TY - CONF A1 - Laquai, René A1 - Schaupp, Thomas A1 - Müller, Bernd R. A1 - Griesche, Axel A1 - Bruno, Giovanni A1 - Kannengießer, Thomas T1 - 3D imaging of hydrogen assisted cracking using analyser-based imaging N2 - To better understand the mechanism of hydrogen assisted cracking (HAC), it is important to investigate the 3D structure of the cracks non-destructively. Since, cracks introduced by HAC are usually very small, conventional x-ray imaging methods often lack the required spatial resolution. However, the detection of those cracks can be enhanced by taking advantage of refraction at interfaces within the sample. To image this refractive deflection we employ analyser based imaging (ABI). In this work we aim at proving the enhanced crack detection of ABI by investigating an alluminum alloy weld. T2 - BESSY User Meeting 2015 CY - Berlin, Germany DA - 09.12.2015 KW - X-ray refraction KW - Synchrotron KW - Analyser-based imaging KW - Hydrogen assisted cracking KW - Welding PY - 2015 AN - OPUS4-38278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Absorbtion and Refraction Techniques: Characterization and Non-Destructive Testing of Additively Manufactured Materials 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 holds equally 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. T2 - c-Kolloquium an dem FRM II Reaktor CY - Munich, Germany DA - 29.07.2016 KW - Computertomographie KW - Metrologie KW - 3D Mikrostruktur KW - Zerstörungsfreie Prüfung KW - Röntgenrefraktion KW - TF Material KW - Analytical Science PY - 2015 AN - OPUS4-38827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cabeza, Sandra A1 - Mishurova, Tatiana A1 - Bruno, Giovanni A1 - Garcés, G. T1 - The role of reinforcement orientation on the damage evolution of AlSi12CuMgNi + 15% Al2O3 under compression N2 - Internal damage of an AlSi12CuMgNi alloy reinforced with planar random short fibres has been investigated after compression. This damage strongly influences the load partition between matrix and reinforcement. For fibres perpendicular to the applied load, breakage and interconnected cracks appear in significantly higher volume fraction than with fibres parallel to load. KW - Neutron Diffraction KW - Damage KW - Metal Matrix Composites KW - Load Partition KW - Synchrotron CT PY - 2016 U6 - https://doi.org/10.1016/j.scriptamat.2016.05.023 SN - 1359-6462 VL - 122 SP - 115 EP - 118 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-36357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bruno, Giovanni A1 - Onel, Yener A1 - Cooper, R. C. A1 - Lange, A. A1 - Watkins, T. R. A1 - Shyam, A. T1 - Young's modulus and Poisson's ratio changes due to machining in porous microcracked cordierite N2 - Microstructural changes in porous cordierite caused by machining were characterized using microtensile testing, X-ray computed tomography, and scanning electron microscopy. Young's moduli and Poisson's ratios were determined on similar to 215- to 380-mu m-thick machined samples by combining digital image correlation and microtensile loading. The results provide evidence for an increase in microcrack density and decrease of Young's modulus due to machining of the thin samples extracted from diesel particulate filter honeycombs. This result is in contrast to the known effect of machining on the strength distribution of bulk, monolithic ceramics. KW - Stress KW - Beta-Eucryptite KW - Brittle materials KW - Ceramic materials KW - Thermal-Expansion KW - Fracture-Toughness KW - Composite materials KW - Differential scheme KW - Elastic-moduli KW - Representative volume element PY - 2016 U6 - https://doi.org/10.1007/s10853-016-0209-9 SN - 0022-2461 VL - 51 IS - 21 SP - 9749 EP - 9760 PB - Springer, NY, USA AN - OPUS4-37867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shashev, Yury A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Britzke, Ralf A1 - Bruno, Giovanni A1 - Müller, Bernd R. A1 - Hentschel, M. P. T1 - Talbot- Lau interferometry with a non- binary phase grating for non-destructive testing N2 - Grating interferometric set-ups have been established in the last decade. They are promising candidates to obtain enhanced image contrast from weakly absorbing micro and nano structures. They are based on X-ray refraction and near-field diffraction using the Talbot effect. At the expense of taking multiple images, Talbot-Lau grating interferometry allows separating the absorption, refraction, and scattering contributions by analysing the disturbances of a phase grating interference pattern. Contrary to other refraction enhanced methods, this technique can be applied using conventional X-ray tubes (divergent, polychromatic source). This makes it attractive to solve typical non-destructive testing problems. We investigated the efficiency of phase gratings, i.e. the visibility (the amplitude of oscillations) upon variation of propagation distance and phase grating rotation around an axis parallel to the grid lines. This grating rotation changes the grating shape (i.e. the distributions of phase shifts). This can yield higher visibilities than derived from rectangular shapes. Our study includes experimental results obtained from synchrotron radiation, as well as simulations for monochromatic radiation. The advantages of Talbot-Lau interferometry are demonstrated at the example of glass capillaries. T2 - 19th World Conference on Non-Destructive Testing 2016 CY - Munich, Germany DA - 13.06.2016 KW - Talbot- Lau interferometry KW - Phase grating KW - Non-destructive testing PY - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-383163 SP - Tu_3_G_2, 1 EP - 9 AN - OPUS4-38316 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bruno, Giovanni A1 - Sevostianov, I. A1 - Cabeza, Sandra A1 - Mishurova, Tatiana T1 - Average phase stress concentrations in multiphase metal matrix composites under compressive loading N2 - We develop a model to predict average over individual phases stress concentrations in a multiphase metal matrix composite under compressive loading. The model accounts for matrix plasticity through variation of the shear modulus with applied stress and for frac- ture of filler through change in the shape of the particles. Three micromechanical models are compared –non interaction approximation, Mori–Tanaka–Benveniste (MTB) scheme, and Maxwell scheme. Comparison with the experimental measurements of Cabeza et al. (2016) shows that Maxwell scheme generally predicts the stress concentration with satis- factory accuracy. Results of MTB scheme vary depending on the loading case and ignoring of the interaction leads to substantial overestimation of the stresses. KW - Average phase stress concentrations KW - metal matrix composite KW - multiphase composite PY - 2016 U6 - https://doi.org/10.1016/j.ijengsci.2016.06.004 SN - 0020-7225 VL - 106 SP - 245 EP - 261 PB - Elsevier Ltd. AN - OPUS4-37738 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shashev, Yury A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Müller, Bernd R. A1 - Bruno, Giovanni T1 - Improving the visibility of phase gratings for Talbot-Lau X-ray imaging N2 - Talbot-Lau interferometry provides X-ray imaging techniques with significant enhancement of the radiographic contrast of weakly absorbing objects. The grating based technique allows separation of absorption, refraction and small angle scattering effects. The different efficiency of rectangular and triangular shaped phase gratings at varying detector distances is investigated. The interference patterns (Talbot carpets) are modeled for parallel monochromatic radiation and measured by synchrotron radiation. In comparison to rectangular shapes of phase gratings much higher visibility is obtained for triangular shapes which yield enhanced contrast of a glass capillary test specimen. KW - Visibility KW - Talbot-Lau interferometry KW - Phase grating KW - Synchrotron imaging KW - X-ray reefraction PY - 2016 U6 - https://doi.org/10.3139/120.110948 SN - 0025-5300 VL - 58 IS - 11-12 SP - 970 EP - 974 PB - Carl Hanser Verlag CY - München AN - OPUS4-38422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni A1 - Cabeza, Sandra A1 - Kromm, Arne A1 - Stegemann, Robert A1 - Lyamkin, Viktor A1 - Boin, Mirko 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 - Shashev, Yury A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Britzke, Ralf A1 - Bruno, Giovanni A1 - Mueller, Bernd R. A1 - Hentschel, Manfred P. T1 - Talbot- Lau interferometry with a non- binary phase grating for non-destructive testing N2 - Grating interferometric set-ups have been established in the last decade. They are promising candidates to obtain enhanced image contrast from weakly absorbing micro and nano structures. They are based on X-ray refraction and near-field diffraction using the Talbot effect. At the expense of taking multiple images, Talbot-Lau grating interferometry allows separating the absorption, refraction, and scattering contributions by analysing the disturbances of a phase grating interference pattern. Contrary to other refraction enhanced methods, this technique can be applied using conventional X-ray tubes (divergent, polychromatic source). This makes it attractive to solve typical non-destructive testing problems. We investigated the efficiency of phase gratings, i.e. the visibility (the amplitude of oscillations) upon variation of propagation distance and phase grating rotation around an axis parallel to the grid lines. This grating rotation changes the grating shape (i.e. the distributions of phase shifts). This can yield higher visibilities than derived from rectangular shapes. Our study includes experimental results obtained from synchrotron radiation, as well as simulations for monochromatic radiation. The advantages of Talbot-Lau interferometry are demonstrated at the example of glass capillaries. T2 - WCNDT2016 CY - Munich, Germany DA - 13.06.2016 KW - Phase-contrast X-ray imaging KW - Talbot- Lau interferometry KW - Phase grating KW - Visibility KW - Synchrotron radiation PY - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-365987 SN - 978-3-940283-78-8 VL - BB 158 SP - Tu.3.G.2., 1 EP - 9 AN - OPUS4-36598 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas A1 - Müller, Bernd R. A1 - Hentschel, M. P. A1 - Lange, A. A1 - Trappe, Volker A1 - Laquai, René A1 - Shashev, Yury A1 - Evsevleev, Sergei A1 - Bruno, Giovanni T1 - Progress survey of X-Ray refraction imaging techniques N2 - The most substantial innovations in radiographic imaging techniques of the last two decades aim at enhanced image contrast of weakly absorbing micro and nano structures by taking advantage of X-ray refraction effects occurring at outer and inner surfaces. The applications range from fibre reinforced plastics to biological tissues. These techniques comprise, among others, X-ray refraction topography, diffraction enhanced imaging, phase contrast imaging, Talbot-Lau grating interferometry, and refraction enhanced imaging. They all make use of selective beam deflections up to a few minutes of arc: the X-ray refraction effect. In contrast to diffraction, this type of interaction has a 100 % scattering cross section, as shown experimentally. Since X-ray refraction is very sensitive to the orientation of interfaces, it is additionally a tool to detect, e.g., fibre or pore orientation. If the detector resolution exceeds the size of (small) individual features, one detects the integral information (of inner surfaces) within the gauge volume. We describe the above-mentioned techniques, and show their experimental implementation in the lab and at a synchrotron source. We also show strategies for data processing and quantitative analysis. T2 - 19th World Conference on Non-Destructive Testing CY - Munich, Germany DA - 13.06.2016 KW - grating KW - topography KW - refraction KW - X-ray PY - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-366194 SN - 978-3-940283-78-8 VL - 2016/158 SP - We.3.B.2, 1 EP - 9 AN - OPUS4-36619 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -