TY - JOUR A1 - Arlt, T. A1 - Kardjilov, N. A1 - Kupsch, Andreas A1 - Manke, I. A1 - Salvemini, F. A1 - Grazzi, F. T1 - Neutronen-Laminografie am Beispiel eines historischen Artefakts T1 - Neutron computed laminography on an ancient metal artifact JF - Materials Testing N2 - Die Computer-gestützte Laminografie (CL) wurde als komplementäre Methode zur Computertomografie für die dreidimensionale Bildgebung von lateral ausgedehnten Objekten entwickelt. Ursprünglich für medizinische Zwecke verwendet, wurde diese Methode kürzlich als zerstörungsfreie nicht-invasive Methode nicht nur in der Materialforschung, sondern auch mit steigendem Interesse für kunsthandwerkliche und historische Objekte eingesetzt. Hier wird die Computer-gestützten Laminografie mit polychromatischer Neutronenstrahlung an einer historischen Tsuba eingesetzt, einem Stichblatt eines japanischen Schwerts. Eine Analyse der Lötstellen gibt Rückschlüsse auf das Herstellungsverfahren. Zudem wurden unterschiedliche Materialsysteme gefunden, vermutlich um dem Tsuba lokal eine höhere Stabilität zu verleihen. Die Messungen wurden an der Imaging-Beamline CONRAD-2 an der Neutronenquelle BER 2 des Helmholtz-Zentrums Berlins (HZB) durchgeführt. KW - Neutronenlaminographie KW - Computertomographie PY - 2018 DO - https://doi.org/10.3139/120.111261 SN - 0025-5300 VL - 60 IS - 12 SP - 1209 EP - 1214 PB - Carl Hanser Verlag CY - München AN - OPUS4-46936 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Al-Falahat, A.M. A1 - Kupsch, Andreas A1 - Hentschel, M.P. A1 - Lange, A. A1 - Kardjilov, N. A1 - Markötter, Henning A1 - Manke, I. T1 - Correction approach of detector backlighting in radiography JF - Review of Scientific Instruments N2 - In various kinds of radiography, deficient transmission imaging may occur due to backlighting inside the detector itself arising from light or radiation scattering. The related intensity mismatches barely disturb the high resolution contrast, but its long range nature results in reduced attenuation levels which are often disregarded. Based on X-ray observations and an empirical formalism, a procedure is developed for a first order correction of detector backlighting. A backlighting factor is modeled as a function of the relative detector coverage by the sample projection. Different cases of sample transmission are regarded at different backlight factors and detector coverage. The additional intensity of backlighting may strongly affect the values of materials’ attenuation up to a few 10%. The presented scenario provides a comfortable procedure for corrections of X-ray or neutron transmission imaging data. KW - X-ray imaging KW - Neutron imaging KW - Radiology KW - Backlighting KW - Digital detector array PY - 2019 DO - https://doi.org/10.1063/1.5097170 SN - 0034-6748 VL - 90 IS - 12 SP - 125108 PB - American Institute of Physics CY - Melville, NY, USA AN - OPUS4-50217 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ziesche, R. F. A1 - Robinson, J. B. A1 - Markötter, Henning A1 - Bradbury, R. A1 - Tengattini, A. A1 - Lenoir, N. A1 - Helfen, L. A1 - Kockelmann, W. A1 - Kardjilov, N. A1 - Manke, I. A1 - Brett, D. J. L. A1 - Shearing, P. R. T1 - Editors’ Choice—4D Neutron and X-ray Tomography Studies of High Energy Density Primary Batteries: Part II. Multi-Modal Microscopy of LiSOCl2 Cells JF - Journal of the Electrochemical Society N2 - The ability to track electrode degradation, both spatially and temporally, is fundamental to understand performance loss during operation of lithium batteries. X-ray computed tomography can be used to follow structural and morphological changes in electrodes; however, the direct detection of electrochemical processes related to metallic lithium is difficult due to the low sensitivity to the element. In this work, 4-dimensional neutron computed tomography, which shows high contrast for lithium, is used to directly quantify the lithium diffusion process in spirally wound Li/SOCl2 primary cells. The neutron dataset enables the quantification of the lithium transport from the anode and the accumulation inside the SOCl2 cathode to be locally resolved. Complementarity between the collected neutron and X-ray computed tomographies is shown and by applying both methods in concert we have observed lithium diffusion blocking by the LiCl protection layer and identified all cell components which are difficult to distinguish using one of the methods alone. KW - Lithium-ion battery KW - Room-temperature KW - Thermal runaway KW - Gas evolution KW - Cells PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520890 DO - https://doi.org/10.1149/1945-7111/abbfd9 VL - 167 SP - 140509 PB - IOP Science AN - OPUS4-52089 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ziesche, R. A1 - Robinson, J. A1 - Kok, M. A1 - Markötter, Henning A1 - Kockelmann, W. A1 - Kardjilov, N. A1 - Manke, I. A1 - Brett, D. A1 - Shearing, P. T1 - Editors’ Choice—4D Neutron and X-ray Tomography Studies of High Energy Density Primary Batteries: Part I. Dynamic Studies of LiSOCl2 during Discharge JF - Journal of the Electrochemical Society N2 - The understanding of dynamic processes in Li-metal batteries is an important consideration to enable the full capacity of cells to be utilised. These processes, however, are generally not directly observable using X-ray techniques due to the low attenuation of Li; and are challenging to visualise using neutron imaging due to the low temporal resolution of the technique. In this work, complementary X-ray and neutron imaging are combined to track the dynamics of Li within a primary Li/SOCl2 cell. The temporal challenges posed by neutron imaging are overcome using the golden ratio imaging method which enables the identification of Li diffusion in operando. This combination of techniques has enabled an improved understanding of the processes which limit rate performance in Li/SOCl2 cells and may be applied beyond this chemistry to other Li-metal cells. KW - Nneutron imaging KW - X-ray imaging KW - Tomography KW - Primary Battery PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515802 DO - https://doi.org/10.1149/1945-7111/abbbbc SN - 1945-7111 VL - 13 IS - 167 SP - 130545 PB - IOP Publishing AN - OPUS4-51580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Y. A1 - Lu, X. A1 - Cho, J.I.S. A1 - Rasha, L. A1 - Whiteley, M. A1 - Neville, T. P. A1 - Ziesche, R. A1 - Kardjilov, N. A1 - Markötter, Henning A1 - Manke, I. A1 - Zhang, X. A1 - Shearing, P. R. A1 - Brett, D. J. L. T1 - Multi-length scale characterization of compression on metal foam flow-field based fuel cells using X-ray computed tomography and neutron radiography JF - Energy Conversion and Management N2 - The mechanical compression of metal foam flow-field based polymer electrolyte fuel cells (PEFCs) is critical in determining the interfacial contact resistance with gas diffusion layers (GDLs), reactant flow and water management. The distinct scale between the pore structure of metal foams and the entire flow-field warrant a multilength scale characterization that combines ex-situ tests of compressed metal foam samples and in-operando analysis of operating PEFCs using X-ray computed tomography (CT) and neutron radiography. An optimal ‘medium’ compression was found to deliver a peak power density of 853 mW/cm². The X-ray CT data indicates that the compression process significantly decreases the mean pore size and narrows the pore size distribution of metal foams. Simulation results suggest compressing metal foam increases the pressure drop and gas velocity, improving the convective liquid water removal. This is in agreement with the neutron imaging results that demonstrates an increase in the mass of accumulated liquid water with minimum compression compared to the medium and maximum compression cases. The results show that a balance between Ohmic resistance, water removal capacity and parasitic power is imperative for the optimal performance of metal foam based PEFCs. KW - Fuel cell KW - Compression effect KW - Metal foam microstructure KW - Neutron radiography KW - X-ray CT PY - 2021 DO - https://doi.org/10.1016/j.enconman.2020.113785 VL - 239 SP - 10 EP - 113785 PB - Elsevier Ltd. AN - OPUS4-53842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hilger, A. A1 - Kardjilov, N. A1 - Lange, A. A1 - Kupsch, Andreas A1 - Hentschel, M. P. A1 - Manke, I. T1 - Neutron darkfield imaging of fiber composites JF - Materials Testing N2 - While X-ray based darkfield imaging with grating interferometers is already widely used, darkfield imaging with neutrons has still a relatively small user community focused mostly on magnetic materials. Here, we demonstrate the application of neutron darkfield imaging byTalbot-Lau type grating interferometry to fiber reinforced plastics. Common carbon and glass fiber composites have been investigated including characteristic damage structures. The darkfield images show a strong signal response caused by fiber delamination, suitable fiber direction, particles, pores and cracks. The basic principles of neutron darkfield imaging applied to fiber composites are highlighted. KW - Neutron radiography KW - Darkfield imaging KW - Talbot-Lau interferometer KW - Fiber composites KW - Non-destructive testing PY - 2021 DO - https://doi.org/10.1515/mt-2020-0103 SN - 2195-8572 SN - 0025-5300 VL - 63 IS - 7 SP - 623 EP - 629 PB - De Gruyter CY - Berlin AN - OPUS4-53077 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peruzzi, N. A1 - Galli, S. A1 - Helmholz, H. A1 - Kardjilov, N. A1 - Krüger, D. A1 - Markötter, Henning A1 - Moosmann, J. A1 - Orlov, D. A1 - Prgomet, Z. A1 - Willumeit-Römer, R. A1 - Wennerberg, A. A1 - Bech, M. T1 - Multimodal ex vivo methods reveal that Gd-rich corrosion byproducts remain at the implant site of biodegradable Mg-Gd screws JF - Acta Biomaterialia N2 - Extensive research is being conducted on magnesium (Mg) alloys for bone implant manufacturing, due to their biocompatibility, biodegradability and mechanical properties. Gadolinium (Gd) is among the most promising alloying elements for property control in Mg alloy implants; however, its toxicity is contro- versial. Investigating Gd behavior during implant corrosion is thus of utmost importance. In this study, we analyzed the degradation byproducts at the implant site of biodegradable Mg-5Gd and Mg-10Gd implants after 12 weeks healing time, using a combination of different imaging techniques: histology, energy-dispersive x-ray spectroscopy (EDX), x-ray microcomputed tomography (μCT) and neutron μCT. The main finding has been that, at the healing time in exam, the corrosion appears to have involved only the Mg component, which has been substituted by calcium and phosphorus, while the Gd remains localized at the implant site. This was observed in 2D by means of EDX maps and extended to 3D with a novel application of neutron tomography. X-ray fluorescence analysis of the main excretory organs also did not reveal any measurable accumulation of Gd, further reinforcing the conclusion that very limited or no removal at all of Gd-alloy happened during degradation. KW - Magnesium-gadolinium alloy KW - Biodegradable implant KW - Multimodal analysis KW - Energy-dispersive x-ray spectroscopy KW - Micro-computed tomography PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-535910 DO - https://doi.org/10.1016/j.actbio.2021.09.047 SN - 1742-7061 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-53591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kardjilov, N A1 - Manke, I A1 - Hilger, A A1 - Arlt, T A1 - Bradbury, R A1 - Markötter, Henning A1 - Woracek, R A1 - Strobel, M A1 - Treimer, W A1 - Banhart, J T1 - The Neutron Imaging Instrument CONRAD — Post‐Operational Review JF - Journal of imaging N2 - The neutron imaging instrument CONRAD was operated as a part of the user program of the research reactor BER‐II at Helmholtz‐Zentrum Berlin (HZB) from 2005 to 2020. The Instrument was designed to use the neutron flux from the cold source of the reactor, transported by a curved neutron guide. The pure cold neutron spectrum provided a great advantage in the use of different neutron optical components such as focusing lenses and guides, solid‐state polarizers, Monochromators and phase gratings. The flexible setup of the instrument allowed for implementation of new methods including wavelength‐selective, dark‐field, phase‐contrast and imaging with polarized neutrons. In summary, these developments helped to attract a large number of scientists and industrial customers, who were introduced to neutron imaging and subsequently contributed to the Expansion of the neutron imaging community. KW - Neutron imaging KW - Neutron scattering KW - Neutron instrument KW - Tomography PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-534190 DO - https://doi.org/10.3390/ jimaging7010011 VL - 7 IS - 11 SP - 7010011 PB - MDPI AN - OPUS4-53419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tran, K. V. A1 - Woracek, R. A1 - Kardjilov, N. A1 - Markötter, Henning A1 - Hilger, A. A1 - Kockelmann, W. A1 - Kelleher, J. A1 - Puplampu, S. B. A1 - Penumadu, D. A1 - Tremsin, A. S. A1 - Banhart, J. A1 - Manke, I. T1 - Spectral neutron tomography JF - Materials Today Advances N2 - Combined three-dimensional (3D) mapping of (micro-)structures with elemental and crystalline phase variations is of significant importance for the characterization of materials. Neutron wavelength selective imaging is a spectral imaging technique that exploits unique contrast differences e.g. for mapping dissimilar elemental, isotope, or phase compositions, and has the particular advantage of being applicable to sample volumes on the meso- and macroscale. While being mostly applied as radiography (2D) so far, we herein report that the extension to tomography allows for the display of the full spectral information for every voxel and in 3D. The development is supported by example data from a continuous as well as a pulsed neutron source. As a practical example, we collected 4D data sets (3D + spectral) of plastically deformed metastable stainless steel and herein demonstrate an improved quantification strategy for crystalline phase fractions. These exemplary results illustrate that localized phase transformations can be quantified even in complex geometries within centimeter-sized samples, and we will discuss the limits and future prospects of the technique that is not limited to crystalline materials. KW - 4D tomographic data KW - Multi-energy CT KW - Spectral CT KW - Phase distribution KW - Full-field phase tomography PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-521668 DO - https://doi.org/10.1016/j.mtadv.2021.100132 VL - 9 SP - 132 PB - Elsevier Ltd. AN - OPUS4-52166 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohseninia, A A1 - Eppler, M A1 - Kartouzian, D A1 - Markötter, Henning A1 - Kardjilov, N A1 - Wilhelm, F A1 - Scholta, J A1 - Manke, I T1 - PTFE Content in Catalyst Layers and Microporous Layers: Effect on Performance and Water Distribution in Polymer Electrolyte Membrane Fuel Cells JF - Journal of the Electrochemical Society N2 - This work describes the effects of catalyst layers (CLs) consisting of hydrophobic PTFE on the performance and water management of PEM fuel cells. Catalyst inks with various PTFE contents were coated on Nafion membranes and characterized using contact angle measurements, SEX-EDX, and mercury porosimetry. Fuel cell tests and electrochemical impedance spectroscopy (EIS) were conducted under varying operating conditions for the prepared materials. At dry conditions, CLs with 5 wt.% PTFE were advantageous for cell performance due to improved membrane hydration, whereas under humid conditions and high air flow rates CLs with 10 wt.% PTFE improved the performance in high current density region. Higher PTFE contents (⩾20 wt.%) increased the mass transport resistance due to reduced porosity of the CLs structure. Operando neutron radiography was utilized to study the effects of hydrophobicity gradients within CLs and cathode microporous layer (MPLC) on liquid water distribution. More hydrophobic CLs increased the water content in adjacent layers and improved performance, especially at dry conditions. MPLC with higher PTFE contents increased the overall liquid water within the CLs and GDLs and escalated the water transfer to the anode side. Furthermore, the role of back-diffusion transport mechanism on water distribution was identified for the investigated cells. KW - Neutron imaging KW - Polymer Electrolyte Membrane Fuel Cell KW - Catalyst Layer KW - Microporous Layer KW - Water Distribution PY - 2021 DO - https://doi.org/10.1149/1945-7111/abec53 VL - 168 IS - 3 SP - 034509 PB - IOP Science AN - OPUS4-52402 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -