TY - JOUR A1 - Bakir, Nasim A1 - Artinov, Antoni A1 - Gumenyuk, Andrey A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Numerical simulation on the origin of solidification cracking in laser welded thick-walled structures N2 - One of the main factors affecting the use of lasers in the industry for welding thick structures is the process accompanying solidification cracks. These cracks mostly occurring along the welding direction in the welding center, and strongly affect the safety of the welded components. In the present study, to obtain a better understanding of the relation between the weld pool geometry, the stress distribution and the solidification cracking, a three-dimensional computational fluid dynamic (CFD) model was combined with a thermo-mechanical model. The CFD model was employed to analyze the flow of the molten metal in the weld pool during the laser beam welding process. The weld pool geometry estimated from the CFD model was used as a heat source in the thermal model to calculate the temperature field and the stress development and distributions. The CFD results showed a bulging region in the middle depth of the weld and two narrowing areas separating the bulging region from the top and bottom surface. The thermo-mechanical simulations showed a concentration of tension stresses, transversally and vertically, directly after the solidification during cooling in the region of the solidification cracking. T2 - 27TH INTERNATIONAL CONFERENCE ON METALLURGY AND MATERIALS - METAL 2018 CY - Brno, Czech Republic DA - 23.05.2018 KW - Laser beam welding KW - Weld pool KW - Full penetration KW - Finite element method (FEM) KW - CFD model KW - Numerical simulation KW - Solidification cracking PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-450595 SN - 2075-4701 VL - 8 IS - 6 SP - 406, 1 EP - 15 PB - MDPI CY - Basel, Switzerland AN - OPUS4-45059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yang, Fan A1 - Meng, Xiangmeng A1 - Putra, Stephen Nugraha A1 - Artinov, Antoni A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Numerical analysis of the effect of an oscillating metal vapor plume on the keyhole and molten pool behavior during deep penetration laser beam welding N2 - The effect of the oscillating metal vapor plume on the keyhole and molten pool behavior during the laser beam welding of AlMg3 aluminum alloys is investigated by experimental and numerical methods. The real-time height of the metal vapor plume is measured by high-speed camera observation. The obtained experimental results are used to evaluate the additional heating source and laser beam attenuation caused by the scattering and absorption based on the Beer–Lambert theory. Furthermore, the dynamic behavior of the metal vapor plume is incorporated into a 3D transient heat transfer and fluid flow model, coupled with the ray tracing method, for the laser beam welding of the AlMg3 alloy. It is found that additional heating resulting from the scattered and absorbed laser beam energy by the metal vapor plume significantly expands the shape of the molten pool on the top region. Moreover, the oscillating metal vapor plume caused the fluctuation of the high-temperature region in the molten pool. The probability of keyhole collapse at the bottom increases 17% due to the oscillating laser power induced by the laser beam attenuation. The internal interplay between the metal vapor plume, molten pool shape, and keyhole collapse is obtained. The developed model has been validated by experiments, which shows a good agreement. T2 - International Congress of Applications of Lasers & Electro-Optics 2023 CY - Chicago, IL, USA DA - 16.10.2023 KW - Deep penetration laser beam welding KW - Numerical simulation KW - Oscillating vapor plume KW - Keyhole collapse PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-587978 SN - 1938-1387 SN - 1042-346X VL - 35 IS - 4 SP - 1 EP - 10 PB - AIP Publishing CY - Melville, NY AN - OPUS4-58797 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -