TY - CONF A1 - Straße, Anne A1 - Üstündag, Ömer A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael ED - Schmidt, M. ED - Vollertsen, F. ED - Govekar, E. T1 - LMD coatings as filler material for laser beam welded 30 mm thick plates N2 - The development of high energy laser sources enables single-pass welds of thick plates up to 30 mm, but often additional materials are needed to influence the properties of the weld seams. However, the homogenous distribution of filler materials in form of e.g. electrodes is only possible up to 7 mm while the elements are only traceable up to a depth of 14 mm. To overcome this problem a two-step process is used where first the edges of the weld partners are coated with the filler material by laser metal deposition (LMD) and afterwards are welded by laser beam. Single-pass welds with electromagnetic weld pool support of 30 mm thick S355 J2+N-plates with austenitic AISI 316L-coatings were investigated as well as the influence of the coatings to the penetration depth of the laser beam without electromagnetic weld pool support in double-sided joints. The weld seams were tested by X-ray inspection and cross sections. T2 - 11th CIRP Conference on Photonic Technologies [LANE 2020] CY - Online meeting DA - 07.09.2020 KW - Penetration depth KW - Laser metal deposition (LMD) KW - Laser beam welding KW - Filler material distribution PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512790 DO - https://doi.org/10.1016/j.procir.2020.09.055 SN - 2212-8271 VL - 94 SP - 293 EP - 297 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-51279 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Scheuschner, Nils A1 - Straße, Anne A1 - Gumenyuk, Andrey A1 - Maierhofer, Christiane T1 - Towards the determination of real process temperatures in the LMD process by multispectral thermography N2 - Due to the rapid thermal cycles involved in additive manufacturing of metals, high internal stresses and peculiar microstructures occur, which influence the parts mechanical properties. To systematically examine their formation, in-process measurements of the temperature are needed. Since the part emissivity is strongly inhomogeneous and rapidly changing in the process, the applicability of thermography for the determination of thermodynamic temperatures is limited. Measuring the thermal radiation in different wavelengths simultaneously, temperature and emissivity can be separated. Here, we present results of a preliminary study using multispectral thermography to obtain real temperatures and emissivities in directed energy deposition (DED) processes. T2 - Thermosense: Thermal Infrared Applications XLIII CY - Online meeting DA - 12.04.2021 KW - Additive Manufacturing KW - Process monitoring KW - Multispectral thermography KW - Laser metal deposition KW - TES KW - LMD KW - Temperature emissivity separation PY - 2021 DO - https://doi.org/10.1117/12.2587881 VL - 2021 SP - 77 EP - 83 PB - SPIE AN - OPUS4-52516 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Straße, Anne A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Nahteigenschaftsverbesserung von dickwandigen laserstrahlgeschweißten Duplexblechen mittels pulveraufgetragenen Pufferschichten N2 - Duplexstähle finden aufgrund ihrer Eigenschaften, wie der guten Korrosionsbeständigkeit, einer hohen Festigkeit bei gleichzeitig guter Duktilität häufig industrielle Anwendung. Durch die hohen Abkühlraten beim Laserstrahlschweißen weisen Schweißnähte jedoch anstelle eines ausgeglichenen Duplexgefüges einen deutlich erhöhten Ferritanteil, im Vergleich zum Basiswerkstoff, auf. Dies führt zu einer verringerten Duktilität sowie Korrosionsbeständigkeit. Um dieses Problem zu lösen, wurde ein Prozess entwickelt, der auf einer Kantenbeschichtung mit nickelhaltigem Zusatzmaterial der zu fügenden Bleche mittels Laser-Pulver-Auftragschweißen (LPA) basiert. Die resultierenden Schweißnähte wurden zerstörend anhand von Schliffbildern, EDX-Aufnahmen, Härtemessungen und Kerbschlagbiegeversuchen geprüft. T2 - 40. Assistentenseminar der Füge- und Schweißtechnik CY - Braunlage, Germany DA - 25.09.2019 KW - Laser-Pulver-Auftragschweißen; Laserstrahlschweißen, Duplex, Pufferschichten PY - 2020 VL - 357 SP - 131 EP - 140 PB - DVS Media CY - Düsseldorf AN - OPUS4-50144 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Straße, Anne A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Quality improvement of laser welds on thick duplex plates by laser cladded buttering N2 - Because of its excellent corrosion resistance, high tensile strength and high ductility, duplex stainless steel 2205 offers many areas of application. Though laser beam welding accompanied by high cooling rates, duplex steels tend to perform higher ferrite contents in weld metal as the base metal, which leads to a reduction of ductility and corrosion resistance of the weld joint. To overcome this problem, a solution, based on buttering the plate edges by laser metal deposition (LMD) with material containing higher Ni concentrations prior to laser welding was suggested. In this context different process parameters for LMD process were investigated. In a second step the possibility of welding those edges defect free while achieving balanced austenite-ferrite ratio was verified with metallographic analysis, Electron Backscatter Diffraction (EBSD) and impact testing according to Charpy. T2 - Lasers in Manufacturing (LiM) 2019 CY - Munich, Germany DA - 24.06.2019 KW - Laser Metal Deposition; Laser Beam Welding; Duplex; Stainless Steel PY - 2020 SP - We_A31_4_4-1 EP - We_A31_4_4-6 PB - WLT (Wissenschaftliche Gesellschaft für Lasertechnik) AN - OPUS4-50143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Straße, Anne A1 - Gumenyuk, Andrey A1 - Scheuschner, Nils A1 - Altenburg, Simon A1 - Pignatelli, Giuseppe A1 - Gornushkin, Igor B. A1 - Baensch, Franziska A1 - Rethmeier, Michael T1 - In-situ Prozessüberwachung beim Laser-Pulver-Auftragschweißen (LPA) mittels Thermografie, optischer Emissionsspektroskopie (OES) und Schallemissionsanalyse (SEA) N2 - Vor allem in den letzten Jahren ist das Interesse der Industrie an der additiven Fertigung deutlich gestiegen. Die Vorteile dieser Verfahren sind zahlreich und ermöglichen eine ressourcenschonende, kundenorientierte Fertigung von Bauteilen, welche zur stetigen Entwicklung neue Anwendungsbereiche und Werkstoffe führen. Aufgrund der steigenden Anwendungsfälle, nimmt auch der Wunsch nach Betriebssicherheit unabhängig von anschließenden kostenintensiven zerstörenden und zerstörungsfreien Prüfverfahren zu. Zu diesem Zweck werden im Rahmen des von der BAM durchgeführten Themenfeldprojektes „Prozessmonitoring in Additive Manufacturing“ verschiedenste Verfahren auf ihre Tauglichkeit für den in-situ Einsatz bei der Prozessüberwachung in der additiven Fertigung untersucht. Hier werden drei dieser in-situ Verfahren, die Thermografie, die optische Emissionsspektroskopie und die Schallmissionsanalyse für den Einsatz beim Laser-Pulver-Auftragschweißen betrachtet. T2 - 41. Assistentenseminar der Füge- und Schweißtechnik CY - Magdeburg, Germany DA - 02.09.2020 KW - Laser-Pulver-Auftragschweißen (LPA) KW - Thermographie KW - Optische Emissionsspektroskopie (OES) KW - Schallemissionsanalyse (SEA) PY - 2021 SN - 978-3-96144-141-9 VL - 370 SP - 132 EP - 140 PB - DVS MEdia CY - Düsseldorf AN - OPUS4-53967 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Maierhofer, Christiane A1 - Straße, Anne A1 - Gumenyuk, Andrey T1 - Comparison of MWIR thermography and high-speed NIR thermography in a laser metal deposition (LMD) process N2 - Additive manufacturing (AM) offers a range of novel applications. However, the manufacturing process is complex and the production of defect-free parts with high reliability and durability is still a challenge. Thermography is a valuable tool for process surveillance, especially in metal AM processes. The high process temperatures allow one to use cameras usually operating in the visible spectral range. Here, we compare the results of measurements during the manufacturing process of a commercial laser metal deposition setup using a mid-wavelength-IR camera with those from a visual spectrum high-speed camera with band pass filter in the near-IR range. T2 - Conference QIRT 2018 CY - Berlin, Germany DA - 25.06.2018 KW - Additive manufacturing KW - Laser metal deposition KW - ProMoAM KW - Thermography PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-454993 UR - http://www.qirt.org/archives/qirt2018/papers/p35.pdf DO - https://doi.org/10.21611/qirt.2018.p35 SP - 1 EP - 5 PB - QIRT Council CY - Quebec, Canada AN - OPUS4-45499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheuschner, Nils A1 - Altenburg, Simon A1 - Straße, Anne A1 - Gumenyuk, Andrey A1 - Maierhofer, Christiane T1 - In-situ thermographic monitoring of the laser metal deposition process N2 - In this paper shortwave infrared (SWIR) thermographic measurements of the manufacturing of thin single-line walls via laser metal deposition (LMD) are presented. As the thermographic camera is mounted fixed to the welding arm, an acceleration sensor was used to assist in reconstructing the spatial position from the predefined welding path. Hereby we could obtain data sets containing the size of the molten pool and the oxide covered areas as functions of the position in the workpiece. Furthermore, the influence of the acquisition wavelength onto the thermograms was investigated in a spectral range from 1250 nm to 1550 nm. All wavelengths turned out to be usable for the in-situ process monitoring of the LMD process. The longer wavelengths are shown to be beneficial for the lower temperature range, while shorter wavelengths show more details within the molten pool. T2 - Sim-AM 2019 - 2. International Conference on Simulation for Additive Manufacturing CY - Pavia, Italy DA - 11.09.2019 KW - Additive manufacturing KW - 3D printing KW - Thermography KW - Direct energy deposition KW - Laser Metal Deposition KW - 3D Druck KW - Laser Pulver Auftragsschweißen KW - Additive Fertigung KW - Thermografie PY - 2019 UR - http://congress.cimne.com/SIM-AM2019/frontal/Doc/proceedings.pdf SN - 978-84-949194-8-0 SP - 246 EP - 255 AN - OPUS4-49086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stankevich, S. A1 - Gumenyuk, Andrey A1 - Straße, Anne A1 - Rethmeier, Michael ED - Reisgen, U. ED - Schmidt, M. ED - Zaeh, M. ED - Rethmeier, Michael T1 - Measurement of thermal cycle at multi-pass layer build-up with different travel path strategies during DLMD process N2 - The shape of the parts, created by the technology of direct laser metal deposition (DLMD), is influenced by various parameters, for example, the power and diameter of the laser source spot. The contribution of energy from the laser affects the temperature distribution in the formed layers. The changing temperature in the working area entails a Change in the geometry of the layers and affects the stability of the process. In this paper, experiments on the measurement of temperature cycles in the DLMD process with different directions of the filling track are carried out. An infrared camera was used to measure thermal cycles. The calibration of the acquired data (i.e. correspondence table between the intensity of thermal radiation of the material and the absolute temperature) was done with help of two-color pyrometer ex situ and in situ measurements. The experiments are carried out on two materials 316L and Inconel 718. The effect of the maximum temperature on the layer height is shown, and thermal cycles in the formation of layers for different filling strategies are presented. T2 - Laser in Manufacturing Conference 2019 CY - Munich, Germany DA - 24.06.2019 KW - Thermography KW - Direct Laser Metal Deposition PY - 2019 SP - 1 EP - 9 AN - OPUS4-48716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -