Ingenieurwissenschaften und zugeordnete Tätigkeiten
Filtern
Erscheinungsjahr
- 2019 (976) (entfernen)
Dokumenttyp
- Vortrag (443)
- Zeitschriftenartikel (257)
- Posterpräsentation (116)
- Beitrag zu einem Tagungsband (104)
- Sonstiges (18)
- Forschungsbericht (10)
- Buchkapitel (9)
- Dissertation (6)
- Monografie (3)
- Zeitschriftenheft (Herausgeberschaft für das komplette Heft) (3)
Sprache
- Englisch (731)
- Deutsch (235)
- Mehrsprachig (8)
- Russisch (1)
- Spanisch (1)
Schlagworte
- Additive Manufacturing (47)
- Corrosion (45)
- Korrosion (33)
- Additive manufacturing (29)
- Additive Fertigung (20)
- Microstructure (17)
- Nanoparticles (17)
- Fluorescence (16)
- Computed tomography (15)
- Mechanochemistry (14)
- Residual stress (14)
- Nanoparticle (13)
- Quantum yield (13)
- Boehmite (12)
- Glass (12)
- In situ (12)
- Laser implantation (12)
- Lifetime (12)
- MIC (12)
- Surface functionalization (12)
- Thermografie (12)
- Welding (12)
- 316L (11)
- Laser beam welding (11)
- TiB2 (11)
- Wasserstoff (11)
- Computed Tomography (10)
- Hydrogen (10)
- Laser-induced periodic surface structures (LIPSS) (10)
- Nano (10)
- Nanocomposites (10)
- Nichtrostender Stahl (10)
- SAXS (10)
- Simulation (10)
- Thermography (10)
- Diffraction (9)
- Dye (9)
- Eigenspannungen (9)
- Friction (9)
- Surface texturing (9)
- TED-GC-MS (9)
- Wear (9)
- 3D printing (8)
- Carbon steel (8)
- Deckschichtbildung (8)
- Degradation (8)
- Korrosionsschutz (8)
- Magnetocaloric (8)
- Material Science (8)
- Nanomaterial (8)
- Photoluminescence (8)
- Qualitätssicherung (8)
- Steel (8)
- Zerstörungsfreie Prüfung (8)
- AISI D2 (7)
- Ageing (7)
- Applications (7)
- Gelartige Elektrolyte (7)
- Hochfeste Feinkornbaustähle (7)
- Kaltrisse (7)
- Laser Metal Deposition (7)
- Mechanical properties (7)
- Methanogens (7)
- NIR (7)
- Neutron Diffraction (7)
- Numerical simulation (7)
- Polymer (7)
- Polymers (7)
- Quantum dot (7)
- Schweißen (7)
- Synthesis (7)
- 3D Druck (6)
- CCS (6)
- Ceramic (6)
- Duplex (6)
- Energy harvesting (6)
- Epoxy (6)
- Fatigue (6)
- Femtosecond laser (6)
- Femtosecond laser ablation (6)
- Gefahrgut (6)
- Gefahrstoff (6)
- Implant-Test (6)
- Ink (6)
- KorroPad (6)
- Lanthanide (6)
- Laserstrahlschweißen (6)
- Low Cycle Fatigue (6)
- MAG-Schweißen (6)
- Microplastics (6)
- Nanocomposite (6)
- Non-destructive testing (6)
- Normung (6)
- Oxidation (6)
- Pitting (6)
- Prüfmethode (6)
- Ringversuch (6)
- Sensor (6)
- Validierung (6)
- Water content (6)
- AIS (5)
- AKR (5)
- AM (5)
- Archaeometry (5)
- Atomic Force Microscopy (AFM) (5)
- CO2 (5)
- Calibration (5)
- Cement (5)
- Characterization (5)
- Coating (5)
- Crack growth (5)
- Creep-resistant steel (5)
- Crystallization (5)
- Cyclization (5)
- Electron microscopy (5)
- Explosionsschutz (5)
- Finite element method (5)
- Flow cytometry (5)
- Hybrid Laser Arc Welding (5)
- Inks (5)
- Korrosionsprüfung (5)
- Künstliche Bewitterung (5)
- Laser Powder Bed Fusion (5)
- MALDI-TOF MS (5)
- Mechanical strength (5)
- Method (5)
- Modeling (5)
- Multiplexing (5)
- NDT (5)
- Non-Destructive testing (5)
- Photophysics (5)
- Polyaniline (5)
- Polylactide (5)
- Pyrotechnik (5)
- Quality assurance (5)
- Quantum dots (5)
- Reference materials (5)
- Residual Stress (5)
- Rigid amorphous fraction (5)
- SLM (5)
- Sicherheitstechnische Kenngrößen (5)
- Solidification cracking (5)
- Standardisation (5)
- Surface (5)
- Synchrotron (5)
- Ti-6Al-4V (5)
- Wärmeführung (5)
- X-ray refraction (5)
- X38CrMoV5-3 (5)
- XRD (5)
- Zink (5)
- Adjustment calculation (4)
- Aluminium (4)
- Analytische Zentrifuge (4)
- Assay (4)
- Bead (4)
- Biodiesel (4)
- Broadband dielectric spectroscopy (4)
- Catalysis (4)
- Composite (4)
- Copper (4)
- Coptic (4)
- Crevice corrosion (4)
- Direct energy deposition (4)
- Durability (4)
- ECA (4)
- EPDM (4)
- Eddy Current (4)
- Encoding (4)
- Environment (4)
- GMR (4)
- Geothermal (4)
- HNBR (4)
- Highspeed-plasma-laser-cladding (4)
- Hybride Gemische (4)
- IR (4)
- Innenhydrophobierung (4)
- Keyhole mode welding (4)
- Klebfestigkeit (4)
- L-PBF (4)
- LBM (4)
- Laser-induced X-ray emission (4)
- Laser-induced periodic surface structures, LIPSS (4)
- MOF (4)
- Manuscripts (4)
- Martensite (4)
- Mechanism (4)
- Metals (4)
- Mikroplastik (4)
- Mikrostruktur (4)
- NMR (4)
- Neutron diffraction (4)
- Open data (4)
- Open science (4)
- Particle size distribution (4)
- Polymers of intrinsic microporosity (4)
- Porosity (4)
- Post weld heat treatment (4)
- Radiation protection (4)
- Raman Spectroscopy (4)
- Residual stresses (4)
- Schadensanalyse (4)
- Schleifen (4)
- Specific heat spectroscopy (4)
- Surface chemistry (4)
- Thin films (4)
- Traceability (4)
- Transmission electron microscopy (4)
- UHPC (4)
- Ultraschall (4)
- Ultrashort laser material interaction (4)
- X-Ray Imaging (4)
- X-Ray imaging (4)
- X-ray computed tomography (4)
- XPS (4)
- Zinküberzüge (4)
- AFM (3)
- ATR (3)
- Absorption edge tomography (3)
- Additive Manufacturing (AM) (3)
- Alloy 2618A (3)
- Analytik (3)
- Anerkennungen (3)
- Anisotropy (3)
- Archaea (3)
- Atmosphärische Korrosion (3)
- AuNP (3)
- Auslagerungsversuche (3)
- Ausnahmegenehmigungen (3)
- Austenitic stainless steels (3)
- Barcoding (3)
- Bending modulus (3)
- Bimetallkorrosion (3)
- Carbon capture (3)
- Carbon nanotubes (3)
- Catalyst (3)
- Ceramic spring (3)
- Ceramics (3)
- Chemical composition (3)
- Composites (3)
- Corrosion monitoring (3)
- Crosslinking (3)
- Cyclic R-curve (3)
- DCB (3)
- Damage detection (3)
- Deposition welding (3)
- Dielectric spectroscopy (3)
- Diesel (3)
- Digitalization (3)
- Diopside (3)
- Discotic Liquid Crystals (3)
- Dosimetry (3)
- EBSD (3)
- EPMA (3)
- Einstufung (3)
- Electromagnetic Weld Pool Support (3)
- Element transport (3)
- End crater (3)
- Energy transfer (3)
- Erstarrungsriss (3)
- Explosionsgrenzen (3)
- FAME (3)
- FKM (3)
- FTIR (3)
- Festlegungen (3)
- Flame retardant (3)
- Flash DSC (3)
- Freibewitterung (3)
- Full Penetration (3)
- Full-Notch Creep Test (FNCT) (3)
- Geant4 (3)
- Graphene (3)
- Guideline (3)
- Haftfestigkeit (3)
- Harmonisation (3)
- Heat conduction (3)
- High power laser beam welding (3)
- High temperature corrosion (3)
- High-strength steels (3)
- Hot-Stamping (3)
- Hybrid laser-arc welding (3)
- IgG (3)
- InP (3)
- Inconel 718 (3)
- Indium phosphide (3)
- Inter-laboratory comparison (3)
- Kunststoffe (3)
- LCF (3)
- LIBS TIG welding (3)
- LLG (3)
- LPA (3)
- Laminography (3)
- Large-scale test (3)
- Laser Powder Bed Fusion (L-PBF) (3)
- Laser Pulver Auftragsschweißen (3)
- Laser beam melting (3)
- Laser metal deposition (3)
- Laserimplantation (3)
- MCS (3)
- Magnetohydrodynamics (3)
- Materials (3)
- Materials Science (3)
- Materials science (3)
- Microdosimetry (3)
- Micromagnetism (3)
- Moisture clog (3)
- Monte-Carlo simulation (3)
- Mueller-Matrix imaging ellipsometry (3)
- Nanofibers (3)
- Nanomaterialien (3)
- Non-destructiv testing (3)
- OECD (3)
- OOMMF (3)
- Orientation (3)
- Passivität (3)
- Phase transformation (3)
- Plastic (3)
- Polycarbonate (3)
- Polymer blends (3)
- Polymere (3)
- Polyurethane (3)
- Pores (3)
- Process monitoring (3)
- Protein G (3)
- Prüfrichtlinie (3)
- Prüfverfahren (3)
- Reflectography (3)
- Research data management (3)
- Restraint (3)
- Rheology (3)
- Richtlinien (3)
- Rigidity (3)
- Roughness (3)
- Rubber (3)
- Röntgenrefraktion (3)
- SWIR (3)
- Sauerstoff (3)
- Scanning electron microscopy (3)
- Selective Laser Melting (3)
- Selective laser melting (3)
- Sicherheitstechnische Bewertung (3)
- Slurry (3)
- Small-angle scattering (3)
- Spectroscopic ellipsometry (3)
- Spectroscopy (3)
- Spectroskopic Imaging (3)
- Stress relief cracking (3)
- Structural health monitoring (3)
- Sulfidation (3)
- Superplasticizer (3)
- Synchrotron tomography (3)
- TEKKEN-Test (3)
- Temperature (3)
- Tensile properties (3)
- Testing (3)
- Thermoelectrics (3)
- Thick Materials (3)
- Tribology (3)
- Tunnel (3)
- Uncertainty (3)
- Upconversion nanoparticle (3)
- Utilization (3)
- Water speciation (3)
- Weld pool shape (3)
- X-ray diffraction (3)
- X-ray scattering (3)
- XRF (3)
- Zinc coatings (3)
- Zugeigenschaften (3)
- Zulassungen (3)
- µ-gravity (3)
- Überzüge (3)
- 1H-NMR (2)
- 3D (2)
- AISI 316L (2)
- AKR-Betonversuche (2)
- ALD-Hybridprozesse (2)
- ASR (2)
- Absolute fluorometry (2)
- Acoustic Emission (2)
- Acoustic levitation (2)
- Adhesive joint (2)
- Adhäsion (2)
- Adsorbed layer (2)
- Adsorption (2)
- Advanced Materials (2)
- Advanced high strength steel (2)
- Aerosol measurements (2)
- Al2O3-Schichten (2)
- Altern (2)
- Antibody coating (2)
- Antikörper (2)
- Arabic Recipes (2)
- Armaturenprüfung (2)
- Artificial weathering (2)
- Atomic Layer Deposition (2)
- Auftragschweißen (2)
- Ausgleichungsrechnung (2)
- BAMline (2)
- BDS (2)
- Baustoffe (2)
- Bauteilprüfung (2)
- Beständigkeit (2)
- Beständigkeitsbewertungen (2)
- Betonfahrbahn (2)
- Bioactive glass (2)
- Bioceramics (2)
- Biofilm (2)
- Biofilmbildung (2)
- Biosensor (2)
- Boundary element method (2)
- Brechungsindex (2)
- Brexit (2)
- Brittle fracture (2)
- Building Materials (2)
- Bulging effect (2)
- C3A (2)
- CAT-Technologie (2)
- CCU (2)
- CCUS (2)
- CFK (2)
- CFRP (2)
- CLP (2)
- CLP-Verordnung (2)
- CMAS (2)
- COD-AGE (2)
- CT (2)
- Capture (2)
- Carbon (2)
- Chaboche model (2)
- Chemikalienrecht (2)
- Chemisch instabile Gase (2)
- Cleavable probe (2)
- Coarsening (2)
- Compatibility (2)
- Compatibility evaluations (2)
- Composite-Druckgefäß (2)
- Compressive Cyclic loading (2)
- Condensate (2)
- Condensation (2)
- Contact resonance (2)
- Continuum mechanics (2)
- Copolymer (2)
- Corrosion Fatigue (2)
- Corrosion inhibition (2)
- Corrosion products (2)
- Corrosion rate (2)
- Corrosion testing (2)
- Crack Propagation (2)
- Crack propagation (2)
- Crevice (2)
- Crystal plasticity (2)
- Cultural heritage (2)
- Cytotoxicity (2)
- DED (2)
- DIN EN 16516 (2)
- DLO (2)
- DNA (2)
- DNA damage (2)
- Damage (2)
- Dangerous goods (2)
- Database (2)
- Deckschichten (2)
- Defokussierung (2)
- Dehnungsfehler (2)
- Delayed addition (2)
- Desiccation (2)
- Desinfection (2)
- Diffusion (2)
- Digital (2)
- Digital image correlation (2)
- Digital material representation (2)
- Digital twin (2)
- Dilatometry (2)
- Direct Energy Deposition (2)
- Direct Laser Metal Deposition (2)
- Distributed fibre optic sensing (2)
- Drinking (2)
- Druckbehältern (2)
- Dual phase steel (2)
- Duplexstahl (2)
- EOS (2)
- EPR (2)
- EU FP7 project NanoValid (2)
- Early hydration (2)
- Early oxidation (2)
- Elastic constants (2)
- Electron energy (2)
- Electron probe microanalysis (EPMA) (2)
- Electronic Detonators (2)
- Elektrochemie (2)
- Elemental composition (2)
- Ellipsometrie (2)
- Ellipsometry (2)
- End-crater (2)
- Endkrater (2)
- Energetic Materials (2)
- Energy deposit (2)
- Energy distribution (2)
- Environmental Simulation (2)
- Erdboden (2)
- Exchange interaction (2)
- Explosivstoffe (2)
- Extensometer (2)
- FT-IR (2)
- Faserverbund (2)
- Faserverbundwerkstoff (2)
- Fatigue crack growth (2)
- Fatigue crack propagation (2)
- FeCr- alloys (2)
- Ferromagnetism (2)
- Fiber reinforced polymer (2)
- Finite-Elemente-Methode (2)
- Formaldehyd (2)
- Fracture mechanics (2)
- Fracture surface analysis (2)
- Fragmentation (2)
- Fraktografie (2)
- Frequenzanalyse (2)
- Fräsen (2)
- Fume (2)
- Funtional Groups (2)
- GFK (2)
- GFRP (2)
- GHS (2)
- GTN model (2)
- Gas-Staub-Gemische (2)
- Gefährliche Stoffe (2)
- Gel-type electrolytes (2)
- Geothermal energy (2)
- Glass transition (2)
- Glass-ceramic (2)
- Gold (2)
- HAZPRED (2)
- HI-Tension (2)
- HPC (2)
- Haftvermittler (2)
- Harmonised Standards (2)
- Hazardous substances (2)
- Heat treatment (2)
- Heizöl (2)
- Heißriss (2)
- Herceptin (2)
- High Alloyed Steel (2)
- High Temperature Testing (2)
- High temperature (2)
- High-entropy alloys (2)
- High-performance concrete (2)
- High-pressure (2)
- High-strength concrete (2)
- High-strength steel (2)
- Hochfester Feinkornbaustahl (2)
- Hot cracking (2)
- Hot steam (2)
- Hybrid composite pressure vessel (2)
- Hydrogen assisted cracking (2)
- Hydrogen-assisted cracking (2)
- Hydrothermal treatment (2)
- Höherfester Feinkornbaustahl (2)
- IN 718 (2)
- Immunoassay (2)
- Immunocapture (2)
- Immunoglobulins (2)
- Immunoprecipitation (2)
- Immunosensor (2)
- Impurities (2)
- In situ Monitoring (2)
- In situ measurement (2)
- Innovation (2)
- Integrated analysis (2)
- Integrating sphere spectroscopy (2)
- Integrierte Analyse (2)
- Interlaboratory comparison (2)
- Internal friction (2)
- Interphase (2)
- Iridium-titanium mixed oxides (2)
- Iron (2)
- Irradiation (2)
- Kaltrissprüfung (2)
- Kavitation (2)
- Kennzeichnung (2)
- Keyhole mode laser beam welding (2)
- Kikuchi pattern (2)
- Kleb- und Haftfestigkeit (2)
- Kleinprobenprüfung (2)
- Kontinuumsmechanik (2)
- Korrosionsuntersuchungen (2)
- Kältemittel (2)
- LEE (2)
- LIMS (2)
- LMD (2)
- LME (2)
- LTT (2)
- Lamb waves (2)
- Landau Lifshitz equation (2)
- Laser (2)
- Laser Beam Melting (2)
- Laser Beam Welding (2)
- Laser cladding (2)
- Laser dispersing (2)
- Laserhybridschweißen (2)
- Laserschutz (2)
- Layer formation (2)
- Layerwise (2)
- Lean Duplex (2)
- Lebensdauerversuche (2)
- Localised corrosion (2)
- Lochkorrosion (2)
- Longitudinal Wave (2)
- Lubricants (2)
- MHD (2)
- MVT (2)
- Magnesium alloy (2)
- Magnetic moment (2)
- Magnetocaloric effect (2)
- Marktüberwachung (2)
- Mass spectrometry (2)
- Material degradation (2)
- Material science (2)
- Materialbearbeitung (2)
- Mehrprobenprüfung (2)
- Melting (2)
- Mesoporous thin films (2)
- Messunsicherheit (2)
- Metallene Werkstoffe (2)
- Metallic seal (2)
- Metallische Materialien (2)
- Metal–organic frameworks (2)
- Methane (2)
- Metrology (2)
- Microbiologically influenced corrosion (2)
- Microcracking (2)
- Microhardness (2)
- Mikroskaliert (2)
- Mixed Ca-K-Na phosphates (2)
- Modelling (2)
- Moisture transport (2)
- Molecular masses (2)
- Molten pool dynamics (2)
- Monte Carlo (2)
- Multi-layered system (2)
- Multiple cracks (2)
- Müller-Matrix-Ellipsometrie (2)
- NEXAFS (2)
- NMR spectroscopy (2)
- Na and K rhenanites (2)
- NanoSIMS (2)
- Nanocharacterisation (2)
- Nanomechanics (2)
- Nanoplastics (2)
- Nanoskaliert (2)
- Nanostructure (2)
- NiCrBSi (2)
- Nichtmetallische Materialien (2)
- Non destructive analytical techniques (2)
- Non destructive testing (2)
- Non-metallic inclusions (2)
- Nondestructive testing (2)
- Normen (2)
- OH radicals (2)
- Oberflächenenergie (2)
- Oberflächengeometrie (2)
- Object oriented micromagnetic framework (2)
- On-site mixed Explosives (2)
- Online Process Monitoring (2)
- Optical Tomography (2)
- Organic peroxides (2)
- Oriented immobilization (2)
- PEG (2)
- POD (2)
- Papyrus (2)
- Partial penetration (2)
- Particle gas emission (2)
- Particle size distributuion (2)
- Phase composition (2)
- Phase diagram (2)
- Phase transformations (2)
- Phononischer Kristall (2)
- Photon counting detector (2)
- Photoresist (2)
- Physikalische Gefahren (2)
- Pipeline (2)
- Pipeline steel X120 (2)
- Pipelines (2)
- Pitting corrosion (2)
- Plasma (2)
- Plasma-Transferred-Arc (2)
- Plume (2)
- Polyamide 12 (2)
- Polycarboxylate ether (PCE) (2)
- Polyethylene (2)
- Polyethylene glycol (2)
- Polyethylene, PE-HD (2)
- Polymer bilayer coatings (2)
- Polymer materials (2)
- Polymer matrix composites (2)
- Polymer nanocomposites (2)
- Powder (2)
- Powder Bed Fusion (2)
- Presshärten (2)
- Probe (2)
- Probengrößeneffekt (2)
- Process simulation (2)
- Protein A (2)
- Proximity-enhanced reaction (2)
- Prozesskette (2)
- Prüfmethoden (2)
- Pufferschichten (2)
- Pyrotechnics (2)
- QSPR (2)
- Quantitative Analysis (2)
- RSW (2)
- Radiationtherapy (2)
- Radioactive decay (2)
- Raman spectroscopy (2)
- Reheat cracking (2)
- Resistance spot welding (2)
- Resonance frequency (2)
- Rissbildung in Stahl (2)
- Round robin test (2)
- Rubber seal (2)
- Rundnaht (2)
- Röntgenbeugung (2)
- Röntgenemission (2)
- Scale-bridging (2)
- Scaled Boundary FEM (2)
- Schadenserkennung (2)
- Schallemission (2)
- Schallemissionsprüfung (2)
- Schallerzeuger (2)
- Schwingfestigkeit (2)
- Schädigung (2)
- Seal performance (2)
- Sekundärstrahlung (2)
- Selected Laser Melting (2)
- Self-reactive substances (2)
- Semiconductor nanocrystal (2)
- Sensibilisierung (2)
- Sensitization (2)
- Shore hardness (2)
- Silica beads (2)
- Silica nanoparticles (2)
- Silicon (2)
- Single particle spectroscopy (2)
- Sintering (2)
- Small angle scattering (2)
- Small-angle X-ray scattering (2)
- Soda-lime silicate glass (2)
- Soda-lime-silica glass (2)
- Software (2)
- Solidification (2)
- Spatter (2)
- Spectral sensitivity (2)
- Speed of sound (2)
- Stainless (2)
- Stainless Steel (2)
- Stainless steel (2)
- Standardization (2)
- Standards (2)
- Stochastic Landau Lifshitz Gilbert equation (2)
- Storage (2)
- Structural anomalies (2)
- Structural inhomogenities (2)
- Sulfate reducing bacteria (2)
- Superelliptic Lamé curves (2)
- Surface crystallization (2)
- Surface modification (2)
- Sustainability (2)
- Synthetic air (2)
- TMDSC (2)
- Tausalzeintrag (2)
- Technical Specification (2)
- Temeprature scaling (2)
- Temperature dependency (2)
- Temperature field (2)
- Temperaturschwankungen (2)
- Tensile Properties (2)
- Ternary quantum dots (2)
- Test method (2)
- Testing method (2)
- Thermal degradation (2)
- Thermal treatment (2)
- Thin polymer films (2)
- Thin polymeric films (2)
- Ti64 (2)
- TiAl5V4 (2)
- Titan (2)
- Titanium (2)
- Topografie (2)
- Tribofilm (2)
- Tribologie (2)
- Tungsten carbide (2)
- UN-GHS (2)
- UV degradation (2)
- Ultrakurze Laserpulse (2)
- Ultraschallunterstütztes Zerspanen (2)
- Ultrasonic Transducer (2)
- Ultrasonic testing (2)
- Upconversion (2)
- Upconversion nanoparticles (2)
- Utilization, and storage (CCUS) technology (2)
- VAMAS (2)
- VSSA (2)
- Validation (2)
- Variational calculus (2)
- Variationsrechnung (2)
- Verbundfestigkeit (2)
- Verifizierung (2)
- Virtual experiments (2)
- Water (2)
- Wear resistance (2)
- Weathering (2)
- Weld metal (2)
- Weld pool behavior (2)
- Weld pool shape approximation (2)
- Wellenprüfung (2)
- Werkstoffprüfung (2)
- Wind energy (2)
- Wirbelstromprüfung (2)
- X-ray CT (2)
- X-ray and electron diffraction (2)
- X-ray refraction techniques (2)
- X-ray-CT (2)
- Zero-g (2)
- Zerspanbarkeitsanalysen (2)
- Zinc coated steel (2)
- Zinkdeckschichten (2)
- Zirconia (2)
- Zonation (2)
- Zugversuch (2)
- Zuverlässigkeit (2)
- Zündenergie (2)
- Zündquellen (2)
- additive manufacturing (2)
- corrosion (2)
- fluorescence (2)
- low energy electrons (2)
- particle scattering (2)
- Überlappbereich (2)
- 16S rRNA gene (1)
- 18HLT01 MetVes II (1)
- 1D-Simulation (1)
- 2,6-diaminopyridine (1)
- 2D nanomaterials (1)
- 3D coherence scanning interferometry (CSI) (1)
- 3D imaging (1)
- 3D inspection (1)
- 3D-Printing (1)
- 3d structuring (1)
- 5G (1)
- 60 °C-Betonversuch (1)
- ABID (1)
- ACM (1)
- ADN Tabelle C (1)
- AEROSIL® OX50 (1)
- AET (1)
- AFM based test methods (1)
- AFM-IR (1)
- AFM-Kraft-Abstand-Kurven (1)
- AGIL (1)
- AIS QD (1)
- AISI 304L (1)
- AISI 321 stainless steel (1)
- AKR, Betonfahrbahndecke, Tausalzeintrag, Innenhydrophobierung (1)
- AM IN718 alloy (1)
- AXRD (1)
- Abrasion (1)
- Abrasive belt (1)
- Abtragende Glasbearbeitung (1)
- Accelerator (1)
- Acetone (1)
- Acoustic Emission (AE) (1)
- Acoustic emission (1)
- Acoustic emission analysis (1)
- Acoustic insulation (1)
- Acrylamide (1)
- Activation energy (1)
- Active Matter (1)
- Active thermography (1)
- Actuating materials (1)
- AdCo Explosives (1)
- Additiv (1)
- Additives (1)
- Admixture (1)
- Admixtures (1)
- Advanced high strength steels (1)
- Advanced materials (1)
- Affinity chromatography (1)
- Affinitätschromatographie (1)
- Affinitätsextraktion (1)
- Africa (1)
- Ageing behaviour (1)
- Ageing treatment (1)
- Aggressive environment (1)
- Aging tests (1)
- Aktive Thermographie (1)
- Akustischer Isolator (1)
- Al-Composite (1)
- Al-Cu-Li alloys (1)
- Al/SiO2 composite (1)
- Alcohols (1)
- Alite (1)
- Alkali-Kieselsäure Reaktion (1)
- Alkali-Kieselsäure-Reaktion (1)
- Alkali-activated materials (1)
- Alkali-silica reaction (1)
- Alkali-silica-reaction (1)
- Alkoxysilanes (1)
- Alpha (1)
- Alterung (1)
- Alumina (1)
- Aluminium-Druckguss (1)
- Aluminiumlegierungen (1)
- Aluminosilicate glasses (1)
- Aluminum alloy (1)
- Ameisensäure (1)
- Amplicon sequencing (1)
- Analysis (1)
- Anatase (1)
- Aneurism (1)
- Anisotropy estimate (1)
- Anoxia (1)
- Antibacterial (1)
- Antibodies (1)
- Antifouling surface coatings (1)
- Antifriction coefficient (1)
- Antimicrobial (1)
- Antiviral activity (1)
- Anwendungen (1)
- Approval (1)
- Aquifer (1)
- Arabic recipes (1)
- Arbitrary trajectories (1)
- Architecture (1)
- Arrhenius (1)
- Artungleiche Werkstoffe (1)
- Atemluftflasche (1)
- Atemschutz (1)
- Atomic force microscopy (1)
- Atomic fraction (1)
- Atomization (1)
- Aufbau von Festkörpern (1)
- Auftriebskräfte (1)
- Ausbildung (1)
- Auslaugung (1)
- Austenitic stainless steel (1)
- Autocorrelation (1)
- Automated expansion measurement (1)
- Automation (1)
- Automatische Dehnungsmessung (1)
- Automobilindustrie (1)
- BAM-Liste (1)
- BODIPY (1)
- BREXIT (1)
- BTS (1)
- Bacteria (1)
- Bacterial adhesion (1)
- Ball milling (1)
- Baumusterprüfungen (1)
- Bead-based assay (1)
- Beamline (1)
- Beanspruchungsanalyse (1)
- Beförderung gefährlicher Güter (1)
- Benannte Stellen (1)
- Bench braking sequence (1)
- Beschichtung (1)
- Bestimmung der Messunsicherheit (1)
- Beständigkeit in Biokraftstoffen (1)
- Beständigkeitsbewertung (1)
- Beta decay (1)
- Betriebsfestigkeit (1)
- Bewegtes Gitter (1)
- Bindemittel (1)
- Binnenwasserstraßen (1)
- Bio-based concrete (1)
- Biochip (1)
- Bioconjugation (1)
- Biofunctional Molecules (1)
- Biogene Brennstoffe (1)
- Biogeochemical cycling (1)
- Biomineralisation (1)
- Biopolymer (1)
- Biopolymers (1)
- Black Ink (1)
- Bloch wall (1)
- Blähen (1)
- Boehmite alumina (1)
- Boehmite nanoparticles (1)
- Bondline (1)
- Borosilikatglas (1)
- Brachytherapy (1)
- Braking load history (1)
- Brass (1)
- Breakdown strength (1)
- Brightness (1)
- Broadband dielectric microscopy (1)
- Bruchflächenanalyse (1)
- Bruchmechanik (1)
- Bubble formation (1)
- Build Angle (1)
- Bulge (1)
- Bulging (1)
- Bulk material (1)
- Bulk properties ageing (1)
- Bulk temperature (1)
- Bundesoberbehörden (1)
- Böden (1)
- Böhmit (1)
- C-C coupling (1)
- C. lap-shear (1)
- C3S (1)
- CAFTP (1)
- CALPHAD (1)
- CALPHAD databases analysis (1)
- CE-ICP-MS (1)
- CO2 Corrosion (1)
- CO2 separation membranes (1)
- CO2-Corrosion (1)
- CO2-Speicherung (1)
- CO2-storage (1)
- COK-12 (1)
- Cable (1)
- Calcination (1)
- Calcium cobaltite (1)
- Calcium peroxid (1)
- Calcium phosphate (1)
- Calculation time (1)
- Cancer (1)
- Cancer treatment (1)
- Carbide (1)
- Carbon Capture, Utilization and Storage (CCUS) (1)
- Carbon capture, utilization and storage technology (1)
- Carbon dioxide (1)
- Carbon dot (1)
- Carbon fibers (1)
- Carbon storage (1)
- Carrier gas hot extraction (1)
- Catalysts (1)
- Catch and release assay (1)
- Catechol (1)
- Cationic photocuring (1)
- Cavitation (1)
- Cell (1)
- Cell size (1)
- Cellulose (1)
- Cement admixtures (1)
- Cement hydration (1)
- Cement paste (1)
- Central Taurus (1)
- Centrifugal Adhesion Testing (1)
- Centrifugal Adhesion Testing (CAT) (1)
- Centrifugal Force (1)
- Certification Standard 22 (1)
- Certified reference materials (1)
- Certified standards (1)
- Characterisation (1)
- Chargenprüfung (1)
- Chemical admixtures (1)
- Chemical durability (1)
- Chemically Complex Alloy (1)
- Chemische Analyse (1)
- Chemo-mechanical coupling (1)
- Chloridbelastete Stahlbetonbauwerke (1)
- Chunky graphite (1)
- Circumferential weld (1)
- Circumferential welds (1)
- Civil Engineering (1)
- Classification (1)
- Cleavable linker (1)
- Click chemistry (1)
- Climate responsive materials (1)
- Cluster (1)
- Co (1)
- Co-axial monitoring (1)
- Co-crystal (1)
- CoO (1)
- Coal dust (1)
- Coarse-grained heat-affected zone (1)
- Cob (1)
- Cobalt (1)
- Cobalt and zinc oxides (1)
- Cocrystal (1)
- Codicology (1)
- Coefficient of thermal expansion (1)
- Coherent exchange (1)
- Cohesive Elements (1)
- Colored glasses (1)
- Combinatorial chemistry (1)
- Combinatorial polymer libraries (1)
- Community composition (1)
- Comparability of Measurement Results (1)
- Compatibility evaluation (1)
- Complex concentrated alloy (CCA) (1)
- Composite pressure vessel (1)
- Compression behavior (1)
- Compression set (1)
- Compression test (1)
- Compressive Stress (1)
- Computed tomography (CT) (1)
- Computer-Tomographie (1)
- Computertomographie (1)
- Concrete Prism Test at 60 °C (1)
- Concrete bridges (1)
- Concrete motorway pavements (1)
- Conductivity (1)
- Conductometry (1)
- Conference (1)
- Conjugates (1)
- Contact angle (1)
- Contact fatigue (1)
- Content of calcium peroxide (1)
- Controlled atmosphere (1)
- Convection coefficient (1)
- Copper-based wood preservatives (1)
- Coputed tomography (1)
- Cordierite (1)
- Core/shell quantum dot (1)
- Corrosion and storage (CCUS) technology (1)
- Corrosion pits (1)
- Corrosion product (1)
- Corrosion resistance (1)
- Coupled corrosive and mechanial load (1)
- Coupled corrosive/mechanical load (1)
- Crack (1)
- Crack arrest (1)
- Cracking (1)
- Creep (1)
- Cristobalite frameworks (1)
- Critical pitting temperature (1)
- Critical strain (1)
- Crosslinker (1)
- Crosslinking density (1)
- Cryogenic Engineering (1)
- Cryogenic Steel (1)
- Crystal Plasticity Modelling (1)
- Crystal Texture (1)
- Crystal orientation (1)
- Crystalline cones (1)
- Curie temperature (1)
- Curing (1)
- Curved surfaces (1)
- Cyclic (1)
- Cyclic J-integral (1)
- Cyclic R-curve analysis (1)
- Cyclic softening (1)
- Cycloaliphatic epoxy oligosiloxane (1)
- Cycloalyphatic epoxy oligosiloxane (1)
- D. aging (1)
- D. creep D. viscoelasticity (1)
- DED-L (1)
- DFG SPP 2005 (1)
- DIC assisted compression (1)
- DIN 50929-3 (1)
- DIN EN 717-1 (1)
- DIN EN ISO/IEC 17025:2018 (1)
- DMA (1)
- DPA (1)
- DRIFTS (1)
- Damage detection and localisation (1)
- Damage tolerant component design (1)
- Damping factor (1)
- Dangerous Goods (1)
- Dark-field transmission electron microscopy (DFTEM) (1)
- Data Processing (1)
- Data fusion (1)
- Data processing (1)
- Data storage (1)
- Dauerhaftigkeit (1)
- Dead Sea Scrolls (1)
- Dealloying (1)
- Declarations of conformity (1)
- Deep learning (1)
- Defect detection (1)
- Defect photoluminescence (1)
- Defects (1)
- Defekte Eigenspannung (1)
- Definition of nanomaterial (1)
- Deformation behavior (1)
- Denkmalpflege (1)
- Dense phase (1)
- Density Functional Theory (1)
- Destabilization (1)
- Deuterium (1)
- Diagnostic antibodies (1)
- Dichtmaterial (1)
- Dichtungswerkstoffe (1)
- Dielectric breakdown (1)
- Dielectric strength (1)
- Diesel Fuel (1)
- Digital Volume Correlation (1)
- Digitalisierung (1)
- Dipole moment (1)
- Directed Energy Deposition (1)
- Directed energy deposition (1)
- Dislocations (1)
- Dispersion of nano materials (1)
- Dissimilar metal weld overlays (1)
- Distortion (1)
- Distortion simulation (1)
- Distributed fiber optic sensing (1)
- Distributed fiber optic sensors (1)
- Distributed humidity sensor (1)
- Distributed sensor (1)
- Domain wall (1)
- Double complex salts (1)
- Drinking water (1)
- Drop test (1)
- Droplet (1)
- Droplet corrosion (1)
- Druckgasbehälter (1)
- Druckstabilität (1)
- Drug (1)
- Dual Energy Imaging (1)
- Dual energy (1)
- Dual sensing (1)
- Dual-Energy (1)
- Dual-energy (1)
- Ductile iron (1)
- Durability testing (1)
- Dye degradation (1)
- Dye labeling (1)
- Dynamic heterogeneity (1)
- Dynamic mechanical analysis (1)
- Dynamisch Mechanische Analyse (1)
- Dünne Schichten (1)
- E10 (Kraftstoff mit bis zu 10% Ethanol) (1)
- EASA (1)
- EC4SafeNano (1)
- EDX Analysis (1)
- EIS (1)
- ELISA (1)
- EMPIR (1)
- EMPIR project (1)
- ESI MS (1)
- Early sulfidation (1)
- Eddy current testing (1)
- Editorial (1)
- Editorial Board (1)
- Education (1)
- Eexisting structures (1)
- Efficient modelling (1)
- Eigenschaften (1)
- Eigenspannung (1)
- Einspanngrad (1)
- Einstufungskriterien (1)
- Elastic Constants (1)
- Elastin (1)
- Elastomerdichtung (1)
- Elastomere (1)
- Electrical conductivity (1)
- Electro-fused zirconia (1)
- Electro-thermomechnical model (1)
- Electrochemical characterisation (1)
- Electrochemical deposition (1)
- Electrochemical deposition (ECD) (1)
- Electrochemical impedance spectroscopy (1)
- Electrochemical potentiodynamic reactivation (1)
- Electrochemical sensing (1)
- Electrochemistry (1)
- Electrode geometry (1)
- Electromagnetic radiation (1)
- Electromagnetic scattering (1)
- Electromagnetic stirring (1)
- Electromagnetic weld pool support (1)
- Electromicroscopy (1)
- Electrospun fibers (1)
- Elektromagnetische Porenreduktion (1)
- Elektromagnetische Schmelzbadunterstützung (1)
- Elektromagnetsiche Schmelzbadbeeinflussung (1)
- Elektronische Zündesysteme (1)
- Elemenet transport (1)
- Elevated temperatures (1)
- Ellipsometric porosimetry (1)
- Emerging technologies (1)
- Emissionsprüfkammer (1)
- Emissionsprüfung (1)
- Enamels (1)
- Endurance Limit (1)
- Energiedissipation im Kontakt (1)
- Energy (1)
- Energy systems (1)
- Engine oil design (1)
- Engine oil testing (1)
- Engineering (1)
- Engineering applications (1)
- Environmental Stress Cracking (ESC) (1)
- Environmental simulation (1)
- Environmental stress cracking (1)
- Environmental stress cracking (ESC) (1)
- Environmentally assisted cracking (1)
- Epoxy conversion degree (1)
- Epoxy-Anhydrid Duroplast (1)
- Equivalent heat source (1)
- Ermüdung (1)
- Europium (1)
- Europäisches Übereinkommen (1)
- Evolution of bulk properties (1)
- Exchange length (1)
- Excitation power density (1)
- Experimental design (1)
- Explosion limits (1)
- Explosion protection (1)
- Explosionsartiges Abplatzen (1)
- Explosionsgefährliche Eigenschaften (1)
- Explosive spalling (1)
- Explosivplattieren (1)
- Explosivstoofe (1)
- Exposed metal sites (1)
- Extracellualr vesicles (1)
- Extracellular matrix (1)
- Extracellular vesicles (EV) (1)
- FIB/SEM (1)
- FLIM (1)
- FPLC (1)
- FRET (1)
- FSDC (1)
- FTIR spectroscopy (1)
- Fabrication (1)
- Facades (1)
- Facilitated activation (1)
- Fahrbahndeckenbetone (1)
- Failure test (1)
- Faser-Kunststoff-Verbunde (1)
- Faserkunststoffverbunde (1)
- Fast scanning calorimeter (1)
- Fast scanning calorimetry (1)
- Fast scanning calormetry (1)
- Fatigue Crack Propagation (1)
- Fatigue Life Evaluation (1)
- Fatigue S-N curve (1)
- Fatigue Testing (1)
- Fatigue crack propagation stages (1)
- Fatigue strength (1)
- Fatigue strength and life (1)
- Fatigue tests (1)
- Fe (1)
- Fe-Ni (1)
- Fe2TiO5 (1)
- Feinkornbaustahl (1)
- Ferritic spheroidal graphite cast iron (1)
- Ferritic steels (1)
- Ferritic–martensitic steel (1)
- Ferumoxytol (1)
- Festphasenextraktion (1)
- Feuerwehr (1)
- Fiber Bragg grating (FBG) (1)
- Fibres (1)
- Filtered back projection (1)
- Filters (1)
- Fine Powder (1)
- Fine-grained Steel (1)
- Fingerprint (1)
- Finite element analysis (1)
- Finite elements (1)
- Finite-element method (1)
- Fire (1)
- Fire damp (1)
- Flammability (1)
- Flammable Gas (1)
- Flammable Liquid (1)
- Flow Chemistry (1)
- Flow-system (1)
- Flowability (1)
- Fluid-flow (1)
- Fluorescence standard (1)
- Fluorescent label (1)
- Flüssigkeitssensor (1)
- Foaming (1)
- Focused Ion Beam (1)
- Force distance curve (1)
- Force distance curves (1)
- Force-distance diagram (1)
- Formation (1)
- Forschungsdatenmanagement (1)
- Forschungsstrategie (1)
- Four-point bending test (1)
- Fractography (1)
- Freeze Drying (1)
- Freeze casting (1)
- Fresnoit (1)
- Friction Stir Welding (1)
- Frozen state photopolymerization (1)
- Full penetration (1)
- Fully aromatic frameworks (1)
- Functionalization (1)
- Functionalized graphene (1)
- Functionalized nanographene (1)
- Fusion zone (1)
- Fügetechnologie (1)
- GMA welding (1)
- GMAW (1)
- GUM-compliance (1)
- Gadolinium (1)
- Gallium doping (1)
- Gamma (1)
- Gas Barrier Properties (1)
- Gas analytic (1)
- Gas permeability (1)
- Gas separation membranes (1)
- Geant4-DNA (1)
- Gefahrenklasse (1)
- Gefahrgruppen (1)
- Gefahrgutregeln (1)
- Gefahrstoffverordnung (1)
- Gefügeuntersuchung (1)
- Gelartige Elektolyte (1)
- Gelelektrolyte (1)
- Geology (1)
- Gesteinskorrosion (1)
- Ggraphene polymer nanocomposite (1)
- Glas (1)
- Glasmonolith (1)
- Glass ceramic (1)
- Glass paints (1)
- Glass powder (1)
- Glass scanning (1)
- Glass screening device (1)
- Gleichgewicht (1)
- Glucose (1)
- Glue (1)
- Gold Nanoparticle (1)
- Gold Nanoparticles (1)
- Gold nanoclusters (1)
- Grain boundary (1)
- Grain size (1)
- Grain structure (1)
- Graphene Oxide (1)
- Graphene polymer nanocomposite (1)
- Graphite modules (1)
- Grating (1)
- Grenzfläche als Material (1)
- Grinding (1)
- Grünfolieneigenschaften (1)
- HAZ (1)
- HDPE Soprption (1)
- HDPE Sorption (1)
- HPLC (1)
- HSLA (1)
- HVO (1)
- Halophile (1)
- Hamonisierung (1)
- Hard machining (1)
- Hardmetal (1)
- Hardness (1)
- Heat control (1)
- Heat saturation function (1)
- Heated concrete (1)
- Heating oil (1)
- Heating oil - biodiesel - blend (1)
- Heating oil tanks (1)
- Heating oil with 10 % FAME (1)
- Heating oil with 10% biodiesel (1)
- Heating oil with 20% biodiesel (1)
- Heating oil-Biodiesel-Blend (1)
- Heavy metal free (1)
- Heissrisse (1)
- Heizöl mit 10% Biodiesel (1)
- Heizöl mit 20 % Biodiesel (1)
- Heizöl mit 20% Biodiesel (B20) (1)
- Heizöl-FAME-Blends (1)
- Heißgaskorrosion (1)
- Heißrisse (1)
- Hierarchical porosities (1)
- High Molecular Polyethylene (1)
- High alloyed steel (1)
- High entropy alloys (1)
- High pressure (1)
- High specific surface area (1)
- High-power laser beam (1)
- High-temperature corrosion (1)
- High-temperature oxidation (1)
- High-voltage testing (1)
- Highspeed plasma (1)
- Hochentropielegierungen (1)
- Hochleistungslaserstrahlschweißen (1)
- Hot Cracking (1)
- Hot crack (1)
- Hot stamping (1)
- Human antibodies (1)
- Human umbilical cell adhesion (1)
- Hybrid components (1)
- Hybrid laser arc welding (1)
- Hybrider Werkstoffverbunde (1)
- Hydration (1)
- Hydrogel (1)
- Hydrogen Assisted Cracking (HAC) (1)
- Hydrogen Embrittlement (1)
- Hydrogen assisted stress corrosion cracking (1)
- Hydrogen dependent mechanical properties (1)
- Hydrogen diffusivity (1)
- Hydrogen methane (1)
- Hydrogen-containing hot gas (1)
- Hydrophobic interaction (1)
- Hydrophobin (1)
- Hydrothermal synthesis (1)
- Hydrothermale Calcinierung (1)
- Hygrothermal (1)
- Hyperbranched (1)
- Hysteresis measurement (1)
- Härte (1)
- IAEA fire (1)
- ICP-MS (1)
- IEQ (1)
- IIT (1)
- IR spectroscopy (1)
- ISO (1)
- ISO 14577 (1)
- ITS region (1)
- ImAFM (1)
- Imaging (1)
- Immobilisierung (1)
- Immobilization (1)
- Immunglobulin (1)
- Immunoaffinity extraction (1)
- Impact behaviour (1)
- Impact damage (1)
- Impedance spectroscopy (1)
- Implant test (1)
- Implant-test (1)
- Implants (1)
- Impurity segregation (1)
- In situ measurement, (1)
- In situ testing (1)
- In-Situ X-ray CT (1)
- In-situ Process Monitoring (1)
- Inclusion cluster (1)
- Inclusion size (1)
- Inconel 625 (1)
- Inconel 686 (1)
- Incremental lifetime models (1)
- Indenter modulus (1)
- Indonesien (1)
- Inertisierung (1)
- Inflammation (1)
- Infrared Thermography (1)
- Infrared nano AFM (1)
- Infrared spectroscopy (1)
- Infrared thermography (1)
- Initial crack size (1)
- Ink terminology (1)
- Inline NMR Spectroscopy (1)
- Innenraumluft (1)
- Insitu test (1)
- Institut Laue Langevin (1)
- Instrumented Indentation Testing (1)
- Instrumentierte Eindringprüfung (1)
- Instrumentierte Eindringprüfung (IIT) (1)
- Integrated Processes (1)
- Integrating sphere spectroscopy, (1)
- Inter-laborator comparison (1)
- Interdisciplinary (1)
- Interfaces (1)
- Interfacial forces (1)
- Intergranular cracking (1)
- Intermodulation (1)
- Intermodulation AFM (1)
- Intermodulation-AFM (1)
- Internal Surfaces (1)
- Internal oxidation (1)
- Introduction (1)
- Inverse Problems (1)
- Ionic porosity (1)
- Ions (1)
- Iron isotope fractionation (1)
- Iron meteorite (1)
- Iron oxide (1)
- Journal (1)
- Kabeltrenner (1)
- Kathodische Korrosionsschutz (1)
- Keramische Folien (1)
- Kieselsol (1)
- Kinetics (1)
- Klebeverbindungen (1)
- Knoevenagel condensation (1)
- Knotenweise Zwangsbedingungen (1)
- Kobaltlegierung (1)
- Kompaktierbarkeit (1)
- Kompressibilität (1)
- Konformitätsbewertung (1)
- Konformitätserklärung (1)
- Kontaktkorrosion (1)
- Korosi (1)
- Korrelationsmatrix (1)
- Korrosionsbeständigkeit (1)
- Korrosionsschnelltest (1)
- Korrosionsschäden (1)
- Korrosionsüberwachung (1)
- Korund (1)
- Kraftstoffabbau (1)
- Kraftstoffbehälter (1)
- Kreislaufwirtschaft (1)
- Kriechen (1)
- Kriechverhalten (1)
- Kristallisation (1)
- Kristallsystem (1)
- Kunststoff (1)
- Kunststoff und Röntgen-Rückstreuung (1)
- Kurz- und Langriss-Ermüdungsbruchmechanik (1)
- Kurzfaser-verstärkte Thermoplaste (1)
- Kurzrisswachstum (1)
- LC / MALDI-TOF-MS coupling (1)
- LC x ESI-TOF-MS (1)
- LC-MS (1)
- LCC (1)
- LCCC (1)
- LEVASIL 50/50 (1)
- LIBS (1)
- LL equation (1)
- LPBF (1)
- LT-FCM (1)
- LTCC multilayer (1)
- LTT filler material (1)
- LTT-Zusatzwerkstoff (1)
- La(Fe,Si)13 phase (1)
- Labelling (1)
- Lack-of-fusion (1)
- Lactide (1)
- Ladetankausrüstung (1)
- Laminates (1)
- Laminographie (1)
- Landau Lifshitz Gilbert equation (1)
- Large-pore (1)
- Laser Metal Deposition (LMD) (1)
- Laser Powder Bed Melting (1)
- Laser Scanning Microscopy (LSM) (1)
- Laser hybrid welding (1)
- Laser powder bed fusion (1)
- Laser processing (1)
- Laser surface texturing (1)
- Laser welding (1)
- Laser-Hybridschweißen (1)
- Laser-Pulver-Auftragschweißen (1)
- Laser-induced nanostructures (1)
- Laser-induced slip casting (1)
- Laser-modified surface (1)
- Laserauftragschweißen (1)
- Laserbearbeitung (1)
- Laserdispergieren (1)
- Laserpulverauftragschweißen (1)
- Laserscanningmikroskopie (LSM) (1)
- Laserstrahlhybridschweißen (1)
- Laserstrahlschmelzen im Pulverbett (1)
- Lattice structure (1)
- Layer system (1)
- Layer-by-layer deposition (1)
- Layerwise Slurry Deposition (1)
- Layerwise slurry deposition (1)
- Leaching of alkalis (1)
- Lead isotope composition (1)
- Lead-free (1)
- Leak-tightness (1)
- Lean duplex (1)
- Leather (1)
- Lebensdauer (1)
- Legierung (1)
- Legionella (1)
- Leichtbau (1)
- Levitation (1)
- Ligand (1)
- Linear polyglycerol (1)
- Liquid Crystals (1)
- Liquid crystals (1)
- Liquid metal embrittlement (1)
- Load history (1)
- Load partition (1)
- Local fatigue spproaches (1)
- Localized Laser Dispersing (1)
- Long-term storage (1)
- Low Reynolds number swimmers (1)
- Low Temperature Toughness (1)
- Low Transformation Temperature (1)
- Low cycle fatigue (1)
- Low heat input GMA welding (1)
- Low melting glasses (1)
- Low-tech approach (1)
- Lubrication (1)
- Luminescence (1)
- MAG (1)
- MALDI TOF MS (1)
- MALDI-TOF (1)
- MEMUS (1)
- MOF-74 (1)
- MPI (1)
- MPLS (1)
- Machine Learning (1)
- Macrophage (1)
- Magmatic and hydrothermal processes (1)
- Magnet coupling (1)
- Magnetic (1)
- Magnetic Nanoparticles (1)
- Magnetic anisotropy (1)
- Magnetic domains (1)
- Magnetic field (1)
- Magnetic interacion (1)
- Magnetic nanoparticle (1)
- Magnetic nanoparticles (1)
- Magnetic resonance imaging (1)
- Magnetic swimmers (1)
- Magnetische Domänen (1)
- Magnetization dynamics (1)
- Magnetocoloric (1)
- Magnetoelastic effect (1)
- Magnetoelastischer Effekt (1)
- Magnéli phase (1)
- Maintenance (1)
- Manual of Tests and Criteria (1)
- Market surveillance (1)
- Maskinteknik (1)
- Mass spectrometry of polymers (1)
- Mass transport (1)
- Massenspektrometrie (1)
- Masterbatch (1)
- Material characterization (1)
- Material defects (1)
- Materialien (1)
- Materialkreislauf (1)
- Materialprüfung (1)
- Measurement (1)
- Measurement uncertainty (1)
- Mechanical Engineering (1)
- Mechanical Properties (1)
- Mechanical behavior (1)
- Mechanical property (1)
- Medical implants (1)
- Medieval glasses (1)
- Mehr-Proben-Prüfverfahren (1)
- Mehrachsige Verformung (1)
- Melt pool behaviour (1)
- Melt-extraction technique (1)
- Mesoporous Silica (1)
- Mesoporous iridium-titanium mixed oxides (1)
- Mesoporous mixed metal oxide films (1)
- Messing (1)
- Messtechnik (1)
- Metal Matrix Composite (1)
- Metal carbides (1)
- Metal matrix composite (1)
- Metal organic framework (1)
- Metal phosphonates (1)
- Metal powder characterization (1)
- Metal reducing bacteria (1)
- Metal-organic-frameworks (1)
- Metalldichtung (1)
- Metallkorrosion (1)
- Metalls (1)
- Metallurgie (1)
- Methanogen (1)
- Method comparison (1)
- Method validation (1)
- Methos comparision (1)
- Micro-shrinkages (1)
- Microanalysis (1)
- Microarray (1)
- Microbeam analysis (1)
- Microbial (1)
- Microbially induced corrosion (1)
- Microbiologically Influrenced Corrosion (MIC) (1)
- Microencapsulation (1)
- Microparticle (1)
- Microparticles (1)
- Microplastic (1)
- Microstructural analysis (1)
- Microstructure Characterization (1)
- Microstructure analysis (1)
- Microstructure characterisation (1)
- Microstructure evolution (1)
- Microwave synthesis (1)
- Mikrostrukturuntersuchung (1)
- Milling (1)
- Mis-match (1)
- Mittelrippendefekt (1)
- Mixed-linkers (1)
- Modell der konstanten Flammentemperaturen (1)
- Modified Varestraint-/Transvarestraint test (1)
- Modular Production (1)
- Module (1)
- Moisture (1)
- Molecular mobility (1)
- Monitoring (1)
- Monte-Carlo (1)
- Mortar (1)
- Mortel (1)
- Moving mesh (1)
- Mueller-Matrix Ellipsometry (1)
- Multiaxial deformation (1)
- Multiphoton laser structuring (1)
- Multiple-layered scaffold (1)
- Multivariate data analysis (1)
- Museum insect pest (1)
- Mussel-inspired adhesives (1)
- NBR (1)
- NDT Monitoring (1)
- NIR dyes (1)
- NP (1)
- Nahtgeometrie (1)
- Nano particle (1)
- Nano screening (1)
- NanoValid (1)
- Nanocasting (1)
- Nanoconfinement (1)
- Nanocrystal (1)
- Nanohybrid (1)
- Nanoindentation (1)
- Nanokomposit (1)
- Nanomaterial Properties (1)
- Nanomechanical properties (1)
- Nanometrology (1)
- Nanoparticle Characterization (1)
- Nanoparticle characterization (1)
- Nanoparticle size measurement (1)
- Nanoparticular TiO2 (Anatase) (1)
- Nanoporous (1)
- Nanorods (1)
- Nanoscale (1)
- Nanosecond laser (1)
- Nanosecond laser irradiation (1)
- Nanostructure quantification (1)
- Nanotechnologie (1)
- Natural (1)
- NbC (1)
- Nd excitation (1)
- Neel wall (1)
- Neuartige Materialien (1)
- Neutron imaging (1)
- Neutronen Abschirmmaterial (1)
- Neutronenbeugung (1)
- Neutronenradiographie (1)
- Neutronentomographie (1)
- New standards (1)
- Next Generation Sequencing (1)
- Ni (1)
- Ni-Resist (1)
- Nicht-lineare Regression (1)
- Nickel (1)
- Nickel alloys (1)
- Nickellegierung (1)
- Niedrigenergie-Polymeren (1)
- Niobium alloying (1)
- Nitrene[2+1]cycloaddition (1)
- Nitride (1)
- Nitrides (1)
- Nitrieren (1)
- Nitrogen (1)
- Non-destructive Materials (1)
- Non-destructuve testing (1)
- Non-spherical shape (1)
- Nonclassical crystallization (1)
- Nosema ceranae (1)
- Notified bodies (1)
- Numerical Simulation (1)
- Numerical analysis (1)
- Numerical modelling (1)
- Numerische ISmulation (1)
- Numerische Simulation (1)
- OTDR (1)
- Oberfläche (1)
- Oberflächenanalytik (1)
- Oberflächenmesstechnik (1)
- Oberflächenpotential (1)
- Oberflächensteifigkeit (1)
- Oberflächentechnik (1)
- Oil and gas industry (1)
- Ooxidation (1)
- Optical Emission Spectroscopy (1)
- Optical assay (1)
- Optical criterion (1)
- Optical emission spectroscopy (1)
- Optical fiber sensor (1)
- Optical fibers (1)
- Optical measurment technique (1)
- Optical near field (1)
- Optical properties (1)
- Optical spectroscopy (1)
- Optical tomography (1)
- Optische Fasern (1)
- Optische Tomografie (1)
- Ordered mesoporous silica (1)
- Ore provenance (1)
- Organic–inorganic nanostructures (1)
- Orientation relationship (1)
- Oscillating magnetic field (1)
- Osmia bicornis (1)
- Outokumpu: Stainless steel (1)
- Oxidation protection (1)
- Oxocobaltates (1)
- Oxygen Evolution Catalyst (1)
- Oxygen evolution reaction (1)
- Oxygen evolution reaction (OER) (1)
- Oxygen permability (1)
- Oxygen reduction reaction (1)
- Oxygen sensitive (1)
- P25 (1)
- P92 (1)
- PC characterisation (1)
- PDT (1)
- PE-HD Sorption (1)
- PEAK (1)
- PH (1)
- PMMA (1)
- PTFE (1)
- PUR (1)
- Package (1)
- Package testing (1)
- Paint (1)
- Pair Distribution Functions (1)
- Papierasche (1)
- Parabolic flight (1)
- Paramagnetism (1)
- Parchment (1)
- Partial penetration laser hybrid welding (1)
- Particle (1)
- Particle accretion (1)
- Particle size (1)
- Partikelgrößenverteilung (1)
- Passivschicht (1)
- Path planning (1)
- Pathogen spillover (1)
- Pentaerythritol (1)
- Peptide (1)
- Peptide Library (1)
- Peptide mass fingerprinting (1)
- Peptides (1)
- Performance assessment (1)
- Performance test (1)
- Performance validation (1)
- Periodic inspections (1)
- Peritectic reaction (1)
- Permeability (1)
- Permitted explosives (1)
- Perovskite (1)
- Phage Display (1)
- Phase mask (1)
- Phase transition (1)
- Phase-field (1)
- Phase-field simulation (1)
- Phasenumwandlung (1)
- Phononic crystal (1)
- Phononische Kristalle (1)
- Phosphate (1)
- Phosphinine (1)
- Phosphonates (1)
- Phosphorus (1)
- Photocatalyst (1)
- Photocuring (1)
- Photogrammetry (1)
- Photoluminescence quantum yield (1)
- Photon Counting Detectors (1)
- Photon counting detectors (1)
- Photonenzählende Detektoren (1)
- Photooxidation (1)
- Photostability (1)
- Plasmon resonance (1)
- Plasmonic nanofocusing spectroscopy (1)
- Plastic deformation (1)
- Plastikstrategie (1)
- Platinum-group-metals (1)
- Polarisation (1)
- Polarization spectroscopy (1)
- Poly(N-vinylpyrrolidone) (1)
- Poly(vinyl chloride) (1)
- Polyamid 12 (1)
- Polycaprolactone (1)
- Polyethylen hoher Dichte (1)
- Polyethylene Glycol (1)
- Polymer Testing (1)
- Polymer aging (1)
- Polymer composites (1)
- Polymer optical fiber (1)
- Polymer particle (1)
- Polymer-based nanocomposites (1)
- Polymere Werkstoffe (1)
- Polymeric materials (1)
- Polymeric membrane (1)
- Polyphosphoester (1)
- Polypropylene (1)
- Polysaccharides (1)
- Pore size tailoring (1)
- Pore solution (1)
- Porosität (1)
- Porous ceramics (1)
- Porphyrin (1)
- Portland cement (1)
- Post-modification by L-cysteine (1)
- Potential (1)
- Potentiometry (1)
- Powder analysis (1)
- Practical aspects (1)
- Pre-standardisation (1)
- Preceramic polymer (1)
- Precipitation hardening (1)
- Precision polymer sequencing (1)
- Prediction (1)
- Pressure-assisted sintering (1)
- Pressverbindung (1)
- Prevention (1)
- Priam's treasure (1)
- Primär- und Sekundärspannungen (1)
- Process Analytical Technology (1)
- Process Monitoring (1)
- Process development (1)
- Process parameters (1)
- Processing window (1)
- Projection matrix (1)
- Projektmanagement (1)
- Propagation modes (1)
- Propane gas fire test facility (1)
- Properties (1)
- Protection (1)
- Protein (1)
- Proton cunductor (1)
- Prozessmanagement (1)
- Prozessmonitoring (1)
- Prozesssimulation (1)
- Prozessüberwachung (1)
- Prüftechnik (1)
- Pseudo peptides (1)
- Pulsed thermography (1)
- Pultruded fiber rods (1)
- Quality assurcance (1)
- Qualitätsmanagement (1)
- Quantum yields (1)
- Quinones (1)
- REACH (1)
- REM (1)
- RME (1)
- ROPPOC (1)
- RRT (1)
- Radiation damage (1)
- Radioactive NP (1)
- Radioactive material (1)
- Radioactive sources (1)
- Radiographie (1)
- Radiography (1)
- Radiological inspections (1)
- Raman microscopy (1)
- Rayleigh scattering (1)
- Reaction Monitoring (1)
- Real-time infrared spectroscopy (1)
- Reconstructed ion chromatograms (1)
- Recycling (1)
- Recycling-by-design (1)
- Reference Nanomaterials (1)
- Reference material (1)
- Reference methods (1)
- Reference particles (1)
- Referenzmaterial (1)
- Referenzorganismus (1)
- Referenzverfahren (1)
- Refraction (1)
- Regeneration (1)
- Regulation (1)
- Reinforcement (1)
- Relaxation fatigue (1)
- Repair patch (1)
- Representative material properties (1)
- Repräsentative Werkstoffeigenschaften (1)
- Residual Stresses (1)
- Residual stress analysis (1)
- Residual stressMultiphase compositesInteractionMicromechanical schemesAnisotropy (1)
- Resonance (1)
- Resonance testing (1)
- Restlebensdauer (1)
- Restoration and conservation (1)
- Reverse microemulsion (1)
- Rh-Ir alloys (1)
- Rheological properties (1)
- Rietveld (1)
- Ring-expansion polymerization (1)
- Ring-opening polymerization (1)
- Rissarrest (1)
- Risstrajektorie (1)
- Rod structure (1)
- Rohrprobekörper (1)
- Rosin (1)
- Rotorblatt (1)
- Round robin tests (1)
- Round-Robin-Tests (1)
- Rundnähte (1)
- Rührreibschweißen (1)
- SBFEM (1)
- SDC (1)
- SEC (1)
- SEM (1)
- SEM/EDS/STRATAGem (1)
- SIMS (1)
- SKPM (1)
- SRB (1)
- STEM (1)
- SWIR photoluminescence (1)
- Safety (1)
- Safety characteristics (1)
- Sailplane Development Panel (1)
- Salicylate (1)
- Salt melt (1)
- Samarium doped ceria (1)
- Sample preparation (1)
- Saure Hydrolyse (1)
- Scaffolds (1)
- Scaled Boundary Finite Element Method (1)
- Scanning Electron Microscopy (SEM) (1)
- Scanning electrochemical microscope (SECM) (1)
- Scanning transmission electron microscopy (1)
- Scattering (1)
- Scavenging effect of iron (1)
- Schadenstolerante Bauteilauslegung (1)
- Schallemmission (1)
- Schmiedeteile (1)
- Schmiermittel (1)
- Schwarzpulverähnliches Reinigungspulver (1)
- Schweißeigenspannungen (1)
- Schweißeigenspannungs-Tiefen-Profile (1)
- Schweißen von kaltzähen Stählen (1)
- Schweißstruktursimulation (1)
- Schädigungsverhalten (1)
- Science (1)
- Sciences (1)
- Scratches (1)
- Screening (1)
- Seal failure (1)
- Security (1)
- Segmentation (1)
- Selective Laser Melting (SLM) (1)
- Selective Laser Sintering (SLS) (1)
- Selektives Lasersintern (1)
- Self-assembly (1)
- Self-lubricating coating (1)
- Semi-metallic friction material (1)
- Semi-metallic sintered material (1)
- Semiconductor (1)
- Semiconductor materials (1)
- Sensitisation (1)
- Sensoren (1)
- Sequence-defined oligomer (1)
- Sequencing (1)
- Service life (1)
- Setting (1)
- Shale (1)
- Shape (1)
- Shape-controlled (1)
- Shear behavior (1)
- Shore Hardness (1)
- Shore-Härte (1)
- Short-distance diffusion (1)
- Shrinkage (1)
- Shrinkages (1)
- Si-Ge (1)
- SiO2 Nanoparticle (1)
- Sicherer Betrieb (1)
- Sicherheit (1)
- Sicherheitsdatenblatt (1)
- Silane (1)
- Silica (1)
- Silica coating (1)
- Silicoborate glasses (1)
- Silicon Carbide (1)
- Silver indium sulfide (1)
- SimCoLas (1)
- Single cell-ICP-ToF-MS (1)
- Single molecule (1)
- Single particle-ICP-ToF-MS (1)
- Single-dot spectroscopy (1)
- Single-source precursors (1)
- Singlet oxygen (1)
- Sintern (1)
- Size (1)
- Size distribution (1)
- Sliding wear (1)
- Slidng wear (1)
- Slow Crack Growth (SCG) (1)
- Slow crack growth (1)
- Small Angle Neutron Scattering (1)
- Small angle neutron scattering (1)
- Small-angle x-ray scattering (1)
- Soda-lime-silica (1)
- Sodium ion batteries (1)
- Soil (1)
- Soil incubation study (1)
- Sol-gel coating (1)
- Solidification Cracking (1)
- Solubilizer (1)
- Sonochemical synthesis (1)
- Sorption (1)
- Spaltkorrosion (1)
- Spannungsrelaxationsrisse (1)
- Spannungsriss (1)
- Spannungsrisskorrosion (1)
- Spar cap design (1)
- Spark plasma sintering (1)
- Speciation analysis (1)
- Specific Surface Area (BET) (1)
- Spectral irradiation (1)
- Spectroscopic Imaging (1)
- Spektrale Ellipsometrie (SE) (1)
- Spin (1)
- Spontaneous emulsification (1)
- Spring constant (1)
- Spring constant (1)
- SrTiO3 (1)
- Stabilität von Eigenspannungen (1)
- Stabilization (1)
- Stabstruktur (1)
- Stahl (1)
- Stahl und Aluminium (1)
- Stained glass (1)
- Stained glass windows (1)
- Stained glasses (1)
- Stand der Normung (1)
- Standardization of Ellipsometry (1)
- Stanzen (1)
- Static Mixing (1)
- Statistics (1)
- Stepwise growth (1)
- Stereocomplex (1)
- Stimuli-responsive polymers (1)
- Stochastic Landau Lifshitz equation (1)
- Stress analysis (1)
- Stress intensity factor (1)
- Stress-strain behavior (1)
- Structural analysis (1)
- Structural defects (1)
- Structural integrity (1)
- Structural safety (1)
- Structural sealant glazing (1)
- Structural steel (1)
- Structure-property relationship (1)
- Structured light scanning (1)
- Structures under extreme conditions (1)
- Struktur (1)
- Struvite (1)
- Sub-oxide (1)
- Subcritical crack growth (1)
- Substitution (1)
- Sulfur (1)
- Superalloy (1)
- Superconducting magnet (1)
- Supercritical CO2 (1)
- Supercritical/dense phase CO2 (1)
- Superimposed loading (1)
- Supermartensit (1)
- Supermartensitic Stainless Steel (SMSS) (1)
- Superparamagnetism (1)
- Surface Chemical Transformation (1)
- Surface Chemistry (1)
- Surface analysis (1)
- Surface characterization (1)
- Surface charge (1)
- Surface group (1)
- Surface group analysis (1)
- Surface group quantification (1)
- Surface roughness (1)
- Surface roughness analysis (1)
- Surface structures (1)
- Surfaces (1)
- Survey (1)
- Survival rates (1)
- Suzuki-Miyaura coupling (1)
- Swarming (1)
- Swept wavelength interferometry (1)
- Switch (1)
- Sychrotron tomography (1)
- Synchrotron CT (1)
- Synchrotron Energy Dispersive Diffraction (1)
- Synchrotron Röntgen Refraktion (1)
- Synchrotron X-ray diffraction (1)
- Synchrotron X-ray refraction radiography (1)
- Synchrotron X-ray tomography (1)
- Synchrotron X‐ray refraction radiography (1)
- Synchrotron computed tomography (1)
- Synchrotron radiation (1)
- Synchrotron x-ray refraction radiography (SXRR) (1)
- Synchrotronbeugung (1)
- TGA-FTIR (1)
- THz-TDS (1)
- TMF (1)
- TaC (1)
- Tafel Plot (1)
- Tankschifftyp (1)
- Tanning (1)
- Tantalum carbide (1)
- Tara Mediterranee (1)
- Technical crack detection (1)
- Technological innovation (1)
- Temperature effects (1)
- Temperature modulated differential scanning calorimetry (1)
- Temple Scroll (1)
- Tensile Stress (1)
- Tensile testing (1)
- Themral cycles (1)
- Therapeutic antibodies (1)
- Thermal analysis (1)
- Thermal arrier coatings (1)
- Thermal barrier coatings (1)
- Thermal conductivity device (1)
- Thermal expansion (1)
- Thermal extraction-desorption gas chromatography mass spectrometry (1)
- Thermal testing (1)
- Thermally-induced moisture transport (1)
- Thermische Belastung (1)
- Thermische Betriebsbelastungen (1)
- Thermische Dehnung (1)
- Thermo-fluid dynamics (1)
- Thermo-fluid flow (1)
- Thermo-responsive polymers (1)
- Thermodynamic analysis (1)
- Thermoelectric properties (1)
- Thermograhy (1)
- Thermogravimetry (1)
- Thermomechanics (1)
- Thermomechanik (1)
- Thermoplastic polyurethane (1)
- Thermoplastics (1)
- Thick materials (1)
- Thick shells (1)
- Thick-walled Structures (1)
- Thick-walled steel (1)
- Thick-walled steels (1)
- Thin film (1)
- Thin film systems (1)
- Thin magnetic films (1)
- Thiol-ene click chemistry (1)
- TiO2 (1)
- TiO2 nanoparticle (1)
- Time-gated emission (1)
- Time-resolved flow cytometry (1)
- Time-temperature superposition (1)
- Tin(II)octanoate (1)
- Titan-Halterung (1)
- Titanium dioxide (1)
- ToF-SIMS (1)
- Tomographie, (1)
- Tool steel (1)
- Topometry (1)
- Topotactic phase transitions (1)
- Torsional fatigue (1)
- Total scattering analysis (1)
- Toughness (1)
- Toxicity (1)
- Transformation pathways (1)
- Transient heat transfer (1)
- Transport und Lagerung von Chemikalien (1)
- Trastuzumab (1)
- Tribologische Datenbank (1)
- Tribologsches Charakterisierungsdienste (1)
- Trilobite compound eyes (1)
- Trinkwasserinstalltion (1)
- Triplet-triplet annihilation (1)
- Trojan silver artefacts (1)
- Tubular X-joints (1)
- Tuff (1)
- Tungsten-Rhenium (1)
- Tunnelatmosphöre (1)
- Two-Photon Polymerization (1)
- Two-dimensional hexagonal boron nitride(h-BN) (1)
- UCST polymers (1)
- UHMWPE (1)
- UN-Test O.3 (1)
- UV Vis (1)
- UV Weathering (1)
- UV-Bestrahlungsstärke (1)
- UV/VIS spectroscopy (1)
- Ultra-high strength steel (1)
- Ultrafast scattering (1)
- Ultraschallmessung (1)
- Ultraschallsensor (1)
- Ultraschallwellen (1)
- Ultrashort laser pulses (1)
- Ultrasonic measurement (1)
- Ultrasound (1)
- Uncertainty budget (1)
- Uncertainty budgets (1)
- Ungleichgewicht (1)
- Uniaxial compression tests (1)
- Unlegierter Baustahl (1)
- UpConversion (1)
- Upconverstion (1)
- VM12 SHC (1)
- Vacuum (1)
- Vacuum hot extraction (1)
- Varestraint (1)
- Verfleckungen (1)
- Vernetzung (1)
- Verschleiß (1)
- Verwitterung (1)
- Vickers (1)
- Vickers indentation (1)
- Viscoelastic model (1)
- Viscoplastic (1)
- Viscoplasticity (1)
- Viscous sintering (1)
- Viskosität (1)
- Vitual computer tomography simulation (1)
- Vorgehensweise (1)
- Vorhaben (1)
- WAXS (1)
- Warmfester Stahl (1)
- Wartung (1)
- Wasser (1)
- Wasserstoffspeicher (1)
- Wastewater (1)
- Water migration (1)
- Weathering resistance (1)
- Weißlichtinterferenzmikroskopie (WLIM, 3D) (1)
- Weld pool (1)
- Welding process simulation (1)
- Werkstoffauswahl (1)
- Werkstoffe (1)
- Werkstoffmechanische Prüfung (1)
- Wetting (1)
- White light interference microscopy(WLIM) (1)
- Wiederkehrende Prüfung (1)
- Wild bees (1)
- Wind rotor blade (1)
- Wirbelstrom (1)
- Wirbesltrom (1)
- Wood materials (1)
- X-ray (1)
- X-ray Absorption Spectroscopy (1)
- X-ray Photoelectron Spectroscopy (XPS) (1)
- X-ray absorption spectroscopy (1)
- X-ray imaging (1)
- X-ray microspectroscopy (1)
- X-ray spectroscopic techniques (1)
- X-ray spectroscopy (1)
- X8Ni9 (1)
- XAFS (1)
- XANES (1)
- Yb(III) complex (1)
- Year in Review (1)
- Young's modulus (1)
- Young´s modulus (1)
- Zement (1)
- Zeolitic Imidazolate Frameworks (1)
- Zeta potential (1)
- ZfP (1)
- Zinc (1)
- Zinc oxide (1)
- ZnO (1)
- Zug-Druck-Schubprüfung (1)
- Zugprüfungen (1)
- abtragende Glasbearbeitung (1)
- alumina (1)
- anion-exchange (1)
- antibody (1)
- arbidic austempered ductile iron (1)
- arbon capture (1)
- attraktive Wechelwirkung (1)
- bacteria (1)
- bacteria detection (1)
- beta particle (1)
- bioactive (1)
- biokompatibel (1)
- biomaterials (1)
- bone (1)
- carbon steel (1)
- ceramics (1)
- clustered nanoparticles (1)
- condensate (1)
- copper (1)
- degradation (1)
- deposition welding (1)
- dielectric spectroscopy (1)
- digital image correlation (1)
- dual phase steel (1)
- electrochemical characterization (1)
- ethylene vinyl acetate (1)
- fatigue crack growth (1)
- flow cytometry (1)
- fluorescence microscopy (1)
- gamma ray (1)
- gas separation membranes (1)
- geothermal energy (1)
- gesintert (1)
- high pressure (1)
- highspeed plasma laser cladding (1)
- i-Tribomat (1)
- immunoseparation (1)
- impurities (1)
- infrared spectroscopy (1)
- leakage (1)
- lifetime (1)
- magnetic nanoparticle (1)
- mechanical properties (1)
- method (1)
- microstructure analysis (1)
- molecular mobility (1)
- nanoindentation (1)
- nanoparticle (1)
- natural ventilation (1)
- pH (1)
- particle (1)
- performance test (1)
- phosphate glasses (1)
- pitting corrosion (1)
- polymers (1)
- polymers of intrinsic microporosity (1)
- polynorbornenes (1)
- product specification (1)
- quantum dot (1)
- quantum yield (1)
- radiolysis (1)
- resistance spot welding (1)
- rubber (1)
- screening tes (1)
- selective laser melting (1)
- shape control (1)
- single cell-ICP-ToF-MS (1)
- single particle-ICP-ToF-MS (1)
- steel (1)
- temeprature dependent exchange length (1)
- uncertainty (1)
- utilization, and storage (CCUS) technology (1)
- volume resistivity (1)
- water speciation (1)
- µ-XRF (1)
- Äquivalente Wärmequelle (1)
- μCT (1)
- кратер шва (1)
- кристаллизация, (1)
- плавление, (1)
- сварочная ванна (1)
- температурное поле (1)
- функция теплонасыщения (1)
Organisationseinheit der BAM
- 6 Materialchemie (229)
- 9 Komponentensicherheit (215)
- 7 Bauwerkssicherheit (164)
- 8 Zerstörungsfreie Prüfung (164)
- 5 Werkstofftechnik (161)
- 9.3 Schweißtechnische Fertigungsverfahren (118)
- 7.6 Korrosion und Korrosionsschutz (96)
- 8.5 Röntgenbildgebung (84)
- 6.6 Physik und chemische Analytik der Polymere (70)
- 1 Analytische Chemie; Referenzmaterialien (68)
Eingeladener Vortrag
- nein (443)
Residual stresses are crucial when assessing the performance of welded components. The present work deals with the possibilities of transferring the real-life boundary conditions of welding, which influence the residual stress, into the laboratory. The possibilities of a test system with a load capacity of 2 MN specifically developed for online monitoring of stress formation and cracking are shown. Due to the structural design, global process, geometry and material-dependent stresses are induced, which can be quantified in-situ during welding and post weld heat treatment. Examples are presented how the conditions to be found during production are simulated in the laboratory. It is shown how welding residual stresses in high-strength steels are affected by the heat control. Elevated working temperatures significantly increase the tensile residual stresses in the heat affected zone (HAZ). The effect of mechanical stresses resulting from welding on stress relief cracking is demonstrated by the example of a creep resistant steel. Reheat cracks were monitored online during post weld heat treatment.
Microstructure ageing of stainless steel AISI 316L manufactured by selective laser melting (SLM)
(2019)
Additive manufacturing (AM) processes, such as SLM, offer a variety of advantages compared to conventional manufacturing. Today AM parts are still comparatively less cost-effective if they are manufactured in large quantities. To make the AM parts more cost-efficient, the AM process has to be improved. It requires a good understanding of microstructure formation, microstructure-property-relations and ageing processes affected by different loads.
In this work the ageing behavior of SLM manufactured AISI 316L stainless steel is evaluated. The microstructure effected by mechanical, thermal and corrosive loads are investigated and compared to as-built microstructure. Tensile tests are used for mechanical ageing. For thermal and corrosive loads the typical application conditions of 316L apply. The methods of microstructure investigation include SEM, TEM, CT and EBSD. The main object of this work is the description of microstructure and ageing processes of AM parts.
Organic and inorganic nanoparticles (NPs) are increasingly used as drug carriers, fluorescent sensors, and multimodal labels in the life and material sciences. These applications require knowledge of the chemical nature, total number of surface groups, and the number of groups accessible for subsequent coupling of e.g., antifouling ligands, targeting bioligands, or sensor molecules. To establish the concept of catch-and-release assays, cleavable probes were rationally designed from a quantitatively cleavable disulfide moiety and the optically detectable reporter 2-thiopyridone (2-TP). For quantifying surface groups on nanomaterials, first, a set of monodisperse carboxy-and amino-functionalized, 100 nm-sized polymer and silica NPs with different surface group densities was synthesized. Subsequently, the accessible functional groups (FGs) were quantified via optical spectroscopy of the cleaved off reporter after its release in solution. Method validation was done with inductively coupled plasma optical emission spectroscopy (ICP-OES) utilizing the sulfur atom of the cleavable probe. This comparison underlined the reliability and versatility of our probes, which can be used for surface group quantification on all types of transparent, scattering, absorbing and/or fluorescent particles. The correlation between the total and accessible number of FGs quantified by conductometric titration, qNMR, and with our cleavable probes, together with the comparison to results of conjugation studies with differently sized biomolecules reveal the potential of catch-and-release reporters for surface analysis. Our findings also underline the importance of quantifying particularly the accessible amount of FGs for many applications of NPs in the life sciences.
The influence of size effects on the thermoelectric properties of thin platinum films is investigated and compared to the bulk. Structural properties, like the film thickness and the grain size, are varied. We correlate the electron mean free path with the temperature dependence of the electrical conductivity and the absolute Seebeck coefficient SPt of platinum. A measurement platform was developed as a standardized method to determine SPt and show that SPt,film is reduced compared to SPt,bulk. Boundary and surface scattering reduce the thermodiffusion and the phonon drag contribution to SPt,film by nearly the same factor. We discuss in detail on behalf of a model, which describes the temperature dependence of the absolute Seebeck coefficient, the influence of size effects of electron-phonon and phonon-phonon interaction on SPt.
Additive manufacturing (AM) offers diverse advantages compared to conventional manufacturing. In this work the microstructure of austenitic steel 316L, manufactured with Selective Laser Melting (SLM), was analyzed and compared to microstructure of 316L hot rolled material. Methods used for analysis are microprobe, optical microscopy and electron backscatter diffraction.
The distributed measurement of relative humidity is a sought-after capability for a wide range of applications in civil engineering and structural health monitoring. We show that polymethyl methacrylate (PMMA) optical fi-bers can be employed as a sensor medium to conduct distributed humidity measurement by analyzing Rayleigh backscattering traces obtained by OTDR. We make use of the effect that water penetrates the fiber core and directly influences the local fiber attenuation and Rayleigh backscatter coefficient. We conducted distributed backscattering analysis for two different pulse wavelengths: 500 nm and 650 nm. The 650 nm results are susceptible to both, attenuation changes and backscatter changes, whereas backscatter results at 500 nm are not affected by humidity-induced attenuation and only exhibit a change of Rayleigh backscattered power as a function of humidity. The combined measurement and analysis of both parameters at these two wavelengths has the advantage that cross-sensitivities on backscatter change and attenuation, such as strain and tempera-ture changes, could be separated from the humidity response of the fiber. We present laboratory results for a humidity range between 30% and 90% for both pulse wavelengths: including step responses, humidity cycles and hysteresis analysis. In addition to the attenuation and backscatter coefficient dependence, we also analyze optical runtime changes as a function of humidity. POFs have the advantage that they can be directly embed-ded into materials such as concrete or soil to measure water content or localize water ingress. Standard step-index PMMA POFs can be used as a distributed relative humidity sensor up to 200 m distance.
Polytetrafluorethylen (PTFE) ist ein Hochleistungskunststoff, der sich aufgrund seiner einzigartigen Eigenschaften als unverzichtbarer Werkstoff in der modernen Industriegesellschaft etabliert hat. PTFE, modifiziertes PTFE und PTFE-Compounds kommen bevorzugt bei systemtechnischen Lösungen im Umfeld komplexer Regelwerke mit hohen Kompatibilitäts- bzw. regulativen Anforderungen, z.B. im Sauerstoff-, Lebensmittel- bzw. Trinkwasserkontakt, zur Anwendung. Beim Einsatz in Sauerstoffanlagen sollten Verarbeiter eine Reihe von Hinweisen beachten.
Degradation of thermal barrier coatings (TBCs) in gas‐turbine engines due to calcium–magnesium–aluminosilicate (CMAS) glassy deposits from various sources has been a persistent issue since many years. In this study, state of the art electron microscopy was correlated with X‐ray refraction techniques to elucidate the intrusion of CMAS into the porous structure of atmospheric plasma sprayed (APS) TBCs and the formation and growth of cracks under thermal cycling in a burner rig. Results indicate that the sparse nature of the infiltration as well as kinetics in the burner rig are majorly influenced by the wetting behavior of the CMAS. Despite the obvious attack of CMAS on grain boundaries, the interaction of yttria‐stabilized zirconia (YSZ) with intruded CMAS has no immediate impact on structure and density of internal surfaces. At a later stage the formation of horizontal cracks is observed in a wider zone of the TBC layer.
Composite pressure vessels for transporting dangerous goods and for hydrogen and natural gas vehicles consist of a load-bearing composite and a gas-tight, metallic or polymeric barrier layer (liner). To investigate the aging behavior of such composite pressure vessels, BAM carried out the interdisciplinary project COD-AGE. The aim of the project was the development of methods and models for the description and determination of the aging behavior of carbon fiber composites using the example of pressure vessels in order to better predict aging and safe working life. One focus of this project was the provision of suitable NDT methods. These included both test-related tests and the possible development of test equipment for later practical use.
In the lecture, test results of the age-related eddy current test on composite pressure vessels are presented.
In aging tests, pressure vessels made of an approximately 4 mm thick aluminum liner and approx. 8 mm thick CFRP layer were examined. Typical application of such pressure vessels are respiratory protective devices of the fire department. The pressure vessels were tested using conventional eddy current technology from the outer and inner side as well as with high-frequency eddy current technology. Both damage to the metallic liner and structures of the CFRP could be detected. A particular mechanical challenge was the inspection of the inside of the liners, since a cylindrical surface with an inside diameter of 150 mm has to be tested with an access of only 15 mm diameter.
Mg is a very promising material for lightweight construction and biomedical applications. However, the applicability of Mg and its alloys is hindered by its high corrosion susceptibility. Moreover, due to the toxicity of most inorganic conversion coating systems, the development of novel pre-treatment strategies for technical alloys are of vital importance. Recently, the application of intrinsically conducting polymers (ICPs) have been introduced as an alternative approach for corrosion protection of Mg alloys. ICPs with electronic conductivity are known to be able to passivate small defects, however they fail in the presence of large defects due to fast coating reduction and increased cation transport if macroscopically extended percolation networks exist.
The aim of this study is to develop graphene-polymer nanocomposite thin films for corrosion protection of Mg-alloys. As polymer matrix, poly(4-vinyl pyridine) (P4VP) was selected due to its semiconducting properties and protonic conductivity. In contrast to ICPs with electronic conductivity, the pH-dependant, reversible protonation/de-protonation capability of the P4VP has been utilized to synthesize environment-responsive coatings. The presentation summarizes our recent results on the synthesis and characterization of this novel coating system with a special focus on their interfacial stability and corrosion protection properties.
Mg is a very promising material for lightweight construction and biomedical applications. However, the applicability of Mg and its alloys is hindered by its high corrosion susceptibility. Moreover, due to the toxicity of most inorganic conversion coating systems, the development of novel pre-treatment strategies for technical alloys are of vital importance. The aim of this study is to develop polymeric bilayer thin films for corrosion protection of Mg-alloys. As polymer matrix, poly(4-vinyl pyridine) (P4VP) was selected due to its semiconducting properties and protonic conductivity. In contrast to ICPs with electronic conductivity, the pH-dependant, reversible protonation/de-protonation capability of the P4VP has been utilized to synthesize environment-responsive coatings. Polyacrylicacid (PAA) was tested as crosslinking layers to improve interfacial interactions between the polymeric layers. The macroscopic corrosion properties of the bilayer coatings were investigated by means of electrochemical methods such as linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in corrosive media simulating technical and biomedical applications. The presentation summarizes our recent results on the synthesis and characterization of this novel coating system with a special focus on their interfacial stability and corrosion protection properties.
Für moderne Hochleistungswerkstoffe scheinen Standardparameter der Erstarrungsrissprüfung mittels MVT-Test in vielen Fällen ungeeignet. Dieser Vortrag erläutert die charakteristischen Besonderheiten der betrachteten Werkstoffe, und zeigt überdies alternative Analysemethoden auf, mit denen fehlerhafte Einschätzungen von Erstarrungsrissanfälligkeiten vermieden werden können.
Konventionelle und innovative Hochtemperaturwerkstoffe sind im technischen Betrieb einer Vielzahl an Belastungen ausgesetzt. Neben mechanischen Beanspruchungen stellt die chemische Belastung durch das Vorhandensein von aggressiven und korrosiven Medien (SO2, CO2, O2, H2O…) bei hoher Temperatur einen Schlüsselfaktor dar, der die Langlebigkeit der Materialien im Einsatz beeinflusst. Neben konventionellen, mikroskopischen Analyseverfahren bieten röntgenbasierte Techniken Möglichkeiten, die Grenzflächenreaktionen zwischen dem Werkstoff und den Medien während der chemischen Belastung (in situ) zu untersuchen. Neuartige Einblicke in die zugrunde liegenden Prozesse der Schädigungsmechanismen werden anhand von klassischen ferritischen Legierungen beschrieben. Das Verständnis von Schlüsselfaktoren zur Induzierung eines Schutzmechanismus ist insbesondere für die Entwicklung von neuartigen Materialklassen wie Hochentropie- und chemisch komplexe Legierungen notwendig. Erste Einblicke in Schädigungsmechanismen durch Gaskorrosion dieser innovativen Materialsysteme werden vorgestellt.
Der Implant-Test nach ISO 17642-3 gehört zur Gruppe der fremdbeanspruchten Kaltrisstests, bei dem eine äußere Beanspruchung auf einen zylindrischen Stab (Implant-Probe) definiert aufgebracht wird. Mit dieser Kaltrissprüfung wurde vergleichende Analysen zur Kaltrissempfindlichkeit der modernen hochfesten Feinkornbaustähle S960MC und S960QL durchgeführt.
Advanced high strength steels are usually coated by a zinc layer for an increased resistance against corrosion. During the resistance spot welding of zinc coated steel grades, liquid metal embrittlement (LME)mayoccur. As a result, cracking inside and around the spot weld indentation is observable. The extent of LME cracks is influenced by a variety of different factors. In this study, the impact of the used electrode geometry is investigated over a stepwise varied weld time.
A spot welding finite element simulation is used to analyse and explain the observed effects. Results show significant differences especially for highly increased weld times. Based on identical overall dimensions, electrode geometries with a larger working plane allow for longer weld times, while still preventing LME within the investigated material and maintaining accessibility.
CEQAT-DGHS Interlaboratory tests for method validation and measurement uncertainty determination
(2019)
An explosion in a chemical plant or a fire on a dangerous goods vessel - the reason for such accidents can be numerous. Prevention starts in the laboratory where chemicals are tested for their hazardous properties in order to be able to assess the risks involved in their handling. For this purpose, test methods have been developed and published. They are applied globally nowadays. Safety experts, manufacturers, suppliers, importers, employers or consumers must be able to rely on the validity of safety-related test methods and on correct test results and assessments in the laboratory.
Interlaboratory tests play a decisive role in assessing the reliability of test results. Participation in interlaboratory tests is not only a crucial element of the quality assurance of laboratories; as such it is explicitly recommended in DIN EN ISO/IEC 17025. In addition, interlaboratory tests are also used to develop and validate test methods and can be used for the determination of the measurement uncertainty.
Interlaboratory tests on different test methods have been performed by Bundesanstalt für Materialforschung und –prüfung (BAM) and Physikalisch-Technische Bundesanstalt (PTB) in collaboration with the QuoData GmbH during the last 10 years. Significant differences between the results of the participating laboratories were observed in all interlaboratory tests. The deviations of the test results were not caused only by laboratory faults but also by deficiencies of the test method (see interlaboratory test reports of the CEQAT-DGHS Centre for quality assurance for testing of dangerous goods and hazardous substances: www.ceqat-dghs.bam.de).
In view of the interlaboratory test results the following conclusions can be drawn:
• To avoid any discrepancy on classification and labelling of chemicals it should become state of the art to use validated test methods and the results accompanied by the measurement uncertainty.
• A need for improvement is demonstrated for all examined test methods. Thus, interlaboratory tests shall initially aim at the development, improvement and validation of the test methods (including the determination of the measurement uncertainty) and not on proficiency tests.
• The laboratory management and the practical execution of the tests need to be improved in many laboratories.
• The term "experience of the examiner" must be seen critically: A "long experience with many tests" is not necessarily a guarantee for correct results.
Chemical compositions of the welds have significant effect on weld quality. Current inspection methods for the weld seams employ mostly post factum methods and cannot prevent weld defects.Elemental burn offs may significantly affect solidification leading to embrittlement or cracking. Control of weld chemical compositions insures a controlled solidification and resistance to related weld defects.
In situ ED XRD und Radiographie während eines Zugversuchs an wasserstoffbeladenem Supermartensit
(2019)
Die Ergebnisse von in-situ Experimenten am Berliner Elektronenspeicherring (BESSY II) werden vorgestellt. Es wurden Zugversuche an wasserstoffbeladenen und wasserstofffreien supermartensitischen Proben durchgeführt und Diffraktionsspektren und radiographische Bilder aufgenommen. Die energiedispersive Röntgendiffraktion ermöglichte dabei die dehnungsinduzierte Phasenumwandlung von Restaustenit zu Martensit in-situ zu beobachten. Die Radiographiebilder der zerreisenden Probe gaben Einblicke in das Bruchverhalten in Abhängigkeit vom Wasserstoffgehalt des Supermartensits.
The laser implantation–named technique aims to address the tribological problems frequently seen on tool surfaces during hot stamping. It is based on the creation of elevated dome- or ring-shaped hard structures on the surface of tool steels by a localized dispersing of hard particles. Therefore, a combination of the two distinct approaches that are normally used in surface Technology for optimizing friction and wear, i.e., surface texturing and surface material optimization, are realized in one processing step. In experimental studies, a localized dispersing of TiB2 particles in the surface layer of the hot work tool steel X38CrMoV5-3 was considered and compared with punctual laser–remelted textures. The structures (micro-) hardness was measured at top- and cross-sections. With the aid of a scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction the interaction between the hard particles and the substrate material were studied. From the results, an optimal parameter range was identified for laser implantation. To the investigation’s end, the implant geometry was measured by optical microscopy and White light microscopy. Furthermore, a mathematic model was introduced, which allows a prediction of the implant geometry as a response to the laser parameters. It was shown that the implantation of TiB2 particles leads to a significant hardness increase up to 1600 HV1 due to the dispersion of initial particles and an in situ precipitation of new titanium-rich phases. It was possible to create defect-free dome- and ring-shaped microstructures on the surfaces. It was also shown that the implants geometry highly depends on the applied laser parameters. The applied central composite design shows a good agreement with the experimental results.
aRTist is an easy-to-use and practical simulation tool to generate realistic radiographic images from CAD objects. A dedicated add-on module makes CT simulation easy (virtual computer tomography). Just choose the number of projections.
Unlike in the practice, simulation can separately image the primary and scatter radiation. This allows studying the scattering artefacts in CT (gray-level variations in regions of homogeneous material).
In this paper, the influence of the bulk temperature (BT) of Polycarbonate (PC) on the occurrence and growth of Laser-induced Periodic Surface Structures (LIPSS) is studied. Ultrashort UV laser pulses with various laser peak fluence levels F_0 and various numbers of overscans (N_OS) were applied on the surface of pre-heated Polycarbonate at different bulk temperatures. Increased BT leads to a stronger absorption of laser energy by the Polycarbonate. For N_OS < 1000 High Spatial Frequency LIPSS (HSFL), Low Spatial Frequency LIPSS perpendicular (LSFL-I) and parallel (LSFL-II) to the laser polarization were only observed on the rim of the ablated tracks on the surface but not in the center of the tracks. For N_OS ≥ 1000 , it was found that when pre-heating the polymer to a BT close its glass transition temperature (T_g), the laser fluence to achieve similar LIPSS as when processed at room temperature decreases by a factor of two. LSFL types I and II were obtained on PC at a BT close to T_g and their periods and amplitudes were similar to typical values found in the literature. To the best of the author’s knowledge, it is the first time both LSFL types developed simultaneously and consistently on the same sample under equal laser processing parameters. The evolution of LIPSS from HSFL, over LSFL-II to LSFL I, is described, depending on laser peak fluence levels, number of pulses processing the spot and bulk temperature.
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.
Residual stresses in Laser Beam Melting (LBM) – Critical Review and outlook of activities at BAM
(2019)
Additive manufacturing (AM) technologies have experienced an exceedingly rapid growth, which is coupled with the knowledge about the resulting material properties and performance. In particular, residual stress (RS) was soon recognized as an important issue in AM parts, such that parts are usually subjected to a post build-heat-treated. Significant effort has been spent on simulations of RS in AM, especially using finite element methods. As a consequence, the experimental determination of RS has thereby become increasingly important as a validation tool for simulations, as well as a method for assessing the influence of process parameters. In particular, diffraction methods, which are fundamentally non-destructive, offer enormous possibilities to gain knowledge on the residual stress state in real components, since synchrotron radiation and neutrons can penetrate even heavy metals up to several millimeters or centimeters, respectively. Indeed, significant progress has been achieved, in the understanding of the origins of the RS fields as a function of process parameters, as well as their stability under thermal and/or mechanical exposure.
In this paper, a few success stories will be outlined. It will be shown how the determination of RS in metallic parts (with the focus on those produced by laser powder bed fusion) has even revealed that process parameters that were previously considered unimportant (e.g. the position and orientation on the base plate) play a major role in the onset of residual stress accumulation.
However, while RS characterization is starting to be considered in the component design, deposition strategy (e.g. build plate temperature), and even in the definition of the relevant metric to assess the quality of a part, much is still to be investigates about the hypotheses underlying its experimental determination. Therefore, some aspects to be aware of, or even those which to date are unclear, will also be discussed. These include the determination of the stress-free reference and of the principal axes of stress. All of these aspects will lead towards a comprehensive understanding of the process-structure-performance relationships in AM materials and parts.
Es wurden Prüfkörper aus additiver Fertigung mittels Laser Sinter Verfahren (Polyamid 12, PA 12) und Fused Layer Modeling (Acrylnitril-Butadien-Styrol, ABS) sowie Prüfkörper aus dem Kunststoff-Spritzguss Verfahren (PA 12 und ABS) über 2000 Stunden künstlich bewittert. Vor, während und nach der Bewitterung erfolgte eine zerstörungsfreie Prüfung mittels Thermografie, optischer Mikroskopie und spektralen Methoden (UV/VIS-Spektroskopie und spektrale Reflexion), um den Alterungsfortschritt zu untersuchen und Schäden durch die künstliche Bewitterung sowie eingedruckte Defekte zu identifizieren und zu detektieren.
Zusätzlich wurden zerstörende Zugprüfungen vorgenommen, welche mit einer IR-Kamera verfolgt wurden. Auf diese Weise konnten lokale Temperaturänderungen, hervorgerufen durch elastische sowie plastische Verformungen, zeitaufgelöst erfasst und ausgewertet werden.
Eleventh canSAS Meeting: International Cooperation and Collaboration in Small-Angle Scattering
(2019)
The eleventh canSAS workshop was held in Freising, Germany, July 8–10, 2019.
These international meetings, promoting collective action for nomadic small-angle scatterers, have been taking place since 1998 and act as forums to catalyze cooperation amongst the SAS community in order to provide better facilities and equipment, combined with reliable data interpretation and analysis. The meeting attracted over 60 participants from major neutron and X-ray laboratories, as well as manufacturers of SAXS equipment, and users from academia and industry. There was also a wide geographical spread with participants from Australia, Asia, and North America joining European colleagues.
Additively manufactured test specimens made of polyamide 12 (PA 12) by Laser Sintering as well as of acrylonitrile butadiene styrene (ABS) by Fused Layer Modelling, were characterised with active thermography directly after manufacturing and after artificial weathering. For this, two different excitation methods (flash and pulse heating) were used and compared, regarding their suitability for the detection of constructed and imprinted defects inside the test specimens. To increase the quality of the thermograms, data processing methods like thermal signal reconstruction (TSR) and Fourier Transformation after TSR were applied. To further investigate the long-term stability of the additively manufactured test specimens towards environmental stress, like UV radiation, heat, humidity, water contact and frost with active thermography, an artificial weathering test over 2000 hours (~3 months) was applied to the specimens. The monitoring of the changes in the optical properties of the weathered plastics was supplemented by spectral reflectance and UV/VIS spectroscopy.
In the present work it was shown that the tribologcal profiles of special model oxides under dry unidirectional sliding have shown, that sub-oxides have a contribution to the tribological behavior of carbides and cermets, when they are tribo-oxidatively formed, because their tribological profiles as monolithic materials are homologous in part or totally, or compete with hardmetals or cermets, depending from the operating conditions regarded.
Welding residual stress engineering by means of an adjusted martensite phase transformation would be highly attractive as detrimental tensile residual stresses may be prevented already during welding without time and cost intensive post processing. The present study shows a synchrotron diffraction analysis of a martensitic steel subjected to thermo-mechanical load cycles. Experiments were conducted regarding the microstructural strain response during the austenite to martensite transformation. The strains are a function of the temperature and the specific loads applied during cooling. The relation between the transformation plasticity of the material, the amount of martensite formed and the arising strains can thus be assessed. The lattice plane specific strains were compared to experimental findings from (macro) dilatation tests. It is shown that the microscopic material behavior differs remarkably from the one observed on the macroscopic scale, what leads to characteristic residual stresses in the material.
Aufgrund der stark korrosiven Atmosphäre in Tunnelbauwerken kommt es aufgrund von Reinigungs- und Sanierungsmaßnahmen an Ein- und Anbauteilen aus nichtrostendem Stahl häufig zu wartungsbedingten Verkehrsbeeinflussungen und Tunnelsperrungen. Bislang ist nur eine kleine Gruppe rostfreier Edelstähle für die Verwendung in Tunnelbauwerken zugelassen. Im Sinne einer mittel- bis langfristigen Reduktion von Wartungsarbeiten besteht jedoch großes Interesse, die Einsatzmöglichkeiten alternativer nichtrostender Stähle zu erhöhen.
Um dies zu ermöglichen, entwickelten die Bundesanstalt für Materialforschung und -prüfung (BAM), gemeinsam mit dem Landesbetrieb Straßenbau NRW, in Zusammenarbeit mit der Informationsstelle Edelstahl Rostfrei (ISER), mit Unterstützung des Edelstahlherstellers Outokumpu und der Wilhelm Modersohn GmbH & Co. KG ein Forschungsprojekt zur Auslagerung von nichtrostenden Duplexstählen in Straßentunnel. Im Oktober 2019 beteiligte sich der Landesbetrieb Straßen, Brücken und Gewässer in Hamburg und ermöglichte die Auslagerung im Elbtunnel auszuweiten.
A high-pressure neutron diffraction study was conducted on polycrystalline samples of the two known polymorphs of 2,4,6-trinitrotoluene [monoclinic (m) and orthorhombic (o) TNT] under hydrostatic conditions. Isothermal equations of state were obtained for both polymorphic forms. Neither polymorph was observed to undergo a phase transition in the pressure region 0–5 GPa, with both polymorphs displaying smooth compression behavior across the pressure range. This differs somewhat from previous X-ray diffraction and Raman spectroscopy investigations in which discontinuities were observed in the P–V curves and spectral changes were reported at ∼2 GPa. The high-pressure response of these materials is supported by dispersion-corrected density functional theory calculations which, while overestimating the experimental bulk moduli, give excellent agreement with the observed smooth compression response of both phases.
The authors describe and interpret curvature-related changes to the ellipsometric readout. As model system for a concave curvature, a set of three spherical microscopic indents in silicon (100) of different sizes was prepared by instrumented indentation testing using a spherical indenter. For reference, these samples were characterized by AFM to reveal the topography of each structure. The concavelike indents were analyzed by Mueller-Matrix imaging ellipsometry to extract lateral intensity images of 12 elements of the Mueller-Matrix. As a result of the detailed analysis of the image elements m22, m23, and m14, it was possible to correlate intensity changes and symmetry properties to depolarization and cross polarization induced by the edge threshold and the curved surface of the indent.
Rapid cooling rates and steep temperature gradients are characteristic of additively manufactured (AM) parts and important factors for residual stress formation which have implications on structural integrity. This study examined the influence of heat input on the distribution of residual stresses in two prisms produced by laser powder bed fusion (L-PBF) of austenitic stainless steel 316L.
The layers of the prisms were exposed using two distinct helix scanning strategies: one scanned from the centre to the perimeter and the other from the perimeter to the centre. Residual stresses were characterised at one plane perpendicular to the building direction at half of its build height using neutron diffraction. In addition, the defect distribution was analysed via micro X-ray computed tomography (µCT) in a twin specimen.
Both scanning strategies reveal residual stress distributions typical for AM: compressive stresses in the bulk and tensile stresses at the surface. However, temperature gradients and maximum stress levels differ due to the different heat input. Regarding the X-ray µCT results, they show an accumulation of defects at the corners where the laser direction turned through 90°.
The results demonstrate that neutron diffraction and X-ray µCT can be successfully used as non-destructive methods to analyse through-thickness residual stress and defect distribution in AM parts, and in the presented case, illustrate the influence of scanning strategies. This approach contributes to deeper assessment of structural integrity of AM materials and components.
Laser based Powder Bed Fusion (L-PBF) is an additive manufacturing technique that has been continuously developed in the past years. It offers unparalleled design freedom and the resulting mechanical properties match, in some cases even exceed, those of materials processed by conventional manufacturing techniques. Nonetheless the process is prone to create Residual Stresses (RS) resulting from the sequential melting and solidification of the material. RS can reduce load bearing capacity and generate unwanted distortions thus diminishing the potential of L-PBF. This research activity aimed at characterizing the RS state in Inconel 718 L-PBF specimens using multiple diffraction methods. The microstructure as well as the surface and bulk residual stresses were investigated. The RS analysis was performed using X-ray, synchrotron and neutron diffraction methods to provide information at different depths within the specimen. The measurements were performed at the Bundesanstalt für Materialforschung und –prüfung (BAM), the EDDI beamline at BESSY II synchrotron and E3 line at BER II neutron reactor of the Helmholtz-Zentrum für Materialien und Energie (HZB) Berlin. The results revealed a depth depending RS state. The longitudinal and transverse stress components measured by X-ray and synchrotron at the surface agree well, exhibiting stress values around the yield strength of the material. In addition, synchrotron mapping showed gradients along the width and length of the sample for the longitudinal and transverse stress components. Lower RS values compared to surface RS were measured in the bulk of the material using neutron diffraction. The longitudinal stress component in the bulk was tensile and gradually decreased towards the edge of the specimen. The normal component however did not change significantly along the specimen dimensions and was of compressive nature. The transversal component was almost negligible. The results indicate that a stress re-distribution takes place during the deposition of the consecutive layers, which has to be further investigated.
Large-pore ordered mesoporous silica (OMS) COK-12, analogous to the well-known SBA-15, but synthesized in a more environmentally friendly way and exhibiting a shorter plate-like structure, was grafted with different amounts of graphene oxide (GO) for the first time in an inexpensive and rapid process, that was successfully upscaled. Samples were examined with nitrogen sorption analysis, SAXS, Raman spectroscopy, XPS, and zeta potential analysis. Adsorption experiments with the cationic dye methylene blue (MB) were conducted on the grafted materials and on pure COK-12, taking into account the influence of initial dye concentration (30–600 mg L-1), adsorbent dosage (0.2–14 g L-1), contact time (0.3–300 min), solution pH (4 10), and influence of salts and temperature (0–1 M NaCl, 80 C) to simulate industrial dye effluent. The adsorption process was found to be represented best by the Langmuir isotherm model, i.e., adsorption is a monolayer process. The calculated maximum Adsorption capacities were found to be 20.2 and 197.5 mg g-1 at dosages of 5 and 0.5 g L-1 for pure COK-12 and COK-12 grafted with 50 wt% GO, respectively, at pH 5.65 and MB concentration of 100 mg L-1.
Adsorption kinetics were found to follow the pseudo-second order model, i.e., chemisorption is the rate controlling step. The adsorption performances could be well preserved at simulated dye effluent.
Desorption was found to be most effective with hydrochloric acid. The COK-12 grafted with GO presented in this work shows superior adsorption properties in comparison to other grafted OMS materials. In addition, grafting with GO remarkably improved the stability of COK-12 in aqueous solution.
Welding residual stress engineering by means of an adjusted martensite phase transformation would be highly attractive as detrimental tensile residual stresses may be prevented already during welding without time and cost intensive post processing. The present study shows a synchrotron diffraction analysis of a martensitic steel subjected to thermo-mechanical load cycles. Experiments were conducted regarding the microstructural strain response during the austenite to martensite transformation. The strains are a function of the temperature and the specific loads applied during cooling. The relation between the transformation plasticity of the material, the amount of martensite formed and the arising strains can thus be assessed. The lattice plane specific strains were compared to experimental findings from (macro) dilatation tests. It is shown that the microscopic material behavior differs remarkably from the one observed on the macroscopic scale, what leads to characteristic residual stresses in the material.
Residual stresses are crucial when assessing the performance of welded components. The present work deals with the possibilities of transferring the real-life boundary conditions of welding, which influence the residual stress, into the laboratory. The possibilities of a test system with a load capacity of 2 MN specifically developed for online monitoring of stress formation and cracking are shown. Due to the structural design, global process, geometry and material-dependent stresses are induced, which can be quantified in-situ during welding and post weld heat treatment. Examples are presented how the conditions to be found during production are simulated in the laboratory. It is shown how welding residual stresses in high-strength steels are affected by the heat control. Elevated working temperatures significantly increase the tensile residual stresses in the heat affected zone (HAZ). The effect of mechanical stresses resulting from welding on stress relief cracking is demonstrated by the example of a creep resistant steel. Reheat cracks were monitored online during post weld heat treatment.
Der Vortrag behandelt die Grundlagen der Korrosion sowie einzelene Aspekte von Korrosionsschutzmethoden. Weiterhin werden Themen wie Bimetallkorrosion und Spaltkorrosion erläutert. Es werden passivierbare Werkstoffe und deren Eigenschaften im Hinblick auf einen korrosionsschutzgerechten Einsatz vorgestellt.
Die Untersuchung und Charakterisierung der Entwicklung/Änderung der Mikrostruktur, der mechanischen Eigenschaften sowie der Lebensdauer additiv gefertigter metallischer Werkstoffe hat bisher, vor allem im Hinblick auf die komplexe Belastungsfälle bei sicherheitsrelevanten Anwendungen, mit der rasanten Entwicklung der Fertigungstechniken nicht Schritt gehalten. Im Rahmen dieser Arbeit wurde eine Charakterisierung des Ermüdungsverhaltens von additiv gefertigten TiAl6V4 im Low-Cycle-Fatigue Bereich (niederzyklische Ermüdung) nach Norm ISO 12206 mit Dehnungsamplituden von 0.3 bis zu 1.0 % und bei Raumtemperatur, 250°C und 400°C durchgeführt. Die TiAl6V4 Proben wurden aus zylindrischen Halbzeugen gefertigt, welche durch Laser-Pulver-Auftragsschweißen mit einer optimierten Aufbaustrategie hergestellt wurden. Die optimierte Aufbaustrategie beinhaltet variierende Spurüberlappungsgraden, die die Fertigung der dünnen zylindrischen Körper ohne weitere Ausgleichslagen ermöglicht. Das Werkstoffverhalten wird anhand von Wechselverformungskurven sowie einer Darstellung der Lebensdauer in einem Wöhler-Diagramm beschrieben. Ein Fitting der Lebensdauer-Daten erfolgt anhand der Manson-Coffin-Basquin Beziehung. Eine Eingangscharakterisierung der mikrostrukturellen Merkmale inklusive Bindefehler aus dem Herstellungsprozess wird durch Lichtmikroskopie und hochauflösende Computertomographie (CT) durchgeführt. Der Versagensmechanismus während der Belastung wird anhand von Zwischenuntersuchungen mit CT und einem unterbrochenen Versuch mit ausgewählten Versuchsparametern beschrieben. Nach dem Versagen wurden die Proben am REM, mit Lichtmikroskopie und mit CT fraktographisch in Längs- und Querrichtung untersucht. Die erfassten Lebensdauern sind ähnlich zu denen aus herkömmlichen Studien und liegen unter derjenigen von dem konventionell hergestellten (geschmiedeten) Werkstoff. In dieser Arbeit wurden für den untersuchten Werkstoff bei anwendungs- und sicherheitsrelevanten Belastungszuständen (hohe Temperaturen, zyklische Plastizität) neue experimentelle Daten und Kennwerte ermittelt und Verständnis über das mechanische Verhalten und die Entwicklung der Mikrostruktur aufgebaut. Darüber hinaus wurde Verständnis über die Rolle von Bindefehlern und anderen typisch für AM auftretenden Gefügemerkmalen auf das Versagensverhalten von DED-L TiAl6V4 gewonnen.
Die Untersuchung und Charakterisierung der Entwicklung/Änderung der Mikrostruktur, der mechanischen Eigenschaften sowie der Lebensdauer additiv gefertigter metallischer Werkstoffe hat bisher, vor allem im Hinblick auf die komplexe Belastungsfälle bei sicherheitsrelevanten Anwendungen, mit der rasanten Entwicklung der Fertigungstechniken nicht Schritt gehalten. Im Rahmen dieser Arbeit wurde eine Charakterisierung des Ermüdungsverhaltens von additiv gefertigten TiAl6V4 im Low-Cycle-Fatigue Bereich (niederzyklische Ermüdung) nach Norm ISO 12206 mit Dehnungsamplituden von 0.3 bis zu 1.0 % und bei Raumtemperatur, 250°C und 400°C durchgeführt. Die TiAl6V4 Proben wurden aus zylindrischen Halbzeugen gefertigt, welche durch Laser-Pulver-Auftragsschweißen mit einer optimierten Aufbaustrategie hergestellt wurden. Die optimierte Aufbaustrategie beinhaltet variierende Spurüberlappungsgraden, die die Fertigung der dünnen zylindrischen Körper ohne weitere Ausgleichslagen ermöglicht. Das Werkstoffverhalten wird anhand von Wechselverformungskurven sowie einer Darstellung der Lebensdauer in einem Wöhler-Diagramm beschrieben. Ein Fitting der Lebensdauer-Daten erfolgt anhand der Manson-Coffin-Basquin Beziehung. Eine Eingangscharakterisierung der mikrostrukturellen Merkmale inklusive Bindefehler aus dem Herstellungsprozess wird durch Lichtmikroskopie und hochauflösende Computertomographie (CT) durchgeführt. Der Versagensmechanismus während der Belastung wird anhand von Zwischenuntersuchungen mit CT und einem unterbrochenen Versuch mit ausgewählten Versuchsparametern beschrieben. Nach dem Versagen wurden die Proben am REM, mit Lichtmikroskopie und mit CT fraktographisch in Längs- und Querrichtung untersucht. Die erfassten Lebensdauern sind ähnlich zu denen aus herkömmlichen Studien und liegen unter derjenigen von dem konventionell hergestellten (geschmiedeten) Werkstoff. In dieser Arbeit wurden für den untersuchten Werkstoff bei anwendungs- und sicherheitsrelevanten Belastungszuständen (hohe Temperaturen, zyklische Plastizität) neue experimentelle Daten und Kennwerte ermittelt und Verständnis über das mechanische Verhalten und die Entwicklung der Mikrostruktur aufgebaut. Darüber hinaus wurde Verständnis über die Rolle von Bindefehlern und anderen typisch für AM auftretenden Gefügemerkmalen auf das Versagensverhalten von DED-L TiAl6V4 gewonnen.
The WelDX research project aims to foster the exchange of scientific data inside the welding community by developing and establishing a new open source file format suitable for documentation of experimental welding data and upholding associated quality standards. In addition to fostering scientific collaboration inside the national and international welding community an associated advisory committee will be established to oversee the future development of the file format. The proposed file format will be developed with regards to current needs of the community regarding interoperability, data quality and performance and will be published under an appropriate open source license.
By using the file format objectivity, comparability and reproducibility across different institutes and experimental setups can be improved.
The additional element from the filler wire in the laser beam welding is usually distributed inhomogeneously in the final weld due to the high solidification rate of weld pool. It has been found that the electromagnetic stirring produced by an external oscillating magnetic field can enhance the material mixing in the weld pool to achieve a more uniform element distribution. However, the magnetic field has a highly non-linear and multi-coupled interaction with the weld pool behavior, which makes the quantitative explanation of the physical mechanism difficult. In this study, the effect of electromagnetic stirring on the transport phenomena in the wire feed laser beam welding is investigated by a numerical modelling. A 3D transient multi-physical model considering the magnetohydrodynamics, heat transfer, fluid flow, keyhole dynamics and element transport is developed. The multiple reflections and the Fresnel absorption of the laser on the keyhole wall are calculated using the ray tracing method. The numerical results show that a Lorentz force produced by the oscillating magnetic field and its induced eddy current gives significant influence on the transport phenomena in the molten pool. The forward and downward flow is enhanced by the electromagnetic stirring, which homogenizes the distribution of the additional elements from a nickel-based filler wire in a steel weld pool. The numerical results show a good agreement with the high-speed images of the molten pool, the fusion line from the optical micrograph and the element distribution from the energy dispersive X-ray spectroscopy. This work provides a physical base for the electromagnetic-controlled laser beam welding and some guidance for the selection of electromagnetic parameters.
In den vergangen Jahren hat das Umweltbewusstsein in der Bevölkerung stark zugenommen und somit auch das Interesse an der Vermeidung von anthropogenen (Schad-)Stoffen in der Umwelt. Eine (neue) Substanzklasse, deren Umweltauswirkungen noch nicht vollständig untersucht sind und die in den vergangenen Jahren immer mehr an Bedeutung gewonnen hat, sind (metallbasierte) Nanomaterialien. Im Gegensatz zu bspw. Elementspezies weisen Nanomaterialien eine Vielzahl von Eigenschaften auf und lassen sich nicht über nur ein Merkmal beschreiben - dies stellt eine große analytische Herausforderung dar. Hier haben sich vor allem die Feld-Fluss-Fraktionierung (AF4) und die single-particle-ICP-MS als leistungsstarke analytische Methoden herausgestellt. In (aquatischen) Umweltmatrizes (z.B. Oberflächengewässern) liegen neben artifiziellen auch natürliche Partikel vor, was eine weitere große Herausforderung für den Nachweis von Nanomaterialien darstellt.
Neben dem Nachweis von anthropogenen Stoffen in der Umwelt ist zudem deren ökotoxikologische Bewertung wichtig. In der aquatischen Ökotoxikologie werden hierzu Testorganismen mit den jeweiligen Substanzen über die Wasserphase exponiert. Effektkonzentrationen (EC50) werden dabei auf Basis der Konzentrationen in der Wasserphase abgeleitet - tatsächlich bioakkumulierte Mengen werden hierbei jedoch meist nicht ermittelt; eine weitere große Herausforderung besteht zudem in der Bewertung von Mischungstoxizitäten. Gängige Testorganismen sind u.a. Kieselalgen (Diatomeen). Diatomeen stehen am Anfang der Nahrungskette - toxikologisch relevante Metalle/Nanomaterialien können sich hierüber im Nahrungsnetz der Oberflächengewässer anreichern und ggf. nachhaltig auswirken.
Im ersten Teil des Vortrages werden zunächst neue elementanalytische Methoden zum Nachweis von metallbasierten Nanopartikeln in Umweltmatrizes auf Basis der AF4/ICP-SFMS sowie stabilen Isotopenlabeln am Beispiel von Eisennanopartikeln vorgestellt.
Im zweiten Teil wird eine neue elementanalytische Methode als komplementäre Technik zur ökotoxikologischen Bewertung von (Schad-)Stoffen vorgestellt. Die neue Methode basiert auf der on-line Kopplung von HPLC mit der single-cell-ICP-(ToF)-MS (sc-ICP-(ToF)-MS) [1, 3-5]. Hierüber konnten wir erfolgreich die automatisierte Multielementanalytik einzelner Diatomeen realisieren und zur Analyse von mit Metallen inkubierten Diatomeen (cyclotella meneghiniana) einsetzen. Wir konnten zeigen, dass die sc-ICP-ToF-MS zukünftig eine leistungsstarke, komplementäre Technik in der aquatischen Ökotoxikologie zum z.B. Test von Metallen und Nanomaterialien darstellt.
Die Strukturierung keramischer Grünfolien und Laminate ist ein wesentlicher Prozessschritt in der keramischen Multilayer-Technologie und begründet die funktionelle Vielfalt keramischer Multilayer. Benötigt wird die Grünbearbeitung für die Herstellung elektrischer und thermischer Vias sowie innerer Kavitäten und Kanäle für Transport und Lagerung von Gasen und Flüssigkeiten in hochintegrierten Schaltungsträgern, Sensoren und Reaktoren. Standardverfahren in der industriellen Fertigung sind Heißschneiden, Stanzen und Laserbearbeitung. Darüber hinaus werden auch Bohren, Fräsen, Sägen und Heißprägen verwendet. Über die Erprobung weiterer Verfahren wie Wasserstrahlschneiden, Dampfstrahlätzen und Powder Blasting wird in der Literatur berichtet.
Im Vortrag werden spezifische Vor- und Nachteile der eingesetzten Verfahren beleuchtet. Abschließend werden die Kriterien für die Auswahl des optimalen Strukturierungsverfahrens diskutiert. Zusammensetzung und Gefüge sowie die dadurch bedingten mechanischen und thermomechanischen Eigenschaften sowie das Absorptionsverhalten von Grünfolien sind sehr unterschiedlich. Daraus resultieren unterschiedliche optimale Bearbeitbarkeitsparameter.
Fireside Chat - Sharing PhD
(2019)
Microbiologically induced corrosion due to bacterial biofilms causes several problems in industrial systems, technical applications and in medicine. Prior to the formation of a biofilm on a substrate, planktonic cells attach on the surface. Hence, the properties of the surface play a key role in biofilm formation and are of great importance for the development of strategies to prevent bacterial attachment and biofilm formation.
This project aims at clarifying to which extent surface micro-/nanostructuring and chemical functionalization affects bacterial attachment and whether a synergistic combination of the two can be used to control bacterial adhesion. To answer these questions, model surfaces with regular patterns of 5-10 micrometers in size have been prepared, which provide distinct zones differing in terms of their chemistry or nano-roughness. This was achieved by micro contact printing of self-assembled monolayers with different functional groups and deposition of patterned ZnO nanorod arrays for studying the effect of surface chemistry and morphology, respectively. Typical contrasts studied were combinations of positively/negatively charged, hydrophobic/hydrophilic or flat/rough.
The attachment behavior of bacteria on tailored surfaces were studied in a flow chamber as a function of time. The strain Pseudomonas fluorescens SBW25 was chosen as a model organism. DNA-intercalating dyes such as Syto9 have a high affinity to adsorb on ZnO nanorods. To overcome this limitation a genetic modification was performed by introducing a gene which expresses a green fluorescent protein in P. fluorescens SBW25 enabling the quantitative evaluation of the flow chamber studies by means of fluorescence microscopy. Further analysis of the attachment behavior was performed by means of scanning electron microscopy.
The presentation will summarize the results of our systematic study on the role of individual parameters on bacterial attachment and highlight synergistic combinations, showing an inhibition or enhancing effect. As the investigations with model substrates enable a precise control of the surface parameters, this approach can be applied to different microorganisms and material systems to achieve a correlative description of bacterial adhesion on solid surfaces.
Multiplexed encoding schemes of nano- and micrometer sized particles with fluorescent dyes or quantum dots (QDs) and their optical detection, are of increasing interest for applications in the life sciences, for example in flow cytometry. Almost all strategies utilizing fluorescence focus on spectrally distinguishable emission bands or colors and different intensity levels as fluorescence codes. The fluorescence parameter lifetime has been, however, barely exploited. In this work the goal is to perform multiplexing with encoding fluorophores with different fluorescence lifetimes (LTs). In comparison to the spectral multiplexing strategies this has the advantage, that the different fluorescence LT codes can be measured with the excitation and emission wavelength, thus reducing instrument costs. Moreover, LTs should not depend on emitter concentration. Unlike organic dyes, the LTs of which are typically < 10 ns, the fluorescence LTs of ternary semiconductor QDs that represent a “green” alternative to conventional Cd-containing QDs are in the range of several hundred ns, independent of oxygen concentration, and can be tuned to a certain extent by chemical composition and surface chemistry. This present a time region that can be barely covered by other emitters that have either much shorter or longer lifetimes. In this project, different encoding strategies will be assessed and the encoded particles will be then used for fluorescence assays for the analysis of several targets in parallel. Therefor the encoded particles will be functionalized with different target-specific bioligands and read out with a specifically designed flow cytometer enabling time-resolved fluorescence detection. With this instrument, the particles will be discriminated by their fluorescence LTs In one detection channel while the analytes will be quantified by fluorescence labels in a second channel in the intensity domain.
Multiplexed encoding schemes of nano- and micrometer sized polymer particles with fluorescent dyes or quantum dots (QDs) and their optical detection, are of increasing interest for applications in the life sciences, for example in flow cytometry. Almost all strategies utilizing fluorescence focus on spectrally distinguishable emission bands or colors and different intensity levels as fluorescence codes.
In this work the goal is to perform multiplexing with encoding fluorophores with different fluorescence lifetimes (LTs). In comparison to the spectral multiplexing strategies this has the advantage, that the different fluorescence LT codes can be measured with the same excitation and emission wavelength, thus reducing instrumental costs. Moreover, LTs should not depend on emitter concentration. Unlike organic dyes, the LTs of which are typically <10ns, the fluorescence LTs of ternary semiconductor QDs which represent a “green” alternative to conventional Cd-containing QDs are in the range of several hundred ns, independent of oxygen concentration, and can be tuned to a certain extent by chemical composition and surface chemistry. This presents a time region that can barely be covered by other emitters that have either much shorter or longer lifetimes. In this project, different encoding strategies will be assessed, and the encoded particles will then be used for fluorescence assays for the analysis of several targets in parallel. Therefore, the encoded particles will be functionalized with different target-specific bioligands and read out with a specifically designed flow cytometer enabling time-resolved fluorescence detection. With this instrument, the particles will be discriminated by their fluorescence LTs in one detection channel while the analytes will be quantified by fluorescence labels in a second channel in the intensity domain.
Since materials play an important role when designing and servicing industrial facilities. Also, for energy systems there is no way around. Selection of appropriate materials is an essential aspect for successful application and reliable service life. Future engineers must be made aware on the importance of this fact. So, they may prevail in techno‐economic discussions.
The book fulfills its intension of providing to students in science and engineering a comprehensive understanding of different energy processes and what role materials play in this conjunction. Also, it gives interested engineers and scientists an insight in this matter. After being introduced the user should dig deeper in the existing detailed knowledge available for materials selection within these special conditions to assure a reliable operation of the energy production facility.
Depending on the specific plastic’s ageing sensitivities, the durations which plastic components remain in the environment can be very long. As, in the past, the advantages in ageing resistance and durability were highly evaluated, we now face the problem of quite stable plastic waste within the environment.
However, there is only little knowledge on the real timescales until macroscopic fragmentation for the different kinds of plastic under various environmental conditions.
Here, weathering methods are presented, which have been used for the failure prediction in specific outdoor conditions. Issues of uncertainty, reproducibility, or validation are discussed.
For the prediction of the plastic’s fragmentation, much longer time scales have to be considered. To do this within a limited project life span, various processes as well as their acceleration potential have to be evaluated separately, such as temperature increase or spectral shift.
The possibilities and limitations of such controlled acceleration will be discussed.
Weathering reference materials are used to characterize the harshness of an exposure, aiming on either reproducibility of a specific exposure or on the comparability between various kinds of weathering exposure.
The materials that are used as weathering reference materials differ in their sensitivities (as well as in interactions and interferences of the latter), conditioned by the different processes which lead to the respective property change. It is also essential to take into account the necessary measurement equipment for the respective property change, in order to allow timely intervention.
What are the key issues on choosing a weathering reference material?
What can be learned from the weathering reference materials, investigated so far?
Possibilities and limitations are discussed on the basis of existing weathering reference materials. Conclusions are drawn, for establishing new weathering reference materials.
First phosphorus AB2 monomer for flame-retardant hyperbranched polyphosphoesters: AB2vs. A2 + B3
(2019)
Branched polymers are an important class of polymers with a high number of terminal groups, lower viscosity compared to their linear analogs and higher miscibility, which makes them especially interesting for flame retardant applications, where the flame retardants (FR) are blended with another polymer matrix. Hyperbranched polyphosphoesters (hbPPEs) are gaining more and more interest in the field of flame retardancy, as low molar mass FRs often have the disadvantage of blooming out or leaching, which is not desired in consumer products. Here, we present the first phosphorus-based AB2 monomer for the synthesis of hbPPEs and assess its flame-retardant performance in an epoxy resin compared to a hbPPE synthesized by an A2 + B3 approach. The hbPPE synthesized from an AB2 monomer exhibited a slightly higher performance compared to a similar hbPPE, which was prepared by A2 + B3 polyaddition, probably due to its higher phosphorus content.
Das Presshärteverfahren hat sich zur ressourceneffizienten Verarbeitung von höchstfesten Stahlwerkstoffen im Karosserieleichtbau weltweit etabliert. Die fehlerfreie Bauteilproduktion wird jedoch durch Reibungs- und Verschleißerscheinungen aufgrund hoher thermo-mechanischer Werkzeugbelastungen und fehlender Schmierstoffsysteme limitiert. Als Lösungsansatz wird eine Modifikation der Werkzeugoberfläche mittels Laserimplantation angestrebt, um folglich deren Verschleißbeständigkeit nachhaltig zu erhöhen. Das Verfahren basiert auf einem lokalen Dispergieren keramischer Hartstoffpartikel in die Werkzeugoberfläche, infolgedessen hochfeste und erhabene Strukturen im Mikrometerbereich entstehen. Aufgrund der signifikanten Reduzierung der Kontaktfläche sowie der hohen Verschleißbeständigkeit der eingesetzten TiB2-Hartstoffe wird ein verbessertes tribologisches Einsatzverhalten unter presshärtetypischen Prozessbedingungen erwartet. Zur Verifizierung dieser Annahmen wurden im Rahmen dieser Arbeit modifizierte Pin-on-Disk Tests durchgeführt, um das Reib- und Verschleißverhalten der laserimplantierten Werkzeugoberflächen unter Presshärtebedingungen zu untersuchen. Zur weiteren Vertiefung des Prozess-verständnisses wurden die verschlissenen Platinen via Tastschnittmessungen und Querschliffaufnahmen analysiert. Durch den Ergebnisvergleich mit konventionellen Werkzeugoberflächen erfolgte eine abschließende Bewertung des tribologischen Einsatzverhaltens der laserimplantierten Strukturen.
Bei der Bestrahlung und Bewitterung von polymeren Werkstoffen wird die Degradation durch eine Absorption von Strahlung initiiert und meistens durch weitere Klimagrößen, wie z.B. Wärme, Feuchte und atmosphärische Gase beeinflusst. Die Messung einer effektiven Bestrahlungsstärke und ihre zeitliche Integration sind deshalb von großer Bedeutung.
Photochemische Prozesse werden beim Sehen oder allgemeiner bei Farbstoffen schon durch sichtbare (VIS) Strahlung, dagegen bei der Erythembildung der Haut und der Photodegradation von Polymeren erst durch die energiereicheren Photonen der ultravioletten (UV) Strahlung initiiert. Die spektrale Empfindlichkeit des Auges und die Erythembildung sind im VIS- bzw. UV-Bereich sehr stark wellenlängenabhängig, was durch die Angabe der mit der spektralen Hellempfindlichkeit V() des Auges bewerteten VIS-Strahlung in Lux (lx) bzw. die mit der Erythem-Wirkfunktion bewertete UV Strahlung als dimensionsloser UV-Index berücksichtigt wird. Spektrale Empfindlichkeiten.
Die Photodegradation von Polymeren ist im UV-Bereich ebenfalls stark wellenlängenab-hängig, was bisher nicht berücksichtigt wurde. Seit Mitte der 70er Jahre, als die lx- bzw lxh- Messung bei der Strahlungsbeanspruchung langsam durch die Ermittlung der radiometrischen UV-Bestrahlungsstärke bzw. der UV-Bestrahlung im gesamten UV-Bereich abgelöst wurde, gab es hier bei der Bewitterungsprüfung keine weiteren Fortschritte auf dem Gebiet der Charakterisierung der Strahlungsbeanspruchung im UV-Bereich.
Seit Jahren liegen zahlreiche Ergebnisse über die spektrale Empfindlichkeit von Photo-degradationsprozessen vor, die zeigen, dass die spektrale Empfindlichkeit im Bereich der Globalstrahlung bei ca. 300 nm, am größten ist und im langwelligen UV-Bereich bei ca. 400 nm gegen Null geht. Die Messungen der radiometrischen Größen UV-Gesamt-bestrahlungsstärke und UV-Gesamtbestrahlung erfasst deshalb über weite Wellen-längenbereiche Strahlungsanteile, die für die Photodegradation bedeutungslos sind und mittelt über potenziell bedeutsame Änderungen im kurzwelligen UV-Bereich hinweg.
Es wird das Konzept eines neuen UV-Radiometers vorgestellt, dessen spektrale Empfindlichkeit einer mittleren spektralen Empfindlichkeit der Photodegradation von Polymeren entspricht. Die effektive UV-Bestrahlungsstärke und UV-Bestrahlung kann dadurch wesentlich genauer erfasst werden.
Specific amounts of oxidizing and reductive impurities as well as some moisture were added to dense phase CO2 to replicate CO2 streams from sources in a CCS pipeline network. Due to the moisture content being only 50 ppmV no visible acid condensation took place. To simulate stress conditions at the inside pipeline surface due to fluid pressure (10 MPa) specimens were preloaded using a load frame. Experiments conducted at 278 K and at 313 K revealed the highest corrosion rate at lower temperature. Corrosive effect of impurities was strongest applying mixed atmosphere, containing oxidizing and reductive components, closely followed by CO2 streams with pure oxidizing character. By far, the lowest corrosion rate (10x lower) resulted from reductive atmosphere. In general, at constant temperature and pressure the CO2 stream composition strongly influences the morphology, thickness and composition of the corrosion products. Applying oxidizing or mixed impurities, iron hydroxides or oxides (e.g. goethite, hematite) occur as dominating corrosion products, capable to incorporate different amounts of sulfur. In contrast, using reductive atmosphere very thin corrosion layers with low crystallinity were developed, and phase identification by XRD was unfeasible. SEM/EDX analysis revealed the formation of Fe-O compounds, most likely attributed to the oxygen partial pressure in the system induced by CO2 (≥0.985 volume fraction) and volatile H2O. In addition to the surface covering corrosion layer, secondary phases had grown locally distributed on top of the layer. These compounds are characteristic for the applied atmosphere and vary in number, shape and chemical composition.
Für Anwender nichtrostender Stähle wird im neu überarbeiteten Merkbaltt 833 eine Planungshilfe für Anwendungen nichtrostender Stähle in Erdböden gegeben. Hinweise und Empfehlungen zur Werkstoffauswahl sowie allgemeine Hinweise zum Einsatz nichtrostender Stähle und auch Anwendungsbeispiele sind im neu überarbeitetn Merkblatt enthalten.
Oxidation effects on the functionality and formation of laser-induced periodic surface structures
(2019)
In the last decades, the formation of laser-induced periodic surface structures (LIPSS) has been widely studied, not only to stablish a general understanding of the main mechanisms present during the irradiation with ultrashort laser pulses, but also to identify the main processing parameters for its fabrication on various technical materials. However, an important and almost always present effect that is typically set aside is the material oxidation during or after the laser processing. Usually, this leads to optical, chemical, structural and mechanical alterations that are seldomly studied in detail. Therefore, in this work we present a study that includes the formation of LIPSS on Ti6Al4V alloy for tribological applications were different oxidations layers are involved.
The material characterization using different techniques, such as energy dispersive X-ray analyses (EDX), X-ray photoelectron spectroscopy (XPS), micro Raman spectroscopy (µ-RS), and depth-profiling Auger electron microscopy (AEM), and other techniques, confirms the formation of a non-negligible superficial oxide layer – strongly dependent on the specific processing parameters. We perform tribological experiments on laser irradiated samples oxidized by alternative ways to have a comparison on its friction performance. The obtained results show significant differences that depend directly on the thickness and the quality of the oxidized layer. This may open a fertile research area until now barely explored with clear impact on LIPSS based applications.
Um das Material- und Schädigungsverhalten von additiv gefertigtem Polyamid 12 (PA12) unter quasistatischer Belastung zu charakterisieren, wurden mechanische Tests und Experimente zur Bestimmung der Mikrostruktur durchgeführt.
Die Proben wurden nach dem Prinzip des Selektiven Lasersinterns (SLS) hergestellt. Unter quasistatischer Belastung mit Haltezeiten ergab sich ein viskoplastisches Materialverhalten. Im Zugversuch wurde eine maximale Zugfestigkeit von 40.6 MPa und eine Bruchdehnung von 7.4% beobachtet. Mittels Digitaler Bildkorrelation (DIC) wurde die Ausbildung von Scherbändern während des Zugs nachgewiesen. Mittels Röntgenrefraktion wurde eine Erhöhung von inneren Oberflächen beobachtet, die senkrecht zur Zugrichtung orientiert sind. Die Analyse der Gesamtporosität aus Computertomographie-Messungen ergab keine Änderung infolge der Zugbelastung. Jedoch wurde eine bimodale Porengrößenverteilung und eine steigende Sphärizität festgestellt.
Das Materialverhalten wurde mit den Ergebnissen des Zugversuchs nach dem Chaboche Modell [3] in sehr guter Übereinstimmung simuliert. Allerdings gestattet dieses Modell nicht, das Bruchverhalten einzuschließen. Daher wurde zur Simulation des Schädigungsverhaltens das Modell gemäß dem Ansatz von Gurson, Tvergaard und Needleman unter Berücksichtigung der mikrostrukturellen Parameter erweitert. Während das Chaboche Modell eine homogene Spannungsverteilung generiert, zeigt das erweiterte Modell die Ausbildung von Scher¬bändern und die korrekte Bruchdehnung.
Der Schwerpunkt des Vortrages liegt auf den Röntgenverfahren zur experimentellen Bestimmung der Mikrostruktur.
Molecular MRI is a promising in-vivo modality to detect and quantify morphological and molecular vessel-wall changes in atherosclerosis. The combination of different molecular biomarkers may improve the risk stratification of patients. This study aimed to investigate the feasibility of simultaneous visualization and quantification of plaque-burden and inflammatory activity by dual-probe molecular
MRI in a mouse-model of progressive atherosclerosis and in response-to-therapy. Homozygous apolipoprotein E knockout mice (ApoE−/−) were fed a high-fat-diet (HFD) for up to four-months prior to MRI of the brachiocephalic-artery. To assess response-to-therapy, a statin was administered for the same duration. MR imaging was performed before and after administration of an elastin-specific gadolinium-based and a macrophage-specific iron-oxide-based probe. Following in-vivo MRI, samples were analyzed using histology, immunohistochemistry, inductively-coupled-mass-spectrometry and laser-inductively-coupled-mass-spectrometry. In atherosclerotic-plaques, intraplaque expression
of elastic-fibers and inflammatory activity were not directly linked. While the elastin-specific probe demonstrated the highest accumulation in advanced atherosclerotic-plaques after four-months of HFD, the iron-oxide-based probe showed highest accumulation in early atherosclerotic-plaques after two months of HFD. In-vivo measurements for the elastin and iron-oxide-probe were in good agreement
with ex-vivo histopathology (Elastica-van-Giesson stain: y = 298.2 + 5.8, R2 = 0.83, p < 0.05; Perls‘ Prussian-blue-stain: y = 834.1 + 0.67, R2 = 0.88, p < 0.05). Contrast-to-noise-ratio (CNR) measurements of the elastin probe were in good agreement with ICP-MS (y = 0.11x-11.3, R² = 0.73, p < 0.05). Late stage atherosclerotic-plaques displayed the strongest increase in both CNR and gadolinium concentration (p < 0.05). The gadolinium probe did not affect the visualization of the iron-oxide-probe and vice versa. This study demonstrates the feasibility of simultaneous assessment of plaque-burden.
This study demonstrates the potential of the concurrent assessment of inflammatory activity and ECM degradation by dual-probe molecular MRI in an experimental mouse model of AAA. Based on the combined information from both molecular probes the rupture of AAAs could reliably be predicted, with higher accuracy compared with each probe alone. The combined in vivo quantification of these biomarkers in 1 imaging session may be useful to improve the in vivo characterization of AAAs.
Non-linear optical emitters are promising materials for energy applications and biotechnologies. Solid-state multi-band emitters like lanthanide doped up-conversion nanoparticles (UCNPs) show excellent photostability, are excitable in the near infrared (NIR), and show emission bands from the UV to SWIR spectral regions. The optical properties of these materials strongly depend on the excitation power density, i.e., the number of photons absorbed per time interval. The upconversion (ΦUC) and downshifting quantum efficiencies (ΦDS) of these materials, the excitation power dependent population, and the deactivation dynamics are influenced by nanoparticle architecture, doping concentration, and the microenvironment. We studied the fundamental changes of the luminescence properties of ß-NaYF4 UCNPs doped with Yb3+ and Er3+ depending on size, different surroundings such as aqueous and organic media, and different surface chemistries. We obtained further insights into shelling procedures, FRET optimization, influence of doping concentration, and advantages of different sensitizer ions.
Das Presshärteverfahren hat sich zur ressourceneffizienten Verarbeitung von höchstfesten Stahlwerkstoffen im Karosserieleichtbau weltweit etabliert. Die fehlerfreie Bauteilproduktion wird jedoch durch Reibungs- und Verschleißerscheinungen aufgrund hoher thermo-mechanischer Werkzeugbelastungen und fehlender Schmierstoffsysteme limitiert. Als Lösungsansatz wird eine Modifikation der Werkzeugoberfläche mittels Laserimplantation angestrebt, um folglich deren Verschleißbeständigkeit nachhaltig zu erhöhen. Das Verfahren basiert auf einem lokalen Dispergieren keramischer Hartstoffpartikel in die Werkzeugoberfläche, infolgedessen hochfeste und erhabene Strukturen im Mikrometerbereich entstehen. Aufgrund der signifikanten Reduzierung der Kontaktfläche sowie der hohen Verschleißbeständigkeit der eingesetzten TiB2-Hartstoffe wird ein verbessertes tribologisches Einsatzverhalten unter presshärtetypischen Prozessbedingungen erwartet. Zur Verifizierung dieser Annahmen wurden im Rahmen dieser Arbeit modifizierte Pin-on-Disk Tests durchgeführt, um das Reib- und Verschleißverhalten der laserimplantierten Werkzeugoberflächen unter Presshärtebedingungen zu untersuchen. Zur weiteren Vertiefung des Prozess-verständnisses wurden die verschlissenen Platinen via Tastschnittmessungen und Querschliffaufnahmen analysiert. Durch den Ergebnisvergleich mit konventionellen Werkzeugoberflächen erfolgte eine abschließende Bewertung des tribologischen Einsatzverhaltens der laserimplantierten Strukturen.
This presentation reviews current and expected developments in the field of laser-induced periodic surface structures (LIPSS, ripples). These surface nanostructures are a universal phenomenon and can be generated on almost any material by irradiation with intense linearly polarized radiation. LIPSS are formed in a “self-ordered” way and are often accompanying laser material processing applications. The structures can be produced in a single-step process and enable surface functionalization through the adaption of optical, mechanical and chemical surface properties. Their spatial periods typically range from several micrometers down to less than 100 nanometers, exhibiting a clear correlation with the polarization direction of the laser radiation used. Various types of LIPSS have been classified, relevant control parameters were identified, and material specific formation mechanisms are analyzed for different types of inorganic solids, i.e., metals, semiconductors, and dielectrics, through time-resolved optical experiments and theoretical simulations. Special attention will be paid to a comparison of the currently available formation theories for LIPSS with a discussion of their respective strengths and weaknesses. Currrently explored applications featuring surface functionalization in the fields of optics, surface wetting, medicine, and tribology will be discussed.
This presentation reviews the current state in the field of Laser-induced Periodic Surface Structures (LIPSS). These surface nanostructures are a universal phenomenon and can be generated on almost any material by irradiation with intense linearly polarized laser radiation. LIPSS are formed in a “self-ordered” way and are often accompanying material processing applications. They can be produced following a single-step process and enable surface functionalization through the adaption of optical, mechanical and chemical surface properties. Their structural sizes typically range from several micrometers down to less than 100 nanometers exhibiting a clear correlation with the polarization direction of the laser radiation. Various types of surface structures are classified, relevant control parameters are identified, and their material specific formation mechanisms are analyzed for different types of inorganic solids, i.e., metals, semiconductors, and dielectrics, through time-resolved optical experiments and theoretical simulations. Finally, technological applications featuring surface functionalization in the fields of optics, fluidics, medicine, and tribology are discussed.
Mechanochemistry paves the way to simple, fast, and green syntheses. Despite considerable effort, there is a lack in understanding of the underlying mechanisms. In situ investigations help to understand these mechanisms, which occur during a mechanochemical reaction. Here we present a universal strategy for simultaneous real-time in situ analysis, combining X-ray diffraction, Raman spectroscopy, and thermography. The potential of of our approach is shown for diffrent model reactions.
Zuverlässigkeitsbetrachtungen bei der Ultraschallprüfung von Radsatzwellen im Ausbildungsbetrieb
(2019)
Im Rahmen des UT1 E W im Ausbildungszentrum Wittenberge der DGZfPwurden statistische Untersuchungen am Beispiel der Radsatzwellenprüfung mit Testradsatzwellen durchgeführt. Diese Untersuchungen hatten zum Ziel, die wesentlichen Einflussparameter bei der Handprüfung auf das Prüfergebnis zu evaluieren. Im Rahmen der Zuverlässigkeitsbetrachtung wurden die ProbabilityofDetection(POD) und die Nachweisgrenzen ermittelt.Die durchgeführte Studie zeigt, dass die Bewertung der gesamten Zuverlässigkeit der ZfP komplex ist. Dieses verlangt eine detaillierte Versuchsplanung und die Einbeziehung von unterschiedlichen Faktoren, von den Anwendungsparametern bis hin zu den komplexen menschlichen und organisatorischen Faktoren. Die im Rahmen der Studie ermittelten Ergebnisse lassen aufgrund der geringen Anzahl an Testreflektoren keine allgemeingültige Übertragung auf beliebige Korbbogen-geometrienund Reflektorgeometrienzu.
Bruchmechanische Untersuchungen werden zur Vorhersage der Lebensdauer und der Wartungszyklen benutzt. Dabei wird davon ausgegangen, dass auch Objekte ohne detektierte Anzeigen Materialfehler mit einer Reflektivität kleiner der Nachweisgrenze aufweisen können. Keine detektierte Anzeige bedeutet daher für Bauteilauslegung, dass sie eine konservative Annahme machen müssen: es wird angenommen, dass das Bauteil Materialfehler in Größe der Nachweisgrenze enthält. Dies macht die Nachweisgrenze zu dem die Lebensdauer limitierenden Faktor. Bei probabilistischen Methoden wird zusätzliches Wissen, wie Zuverlässigkeit und Fehlerauffindwahrscheinlichkeiten bei der zerstörungsfreien Prüfung mit in die Berechnung einbezogen, um zu konservative Annahmen zu vermeiden. Ziel ist es eine Model-Assisted-POD aufzubauen mit der die reale volumetrische Ultraschallprüfung großer Schmiedeteile nachgebildet werden kann. Die resultierende POD soll im Weiteren in bruchmechanischen Betrachtungen Verwendung finden. In vorangegangenen Arbeiten [Preißel2015] wurde dazu der Einfluss des Prüfrasters nach der DGZfP-Richtlinie US 07:2014 auf die Fehlerauffindwahrscheinlichkeit (parametrisch) simulativ betrachtet und die Simulationstechnik experimentell validiert. In diesem Paper werden die Ergebnisse von Preißel überprüft und um eine Prüfraster-Summen-POD, die das Szenario der realen Bauteilprüfung beschreibt, erweitert. Zudem wird eine experimentell validierte, simulative, nicht-parametrische POD für schrägliegende Defekte aufgebaut. Schließlich werden erste Untersuchungen zur Defektmorphologie vorgestellt. Diese Arbeit ist im Rahmen eines Studenten-Stipendiums der DGZfP entstanden.
Zuverlässigkeitsbetrachtungen bei der Ultraschallprüfung von Radsatzwellen im Ausbildungsbetrieb
(2019)
Im Rahmen der UT1-M1 Ausbildung im Ausbildungszentrum Wittenberge der DGZfP wurden statistische Untersuchungen am Beispiel der Radsatzwellenprüfung mit Testradsatzwellen durchgeführt. Diese Untersuchungen hatten zum Ziel, die wesentlichen Einflussparameter bei der Prüfung auf das Prüfergebnis zu evaluieren. Dabei wurde unter anderem die intrinsische Fähigkeit des Prüfverfahrens zum Auffinden verschiedener Reflektorgeometrien ermittelt. Die Ergebnisse der Handprüfung wurden mit Ergebnissen mechanisierter Prüfungen verglichen. Im Rahmen der Zuverlässigkeitsbetrachtung wurden die Probability of Detection (POD) und die Nachweisgrenzen ermittelt.
Ziel dieser Arbeit war es auch, menschliche und organisatorische Einflussfaktoren auf die Ultraschall-Handprüfung von Radsatzwellen zu identifizieren, um Empfehlungen zur Optimierung der Ausbildung auszuarbeiten. Dazu wurden prüfungsbezogene Risiken in der Praxis mittels Fehlzustandsart- und –auswirkungsanalyse (FMEA) analysiert sowie von den Prüfern empfundene Probleme während der Ausbildung und in der Praxis mittels Fragebogen identifiziert. Die Ergebnisse der FMEA haben gezeigt, dass während des gesamten Prozesses Fehler auftreten können, für die Gegenmaßnahmen getroffen und implementiert werden sollten. Aus den Hinweisen und Erkenntnissen wurden einige Empfehlungen zur Optimierung der Ausbildung erarbeitet.
The properties of fiber-reinforced polymers (CFRP) or concretes (ECC) strongly depend on the interface between the fiber and the surrounding matrix. Different methods such as plasma oxidation, chemical or electrolytic etching and chemical vapor deposition have been investigated to increase, for example, the bonding strength. The present study deals with the functionalization of the fiber surface based on laser-induced periodic surface structures (LIPSS). They can be characterized as a modulation of the surface topography on the nano- and microscale that results from the irradiation of the surface with linearly polarized laser radiation close to the ablation threshold. According to their spatial period, LIPSS are classified into low-spatial frequency LIPSS (LSFL) and high-spatial frequency LIPSS (HSFL). The great potential of both types of LIPSS structures regarding functional surface properties was demonstrated in numerous investigations. The objective of the present study was the homogenous manufacturing of both types of LIPSS on large areas of carbon fiber arrangements without damage. The results are discussed based on a detailed analysis of the topographic and chemical surface properties.
Laser-induced periodic surface structures (LIPSS, ripples) are a universal phenomenon that can be observed on almost any material after the irradiation by linearly polarized laser beams, particularly when using ultrashort laser pulses with durations in the femtosecond to picosecond range. During the past years significantly increasing industrial and research activities have been reported in the field of LIPSS, since their generation in a single-step process provides a simple way of nanostructuring and surface functionalization towards the control of optical, mechanical or chemical surface properties. In this contribution the mechanisms of formation and current trends and applications of LIPSS are reviewed, including the colorization of technical surfaces, the control of surface wetting properties, the mimicry of the natural texture of animals, the tailoring of surface colonization by bacterial biofilms, the advancement of leadless medical pacemakers, and the improvement of the tribological performance of nanostructured metal surfaces.
Two kinds of cyclic poly(D- and L-lactide)s were synthesized, namely CI labeled samples mainly consisting of even-numbered cycles with low dispersity and CII, CIII or CIV-labeled ones consisting of equal amounts of even and odd-numbered cycles with high dispersity and igher molecular weights (Mw up to 300 000). Furthermore, linear poly L-lactide)s were prepared by initiation with ethanol and in both series the molecular weight was varied. The formation of stereocomplexes from cyclic poly(D-lactide)s and all kinds of poly L-lactide)s was performed in dichloromethane/toluene mixtures. The stereocomplexes crystallized from the reaction mixture were characterized in the virgin state and after annealing at 205 °C.
Stereocomplexes free of stereohomopolymers with crystallinities up to 80% were obtained from all experiments in yields ranging from 60 to 80%. Despite the high annealing temperature (maintained for 1 h), little transesterification was observed and the crystallinity slightly increased.
Due to the favorable properties of polymers, their production and thus their input into the environment has increased significantly in recent decades. Currently, FTIR or Raman spectroscopy are mainly applied for the analysis of microplastic particles (MP) in environmental samples. However, these methods have great difficulties in determining metrologically traceable MP values, especially with regard to the limiting values, as preferred in regulation. Therefore, we developed a systematic and fast thermoanalytical method called TED-GC-MS (thermal extraction desorption gas chromatography mass spectrometry), which determines mass contents. Now the current goal is the determination of its process parameters.
This poster illustrates the theoretical requirements for MP analysis (left side) and contrast them with the current state of research (right side).Unexpected practical problems are presented and the relatively new method is discussed concerning the quality requirements of well-established methods such as LC-or GC-MS.
Wild bees are important pollinators for agricultural crops and solitary species such as Osmia bicornis are particularly suitable for pollination management. Wild bees share floral resources with managed honey bees and may be exposed to emerging infectious diseases. Although studies have explored the prevalence of pathogens in solitary wild bee species, data regarding the impact of pathogens on solitary bee health are lacking.
We carried out experiments examining whether the solitary bee species O. bicornis is susceptible to infection with the emerging pathogen The results obtained indicate that N. ceranae may be able to infect O. bicornis but its impact on host fitness is negligible: survival rates did not differ between Control and inoculated bees, although male survival was marginally lower after infection. To explore the possible field-relevance of our findings, we collected wild bees near an infected and a non-infected hive and showed that N. ceranae was shared between managed and wild bees, although only the in presence of infected honey bees.
The findings of the present study show that O. bicornis is susceptible to pathogen spillover and could act as a potential reservoir host for N. ceranae in pollinator networks. Additional studies on this species incorporating sublethal effects, multiple infections and other interacting stressors are warranted.
Der Duplexstahl 2205 bietet aufgrund seiner guten Korrosionsbeständigkeit und der hohen erreichbaren Festigkeitswerte bei guter Duktilität, zahlreiche Anwendungsmöglichkeiten. Jedoch wurde beim Schweißen von Duplexstählen eine Verschiebung des Gleichgewichts zwischen Austenit- und Ferritanteil hin zu höheren Ferritgehalten und damit negativen mechanischen und Korrosionseigenschaften beobachtet. Um diesem Umstand entgegenzuwirken, werden häufig spezielle Schweißzusätze mit höheren Nickelanteilen genutzt, welche bei dickwandigen Strukturen jedoch nicht über die gesamte Schweißnahttiefe nachgewiesen werden können. Dies führt zu unterschiedlichen Eigenschaften und einer höheren Korrosionsanfälligkeit im Wurzelbereich.
Eine Möglichkeit die gleichmäßige Verteilung von Legierungselementen innerhalb der Naht zu gewährleisten, bietet die Erzeugung von Pufferschichten mittels Laser-Pulver-Auftragschweißen (LPA). In diesem Zusammenhang wurden Duplexpulver mit unterschiedlichen Nickelgehalten und verschiedene LPA-Prozessparameter untersucht, die eine ebene Schichtbildung mit verringerten Ferritgehalten ermöglichen. In einem zweiten Schritt konnte nachgewiesen werden, dass das Laserstrahlschweißen der beschichteten Kanten bei üblichen Prozessparametern möglich ist und zu fehlerfreien Schweißnähten mit ausgeglichenem austenitisch- ferritischem Gefüge führt. Der Einfluss unterschiedlicher Schutzgase und verschiedener Nickelgehalte auf die Gefügestruktur wurde für die Beschichtungen und Laserstrahlschweißungen mit Hilfe von Schliffbildern und Electron Backscatter Diffraction (EBSD) ausgewertet, wobei gezeigt werden konnte, dass bei ausreichend hohem Nickelgehalt ein feinkörniges Gefüge sowohl in der Pufferschicht als auch der Schweißnaht vorliegt. Die Korrosionsbeständigkeit der Schweißnähte wurde durch Korrosionsuntersuchungen überprüft.
During the last years Additive Manufacturing (AM) became increasingly important. That becomes clear, while looking at the advantages like a high degree of freedom concerning the geometry of the parts, low waste rates and a reduction of postprocessing, to name just three. Laser Metal Deposition (LMD) is one of those AM- methods. It can be used for different kinds of applications, e.g. repair weldings of used parts, coatings to increase the corrosion resistance or to build up new components. But for all applications, the production of defect free parts is crucial. Therefore, different kinds of non-destructive monitoring techniques were tested for the LMD-process to identify their potential to detect imperfections in-situ.
Der Duplexstahl 2205 bietet aufgrund seiner guten Korrosionsbeständigkeit und der hohen erreichbaren Festigkeitswerte bei guter Duktilität, zahlreiche Anwendungsmöglichkeiten. Jedoch wurde beim Schweißen von Duplexstählen eine Verschiebung des Gleichgewichts zwischen Austenit- und Ferritanteil hin zu höheren Ferritgehalten und damit negativen mechanischen und Korrosionseigenschaften beobachtet. Um diesem Umstand entgegenzuwirken, werden häufig spezielle Schweißzusätze mit höheren Nickelanteilen genutzt, welche bei dickwandigen Strukturen jedoch nicht über die gesamte Schweißnahttiefe nachgewiesen werden können. Dies führt zu unterschiedlichen Eigenschaften und einer höheren Korrosionsanfälligkeit im Wurzelbereich.
Eine Möglichkeit die gleichmäßige Verteilung von Legierungselementen innerhalb der Naht zu gewährleisten, bietet die Erzeugung von Pufferschichten mittels Laser-Pulver-Auftragschweißen (LPA). In diesem Zusammenhang wurden Duplexpulver mit unterschiedlichen Nickelgehalten und verschiedene LPA-Prozessparameter untersucht, die eine ebene Schichtbildung mit verringerten Ferritgehalten ermöglichen. In einem zweiten Schritt konnte nachgewiesen werden, dass das Laserstrahlschweißen der beschichteten Kanten bei üblichen Prozessparametern möglich ist und zu fehlerfreien Schweißnähten mit ausgeglichenem austenitisch- ferritischem Gefüge führt. Der Einfluss unterschiedlicher Schutzgase und verschiedener Nickelgehalte auf die Gefügestruktur wurde für die Beschichtungen und Laserstrahlschweißungen mit Hilfe von Schliffbildern und Electron Backscatter Diffraction (EBSD) ausgewertet, wobei gezeigt werden konnte, dass bei ausreichend hohem Nickelgehalt ein feinkörniges Gefüge sowohl in der Pufferschicht als auch der Schweißnaht vorliegt. Die Korrosionsbeständigkeit der Schweißnähte wurde durch Korrosionsuntersuchungen überprüft.
Laser-induced periodic surface structures (LIPSS, ripples) are a universal phenomenon that can be observed on almost any material after the irradiation by linearly polarized laser beams, particularly when using ultrashort laser pulses with durations in the femtosecond to picosecond range. During the past years significantly increasing industrial and research activities have been reported in the field of LIPSS, since their generation in a single-step process provides a simple way of nanostructuring and surface functionalization towards the control of optical, mechanical, biological, or chemical surface properties. In this contribution the mechanisms of formation and current trends and applications of LIPSS are reviewed, including the colorization of technical surfaces, the control of surface wetting properties, the mimicry of the natural texture of animals, the tailoring of surface colonization by bacterial biofilms, the advancement of leadless medical pacemakers, and the improvement of the tribological performance of nanostructured metal surfaces.
Ein neuer Ansatz bei elektrochemischen Korrosionsuntersuchungen kann durch den Einsatz von gelartigen Elektrolyten als Alternative zu wässrigen Prüfelektrolyten beschritten werden. Gelartige Elektrolyte ermöglichen minimalinvasive Untersuchungen an natürlich gebildeten Zinkdeckschichten. Dadurch können korrosionsrelevante Kennwerte ermittelt werden, die Aussagen zur Deckschichtbildung und zur Stabilität von atmosphärisch gebildeten Deckschichten erlauben. In diesem Beitrag wird anhand verschiedener Untersuchungen an Reinzink der Mehrwert von gelartigen Elektrolyten für die Korrosionsforschung und -prüfung verdeutlicht. Darüber hinaus werden neue Erkenntnisse zur Deckschichtbildung von Zink unter atmosphärischen Bedingungen vorgestellt.
Ein neuer Ansatz bei elektrochemischen Korrosionsuntersuchungen kann durch den Einsatz von gelartigen Elektrolyten als Alternative zu wässrigen Prüfelektrolyten beschritten werden. Gelartige Elektrolyte ermöglichen minimalinvasive Untersuchungen an natürlich gebildeten Zinkdeckschichten. Dadurch können korrosionsrelevante Kennwerte ermittelt werden, die Aussagen zur Deckschichtbildung und zur Stabilität von atmosphärisch gebildeten Deckschichten erlauben. In diesem Beitrag wird anhand verschiedener Untersuchungen an Reinzink der Mehrwert von gelartigen Elektrolyten für die Korrosionsforschung und -prüfung verdeutlicht. Darüber hinaus werden neue Erkenntnisse zur Deckschichtbildung von Zink unter atmosphärischen Bedingungen vorgestellt.
Aluminum alloys are extensively used in the automotive industry. Particularly, squeeze casting production of Al-Si alloys is employed in the conception of metal matrix composites (MMC) for combustion engines. Such materials are of a high interest since they allow combining improved mechanical properties and reduced weight and hence improve efficiency. We investigate two types of MMCs, which can be potentially used for production of combustion engine pistons: 1) a near-eutectic cast AlSi12CuMgNi alloy reinforced with 15%vol. Al2O3 random planar oriented short fibers and 2) the same alloy reinforced with 7%vol. Al2O3 random planar oriented short fibers + 15%vol. SiC particles.
Complex 3D microstructure of the samples in as-cast condition, consisting of four and five phases (Al matrix, eutectic Si, intermetallics, Al2O3 fibers and SiC particles) was investigated by synchrotron computed tomography (CT). Advanced methods based on machine learning were applied for segmentation of all phases. This allowed extracting quantitative information such as volume fraction, shape and interconnectivity of every phase.
In-situ compression tests during neutron diffraction experiments were used to track the load transfer among phases, while CT on pre-strained samples to monitor and quantify damage. A micromechanical model was developed to simulate the evolution of the internal stress of each phase during uniaxial compression. We showed that in composites with the Al2O3 fiber mat plane perpendicular to the load axis the Al-alloy matrix presents a large hydrostatic stress component, i.e. undergoes compression also in the direction transverse to the external load. This feature holds with and without the addition of SiC ceramic reinforcement and is absent in the case when the Al2O3 fiber mat plane is parallel to the load axis. We show, that the intermetallics play a decisive role at very high loads, when all other reinforcement phases suffer (extensive) damage. The addition of SiC particles does alleviate the load on the Al2O3 fibers, on the eutectic Si, and on the intermetallic phases in both cases of parallel and orthogonal (to the load axis) Al2O3 fiber orientation. Apart from the beneficial addition of ceramic reinforcement, the presence of intermetallic phase and eutectic silicon, forming an interconnected network even at high loads, when single particles break, confers peculiar properties to these multi-phase composites.
Are we ready for putting a human footprint on Mars? Obviously, it is possible to send technologically challenging missions to our earth neighbors with a high level of complexity, such as enabling autonomous planetary mobility. As humanity contemplates mounting manned missions to Mars, strategies need to be developed for the design and operation of hospitable environments safely working in space for years. Humans require water and air provided by complicated equipment. Its safe operation is a great challenge and implies being prepared for all eventualities. Instead of foreseeing and preparing for all possible scenarios of machine failures and accidents, it appears logic taking advantage of the flexibility of humans and providing essential equipment for the reaction on critical situations. The supply of spare parts for repair and replacement of lost equipment would be one key pillar of such a strategy. Bearing in mind the absolute distance and flight trajectories for manned missions to Mars, supplying spare parts from Earth is impossible. Thus, in space manufacturing remains the only option for a timely supply. With a high flexibility in design and the ability to manufacture ready to use components directly from a computer aided model, additive manufacturing technologies appear extremely attractive. For metal parts manufacturing the Laser Beam Melting process is the most widely used additive manufacturing process in industrial application. However, envisioning the handling of metal powders in the absence of gravitation is one prerequisite for its successful application in space. A gas flow throughout the powder bed has been successfully applied to compensate for missing gravitational forces in micro gravity experiments. The so-called Gas Flow Assisted Powder Deposition is based on a porous building platform acting as a filter for the fixation of metal particles in a gas flow driven by a pressure difference maintained by a vacuum pump.
Are we ready for putting a human footprint on Mars? Obviously, it is possible to send technologically challenging missions to our earth neighbors with a high level of complexity, such as enabling autonomous planetary mobility. As humanity contemplates mounting manned missions to Mars, strategies need to be developed for the design and operation of hospitable environments safely working in space for years. Humans require water and air provided by complicated equipment. Its safe operation is a great challenge and implies being prepared for all eventualities. Instead of foreseeing and preparing for all possible scenarios of machine failures and accidents, it appears logic taking advantage of the flexibility of humans and providing essential equipment for the reaction on critical situations. The supply of spare parts for repair and replacement of lost equipment would be one key pillar of such a strategy. Bearing in mind the absolute distance and flight trajectories for manned missions to Mars, supplying spare parts from Earth is impossible. Thus, in space manufacturing remains the only option for a timely supply. With a high flexibility in design and the ability to manufacture ready to use components directly from a computer aided model, additive manufacturing technologies appear extremely attractive. For metal parts manufacturing the Laser Beam Melting process is the most widely used additive manufacturing process in industrial application. However, envisioning the handling of metal powders in the absence of gravitation is one prerequisite for its successful application in space. A gas flow throughout the powder bed has been successfully applied to compensate for missing gravitational forces in micro gravity experiments. The so-called Gas Flow Assisted Powder Deposition is based on a porous building platform acting as a filter for the fixation of metal particles in a gas flow driven by a pressure difference maintained by a vacuum pump.
Many of the most successful and precise additive manufacturing (AM) technologies are based on the deposition layer-by-layer of a flowable powder. Since the first pioneering work at the end of the 1980th many developments have been introduced, greatly extending the use of different materials, improving the physical properties of the components built and enhancing the accuracy of the process. Still very important issues remain nowadays, hampering a completely autonomous production of parts and even restricting the freedom of design by means of these technologies. One of the major issues is the low density and stability of the parts during the building process, which implies the need of support structures: The powder bed surrounding the part has an essential role, since it should support the structure during building, until it’s ready for removal. Moreover, the microstructure of the powder bed is a template for the microstructure of the part produced. In this context, the use of submicron ceramic powders is still a challenge. Three approaches for the stabilization and densification of powder beds will be presented: The Layerwise Slurry Deposition process LSD, the gas flow assisted powder deposition and the Laser Induced Slipcasting (LIS) of ceramic powder compacts.
Biomaterials for bone replacement and grafting should possess sufficient strength, be bioresorbable and demonstrate osteoconductive and osteoinductive properties. However, resorption of modern materials for bone grafting (hydroxyapatite (HA) and tricalcium phosphate (TCP)) is reported, in some cases, to be not enough, this is why the search for more soluble compounds compared to HA and TCP looks very perspective. A possible way to increase ceramics solubility leads to partial substitution of Ca2+ -ions in Ca3(PO4)2 by alkali cations, like Na+ or/and K+. Improvement of solubility stems from decreasing lattice energy of a substituted phase, as well as the increase in hydration energy of the ions releasing from the phase to ambient solution. From this viewpoint, bioceramics based on compositions from Ca3(PO4)2 - CaKPO4 - CaNaPO4 ternary system seems to be prospective for bone replacement and grafting in the sense of resorption properties. At the same time, one should bear in mind that solubility level (resorbability) is governed not only by reduction of lattice energy but also by microstructure features. Grain sizes and porosity contribute much to dissolution rate making the study of sintering of the ceramics mentioned above highly important.
To control Ca3(PO4)2 - CaKPO4 - CaNaPO4 based ceramic microstructure it is necessary to know possible phase transformations in the system and the way to manage microstructure by sintering schedule or sintering process.
In this work, an isothermal section for phase diagram of Ca3(PO4)2 - CaKPO4 - CaNaPO4 ternary system is studied with several techniques. According to the XRD of quenched samples, this phase triangle has four single-phase areas at 1200˚C (Figure 1). It was shown that single-phase CaK0.6Na0.4PO4 cannot be sintered to full-dense ceramics by conventional sintering regardless time-temperature schedule. Two-step sintering technique, beneficial in the case of HA-ceramics, was unsuccessful in all cases of calcium-alkali phosphate compositions. However, field-assisted sintering techniques like, e.g. Spark Plasma Sintering (SPS), can overcome this problem due to significant impact on grain boundary diffusion. In connection with this fact, grains grow much slower retaining sintering process in a pore control regime. In this work CaK0.6Na0.4PO4 low-porous ceramics was also fabricated by FAST-methods of sintering. Moreover, other alternative sintering techniques, such as reaction sintering, may be useful in accelerating ions diffusion but stopping excessive grain growth.Strength properties of ceramics were evaluated by B3B-testing, micro- and nanoindentation techniques. Fracture toughness also becomes higher with potassium content increase, guiding porosity level.
Resorption properties of sintered ceramics were studied in different solutions with pH=5 and 7.4.
Acknowledgements. The research of sintering processes in calcium phosphate materials were funded by RFBR according to the research project № 18-33-00974.
An investigation of the two-component phase diagram of the CaNaPO4- CaKPO4system performed using various analysis techniques is reported. The continuous solid solution series of α-CaMPO4 existing above 700 °C undergoes eutectoid decomposition during cooling to β-CaMPO4-based solid solutions enriched with Na and K, and to an intermediate nonstoichiometric compound with an ideal composition of CaK0.6Na0.4PO4. All three compounds exhibit significant volumetric effects associated with first-order phase transitions, with positive volume changes under cooling for the intermediate compound. Increased K content in ceramics based on CaKyNa1-yPO4 compositions enhances the strength properties of those ceramics, including their fracture toughness, which is associated with increased density. Increased K content also has a smaller effect of inducing phase transformations accompanied by strong volume changes.
The crystallization behavior of sodium ion conductive Na2MnP2O7 glass was examined to clarify the crystallization mechanism. The formation of thermodynamically metastable phase, layered Na2MnP2O7, at the surface of the glass occurred. Heat treatment at 430 °C for 3 h lead to surface crystals of Na2MnP2O7 oriented with the (101) direction perpendicular to the sample surface. As the heat treatment temperature increased, the glass-ceramic samples deformed, and the presence numerous micro bubbles due to dissolved water was detected.