TY - CONF A1 - Léonard, Fabien T1 - XCT simulation: Effects of error sources on dimensional measurements for medical and standard objects N2 - The quantification of experimental and data analysis errors is most of the times jeopardised by the presence of surface roughness, waviness, as well as by typical measurement artefacts of the XCT technique (for instance refraction at sharp edges). One way to at least estimate the influence of those factors on dimensional measurements and on tolerances is to simulate them using Monte-Carlo method. An alternative strategy is to use independent knowledge (e.g. CMM data) to smoothen/calibrate/correct XCT data. T2 - Workshop on additive manufacturing CY - Berlin, Germany DA - 13.05.2019 KW - aRTist KW - Part geometry KW - Part material KW - Beam hardening KW - Partial volume effect PY - 2019 AN - OPUS4-48263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien T1 - Digital image analysis procedures for dimension, dimensional error, and 3D bulk defect assessment N2 - XCT is a powerful technique for dimensional measurements of AM parts. AM parts pose new challenges to the metrologists and CT specialists. Robust digital image analysis have been proposed for dimensional measurements and defect detections based on experience within the MetAMMI project. T2 - Workshop on additive manufacturing CY - Berlin, Germany DA - 13.05.2019 KW - X-ray computed tomography KW - Metrology KW - Implant PY - 2019 AN - OPUS4-48264 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien T1 - Distance transforms and correlation maps: advanced impact damage characterisation in composite panels N2 - One of the great strengths of X-ray computed tomography over conventional inspection methods (ultrasound, thermography, radiography) is that it can image damage in 3D. However for curved or deformed composite panels, it can be difficult to automatically ascribe the damage to specific plies or inter-ply interfaces. An X-ray computed tomography (CT) data processing methodology is developed to extract the through-thickness distribution of damage in curved or deformed composite panels. The method is applied to [(0°/90°)2]s carbon fibre reinforced polymer (CFRP) panels subjected low velocity impact damage (5 J up to 20 J) providing 3D ply-by-ply damage visualisation and analysis. Our distance transform approach allows slices to be taken that approximately follow the composite curvature allowing the impact damage to be separated, visualised and quantified in 3D on a ply-by-ply basis. In this way the interply delaminations have been mapped, showing characteristic peanut shaped delaminations with the major axis oriented with the fibres in the ply below the interface. This registry to the profile of the panel constitutes a significant improvement in our ability to characterise impact damage in composite laminates and extract relevant measurements from X-ray CT datasets. T2 - Dagstuhl Seminar 19151 Quantitative data visualisation challenge CY - Dagstuhl, Germany DA - 11.04.2019 KW - Computed tomography KW - X-ray computed tomography KW - Data processing PY - 2019 AN - OPUS4-47830 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien A1 - Zhang, Zhen A1 - Malow, Marcus A1 - Bruno, Giovanni T1 - 3D characterisation of ammonium nitrate powders by X-ray computed tomography N2 - The mixture of ammonium nitrate (AN) prills and fuel oil (FO), usually called ANFO, is extensively used in the mining industry as a bulk industrial explosive. One of the major performance predictors of ANFO mixtures is the fuel oil retention, which is itself governed by the porosity of the AN prills. Standardised tests routinely used to assess oil retention face several important limitations; the first being the difficulty to cover the wide range of porosity contents and morphologies from different types of ammonium nitrate prills; the second being the inability to evaluate the closed porosity, which is an important factor regarding the sensitivity of the explosive to detonation. In this study, we present how X-ray computed tomography (XCT), and the associated advanced data processing workflow, can be used to fully characterise the structure and morphology of AN prills. We show that structural parameters such as volume fraction of the different phases and morphological parameters such as specific surface area and shape factor can be reliably extracted from the XCT data, and that there is a good agreement with the measured oil retention values. XCT can therefore be employed to non-destructively and accurately evaluate and characterise porosity in ammonium nitrate prills. T2 - 23rd Seminar on New Trends in Research of Energetic Materials CY - Meeting was canceled DA - 01.04.2020 KW - Ammonium nitrate KW - Prill KW - Non-destructive characterisation KW - Porosity KW - Specific surface area PY - 2020 SP - 163 EP - 171 AN - OPUS4-51272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schob, D. A1 - Sagradov, I. A1 - Roszak, R. A1 - Sparr, H. A1 - Franke, R. A1 - Ziegenhorn, M. A1 - Kupsch, Andreas A1 - Léonard, Fabien A1 - Müller, Bernd R. A1 - Bruno, Giovanni T1 - Experimental determination and numerical simulation of material and damage behaviour of 3D printed polyamide 12 under cyclic loading N2 - The material and damage behaviour of additively manufactured polyamide 12 under cyclic loading was characterized by cyclic tests and microstructure analysis by using microscopy, X-ray refraction, and computed tomography. The results were used to determine parameters for the viscoplastic material model by Chaboche and a damage model by Gurson-Tvergaard-Needleman. The temperature was monitored during the experiments and the self-heating effect was observed. By including this effect, a higher accuracy could be achieved with the results of mechanical experiments. KW - 3D printing Polyamide 12 KW - Chaboche model KW - GTN model KW - Material and damage behaviour KW - X-ray refraction KW - Computed tomography PY - 2020 DO - https://doi.org/10.1016/j.engfracmech.2019.106841 SN - 0013-7944 VL - 229 SP - 106841-1 EP - 106841-13 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-50557 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lorenzoni, R. A1 - Curosu, I. A1 - Léonard, Fabien A1 - Paciornik, S. A1 - Mechtcherine, V. A1 - Silva, F. A. A1 - Bruno, Giovanni T1 - Combined mechanical and 3D-microstructural analysis of strain-hardening cement-based composites (SHCC) by in-situ X-ray microtomography N2 - The paper presents the results of a series of combined mechanical and in-situ morphological investigations on highstrength strain-hardening cement-based Composites (SHCC). Tension and compression experiments were performed in a CT scanner employing a dedicated mechanical testing rig. The in-situ microtomographic scans enabled correlating the measured specimen response with relevant microstructural features and fracture processes. The microstructural segmentation of SHCC was performed in the framework of Deep Learning and it targeted an accurate segmentation of pores, fibers and aggregates. Besides their accurate volumetric representation, these phases were quantified in terms of content, size and orientation. The fracture processes were monitored at different loading stages and Digital Volume Correlation (DVC) was employed to spatially map the strains and cracks in the specimens loaded in compression. The DVC analysis highlighted the effect of loading conditions, specimen geometry and material heterogeneity at the mesolevel on the strain distribution and fracture localization. KW - Digital Volume Correlation KW - High Strength Concrete KW - In-situ Computed Tomography KW - composites PY - 2020 DO - https://doi.org/10.1016/j.cemconres.2020.106139 VL - 136 SP - 106139 PB - Elsevier Ltd. AN - OPUS4-51054 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Berndard, D. A1 - Léonard, Fabien A1 - Plougonven, E. A1 - Bruno, Giovanni T1 - On the use of autocorrelation functions, permeability tensors, and computed tomography to characterise the anisotropy of diesel particulate filter materials N2 - We show how the combination of the spatial autocorrelation function and permeability calculations, applied to 3D X-ray computed tomography data, can yield quantitative information on the anisotropy of both meso-structure and fluid flow in Diesel Particulate Filter (DPF) materials, such as Cordierite and SiC. It was found that both the degree of anisotropy, and the orientation of the permeability and meso-structure are similar, but not identical. We confirm that the morphological anisotropy of cordierite materials is weak, and clearly influenced by the extrusion process that determines the main direction of anisotropy. Properties of the autocorrelation function are discussed and it is shown why estimating the characteristic length of real meso-structures (grain or ?pore? size) is not possible. Finally, we show that the autocorrelation function applied on grey-level images can give a good estimate of the degree of anisotropy even with limited resolution. KW - Anisotropy KW - Autocorrelation function KW - Computed tomography KW - Permeability tensor KW - Diesel particulates filter KW - Ceramics PY - 2020 DO - https://doi.org/10.1080/14786435.2020.1798532 SN - 1478-6435 VL - 100 IS - 22 SP - 2802 EP - 2835 PB - Taylor & Francis AN - OPUS4-52291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kupsch, Andreas A1 - Schob, D. A1 - Léonard, Fabien A1 - Müller, Bernd R. A1 - Sagradov, I. A1 - Roszak, R. A1 - Sparr, H. A1 - Franke, R. A1 - Ziegenhorn, M. A1 - Bruno, Giovanni T1 - Bestimmung der Mikrostruktur und Simulation des Schädigungsverhaltens von lasergesintertem Polyamid 12 unter quasistatischer Zugbelastung N2 - Um das Material- und Schädigungsverhalten von additiv gefertigtem Polyamid 12 (PA12) unter quasistatischer Belastung zu charakterisieren, wurden mechanische Tests und Röntgenverfahren zur Bestimmung der Mikrostruktur eingesetzt. Die Proben wurden nach dem Prinzip des Selektiven Lasersinterns (SLS) hergestellt. Unter quasistatischer Belastung mit Haltezeiten ergab sich ein viskoplastisches Materialverhalten. Im Zugversuch wurde eine maximale Zugfestigkeit von 40.6 MPa und eine Bruchdehnung von 7.4% beobachtet. Mittels Röntgenrefraktion wurde eine Erhöhung von inneren Oberflächen beobachtet, die senkrecht zur Zugrichtung orientiert sind. Die Analyse der Gesamtporosität aus Computertomographie-Messungen ergab keine Änderung infolge der Zugbelastung. Jedoch wurde eine bimodale Porengrößenverteilung und eine steigende Sphärizität festgestellt. Das Materialverhalten wurde mit dem Chaboche-Modell simuliert und ergab eine sehr gute Übereinstimmung mit den experimentellen Ergebnissen. Allerdings gestattet dieses Modell nicht, das Schädigungsverhalten abzubilden. Daher wurde zur Simulation des Schädigungsverhaltens das Modell gemäß dem Ansatz von Gurson, Tvergaard und Needleman unter Berücksichtigung der mikrostrukturellen Parameter erweitert. Der Schwerpunkt des Beitrags liegt auf den Röntgenverfahren zur experimentellen Bestimmung der Mikrostruktur. T2 - DGZfP-Jahrestagung 2021 CY - Online meeting DA - 10.05.2021 KW - Additive Fertigung (AM) KW - Polyamid 12 KW - Röntgenrefraktion KW - Computertomographie KW - Numerische Simulation PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-526833 UR - https://jahrestagung.dgzfp.de/Portals/jt2021/bb/P16.pdf SP - 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-52683 LA - deu 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 - Mechanical Engineering KW - Maskinteknik PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510763 DO - https://doi.org/10.1088/1742-6596/1145/1/012044 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 - Schob, D. A1 - Roszak, R. A1 - Sagradov, I. A1 - Sparr, H. A1 - Ziegenhorn, M. A1 - Kupsch, Andreas A1 - Léonard, Fabien A1 - Müller, Bernd R. A1 - Bruno, Giovanni T1 - Experimental determination and numerical simulation of material and damage behaviour of 3D printed polyamide 12 under quasi-static loading N2 - In order to characterise the material and damage behaviour of additively manufactured polyamide 12 (PA12) under quasi-static load and to implement it in a numerical model, experiments under quasi-static load as well as microstructural investigations were carried out. Selective laser sintering (SLS) was used as the manufacturing process. For the classification of the material behaviour, quasi-static cyclic tests with holding times as well as tensile tests were performed. X-ray refraction and computed tomography (CT) were used to investigate the damage behaviour. The Chaboche model, which has already been applied for metallic materials under thermomechanical loading, served as the basis for the selection of the numerical material model. The same procedure was used for the selection of the damage model, where the Gurson–Tvergaard–Needleman (GTN) model was chosen, which was already used for porous metallic materials. The Chaboche model shows very good agreement with experimental results. Furthermore, the coupling with the GTN model allows a very good modelling of the damage behaviour. Finally, it could be shown that the selected models are suitable to simulate the material and damage behaviour of 3D printed PA12. KW - Polyamide 12 KW - 3D printing KW - Viscoplastic KW - Chaboche model KW - Damage KW - GTN model KW - X-ray refraction KW - Computed tomography PY - 2019 DO - https://doi.org/10.24423/aom.3162 SN - 0373-2029 VL - 71 IS - 4-5 SP - 507 EP - 526 PB - IPPT PAN - Polish Academy of Sciences, Institute of Fundamental Technological Research CY - Warsaw AN - OPUS4-49409 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien A1 - Bruno, Giovanni T1 - Evaluating porosity in cordierite diesel particulate filter materials: advanced X-ray and new statistical analysis methods N2 - Complex materials (e.g., porous ceramics) need high resolution techniques at multi-scale levels. Microstructure is intimately linked to properties and performance. One technique (or even a few techniques) is not enough. X-ray refraction and CT are very powerful tools. Non-destructive characterisation and quantitative image analysis techniques (2D and 3D) are necessary to understand the anisotropy. T2 - 40th International Conference and Expo on Advanced Ceramics and Composites ( ICACC) CY - Daytona Beach, USA DA - 24.01.2016 KW - X-ray computed tomography KW - X-ray refraction KW - Directional interface variance analysis (DIVA) KW - FFT periodogram PY - 2016 AN - OPUS4-41725 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien T1 - Selective laser melting process optimisation: X-ray and neutron sources for information from powder grains to printed structures N2 - Selective laser melting process optimisation: X-ray and neutron sources for information from powder grains to printed structures T2 - BPWT/BAM Workshop " Innovative Materialien und Qualitätskontrolle für additive Fertigung" CY - Berlin, Germany DA - 12.09.2018 KW - SLS KW - X-ray computed tomography KW - Refraction KW - Neutron diffraction KW - Additive manufacturing KW - Industry 4.0 PY - 2018 AN - OPUS4-45924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien T1 - On nominal-actual comparisons for additive manufacturing applications N2 - Nominal-actual comparisons are routinely performed to compare a manufactured specimen to a reference specimen. X-ray Computed Tomography (CT) has brought a profound change in the way that tolerance verifications are performed in industry, by allowing the inner and outer geometries of an object to be measured, without the need for external access or destructive testing. As a results, CT is increasingly used in additive manufacturing applications, where a nominal-actual comparison performed between the digital model (CAD file), used as an input for the 3D printer, and the CT volume from the printed part, can provide invaluable information as to the accuracy of the printing process. However, the nominal-actual comparison process is somewhat different when applied to additively manufactured specimens by comparison to conventionally manufactured specimens. T2 - 9th Conference on Industrial Computed Tomography CY - Padova, Italy DA - 14.02.2019 KW - Computed tomography KW - X-ray computed tomography KW - Implants PY - 2019 AN - OPUS4-47832 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien T1 - Synchrotron X-ray computed tomography for assessment of shock tube systems N2 - Shock tube systems are non-electric explosive fuses employed in blasting and demolition applications to trigger the detonation of explosive charges. Their working principle is based on the explosive reaction of a fine powder on the tubing´s inner surface, generating a percussive wave travelling at a velocity of 2,100 m/s along the length of the tube, without destroying it. One of the key aspects of the manufacturing process of these shock tubes is the size and morphology of the explosive powder grains and their distribution on the inner wall of the tube, in order to propagate the shockwave efficiently and reliably. For the first time, synchrotron X-ray computed tomography has been used to characterize non-destructively the explosive powder grains, typically Al/HMX between 10 and 20 μm in size, in terms of morphology and 3D distribution but also to characterise the presence and location of defects within the shock tube walls. T2 - 7th Conference on Industrial Computed Tomography CY - Leuven, Belgium DA - 07.02.2017 KW - Explosive KW - Nonel KW - Shock wave KW - Blasting KW - Energetic systems PY - 2017 AN - OPUS4-39168 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien T1 - Distance transform methodology for advanced impact damage characterisation of composite laminates by X-ray computed tomography N2 - During their life cycle, composite structures used in aircraft structures can be subjected to high- and low-velocity impact loading. High velocity impact damage is usually easy to detect as it creates visible external damage. Low-velocity impacts are more complex to assess because, although significant damage can be generated internally, there can be little indication of external damage on the impacted surface, leading to the term BVID. Impact damage, especially barely visible impact damage, is therefore of primary concern for design and maintenance of modern aircraft composite structures. As a result there is a concerted research effort to improve the damage resistance and tolerance of these materials. One of the great strengths of X-ray computed tomography over conventional inspection methods (ultrasound, thermography, radiography) is that it can image damage in 3D. or inter-ply interfaces. An X-ray computed tomography (CT) data processing methodology is developed to extract the through-thickness distribution of damage in curved or deformed composite panels. The method is applied to [(0°/90°)2]s carbon fibre reinforced polymer (CFRP) panels subjected to low velocity impact damage (5 J up to 20 J) providing 3D ply-by-ply damage visualisation and analysis. Our distance transform approach allows slices to be taken that approximately follow the composite curvature allowing the impact damage to be separated, visualised and quantified in 3D on a ply-by-ply basis. In this way the interply delaminations have been mapped, showing characteristic peanut shaped delaminations with the major axis oriented with the fibres in the ply below the interface. This registry to the profile of the panel constitutes a significant improvement in our ability to characterise impact damage in composite laminates and extract relevant measurements from X-ray CT datasets. T2 - ECNDT2018 CY - Gothenburg, Sweden DA - 11.06.2018 KW - Panels KW - Data processing KW - Correlation map KW - CT KW - Delamination PY - 2018 AN - OPUS4-45207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishurova, Tatiana A1 - Léonard, Fabien A1 - Oesch, Tyler A1 - Meinel, Dietmar A1 - Bruno, Giovanni A1 - Rachmatulin, Natalia A1 - Fontana, Patrick A1 - Sevostianov, I. T1 - Evaluation of fiber orientation in a composite and its effect on material behavior N2 - The reinforcement of concrete with polymer fibers provides resistance to crack formation. The orientation distribution of these fibers has a significant influence on the mechanical behavior of the material. To optimize material performance, micromechanical models that are capable of making accurate predictions of the mechanical behavior of composite materials are needed. These models must be calibrated using experimental results from microstructural characterization. For the fiber orientation distribution analysis in the present study, computed tomography (CT) data were used to evaluate the properties of a fiber-reinforced cement mortar. The results have indicated that the fibers in this material have highly anisotropic orientation characteristics and that there is a clear tendency for the polymer fibers to agglomerate during mixing and casting. The incorporation of this experimental data into micromechanical models will increase the accuracy of those models for material simulation and optimization. T2 - 7th Conference on Industrial Computed Tomography (iCT 2017) CY - Leuven, Belgium DA - 07.02.2017 KW - Orientation distribution KW - Fiber-reinforced concrete KW - Computed tomography PY - 2017 UR - http://www.ndt.net/?id=20818 SN - 1435-4934 VL - 22 IS - 3 SP - 1 EP - 7 PB - NDT.net CY - Kirchwald AN - OPUS4-39338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien T1 - On nominal-actual comparisons for additive manufacturing applications N2 - Nominal-actual comparisons are routinely performed to compare a manufactured specimen to a reference specimen. X-ray Computed Tomography (CT) has brought a profound change in the way that tolerance verifications are performed in industry, by allowing the inner and outer geometries of an object to be measured, without the need for external access or destructive testing. As a results, CT is increasingly used in additive manufacturing applications, where a nominal-actual comparison performed between the digital model (CAD file), used as an input for the 3D printer, and the CT volume from the printed part, can provide invaluable information as to the accuracy of the printing process. However, the nominal-actual comparison process is somewhat different when applied to additively manufactured specimens by comparison to conventionally manufactured specimens. T2 - 9th Conference on Industrial Computed Tomography CY - Padova, Italy DA - 14.02.2019 KW - Computed tomography KW - X-ray computed tomography PY - 2019 AN - OPUS4-47833 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien T1 - Metrology for Additively Manufactured Medical Implants: The MetAMMI project N2 - Additive manufacturing (AM) offers an effective solution to the medical sector. It enables the production, on demand, of customised implants which match the patient’s anatomy, with grafts that promote bone growth, as well as surgical guides that help the surgeons. The objective of this project is to provide a comprehensive basis to enable the safe use of medical AM products with traceable and reliable dimensionalmeasurements. This will guarantee the reliability of medical AM products to notified bodies and facilitate acceptance of AM in the medical sector for a better quality of life. T2 - BPWT/BAM Workshop " Innovative Materialien und Qualitätskontrolle für additive Fertigung" CY - Berlin, Germany DA - 12.09.2018 KW - Additive manufacturing KW - X-ray computed tomography PY - 2018 AN - OPUS4-45926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien T1 - Metrology for additively manufactured medical implants N2 - Additive manufacturing (AM) offers an effective solution to the medical sector. It enables the production, on demand, of customised implants which match the patient’s anatomy, with grafts that promote bone growth, as well as surgical guides that help the surgeons. The objective of this project is to provide a comprehensive basis to enable the safe use of medical AM products with traceable and reliable dimensionalmeasurements. This will guarantee the reliability of medical AM products to notified bodies and facilitate acceptance of AM in the medical sector for a better quality of life. T2 - 8th iCT 2018 conference CY - Wels, Austria DA - 06.02.2018 KW - Implants KW - Metrology KW - Additive manufacturing PY - 2018 AN - OPUS4-44400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Bernd R. A1 - Léonard, Fabien A1 - Lange, Axel A1 - Kupsch, Andreas A1 - Bruno, Giovanni T1 - X-ray refraction techniques for fast, high-resolution microstructure characterization and non-destructive testing of lightweight composites N2 - X-ray refraction is based on optical deflection of X-rays, similar to the well-known small angle X-ray scattering, but hundreds of times more intense, thus enabling shorter measurement time. We show that X-ray refraction techniques are suitable for the detection of pores, cracks, and in general defects. Indeed, the deflected X-ray intensity is directly proportional to the internal specific surface (i.e., surface per unit volume) of the objects. Although single defects cannot be imaged, the presence of populations of those defects can be detected even if the defects have sizes in the nanometer range.We present several applications of X-ray refraction techniques to composite materials:- To visualize macro and microcracks in Ti-SiC metal matrix composites (MMC);- To correlate fatigue damage (fibre de-bonding) of carbon fibre reinforced plastics (CFRP) to X-ray refraction intensity;- To quantify the impact damage by spatially resolved single fibre de-bonding fraction as a function of impact energy in CFRP laminates.An example of classic high-resolution computer tomography of an impact-damaged CFRP will also be presented, as a benchmark to the present state-of-the-art imaging capabilities. It will be shown that while (absorption) tomography can well visualize and quantify delamination, X-ray refraction techniques directly yield (spatially resolved) quantitative information about fibre de-bonding, inaccessible to absorption tomography. KW - X-ray KW - Synchrotron radiation KW - Refraction KW - Metal matrix composites KW - Delamination KW - Fiber de-bonding PY - 2015 DO - https://doi.org/10.4028/www.scientific.net/MSF.825-826.814 SN - 0255-5476 VL - 825-826 SP - 814 EP - 821 PB - Trans Tech Publications CY - Aedermannsdorf, Switzerland AN - OPUS4-33265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lüchtenborg, Jörg A1 - Mühler, T. A1 - Léonard, Fabien A1 - Günster, Jens T1 - Laser-induced slip casting (LIS) – a new additive manufacturing process for dense ceramics demonstrated with Si3N4 N2 - Up to now, there exists a lack of methods for the additive manufacturing of voluminous ceramic parts with properties comparable to those of conventionally manufactured ones. A high density after sintering is needed to reach the superior properties of ceramic materials. We have developed a new additive manufacturing method, Laser-Induced Slip casting (LIS), to generate ceramic green bodies with high particle packing density and with virtually no restriction in the particle size of the feedstock, especially in terms of small particles. This is achieved by laser-induced local drying of slurries, with the process resembling many features of the well-established stereolithography, but without the excessive use of polymeric material. Thus, unlike the stereolithography process, the resulting green bodies can be processed like traditionally produced ceramic parts. This method allows large and dense additive-manufactured parts to be obtained from conventional water-based ceramic slurries. As an example, we will demonstrate the application of this novel technique with Si3N4. KW - Additive manufacturing KW - Ceramics PY - 2017 DO - https://doi.org/10.4416/JCST2017-00091 SN - 2190-9385 VL - 8 IS - 4 SP - 531 EP - 540 PB - Göller Verlag CY - Baden-Baden AN - OPUS4-43738 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zocca, Andrea A1 - Lüchtenborg, Jörg A1 - Mühler, T. A1 - Wilbig, Janka A1 - Mohr, Gunther A1 - Villatte, T. A1 - Léonard, Fabien A1 - Nolze, Gert A1 - Sparenberg, M. A1 - Melcher, J. A1 - Hilgenberg, Kai A1 - Günster, Jens T1 - Enabling the 3D Printing of Metal Components in μ-Gravity N2 - As humanity contemplates manned missions to Mars, strategies need to be developed for the design and operation of hospitable environments to safely work in space for years. The supply of spare parts for repair and replacement of lost equipment will be one key need, but in-space manufacturing remains the only option for a timely supply. With high flexibility in design and the ability to manufacture ready-to-use components directly from a computeraided model, additive manufacturing (AM) technologies appear extremely attractive. For the manufacturing of metal parts, laser-beam melting is the most widely used AM process. However, the handling of metal powders in the absence of gravity is one prerequisite for its successful application in space. A gas flow throughout the powder bed is successfully applied to compensate for missing gravitational forces in microgravity experiments. This so-called gas-flow-assisted powder deposition is based on a porous Building platform acting as a filter for the fixation of metal particles in a gas flow driven by a pressure difference maintained by a vacuum pump. KW - Additive manufacturing KW - µ-gravity KW - Laser beam melting KW - Parabolic flight KW - 3D printing PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-492190 DO - https://doi.org/10.1002/admt.201900506 SP - 1900506 PB - WILEY-VCH Verlag GmbH AN - OPUS4-49219 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -