TY - JOUR A1 - Griesche, Axel A1 - Dabah, Eitan A1 - Kardjilov, N. A1 - Hilger, A. A1 - Manke, I. A1 - Kannengießer, Thomas T1 - Imaging of hydrogen in steels using neutrons N2 - We investigated the hydrogen distribution spatially and temporally in technical iron at room temperature. Samples were charged electrochemically and subsequently analysed by means of neutron radiography and tomography. The radiographic images allowed for a time-resolved analysis of hydrogen fluxes. The three-dimensional distribution of hydrogen measured by neutron tomography delivered valuable information for the damage analysis of hydrogen-induced cracks. For the first time hydrogen concentration gradients inside the material could be detect directly together with the cracks. The neutron radiography and tomography results were gained at the Research Reactor BER II of the HZB in Berlin. KW - Hydrogen embrittlement KW - Hydrogen diffusion KW - Neutron tomography KW - Blister PY - 2014 DO - https://doi.org/10.3139/146.111043 SN - 1862-5282 VL - 105 IS - 7 SP - 640 EP - 644 PB - Carl Hanser CY - München AN - OPUS4-31084 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dabah, Eitan A1 - Pfretzschner, Beate A1 - Schaupp, Thomas A1 - Kardjilov, N. A1 - Manke, I. A1 - Boin, M. A1 - Woracek, R. A1 - Griesche, Axel T1 - Time-resolved Bragg-edge neutron radiography for observing martensitic phase transformation from austenitized super martensitic steel N2 - Neutron Bragg-edge imaging was applied for the visualization of a γ-Austenite to α'-martensite phase transformation. In the present study, a super martensitic stainless steel sample was heated until complete austenitization and was subsequently cooled down to room temperature. The martensitic phase Transformation started at Ms = 190 °C. Using a monochromatic neutron beam with λ = 0.390 nm, the transmitted intensity was significantly reduced during cooling below Ms, since the emerging martensitic phase has a higher attenuation coefficient than the austenitic phase at this wavelength. The phase Transformation process was visualized by filming the transmission images from a scintillator screen with a CCD camera with a temporal resolution of 30 s and a spatial resolution of 100 µm. KW - Neutron imaging KW - Bragg-edge imaging KW - Phase transformation PY - 2017 DO - https://doi.org/10.1007/s10853-016-0642-9 SN - 0022-2461 SN - 1573-4803 VL - 52 IS - 6 SP - 3490 EP - 3496 AN - OPUS4-38574 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Arlt, Tobias A1 - Klages, M. A1 - Messerschmidt, M. A1 - Riesemeier, Heinrich A1 - Scholta, J. A1 - Banhart, J. A1 - Manke, I. T1 - Influence of artificial aging of gas diffusion layers on the water management of PEM fuel cells N2 - The influence of artificial aging of gas diffusion layers (GDL) on the water management within the GDL was investigated in-operando by synchrotron X-ray radiography. One GDL was subjected to an accelerated aging procedure in 30% H2O2 solution, while another GDL was pristine. Radiographic measurements were combined with temporally resolved electrical analyzes. Significant differences in cell voltage and water accumulation were observed during cell operation at steady-state conditions. The cell which contained the aged GDL featured a higher water amount especially at the anode side and a lower cell voltage. KW - Degradation KW - Liquid water PY - 2014 DO - https://doi.org/10.1149/2.004402eel SN - 2162-8726 VL - 3 IS - 2 SP - F7 EP - F9 PB - ECS CY - Pennington, NJ, USA AN - OPUS4-32410 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kardjilov, N. A1 - Hilger, A. A1 - Manke, I. A1 - Banhart, J. A1 - Griesche, Axel T1 - Imaging with Cold Neutrons at the CONRAD-2 Facility N2 - CONRAD-2 is an imaging instrument using low-energy (cold) neutrons. The instrument is installed at the end of a curved neutron guide which avoids the direct line of sight towards the reactor core. This ensures a very low background of high-energy neutrons and. photons at the sample position. The cold neutron beam provides a wavelength range which is suitable for phase-and diffraction-contrast imaging such as grating interferometry and Bragg edge mapping. The instrument is well suited for high resolution imaging due to the high efficiency of the very thin scintillators that can be used for the detection of cold neutrons. An instrument upgrade was performed recently as a part of an upgrade program for the cold neutron instrumentation at HZB. The parameters of the instrument as well as some research highlights will be presented. T2 - 10th World Conference on Neutron Radiography (WCNR) CY - Grindelwald, SWITZERLAND DA - 05.10.2014 KW - iron embrittlement KW - neutron imaging KW - neutron instrumentation KW - cold neutrons PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-373239 DO - https://doi.org/10.1016/j.phpro.2015.07.008 SN - 1875-3892 VL - 69 SP - 60 EP - 66 PB - Elsevier B.V. CY - Amsterdam, NL AN - OPUS4-37323 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zabler, S. A1 - Rack, A. A1 - Manke, I. A1 - Thermann, K. A1 - Tiedemann, J. A1 - Harthill, N. A1 - Riesemeier, Heinrich T1 - High-resolution tomography of cracks, voids and micro-structure in greywacke and limestone N2 - Rocks are commonly very heterogeneous materials. Randomly distributed micro-flaws inside the rock are believed to initiate tensile cracks from which shear fractures develop and coalescence through en echelon interactions leads to fracture. In this paper, we describe the results of applying high-resolution X-ray tomography to samples of greywacke and limestone experimentally deformed under unconfined axial shortening at various loads equivalent to different fractions of the sample strength. Mineral grains, pores, micro-cracks and other voids were imaged with a resolution of 10 µm. 3D image analysis enabled us to monitor the initial state of the samples and the changes in them due to compression. Crack morphology is characterized and compared to the micro-structure of the sample before and after deformation. In the greywacke, formation of a macro-crack ~10° oblique to the stress direction is observed. It initiated in fine intergranular material at the top tip of the sample and is composed of tensile fractures connected by wing cracks. None of the voids defined in the initial state fractured, and the crack is interpreted to have started either as a micro-crack which was smaller than the resolution of the tomography, or, as a completely new crack. In the limestone, cracks are observed to initiate in features that are too small to be imaged by the tomography, or also in newly created cracks. KW - Rock porosity KW - Crack formation KW - X-ray imaging KW - Micro-tomography KW - 3D image analysis PY - 2008 DO - https://doi.org/10.1016/j.jsg.2008.03.002 SN - 0191-8141 SN - 1873-1201 VL - 30 IS - 7 SP - 876 EP - 887 PB - Pergamon Press CY - Oxford AN - OPUS4-18566 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Arlt, Tobias A1 - Manke, I. A1 - Wippermann, K. A1 - Schröder, A. A1 - Mergel, J. A1 - Riesemeier, Heinrich A1 - Banhart, J. T1 - Röntgen-Kanten-Tomografie und -Radiografie zur Untersuchung von Alterungseffekten in Brennstoffzellenmaterialien KW - Resolution neutron-radiography KW - Local current distribution KW - Water transport KW - Carbon-dioxide KW - Methanol KW - Platinum KW - Oxidation PY - 2010 SN - 0025-5300 VL - 52 IS - 10 SP - 692 EP - 697 PB - Hanser CY - München AN - OPUS4-23045 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manke, I. A1 - Hartnig, C. A1 - Kardjilov, N. A1 - Riesemeier, Heinrich A1 - Goebbels, Jürgen A1 - Kuhn, R. A1 - Krüger, P. A1 - Banhart, J. T1 - In situ synchrotron X-ray radiography investigations of water transport in PEM fuel cells N2 - Water transport in an operating PEM fuel cell was investigated with synchrotron X-ray radiography with a spatial resolution of 3 µm and a temporal resolution of 5 s. This method allows for the detection of water accumulations with less than 10 µm diameter. We demonstrate that synchrotron X-ray imaging can dramatically expand the possibilities of imaging with high spatial and time resolution, especially as a complement to neutron radiography. Water transport processes from the first appearance of small water accumulations in the gas diffusion layer to their transport into the channel system were analysed in situ. Correlations between local effects such as water formation and operating conditions of the whole system, e.g. power variations, were found. A recently described eruptive water transport mechanism is analysed in detail. KW - Fuel cell KW - Gas diffusion layer KW - Imaging KW - Synchrotron KW - X-ray radiography KW - Two-phase flow KW - Water transport PY - 2010 DO - https://doi.org/10.1002/fuce.200800123 SN - 1615-6846 SN - 1615-6854 VL - 10 IS - 1 SP - 26 EP - 34 PB - Wiley-VCH CY - Weinheim AN - OPUS4-22730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zabler, S. A1 - Rueda, A. A1 - Rack, A. A1 - Riesemeier, Heinrich A1 - Zaslansky, P. A1 - Manke, I. A1 - Garcia-Moreno, F. A1 - Banhart, J. T1 - Coarsening of grain-refined semi-solid Al-Ge32 alloy: X-ray microtomography and in situ radiography KW - Microtomography KW - Radiography KW - 2D/3D imageanalysis KW - Technical binary alloys KW - LSW PY - 2007 DO - https://doi.org/10.1016/j.actamat.2007.05.028 SN - 1359-6454 SN - 1873-2453 VL - 55 IS - 15 SP - 5045 EP - 5055 PB - Elsevier Science CY - Kidlington AN - OPUS4-20583 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hartnig, C. A1 - Manke, I. A1 - Schloesser, J. A1 - Krüger, P. A1 - Kuhn, R. A1 - Riesemeier, Heinrich A1 - Wippermann, K. A1 - Banhart, J. T1 - High resolution synchrotron X-ray investigation of carbon dioxide evolution in operating direct methanol fuel cells N2 - The carbon dioxide evolution and bubble formation in an operating fuel has been studied by means of synchrotron X-ray radiography. Two different observation directions have been chosen: a through-plane insight has been employed to track the formation of bubbles starting at the corner of the lands of the flow field; a depth profile of the carbon dioxide evolution has been derived from cross sectional studies describing an affected area of up to 100 µm. The dynamics of the bubble formation and detachment of the bubbles from the position of formation is strongly correlated with the current density. Cracks and breaks in the catalyst layer which result from the preparation process are visible under operating conditions and a possible swelling of the catalyst layer does not reach a complete vanishing of the cracks. KW - DMFC KW - Carbon dioxide evolution KW - Synchrotron radiography KW - In situ study KW - Cross section KW - Through-plane PY - 2009 DO - https://doi.org/10.1016/j.elecom.2009.05.047 SN - 1388-2481 VL - 11 IS - 8 SP - 1559 EP - 1562 PB - Elsevier CY - Amsterdam AN - OPUS4-20577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Treimer, W. A1 - Feye–Treimer, U. A1 - Radke, C. A1 - Hilger, A. A1 - Neumann, O. A1 - Manke, I. A1 - Haibel, A. A1 - Rack, A. A1 - Riesemeier, Heinrich T1 - Investigations of mamma biopsies by means of µ-tomography PY - 2005 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2004.pdf#page=452 SN - 0179-4159 SP - 452 EP - 453 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-7383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -