5 Werkstofftechnik
Filtern
Erscheinungsjahr
- 2019 (187) (entfernen)
Dokumenttyp
- Vortrag (73)
- Zeitschriftenartikel (55)
- Posterpräsentation (31)
- Beitrag zu einem Tagungsband (19)
- Buchkapitel (2)
- Sonstiges (2)
- Forschungsbericht (2)
- Monografie (1)
- Dissertation (1)
- Forschungsdatensatz (1)
Sprache
- Englisch (156)
- Deutsch (30)
- Mehrsprachig (1)
Schlagworte
- Corrosion (17)
- Additive Manufacturing (14)
- Glass (12)
- Carbon steel (8)
- Low Cycle Fatigue (8)
- Microstructure (7)
- CO2 (6)
- Degradation (6)
- Fatigue (6)
- Water content (6)
- Additive manufacturing (5)
- CCS (5)
- Ceramic (5)
- Crack growth (5)
- Crystallization (5)
- EBSD (5)
- Oxidation (5)
- 3D printing (4)
- LCF (4)
- Mikrostruktur (4)
- P92 (4)
- Ti-6Al-4V (4)
- Transmission electron microscopy (4)
- 316L (3)
- Alloy 2618A (3)
- Anisotropy (3)
- Carbon capture (3)
- Ceramic spring (3)
- Ceramics (3)
- DCB (3)
- Diesel (3)
- Diffraction (3)
- Diopside (3)
- Full-Notch Creep Test (FNCT) (3)
- High temperature corrosion (3)
- In situ (3)
- Modeling (3)
- Orientation (3)
- Pitting (3)
- Polymer (3)
- Sandwich (3)
- Simulation (3)
- Sintering (3)
- Slurry (3)
- Steel (3)
- Sulfidation (3)
- Tempered Martensite Ferritic Steels (3)
- Thermo-Mechanical Fatigue (3)
- Utilization (3)
- Water speciation (3)
- µ-gravity (3)
- 3D (2)
- AISI 316L (2)
- Additive Fertigung (2)
- Al-Cu-Li alloys (2)
- Alterung (2)
- Aluminium (2)
- Betriebsfestigkeit (2)
- Bioactive glass (2)
- Bioceramics (2)
- CCU (2)
- CCUS (2)
- CT (2)
- Capture (2)
- Carbon (2)
- Coarsening (2)
- Composite (2)
- Computed Tomography (2)
- Condensate (2)
- Condensation (2)
- Corrosion Fatigue (2)
- Crack Propagation (2)
- Crack propagation (2)
- Creep-Fatigue (2)
- Crevice corrosion (2)
- Crystal plasticity (2)
- Dehnungsfehler (2)
- Digital material representation (2)
- Distribution function (2)
- Ductile iron (2)
- Early oxidation (2)
- Elastic constants (2)
- Electron energy (2)
- Energy distribution (2)
- Extensometer (2)
- FeCr- alloys (2)
- Fiber reinforced polymer (2)
- Fracture surface analysis (2)
- Fraktografie (2)
- Geothermal (2)
- Glas (2)
- Glass fiber reinforced polymers (2)
- Glass-ceramic (2)
- High Alloyed Steel (2)
- High Temperature Testing (2)
- High temperature (2)
- IN 718 (2)
- IR (2)
- Impurities (2)
- Internal friction (2)
- Kavitation (2)
- Kikuchi pattern (2)
- Kleinprobenprüfung (2)
- Laminography (2)
- Layerwise (2)
- Layerwise slurry deposition (2)
- Lightweight materials (2)
- Material degradation (2)
- Microhardness (2)
- Mixed Ca-K-Na phosphates (2)
- Monte-Carlo Simulation (2)
- NMR spectroscopy (2)
- Na and K rhenanites (2)
- Niobium alloying (2)
- Non-destructive testing (2)
- Phase diagram (2)
- Phase transformations (2)
- Photon counting detector (2)
- Pipelines (2)
- Polyethylene, PE-HD (2)
- Polymer matrix composites (2)
- Pores (2)
- Powder (2)
- Probengrößeneffekt (2)
- Roughness (2)
- Röntgenbeugung (2)
- Röntgenrefraktion (2)
- Scale-bridging (2)
- Schadensanalyse (2)
- Schädigung (2)
- Selective laser melting (2)
- Silicon Carbide (2)
- Soda-lime silicate glass (2)
- Soda-lime-silica glass (2)
- Storage (2)
- Surface (2)
- Surface crystallization (2)
- Synthetic air (2)
- TMF (2)
- Temperaturschwankungen (2)
- Tensile Properties (2)
- Ti64 (2)
- TiAl5V4 (2)
- Titan (2)
- Titanium (2)
- Topografie (2)
- Utilization, and storage (CCUS) technology (2)
- VSSA (2)
- Vickers indentation (2)
- Virtual experiments (2)
- Weibull Distribution (2)
- Werkstoffprüfung (2)
- Wind energy (2)
- Wind turbine blades (2)
- Zero-g (2)
- Zugeigenschaften (2)
- Zugversuch (2)
- 3D imaging (1)
- 5G (1)
- AFM based test methods (1)
- AISI 304L (1)
- AM (1)
- Abrasion (1)
- Aggressive environment (1)
- Alkali-activated materials (1)
- Alumina (1)
- Aluminosilicate glasses (1)
- Analytische Zentrifuge (1)
- Anwendungen (1)
- Aquifer (1)
- Artificial weathering (1)
- Atomization (1)
- Aufbau von Festkörpern (1)
- Aussonderugnsrate (1)
- BTS (1)
- Berstdruck (1)
- Biodiesel (1)
- Biogeochemical cycling (1)
- Biomineralisation (1)
- Biopolymer (1)
- Blähen (1)
- Breakdown strength (1)
- Brittle fracture (1)
- Bruchflächenanalyse (1)
- Bubble formation (1)
- C. lap-shear (1)
- CALPHAD (1)
- CALPHAD databases analysis (1)
- CFRP (1)
- CO2 Corrosion (1)
- CO2 separation membranes (1)
- CO2-Speicherung (1)
- CO2-storage (1)
- Calcination (1)
- Calcium cobaltite (1)
- Calibration (1)
- Carbidic austempered ductile iron (1)
- Carbon Capture, Utilization and Storage (CCUS) (1)
- Carbon capture, utilization and storage technology (1)
- Carbon fibres (1)
- Carbon storage (1)
- Cavitation (1)
- Cellulose (1)
- Cement (1)
- Certification Standard 22 (1)
- Chalcogenides (1)
- Characterisation (1)
- Chemically Complex Alloy (1)
- Chemische Analyse (1)
- Chemo-mechanical coupling (1)
- Co-axial monitoring (1)
- Coefficient of thermal expansion (1)
- Complex concentrated alloy (CCA) (1)
- Contact angle (1)
- Contact fatigue (1)
- Copper vacancies (1)
- Corrosion and storage (CCUS) technology (1)
- Corrosion pits (1)
- Corrosion resistance (1)
- Crack arrest (1)
- Crack healing (1)
- Creep (1)
- Crosslinking (1)
- Crystal Plasticity Modelling (1)
- Crystal Texture (1)
- Crystal orientation (1)
- Cyclic softening (1)
- D. aging (1)
- D. creep D. viscoelasticity (1)
- DED-L (1)
- Damage (1)
- Dark-field transmission electron microscopy (DFTEM) (1)
- Data storage (1)
- Defects (1)
- Deformation behavior (1)
- Dense phase (1)
- Destabilization (1)
- Deuterium (1)
- Dielectric breakdown (1)
- Dielectric strength (1)
- Diesel Fuel (1)
- Dislocation (1)
- Dislocations (1)
- Distributed fiber optic sensing (1)
- Distributed fiber optic sensors (1)
- Droplet (1)
- Droplet corrosion (1)
- Druckgasspeicher (1)
- Dual-energy (1)
- Dynamic mechanical analysis (1)
- Dynamisch Mechanische Analyse (1)
- EASA (1)
- EIS (1)
- Early sulfidation (1)
- Eigenschaften (1)
- Electrochemical characterisation (1)
- Electrochemical deposition (1)
- Electrochemical dressing (1)
- Electrochemical impedance spectroscopy (1)
- Electromicroscopy (1)
- Electron backscattered diffraction (EBSD) (1)
- Electron microscopy (1)
- Electropolishing (1)
- Endurance Limit (1)
- Energiespeicherung (1)
- Environment (1)
- Environmental Stress Cracking (ESC) (1)
- Environmental stress cracking (1)
- Environmental stress cracking (ESC) (1)
- Environmentally assisted cracking (1)
- Ermüdung (1)
- Erneuerbare Energien (1)
- Explosionsschutz (1)
- Exposed metal sites (1)
- FSDC (1)
- Fabrication (1)
- Facilitated activation (1)
- Failure test (1)
- Faser-Kunststoff-Verbunde (1)
- Faserkunststoffverbunde (1)
- Fatigue Life Evaluation (1)
- Fatigue Testing (1)
- Fatigue crack propagation stages (1)
- Ferritic steels (1)
- Ferritic–martensitic steel (1)
- Fiber reinforced polymers (1)
- Fine Powder (1)
- Finite element analysis (1)
- Flowability (1)
- Foaming (1)
- Focused Ion Beam (1)
- Force-distance diagram (1)
- Four-point bending test (1)
- Fracture (1)
- Fracture mechanics (1)
- Freeze Drying (1)
- Freeze casting (1)
- Fresnoit (1)
- Friction Stir Welding (1)
- Frozen state photopolymerization (1)
- GFRP (1)
- Gasdetektion (1)
- Gassensorik (1)
- Gefügeuntersuchung (1)
- Glass ceramic (1)
- Glass matrix composite (1)
- Glass powder (1)
- Glass screening device (1)
- Glasspeicher (1)
- Gleichgewicht (1)
- Gold (1)
- Grain boundary (1)
- Grünfolieneigenschaften (1)
- HDPE Soprption (1)
- HDPE Sorption (1)
- Hard machining (1)
- Hardness (1)
- Heat treatment (1)
- Heißgasextraktion (1)
- Heißgaskorrosion (1)
- Hierarchical porosities (1)
- High alloyed steel (1)
- High entropy alloys (1)
- High pressure (1)
- High-entropy alloys (1)
- High-temperature corrosion (1)
- High-temperature oxidation (1)
- High-temperature properties (1)
- High-voltage testing (1)
- Hochentropielegierungen (1)
- Hochtemperaturermüdung (1)
- Honing (1)
- Honing Stone (1)
- Hydrogel (1)
- Hydrogen (1)
- Hydrogen diffusivity (1)
- Hygrothermal (1)
- Impact damage (1)
- In-situ Process Monitoring (1)
- Inclusion cluster (1)
- Inclusion size (1)
- Inconel 625 (1)
- Inconel 686 (1)
- Incremental lifetime models (1)
- Infrared nano AFM (1)
- Infrared spectroscopy (1)
- Intermodulation AFM (1)
- Internal Surfaces (1)
- Internal oxidation (1)
- Interphase (1)
- Ionic porosity (1)
- Iron meteorite (1)
- Irregular topography (1)
- Keramikfeder (1)
- Keramische Folien (1)
- Korrosion (1)
- Kreislaufwirtschaft (1)
- Kriechen (1)
- Kristallisation (1)
- Kristallsystem (1)
- Kurzfaser-verstärkte Thermoplaste (1)
- LMD (1)
- LSD print (1)
- LTCC multilayer (1)
- Langzeitstabilität (1)
- Laser Beam Melting (1)
- Laser Scanning Microscopy (1)
- Laser Scanning Microscopy (LSM) (1)
- Laser beam melting (1)
- Laser cladding (1)
- Laser-induced slip casting (1)
- Laserbearbeitung (1)
- Laserscanningmikroskopie (LSM) (1)
- Layer system (1)
- Layerwise Slurry Deposition (1)
- Lebensdauer (1)
- Long-term storage (1)
- Low cycle fatigue (1)
- MOF-74 (1)
- Machine Learning (1)
- Magmatic and hydrothermal processes (1)
- Magnetic domains (1)
- Magnetische Domänen (1)
- Magnetoelastic effect (1)
- Magnetoelastischer Effekt (1)
- Martensite (1)
- Mass transport (1)
- Materialkreislauf (1)
- Materialprüfung (1)
- Materials science (1)
- Mechanical behavior (1)
- Mechanical properties (1)
- Mehrachsige Verformung (1)
- Metal powder characterization (1)
- Metrology (1)
- Micro-shrinkages (1)
- Micromechanical model (1)
- Microstructure analysis (1)
- Microstructure characterisation (1)
- Microstructure evolution (1)
- Microstructure modification (1)
- Mikrostrukturuntersuchung (1)
- Mindedestberstdruck (1)
- Mini-UAV (1)
- Mis-match (1)
- Mixed-linkers (1)
- Modell (1)
- Moisture (1)
- Mortel (1)
- Multiaxial deformation (1)
- Multiple cracks (1)
- NDT (1)
- NMR (1)
- Nano particle (1)
- Nano screening (1)
- Nanocomposites (1)
- Nanomaterial (1)
- Nanoparticles (1)
- Natural (1)
- Neutron diffraction (1)
- New standards (1)
- Ni-Resist (1)
- Nitride (1)
- Non-destructive Materials (1)
- Non-metallic inclusions (1)
- Nondestructive testing (1)
- Normung (1)
- Ooxidation (1)
- Optical criterion (1)
- Orientation relationship (1)
- Oxidation protection (1)
- PE-HD Sorption (1)
- Parabolic flight (1)
- Particle size (1)
- Partikelgrößenverteilung (1)
- Permeability (1)
- Phase transformation (1)
- Phase-field (1)
- Phase-field simulation (1)
- Phosphate (1)
- Physically based material model (1)
- Pipeline (1)
- Pitting corrosion (1)
- Plastic deformation (1)
- Platinum-group-metals (1)
- Polyaniline (1)
- Polyethylen hoher Dichte (1)
- Polyurethane (1)
- Power plant (1)
- Power-to-Gas (1)
- Preceramic polymer (1)
- Pressure-assisted sintering (1)
- Process Monitoring (1)
- Process development (1)
- Process monitoring (1)
- Processing window (1)
- Pultruded fiber rods (1)
- REM (1)
- Referenzmaterial (1)
- Referenzorganismus (1)
- Referenzverfahren (1)
- Relaxation fatigue (1)
- Repair patch (1)
- Residual stress (1)
- Resonance testing (1)
- Restberstfestigkeit (1)
- Risikoanalyse (1)
- Rohrprobekörper (1)
- SDC (1)
- STEM (1)
- Safety (1)
- Sailplane Development Panel (1)
- Salt melt (1)
- Samarium doped ceria (1)
- Sample preparation (1)
- Sandwich structures (1)
- Scaffolds (1)
- Scanning Electron Microscopy (SEM) (1)
- Scanning electron microscopy (1)
- Scavenging effect of iron (1)
- Scratches (1)
- Semiconductor materials (1)
- Sensor (1)
- Sensorik (1)
- Silicoborate glasses (1)
- Silver glass paste (1)
- Sintern (1)
- Slip-rolling (1)
- Slow Crack Growth (SCG) (1)
- Slow crack growth (1)
- Soda-lime-silica (1)
- Sodium ion batteries (1)
- Sol-gel coating (1)
- Sorption (1)
- Spannungs-Dehnungs-Verhalten (1)
- Spannungsriss (1)
- Spar cap design (1)
- Spectroscopy (1)
- Spring constant (1)
- Spring constant (1)
- Standardisation (1)
- Stanzen (1)
- Statistics (1)
- Stress intensity factor (1)
- Stress-strain behavior (1)
- Streuung (1)
- Structural composites (1)
- Structural defects (1)
- Structural health monitoring (1)
- Structural steel (1)
- Struktur (1)
- Subcritical crack growth (1)
- Superalloy (1)
- Superconducting magnet (1)
- Supercritical CO2 (1)
- Supercritical/dense phase CO2 (1)
- Surface treatments (1)
- Swept wavelength interferometry (1)
- Synthesis (1)
- TEM (1)
- Tempered martensite ferritic steel (1)
- Tempered martensite ferritic steels (1)
- Tensile testing (1)
- Thermodynamic analysis (1)
- Thermoelectric properties (1)
- Thermomechanics (1)
- Thermomechanik (1)
- Thiol-ene click chemistry (1)
- ToF-SIMS (1)
- Transmission electron microscopy (TEM) (1)
- Tribologie (1)
- Tungsten-Rhenium (1)
- Ultrasound (1)
- Ungleichgewicht (1)
- Unlegierter Baustahl (1)
- VM12 SHC (1)
- Vacuum hot extraction (1)
- Vickers (1)
- Viscoelastic model (1)
- Viscous sintering (1)
- Viskoplastisch (1)
- WAXS (1)
- Wasserstoff (1)
- Wasserstofferzeugung (1)
- Werkstoffmechanische Prüfung (1)
- Wetting (1)
- Wind turbine blade shells (1)
- Windenergie (1)
- X-ray absorption spectroscopy (1)
- X-ray refraction (1)
- XRD (1)
- Young´s modulus (1)
- Zerstörungsfreie Prüfung (1)
- ZnO (1)
- Zug-Druck-Schubprüfung (1)
- alumina (1)
- arbidic austempered ductile iron (1)
- arbon capture (1)
- ausfgallfreie Lastwechsel (1)
- bioactive (1)
- biomaterials (1)
- bone (1)
- carbon steel (1)
- ceramics (1)
- coarsening (1)
- condensate (1)
- corrosion (1)
- electrochemical characterization (1)
- hardness (1)
- high pressure (1)
- impurities (1)
- infrared spectroscopy (1)
- microstructure analysis (1)
- phosphate glasses (1)
- pitting corrosion (1)
- selective laser melting (1)
- statistische Auswertung (1)
- utilization, and storage (CCUS) technology (1)
- volume resistivity (1)
- water speciation (1)
Organisationseinheit der BAM
- 5 Werkstofftechnik (187) (entfernen)
Eingeladener Vortrag
- nein (73)
The ferritic steel 13CrMo4-5 due to good properties with relation to attractive price is frequently use in power plants industry. According EN10028-2 this steel can be used up to 570 °C because of its creep behavior but its corrosion resistance limits the use frequently to lower temperatures, depending on gas temperature and slag formation. The corrosion test were performed in environment containing mixture of gases like: O2, COx, SOx and ashes, with elements e.g. Na, Cl, Ca, Si, C, Fe, Al. Exposure time was respectively 240 h, 1000 h and 4500 h in temperature 600 °C. The oxide scale on the 13CrMo4-5 steel was significant thicker than for In686 coating and the difference increase according for longer exposure time.
The microstructure, chemical and phase composition of the oxide scales were investigated by means of a light microscope, the electron scanning and transmission microscopes (SEM,TEM) equipped with the EDS detectors.
An overview of the BAM funed Focus Area Materials Project "AGIL" will be presented. AGIL focussed on the stdiy of the ageing characteristics of additively manufactured austenitic stainless steel with a "powder to mechanical failure" Approach. Recent Highlights are presented and a perspective for future studies.
In this study an approach for dressing metallic bonded honing stones with hard cutting grains on the basis of electrolysis is investigated. By a combination of concepts from electrochemical machining (ECM) and electropolishing a test rig was designed and put into operation. In general, it can be stated that the Approach investigated in this paper has proved to be a suitable dressing method for honing stones. However, the dressing result is highly dependent on bond components, cutting grain size and concentration which lead to local differences in the material removal and irregular topographies. This could be overcome, for example, by setting the dressing parameters more precisely based on the best results presented in this paper.
Despite of the significant advances in AM process optimization there is still a lack of experimental results and understanding regarding the mechanical behavior and microstructural evolution of AMparts, especially in loading conditions typical for safety-relevant applications e.g. in the aerospace or power engineering. Within the scope of the presented investigations, a characterization of the fatigue behavior of additively manufactured Ti-6Al-4V in the low cycle fatigue regime was carried out in the range of 0.3 to 1.0 % strain amplitude at room temperature, 250°C and 400°C. The Ti-6Al-4V specimens are machined out of lean cylindrical rods, which were fabricated using powder laser metal deposition (LMD) with an improved build-up strategy. The improved strategy incorporates variable track overlap ratios to achieve a constant growth in the shell and core area. The low-cycle-fatigue behavior is described based on cyclic deformation curves and strain-based fatigue life curves. The lifetimes are fitted based on the Manson-Coffin-Basquin relationship. A characterization of the microstructure and the Lack-of-Fusion (LoF)-defect-structure in the as-built state is performed using optical light microscopy and high-resolution computed tomography (CT) respectively. The failure mechanism under loading is described in terms of LoF-defects-evolution and crack growth mechanism based on an interrupted LCF test with selected test parameters. After failure, scanning electron microscopy, digital and optical light microscopy and CT are used to describe the failure mechanisms both in the longitudinal direction and in the cross section of the specimens. The fatigue lives obtained are comparable with results from previous related studies and are shorter than those of traditionally manufactured (wrought) Ti-6Al-4V. In this study new experimental data and understanding of the mechanical behavior under application-relevant loading conditions (high temperature, cyclic plasticity) is gained. Furthermore, a better understanding of the role of LoFdefects and AM-typical microstructural features on the failure mechanism of LMD Ti-6Al-4V is achieved.
Crack propagation in polymers: Separation of surface energy and irreversible deformation energy
(2019)
Fiber-reinforced-polymers (FRPs) are in current research focus in the lightweight construction industry, because of their extraordinary characteristics (stiffness and strength-to-density relation). The structure of polymer matrix and the interaction with reinforcement are crucial for optimization of the mechanical and thermal properties of FRPs. Due to the macromolecular chain structure, the mechanical properties of a polymer strongly vary with temperature: Below the glass transition, the chain segments of a polymer are “frozen”. Regarding fracture, the total changed energy during fracture if only dissipates for the generation of the new surfaces. However, in the region of the glass transition, the polymer chain segments start to get “unfrozen”, and the energy is not only required for generating new surfaces, but also for irreversibly deformation. This irreversible deformation is affected by the global temperature and the local temperature near the crack tip, which is affected by the local strain rate and crack propagation velocity.
Hence, in this research project, the irreversible deformation of neat and reinforced polymers will be controlled by changing the global temperature as well as the local temperature. With using different fracture experiments, the amount of energy required for creating new surfaces and for the irreversible deformation will be separated. This poster is the summary of the first part of the whole project. In the first part, the basic crack propagation theory for neat polymers is established and the special fracture experiment sample is prepared and tested at room temperature. In addition, the fracture experiment at room temperature is validated numerically.
Fiber-reinforced-polymers (FRPs) are in current research focus in the lightweight construction industry, because of their extraordinary characteristics (stiffness and strength-to-density relation). The structure of polymer matrix and the interaction with reinforcement are crucial for optimization of the mechanical and thermal properties of FRPs. Due to the macromolecular chain structure, the mechanical properties of a polymer strongly vary with temperature: Below the glass transition, the chain segments of a polymer are “frozen”. Regarding fracture, the total changed energy during fracture if only dissipates for the generation of the new surfaces. However, in the region of the glass transition, the polymer chain segments start to get “unfrozen”, and the energy is not only required for generating new surfaces, but also for irreversibly deformation. This irreversible deformation is affected by the global temperature and the local temperature near the crack tip, which is affected by the local strain rate and crack propagation velocity.
Hence, in this research project, the irreversible deformation of neat and reinforced polymers will be controlled by changing the global temperature as well as the local temperature. With using different fracture experiments, the amount of energy required for creating new surfaces and for the irreversible deformation will be separated. In this presentation, I summarized of the first 15 months the whole project. In this period, the basic crack propagation theory for neat polymers is established and the special fracture experiment sample is prepared and tested at room temperature. In addition, the model of the specimen is first established.
Der Aufbau der Werkstoffe wird durch Merkmale wie Bindungsart, atomare Strukturen, Kristallstrukturen einschließlich ihrer Gitterbaufehler, Körner und Phasen bestimmt. Die Mikrostruktur (Gefüge) stellt den Verbund der Kristalle, Phasen und Gitterbaufehler auf mikroskopischer und nanoskopischer Skala dar. Die Grundlagen der Phasenumwandlungen werden behandelt und die Bedeutung von Diffusionsprozessen erläutert. Werkstoffe sind bedeutend für Kultur, Wirtschaft, Technik und Umwelt. Ihre Herstellung benötigt Ressourcen und Energie. Recycling ist eine Möglichkeit zur Erhöhung der Ressourcenproduktivität.
Understanding the interaction between boehmite and epoxy and the formation of their interphases with different mechanical and chemical structures is crucial to predict and optimize the properties of epoxy-boehmite nanocomposites. Probing the interfacial properties with atomic force microscopy (AFM)-based methods, especially particle-matrix long-range interactions, is challenging. This is due to size limitations of various analytical methods in resolving nanoparticles and their interphases, the overlap of interphases, and the effect of buried particles that prevent the accurate interphase property measurement. Here, we develop a layered model system in which the epoxy is cured in contact with a thin layer of hydrothermally synthesized boehmite. Different microscopy methods are employed to evaluate the interfacial properties. With intermodulation atomic force microscopy (ImAFM) and amplitude dependence force spectroscopy (ADFS), which contain information about stiffness, electrostatic, and van der Waals forces, a soft interphase was detected between the epoxy and boehmite. Surface potential maps obtained by scanning Kelvin probe microscopy (SKPM) revealed another interphase about one order of magnitude larger than the mechanical interphase. The AFM-infrared spectroscopy (AFM-IR) technique reveals that the soft interphase consists of unreacted curing agent. The long-range electrical interphase is attributed to the chemical alteration of the bulk epoxy and the formation of new absorption bands.
Depending on the CO2 generating and the capture process as well as on consecutive purification steps applied, CO2 streams from different emitters may differ in their composition. When CO2 streams with different compositions are fed into a larger pipeline network, there are several aspects that must be considered: i) chemical reactions, such as acid formation, may occur within the joint CO2 stream; ii) there may be a variation of mass flow rate and CO2 stream composition within the pipeline network if the feed-in behavior of different CO2 sources changes with time. Potential impacts of changing CO2 stream compositions and mass flow rates in CCS cluster systems were investigated in the collaborative project "CLUSTER" (see also www.bgr.bund.de/CLUSTER). In this presentation, we focus on the experimental investigations of formation and condensation of strong acids and their impacts on the corrosion of pipeline steels. When SO2, NO2, O2 and H2O are present simultaneously in CO2 streams chemical cross-reactions may occur leading to the formation of strong acids such as sulfuric and nitric acid. To prevent this acid formation the concentration of at least one of these four impurities must be kept very low (e.g., Rütters et al., 2016). At temperatures below the acid dew point temperature, acids will condense, e.g., on pipeline steel surfaces. In turn, these acid condensates may trigger steel corrosion. To better understand the process of acid formation and condensation and its implications for steel corrosion, exposure tests were performed on pipeline steel X70 in dense CO2 with varying SO2, NO2 and O2 concentration under high pressure and at 278 K in an observable autoclave, in which water was added as droplets or as vapor. Further, electrochemical tests were carried out with X70 specimens immersed in 500 mL CO2-saturated synthetic condensate solution or in droplets of the same solution on the specimen’s surface. Depending on impurity concentrations in the CO2 streams, condensates consisting of different relative amounts of nitric and sulfuric acid were formed. In condensates containing both nitric and sulfuric acid, corrosion rates were higher than the sum of those of the individual acids. In addition, corrosion products and forms depended on the condensate composition. Investigations of water droplets on steel surfaces in impurity-containing dense-phase CO2 revealed the diffusion of SO2 and NO2, followed by cross-reactions forming corresponding acids. An increase in droplet size (from 1 to 5 µl) lead to higher corrosion rates. However, in comparison to measurements in bulk solution, corrosion reactions in droplets resulted in thick, high-resistance corrosion products and observed droplet corrosion rates were significantly lower. In addition, the possibility of acid droplet formation and growth in impure liquid CO2 is influenced by the wetting behavior of the acid droplet on the steel surface. Thus, the contact angle between a water droplet and the surface steel specimens in a CO2 atmosphere was investigated in a high pressure view cell following the sessile drop method. The contact angle wasand found to be larger at higher CO2 pressures (studied from 5 to 20 MPa) and at higher temperatures (e.g. 278 K to 333 K). Further, measured contact angles were larger on rough than on smooth metal surfaces. In addition, acid formation reduced the contact angle, i.e. lead to better wetting, thereby stimulating condensation that was followed by a corrosion process. These detailed insights on the complex interplay of acid formation, condensation, wetting behavior and corrosion allow a better assessment of material suitability for pipeline transportation of impure CO2 streams