TY - CONF A1 - Hilgenberg, Kai T1 - Additive Fertigungsverfahren und Defekte N2 - Überblick über die derzeitig wichtigsten additiven Fertigungsverfahren für metallische Werkstoffe in der Industrie (PBF, DED, BJT) und Berücksichtigung der wesentlichen Prozessmerkmale und Nachbearbeitungsschritte. Vorstellung der wichtigsten Defektphänomene und Nennung von Ursachen und Abhilfemaßnahmen. T2 - BAM Akademie: Qualitätssicherung in der additiven Fertigung CY - Online meeting DA - 17.09.2024 KW - Additive Fertigung KW - Defekte KW - Überblick PY - 2024 AN - OPUS4-61172 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schob, Daniela T1 - Deformation-Induced Martensitic Transformation in Fused Filament Fabricated Austenitic Stainless Steels During Tension at Wide Range of Temperatures. Part 2: Numerical Simulation N2 - Structural components of superconducting magnets (e.g., collars, bladders, or keys) with complex shapes, operating at cryogenic temperatures (4K, 77K), as well as additional elements of tanks for storing liquid hydrogen (20K), such as hoses and valves, are made of austenitic steel. With conventional manufacturing technologies, complex geometries are difficult to manufacture. In contrast, additive manufacturing offers the possibility of easier production of complex geometries, although the knowledge about the material behavior is not yet comprehensively available. The scientific objective of the project is the experimental identification and numerical simulation of the evolution of the deformation-induced martensitic transformation and the prediction of the material behavior of Fused Filemant Fabricated (FFF) 316L for cryogenic applications. The material behavior of FFF-316L under tensile stress at both room temperature and 77K was characterized. Utilizing experimental data and microstructure analysis through scanning electron microscopy, a comprehensive material model [1] was used. This constitutive model is centered on the deformation-induced martensitic transformation at both ambient and cryogenic temperatures. The linear kinetic law of evolution of deformation-induced phase transformation in ASS is adopted [1]. It posits that the phase transformation is driven by the accumulated plastic strain. The model intricately links the intensity of plastic deformation to the phase transformation, employing a mixed kinematic/isotropic linear plastic hardening approach based on Mori-Tanaka homogenization. A numerical results will be verified experimentaly at room and at 77K. T2 - 43rd Solid Mechanics Conference CY - Wroclaw, Poland DA - 16.09.2024 KW - Phase transformation KW - Deformation-induced martensitic transformation KW - 316L KW - Fused Deposition Modelling PY - 2024 AN - OPUS4-61181 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zhu, Jiangchao A1 - Madia, Mauro A1 - Schurig, M. A1 - Schlums, H. A1 - Zerbst, Uwe T1 - Fracture mechanics-based structural integrity assessment of aeroengine turbine disks under overspeed conditions N2 - Aero-engine turbine disks are safety-relevant components which are operated under high thermal and mechanical stress conditions. The actual part qualification and certification procedures make use of spin-tests conducted on productionsimilar disks. While these tests provide, on the one hand, a reliable definition of the critical conditions for real components, on the other hand they represent a relevant cost item for engine manufacturers. The aim of this work is to present part of a fracture mechanics-based procedure under development which aims at replacing the tests on production-similar disks with lab tests on fracture mechanics specimens. In particular, the rimpeeling failure mode is considered as case study. A semi-circular surface crack is modelled at the most stressed region at the diaphragm of a turbine disk, with the crack plane perpendicular to the radial direction. The crack is therefore subjected to a biaxial stress state and grows under increasing rotational speed until it triggers the rim-peeling failure. The finite element simulation of the cracked disk considers the real thermal and mechanical loading conditions. In order to design a lab representative specimen, beside the crack driving force, expressed in terms of � -integral, also the constraint to plastic deformation e.g., stress triaxiality, at the crack-tip must be similar for the same crack in the specimen and in the disk. This has been achieved and as expected, both the highest � -integral and constraint factor are calculated at the same location along the crack front for both disk and specimen. The results of the structural integrity assessment in the form of a Failure Assessment Diagram (FAD) show good agreement between designed specimen and disk both in terms of expected failure mode and value of the critical speed. Probabilistic aspects are also considered in the calculations. T2 - ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition (GT2022) CY - Rotterdam, The Netherlands DA - 13.06.2022 KW - Fracture mechanics KW - Burst KW - Turbine disk PY - 2022 SP - 1 EP - 7 PB - ASME AN - OPUS4-55903 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epperlein, Martin T1 - Eine digital gestützte Qualitätssicherung für die additive Fertigung N2 - Die Digitalisierung der Qualitätsinfrastruktur (QI) am Beispiel der Additiven Fertigung. Der Vortrag erörtert, wie die Elemente einer digitalen QI zur Qualitätssicherung und Zertifizierung in der Additiven Fertigung beitragen können. T2 - Treffen der Arbeitsgemeinschaft Additive Fertigung des VDMA CY - Coburg, Germany DA - 27.10.2022 KW - Qualitätsinfrastruktur KW - Additive Fertigung KW - Digitalisierung PY - 2022 AN - OPUS4-56165 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk A1 - Klinger, Christian T1 - Schadensanalyse an Fahrradkomponenten - Fraktographie, Ursachen, Prävention N2 - Komponenten von Fahrrädern werden im Betrieb vorwiegend schwingend beansprucht. Typische Werkstoffe sind Stahl, Aluminiumlegierungen, Messing, CFK und thermoplastische Kunststoffe. Da es sich, unabhängig von der Preiskategorie, um konstruktiven Leichtbau handelt, werden einige Bauteile betriebsfest mehr oder weniger weit oberhalb der Dauerfestigkeit ausgelegt. Die im normalen Betrieb auftretenden Schäden sind daher weit überwiegend Schwingbrüche. Andere Schadensmechanismen wie z.B. Korrosion spielen quantitativ eine untergeordnete Rolle. Schwingbrüche treten nach einer Periode unbemerkten Risswachstums oft ohne Vorwarnung und ohne makroskopische Verformung auf. Im Falle von sicherheitsrelevanten Komponenten wie Rahmen, Gabeln, Lenkern, Sattelstützen, Kurbelarmen oder Pedalen kann dies zu erheblichen Personenschäden führen, die den Wert des ursächlichen Bauteilschadens weit überschreiten. Über einen langjährigen Zeitraum wurden gebrochene Komponenten aus dem Alltag und aus Gerichtsverfahren analysiert. Das Hauptaugenmerk lag hierbei auf der fraktographischen Analyse, teilweise wurden die zu Grunde liegenden Schadensursachen ermittelt. Einflussfaktoren sind beispielsweise konstruktive Kerben an ungünstigen Stellen, aber auch Werkstoffwahl und Fertigungsqualität spielen eine Rolle. In den meisten Fällen wurde jedoch die konstruktive Lebensdauer überschritten. Diese wird praktisch nie mitgeteilt, und eine wiederkehrende Prüfung sicherheitsrelevanter Bauteile findet nicht statt. Im Sinne der Vermeidung von Schäden und Unfällen könnte darauf hingewirkt werden, für sicherheitsrelevante Komponenten Lebensdauern besser abzuschätzen und von der Laufleistung abhängige Sichtprüfungen zu empfehlen. T2 - DGM Tagung Werkstoffprüfung CY - Dresden, Germany DA - 26.10.2022 KW - Fraktographie KW - Fahrrad KW - Lebensdauer KW - Öffentliche Sicherheit KW - Schadensanalyse KW - Schadensprävention PY - 2022 AN - OPUS4-56122 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, T. T1 - Evaluation of electric conductivity and mechanical load capacity of copper deposits for application in large winding components for electrical high-voltage machines made with cold spray additive manufacturing N2 - In line with the industrial trend of additive manufacturing, cold spray as a non-laser-based process is becoming increasingly important for many fields of application. For the evaluation of additive manufacturing of winding components made of copper for large electrical high-voltage machines, material and component properties such as electrical conductivity, mechanical load capacity and the component size that can be produced are of particular importance. In this context, the cold spray process offers advantages over laser-based additive manufacturing processes such as laser powder bed fusion (LPBF) or laser cladding by using the kinetic energy of the copper powder particles to generate particle cohesion. To investigate the electrical conductivity as well as the mechanical load capacity of cold spray parts, specimens were machined out of cold sprayed bulk copper deposits. The characteristic values were obtained with regard to the direction of deposition, which is defined by the direction of the robot’s movement. Thus, for the investigation of the component properties, specimens were provided that had been produced both longitudinally and transversely as well as orthogonally to the direction of deposition. The results of the investigations show that both the electrical conductivity and the mechanical load capacity of the specimen have a strong preferential direction of the specimen orientation with respect to the direction of deposition. Furthermore, it could be shown that by increasing the deposition height, there is an increasing oxygen content in the sample material, combined with increasingly significant defect networks. These effects have a negative impact on the electrical conductivity as well as on the mechanical load capacity. As a conclusion, further need for investigation is identified in the optimization of the process parameters as well as in the deposition strategy for the additive manufacturing of large-volume components with cold spray. T2 - ITSC 2022 CY - Vienna, Austria DA - 04.05.2022 KW - Cold Spray KW - Copper powder particles KW - Electrical conductivity KW - Large electrical high-voltage machine PY - 2022 AN - OPUS4-56127 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, T. A1 - Uhlmann, E. A1 - Häcker, Ralf A1 - Jäger, M. A1 - Rauch, H. A1 - Kondas, J. A1 - Brach, K. A1 - Singh, R. T1 - Evaluation of electric conductivity and mechanical load capacity of copper deposits for application in large winding components for electrical high-voltage machines made with cold spray additive manufacturing N2 - In line with the industrial trend of additive manufacturing, cold spray as a non-laser-based process is becoming increasingly important for many fields of application. For the evaluation of additive manufacturing of winding components made of copper for large electrical high-voltage machines, material and component properties such as electrical conductivity, mechanical load capacity and the component size that can be produced are of particular importance. In this context, the cold spray process offers advantages over laser-based additive manufacturing processes such as laser powder bed fusion (LPBF) or laser cladding by using the kinetic energy of the copper powder particles to generate particle cohesion. To investigate the electrical conductivity as well as the mechanical load capacity of cold spray parts, specimens were machined out of cold sprayed bulk copper deposits. The characteristic values were obtained with regard to the direction of deposition, which is defined by the direction of the robot’s movement. Thus, for the investigation of the component properties, specimens were provided that had been produced both longitudinally and transversely as well as orthogonally to the direction of deposition. The results of the investigations show that both the electrical conductivity and the mechanical load capacity of the specimen have a strong preferential direction of the specimen orientation with respect to the direction of deposition. Furthermore, it could be shown that by increasing the deposition height, there is an increasing oxygen content in the sample material, combined with increasingly significant defect networks. These effects have a negative impact on the electrical conductivity as well as on the mechanical load capacity. As a conclusion, further need for investigation is identified in the optimization of the process parameters as well as in the deposition strategy for the additive manufacturing of large-volume components with cold spray. T2 - ITSC 2022 CY - Wien, Austria DA - 04.05.2022 KW - Cold Spray KW - Electrical conductivity KW - Copper powder particles KW - Large electrical high-voltage machine PY - 2022 SP - 1 EP - 7 AN - OPUS4-56108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zhu, Jiangchao T1 - Kennwertermittlung für die Bewertung der Integrität einer Turbinenscheibe bei Überdrehzahl N2 - Turbinenscheiben sind thermisch und mechanisch hochbeanspruchte, sicherheitsrelevante Komponenten in Gasturbinen. Ihre Integrität wird in Bauteiltests unter Überdrehzahlbedingungen nachgewiesen. Kontext des Aufsatzes ist die Erarbeitung einer zusätzlichen Bewertungsebene auf der Grundlage von Versuchen unter monotoner Beanspruchung, die die Beanspruchung im Bauteil realistisch wiedergeben soll. Dazu werden zwei Typen von bruchmechanischen Proben anwendungsnah ausgelegt und aus einer Turbinenscheibe ausgeschnitten: Der erste Typ ist eine biaxiale Probe, die die Beanspruchung und den Dehnungsbehinderungszustand am Diaphragm der Turbinenscheibe abbildet, die zweite eine bruchmechanische Probe, die die einachsige Beanspruchung und den Dehnungsbehinderungszustand am Bore der Turbinenscheibe wiedergibt. Im Rahmen eines Schadentoleranzansatzkonzepts ist anschließend jeweils ein halbelliptischer Riss an den genannten Stellen der Turbinenscheibe zu betrachten. Mittels numerischer Berechnungen wird ein kritischer Punkt auf der Rissfront des Risses am Diaphragm bestimmt, dort wo die höchste Rissspitzenbelastung (J-Integral) auftritt. Auf der Basis der Rissspitzenbelastung, des Dehnungsbehinderungszustands und des entsprechenden Spannungsverhältnisses an diesem kritischen Punkt wird eine Kreuzprobe mit einem Durchriss konzipiert, die diese Verhältnisse im Bauteil widerspiegelt. Die Versuche werden unter der Temperatur am Diaphragm der Turbinenscheibe durchgeführt. Die J-R-Kurve und die plastische Kollapsgrenze werden bestimmt. Auch die einachsigen Versuche werden unter der Temperatur am Bore der Turbinenscheibe durchgeführt. Die Zugprobe enthält halbelliptische Oberflächenrisse. Ähnlich wie bei der Auslegung der Kreuzproben werden die Rissspitzenbelastung, der Dehnungsbehinderungszustand und das Spannungsverhältnis vergleichbar mit der Turbinenscheibe eingestellt. Die J-R-Kurve und die plastische Kollapsgrenze werden bestimmt. Mit den Versuchsergebnissen werden die kritischen Lasten für verschiedene Versagensmechanismen (instabiles Risswachstum, plastischer Kollaps) der bruchmechanischen Proben ermittelt, die der kritischen Überdrehzahl der Turbinenscheibe entsprechen. T2 - 40. Vortrags- und Diskussionstagung Werkstoffprüfung 2022 CY - Dresden, Germany DA - 27.10.2022 KW - Turbine disk KW - Fracture mechanics KW - Biaxial test KW - Burst PY - 2022 AN - OPUS4-56148 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heßmann, Jennifer T1 - New approach for multi material design: combination of laser beam and electromagnetic melt pool displacement by induced lorentz forces N2 - Multi-material structures are a promising solution to reduce vehicle weight and save fuel or electric energy in automotive design. However, thermal joining of steel and aluminum alloys is a challenge to overcome due to different material properties and the formation of brittle intermetallic phases. In this study, a new joining approach for producing overlap line-shaped joints is presented. The lower joining partner (EN AW 5754) is melted by a laser beam and this melt is displaced into a line-shaped cavity of the upper joining partner (1.0330) by induced Lorentz forces. The melt solidifies in the cavity to a material and form-fitting joint. This approach needs no auxiliary joining elements or filler materials. Previous investigation to produce spot-shaped joints by using this approach showed that quality and reproducibility were limited by known melt pool dynamics of aluminum alloys (keyhole collapses). For line-shaped joints, the melt displacement can take place behind the keyhole. This allows the displacement process to be spatial uncoupled from the influence of the keyhole collapses. The study shows that this improved the process stability and the quality of the joint. The created line-shaped joints were microstructurally characterized by transversal sections. Intermetallic phases were identified by electron backscatter diffraction (EBSD) and EDX-Analysis. The detected intermetallic phases consist of a 5 µm - 6 µm compact phase seam of Al5.6Fe2 and a needle shaped phase of Al13Fe4. Tensile shear tests were carried out to quantify the load capacity. It was possible to create a joint with a load capacity of about 2 kN. T2 - ICALEO Orlando 2022 CY - Orlando, Florida, USA DA - 17.10.2022 KW - Electromagnetic forces KW - Joining dissimilar materials KW - Laser beam welding KW - Steel and aluminium PY - 2022 AN - OPUS4-56149 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Raute, J. A1 - Marquardt, R. A1 - Biegler, M. A1 - Rethmeier, Michael T1 - Untersuchung zum Elektronenstrahlschweißen additiv gefertigter Ni-Basis-Bauteile N2 - Die vorliegende Untersuchung befasst sich mit dem Einfluss des Additive Manufacturing auf die Schweißeignung von Bauteilen aus Inconel 718. Hierfür wurden Proben mittels DED und L-PBF hergestellt und ihr Verhalten in Blindschweißversuchen anhand eines Vergleichs mit konventionellen Gussblechen untersucht. Im zweiten Schritt wurden die verschiedenen additiv hergestellten Proben mit dem Gussmaterial im I-Stoß sowie untereinander verschweißt. Als Schweißverfahren wurde für alle Proben das Elektronenstrahlschweißen angewandt. Zur Auswertung wurde anhand von Schliffen das Nahtprofil vermessen und die Proben auf Poren und Risse untersucht. Zusätzlich wurde die Dichte vermessen und eine Prüfung auf Oberflächenrisse durchgeführt. Das AM-Material zeigte dabei Unterschiede in Nahtform und Defektneigung im Vergleich zum Gusswerkstoff. Insbesondere die DED-proben neigten unter bestimmten Parameterkonstellationen verstärkt zu Porenbildung. Risse konnten nicht beobachtet werden. Trotz auftretender Nahtunregelmäßigkeiten wurde in den kombinierten AM-Schweißproben die Bewertungsgruppe C erreicht. Eine Prüfung der bestehenden Regelwerke zur Schweißnahtbewertung anhand der gewonnenen Erkenntnisse zu additiv gefertigten Proben im Elektronenstrahlschweißprozess zeigte keinen Ergänzungsbedarf. T2 - #additivefertigung: Metall in bestForm CY - Essen, Germany DA - 26.10.2022 KW - Elektronenstrahlschweißen KW - Additive Fertigung KW - Schweißnahtbewertung PY - 2022 SN - 978-3-96144-202-7 VL - 383 SP - 81 EP - 92 PB - DVS-Media GmbH AN - OPUS4-56173 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heßmann, Jennifer A1 - Hilgenberg, Kai T1 - New approach for multi-material design: Combination of laser beam and electromagnetic melt pool displacement by induced Lorentz forces N2 - Multimaterial structures are a promising solution to reduce vehicle weight and save fuel or electric energy in automotive design. However, thermal joining of steel and aluminum alloys is a challenge to overcome due to different material properties and the formation of brittle intermetallic phases. In this study, a new joining approach for producing overlap line-shaped joints is presented. The lower joining partner (EN AW 5754) is melted by a laser beam, and this melt is displaced into a line-shaped cavity of the upper joining partner (1.0330) by induced Lorentz forces. The melt solidifies in the cavity to a material and form-fitting joint. This approach needs no auxiliary joining elements or filler materials. Previous investigation to produce spot-shaped joints by using this approach showed that quality and reproducibility were limited by known melt pool dynamics of aluminum alloys (keyhole collapses). For line-shaped joints, the melt displacement can take place behind the keyhole. This allows the displacement process to be spatially uncoupled from the influence of keyhole collapses. The study shows that this improved the process stability and the quality of the joint. The created line-shaped joints were microstructurally characterized by transversal sections. Intermetallic phases were identified by electron backscatter diffraction and EDX analysis. The detected intermetallic phases consist of a 5–6 μm compact phase seam of Al5.6Fe2 and a needle-shaped phase of Al13Fe4. Tensile shear tests were carried out to quantify the load capacity. It was possible to create a joint with a load capacity of about 2 kN. KW - Electromagnetic forces KW - Joining dissimilar materials KW - Laser beam welding KW - Steel and aluminium KW - Lorentz forces PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564840 DO - https://doi.org/10.2351/7.0000763 SN - 1042-346X VL - 35 IS - 1 SP - 1 EP - 8 PB - Laser Institute of America CY - Orlando, Fla. AN - OPUS4-56484 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hilgenberg, Kai T1 - Herausforderungen in der additiven Fertigung sicherheitsrelevanter Komponenten N2 - Der Vortrag stellt nach einer kurzen allgemeinen Einleitung zur additiven Fertigung und des Laser Powder Bed Fusion Verfahrens einige Herausforderungen vor, die derzeitig den Einsatz von AM-Komponenten in sicherheitsrelevanten Anwendungen erschweren. Abschließend werden zwei Beispiele von Arbeiten der BAM gezeigt, die zur Überwindung dieser Herausforderungen beitragen können. T2 - Anwendertreffen des Laserverbundes Berlin-Brandenburg CY - Berlin, Germany DA - 25.11.2022 KW - Additive Fertigung KW - Laser Powder Bed Fusion PY - 2022 AN - OPUS4-56435 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hübler, Daniela T1 - Tribological behavior and cutting performance of a NbC-Ni-WC-TiC cermet N2 - The addition of WC and TiC in a nickel bonded NbC cermet was investigated regarding the tribological behavior under dry oscillating sliding at different relative humidities φ and the cutting performance in dry cylindrical turning of C45E at different cutting speeds. NbC-12Ni-12WC-14TiC shows similar coefficient of friction f and wear rate compared to NbC-12Ni at φ = 2 %, but no pronounced decrease in f with increasing humidity. When turning C45E, NbC-12Ni-12WC-14TiC shows lower material removal VW compared to other NbC-based cermets, which can be attributed to inhomogeneities in the cutting material and a low hardness. T2 - 7th World Tribology Congress - WTC 2022 CY - Lyon, France DA - 11.07.2022 KW - Niobium carbide KW - NbC cermets KW - Tribology KW - Dry cylindrical turning PY - 2022 AN - OPUS4-56042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, M. A1 - Bettge, Dirk A1 - Hilgenberg, Kai A1 - Binder, M. A1 - Dollmeier, K. A1 - Dreyer, M. A1 - Klöden, B. A1 - Schlingmann, T. A1 - Schmidt, J. T1 - Reproducibility and Scattering in Additive Manufacturing: Results from a Round Robin on PBF-LB/M AlSi10Mg Alloy T1 - Reproduzierbarkeit und Streuung bei der additiven Fertigung: Ergebnisse eines Ringversuchs mit einer PBF-LB/M AlSi10Mg-Legierung N2 - The round robin test investigated the reliability users can expect for AlSi10Mg additive manufactured specimens by laser powder bed fusion through examining powder quality, process parameter, microstructure defects, strength and fatigue. Besides for one outlier, expected static material properties could be found. Optical microstructure inspection was beneficial to determine true porosity and porosity types to explain the occurring scatter in properties. Fractographic analyses reveal that the fatigue crack propagation starts at the rough as-built surface for all specimens. Statistical analysis of the scatter in fatigue using statistical derived safety factors concludes that at a stress of 36.87 MPa the fatigue limit of 107 cycles could be reached for all specimen with a survival probability of 99.999 %. N2 - Im Rahmen eines Ringversuchs wurde durch die Untersuchung der Pulverqualität, der Prozessparameter, der Gefügefehler, der Festigkeit und der Ermüdung die Zuverlässigkeit bestimmt, die Nutzer von AlSi10Mg-Proben erwarten können, die mit pulverbettbasiertes Schmelzen mittels Laser (engl. Laser Powder Bed Fusion) gefertigt worden sind. Abgesehen von einem Ausreißer wurden die erwarteten statischen Materialeigenschaften erreicht. Eine optische Gefügeprüfung diente dazu, die tatsächliche Porosität und Arten von Porosität zu ermitteln, um die bei den Eigenschaften auftretende Streuung zu erklären. Fraktographische Unterschungen zeigen eine bei allen Proben von der rauen Oberfläche im As-built-Zustand ausgehende Ermüdungsrissausbreitung. Aus der statistischen Analyse der Streuung bezüglich der Ermüdung unter Anwendung von statistischen abgeleiteten Sicherheitsfaktoren geht hervor, dass alle Proben die Dauerfestigkeit von 107 Zyklen bei einer Spannung von 36,87 MPa mit einer Überlebenswahrscheinlichkeit von 99,999 % erreichten. KW - Additive manufacturing KW - Reproducibility KW - Reliability PY - 2022 DO - https://doi.org/10.1515/pm-2022-1018 SN - 2195-8599 VL - 59 IS - 10 SP - 580 EP - 614 PB - De Gruyter AN - OPUS4-55935 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yang, Chunliang T1 - Numerical analysis of ultrasonic vibration enhanced friction stir welding of dissimilar Al/Mg alloys N2 - The ultrasonic vibration enhanced friction stir welding (UVeFSW) process has unique advantages in joining dissimilar Al/Mg alloys. While there are complex coupling mechanisms of multi-fields in the process, it is of great significance to model this process, to reveal the influence mechanism of ultrasonic vibration on the formation of Al/Mg joints. In this study, the acoustic-plastic constitutive equation was established by considering the influence of both ultrasonic softening and residual hardening on the flow stress at different temperatures and strain rates. And the ultrasonic induced friction reduction (UiFR) effect on friction coefficient in different relative directions at the FSW tool-workpiece interface was quantitatively calculated and analyzed. The Al/Mg UVeFSW process model was developed through introducing the above acoustic effects into the model of Al/Mg friction stir welding (FSW). The ultrasonic energy is stronger on the aluminum alloy side. In the stirred zone, there is the pattern distribution of ultrasonic sound pressure and energy. The heat generation at the tool-workpiece contact interface and viscous dissipation were reduced after applying ultrasonic vi-bration. Due to the UiFR effect, the projection of friction coefficient and heat flux distributions at the tool-workpiece interface present a "deformed" butterfly shape. The calculated results show that ultrasonic vibration enhanced the material flow and promoted the mixing of dissimilar materials. T2 - The 13th International Seminar "Numerical Analysis of Weldability" CY - Graz, Austria DA - 04.09.2022 KW - Numerical simulation KW - Friction stir welding KW - Ultrasonic vibration KW - Al/Mg alloys PY - 2022 AN - OPUS4-56319 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rethmeier, Michael T1 - Welding of thick metal plates with laser - Where are the limits? N2 - -With modern high-power lasers (and vacuum) penetration around 100 mm is possible -Important for industrial applications: single-pass full penetration welds with tolerances -Contactless EM-backing helps to overcome many main restrictions: -Single-pass HLAW of up to 30 mm can be realized with 20 kW laser power -Increase of the gap bridgeability and misalignement of edges -Lower sensitivity to manufacturing tolerances and edge quality; samples can be prepared by a plasma-cut instead of time-consuming milling process -Gives the possibility to increase the welding parameter window and cooling rate so that the required mechanical properties can be reached -Improved filler wire mixing behaviour T2 - AKL22 - International Laser Technology Congress CY - Aachen, Germany DA - 04.05.2022 KW - Laser hybrid welding KW - Thick-walled steel KW - High-power laser KW - Electromagnetic backing PY - 2022 AN - OPUS4-56367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer T1 - Einlagiges MSG-Hochleistungsschweißen von dickwandigen Baustählen mit kontaktloser elektromagnetischer Schmelzbadsicherung N2 - Diese Arbeit zeigt erstmals die Anwendung einer elektromagnetischen Schmelzbadstütze beim einlagigen MSG-Schweißen von dickwandigen Stählen. Die innovativen Entwicklungen im Bereich des Lichtbogenschweißverfahrens ermöglichen eine Erhöhung der Abschmelzleistung, um die Einschweißtiefe zu steigern. Somit kann die Lagenanzahl reduziert und die Produktivität gesteigert werden. Allerdings besteht insbesondere beim einlagigen Schweißen von dickwandigen Bauteilen in PA-Position ein erhöhtes Risiko für das gravitationsbedingte Austropfen der Schmelze an der Wurzel. Zur Verhinderung werden Badstützen eingesetzt, die mechanisch angebracht und nach dem Schweißen entfernt werden müssen, was zeit- und kostenintensiv ist. Die im Rahmen dieser Studie eingesetzte elektromagnetische Schmelzbadstütze wirkt dem gravitationsbedingten Austropfen der Schmelze entgegen und kompensiert den hydrostatischen Druck. Sie wirkt kontaktlos, was im Gegensatz zu herkömmlichen Badstützen vorteilhaft ist, so dass auf eine zeit- und kostenintensive Nachbearbeitung der Schweißnahtwurzel verzichtet werden kann. Das auf extern angelegten oszillierenden Magnetfeldern beruhende Verfahren wird dabei unterhalb des zu schweißenden Bauteils positioniert. Die Magnetfeldlinien sind quer zur Schweißrichtung ausgerichtet, sodass längs zur Schweißrichtung Wirbelströme im Werkstück und eine stets nach oben gerichtete Lorentzkraft generiert werden. Mit Hilfe der elektromagnetischen Badstütze konnten beim einlagigen MSG-Schweißen von 8 mm bis 12 mm die Tropfenbildung vermieden werden. Die innovative Technologie ermöglicht es dickwandige Bauteile einlagig zu schweißen und reduziert die Nachbearbeitungszeit deutlich. T2 - DVS Congress 2022 - Große Schweißtechnische Tagung CY - Koblenz, Germany DA - 19.09.2022 KW - Hochleistungsschweißen KW - MSG-Schweißen KW - Elektromagnetische Schmelzbadsicherung PY - 2022 AN - OPUS4-56368 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer A1 - Bakir, Nasim A1 - Pittner, Andreas A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Einlagiges MSG-Hochleistungsschweißen von dickwandigen Baustählen mit kontaktloser elektromagnetischer Schmelzbadsicherung N2 - Diese Arbeit zeigt erstmals die Anwendung einer elektromagnetischen Schmelzbadsicherung beim einlagigen MSG-Schweißen von dickwandigen Stählen. Die innovativen Entwicklungen im Bereich des Lichtbogenschweißverfahrens ermöglichen eine Erhöhung der Abschmelzleistung, um die Einschweißtiefe zu steigern. Somit kann die Lagenanzahl reduziert und die Produktivität gesteigert werden. Allerdings besteht insbesondere beim einlagigen Schweißen von dickwandigen Bauteilen in PA-Position ein erhöhtes Risiko für das gravitationsbedingte Austropfen der Schmelze an der Wurzel. Zur Verhinderung werden Badsicherungen eingesetzt, die mechanisch angebracht und nach dem Schweißen entfernt werden müssen, was zeit- und kostenintensiv ist. Die im Rahmen dieser Studie eingesetzte elektromagnetische Schmelzbadsicherung wirkt dem gravitationsbedingten Austropfen der Schmelze entgegen und kompensiert den hydrostatischen Druck. Sie wirkt kontaktlos, was im Gegensatz zu herkömmlichen Badsicherungen vorteilhaft ist, so dass auf eine zeit- und kostenintensive Nachbearbeitung der Schweißnahtwurzel verzichtet werden kann. Das auf extern angelegten oszillierenden Magnetfeldern beruhende Verfahren wird dabei unterhalb des zu schweißenden Bauteils positioniert. Die Magnetfeldlinien sind quer zur Schweißrichtung ausgerichtet, sodass längs zur Schweißrichtung Wirbelströme im Werkstück und eine stets nach oben gerichtete Lorentzkraft generiert werden. Mit Hilfe der elektromagnetischen Badsicherung konnten beim einlagigen MSG-Schweißen von bis zu 10 mm dicken Blechen die Tropfenbildung vermieden werden. Die innovative Technologie ermöglicht es, dickwandige Bauteile einlagig zu schweißen und reduziert die Nachbearbeitungszeiten und -kosten deutlich. T2 - DVS Congress 2022 - Große Schweißtechnische Tagung CY - Koblenz, Germany DA - 19.09.2022 KW - Elektromagnetische Schmelzbadsicherung KW - Hochleistungsschweißen KW - MSG-Schweißen PY - 2022 SN - 978-3-96144-189-1 VL - 382 SP - 640 EP - 645 PB - DVS Media GmbH AN - OPUS4-56371 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jokisch, T. A1 - Gook, S. A1 - Marko, A. A1 - Üstündag, Ömer A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Laser beam welding of additive manufactured components: Applicability of existing valuation regulations N2 - With additive manufacturing in the powder bed, the component size is limited by the installation space. Joint welding of additively manufactured parts offers a possibility to remove this size limitation. However, due to the specific stress and microstructure state in the additively built material, it is unclear to what extent existing evaluation rules of joint welding are also suitable for welds on additive components. This is investigated using laser beam welding of additively manufactured pipe joints. The welds are evaluated by means of visual inspection, metallographic examinations as well as computed tomography. The types of defects found are comparable to conventional components. This is an indicator that existing evaluation regulations also map the possible defects occurring for weld seams on additive components. KW - Weld imperfections KW - Additive manufacturing KW - Weldability KW - Laser welding PY - 2022 VL - 2 SP - 109 EP - 113 PB - DVS Media GmbH AN - OPUS4-56374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer A1 - Bakir, Nasim A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Elektromagnetische Schmelzbadbeeinflussung beim Laserhybridschweißen von Dickblechen N2 - Die technischen Entwicklungen in der Lasertechnologie in den letzten Jahrzehnten haben eine neue Generation von Hochleistungslasersystemen im Leistungsbereich bis zu 100 kW auf den Markt gebracht. Dennoch ist die industrielle Anwendung des Hochleistungslaserstrahlschweißens auf bis zu 15 mm dicke Bleche beschränkt. Mögliche Ursachen der Einschränkungen des Verfahrens sind z.B. die Sensibilität des Verfahrens auf Fertigungstoleranzen wie Spalt und Kantenversatz, die erhöhte Tropfenbildung bei höheren Blechdicken und eine inhomogene Verteilung des Zusatzwerkstoffes beim Laserhybridschweißen. In dieser Studie wird ein auf extern angelegte Magnetfelder basierte elektromagnetische Schmelzbadstütze eingesetzt, um die Grenzen des Verfahrens zu erweitern und die Herausforderungen zu minimieren. Der wesentliche Vorteil der elektromagnetischen Schmelzbadstütze ist, dass sie berührungslos arbeitet. Mit Hilfe der elektromagnetischen Schmelzbadstütze konnten bei 20 mm dicken Proben aus S355J2 die Tropfenbildung an der Wurzel vermieden werden. Zudem wurde der Einfluss der Kantenqualität auf die Schweißnahtqualität untersucht, wobei verschiedene Schneidverfahren zur Kantenvorbereitung eingesetzt wurden, wie z.B. Plasma-, Brenn- oder Laserschneiden. Es konnte gezeigt werden, dass auch bei schlechteren Kantenvorbereitung im Gegensatz zu gefrästen Bauteilen die Werkstoffe einlagig mittels Laserhybridschweißen bei einer hohen Schweißnahtqualität gefügt werden konnten. Bei plasmageschnittenen Proben wurden zudem eine Spaltüberbrückbarkeit bzw. Kantenversatz von bis zu 2 mm sicher überbrückt. Des Weiteren war es mit Hilfe der externen Magnetfelder möglich, die Durchmischung des Zusatzwerkstoffes über die gesamte Schweißnahttiefe deutlich zu homogenisieren. T2 - 42. Assistentenseminar der Wissenschaftlichen Gesellschaft Fügetechnik e.V. CY - Blankenau, Germany DA - 06.10.2021 KW - Elektromagnetische Schmelzbadstütze KW - Laserhybridschweißen KW - Dickblech PY - 2022 VL - 385 SP - 1 EP - 7 PB - DVS Media GmbH AN - OPUS4-56375 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epperlein, Martin T1 - QI-Digital - Qualitätssicherung für die Additive Fertigung N2 - Für die konventionelle Fertigung hat sich das bestehende System der Qualitätsinfrastruktur (QI) bewährt. Die additive Fertigung vergrößert den gestalterischen Spielraum von möglichen Bauteilgeometrien und Prozessfehlern jedoch erheblich. Hier gerät die QI an ihre Grenzen, sodass die Fertigung und Zulassung sicherheits-relevanter Bauteile sehr zeit- und kostenintensive Versuche erfordern. Eine moderne digitale QI erlaubt eine effizientere Qualitätssicherung für additiv gefertigte Bauteile. Dies erfordert eine durchgängig digitale Abbildung des physischen Materialflusses. T2 - QI-Forum CY - Berlin, Germany DA - 11.10.2022 KW - Additive Fertigung KW - Qualitätssicherung KW - Digitalisierung PY - 2022 AN - OPUS4-56382 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epperlein, Martin T1 - Digitalisierung der Qualitätsinfrastruktur am Beispiel der Additiven Fertigung N2 - Die Digitalisierung der Qualitätsinfrastruktur (QI) am Beispiel der Additiven Fertigung. Der Vortrag erörtert, wie man mit Elementen einer digitalen QI (DPP, DCoC, Smart Standard, DCC, etc.) aktuelle Herausforderungen in der Qualitätssicherung additiv gefertigter Bauteile adressieren kann. T2 - FORUM Qualitätssicherung in der additiven Fertigung – Quality Engineering CY - Online meeting DA - 13.09.2022 KW - Additive Fertigung KW - Qualitätssicherung KW - Digitalisierung KW - Qualitätsinfrastruktur PY - 2022 AN - OPUS4-56383 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bakir, Nasim T1 - Influence of the weld pool geometry on solidification cracking in partial penetration high power laser beam welding N2 - Solidification cracking is still a serious problem in laser beam welding, especially in the welding of thick-walled plates. The influence of weld pool geometry on solidification cracking in partial penetration welding of thick plates is investigated within scope of this study. Therefore, a specific experimental setup of steel and quartz glass in butt configuration and on the side with high-speed camera were used to record the weld pool shape. In addition, the influence of laser inclination angle on the weld pool geometry and on solidification crack formation was investigated. The results show a bulge in the weld pool root, which is separated from an upper region by a necking region. This leads to a case where there are three different longitudinal region lengths with different solidification zones. This temporal sequence of solidification strongly promotes the formation of solidification cracks in the weld root. T2 - LANE 2022: 12th CIRP Conference on Photonic Technologies CY - Fürth, Germany DA - 04.09.2022 KW - Laser beam welding KW - Weld pool shape KW - Solidification craking PY - 2022 AN - OPUS4-56395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yang, Fan T1 - Numerical analysis of the influence of an auxiliary oscillating magnetic field on suppressing the porosity formation in deep penetration laser beam welding of aluminum alloys N2 - The contactless magnetohydrodynamic technology has been considered as a potential and promising method to improve the weld qualities of deep penetration laser beam welding. In this paper, numerical investigations are conducted to study the influence of the auxiliary oscillating magnetic field on the porosity suppression in laser beam welding of 5754 aluminum alloy. To obtain a deeper insight into the suppression mechanism, a three-dimensional transient multi-physical model is developed to calculate the heat transfer, fluid flow, keyhole dynamic, and magnetohydrodynamics. A ray tracing algorithm is employed to calculate the laser energy distribution on the keyhole wall. A time-averaged downward Lorentz force is produced by an oscillating magnetic field. This force acts in the molten pool, leading to a dominant downward flow motion in the longitudinal section, which blocks the bubble migration from the keyhole tip to the rear part of the molten pool. Therefore, the possibility for the bubbles to be captured by the solidification front is reduced. The electromagnetic expulsive force provides an additional upward escaping speed for the bubbles of 1 m/s ~ 5 m/s in the lower and middle region of the molten pool. The simulation results are in a good agreement with experimental measurements. Based on the results obtained in this study, a better understanding of the underlying physics in laser beam welding enhanced by an auxiliary oscillating magnetic field can be provided and thus the welding process can be further optimized reducing the porosity formation. T2 - The 13th International Seminar "Numerical Analysis of Weldability" CY - Graz, Austria DA - 04.09.2022 KW - Deep penetration laser beam welding KW - Oscillating magnetic field KW - Numerical simulation KW - Porosity KW - Molten pool behaviour PY - 2022 AN - OPUS4-56328 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bachmann, Marcel T1 - Evaluation of narrowed weld pool shapes and their effect on resulting potential defects during deep penetration laser beam welding N2 - This study presents mechanisms of the evolution of a narrowed region in the weld pool center during deep penetration laser beam welding. In numerous numerical studies presented in this study, it was also found that the local reduction of the weld pool size can cause detrimental effects on the melt flow behavior and the resulting properties of the welds. A particularly large influence of this effect was identified in three aspects. First, the local variation of the solidification sequence of the weld pool causes an increase in the hotcracking susceptibility due to a locally delayed solidification. Second, it was proven that a change in the local length and width of the weld pool is associated with an adverse impact on the potential flow routes of the molten material that induces stronger local variations of its solidification. Thus, the element mixing, e.g., during the welding with filler materials, is blocked. This leads to a nonhomogeneous chemical composition of the final weld and can cause undesired effects on the final material properties. Finally, another observed effect is related to the reduced ability of process pores to reach the top surface. As this type of porosity is usually produced around the keyhole tip, the change of the fluid flow regime above this area plays a significant role in determining the final path of the pores until the premature solidification in the middle of the weld pool captures them. This study summarizes mainly numerical results that were supported by selected experimental validation results. T2 - International Congress of Applications of Lasers & Electro-Optics 2022 CY - Orlando, FL, USA DA - 17.10.2022 KW - Weld pool shape KW - Laser beam welding KW - Solidification KW - Porosity KW - Element distribution KW - Numerical process simulation PY - 2022 AN - OPUS4-56335 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Marko, A. A1 - Bähring, S. A1 - Raute, J. A1 - Biegler, M. A1 - Rethmeier, Michael T1 - Transferability of ANN-generated parameter sets from welding tracks to 3D-geometries in Directed Energy Deposition N2 - Directed energy deposition (DED) has been in industrial use as a coating process for many years. Modern applications include the repair of existing components and additive manufacturing. The main advantages of DED are high deposition rates and low energy input. However, the process is influenced by a variety of parameters affecting the component quality. Artificial neural networks (ANNs) offer the possibility of mapping complex processes such as DED. They can serve as a tool for predicting optimal process parameters and quality characteristics. Previous research only refers to weld beads: a transferability to additively manufactured three-dimensional components has not been investigated. In the context of this work, an ANN is generated based on 86 weld beads. Quality categories (poor, medium, and good) are chosen as target variables to combine several quality features. The applicability of this categorization compared to conventional characteristics is discussed in detail. The ANN predicts the quality category of weld beads with an average accuracy of 81.5%. Two randomly generated parameter sets predicted as “good” by the network are then used to build tracks, coatings,walls, and cubes. It is shown that ANN trained with weld beads are suitable for complex parameter predictions in a limited way. KW - Welding parameter KW - Quality assurance KW - DED KW - Artificial neural network KW - Additive manufacturing PY - 2022 DO - https://doi.org/10.1515/mt-2022-0054 SN - 0025-5300 VL - 64 IS - 11 SP - 1586 EP - 1596 PB - De Gruyter AN - OPUS4-56278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Marko, A. A1 - Bähring, S. A1 - Raute, J. A1 - Biegler, M. A1 - Rethmeier, Michael T1 - Prognose von Qualitätsmerkmalen durch Anwendung von KI-Methoden beim Directed 10 Energy Deposition N2 - Dieser Beitrag enthält die Ergebnisse eines im Rahmen der DVS Forschung entwickelten Ansatzes zur Qualitätssicherung im Directed Energy Deposition. Es basiert auf der Verarbeitung verschiedener während des Prozesses gesammelter Sensordaten unter Anwendung Künstlicher Neuronale Netze (KNN). So ließen sich die Qualitätsmerkmale Härte und Dichte auf der Datenbasis von 50 additiv gefertigten Probenwürfel mit einer Abweichung < 2 % vorhersagen. Des Weiteren wurde die Übertragbarkeit des KNN auf eine Schaufelgeometrie untersucht. Auch hier ließen sich Härte und Dichte hervorragend prognostizieren (Abweichung < 1,5 %), sodass der Ansatz als validiert betrachtet werden kann. KW - Kl KW - Directed Energy Depositio KW - Qualitätssicherung PY - 2022 SN - 0036-7184 VL - 74 IS - 10 SP - 672 EP - 679 PB - DVS Media CY - Düsseldorf AN - OPUS4-56284 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shi, L. A1 - Chen, J. A1 - Yang, Chunliang A1 - Chen, G. A1 - Wu, C. T1 - Thermal-fluid-structure coupling analysis of void defect in friction stir welding N2 - Understanding the void defect formation mechanism and simultaneous predicting the tool service life in friction stir welding are critical for optimizing the welding parameters. However, the void defect formation mechanism in friction stir welding is not yet elucidated. In this study, a novel integrated thermal-fluid-structure coupling model of the friction stir welding process was proposed for simultaneous prediction of the weld formation and tool service life. A new non-uniform distribution model of the tool-workpiece contact pressure was proposed to describe the interaction between the tool and the workpiece. The void defect formation mechanism was quantitatively studied using the proposed integrated thermal-fluid-structure coupling model. The results show that the plastic material flows in the horizontal direction and can completely fill the cavity behind the tool for the welding condition of forming a sound weld. While the tool-workpiece contact interfacial frictional shear stress in the rear of the tool is decreased significantly which leads to a severe decrease in the plastic material flow velocity. Therefore, after bypassing the tool from the retreating side, the plastic material at the bottom of the weld stagnates, and void defect forms in the middle and lower part of the weld at the advancing side. The difference between the maximum and the minimum tool-workpiece contact pressure could serve as a numerical criterion to predict void defects. A sound joint is formed when the difference is lower than the critical value of 15 MPa, while a void defect is formed in the weld if it is higher than this critical value. The maximum equivalent stress acting on the tool is located at the pin root with severe stress concentration at a high welding speed. The front of the tool is subjected to tensile stress while its rear is subjected to compressive stress, therefore the tool is apt to fracture at its root under an inappropriate welding condition. The average normal stress of the tool varies periodically with its period consistent with the rotation period of the tool. The service life of the tool is decreased with the increase in welding speed and the decrease in rotation speed. The model is validated by experimental results. KW - Friction stir welding KW - Thermal-fluid-structure coupling model KW - Tool-workpiece interaction KW - Void defect formation mechanism KW - Tool service life PY - 2023 DO - https://doi.org/10.1016/j.ijmecsci.2022.107969 SN - 0020-7403 VL - 241 SP - 1 EP - 17 PB - Elsevier Ltd. AN - OPUS4-56929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Merz, Benjamin A1 - Nilsson, R. A1 - Garske, C. A1 - Hilgenberg, Kai T1 - Camera-based high precision position detection for hybrid additive manufacturing with laser powder bed fusion N2 - Additive manufacturing (AM) in general and laser powder bed fusion (PBF-LB/M) in particular are becoming increasingly important in the field of production technologies. Especially the high achievable accuracies and the great freedom in design make PBF-LB/M interesting for the manufacturing and repair of gas turbine blades. Part repair involves building AM-geometries onto an existing component. To minimise the offset between component and AM-geometry, a precise knowledge of the position of the component in the PBF-LB/M machine is mandatory. However, components cannot be inserted into the PBF-LB/M machine with repeatable accuracy, so the actual position will differ for each part. For an offset-free build-up, the actual position of the component in the PBF-LB/M machine has to be determined. In this paper, a camera-based position detection system is developed considering PBF-LB/M constraints and system requirements. This includes finding an optimal camera position considering the spatial limitations of the PBF-LB/M machine and analysing the resulting process coordinate systems. In addition, a workflow is developed to align different coordinate systems and simultaneously correct the perspective distortion in the acquired camera images. Thus, position characteristics can be determined from images by image moments. For this purpose, different image segmentation algorithms are compared. The precision of the system developed is evaluated in tests with 2D objects. A precision of up to 30μm in translational direction and an angular precision of 0.021∘ is achieved. Finally, a 3D demonstrator was built using this proposed hybrid strategy. The offset between base component and AM-geometry is determined by 3D scanning and is 69μm. KW - Laser powder bed fusion KW - Additive manufacturing KW - Hybrid repair KW - Machine vision KW - Image processing KW - Position detection PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568583 DO - https://doi.org/10.1007/s00170-022-10691-5 SP - 1 EP - 16 PB - Springer AN - OPUS4-56858 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strauß, Lea T1 - Empirical Model for Fatigue Life Prediction N2 - Laser-based powder bed fusion (PBF-LB) is an advanced additive manufacturing technique renowned for its precision and capability to fabricate complex metal components. However, the high thermal gradients and rapid cooling rates intrinsic to this process introduce significant process-induced effects, such as inhomogeneities, surface roughness, anisotropy, and residual stress, all of which critically influence the fatigue behavior of the produced parts. This study investigates the fatigue performance of AlSi10Mg samples produced by PBF-LB, examining the impact of varying surface conditions, geometries, and residual stress levels. Fatigue life prediction models are formulated based on nominal stress amplitude, residual stress, notch factor, crackinitiating inhomogeneity, and surface roughness, with smooth samples serving as a baseline reference. The study presents two empirical models for predicting fatigue life and fatigue strength using S-N curves and the Kitagawa-Takahashi diagram with the El Haddad approach, derived from comprehensive experimental data, including finite element modelling, fatigue life measurements, surface roughness evaluations, and residual stress analysis. T2 - ICAM2024 CY - Atlanta, GA, USA DA - 28.10.2024 KW - AlSi10Mg KW - Kitagawa-Takahashi diagram KW - Equivalent stress KW - Fatigue life prediction KW - PBF-LB/M PY - 2024 AN - OPUS4-61538 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madia, Mauro T1 - Fatigue Strength of Aerospace Parts Repaired by Cold Spray N2 - Aerospace components are safety critical parts, which are often replaced when found defective after the fabrication process or after periodic inspection in-service. Cold spray repair is a promising and cost-saving alternative to replacing worn parts. Depositing materials in decent quality fill machined damage volumes can enhance the performance of refurbished parts and extend their working life. Furthermore, repair represents a resource-efficient and green process in a world targeting at decarbonization of many industrial sectors. Component repair consists of a defined sequence of operations. First, damage is removed by machining, then new material is applied by cold spray on the machined substrate. Usually, the original functional shape of the component is restored by machining. Post-spraying heat treatments can be applied where required. Despite the advantages, cold spray repair still suffers from major limitations which prevent its application in safety relevant parts. The main challenges are posed by the poor adhesion strength, the porosity inherent in the manufacturing process, the reduced ductility and the presence of residual stresses. This work presents recent results obtained in the frame of the cluster project CORE devoted to the development of automatized repair of aerospace parts by cold spray. The investigations consider high-strength aluminum alloys typically used in structural applications in the aerospace industry. As the fatigue properties are crucial to the safe application of repaired components, and given the presence of process-induced defects, a damage tolerant framework is peculiarly suitable for the structural integrity assessment of repaired commponents and give an indication of the permissible defects to optimize the parameters of the cold spray process. Several high cycle fatigue and fatigue crack propagation tests have been performed to compare the fatigue performance of base and repaired materials. The mechanical tests are corroborated by fractographic and microstructural investigations. T2 - ICAM2024 CY - Atlanta, GA, USA DA - 28.10.2024 KW - Cold Spray KW - Aerospace KW - Repair KW - Structural Integrity KW - Fatigue Strength PY - 2024 AN - OPUS4-61539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kardjilov, Nikolay T1 - Neutron Thermo Tomography N2 - This study presents an investigation of the neutron transmission signal as a function of martensitic steel sample temperature and phase transformation during a welding process. A theoretical description that includes the Debye-Waller factor was used to describe the temperature influence on the neutron cross-sections. Neutron imaging using a monochromatic beam helps to observe transmission variations related to the martensitic-austenitic phase transformations before the Bragg-edge and to the material temperature above the Bragg-edge. In-situ neutron imaging of welding experiments show the distribution of the phase transformation and of the temperature in bulk steel samples. The performed finite element modelling of expected temperature distributions shows good agreement with the obtained experimental data. T2 - Neutron Wavelength-Dependent Imaging Workshop (NEUWAVE-12) CY - Lund, Sweden DA - 01.09.2024 KW - Neutron Imaging KW - Energy Selective KW - Neutron Thermo Tomography PY - 2024 AN - OPUS4-61265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Jonathan T1 - Hochaufgelöste visuelle In-situ Prozessüberwachung im PBF-LB/M N2 - Im Rahmen dieses Vortrags werden die bisherigen Arbeiten des Fachbereichs 9.6 zur hochauflösenden visuellen In-Situ Prozessüberwachung im pulverbettbasierten Schmelzen von Metall mittels Laserstrahl (PBF-LB/M) vorgestellt. Als Kamerasystem dient eine 65-Megapixel-Monochromkamera, die in eine kommerzielle PBF-LB/M-Maschine integriert wurde und eine räumliche Auflösung von 17,2 µm/Pixel erreicht. Zur Problemstrukturierung werden Defekte im PBF-LB/M als indirekte und direkte Defekte klassifiziert und ihre Erkennung anhand von Schichtbildern diskutiert. Zudem wird der Einfluss der Beleuchtungssituation auf die Erkennbarkeit von Defekten untersucht. Darüber hinaus wird der Kontrast der Grauwertmatrix als Indikator für das Vorliegen von Bindefehlern vorgestellt. T2 - 11. Mitteldeutsches Forum 3D-Druck in der Anwendung CY - Merseburg, Germany DA - 16.10.2024 KW - Additive manufacturing KW - Image processing KW - In-situ monitoring PY - 2024 AN - OPUS4-61376 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hilgenberg, Kai T1 - Digitale Qualitätssicherung in der Additiven Fertigung N2 - Der Vortrag stellt das Pilotprojekt Additive Fertigung innerhalb von QI Digital vor und zeigt bisher Erreichtes. Dies umfasst eine digital durchgängige Baujobvorbereitung, automatisierte Datenerhebung und -registrierung sowie die Einbindung des Prozessmonitorings. Seitens der PTB wird ein digitaler Prüfbericht vorgestellt. T2 - QI Forum 2024 CY - Berlin, Germany DA - 09.10.2024 KW - Additive Fertigung KW - Digitale Qualitätssicherung KW - QI Digital PY - 2024 AN - OPUS4-61361 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kromm, Arne T1 - Möglichkeiten zur Optimierung von schweißbedingten Beanspruchungen durch Einsatz von LTT-Zusatzwerkstoffen N2 - Der Vortrag gibt einen Überblick zum Thema Low Transformation Temperature (LTT) Zusatzwerkstoffe. Es wird gezeigt, wie mit einem Experiment unter Nutzung von Sychrotronstrahlung das Phänomen der Umwandlungsplastizität untersucht werden kann. T2 - 12. Vollversammlung des SFB 1120: Summer School 2024 CY - Steinfeld (Kall), Germany DA - 11.06.2024 KW - Eigenspannungen KW - LTT-Zusatzwerkstoffe KW - Hochfester Stahl PY - 2024 AN - OPUS4-60259 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Griesche, Axel T1 - Crystallographic phase transformations and corresponding temperature distributions during gtaw of supermartensitic stainless steel visualized by nbei N2 - We investigated the phase transformations during butt-welding of supermartensitic steel plates with help of Neutron-Bragg-Edge Imaging (NBEI). Gas tungsten arc welding (GTAW) was used with a motorized torch allowing for automated weldments. The austenitization in the heat affected zone (HAZ) could be clearly visualized at λ = 0.39 nm, a wavelength smaller than the Bragg edge wavelengths of both austenite and martensite. The re-transformation into the martensitic phase during cooling was clearly detected. However, we observed an unexpected additional change in transmission at λ = 0.44 nm, a wavelength larger than the wavelength of the Bragg edges of both the martensitic and austenitic phases. We attribute this change to the Deybe-Waller-Factor that describes the temperature dependence of coherent scattering at a crystal lattice. The observed two-dimensional attenuation map corresponds well with a temperature distribution modelling by software macros in ANSYS [3]. Here, the absolute temperature values could be achieved by calibrating the modelled attenuation with help of a thermocouple placed at the steel plate. This allows in return for a direct two-dimensional temperature reading based on the Debye-Waller-relation between neutron attenuation and sample temperature. T2 - WCNR-12 CY - Idaho Falls, Id, USA DA - 02.06.2024 KW - Neutron KW - Radiography KW - Welding PY - 2024 AN - OPUS4-60242 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Poka, Konstantin A1 - Ali, Sozol A1 - Saeed, Waleed A1 - Merz, Benjamin A1 - Epperlein, Martin A1 - Hilgenberg, Kai T1 - Design and implementation of a machine log for PBF-LB/M on basis of IoT communication architectures and an ETL pipeline N2 - AbstractPowder Bed Fusion with Laser Beam of Metals (PBF-LB/M) has gained more industrial relevance and already demonstrated applications at a small series scale. However, its widespread adoption in various use cases faces challenges due to the absence of interfaces to established Manufacturing Execution Systems (MES) that support customers in the predominantly data-driven quality assurance. Current state-of-the-art PBF-LB/M machines utilize communication architectures, such as OPC Unified Architecture (OPC UA), Message Queuing Telemetry Transport (MQTT) and Representational State Transfer Application Programming Interface (REST API). In the context of the Reference Architecture Model Industry 4.0 (RAMI 4.0) and the Internet of Things (IoT), the assets, particularly the physical PBF-LB/M machines, already have an integration layer implemented to communicate data such as process states or sensor values. Missing is an MES component acting as a communication and information layer. To address this gap, the proposed Extract Transform Load (ETL) pipeline aims to extract relevant data from the fabrication of each build cycle down to the level of scan vectors and additionally to register process signals. The suggested data schema for archiving each build cycle adheres to all terms defined by ISO/TC 261—Additive Manufacturing (AM). In relation to the measurement frequency, all data are reorganized into entities, such as the AM machine, build cycle, part, layer, and scan vector. These scan vectors are stored in a runtime-independent format, including all metadata, to be valid and traceable. The resulting machine log represents a comprehensive documentation of each build cycle, enabling data-driven quality assurance at process level. KW - FAIR data KW - Data-driven quality assurance KW - Laser powder bed fusion PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601256 DO - https://doi.org/10.1007/s40964-024-00660-7 SN - 2363-9512 SP - 1 EP - 12 PB - Springer Science and Business Media LLC AN - OPUS4-60125 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kromm, Arne T1 - Best practice: How to work with a mobile diffractometer N2 - Beginning with a general overview about resdiual stress determination by X-ray diffraction, the presentation is focussing on some does and dont's when working with a portable diffractometer. T2 - European Conference on Residual Stresses 11 - Tutorial 1: Residual stresses in additive manufacturing CY - Prague, Czech Republic DA - 03.06.2024 KW - Residual stress KW - X-ray diffraction PY - 2024 AN - OPUS4-60287 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schob, Daniela T1 - Comparative Analysis FFF vs. cold rolled 316L Samples N2 - This study provides insights into the properties of 316L stainless steel produced by additive manufacturing using fused filament fabrication (FFF). One key finding is particularly noteworthy: in significant contrast to cold-rolled 316L, FFF316L develops a pronounced martensite phase after fabrication. The comprehensive comparative analysis shows that FFF316L not only retains the ferrite volume content, but that this is also significantly influenced by the build-up direction. Despite the sintering process, which typically involves densification of the material, a pore volume fraction of 8.45 % remains, which influences the mechanical properties. Although FFF316L has lower elastic modulus and tensile strength values compared to cold-rolled 316L, its ductility is still competitive. The study further reveals that deformation-induced martensite forms at the intersections of the deformation twins and ferrite islands form at the grain boundaries during the compression and sintering phases. These findings highlight the challenges associated with FFF316L in specific application fields and signal the need to continue to carefully evaluate and improve the development of manufacturing technologies. T2 - 4th Symposium on Materials and Additive Manufacturing - Additive 2024 CY - Berlin, Germany DA - 12.06.2024 KW - Additive manufacturing KW - Fused Filament Fabrication KW - Computed Tomography KW - 316L Stainless Steel KW - Deformation-Induced Martensite PY - 2024 AN - OPUS4-60302 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nietzke, Jonathan T1 - Mechanische Eigenschaften von additiv gefertigtem AISI 316L unter Wasserstoffatmosphäre N2 - Wasserstoff führt zu einer Degradation der mechanischen Eigenschaften vieler Stähle. In dieser Arbeit wurde dieser Effekt in additiv hergestelltem AISI 316L (1.4404) mithilfe von in-situ SSRT-Versuchen untersucht. T2 - BMDK / Forschungsseminar Otto-von-Guericke-Universität Magdeburg CY - Magdeburg, Germany DA - 11.12.2024 KW - Wasserstoff KW - AISI 316L KW - 1.4404 KW - SSRT PY - 2024 AN - OPUS4-62166 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grimault de Freitas, Tomás T1 - Closing the gaps towards the Standardisation of the Hollow Specimen Method for Tests in High-Pressure Hydrogen Gas N2 - Metallic materials, mainly steels, are the most commonly used structural materials in various components throughout the hydrogen supply chain. Ensuring their sustainable and safe use in hydrogen technologies is a crucial factor in the development of the hydrogen economy. This is particularly important since hydrogen can promote crack formation and ultimately lead to premature failure in these materials when combined with mechanical load. This process is commonly known as Hydrogen Embrittlement and can occur in a large number of steels used for the hydrogen technologies.[1] Extensive materials qualification is required for the rapid implementation of hydrogen technologies, however, most accepted, and standardised test methods for determining the effect of gaseous hydrogen on metallic materials describe complex and costly procedures (e.g. in-situ autoclave technique) that are only available to a very limited extent worldwide. The hollow specimen technique is a simple and economical method that has the potential to overcome the limitations of the current methods and complement them for qualifying metallic materials under high-pressure hydrogen gas. Unlike the conventional autoclave technique, this method requires significantly lower amounts of hydrogen, resulting in fewer safety measures and no need for complex equipment or a specialised laboratory. The technique's low investment and testing costs, simple operation, and shorter testing time make it an optimal for widespread use around the world, thereby increasing the output of results. Initial studies have demonstrated the feasibility of assessing hydrogen effects in metallic materials using the hollow specimen technique. This led to the establishment of an ISO committee to standardise the method, however, there are open questions that currently prevent the technique from being standardised for hydrogen testing. These open questions relate to specimen geometry, inner hole surface and gas quality and are being addressed in the TransHyDE - H2HohlZug project. The aim of the project is to systematically address and close the gaps towards the standardisation of this technique for tests in hydrogen. The project is divided into four work packages. First, the elastic-plastic behaviour of a hollow tensile specimen is compared with that of a conventional solid tensile specimen of identical external dimensions using finite element methods (3D-FEM) and subsequently validated by experimental results. In the second, the influence of the inner hole surface quality of the specimen on the hydrogen effects is evaluated. Five different methods of producing the inner axial hole were chosen to ensure different average roughness values and residual stresses (drilling vs. EDM), and also to ensure a good representation of the more common and easily accessible processes (drilling and reaming) to the more complex ones (EDM and honing). Next, the influence of gas purity (different compositions) and purging process (different routines) is evaluated. Finally, an optimal specimen geometry, inner hole production process, gas quality and purging process are proposed from each working package and its reproducibility and repeatability is evaluated in a round robin with national and international partners. This contribution presents the structure and milestones of the project, followed by initial results regarding the influence of different manufacturing and finishing processes on the inner hole surface of the hollow specimen and its response to hydrogen effects. T2 - MPA Seminar 2024 - Materials, Processes, Applications CY - Stuttgart, Germany DA - 08.10.2024 KW - Hydrogen KW - Hydrogen Embrittlement KW - Tensile Test KW - High-Pressure Gaseous Hydrogen KW - Hollow Specimen Technique KW - Standardisation KW - TransHyDE KW - H2HohlZug PY - 2024 AN - OPUS4-61286 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tabin, Jakub T1 - Deformation-Induced Martensitic Transformation In Fused Filament Fabricated Austenitic Stainless Steels During Tension At Wide Range Of Temperatures. Part 1: Experimental Results N2 - Structural components of superconducting magnets (e.g., collars, bladders, or keys) with complex shapes, operating at cryogenic temperatures (4K, 77K), as well as additional elements of tanks for storing liquid hydrogen (20K), such as hoses and valves, are made of austenitic steel. It is well known that achieving a complex shape for these elements using traditional machining methods is challenging. A viable solution lies in using additive manufacturing methods (AM), notably the cost-effective Fused Filament Fabrication (FFF) method. The scientific objective of the project is the experimental identification and numerical simulation of the evolution of the deformation-induced martensitic transformation in Fused Filament Fabricated Austenitic Stainless Steel (FFF ASS) 316L at a wide range of temperatures. We will investigate how deformation-induced phase transformation develops in printed austenitic steels, how the initial state of the sample (e.g., pore distribution) affects it, and whether deformation-induced martensitic transformation influences the rate of damage development, especially at very low temperatures. Does the manufacturing technology of the sample affect the rate of phase transformation or damage development? Finally, but no less important, is whether, as in the case of traditional austenitic steels, the adverse effect of the microdamage field is inhibited by deformation-induced martensitic transformation. Which of these effects dominates in printed austenitic steels and under what conditions? The experimental setup developed in the Institute of Fundamental Technological Research (IPPT PAN) allows for monitoring the evolution of the 3D strain field during the kinematically-controlled tensile tests of macroscopic specimens at 77K. Moreover, the correlation between plastic strain field evolution, martensitic transformation, thermal distributions and acoustic emission will be defined for FFF 316L at 77K and room temperatures. EBSD and EDS investigation of samples pre-strained in uniaxial tensile tests at a wide range of temperatures are also performed. T2 - 43rd Solid Mechanics Conference CY - Wroclaw, Poland DA - 16.09.2024 KW - Deformation-induced martensitic transformation KW - Austenitic Stainless Steel KW - Additive Manufacturing KW - DIC KW - Cryogenic temperatures PY - 2024 AN - OPUS4-61187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Duarte, Larissa A1 - Madia, Mauro A1 - Kanna, Naveen A1 - Bär, Jürgen ED - Ricoeur, Andreas T1 - Anwendung der zyklischen R-Kurven-Analyse zur Abschätzung des Kitagawa-Takahashi-Diagramms N2 - Die ausgeprägte Langzeitfestigkeit eines Werkstoffes entspricht der maximalen Spannung, unterhalb derer alle ursprünglich wachstumsfähigen Mikrorisse arretieren. Für fehlerbehaftete Werkstoffe stellt das Kitagawa-Takahashi (KT)-Diagramm die Abhängigkeit der ausgeprägten Langzeitfestigkeit von der Defektgröße dar. Das KT-Diagramm kann mit großem Aufwand experimentell bestimmt oder durch verschiedene Modelle abgeschätzt werden. Solche Ansätze ergeben oft nichtkonservative Prognosen und berücksichtigen weder den Aufbau der Rissschließeffekte noch lokale Spannungen. In dieser Arbeit wird ein Kurzrissmodell auf Grundlage der zyklischen R-Kurve und des Rissarrestphänomens zur Abschätzung des KT-Diagramms vorgestellt. Die Abschätzungen werden mit experimentellen Daten validiert, die mit gekerbten Proben nach dem Treppenstufenverfahren ermittelt wurden. T2 - 57. Tagung des DVM-Arbeitskreises Bruchmechanik und Bauteilsicherheit CY - Köln, Germany DA - 18.02.2025 KW - Langzeitfestigkeit KW - KT-Diagramm KW - zyklische R-Kurven-Analyse PY - 2025 DO - https://doi.org/10.48447/BR-2025-512 VL - 257 SP - 93 EP - 104 PB - Deutscher Verband für Materialforschung und -prüfung e.V. CY - Berlin, Deutschland AN - OPUS4-62603 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krankenhagen, Rainer A1 - Chaudhuri, Somsubhro A1 - Pittner, Andreas A1 - Winterkorn, Rene A1 - de Finis, Rosa A1 - Palumbo, Davide A1 - Galietti, Umbero T1 - Thermographic investigation of the anisotropic behaviour of additively manufactured AISI316 steel using DED-Arc N2 - Additive manufacturing is one of the most promising techniques for industrial production and maintenance, but the specifics of the layered structure must be considered. The Direct Energy Deposition-Arc process enables relatively high deposition rates, which is favourable for larger components. For this study, specimens with different orientations were prepared from one AISI316 steel block – parallel and orthogonal to the deposition plane. Quasistatic tensile loading tests were carried out, monitored by an infrared camera. The obtained surface temperature maps revealed structural differences between both orientations. The consideration of surface temperature transients yields more details about the behaviour of the material under tensile loading than the conventional stress-strain-curve. These preliminary investigations were supplemented by thermographic fatigue trials. Although the anisotropy was also observed during fatigue loading the fatigue behaviour in general was the same, at least for both inspected specimens. The presented results demonstrate the abilities and the potential of thermographic techniques for tensile tests. T2 - 17th Quantitative Infrared Thermography Conference CY - Zagreb, Croatia DA - 01.07.2024 KW - WAAM PY - 2024 SP - 1 EP - 8 AN - OPUS4-62548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Genga, R. M. A1 - Glaser, D. A1 - Rokebrand, P. A1 - Cornish, L. A. A1 - Woydt, M. A1 - Gradt, Thomas A1 - Janse van Vuuren, A. A1 - Polese, C. ED - von Leipzig, K. ED - Sacks, N. ED - McClelland, M. T1 - Laser shock peening: A NbC based cermet enhancement alternative for improved GCI interrupted face-milling N2 - Attempts were made to improve the properties and machining performance of NbC based cermet cutting inserts for face milling of grey cast iron (GCI) (BS 1452/GG35) by spark plasma sintering (SPS), use of sub-stoichiometric NbC (NbC₀ˏ₈₈), Cr₃C₂ and Mo₂C additives and laser shock peening (LSP). The microstructure, hardness, fracture toughness and Young’s modulus of WC–Co, NbC₀ˏ₈₈-Co and NbC₀ˏ₈₈-Ni cermet-based inserts were investigated for machining performance. Additions of Mo₂C and manufacture by SPS significantly refined the NbC₀ˏ₈₈-Ni/Co cermet’s carbide grain size from ~5.0 μm to <0.9 μm, which increased the hardness (by ~4GPa) and wear resistance. Laser shock peening (LSP) improved the fracture toughness of all the inserts, from 10% (in the SPS WC based in cermets) to ~100% (in the LPS NbC based cermets). Uncoated cutting inserts were manufactured from the sintered cermets in an SNMA (double sided square insert without a chipformer on the cutting edge) shape (12.7 × 12.7 × 4.3 mm³, 1.6 mm nose radius). The inserts were used for interrupted face-milling of GCI at cutting speeds (ν˛) ranging from 100 m/minute (400 rpm)–500 m/minute (2000 rpm) and depths of cut (ɑₚ) of 0.2–1.0 mm. The insert wear was measured after every pass and analyzed by annular dark field scanning transmission electron microscopy (ADF-STEM). Cutting temperatures were measured with a high-speed thermal camera and forces were measured using a Kistler dynamometer. During machining at ν˛ = 200 m/minute and ɑₚ = 1.0 mm, WC–Co inserts had the lowest flank wear rate (FWR), although LSP significantly improved the tool life of the NbC₀ˏ₈₈-Ni inserts, significantly reducing the FWR from 148.63 μm/minute to 99.79 μm/minute (by ~33%) and the average resultant force from 1257 ± 15 N to 535 ± 15 N. During machining at ν˛ = 500 m/minute and ɑₚ = 0.2 mm, LSP significantly lowered the FWRs of the NbC₀ˏ₈₈ inserts, giving better tool life than all the WC based inserts. Generally, LSP improved the NbC₀ˏ₈₈ inserts’ tool life, reducing the flank wear rate by up to 33% during roughing and 63% during finishing. T2 - 8th International Conference on Competitive Manufacturing (COMA ’22) CY - Stellenbosch, South Africa DA - 09.03.2022 KW - Niobium carbide KW - Laser shock peening KW - Face milling KW - Tool wear PY - 2023 SN - 978-3-031-15602-1 SN - 978-3-031-15601-4 SN - 978-3-031-15604-5 DO - https://doi.org/10.1007/978-3-031-15602-1_62 SN - 2194-0525 SN - 2194-0533 N1 - Serientitel: Lecture notes in production engineering – Series title: Lecture notes in production engineering SP - 871 EP - 889 PB - Springer CY - Cham AN - OPUS4-62689 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brunner-Schwer, Christian T1 - Von der Young Professional-Förderung zum Start-up der WeldNova GmbH N2 - Das Unterpulverschweißen (UP) ist das Lichtbogenschweißverfahren mit der höchsten Abschmelzrate. Beim Schweißen von dicken Blechen ist dieses Verfahren jedoch besonders für die Wurzellage von Nachteil. Voll-ständiges Umschmelzen ohne extremen Wurzeldurchhang oder ein Austropfen der Schmelze ist ohne weitere Hilfsmittel schwer zu erreichen. Aus diesem Grund werden Pulver-, Kupfer-, keramische Badstützen oder Ble-che zur Vermeidung des Wurzeldurchhangs verwendet. Bei der Verwendung von Kupfer- oder Keramikstützen beeinflusst beispielsweise die Diffusion chemischer Elemente in die Schweiß- oder Schmelzlinie die mecha-nischen Eigenschaften der Schweißnaht. All diese Badstützen erfordern zusätzliche Schritte zur Vorbereitung und Entfernung sowie zur Reinigung der Schweißwurzel. Die Verwendung einer elektromagnetischen Bad-stütze hat dagegen viele Vorteile. Der Magnet kommt nicht mit dem Werkstück in Kontakt, sodass ein zusätz-licher Schritt des Entfernens nicht erforderlich ist. Versuche mit Laserstrahlschweißen oder Laserhybrid-schweißen haben bereits erstmalig gezeigt, dass Blechdicken bis 30 mm einlagig einseitig geschweißt werden können und zusätzlich ein Spalt oder Kanterversatz von bis zu 2 mm überbrückt werden können. In dieser Arbeit wird die elektromagnetische Badstütze für den UP-Prozess eingesetzt. Die Wurzellage wird an 15 mm dicken Blechen mit einer Spaltgröße von 2 mm geschweißt. Die Verwendung eines elektromagnetischen Sys-tems stellt hier sicher, dass die Schmelze nach oben gedrückt und in Position gehalten wird. Ferner kann die Schweißtiefe entsprechend den magnetischen Parametern angepasst werden. Dieses Verfahren kann die Produktivität im Schweißbereich von vielen Betrieben deutlich steigern und Kosten gleichzeitig senken und kann dazu beitragen, diese Arbeitsplätze in Deutschland zu sichern. T2 - DVS CONGRESS 2024 Große Schweißtechnische Tagung CY - Erfurt, Germany DA - 16.09.2024 KW - Hochleistungs-Lichtbogenschweißen KW - Unterpulverschweißen PY - 2024 AN - OPUS4-62038 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brunner-Schwer, Christian T1 - Hochleistungslaserhybridschweißen von dickwandigen Stählen – potenzielle Anwendungen in der Windenergieindustrie N2 - Das Laserstrahl-Lichtbogen-Hybridschweißverfahren kombiniert Laserstrahl- und Lichtbogenschweißverfahren in einem gemeinsamen Schmelzbad. Das Verfahren wurde Ende der 70er Jahre entwickelt, um die Synergieeffekte der Schweißprozesse effektiv zu nutzen. Durch die hohe Strahlungsintensität des Laserstrahls werden hohe Einschweißtiefen erreicht. Es ist möglich, die Anzahl der Schweißlagen zu reduzieren und somit die thermische Belastung des Grundwerkstoffes zu senken, da der Wärmeeintrag verringert wird. Die Überbrückung von Spalten und Kantenversatz kann durch die Zufuhr eines geschmolzenen Zusatzdrahtes durch das MSG-Verfahren erreicht werden. Der Zusatzdraht kann zudem das metallurgische Gefüge positiv beeinflussen. Daher ist das Laser-Hybridschweißverfahren ideal für das einlagige Schweißen von Dickblechen und wird bereits erfolgreich in der Schiffbauindustrie zum Schweißen von Blechen mit einer Dicke von bis zu 15 mm verwendet. Obwohl Hochleistungslaser heutzutage bereits im Multi-Kilowatt-Bereich verfügbar sind, sind sie für den industriellen Einsatz nur auf Stahlbleche mit einer Dicke von max. 15 mm geeignet. Hohe Abkühlgeschwindigkeiten, gravitationsbedingtes Austropfen beim einlagigen Schweißen von Dickblechen, Prozessinstabilitäten bei höheren Laserleistungen und Schweißnahtimperfektionen wie Rissbildung sind einige Faktoren, die den Einsatz von Laser-Hybridschweißtechnologien aktuell begrenzen. Ohne eine Badstütze ist eine Verringerung der Schweißgeschwindigkeit und somit der Abkühlgeschwindigkeit aufgrund unzulässiger Wurzelüberhöhungen oder gravitationsbedingtem Austropfen nicht möglich. Bei herkömmlichen Badstützen ist es allerdings erforderlich, dass sie mechanisch befestigt und die Wurzel entfernt oder nachbearbeitet werden muss. In dieser Arbeit wird als Alternative das innovative Konzept der elektromagnetischen Schweißbadsicherung vorgestellt und die Fähigkeiten dieses Verfahrens erläutert. T2 - 21. Tagung Schweißen in der maritimen Technik und im Ingenieurbau CY - Hamburg, Germany DA - 24.04.2024 KW - Schweißen KW - Laserschweißen KW - Behälterbau PY - 2024 AN - OPUS4-62039 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brunner-Schwer, Christian T1 - Auf dem Weg zum einlagigen Schweißen von dickwandigen Bauteilen – Prozesse, Potenziale, Beispiele N2 - Bislang kommt das Laserstrahlschweißen bzw. Laserhybridschweißen hauptsächlich bei Dickblechen mit einer Wandstärke von bis zu 15 mm zum Einsatz. Für Anwendungen über 20 mm war dieses Verfahren aufgrund einiger Herausforderungen bisher nur bedingt realisierbar. Die von der Ausgründung WeldNova GmbH der Bundesanstalt für Materialforschung und -prüfung (BAM) entwickelte Schweißbadsicherung ermöglicht nun ein einlagiges Schweißen von bis zu 40 mm Wandstärken mit einer Laserleistung von bis zu 20 kW. T2 - 52. Sondertagung Schweißen im Anlagen und Behälterbau 2024 CY - Munich, Germany DA - 12.03.2024 KW - Schweißen KW - Laserschweißen KW - Windeneergie PY - 2024 AN - OPUS4-62042 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rasool, Muhammad Hammad A1 - Ahmad, Maqsood A1 - Siddiqui, Numair Ahmed A1 - Junejo, Aisha Zahid T1 - Eco-friendly drilling fluid: Calcium chloride-based natural deep eutectic solvent (NADES) as an all-rounder additive N2 - Designing an effective drilling mud is a critical aspect of the drilling process. A well-designed drilling mud should not only provide efficient mud hydraulics but also fulfill three important functions: enhancing mud rheology, inhibiting hydrate formation in deepwater drilling, and suppressing shale swelling when drilling through shale formations. Achieving these functions often requires the use of various additives, but these additives are often expensive, non-biodegradable, and have significant environmental impacts. To address these concerns, researchers have explored the potential applications of ionic liquids and deep eutectic solvents in drilling mud design, which have shown promising results. However, an even more environmentally friendly alternative has emerged in the form of natural deep eutectic solvents (NADES). This research focuses on an in-house-prepared NADES based on calcium chloride and glycerine, with a ratio of 1:4, prepared at 60 °C, and utilizes it as a drilling mud additive following the API 13 B-1 standards and checks its candidacy as a rheology modifier, hydrates, and shale inhibitor. The findings of the study demonstrate that the NADES-based mud significantly improves the overall yield point to plastic viscosity ratio (YP/PV) of the mud, provides good gel strength, and inhibits hydrate formation by up to 80%. Additionally, it has shown an impressive 62.8% inhibition of shale swelling while allowing for 84.1% improved shale recovery. Moreover, the NADES-based mud exhibits a 28% and 25% reduction in mud filtrate and mud cake thickness, respectively, which is further supported by the results of XRD, zeta potential, and surface tension. Based on these positive outcomes, the calcium chloride–glycerine NADES-based mud is recommended as a versatile drilling mud additive suitable for various industrial applications. Furthermore, it presents a more environmentally friendly option compared to traditional additives, addressing concerns about cost, biodegradability, and environmental impact in the drilling process for an ultimate global impact. KW - NADES KW - Shale swelling KW - Drilling fluid KW - Mud rheology KW - Hydrate inhibition PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623918 DO - https://doi.org/10.3390/en16145533 SN - 1996-1073 VL - 16 IS - 14 SP - 1 EP - 17 PB - MDPI CY - Basel AN - OPUS4-62391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hilgenberg, Kai T1 - EOS M300 as the heart of the QI living lab: Advancing with digital process chains N2 - This presentation shows how the connectivity of the EOS-M300/4 laser powder bed system is used to capture machine and process data as part of the living lab in QI Digital and how this can enable future digital quality assurance in additive manufacturing. T2 - AM Forum 2025 CY - Berlin, Germany DA - 17.03.2025 KW - Additive manufacturing KW - Quality assurance KW - QI Digital KW - Living lab PY - 2025 AN - OPUS4-62740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nietzke, Jonathan T1 - H2HohlZug: Standardisation of a New, Cost-effective Method for Material Characterisation for the Hydrogen Economy N2 - The feasibility of the method for slow strain tensile tests has been demonstrated in several studies, leading to the establishment of the ISO/TC 164/SC 1/WG 9 ISO committee for its standardisation. Questions have emerged during this process, that currently prevent the method from being standardised for hydrogen testing. These questions relate to specimen geometry, specimen manufacturing and gas quality and are being systematically addressed in the TransHyDE-H2HohlZug project. T2 - TrasnsHyDE Abschlusskonferenz CY - Berlin, Germany DA - 25.03.2025 KW - Hydrogen KW - Hydrogen Embrittlement KW - High-Pressure Gaseous Gas KW - Hollow Specimen Technique KW - TransHyDE KW - H2HohlZug PY - 2025 AN - OPUS4-62823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strauß, Lea A1 - Duarte, Larissa A1 - Kruse, Julius A1 - Madia, Mauro A1 - Löwisch, Günther T1 - An equivalent stress approach for predicting fatigue behavior of additively manufactured AlSi10Mg N2 - Laser-based powder bed fusion (PBF-LB) is an advanced additive manufacturing technique renowned for its precision and capability to fabricate complex metal components. However, the high thermal gradients and rapid cooling rates intrinsic to this process introduce significant process-induced effects, such as inhomogeneities, surface roughness, anisotropy, and residual stress, all of which critically influence the fatigue behavior of the produced parts. This study investigates the fatigue performance of AlSi10Mg samples produced by PBF-LB, examining the impact of varying surface conditions, geometries, and residual stress levels. Fatigue-life prediction models are formulated based on nominal stress amplitude, residual stress, form factor, crack-initiating inhomogeneity, and surface roughness, with smooth samples serving as a baseline reference. The study presents two empirical models for predicting fatigue life and fatigue strength using S–N curves and the Kitagawa–Takahashi diagram with the El Haddad approach, derived from comprehensive experimental data, including finite element modeling, fatigue-life measurements, surface roughness evaluations, and residual stress analysis. KW - AlSi10Mg KW - Kitagawa–Takahashi diagram KW - El Haddad KW - Equivalent stress KW - Fatigue-life prediction KW - PBF-LB/M PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625176 DO - https://doi.org/10.1007/s40964-025-00974-0 SP - 1 EP - 16 PB - Springer Science and Business Media LLC AN - OPUS4-62517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -