TY - CONF A1 - Laquai, René A1 - Schaupp, Thomas A1 - Müller, Bernd R. A1 - Griesche, Axel A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Kannengießer, Thomas A1 - Bruno, Giovanni T1 - 3D Crack analysis in hydrogen charged lean duplex stainless steel with synchrotron refraction CT N2 - Hydrogen in metals can cause a degradation of the mechanical properties, the so-called hydrogen embrittlement. In combination with internal stresses, hydrogen assisted cracking (HAC) can occur. This phenomenon is not completely understood yet. To better characterise the cracking behaviour, it is important to gain information about the evolution of the 3D crack network. For this purpose samples of lean duplex stainless steel were loaded with hydrogen by means of electrochemical charging and investigated by means of synchrotron refraction CT and SEM fractography after uniaxial tensile loading. Synchrotron refraction CT is an analyser-based imaging (ABI) technique. It uses a Si (111) single crystal as analyser, which is placed into the beam path between sample and detector. According to Bragg’s law only incident x-rays within a narrow range around the Bragg-angle are diffracted from the analyser into the detector. Hence, the analyser acts as an angular filter for the transmitted beam. This filtering allows to turn the refraction and scattering of x-rays into image contrast. Refraction occurs at all interfaces, where the density of the material changes and is more sensitive to density changes than the attenuation. Therefore, it is possible to detect smaller cracks than with classical x-ray imaging techniques, like CT, with comparable spacial resolution. It also visualises the 3D structure of the cracks and gains quantitative information about their morphology and distribution. Since cracks introduced by HAC are usually very small and have a small opening displacement, synchrotron refraction CT is expected to be well suited for imaging this cracking mechanism and can be a valuable tool to characterise the formation and the evolution of a 3D crack network. T2 - WCNDT 2016 CY - München, Germany DA - 13.06.2016 KW - X-ray refraction KW - Computed tomography KW - Hydrogen assisted cracking KW - Duplex stainless steel PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366481 SN - 978-3-940283-78-8 VL - BB 158 SP - Tu.4.B.3, 1 EP - 9 AN - OPUS4-36648 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tzschichholz, Grit A1 - Steinborn, Gabriele A1 - Hentschel, Manfred P. A1 - Lange, Axel A1 - Klobes, Peter T1 - Characterisation of porous titania yttrium oxide compounds by mercury intrusion porosimetry and X-ray refractometry N2 - Aiming at ceramic materials of low thermal radiation emittance titania yttrium oxide ceramics have been prepared by sintering in air at 1,100 and 1,400 °C, respectively, and characterised. Due to its high infrared refractive index, average pore sizes up to 1 µm for optimal Mie scattering cross sections and over 35% porosity the material is a promising candidate for elevated temperature insulations. The essentially in large pore growth is achieved by graphitic nano and micro particle additives. The microstructure parameters of porosity, specific surface area, median and average pore sizes are determined by mercury intrusion porosimetry. Beyond this classical technique supplementary measurements by X-ray Absorption and X-ray refractometry reveal considerably larger average pore sizes due to closed pores not accessible for mercury. An additional advantage of the X-ray techniques is their non-destructive application, which allows other treatments afterwards. The combined application of both methods provides additional information and reliability in case of complex ceramic microstructures and may serve for improved developments of porous ceramics with optimised thermal scattering for energy savings in high temperature applications. KW - Porous ceramics KW - Mercury intrusion porosimetry KW - X-ray refractometry KW - Porosity KW - Specific surface area KW - Average pore size PY - 2011 DO - https://doi.org/10.1007/s10934-010-9358-4 SN - 1380-2224 SN - 1573-4854 VL - 18 IS - 1 SP - 83 EP - 88 PB - Kluwer CY - Dordrecht AN - OPUS4-22977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lange, Axel A1 - Hentschel, Manfred P. A1 - Schors, Jörg ED - Gerhard Busse, ED - Danny Van Hemelrijck, ED - Igor Solodov, ED - Anastasopoulos, Athanasios T1 - Direct iterative reconstruction of computed tomography trajectories (DIRECTT) T2 - 4th International Conference of Emerging Technologies in Non-Destructive Testing (ETNDT 4) CY - Stuttgart, Germany DA - 2007-04-02 KW - Computed tomography KW - Reconstruction algorithm PY - 2007 SN - 978-0-415-46476-5 SP - 229 EP - 236 PB - Taylor & Francis CY - London, UK AN - OPUS4-17560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Lange, Axel A1 - Harwardt, Michael A1 - Hentschel, Manfred P. T1 - Zerstörungsfreie Charakterisierung der oxidativen Schädigung faserverstärkter 2D-C/C-Keramiken mit Hilfe der Röntgen-Refraktions-Topographie N2 - Kohlenstofffaser verstärkte Kohlenstoffe werden während ihres Ge-brauches an Luft zwischen 600°C und 1000°C korrodiert. Um zu überprüfen, ob die Röntgerefraktionsmethode als zerstörungsfreies Prüfverfahren die bei der Oxidation auftretenden morphologischen Änderungen im Probekörper signifikant nachweisen können, wurden bei 630°C oxidativ geschädigte gasphaseninfiltrierte C/C Kerami-ken untersucht. Anhand eines Kugelmodells werden die aus dem Experiment ableit-baren Größen der spezifischen Oberfläche und Porosität erläutert. Die experimen-tellen Ergebnisse konntne nachweisen, dass infiltrierten C/C Keramiken während einer oxidativen Belastung aufgrund des lokal unterschiedlichen Oxidationsverhal-tens eine ausgeprägte Kern Schale Struktur ausbilden. T2 - DGZfP-Jahrestagung 2007 CY - Fürth, Deutschland DA - 2007-05-14 KW - C/C Keramiken KW - Oxidative Schädigung KW - Röntgen-Refraktion PY - 2007 SN - 978-3-931381-98-1 SP - 1 EP - 10 (Poster 30) PB - DGZfP CY - Berlin AN - OPUS4-18347 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hentschel, Manfred P. A1 - Lange, Axel A1 - Harbich, Karl-Wolfram T1 - X-Ray Diffraction Scanning Microscopy - A new method of nondestructive Characterization of inhomogeneous materials T2 - ESA Symposium on Space Applications of Advanced Structural Materials (ESTEC) CY - Noordwijk, Netherlands DA - 1990-03-21 PY - 1990 IS - MBB-Z--0301-90-PUB SP - 447 EP - 450 PB - Zentrale Berichtsstelle, Technisch-wissenschaftliche Information, Messerschmitt-Bölkow-Blohm GmbH CY - München AN - OPUS4-3269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hentschel, Manfred P. A1 - Harbich, Karl-Wolfram A1 - Lange, Axel ED - Burke, W. T1 - New X-ray scanning topographic approaches to nondestructive evaluation of composites T2 - International Symposium "Advanced Materials for Lightweight Structures" CY - Noordwijk, Netherlands DA - 1992-03-25 PY - 1992 SN - 92-9092-186-2 N1 - Serientitel: ESA SP – Series title: ESA SP IS - 336 SP - 229 EP - 232 PB - ESTEC, ESA Publ. Division CY - Noordwijk AN - OPUS4-3271 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Harbich, Karl-Wolfram A1 - Hentschel, Manfred P. A1 - Ekenhorst, Derk A1 - Schors, Jörg A1 - Lange, Axel T1 - X-Ray Refraction for NDT of Micro Cracks and Impacts N2 - High performance composites and other light weight materials are generally a comple problem to the performance of nondestructive testing methods. X-ray refraction provide unconventional X-ray scattering techniques to meet the actual demand for improve nondestructive characterization of these advanced materials. Scanning the samples across collimated narrow incident X-ray beam permits to image integral micro-structures (a present) with a resolution of 10 µm. Investigations of samples after strain-induced micro cracks and fibre debonding in impact damaged epoxy are shown. The physics of X-ray refraction are analogous to the well known refraction of light b optical lenses and prisms, governed by Snell's law. The special feature is the deflection a very small angles of few minutes of arc, as the refractive index of X-rays in matter i nearly one. Due to the density differences at inner surfaces most of the incident X-rays ar deflected. As the scattered intensity of refraction is proportional to the specific surface of sample, a reference standard gives a quantitative measure for analytical determinations. Figure 1 represents a two-dimensional damage distribution of an impact in a 0/90° CFR laminate of 3 mm, thickness. Unlike in ultrasonic testing, there is no shadowing effect o the successive layers. By use of X-ray refraction the exact concentration of debonde fibres is calculated for each position. Additionally the refraction allows the selection of th fibre orientation. T2 - 7th European Conference on Non-Destructive Testing (ECNDT) CY - Copenhagen, Denmark DA - 1998-05-26 PY - 1998 UR - http://www.ndt.net/abstract/ecndt98/435.htm SN - 87-986898-0-0 VL - 3 CY - Broendy, Denmark AN - OPUS4-3328 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hentschel, Manfred P. A1 - Lange, Axel A1 - Harbich, Karl-Wolfram A1 - Ekenhorst, Derk A1 - Schors, Jörg T1 - Röntgentopographische Verfahren - Zerstörungsfreie Charakterisierung moderner Werkstoffe PY - 1998 SN - 0025-5300 VL - 40 IS - 5 SP - 170 EP - 174 PB - Carl Hanser Verlag CY - München AN - OPUS4-3329 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hentschel, Manfred P. A1 - Ekenhorst, Derk A1 - Harbich, Karl-Wolfram A1 - Lange, Axel A1 - Schors, Jörg ED - Green, R. E. T1 - New X-ray refractography for non-destructive evaluation of advanced materials T2 - 8th International Symposium on Nondestructive Characterization of Materials CY - Boulder, CO, USA DA - 1997-06-15 PY - 1998 SN - 0-306-45900-0 VL - 8 SP - 409 EP - 416 PB - Plenum Press CY - New York AN - OPUS4-3330 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hentschel, Manfred P. A1 - Harbich, Karl-Wolfram A1 - Lange, Axel A1 - Schors, Jörg A1 - Ekenhorst, Derk A1 - Judd, M.D. A1 - Raynal, R. T1 - X-ray refraction characterizes leight weight materials PY - 1998 SN - 1018-8657 VL - 8 IS - 3 SP - 14 EP - 15 PB - European Space Agency CY - Noordwijk AN - OPUS4-3331 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -