TY - CONF A1 - Stegemann, Robert T1 - Characterization of Residual Stress State on Intert Gas Welded Joints by Neutron Diffraction at E3 line T2 - 7th joint BER II and BESSY II User Meeting CY - Berlin DA - 2015-12-11 PY - 2015 AN - OPUS4-35070 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Evans, Alexander T1 - Non destructive characterization in Additive manufacturing N2 - An overview of non destructive characterisation in additively manufactured materials using computed tomography, refraction and diffraction based stress analysis T2 - BAM-IFW workshop CY - IFW Dresden, Germany DA - 28.03.2019 KW - Residual stress analysis KW - Additive manufacturing KW - Computed tomography KW - Diffraction KW - X-ray refraction PY - 2019 AN - OPUS4-49842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - An assessment of bulk residual stress in selective laser melted in 718 N2 - Having been introduced almost two decades ago, Additive Manufacturing (AM) of metals has become industrially viable for a large variety of applications, including aerospace, automotive and medicine. Powder bed techniques such as Selective Laser Melting (SLM) based on layer-by-layer deposition and laser melt enable numerous degrees of freedom for the geometrical design. Developing during the manufacturing process, residual stresses may limit the application of SLM parts by reducing the load bearing capacity as well as induce unwanted distortion depending on the boundary conditions specified in manufacturing. The residual stress distribution in IN718 elongated prisms produced by SLM was studied non-destructively by means of neutron (bulk) and laboratory X-ray (surface) diffraction. The samples with different scanning strategies, i.e. hatching length, were measured in as-built condition (on a build plate) and after removal from the build plate. While surface stress fields seem constant for AB condition, X-ray diffraction shows stress gradients along the hatch direction in the RE condition. The stress profiles correlate with the distortion maps obtained by tactile probe measurements. Neutron diffraction shows bulk stress gradients for all principal components along the main sample directions. We correlate the observed stress patterns with the hatch length, i.e. with its effect on temperature gradients and heat flow. The bulk stress gradients partially disappear after removal from the baseplate. Together with surface scan utilizing a coordinate-measuring machine (CMM), it is possible to link the stress release to the sample distortion. We finally propose an explanation of those stress profiles based on the deposition strategy. T2 - ECRS10 CY - Leuven, Belgium DA - 09.09.2018 KW - Residual stress KW - Influence of rheology modifying admixtures on hydration of cementitious suspensions PY - 2018 AN - OPUS4-45997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni A1 - Cabeza, Sandra T1 - Neutron diffraction: the forgotten non-destructive technique for residual stress analysis … and more N2 - 3-D Stress Analysis (Bulk) Stress mapping Thick (and thin) films & Interfaces Bulk high temperature Real time In-situ testing: Large sample environment (Stress rigs, Furnaces, …) Neutrons and Synchrotron Radiation allow all this because they are FASTER , DEEPER and MORE PRECISE than lab equipment (Flux)(Energy)(Parallel Beam) T2 - World Non Destructive Testing CY - München, Germany DA - 11.06.2016 KW - Neutron diffraction KW - Stress analysis PY - 2016 AN - OPUS4-38396 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröder, Jakob T1 - On the influence of heat treatment on microstructure and mechanical behavior of laser powder bed fused Inconel 718 N2 - Since additive manufacturing processes typically introduce heterogeneous microstructures and residual stresses, the applicability of parts produced in an as-built state is limited. Therefore, often different post-processing treatments are necessary to obtain the desired stress state and properties. For additively manufactured Inconel 718, the recently developed standard ASTM F3301 provides guidance for the heat treatment of powder bed fusion specimens. Although this standard is based on standards developed for wrought Inconel 718, it does not include the direct aging variant. In this study, we characterized the microstructure and tensile behavior of Inconel 718 specimens produced by a laser powder bed fusion process. The specimens were heat-treated according to two different routines after stress relieving: a full heat treatment cycle versus a one-step aging process. Differences in the resulting texture and grain morphology were observed. Although these differences prevail, the ex-situ tensile behavior was broadly similar. Minor differences were observed in yield strength and work hardening rate for the direct aged specimen. In order to understand this behavior, investigations with in-situ tensile testing during synchrotron energy-dispersive X-ray diffraction measurements revealed differences in the load partitioning among different crystal directions. This was attributed to microstructural differences between the heat treatment variants. Further analysis emphasized that the various strengthening mechanisms are present to a different extent depending on the heat-treatment cycle applied. In addition, the elastic anisotropy expressed by the differences in the diffraction elastic constants displayed a dependence on the microstructure. Importantly, a precise knowledge of such constants is indispensable to reliably determine residual stresses in parts. T2 - EUROMAT 2021 - European Congress and Exhibition on Advanced Materials and Processes CY - Online meeting DA - 13.09.2021 KW - Electron microscopy KW - X-ray analysis KW - Inconel 718 KW - Additive manufacturing (AM) KW - Mechanical behavior KW - Diffraction elastic constants (DECs) PY - 2021 AN - OPUS4-53301 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stegemann, Robert T1 - Evaluation magneto-mechanischer Effekte in hochauflösenden Magnetfeldmessungen durch Neutronendiffraktion N2 - Die mechanische Spannung ist ein maßgeblicher Parameter ferromagnetischer Materialien. Wird ein solches Material unter die Curie Temperatur abgekühlt, zerfällt es spontan in nahezu selbstgesättigte magnetische Domänen. Diese Magnetisierung führt gleichzeitig zu einer Verformung der mit ihr gekoppelten Kristallgitter. Ein Effekt der auch reziprok gilt: wird die Gitterverformung durch eine Spannung behindert ändert sich zwangsweise der magnetische Zustand. Man kann annehmen, dass zwischen unterschiedlichen, für sich aber homogen verspannten Werkstoffbereichen, lokale magnetische Streufelder auftreten, weil magneto-mechanische Effekte eine Inkompatibilität der Domänenstruktur induzieren. Bekanntlich bilden sich Spannungsgradienten nach Schweißprozessen durch ungleichmäßigen Wärmeeintrag, thermischer Dehnung, und unterschiedlichen Abkühlraten aus. Unter dieser Prämisse untersuchen wir Wolfram-Inertgas geschweißte Blindnahtproben (250x100x4,8 mm^3) aus einem hypereutektoiden Baustahl. Der Spannungszustand der Proben wurde anhand von Neutronendiffraktometrie (ND) am Instrument E3 am Reaktor BERII (Helmholzzentrum Berlin, HZB) charakterisiert. ND ist ein Referenzverfahren für die quantitative Bestimmung von elastischen Dehnungen in kristallinen Materialien, deren Gitter selbst der Messmaßstab ist. Die Auswertung zeigt hohe Längsspannungen mit lokalen Maxima in Größenordnung von 600 MPa, die von umgebenen Druckspannungszonen kompensiert werden. Zur Detektion der magnetischen Kleinststreufelder verwenden wir speziell designte GMR-Sensorik (GMR - Giant Magneto Resistance), die aufgrund der geringen Größe ihrer aktiven Sensorelemente hohe Ortsauflösung mit Sensitivität vereint. Die Visualisierung der Messergebnisse lässt eine klare magnetische Mikrostruktur der Schweißnähte erkennen, in der die Streufelder lateral in Größenordnung des Erdmagnetfeldes variieren (~50 µT). Wir zeigen durch einen Vergleich beider Messverfahren, dass lokale magnetische Streufeldmaxima in hohem Maße mit den Spannungsgradienten übereinstimmen. T2 - DGZfP-Jahrestagung CY - Koblenz, Germany DA - 22.05.2017 KW - GMR-Sensorik KW - Neutronendiffratkion KW - Eigenspannungen KW - Baustahl PY - 2017 AN - OPUS4-40386 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hejazi, Bardia A1 - Fritsch, Tobias A1 - Benz, Christopher A1 - Radtke, Lars A1 - Sander, Manuela A1 - Bruno, Giovanni T1 - In-situ very high cycle fatigue experiments of additively manufactured Ti-6Al-4V using X-ray computed tomography N2 - X-ray computed tomography (XCT) is an invaluable method for evaluating the properties and performance of components both during service and after failure in a non-destructive manner. XCT is particularly useful for the investigation of additively manufactured (AM) components, which often have production defects that are inherent to the manufacturing process, such as lack of fusion defects. Understanding the mechanisms of fatigue crack growth throughout the life cycle of such components is crucial and so to address this need, we designed and performed experiments to investigate the fatigue life and fatigue crack growth behavior of Ti-6Al-4V components under very high cycle fatigue (VHCF) testing. The titanium samples were additively manufactured with intentional internal defects to control crack initiation location. XCT of the component was carried out to identify crack initiation sites and characterize the dynamics of crack growth. The findings from this work will benefit industries that rely on the AM of titanium alloys, aiding in the improvement of component design and manufacturing processes. T2 - Alloys for additive manufacturing 2025 (AAMS 2025) CY - Neuchâtel, Switzerland DA - 02.09.2025 KW - X-ray computed tomography KW - Deep learning KW - Titanium alloy KW - Very high-cycle fatigue PY - 2025 DO - https://doi.org/10.5281/zenodo.15261296 AN - OPUS4-64096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - In-Situ Compression CT on Additively Manufactured in 625 Lattice Structures N2 - The porosity and the surface roughness are recently discussed problems for SLM parts. The influence of SLM process parameters on porosity is well studied for different materials. Nevertheless, the build angle (i.e. the angle between part orientation and build plate) needs to be understood as an additional SLM process parameter, as it has been shown, that the microstructure and hence the mechanical performance of various materials depend on the build angle. The inherent build angle of each strut as a part of a lattice structure is the motivation to investigate the influence of the build angle on the porosity and roughness on round-shaped (1 mm diameter) struts by means of CT. Conventional Coordinate Measuring Machine (CMM) has the limitation towards small and round shaped samples. The need for Computed Tomography (CT) regarding investigations of SLM parts will increase because no other non-destructive technique allows the assessment of complex geometries with inner laying surfaces. We used CT to assess the pores and the strut surface. Seven struts out of the nickel alloy Inconel 625 with build angles from 30° to 90° were studied. It was found that the number of pores is smaller, and the size of pores is larger for the 90° strut. In case of 30° strut, the number of pores is increased towards down-skin side, additionally, this strut orientation showed to have the largest number of attached powder particles. The elongated pores exist exclusively near the strut surface. While the roughness at the down-skin surface is highly depending of the biud angle, the roughness at the up-skin surface is the same for all struts. The mechanisms of pore and surface roughness formation is not mainly driven by gravity. T2 - ISAM Konferenz 2019 CY - Dresden, Germany DA - 29.01.2019 KW - Computed Tomography KW - Additive Manufacturing KW - Metals KW - Microstructure PY - 2019 AN - OPUS4-47327 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas T1 - Optimizing visibility of phase gratings for Talbot-Lau X-ray imaging N2 - We investigated the efficiency of phase gratings, i.e., the visibility upon variation of different parameters. Rotating around an axis parallel to the grid lines of the phase grating changes the grating’s shape and thereby the initial distribution of phase shifts. This yields high visibilities for shorter propagation distances than derived from box shapes. Tilting the grating in the scattering plane allows continuous tuning of the grating’s height that corresponds to an ideal phase shift for a particular photon energy. This opens the way for tuning the design energy suitable for the material under investigation. Our study included simulations for monochromatic sources with the sampling procedure for rectangular and triangular phase gratings. T2 - User-Meeting CY - Berlin, Germany DA - 8.12.2016 KW - Talbot-Lau interferomerty KW - Phase grating KW - Synchrotron radiation PY - 2016 AN - OPUS4-39096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Riedel, Jens T1 - Acoustic Ion Manipulation: Electric-field-free Approach to Gate, Focus, and Separate Ions at Atmospheric Pressure N2 - Approaches to control the motion and direction of ionized particles and mole-cules are an essential aspect of ion-based spectrometries, such as mass spec-trometry (MS) and ion mobility spectrometry (IMS). A wide variety of ion optics exist to reflect, focus, separate, gate, and filter ions based on physical proper-ties. Notably all rely on electric and magnetic fields to alter the trajectory of ionized atoms and molecules. While these optics are quite efficient at low pressures due to the large mean free path, diffusion and electrostatic repulsion between ions dominate at higher pressures. Conventional ion optics, that use electric or magnetic fields, can guide ions at atmospheric pressure (AP), but require high field strengths to overcome the dominating aerodynamic effects. Here, we describe a remarkable phenomenon whereby low-power acoustic fields are used to move, shape, gate, and separate beams of gaseous ions at atmospheric pressure. We refer to this approach as Acoustic Ion Manipulation (AIM). Gaseous ions at AP are directed towards and separated by the presence of the acoustic field. To better understand the phenomenon, an ion-detector array provided a measure of bulk ion movement, while mass spectrometry (MS) offered chemical-specific information. As one example of an AIM setup, a standing acoustic wave was formed with two ultrasonic speakers and placed between an ionization source and ion detector. Ion beams preferentially travel through regions of stable pressure gradients (i.e. nodes) and deflect from un-stable regions (i.e. antinodes). Shadowgraphy revealed that the ions are sepa-rated from a neutral gas stream. Specific examples of ion focusing, gating, and separation (based on ion size) will be shown. In addition, experimental findings will be used to postulate a theory to develop a better understand of the behav-ior of gas-phase ions in acoustic fields. This discovery could have profound im-pacts in IMS/MS instrumentation as well as materials processing and charac-terization. T2 - 56. Jahrestagung der DGMS CY - Göttingen, Germany DA - 04.03.2025 KW - Acoustic Ion Manipulation KW - Mass spectrometry KW - Ultrasound PY - 2025 AN - OPUS4-64208 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn T1 - Sintering and interconnecting thermoelectric oxides for energy applications N2 - Today, more than 12% of the primary energy is lost in the form of waste heat. Thermoelectric generators (TEGs) can convert waste heat directly into electrical power by utilizing the Seebeck effect. The performance of such a generator is defined by a dimensionless figure of merit ZT of the thermoelectric pairs and the resistance R of the metallic contacts between these pairs. The figure of merit of thermoelectric oxides is considerably smaller compared to semiconductors. Still, thermoelectric oxides like calcium cobaltite (Ca3Co4O9) are attractive for applications at elevated temperatures in air. In contrast to the established π-type architecture of common TEGs, tape casting and multilayer technology may be applied for cost-effective manufacturing of oxide TEGs. Promising demonstrations of multilayer TEGs have been published in the last years. Still, the development of reliable and scalable manufacturing processes and proper material combinations is necessary. The aim of our project is to evaluate the feasibility of low temperature co-fired ceramics (LTCC) technology for a practical manufacturing of oxide multilayer TEGs of Ca3Co4O9 (p-type) and calcium manganate (CaMnO3, n-type). Ca3Co4O9 exhibits an undesired phase decomposition at 926 °C. Because of that, the application of sintering strategies and interconnect concepts well known from LTCC technology is a promising approach. We present results of pressure-assisted sintering of Ca3Co4O9 multilayer at 900 °C and axial pressures of up to 7.5 MPa. Ca3Co4O9 was produced by solid state reaction of CaCO3 and cobalt(II,III)oxide at 900 °C. Green tapes were prepared by a doctor-blade process, manually stacked and laminated by uniaxial thermocompression. Sintering was conducted in a LTCC sintering press between SiC setter plates. The thickness shrinkage was recorded by an in-situ technique. After sintering under 7.5 MPa, the microstructure of the single phase material shows a high density of 95 % and an advantageous alignment of the platelet grains. This results in good electrical conductivity and a comparatively high ZT of 0.018 at room temperature. However, the lowering of CaMnO3 sintering temperature from above 1200 °C to below 920 °C remains a challenge. To select a proper metal paste for interconnections of an oxide TEG, several pastes have been investigated regarding contact resistance of internal and external (soldered) connections in a preliminary study. Commercial pastes containing Ag, Au, Au/Pt, Ag/Pd, and Ag/Pd/Bi were manually applied and post-fired on sintered test bars of Ca3Co4O9 and CaMnO3 at 900 °C for 2 h. All tested pastes formed mechanically stable metallization after firing. For resistance measurement, 4-wire method and a custom-made probe head were used. The contacts on Ca3Co4O9 exhibit significantly (2-sample t-test, α = 5%) higher resistance compared to contacts on CaMnO3. Pure silver paste exhibits the lowest resistance for internal contacts on both materials, lower than 5 mΩ on CaMnO3. Ag/Pd/Bi paste resulted in conspicuously high variance of resistance. EDX analyses clarified an enrichment of Bi in the thermoelectric material near the interface and thereby the formation of an oxide layer with probably high electrical resistance. The thickness of that layer varies with the thickness of metallization. In conclusion, the use of Bi containing pastes is not advisable. Pure Ag paste shows the best results regarding resistance and solderability. T2 - CICMT 2018 CY - Aveiro, Portugal DA - 18.04.2018 KW - Thermoelectric oxide KW - Thermoelectric generator KW - Multilayer technology KW - Pressure-assisted sintering PY - 2018 AN - OPUS4-44740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kromm, Arne T1 - Residual stress formation in selective laser melted parts of alloy 718 N2 - Additive Manufacturing (AM) through the Selective Laser Melting (SLM) route offers ample scope for producing geometrically complex parts compared to the conventional subtractive manufacturing strategies. Nevertheless, the residual stresses which develop during the fabrication can limit application of the SLM components by reducing the load bearing capacity and by inducing unwanted distortion, depending on the boundary conditions specified during manufacturing. The present study aims at characterizing the residual stress states in the SLM parts using different diffraction methods. The material used is the nickel based superalloy Inconel 718. Microstructure as well as the surface and bulk residual stresses were characterized. For the residual stress analysis, X-ray, synchrotron and neutron diffraction methods were used. The measurements were performed at BAM, at the EDDI beamline of -BESSY II synchrotron- and the E3 line -BER II neutron reactor- of the Helmholtz-Zentrum für Materialien und Energie (HZB) Berlin. The results reveal significant differences in the residual stress states for the different characterization techniques employed, which indicates a dependence of the residual state on the penetration depth in the sample. For the surface residual stresses, longitudinal and transverse stress components from both X-ray and synchrotron agree well and the obtained values were around the yield strength of the material. Furthermore, synchrotron mapping disclosed gradients along the width and length of the sample for the longitudinal and transverse stress components. On the other hand, lower residual stresses were found in the bulk of the material measured using neutron diffraction. The longitudinal component was tensile and decreased towards the boundary of the sample. In contrast, the normal component was nearly constant and compressive in nature. The transversal component was almost negligible. The results indicate that a stress re-distribution takes place during the deposition of the consecutive layers. Further investigations are planned to study the phenomenon in detail. T2 - Forschungsseminar OvGU Magdeburg CY - Magdeburg, Germany DA - 15.11.2018 KW - Additive Manufacturing KW - Selective Laser Melting KW - Residual Stresses PY - 2018 AN - OPUS4-46876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröter, Felix T1 - Fluorescence? Not on my Shift! Excitation- Shifted UV Raman Microspectroscopy N2 - Spectroscopic analysis of samples provides elemental information, which is useful when the sample is homogenous. But many samples are not and consequently the creation of maps detailing the spatial composition of materials is needed. Raman microscopy can be used for this exact purpose but suffers a big drawback. The inherently weak Raman scattering results in long measurement times, especially when maps with many data points are created. This is due to the long exposure times needed when visible light lasers are used. A shift to UV-Lasers significantly increases the Raman intensity, as it scales with the fourth power of the inverse of the laser wavelength. But UV excitation often leads to fluorescence which can obscure the relatively weak Raman signal. Consequently, UV-Raman can only be used with specially prepared samples, for example through photo-bleaching, or with samples producing no fluorescence background in the measurement region. A solution is proposed that uses shifted-excitation Raman difference spectroscopy (SERDS) in a confocal microscope to obtain fluorescence-free Raman spectra. This is possible due to the collection of two Raman spectra at different excitation wavelengths. SERDS then allows for the calculation of just the Raman signal from the difference spectrum, which eliminates any fluorescence backgrounds, as they are not excitation wavelength dependent. The presented approach employs a polarized beamsplitter to irradiate the same spot with two lasers of different wavelengths which share the same beam path in the microscope. Consequently, a SERDS UV Raman Microscope is created, which utilizes the speed of UV-Raman without the drawbacks of possible broad fluorescence backgrounds. Here we present the instruments methodology and some first results. T2 - ANAKON 2025 CY - Leipzig, Germany DA - 10.03.2025 KW - UV Raman Spectroscopy KW - UV Raman Microspectroscopy KW - Confocal Microscopy KW - Excitation-Shifted Raman Spectroscopy PY - 2025 AN - OPUS4-62734 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blume, Simon T1 - Exploiting Lithium Self-Absorption in a Laser-Induced Breakdown Plasma for Isotopic Analysis via Spatial Heterodyne Spectroscopy N2 - Lithium-ion batteries are ubiquitous in modern life. From powering consumer electronics to enabling electric mobility and energy storage, they are a key building block of a sustainable future. Determination of the ratio of the two naturally abundant stable isotopes, 7Li and 6Li, provides access to a wide variety of information, such as studying the aging processes of lithium-ion batteries or elucidating the isotopic fingerprinting of natural or recycled sources of lithium. However, accurately measuring the lithium isotope ratio in complex samples remains challenging, often requiring either extensive sample pretreatment or specialized equipment, thus impeding in-situ and high-throughput demands of global industries. Recognition and determination of the individual lithium isotopes with conventional laser-induced breakdown spectroscopy (LIBS) setups is nearly impossible. While LIBS offers several advantages, such as obviating time- and resource-intensive sample preparation and enabling rapid measurements, the high temperature (~20,000 K) of the plasma, as well as the Stark-broadening caused by the nascent free electrons spectrally broaden the atomic emission lines to such an extent that the isotopic shift of the lithium doublet at 670 nm cannot be resolved. Since, the excited state energy for this transition amounts to only 14,900 cm-1, lithium exhibits a pronounced self-absorption dip in the emission signal. This self-absorption dip is significantly less affected by the broadening effects, therefore, allowing for the resolution of the isotopic shift from its line shape. Spatial heterodyne spectroscopy (SHS) offers the superior resolution capabilities necessary to differentiate the individual isotopic contributions. To address the generally limited sensitivity of SHS, a high-repetition-rate (>10 kHz) laser allows the accumulation of more than 10,000 lasing events per spectral recording for a sufficient signal-to-noise ratio and gain statistical validity. Optical lithium fluoride serves as a model sample to showcase the analytical performance. Additionally, the impact of the laser parameters on the self-absorption will also be discussed. T2 - ANAKON 2025 CY - Leipzig, Germany DA - 10.03.2025 KW - Isotopic Analysis KW - Spatial Heterodyne Spectroscopy PY - 2025 AN - OPUS4-63559 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sander, Luise T1 - Multi-Scale Analysis of Commercially Available Sodium-Ion Cells N2 - As the first commercial sodium-ion-batteries (SIBs) are available for purchase, it is possible to investigate material composition. Gaining an insight into the material composition of these SIBs is of interest not only for the classification of possible safety risks and hazards, but also in regards to recycling. Herein we report the preliminary investigations of the chemical and structural composition of first commercial SIB-cells. Two different SIB-cells with different specification were compared regarding electrode size, thickness and further parameters. Furthermore, the composition of the active materials and electrolyte was investigated and compared. T2 - Solid State Ionics (SSI) CY - London, United Kingdom DA - 15.07.2024 KW - Sodium Ion-Cells KW - Multi-Scale PY - 2024 AN - OPUS4-60764 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Sophie T1 - Lowering the sintering temperature of calcium manganate CaMnO3 for thermoelectric applications N2 - Thermoelectric materials can convert waste heat directly into electrical power by utilizing the Seebeck effect. Calcium cobaltite (p-type) and calcium manganate (n-type) are two of the most promising oxide thermoelectric materials. The development of cost-effective multilayer thermoelectric generators requires the co-firing of these materials and therefore the adjustment of sintering temperatures. Calcium manganate is conventionally sintered between 1200 °C and 1350 °C. Calcium cobaltite exhibits an undesired phase transition at 926 °C but can be sintered to high relative density of 95 % at 900 °C under axial pressure of 7.5 MPa. Hence, co-firing at 900 °C would be favourable. Therefore, strategies for lowering the sintering temperature of calcium manganate have been investigated. Basically, two approaches are common: i) addition of low melting additives like Bi2O3-ZnO-B2O3-SiO2 (BBSZ) glass or Bi2O3, and ii) addition of additives that form low-melting eutectics with the base material, for example CuO. In this study, several low melting additives including BBSZ glass and Bi2O3, as well as CuO were tested regarding their effect on calcium manganate densification. Bi2O3 did not improve the densification, whereas BBSZ glass led to 10 % higher relative density at 1200 °C. An addition of 4 wt% CuO decreases the temperature of maximum sinter rate from above 1200 °C to 1040 °C. By reducing the particle size of the raw materials from 2 μm to 0.7 μm the maximum sinter rate could be further shifted 20 K towards lower temperatures and the sinter begin decreased from 920 °C to 740 °C. It is shown that eutectic phase formation is more effective in lowering sintering temperature and accelerating densification than low-melting additives. T2 - 93. DKG-Jahrestagung und Symposium Hochleistungskeramik 2018 CY - Munich, Germany DA - 10.04.2018 KW - Thermoelectrics KW - Sinter additive PY - 2018 AN - OPUS4-44818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Yi T1 - Advanced Repetition-Rate Modulation and Computational Strategies for Background-Free LIBS Using Non-Gated Spectrometers N2 - Laser-induced breakdown spectroscopy (LIBS) is recognized for its rapid, direct elemental analysis capabilities. However, its general adoption is constrained by the reliance on expensive, high-power consumption, gated cameras such as intensified charge-coupled devices (CCDs). These devices, while sensitive, are expensive and possess low frame rates, limiting their efficacy in dynamic or challenging environments. Our study proposes an innovative approach that leverages non-gated spectrometers in conjunction with the framework of correlation spectroscopy to isolate analyte signals responsive to a specific repetition-rate modulation pattern, thereby yielding spectra with zero background. We utilized a diode-pumped solid-state laser, with repetition rates ranging from 10 Hz to 30 kHz, to induce plasma in aqueous solutions containing various alkaline and earth-alkaline metals. With a non-gated single-grating linear CCD spectrometer, we found that the continuum signal plateaued at approximately 7 kHz. In contrast, atomic emissions from the dissolved analytes showed continued increases. Notably, atomic emissions from the solvent (water) were observable only above 8.5 kHz, at a significant high rate of increase. Through computational synthesis of a modulation pattern, we determined an optimized scheme that effectively discriminates continuum and analyte signals; this pattern was optimized with a genetic algorithm. The spectral matrix correlating signal intensity with laser repetition rate and wavelength was used as the input of the model. Meanwhile, the fitness function that extracts the background-free spectra was built in-house and inspired by the Gardner transform, which exploits the power of Fourier transform, allowing for flagging and splitting analyte signal from other undesired features. This approach bypasses the limitations associated with gated cameras, while providing a cost-effective alternative for robust LIBS applications. This advancement is particularly relevant in field, portable and remote applications, aligning with the ongoing demand for accessible, high-performance analytical tools in diverse scientific fields. T2 - SCIX 2024 Conference CY - Raleigh, NC, USA DA - 20.10.2024 KW - LIBS KW - Data Processing KW - High Repetition Rate KW - Repetition Rate Modulation KW - Data-Oriented Experimental Design PY - 2024 AN - OPUS4-62137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Applications of X-ray refraction to non-destructive characterization of and composites T2 - 14th International Conference of the European Ceramic Society CY - Toledo, Spain DA - 2015-06-21 PY - 2015 AN - OPUS4-33974 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn T1 - Tieftemperaturfügen mit Nano- und Submikronsilberpasten T2 - DKG-Symposium "Fügen von Keramik: Grundlagen - Verfahren - Anwendungen" CY - Erlangen, Germany DA - 2012-12-04 PY - 2012 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. AN - OPUS4-27285 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arlt, Tobias T1 - Tomographic methods for investigation for fuel cell materials T2 - Ulm Electro Chemical Talks CY - Ulm, Germany DA - 2010-06-15 PY - 2010 AN - OPUS4-21518 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Anita T1 - Eine sichere Zukunft für Lithium-Ionen Batterien N2 - Eine sichere Zukunft hat eine Technologie dann, wenn sie die Gesellschaft auch von ihrer Sicherheit überzeugen kann. Dies ist insbesondere für Lithiumbatterien von hoher Bedeutung. Die BAM trägt auf den verschiedene Ebenen auf vielfältige Art und Weise dazu bei, diese Sicherheit zu untersuchen und zu verbessern. T2 - 4. Batterieforum Berlin Brandenburg CY - Potsdam, Germany DA - 22.11.2024 KW - LIthiumbatterien KW - Sicherheit PY - 2024 AN - OPUS4-62328 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Widjaja, Martinus Putra T1 - Accumulation of Fibre Breaks under Time Dependent Loads in CFRP Materials of Pressure Vessels N2 - BAM has discovered that the reliability of tested composite pressure vessel will be altered when the loading speed is varied. The ageing of composite materials in general gives negative effect to the structure, however there might be positive effect occurs due to the load redistribution between the fibres. The study on the negative effect of ageing has been compared favourably with the fibre break model from Mines ParisTech. To improve the model's capability, this positive effect should also be implemented. The problem however to evaluate real scale model that might take extensive computation time. The reduced volume method then was proposed to improve the calculation time. The next study is then to check the approach on different loading condition and compare the result with experimental data provided by BAM. T2 - PhD Day 2018 CY - Evry, France DA - 20.06.2018 KW - Fibre Break Accumulation KW - Carbon Fibre Pressure Vessels KW - Time Effect KW - Integral Range PY - 2018 AN - OPUS4-45567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - A few Aspects of the Current Understanding of DPF Materials Thermal and Mechanical Properties N2 - Bi-continuous porous ceramics for filtration applications possess a particularly complicated microstructure, whereby porosity and solid matter are intermingled. Moreover, they very often display a microcrack network, resulting from the strong anisotropy of the microscopic coefficient of thermal expansion (CTE). Mechanical, thermal, and filtration properties, they all strongly depend on the morphology of both solid matter and porosity, and on the degree of microcracking (also, the microcrack density), which is in its turn tightened to the grain size. Recent industrial and academic research has enormously progressed in understanding the microstructure-property-performance relationships existing in these complicated materials: - Using 3D computed tomography (CT) at different resolutions, and several X-ray refraction-based techniques, porosity and pore orientation could be quantitatively evaluated (in the example of cordierite). - Neutron and X-ray Diffraction has been instrumental to disclose a) the non-linear character of the stress-strain response, and b) the negative CTE of these materials, and its consequences on the materials properties; - Analytical and numerical models have been elaborated to rationalize these behaviours in terms of microcracking and microstructural features. Here these results will be reviewed, and a outlook at (some of the) outstanding problems will be given. T2 - HELSMAC CY - Cambridge UK DA - 7.04.2016 KW - Thermal KW - Materials PY - 2016 AN - OPUS4-35752 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blume, Simon T1 - Femtosecond Laser-induced XUV Spectroscopy (LIXS) for Elemental Analysis N2 - In a typical laser-induced breakdown spectroscopy (LIBS) setup, emissions from collisional excitation of the atoms in the later stages of the plasma are detected and provide information about the elemental fingerprint of the sample. However, precise measurements, in particular quantification efforts, suffer from fluctuations of the intensity of the detected emission lines due to matrix effects and plasma-flicker noise, as well as significant background noise. In contrast, the early stages of the plasma are dominated by electron-ion recombination and Bremsstrahlung, which lead to sharp and intense x-ray emissions with consistent intensity profiles between laser pulses and suppressed background noise, therefore improving the limit of detection, especially for lighter elements. These emissions are detected in laser-induced XUV spectroscopy (LIXS).[1] Introduction of a femtosecond laser (pulse length ~100 fs) to the LIXS setup fundamentally changes the laser energy absorption and ablation process. The laser pulse energy is absorbed and redistributed by multiphoton absorption and inverse Bremsstrahlung and operates on a time frame faster than the plasma formation. Additionally, the plasma formation itself is accelerated leading to signal generation in the XUV-range before generation of the undesired background emissions. Thus, utilization of a femtosecond laser allows for further suppression of broadband emissions from the plasma allowing for sharper separation of the emission lines and improved limit of detection. This work presents the results of the combination of a LIXS setup with a femtosecond laser and assess the capabilities of this system with a model sample of cathode material from a spent lithium-ion battery. T2 - AMACEE 2025 CY - Brno, Czech Republic DA - 26.8.2025 KW - LIXS KW - Femtosecond laser KW - Instrumentation PY - 2025 AN - OPUS4-64118 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Palásti, Dávid jenö T1 - Interferometric sensing in the UV range – Investigation and comparison of the all-reflective spatial heterodyne spectrometer designs N2 - Spatial heterodyne spectrometers (SHS) are optical interferometric devices, working in the UV and visible spectral ranges [1]. The most common SHS setup is similar to the Michelson interferometer, both utilizes a beam splitter in the incoming beam path. In case of the SHS the split beams are not aimed towards orthogonal mirrors, but reflective optical gratings, set under a selected angle. These optical gratings diffract the beams, the direction of every wavelength will depend on the grating constant and the angle of the gratings. The wavefronts belonging to different wavelengths are going to cross each other under a unique angle, resulting in a spatial interference, which is recorded by a digital camera. This relatively compact setup provides high resolution and light throughput, which properties were harnessed for tasks requiring good line separation and/or high sensitivity [2]. However, SHS are only applicable on wavelengths for which an adequate transmissive beam splitter is available like the visible range, but not the far UV. To overcome this limitation, different all-reflective designs were introduced [3]. These instruments utilize symmetric optical gratings for the splitting and recombination of the beams. Although these SHS devices solve the main limitations of the traditional ones, they come with their fair share of drawbacks as well, such as more complex arrangement and the requirement for more delicate tuning. The behaviour of the traditional SHS is well documented [4,5], but in regards of the all-reflective ones we have much less available information. In this current study we utilized computational modelling to predict the behaviour of the all-reflective SH spectrometers, with special attention to the effects of the different alignment errors. Later we utilize this knowledge to fine tune an SHS for sensing (LIBS, Raman) in the UV region. Furthermore, we are introducing two new all-reflective SHS setups and compering them to their older counterparts. T2 - ANAKON 2025 CY - Leipzig, Germany DA - 10.03.2025 KW - SHS KW - Spectroscopy PY - 2025 AN - OPUS4-63556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn T1 - Anwendung der Master-Sinter-Kurve bei druckunterstützter Sinterung von Low Temperature Co-Fired Ceramics T2 - DKG-Jahrestagung 2014 CY - Clausthal-Zellerfeld, Germany DA - 2014-03-24 PY - 2014 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. AN - OPUS4-30472 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Evaluating Porosity in Cordierite DPF Materials: Advanced X-ray Techniques and New Statistical Anlaysis Methods T2 - CIMTEC 2014 CY - Montecatine Terme, Italy DA - 2014-06-08 PY - 2014 AN - OPUS4-30875 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Analyse von Schädigungsprozessen in Beton - Was leistet die CT? Teil1: Einblick in die Computertomographie N2 - Ein Nachteil der klassischen Durchstrahlungstechnik mit Röntgenstrahlen ist die, in der Abbildung des Untersuchungsobjektes, fehlende Tiefeninformation. Die Anwendung von radiografischen Verfahren, die das Objekt unter zwei oder mehreren Winkelpositionen durchstrahlen, erlauben die Rekonstruktion räumlicher Abbildungen. Dazu zählen Stereoradiografie, Translations- und Rotationslaminographie. Bei der Computertomographie erfolgt die Durchstrahlung unter einem Winkelbereich von 180° oder 360°. Die dabei aufgenommenen Projektionen werden anschließend durch Anwendung der Fourier Transformation und der gefilterten Rückprojektion zu einem 3D-Bilddatensatz rekonstruiert. Verschiedene systembedingte Artefakte, die das Ergebnis negativ beeinflussen können, lassen sich durch geeignete Meß- und Rekonstruktionsparameter, sowie einer nachfolgende Bildverarbeitung eliminieren oder reduzieren. T2 - Summer School im Rahmen des DFG Schwerpunktprogramms 2020 "Zyklische Schädigungsprozesse in Hochleistungsbetonen im Experimental-Virtual-Lab" CY - Hotel Park Soltau, Soltau, Germany DA - 25.06.2018 KW - Computertomographie KW - Durchstrahlungsverfahren KW - Bildverarbeitung KW - Rekonstruktionsverfahren KW - Bildartefakte PY - 2018 AN - OPUS4-45432 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cabeza, Sandra T1 - Characterization of multiphase metal matrix composites by means of CT and neutron diffraction N2 - The present study examines the relationship between the microstructure of multiphase MMC and their damage mechanisms. The matrix AlSi12CuMgNi was combined with 15% vol. Al2O3 (short fibres) and with 7% vol. Al2O3 + 15% vol. SiC (short fibres and whiskers, respectively). The experimental approach encompasses 3D microstructure characterization by means of computed tomography of samples (a) as-received, (b) after heat treatment, and (c) after compression tests at room temperature. The volume fraction of different phases, their distribution, their orientation and the presence of defects and damage are studied. Influence of addition of SiC whiskers on mechanical properties of composite was investigated. Phase-specific load partition analysis for samples with fibre plane parallel to load was perform by using neutron diffraction measurements during in-situ compression. It shows damage in the Si phase, while Al2O3 short fibres carry load without damage until failure. The computed tomography observations confirm the load partition analysis. T2 - World Non Destructive Testing CY - München, Germany DA - 11.06.2016 KW - CT KW - Neutron diffraction KW - Aluminium KW - Composite PY - 2016 AN - OPUS4-38395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schaupp, Thomas T1 - 3D Charakterisierung wasserstoffunterstüzter Risse in Stahl mittels Synchrotron-Refraktions-CT N2 - Die Fehlertoleranz moderner hochfester Stähle gegenüber Prozessfehlern beim Fügen nimmt stetig ab und erfordert eine immer kritischere Beurteilung der Ergebnisse aus den vorhandenen Prüfverfahren. Deren Aussagekraft ist häufig zu gering und daher muss zum einen das wissenschaftliche Verständnis der Mikrokaltriss-Entstehung in diesen Stählen vertieft werden und zum anderen müssen die Prüfmethoden und Bewertungskriterien angepasst werden. Dies erfordert ein besseres Verständnis insbesondere der Kopplung von Eigenspannungen, Wasserstoffgehalten und der Wirkung äußerer Kräfte auf die Rissentstehung und das Risswachstum. Erstmals soll mittels 3D-Synchrotron-Refraktions-Topographie an der BAMline am BESSY die Rissentstehung in mit Wasserstoff beladenen Zugproben charakterisiert werden. Diese Kenntnisse sollen in weiteren Untersuchungen auf Schweißnähte übertragen werden. T2 - MDDK – Master-, Diplomanden- und Doktorandenkolloquium CY - Universität Magdeburg, Germany DA - 23.06.2016 KW - Duplexstahl KW - Wasserstoffunterstützte Rissbildung KW - Computertomographie KW - Synchrotron-Refraktion PY - 2016 AN - OPUS4-36733 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Evsevleev, Sergei T1 - Stress-induced damage evolution in aluminum matrix composites N2 - Two metal matrix composites, both consisting of a near-eutectic cast AlSi12CuMgNi alloy, one reinforced with 15%vol. Al2O3 short fibers and the other with 7%vol. Al2O3 short fibers + 15%vol. SiC particles were studied. Distribution, orientation, and volume fraction of the different phases was determined by means of synchrotron computed tomography. The load partitioning between phases was investigated by in-situ neutron diffraction compression tests. The internal damage of the eutectic Si phase and Al2O3 fibers after ex-situ compression tests was directly observed in CT reconstructed volumes. Significant debonding between Al-matrix and SiC particles was found. Those observations allowed rationalizing the load transfer among the constituent phases of two different composites. Finally, based on the Maxwell scheme, a micro-mechanical model was utilized for the composite with one and two ceramic reinforcements. The model rationalizes the experimental data, and predicts the evolution of principal stresses in each phase. T2 - The 4th International Congress on 3D Material Science 2018 CY - Elsinore, Denmark DA - 10.06.2018 KW - Computed Tomography KW - Aluminium KW - Metal Matrix Composite KW - Load Partition PY - 2018 AN - OPUS4-45397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Characterization of Additive Manufacturing Materials at BAM N2 - The combination of tomographic, microstructural data with other experimental techniques and with modeling is paramount, if we want to extract the maximum amount of information on material and component properties. In particular, quantitative image analysis, statistical approaches, direct discretization of tomographic reconstructions represent concrete possibilities to extend the power of the tomographic 3D representation to insights into the material and component performance. This logic thread equally holds for industrial and academic research and valorizes expensive experiments such as those carried out at synchrotron sources, which cannot be daily repeated. I will show a few examples of possible use of X-ray tomographic data for quantitative assessment of damage evolution and microstructural properties, as well as for non-destructive testing. Examples of micro-structured inhomogeneous materials will be given, such as Composites, Ceramics, Concrete, and Additively manufactured parts. I will also show how X-ray refraction computed tomography (CT) can be highly complementary to classic absorption CT, being sensitive to internal interfaces. Additionally, I will show how Neutron Diffraction, which is extremely well suited to the study of internal stresses, both residual and under external load, can well be coupled to the microstructural framework gained by CT, allowing understanding the microstructure-property relationships in materials. Finally, I will show that BAM is very active in standardization and certification, including production of Reference Materials and Methods. T2 - Skoltech Determination of the microscopic residual stress CY - Moscow, Russia DA - 20.11.2019 KW - Additive Manufacturing KW - Computed Tomography KW - Neutron Diffraction KW - X-ray refraction techniques KW - Composites PY - 2019 AN - OPUS4-49929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn T1 - Heißprägen im Grünzustand und Sinterprägen - Zwei Verfahren zur Strukturierung keramischer Folien und Laminate N2 - Prägeverfahren bieten eine interessante Alternative zur Strukturierung keramischer Folien und Laminate. Im Gegensatz zur etablierten Stanz- oder Laserbearbeitung von Einzelfolien sind damit einerseits Strukturtiefen realisierbar, die nicht einem Vielfachen der Einzelfoliendicke entsprechen, andererseits können Strukturierungsgrade erzielt werden, bei denen perforierte Einzelfolien nicht mehr handhabbar sind. Heißprägen grüner Folien und Laminate erfolgt bei Temperaturen um 130 °C mit Metallstempeln. Die plastische Verformung erfolgt zeitabhängig. Dabei sind die Fließeigenschaften des polymeren Binders der Grünfolie maßgeblich für die Konturtreue der Prägung. Randeinzug und Gründichtegradienten um den Eindruck können zu Defekten im Sintergefüge führen. Je nach Sinterverfahren muss die Schwindung der geprägten Struktur berücksichtigt werden, eine Kombination dieses Verfahrens mit zero-shrinkage Techniken ist aber möglich. Sinterprägen stellt eine Erweiterung der Drucksintertechnologie für glaskeramische Komposite dar. Dabei wird ein Pressstempel aus glasartigem Kohlenstoff während des Brandes in die erweichte Glasphase des Komposits gedrückt. Die Abformung erfolgt durch viskosen Fluss der Glasphase. Mit Kenntnis des Dichte- und Viskositätsverlaufs des Werkstoffs kann das Verfahren so gestaltet werden, dass die Pressform konturtreu abgeformt wird. Mittels Sinterprägen lassen sich auch erhabene Strukturen realisieren, wobei diese häufig eine erhöhte Porosität aufweisen. T2 - Herbstsymposium 2016 | Keramische Mehrlagentechnik - Herstellverfahren und Anwendungen CY - Erlangen, Germany DA - 30.11.2016 KW - Folientechnik KW - Keramische Substrate KW - Low temperature co-fired ceramics (LTCC) PY - 2016 AN - OPUS4-38582 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Xue, Boyang T1 - Ultrasound-Assisted Underwater Laser-induced Breakdown Spectroscopy with HighRepetition-Rate μJ-DPSS laser N2 - The elemental analysis of seawater is often critical to the understanding of marinechemistry, marine geochemistry, and the deep-sea ecosystems. Laser-induced breakdownspectroscopy (LIBS) with the advantage of rapid multi-elements detection, has a greatpotential for in-situ elemental analysis of seawater. In practice, it is crucial to create acompact, low cost and power saving instrument for the long-term deep-sea observation. Arecently appeared diode-pumped solid-state (DPSS) laser seems to be a promising candidateas it is both compact and robust. Additionally, its high repetition rate up to hundreds of kHzcan provide a considerable throughput for LIBS analysis. However, the DPSS lasers operateat moderate pulse energies, usually less than one mJ, which cannot sustain stablebreakdowns in bulk water. To ensure stable laser-induced plasmas underwater with such aμJ-DPSS laser, we introduced an ultrasound source to assist the breakdown process. Thephase interface and mass flow generated by the near-field ultrasound can greatly reduce thebreakdown threshold and enhance element-specific emissions. Meanwhile, the highrepetition-rate pulses can also improve the breakdown probability and generate uniqueemission lines originated from the water molecule. We further demonstrate that the highrepetition-rate DPSS laser combined with the Echelle spectrometer can provide effectivequantitative analysis for metal elements in bulk water. T2 - 10th Euro-Mediterranean Symposium on Laser-Induced Breakdown Spectroscopy CY - Brno, Czech Republic DA - 08.09.2019 KW - LIBS KW - Laser induced plasma KW - Plasma modeling KW - Plasma diagnostics KW - Underwater LIBS PY - 2019 AN - OPUS4-49769 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blume, Simon T1 - Isotopic analysis of lithium via acousto-optically gated high-repetition laser-induced breakdown spectroscopy and spatial heterodyne spectroscopy N2 - Acousto-optically gating the emission signal from a laser-induced breakdown spectroscopy (LIBS) plasma negates some of the line-broadening effects, therefore, improving the signal line shape. However, the remaining influences disallow the differentiation of the contributions of the individual lithium isotopes, even when utilizing a high-resolution spatial heterodyne spectrometer (SHS). Nevertheless, isotopic analysis of lithium with LIBS is still feasible, because lithium exhibits a strong self-absorption dip in the emission signal, which is likewise characterized by the isotopic shift and even benefits from the broad emission lines typically observed in LIBS. The isotopic ration can be resolved from the absorption dip via high-resolution SHS. T2 - SciX 2024 CY - Raleigh, NC, USA DA - 20.10.2024 KW - LIBS KW - SHS KW - Isotopic analysis KW - Lithium PY - 2024 AN - OPUS4-62012 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas T1 - 3D Analysis of transport structures in realistically compressed gas diffusion layer T2 - 6th Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 2014-12-03 PY - 2014 AN - OPUS4-32212 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas T1 - Talbot-Lau interferometry for non-destructive testing T2 - 23. Sitzung des DGZfP-Fachausschusses Zerstörunfreie Materialcharakterisierung CY - Berlin, Germany DA - 2015-11-12 PY - 2015 AN - OPUS4-34823 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn T1 - Druckunterstütztes Sintern von Low Temperature Co-Fired Ceramics: Einfluss der Brennhilfsmittel auf die Oberflächenqualität T2 - DKG-Jahrestagung 2014 CY - Clausthal-Zellerfeld, Germany DA - 2014-03-24 PY - 2014 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. AN - OPUS4-30471 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabe, Torsten T1 - Co-Sinterung von Multilayer-Werkstoffverbunden - Möglichkeiten und Grenzen T2 - DKG-Jahrestagung 2014 CY - Clausthal-Zellerfeld, Germany DA - 2014-03-24 PY - 2014 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. AN - OPUS4-30441 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Evaluating Porosity and Properties in Diesel Particulate Filter Ceramics: a Problem to solve with Neutrons and Synchrotron Radiation T2 - Industrie Workshop HZB CY - Berlin, Germany DA - 2013-12-03 PY - 2013 AN - OPUS4-31320 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas T1 - X-ray dark field imaging T2 - 11th European Conference on Non-Destructive Testing CY - Prag, CZ DA - 2014-10-06 PY - 2014 AN - OPUS4-31918 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabe, Torsten T1 - Prozessbegleitende Prüfung beim Sintern keramischer Schichtverbunde N2 - Die zuverlässige Herstellung von Bauteilen aus Hochleistungskeramik erfordert den Einsatz von prozessbegleitenden Prüfverfahren in allen Fertigungsstufen. Prozessbegleitende Prüfung umfasst sowohl die Bewertung von Ausgangs- und Zwischenprodukten (Pulver, Suspensionen, Grünkörper) als auch die in-situ Überwachung kritischer Fertigungsstufen (Aufbereitung, Formgebung, Entbinderung, Sinterung). Der Arbeitskreis „Prozessbegleitende Prüfverfahren“ im DKG/DGM-Gemeinschaftsausschuss „Hochleistungskeramik“ bietet eine Plattform zum Informationsaustausch über neue Messverfahren und zur Initiierung von Ringversuchen und Referenzmaterialentwicklung. Als aktuelle Beispiele werden zwei applikationsnahe Verfahren zur in-situ Charakterisierung von Geometrieveränderungen (Schwindung, Verformung) an großformatigen keramischen Schichtverbunden vorgestellt. Die Hochtemperatur-3D-Laserprofilometrie ermöglicht die Visualisierung und Quantifizierung der lokalen Verformung keramischer Multilayer während der drucklosen Sinterung. Beobachtet wurden an LTCC-Multilayern starke Verformungen bereits während der Entbinderung und in der Abkühlphase. Das Wissen um zwischenzeitliche Verformungen erweitert das Verständnis über die Ursachen von Defekten in Multilayer-Bauteilen. Die in-situ Messung der Dickenschwindung an realen, großformatigen LTCC-Bauteilen während der druckunterstützten Sinterung wurde erstmals durch die Entwicklung eines LTCC-kompatiblen Drucksinteraggregat mit integriertem Dilatometer ermöglicht. Zusätzlich wurde das Drucksinteraggregat mit einer prozessbegleitende Mess- und Regelungseinrichtung für den Sauerstoffpartialdruck ausgestattet. Durch ein optimiertes Sauerstoffpartialdruckregime konnte an LTCC-Modulen eine qualitätsgefährdende Silberdiffusion aus den Leiterbahnen in das umgebende keramische Dielektrikum drastisch reduziert werden. Das mit einem industriellen Partner entwickelte Drucksinteraggregat eröffnet unikale Möglichkeiten zur Optimierung von Aufheizgeschwindigkeit, Druck und Sinteratmosphäre in allen Phasen des Sinterprozesses. T2 - Werkstoffwoche CY - Dresden, Germany DA - 27.09.2017 KW - In situ Prüfung KW - Keramische Multilayer KW - Laserprofilometrie KW - Drucksintern PY - 2017 AN - OPUS4-42297 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Palásti, Dávid jenö T1 - The effects of the laser pulse profile on the plasma emission properties N2 - Intense laser pulses create plasmas upon radiation on targets, and the properties of such plasmas are generally determined by both the properties of the target and the laser pulse. In terms of laser intensity, the irradiance and even more importantly the fluence are the critical parameters [1]. Since most lasers emit pulses of a constant pulse duration dictated by the design of the resonator and Q-switch, these two parameters are usually used interchangeably in studies. However, with the emergence of fiber laser based light sources [2], which are capable not just to freely tune the pulse duration, but to generate variable and high pulse repetition rates, up to the MHz range, a new and interesting optimization aspect is given to the laser spectroscopy community. In our study a low alloy steel standard sample (BAS 403/1) was investigated using a variable pulse duration and pulse repetition rate MOPA laser with 80W power of  = 1064 nm emission (JPT M7, VONJAN Technology GmbH, Wessling, Germany). In our experiments the laser was set to pulses with low individual energy (0.4 mJ) at 200 kHz pulse repetition rate, while the pulse duration was varied between 50 and 500 ns. The plasma emission was recorded by an LTB Demon spectrometer in several spectral regions, which included iron, chromium and manganese lines. Utilizing the variable pulse duration of this laser source, it was possible to assess the effects of changing the fluence, while the irradiance was kept at the same value. Among the investigated parameters are the emission intensity, peak width and self-absorption characteristics of major and minor components, as well as the plasma temperature. While the effects for the peak intensity are quite well correlated with the fluence, its interplay with other peak parameters appear to be more complicated. T2 - AMACEE 2025 CY - Brno, Czech Republic DA - 26.08.2025 KW - LIBS KW - Fiberlaser KW - Plasma properties PY - 2025 AN - OPUS4-64218 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Riesemeier, Heinrich T1 - Combined synchrotron X-ray and neutron imaging for the characterization of fuel cells T2 - Third Joint BER II and BESSY II Users´ Meeting CY - Berlin, Germany DA - 2011-11-30 PY - 2011 AN - OPUS4-25125 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tötzke, C. T1 - Synchrotron tomographic study on the inhomogeneous compression of gas diffusion layers in fuel cells T2 - 10th Symposium on Fuel Cell and Battery Modelling and Experimental Validation - ModVal 10 CY - Bad Boll, Germany DA - 2013-03-19 PY - 2013 AN - OPUS4-28078 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tötzke, Chr. T1 - 3D Analysis of transport structures in realistically compressed gas diffusion layers T2 - HZB User Meeting 2013 CY - Berlin, Germany DA - 2013-12-04 PY - 2013 AN - OPUS4-17666 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn T1 - Druckgesinterte LTCC-Substrate für die Dünnfilmbeschichtung T2 - DKG-Jahrestagung 2011 CY - Saarbrücken, Germany DA - 2011-03-28 PY - 2011 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. AN - OPUS4-23490 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas T1 - Direct X-Ray Refraction of Microstructures T2 - HZB User Meeting CY - Berlin, Germany DA - 2013-12-04 PY - 2013 AN - OPUS4-26611 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Bewertung von Porositätsparametern in Cordierit-Diesel-Partikelfilter-Materialien mit fortgeschrittenen Röntgenverfahren und statistischer Analyse T2 - DGZfP-Jahrestagung 2014 CY - Potsdam, Germany DA - 2014-05-26 PY - 2014 AN - OPUS4-30843 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Evaluating Porosity in Cordierite Diesel Particulate Filter Materials: Advanced X-ray and new Statistical Analysis Methods T2 - 11th European Conference on Non-Destructive Testing CY - Prag, CZ DA - 2014-10-06 PY - 2014 AN - OPUS4-31916 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -