that powder-in-tube processing of these functional materials is a straightforward and efficient way to obtain wires and stacked structures for heat exchange. T2 - Eingeladener Vortrag / Symposiumsorganisation und Vortrag CY - Stockholm, Sweden DA - 05.09.2019 KW - X-Ray imaging KW - Additive Manufacturing KW - Magnetocaloric KW - Material Science KW - Non-Destructive testing PY - 2019 AN - OPUS4-50177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Magnetocaloric materials for cooling and harvesting of low-grade waste heat N2 - To date, there are very few technologies available for the conversion of low-temperature waste heat into electricity. Thermomagnetic generators are one approach proposed more than a century ago. Such devices are based on a cyclic change of magnetization with temperature. For thermomagnetic materials, we used a commercial magnetocaloric alloy with a transition temperature of 300 K. T2 - Symposiumsorganisation und Vortrag CY - Stockholm, Sweden DA - 05.09.2019 KW - X-Ray imaging KW - Energy harvesting KW - Additive Manufacturing KW - Magnetocaloric KW - Material Science KW - Non-Destructive testing PY - 2019 AN - OPUS4-50178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - A thermomagnetic generator for harvesting low-grade waste heat N2 - To date, there are only very few technologies available for the conversion of low temperature waste heat to electricity. In this talk, we first describe the principle of thermomagnetic generators. Then we focus on the impact of topology of the magnetic circuit within thermomagnetic generators. We demonstrate that the key operational parameters strongly depend on the genus, i.e. the number of holes within the magnetic circuit. T2 - Eingeladener Vortrag / Symposiumsorganisation und Vortrag CY - Uppsala, Sweden DA - 28.08.2019 KW - Energy harvesting KW - Magnetocaloric KW - Material Science KW - Non-Destructive testing PY - 2019 AN - OPUS4-50179 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Mikro-Computertomographie für die zerstörungsfreie Untersuchung von Pulvern und additiv gefertigten Bauteilen N2 - In diesem Vortrag wird am Beispiel magnetischer Werkstoffe zur Energiewandlung gezeigt, wie röntgentomographische Untersuchungen zur Strukturaufklärung in Kompositen und Massivproben beitragen können. Die Bauteile werden zerstörungsfrei geprüft, um Risse, Poren und andere Defekte und ihren Einfluss auf die funktionellen Eigenschaften dreidimensional und rechtzeitig im Lebenszyklus des Werkstoffs zu charakterisieren. Kombiniert man Mikrotomographie mit anderen Methoden der magnetischen Werkstoffcharakterisierung, lassen sich einzigartige Aussagen über den Aufbau und die funktionellen Eigenschaften treffen. T2 - TU München Vortragsreihe CY - Munich, Germany DA - 24.01.2019 KW - X-Ray Imaging KW - Additive Manufacturing KW - Material Science KW - Non-destructive testing PY - 2019 AN - OPUS4-50156 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Mikrocomputertomographie für die zerstörungsfreie Untersuchung von Pulvern und additiv gefertigten Bauteilen N2 - In diesem Vortrag wird am Beispiel magnetischer Werkstoffe zur Energiewandlung gezeigt, wie röntgentomographische Untersuchungen zur Strukturaufklärung in Kompositen und Massivproben beitragen können. Die Bauteile werden zerstörungsfrei geprüft, um Risse, Poren und andere Defekte und ihren Einfluss auf die funktionellen Eigenschaften dreidimensional und rechtzeitig im Lebenszyklus des Werkstoffs zu charakterisieren. Kombiniert man Mikrotomographie mit anderen Methoden der magnetischen Werkstoffcharakterisierung, lassen sich einzigartige Aussagen über den Aufbau und die funktionellen Eigenschaften treffen. T2 - Seminar Yxlon CY - Dresden, Germany DA - 15.05.2019 KW - X-Ray imaging KW - Additive Manufacturing KW - Materials Science KW - Non-destructive testing PY - 2019 AN - OPUS4-50157 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja A1 - Funk, Alexander A1 - Jaenisch, Gerd-Rüdiger A1 - Zscherpel, Uwe A1 - Moosavi, Robabeh A1 - Grunwald, Marcel A1 - Redmer, Bernhard A1 - Nazarzadehmoafie, Maryam T1 - X-ray non-destructive testing of materials and composites N2 - Functional materials for energy conversion are important technology drivers needed for the implementation of low carbon energy. Therefore, researchers commonly focus on improving the intrinsic properties of a functional material. However, for applications, the extrinsic properties are at least as important as the intrinsic ones. Consequently, it is important to investigate and understand the external and internal structure of semi-finished products and especially defect dependent properties. The extrinsic properties may change during application and the life cycle of the material as well as through processing and molding steps. Our studies show how X-ray tomographic (XCT) investigations can contribute to structure investigations in composites and massive samples using the example of magnetic materials for energy conversion. The components are tested non-destructively in 3D in order to localize and characterize cracks, pores, inclusions as well as other defects and their influence on the functional properties and also “in-time” during the life cycle of the material. Exsitu and in-situ experiments performed with non-destructive XCT are predestinated to follow damaging mechanisms of materials under certain load conditions, atmospheres or liquids, e.g. went through several working cycles of a functional material. By combining microtomography with other methods of magnetic and classical material characterization, unique statements about the structure and the functional properties can be made. From the applications point of view, sometimes complex, three-dimensional geometries are needed to fully exploit the functional properties of the materials, e.g. to ensure a high surface area for heat exchange. Since many functional materials are brittle and difficult to form, shaping is often a big challenge. In principle, additive manufacturing processes offer the possibility to produce complex, porous components from poorly formable alloys. If all stages of additive manufacturing are accompanied by X-ray tomographic imaging, the process of finding the optimal parameters for material processing can be significantly accelerated. Based on the quality control of the initial powder material used and also investigations of the shape and arrangement of defects within the molten structure and their relationship with the melting path scanning strategy, Xray tomography has proven to be an ideal tool for additive manufacturing, even for functional materials. Overall, tomographic methods are important tools for the development of functional materials to application maturity. T2 - Physikalisches Kolloquium TU Chemnitz CY - Chemnitz, Germany DA - 04.12.2019 KW - Non-destructuve testing KW - X-ray imaging KW - Additive manufacturing KW - Materials science PY - 2019 AN - OPUS4-50100 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waniek, Tassilo A1 - Zarinwall, A. A1 - Silbernagl, Dorothee A1 - Garnweitner, G. A1 - Sturm, Heinz T1 - Mechanical coupling of matrix and nanoparticles depending on particle surface modification N2 - Boehmite nanoparticles has been successfully functionalized with APTES. After APTES functionalization further modification with tailored molecules e.g. via carboxylic acids is possible. The tailored surface functionalization is strongly enhanced by improved coupling protocols. Arbitrary variation of the functionalization degree is possible. Thereby the temperature stable APTES functionalization enables a wide range of functional groups. By TGA-MS analysis strong evidence for the bonding situation of the APTES on the boehmite surface has been found. Additionally first experiments has been performed to predict the polymer-particle compatibility enhancement via reverse wetting angle measurements with AFM. T2 - Workshop Acting Principles of Nano-Scaled Matrix Additives for Composite Structures CY - BAM, Berlin, Germany DA - 11.10.2019 KW - Surface modification KW - Nanocomposites KW - Boehmite KW - Silane KW - Thermogravimetry KW - Mass spectrometry PY - 2019 AN - OPUS4-49435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -