TY - CONF A1 - Bäßler, Ralph T1 - Components in CO2-stream, corrosive to Materials to be Used in CC(U)S Applications N2 - CO2 quality specifications are not only a matter of CO2 purity (i.e. CO2 content). The “rest” also matters, in particular contents of reactive impurities affecting material corrosion (and rock alteration). Also chemical reactions in CO2 stream needs to be considered, in particular when combining CO2 streams of different compositions. T2 - WCO Forum at AMPP Annual International Corrosion Conference 2021 CY - Online Meeting DA - 26.04.2021 KW - Carbon capture storage KW - Corrosion PY - 2021 AN - OPUS4-52502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hmood, F. J. A1 - Wilbig, Janka A1 - Nicolaides, Dagmar A1 - Zocca, Andrea A1 - Günster, Jens T1 - An approach to monitor the real-time deformation during heat treatment of 3D-printed glass N2 - This study suggests a tool for a better control on the sintering/crystallization of 3D-printed bioactive glassceramics bodies. A small cantilever in form of a bar with square cross section attached to a base and inclined 34◦ with the horizon, was used to monitor the viscous flow and sintering/crystallization headway of a glassceramic systems. 3D printing and sintering of bioactive glass-ceramics is of great interest for medical care applications. Viscous flow ensures sufficient densification of the typically low density printed green bodies, while crystallization prevents the structure from collapsing under the gravitational load. As a model system, a bioactive glass called BP1 (48.4 SiO2, 1 B2O3, 2 P2O5, 36.6 CaO, 6.6 K2O, 5.6 Na2O (mol%)), which has a chemical composition based on that of ICIE16, was employed in this work. In addition, ICIE16 was used as a reference glass. The results show that the suggested design is a very promising tool to track the real-time deformation of 3D printed glass-ceramic specimens and gives a good indication for the onset of crystallization as well. KW - Real-time deformation KW - Sintering KW - 3D-printing KW - Bioactive glass PY - 2021 DO - https://doi.org/10.1016/j.ceramint.2021.03.334 VL - 47 IS - 14 SP - 20045 EP - 20050 PB - Elsevier Ltd. AN - OPUS4-53449 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Yevtushenko, Oleksandra A1 - Le, Quynh Hoa A1 - Bettge, Dirk T1 - Suitability of Metallic Materials in CC(U)S Applications N2 - Carbon Capture Utilization and Storage (CCUS) is a promising technology to reach the target for reduction of CO2 emissions, e.g. from fossil-fuel operated power plants or cement mills. Crucial points for a sustainable and future-proof CCUS procedure are reliability and cost efficiency of the whole process chain, including separation of CO2 from the source, compression of CO2, its subsequent transportation to the injection site and injection into geological formations, e.g. aquifers. Most components that are in contact with CO2-stream consist of steel. Depending on the operating conditions (e.g. temperature, pressure, and CO2-stream composition) specific suitable steels should be used. The compressed CO2-stream is likely to contain process specific impurities; small amounts of SO2 and NO2 in combination with oxygen and water are most harmful. One approach, as currently preferred by pipeline operators, is to clean the CO2-stream to such levels, acceptable for carbon steel, commonly used as pipeline material. Another consideration would be, to use more corrosion resistant alloys for CO2-streams with higher amounts of impurities. Due to the absence of certified benchmarks for upper limits, systematic experiments with impurities in the CO2-stream were carried out reflecting mainly transport and injection conditions. Within the COORAL project (German acronym for “CO2 purity for capture and storage”) levels of impurities in the CO2-stream, being acceptable when using specific steels, were evaluated. Material exposure to dense or multiphase carbon dioxide (CO2) containing specific amounts of water vapor, oxygen (O2) sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) can be a challenge to steels. In some situations, condensation of impurities and reaction products from the CO2 stream can occur. CO2 saturated brine is supposed to rise in the well when the injection process is interrupted. The material selection shall ensure that neither CO2 nor brine or a combination of both will leak out of the inner tubing. This COORAL-work was extended by a follow-up project, called CLUSTER. Here the additional influence of impurities was investigated when merging CO2 streams from different sources, combined within a “so-called” cluster. Results are summarized within the following table regarding suitability for different parts of the process chain. T2 - EUROCORR 2021 CY - Online meeting DA - 20.09.2021 KW - Carbon capture storage KW - Corrosion KW - Steel KW - CCS KW - CCU KW - CO2 PY - 2021 SP - 1 EP - 2 AN - OPUS4-53460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Derlet, P. A1 - Bocquet, H. A1 - Maaß, Robert T1 - Viscosity and transport in a model fragile metallic glass N2 - How thermally activated structural excitations quantitatively mediate transport and microplasticity in a model binary glass at the microsecond timescale is revealed using atomistic simulation. These local excitations, involving a stringlike sequence of atomic displacements, admit a far-field shear-stress signature and underlie the transport of free-volume and bond geometry. Such transport is found to correspond to the Evolution of a disclination network describing the spatial connectivity of topologically distinct bonding environments, demonstrating the important role of geometrical frustration in both glass structure and its underlying dynamics. KW - Metallic glass KW - Viscosity PY - 2021 DO - https://doi.org/10.1103/PhysRevMaterials.5.125601 SN - 2475-9953 VL - 5 SP - 1 EP - 7 PB - American Physical Society CY - College Park, MD AN - OPUS4-54152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ikeda, Yuki A1 - Nishijima, M. A1 - Kiguchi, T. A1 - Konno, T. T1 - Crystal structure characterization of martensite of Cu–Zn–Al ternary alloy by spherical aberration corrected scanning transmission electron microscopy N2 - The crystal structure of martensite in Cu-27at.%Zn-9.0 at.%Al alloy has been studied by using sphericalaberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and geometrical phase analysis (GPA) to examine possible changes in atomic rearrangements during martensitic transformation of this ternary system. Observation along [100]M zone axis is suitable for examining a chemical order of the martensite, and showed that, despite the non-stoichiometry of the alloy, atomic columns containing Al atoms are imaged and distinguished from the others. On the other hand, observation along [010]M zone axis directly revealed that the parent and martensitic phases possess L21 and 18R (21) structures, respectively. These observations suggested that the martensite retained the local chemical order of the parent phase without shuffling before and after the transformation. GPA revealed that the interface between the two phases was coherent with tilting of the basal plane approximately 6◦ across the boundary, which makes otherwise large inclination small during the martensitic transformation. KW - Shape-memory alloys KW - Martensitic transformation KW - Martensitic structure KW - Electron microscopy, transmission PY - 2021 DO - https://doi.org/10.1016/j.intermet.2021.107286 SN - 0966-9795 VL - 137 PB - Elsevier Ltd. AN - OPUS4-53076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abboud, M. A1 - Motallebzadeh, A. A1 - Duygulu, O. A1 - Maaß, Robert A1 - Özerinc, S. T1 - Microstructure and nanomechanical behavior of sputtered CuNb thin films N2 - We report on the mechanical properties of Cu–Nb alloys produced by combinatorial magnetron sputtering. Depending on the composition, the microstructure is either fully amorphous (~30–65 at.% Cu), a dispersion of Cu crystallites in an amorphous matrix (~70 at.%), or a dominant crystalline phase with separated nanoscale amorphous zones (~80 at.% Cu). Nanomechanical probing of the different microstructures reveals that the hardness of the fully amorphous alloy is much higher than a rule of mixture would predict. We further demonstrate a remarkable tunability of the resistance to plastic flow, ranging from ca. 9 GPa in the amorphous regime to ca. 2 GPa in the fully crystalline regime. We rationalize these findings based on fundamental structural considerations, thereby highlighting the vast structure-property design space that this otherwise immiscible binary alloy provides. KW - Deposition microstructure KW - Metallic glasses KW - Thin films KW - Mechanical properties KW - Nanocrystalline structure PY - 2021 DO - https://doi.org/10.1016/j.intermet.2021.107249 SN - 0966-9795 VL - 136 SP - 1 EP - 7 PB - Elsevier CY - Amsterdam AN - OPUS4-52777 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rizzardi, Q. A1 - Derlet, P. M. A1 - Maaß, Robert T1 - Microstructural signatures of dislocation avalanches in a high-entropy alloy N2 - Here, we trace in situ the slip-line formation and morphological signature of dislocation avalanches in a highentropy alloy with the aim of revealing their microstructural degree of localization. Correlating the intermittent microplastic events with their corresponding slip-line patterns allows defining two main event types, one of which is linked to the formation of new slip lines, whereas the other one involves reactivation of already existing slip lines. The formation of new slip lines reveals statistically larger and faster avalanches. The opposite tendency is seen for avalanches involving reactivation of already existing slip lines. The combination of both these types of events represents the highest degree of spatial avalanche delocalization that spans the entire sample, forming a group of events that determine the truncation length scale of the truncated power-law scaling. These observations link the statistics of dislocation avalanches to a microstructural observable. KW - High-entropy alloy KW - Dislocation avalanches PY - 2021 DO - https://doi.org/10.1103/PhysRevMaterials.5.043604 SN - 2475-9953 VL - 5 IS - 4 SP - 3604 PB - American Physical Society CY - College Park, MD AN - OPUS4-52458 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ikeda, Yuki A1 - Mancias, J. A1 - Gan, B. A1 - Maaß, Robert T1 - Evidence of room-temperature shear-deformation in a Cu-Al intermetallic N2 - Lamellar eutectics are known to evidence plastic shear in otherwise brittle intermetallics, if the lamella spacing is small enough. Here we pursue this idea of confined plasticity in intermetallics further and demonstrate room-temperature shear-deformation in a two-phase CuAl 2 -CuAl intermetallic nano- composite. The presence of a phase with a 3-fold symmetry is also revealed after deformation. Simula- tion of transmission electron microscopy images shows this to be monoclinic CuAl. These observations are made in the deformation zone underneath locations of nanoindents, of which the force-displacement curves exhibit an unusual response of continuously increasing pop-in sizes with load. KW - Nanoindentation KW - Intermetallic KW - Nano-composite KW - Shear bands KW - Plasticity PY - 2021 DO - https://doi.org/10.1016/j.scriptamat.2020.08.033 VL - 190 SP - 126 EP - 130 PB - Elsevier Ltd. AN - OPUS4-52455 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maaß, Robert A1 - Derlet, P. T1 - Micro-plasticity in a fragile model binary glass N2 - Atomistic deformation simulations in the nominally elastic regime are performed for a model binary glass with strain rates as low as 10 4 /s (corresponding to 0.01 shear strain per 1 μs). A strain rate dependent elastic softening due to a micro-plasticity is observed, which is mediated by thermally-activated localized structural transformations (LSEs). A closer inspection of the atomic-scale structure indicates the material response is distinctly different for two types of local atomic environments. A system spanning iscosahe- drally coordinated substructure responds purely elastically, whereas the remaining substructure admits both elastic and microplastic evolution. This leads to a heterogeneous internal stress distribution which, upon unloading, results in negative creep and complete residual-strain recovery. A detailed structural analysis in terms of local stress, atomic displacement, and SU(2) local bonding topology shows such mi- croscopic processes can result in large changes in local stress and are more likely to occur in geomet- rically frustrated regions characterized by higher free volume and softer elastic stiffness. The thermally- activated LSE activity also mediates structural relaxation, and in this way should be distinguished from stress-driven shear transformation activity which only rejuvenates glass structure. The frequency of LSE activity, and therefore the amount of micro-plasticity, is found to be related to the degree to which the glassy state is relaxed. These insights shed atomistic light onto the structural origins that may govern re- cent experimental observations of significant structural evolution in response to elastic loading protocols. KW - Molecular dynamics KW - Bulk metallic glasses KW - Plasticity KW - Residual strains PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-523782 DO - https://doi.org/10.1016/j.actamat.2021.116771 VL - 209 SP - 116771 PB - Elsevier Ltd. AN - OPUS4-52378 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ikeda, Yuki A1 - Yuan, R. A1 - Chakraborty, A. A1 - Ghassemi-Armaki, H. A1 - Zuo, J. M. A1 - Maaß, Robert T1 - Early stages of liquid-metal embrittlement in an advanced high-strength steel N2 - Grain-boundary degradation via liquid-metal embrittlement (LME) is a prominent and long-standing failure process in next generation advanced high-strength steels. Here we reveal, well ahead of the crack tip, the presences of nano-scale grains of intermetallic phases in Zn-infiltrated but uncracked grain boundaries with scanning- and 4D transmission electron microscopy. Instead of the often-reported Znrich Fe-Zn intermetallics, the nano-scale phase in the uncracked infiltrated grain boundaries is identified as the G-phase, and its presence reveals the local enhancement of strain heterogeneities in the grain boundary network. Based on these observations, we argue that intermetallic phase formation is not occurring after cracking and subsequent liquid Zn infiltration but is instead one of the primary nanoscopic drivers for grain-boundary weakening and crack initiation. These findings shift the focus of LME from micro- and meso-scale crack investigations to the very early stages immediately following Zn diffusion, after which secondary phase nucleation and growth emerge as the root-cause for failure. KW - Advanced high strength steels KW - Liquid metal embrittlement KW - Transmission electron microscopy KW - 4-Dimensional scanning transmission KW - electron microscopy PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-539716 DO - https://doi.org/10.1016/j.mtadv.2021.100196 SN - 2590-0498 VL - 13 IS - 196 SP - 1 EP - 8 PB - Elsevier Ltd. AN - OPUS4-53971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -