TY - CONF A1 - Saliwan Neumann, Romeo A1 - Nolze, Gert A1 - Hünecke, Joachim A1 - Schöne, Dieter T1 - Characterisierung von Schwingungsrissen mittels EBSD T2 - 37. Metallographie-Tagung 2003 T2 - 37. Metallographie-Tagung 2003 CY - Berlin, Germany DA - 2003-09-17 PY - 2003 AN - OPUS4-5230 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert A1 - Wagner, G. A1 - Saliwan Neumann, Romeo A1 - Skála, R. A1 - Geist, V. T1 - Investigation of the orientation relationships of carlsbergite in the North Chile iron meteorite JF - Meteoritics & planetary science KW - Orientation realtionships KW - CrN KW - (Fe,Ni)3P PY - 2005 SN - 1086-9379 SN - 0026-1114 SP - 14 pages PB - Allen Press CY - Lawrence, Kan. AN - OPUS4-7592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Engelhardt, Monika A1 - Gesatzke, Wolfgang A1 - Österle, Werner A1 - Müller, Urs A1 - Rooch, Heidemarie A1 - Saliwan Neumann, Romeo A1 - Urban, Ingrid T1 - Makro- und Mikrogefüge von Bremsbelägen T2 - Fortschritte in der Metallographie - Vortragstexte der 39. Metallographie-Tagung KW - Bremsbelag KW - Polymermatrix-Verbundstoff KW - Röntgenfluoreszenzanalyse KW - REM KW - FIB KW - TEM PY - 2005 SN - 3-88355-343-3 SN - 0343-3579 N1 - Serientitel: Sonderbände der praktischen Metallographie – Series title: Sonderbände der praktischen Metallographie IS - 37 SP - 105 EP - 110 PB - Werkstoff-Informationsges. CY - Frankfurt AN - OPUS4-10996 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nolze, Gert A1 - Saliwan Neumann, Romeo A1 - Buchheim, Michaela T1 - Microstructure investigations of iron meteorites by EBSD and EDS analyses T2 - EMC 2012 - 15th European Microscopy Congress T2 - EMC 2012 - 15th European Microscopy Congress CY - Manchester, UK DA - 2012-09-16 KW - Orientation relationship KW - Weathering KW - Hibbingite PY - 2012 UR - http://www.emc2012.org.uk//documents/Abstracts/Abstracts/EMC2012_0090.pdf SP - 1 EP - 2(?) AN - OPUS4-27922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kranzmann, Axel A1 - Neddemeyer, Torsten A1 - Ruhl, Aki Sebastian A1 - Hünert, Daniela A1 - Bettge, Dirk A1 - Oder, Gabriele A1 - Saliwan Neumann, Romeo T1 - The challenge in understanding the corrosion mechanisms under oxyfuel combustion conditions JF - International journal of greenhouse gas control N2 - Basic research on the corrosive effect of flue gases has been performed at the BAM Federal Institute for Materials Research and Testing (Germany). Conditions at both high and low temperatures were simulated in specially designed experiments. Carburization occured in flue gases with high CO2 content and temperatures higher than 500 °C. In SO2 containing flue gases sulphur was detected in the oxide scale. At lower temperatures no corrosion was observed when gases with low humidity were investigated. Humidity higher than 1500 ppm was corrosive and all steels with Cr contents lower than 12% revealed corroded surfaces. At low temperatures below 10 °C a mixture of sulphuric and nitric acid condensed on metal surfaces. Acid condensation caused severe corrosion. Humidity, CO2, O2, and SO2 contents are the important factors determining corrosion. Below 300 °C acid condensation is the primary reason for corrosion. Low humidity and low temperatures are conditions which can be expected in the CO2 separation and treatment process. This work includes major conditions of the flue gas and CO2 stream in CCS plants and CCS technology. KW - Coal KW - Oxyfuel power plant KW - Corrosion KW - Carburization KW - Sulphur KW - Sulphuric acid PY - 2011 DO - https://doi.org/10.1016/j.ijggc.2011.05.029 SN - 1750-5836 VL - 5 IS - Supplement 1 SP - S168 EP - S178 PB - Elsevier CY - New York, NY [u.a.] AN - OPUS4-24705 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulz, Wencke A1 - Nofz, Marianne A1 - Feigl, Michael A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel T1 - Corrosion of uncoated and alumina coated steel X20CrMoV12-1 in H2O-CO2-O2 and air at 600 °C JF - Corrosion science N2 - Future coal power plants will in case of oxyfuel combustion be operated with altered atmospheres. Hence, corrosion attack might become more severe and steels have to be protected. An alumina-sol was used to coat X20CrMoV12-1 (X20) with alumina to test the protection. Testing was performed at 600 °C in flowing H2O–CO2–O2 and static laboratory air for 1000 h. Oxidation under air is minor compared to exposure in oxyfuel atmosphere. In both cases a multilayered oxide (hematite, magnetite, spinel) was formed on uncoated steels. Carburization appeared on uncoated X20 in H2O–CO2–O2. The coating demonstrates a high protection. KW - A. Steel KW - B. SEM KW - B. STEM KW - C. Carburization KW - C. High temperature corrosion KW - C. Oxide coatings PY - 2013 DO - https://doi.org/10.1016/j.corsci.2012.10.031 SN - 0010-938X VL - 68 SP - 44 EP - 50 PB - Elsevier Ltd. CY - Orlando, Fla. AN - OPUS4-27636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Saliwan Neumann, Romeo A1 - Dörfel, Ilona A1 - Griepentrog, Michael T1 - Sol-gel derived alumina layers on nickel-base superalloy Inconel-718 (IN-718) JF - Thin solid films N2 - Modified Yoldas sols can be used to prepare crack-free well adherent layers on different substrate materials such as soda–lime glass, corundum and metal (IN-718). These layers having thicknesses of 0.6 µm are strain tolerant and withstand thermal cycling between 810 °C and room temperature. Introducing alpha-Al2O3 filler particles into modified Yoldas sols allows the preparation of thicker layers of 1.6 µm, which as well can be thermally cycled without noticeable delaminations. Chemical bonding seems to be the predominant layer bonding mechanism. KW - Sol-gel KW - Alumosol KW - Filler particles KW - Inconel-718 KW - Scanning electron microscopy PY - 2008 DO - https://doi.org/10.1016/j.tsf.2008.08.124 SN - 0040-6090 VL - 517 IS - 2 SP - 786 EP - 792 PB - Elsevier CY - Amsterdam AN - OPUS4-18263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Dreßler, Martin A1 - Dörfel, Ilona A1 - Reinsch, Stefan A1 - Saliwan Neumann, Romeo T1 - Korundhaltige Aluminiumoxidschichten T2 - Tagungsband des 15. Symposium: Verbundwerkstoffe und Werkstoffverbunde T2 - 15. Symposium: Verbundwerkstoffe und Werkstoffverbunde CY - Kassel, Germany DA - 2005-04-06 PY - 2005 UR - http://www.dgm.de/download/tg/706/706_85.pdf SP - 5 Seiten PB - DGM CY - Kassel AN - OPUS4-7522 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert A1 - Wagner, G. A1 - Saliwan Neumann, Romeo A1 - Skála, R. A1 - Geist, V. T1 - Orientation relationships of carlsbergite in schreibersite and kamacite in the north Chile iron meteorite JF - Mineralogical magazine N2 - The crystallographic orientation of carlsbergite (CrN) in the north Chile meteorite (hexahedrite) was investigated using electron backscatter diffraction and transmission electron microscopy. These studies examined the CrN crystals in the rhabdites (idiomorphic schreibersite) and in kamacite. It was found that the CrN crystals embedded in rhabdite show a number of different orientation relationships with the host crystals. These orientations can be explained based on the lattice dimensions of both coexisting crystalline materials. It was also found that both carlsbergite and kamacite are characterized by a high dislocation density (109 cm–2) while rhabdite is free of dislocations. It is supposed that in spite of the deformed metallic matrix, a general connection between the orientation relation of all the phases involved exists. KW - EBSD KW - Phosphides KW - Carlsbergite KW - Orientation relationship KW - Iron meteorites PY - 2006 DO - https://doi.org/10.1180/0026461067040342 SN - 0026-461x SN - 1471-8022 VL - 70 IS - 4 SP - 373 EP - 382 PB - Mineralogical Society of Great Britain and Ireland CY - London AN - OPUS4-14424 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo T1 - Influence of sol-gel derived alumina coatings on oxide scale growth of nickel-base superalloy Inconel-718 JF - Surface and coatings technology N2 - Alumina coatings with differing phase compositions were deposited on Inconel-718 (IN-718) Ni-base superalloy substrates using sol–gel processing. Mass gain measurements served for studying the oxidation behavior of coated metal surfaces if exposed to 800°C and 900°C for up to 4000 h in static air. Itwas found, that alumina coatings significantly reduce the oxidation related mass gain of IN-718 even after heating to 900°C for 4000 h. Transmission electron microscopy (TEM) studies revealed diffusion of elements from the metal substrate (IN-718) into the alumina coatings and — to a much lower degree — from the coating into the substrate. These diffusion processes are greatly influenced by the phase composition of the coatings, especially by the presence of alpha-alumina. KW - Oxide scale growth KW - Inconel-718 KW - Alumina coating KW - TEM PY - 2008 DO - https://doi.org/10.1016/surfcoat.2008.07.018 SN - 0257-8972 VL - 202 SP - 6095 EP - 6102 PB - Elsevier Science CY - Lausanne AN - OPUS4-17857 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk A1 - Klinger, Christian A1 - Ell, Matthias A1 - Klingbeil, Dietmar A1 - von Oppel, Kay A1 - Singh, Kai A1 - Eberle, Arno A1 - Engelhardt, Monika A1 - Bogel, Bärbel A1 - Saliwan Neumann, Romeo T1 - Schadensanalyse an Rohrbögen von Dampferzeugeranlagen T2 - VGB-Fachtagung Dampferzeuger, Industrie- und Heizkraftwerke 2006 T2 - VGB-Fachtagung "Dampferzeuger, Industrie und Heizkraftwerke 2006" CY - Würzburg, Deutschland DA - 2006-09-04 KW - Schadensanalyse KW - Brüche KW - Dampferzeuger KW - Transportschaden PY - 2006 PB - VGB PowerTech e.V. CY - Essen AN - OPUS4-12817 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Dreßler, Martin A1 - Hünert, Daniela A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo T1 - Sol-gel alumina coatings for high-temperature corrosion protection of Ni-base alloy SC16 in water vapour containing atmosphere JF - Interceram N2 - Alumosols in combination with well dispersed corundum were successfully used to form up to 2.5 ìm thick coatings on the Ni-base alloy SC16. These coatings withstood heat treatments at 700 °C in a water vapour containing atmosphere. The heat treatment caused formation of delta-alumina in the coating and diffusion of chromium and titanium into the coating. KW - Alumina KW - Coating KW - Sol-gel KW - Corrosion KW - Protection PY - 2009 SN - 0020-5214 VL - 58 IS - 4 SP - 192 EP - 195 PB - DVS-Verl. CY - Düsseldorf AN - OPUS4-19726 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hünert, Daniela A1 - Schulz, Wencke A1 - Nitschke, Heike A1 - Saliwan Neumann, Romeo A1 - Oder, Gabriele A1 - Kranzmann, Axel T1 - Corrosion behaviour of ferritic and martensitic power plant steels under conditions of dual atmospheres T2 - NACE International corrosion conference 2009 (Proceedings) N2 - The most efficient construction materials for boiler water walls and superheaters in steam power plants are ferritic and martensitic steels. In practical operation tubes are simultaneously exposed to combustion gas and air/steam on their opposite surfaces. The corrosion behaviour of ferritic-martensitic steels under such dual atmospheres is nondistinctive and has therefore been investigated in a special designed test equipment between 500 and 620°C. The power plant conditions were simulated wi th a flowing and pressurised (80 bar) combustion gas on the inner side of the tube which mainly consists of H2O and/or CO2. On the outer side, the tube material was exposed to air. It was discovered that under similar temperatures the oxides formed on the air side under dual atmosphere conditions were significantly different to the oxide scales formed when the alloy was exposed to air only. It is assumed that the anomalous corrosion behaviour during the dual atmosphere exposure is due to the hydrogen transport through the bulk alloy from the combustion gas side to the air side. T2 - NACE International corrosion conference 2009 CY - Atlanta, Georgia, USA DA - 2009-03-22 KW - High temperature corrosion KW - Dual atmosphere KW - Corrosive gases KW - Mild steels KW - 9-12% Cr-steels KW - Hydrogen transport PY - 2009 SP - 1 EP - 10 (Paper 09263) AN - OPUS4-22335 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo T1 - Diffusion of Cr, Fe, and Ti ions from Ni-base alloy inconel-718 into a transition alumina coating JF - Thin solid films N2 - Heat treating metals at high temperatures trigger diffusion processes which may lead to the formation of oxide layers. In this work the diffusion of Cr, Fe and Ti into an alumina coating applied to Inconel-718 is being investigated. Mass gain measurements, UV–vis spectroscopy and transmission electron microscopy were applied in order to study the evolution of the diffusion process. It was found that mainly Cr as well as minor amounts of Fe and Ti are being incorporated into the alumina coating upon prolonged heat treatment at 700 °C. It could be shown that alumina coatings being void of Cr have the same oxidation related mass gain as uncoated samples. However, incorporation of Cr into the alumina coating decreased their mass gain below that of uncoated substrates forming a Cr oxide scale only. KW - Diffusion KW - UV–vis spectroscopy KW - Transmission electron microscopy KW - Alumina coatings KW - Sol-gel deposition PY - 2012 DO - https://doi.org/10.1016/j.tsf.2012.02.006 SN - 0040-6090 VL - 520 IS - 13 SP - 4344 EP - 4349 PB - Elsevier CY - Amsterdam AN - OPUS4-25830 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano Munoz, Itziar A1 - Fernández, R. A1 - Saliwan Neumann, Romeo A1 - González-Doncel, G. A1 - Bruno, Giovanni T1 - Dislocation substructures in pure aluminium after creep deformation as studied by electron backscatter diffraction JF - Journal of applied crystallography N2 - In the present work, electron backscatter diffraction was used to determine the microscopic dislocation structures generated during creep (with tests interrupted at the steady state) in pure 99.8% aluminium. This material was investigated at two different stress levels, corresponding to the power-law and power-law breakdown regimes. The results show that the formation of subgrain cellular structures occurs independently of the crystallographic orientation. However, the density of these cellular structures strongly depends on the grain crystallographic orientation with respect to the tensile axis direction, with <111> grains exhibiting the highest densities at both stress levels. It is proposed that this behaviour is due to the influence of intergranular stresses, which is different in <111> and <001> grains. KW - Creep KW - Pure aluminium KW - Electron backscatter diffraction KW - Cellular structures KW - Power law and power-law breakdown PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552003 DO - https://doi.org/10.1107/S1600576722005209 SN - 0021-8898 SN - 1600-5767 VL - 55 SP - 860 EP - 869 PB - Wiley-Blackwell CY - Copenhagen AN - OPUS4-55200 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheibe, Maximilian A1 - Binkowski, Sigrid A1 - Benemann, Sigrid A1 - Saliwan Neumann, Romeo T1 - Vergleich verschiedener Präparationstechniken zur Charakterisierung von Niobcarbiden T2 - 14. Internationale Metallographie-Tagung T2 - 14. Internationale Metallographie-Tagung CY - Leoben, Austria DA - 2014-09-17 PY - 2014 SN - 978-3-88355-403-7 N1 - Serientitel: Sonderbände der Praktischen Metallographie / Fortschritte in der Metallographie – Series title: Sonderbände der Praktischen Metallographie / Fortschritte in der Metallographie IS - 46 SP - 51 EP - 58 AN - OPUS4-31484 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Davydenko, L. A1 - Nazarchuk, M. A1 - Nasiedkin, D. A1 - Plyuto, Y. A1 - Mosquera Feijoo, Maria A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel A1 - Pérez, F.J. T1 - Anticorrosion hybrid AlPO4/Al2O3 coatings on the surface of P92 steel for oxy-fuel power plant application T2 - XtremeCOAT 2014 - Surface engineering for functional applications under extreme conditions T2 - XtremeCOAT 2014 - Surface engineering for functional applications under extreme conditions CY - Madrid, Spain DA - 2014-10-20 KW - Corrosion protection KW - Hybrid coatings KW - Boehmite KW - AlPO4 PY - 2014 SP - P 5, 1 EP - 2 AN - OPUS4-31453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schulz, Wencke A1 - Feigl, Michael A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Nofz, Marianne A1 - Kranzmann, Axel T1 - Alumina coatings against carburization and oxidation under oxyfuel conditions T2 - 1st International conference on materials for energy T2 - 1st International conference on materials for energy CY - Karlsruhe, Germany DA - 2010-07-04 PY - 2010 SN - 978-3-89746-117-8 SP - 1012 AN - OPUS4-24179 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schulz, Wencke A1 - Hünert, Daniela A1 - Nitschke, Heike A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel T1 - Comparison of the corrosion behaviour of 9-12 % Cr steels in H2O, H2O-CO2 and H2O-CO2-O2 T2 - NACE International corrosion conference 2009 (Proceedings) T2 - NACE International corrosion conference 2009 CY - Atlanta, Georgia, USA DA - 2009-03-22 KW - 9-12%Cr-steels KW - Steam KW - CO2 KW - O2 KW - High-temperature corrosion KW - Evaporation of chromium PY - 2009 SP - 1 EP - 10 (Paper No. 09264) AN - OPUS4-19464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epishin, A. A1 - Link, T. A1 - Svetlov, I. L. A1 - Nolze, Gert A1 - Saliwan Neumann, Romeo A1 - Lucas, H. T1 - Mechanism of porosity growth during homogenisation in single crystal nickel-based superalloys JF - International Journal of Materials Research N2 - Several mechanisms for porosity growth in single crystal nickel-based superalloys during homogenisation heat treatment have been proposed in the literature. They were carefully checked using different experimental methods, namely quantitative light microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and density measurements. It is shown that the main mechanism is the Kirkendall–Frenkel effect, i.e. generation of voids due to uncompensated efflux of Al atoms from dissolving γ/γ′-eutectic areas. The Al diffusion is supported by the afflux of vacancies from surrounding γ-matrix which results in porosity growth. This conclusion is confirmed by the estimation of the vacancy afflux towards the dissolving eutectic. KW - Ni-base superalloy KW - Eutectic KW - Vacancies KW - Porosity PY - 2013 VL - 104 IS - 8 SP - 776 EP - 782 PB - Carl Hanser Verlag AN - OPUS4-37983 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epishin, A. I. A1 - Link, T. A1 - Nolze, Gert A1 - Svetlov, I. L. A1 - Bokshtein, B. S. A1 - Rodin, A. O. A1 - Saliwan Neumann, Romeo A1 - Oder, Gabriele T1 - Diffusion processes in multicomponent nickel-base superalloy-nickel system JF - The Physics of Metals and Metallography N2 - Optical and scanning electron microscopy, as well as electron microprobe analysis and electron backscatter diffraction, have been used to study diffusion processes that occur in a diffusion pair that consistsof a single-crystal CMSX-10 nickel-base superalloy and polycrystalline nickel, at temperatures of 1050–1250°C. It has been found that, in this system, the distributions of γ-stabilizing elements (Cr, Co, W, and Re) are described by the Boltzmann solution for diffusion between two semiinfinite plates of a binary alloy. The processing of these distributions has shown that the diffusion coefficients of Cr, Co, W, and Re in the multicomponent system are close to those in binary alloys of these elements with Ni. The diffusion redistribution of the elements leads to the dissolution of the γ′ phase in the nickel-base superalloy, growth of nickel grains toward the superalloy constituent of the diffusion pair, and the formation of porosity on both sides of the migrating interface, which is determined from a crystal misorientation of the alloy single crystal and nickel grains. KW - Ni-base superalloy KW - Interface KW - Diffusion KW - Phase transformation KW - Porosity PY - 2014 SN - 0031-918X VL - 115 IS - 1 SP - 21 EP - 29 AN - OPUS4-37980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nolze, Gert A1 - Saliwan Neumann, Romeo A1 - Buchheim, Michaela T1 - Microstructure investigations of iron meteorites by EBSD and EDS analyses T2 - 15th European Microscopy Congress N2 - Meteorites are a unique and inspiring material for microstructural studies because if their very specific genesis. Iron meteorites have been formed under unimaginable cooling rates of a few ten Kelvins per million years so that the observable transformation of the formerly huge Fe-Ni single crystals of taenite occurred under nearly-equilibrium conditions. Octahedrites (meteorites having a Ni content between 6...15%) are characterized by ribbons of the low-temperature Fe-Ni phase kamacite separated by rims of residual taenite. This very specific feature is known as Widmanstaetten structure and has been investigated by synchrotron radiation in order to cover a higher volume fraction for a statistically relevant description of orientation relationships. However, plessite – a microstructure mainly consisting of the same phases – reflects the orientation relationship between kamacite and taenite as well. For their characterization, a scanning electron microscope is very suitable in order to investigate crystal orientations or identify phases. Despite the apparently ideal formation circumstances of iron meteorites, Ni concentration profiles prove non-equilibrium conditions. Combined EDS (energy dispersive spectroscopy) and EBSD (electron backscatter diffraction) measurements at a selected plessitic region of the Cape York iron shows that a correlation exists between Ni-concentration and the locally detected orientation relationship. T2 - 15th European Microscopy Congress CY - Manchester, UK DA - 16.09.2012 KW - Phase identification KW - Corrosion KW - Chloride KW - Dermbach PY - 2012 SP - 90 AN - OPUS4-37775 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulz, Wencke A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel T1 - Aluminiumoxid als Schutzschicht für kommerzielle Kraftwerksstähle (Teil 1) JF - Galvanotechnik N2 - In Kohlekraftwerken mit Oxyfuel-Technologie erfolgt die Verbrennung unter Zufuhr von reinem Sauerstoff. Damit steht für die Abscheidung und Speicherung von CO2 ein Rauchgas mit hohem CO2-Anteil zur Verfügung (CCS-Technologie). Aufgrund dieses Verbrennungsprozesses ändert sich im Wesentlichen die Rauchgaszusammensetzung hin zu hohem H2O- und SO2 -Anteil. Deshalb wurden in verschiedenen Laboratorien kommerzielle Kraftwerksstähle unter den entsprechenden korrosiven Bedingungen getestet. Im Vergleich zur herkömmlichen Verbrennungsmethode zeigten die ferritisch-martensitischen Stähle schon nach 1000 h Auslagerungszeit unter Oxyfuel-Bedingungen eine durch einen deutlich erhöhten Materialverlust gekennzeichnete Korrosion. Eine Möglichkeit um dennoch die Lebensdauer dieser Stähle zu gewährleisten, besteht im Aufbringen geeigneter Schutzschichten auf die Stahloberfläche. Die vorliegende Arbeit befasst sich mit der Herstellung und Bewertung von Sol-Gel-Aluminiumoxidschichten als Schutz vor Korrosion in Oxyfuel-Rauchgas-Atmosphäre. Diese wurden auf den warmfesten Stahl X20CrMoV12-1 (X20) mittels der Tauchmethode aufgebracht. Anschließend erfolgte eine Auslagerung der beschichteten Proben für 1000 h bei 600 °C in einer H2O-CO2-O2-SO2 -Atmosphäre. Im Vergleich zum unbeschichteten Stahl X20 war der Materialverlust des beschichteten Stahls deutlich geringer. Insbesondere konnte durch die Aluminiumoxidschicht der Transport von CO2 und SO2 zur Stahloberfläche verhindert werden. KW - Stahl KW - Korrosion KW - Aluminiumoxid KW - Sol-Gel PY - 2016 SN - 0016-4232 VL - 107 IS - 9 SP - 1900 EP - 1903 PB - Leuze Verlag CY - Bad Saulgau AN - OPUS4-38148 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulz, Wencke A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel ED - Leuze-Reichert, Sylvia T1 - Aluminiumoxid als Schutzschicht für kommerzielle Kraftwerksstähle (Teil 2) JF - Galvanotechnik N2 - In Kohlekraftwerken mit Oxyfuel-Technologie erfolgt die Verbrennung unter Zufuhr von reinem Sauerstoff. Damit steht für die Abscheidung und Speicherung von CO2 ein Rauchgas mit hohem CO2-Anteil zur Verfügung (CCS-Technologie). Aufgrund dieses Verbrennungsprozesses ändert sich im Wesentlichen die Rauchgaszusammensetzung hin zu hohem H2O- und SO2 -Anteil. Deshalb wurden in verschiedenen Laboratorien kommerzielle Kraftwerksstähle unter den entsprechenden korrosiven Bedingungen getestet. Im Vergleich zur herkömmlichen Verbrennungsmethode zeigten die ferritisch-martensitischen Stähle schon nach 1000 h Auslagerungszeit unter Oxyfuel-Bedingungen eine durch einen deutlich erhöhten Materialverlust gekennzeichnete Korrosion. Eine Möglichkeit um dennoch die Lebensdauer dieser Stähle zu gewährleisten, besteht im Aufbringen geeigneter Schutzschichten auf die Stahloberfläche. Die vorliegende Arbeit befasst sich mit der Herstellung und Bewertung von Sol-Gel-Aluminiumoxidschichten als Schutz vor Korrosion in Oxyfuel-Rauchgas-Atmosphäre. Diese wurden auf den warmfesten Stahl X20CrMoV12-1 (X20) mittels der Tauchmethode aufgebracht. Anschließend erfolgte eine Auslagerung der beschichteten Proben für 1000 h bei 600 °C in einer H2O-CO2-O2-SO2 -Atmosphäre. Im Vergleich zum unbeschichteten Stahl X20 war der Materialverlust des beschichteten Stahls deutlich geringer. Insbesondere konnte durch die Aluminiumoxidschicht der Transport von CO2 und SO2 zur Stahloberfläche verhindert werden. KW - Stahl KW - Korrosion KW - Aluminiumoxid KW - Sol-Gel PY - 2016 SN - 0016-4232 VL - 107 IS - 10 SP - 2098 EP - 2102 PB - Leuze-Verlag CY - Bad Saulgau AN - OPUS4-38149 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scheibe, Maximilian A1 - Binkowski, Sigrid A1 - Benemann, Sigrid A1 - Saliwan Neumann, Romeo T1 - Comparing different preparation techniques for the characterisation of niobium carbides JF - Struers Structure news PY - 2014 UR - http://www.struers.com/article-niobium_carbides_EN UR - http://www.struers.com/article-niobium_carbides_DE IS - 19 SP - 1 EP - 12 AN - OPUS4-32432 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chandra, Kamlesh A1 - Kranzmann, Axel A1 - Saliwan Neumann, Romeo A1 - Rizzo, F. T1 - Comparative study on high temperature oxidation of T92 steel in dry and wet oxyfuel environments JF - Oxidation of metals N2 - Fireside oxidation of T92 steel was studied after exposure times up to 1000 h in the temperature range of 580–650 °C in simulated dry (CO2–27 % N2–2 % O2–1 % SO2) and wet (CO2–20 % H2O–7 % N2–2 % O2–1 % SO2) oxyfuel environments. Water vapour addition to the oxyfuel gas substantially increased the oxidation rate. The oxide scales developed under wet environment contained more defects, resulting in higher access of oxidants to the substrate material and enhanced oxidation. In addition, the oxide scales had lower chromium enrichment in the inner layer as compared to that in the dry condition. The oxide scales consisted of hematite and magnetite in the outer layer and a mixture of (Fe, Cr)-spinel, sulphides and wustite in the inner layer. The sulphur distribution differed between the oxide scales developed in dry and wet oxyfuel environments. Sulphur was mainly concentrated in the inner layer and at the oxide/alloy interface. In contrast to the wet oxyfuel gas, very high sulphur concentration was measured in the inner oxide scale formed in the dry oxyfuel gas. Additionally, Fe-sulphide was formed at the interface of inner and outer oxide layer in the wet condition. KW - Oxyfuel environment KW - Oxidation KW - High temperature corrosion KW - Water vapour KW - Sulphur PY - 2015 DO - https://doi.org/10.1007/s11085-015-9565-0 SN - 0030-770X SN - 1573-4889 VL - 84 IS - 3-4 SP - 463 EP - 490 PB - Springer CY - New York, NY AN - OPUS4-34585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chandra, Kamlesh A1 - Kranzmann, Axel A1 - Saliwan Neumann, Romeo A1 - Oder, Gabriele A1 - Rizzo, F. T1 - High temperature oxidation behavior of 9-12 % Cr ferritic/martensitic steels in a simulated dry oxyfuel environment JF - Oxidation of metals N2 - The materials in oxyfuel power plant will be subjected to CO2– and SO2–rich gases on the fireside. The oxidation behaviour of two 9–12 % Cr steels T92 and VM12 was studied under dry oxyfuel environment in the temperature range of 580–650 °C for up to 1,000 h. The oxide structure and morphology were analyzed using various experimental techniques. A complex temperature dependence of oxidation rate is observed for both T92 and VM12 whereby the oxidation rate decreased with increasing temperature. This is attributed to increased Cr-enrichment in the inner scale with increasing temperature. T92 and VM12 alloys are also susceptible to carburization in an oxyfuel environment. KW - Oxyfuel environment KW - Ferritic/martensitic steel KW - Oxidation KW - High temperature corrosion KW - Carburization KW - Steel KW - EPMA KW - SEM PY - 2015 DO - https://doi.org/10.1007/s11085-014-9521-4 SN - 0030-770X SN - 1573-4889 VL - 83 IS - 3-4 SP - 291 EP - 316 PB - Springer CY - New York, NY AN - OPUS4-32737 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Zietelmann, Christina A1 - Feigl, Michael A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo T1 - Microstructural origin of time-dependent changes in alumina sol-gel-coated Inconel 718 exposed to NaCl solution JF - Journal of sol gel science and technology N2 - Inconel 718 was spin coated twice and fourfold with a sol to obtain 200- and 400-nm-thick transition alumina films on the surface. Bare and sol–gel alumina-coated Inconel 718 samples were exposed to NaCl solution to study their corrosion behavior by means of electrochemical impedance spectroscopy. In combination with scanning electron microscopy, it was shown that bare Inconel 718 is after initial passivation prone to pitting corrosion. For the coated Inconel 718 samples, an improvement in the protective effect of the coatings with time was observed. This observation is in contradiction to the results of other authors who observed degradation of alumina coatings exposed to NaCl solution with time. Transmission electron microscopy revealed a formation of (1) a compacted region at the coating surface as well as (2) a chromium-rich region at the interface between coating and alloy during the contact with a NaCl solution. The last one mainly contributes to the observed chronological sequence of electrochemical characteristics of the samples. KW - Alumina coatings KW - Superalloys KW - Corrosion protection KW - EIS KW - SEM KW - TEM PY - 2015 DO - https://doi.org/10.1007/s10971-015-3668-6 SN - 0928-0707 SN - 1573-4846 VL - 75 IS - 1 SP - 6 EP - 16 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-33338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sobol, Oded A1 - Nolze, Gert A1 - Saliwan Neumann, Romeo A1 - Eliezer, D. A1 - Böllinghaus, Thomas A1 - Unger, Wolfgang T1 - Novel approach to image hydrogen distribution and related phase transformation in duplex stainless steels at the sub-micron scale JF - International Journal of Hydrogen Energy N2 - The effect of electrochemical charging of hydrogen on the structure of a lean duplex stainless steel LDX 2101® (EN 1.4162, UNS S32101) was examined by both Time-of-Flight secondary ion mass spectrometry and electron back-scatter diffraction. The goal is to correlate hydrogen concentration and induced structural changes. Chemical and structural characterizations were done for the same region at the sample's surface with sub-micron spatial resolution. Regions of interest were varying in size between 50 × 50 μm and 100 × 100 μm. The results show a phase transformation of austenite to mainly a defect-rich BCC and scarcely a HCP phase. The phase transformation occurred in deuterium rich regions in the austenite. KW - Time-of-flight secondary ion mass spectrometry KW - ToF-SIMS KW - Electron backscatter diffraction KW - EBSD KW - Hydrogen-assisted cracking KW - Data fusion KW - Lean duplex stainless steel PY - 2017 DO - https://doi.org/10.1016/j.ijhydene.2017.08.016 SN - 0360-3199 VL - 42 IS - 39 SP - 25114 EP - 25120 AN - OPUS4-42022 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mosquera Feijoo, Maria A1 - Oder, Gabriele A1 - Saliwan Neumann, Romeo A1 - Buchheim, Michaela A1 - Kranzmann, Axel A1 - Olbricht, Jürgen T1 - Impact of Sample Geometry and Surface Finish on VM12‑SHC Ferritic–Martensitic Steel Under Cyclic Steam Atmosphere Operating Conditions JF - Oxidation of Metals N2 - The steam side oxidation of ferritic–martensitic VM12-SHC steel was investigated under thermo-cyclic conditions in water steam at 620/320 °C and 30 bar with a focus on assessing the influence of pre-oxidation time, specimen geometry and surface finish. The specimens were pre-oxidized under isothermal conditions in water steam at 620 °C and 30 bar for 500 h or 1500 h. After pre-oxidation treatment, all specimens were subjected up to 258 thermal cycles. Three different geometries—rectangular coupons, U-shaped ring segments and ring samples—were investigated to evaluate the influence of open/closed shape, and flat/curved surface on corrosion rate. At the same time, two types of surface finish were considered: “as received” and “ground.” The formation of a protective scale by pre-oxidation was investigated. EBSD and ESMA analyses revealed that the Cr-content of the alloy appeared to be insufficient for obtaining a protective oxide scale under studied conditions, at the same time the anayses confirmed that initial oxidation depends on presence of minor alloying elements as Si and Mn, strong oxide formers which can alter the kinetics and morphology of the corrosion reaction. Moreover, rectangular coupons with small wall thickness and flat surface exhibited the highest corrosion rate, while “ground” curved samples showed only local oxidation. This indicates that for same pre-oxidation time, oxidation kinetics is controlled by curvature. KW - Cyclic steam oxidation KW - 12%Cr steel KW - Specimen geometry KW - Surface treatments PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551808 DO - https://doi.org/10.1007/s11085-022-10114-6 SN - 0030-770X SP - 1 EP - 18 PB - Springer AN - OPUS4-55180 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Tim A1 - Schroepfer, Dirk A1 - Rhode, Michael A1 - Boerner, Andreas A1 - Saliwan Neumann, Romeo A1 - Schneider, M. A1 - Laplanche, G. T1 - Influence of machining on the surface integrity of high- and medium-entropy alloys JF - Materials Chemistry and Physics N2 - High- and medium-entropy alloys (HEAs) are a quite new class of materials. They have a high potential for applications from low to high temperatures due to the excellent combination of their structural properties. Concerning their application as components; processing properties, such as machinability, have hardly been investigated so far. Hence, machinability analyses with a focus on the influence of the milling process and its basic parameters (cutting speed, feed per cutting edge) on the resulting surface integrity of specimens from an equiatomic high- (CoCrFeMnNi) and a medium- (CoCrNi) entropy alloy have been carried out. A highly innovative milling process with ultrasonic assistance (USAM) was compared to conventional milling processes. Recent studies have shown that USAM has a high potential to significantly reduce the mechanical load on the tool and workpiece surface during milling. In this study, the basic machining and ultrasonic parameters were systematically varied. After machining, the surface integrity of the alloys was analyzed in terms of topography, defects, subsurface damage, and residual stresses. It was observed that USAM reduces the cutting forces and increases the surface integrity in terms of lower tensile residual stresses and defect density near the surfaces for the CoCrFeMnNi alloy. It was shown that the cutting forces and the metallurgical influence in the sub surface region are reduced by increasing the cutting speed and reducing the feed rate per cutting edge. With the CoCrNi alloy, the tool revealed severe wear. As a result, for this alloy no influence of the parameters on the machinability could be determined. KW - High Entropy Alloy KW - Medium Entropy Alloys KW - Ultrasonic assited machining PY - 2022 DO - https://doi.org/10.1016/j.matchemphys.2021.125271 SN - 0254-0584 VL - 275 SP - 125271 PB - Elsevier B.V. AN - OPUS4-53606 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nadammal, Naresh A1 - Kromm, Arne A1 - Saliwan Neumann, Romeo A1 - Farahbod, Lena A1 - Haberland, Christoph A1 - Portella, Pedro Dolabella T1 - Influence of support configurations on the characteristics of selective laser-melted Inconel 718 JF - JOM-The Journal of The Minerals, Metals & Materials Society (TMS) N2 - Samples fabricated using two different support configurations by following identical scan strategies during selective laser melting of superalloy Inconel 718 were characterized in this study. Characterization methods included optical microscopy, electron back-scattered diffraction and x-ray diffraction residual stress measurement. For the scan strategy considered, microstructure and residual stress development in the samples were influenced by the support structures. However, crystallographic texture intensity and the texture components formed within the core part of the samples were almost independent of the support. The formation of finer grains closer to the support as well as within the columnar grain boundaries resulted in randomization and texture intensity reduction by nearly half for the sample built on a lattice support. Heat transfer rates dictated by the support configurations in addition to the scan strategy influenced the microstructure and residual stress development in selective laser-melted Inconel 718 samples. KW - Additive manufacturing KW - Selective laser melting KW - Support configurations KW - Microstructure and texture KW - Residual stress PY - 2018 DO - https://doi.org/10.1007/s11837-017-2703-1 SN - 1047-4838 SN - 1543-1851 VL - 70 IS - 3 SP - 343 EP - 348 PB - Springer CY - USA AN - OPUS4-44175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kianinejad, kaveh A1 - Fedelich, Bernard A1 - Darvishi Kamachali, Reza A1 - Schriever, Sina A1 - Manzoni, Anna Maria A1 - Agudo Jacome, Leonardo A1 - Megahed, Sandra A1 - Kamrani, Sepideh A1 - Saliwan-Neumann, Romeo T1 - Experimentally informed multiscale creep modelling of additive manufactured Ni-based superalloys N2 - Excellent creep resistance at elevated temperatures, i.e. T / T_m> 0.5, due to γ-γ’ microstructure is one of the main properties of nickel-based superalloys. Due to its great importance for industrial applications, a remarkable amount of research has been devoted to understanding the underlying deformation mechanism in a wide spectrum of temperature and loading conditions. Additive manufactured (AM) nickel-based superalloys while being governed by similar γ-γ’ microstructure, exhibit AM-process specific microstructural characteristics, such as columnar grains, strong crystallographic texture (typically <001> fiber texture parallel to build direction) and compositional inhomogeneity, which in turn leads to anisotropic creep response in both stationary and tertiary phases. Despite the deep insights achieved recently on the correlation between process parameters and the resulting microstructure, the anisotropic creep behavior and corresponding deformation mechanism of these materials are insufficiently understood so far. One reason for this is the lack of capable material models that can link the microstructure to the mechanical behavior. To overcome this challenge, a multiscale microstructure-based approach has been applied by coupling crystal plasticity (CP) and polycrystal model which enables the inclusion of different deformation mechanisms and microstructural characteristics such as crystallographic texture and grain morphology. The method has been applied to experimental data for AM-manufactured INCONEL-738LC (IN738). The effect of different slip systems, texture, and morphology on creep anisotropy at 850°C has been investigated. Results suggest a strong correlation between superlattice extrinsic stacking fault (SESF) and microtwinning and observed creep anisotropy. T2 - EUROMAT 23 CY - Frankfurt a. M., Germany DA - 04.09.2023 KW - IN738LC KW - Creep anisotropy KW - Crystal plasticity PY - 2023 AN - OPUS4-58263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano Munoz, Itziar A1 - Fernández, R. A1 - Saliwan-Neumann, Romeo A1 - González-Doncel, G. A1 - Bruno, Giovanni T1 - Dislocation structures after creep in an Al-3.85 %Mg alloy studied using EBSD-KAM technique JF - Materials Letters N2 - The electron backscatter diffraction (EBSD) technique is used to investigate the dislocation structures formed after steady-state creep deformation of an Al-3.85%Mg alloy. This material is crept at two different stress levels, corresponding to the so-called power-law and power-law breakdown regimes. The results show that, regardless of the creep stress level, the strain tends to localize, leading to the formation of intragranular bands. The thickness of such bands is larger when the material is tested at loads corresponding to the power-law breakdown. This suggests enhanced diffusion by dislocation pipes. KW - Steady-state creep KW - Al-3.85%Mg alloy KW - Power-law breakdown KW - Electron backscatter diffraction (EBSD) KW - Denoising filter PY - 2023 DO - https://doi.org/10.1016/j.matlet.2023.133978 SN - 0167-577X VL - 337 SP - 1 EP - 4 PB - Elsevier B.V. AN - OPUS4-56941 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fritsch, Tobias A1 - Sprengel, Maximilian A1 - Evans, Alexander A1 - Farahbod-Sternahl, L. A1 - Saliwan Neumann, Romeo A1 - Hofmann, M. A1 - Bruno, Giovanni T1 - On the determination of residual stresses in additively manufactured lattice structures JF - Journal of Applied Crystallography N2 - The determination of residual stresses becomes more complicated with increasing complexity of the structures investigated. Additive manufacturing techniques generally allow the production of ‘lattice structures’ without any additional manufacturing step. These lattice structures consist of thin struts and are thus susceptible to internal stress-induced distortion and even cracks. In most cases, internal stresses remain locked in the structures as residual stress. The determination of the residual stress in lattice structures through nondestructive neutron diffraction is described in this work. It is shown how two difficulties can be overcome: (a) the correct alignment of the lattice structures within the neutron beam and (b) the correct determination of the residual stress field in a representative part of the structure. The magnitude and the direction of residual stress are discussed. The residual stress in the strut was found to be uniaxial and to follow the orientation of the strut, while the residual stress in the knots was more hydrostatic. Additionally, it is shown that strain measurements in at least seven independent directions are necessary for the estimation of the principal stress directions. The measurement directions should be chosen according to the sample geometry and an informed choice on the possible strain field. If the most prominent direction is not measured, the error in the calculated stress magnitude increases considerably. KW - Additive manufacturing KW - Laser powder bed fusion KW - Residual stress KW - Principal stress components KW - Neutron diffraction KW - Lattice structures PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520663 DO - https://doi.org/10.1107/S1600576720015344 SN - 1600-5767 VL - 54 SP - 228 EP - 236 AN - OPUS4-52066 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Blank, Robin A1 - Nitschke, Heike A1 - Saliwan Neumann, Romeo A1 - Kranzmann, Axel T1 - Materialographic Preparation of Salt JF - Praktische Metallographie N2 - Molten salt containing systems gain in importance for sustainable energy use and production. For research and development, interactions of molten salts with potential container materials are of major interest. This article introduces preparation procedures to display an intact metal and salt microstructure and their interface using light optical microscopy and scanning electron microscopy. The exemplary material combination is the ternary salt mixture NaCl-KCl-MgCl2 and the low alloyed steel 1.4901 (T92) with a maximum service temperature of 550 °C. These are potential elements/materials for use in latent heat thermal energy storages. KW - Molten salt KW - Corrosion KW - Steel KW - Aging KW - Dry preparation PY - 2021 DO - https://doi.org/10.1515/pm-2022-0058 VL - 59 IS - 10 SP - 628 EP - 640 PB - De Gruyter AN - OPUS4-56048 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Charmi, Amir A1 - Falkenberg, Rainer A1 - Ávila, Luis A1 - Mohr, Gunther A1 - Sommer, Konstantin A1 - Ulbricht, Alexander A1 - Sprengel, Maximilian A1 - Saliwan Neumann, Romeo A1 - Evans, Alexander A1 - Skrotzki, Birgit T1 - Mechanical anisotropy of additively manufactured stainless steel 316L: An experimental and numerical study JF - Materials Science and Engineering: A N2 - The underlying cause of mechanical anisotropy in additively manufactured (AM) parts is not yet fully understood and has been attributed to several different factors like microstructural defects, residual stresses, melt pool boundaries, crystallographic and morphological textures. To better understand the main contributing factor to the mechanical anisotropy of AM stainless steel 316L, bulk specimens were fabricated via laser powder bed fusion (LPBF). Tensile specimens were machined from these AM bulk materials for three different inclinations: 0◦, 45◦, and 90◦ relative to the build plate. Dynamic Young’s modulus measurements and tensile tests were used to determine the mechanical anisotropy. Some tensile specimens were also subjected to residual stress measurement via neutron diffraction, porosity determination with X-ray micro-computed tomography (μCT), and texture analysis with electron backscatter diffraction (EBSD). These investigations revealed that the specimens exhibited near full density and the detected defects were spherical. Furthermore, the residual stresses in the loading direction were between −74 ± 24 MPa and 137 ± 20 MPa, and the EBSD measurements showed a preferential ⟨110⟩ orientation parallel to the build direction. A crystal plasticity model was used to analyze the elastic anisotropy and the anisotropic yield behavior of the AM specimens, and it was able to capture and predict the experimental behavior accurately. Overall, it was shown that the mechanical anisotropy of the tested specimens was mainly influenced by the crystallographic texture. KW - Mechanical anisotropy KW - Residual stress KW - Crystal plasticity KW - Selective laser melting (SLM) KW - Laser beam melting (LBM) PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511719 DO - https://doi.org/10.1016/j.msea.2020.140154 SN - 0921-5093 VL - 799 SP - 140154 PB - Elsevier B.V. AN - OPUS4-51171 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano Munoz, Itziar A1 - Mishurova, Tatiana A1 - Thiede, Tobias A1 - Sprengel, Maximilian A1 - Kromm, Arne A1 - Nadammal, Naresh A1 - Nolze, Gert A1 - Saliwan Neumann, Romeo A1 - Evans, Alexander A1 - Bruno, Giovanni T1 - The residual stress in as‑built Laser Powder Bed Fusion IN718 alloy as a consequence of the scanning strategy induced microstructure JF - Scientific reports N2 - The effect of two types of scanning strategies on the grain structure and build-up of Residual Stress (RS) has been investigated in an as-built IN718 alloy produced by Laser Powder Bed Fusion (LPBF). The RS state has been investigated by X-ray diffraction techniques. The microstructural characterization was performed principally by Electron Backscatter Diffraction (EBSD), where the application of a post-measurement refinement technique enables small misorientations (< 2°) to be resolved. Kernel average misorientation (KAM) distributions indicate that preferably oriented columnar grains contain higher levels of misorientation, when compared to elongated grains with lower texture. The KAM distributions combined with X-ray diffraction stress maps infer that the increased misorientation is induced via plastic deformation driven by the thermal stresses, acting to self-relieve stress. The possibility of obtaining lower RS states in the build direction as a consequence of the influence of the microstructure should be considered when envisaging scanning strategies aimed at the mitigation of RS. KW - Additive manufacturing KW - LPBF KW - Residual stress KW - Inconel 718 KW - Kernel average misorientation KW - Texture PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511769 DO - https://doi.org/10.1038/s41598-020-71112-9 VL - 10 IS - 1 SP - 14645 AN - OPUS4-51176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert A1 - Saliwan Neumann, Romeo A1 - Reith, F. A1 - Etschmann, B. A1 - Kilburn, M. R. A1 - Brugger, J. T1 - Unravelling the formation histories of placer gold and platinum-group mineral particles from Corrego Bom Successo, Brazil: A window into noble metal cycling JF - Gondwana research N2 - Gold and platinum-group-metals (PGM) are cycled through Earth's environments by interwoven geological, physical, chemical and biological processes leading to the trans/neoformation of metallic particles in placers. The placer deposit at Corrego Bom Successo (CBS, Brazil) is one of the few localities worldwide containing secondary gold- and PGM-particles. Placer gold consists of detrital particles from nearby hydrothermal deposits that were transformed in the surface environment. Processes that have affected these particles include shortdistance transport, chemical de-alloying of the primary Gold silver, and (bio)geochemical dissolution/reprecipitation of Gold leading to the formation of pure, secondary gold and the Dispersion of gold nanoparticles. The latter processes are likely mediated by non-living organic matter (OM) and bacterial biofilms residing on the particles. The biofilms are largely composed of metallophillic β- and γ-Proteobacteria. Abundant mobile gold and platinum nanoparticles were detected in surface waters, suggesting similar mobilities of these metals. Earlier hydrothermal processes have led to the formation of coarsely-crystalline, arborescent dendritic potarite (PdHg). On potarite surfaces, biogeochemical processes have then led to the formation of platinum- and palladium-rich micro-crystalline layers, which make up the botryoidal platinum palladium aggregates. Subsequently potarite was dissolved from the core of many aggregates leaving voids now often filled by secondary anatase (TiO2) containing biophilic elements. The presence of fungal structures associated with the anatase suggests that fungi may have contributed to ist formation. For the first time a primary magmatic PGM-particle comprising a mono-crystalline platinum palladium-alloy with platinum iridium osmium inclusions was described from this locality, finally defining a possible primary source for the PGM mineralisation. In conclusion, the formation of modern-day placer gold- and PGM-particles at CBS began 100s ofmillions of years ago bymagmatic and hydrothermal processes. These provided the metal sources for more recent biogeochemical cycling of PGEs and gold that led to the trans/neoformation of gold- and PGM-particles. KW - Gold KW - Platinum-group-metals KW - Biogeochemical cycling KW - Magmatic and hydrothermal processes KW - Biomineralisation PY - 2019 DO - https://doi.org/10.1016/j.gr.2019.07.003 SN - 1342-937X VL - 76 SP - 246 EP - 259 PB - Elsevier AN - OPUS4-48657 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Dörfel, Ilona A1 - Sojref, Regine A1 - Saliwan Neumann, Romeo T1 - Microstructure of bare and sol-gel alumina-coated nickel-base alloy Inconel 625 after long-term oxidation at 900 °C JF - Oxidation of Metals N2 - Though Ni-base superalloys show a high oxidation and corrosion resistance, coatings could still improve these properties, especially if used at temperatures up to 1000 °C. Here, a coating was prepared by applying a boehmite-sol via dip-coating and a subsequent heat treatment at 600 °C for 30 minutes. To evaluate the coating, the oxidation behavior of bare and alumina coated Ni-base alloy Inconel 625 in air at 900 °C was studied for up to 2000 h. Electron microscopic studies of sample surfaces and cross-sections showed that (i) in the 3.5 µm – 6.3 mm thick scale formed on the bare alloy, Fe and Ni are located as fine precipitates at the grain boundaries of the chromia-rich scale, (ii) Ni and Ti are concentrated to a minor degree at the grain boundaries of the scale, too; and for the coated sample: (iii) the only 1.8 µm thick sol-gel alumina coating slows down the formation of chromia on the alloy surface and reduces the outward diffusion of the alloy constituents. The protective effect of the coating was evidenced by (i) diminished chromium diffusion at grain boundaries resulting in less pronounced string-like protrusions at the outer surface of the coated IN 625, (ii) formation of a Cr-enriched zone above the alloy surface which was thinner than the scale on the uncoated sample, (iii) no detectable Cr-depleted zone at the alloy surface, and (iv) a narrower zone of formation of Kirkendall pores. KW - Inconel 625 KW - High-temperature oxidation KW - Oxidation protection KW - Sol-gel coating PY - 2019 DO - https://doi.org/10.1007/s11085-019-09888-z SN - 0030-770X VL - 91 IS - 3-4 SP - 395 EP - 416 PB - Springer Science+Business Media AN - OPUS4-47665 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kianinejad, Kaveh A1 - Darvishi Kamachali, Reza A1 - Khedkar, Abhinav A1 - Manzoni, Anna A1 - Agudo Jácome, Leonardo A1 - Schriever, Sina A1 - Saliwan Neumann, romeo A1 - Megahed, Sandra A1 - Heinze, Christoph A1 - Kamrani, Sepideh A1 - Fedelich, Bernard T1 - Creep anisotropy of additively manufactured Inconel-738LC: Combined experiments and microstructure-based modeling JF - Materials Science and Engineering: A N2 - The current lack of quantitative knowledge on processing-microstructure–property relationships is one of the major bottlenecks in today’s rapidly expanding field of additive manufacturing. This is centrally rooted in the nature of the processing, leading to complex microstructural features. Experimentally-guided modeling can offer reliable solutions for the safe application of additively manufactured materials. In this work, we combine a set of systematic experiments and modeling to address creep anisotropy and its correlation with microstructural characteristics in laser-based powder bed fusion (PBF-LB/M) additively manufactured Inconel-738LC (IN738LC). Three sample orientations (with the tensile axis parallel, perpendicular, and 45° tilted, relative to the building direction) are crept at 850 °C, accompanied by electron backscatter secondary diffraction (EBSD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations. A crystal plasticity (CP) model for Ni-base superalloys, capable of modeling different types of slip systems, is developed and combined with various polycrystalline representative volume elements (RVEs) built on the experimental measurements. Besides our experiments, we verify our modeling framework on electron beam powder bed fusion (PBF-EB/M) additively manufactured Inconel-738LC. The results of our simulations show that while the crystallographic texture alone cannot explain the observed creep anisotropy, the superlattice extrinsic stacking faults (SESF) and related microtwinning slip systems play major roles as active deformation mechanisms. We confirm this using TEM investigations, revealing evidence of SESFs in crept specimens. We also show that the elongated grain morphology can result in higher creep rates, especially in the specimens with a tilted tensile axis. KW - Additive manufactured Ni-base superalloys KW - Creep KW - Crystal plasticity KW - Superlattice extrinsic stacking faults PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601576 DO - https://doi.org/10.1016/j.msea.2024.146690 SN - 0921-5093 VL - 907 SP - 1 EP - 16 PB - Elsevier B.V. AN - OPUS4-60157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -