TY - CONF A1 - Simón Muzás, Juan A1 - Brunner-Schwer, C. A1 - Hilgenberg, Kai A1 - Rethmeier, Michael T1 - Weldability of PBF-LB/M Inconel 718 lattice structures by laser beam N2 - The present research focuses on the weldability of PBF-LB/M lattice structure parts of Inconel 718 by means of laser beam welding. The integration of complex and lightweight AM structures into assemblies employing conventional joining methods is challenging. During the welding process, dissipation of the laser heat input through thin-walled structures of these lightweight structures is strongly limited, resulting in heat accumulation, atypical cooling rates, and affecting weld geometry, quality of the joint and microstructure. PBF-LB/M parts have been manufactured in three characteristic build directions. They were all stress relieved, then a group of them were submitted to an additional solution annealing and the second group to a two-step aging treatment. Afterwards, these parts were welded to identical PBF-LB/M parts and to wrought ones in butt position. To gain insight into the welding temperature field and to explain segregation mechanisms, grain growth and asymmetries, thermocouples have been attached on the surface’s regions and struts nearby. Joining a lattice structure with a full material wrought sample results in clear asymmetric welds due to dissimilar heat dissipation on both sides of the seam. Selected pre-weld heat treatments have a crucial influence on the quality of the seam on the AM part. T2 - International Institute of Welding IIW 2023 Conference CY - Singapore DA - 16.07.2023 KW - Additive manufacturing (AM) KW - Laser-based powder bed fusion of metal (PBF-LB/M) KW - Laser beam welding KW - Lattice structure KW - Hybrid part KW - Heat treatment KW - Inconel 718 PY - 2023 AN - OPUS4-58017 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheuschner, Nils A1 - Altenburg, Simon A1 - Straße, Anne A1 - Gumenyuk, Andrey A1 - Maierhofer, Christiane T1 - In-situ thermographic monitoring of the laser metal deposition process N2 - By allowing economic on demand manufacturing of highly customized and complex workpieces, metal based additive manufacturing (AM) has the prospect to revolutionize many industrial areas. Since AM is prone to the formation of defects during the building process, a fundamental requirement for AM to become applicable in most fields is the ability to guarantee the adherence to strict quality and safety standards. A possible solution for this problem lies in the deployment of various in-situ monitoring techniques. For most of these techniques, the application to AM is still very poorly understood. Therefore, the BAM in its mission to provide safety in technology has initiated the project “Process Monitoring of AM” (ProMoAM). In this project, a wide range of in-situ process monitoring techniques, including active and passive thermography, optical tomography, optical emission and absorption spectroscopy, eddy current testing, laminography, X-ray backscattering and photoacoustic methods, are applied to laser metal deposition (LMD), laser powder bed fusion and wire arc AM. Since it is still unclear which measured quantities are relevant for the detection of defects, these measurements are performed very thoroughly. In successive steps, the data acquired by all these methods is fused and compared to the results of reference methods such as computer tomography and ultrasonic immersion testing. The goal is to find reliable methods to detect the formation of defects during the building process. The detailed acquired data sets may also be used for comparison with simulations. Here, we show first results of high speed (> 300 Hz) thermographic measurements of the LMD process in the SWIR range using 316L as building material. For these experiments, the camera was mounted fixed to the welding arm of the LMD machine to keep the molten pool in focus, regardless of the shape of the specimen. As the thermograms do not contain any information about the current spatial position during the building process, we use an acceleration sensor to track the movement and synchronize the measured data with the predefined welding path. This allows us to reconstruct the geometry of the workpieces and assign the thermographic data to spatial positions. Furthermore, we investigate the influence of the acquisition wavelength on the thermographic data by comparing measurements acquired with different narrow bandpass filters (50 nm FWHM) in a spectral range from 1150 nm to 1550 nm. This research was funded by BAM within the Focus Area Materials. T2 - Sim-AM 2019 - 2. International Conference on Simulation for Additive Manufacturing CY - Pavia, Italy DA - 11.09.2019 KW - Additive manufacturing KW - 3D printing KW - Thermography KW - Direct energy deposition KW - Laser Metal Deposition KW - 3D Druck KW - Laser Pulver Auftragsschweißen KW - Additive Fertigung KW - Thermografie PY - 2019 AN - OPUS4-49070 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pittner, Andreas A1 - Winterkorn, René A1 - Fabry, Çağtay A1 - Rethmeier, Michael A1 - Ulbricht, Alexander A1 - Bruno, Giovanni T1 - Additive Manufacturing of High Strength Al-Mg-Si Alloys with DED-Arc N2 - Direct energy deposition additive manufacturing technologies that utilize an electric arc have great potential for generating large volume metal components. However, selecting process parameters that yield the desired near net shape design and requested mechanical component behavior is not a trivial task due to the complex relationship between all process parameters and material characteristics. This presentation exemplifies the application of a newly developed solid welding wire doped with TiB to enhance grain refinement in the deposited metal for additive manufacturing based on DED-Arc of high-strength precipitation hardening AlMgSi-aluminum alloys. It is worth noting that the solid wire is the result of our preliminary metallurgical studies on grain refinement in aluminum weld metal. Consequently, research focuses on the correlation between process parameters and component quality to understand the underlying mechanisms. This is crucial for evaluating a robust process parameter space that yields component quality in line with corresponding standards which are mainly taken from welding technology. Specifically, we examine component quality by analyzing pore size and distribution, as well as grain morphology. To enhance the mechanical properties of the deposited metal, a post-weld heat treatment was conducted, comprising of solution treatment, quenching, and artificial aging. The study also evaluates the effects of various heat treatment strategies on the final mechanical properties of the material. To demonstrate the applicability of 3D metal printing of high-strength aluminium alloys, a more complex demonstrator was created. It has been shown that DED-Arc can produce high-volume aluminium parts with the same quality as the corresponding subtractive processing strategy. Additionally, the entire additive manufacturing chain has been digitally integrated, enabling traceability of all relevant process steps, which is essential for reliable subsequent quality assessment. T2 - 4th Symposium on Materials and Additive Manufacturing - Additive 2024 CY - Berlin, Germany DA - 12.06.2024 KW - DED-Arc KW - High-stength aluminium alloys KW - Grain refinement KW - Quality assurance PY - 2024 AN - OPUS4-60248 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Fabry, Çağtay A1 - Hirthammer, Volker A1 - Scherer, Martin K. T1 - weldx - welding data exchange format N2 - Scientific welding data covers a wide range of physical domains and timescales and are measured using various different sensors. Complex and highly specialized experimental setups at different welding institutes complicate the exchange of welding research data further. The WelDX research project aims to foster the exchange of scientific data inside the welding community by developing and establishing a new open source file format suitable for the documentation of experimental welding data and upholding associated quality standards. In addition to fostering scientific collaboration inside the national and international welding community an associated advisory committee will be established to oversee the future development of the file format. The proposed file format will be developed with regard to current needs of the community regarding interoperability, data quality and performance and will be published under an appropriate open source license. By using the file format objectivity, comparability and reproducibility across different experimental setups can be improved. KW - Welding KW - Research data management KW - Open science KW - Open Data KW - WelDX PY - 2021 DO - https://doi.org/10.5281/zenodo.6563282 PB - Zenodo CY - Geneva AN - OPUS4-55226 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Silvestro, L. A1 - Ruviaro, A. S. A1 - Lima, G. A1 - Durlo Tambara, Luis Urbano A1 - Feys, D. A1 - Kirchheim, A. P. T1 - Rotational rheometry test of Portland cement-based materials - A systematic literature review N2 - This study systematically reviews 62 papers on the use of rotational rheometry to assess the fresh state behavior of Portland cement-based materials. The research highlights the wide variation in test methods and aims to provide a comprehensive overview. Findings reveal that 50.0% of studies employed vane geometry, despite its limitations in providing transformation equations. Regarding dynamic shearing tests, 67.0% followed a consensus using a pre-shearing step and a step-wise routine with stabilization times ≥ 10 s. While the Bingham model is commonly used, the study emphasizes the importance of considering shear-thinning behavior in cementitious materials. Models like Herschel-Bulkley and modified Bingham may be more appropriate. This review offers insights into testing conditions for rotational rheometry of cementitious materials, serving as a foundation for future research in the field. KW - Review KW - Rheology KW - Rheometry KW - Rotational KW - Cement PY - 2024 DO - https://doi.org/10.1016/j.conbuildmat.2024.136667 SN - 0950-0618 VL - 432 SP - 1 EP - 14 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-60075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pittner, Andreas A1 - Winterkorn, René A1 - Fabry, Çağtay A1 - Rethmeier, Michael T1 - Life cycle assessment of fusion welding processes strategies and implementation N2 - In manufacturing, fusion welding processes use a lot of resources, which presents an opportunity to reduce environmental impact. While there is a general understanding of the environmental impact of these processes, it is difficult to quantitatively assess key parameters. This study introduces a welding-specific methodology that uses life cycle assessment (LCA) to evaluate the environmental impact of fusion welding technologies. Our approach analyses the main parameters that affect the environmental performance of different welding techniques, including traditional methods and additive manufacturing through the Direct Energy Deposition-Arc (DED-Arc) process. We integrate real-time resource usage data to offer an innovative framework for directly deriving environmental impacts. This research contributes to optimising welding processes by providing a precise and quantifiable measure of their ecological impact, facilitating the advancement of sustainable manufacturing practices. T2 - CEMIVET - Circular Economy in Metal Industries CY - Berlin, Germany DA - 06.06.2023 KW - Life Cycle Assessment KW - Fusion welding KW - Additive manufacturing KW - DED-Arc PY - 2023 AN - OPUS4-59499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pittner, Andreas A1 - Winterkorn, René A1 - Fabry, Çağtay A1 - Rethmeier, Michael T1 - Life cycle assessment of fusion welding processes considering upstream and downstream process steps N2 - In manufacturing, fusion welding processes consume significant resources, presenting a significant opportunity for reducing environmental impact. Although there is a qualitative understanding of the environmental implications of these processes, a quantitative assessment of key parameters remains complex. This study introduces a welding-specific methodology that employs life cycle assessment (LCA) to quantitatively evaluate the environmental footprint of fusion welding technologies. Our approach identifies and analyses the principal parameters affecting the environmental performance of various welding techniques, including traditional joint welding and additive manufacturing via the Direct Energy Deposition-Arc (DED-Arc) process. Real-time resource usage data is integrated to offer an innovative framework for directly deriving environmental impacts. This research contributes to optimising welding processes by providing a precise and quantifiable measure of their ecological impact. This facilitates the advancement of sustainable manufacturing practices. T2 - Joining Smart Technologies - International Automotive Conference CY - Wels, Austria DA - 10.05.2023 KW - Life Cycle Assessment KW - Arc welding KW - Additive manufacturing KW - DED-Arc PY - 2023 AN - OPUS4-59494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pittner, Andreas A1 - Winterkorn, René A1 - Fabry, Çağtay A1 - Rethmeier, Michael T1 - Wire arc additive manufacturing of high strength al-mg-si alloys N2 - Direct energy deposition additive manufacturing technologies utilizing an electric arc offer a great potential in generating large volume metal components. However, the selection of process parameters that yield the desired near net shape design as well as the requested mechanical component behavior is not a trivial task due to the complex relationship. Exemplarily for additive manufacturing of high-strength precipitation hardening AlMgSi-aluminum alloy this paper shows the application of a newly developed matching solid welding wire doped with TiB as grain refiner. The correlation between process parameters and component quality is examined analyzing the size and distribution of pores as well as the grain morphology. Furthermore, the influences of different post-weld heat treatments are evaluated to meet the reference mechanical properties of the corresponding wrought material. Finally, the digital integration of the entire additive manufacturing chain enables an overall traceability of the relevant process steps which is the basis for a reliable subsequent quality assessment. T2 - THERMEC'2023 International Conference on PROCESSING & MANUFACTURING OF ADVANCED MATERIALS: Processing, Fabrication, Properties, Applications CY - Vienna, Austria DA - 02.07.2023 KW - Additive Manufacturing KW - DED-Arc KW - Grain refinement KW - High strength AlMgSi aluminium alloys KW - Mechanical properties PY - 2023 AN - OPUS4-59500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fabry, Çağtay A1 - Hirthammer, Volker A1 - Pittner, Andreas A1 - Rethmeier, Michael T1 - WelDX - a file format for processing and archiving welding research data N2 - The talk gives an introduction into gas metal arc welding and its relation to plasma science as well as current challenges in welding research concerning research data management and the application of the FAIR principles. The WelDX project is introduced and the main goals are discussed and contrasted with the current features of the weldx API. Different internal and public facing use cases focusing on research data management and their implementation using weldx are presented. The interactive part of the presentation displays some advanced multi layer use cases and data analysis using the weldx API as well as the integration of materials properties into weldx. T2 - International Workshop on FAIR Data in Plasma Science CY - Online meeting DA - 16.05.2022 KW - WelDX KW - Open science KW - Research data management KW - Arc welding KW - Digital transformation PY - 2022 AN - OPUS4-55153 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fabry, Çağtay A1 - Hirthammer, Volker A1 - Scherer, Martin K. A1 - Pittner, Andreas A1 - Rethmeier, Michael T1 - WelDX – progress report on the welding data exchange format N2 - The presentation shows the current development status of the Welding Data Exchange (weldx) format based on the Advanced Scientific Data Format (ASDF). The use of a complete single pass arc welding experiment example stored in a single weldx file and validated against a predefined schema definition is presented. The example includes generic experimental metadata, the workpiece geometry and materials definition following associated standards, the weld process spatial movement description, the welding process parameter descriptions and welding process measurements. The inclusion of 3D scan data of the workpiece description is also included. The full code and data is available on GitHub: https://github.com/BAMWelDX/IIW2021_AA_CXII T2 - 2021 IIW Annual Assembly and International Conference on welding and Joining CY - Online meeting DA - 07.07.2021 KW - Arc welding KW - Digitalization KW - Open science KW - Research data management KW - WelDX PY - 2021 AN - OPUS4-53401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -