TY - JOUR A1 - Roveda, Ilaria A1 - Serrano-Munoz, Itziar A1 - Haubrich, Jan A1 - Requena, Guillermo A1 - Madia, Mauro T1 - Investigation on the fatigue strength of AlSi10Mg fabricated by PBF-LB/M and subjected to low temperature heat treatments N2 - This work provides an investigation of the influence of low temperature heat treatments on the fatigue behavior of a PBF-LB AlSi10Mg alloy. Fatigue specimens are produced in form of round bars on a build platform preheated at 200 ◦C. The specimens have been tested in three different conditions: as-built, and after heat treatments at 265 ◦C for 1 h and 300 ◦C for 2 h. Prior to the fatigue testing, the defect distribution is analyzed by means of micro computed tomography. Subsequently, the peak over threshold method is successfully applied to provide a prediction of the size of killer defect. The defect population was of gas porosity type. No clear improvement of the fatigue performance is observed after the heat treatments. The fatigue strength predicted using fracture mechanics-based approaches is in good agreement with the experimental data. Among the studied approaches, short crack models provided the most conservative predictions. KW - PBF-LB/M AlSi10Mg KW - Fatigue strength KW - Defects KW - Kitagawa-Takahashi Diagram KW - Short Crack Models PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607071 DO - https://doi.org/10.1016/j.matdes.2024.113170 SN - 0264-1275 VL - 244 SP - 1 EP - 12 PB - Elsevier Ltd. AN - OPUS4-60707 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mege-Revil, Alexandre A1 - Rapontchombo-Omanda, Jessie A1 - Serrano-Munoz, Itziar A1 - Cristol, Anne-Lise A1 - Magnier, Vincent A1 - Dufrenoy, Philippe T1 - Sintered Brake Pads Failure in High-Energy Dissipation Braking Tests: A Post-Mortem Mechanical and Microstructural Analysis N2 - The industrial sintering process used to produce metallic matrix pads has been altered to diminish the amount of copper used. Unfortunately, replacing a large part of the copper with iron seems to have reached a limit. In the high-energy, emergency-type rail braking used in this study, the materials are put to the very limit of their usage capacity, allowing us to observe the evolution of the microstructure and mechanical properties of sintered, metallic matrix pads. After the braking test, their compressive behaviour was assessed using digital image correlation (DIC), and their microstructure with scanning electron microscopy (SEM). The worn material has three flat layers with different microstructures and compressive behaviours. The bo􀁇om layer seems unmodified. Macroscopic and microscopic cracks run through the intermediate layer (2–15 mm depth). The top layer has stiffened thanks to resolidification of copper. The temperature reaches 1000 °C during the braking test, which also explains the carbon diffusion into iron that result in the weakening of iron–graphite interfaces in the pad. Finally, submicronic particles are detected at many open interfaces of the worn and compressed pad. Associated with the predominant role of graphite particles, this explains the weak compressive behaviour of the pads. KW - Friction braking KW - Sintering KW - Metallic matrix pad KW - Microstructure KW - Scanning electron microscopy (SEM) KW - Compressive test KW - Cracks KW - Digital image correlation (DIC) KW - Diffusion PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-587318 DO - https://doi.org/10.3390/ma16217006 SN - 1996-1944 VL - 16 IS - 21 SP - 1 EP - 18 PB - MDPI AN - OPUS4-58731 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano-Munoz, Itziar A1 - Magnier, V. A1 - Brunel, F. A1 - Dufrenoy, P. T1 - Influence of the Composition on the Compressive Behaviour of a Semi-Metallic Brake-Pad Material N2 - The contact interface between the rotation and static part of a friction brake is central to the optimal functioning of the brake system due to the occurrence of heat dissipation, mechanical interaction and thermal exchanges. Generally, braking performances are evaluated by the energetic efficiency and wear rates of the contact surface. However, the compressive behaviour of the contact materials has also a significant contribution to the overall performances. In this work, the meso- and microscopic compressive behaviour of a sintered semi-metallic brake-pad material is investigated mainly via compression testing coupled with Digital Image Correlation (DIC) technique, as well as optical and scanning electron microscopy (SEM) analysis. The composition of a reference material (RM) is simplified to a selection of nine components, as opposed to up to thirty components typically used in commercial brake-pad materials. The retained components are considered as the most crucial for safe-operating performances. At the studied stress levels, the RM material is flexible (E = 5330 MPa), deformable (Ezz−plastic = −0.21%), and exhibits hysteresis loops. Subsequently, the contribution to the mechanical response of each individual component is investigated by producing the so-called dissociated materials, where the number of components is, at a time, further reduced. It is observed that the macroscopic behaviour is mainly controlled by the content (i.e., size distribution, shape and nature) of graphite particles, and that the hysteresis is only related to one of the two types of graphite used (G2 particles). Moreover, RM containing 13 wt% of G2 particles embedded in a relatively soft matrix (10.86 GPa) is able to increase the hysteresis (by 35%) when compared to the dissociated material containing 20 wt% of G2 particles which is embedded in a stiffer matrix (E = 106 GPa). KW - Semi-metallic brake-pad material KW - Powder metallurgy KW - Components influence KW - Graphite induced hysteresis KW - Digital image correlation (DIC) KW - Compression testing PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-562003 DO - https://doi.org/10.3390/ma15227911 VL - 15 IS - 22 SP - 7911 PB - MDPI AN - OPUS4-56200 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Roveda, Ilaria A1 - Serrano-Munoz, Itziar A1 - Kromm, Arne A1 - Madia, Mauro T1 - Investigation of residual stresses and microstructure effects on the fatigue behaviour of a L-PBF AlSi10Mg alloy N2 - Al-Si alloys produced by Laser Powder Bed Fusion (L-PBF) techniques allow the fabrication of lightweight free-shape components that find space in aerospace, automotive, biomedical and military applications. Due to the high cooling rates occurring during the building process, L-PBF AlSi10Mg alloys exhibit an ultra-fine microstructure that leads to superior mechanical properties in the as-built condition compared to conventional cast Al-Si materials. Nevertheless, L-PBF processing induces high thermal gradients, leading to deleterious residual stress levels that must be considered to avoid part distortion and unpredicted failures. In order to relax detrimental residual stress and to increase the ductility, post-processing stress relief treatments are generally performed. In as-built condition the hypoeutectic AlSi10Mg microstructure consist of fine α-Al cells containing uniformly dispersed silicon nanoparticles, which are, in addition, surrounded by a eutectic Si network. Above 260°C the silicon interconnectivity starts to breakdown into spheroidized particles and to coarsen. At the same time, the heating residual stresses are relieved. The objective of the contribution is to investigate, under different heat treatment conditions, the evolution of microstructure and residual stresses in view of optimizing the fatigue performance of the alloy. To this purpose various heat treatments in a range of temperatures between 265°C and 300°C for a duration between 15 minutes and 2 hours are performed. The microstructure modifications are analysed using a scanning electron microscope and the residual stress state is measured by laboratory X-ray diffraction. T2 - FATIGUE DESIGN 2021 CY - Online meeting DA - 17.11.2021 KW - AlSi10Mg alloy KW - Additive manufacturing KW - L-PBF KW - Residual stress KW - Heat treatment PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-544942 DO - https://doi.org/10.1016/j.prostr.2022.03.057 SN - 2452-3216 VL - 38 SP - 564 EP - 571 PB - Elsevier B.V. AN - OPUS4-54494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Roveda, Ilaria A1 - Serrano-Munoz, Itziar A1 - Haubrich, J. A1 - Requena, G. A1 - Madia, Mauro T1 - Influence of post-process heat treatments on the fatigue crack propagation behaviour of a PBF-LB/M AlSi10Mg alloy N2 - The microstructure has a great influence on short fatigue crack growth in metallic materials. Laser-based Powder Bed Fusion AlSi10Mg alloys exhibit in the as-built condition a fine fibrous Si structure and a supersaturated solid solution of Si in the α-Al matrix, which is significantly modified by heat treatments starting already at temperatures under 260 °C. This study focuses on the influence of post-process heat treatments on the microstructural evolution and the resulting fatigue crack growth resistance. As compared to the as-built condition, two heat treatments at 265 °C/1 h and at 300 °C/2 h are found to be beneficial to the fatigue crack growth resistance of the investigated material. KW - Additive manufacturing KW - Fatigue crack growth KW - Cyclic R-curve KW - Heat treatment PY - 2023 DO - https://doi.org/10.1016/j.ijfatigue.2023.107808 SN - 0142-1123 VL - 175 SP - 1 EP - 12 PB - Elsevier Ltd. AN - OPUS4-57822 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mishurova, Tatiana A1 - Serrano-Munoz, Itziar T1 - Multiscale residual stress analysis and synchrotron X-ray refraction of additively manufactured parts N2 - The overview of the activity of group 8.5 Micro-NDT (BAM, Belin, Germany) in the field of additively manufacturing material characterization will be presented. The challenges in the residual stress analysis of AM components are discussed on the basis on the show studies performed in BAM. Also, the synchrotron X-ray refraction technique, available in BAM, is presented, showing example of in-situ heating test of Al10SiMg AM material. T2 - Seminar at Grenoble INP, Science et Ingénierie des Matériaux et Procédés (SIMaP) CY - Grenoble, France DA - 01.07.2022 KW - Additive manufacturing KW - Residual stress KW - X-ray refraction KW - Computed tomography PY - 2022 AN - OPUS4-55232 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Serrano-Munoz, Itziar T1 - Influence of microstructure and residual stress state on the fatigue behaviour of a PBF-LB/M AlSi10Mg alloy N2 - The high cooling rates (~106 K/s) occurring during Laser Powder Bed Fusion (PBF-LB/M) of AlSi10Mg induce to the formation of a fine nanometric silicon network in the as-built condition. Such unprecedented microstructure enhances the mechanical strength when compared to equivalent as-cast materials. Nevertheless, PBF-LB/M also leads to high magnitude residual stress (RS) due to the extreme localized temperature gradients. The presence of RS can be detrimental to the fatigue life of engineering components, and great efforts are focused on understanding their generation and evolution after post-process heat treatments. Typically, T6 heat treatments are used to mitigate RS and improve mechanical performances by Mg2Si precipitation during ageing at 160-180°C. Nevertheless, the solutionizing at 500-540°C vanishes the fine silicon network, leading to the formation of micrometric (average of ~2-5 µm) polygonal Si particles, similar to those observed in T6 heat-treated Al-Si cast materials. Therefore, the aim of this work is to evaluate the ability of two so-called low temperature heat treatments (i.e., at 265°C and 300°C) to mitigate RS while retaining the fine as-built microstructure inherent to PBF-LB/M AlSi10Mg. The fatigue behavior of the as-built material is subsequently compared to the two low temperature conditions. T2 - LightMat 2023 CY - Trondheim, Norway DA - 21.06.2023 KW - AlSi10Mg KW - Fatigue crack propagation KW - Residual stress KW - Post processing heat treatment PY - 2023 AN - OPUS4-57807 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Serrano-Munoz, Itziar T1 - 3D imaging and residual stress analysis for AM Materials N2 - Metal Additive Manufacturing (AM) technologies such as Laser Powder Bed Fusion (LPBF) are characterized by layer wise construction, which enable advancements of component design, leading to potential efficiency and performance improvements. However, the rapid cooling rates associated with the process consequently leads to the generation of high magnitude residual stresses (RS). Therefore, a deep understanding of the formation of RS, the influence of process parameters on their magnitude and the impact on mechanical performance is crucial for widespread application. The experimental characterization of these RS is essential for safety related engineering application and supporting the development of reliable numerical models. Diffraction-based methods for RS analysis using high energy synchrotron X-rays and neutrons enable non-destructive spatially resolved characterization of both surface and bulk residual stresses in complex components. This presentation will provide an overview of recent research conducted by the BAM at large scale facilities for the characterization of residual stresses in LPBF metallic alloys. Special focus will be given to the challenges posed by textured LPBF materials for the reliable choice of the diffraction elastic constants (DECs), which is crucial to the accurate calculation of the level of RS. T2 - Seminar at LTDS, Ecole Centrale de Lyon CY - Lyon, France DA - 15.06.2023 KW - Residual stress KW - Additive manufacturing KW - Diffraction methods PY - 2023 AN - OPUS4-57808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano-Munoz, Itziar A1 - Magnier, Vincent A1 - Dufrenoy, Philippe T1 - Identification of damage mechanisms in a metal-matrix composite material via digital volume correlation and finite element model updating N2 - A 3D experimental and numerical investigation of the damage mechanisms induced by compression in a metal matrix composite is presented. The investigated composite is a simplified version of those typically used for heavy-duty brake linings, comprising only nine constituents. The analysis combines laboratory X-ray computed tomography (XCT), image volume correlation (DVC), as well as image-based finite element method (FEM) paired with an inverse identification approach known as finite element model updating (FEMU). The combination of in situ XCT and DVC allows the rationalization of the mechanisms controlling strain localization and damage accumulation within the heterogeneous metal matrix. The damage mainly occurs in the form of fractured material within thin cell-walls located between large graphite G2 particles. In addition, the herein developed FEMU approach enables the identification of the elastic moduli of the two defined key constituents controlling the macroscopic compressive behavior (i.e., the Matrix –where eight of the nine constituents are lumped– and G2 particles), as well as the prediction of the damaged regions within the Matrix. It is emphasized that an implementation of the damage mechanisms within the FEMU is essential for a reliable numerical prediction of the compressive response of the composite. KW - Metallic brake lining KW - Compression tests KW - In situ X-ray computed tomography (XCT) KW - Image-based finite element method (FEM) KW - Damage mechanisms KW - Digital volume correlation (DVC) KW - Finite element model updating (FEMU) PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639388 DO - https://doi.org/10.1016/j.mtcomm.2025.113459 SN - 2352-4928 VL - 48 SP - 1 EP - 13 PB - Elsevier Ltd. AN - OPUS4-63938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Santi, Alberto A1 - Schröder, Jakob A1 - Serrano-Munoz, Itziar A1 - Bayat, Mohamad A1 - Hattel, Jesper Henri T1 - Exploring the Flash Heating method in additive manufacturing for residual stress prediction: A comparative study with diffraction results from X-ray and neutron techniques N2 - Residual stress (RS) control is crucial for ensuring the performance and reliability of components produced through laser-based powder bed fusion (PBF-LB) additive manufacturing (AM). This study evaluates the Flash Heating (FH) method as an efficient approach for RS prediction, comparing its outcomes with multiple experimental techniques, including X-ray diffraction, neutron diffraction, and layer removal methods. These experimental assessments are conducted in different regions of the component, both before and after detachment from the baseplate. The study validates the FH method and analyzes key numerical parameters, such as meta-layer height, contact time, and time-stepping strategies. Results indicate that FH effectively predicts bulk RS distributions but shows discrepancies in surface stress estimations, likely due to unaccounted factors like surface roughness. Additionally, implementing experimentally derived material properties from as-built AM samples significantly enhances model accuracy compared to conventional material datasets. These findings underscore the potential of FH for efficient RS prediction in PBF-LB while identifying areas for further improvement. Refinements should focus on incorporating anisotropic, temperature-dependent material behavior derived from as-built AM samples and surface roughness effects. This work advances the understanding of key factors necessary for accurate and computationally efficient RS prediction, supporting the optimization of AM processes. KW - Finete element method KW - Inconel 718 KW - Metal additive manufacturing KW - Residual stress KW - Thermomechanics PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639533 DO - https://doi.org/10.1080/01495739.2025.2541862 SN - 0149-5739 SP - 1 EP - 24 PB - Taylor & Francis AN - OPUS4-63953 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano-Munoz, Itziar A1 - Shiozawa, D. A1 - Dancette, S. A1 - Verdu, C. A1 - Buffiere, J.-Y. T1 - Torsional fatigue mechanisms of an A357-T6 cast aluminium alloy N2 - The mechanisms controlling the fatigue response of an A357-T6 cast aluminium alloy under cyclic torsional loading are investigated. Surface crack monitoring coupled with Electron BackScattering Diffraction (EBSD) analysis is used to study crack initiation. Determination of S-N curve combined with interrupted in situ fatigue testing using synchrotron tomography allows the study of the propagation behaviour. It is observed that fractographic morphologies depend on the stress level. At intermediate-low stress levels ( τmax < 100 MPa), the grain structure controls the crack initiation and propagation periods. Cracks are usually nucleated in mode II from slip planes close to the specimen axis or perpendicular to it. Mode II crack growth dominates the early stages of crack propagation as mode III inward crack growth is rapidly decelerated. This behaviour leads to the formation of characteristic shallow surface cracks. Once the crack is long enough for the mode II driving force to be overtaken by mode III, propagation branches into ~45 ◦mode I. KW - A357-T6 casting KW - Fractographic observations KW - EBSD analysis KW - X-ray synchrotron tomography KW - Torsional in situ fatigue testing KW - SIF evaluation PY - 2020 DO - https://doi.org/10.1016/j.actamat.2020.09.046 VL - 201 SP - 435 EP - 447 PB - Elsevier Ltd. AN - OPUS4-51461 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano-Munoz, Itziar A1 - Dancette, S. A1 - Verdu, C. A1 - Buffiere, J.-Y. T1 - Influence of Pore Size and Crystallography on the Small Crack HCF Behavior of an A357-T6 Cast Aluminum Alloy N2 - The high-cycle fatigue, small crack propagation behavior of an A357-T6 cast aluminum alloy is investigated. Laboratory X-ray micro-computed tomography (μCT) is used to assist in the manufacturing of two flat fatigue specimens containing subsurface shrinkage pores of different sizes (Pore 1 √A=522μm against Pore 2 √A=280μm). Surface crack monitoring is performed by means of optical microscopy and the cracked specimens are analyzed via scanning electron microscopy and electron backscatter diffraction techniques. The subsurface pores tend to induce intergranular crack nucleation, principally when the grain boundaries are oriented perpendicular to the loading direction. Pore 1 induces a fatigue life reduction of 500.000 cycles when compared to Pore 2. The crystallography is able to influence small crack propagation by slightly decelerating the crack growth rates as well as by altering the crack path topography. Tailoring of the crystallography for improved fatigue resistance requires an investigation of the optimal largest defect to grain size ratio. KW - A357-T6 cast aluminum alloy KW - EBSD analysis KW - Laboratory XµCT KW - Pore size KW - Crack initiation period KW - Crystal plasticity finite element modeling (CPFEM) PY - 2020 DO - https://doi.org/10.1007/s11661-019-05590-6 SN - 1543-1940 SN - 1073-5623 SP - 1 EP - 12 PB - Springer AN - OPUS4-50206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano-Munoz, Itziar A1 - Agudo Jácome, Leonardo A1 - Thompsom, Sean A1 - Schneider, Judy T1 - On the transferability of post-processing heat treatments designed for PBF-LB IN718 alloys to directed energy deposition specimens N2 - Many processes are being developed for metal additive manufacturing (AM) which vary by their heat source and feedstock. The use of directed energy deposition (DED) is growing due to its ability to build larger structures outside of a contained powder bed chamber. However, the only standard exclusively for post-build heat treatment of AM IN718 is ASTM standard F3055-14a, developed for powder bed fusion (PBF). This study evaluates the applicability of this current heat treatment standard to AM IN718 specimens produced using two methods of DED: laser-blown powder (LP)-DED and arc-wire (AW)-DED. Electron microscopy and X-ray diffraction techniques were used to characterize the specimens in the as-built condition and after the full heat treatment (FHT) specified in F3055. No evidence of remaining Laves phase was observed in the two DED specimens after the FHT. Yield strengths for the DED specimens were 1049 MPa for FHT AW-DED and 1096 MPa for LP-DED, higher than the minimum stated for PBF-LB IN718 of 920 MPa. The size, morphology, inter-spacing, and diffraction patterns of the γ´ and γ´´ strengthening precipitates are found to be similar for both DED processes. Differences were observed in the microstructure evolution where the F3055 heat treatments resulted in partial recrystallization of the grain structure, with a higher content of annealing twins observed in the AW-DED. These microstructural differences correlate with differences in the resulting elongation to failure. Thus, it is proposed that variations in heat treatments are needed for optimizing IN718 produced by different AM processes. KW - Additive manufacturing variants KW - Directed energy deposition (DED) KW - Post-process heat treatments KW - SEM-EBSD and TEM microscopy KW - XRD phase analysis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628165 DO - https://doi.org/10.1007/s00170-025-15386-1 SN - 1433-3015 VL - 137 IS - 7-8 SP - 3949 EP - 3965 PB - Springer Science and Business Media LLC AN - OPUS4-62816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ferrari, Bruno A1 - Fantin, Andrea A1 - Said, D. A1 - Fitch, A. N. A1 - Suárez Ocano, Patricia A1 - Mishurova, Tatiana A1 - Roveda, Ilaria A1 - Kromm, Arne A1 - Darvishi Kamachali, Reza A1 - Bruno, Giovanni A1 - Evans, Alexander A1 - Requena, G. A1 - Agudo Jácome, Leonardo A1 - Serrano Munoz, Itziar T1 - The impact of scanning strategy on cell structures in PBF-LB/M/IN718: an in situ synchrotron x-ray diffraction study N2 - In additive manufacturing, any change of the process parameters, such as scanning strategy, directly affects the cooling rates, heat accumulation, and overall thermal history of the build. Consequently, parts built with different process parameters tend to have different levels of crystallographic texture, residual stress, and dislocation density. These features can influence the properties of the material and their development during post-processing operations. In this study, IN718 prisms were built by laser powder bed fusion (PBF-LB/M) using two different scanning strategies (continuous 67° rotations around the build direction, ROT, and alternating 0°/67° scans, ALT) to provide two different as-built conditions. In situ time-resolved synchrotron diffraction was performed during a solution heat treatment at 1027 °C for 1 h. Ex situ scanning electron microscopy was used to support and complement the in situ observations. An approach to quantify the effect of elemental microsegregation at the cell walls is developed based on the deconvolution of asymmetric γ-nickel matrix peaks. Following this approach, the scanning strategies are shown to affect the as-built fraction of cell walls in the material, resulting in a difference of approximately 5 %, in weight fraction, between ROT and ALT (19 % vs. 24 %, respectively). This microsegregation was observed to be rapidly homogenized during the heating ramp, and no significant changes to the peak shape in the γ peaks occurred during the isothermal part of the heat treatment, regardless of the scanning strategy. KW - Additive manufacturing KW - Inconel 718 KW - Synchrotron x-ray diffraction KW - Heat treatment KW - Laser powder bed fusion KW - Cellular microstructure PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650958 DO - https://doi.org/10.1016/j.jmrt.2025.11.214 SN - 2238-7854 VL - 41 SP - 593 EP - 608 PB - Elsevier B.V. AN - OPUS4-65095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Serrano-Munoz, Itziar T1 - Synchrotron x ray refraction detects microstructure and porosity evolution during in situ heat treatments in an LPBF ALSI10MG alloy N2 - The complexity of any microstructural characterization significantly increases when there is a need to evaluate the icrostructural evolution as a function of temperature. To date, this characterization is primarily performed by undertaking elaborative ex-situ experiments where the material’s heating procedure is interrupted at different temperatures or times. Moreover, these studies are often limited to a region smaller than the representative elementary volume, which can lead to partial or even biased interpretations of the collected data. This limitation can be greatly overcome by using in-situ synchrotron X-ray refraction (SXRR). T2 - ICTMS 2022 CY - Grenoble, France DA - 27.06.2022 KW - Synchrotron refraction KW - In situ heating KW - AlSi10Mg alloy KW - Additive manufacturing KW - Microstructural evolution PY - 2022 AN - OPUS4-55199 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Serrano-Munoz, Itziar T1 - Residual stress analysis in selective laser melted parts of superalloy IN718 N2 - Additive Manufacturing by Selective Laser Melting (SLM) offers an ample scope for producing geometrically complex parts as compared to the traditional subtractive manufacturing strategies. However, the residual stresses (RS) developed during the processing can reduce the load bearing capacity as well as induce unwanted distortion, limiting the life time and the application of SLM parts. T2 - BESSY II User meeting CY - BESSY II Photon Source, Adlershof Berlin, Germany DA - 06.12.2018 KW - Laser Beam Melting KW - AM IN718 KW - Residual stress measurements PY - 2018 AN - OPUS4-47179 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano-Munoz, Itziar A1 - Fernández, R. A1 - Saliwan Neumann, Romeo A1 - González-Doncel, G. A1 - Bruno, Giovanni T1 - Dislocation substructures in pure aluminium after creep deformation as studied by electron backscatter diffraction N2 - In the present work, electron backscatter diffraction was used to determine the microscopic dislocation structures generated during creep (with tests interrupted at the steady state) in pure 99.8% aluminium. This material was investigated at two different stress levels, corresponding to the power-law and power-law breakdown regimes. The results show that the formation of subgrain cellular structures occurs independently of the crystallographic orientation. However, the density of these cellular structures strongly depends on the grain crystallographic orientation with respect to the tensile axis direction, with <111> grains exhibiting the highest densities at both stress levels. It is proposed that this behaviour is due to the influence of intergranular stresses, which is different in <111> and <001> grains. KW - Creep KW - Pure aluminium KW - Electron backscatter diffraction KW - Cellular structures KW - Power law and power-law breakdown PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552003 DO - https://doi.org/10.1107/S1600576722005209 SN - 0021-8898 SN - 1600-5767 VL - 55 SP - 860 EP - 869 PB - Wiley-Blackwell CY - Copenhagen AN - OPUS4-55200 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Serrano-Munoz, Itziar T1 - Microstructural characterization of the influence of SLM scan parameters by means of X ray and neutrons sources N2 - An overview of the main Non-Destructive activities conducted at BAM for the microstructural characterization of Additive Manufacturing (AM) materials will be presented. Focus is made on the study of the influence of Selective Laser Melted (SLM) scan strategies on the defect population of a Ti-6Al-4V alloy using the Analyzer Based Imaging (ABI) technique available at the BAMline (BESSY II synchrotron facility). ABI technique takes advantage of X Ray refraction at interfaces to enable the determination of porosity features (orientation, homogeneity, etc.) within large volumes, otherwise not possible to image by means X ray micro Computed Tomography. Additionally, for a SLM IN718 material, Energy Dispersive X Ray Diffraction (subsurface measurements at 100 µm depth) and neutrons diffraction (internal measurements at 3 mm depth) are combined with distortion measurements to produce a 3D description of the Residual Stress distribution throughout the entire sample. T2 - TMS (The Minerals, Metals & Materials Society) CY - Gaithersburg, Maryland, USA DA - 18.06.2018 KW - X-Ray refraction KW - Selective laser melted materials KW - Energy dispersive X Ray diffraction KW - Neutrons diffraction PY - 2018 AN - OPUS4-45435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Serrano-Munoz, Itziar T1 - Synchrotron X-Ray Refraction detects microstructure and porosity evolution during in-situ heat treatments N2 - The complexity of any microstructural characterization significantly increases when there is a need to evaluate the microstructural evolution as a function of temperature. To date, this characterization is primarily performed by undertaking elaborative ex-situ experiments where the material’s heating procedure is interrupted at different temperatures or times. Moreover, these studies are often limited to a region smaller than the representative elementary volume, which can lead to partial or even biased interpretations of the collected data. This limitation can be greatly overcome by using in-situ synchrotron X-ray refraction (SXRR). In this study, SXRR has been combined with in-situ heat treatment to monitor the porosity evolution as a function of temperature. It is shown that SXRR is a robust and straightforward method for time-resolved (3-5 min required per scan) evaluation of thermally induced microstructural changes over macroscopically relevant volumes. T2 - SNI2022, German conference for research with synchrotron radiation, neutrons and ion beams at large facilities CY - Berlin, Germany DA - 05.09.2022 KW - Synchrotron X-Ray Refraction KW - In situ heating KW - AlSi10Mg KW - Laser powder bed fusion KW - Thermally induced porosity PY - 2022 AN - OPUS4-55778 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröder, Jakob A1 - Evans, Alexander A1 - Polatidis, E. A1 - Čapek, J. A1 - Mohr, Gunther A1 - Serrano-Munoz, Itziar A1 - Bruno, Giovanni T1 - Understanding the impact of texture on the micromechanical anisotropy of laser powder bed fused Inconel 718 N2 - The manufacturability of metallic alloys using laser-based additive manufacturing methods such as laser powder bed fusion has substantially improved within the last decade. However, local melting and solidification cause hierarchically structured and crystallographically textured microstructures possessing large residual stress. Such microstructures are not only the origin of mechanical anisotropy but also pose metrological challenges for the diffraction-based residual stress determination. Here we demonstrate the influence of the build orientation and the texture on the microstructure and consequently the mechanical anisotropy of as-built Inconel 718. For this purpose, we manufactured specimens with [001]/[011]-, [001]- and [011]/[111]-type textures along their loading direction. In addition to changes in the Young’s moduli, the differences in the crystallographic textures result in variations of the yield and ultimate tensile strengths. With this in mind, we studied the anisotropy on the micromechanical scale by subjecting the specimens to tensile loads along the different texture directions during in situ neutron diffraction experiments. In this context, the response of multiple lattice planes up to a tensile strain of 10% displayed differences in the load partitioning and the residual strain accumulation for the specimen with [011]/[111]-type texture. However, the relative behavior of the specimens possessing an [001]/[011]- and [001]-type texture remained qualitatively similar. The consequences on the metrology of residual stress determination methods are discussed. KW - Laser powder bed fusion KW - Additive manufacturing KW - Electron backscatter diffraction KW - Tensile testing KW - Diffraction PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555840 DO - https://doi.org/10.1007/s10853-022-07499-9 SN - 1573-4803 VL - 2022 IS - 57 SP - 15036 EP - 15058 PB - Springer Science + Business Media B.V. CY - Dordrecht AN - OPUS4-55584 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -