TY - JOUR A1 - Üstündag, Ömer A1 - Gook, S. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Hybrid laser-arc welding of thick-walled pipe segments with optimization of the end crater N2 - The study deals with the application of the high-power hybrid-laser arc welding process on up to 15 mm thick pipe segments with the intention to avoid end crater imperfections during closing of the circumferential welds, where the pipes were turned during welding in 1G- and 2Gpositions. Different techniques such as laser power ramp-down, abrupt switch-off of the laser power and change of the magnification of the laser spot diameter and defocusing of the laser beam relative to the workpiece were tested to remove the laser energy from the process. It could be shown that a high defocusing of the optic system above 40 mm with a resulting beam diameter > 2.9 mm in a short overlap length of approx. 20 mm leads to the formation of a cup-shaped weld seam, which is preferred for avoidance of cracks and pores in the end crater. A laser optics with motor-driven lens system was used for the welding experiments to defocuse the laser beam without changing the position of the arc. KW - Hybrid laser-arc welding KW - Circumferential weld KW - Thick-walled steel KW - Single-pass welding KW - End crater PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513260 DO - https://doi.org/10.1016/j.procir.2020.09.106 VL - 94 SP - 676 EP - 679 PB - Elsevier B.V. AN - OPUS4-51326 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Üstündag, Ömer A1 - Bakir, Nasim A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Investigation of the gap bridgeability at high-power laser hybrid welding of plasma-cut thick mild steels with AC magnetic support N2 - One of the challenges of the high-power hybrid laser welding of thick steels is the sensitivity of the process of the process to manufacturing tolerances. This usually leads to a time-consuming preparation of the welding edges, such as milling. The study deals with the influence of the edge quality of milled and plasma-cut steel made of S355J2 with a wall thickness of 20 mm on the laser hybrid welded seam quality. Furthermore, the gap bridgeability and the tolerances towards edge misalignment was investigated. An AC magnet was used as backing support to prevent sagging and positioned under the workpiece, to generate an upwards directed electromagnetic pressure. The profiles of the edges and the gap on the top and root side were measured using a digital camera. Single-pass laser hybrid welds of plasma-cut edges could be welded using a laser beam power of just 13.7 kW. A gap bridgeability up to 2 mm and misalignment of edges up to 2 mm could be achieved successful. Additionally, the independence of the cutting side and the welding side was shown, so that samples were welded to the opposite side to their cutting. For evaluation of internal defects or irregularities, X-ray images were carried out. Charpy impact strength tests were performed to determine the toughness of the welds. T2 - X International Conference «Beam Technologies & Laser Application» KW - Laser hybrid welding KW - Magnetic bath support KW - Plasma-cut samples KW - Thick plate welding PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-539248 DO - https://doi.org/10.1088/1742-6596/2077/1/012007 VL - 2077 IS - 012007 SP - 1 EP - 8 PB - IOP Publishing AN - OPUS4-53924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Üstündag, Ömer A1 - Bakir, Nasim A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Improvement of Charpy impact toughness by using an AC magnet backing system for laser hybrid welding of thick S690QL steels N2 - The study deals with the influence of the heat input and the resulting cooling times on the microstructure and Charpy impact toughness of single-pass laser hybrid welded 20-mm thick high-strength steel S690QL. The main focus is on the change of the mechanical properties over the entire seam thickness. The cooling times were measured in-situ using a pyrometer and an optical fibre in three different depths of the seam where Charpy impact test specimens were also later taken. Thereby, three different heat inputs from 1.3 kJ/mm to 2 kJ/mm were investigated. Despite the observed decreased values of both t8/5-cooling time and the Charpy impact toughness in the root part of the seam, the required impact toughness of 38 J/cm2 could be reached in dependance on applied heat input, especially at the heat input of 1.6 kJ/mm. T2 - 12th CIRP conference on photonic technologies [lane 2022] CY - Fürth, Germany DA - 04.09.2022 KW - Thick-plate welding KW - Laser hybrid welding KW - Electromagnetic backing KW - Charpy impact toughness KW - Thermal cycles PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-563731 DO - https://doi.org/10.1016/j.procir.2022.08.067 VL - 111 SP - 462 EP - 465 PB - Elsevier B.V. AN - OPUS4-56373 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 - Thermal Cycles and Charpy Impact Toughness of Single-Pass Hybrid Laser-Arc Welded Thick-Walled Structures N2 - The study deals with the influence of the heat input on the thermal cycles and Charpy impact toughness for hybrid laser-arc welding of 25 mm thick structural steel S355J2 using a 20-kW high-power laser in combination with an electromagnetic weld pool support. The main focus is on the change of the mechanical properties over the entire seam thickness. The cooling times were measured using a pyrometer in combination with an optical fibre in three different locations near to fusion lines corresponding to different heights of the seam. Also, Charpy impact specimens were taken from different parts of the weld joint corresponding to the different heights. The influence of the heat input was investigated for 1.8 kJ mm-1 and 3.2 kJ mm-1. Despite the observed decreased values of both t8/5-cooling time and the Charpy impact toughness in the root part of the seam, the required values could be reached in dependance on applied heat input. T2 - Lasers in Manufacturing Conference 2021 CY - Online meeting DA - 21.06.2021 KW - laser hybrid welding KW - Charpy impact toughness KW - thick plate welding KW - thermal cycles PY - 2021 SP - 1 EP - 8 AN - OPUS4-53926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer T1 - High-power hybrid laser arc welding of thick materials with electromagnetic weld pool support N2 - In addition to the many advantages of deep penetration, increased welding speed and a low sensitivity to manufacturing tolerances such as gap and edge offset, the hybrid laser arc welding (HLAW) process is used increasingly in industrial applications such as shipbuilding or pipeline manufacturing. Nonetheless, thick-walled sheets with a wall thickness of 20 mm or more are still multi-pass welded using the arc welding process, due to increased process instability by increasing laser power. Welding at reduced speed, especially in a flat position, leads to an irregular formation of the root part such as dropping. The hydrostatic pressure exceeds the surface tension, which decreases with increasing seam width. In order to prevent gravity drop-outs, the use of a melt pool support is necessary. Usual weld pool supports such as ceramic or powder supports require time-consuming mechanical detachment. The electromagnetic weld pool support system, which is described in this study, operates without contact and based on generating Lorentz forces in the weld pool. An externally applied oscillating magnetic field induces eddy currents and generates an upward directed Lorentz force, which counteracts the hydrostatic pressure. This allows single-pass welds up to 30 mm by hybrid laser arc welding process with a 20-kW fibre laser. Moreover, it is favoured by the diminished welding speed the cooling rate which leads to an improvement of the mechanical-technological properties of the seams – the lower formation of martensite in the microstructure enables better Charpy impact toughness. The electromagnetic weld pool support extends the limitation of the laser hybrid welding process in the thick sheet area. By adapting the electromagnetic weld pool support to the laser and laser hybrid welding process, the application potential of these technologies for industrial implementation can be drastically increased. T2 - 23rd Technical Conference on Welding and Joining Technologies CY - Irun, Spain DA - 07.03.2023 KW - Laser hybrid welding KW - Thick-walled steel KW - Electromagnetic backing KW - High-power laser PY - 2023 AN - OPUS4-58613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer T1 - Influence of shielding gas on filler wire mixing at laser hybrid welding of thick high strength steels N2 - The laser hybrid welding process offers many advantages during welding oft hick-walled steels, such as the increased penetration depth and, thus, reduced number of layers, reduced heat input and decreased distortion compared to arc-based welding processes. Especially, when welding high-strength steels (HSS), the reduced heat input plays an essential role. However, a major challenge when laser hybrid welding of thick-walled steels is the limited filler wire mixing over the entire seam thickness, which can lead to changed mechanical properties over the depth. To overcome this issue, the add of oxygen into the shielding gas and its influence on the filler wire mixing and finally to the mechanical properties were investigated within this work. Therefore, 20 mm thick S690QL steels were laser hybrid welded in a single-pass. A contactless electromagnetic backing was used to avoid sagging. The admixture of oxygen was performed by a gas mixer, where the oxygen content was varied between 0 % and 7.2 %. The experiments were also accompanied by laser beam welding tests in steel/glass configuration, where the melt pool geometry as well as the melt flow characteristics were captured by a high-speed camera. It can be concluded, that adding of 2 % to 4 % oxygen into the shielding gas had a positive effect on the filler wire mixing, were up to a depth of 18 mm elements of the filler wire could be observed. T2 - 19th Nordic Laser Material Processing Conference CY - Turku, Finland DA - 22.08.2023 KW - Laser hybrid welding KW - Electromagnetic backing KW - Shielding gas KW - Charpy impact toughness KW - Thick-plate welding KW - Filler wire mixing PY - 2023 AN - OPUS4-58615 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer T1 - Hybrid laser-arc welding of thick-walled pipe segments with optimization of the end crater N2 - The study deals with the application of the high-power hybrid-laser arc welding process on up to 15 mm thick pipe segments with the intention to avoid end crater imperfections during closing of the circumferential welds, where the pipes were turned during welding in 1G- and 2G-positions. Different techniques such as laser power ramp-down, abrupt switch-off of the laser power and change of the magnification of the laser spot diameter and defocusing of the laser beam relative to the workpiece were tested to remove the laser energy from the process. It could be shown that a high defocusing of the optic system above 40 mm with a resulting beam diameter > 2.9 mm in a short overlap length of approx. 20 mm leads to the formation of a cup-shaped weld seam, which is preferred for avoidance of cracks and pores in the end crater. A laser optics with motor-driven lens system was used for the welding experiments to defocuse the laser beam without changing the position of the arc. T2 - 11th CIRP Conference on Photonic Technologies LANE 2020 CY - Online Meeting DA - 07.09.2020 KW - End crater KW - Hybrid laser-arc welding KW - Circumferential weld PY - 2020 AN - OPUS4-51634 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer T1 - Influence of heat input on cooling rates and mechanical properties of laser hybrid welded thick structural steels N2 - The laser hybrid welding process offers many advantages such as the high penetration depth and high welding speed, and it is characterized by its low heat input compared to the arc-based welding processes, which makes the laser hybrid welding process as a suitable alternative process when welding thick-walled steels. However, there are some challenges when using laser hybrid welding process for thick steels. Due to the uneven cooling conditions and the inhomogeneous filler wire mixing, a typical laser hybrid weld can be divided into two different zones over the depth: the arc-dominated zone on the upper part and the laser-dominated zone in the root part. This leads to different mechanical properties in a laser hybrid welded joint. Due to the high cooling rates and the lack of filler wire in the laser-dominated zone, this area is more critical regarding the mechanical properties, especially the Charpy impact toughness. A low heat input can lead to undesired microstructure consisting of martensite, hardening and deteriorated impact toughness due to the high cooling rate, where higher heat inputs can lead to grain-coarsening and even loss of impact strength. This study deals with the influence of the welding speed and resulting heat input on the cooling rates, the microstructure and the mechanical properties of single-pass laser hybrid welded steels of S355J2 with thickness up to 30 mm. The experiments were performed with a 20-kW fibre laser system and a contactless electromagnetic weld backing on up to 30 mm thick steels in butt-joint configuration in 1G welding position. The cooling time was measured in three different locations near to fusion lines corresponding to different heights of the seam using a special configuration with pyrometers, collimators, and optical fibres. The test specimens for the Charpy impact testing and tensile testing were extracted in up to three different depths. Based on the experiments, a heat input of 1.3 kJ/mm - 1.6 kJ/mm, 2 kJ/mm - 2.4 kJ/mm and 3.7 kJ/mm were recommended when single-pass laser hybrid welding of 20 mm, 25 mm and 30 mm thick structural steels in regard to the minimum requirements of the mechanical properties, respectively. The optical measurement of the cooling times in different depths could be carried out reproducibly. T2 - Advances in Welding and Metal Additive Manufacturing Technologies 2023 CY - Istanbul, Türkiye DA - 30.10.2023 KW - Laser hybrid welding KW - Electromagnetic backing KW - Charpy impact toughness KW - Thick-plate welding KW - Thermal cycles PY - 2023 AN - OPUS4-58942 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer T1 - Thermal Cycles and Charpy Impact Toughness of Single-Pass Hybrid Laser-Arc Welded Thick-Walled Structures N2 - The study deals with the influence of the heat input on the thermal cycles and Charpy impact toughness for hybrid laser-arc welding of 25 mm thick structural steel S355J2 using a 20-kW high-power laser in combination with an electromagnetic weld pool support. The main focus is on the change of the mechanical properties over the entire seam thickness. The cooling times were measured using a pyrometer in combination with an optical fibre in three different locations near to fusion lines corresponding to different heights of the seam. Also, Charpy impact specimens were taken from different parts of the weld joint corresponding to the different heights. The influence of the heat input was investigated for 1.8 kJ mm-1 and 3.2 kJ mm-1. Despite the observed decreased values of both t8/5-cooling time and the Charpy impact toughness in the root part of the seam, the required values could be reached in dependance on applied heat input. T2 - Lasers in Manufacturing Conference 2021 CY - Online meeting DA - 21.06.2021 KW - Hybrid laser-arc welding KW - Thick-walled structures KW - Charpy impact toughness KW - Thermal cycles PY - 2021 AN - OPUS4-53576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer T1 - Improvement of Charpy impact toughness by using an AC magnet backing system at laser hybrid welding of thick S690QL steels N2 - The study deals with the influence of the heat input and the resulting cooling times on the microstructure and Charpy impact toughness of single-pass laser hybrid welded 20-mm thick high-strength steel S690QL. The main focus is on the change of the mechanical properties over the entire seam thickness. The cooling times were measured in-situ using a pyrometer and an optical fibre in three different depths of the seam where Charpy impact test specimens were also later taken. Thereby, three different heat inputs from 1.3 kJ/mm to 2 kJ/mm were investigated. Despite the observed decreased values of both t8/5-cooling time and the Charpy impact toughness in the root part of the seam, the required impact toughness of 38 J/cm2 could be reached in dependance on applied heat input, especially at the heat input of 1.6 kJ/mm. T2 - LANE 2022: 12th CIRP Conference on Photonic Technologies CY - Fürth, Germany DA - 04.09.2022 KW - Laser hybrid welding KW - Electromagnetic backing KW - Charpy impact toughness KW - Thick-plate welding KW - Thermal cycles PY - 2022 AN - OPUS4-56369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer T1 - Analysis of microstructure and mechanical properties of single-pass laser hybrid welded thick-walled steels up to 30 mm with contactless electromagnetic backing N2 - The study deals with the influence of the heat input on the thermal cycles, the microstructure and the mechanical properties for laser-hybrid welded steels of S355J2 with thicknesses up to 30 mm using a 20-kW high-power laser with contactless electromagnetic backing. The focus is on the change of the mechanical properties over the seam thickness. Therefore, the impact toughness and tensile strength were tested in different depths. Based on the experiments, a heat input of 1.3 kJ/mm - 1.6 kJ/mm, 2 kJ/mm - 2.4 kJ/mm and 3.7 kJ/mm were recommended when single-pass welding of 20 mm, 25 mm and 30 mm with a 20-kW laser in regard to the minimum requirements of the mechanical properties, respectively. Lower heat inputs led to undesired microstructure consisting of martensite, hardening and deteriorated impact toughness, where higher heat inputs led to grain-coarsening and even loss of impact strength due to the formation of retained-austenite on the grain boundaries. T2 - EMPOrIA 2023 - International Joint Conference CY - Aachen, Germany DA - 16.05.2023 KW - Laser hybrid welding KW - Electromagnetic backing KW - Thermal cycles KW - Charpy impact toughness KW - Thick-plate welding PY - 2023 AN - OPUS4-58614 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer T1 - Hybrid laser-arc welding of laser and plasma-cut 20 mm thick structural steels N2 - It is already known that the laser beam welding (LBW) or hybrid laser-arc welding (HLAW) processes are sensitive to manufacturing tolerances such as gaps and misalignment of the edges, especially at welding of thick-walled steels due to its narrow beam diameter. Therefore, the joining parts preferably have to be milled. The study deals with the influence of the edge quality, the gap and the misalignment of edges on the weld seam quality of hybrid laser-arc welded 20 mm thick structural steel plates which were prepared by laser and plasma-cutting. Single-pass welds were conducted in butt-joint configuration. An AC magnet was used as a contactless backing. It was positioned under the workpiece during the welding process to prevent sagging. The profile of the edges and the gap between the workpieces were measured before welding by a profile scanner or a digital camera, respectively. With a laser beam power of just 13.7 kW, the single-pass welds could be performed. A gap bridgeability up to 1 mm at laser-cut and 2 mm at plasma-cut samples could be reached respectively. Furthermore, a misalignment of the edges up to 2 mm could be welded in a single-pass. The new findings may eliminate the need for cost and time-consuming preparation of the edges. T2 - 74th IIW Annual Assembly and International Conference 2021 CY - Online meeting DA - 07.07.2021 KW - Hybrid laser-arc welding KW - Thick-walled steel KW - Edge quality KW - Gap bridgeability KW - Misalignment of the edges KW - Plasma-cutting KW - Laser-cutting PY - 2021 AN - OPUS4-53577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ömer T1 - Investigation of the mechanical properties of single-pass hybrid laser-arc welded thick X120 pipeline steel plates N2 - High heat input leads to grain coarsening and softening in WM and HAZ; the tensile strength is reduced. Low heat input leads to inadmissible hardening in the WM; the impact strength is reduced. The proposed t8/5-time of 3 s to 15 s could be achieved through the reduced welding velocity. The concept of electromagnetic weld pool support system allowed single-pass welds in flat position without gravity drop-outs even for reduced welding speeds; in this way the heat input can be controlled. The adaptation of the electromagnetic weld pool support system to laser and laser hybrid welding process can dramatically increase the potential field of application of these technologies for real industrial implementation. T2 - 14th Pipeline Technology Conference 2019 CY - Berlin, Germany DA - 18.03.2019 KW - Toughness KW - Hybrid laser-arc welding KW - Pipeline steel X120 KW - Electromagnetic weld pool support KW - Mechanical properties PY - 2019 AN - OPUS4-49894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ö. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Single-pass Hybrid Laser Arc Welding of Thick Materials Using Electromagnetic Weld Pool Support N2 - Hybrid laser-arc welding process allows single-pass welding of thick materials, provides good quality formation of joints with minimal thermal deformations and a high productivity in comparison with arc-based welding processes. Nevertheless, thick-walled steels with a thickness of 20 mm or more are still multi-pass welded using arc welding processes, due to increased process instability by increasing laser power. One limitation factor is the inadmissible formation of gravity drop-outs at the root. To prevent this, an innovative concept of electromagnetic weld pool support is used in this study. With help of such system a stable welding process can be established for 25 mm thick steel plates and beyond. Sound welds could be obtained which are tolerant to gaps and misalignment of the welded parts. The adaptation of this system to laser and hybrid laser-arc welding process can dramatically increase the potential field of application of these technologies for real industrial implementation. T2 - Lasers in Manufacturing Conference 2019 CY - Munich, Germany DA - 24.06.2019 KW - Full Penetration KW - Hybrid Laser Arc Welding KW - Electromagnetic Weld Pool Support KW - Thick Materials PY - 2019 SP - 1 EP - 8 PB - WLT Wissenschaftliche Gesellschaft Lasertechnik e.V. AN - OPUS4-48971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Üstündag, Ö. A1 - Gook, S. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Mechanical Properties of Single-pass Hybrid Laser Arc Welded 25 mm Thick-walled Structures Made of Fine-grained Structural Steel N2 - The presented study deals with the performing and mechanical testing of single pass hybrid laser-arc welds (HLAW) on 25 mm thick plates made of steel grade S355J2. One of the challenges have to be solved at full penetration HLAW of thick plates is the drop formation occurring due to the disbalances of the forces acting in the keyhole and on the melt pool surface. Such irregularities mostly limit the use of high-power laser beam welding or HLAW of thick-walled constructions. To overcome this problem, an innovative concept of melt pool support based on generating Lorentz forces in the weld pool is used in this work. This method allows to perform high quality welds without sagging even for welding of 25 mm thick plates in flat position at a welding speed of 0.9 m min-1. For the obtain of full penetrated welds a laser beam power of 19 kW was needed. A high V-impact energy of up to 160 J could be achieved at the test temperature of 0 °C. Even at the most critical part in the weld root an impact energy of 60 J in average could be reached. The tensile strength of the weld reaches that of the base material. An introduce of the HLAW process with electromagnetic support of the melt pool in the industrial practice is an efficient alternative to the time- and cost-intensive arc-based multi-layer welding techniques which are established nowadays for joining of thick-walled constructions. KW - Mechanical Properties KW - Hybrid Laser Arc Welding KW - Thick-walled Structures KW - Fine-grained Steel PY - 2019 DO - https://doi.org/10.1016/j.promfg.2019.08.016 SN - 2351-9789 VL - 36 SP - 112 EP - 120 PB - Elsevier B.V. AN - OPUS4-48969 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Üstündag, Ö. A1 - Gook, S. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Investigation of the mechanical properties of single-pass hybrid laser-arc welded thick X120 pipeline steel plates N2 - With global increases in clean energy demand, the natural gas is gaining in importance. Pipelines are the safest and most cost-effective way of transporting natural gas. Due to high transport volume and resulting high operation pressure, the demand for ultra-high strength steel grades such as X120 is very strong. As a result of the fact that these steels are produced by thermo-mechanical controlled processing, the welding process must be selected accordingly. Based on investigations, a high heat input such as by submerged arc welding process leads to softening in the weld metal and loss of strength whereas pure laser beam welding results in high cooling rates and deteriorate toughness of the weld metal. The objective of this research is to investigate the influence of heat input to mechanical properties of hybrid laser-arc welded pipeline steels of grade X120. Test specimens with a thickness of 20 mm could be welded without preheating in a single-pass with different welding velocities to observe the largest possible parameter window of the heat input. The achieved V-notch impact energy for hybrid laser-arc welded samples was 144±37 J at a testing temperature of -40 °C. With a tensile strength of 930±4 MPa the requirements of API 5L was achieved. To prevent gravity drop-outs at the slow welding speeds, an electromagnetic weld pool support system was used, which works contactless and is based on generating Lorentz forces. It was therefore possible to control the cooling rate in order to meet the requirements of the mechanical properties. By adapting the electromagnetic weld pool support to the laser and laser hybrid welding process, the application potential of these technologies for industrial implementation can be drastically increased. T2 - 14th Pipeline Technology Conference CY - Berlin, Germany DA - 18.03.2019 KW - Mechanical properties KW - Hybrid laser arc welding KW - Pipeline steel X120 PY - 2019 UR - https://www.pipeline-conference.com/conferences/14th-pipeline-technology-conference-2019 SN - 2510-6716 SP - 1 EP - 10 AN - OPUS4-48970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Üstündag, Ö. A1 - Fritzsche, André A1 - Avilov, V. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Study of gap and misalignment tolerances at hybrid laser arc welding of thick-walled steel with electromagnetic weld pool support system N2 - The hybrid laser arc welding (HLAW) process provides many advantages such as improved gap bridgeability, deep penetration and misalignment of edges, that is why the process is used increasingly in industrial applications e.g. shipbuilding, power plant industry and line-pipe manufacturing. The obvious encountered problem for single pass welding in flat position is the gravity drop-out at low welding velocities. With the usage of an electromagnetic weld pool support system, which is based on generating Lorentz forces within the weld pool, wide seams followed by reduced welding velocities could be achieved in this study leading to the realization of a gap bridgeability up to 1 mm, misalignment of edges up to 2 mm and a single pass weld up to 28 mm thickness with a 20-kW fibre laser. These developments expand the boundaries of the HLAW process for different industrial applications. As a result, less accurate preparation of the edges would be sufficient, which saves time for manufacturing. KW - Hybrid laser-arc welding KW - Electromagnetic weld pool support system KW - Thick-walled steel KW - Gap bridgeability KW - Single pass welding KW - Misalignment of edges PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-468263 DO - https://doi.org/10.1016/j.procir.2018.08.016 SN - 2212-8271 VL - 74 SP - 757 EP - 760 PB - Elsevier AN - OPUS4-46826 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Üstündag, Ö. A1 - Avilov, V. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Full penetration hybrid laser arc welding of up to 28 mm thick S355 plates using electromagnetic weld pool support N2 - The laser hybrid welding process offers many advantages regarding deep penetration, increased welding velocity and with the help of the supplied filler wire an improved bridgeability to gap and misalignment tolerances. High power laser systems with a power of approx. 30 kW are already available on the market. Nevertheless, multi-layer technology with an arc process is still used for welding of plates from a thickness from 20 mm. A potential cause is the process instability with increasing laser power. It is inevitable that gravity drop-out due to the high hydrostatic pressure at increasing wall thickness especially at welding in flat position and with a low welding speed. The surface tension decreases with increasing root width resulting from low welding velocities. To prevent such inadmissible defects of the seam a use of weld pool support is required. Usual weld pool support systems such as ceramic or powder supports require a mechanical detachment which is time-consuming. The electromagnetic weld pool support system described in this work shows an alternative weld pool support which works contactless. It is based on generating Lorentz forces in the weld pool due to oscillating magnetic field and induced eddy currents. This innovative technology offers single pass welds up to 28 mm in flat position and reduced welding velocity with a laser power of just 19 kW. It also leads to improved mechanical-technological properties of the seams because of the slow cooling rate. With usage of an electromagnetic weld pool support the limitation of the hybrid laser arc welding process in the thick sheet metal will be extend. KW - Electromagnetic weld pool support KW - Hybrid laser arc welding KW - Thick-walled steel KW - Single pass welding PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-468276 DO - https://doi.org/10.1088/1742-6596/1109/1/012015 SN - 1742-6596 VL - 1109 SP - 1 EP - 7 PB - IOP Publ. AN - OPUS4-46827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - DELTA - Investigation of corrosion and microbially influenced corrosion processes by means of X-Ray absorption spectroscopy N2 - Alloys relevant for corrosion research are inherently complex in chemical composition and microstructure. Their local surface chemistry differs significantly from the bulk composition and their surfaces are subjected to ever changing environmental conditions. Thus, a thorough understanding of the mechanisms leading to material degradation and failure requires a detailed characterisation of the initial and final states as well as an adequate monitoring of the relevant properties as a function of time. Moreover, corrosion products tend to oxidize in contact with the atmosphere. Microbially influenced corrosion (MIC) poses a particular challenge regarding the experimental methods that can be used for the investigations. The use of highly sensitive methods of ultra-high vacuum surface analysis requires the removal of the biofilm, which leads to significant changes in the interfacial chemistry. In recent projects we applied X-ray absorption near edge spectroscopy (XANES) to investigate mechanisms of aqueous corrosion, high temperature corrosion and MIC processes of stainless steel and multi-principal element alloys (MPEAs). By combining in situ XANES studies on model thin films with ex situ XANES analysis of technical samples we aimed to obtain a holistic understanding of degradation processes. In this presentation we will summarize our results on the application of XANES to corrosion and MIC research with two case studies. In the first case study, in situ and ex situ XANES were used for the investigation of aqueous and high-temperature corrosion processes of alloys from FeNiCr-Mn MPEA family to clarify the role of Mn in determining the corrosion resistance and passive film formation. Our results indicate that Mn plays a major role in suppressing Fe oxidation. In the second example we have shown by means of in situ and ex situ XANES analysis that cultivation of metal reducing bacteria (MRB) in abundance of Fe(III) ions leads to a significant increase in electrochemical activity and thus, to an accelerated corrosion of the metallic substrate. This implies that bacterial colonies released from active corrosion sites might show a preconditioning effect and pose a higher corrosion risk. T2 - eMRS 2024 Spring Meeting CY - Strasbourg, France DA - 27.05.2024 KW - Corrosion KW - XANES KW - MIC KW - Multi-principal element alloys PY - 2024 AN - OPUS4-62636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Neue Projekte im Bereich Biokorrosion: Spektro-elektrochemische Untersuchungen der Biofilmbildung und MIC auf Metalloberflächen N2 - In this presentation, new projects of FB 6.2 focussing on the Analysis of microbiologically influenced corrosion (MIC) have been summarized. T2 - Sitzung der DECHEMA-GfKORR-Fachgruppe: Mikrobielle Materialzerstörung und Materialschutz CY - DECHEMA Forschungsinstitut, Frankfurt am Main, Germany DA - 30.05.2016 KW - MIC KW - Microbiologically influenced corrosion KW - Local electrochemical methods KW - Spectroelectrochemistry PY - 2016 AN - OPUS4-38200 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Material Acceleration Platforms of BAM (MAPs@BAM) N2 - Material Acceleration Platforms (MAPs) represent a transformative approach to the development of resilient and sustainable technology value chains. These platforms can identify candidate chemistries and structures via simulations, and database searches and leverage machine learning-based rapid screening to accelerate the discovery and deployment of novel materials, thereby addressing critical challenges in modern technology sectors. Incorporating high-fidelity advanced characterization in the early phases of material development is crucial for early de-risking. Advanced characterization techniques, such as X-ray diffraction, advanced electrochemical and spectroscopic techniques provide comprehensive insights into the structural, chemical, and physical properties of materials. Long-term testing further contributes to the de-risking process by evaluating the durability and stability of materials under various environmental and operational conditions. This presentation will briefly summarize how we address these issues at MAPs@BAM and provide deep-dives on best practices. As the demand for advanced materials continues to grow, MAPs will play an increasingly vital role in driving technological advancements and addressing global challenges. T2 - FutureLabsLive Basel CY - Basel, Switzerland DA - 25.06.2024 KW - MAPs@BAM PY - 2024 AN - OPUS4-62643 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Material Acceleration Platforms of BAM (MAPs@BAM) N2 - Material Acceleration Platforms (MAPs) represent a transformative approach to the development of resilient and sustainable technology value chains. These platforms can identify candidate chemistries and structures via simulations, and database searches and leverage machine learning-based rapid screening to accelerate the discovery and deployment of novel materials, thereby addressing critical challenges in modern technology sectors. Incorporating high-fidelity advanced characterization in the early phases of material development is crucial for early de-risking. Advanced characterization techniques, such as X-ray diffraction, advanced electrochemical and spectroscopic techniques provide comprehensive insights into the structural, chemical, and physical properties of materials. Long-term testing further contributes to the de-risking process by evaluating the durability and stability of materials under various environmental and operational conditions. This presentation will briefly summarize how we address these issues at MAPs@BAM and provide deep-dives on best practices. As the demand for advanced materials continues to grow, MAPs will play an increasingly vital role in driving technological advancements and addressing global challenges. T2 - EERA-JPNM Days Workshop (EERA-Joint Programme on Nuclear Materials) CY - Online meeting DA - 29.05.2024 KW - MAPs@BAM PY - 2024 AN - OPUS4-62642 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - The interplay of anodic passivation and oxygen evolution on multi-principal element alloys (MPEAs) N2 - Multi-principal element alloys (MPEAs) are of great academic and industrial interest as emerging materials for engineering applications as well as potential electrode materials in energy conversion and storage. Several MPEAs have been studied for their general corrosion behavior, but studies on their dissolution in the high anodic “transpassive” potentials relevant for oxygen evolution reaction (OER) and local corrosion behavior remained scarce. In this project we have investigated CrMnFeCoNi, FeCrNi and CrCoNi MPEAs in terms of their transpassive behavior in NaCl electrolytes and artificial seawater [1, 2]. We introduced a characterization procedure to distinguish the individual contributions of oxygen evolution reaction (OER) and alloy dissolution [2]. This scheme utilizes scanning electrochemical microscopy (SECM) for detecting the onset of OER and employs quantitative chemical analysis methods, namely inductively coupled mass spectrometry (ICP-MS) and ultraviolet-visible light (UV-Vis) spectroscopy, to elucidate the processes of metal dissolution. In-situ atomic force microscopy (AFM) and scanning Kelvin probe force microscopy (SKPFM) were used to analyze the corrosion morphology and surface potentials before, during, and after passivity breakdown. Our results clearly demonstrate the superior corrosion behavior of CrCoNi and FeCrNi MPEA in comparison to the CrFeMnCoNi HEA, as well as AISI 304 stainless steel. We have observed that significant OER occurs in parallel with metal dissolution on the CrCoNi and FeCrNi MPEA surfaces during anodic polarization at potentials relevant to water electrolysis. Most importantly, our findings underscore the necessity of analyzing metal ions dissolved into the electrolyte to accurately assess the Faradaic efficiencies of non-noble metal OER electrocatalysts. The presentation will summarize our characterization procedure and give an overview on the key properties of the studied MPEAs.  [1] A. Wetzel, M. von der Au, P.M. Dietrich, J. Radnik, O. Ozcan, J. Witt, The comparison of the corrosion behavior of the CrCoNi medium entropy alloy and CrMnFeCoNi high entropy alloy, Appl. Surf. Sci., 601 (2022) 154171. [2] A. Wetzel, D. Morell, M. von der Au, G. Wittstock, O. Ozcan, J. Witt, Transpassive Metal Dissolution vs. Oxygen Evolution Reaction: Implication for Alloy Stability and Electrocatalysis, Angew. Chem. Int. Ed. Engl., n/a (2024) e202317058. T2 - ECASIA 2024 CY - Gothenburg, Sweden DA - 09.06.2024 KW - CCMat KW - Corrosion KW - Electrocatalysis KW - Oxygen evolution reaction PY - 2024 AN - OPUS4-62637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - State-of-the-art in map development: Best practices for application in nuclear materials N2 - Material Acceleration Platforms (MAPs) represent a transformative approach to the development of resilient and sustainable technology value chains. These platforms can identify candidate chemistries and structures via simulations, and database searches and leverage machine learning-based rapid screening to accelerate the discovery and deployment of novel materials, thereby addressing critical challenges in modern technology sectors. Incorporating high-fidelity advanced characterization in the early phases of material development is crucial for early de-risking. Advanced characterization techniques, such as X-ray diffraction, advanced electrochemical and spectroscopic techniques provide comprehensive insights into the structural, chemical, and physical properties of materials. Long-term testing further contributes to the de-risking process by evaluating the durability and stability of materials under various environmental and operational conditions. This presentation will briefly summarize how we address these issues at MAPs@BAM and provide deep-dives on best practices. As the demand for advanced materials continues to grow, MAPs will play an increasingly vital role in driving technological advancements and addressing global challenges. T2 - CONNECT-NM European Partnership Kick-off Meeting CY - Madrid, Spain DA - 02.10.2024 KW - MAPs@BAM KW - Corrosion PY - 2024 AN - OPUS4-62646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Material Acceleration Platforms of BAM (MAPs@BAM) N2 - Material Acceleration Platforms (MAPs) represent a transformative approach to the development of resilient and sustainable technology value chains. These platforms can identify candidate chemistries and structures via simulations, and database searches and leverage machine learning-based rapid screening to accelerate the discovery and deployment of novel materials, thereby addressing critical challenges in modern technology sectors. Incorporating high-fidelity advanced characterization in the early phases of material development is crucial for early de-risking. Advanced characterization techniques, such as X-ray diffraction, advanced electrochemical and spectroscopic techniques provide comprehensive insights into the structural, chemical, and physical properties of materials. Long-term testing further contributes to the de-risking process by evaluating the durability and stability of materials under various environmental and operational conditions. This presentation will briefly summarize how we address these issues at MAPs@BAM and provide deep-dives on best practices. As the demand for advanced materials continues to grow, MAPs will play an increasingly vital role in driving technological advancements and addressing global challenges. T2 - International Cooperation on Innovative Materials for Energy Workshop CY - Brussels, Belgium DA - 19.04.2024 KW - MAPs@BAM PY - 2024 AN - OPUS4-62641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Coupled electrochemical, microscopic and spectroscopic techniques for the analysis of local corrosion and mic processes N2 - Summary of the research topics of the division 6.2 and recent results T2 - HZDR-IRE Institutscolloquium CY - Dresden, Germany DA - 24.09.2019 KW - MIC KW - Localised corrosion KW - Corrosion monitoring KW - Biofilmbildung KW - Atomic Force Microscopy (AFM) PY - 2019 AN - OPUS4-50295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Autonomous exploration of new alloy chemistries using a Material Acceleration Platform (MAP) N2 - The discovery and commercialization of new corrosion resistant alloys by conventional approaches and manual experimentation is a slow and expensive process. In the last few years, efforts have been dedicated internationally to design self-driving-laboratories, also called Material Acceleration Platforms (MAPs). MAPs integrate material synthesis, characterization and testing modules into circular workflows through automation and use artificial intelligence (AI) for efficient and autonomous experiment design, property prediction and data analysis. We have established a MAP for corrosion research by automating diverse liquid operations, electrochemical testing and data evaluation, where the test results are interpreted via a machine learning (ML)-based backend. The workflows of the electrochemistry module are configured for electrodeposition of different alloys and subsequently performing electrochemical corrosion testing. The platform uses the results of the electrochemical tests to determine the next set of deposition parameters in a continuous and autonomous loop until the user-defined objectives are met. In this project we used the MAP to design new multi-principal element alloys (MPEAs) as corrosion resistant electrode materials for H2O and CO2 electrolysis. One campaign contains a maximum of 144 runs. From each successful campaign top five leads and another five randomly selected materials proceed to upscaling either by electrodeposition at larger scale or as bulk ingots cast by means of arc-melting. With these samples, a detailed chemical and electrochemical characterization using surface analysis techniques was performed to validate the success of the MAP-based optimization. The presentation will give an overview of the design and build phases of our MAP, its modules and workflows. Moreover, we will summarize our results from the FeNiCrCuCoMo MPEA system. T2 - EUROCORR 2024 CY - Paris, France DA - 01.09.2024 KW - MAPs@BAM KW - Corrosion KW - Electrodeposition KW - Material Acceleration Platform KW - Electrochemistry PY - 2024 AN - OPUS4-62635 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - MAPz@BAM Material Acceleration Plattform Zentrum @ BAM N2 - Die Material Acceleration Platform der BAM (MAPz@BAM) bündelt unsere Automatisierungs-Expertise auf dem Gebiet der Materialwissenschaft und -prüfung. Wir entwickeln modulare Experimentmodule, automatische Prüf- und Auswerteverfahren und setzen künstliche Intelligenz für eine effiziente und autonome Versuchsplanung, - vorhersage und Datenanalyse ein. T2 - Kick off Meeting / EnerMAC ZIM Network CY - Berlin, Germany DA - 07.12.2023 KW - Material Acceleration Platforms (MAPs) KW - Self-driving-labs (SDLs) KW - MAPz@BAM PY - 2023 AN - OPUS4-59411 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - MAPz@BAM Material Acceleration Plattform Zentrum @ BAM N2 - Die Material Acceleration Platform der BAM (MAPz@BAM) bündelt unsere Automatisierungs-Expertise auf dem Gebiet der Materialwissenschaft und -prüfung. Wir entwickeln modulare Experimentmodule, automatische Prüf- und Auswerteverfahren und setzen künstliche Intelligenz für eine effiziente und autonome Versuchsplanung, - vorhersage und Datenanalyse ein. T2 - TechConnect Adlershof: Grand Solutions CY - Berlin, Germany DA - 06.11.2023 KW - Material Acceleration Platforms (MAPs) KW - Self-driving-labs (SDLs) KW - MAPz@BAM PY - 2023 AN - OPUS4-59412 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - In situ imaging of corrosion processes N2 - The presentation summarizes our recent results on the coupled electrochemical methods for high resolution corrosion studies. The combination of Scanning Electrochemical Microscopy (SECM) and multielectrode (MMA) based real-time corrosion monitoring was presented as a new method for achieving high time resolution in local electrochemical analysis. Correlative imaging by means of Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) was demonstrated as a tool for the investigation of local corrosion processes initiated by the intermetallic particles (IMPs) on AA2024-T3 aluminium alloy. T2 - BAM-IfW Workshop CY - Dresden, Germany DA - 28.03.2019 KW - MIC KW - Atomic Force Microscopy (AFM) KW - Corrosion monitoring KW - Corrosion PY - 2019 AN - OPUS4-50291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Changes in passive film chemistry of stainless steels in the presence of iron reducing bacteria N2 - Summary of the results obtained at DELTA-Beamline 8 in 2018. T2 - DELTA User Treffen CY - Dortmund, Germany DA - 28.11.2018 KW - MIC KW - Corrosion KW - XANES PY - 2018 AN - OPUS4-50312 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Combined electrochemical techniques for the investigation of corrosion processes N2 - Short presentation of BAM, a summary of the methods available in FB 6.2 and recent results on MIC and high resolution corrosion studies T2 - Institute Seminar: Jerzy Haber Institute of Catalysis and Surface Chemistry CY - Cracow, Poland DA - 07.11.2018 KW - MIC KW - Corrosion KW - Atomic Force Microscopy (AFM) KW - Combined corrosive and mechanical load PY - 2018 AN - OPUS4-50313 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Exploration of Fe-Ni-Cr-X systems using diffusion couples for new alloy chemistries with improved mechanical and corrosion properties N2 - Multi-principal element alloys (MPEAs) are disrupting methodologies in conventional alloy design, characterized by a singular dominant element dictating composition. The traditional optimization of the functional properties of alloys primarily relies on microalloying techniques. The advent of MPEAs has significantly broadened the chemical landscape available for exploration, approaching near-infinite possibilities. Consequently, innovative methodologies are imperative for discovering new alloys that exhibit properties customized for specific applications, simultaneously mitigating dependence on critical minerals. One promising approach for rapid screening of possible alloy chemistries and exploring the hitherto untouched regions of ternary, quaternary or higher order phase diagrams is the use of diffusion couples and multiples. The present study focusses on the exploration of quaternary multi-principle-element alloys (MPEAs) using diffusion multiples. We established diffusion systems by combining an equimolar ternary alloy (FeNiCr) with single diffusing elements Mn, Mo and Ta. Using ThermoCalc® and DICTRA® simulations, we determined suitable parameters (temperature and diffusion time) that would lead to the formation of single-phase alloys and diffusion lengths (>50 μm) that suit the application of high-resolution characterization methods. Microstructural and compositional characterization was performed via scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), electron probe microanalyzer (EPMA) and correlated to local mechanical properties evaluated by means of nanoindentation. Selected compositions from the diffusion couples were recast and homogenized to obtain bulk samples for the assessment of high-temperature and aqueous corrosion properties. Our results indicate that the ThermoCalc simulations have a good predictive power for crystallographic phases for Mn and Mo containing MPEAs derived from the diffusion couples. Moreover, our data on FeCrNi-Ta system provides valuable experimental input for respective databases necessary for simulation of phase diagrams. The presentation will summarize our methodology using diffusion couples as an efficient tool for exploring compositional spaces of MPEAs in the search for novel alloy chemistries and the results of our correlative study on the mechanical and corrosion properties of the selected quaternary systems. T2 - EUROCORR 2024 CY - Paris, France DA - 01.09.2024 KW - CCMat KW - Corrosion KW - Diffusion couples KW - Multi-principal element alloys PY - 2024 AN - OPUS4-62634 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Nanotechnology at BAM N2 - The presentation gives a brief summary of the research activities of BAM in the field of nanotechnology. It was held at INERIS in the frame of a delegation meeting to identify topics for future collaborations. T2 - Kooperationstreffen mit INERIS CY - Verneuil-en-Halatte, France DA - 23.10.2017 KW - Nanotechnology KW - Nano Referenzmaterialien KW - Nanosafety PY - 2017 AN - OPUS4-43408 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Material acceleration platforms (MAPs) - Global activities and developments at BAM N2 - Die Material Acceleration Platform der BAM (MAPz@BAM) bündelt unsere Automatisierungs-Expertise auf dem Gebiet der Materialwissenschaft und -prüfung. Wir entwickeln modulare Experimentmodule, automatische Prüf- und Auswerteverfahren und setzen künstliche Intelligenz für eine effiziente und autonome Versuchsplanung, - vorhersage und Datenanalyse ein. T2 - WPFM Expert Group on Structural Materials (EGSM) CY - Online meeting DA - 23.05.2023 KW - Material Acceleration Platforms (MAPs) KW - MAPz@BAM KW - Self-driving-labs PY - 2023 AN - OPUS4-59409 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - High-throughput, automated and autonomous approaches for the design of corrosion resistant materials N2 - The integration of high-throughput electrochemistry, experimental automation and AI-driven processes is enabling the rapid discovery and optimization of advanced materials. This presentation will summarize our research in this field. T2 - GfKORR Grundlagen und Simulation Arbeitsgruppentreffen CY - Online meeting DA - 04.07.2024 KW - MAPs@BAM KW - CCMat KW - Corrosion KW - Electrochemistry PY - 2024 AN - OPUS4-62644 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Application of atomic force microscopy (AFM) for in situ corrosion studies of thin film covered AA2024 T3 aluminium alloy surface N2 - The performance of functional coatings and adhesively joined hybrid components relies strongly on the stability of the polymer-metal interface. With the increasing utilization of multi-material structures in the automotive and aerospace industry, it is of great scientific and technical interest to understand the processes leading to interface degradation and to develop novel strategies to increase corrosion and delamination resistance. The aim of this project is to develop thin epoxy-based films and their carbon nanofiller loaded composites on aluminium alloy AA2024-T3 as a model system and to investigate their interfacial stability under corrosive and coupled corrosive-mechanical load. Spin coating was used for the layer-by-layer deposition of poly[(o-cresyl glycidyl ether)-co-formaldehyde] and poly-(ethylenimine) bi-layers. Atomic force microscopy (AFM) results indicate a very homogeneous and dense film with low surface roughness. Carbon nanofillers were introduced either by mixing into the coating components or in between individual layers to control the separation between the carbon nanofillers and alloy surface. The film chemistry and barrier properties were characterized by means of spectroscopic and electrochemical methods, respectively. The degradation and delamination behavior of the epoxy-based films was characterized by means of in situ AFM corrosion experiments. The quantitative imaging (QI) mode allowed the observation of hydrogen-generation induced blister formation during exposure to corrosive electrolyte and how the local corrosion processes evolved with exposure time. Complementary energy dispersive X-ray spectroscopy (EDX) analysis was performed to correlate the corrosion behavior with the different intermetallic particle chemistries and distributions. The presentation will summarize our results on the effect of interface chemistry and carbon nanofiller – alloy separation on the initiation of local corrosion processes on thin film covered AA2024-T3 aluminium alloys. T2 - EuroCorr2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Corrosion KW - Atomic Force Microscopy (AFM) PY - 2019 AN - OPUS4-50293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - In situ atomic force microscopy (AFM) analysis of materials under combined corrosive and mechanical load N2 - In service, most materials are operated under simultaneous corrosive and mechanical load and there are very few methods capable for testing material degradation under these conditions, especially when it comes to high resolution analysis. For this purpose, in this work, a tensile module capable of uniaxial stretching and compression with up to 5 kN force was integrated into an AFM stage. The elimination of the need for sample unmounting and remounting and the resulting possibility of keeping the sample under constant mechanical load during AFM measurements not only enables a precise positioning of the area of interest but also allows for the analysis of processes in the elastic deformation regime. This methodology was demonstrated for two case studies. Scanning Kelvin Probe Force Microscopy (SKPFM) was used as the main tool to characterize the deformation behavior. Moreover, a flexible electrochemical measurement cell was used to enable electrochemical analysis by means of electrochemical impedance spectroscopy (EIS) and Linear Sweep Voltammetry (LSV) during AFM measurements at different levels of strain. The in situ AFM results are complemented by microstructure analysis by means of electron backscatter diffraction (EBSD). In the first case study, the deformation induced delamination of a thin organic coating on AA2024 T3 aluminium alloy was investigated as a function of alloy surface treatment. The formation of cracks in the insulating passive film enabled an early detection of deformation processes by means of SKPFM. The second case study focused on the comparison of corrosion and deformation behavior of conventional and additively manufactured 316 stainless steels. In comparison to the conventional 316 stainless steel, the effect of processing was clearly detectable on the additively manufactured material as zones of inhomogeneous potential, which also affected the initiation of local corrosion processes. The contribution will provide detailed information on the new AFM setup and summarize our results from both case studies. T2 - EuroCorr2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Corrosion KW - Coupled corrosive and mechanial load KW - Atomic Force Microscopy (AFM) PY - 2019 AN - OPUS4-50294 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Nikonov, A. Y. A1 - Dmitriev, A. I. ED - Krzanowski, J. T1 - MD sliding simulations of amorphous tribofilms consisting of either SiO2 or carbon N2 - The sliding behaviors of two simplified tribofilms with amorphous structure consisting either of SiO₂ molecules or C atoms were simulated by molecular dynamics modeling. The objective was to identify mechanisms explaining the experimentally observed lubricating properties of the two amorphous films. The impacts of layer thickness, normal pressure, temperature and different substrate materials were studied systematically, while the sliding velocity was kept constant at 30 m/s. While the layer thickness was not critical, all the other parameters showed special effects under certain conditions. Normal pressure impeded void formation and could even eliminate voids if applied at high temperature. Stick-slip sliding was changed to smooth sliding at high temperature due to void healing. Considering the carbon film, high friction forces and shearing of the entire film was observed with diamond substrates, whereas interface sliding at low friction forces and an amorphous layer of iron mixed with carbon was observed if the supporting substrates consisted of α-Fe. Both films show a decrease of friction forces and smooth sliding behavior at elevated temperature, corresponding well to the tribological behavior of and advanced nanocomposite sliding against a steel disc under severe stressing conditions when high flash temperatures can be expected. KW - dry friction KW - amorphous silica film KW - amorphous carbon film KW - sliding simulation KW - molecular dynamics PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-379367 DO - https://doi.org/10.3390/lubricants4030024 VL - 4 IS - 24 PB - MDPI CY - Basel, Switzerland AN - OPUS4-37936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis A1 - Shakeel, Yusra T1 - NFDI-MatWerk PP18 / IUC02 Reference Data: Creep Data of a single crystalline Ni-Base Alloy N2 - Reference datasets in the MSE domain represent specific material properties, e.g., structural, mechanical, … characteristics. A reference dataset must fulfill high-quality standards, not only in precision of measurement but also in a comprehensive documentation of material, processing, and testing history (metadata). This Infrastructure Use Case (IUC) of the consortium Materials Science and Engineering (MatWerk) of National Research Data Infrastructure (NFDI) aims to develop, together with BAM and other Participant Projects (PP), a framework for generating reference material datasets using creep data of a single crystal Ni-based superalloy as a best practice example. In a community-driven process, we aim to encourage the discussion and establish a framework for identifying reference material datasets. In this poster presentation, we highlight our current vision and activities and intend to stimulate the discussion about the topic reference datasets and future collaborations and work. T2 - All-Hands-on-Deck congress from the NFDI-MatWerk CY - Siegburg, Germany DA - 08.03.2023 KW - Referenzdaten KW - Reference data KW - Creep KW - Syngle Crystal alloy KW - Metadata schema PY - 2023 AN - OPUS4-57146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ávila Calderón, Luis A1 - Shakeel, Y. A1 - Schriever, Sina A1 - Gedsun, A. A1 - Forti, M. A1 - Jordan, Hans A1 - Han, Ying A1 - Baer, O. A1 - Aversa, R. A1 - Olbricht, Jürgen A1 - Hammerschmidt, T. A1 - Hickel, T. A1 - Skrotzki, Birgit T1 - NFDI-MatWerk/IUC02 Data schema for creep data of Ni-based superalloys including a comprehensive documentation of test results and metadata N2 - This data schema was developed within the infrastructure use case IUC02: “Framework for curation and distribution of reference datasets” of the consortium NFDI-MatWerk. It intends to define a structured approach for collecting all required information on a creep experiment using the established terminology of the respective test standard ISO 204:2022 and additional terminology agreed upon by the domain experts. The individual entries are grouped according to their content type and sub-summarized under respective headlines, thereby suggesting a basic categorization and a related hierarchy of concepts. This hierarchy can be similarly applied to other test methods and different metallic (and other) materials. In version 1.1 some editorial and formal changes were made. KW - NFDI-MatWerk KW - Digitalisierung KW - Referenzdaten KW - Kriechen KW - Ni-based Superalloys PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611629 DO - https://doi.org/10.5281/zenodo.11668375 PB - Zenodo CY - Geneva AN - OPUS4-61162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ávila Calderón, Luis A1 - Schriever, Sina T1 - BAM Reference Data: Creep of Single-Crystal Ni-Based Superalloy CMSX-6 N2 - This publication provides comprehensive metadata and test results of constant force creep tests according to DIN EN ISO 204:2019-4 on the single crystal Ni-based superalloy CMSX-6 at T = 980 °C and initial stresses between 140 MPa and 230 MPa. The tests were carried out in an accredited test laboratory using calibrated measuring equipment. The data were audited and are BAM reference data. KW - NFDI-MatWerk KW - Digitalisierung KW - CMSX-6 KW - Creep KW - Reference Data KW - Referenzdaten KW - Ni-Based Superalloy PY - 2024 DO - https://doi.org/10.5281/zenodo.13937986 PB - Zenodo CY - Geneva AN - OPUS4-61649 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ávila Calderón, Luis A1 - Han, Ying A1 - Matzak, Kathrin A1 - Olbricht, Jürgen A1 - Skrotzki, Birgit T1 - NFDI-MatWerk/IUC02 data schema for elevated temperature tensile data of Ni-based superalloys N2 - Strength characteristics, such as proof strength and tensile strength, of metallic materials are usually measured at room temperature. However, for high-temperature materials, the values at operational temperatures are equally important for analyzing the mechanical behavior of components or for designing purposes. Elevated temperature tensile tests (often referred to as hot tensile tests) generally enable the measurement of the same material parameters as those obtained at room temperature. Typically, tensile and proof strength, elongation after fracture, and reduction of area are analyzed, with the focus often being on proof strength. The attached data schema for elevated temperature tensile tests was developed within the German NFDI-MatWerk initiative (https://nfdi-matwerk.de/). It builds on a previously published creep data schema and follows a reference data methodology that has also been previously outlined. The presented schema constitutes a structured approach for collecting all relevant information on an elevated temperature tensile test experiment. Overall, this development, as defined in the previously published data schema for creep data, aims to provide a comprehensive hierarchical data description that can be implemented in data management platforms (such as electronic laboratory notebooks), facilitate consistent quality assessment across different users and data providers, and promote the alignment of datasets to the FAIR principles by providing easy interoperability and full reusability. The presented schema was initially developed for datasets of Ni-based high-temperature alloys. However, thanks to its modular structure, it can also be applied to tensile tests of various metallic and other materials. Although the focus is on elevated temperature tensile testing, the data schema also offers a solid foundation for documenting room temperature tensile tests. In such cases, an adjustment of the requirement profile might be necessary, and categories or entries specific to mechanical testing at elevated temperatures, such as “temperature-measuring system”, “specified temperature”, or “soaking time”, become irrelevant. Overall, a detailed approach was followed to ensure the collection of all relevant information, including both metadata and test results. This includes, for example, comprehensive descriptions of the material’s manufacturing history and of the laboratory equipment, and basic strength and deformation characteristic values. The resulting data schema aims to support the description and identification of high-quality datasets, which may qualify as reference data of materials. Our current definition of reference data of materials has been published elsewhere. It should be noted, however, that not all research datasets —depending on their origin and purpose— require this full level of detail. Nevertheless, the presented data schema can support data providers in evaluating the completeness and value of their datasets. This version of the data schema covers elevated temperature tensile tests on both single- and polycrystalline specimen materials. The terminology is aligned with DIN EN ISO 6892-1 and DIN EN ISO 6892-2. It is designed to record the use of temperature measurement using thermocouples and the use of contacting extensometer systems. The requirement profile refers to the highest quality class of reference data, taken from calibrated instruments, and which shall enable the following usages: 1. Checking one's own elevated temperature tensile test results on nominally similar material 2. Verification of own testing set-up (e.g., by testing the same or a similar material) 3. Using the data as input data for simulations in the context of design or alloy development KW - NFDI MatWerk KW - Referenzdaten KW - Zugversuch KW - CMSX-6 KW - Datenschema KW - NFDI MatWerk KW - CMSX-6 KW - Data schema KW - Reference data KW - Tensile test PY - 2025 UR - https://doi.org/10.5281/zenodo.17846436 DO - https://doi.org/10.5281/zenodo.17846435 PB - Zenodo CY - Geneva AN - OPUS4-65190 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis A1 - Hammerschmidt, T. A1 - Stotzka, R. T1 - Demonstration of the Infrastructure Use Case 02: Framework for curation and distribution of reference datasets N2 - In our current view, reference datasets in the MSE domain represent specific material properties, e.g., structural, mechanical, … characteristics. A reference dataset must fulfill high-quality standards, not only in precision of measurement but also in a comprehensive documentation of material, processing, and testing history (metadata). This Infrastructure Use Case (IUC) aims to develop a framework for generating reference material datasets using creep data of a single crystal Ni-based superalloy as a best practice example. In a community-driven process, we aim to encourage the discussion and establish a framework for the creation and distribution of reference material datasets. In this poster presentation, we highlight our current vision and activities and intend to stimulate the discussion about the topic reference datasets and future collaborations and work. T2 - NFDI-MatWerk Conference CY - Siegburg, Germany DA - 27.06.2023 KW - Referenzdaten KW - Reference data KW - Creep KW - Metadata schema KW - Syngle Crystal alloy PY - 2023 AN - OPUS4-57924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis A1 - Hammerschmidt, T. A1 - Gedsun, A. A1 - Forti, M. A1 - Olbricht, Jürgen A1 - Stotzka, R. A1 - Skrotzki, Birgit T1 - IUC02 Framework for Curation and Distribution of Reference Datasets using Creep Data of Ni-Base Superalloys as an Example N2 - In our current view, reference datasets in the MSE domain represent specific material properties, e.g., structural, mechanical, … characteristics. A reference dataset must fulfill high-quality standards, not only in precision of measurement but also in a comprehensive documentation of material, processing, and testing history (metadata). This Infrastructure Use Case (IUC) aims to develop a framework for generating reference material datasets using creep data of a single crystal Ni-based superalloy as a best practice example. In a community-driven process, we aim to encourage the discussion and establish a framework for the creation and distribution of reference material datasets. In this poster presentation, we highlight our current vision and activities and intend to stimulate the discussion about the topic reference datasets and future collaborations and work. T2 - NFDI-MatWerk Conference CY - Siegburg, Germany DA - 27.06.2023 KW - Referenzdaten KW - Reference data KW - Syngle Crystal alloy KW - Creep KW - Metadata schema PY - 2023 AN - OPUS4-57923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ávila Calderón, Luis Alexander A1 - Matzak, Kathrin A1 - Olbricht, Jürgen A1 - Dolabella Portella, Pedro A1 - Skrotzki, Birgit T1 - BAM Reference Data: High Temperature Tensile Data of Single-Crystal Ni-Based Superalloy CMSX-6 N2 - This publication provides comprehensive metadata and test results of tensile tests at elevated temperature according to DIN EN ISO 6892-2:2018-09 on the single crystal Ni-based superalloy CMSX-6 at T = 980 °C. The tests were performed in an ISO 17025-accredited test laboratory. The calibrations of measuring equipment are documented, meet the requirements of the measurement standard, and are metrologically traceable. The provided data were audited and are BAM reference data. KW - Digitalisierung KW - Referenzdaten KW - CMSX-6 KW - Zugversuch KW - NFDI-MatWerk KW - Ni-Basis-Superlegierung PY - 2025 DO - https://doi.org/10.5281/zenodo.17846616 PB - Zenodo CY - Geneva AN - OPUS4-65338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Creep Behavior of Stainless Steel 316L Manufactured by Laser Powder Bed Fusion N2 - Metal additive manufacturing (Metal AM) continues to gain momentum. Many companies explore the manufacturing of innovative products, including components for safety critical applications. Despite the intensive research of recent years, a fundamental understanding of the process‑structure‑property relationships remains challenging due to, i.a., the inherently complex and highly hierarchical microstructures arising from the wide range of build process parameter variability. This contribution presents the resu lts of an experimental study on the creep behavior of an austenitic 316L stainless steel produced by laser powder bed fusion (PBF LB/M/316L) with an emphasis on understanding the effects of microstructure on creep mechanisms. Hot tensile tests and constant force creep tests at 600 °C and 650 °C, X ray computed tomography, as well as optical and electron microscopy were performed. The produced PBF LB/M/316L exhibits a low void population 0.01 %) resulting from the manufacturing parameters used and which a llowed us to understand the effects of other microstructural aspects on creep behavior, e.g., grain morphology and dislocation substructure. A hot‑rolled variant of 316L hwas also tested as a reference. The produced PBF LB/M/316L possesses shorter primary and secondary creep stages and times to rupture and smaller creep stress exponents than the hot‑rolled variant. Overall, the creep damage is more extensive in the PBF LB/M/316L and is characterized as predominantly intergranular. It is considered that the damage behavior is mainly impacted by the formation of precipitates at the grain boundaries combined with their unfavorable orientation. The dislocation substructure and local elemental segregation appear to have a decisive impact on the overall creep behavior. T2 - 16th International Conference on Creep and Fracture of Engineering Materials and Structures CY - Bangalore, India DA - 28.07.2024 KW - AGIL KW - 316L KW - Additive Manufacturing KW - Creep KW - Microstructure evolution PY - 2024 AN - OPUS4-60839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Mechanical behaviour of AM metals: Creep of LPBF 316L and low-cycle-fatigue of LMD Ti-6Al-4V N2 - Additively manufactured metallic materials have already started to find application in safety-relevant components. However, this has only happened for certain materials and specific applications and loading conditions, since there is still an extensive lack of knowledge as well as of historical data regarding their mechanical behaviour. This contribution aims to address this lack of understanding and historical data concerning the creep behaviour of the austenitic stainless steel 316L manufactured by Laser-Powder-Bed-Fusion (L-PBF) and the low-cycle-fatigue behaviour of the titanium alloy Ti-6Al-4V manufactured by Laser-Metal-Deposition (LMD). Furthermore, it aims to assess their mechanical behaviour against their conventional counterparts. With that in mind, specimens from conventional and additive materials are tested and their mechanical behaviour analysed based on characteristic curves. To understand the damage behaviours the materials are characterized by destructive and non-destructive techniques before and after failure. T2 - 1st Workshop on In-situ Monitoring and Microstructure Development in Additive Manufacturing CY - Online Meeting DA - 10.12.2020 KW - Ti-6Al-4V KW - 316L KW - Additive manufacturing KW - Creep behaviour KW - Low-cycle-fatigue behaviour PY - 2020 AN - OPUS4-51879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Creep behavior and microstructural evolution of LPBF 316L N2 - This presentation shows some experimental results of the characterization of the creep behavior of LPBF 316L, which has been poorly studied and understood to date. The presentation includes results regarding the mechanical properties, the initial microstructural state and its evolution under loading, and the damage mechanism. This work was done within the BAM focus area materials project AGIL. As a benchmark to assess the material properties of the LPBF 316L, a conventionally manufactured variant was also tested. T2 - 2nd Workshop on In-situ Monitoring and Microstructure Development in Additive Manufactured alloys at BAM CY - Online Meeting DA - 19.04.2021 KW - 316L KW - Additive Manufacturing KW - Creep behavior PY - 2021 AN - OPUS4-52682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Management of Reference Data of Creep of Ni-Based Superalloys Exemplified for CMSX-6 N2 - The identification of process-structure-property relationships of materials inevitably requires the combination of research data from different measurements. Therefore, the concepts related to FAIR (findable, accessible, interoperable, reusable) data handling, increasingly reported in literature, are particularly important in the materials science and engineering domain. However, they have not yet been integrated into a single, overarching methodological framework, particularly for reference data. Here, we introduce such a framework, which covers data generation, documentation, handling, storage, sharing, data search and discovery, retrieval, and usage. Furthermore, we prototypically implement it using a real dataset with creep data of a single-crystal CMSX-6 Ni-based superalloy. The implementation is traceable and permanently accessible through open repositories. The individual elements considered in the framework ensure the functionality and usability of the data and, thus, the adherence to the FAIR principles. In conjunction with this, we present a definition for reference data of materials. Our definition underlines particularly the importance of a comprehensive documentation, e.g., on material provenance, data processing procedures, and the software and hardware used, including software-specific input parameters, as these details enable data users or independent parties to assess the quality of the datasets and to reuse and reproduce the results. Reference data that is managed according to the proposed framework can be used to advance knowledge in the materials science and engineering domain, e.g., by identifying new process-structure-property relations. T2 - The 20th International Conference on Strength of Materials CY - Kyoto, Japan DA - 02.06.2025 KW - NFDI-MatWerk KW - Referenzdaten KW - Data schema KW - Creep PY - 2025 AN - OPUS4-63428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -