TY - GEN A1 - Rack, A. A1 - Zabler, S. A1 - Riesemeier, Heinrich A1 - Weidemann, Gerd A1 - Müller, Bernd R. A1 - Helfen, L. A1 - Stiller, M. A1 - Knabe, C. A1 - Goebbels, Jürgen A1 - Banhart, J. T1 - Nondestructive 3D insights into foamy metals and bioregenerative ceramics KW - X-ray Computed Tomography KW - Metal foams KW - Bioregenerative ceramics PY - 2008 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/infos/bessy/highlights2007.pdf#page=34 SN - 1611-6127 SP - 34 EP - 35 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-17538 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rack, A. A1 - Riesemeier, Heinrich A1 - Zabler, S. A1 - Weitkamp, T. A1 - Müller, Bernd R. A1 - Weidemann, Gerd A1 - Modregger, P. A1 - Banhart, J. A1 - Helfen, L. A1 - Danilewsky, A.N. A1 - Gräber, H.G. A1 - Heldele, R. A1 - Mayzel, B. A1 - Goebbels, Jürgen A1 - Baumbach, T. ED - Stuart R. Stock, T1 - The high-resolution synchrotron-based imaging stations at the BAMline (BESSY) and TopoTomo (ANKA) N2 - The BAMline at the BESSY light source in Berlin and the TopoTomo beamline at the ANKA synchrotron facility in Karlsruhe (both Germany) operate in the hard X-ray regime (above 6 keV) with similiar photon flux density. For typical imaging applications, a double multilayer monochromator or a filtered white beam is used. In order to optimise the field of view and the resolution of the available indirect pixel detectors, different optical systems have been installed, adapted, respectively, to a large field of view (macroscope) and to high spatial resolution (microscope). They can be combined with different camera systems, ranging from 16-bit dynamic range slow-scan CCDs to fast CMOS cameras. The spatial resolution can be brought substantially beyond the micrometer limit by using a Bragg magnifier. The moderate flux of both beamlines compared to other 3rd generation light sources is compensated by a dedicated scintillator concept. For selected applications, X-ray beam collimation has proven to be a reliable approach to increase the available photon flux density. Absorption contrast, phase contrast, holotomography and refraction-enhanced imaging are used depending on the application. Additionally, at the TopoTomo beamline digital white beam synchrotron topography is performed, using the digital X-ray pixel detectors installed. KW - Microtomography KW - Non-destructive evaluation KW - Coherent imaging KW - X-ray refraction KW - X-ray phase contrast KW - Synchrotron-CT KW - Synchrotron instrumentation KW - Scintillator KW - Bragg magnification KW - Holotomography KW - X-ray topography PY - 2008 DO - https://doi.org/10.1117/12.793721 SN - 0277-786X VL - 7078 SP - 70780X-1 - 70780X-9 AN - OPUS4-18296 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, Y. A1 - Ulbricht, Alexander A1 - Schmidt, F. A1 - Müller, Bernd R. A1 - Kupsch, Andreas A1 - Schwitalla, A.D. T1 - Micro-CT analysis and mechanical properties of low dimensional CFR-PEEK specimens additively manufactured by material extrusion N2 - Material extrusion of thermoplastic polymers enables the realization of complex specific designs with high performance composites. The present study aims at evaluating the mechanical properties of carbon fiberreinforced semi-crystalline thermoplastic polymer polyether ether ketone (CFR-PEEK) manufactured by material extrusion and correlating them with results obtained by micro-CT. Samples in the shape of small bars were provided by Kumovis (Munich, Germany). The determination of surface roughness and density was followed by three-point bending tests. To reveal the pore distribution as well as the fusion quality of CFR PEEK when applied with external forces, micro-CT scans were performed with an X-ray microscope before and after the mechanical test to localize the sites where the fracture is generated. The density of CFR-PEEK bars indicated that they had superior mechanical properties compared with our previous study on unfilled 3D printed PEEK (bending modulus: (5.4 ± 0.5) GPa vs. (1.05 ± 0.05) GPa to (1.48 ± 0.10) GPa; bending strength: (167 ± 11) MPa vs. (51 ± 15) to (193 ± 7) MPa). Micro-CT analyses revealed the local 3D-distribution of voids. Voids of 30 μm diameter are nearly spherical and make up the main part of the total porosity. The larger the voids, the more they deviate from a spherical shape. Significant lack-of-fusion voids are located between the deposited filaments. By growing and merging, they act as seeds for the forming fracture line in the region of the flexural specimens where the maximum local tensile stresses occurred under bending load. Our work provides a detailed analysis of printed PEEK with fiber additive and relates this with mechanical properties. KW - CFR-PEEK KW - Material extrusion (MEX) KW - FFF KW - Surface topography KW - Bending property KW - Micro-CT PY - 2023 DO - https://doi.org/10.1016/j.jmbbm.2023.106085 SN - 1751-6161 VL - 146 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-58112 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Bernd R. A1 - Hentschel, Manfred P. T1 - Synchrotron radiation refraction topography for charcterization of lightweight materials N2 - The employment of synchrotron radiation for refraction topography of materials has considerable advantages over standard x-ray sources. The much higher beam intensity and the parallel and monochromatic radiation provide faster measurements and better angular and spatial resolution. X-ray refraction techniques image the inner surface and interface concentration of micro-structured materials. This effect of x-ray optics is additional to small-angle scattering by diffraction, when the scattering objects reach micrometre dimensions. We have developed x-ray refraction techniques within the last decade in order to meet the growing demands for improved non-destructive characterization of high-performance composites, ceramics and other low-density materials. Sub-micron particle dimensions, the pore size of ceramics, the crack density distribution and single fibre debonding within damaged composites can be measured and visualized by computer-generated interface topographs. For this purpose investigations are now being performed at the new hard x-ray beamline of the Federal Institute for Materials Research and Testing (BAM) at BESSY, Berlin. This BAMline provides monochromatic radiation of photon energies from 5 to 60 keV from a double multilayer and/or a double-crystal monochromator. A separate instrument is dedicated to the further development and application of synchrotron radiation refraction (SRR) topography. Different from conventional small-angle scattering cameras with collimating slits and pinholes, scattering angles down to a few seconds of arc are selected by a single-crystal analyser, similar to a Bonse-Hart diffractometer. A 20 µm spatial resolution of the scattering micro-structures is achieved by a CCD camera with a fluorescent converter. First SRR topographs of aircraft composites [carbon fibre-reinforced plastics (CFRP), carbon fibre-reinforced ceramics (C/C), metal matrix ceramics (MMC)] will be reported. KW - BAMline KW - Refraction topography PY - 2004 DO - https://doi.org/10.1002/xrs.736 SN - 0049-8246 VL - 33 IS - 6 SP - 402 EP - 406 PB - Wiley CY - Chichester AN - OPUS4-11930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Müller, Bernd R. A1 - Lange, Axel A1 - Harwardt, Marco A1 - Hentschel, Manfred P. A1 - Illerhaus, Bernhard A1 - Goebbels, Jürgen A1 - Bamberg, J. A1 - Heutling, F. ED - Danny Van Hemelrijck, ED - Igor Solodov, ED - Anastasopoulos, Athanasios ED - Gerhard Busse, T1 - Synchrotron-Refraction-Computed-Tomography for NDT and characterisation of lightweight composite materials T2 - 4th International Conference of Emerging Technologies in Non-Destructive Testing (ETNDT 4) CY - Stuttgart, Germany DA - 2007-04-02 KW - Refraction KW - Computed Tomography KW - NDE KW - Ti-MMC PY - 2008 SN - 978-0-415-46476-5 SP - 217 EP - 221 PB - Taylor & Francis CY - London, UK AN - OPUS4-18680 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Müller, Bernd R. A1 - Lange, Axel A1 - Harwardt, Michael A1 - Hentschel, Manfred P. A1 - Illerhaus, Bernhard A1 - Goebbels, Jürgen A1 - Bamberg, J. A1 - Heutling, F. T1 - Micro Crack Characterization of Metal Matrix Composites by 3D-Refraction-Computed-Tomography T2 - 16th World Conference on Nondestructive Testing CY - Montreal, Canada DA - 2004-08-30 KW - NDE KW - X-ray refraction KW - Composites KW - MMC PY - 2004 SP - 9 pages PB - International Committee for Non-Destructive Testing CY - Montreal AN - OPUS4-5486 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hentschel, Manfred P. A1 - Müller, Bernd R. A1 - Lange, Axel A1 - Harbich, Karl-Wolfram A1 - Schors, Jörg A1 - Wald, Oliver T1 - New Developments in X-ray-Topography of Advanced Non-Metallic Materials T2 - 15th World Conference on Non-Destructive Testing (WCNDT) CY - Roma, Italy DA - 2000-10-15 PY - 2000 UR - http://www.ndt.net/article/wcndt00/papers/idn258/idn258.htm SN - 1435-4934 VL - 5 IS - 11 PB - NDT.net CY - Kirchwald AN - OPUS4-928 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Müller, Bernd R. A1 - Hentschel, Manfred P. A1 - Lange, Axel A1 - Harwardt, Michael T1 - Characterization of fibre reinforced metals by X-ray refraction CT PY - 2003 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2002.pdf#page=336 SN - 0179-4159 SP - 336 EP - 337 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-2493 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hakim, I. A1 - Laquai, René A1 - Schumacher, David A1 - Müller, Bernd R. A1 - Graja, P. A1 - Meyendorf, N. A1 - Donaldson, S. T1 - The Effect of Manufacturing Conditions on Discontinuity Population and Fatigue Fracture Behavior in Carbon/Epoxy Composites N2 - Carbon fiber composites have been increasingly used in aerospace, military, sports, automotive and other fields due to their excellent properties, including high specific strength, high specific modulus, corrosion resistance, fatigue resistance, and low thermal expansion coefficient. Interlaminar fracture is a serious failure mode leading to a loss in composite stiffness and strength. Iscontinuities formed during manufacturing process degrade the fatigue life and interlaminar fracture resistance of the composite. In his study, three approaches were implemented and their results were correlated to quantify discontinuities effecting static and fatigue interlaminar fracture behavior of carbon fiber composites. Samples were fabricated by hand layup vacuum bagging manufacturing process under three different vacuum levels, indicated High (-686 mmHg), Moderate (-330 mmHg) and Poor (0 mmHg). Discontinuity content was quantified throughthickness by destructive and nondestructive techniques. Eight different NDE methods were conducted including imaging NDE methods: X-Ray laminography, ultrasonic, high frequency eddy current, pulse thermography, pulse phase thermography and lock-in-thermography, and averaging NDE techniques: X-Ray refraction and thermal conductivity measurements. Samples were subsequently destructively serial sectioned through-thickness into several layers. Both static and fatigue interlaminar fracture behavior under Mode I were conducted. The results of several imaging NDE methods revealed the trend in percentages of discontinuity. However, the results of averaging NDE methods showed a clear correlation since they gave specific values of discontinuity through-thickness. Serial sectioning exposed the composite’s internal structure and provided a very clear idea about the type, shape, size, distribution and location of most discontinuities included. The results of mechanical testing showed that discontinuities lead to a decrease in Mode I static interlaminar fracture toughness and a decrease in Mode I cyclic strain energy release rates fatigue life. Finally, all approaches were correlated: the resulted NDE percentages and parameters were correlated with the features revealed by the destructive test of serial sectioning and static and fatigue values in order to quantify discontinuities such as delamination and voids. T2 - QNDE 2016 CY - Atlanta, GA, USA DA - 17.07.2016 KW - Carbon Fber Reinforced Polymers KW - Nondestructive Testing KW - X-ray Imaging KW - Ultrasound KW - Thermography PY - 2017 SN - 978-0-7354-1474-7 DO - https://doi.org/10.1063/1.4974661 SN - 0094-243X N1 - Geburtsname von Schumacher, David: Walter, D. - Birth name of Schumacher, David: Walter, D. VL - 1806 SP - UNSP 090017, 1 EP - 11 PB - AIP Publishing CY - Melville, NY, USA AN - OPUS4-39716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Bernd R. A1 - Lange, Axel A1 - Harwardt, Michael A1 - Hentschel, Manfred P. A1 - Illerhaus, Bernhard A1 - Goebbels, Jürgen A1 - Bamberg, J. A1 - Heutling, F. T1 - X-Ray Refraction Topography and Computed Tomography for NDE of Lightweight Materials T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - Synchrotron Refraction CT KW - MMC KW - Bragg-Magnification PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 9(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-13703 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -