TY - JOUR A1 - Mishurova, Tatiana A1 - Evsevleev, Sergei A1 - Piault, Pierre A1 - King, Andrew A1 - Henry, Laura A1 - Bruno, Giovanni T1 - Understanding the hot isostatic pressing efectiveness of laser powder bed fusion Ti‑6Al‑4V by in‑situ X‑ray imaging and difraction experiments N2 - In the present study, in-situ observation of Hot Isostatic Pressure (HIP) procedure of laser powder bed fusion manufactured Ti-6Al-4V parts was performed to quantitatively estimate the densifcation rate of the material and the infuence of the defect initial size and shape on such rate. The observations were performed in-situ using the Ultrafast Tomography Paris-Edinburgh Cell and the combination of fast phase-contrast synchrotron X-ray tomography and energy dispersive difraction. With this strategy, we could quantify how the efectiveness of HIP depends on the characteristics of a defect. Smaller defects showed a higher densifcation rate, while the defect shape did not have signifcant efect on such rate. KW - Additive manufacturing KW - Laser powder bed fusion KW - X-ray computed tomography KW - Hot isostatic pressing PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-587702 DO - https://doi.org/10.1038/s41598-023-45258-1 SN - 2045-2322 VL - 13 IS - 1 SP - 1 EP - 11 AN - OPUS4-58770 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Khrapov, D. A1 - Paveleva, A. A1 - Kozadayeva, M. A1 - Evsevleev, Sergei A1 - Mishurova, Tatiana A1 - Bruno, Giovanni A1 - Surmenev, R. A1 - Koptyug, A. A1 - Surmeneva, M. T1 - Trapped powder removal from sheet-based porous structures based on triply periodic minimal surfaces fabricated by electron beam powder bed fusion N2 - Electron Beam Powder Bed Fusion-manufactured (E-PBF) porous components with narrow pores or channels and rough walls or struts can be filled with trapped powder after the manufacturing process. Adequate powder removal procedures are required, especially for high-density porous structures. In the present research, sheetbased porous structures with different thicknesses based on triply periodic minimal surfaces fabricated by EPBF were subjected to different post-processing methods, including a traditional powder recovery system for EPBF, chemical etching and ultrasound vibration-assisted powder removal. Wall thickness, internal defects, microstructure and morphology features, powder distribution inside the specimens, mechanical properties and deformation modes were investigated. A powder recovery system could not remove all residual powder from dense structures. In turn, chemical etching was effective for surface morphology changes and subsurface layers elimination but not for powder removal, as it affected the wall thickness, considerably influencing the mechanical properties of the whole structure. The ultrasound vibration method was quite effective for the removal of residual powder from sheet-based TMPS structures and without a severe degradation of mechanical properties. 10.1016/j.msea.2022.144479 Ultrasound vibration also caused grain refinement. KW - Additive manufacturing KW - Residual powder removal KW - Ti6Al4V alloy KW - Electron beam powder bed fusion KW - TPMS structures PY - 2023 DO - https://doi.org/10.1016/j.msea.2022.144479 VL - 862 SP - 1 EP - 16 PB - Elsevier B.V. AN - OPUS4-56564 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishurova, Tatiana A1 - Cabeza, Sandra A1 - Thiede, Tobias A1 - Nadammal, Naresh A1 - Kromm, Arne A1 - Klaus, Manuela A1 - Genzel, Christoph A1 - Haberland, Christoph A1 - Bruno, Giovanni T1 - The influence of the support structure on residual stress and distortion in SLM Inconel 718 parts N2 - The effect of support structure and of removal from the base plate on the residual stress state in selective laser melted IN718 parts was studied by means of synchrotron X-ray diffraction. The residual stresses in subsurface region of two elongated prisms in as-built condition and after removal from the base plate were determined. One sample was directly built on a base plate and another one on a support structure. Also, the distortion on the top surface due to stress release was measured by contact profilometry. High tensile residual stress values were found, with pronounced stress gradient along the hatching direction. In the sample on support, stress redistribution took place after removal from the base plate, as opposed to simple stress relaxation for the sample without support. The sample on support structure showed larger distortion compared to sample without support. We conclude that the use of a support decreases stress values but stress-relieving heat treatments are still needed. KW - Additive manufacturing KW - SLM KW - Residual stress KW - Synchrotron X-ray diffraction KW - IN718 PY - 2018 DO - https://doi.org/10.1007/s11661-018-4653-9 SN - 1073-5623 VL - 49A IS - 7 SP - 3038 EP - 3046 PB - Springer Sciences & Business Media CY - New York, NY AN - OPUS4-45100 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 - 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 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 - Shaikh, Abdul Shaafi A1 - Fardan, Ahmed A1 - Mishurova, Tatiana A1 - Hryha, Eduard T1 - The Impact of High‐Productivity Processing on the Fatigue Failure of an Additive Manufactured Superalloy HAYNES 282 N2 - The elevated temperature low cycle fatigue life of additively manufactured HAYNES 282 superalloy from conventional 40 µm layer thickness process parameters was compared with that of high‐productivity 80 µm layer thickness process parameters. Wrought 282 alloy was also tested in parallel for comparison. The 40 µm process parameters produced fatigue life between 1400 and 1700 cycles to failure, the 80 µm process parameter specimens failed after ≈1200 cycles, and the wrought alloy reached 1350 cycles to failure. Microstructure investigations did not reveal systematic differences in phase constituents or grain structure between 40 and 80 µm processed 282 alloy. While both process parameters produced porosity of less than 0.05% by volume, high‐resolution X‐ray computed tomography showed the occurrence of large aspect ratio lack of fusion defects in the 80 µm material. These defects were also identified on fracture surfaces and could be related to the accelerated initiation and propagation of cracks, especially when oriented perpendicular to the load axis in samples built parallel to the building direction. The results emphasize the criticality of seemingly minor variations in defect characteristics on performance in cyclic loading conditions for high strength alloys. KW - Additive manufacturing KW - Laser powder bed fusion KW - PBF-LB KW - Fatigue KW - EBSD PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655732 DO - https://doi.org/10.1002/adem.202502048 SN - 1438-1656 SP - 1 EP - 13 PB - Wiley-VCH GmbH AN - OPUS4-65573 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zurcher, Theo A1 - Serrano-Munoz, Itziar A1 - Mishurova, Tatiana A1 - Abreu Faria, Guilherme A1 - Degener, Sebastian A1 - Fridrici, Vincent A1 - Charkaluk, Eric A1 - Bruno, Giovanni T1 - Sliding wear resistance and residual stresses of parts repaired by laser metal deposition N2 - Large temperature gradients inherent to additive manufacturing (AM) processes induce large residual stress (RS) in the final part. Because RS can influence the tribological properties, this study focuses on the relationship between wear sliding properties and RS in IN718 coatings. Such coatings were deposited with a Laser metal deposition (LMD) machine using two different scanning strategies. The wear resistance and RS state were investigated after surface milling. RS were measured before and after wear tests on a reciprocating sliding test apparatus. Two different X-ray diffraction techniques were employed to measure the surface and subsurface state RS: Laboratory Energy Dispersive X-ray Diffraction (LEDXD) and Synchrotron X-ray Energy Dispersive Diffraction (SXEDD). Due to the milling process, the coatings show similar depth distributions of RS from 22 to 92 μm depth, but exhibit different magnitudes depending on the scanning strategy used. Reciprocating sliding wear tests induced high compressive residual stresses that erased the initial RS state, and a similar wear behavior was observed in the two samples. These samples possess similar texture and grain morphology. This demonstrates that the influence of RS on wear resistance is a second-order effect. Nevertheless, it was observed that RS can still impact the wear performance at the early testing stages of the repaired parts. KW - Additive manufacturing KW - Wear resistance KW - Residual stress PY - 2023 DO - https://doi.org/10.1007/s10853-023-09129-4 SN - 0022-2461 SP - 1 EP - 18 PB - Springer AN - OPUS4-59084 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishurova, Tatiana A1 - Artzt, K. A1 - Rehmer, Birgit A1 - Haubrich, J. A1 - Ávila Calderón, Luis A1 - Schoenstein, F. A1 - Serrano-Munoz, Itziar A1 - Requena, G. A1 - Bruno, Giovanni T1 - Separation of the impact of residual stress and microstructure on the fatigue performance of LPBF Ti-6Al-4V at elevated temperature N2 - Manufacturing defects, high residual stress (RS), and microstructures affect the structural integrity of laser powder bed fusion (LPBF) Ti-6Al-4V. In this study, the individual effect of these factors on fatigue performance at elevated temperature (300 °C) was evaluated. Material in as-built condition and subjected to post-processing, including two heat treatments and hot isostatic pressing, was investigated. It was found that in the absence of tensile RS, the fatigue life at elevated temperature is primary controlled by the defects; and densification has a much stronger effect than the considered heat treatments on the improvement of the mechanical performance. KW - Additive manufacturing KW - Ti-6Al-4V KW - Residual stress KW - Fatigue performance KW - Computed tomography PY - 2021 DO - https://doi.org/10.1016/j.ijfatigue.2021.106239 SN - 0142-1123 VL - 148 SP - 106239 PB - Elsevier Ltd. AN - OPUS4-52369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pauzon, C. A1 - Mishurova, Tatiana A1 - Evsevleev, Sergei A1 - Dubiez-Le Goff, S. A1 - Murugesan, S. A1 - Bruno, Giovanni A1 - Hryha, E. T1 - Residual stresses and porosity in Ti-6Al-4V produced by laser powder bed fusion as a function of process atmosphere and component design N2 - The influence of the process gas, laser scan speed, and sample thickness on the build-up of residual stresses and porosity in Ti-6Al-4V produced by laser powder bed fusion was studied. Pure argon and helium, as well as a mixture of those (30% helium), were employed to establish process atmospheres with a low residual Oxygen content of 100 ppm O2. The results highlight that the subsurface residual stresses measured by X-ray diffraction were significantly lower in the thin samples (220 MPa) than in the cuboid samples (645 MPa). This difference was attributed to the shorter laser vector length, resulting in heat accumulation and thus in-situ stress relief. The addition of helium to the process gas did not introduce additional subsurface residual stresses in the simple geometries, even for the increased scanning speed. Finally, larger deflection was found in the cantilever built under helium (after removal from the baseplate), than in those produced under argon and an argon-helium mixture. This result demonstrates that complex designs involving large scanned areas could be subjected to higher residual stress when manufactured under helium due to the gas’s high thermal conductivity, heat capacity, and thermal diffusivity. KW - Additive manufacturing KW - Ti-6Al-4V KW - Residual stress KW - Process atmosphere KW - Helium PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-534209 DO - https://doi.org/10.1016/j.addma.2021.102340 VL - 47 SP - 2340 PB - Elsevier B.V. AN - OPUS4-53420 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Thiede, Tobias A1 - Cabeza, S. A1 - Mishurova, Tatiana A1 - Nadammal, N. A1 - Kromm, Arne A1 - Bode, Johannes A1 - Haberland, C. A1 - Bruno, Giovanni T1 - Residual stress in selective laser melted Inconel 718: Influence of the removal from base plate and deposition hatch length N2 - The residual stress distribution in IN718 elongated prisms produced by Selective Laser Melting was studied by means of neutron (bulk) and laboratory X-ray (surface) diffraction. Two deposition hatch lengths were considered. A horizontal plane near the top surface (perpendicular to the building direction) and a vertical plane near the lateral surface (parallel to the building direction) were investigated. Samples both in as-built (AB) condition and removed (RE) from the base plate were characterized. While surface stress fields seem constant for AB condition, X-ray diffraction shows stress gradients along the hatch direction in the RE condition. The stress profiles correlate with the distortion maps obtained by tactile probe measurements. Neutron diffraction shows bulk stress gradients for all principal components along the main sample directions. We correlate the observed stress patterns with the hatch length, i.e. with its effect on temperature gradients and heat flow. The bulk stress gradients partially disappear after removal from the baseplate. KW - Residual stress KW - Additive manufacturing KW - Neutron diffraction KW - Selective laser melting KW - Laboratory X-ray diffraction KW - Coordinate measurement machine KW - IN718 PY - 2018 DO - https://doi.org/10.1520/MPC20170119 SN - 2379-1365 VL - 7 IS - 4 SP - 717 EP - 735 PB - ASTM International CY - USA, West Conshohocken AN - OPUS4-46673 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -