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 T2 - Tagungsband der DGZfP-Jahrestagung 2021 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 - CONF A1 - Léonard, Fabien A1 - Bruno, Giovanni 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 - Örnek, C. A1 - Léonard, Fabien A1 - McDonald, S. A1 - Prajapati, A A1 - Withers, P. J. A1 - Engelberg, D. T1 - Time-dependent in situ measurement of atmospheric corrosion rates of duplex stainless steel wires JF - npj Materials Degradation N2 - Corrosion rates of strained grade UNS S32202 (2202) and UNS S32205 (2205) duplex stainless steel wires have been measured, in situ, using time-lapse X-ray computed tomography. Exposures to chloride-containing (MgCl2) atmospheric environments at 50 °C (12–15 M Cl− and pH ~5) with different mechanical elastic and elastic/plastic loads were carried out over a period of 21 months. The corrosion rates for grade 2202 increased over time, showing selective dissolution with shallow corrosion sites, coalescing along the surface of the wire. Corrosion rates of grade 2205 decreased over time, showing both selective and pitting corrosion with more localised attack, growing preferentially in depth. The nucleation of stress corrosion cracking was observed in both wires. KW - X-ray computed tomography KW - Time-lapse X-ray computed tomography PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-444153 UR - https://www.nature.com/articles/s41529-018-0030-9 DO - https://doi.org/10.1038/s41529-018-0030-9 SN - 2397-2106 VL - 2 SP - Article 10, 1 EP - 15 PB - Nature CY - London AN - OPUS4-44415 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien A1 - Bruno, Giovanni 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 - 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 JF - Cement and Concrete Research 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 - 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 JF - IOP Conf. Series: Journal of Physics 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 - Khrapov, D A1 - Koptyug, A. A1 - Manabaev, K. A1 - Léonard, Fabien A1 - Mishurova, Tatiana A1 - Bruno, Giovanni A1 - Cheneler, D. A1 - Loza, K. A1 - Epple, M. A1 - Surmenev, R. A1 - Surmeneva, M. T1 - The impact of post manufacturing treatment of functionally graded Ti6Al4V scaffolds on their surface morphology and mechanical strength JF - Journal of Material Research and Technology N2 - An ultrasonic vibration post-treatment procedure was suggested for additively manufac-tured lattices. The aim of the present research was to investigate mechanical properties andthe differences in mechanical behavior and fracture modes of Ti6Al4V scaffolds treated withtraditional powder recovery system (PRS) and ultrasound vibration (USV). Scanning electronmicroscopy (SEM) was used to investigate the strut surface and the fracture surface mor-phology. X-ray computed tomography (CT) was employed to evaluate the inner structure,strut dimensions, pore size, as well as the surface morphology of additively manufacturedporous scaffolds. Uniaxial compression tests were conducted to obtain elastic modulus,compressive ultimate strength and yield stress. Finite element analysis was performedfor a body-centered cubic (BCC) element-based model and for CT-based reconstructiondata, as well as for a two-zone scaffold model to evaluate stress distribution during elasticdeformation. The scaffold with PRS post treatment displayed ductile behavior, while USVtreated scaffold displayed fragile behavior. Double barrel formation of PRS treated scaffoldwas observed during deformation. Finite element analysis for the CT-based reconstructionrevealed the strong impact of surface morphology on the stress distribution in comparisonwith BCC cell model because of partially molten metal particles on the surface of struts,which usually remain unstressed. KW - Additive manufacturing KW - Electron beam melting KW - Computed tomography KW - FEM KW - Lattice structures PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505960 DO - https://doi.org/10.1016/j.jmrt.2019.12.019 SN - 2238-7854 VL - 9 IS - 2 SP - 1866 EP - 1881 PB - Elsevier B.V. AN - OPUS4-50596 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 JF - Archives of Mechanics 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 - 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 JF - Enginnering Fracture Mechanics 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 - Léonard, Fabien A1 - Zhang, Zhen A1 - Krebs, Holger A1 - Bruno, Giovanni T1 - Structural and Morphological Quantitative 3D Characterisation of Ammonium Nitrate Prills by X-ray Computed Tomography JF - Materials N2 - The mixture of ammonium nitrate (AN) prills and fuel oil (FO), usually referred to as ANFO, is extensively used in the mining industry as a bulk explosive. One of the major performance predictors of ANFO mixtures is the fuel oil retention, which is itself governed by the complex pore structure of the AN prills. 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. Importantly, oil retention measurements (qualifying the efficiency of ANFO as explosives) correlate well with the specific surface area determined by XCT. XCT can therefore be employed non-destructively; it can accurately evaluate and characterise porosity in ammonium nitrate prills, and even predict their efficiency. KW - ANFO KW - Explosives KW - Surface area KW - Porosity KW - XCT KW - Data processing PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505395 DO - https://doi.org/10.3390/ma13051230 VL - 13 IS - 5 (Special Issue "Micro Non-Destructive Testing and Evaluation") SP - 1230 PB - MDPI AN - OPUS4-50539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien A1 - Zhang, Zhen A1 - Krebs, Holger A1 - Bruno, Giovanni T1 - Morphological characterisation of explosive powders by XCT: When grain numbers count N2 - Ammonium nitrate (AN) prills are commonly used as an ingredient in industrial explosives and in fertilisers. Conventional techniques (such as BET or mercury intrusion porosimetry) can measure the open porosity and specific surface area of AN prill, but the closed porosity is not obtainable. This work was focused on evaluating X-ray computed tomography (XCT) as a non-destructive technique for the assessment of porosity in AN prills. An advanced data processing workflow was developed so that the segmentation and quantification of the CT data could be performed on the entire 3D volume, yet allowing the measurements (e.g.; volume, area, shape factor…) to be extracted for each individual phase (prill, open porosity, closed porosity) of each individual prill, in order to obtain statistically relevant data. Clear morphological and structural differences were seen and quantified between fertiliser and explosive products. Overall, CT can provide a very wide range of parameters that are not accessible to other techniques, destructive or non-destructive, and thus offers new insights and complementary information. T2 - iCT2020 CY - Wels, Austria DA - 04.02.2020 KW - Ammonium nitrate KW - Prill KW - Non-destructive characterisation KW - Porosity KW - Specific surface area PY - 2020 AN - OPUS4-50347 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Léonard, Fabien A1 - Zhang, Zhen A1 - Krebs, Holger A1 - Bruno, Giovanni T1 - Morphological characterisation of explosive powders by XCT: When grain numbers count JF - The e-journal of nondestructive testing & ultrasonics N2 - Ammonium nitrate (AN) prills are commonly used as an ingredient in industrial explosives and in fertilisers. Conventional techniques (such as BET or mercury intrusion porosimetry) can measure the open porosity and specific surface area of AN prill, but the closed porosity is not obtainable. This work was focused on evaluating X-ray computed tomography (XCT) as a non-destructive technique for the assessment of porosity in AN prills. An advanced data processing workflow was developed so that the segmentation and quantification of the CT data could be performed on the entire 3D volume, yet allowing the measurements (e.g.; volume, area, shape factor…) to be extracted for each individual phase (prill, open porosity, closed porosity) of each individual prill, in order to obtain statistically relevant data. Clear morphological and structural differences were seen and quantified between fertiliser and explosive products. Overall, CT can provide a very wide range of parameters that are not accessible to other techniques, destructive or non-destructive, and thus offers new insights and complementary information. T2 - 10th Conference on Industrial Computed Tomography (iCT 2020) CY - Wels, Austria DA - 04.02.2020 KW - Ammonium nitrate KW - Prill KW - Non-destructive characterisation KW - Porosity KW - Specific surface area PY - 2020 UR - http://www.ndt.net/?id=25118 SN - 1435-4934 VL - 25 IS - 2 SP - 1 EP - 6 PB - NDT.net CY - Kirchwald AN - OPUS4-50348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Léonard, Fabien T1 - Good practice guide on the correct choice of characterisation technique based on level of accuracy and type of measurement N2 - The characterisation of AM structures is an important aspect of the AM process, required in order to: 1. optimise the AM printing process 2. assess the quality of produced parts A wide range of characterisation techniques are available, and the selection can be complex, based on multiple factors. One output from the MetAMMi project is a good practice guide on the correct choice of characterisation technique. T2 - Workshop on additive manufacturing CY - Berlin, Germany DA - 13.05.2019 KW - X-ray computed tomography KW - Mechanical properties KW - Microstructural analysis KW - Defect detection PY - 2019 AN - OPUS4-48262 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - GEN A1 - Léonard, Fabien T1 - Overview of XCT data processing workflow for ammonium nitrate prills quantitative analysis N2 - This video presents the data processing workflow that was developed to perform the quantitative structural and morphological analysis of ammonium nitrate prills by x-ray computed tomography. KW - ANFO KW - Data processing KW - Explosives KW - Porosity KW - Surface area KW - XCT PY - 2020 DO - https://doi.org/10.5281/zenodo.3611339 PB - Zenodo CY - Geneva AN - OPUS4-51897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ulbricht, Alexander A1 - Gollwitzer, Christian A1 - Kupsch, Andreas A1 - Léonard, Fabien A1 - Müller, Bernd R. A1 - Oesch, Tyler A1 - Onel, Yener A1 - Thiede, Tobias A1 - Zscherpel, Uwe ED - Puente León, F. ED - Zagar, B. T1 - Moderne Methoden der CT-gestützten Strukturanalyse T1 - Modern techniques of CT based structure analysis JF - tm - Technisches Messen N2 - Durch den großflächigen Einsatz der Computertomographie (CT) in unterschiedlichen Industriebereichen steigen auch die Anforderungen an die quantitative Bildanalyse. Subjektive Bildwahrnehmung muss durch objektive Algorithmen ersetzt werden. In diesem Artikel stellt die Bundesanstalt für Materialforschung und -prüfung (BAM), die seit den 1980er Jahren an der Entwicklung der industriellen CT beteiligt ist, anhand ausgewählter Beispiele den aktuellen Stand ihrer Analysemethoden an verschiedenen Anwendungsbeispielen der CT vor. N2 - The increasing use of computed tomography (CT) in various industrial sectors requires more sophisticated techniques of quantitative image analysis. Subjective image perception needs to be replaced by objective algorithms. The German Federal Institute for Materials Research and Testing (BAM) has been involved in the development of industrial CT since the 1980s. This paper summarizes the current status of quantitative 3D image analysis techniques based on selected examples. KW - Computed tomography KW - Computertomographie KW - Röntgen-Refraktion KW - X-Ray refraction KW - Schadensanalyse KW - Damage analysis KW - Normung KW - standardization PY - 2020 DO - https://doi.org/10.1515/teme-2019-0125 SN - 0171-8096 SN - 2196-7113 VL - 87 IS - 2 SP - 81 EP - 91 PB - de Gruyter CY - Berlin AN - OPUS4-50337 LA - deu 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 JF - Philosophical Magazine 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 - Léonard, Fabien T1 - Distance maps and Avizo workflows for impact damage characterisation in composite panels 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 - Avizo/Amira User group meeting CY - Berlin, Germany DA - 14.11.2018 KW - Impact damage KW - Damage histogram KW - Damage correlation map KW - Composite panel KW - X-ray computed tomography PY - 2018 AN - OPUS4-46598 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 JF - Journal of Physics Conference Series 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 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-471931 UR - http://stacks.iop.org/1742-6596/1145/i=1/a=012044 DO - https://doi.org/10.1088/1742-6596/1145/1/012044 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 - Léonard, Fabien A1 - Tiede, Tobias A1 - Mishurova, Tatiana A1 - Laquai, René A1 - Bruno, Giovanni 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 A1 - Bruno, Giovanni 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 - 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 - Bruno, Giovanni 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 A1 - Bruno, Giovanni 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 - 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 JF - Advanced Materials Technologies 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 -