TY - JOUR A1 - Khrapov, D. A1 - Surmeneva, M. A1 - Koptioug, A. A1 - Evsevleev, Sergei A1 - Léonard, Fabien A1 - Bruno, Giovanni A1 - Surmenev, R. T1 - X-ray computed tomography of multiple-layered scaffolds with controlled gradient cell lattice structures fabricated via additive manufacturing N2 - In this paper we report on the characterization by X-ray computed tomography of calcium phosphate (CaP) and polycaprolactone (PCL) coatings on Ti-6Al-4V alloy scaffolds used as a material for medical implants. The cylindrical scaffold has greater porosity of the inner part than the external part, thus, mimicking trabecular and cortical bone, respectively. The prismatic scaffolds have uniform porosity. Surface of the scaffolds was modified with calcium phosphate (CaP) and polycaprolactone (PCL) by dip-coating to improve biocompatibility and mechanical properties. Computed tomography performed with X-ray and synchrotron radiation revealed the defects of structure and morphology of CaP and PCL coatings showing small platelet-like and spider-web-like structures, respectively.  KW - Mechanical Engineering KW - Maskinteknik PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-510763 SN - 17426588 VL - 1145 SP - 012044 PB - IOP AN - OPUS4-51076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Khrapov, D. A1 - Surmeneva, M. A1 - Koptioug, A. A1 - Evsevleev, Sergei A1 - Léonard, Fabien A1 - Bruno, Giovanni A1 - Surmenev, R. T1 - X-ray computed tomography of multiple-layered scaffolds with controlled gradient cell lattice structures fabricated via additive manufacturing N2 - In this paper we report on the characterization by X-ray computed tomography of calcium phosphate (CaP) and polycaprolactone (PCL) coatings on Ti-6Al-4V alloy scaffolds used as a material for medical implants. The cylindrical scaffold has greater porosity of the inner part than the external part, thus, mimicking trabecular and cortical bone, respectively. The prismatic scaffolds have uniform porosity. Surface of the scaffolds was modified with calcium phosphate (CaP) and polycaprolactone (PCL) by dip-coating to improve biocompatibility and mechanical properties. Computed tomography performed with X-ray and synchrotron radiation revealed the defects of structure and morphology of CaP and PCL coatings showing small platelet-like and spider-web-like structures, respectively. KW - Additive manufacturing KW - Lattice structure KW - Multiple-layered scaffold KW - Coating KW - Medical implants KW - Computed tomography KW - Polycaprolactone KW - Calcium phosphate PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-471931 UR - http://stacks.iop.org/1742-6596/1145/i=1/a=012044 SN - 1742-6596 VL - 1145 SP - 012044, 1 EP - 7 PB - IOP AN - OPUS4-47193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bircher, B. A1 - Meli, F. A1 - Küng, A. A1 - Bellon, Carsten A1 - Evsevleev, Sergei A1 - Katic, M. A1 - Heikkinen, V. A1 - Hemming, B. A1 - Lassila, A. T1 - Traceable determination of non-static XCT machine geometry: New developments and case studies N2 - It is fundamental to determine the machine geometry accurately for dimensional X-ray computed tomography (XCT) measurements. When performing high-accuracy scans, compensation of a non-static geometry, e.g. due to rotary axis errors or drift, might become necessary. Here we provide an overview of methods to determine and account for such deviations on a per projection basis. They include characterisation of stage error motions, in situ geometry measurements, numerical simulations, and reconstruction-based optimization relying on image quality metrics and will be discussed in terms of their metrological performance. Since a radiographic calibration is always required to provide an initial absolute geometry, this method will be presented as well. The improvements of the XCT geometry correction methods are presented by means of case studies. The methods can be applied individually or in combination and are intended to provide a toolbox for XCT geometry compensation. T2 - 11th Conference on Industrial Computed Tomography (iCT 2022) CY - Online meeting DA - 08.02.2022 KW - Radiographic XCT geometry determination KW - Dimensional metrology KW - traceability KW - XCT machine geometry KW - Calibrated reference standards PY - 2022 SP - 1 EP - 10 PB - Research Group Computed Tomography, Upper Austrian University of Applied Sciences (FH OÖ) CY - Wels, Austria AN - OPUS4-54479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shashev, Yury A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Evsevleev, Sergei A1 - Britzke, Ralf A1 - Bruno, Giovanni A1 - Müller, Bernd R. T1 - Talbot-Lau Röntgen-Interferometrie für die zerstörungsfreie Prüfung N2 - Im vergangenen Jahrzehnt sind gitterinterferometrische Röntgenabbildungen zunehmend in den Fokus des Interesses gerückt. Sie sind insbesondere dann Vorteil, wenn der in der Standardradiographie erreichbare Kontrast nicht genügt, schwach absorbierende Mikro- und Nanostrukturen abzubilden. Auf Kosten mehrerer Aufnahmen gestattet die Talbot-Lau Gitterinterferometrie, die Beiträge aus Absorption, Refraktion und (refraktiver) Streuung zu trennen. Dazu werden die Störungen der Interferenzmuster von Phasengittern ausgewertet. Im Gegensatz zu einer Vielzahl anderer refraktionsbasierter Abbildungsmethoden kann diese Technik mit konventionellen Röntgenröhren (mit divergenter, polychromatischer Strahlung) angewendet werden. Damit ist die Technik geeignet, typische ZfP-Fragestellungen zu lösen. Hier stellen wir Untersuchungen zur Effizienz von Phasengittern vor. Die Visibilität (d.h. die Höhe der Oszillation im Interferenzmuster) wird als Funktion verschiedener geometrischer Parameter verfolgt. Eine Rotation um die Achse parallel zu den Gitterstegen ändert die Form des Gitterprofils (d.h. die Verteilung der Phasenschiebungen). Die kontinuierliche Variation des Winkels und des Detektionsabstandes führt zur Identifikation von ausgezeichneten Kombinationen mit maximaler Visibilität, wobei die Abstände deutlich geringer sind als im Standardaufbau mit senkrechter Gitterbestrahlung. Unsere Studie umfasst Simulationen für monochromatische Quelle und den Vergleich zu experimentellen Ergebnissen mit der Synchrotronstrahlung. In der Literatur wurden die Vorteile der Talbot-Lau Interferometrie für die zerstörungsfreie Prüfung von Faserkompositen und Verbundwerkstoffen demonstriert. Hier werden als Beispiele Messungen an Aluminiumtitanat (Al2TiO5) Pulver gezeigt. T2 - DGZfP 2017 CY - Koblenz, Germany DA - 22.05.2017 KW - Gitterinterferometrische Röntgenabbildung KW - Phasengitter KW - Talbot-Lau Interferometrie KW - Zerstörungsfreie Prüfung PY - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-404691 SP - 1 EP - 10 PB - DGZfP AN - OPUS4-40469 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Evsevleev, Sergei A1 - Mishurova, Tatiana A1 - Cabeza, Sandra A1 - Garces, Gerardo A1 - Requena, Guillermo A1 - Sevostianov, Igor A1 - Bruno, Giovanni T1 - Stress-induced damage evolution in aluminum matrix composites N2 - Two metal matrix composites, both consisting of a near-eutectic cast AlSi12CuMgNi alloy, one reinforced with 15%vol. Al2O3 short fibers and the other with 7%vol. Al2O3 short fibers + 15%vol. SiC particles were studied. Distribution, orientation, and volume fraction of the different phases was determined by means of synchrotron computed tomography. The load partitioning between phases was investigated by in-situ neutron diffraction compression tests. The internal damage of the eutectic Si phase and Al2O3 fibers after ex-situ compression tests was directly observed in CT reconstructed volumes. Significant debonding between Al-matrix and SiC particles was found. Those observations allowed rationalizing the load transfer among the constituent phases of two different composites. Finally, based on the Maxwell scheme, a micro-mechanical model was utilized for the composite with one and two ceramic reinforcements. The model rationalizes the experimental data, and predicts the evolution of principal stresses in each phase. T2 - The 4th International Congress on 3D Material Science 2018 CY - Elsinore, Denmark DA - 10.06.2018 KW - Computed Tomography KW - Aluminium KW - Metal Matrix Composite KW - Load Partition PY - 2018 AN - OPUS4-45397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Evsevleev, Sergei A1 - Mishurova, Tatiana A1 - Cabeza, Sandra A1 - Garcés, Gerardo A1 - Requena, Guillermo A1 - Sevostianov, Igor A1 - Bruno, Giovanni T1 - Stress partitioning and damage evolution in near-eutectic cast AlSi12CuMgNi alloy N2 - Near eutectic cast Al–Si alloys are the basis of all Al-alloys used for pistons due to their high fluidity and relatively high strength-to-weight ratio. Their microstructure is characterized by the presence of eutectic-Si embedded in an age hardenable -Al matrix. During solution heat treatment, the eutectic Si network undergoes a process of gradual disintegration, reducing the load bearing capability and the strength of the alloy. The improvement of the high temperature strength is achieved by addition of transition elements such as Cu, Mg or Ni through the formation of stiff intermetallic (IM) phases. In present study a near-eutectic AlSi12CuMgNi alloy produced by squeeze casting was investigated in as-cast condition. The in-situ neutron diffraction compression tests revealed the stress partitioning mechanism between phases of the alloy. Large stresses were found in IMs, showing their significant role as a reinforcement elements. After the failure of IM and Si phases the load is transferred back to the Al matrix, inducing further plastic deformation in it, yet without creating microcracking. The neutron diffraction experiments were coupled with assessment of internal damage after ex-situ compression tests by synchrotron radiation computed tomography. The quantitative analysis of CT data revealed that local tensile stresses in IM and Si phases induce microcracks with preferential orientation, parallel to the axis of applied load. Altogether, present experimental data was used as an input for the developed micromechanical model based on Maxwell homogenization scheme. In contrast to the neutron diffraction experiment, which can only determine stress differences between the axial and radial sample directions, the model allows predicting the principal stresses in each phase of the alloy. T2 - European Conference on Residual Stresses - ECRS10 CY - Leuven, Belgium DA - 11.09.2018 KW - Aluminum alloy KW - Intermetallics KW - Computed tomography KW - Neutron diffraction KW - Stress analysis KW - Load partition PY - 2018 AN - OPUS4-46054 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 - TY - JOUR A1 - Tsamos, Athanasios A1 - Evsevleev, Sergei A1 - Bruno, Giovanni T1 - Noise and blur removal from corrupted X-ray computed tomography scans: A multilevel and multiscale deep convolutional framework approach with synthetic training data (BAM SynthCOND) N2 - Regardless of the experimental care practiced in acquiring X-ray computed tomography (XCT) data, artifacts might still exist, such as noise and blur. This is typical for fast XCT data acquisitions (e.g., in-situ investigations), or low-dose XCT. Such artifacts can complicate subsequent analysis of the data. Digital filters can moderately cure extensive artifacts. The selection of filter type, intensity, and order of application is not always straight forward. To tackle these problems, a complete sequential multilevel, multi-scale framework: BAM SynthCOND, employing newly designed deep convolutional neural networks (DCNNs), was formulated. Although data conditioning with neural networks is not uncommon, the main complication is that completely artifact-free XCT data for training do not exist. Thus, training data were acquired from an in-house developed library (BAM SynthMAT) capable of generating synthetic XCT material microstructures. Some novel DCNN architectures were introduced (2D/3D ACEnet_Denoise, 2D/3D ACEnet_Deblur) along with the concept of Assertive Contrast Enhancement (ACE) training, which boosts the performance of neural networks trained with continuous loss functions. The proposed methodology accomplished very good generalization from low resemblance synthetic training data. Indeed, denoising, sharpening (deblurring), and even ring artifact removal performance were achieved on experimental post-CT scans of challenging multiphase Al-Si Metal Matrix Composite (MMC) microstructures. The conditioning efficiencies were: 92% for combined denoising/sharpening, 99% for standalone denoising, and 95% for standalone sharpening. The results proved to be independent of the artifact intensity. We believe that the novel concepts and methodology developed in this work can be directly applied on the CT projections prior to reconstruction, or easily be extended to other imaging techniques such as: Microscopy, Neutron Tomography, Ultrasonics, etc. KW - XCT Data Conditioning KW - Denoising Deblurring Sharpening KW - Deep Convolutional Neural Network (DCNN) KW - Synthetic Training Data KW - ACEnet KW - Metal Matrix Composite (MMC) PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-579129 VL - 2 SP - 1 EP - 16 PB - Elsevier B.V. AN - OPUS4-57912 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Evsevleev, Sergei A1 - Mishurova, Tatiana A1 - Garces, G. A1 - Sevostianov, I. A1 - Hofmann, M. A1 - Bruno, Giovanni T1 - Micromechanical response of multi-phase Al-alloy matrix composites under uniaxial compression N2 - Aluminum alloys are extensively used in the automotive industry. Particularly, squeeze casting production of Al-Si alloys is employed in the conception of metal matrix composites (MMC) for combustion engines. Such materials are of a high interest since they allow combining improved mechanical properties and reduced weight and hence improve efficiency. Being a multiphase material, most MMCs show complex micromechanical behavior under different load conditions. In this work we investigated the micromechanical behavior of two MMCs, both consisting of a near-eutectic cast AlSi12CuMgNi alloy, one reinforced with 15%vol. Al2O3 short fibers and the other with 7%vol. Al2O3 short fibers + 15%vol. SiC particles. Both MMCs have complex 3D microstructure consisting of four and five phases: Al-alloy matrix, eutectic Si, intermetallics, Al2O3 fibers and SiC particles. The in-situ neutron diffraction compression experiments were carried out on the Stress-Spec beamline and disclosed the evolution of internal phase-specific stresses in both composites. In combination with the damage mechanism revealed by synchrotron X-ray computed tomography (SXCT) on plastically pre-strained samples, this allowed understanding the role of every composite’s phase in the stress partitioning mechanism. Finally, based on the Maxwell scheme, a micromechanical model was utilized. The model perfectly rationalizes the experimental data and predicts the evolution of principal stresses in each phase. T2 - MLZ User Meeting 2020 CY - Online meeting DA - 09.12.2020 KW - Metal matrix composite KW - Neutron diffraction KW - Damage mechanism KW - Load transfer KW - Computed tomography PY - 2020 AN - OPUS4-52032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishurova, Tatiana A1 - Evsevleev, Sergei A1 - Artzt, K. A1 - Haubrich, J. A1 - Sevostianov, I. A1 - Requena, G. A1 - Bruno, Giovanni T1 - Micromechanical behavior of annealed Ti-6Al-4V produced by Laser Powder Bed Fusion N2 - The micromechanical behavior of an annealed Ti-6Al-4V material produced by Laser Powder Bed Fusion was characterized by means of in-situ synchrotron X-ray diffraction during a tensile test. The lattice strain evolution was obtained parallel and transversal to the loading direction. The elastic constants were determined and compared with the conventionally manufactured alloy. In the plastic regime, a lower plastic anisotropy exhibited by the lattice planes was observed along the load axis (parallel to the building direction) than in the transverse direction. Also, the load transfer from α to β phase was observed, increasing global ductility of the material. The material seems to accumulate a significant amount of intergranular strain in the transverse direction. KW - Additive manufacturing KW - Ti-6Al-4V KW - Anisotropy KW - Intergranular strain KW - Synchrotron X-ray diffraction PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-547406 VL - 2 IS - 1 SP - 186 EP - 201 PB - Taylor & Francis AN - OPUS4-54740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -