5 Werkstofftechnik
Filtern
Dokumenttyp
- Vortrag (358) (entfernen)
Sprache
- Englisch (358) (entfernen)
Referierte Publikation
- nein (358)
Schlagworte
- Additive Manufacturing (43)
- Additive manufacturing (23)
- Microstructure (21)
- Corrosion (20)
- Ontology (20)
- Glass (19)
- Ceramics (13)
- Fatigue (12)
- Ceramic (9)
- Crack growth (9)
- Creep (9)
- Sintering (9)
- Transmission electron microscopy (9)
- 316L (8)
- Diffraction (7)
- Thermoelectrics (7)
- CCUS (6)
- EBSD (6)
- Fractography (6)
- High entropy alloys (6)
- Powder (6)
- Robotic melting (6)
- Scanning electron microscopy (6)
- Slurry (6)
- 3D printing (5)
- AGIL (5)
- Anisotropy (5)
- Crystal plasticity (5)
- Crystallization (5)
- DCB (5)
- Degradation (5)
- FAIR (5)
- FAIR data management (5)
- Glass fiber reinforced polymers (5)
- LCF (5)
- Layerwise slurry deposition (5)
- Oxidation (5)
- Residual Stress (5)
- Ti-6Al-4V (5)
- Water speciation (5)
- Alloy 2618A (4)
- Aluminium (4)
- CALPHAD (4)
- CCS (4)
- CO2 (4)
- Coarsening (4)
- Creep behavior (4)
- Digitalization (4)
- Droplet corrosion (4)
- EN AW-2618A (4)
- Fatigue crack growth (4)
- Fe-Al alloys (4)
- Foaming (4)
- High-temperature corrosion (4)
- In situ (4)
- In-space manufacturing (4)
- Intermetallics (4)
- Iron aluminides (4)
- Knowledge graph and ontologies (4)
- Laser powder bed fusion (4)
- Machine Learning (4)
- Martensitic steel (4)
- Mechanical properties (4)
- Microgravity (4)
- Neutron diffraction (4)
- Nickel-base superalloys (4)
- Non-destructive testing (4)
- Polymer matrix composites (4)
- Semantic Interoperability (4)
- Simulation (4)
- Sulfidation (4)
- Supercritical/dense phase CO2 (4)
- Workflow (4)
- AISI 316L (3)
- Additive Fertigung (3)
- Advanced ceramics (3)
- Alkali ions (3)
- Alumina (3)
- Aluminium Alloy (3)
- Aluminium alloy (3)
- CCU (3)
- Carbon steels (3)
- Ceramic spring (3)
- Computed Tomography (3)
- Data Interoperability (3)
- Data Space (3)
- Dielectric strength (3)
- Geothermal (3)
- Glas (3)
- Heat treatment (3)
- High temperature corrosion (3)
- Laser Powder Bed Fusion (3)
- Low Cycle Fatigue (3)
- Mechanical behavior (3)
- Mechanical testing (3)
- Nanoparticles (3)
- PMD (3)
- PMD Core Ontology (3)
- Residual stress (3)
- S-phase (3)
- Scarf repairs (3)
- Scintillators (3)
- Silicate Glasses (3)
- Soda-lime silicate glass (3)
- Spectroscopy (3)
- Superaustenite steel (3)
- Tensile Test Ontology (3)
- Texture (3)
- Thermomechanical fatigue (3)
- Transmission electron microscopy (TEM) (3)
- Vickers (3)
- Water content (3)
- Welding (3)
- Wind turbine blades (3)
- X-ray diffraction (3)
- μ-gravity (3)
- Alkali zinc borate glasses (2)
- CO2 quality (2)
- Carbon capture (2)
- Carbon capture storage (2)
- Carbon dioxide (2)
- Carbon steel (2)
- Characterization (2)
- Chemically complex alloy (2)
- Composites (2)
- Concrete (2)
- Copper (2)
- Crack tip opening displacement (2)
- Creep data (2)
- Dark-field transmission electron microscopy (2)
- Data mapping (2)
- Dielectric breakdown (2)
- Diffraction Elastic Constants (2)
- Digital image correlation (2)
- Digitization (2)
- Digtial Representation (2)
- Diopside (2)
- Dislocation (2)
- EDXRD (2)
- Electron Backscatter Diffraction (2)
- Electron microscopy (2)
- Electron-beam-induced modification (2)
- Electronic Lab Notebook (2)
- Environmental stress cracking (2)
- Ferritic-martensitic steels (2)
- Fracture Toughness (2)
- Fracture surface (2)
- Gender gap (2)
- Gitterkonstanten (2)
- Glass Digital (2)
- Glass-ceramics (2)
- Hard machining (2)
- High Cycle Fatigue (2)
- High Entropy Alloy (2)
- High Temperature Corrosion (2)
- High entropy alloy (2)
- High temperature (2)
- High temperature mechanical properties (2)
- High-entropy alloy (2)
- High-entropy alloys (2)
- Impurities (2)
- In-situ (2)
- Interoperability (2)
- Joined nickel-based alloys (2)
- Knowledge Representation (2)
- LSD-print (2)
- Laser (2)
- Laser Powder Bed fusion (2)
- Laser beam melting (2)
- Layerwise (2)
- Lunar regolith simulant (2)
- Material digital (2)
- Microplastics (2)
- Microstrucrue Design (2)
- Microstructural analysis (2)
- Microstructure Design (2)
- Mixed gas atmosphere (2)
- Modeling (2)
- Multifunctional nanoparticles (2)
- Multilayer (2)
- Multilayer technology (2)
- NDT (2)
- Notches (2)
- Ontologie (2)
- Ontology development (2)
- Orientation (2)
- Oriented surface crystallization (2)
- Oxidation behavior (2)
- Oxide Glasses (2)
- PBF-LB/M/316L (2)
- PE-HD (2)
- Particle size (2)
- Phasenidentifikation (2)
- Pipeline (2)
- Plattform Material Digital (2)
- Plattform MaterialDigital (2)
- Process monitoring (2)
- Push-out Test (2)
- Reaction sintering (2)
- Research Data Management (2)
- Residual Stresses (2)
- Ressidual stress (2)
- Rotor blade (2)
- SEM (2)
- Scale-bridging (2)
- Selective Laser Melting (2)
- Semantic Data (2)
- Semantic Representation (2)
- Semantic Web Technologies (2)
- Silicon Carbide (2)
- Silver diffusion (2)
- Silver-glass-metallization-paste (2)
- Sintering additives (2)
- Spray drying (2)
- Spring constant (2)
- Standard (2)
- Standardization (2)
- Superalloy (2)
- Surface energy (2)
- Tensile Test (2)
- Tensile data (2)
- Tensile test (2)
- Thermo-Mechanical Fatigue (2)
- Thermoelectric (2)
- Topography (2)
- Transparent ceramics (2)
- Two Photon Polymerization (2)
- UV-irradiation (2)
- Ultrasound (2)
- Virtual experiments (2)
- Viscoplasticity (2)
- Viscosity (2)
- Wall thickness (2)
- Wind turbine blade shells (2)
- XANES (2)
- Zero-g (2)
- µ-gravity (2)
- 3D (1)
- 3D Reconstruction (1)
- 3D glass structure model (1)
- 3D materialography (1)
- 3D-printing (1)
- 9-12% Cr ferritic-martensitic steels (1)
- AM (1)
- Accelerated integration scheme (1)
- Acids (1)
- Active thermography (1)
- Adiabatic shear bands (1)
- Advanced manufacturing (1)
- Aerospace (1)
- Ageing (1)
- Agglomerates (1)
- Aggressive gases (1)
- Aging (1)
- Air-coupled ultrasonic testing (1)
- Airborne ultrasonic testing (1)
- Al-Li alloys (1)
- Alkali zinc borate glass (1)
- Aluminum (1)
- Aluminum alloys (1)
- Analysis (1)
- Annealing (1)
- Atmospheric plasma spraying (1)
- Austenitic cast iron (1)
- Austenitic steel 316L (1)
- Automatable digital approach (1)
- Automation (1)
- Biaxial strength (1)
- Binder Jetting (1)
- Binder jetting (1)
- Bioactive (1)
- Bioactive Glass (1)
- Bioceramic (1)
- Bioceramics (1)
- Biodiesel (1)
- Blähen (1)
- Bond energy (1)
- Breakdown strength (1)
- Brinell hardness (1)
- CO2-corrosion (1)
- Calcination (1)
- Calcium cobaltite (1)
- Calcium manganate (1)
- Calcium sulfates (1)
- Calibration (1)
- Cantor alloy (1)
- Capture (1)
- Carbon (1)
- Carbon steels (1)
- Carbon Capture (1)
- Carbon Capture, Utilization and Storage (CCUS) (1)
- Carbon Fiber Reinforced Plastics (1)
- Carbon Fibers (1)
- Casting (1)
- Centrifugal casting (1)
- Ceramic multilayer (1)
- Ceramic springs (1)
- Certification Standard 22 (1)
- Certified Referencematerial (1)
- Chemically complex alloys (1)
- Chemo-mechanical coupling (1)
- Chromatography (1)
- Chromia (1)
- Chromium oxide (1)
- Co-firing (1)
- Co-segregation (1)
- Coatings (1)
- Complex borides (1)
- Complex loading (1)
- Component assessment (1)
- Composite (1)
- Composite materials (1)
- Composite testing (1)
- Compositionally complex alloys (1)
- Computed tomography (1)
- Condensation (1)
- Contamination (1)
- Continnum damage model (1)
- Cooling simulations (1)
- Cow stress (1)
- Cr2O3 (1)
- Crack Propagation (1)
- Crack evolution (1)
- Crack propagation (1)
- Creep anisotropy (1)
- Creep behaviour (1)
- Creep-Fatigue (1)
- Creep-fatigue (1)
- Crevice corrosion (1)
- Cross linking (1)
- Crystal Defects (1)
- Crystal Orientation (1)
- Crystal Plasticity Modelling (1)
- Cubical Iron Oxide (1)
- Cure process (1)
- Cycle jump (1)
- Cyclic R-Curve (1)
- Cyclic oxidation (1)
- Cyclic softening (1)
- Damage (1)
- Damage Behavior (1)
- Damage Tolerance (1)
- Damage behavior (1)
- Damage mechanisms (1)
- Dark-field transmission electron microscopy (DFTEM) (1)
- Data Exchange (1)
- Data Fusion (1)
- Data Management (1)
- Data Structures (1)
- Data linking (1)
- Data management (1)
- Data pipeline concept (1)
- Data space (1)
- Data storage (1)
- Data structure (1)
- Deep learning (1)
- Defects (1)
- Defects phase diagram (1)
- Defects thermodynamics (1)
- Deformation behavior (1)
- Density-based Thermodynamics (1)
- Density-based model (1)
- Density-based phase-field modelling (1)
- Dental (1)
- Dental ceramics (1)
- Destabilization (1)
- Die casting (1)
- Dielectric breakdown strength (1)
- Dielectric characterization (1)
- Diesel (1)
- Diffraction Enhanced Imaging (1)
- Diffraction contrast (1)
- Diffusion (1)
- Diffusion coefficient (1)
- Digital Transformation (1)
- Digital Twin (1)
- Digital representation (1)
- Digital workflow (1)
- Dislocation substructure (1)
- Dislocations (1)
- Disordered assemblies (1)
- Dispersion process (1)
- Dissimilar metal weld (1)
- Dissolved water (1)
- Distribution function (1)
- Driving physical mechanism (1)
- Dual-energy (1)
- Dynamic mechanical analysis (1)
- Dynamic mechanical analysis (DMA) (1)
- Dynamisch Mechanische Analyse (1)
- EAC-1A (1)
- EASA (1)
- EDX (1)
- EN AW 2618A (1)
- EPR (1)
- Early oxidation (1)
- Elastic constants (1)
- Elctronic Lab Notebook (1)
- Electric field distribution (1)
- Electric field strength (1)
- Electrical insulation (1)
- Electron Microscopy (1)
- Electron backscatter diffraction (1)
- Electron backscattered diffraction (EBSD) (1)
- Environmental Stress Cracking (1)
- Etching (1)
- FAIR Data Management (1)
- FAIR data (1)
- FCH JU (1)
- FIB (1)
- FT-IR (1)
- Fabrication method (1)
- Failure test (1)
- Fatigue Crack Growth (1)
- Fatigue Life Evaluation (1)
- Fatigue damage (1)
- Fatigue fracture (1)
- Fatigue of sandwich shell structures (1)
- Fatigue of sandwich structures (1)
- Fatigue performance (1)
- FeCr- alloys (1)
- Feldspar (1)
- Fem (1)
- Female noble prize winners (1)
- Ferritic Alloys (1)
- Ferroelectret (1)
- Fiber (1)
- Fiber reinforced polymer (1)
- Fiber reinforced polymers (1)
- Fine Powder (1)
- Finite element analysis (1)
- Finite elmenet simulation (1)
- Flowability (1)
- Fluorescence spectroscopy (1)
- Fluoride phosphate glasses (1)
- Force-distance diagram (1)
- Fracture Mechanics (1)
- Fracture Surface Analysis (1)
- Fracture behavior (1)
- Fracture surface analysis (1)
- Fracture toughness (1)
- Freeze Drying (1)
- Full Notch Creep Test (1)
- Full-Notch Creep Test (FNCT) (1)
- GD-OES (1)
- Gas storage (1)
- Gasabgabe (1)
- Gasgehalt (1)
- Geopolymers (1)
- Glass Fibres (1)
- Glass composition (1)
- Glass fibre reinforced plastics (1)
- Glass melting (1)
- Glass powder (1)
- Glass screening device (1)
- Glasses (1)
- Gold nanoparticle synthesis (1)
- Gold nanoparticles (1)
- Gradient-enhanced damage (1)
- Grain boundaries (1)
- Grain boundary engineering (1)
- Granules (1)
- Graphic design (1)
- HEA (1)
- Hardness (1)
- Heat Treatment (1)
- Heat Treatments (1)
- Heißgasextraktion (1)
- High Entropy Alloys (1)
- High Temperature Testing (1)
- High energy radiation (1)
- High entropy superalloys (1)
- High-Temperature Corrosion (1)
- High-density polyethylene (1)
- Hochentropie-Legierung (1)
- Horizon 2020 (1)
- Host-guest hybrid materials (1)
- Hot Press (1)
- Hot isostatic pressing (1)
- Hot pressing (1)
- Hydrogen (1)
- Hydrogen permeation (1)
- Hydrogen sensor (1)
- Hydrogen sensors (1)
- Hyper-arid (1)
- IN738LC (1)
- IR (1)
- ISRU (1)
- Implant failures (1)
- Implants (1)
- In situ tensile test (1)
- In-Situ Testing (1)
- Inconel 686 coating (1)
- Inconel 718 (1)
- Infrastructure (1)
- Initial attachment (1)
- Injection (1)
- Interface Strength (1)
- Interfacial Spinodal (1)
- Internal friction (1)
- Inverse ostwald ripening (1)
- Investment casting (1)
- Iron oxide nanoparticles (1)
- Knowledge Graphs (1)
- Knowledge graph (1)
- Kristallisation (1)
- L-PBF (1)
- LTCC (1)
- Laminography (1)
- Laser Poeder Bed Fusion (1)
- Laser Scanning Microscopy (LSM) (1)
- Laser cladding (1)
- Laser curing (1)
- Laser induced slipcasting (1)
- Lattice misfit (1)
- Layer depostion (1)
- Layerwise Slurry Deposition (1)
- Legierung mit komplexer Zusammensetzung (1)
- Li-ion battery (1)
- Life cycle (1)
- Lightweight materials (1)
- Lightweighting (1)
- Lithium Ion Batteries (1)
- Localized plasmons (1)
- Long-term storage (1)
- Low cycle fatigue (1)
- Low-Cycle-Fatigue (1)
- Low-cycle-fatigue behaviour (1)
- Lunar habitat (1)
- MEA (1)
- Manganese oxide (1)
- Manufacturing (1)
- Martensitic steel (1)
- Mat-o-lab (1)
- Material Digital (1)
- Material Life Cycle (1)
- Material defects (1)
- MaterialDigital (1)
- Materials Data Space (1)
- Materials Modelling (1)
- Materials Science (1)
- Materials and Processes Data Reusability (1)
- Materials science (1)
- Materials testing (1)
- Mechanical and thermal testing (1)
- Mechanistic Modelling (1)
- Medium Entropy Alloys (1)
- Medium entopy alloy (1)
- Medium-entropy alloy (1)
- Melt pool boundary (1)
- Metadata schema (1)
- Metallic components (1)
- Metallic silver precipitates (1)
- Metallography (1)
- Micro-shrinkages (1)
- Microbiologically influenced corrosion (1)
- Microhardness (1)
- Micromechanical model (1)
- Microstructural characterization (1)
- Microstructural evolution (1)
- Microstructural orientation (1)
- Microstructure Characterization (1)
- Microstructure Evolution (1)
- Microstructure characterisation (1)
- Microstructure design (1)
- Microstructure evolution (1)
- Microstructure modification (1)
- Microstructure-property-correlation (1)
- Mid-Level Ontology for MSE (1)
- Mikroplastik (1)
- Mikrostruktur (1)
- Mixed Ca-K-Na phosphates (1)
- Mn3O4 (1)
- Monte-Carlo Simulation (1)
- Mortar (1)
- Mortel (1)
- Multi-principal element alloys (1)
- Multilayertechnik (1)
- NIST (1)
- NTE (1)
- Na and K rhenanites (1)
- Nano particle (1)
- Nano screening (1)
- Nano-assemblies (1)
- Nano-powder (1)
- Nanoparticle synthesis (1)
- Nanoplattform (1)
- Negative charged microparticle (1)
- Neutron Diffraction (1)
- New standards (1)
- Ni-Resist (1)
- Nickel-base superalloy (1)
- Noble metal nanoparticles (1)
- Non-desired foaming (1)
- Nondestructive testing (1)
- Normung (1)
- Nucleation (1)
- Nucleation mode (1)
- Online quality control (1)
- Ontologies (1)
- Ooxidation (1)
- Optic (1)
- Optical properties (1)
- Optical properties of glasses and ceramics (1)
- Optical spectroscopy (1)
- Overaging (1)
- Oxide glass (1)
- P92 (1)
- P92 steels (1)
- PA6.6 (1)
- PMDco (1)
- PPA (1)
- Paving (1)
- Persistent luminescence (1)
- Persistent luminescent (1)
- Phase Diagrams (1)
- Phase Separation (1)
- Phase analysis (1)
- Phase diagram (1)
- Phase field simulation (1)
- Phase separation (1)
- Phase transformation (1)
- Phase transformations (1)
- Phase-Field Simulation (1)
- Phase-Field Simulations (1)
- Phase-field Simulation (1)
- Phase-field simulation (1)
- Phosphors (1)
- Photodynamic therapy (1)
- Photon counting detector (1)
- Physically based material model (1)
- Physics-informed Neural Network (1)
- Pipeline network (1)
- Planetary surface (1)
- Platform Material Digital (1)
- Platform Material Digital (PMD) (1)
- Platform MaterialDigital (1)
- Platform MaterialDigital (PMD) (1)
- Pole figures (1)
- Polyaniline (1)
- Polyethylen (1)
- Polyethylene, PE-HD (1)
- Polymer (1)
- Polymer Matrix Composite (1)
- Polymer Matrix Composites (1)
- Porcelain (1)
- Pores (1)
- Powder deposition (1)
- Power plant (1)
- Precipitation (1)
- Precipitation Analysis (1)
- Precipitation hardening (1)
- Preparation (1)
- Pressure assisted sintering (1)
- Pressure-assisted sintering (1)
- Protective coating (1)
- Quantitative Precipitation Analysis (1)
- Quantitative image analysis (1)
- Quantum dots (1)
- Radiation-matter interaction (1)
- Rafting (1)
- Raman (1)
- Recommendations (1)
- Recycling (1)
- Reference data (1)
- Reference material (1)
- Referenzdaten (1)
- Refractory chemically complex alloy (1)
- Refractory chemically complex alloys (1)
- Relaxation (1)
- Relaxation metallic glasses (1)
- Relaxationsphänomene (1)
- Repair of sandwich shell structures (1)
- Reproducibility (1)
- Residual stress analysis (1)
- Residual stresses (1)
- Resistance (1)
- Reusability (1)
- Review (1)
- Roboter (1)
- Robotic glass melting (1)
- Roughness (1)
- S355 steel sheet (1)
- SHM (1)
- SIMS (1)
- SLM (1)
- Safety assessment (1)
- Sailplane Development Panel (1)
- Sandwich (1)
- Sandwich structures (1)
- Scanning Electron Microscopy (SEM) (1)
- Scanning electron microscope (1)
- Scanning transmission electron microscopy (STEM) (1)
- Scarf joint repair (1)
- Screen printing (1)
- Selective laser melting (1)
- Semantic Interioerability (1)
- Semantic Web (1)
- Semantic structuring (1)
- Semantic web (1)
- Sensing (1)
- Sensor (1)
- SiO2 (1)
- Sibayak (1)
- Silicatglas (1)
- Silver cluster (1)
- Silver metallization paste (1)
- Silver precipitates (1)
- Silver-glass metallization paste (1)
- Simulation of concrete (1)
- Single-Crystal (1)
- Single-crystals (1)
- Sinter additive (1)
- Sintering atmosphere (1)
- Sintern (1)
- Slow crack growth (1)
- Small-Angle X-ray Scattering (1)
- Soda-lime-silica glass (1)
- Sol-gel coating (1)
- Solar sintering (1)
- Solid solution strengthening (1)
- Space exploration (1)
- Spark plasma sintering (1)
- Spinodal Decomposition (1)
- Split Hopkinson bar (1)
- Spring constant (1)
- Stainless steel (1)
- Steel (1)
- Storage (1)
- Strain rate dependence (1)
- Structure (1)
- Structure property correlations (1)
- Structure-property correlation (1)
- Structured heating (1)
- Subsurface defects (1)
- Sulfiding (1)
- Superalloys (1)
- Superaustenite steel (1)
- Supercritical/dense phase CO 2 (1)
- Superlegierung (1)
- Surface Energy (1)
- Surface Nucleation (1)
- Surface crystallization (1)
- Surface nucleation (1)
- Synchrotron CT (1)
- Synchrotron radiation (1)
- Syngle Crystal alloy (1)
- Synthetic air (1)
- TAHYA (1)
- TED (1)
- TED-GC-MS (1)
- TEM (1)
- TMF (1)
- TMF experiments (1)
- Temperature (1)
- Temperature driven process (1)
- Tempered Martensite Ferritic Steels (1)
- Tempered martensite ferritic steel (1)
- Tempered martensite ferritic steels (1)
- Tensile Properties (1)
- Tensile stress relaxation (1)
- Tensile testing (1)
- Texturation (1)
- Theranostics (1)
- Thermal degradation (1)
- Thermal stress (1)
- Thermo mechanical fatigue (1)
- Thermo-mechanical fatigue (1)
- Thermo-mechanical-loading (1)
- Thermo-optical measurement (1)
- Thermoanalytical Methods (1)
- Thermoelectric generator (1)
- Thermoelectric oxide (1)
- Thermogravimetric analysis (1)
- Thermogravimetry (1)
- Thermomechanics (1)
- Thermoset polymers (1)
- Thesaurus (1)
- Titanium (1)
- Tomography (1)
- Tools (1)
- Under cyclic loading (1)
- Upconversion (1)
- Upconversion nanoparticles (1)
- Utilization (1)
- Utilization, and storage (CCUS) technology (1)
- VCSEL (1)
- VSSA (1)
- Vacuum hot extraction (1)
- Vickers hardness (1)
- Viscose sintering (1)
- Wasser (1)
- Waste water (1)
- Water-based (1)
- Weibull Distribution (1)
- Weibull distribution (1)
- Welding processing influences (1)
- White light emitters (1)
- Whole-chain CCS scenario (1)
- Wind energy (1)
- Wind turbine (1)
- Wind turbine blade shell structures (1)
- Withstand voltage tests (1)
- Women in science (1)
- Workshop (1)
- X-Ray Diffraction (1)
- X-ray imaging (1)
- X-ray laminography (1)
- X-ray refraction (1)
- XRD (1)
- alumina (1)
- arbon capture (1)
- carbon steel (1)
- ceramic (1)
- ceramics (1)
- condensate (1)
- corrosion (1)
- dental (1)
- electrochemical characterization (1)
- impurities (1)
- microstructure analysis (1)
- multi scale testing (1)
- pitting corrosion (1)
- selective laser melting (1)
- utilization, and storage (CCUS) technology (1)
- volume resistivity (1)
Organisationseinheit der BAM
- 5 Werkstofftechnik (358) (entfernen)
Due to the advantages of Laser Powder Bed Fusion (PBF-LB), i.e., design freedom and the possibility to manufacture parts with filigree structures, and the considerable amount of knowledge available for 316L in its conventional variant, the mechanical behavior, and related microstructure-property relationships of PBF-LB/316L are increasingly subject of research. However, many aspects regarding the - application-relevant - mechanical behavior at high temperatures are not yet fully understood. Here, we present the results of an experimental study on the LCF behavior of PBF-LB/316L featuring a low defect population, which makes this study more microstructure-focused than most of the studies in the literature. The LCF tests were performed between room temperature (RT) and 600 °C. The mechanical response is characterized by strain-life curves, and hysteresis and cyclic deformation curves. The damage and deformation mechanisms are studied with X-ray computed tomography, and optical and electron microscopy. The PBF-LB/M/316L was heat treated at 450 °C for 4 h, and a hot‑rolled (HR) 316L variant with a fully recrystallized equiaxed microstructure was tested as a reference. Besides, selected investigations were performed after a subsequent heat treatment at 900 °C for 1 h. The PBF-LB/316L exhibits higher cyclic stresses than HR/316L for most of the fatigue life, especially at room temperature. At the smallest strain amplitudes, the fatigue lives of PBF-LB/M/316L are markedly shorter than in HR/316L. The main damage mechanisms are multiple cracking at slip bands (RT) and intergranular cracking (600 °C). Neither the melt pool boundaries nor the gas porosity have a significant influence on the LCF damage mechanism. The cyclic stress-strain deformation behavior of PBF-LB/M/316L features an initial hardening followed by a continuous softening. The additional heat treatment at 900 °C for 1 h led to decreased cyclic stresses, and a longer fatigue life.
The strength of age-hardenable aluminum alloys is based on the controlled formation of nm-sized precipitates, which represent obstacles to dislocation movement. Transmission electron microscopy (TEM) is generally used to identify precipitate types and orientations and to determine their size. This geometric quantification (e.g., length, diameter) is often performed by manual image analysis, which is very time consuming and sometimes poses reproducibility problems. The present work aims at the digital representation of this characterization method by proposing an automatable digital approach. Based on DF-TEM images of different precipitation states of alloy EN AW-2618A, a modularizable digital workflow is described for the quantitative analysis of precipitate dimensions. The integration of this workflow into a data pipeline concept is also presented. The semantic structuring of data allows data to be shared and reused for other applications and purposes, which enables interoperability.
The influence of test temperature and frequency on the fatigue life of the alloy EN AW-2618A (2618A) was characterized. The overaged condition (T61 followed by 1000 h/230 °C) was investigated in load-controlled tests with a stress ratio of R = -1 and two test frequencies (0.2 Hz, 20 Hz) at room temperature and at 230°C, respectively. An increase in the test temperature reduces fatigue life, whereby this effect is more pronounced at lower stress amplitudes. Decreasing the test frequency in tests at high temperatures further reduces the service life.
Optical glasses and glass ceramics are present in many devices often used in our daily routine, such as the mobile phones and tablets. Since the 1960´s with the development of glass lasers, and more recently, within the search for efficient W-LEDs, sensors and solar converters, this class of materials has experienced extreme research progress. In order to tailor a material for such applications, it is very important to understand and characterize optical properties such as refractive index, transmission window, absorption and emission cross sections, quantum yields, etc. These properties can often be tuned by appropriate compositional choice and post-synthesis processing. In this lecture we will discuss the optical properties of glasses and glass ceramics, relevant to that end.
Following the new paradigm of materials development, design and optimization, digitalization is the main goal in materials sciences (MS) which imposes a huge challenge. In this respect, the quality assurance of processes and output data as well as the interoperability between applications following FAIR (findability, accessibility, interoperability, reusability) principles are to be ensured. For storage, processing, and querying of data in contextualized form, Semantic Web Technologies (SWT) are used since they allow for machine-understandable and human-readable knowledge representations needed for data management, retrieval, and (re)use.
The project ‘platform MaterialDigital’ (PMD) is part of an initiative that aims to bring together and support interested parties from both industrial and academic sectors in a sustainable manner in solving digitalization tasks and implementing digital solutions. Therefore, the establishment of a virtual material data space and the systematization of the handling of hierarchical, process-dependent material data are focused. Core points to be dealt with are the development of agreements on data structures and interfaces implemented in distinct software tools and to offer users specific added values in their projects. Furthermore, the platform contributes to a standardized description of data processing methods in materials research. In this respect, selected MSE methods are ontologically represented which are supposed to serve as best practice examples with respect to knowledge representation and the creation of knowledge graphs used for material data.
Accordingly, this presentation shows the efforts taken within the PMD project to store data in accordance with a testing standard compliant ontological representation of a tensile test of metals at room temperature (ISO 6892-1:2019-11). This includes the path from developing an ontology in accordance with the respective standard up to connecting the ontology and data. The semantic connection of the ontology and data leads to interoperability and an enhanced ability of querying. For further enhanced reusability of data and knowledge from synthesis, production, and characterization of materials, the PMD core ontology (PMDco) was developed as mid-level ontology in the field of MSE. The semantic connection of the tensile test ontology (TTO) to the PMDco leads to enhanced expressivity and interoperability.
Moreover, as a best practice example, generation and acquisition of test data semantically connected to the ontology (data mapping) was realized by applying an electronic laboratory notebook (ELN). Corresponding tensile tests were performed by materials science students at university. This enabled a fully digitally integrated experimental procedure that can be transferred to other test series and experiments. In addition to facilitating the acquisition, analysis, processing, and (re)usability of data, this also raises the awareness of students with respect to data structuring and semantic technologies in the sense of education and training. The entire data pipeline is further seamlessly integrable in a laboratory information management system (LIMS). More specifically, the integration of semantic conceptualization and knowledge graphs may become essential parts in LIMS as this would be very beneficial. Therefore, some first approaches of SWT integration in LIMS will also be presented briefly.
The digital era has led to a significant increase in innovation in scientific research across diverse fields and sectors. Evolution of data-driven methodologies lead to a number of paradigm shifts how data, information, and knowledge is produced, understood, and analyzed. High profile paradigm shifts in the field of materials science (MS) include exploitative usage of computational tools, machine learning algorithms, and high-performance computing, which unlock novel avenues for investigating materials. In these presentations, we highlight prototype solutions developed in the context of the Platform MaterialDigital (PMD) project that addresses digitalization challenges. As part of the Material Digital Initiative, the PMD supports the establishment of a virtual materials data space and a systematic handling of hierarchical processes and materials data using a developed ontological framework as high priority work items. In particular, the mid-level ontology PMDco and its augmentation through application-specific ontologies are illustrated. As part of the conclusion, a discussion encompasses the evolutionary path of the ontological framework, taking into account standardization efforts and the integration of modern AI methodologies such as natural language processing (NLP). Moreover, demonstrators illustrated in these presentations highlight: The integration and interconnection of tools, such as digital workflows and ontologies, Semantic integration of diverse data as proof of concept for semantic interoperability, Improved reproducibility in image processing and analysis, and Seamless data acquisition pipelines supported by an ontological framework. In this context, concepts regarding the application of modern research data management tools, such as electronic laboratory notebooks (ELN) and laboratory information management systems (LIMS), are presented and elaborated on. Furthermore, the growing relevance of a standardized adoption of such technologies in the future landscape of digital initiatives is addressed. This is supposed to provide an additional basis for discussion with respect to possible collaborations.
Glasses stand out by their wide and continuously tunable chemical composition and large variety of unique shaping techniques making them a key component of modern high technologies. Glass development, however, is still often too cost-, time- and energy-intensive. The use of robotic melting systems embedded in an ontology-based digital environment is intended to overcome these problems in future.
For this purpose, a robotic high throughput glass melting system is equipped with novel inline sensors for process monitoring, machine learning (ML)-based, adaptive algorithms for process monitoring and optimization, novel tools for high throughput glass analysis and ML-based algorithms for glass design. This includes software tools for data mining as well as property and process modelling. The presentation provides an overview of how all these tools merge into a digital infrastructure and illustrates their usability using examples.
All infrastructural parts were developed by a consortium consisting of the Fraunhofer ISC in Würzburg, the Friedrich-Schiller-University Jena (OSIM), the Clausthal University of Technology (INW) and the Federal Institute for Materials Research and Testing (BAM, Division Glasses) as part of a joint project of the German research initiative MaterialDigital.
Digital Transformation in Materials Science: Insights From the Platform MaterialDigital (PMD)
(2024)
The digital era has led to a significant increase in innovation in scientific research across diverse fields and sectors. Evolution of data-driven methodologies lead to a number of paradigm shifts how data, information, and knowledge is produced, understood, and analyzed. High profile paradigm shifts in the field of materials science (MS) include exploitative usage of computational tools, machine learning algorithms, and high-performance computing, which unlock novel avenues for investigating materials. In these presentations, we highlight prototype solutions developed in the context of the Platform MaterialDigital (PMD) project that addresses digitalization challenges. As part of the Material Digital Initiative, the PMD supports the establishment of a virtual materials data space and a systematic handling of hierarchical processes and materials data using a developed ontological framework as high priority work items. In particular, the mid-level ontology PMDco and its augmentation through application-specific ontologies are illustrated. As part of the conclusion, a discussion encompasses the evolutionary path of the ontological framework, taking into account standardization efforts and the integration of modern AI methodologies such as natural language processing (NLP). Moreover, demonstrators illustrated in these presentations highlight: The integration and interconnection of tools, such as digital workflows and ontologies, Semantic integration of diverse data as proof of concept for semantic interoperability, Improved reproducibility in image processing and analysis, and Seamless data acquisition pipelines supported by an ontological framework. In this context, concepts regarding the application of modern research data management tools, such as electronic laboratory notebooks (ELN) and laboratory information management systems (LIMS), are presented and elaborated on. Furthermore, the growing relevance of a standardized adoption of such technologies in the future landscape of digital initiatives is addressed. This is supposed to provide an additional basis for discussion with respect to possible collaborations.
Gläser zeichnen sich durch eine breite und kontinuierlich abstimmbare chemische Zusammensetzung sowie einzigartige Formgebungstechniken aus, was sie oft zur Schlüsselkomponente moderner Hochtechnologien macht. Die Glasentwicklung ist jedoch oft noch zu kosten-, zeit- und energieintensiv. Der Einsatz von robotergestützten Schmelzsystemen, eingebettet in eine Ontologie-basierte digitale Umgebung, soll diese Probleme in Zukunft überwinden. Im Rahmen der BMBF Forschungsinitiative MaterialDigital unternimmt das Verbundprojekt GlasDigital „Datengetriebener Workflow für die beschleunigte Entwicklung von Glas“ erste Schritte in diese Richtung. Das Projektkonsortium, an dem das Fraunhofer ISC in Würzburg, die Friedrich-Schiller-Universität Jena (OSIM), die Technische Universität Clausthal (INW) und die Bundesanstalt für Materialforschung und -prüfung (BAM, Fachgruppe Glas) beteiligt sind, will alle wesentlichen Basiskomponenten für eine beschleunigte datengetriebene Glasentwicklung zusammenführen. Zu diesem Zweck wird ein robotergestütztes Hochdurchsatz-Glasschmelzsystem mit neuartigen Inline-Sensoren zur Prozessüberwachung, auf maschinellem Lernen (ML) basierenden adaptiven Algorithmen zur Prozessüberwachung und -optimierung, neuartigen Werkzeugen für die Hochdurchsatz-Glasanalyse sowie ML-basierten Algorithmen zum Glasdesign, Data Mining sowie Eigenschafts- und Prozessmodellierung ausgestattet. Der Vortrag gibt einen Überblick darüber, wie all diese Komponenten miteinander verzahnt sind, und veranschaulicht ihre Nutzbarkeit anhand einiger Beispiele.
Age-hardenable aluminum alloys undergo precise heat treatments to yield nanometer-sized precipitates that increase their strength and durability by hindering the dislocation mobility. Tensile tests provide mechanical properties, while microstructure evaluation relies on transmission electron microscopy (TEM), specifically the use of dark-field TEM images for precise dimensional analysis of the precipitates. However, this manual process is time consuming, skill dependent, and prone to errors and reproducibility issues.
Our primary goal is to digitally represent these processes while adhering to FAIR principles. Ontologies play a critical role in facilitating semantic annotation of (meta)data and form the basis for advanced data management. Publishing raw data, digital workflows, and ontologies ensures reproducibility.
This work introduces innovative solutions to traditional bottlenecks and offers new perspectives on digitalization challenges in materials science. We support advanced data management by leveraging knowledge graphs and foster collaborative and open data ecosystems that potentially revolutionize materials research and discovery.
Spectroscopy Lectures
(2024)
As a guest professor of FUNGLASS, I delivered 3 lectures on spectroscopy to the Graduate School Program, the postdoctoral fellows and other researchers: 1) Introduction to spectroscopy applied to solid state materials (with focus on glass and glass ceramics); 2) Vibrational spectroscopy (Infrared and Raman); 3) Electron Paramagnetic Resonance
lasses stand out by their wide and continuously tunable chemical composition and large variety of unique shaping techniques making them a key component of modern high technologies. Glass development, however, is still often too cost-, time- and energy-intensive. The use of robotic melting systems embedded in an ontology-based digital environment is intended to overcome these problems in future. As part of the German research initiative MaterialDigital, the joint project GlasDigital takes first steps in this direction. The project consortium involves the Fraunhofer ISC in Würzburg, the Friedrich Schiller University Jena (OSIM), the Clausthal University of Technology (INW), and the Federal Institute for Materials Research and Testing (BAM, Division Glasses) and aims to combine all main basic components required for accelerated data driven glass development. For this purpose, a robotic high throughput glass melting system is equipped with novel inline sensors for process monitoring, machine learning (ML)-based, adaptive algorithms for process monitoring and optimization, novel tools for high throughput glass analysis and ML-based algorithms for glass design, including software tools for data mining as well as property and process modelling. The talk gives an overview how all these tools are interconnected and illustrates their usability with some examples.
When it comes to dental treatments, success is not only measured by attained functionality but, to a large extent, the associated aesthetics. This can become challenging for certain restorations and implants due to the complex optical characteristic of a tooth, which reflects, absorbs, diffuses, transmits, and even emits light. Thus, to get acceptable aesthetic results, favourable shade matching of ceramic restorations and implants should be achieved by strict control of optical response, which translates into a materials design question. Optical response is affected by several factors such as the composition, crystalline content, porosity, additives, grain size and the angle of incidence of light on the dental ceramics. The properties to be characterized are colour (and its stability), translucency, opalescence, refractive index, and fluorescence. Several techniques can be applied for the characterization of these properties and in this presentation, an overview will be given. Moreover, particular emphasis will be given on the capacitation of less familiarized public to UV-Vis absorption and photoluminescence (PLE) spectroscopies that are versatile and widely employed for functional and structural characterization of glasses and glass ceramic materials.
Suitable material solutions are of key importance in designing and producing components for engineering systems – either for functional or structural applications. Materials data are generated, transferred, and introduced at each step along the complete life cycle of a component. A reliable
materials data space is therefore crucial in the digital transformation of an industrial branch.
A great challenge in establishing a materials data space lies in the complexity and diversity of materials science and engineering. It must be able to handle data from different knowledge areas over several magnitudes of length scale.
The Platform MaterialDigital (PMD) is expected to network a large number of repositories of materials data, allowing the direct contact of different stakeholders as materials producers, testing labs, designers and end users. Following the FAIR principles, it will promote the semantic
interoperability across the frontiers of materials classes. In the frame of a large joint initiative, PMD works intensively together with currently near 20 research consortia in promoting this exchange (www.material-digital.de).
In this presentation we will describe the status of our Platform MaterialDigital. We will also present in more detail the activities of GlasDigital, one of the joint projects mentioned above dealing with the digitalization of glass design and manufacturing.
(https://www.bam.de/Content/EN/Projects/GlasDigital/glasdigital.html)
Glasses stand out by their wide and continuously tunable chemical composition and large variety of unique shaping techniques making them a key component of modern high technologies. Glass development, however, is still often too cost-, time- and energy-intensive. The use of robotic melting systems embedded in an ontology-based digital environment is intended to overcome these problems in future. As part of the German research initiative MaterialDigital, the joint project GlasDigital takes first steps in this direction. The project consortium involves the Fraunhofer ISC in Würzburg, the Friedrich Schiller University Jena (OSIM), the Clausthal University of Technology (INW), and the Federal Institute for Materials Research and Testing (BAM, Division Glasses) and aims to combine all main basic components required for accelerated data driven glass development. For this purpose, a robotic high throughput glass melting system is equipped with novel inline sensors for process monitoring, machine learning (ML)-based, adaptive algorithms for process monitoring and optimization, novel tools for high throughput glass analysis and ML-based algorithms for glass design, including software tools for data mining as well as property and process modelling. The talk gives an overview how all these tools are interconnected and illustrates their usability with some examples.
The research carried out at the Laboratory of Spectroscopy of Functional Materials at IFSC/USP, in Brazil, is focused on the synthesis and structural-property correlation of luminescent materials including rare-earth (RE) doped glasses, ceramics and hybrid host-guest materials. For the past five years, we have been particularly interested in the development of single- and multifunctional nanosystems based on core-shell upconversion nanoparticles (UCNP) associated with dyes, organometallic complexes and other organic molecules, for biophotonic and sensing applications. In these systems, we take advantage of energy transfer between the UCNPs and the molecules to either supress or enhance luminescent response. Examples include the possibility of bioimaging and photodynamic therapy of bacteria and cancer cells, simultaneous magnetothermia and thermometry, localized O2 sensing, fast detection and quantification of biological markers (e.g. kidney disease) and microorganisms. On what concerns the development of luminescent sensors - a recently started project, our aim is to develop paper-based platforms for point-of-care devices. In this presentation, an overview of our contributions for the past years and our future aims will be presented with several examples.
Recently, detection and conversion of high energy radiation such as ultraviolet and X-rays has gained renewed attention. In part, technological applications in radioimaging and tomography have developed considerably as to allow lower dosages and higher resolutions, which require optimized scintillators and dosimeters. On the other hand, the increasing effort to reduce carbon footprint in energy production has triggered an intensive search for materials that can be excited with sunlight, ranging from photocatalysts to solar concentrators. At LEMAF – Laboratory of Spectroscopy of Functional Materials at IFSC/USP, we have been developing bulk glasses, polycrystalline and composite materials designed to target both challenges and, in this work an overview of recent progresses and of the state of art of these materials will be given.
For instance, the few available comercial scintillators are crystalline materials with costly and time consuming growth which hinders the development of new compositions. Glasses and glass ceramics, such as the NaPGaW composition developed in our lab, present high density, very good optical properties and high chemical stability which allow them radioluminescent response when doped with low concentrations of Ce3+, Eu3+ and Tb3+ offering a promise as alternatives to crystal scintillators. On the other hand, phosphor in glass (PiG) composites based on the persistent luminescent polycrystalline material Sr2MgSi2O7:Eu2+,Dy3+ (SMSO) embedded into NaPGa glasses offer interesting perspectives for the of UV light into visible, useful for white light generation (lighting), improved harvesting and conversion of solar light when coupled to c-Si PV cells and photocatalysis. These and other examples will be discussed.
The glasses are prepared through the conventional melt quenching technique, followed by controlled heating when glass ceramics are desired. The persistent luminescent phosphor is prepared by the microwave assisted technique (MAS) much faster and with considerable energy consumption reduction than in the usual solid state synthesis. The materials are characterized from the structural, morphological and spectroscopic (optical – UV-Vis, PL, PLE, and structural – NMR, EPR) points of view such that structure-property correlations are constantly sought to feedback synthesis and processing. Fig. 1, illustrates two examples of scintillator glasses doped with Tb3+ and PiG composites doped with Eu2+ and Dy3+.
As the development of optimized glass compositions by traditional trial-and-error methods is laborious, time consuming, and expensive, it is desirable to develop glass compositions based on a fundamental understanding of the glass structure and to establish structure-property relation models. Particularly, when it comes to optical applications of glasses doped with emissive trivalent rare earth ions (RE), the chemical environmental around the ions will have a direct influence on the radiative/non-radiative emission probabilities. The local vibrational environment and the chemical nature of the bonds in the first coordination sphere of the ions can be tailored, to good extent, based on structural information given by magnetic resonance techniques (NMR and EPR), associated to Raman and photophysical characterization. For the past 5 years, while still employed at the University of São Paulo, in Brazil, one of the interests of my research group has been the development of high-density fluoride-phosphate glasses as promising UV and X-ray scintillator materials. The targeted glasses offer a lower vibrational energy, less hygroscopic fluoride environment for the RE ions whereas the phosphate network provides better mechanical and chemical stability than a purely fluoride glass matrix. Different sets of glasses, based on the compositional system (Ba/Sr)F2-M(PO3)3-MF3-(Sc/Y)F3 where M = Al, In, Ga, and the phosphate component is substituted by the fluoride analogue in 10 - 30 mol%, were investigated, using Sc3+, Y3+, and the Eu3+ and Yb3+ dopants, as structural probes. Overall, results show that the desired RE coordination by fluorine, at a given F/P ratio, is proportional to the atomic mass of M (In> Ga> Al) and that the Ga- and In- based systems differ from the Al- one by near absence of P-O-P network linkages. That is, the network structures are dominated by Ga-O-P or In-O-P linkages, as evidenced by 31P MAS-NMR and Raman. These results are nicely corroborated by observation of decreased intensity of the vibronic band in Eu3+-doped glasses and marked increase in excited state lifetime values. Radioluminescence studies were carried out for a series of In-based glasses doped with Ce3+ and Tb3+, yielding intense emissions in the blue and green, respectively, compatible to the spectral region of the highest sensitivity of radiation sensor detectors. The aim of the presentation is to show how powerful the NMR and EPR techniques can be to provide decisive structural information, and to present the research perspectives in my new role as the Head of Division 5.6 – Glass at BAM.
Structure-property correlations in RE-doped fluoride-phosphate glasses sought by NMR, EPR & PL
(2024)
As the development of optimized glass compositions by traditional trial-and-error methods is laborious, expensive, and time consuming, it is desirable to gather fundamental understanding of structure and to develop structure-property relation models, which allow best and faster choices. Particularly, when it comes to optical applications of glasses doped with emissive trivalent rare earth ions (RE), the chemical environmental around the ions will have a direct influence on the radiative/non-radiative emission probabilities. The vibrational environment and the chemical nature of the bonds in the first coordination sphere of the ions can be tailored, to some extent, based on structural information given by magnetic resonance (NMR and EPR) techniques associated to Raman and photophysical characterization. For the past 5 years, one of the interests of my research group at the University of São Paulo, in Brazil, has been the development of high-density fluoride-phosphate glasses as promising UV and X-ray scintillator materials. The targeted glasses offer a lower vibrational energy, less hygroscopic fluoride environment for the RE ions whereas the phosphate network provides improved mechanical and chemical stability than a purely fluoride glass matrix. Different sets of glasses, based on the compositional system (Ba/Sr)F2-M(PO3)3-MF3-(Sc/Y)F3 where M = Al, In, Ga, and the phosphate component is substituted by the fluoride analogue in 10-30 mol%, were investigated, using Sc3+, Y3+, and the Eu3+ and Yb3+ dopants, as structural probes. Overall, results show that the desired RE coordination by F, at a given F/P ratio, is proportional to the atomic mass of M (In> Ga> Al) and that the Ga- and In- based systems differ from the Al- one by near absence of P-O-P network linkages i.e, the network structures are dominated by Ga-O-P or In-O-P linkages as evidenced by 31P MAS-NMR and Raman. These results are nicely corroborated by observation of decreased intensity in the vibronic band of Eu3+ and significant increase in the excited state lifetime values. Radioluminescence studies were carried out for a series of In-based glasses doped with Ce3+ and Tb3+ yielding intense emissions in the blue and green, respectively, compatible to the spectral region of highest sensitivity of radiation sensor detectors. The aim of the presentation is to show how powerful the combination of NMR, EPR, Raman and PLE spectroscopies can be to provide structural information and to present the perspectives for their introduction in the research agenda of Division 5.6 – Glass, which I now lead, at the Federal Institute for Materials Research and Testing (BAM) in Berlin, Germany.
Laser Powder Bed Fusion (PBF-LB/M) of AISI 316L stainless steel has gained popularity due to its exceptional capacity to produce complex geometries and hierarchical microstructures, which can increase the yield strength while maintaining good ductility. Nevertheless, owing to high thermal gradients encountered during the process, the as printed 316L stainless steel often exhibit microstructural heterogeneities and residual stresses, which can limit its performance in demanding environments. Hence, employing heat treatments which balance the reduction of residual stresses while retaining improved static strength may be beneficial in various scenarios and applications. This study investigates the impact of post-processing heat treatments on the microstructure of 316L stainless steel manufactured via PBF-LB/M, along with its correlation with micro-hardness properties. To this end, 6 different heat treatments, i.e., 450 °C for 4h, 700 °C for 1h, 700 °C for 3h, 800 °C for 1h, 800 °C for 3h, and 900 °C for 1h, were applied to different specimens and Vickers hardness measurements (HV1) were performed in all states. At 800 °C, although the cellular structure appears to be retained, there is an observable increase in cellular size. However, while treatments exceeding 900 °C indicate no significant grain growth compared to other conditions, the cellular structure is entirely dissolved, which leads to a reduced Vickers hardness. The effect of the heat treatments on other microstructural features such as grain size and morphology, melt pool boundaries (MPB), crystallographic texture, chemical segregation, dispersoids and phase stability are also discussed in the present work
The general term additive manufacturing (AM) encompasses processes that enable the production of parts in a single manufacturing step. Among these, laser powder bed fusion (PBF-LB) is one of the most commonly used to produce metal components. In essence, a laser locally melts powder particles in a powder bed layer-by-layer to incrementally build a part. As a result, this process offers immense manufacturing flexibility and superior geometric design capabilities compared to conventional processes. However, these advantages come at a cost: the localized processing inevitably induces large thermal gradients, resulting in the formation of large thermal stress during manufacturing. In the best case, residual stress remains in the final parts produced as a footprint of this thermal stress. Since residual stress is well known to exacerbate the structural integrity of components, their assessment is important in two respects. First, to optimize process parameter to minimize residual stress magnitudes. Second, to study their effect on the structural integrity of components (e.g., validation of numerical models). Therefore, a reliable experimental assessment of residual stress is an important factor for the successful application of PBF-LB. In this context, diffraction-based techniques allow the non-destructive characterization of the residual stress. In essence, lattice strain is calculated from interplanar distances by application of Braggs law. From the known lattice strain, macroscopic stress can be determined using Hooke’s law. To allow the accurate assessment of the residual stress distribution by such methods, a couple of challenges in regard of the characteristic PBF-LB microstructures need to be overcome.
This presentation highlights some of the challenges regarding the accurate assessment of residual stress in PBF-LB on the example of the Nickel-based alloy Inconel 718. The most significant influencing factors are the use of the correct diffraction elastic constants, the choice of the stress-free reference, and the consideration of the crystallographic texture. Further, it is shown that laboratory X-ray diffraction methods characterizing residual stress at the surface are biased by the inherent surface roughness. Overall, the impact of the characteristic microstructure is most significant for the selection of the correct diffraction elastic constants. In view of the localized melting and solidification, no significant gradients of the stress-free reference are observed, even though the cell-like solidification sub-structure is known to be heterogeneous on the micro-scale.
The damage mechanisms of metallic components produced by process laser powder bed fusion differ significantly from those typically observed in conventionally manufactured variants of the same alloy. This is due to the unique microstructures of additively manufactured materials. Herein, the focus is on the study of the evolution of creep damage in stainless steel 316L specimens produced by laser powder bed fusion. X-ray computed tomography is used to unravel the influence of the process-specific microstructure from the influence of the initial void distribution on creep damage mechanisms. The void distribution of two specimens tested at 600 °C and 650 °C is analyzed before a creep test, after an interruption, and after fracture. The results indicate that the formation of damage is not connected to the initial void distribution. Instead, damage accumulation at grain boundaries resulting from intergranular cracking is observed.
Laser powder bed fusion (PBF-LB/M) of metallic alloys is a layer-wise additive manufacturing process that provides significant scope for more efficient designs of components, benefiting performance and weight, leading to efficiency improvements for various sectors of industry. However, to benefit from these design freedoms, knowledge of the high produced induced residual stress and mechanical property anisotropy associated with the unique microstructures is critical. X-ray and neutron diffraction are considered the benchmark for non-destructive characterization of surface and bulk internal residual stress. The latter, characterized by the high penetration power in most engineering alloys, allows for the use of a diffraction angle close to 90° enabling a near cubic sampling volume to be specified. However, the complex microstructures of columnar growth with inherent crystallographic texture typically produced during PBF-LB/M of metallics present significant challenges to the assumptions typically required for time efficient determination of residual stress. These challenges include the selection of an appropriate set of diffraction elastic constants and a representative lattice plane suitable for residual stress analysis. In this contribution, the selection of a suitable lattice plane family for residual stress analysis is explored. Furthermore, the determination of an appropriate set of diffraction and single-crystal elastic constants depending on the underlying microstructure is addressed.
In-situ loading experiments have been performed at the Swiss Spallation Neutron Source with the main scope to study the deformation behaviour of laser powder bed fused Inconel 718. Cylindrical tensile bars have been subjected to an increasing mechanical load. At pre-defined steps, neutron diffraction data has been collected. After reaching the yield limit, unloads have been performed to study the accumulation of intergranular strain among various lattice plane families.
The manufacture of sintered glasses and glass-ceramics, glass matrix composites, and glass-bounded ceramics or pastes is often affected by un-expected gas bubble formation also named foaming. Against this background, in this presentation the main aspects and possible reasons of foaming are shown for completely different glass powders: a barium silicate glass powders used as SOFC sealants, and bioactive glass powders using different powder milling procedures.
Sintering and foaming were measured by means of heating microscopy backed up by XRD, differential thermal analysis (DTA), vacuum hot extraction (VHE), optical and electron microscopy, and infrared spectroscopy, and time-of-flight secondary ion mass spectrometry (ToF-SIMS).
Different densification was reached followed by significant foaming starting partly immediately, partly at higher temperature. Foaming increased significantly as milling progressed. For moderately milled glass powders, subsequent storage in air could also promote foaming. Although the milling atmosphere significantly affects the foaming of uniaxially pressed powder compacts sintered in air.
VHE studies show that foaming is driven by carbon gases and carbonates were detected by Infrared spectroscopy to provide the major foaming source. Carbonates could be detected even after heating to 750 °C, which hints on a thermally very stable species or mechanical trapping or encapsulating of CO2. Otherwise, dark gray compact colors for milling in isopropanol indicate the presence of residual carbon as well. Its significant contribution to foaming, however, could not be proved and might be limited by the diffusivity of oxygen needed for carbon oxidation to carbon gas.
Up to now, oriented surface crystallization phenomena are discussed controversially, and related studies are restricted to few glasses. For silicate glasses we found a good correlation between the calculated surface energy of crystal faces and oriented surface nucleation. Surface energies were estimated assuming that crystal surfaces resemble minimum energy crack paths along the given crystal plane. This concept was successfully applied at the Institute of Physics of Rennes in calculating fracture surface energies of glasses. Several oriented nucleation phenomena can be herby explained assuming that high energy crystal surfaces tend to be wetted by the melt. This would minimize the total interfacial energy of the nucleus. Furthermore, we will discuss the evolution of the microstructure and its effect on the preferred crystal orientation.
Motivated by the aim of developing an additive manufacturing (AM) technology easily integrated in the process chains of the ceramic industry, the LSD-print technology was conceived as a slurry-based variation of binder jetting (BJ).
BJ and other powder bed technologies (such as powder bed fusion) are amongst the most successful AM techniques, especially for metals and polymers, thanks to their high productivity and scalability. The possibility to use commercially available feedstocks (in the form of powders or granules) makes BJ also attractive for ceramic materials. The application of these techniques to most advanced ceramics has however been difficult so far, because of the limitations in depositing homogeneous layers with fine, typically poorly flowable powders.
In this context, the "layerwise slurry deposition" (LSD) was proposed at TU Clausthal (Germany) as a slurry-based deposition of ceramic layers by means of a doctor blade. Combined with layer-by-layer laser sintering of the material, the LSD process was originally demonstrated for the rapid prototyping of silicate ceramics. Due to the difficulties in controlling the microstructure and the defect formation in laser-sintered technical ceramics, the LSD process was later combined with inkjet printing in the LSD-print technology, which has been further developed at BAM (Germany) in the past decade.
The LSD-print technology combines the high speed of inkjet printing, typical of BJ, with the possibility of producing a variety of high-quality ceramics with properties comparable to those achieved by traditional processing. Due to the mechanical stability of the powder bed, the process can also be carried out with continuous layer deposition on a rotating platform, which further increases its productivity.
This presentation will delve into 10 years of research on the LSD-print of a wide variety of technical ceramics including alumina, silicon carbides and dental ceramics. The discussion highlights how a seemingly small process and feedstock modification (from powders to slurries) has great influence on the challenges and potential of this process, which are being addressed on its path to industrialization.
Powder bed technologies are amongst the most successful Additive Manufacturing (AM) techniques. The application of these techniques to most ceramics has been difficult so far, because of the challenges related to the deposition of homogeneous powder layers when using fine powders.
In this context, the "layerwise slurry deposition" (LSD) has been developed as a layer deposition method enabling the use of powder bed AM technologies also for advanced ceramic materials. The layerwise slurry deposition consists of the layer-by-layer deposition of a ceramic slurry by means of a doctor blade, in which the slurry is deposited and dried to achieve a highly packed powder. Not only very fine, submicron powders can be processed with low organics, but also the dense powder bed provides excellent support to the parts built. The LSD technology can be combined with binder jetting to develop the so-called “LSD-print” process. LSD-print combines the high-speed printing of binder jetting with the possibility of producing a variety of high-quality ceramics with properties comparable to traditional processing.
The latest development of this technology shows that it is possible to print ceramic parts in a continuous process by depositing a layer onto a rotating platform, growing a powder bed following a spiral motion. The unique mechanical stability of the layers in LSD-print allows to grow a powder bed several centimeters thick without any lateral support. The continuous layer deposition allows to achieve a productivity more than 10X higher compared to the linear deposition, approaching a build volume of 1 liter/hour.
The Laser-Induced Slip Casting is an additive manufacturing technology specifically developed for ceramic materials using water-based ceramic slurries. The process takes place layer-by-layer in a similar fashion as top-down vat photopolymerization, selectively consolidating each layer by means of a laser energy source positioned on the top. Contrary to vat photopolymerization, in which the consolidation is achieved by selectively cross-linking a ceramic-filled resin, LIS uses water-based slurries with a low amount of organic additives (typically < 5 wt%) as feedstocks.
In LIS, a green body is formed by local evaporation of water which causes the suspension to collapse forming a cast, following a mechanism similar to slip casting. Only a small content of organic additives is needed to effectively disperse the ceramic particles and to increase the green strength.
The technology is very versatile and can be applied to all ceramic systems that can be dispersed in water. One of the main advantages is that even dark materials such as silicon carbide can be processed without issues related to light scattering and absorption.
The presentation will discuss strengths and limitations of LIS compared to other AM technologies and will highlight the latest results for alumina and for silicon carbide ceramics.
The presentation will start with an overview of ceramic additive manufacturing (AM) technologies and will discuss the potential of AM in the field of bioceramics.
The presentation will then focus on two possible use cases of binder jetting technologies.
In the first example, standard powder-based binder jetting is used to manufacture a porous implant design for large scale bone defects. The related challenges in the process chain will be discussed, from powder synthesis to sintering and characterization of the printed part.
In the second example, the LSD-print slurry-based binder jetting technology is presented as a possibility to adapt powder-bed AM to produce dense ceramic parts. The use case will focus on an application in the field of dental ceramics, specifically for the manufacturing of patient individualized single tooth restorations (veneers, crowns) with a high throughput process chain.
This study aims to represent an approach for transferring the materials testing datasets to the digital schema that meets the prerequisites of the semantic web. As a use case, the tensile stress relaxation testing method was evaluated and the testing datasets for several copper alloys were prepared. The tensile stress relaxation testing ontology (TSRTO) was modeled following the test standard requirements and by utilizing the appropriate upper-level ontologies. Eventually, mapping the testing datasets into the knowledge graph and converting the data-mapped graphs to the machine-readable Resource Description Framework (RDF) schema led to the preparation of the digital version of testing data which can be efficiently queried on the web.
The heat-resistant cast iron EN-GJSA-XNiSiCr35-5-2 (Ni-Resist D-5S) was investigated for its fatigue crack growth behavior at room and high temperatures. Force-controlled tests were carried out at constant temperatures (20 °C, 500 °C, 700 °C) without and with hold time and different load ratios. The crack growth behavior was also characterized under TMF loading (Tmin = 400 °C, Tmax = 700 °C) by applying IP and OP conditions and different load ratios. Three different techniques were combined to monitor crack growth: potential drop, thermography, and compliance method. The effect of the different loading conditions on the fatigue crack growth behavior will be presented and discussed.
In this presentation, the results of the determination of the diffraction and single-crystal elastic constants of laser powder bed fused Inconel 718 are presented. The analysis is based on high-energy synchrotron diffraction experiments performed at the Deutsches Elektronen-Synchrotron. It is shown that the characteristic microstructure of laser powder bed fused Inconel 718 impacts the elastic anisotropy and therefore the diffraction and single-crystal elastic constants. Finally, the consequences on the diffraction-based residual stress determination of laser powder bed fused Inconel 718 are discussed.
Manipulating ceramic powder compacts and ceramic suspensions (slurries) within their volume with light requires a minimum transparency of the materials. Compared to polymers and metals, ceramic materials are unique as they offer a wide electronic band gap and thus a wide optical window of transparency. The optical window typically ranges from below 0.3 µm up to 5µm wavelength. Hence, to penetrate with laser light into the volume of a ceramic powder compound its light scattering properties need to be investigated and tailored. In the present study we introduce the physical background and material development strategies to apply two-photon-polymerization (2PP) for the additive manufacture of filigree structures within the volume of ceramic slurries.
Manipulating ceramic powder compacts and ceramic suspensions (slurries) within their volume with light requires a minimum transparency of the materials. Compared to polymers and metals, ceramic materials are unique as they offer a wide electronic band gap and thus a wide optical window of transparency. The optical window typically ranges from below 0.3 µm up to 5µm wavelength. Hence, to penetrate with laser light into the volume of a ceramic powder compound its light scattering properties need to be investigated and tailored. In the present study we introduce the physical background and material development strategies to apply two-photon-polymerization (2PP) for the additive manufacture of filigree structures within the volume of ceramic slurries.
Manipulating ceramic powder compacts and ceramic suspensions (slurries) within their volume with light requires a minimum transparency of the materials. Compared to polymers and metals, ceramic materials are unique as they offer a wide electronic band gap and thus a wide optical window of transparency. The optical window typically ranges from below 0.3 µm up to 5µm wavelength. Hence, to penetrate with light into the volume of a ceramic powder compound, its light scattering properties need to be investigated and tailored. In the present study we introduce the physical background and material development strategies to apply two-photon-polymerization (2PP), and other volumetric methods for the additive manufacture of filigree structures within the volume of ceramic slurries.
In order to be able to manipulate ceramic powder compacts and ceramic suspensions (slurries) within their volume with light, a minimum transparency of the materials is required. Compared to polymers and metals, ceramic materials are characterized by the fact that they have a wide electronic band gap and therefore a wide optical window of transparency. The optical window generally ranges from less than 0.3 µm to 5 µm wavelength. In order to focus light into the volume of a ceramic powder compact, its light scattering properties must therefore be tailored. In this study, we present the physical background and material development strategies for the application of two-photon polymerization (2PP) and selective volumetric sintering for the additive manufacturing of structures in the volume of ceramic slips and green compacts.
The Binder Jetting BJ process is one of the most versatile additive manufacturing technologies in use. In this process a binder is locally jetted into a powder bed for the consolidation of a 3D structure, layer by layer. Basically, all materials which can be provided as a flowable powder and, thus, spreadable to a thin layer, can be processed. Metals, ceramics and polymers are processable, but also materials from nature, such as sand, wood sawdust and insect frass. Moreover, the BJ technology is adapted to large building volumes of some cubic meters easily. Besides these striking advantages, the manufacture of ceramic parts by BJ is still challenging, as the packing density of the powder bed is generally too low and the particle size of a flowable powder too large for a successful densification of printed parts in a subsequent sintering step to an advanced ceramic product. After an introduction of binder jetting in general and highlighting some examples, strategies for obtaining dense ceramic parts by BJ will be introduced.
Regarding feedstocks for the additive manufacturing (AM) of ceramics, two features are most critical in classical powder based AM processes: a high particle packing density (typically >50% TD) must be achieved with very fine particles (typically submicron) in order to ensure sufficient sintering activity. Three innovative approaches will be introduced to overcome this problem:
1. Layer wise slurry deposition: The use of water based ceramic slurries as feedstock for the additive manufacture of ceramics has many advantages which are not fully exploit yet. In the layerwise slurry deposition (LSD) process a slurry with no or low organic content is repetitively spread as thin layers on each other by means of a doctor blade. During the deposition, the ceramic particles settle on the previously deposited and dried material to form thin layers with a high packing density (55-60%). The LSD therefore shares aspects both of tape casting and slip casting. The LSD differentiates from the classical powder-based AM layer deposition, which typically achieves with a flowable coarse grained powder a low packing density (35-50%) only, consequently hindering the ability of sintering ceramic parts to full density. The LSD is coupled with the principles of selective laser sintering (SLS) or binder jetting, to generate novel processes which take advantage of the possibility of achieving a highly dense powder-bed.
2. Laser induced slip casting: Contrary to the LSD process, which requires drying of each individual layer, the direct interaction of ceramic slurries with intense laser radiation, for the laser induced slip casting (LIS), is a promising approach for the additive manufacture of voluminous parts.
3. Gas flow assisted powder deposition: By the application of a vacuum pump a gas flow is realized throughout the powder bed. This gas flow stabilizes the powder bed and results into an enhanced flowability and packing density of the powder during layer deposition.
The presentation will provide a detailed discussion of potentialities and issues connected to the mentioned technologies and will describe the most recent developments in their application to technical ceramics.
Gas turbine components, made of nickel-based alloys, undergo material damage due to high temperatures and mechanical stresses. These components need periodic replacement to avoid efficiency loss and failure. Repair of these parts is more cost-effective than replacement. State-of-the-art repair technologies, including different additive manufacturing (AM) and brazing processes, are considered for efficient restoration. Materials properties mismatches and/or internal defects in repaired parts may expedite crack initiation and propagation, reducing fatigue life. To understand the crack growth behavior in joining zones and predict the remaining life of repaired components, fatigue crack growth (FCG) tests were conducted on specimens of nickel-based alloys joined via brazing, pre-sintered preforms and AM. The FCG experimental technique was successfully adapted for joined specimens and results indicate that the investigated braze material provides a lower resistance to crack growth. In AM-sandwich specimens, the crack growth rates are significantly reduced at the interface of AM and cast material.
Unlike conventional alloys, which typically consist of one main element, high-entropy alloys (HEAs) contain five or more principal elements, which broaden chemical complexity and with it a realm of synergistic mechanisms. The AlMo0.5NbTa0.5TiZr HEA initiated a subclass of Al-containing refractory (r)HEAs that has recently drawn attention [2]. The alloy has a superalloy-resembling B2/bcc nanostructure, which inspired its name refractory high entropy superalloy (RSA). With high-temperature (HT) compressive strengths beyond conventional Ni-based superalloys, this nanostructure could be used for improved HT structural applications. However, in the application-relevant HT regime the Al-Zr-rich B2 phase decomposes to form a hexagonal Al-Zr-based intermetallic (Al4-xZr5; x: 0..1) [3,4]. This work explores the fascinating yet fatal micromechanisms associated to this phase transformation, in the context of creep, annealing and oxidation experiments performed between 800 and 1200 °C.
The material was produced by arc-melting and heat treatment in argon, which lead to grain boundaries decorated with up to 7%. Interrupted constant-load creep tests were performed under vacuum (at 10-4 Pa), at 900–1100 °C with external tensile stresses of 30–120 MPa. Oxidation experiments were separately conducted for 24 hours at 800 and 1000 °C in both dry (21% O2 + 79% N2) and humid (8% O2 + 74% N2 + 18% H2O) air. After the experiments, the samples were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy to reveal degradation mechanisms. Crystallographic texture, orientation relationships and stabilization of an oxygen-containing iso structure (Al4-xZr5(Ox-y); y: 0..x) of the Al-Zr-rich intermetallic are found and discussed.
This contribution presents the results of an experimental study on the LCF behavior of an austenitic 316L stainless steel produced by laser powder bed fusion featuring a low defect population, which allows for an improved understanding of the role of other typical aspects of a PBF‑LB microstructure. The LCF tests were performed between room temperature and 600 °C. A hot‑rolled 316L variant was tested as a reference. The mechanical response is characterized by strain-life curves, a Coffin‑Manson‑Basquin fitting, and cyclic deformation curves. The damage and deformation mechanisms are studied with X-ray computed tomography, optical and electron microscopy. The PBF‑LB/M/316L exhibits lower fatigue lives at lower strain amplitudes. The crack propagation is mainly transgranular. The solidification cellular structure seems to be the most relevant underlying microstructural feature determining the cyclic deformation behavior.
Several studies have been shown that the electron beam can be used to create nanomaterials from microparticle targets in situ in a transmission electron microscope (TEM). Here, we show how this method has to be modified in order to synthesize plasmonic gold nanoparticles (NPs) on insulating silicon oxide substrate by employing a scanning electron microscope with a comparatively low acceleration voltage of 30 kV. The synthesized NPs exhibit a random distribution around the initial microparticle target: Their average size reduces from 150 nm to 3 nm with growing distance to the initial Au microparticle target. Similarly, their average distance increases. The synthesized NP assemblies therefore show distinctly different plasmonic behaviour with growing distance to the target, which allows to study consequences of random hybridization of surface plasmon in disordered system, such as Anderson localization. To reveal the surface plasmons and their localization behaviour we apply electron energy loss spectroscopy in the TEM.
Following the new paradigm of materials development, design, and optimization, digitalization is the main goal in materials sciences and engineering (MSE) which imposes a huge challenge. In this respect, the quality assurance of processes and output data as well as the interoperability between applications following FAIR principles are to be ensured. For storage, processing, and querying of data in contextualized form, Semantic Web technologies (SWT) are used since they allow for machine-actionable and human-readable knowledge representations needed for data management, retrieval, and (re)use.
The project ‘platform MaterialDigital’ (PMD, https://materialdigital.de) aims to bring together and support interested parties from both industrial and academic sectors in a sustainable manner in solving digitalization tasks and implementing digital solutions. Therefore, the establishment of a virtual material data space and the systematization of the handling of hierarchical, process-dependent material data are focused. Core points to be dealt with are the development of agreements on data structures and interfaces implemented in distinct software tools and to offer users specific support in their projects. Furthermore, the platform contributes to a standardized description of data processing methods in materials research. In this respect, selected MSE methods are semantically represented which are supposed to serve as best practice examples with respect to knowledge representation and the creation of knowledge graphs used for material data.
Accordingly, this presentation shows the efforts taken within the PMD project towards the digitalization in MSE such as the development of the mid-level PMD core ontology (PMDco, https://github.com/materialdigital/core-ontology). Furthermore, selected results of a PMD partner project use case addressing data and knowledge management from synthesis, production, and characterization of materials are shown.
Highly unrelaxed structural states of metallic glasses have often advantageous mechanical properties. Since metallic glasses continuously relax with time (age) or inherently are well relaxed after processing, methods to uniformly rejuvenate the material are needed. One approach that has received attention is the so-called cryogenic-cycling method, during which a metallic glass is repeatedly immersed into liquid nitrogen. In some cases, cryogenic cycling is truly efficient in increasing the stored excess enthalpy of metallic glasses, but it does not seem to be universally applicable to all alloys and structural states. The origins for these differences remain unclear due to our limited understanding of the underlying structural evolution. In order to shed more light onto the fundamental structural processes of cryogenic cycling, we pursue in-situ x-ray photon correlation spectroscopy (XPCS) to trace the atomic-scale structural dynamics of a Zr-based metallic glass in two different structural states (ribbon and bulk metallic glass). This method allows calculating the relaxation times as a function of time throughout the thermal cycling. It is found that the investigated glasses exhibit heterogeneous structural dynamics at 300 K, which changes to monotonic aging at 78 K. Cryogenic cycling homogenizes the relaxation time distribution for both structural states. This effect is much more pronounced in the ribbon, which is the only structural state that rejuvenates upon cycling. We furthermore reveal how fast atomic-scale dynamics is correlated with long-time average structural relaxation times irrespective of the state, and that the ribbon exhibits unexpected additional fast atomic-scale relaxation in comparison to the plate material. Overall, a picture emerges that points towards heterogeneities in fictive temperature as a requirement for cryogenic energy storage.