5 Werkstofftechnik
Filtern
Dokumenttyp
- Vortrag (111) (entfernen)
Referierte Publikation
- nein (111)
Schlagworte
- Corrosion (17)
- Microstructure (12)
- Additive Manufacturing (9)
- Fraktographie (9)
- 316L (6)
- CCUS (6)
- High entropy alloys (6)
- Scanning electron microscopy (6)
- Transmission electron microscopy (6)
- Diffraction (5)
- EBSD (5)
- Fractography (5)
- Machine Learning (5)
- Additive manufacturing (4)
- CCS (4)
- CO2 (4)
- Droplet corrosion (4)
- High-temperature corrosion (4)
- Laser powder bed fusion (4)
- Martensitic steel (4)
- Residual Stress (4)
- Sulfidation (4)
- Supercritical/dense phase CO2 (4)
- Additive Fertigung (3)
- CCU (3)
- Carbon steels (3)
- Creep (3)
- Creep behavior (3)
- Fatigue (3)
- Geothermal (3)
- High temperature corrosion (3)
- In situ (3)
- Mechanical properties (3)
- Oxidation (3)
- SEM (3)
- Superaustenite steel (3)
- Transmission electron microscopy (TEM) (3)
- Welding (3)
- X-ray diffraction (3)
- AGIL (2)
- AISI 316L (2)
- CO2 quality (2)
- Carbon capture (2)
- Carbon capture storage (2)
- Carbon dioxide (2)
- Carbon steel (2)
- Chemically complex alloy (2)
- Datenbank (2)
- Digitalisierung (2)
- Dislocation (2)
- Electron microscopy (2)
- Electron-beam-induced modification (2)
- Ferritic-martensitic steels (2)
- Fracture surface (2)
- Gitterkonstanten (2)
- High Entropy Alloy (2)
- High entropy alloy (2)
- High-entropy alloy (2)
- High-entropy alloys (2)
- Hochentropie-Legierung (2)
- Impurities (2)
- L-PBF (2)
- Mechanical behavior (2)
- Microstructural analysis (2)
- Mikrostruktur (2)
- Mixed gas atmosphere (2)
- Neutron diffraction (2)
- Oxidation behavior (2)
- Phasenidentifikation (2)
- Pipeline (2)
- REM (2)
- Schadensanalyse (2)
- Silver diffusion (2)
- Thermo-Mechanical Fatigue (2)
- Topographie (2)
- Topography (2)
- XANES (2)
- 3D (1)
- 3D REM (1)
- 3D Reconstruction (1)
- AFM based test methods (1)
- Additiv gefertigter Stahl (1)
- Ageing (1)
- Aggressive gases (1)
- Alkali zinc borate glass (1)
- Alkali zinc borate glasses (1)
- Aluminium Alloy (1)
- Annealing (1)
- Austenitic steel 316L (1)
- Automation (1)
- Bruchflächen (1)
- CO2-corrosion (1)
- Calcium sulfates (1)
- Cantor alloy (1)
- Capture (1)
- Carbon (1)
- Carbon steels (1)
- Carbon Capture (1)
- Carbon Capture, Utilization and Storage (CCUS) (1)
- Characterization (1)
- Chemically complex alloys (1)
- Chromia (1)
- Chromium oxide (1)
- Coatings (1)
- Complex loading (1)
- Component assessment (1)
- Compositionally complex alloys (1)
- Computed Tomography (1)
- Condensation (1)
- Contamination (1)
- Cow stress (1)
- Cr2O3 (1)
- Crack propagation (1)
- Creep-Fatigue (1)
- Creep-fatigue (1)
- Crevice corrosion (1)
- Crystal Orientation (1)
- Crystal Plasticity Modelling (1)
- Cyclic R-Curve (1)
- Cyclic oxidation (1)
- Damage Tolerance (1)
- Deep learning (1)
- Defects (1)
- Degradation (1)
- Diffraction Elastic Constants (1)
- Diffraction contrast (1)
- Digital image correlation (1)
- Dislocation substructure (1)
- Disordered assemblies (1)
- Dissimilar metal weld (1)
- Driving physical mechanism (1)
- EDX (1)
- EDXRD (1)
- Early oxidation (1)
- Eigenspannung (1)
- Electron backscatter diffraction (1)
- Electron backscattered diffraction (EBSD) (1)
- Entwicklung (1)
- Ermüdungsriss (1)
- FIB (1)
- Fabrication method (1)
- Fahrrad (1)
- Fatigue Crack Growth (1)
- Fatigue fracture (1)
- FeCr- alloys (1)
- Fluorescence spectroscopy (1)
- Focused Ion Beam (1)
- GD-OES (1)
- Gas storage (1)
- Gitterfehlpassung (1)
- Gold nanoparticle synthesis (1)
- Gold nanoparticles (1)
- HEA (1)
- Heat Treatments (1)
- High Entropy Alloys (1)
- High Temperature Corrosion (1)
- High entropy superalloys (1)
- High-Temperature Corrosion (1)
- Hot isostatic pressing (1)
- Hydrogen (1)
- Hyper-arid (1)
- Implant failures (1)
- In-Situ Testing (1)
- In-situ (1)
- Inconel 686 coating (1)
- Inconel 718 (1)
- Injection (1)
- Kontrastierung (1)
- Korrosion (1)
- Kriechen (1)
- Kriechversuche (1)
- Kunststoffe (1)
- Kurzzeitfestigkeit (1)
- L-PBF 316L (1)
- LCF (1)
- Laser Powder Bed Fusion (1)
- Laser Powder Bed fusion (1)
- Laser cladding (1)
- Lattice misfit (1)
- Layer system (1)
- Lebensdauer (1)
- Legierung mit komplexer Zusammensetzung (1)
- Lithium Ion Batteries (1)
- Localized plasmons (1)
- Low Cycle Fatigue (1)
- Low cycle fatigue (1)
- MEA (1)
- Manganese oxide (1)
- Martensitic steel (1)
- Material defects (1)
- Mechanische Eigenschaften (1)
- Medium Entropy Alloys (1)
- Medium entopy alloy (1)
- Medium-entropy alloy (1)
- Melt pool boundary (1)
- Metallic components (1)
- Metallic silver precipitates (1)
- Metallography (1)
- Micro-shrinkages (1)
- Microbiologically influenced corrosion (1)
- Microstructural characterization (1)
- Microstructure Characterization (1)
- Microstructure characterisation (1)
- Microstructure evolution (1)
- Microstructure modification (1)
- Mikro-Computertomographie (1)
- Mikrostrukturentwicklung (1)
- Mn3O4 (1)
- Modeling (1)
- Mortar (1)
- Mortel (1)
- Multi-principal element alloys (1)
- Multiaxial stress state (1)
- Nano-assemblies (1)
- Nanoparticle synthesis (1)
- Negative charged microparticle (1)
- Neutron Diffraction (1)
- Non-destructive testing (1)
- Nucleation (1)
- Ontologie (1)
- Ontologien (1)
- Ooxidation (1)
- P92 (1)
- PBF-LB/M/316L (1)
- Phase analysis (1)
- Phase separation (1)
- Physically based material model (1)
- Pipeline network (1)
- Planetary surface (1)
- Plattform Material Digital (1)
- Polyaniline (1)
- Power plant (1)
- Protective coating (1)
- Präparation (1)
- Recommendations (1)
- Refractory chemically complex alloy (1)
- Refractory chemically complex alloys (1)
- Regelwerke (1)
- Residual stress (1)
- Residual stress analysis (1)
- Review (1)
- Roboter (1)
- Salzschmelzen (1)
- Sample preparation (1)
- Scanning electron microscope (1)
- Scanning transmission electron microscopy (STEM) (1)
- Schadensprävention (1)
- Schwingbrüche (1)
- Schwingstreifen (1)
- Selective laser melting (1)
- Semantisches Web (1)
- Semiconductor materials (1)
- SiO2 (1)
- Sibayak (1)
- Silver cluster (1)
- Sol-gel coating (1)
- Solid solution strengthening (1)
- Steel (1)
- Storage (1)
- Strain rate dependence (1)
- Sulfiding (1)
- Superalloy (1)
- Superalloy single crystals (1)
- Superalloys (1)
- Superaustenite steel (1)
- Supercritical/dense phase CO 2 (1)
- Superlegierung (1)
- Symbolik (1)
- Synchrotron radiation (1)
- Synthetic air (1)
- Systematische Schadensanalysen, Prozeduren (1)
- TEM (1)
- TMF (1)
- Temperature driven process (1)
- Tempered Martensite Ferritic Steels (1)
- Tempered martensite ferritic steel (1)
- Tempered martensite ferritic steels (1)
- Tensile testing (1)
- Texture (1)
- Thermo-mechanical fatigue (1)
- Thermogravimetric analysis (1)
- Transmissionselektronenmikroskopie (1)
- Utilization (1)
- Utilization, and storage (CCUS) technology (1)
- Vernetzung (1)
- Versetzungsstrukturen (1)
- Virtueller Materialdatenraum (1)
- Welding processing influences (1)
- Whole-chain CCS scenario (1)
- Wissensrepräsentation (1)
- Wärmespeicher (1)
- X-Ray Diffraction (1)
- Zugversuch (1)
- Zyklische R-Kurve (1)
- arbon capture (1)
- carbon steel (1)
- condensate (1)
- corrosion (1)
- electrochemical characterization (1)
- impurities (1)
- microstructure analysis (1)
- pitting corrosion (1)
- selective laser melting (1)
- utilization, and storage (CCUS) technology (1)
- Öffentliche Sicherheit (1)
Organisationseinheit der BAM
- 5.1 Mikrostruktur Design und Degradation (111) (entfernen)
Eine kritische Aufgabe im Rahmen der Etablierung von Prozess-Struktur-Eigenschafts-Performance-Beziehungen bei der additiven Fertigung (AM) von Metallen ist die Ermittlung von zuverlässigen und gut dokumentierten Kennwerten zum Materialverhalten sowie das Schaffen von Wissen über die Struktur-Eigenschafts-Korrelation. Schließlich ist dies die Grundlage für die Entwicklung gezielterer Prozessoptimierungen und zuverlässigerer Lebensdauer-Vorhersagen. In diesem Zusammenhang zielt dieser Beitrag darauf ab, Daten und Erkenntnisse über das Kriechverhalten des austenitischen Edelstahls 316L zu liefern, der mittels Laser-Powder-Bed-Fusion (L-PBF) hergestellt wird. Um dieses Ziel zu erreichen, wurden Proben aus konventionellem warmgewalztem sowie AM-Material gemäß den bestehenden Normen für konventionelles Material geprüft und vor und nach dem Versagen mikrostrukturell charakterisiert. Die Probekörper wurden aus einzelnen Blöcken des AM-Materials gefertigt. Die Blöcke wurden mit einer Standard-Scan- und Aufbaustrategie hergestellt und anschließend wärmebehandelt. Das Kriechverhalten wird anhand der Kriechlebensdauer und ausgewählter Kriechkurven und Kennwerte beschrieben und vergleichend bewertet. Der Einfluss von Defekten und Mikrostruktur auf das Materialverhalten wird anhand von zerstörenden und zerstörungsfreien Auswertungen an ausgewählten Proben analysiert. Der AM-Werkstoff zeigt kürzere Kriechlebensdauern, erreicht das sekundäre Kriechstadium deutlich schneller und bei geringerer Dehnung und weist eine geringere Kriechduktilität im Vergleich zu seinem konventionellen Gegenstück auf. Das Kriechschädigungsverhalten des AM-Werkstoffs ist eher mikrostruktur- als defektgesteuert und ist durch die Bildung intergranularer Kriechrisse gekennzeichnet. Als kritische Merkmale werden die Versetzungsdichte sowie die Versprödung der Korngrenzen identifiziert. Die Mikro-Computertomographie (µCT) erweist sich als Alternative zur Metallographie, um die Kriechschädigung zu analysieren.
Creep and fracture behavior of conventionally and additively manufactured stainless steel 316L
(2020)
A critical task within the frame of establishing process-structure-property-performance relationships in additive manufacturing (AM) of metals is producing reliable and well-documented material behavior’s data and knowledge regarding the structure-property correlation, including the role of defects. After all, it represents the basis for developing more targeted process optimizations and more reliable predictions of performance in the future. Within this context, this contribution aims to close the actual gap of limited historical data and knowledge concerning the creep behavior of the widely used austenitic stainless steel 316L, manufactured by Laser-Powder-Bed-Fusion (L-PBF). To address this objective, specimens from conventional hot-rolled and AM material were tested under application-relevant conditions according to existing standards for conventional material, and microstructurally characterized before and after failure. The test specimens were machined from single blocks from the AM material. The blocks were manufactured using a standard scan and build-up strategy and were subsequently heat-treated. The creep behavior is described and comparatively assessed based on the creep lifetime and selected creep curves and characteristic values. The effect of defects and microstructure on the material’s behavior is analyzed based on destructive and non-destructive evaluations on selected specimens. The AM material shows shorter creep lives, reaches the secondary creep stage much faster and at a lower strain, and features lower creep ductility compared to its conventional counterpart. The creep damage behavior of the AM material is more microstructure than defect controlled and is characterized by the formation and accumulation of single intergranular damage along the whole volume. Critical features identified are the grain morphology and the grain-boundary as well as the dislocation’s density. Micro-computed tomography (µCT) proves to be an alternative to metallography to analyze the creep damage.
The Topic of the presentationis a discussion on defects which can cause failure in cyclically loaded metallic components. Although also touching Features such as material defects such as pores or micro-shrinkages, etc. and geometric defects such as surface roughness and secondary notches (which are not considered in the design process) which origin in manufacturing, and others the presentation concentrates on non-metallic inclusions. It is prefaced by an introduction to the life cycle of a fatigue crack from initiation up to fracture. Special emphasis is put on the fact that only cracks which are not arrested during one of their distinct Propagation stages can grow to a critical size.
Investigation of degradation of the aluminum current collector in lithium-ion batteries by GD-OES
(2022)
Lithium-ion batteries (LIBs) are one technology to overcome the challenges of climate and energy crisis. They are widely used in electric vehicles, consumer electronics, or as storage for renewable energy sources. However, despite innovations in batteries' components like cathode and anode materials, separators, and electrolytes, the aging mechanism related to metallic aluminum current collector degradation causes a significant drop in their performance and prevents the durable use of LIBs. Glow-discharge optical emission spectroscopy (GD-OES) is a powerful method for depth-profiling of batteries' electrode materials. This work investigates aging-induced aluminum deposition on commercial lithium cobalt oxide (LCO) batteries' cathodes. The results illustrate the depth-resolved elemental distribution from the cathode surface to the current collector. An accumulation of aluminum is found on the cathode surface by GD-OES, consistent with results from energy-dispersive X-ray spectroscopy (EDX) combined with focused ion beam (FIB) cutting. In comparison to FIB-EDX, GD-OES allows a fast and manageable depth-profiling. Results from different positions on an aged cathode indicate an inhomogeneous aluminum film growth on the surface. The conclusions from these experiments can lead to a better understanding of the degradation of the aluminum current collector, thus leading to higher lifetimes of LIBs.
Fracture mechanics is a key to fatigue assessment in AM metal components. Short fatigue cracks are initiated at defects and pronounced surface roughness intrinsic to AM. The subsequent crack-propagation is strongly influenced by microstructural interactions and the build-up of crack-closure. The aim of the present study is to give an insight into short-crack propagation in AM-metals. Fatigue crack propagation resistance curves were determined experimentally for AISI 316L manufactured by Laser Powder Bed Fusion (L-PBF) which was heat treated at three different temperatures. Differences in the build-up of the fatigue-crack propagation threshold in between the L-PBF specimens and compared to wrought material are due to the residual stress states, a pronounced roughness of the crack-faces in the L-PBF specimens and phase transformation in the vicinity of the crack-tip, resulting in increased crack-closure. This, together with crack-branching found along the crack path, enhances the resistance to the propagation of fatigue cracks.
Diese Untersuchung beschäftigt sich mit der Charakterisierung von Kurzrisswachstum in mittels Laser-Pulverbett-Verschmelzen (LPBF - Laser Powder Bed Fusion) hergestelltem rostfreien austenitischen Stahl. Spezifischer wird die Ermittlung zyklischer R-Kurven untersucht. Diese beschreiben den Aufbau des Widerstands gegen Ermüdungsrisswachstum - d.h. des Schwellenwertes - aufgrund von Rissschließeffekten bei physikalisch kurzen Rissen. Mit Hilfe der zyklischen R-Kurven kann die Fähigkeit eines Bauteils, physikalisch kurze Risse zu arretieren, charakterisiert werden. Wir verfügen damit über eine Schnittstelle zwischen klassischer Ermüdung und Bruchmechanik. Das ist gerade auch für additiv gefertigte (AM – Additive Manufacturing) Materialien von Interesse. Diese weisen prozessintrinsische Defekte auf, die als Initiierungsstellen kurzer Ermüdungsrisse agieren. Im Rahmen der experimentellen Untersuchungen wurden zyklische R-Kurven für konventionellen und LPBF AISI-316L-Stahl ermittelt. Insbesondere wurde der Einfluss verschiedener Wärmebehandlungen (WB1: 450°C, WB2: 800°C und WB3: 900°C) auf das Wachstumsverhalten physikalisch kurzer Risse im LPBF-Material untersucht. Aufgrund hoher Eigenspannungen war die Ermittlung des Kurzrisswachstumsverhaltens bei WB1 nicht möglich. Für WB2 und WB3 ergaben sich sehr unterschiedliche zyklische R-Kurven. Untersuchungen der Eigenspannungen, der Bruchfläche (insbesondere der Rauheit) und der Mikrostruktur sollen die Ursachen für das unterschiedliche Verhalten erklären. Die Ergebnisse werden mit den Verhältnissen in konventionellem Material verglichen.
Das zyklische plastische Verformungsverhalten von additiv gefertigtem Edelstahl AISI 316L wurde in dehnungsgeregelten Kurzzeitfestigkeitsversuchen (LCF-Versuchen) untersucht. Dabei wurden zwei Wärmebehandlungszustände betrachtet: Beim ersten Zustand war die fertigungsbedingte zelluläre Struktur vorhanden, während sie durch die zweite Wärmebehandlung aufgelöst wurde. Untersuchungen im Transmissions-Elektronen-Mikroskop (TEM) zeigten, dass die zyklische Verformung die Zellstruktur lokal zerstörte und Gleitbänder entstanden, was die Entfestigung in diesem Fall erklärt. Für Material ohne Zellstrukturen resultierten nach zyklischer Verformung ähnliche Versetzungsstrukturen wie in konventionell gefertigtem (warmgewalzten) Material.
Several studies have been shown that the electron beam can be used to create nanomaterials from microparticle targets in situ in a transmission electron microscope (TEM). Here, we show how this method has to be modified in order to synthesize plasmonic gold nanoparticles (NPs) on insulating silicon oxide substrate by employing a scanning electron microscope with a comparatively low acceleration voltage of 30 kV. The synthesized NPs exhibit a random distribution around the initial microparticle target: Their average size reduces from 150 nm to 3 nm with growing distance to the initial Au microparticle target. Similarly, their average distance increases. The synthesized NP assemblies therefore show distinctly different plasmonic behaviour with growing distance to the target, which allows to study consequences of random hybridization of surface plasmon in disordered system, such as Anderson localization. To reveal the surface plasmons and their localization behaviour we apply electron energy loss spectroscopy in the TEM.
Several studies have shown that the electron beam (e-beam) can be used to create nanomaterials from microparticles in situ in a TEM. However, attempts to produce gold nanoparticles (NPs) on silicon oxide substrate remained to be accomplished. Here, we show that the production of gold NPs is possible by using the e-beam in a SEM, under a set of parameters. The NPs produced present a size gradient along the radial direction. A parameter study shows that the microparticles may: 1) flicker away without producing NPs, 2) fragment to form NPs and/or 3) react with the silicon oxide substrate, depending on the applied current. A hypothesis regarding the driving physical phenomena that lead the microparticles to fragment into NPs is discussed. Fabrication of gold NPs in the SEM provides a more cost-effective option as compared to the established method in the TEM.
Several studies have shown that the electron beam (e-beam) can be used to create nanomaterials from microparticles in situ in a TEM. However, attempts to produce gold nanoparticles (NPs) on silicon oxide substrate remained to be accomplished. Here, we show that the production of gold NPs is possible by using the e-beam in a SEM, under a set of parameters. To understand the physical mechanisms leading to the gold NPs, the mechanisms of e-beam induced charging as well as e-beam induced heating of the MPs were discussed. Several hints point to heating as the driving mechanism.