Additive Fertigung
Filtern
Dokumenttyp
- Vortrag (227)
- Zeitschriftenartikel (190)
- Posterpräsentation (66)
- Beitrag zu einem Tagungsband (39)
- Forschungsdatensatz (9)
- Buchkapitel (3)
- Dissertation (3)
- Sonstiges (2)
Sprache
- Englisch (539) (entfernen)
Schlagworte
- Additive manufacturing (194)
- Additive Manufacturing (145)
- Laser powder bed fusion (49)
- Residual stress (49)
- Thermography (46)
- Computed tomography (28)
- Microstructure (25)
- Laser Powder Bed Fusion (24)
- 316L (20)
- Ti-6Al-4V (20)
- Process monitoring (19)
- L-PBF (18)
- Laser metal deposition (18)
- Computed Tomography (16)
- Neutron diffraction (16)
- 3D printing (14)
- Residual Stress (14)
- X-ray computed tomography (14)
- AGIL (13)
- Inconel 718 (13)
- Selective laser melting (13)
- Additive Fertigung (12)
- Diffraction (12)
- Porosity (11)
- AlSi10Mg (10)
- Ceramic (10)
- Infrared thermography (10)
- AISI 316L (9)
- Heat treatment (9)
- In situ monitoring (9)
- In-situ monitoring (9)
- Laser beam melting (9)
- Residual stresses (9)
- Ceramics (8)
- Crystal plasticity (8)
- Fatigue (8)
- Heat accumulation (8)
- Laser Metal Deposition (8)
- Metrology (8)
- PBF-LB/M (8)
- SLM (8)
- Selective Laser Melting (8)
- AM (7)
- Additive manufacturing (AM) (7)
- Anisotropy (7)
- Creep (7)
- DED (7)
- Defect detection (7)
- LMD (7)
- Layerwise slurry deposition (7)
- Neutron Diffraction (7)
- Residual Stresses (7)
- Selective Laser Melting (SLM) (7)
- Synchrotron X-ray diffraction (7)
- Arc welding (6)
- IN718 (6)
- LPBF (6)
- Laser Powder Bed Fusion (L-PBF) (6)
- Mechanical properties (6)
- Multiphoton lithography (6)
- Open science (6)
- Optical tomography (6)
- Powder (6)
- Quality assurance (6)
- Research data management (6)
- X-ray diffraction (6)
- 3D-printing (5)
- Additive Manufacturing (AM) (5)
- Advanced manufacturing (5)
- Binder Jetting (5)
- Cyclic R-curve (5)
- Fatigue crack growth (5)
- Hochfester Stahl (5)
- Laser beam welding (5)
- Machine Learning (5)
- Micropatterning (5)
- Polydopamine (5)
- ProMoAM (5)
- Representative specimens (5)
- Residual stress analysis (5)
- Selective laser melting (SLM) (5)
- Sintering (5)
- Slurry (5)
- Texture (5)
- Thermal history (5)
- Ultrafine particles (5)
- WAAM (5)
- WelDX (5)
- 3D-Printing (4)
- Cold cracking safety (4)
- DED-Arc (4)
- Defects (4)
- Direct energy deposition (4)
- Directed Energy Deposition (4)
- Eigenspannungen (4)
- Elastic modulus (4)
- Heat control (4)
- High-strength steel (4)
- In-situ Monitoring (4)
- In-space manufacturing (4)
- Inter layer time (4)
- Laboratory specimens (4)
- Lattice structures (4)
- Mechanical behavior (4)
- Metals (4)
- Microgravity (4)
- Position detection (4)
- Scale-bridging (4)
- Shear modulus (4)
- Simulation (4)
- Strategic Research Agenda (SRA) (4)
- Virtual experiments (4)
- Welding (4)
- Wind energy (4)
- X-ray refraction (4)
- Young's modulus (4)
- Advanced ceramics (3)
- AlSi10Mg alloy (3)
- Alumina (3)
- Artificial neural network (3)
- BAMline (3)
- Binder jetting (3)
- Component assessment (3)
- Composites (3)
- Convolutional Neural Networks (3)
- Crack propagation (3)
- Creep behavior (3)
- Cyclic R-Curve (3)
- DED-arc (3)
- Data fusion (3)
- Digitalization (3)
- Dimensional accuracy (3)
- Direct laser writing (3)
- Directed energy deposition (3)
- Electron Backscatter Diffraction (3)
- Electron beam melting (3)
- European Metrology Network (EMN) (3)
- FEM (3)
- GMR (3)
- Grain refinement (3)
- Heat Treatment (3)
- High-strength Steels (3)
- Hybrid components (3)
- Hybrid repair (3)
- Hydrogen (3)
- ISRU (3)
- Implants (3)
- Interpenetrating polymer network (3)
- Laser (3)
- Laser Beam Melting (3)
- Laser Welding (3)
- Laser beam melting (LBM) (3)
- Laser powder bed fusion (L-PBF) (3)
- Laser welding (3)
- Lattice structure (3)
- Layerwise Slurry Deposition (3)
- Low Cycle Fatigue (3)
- MAG-Schweißen (3)
- Material Science (3)
- Mechanical Engineering (3)
- Multispectral thermography (3)
- Non-destructive testing (3)
- Online Process Monitoring (3)
- Optical Tomography (3)
- PBF-LB/M/316L (3)
- Process Monitoring (3)
- Resistance spot welding (3)
- Review (3)
- Scaffold (3)
- Silicon Carbide (3)
- Stainless Steel (3)
- Synchrotron X-ray computed tomography (3)
- TES (3)
- Temperature emissivity separation (3)
- Tensile properties (3)
- Thermografie (3)
- Ultrasonic-assisted milling (3)
- Welding simulation (3)
- X-Ray imaging (3)
- µ-gravity (3)
- μ-gravity (3)
- 3D Druck (2)
- Active thermography (2)
- Advanced Manufacturing (2)
- Aerosol measurements (2)
- Affinity Chromatography (2)
- Ageing (2)
- Alkali-activated materials (2)
- Artificial weathering (2)
- Atomic force microscopy (2)
- Austenitic steel 316L (2)
- Bead-on-plate welds (2)
- Bioactive glass (2)
- Bragg-edge (2)
- Bridging voids (2)
- Build direction (2)
- Build-up Orientation (2)
- Cold Spray (2)
- Computed tomography (CT) (2)
- Condensed Matter Physics (2)
- Condition monitoring (2)
- Copper powder particles (2)
- Crack (2)
- Damage evolution (2)
- Data preparation (2)
- Design for Additive Manufacturing (DfAM) (2)
- Dielectric properties (2)
- Diffraction Elastic Constants (2)
- Digital transformation (2)
- Digitalisation (2)
- Distortion (2)
- Duplex AISI 2205 (2)
- EMN (2)
- Eddy Current (2)
- Eddy current testing (2)
- Electrical conductivity (2)
- Electron backscatter diffraction (2)
- Electron microscopy (2)
- Embedded electronics (2)
- Emission testing (2)
- Emissivity (2)
- European Metrology Networks (EMNs) (2)
- FPLC (2)
- Fatigue Crack Propagation (2)
- Fatigue performance (2)
- Fatigue properties (2)
- Flowability (2)
- Flying Spot Laser Thermography (2)
- Fume (2)
- Fused Filament Fabrication (2)
- General Materials Science (2)
- HPLC (2)
- Heat treatments (2)
- High Temperature Testing (2)
- High strength steel (2)
- High-resolution camera (2)
- High-strength structural steels (2)
- Hot stamping (2)
- Hybrid Part (2)
- Image processing (2)
- In-process monitoring (2)
- In-situ process monitoring (2)
- Indoor air quality (2)
- Industrial and Manufacturing Engineering (2)
- Infrastructure (2)
- Joined nickel-based alloys (2)
- Kaltrisssicherheit (2)
- Keyhole porosity (2)
- LBM (2)
- LCF (2)
- LSD-print (2)
- Lack-of-fusion (2)
- Large electrical high-voltage machine (2)
- Laser Powder Bed Fusion (PBF-LB/M) (2)
- Laser Powder Bed Fusion (PBF-LB/M, L-PBF) (2)
- Laser Powder Bed fusion (2)
- Laser Pulver Auftragsschweißen (2)
- Laser implantation (2)
- Laser powderbed fusion (2)
- Laser-induced slip casting (2)
- Lattice Structures (2)
- Lattices (2)
- Layerwise (2)
- Life Cycle Assessment (2)
- Lightweight structures (2)
- Liquation Cracking (2)
- Liquid metal embrittlement (2)
- Lunar habitat (2)
- Lunar regolith (2)
- Lunar regolith simulant (2)
- MMC (2)
- Machine learning (2)
- Magnetocaloric (2)
- Mechanics of Materials (2)
- Melt pool boundary (2)
- Micro-CT (2)
- Microstructural characterization (2)
- Microstructure and texture (2)
- Multiphoton Lithography (2)
- NDT (2)
- Nickel (2)
- Non-Destructive testing (2)
- Nondestructive Testing (2)
- PBF/LB-M (2)
- Particle gas emission (2)
- Path planning (2)
- Paving (2)
- Plume (2)
- Porcelain (2)
- Pores (2)
- Porosity prediction (2)
- Powder Bed Fusion (2)
- Pre-weld Preparation (2)
- Process atmosphere (2)
- Process chain (2)
- Process parameter optimization (2)
- Quality Assurance (2)
- Raman spectroscopy (2)
- Reference data (2)
- Refill friction stir spot welding (2)
- Refraction (2)
- Repair of gas turbine blades (2)
- Reproducibility (2)
- Residual stress state (2)
- Ressidual stress (2)
- Roughness (2)
- Round robin (2)
- SWIR camera (2)
- SZ2080 negative photo-resist (2)
- Selected Laser Melting (2)
- Selektive-laser-melting (2)
- Silicon carbide (2)
- Solar sintering (2)
- Solidification cracking (2)
- Space (2)
- Spark plasma sintering (2)
- Spatter (2)
- Stakeholder (2)
- Submerged arc welding (2)
- Supportless (2)
- Surface integrity (2)
- Surface modification (2)
- Surface roughness analysis (2)
- Tensile Properties (2)
- Tensile performance (2)
- Tensile testing (2)
- Thermal Spray (2)
- Ti-Nb alloy (2)
- Time over threshold (2)
- Titanium (2)
- Transmission electron microscopy (2)
- Transparent ceramics (2)
- Two Photon Polymerization (2)
- Two photon polymerisation (2)
- Two-photon polymerisation (2)
- Two-photon polymerization (2)
- Vickers hardness (2)
- Windenergie (2)
- Wire Arc Additive Manufacturing (2)
- Wire arc additive manufacturing (2)
- X-Ray Diffraction (2)
- X-ray analysis (2)
- X-ray imaging (2)
- X-ray refraction techniques (2)
- ZCF (2)
- Zero-g (2)
- 2PP (1)
- 316L Stainless Steel (1)
- 316L stainless steel (1)
- 3D printer (1)
- 3D-Metal-Printing (1)
- 3d printing (1)
- 3d structuring (1)
- AFM (1)
- AHSS (1)
- AM IN718 (1)
- AM feature integration (1)
- ATZ (1)
- Absorption edge tomography (1)
- Acoustic Emission (1)
- Additive manufactured Ni-base superalloys (1)
- Additive surface treatment (1)
- Advanced High-Strength Steel (AHSS) (1)
- Advanced Materials (1)
- Advanced high strength steels (1)
- Advanced high-strength steel (1)
- Aerospace (1)
- Affinity Extraction (1)
- Affinity Separation (1)
- Aging (1)
- Air Void System (1)
- Air pollution (1)
- Air-coupled ultrasonic testing (1)
- Al alloy (1)
- AlMg0.7SiTiB filler wire (1)
- Alcium alkali phosphate (1)
- Alloy 36 (1)
- Alloys (1)
- Alpha-tricalcium phosphate (1)
- Alumina toughened zirconia (1)
- Aluminium Alloy (1)
- Aluminum bronze (1)
- Analytical model (1)
- Antibodies (1)
- Antibody Purification (1)
- Artificial intelligence (1)
- As-built LPBF IN718 alloy (1)
- Atmospheric Plasma Spraying (1)
- Atmospheric plasma spraying (1)
- Atmospheric pressure plasma (1)
- Austenitischer Stahl (1)
- Automated Purification (1)
- Automotive (1)
- BPF-LB/M (1)
- Bending property (1)
- Bending test (1)
- Binders/binding (1)
- Bio Ceramic (1)
- Bio active ceramic (1)
- Bio-ceramic engineering (1)
- Bioactivity (1)
- Bioceramic (1)
- Biomaterials (1)
- Biphasic calcium phosphate (1)
- Bone regeneration (1)
- Borosilicate Glass (1)
- Bragg-edge neutron 2D imaging (BENI) (1)
- Build Angle (1)
- Build-up strategy (1)
- C-F bond activation (1)
- CFR-PEEK (1)
- COFs (1)
- CONSENS (1)
- Calcium phosphate (1)
- Calculation time (1)
- Calibration structure (1)
- Camera (1)
- Cellular substructure (1)
- Cement (1)
- Ceramic nano particles (1)
- Ceramics 3D printing (1)
- Characterisation (1)
- Cimensional Accuracy (1)
- Citizen Science (1)
- Clad steels (1)
- Cladding (1)
- Clay ISRU (1)
- Coating (1)
- Column holder (1)
- Component (1)
- Computer Aided Manufacturing (1)
- Concentration step (1)
- Concrete modelling (1)
- Confocal raman imaging (1)
- Construction (1)
- Contour scan strategy (1)
- Convolutional neural network (1)
- Convolutional neural networks (CNN) (1)
- Coordinate measurement machine (1)
- Corrosion (1)
- Crater (1)
- Creep anisotropy (1)
- Creep behaviour (1)
- Critical strain (1)
- Crystal Plasticity Modelling (1)
- Crystallization (1)
- Crystallographic texture control (1)
- Cutting forces (1)
- Cuttlefish (1)
- DED-EB (1)
- DED-L (1)
- DIC (1)
- Damage Tolerance (1)
- Damage prediction (1)
- Damage tolerance (1)
- Data (1)
- Data Fusion (1)
- Data Integrity (1)
- Data-driven quality assurance (1)
- Debinding (1)
- Defect Detection (1)
- Defect Prediction (1)
- Defect prediction (1)
- Deformation-Induced Martensite (1)
- Density measurement (1)
- Dental (1)
- Deposition rate (1)
- Design of experiments (1)
- Diagnostic Antibodies (1)
- Dielectric Spectroscopy (1)
- Dielectric characterization (1)
- Diffraction contrast neutron imaging (1)
- Diffraction elastic constants (1)
- Diffraction elastic constants (DECs) (1)
- Diffraction methods (1)
- Diffraction-elastic constants (1)
- Digital Image Correlation (1)
- Digital Twin (1)
- Digital image correlation (1)
- Direct Energy Deposition (1)
- Directional grain growth (1)
- Dissimilar joints (1)
- Distortion simulation (1)
- Distortion upon baseplate removal (1)
- Ditigtal image correlation (1)
- Down Stream Processing (1)
- Drywood termite (1)
- Dwell-time (1)
- EAC-1A (1)
- EBAM (1)
- EBSD (1)
- EBSD analysis (1)
- Early-age concrete (1)
- Eddy-current testing (1)
- Edge effects (1)
- Edge quality (1)
- Effect of scanning strategies (1)
- Efficient modelling (1)
- Elastic Constants (1)
- Elastic constants (1)
- Electrical insulation (1)
- Electromagnetic support (1)
- Electron backscatter diffraction (EBSD) (1)
- Electron backscattered diffraction (1)
- Electron beam (1)
- Electron beam powder bed fusion (1)
- Electron beam welding (1)
- Emerging technologies (1)
- Emission (1)
- Emission test chamber (1)
- Emisssivity (1)
- Energy dispersive X Ray diffraction (1)
- Energy harvesting (1)
- Energy parameters of the arc (1)
- Environment (1)
- Ermüdung (1)
- European Metrology Network (1)
- European Metrology Network for Advanced Manufacturing, Strategic Research Agenda (1)
- Exposure risk (1)
- FAIR data (1)
- FEM Simulation (1)
- FFF (1)
- FFF-3D printer (1)
- FFF-3D printing (1)
- FFF-3D-Printer (1)
- Fabrication parameters (1)
- Fartigue Strength (1)
- Fast scanning calorimetry (1)
- Fatigue Crack Growth (1)
- Fatigue crack propagation (1)
- Fatigue crack propagation stagesdefects (1)
- Fatigue damage (1)
- Fatigue life (1)
- Fatigue loading (1)
- Fatigue strength (1)
- Feedstock powder (1)
- Feldspar (1)
- Fenics (1)
- Finish milling (1)
- Finite Element Method (1)
- Finite element method (1)
- Finite element simulation (1)
- Finite-Elemente-Methode (1)
- Firing (1)
- Flange width (1)
- Flaw detection (1)
- Flexible Magnetic Sensors (1)
- Flow Cell (1)
- Flüssigmetallinduzierte Rissbildung (1)
- Force-distance-curve (1)
- Fractography (1)
- Fracture Mechanics (1)
- Fracture mechanics (1)
- Friction (1)
- Functional Materials (1)
- Functionally graded porous scaffolds (1)
- Fusion welding (1)
- GMA welding (1)
- Galvanized steel (1)
- Gap bridgeability (1)
- Gas discharges (1)
- Gas flow assisted powder deposition (1)
- Gefügedegradation (1)
- Giant magnetoresistance (1)
- Glass (1)
- Glass Support (1)
- Glass-ceramics definition (1)
- Grain growth (1)
- Graphs (1)
- Gyroid lattice (1)
- HCF (1)
- HF-shuttle (1)
- HIP (1)
- HV-Insulation (1)
- Hardness (1)
- Hausner ratio (1)
- Haynes 282 (1)
- Haynes282 (1)
- Heat Input (1)
- Heat Treatments (1)
- Heat flow (1)
- Helium (1)
- Heterodyning (1)
- Heterogeneous catalysis (1)
- High Cycle Fatigue (1)
- High Voltage Insulation (1)
- High speed laser cladding (1)
- High strength AlMgSi aluminium alloys (1)
- High strength steels (1)
- High temperature alloys (1)
- High-Power Welding (1)
- High-Speed Separations (1)
- High-stength aluminium alloys (1)
- High-strength filler metals (1)
- High-strength fine-grained steels (1)
- High-strength steel filler metal (1)
- Hot Cracks (1)
- Hot isostatic pressing (1)
- Hot stage microscopy (1)
- Human Plasma (1)
- Hybrid Laser-Arc Welding (1)
- Hybrid Manufacturing (1)
- Hybrid laser arc welding (1)
- Hybrid laser-arc welding (1)
- Hybrid manufacturing (1)
- Hybrid part (1)
- Hygienische Bewertung (1)
- Hyperspectral (1)
- IBESS model for short cracks (1)
- IN 625 (1)
- IN 718 (1)
- IN718 PBF-LB/M (1)
- IN725 (1)
- IN738LC (1)
- INCONEL 718 (1)
- IgG determination (1)
- Image registration (1)
- Images (1)
- Imaging (1)
- In situ NDE (1)
- In situ alloying (1)
- In situ heating (1)
- In-Situ Techniques (1)
- In-Situ Testing (1)
- In-situ (1)
- In-situ CT (1)
- In-situ Process Monitoring (1)
- In-situ compression CT (1)
- In-situ heat treatment (1)
- In-situ thermography (1)
- In-situ tomography (1)
- In-vivo (1)
- In718 (1)
- Inconel 625 (1)
- Inconel 939 (1)
- Indoor emission (1)
- Industry 4.0 (1)
- Influence of rheology modifying admixtures on hydration of cementitious suspensions (1)
- Infrared Thermography (1)
- Inkjet (1)
- Integrated alignment features (1)
- Inter-layer time (1)
- Intergranular strain (1)
- Intermodulation AFM (1)
- Interpenetrating polymer networks (1)
- Interphase residual stress (1)
- JNP (1)
- JNP AdvManuNet (1)
- Joining process (1)
- Kernel average misorientation (1)
- Kitagawa-Takahashi (K-T) diagram (1)
- Korrosion (1)
- L-PBF IN718 material (1)
- LSD print (1)
- LTCC (1)
- LW (1)
- Laboratory X-ray diffraction (1)
- Laboratory energy-dispersive X-ray diffraction (EDXRD) (1)
- Large Scale Facilities (1)
- Laser Beam Welding (1)
- Laser Implantation (1)
- Laser Metal Deposition (LMD) (1)
- Laser Powder Bed Fusion (LPBF) (1)
- Laser Welding (LW) (1)
- Laser cutting (1)
- Laser direct writing (1)
- Laser induced slipcasting (1)
- Laser methods (1)
- Laser powder bed fusion (PBF-LB/M, L-PBF) (1)
- Laser powder-based directed energy deposition (1)
- Laser powder-bed fusion (1)
- Laser surfacing (1)
- Laser thermography (1)
- Laser writing (1)
- Laser-based additive manufacturing (1)
- Laser-based powder bed fusion of metal (PBF-LB/M) (1)
- Laser-metal-deposition (1)
- Laser-metal-depositon (1)
- Layered double hydroxide (1)
- Liquid Metal Embrittlement (1)
- Liquid Metal Embrittlement (LME) (1)
- Lithium (1)
- Lithium aluminosilicates (1)
- Lithography-based technologies (1)
- Low cycle fatigue (1)
- Low-Cycle-Fatigue (1)
- Low-cycle fatigue (1)
- Low-cycle-fatigue behaviour (1)
- MAG-Welding (1)
- MANUFACT (1)
- MGS-1 regolith simulant (1)
- MOUSE (1)
- MPI (1)
- MPLS (1)
- MWIR (1)
- Machine learning segmentation (1)
- Machine vision (1)
- Machine-Learning Segmentation (1)
- Machining (1)
- Magnesium Alloy (1)
- Magnesium alloy (1)
- Magnetic nano-particles (1)
- Magnetic swimmers (1)
- Magnetocoloric (1)
- Manufact (1)
- Maritime Components (1)
- Mars (1)
- Maskinteknik (1)
- Material characterization (1)
- Material extrusion (MEX) (1)
- Material properties (1)
- Material science (1)
- Materials Science (1)
- Materials science (1)
- Mean-field modelling (1)
- Mechanical Behavior (1)
- Mechanical properties of the joints (1)
- Medical implants (1)
- Mehrskalenmodell (1)
- Melt pool depth (1)
- Melt pool dinamics (1)
- Melt pool monitoring (1)
- Melt-pool-monitoring (1)
- Melting (1)
- Metal (1)
- Metal additive manufacturing (MAM) (1)
- Metal matrix composites (1)
- Metal organic framework (1)
- Metal powder characterization (1)
- Metallic Glass (1)
- Metals and Alloys (1)
- Micro computed tomography (1)
- Micro-computed tomography (1)
- Microfabrication (1)
- Micromechnical properties (1)
- Microprinting (1)
- Microscopy (1)
- Microstructural evolution (1)
- Microstructure analysis (1)
- Microstructure characterisation (1)
- Microstructure characterization (1)
- Microstructure evolution (1)
- Mikrostruktur (1)
- Miniature specimens (1)
- Model calibration (1)
- Monoclonal Antibodies (1)
- Monolith (1)
- Moon (1)
- Multi photon lithography (1)
- Multi-materials joining (1)
- Multi-photon light structuring (1)
- Multi-principal element alloys (1)
- Multiphoton laser structuring (1)
- Multiple-layered scaffold (1)
- Mussel inspired materials (1)
- Mussel-inspired materials (1)
- NIR (1)
- Nano-ceramic-additive-manufacturing photoresin (1)
- NanoCAM (1)
- Nanostructured powder (1)
- Near-surface X-ray diffraction (1)
- Networking (1)
- Neutron (1)
- Neutron and X-ray diffraction (1)
- Neutrons diffraction (1)
- Ni alloy (1)
- Nickel-based superalloy (1)
- Nickel-based superalloys (1)
- Non-destructiv testing (1)
- Non-destructive Materials (1)
- Non-destructuve testing (1)
- Non-weldable superalloy (1)
- Nondestructive testing (1)
- Numerical Simulation (1)
- Numerical simulation (1)
- Numerical simulations (1)
- OMS (1)
- On-line monitoring (1)
- Online NMR Spectroscopy (1)
- Online monitoring (1)
- Online quality control (1)
- Ontology (1)
- Open Data (1)
- Open Science (1)
- Open data on zenodo (1)
- Open source (1)
- Optical Emission Spectroscopy (1)
- Optical emission spectroscopy (1)
- Optical flow (1)
- Optics (1)
- Optimization workflow (1)
- Osseointegration (1)
- Overview (1)
- PBFLB/M AlSi10Mg alloy (1)
- Packing density (1)
- Parabolic flight (1)
- Particle size distribution (1)
- Pearlitic microstructure (1)
- Performance oriented concrete design (1)
- Phase-field simulation (1)
- Photopolymerization (1)
- Pipe Welding (1)
- Pipe weld preparation (1)
- Plasma acoustics (1)
- Plasma cutting (1)
- Plasma spray (1)
- Plastic deformation (1)
- Polycaprolactone (1)
- Polyclonal Antibodies (1)
- Polyethylene glycol diacrylate (1)
- Polyglycerol (1)
- Polymer (1)
- Polymer nanocomposites (1)
- Polymer-Ceramic-Composite (1)
- Polymer-ceramic mixtures (1)
- Polymeric Materials (1)
- Polymers (1)
- Polyurethane acetate vinyl acrylate (1)
- Pore formation (1)
- Porosity growth (1)
- Porous materials (1)
- Post NDE (1)
- Post processing heat treatment (1)
- Powder Analysis (1)
- Powder Characterization (1)
- Powder analysis (1)
- Powder bed additive manufacturing (1)
- Powder bed density (1)
- Powder bed fusion (1)
- Powder bed fusion Laser beam (1)
- Powder deposition (1)
- Powder flow (1)
- Powder methods (1)
- Powder rheology (1)
- Powder-based processes (1)
- Ppreheating temperature (1)
- Precast concrete (1)
- Preceramic polymer (1)
- Precipitation hardening aluminum alloys (1)
- Preferential orientation (1)
- Preheatin (1)
- Preheating temperature (1)
- Principal stress (1)
- Principal stress components (1)
- Printed Electronics (1)
- Printing (1)
- Process (1)
- Process Chain Integration (1)
- Process Control (1)
- Process Simulation (1)
- Process development (1)
- Process simulation (1)
- Protein A (1)
- Protein Purification (1)
- Purification (1)
- Quality monitoring (1)
- Radiography (1)
- Radiological inspections (1)
- Rail tracks (1)
- Rapid prototyping (1)
- Re-entrant surface feature (1)
- Real-time deformation (1)
- Recycling (1)
- Reduced order modelling (1)
- Reference material (1)
- Reference structure (1)
- Regeneration (1)
- Regolith (1)
- Repair welding (1)
- Reparaturschweißen (1)
- Representative Specimens (1)
- Research (1)
- Research and Development (1)
- Research data (1)
- Residual powder removal (1)
- Residual stress in AM (1)
- Residual stress measurements (1)
- Resistance Spot Welding (RSW) (1)
- Rheology (1)
- Rheometry (1)
- Robocasting (1)
- Robustness (1)
- Roll-to-Roll Processing (1)
- Rotational (1)
- SAXS (1)
- SEM micrography (1)
- SLS (1)
- SRA (1)
- SWIR (1)
- SWIR thermography (1)
- Safety (1)
- Scaffold geometry (1)
- Scan strategies (1)
- Scan strategy influence (1)
- SchwarzP cells (1)
- Seam geometry (1)
- Selective laser beam melting (1)
- Selective laser melted materials (1)
- Self-Assembly (1)
- Self-organization (1)
- Sensors (1)
- Separation (1)
- Shipbuilding steel (1)
- Silicate glass-ceramics (1)
- Sintered Material (1)
- Slicers (1)
- Smectite (1)
- Softening temperature (1)
- Sol-gel (1)
- Solid support (1)
- Solidification behaviour (1)
- Space exploration (1)
- Stainless steel (1)
- Stainless steels (1)
- Standardisation (1)
- Standardization (1)
- Standards (1)
- Steel (1)
- Steel 316L (1)
- Strain fields prediction (1)
- Strain measurement (1)
- Strain-free lattice references (1)
- Strain-free lattice spacing (1)
- Strategic Research Agenda (SRA), (1)
- Strengthening mechanisms (1)
- Stress balance (1)
- Stress balance condition (1)
- Stress concentration tensor (1)
- Stress-relief heat-treatments (1)
- Structural Integrity (1)
- Structural precision (1)
- Sub-4nm particles (1)
- Superalloy (1)
- Superlattice extrinsic stacking faults (1)
- Support configurations (1)
- Surface coating (1)
- Surface properties (1)
- Surface roughness (1)
- Surface structuring (1)
- Surface temperature (1)
- Surface topography (1)
- Synchrotron CT (1)
- Synchrotron Radiation (1)
- Synchrotron X-ray CT (1)
- Synchrotron X-ray Refraction (1)
- Synchrotron X-ray diffraction (SXRD) (1)
- Synchrotron X-ray refraction radiography (1)
- Synchrotron computed tomography (1)
- Synchrotron refraction (1)
- Synchrotron refraction radiography (1)
- Synchrotron tomography (1)
- TIG welding (1)
- TPMS structures (1)
- Technical Ceramics (1)
- Technological innovation (1)
- Technologies (1)
- Temperature behavior (1)
- Temperature dependence (1)
- Temperature distribution (1)
- Tensile resistance spot welding experiment (1)
- Tensile strength (1)
- Tensile tests (1)
- Terpolymer (1)
- Test method (1)
- Test structure (1)
- Textile binder (1)
- Therapeutic Antibodies (1)
- Thermal imaging (1)
- Thermocouple (1)
- Thick-Walled Steel (1)
- Thick-walled steel (1)
- Ti6Al4V alloy (1)
- Titanium alloy (1)
- Tomography (1)
- Tool steel (1)
- Tricalcium Phosphate (1)
- Trinkwasser (1)
- Triobology (1)
- Triply Periodical Minimal Surface (1)
- Triply periodic minimal surfaces (1)
- Turbine components (1)
- Two-Photon Polymerization (1)
- Two-photon adsorption (1)
- Two-photon polymerisatio (1)
- Two-run welding technique (1)
- UV/VIS spectroscopy (1)
- Upscaling (1)
- VHCF (1)
- VOC (1)
- Vinyl monomer (1)
- WAAM Ti-6Al-4V (1)
- Water-based (1)
- Wear (1)
- Weld geometry (1)
- Welding Current (1)
- Welding Simulation (1)
- Welding parameter (1)
- Weldx (1)
- Wetting (1)
- White light interferometry microscopy (1)
- Widerstandspunktschweißen (1)
- Wire electron beam additive manufacturing (1)
- Wire-based additive manufacturing (1)
- Wärmeführung (1)
- X-Ray Computed Tomography (1)
- X-Ray Imaging (1)
- X-Ray refraction (1)
- X-ray CT (1)
- X-ray Computed tomography (1)
- X-ray Diffraction (1)
- X-ray Refaction radiography (1)
- X-ray and neutron diffraction (1)
- X-ray computed tomography (XCT) (1)
- X-ray photoelectron spectroscopy (1)
- X-ray refraction radiography (1)
- X-ray scattering (1)
- X-ray tomographic (1)
- X-ray-refraction (1)
- Young´s modulus (1)
- Zink (1)
- Zirconium (1)
- additive manufacturing (1)
- bioactive (1)
- biomaterials (1)
- bone (1)
- ceramic (1)
- cold cracking safety (1)
- dental (1)
- fatigue crack growth (1)
- high-resolution camera (1)
- high-strength steel (1)
- hybrid repair (1)
- in-situ (1)
- infrared Thermography (1)
- microstructure analysis (1)
- position detection (1)
- powder bed fusion of metals utilizing a laser beam (1)
- selective laser melting (1)
- stl code (1)
Organisationseinheit der BAM
- 8 Zerstörungsfreie Prüfung (264)
- 9 Komponentensicherheit (254)
- 8.5 Röntgenbildgebung (197)
- 5 Werkstofftechnik (153)
- 9.3 Schweißtechnische Fertigungsverfahren (100)
- 9.4 Integrität von Schweißverbindungen (91)
- 8.0 Abteilungsleitung und andere (82)
- 9.6 Additive Fertigung metallischer Komponenten (78)
- 5.4 Multimateriale Fertigungsprozesse (77)
- 5.2 Metallische Hochtemperaturwerkstoffe (42)
Paper des Monats
- ja (6)
Modern and energy-efficient materials are essential for innovative designs for aerospace and automotive industries. Current technologies for rapid manufacturing such as additive manufacturing and liquid composite moulding by polymer Extrusion allow innovative ways of creating robust and lightweight constructions. Commercially available printing devices often use polylactide (PLA) or acrylonitrile butadiene styrene (ABS) as raw material. Therefore, parameters like the infill ratio, influencing the ability to resist mechanical stress, may have a beneficial impact on the lifetime of components.
These manufacturing technologies require a good knowledge about materials and even adapted non-destructive testing technologies and methods. Airborne ultrasonic testing has beneficial advantages for testing those lightweight constructions. It is a contact-free testing method, which does not require a liquid couplant. Therefore, it allows fast test cycles without any unwanted alternations of the material properties due to interactions with any coupling liquid. This contribution deals with the characterisation of printed specimens based on PLA by using airborne ultrasound and presents the current edge of non-destructive testing and evaluation using airborne ultrasonic transducers. The specimens, manufactured by polymer extrusion, are printed as thin plates. The infill ratio, as well as the material thickness, were varied to model density imperfections with different geometric shapes and properties. For better understanding of the limits of airborne ultrasonic testing in transmission, we compared own-developed transducers based on different physical principles: on ferroelectrets, on the thermoacoustic effect, as well as a new type of transducers based on gas discharges.
Virtual-lab-based determination of a macroscopic yield function for additively manufactured parts
(2018)
This work presents a method for the yield function determination of additively manufactured parts of S316L steel. A crystal plasticity model is calibrated with test results and used afterwards to perform so-called virtual experiments, that account for the specific process-related microstructure including crystallographic and morphological textures. These simulations are undertaken on a representative volume element (RVE), that is generated from EBSD/CT-Scans on in-house additively manufactured specimen, considering grain structure and crystal orientations. The results of the virtual experiments are used to determine an anisotropic Barlat yield function, that can be used in a macroscopical continuum-sense afterwards. This scale-bridging approach enables the calculation of large-scale parts, that would be numerically too expensive to be simulated by a crystal plasticity model.
Pores in additive manufactured metal parts occur due to different reasons and affect the part Quality negatively. Few investigations on the origins of porosity are available, especially for Ni-based super alloys. This paper presents a new study to examine the influence of common processing Parameters on the Formation of pores in parts built by laser metal Deposition using Inconel 718 powder. Further, a comparison between the computed tomography (CT) and the Archimedes method was made. The Investigation Shows that CT is able to identify different kinds of pores and to give further Information about their distribution. The identification of some pores as well as their shape can be dependent on the Parameter Setting of the Analysis tool. Due to limited measurement Resolution, CT is not able to identify correctly pores with Diameters smaller than 0.1 mm, which leads to a false decrease on Overall porosity. The applied Archimedes method is unable to differentiate between gas porosity and other Kinds of holes like internal cracks or lack of Fusion, but it delivered a proper value for Overall porosity. The method was able to provide suitable data for the statistical Evaluation with design of Experiments, which revealed significant Parameters ont he Formation of pores in LMD.
Additive Manufacturing (AM) offers the opportunity to produce easier geometrically complex parts compared to traditional production technologies. An important AM technology for metals is selective laser melting (SLM) where a part is produced by melting and solidifying powder in layers. This technique is known to cause a pronounced texture in the produced AM products due to the specific heat flow and the associated solidification of the material during SLM deposition. In order to evaluate the influence of the deposition hatch length during SLM of nickel based superalloy Inconel 718 samples on the texture and in order to identify any preferred crystallographic direction, we performed monochromatic neutron radiography scans (using wavelength from 1.6 Å to 4.4 Å, step size 0.05 Å) to image the samples while rotating it through 90°. Samples produced with short hatch length showed fine textured columnar grains oriented along the sample building direction in high-resolution radiographs. Whereas processing the sample using a ten-fold longer hatch length reduced the texture. The neutron radiographic experiments were accompanied by scanning electron microscopy including electron back-scattered diffraction to visualize and verify the microstructure and texture.
Microstructure characterisation of advanced materials via 2D and 3D X-ray refraction techniques
(2018)
3D imaging techniques have an enormous potential to understand the microstructure, its evolution, and its link to mechanical, thermal, and transport properties. In this conference paper we report the use of a powerful, yet not so wide-spread, set of X-ray techniques based on refraction effects. X-ray refraction allows determining internal specific surface (surface per unit volume) in a non-destructive fashion, position and orientation sensitive, and with a nanometric detectability. We demonstrate showcases of ceramics and composite materials, where microstructural parameters could be achieved in a way unrivalled even by high-resolution techniques such as electron microscopy or computed tomography. We present in situ analysis of the damage evolution in an Al/Al2O3 metal matrix composite during tensile load and the identification of void formation (different kinds of defects, particularly unsintered powder hidden in pores, and small inhomogeneity’s like cracks) in Ti64 parts produced by selective laser melting using synchrotron X-ray refraction radiography and tomography.
Additive Manufacturing by Selective Laser Melting (SLM) offers an ample scope for producing geometrically complex parts as compared to the traditional subtractive manufacturing strategies. However, the residual stresses (RS) developed during the processing can reduce the load bearing capacity as well as induce unwanted distortion, limiting the life time and the application of SLM parts.
With the recent rise in the demand for additive manufacturing (AM), the need for reliable simulation tools to support experimental efforts grows steadily. Computational welding mechanics approaches can simulate the AM processes but are generally not validated for AM-specific effects originating from multiple heating and cooling cycles. To increase confidence in the outcomes and to use numerical simulation reliably, the result quality Needs to be validated against experiments for in-situ and post-process cases. In this article, a validation is demonstrated
for a structural thermomechanical simulation model on an arbitrarily curved Directed Energy Deposition (DED)part: at first, the validity of the heat input is ensured and subsequently, the model’s predictive quality for in-situ
deformation and the bulging behaviour is investigated. For the in-situ deformations, 3D-Digital Image Correlation measurements are conducted that quantify periodic expansion and shrinkage as they occur. The results show a strong dependency of the local stiffness of the surrounding geometry. The numerical Simulation model is set up in accordance with the experiment and can reproduce the measured 3-dimensional in-situ displacements. Furthermore, the deformations due to removal from the substrate are quantified via 3D-scanning, exhibiting considerable distortions due to stress relaxation. Finally, the prediction of the deformed shape is discussed in regards to bulging simulation: to improve the accuracy of the calculated final shape, a novel Extension of the model relying on the modified stiffness of inactive upper layers is proposed and the experimentally observed bulging could be reproduced in the finite element model.
Additive Manufacturing (AM) through the Selective Laser Melting (SLM) route offers ample scope for producing geometrically complex parts compared to the conventional subtractive manufacturing strategies. Nevertheless, the residual stresses which develop during the fabrication can limit application of the SLM components by reducing the load bearing capacity and by inducing unwanted distortion, depending on the boundary conditions specified during manufacturing. The present study aims at characterizing the residual stress states in the SLM parts using different diffraction methods. The material used is the nickel based superalloy Inconel 718. Microstructure as well as the surface and bulk residual stresses were characterized. For the residual stress analysis, X-ray, synchrotron and neutron diffraction methods were used. The measurements were performed at BAM, at the EDDI beamline of -BESSY II synchrotronand the E3 line -BER II neutron reactor- of the Helmholtz-Zentrum für Materialien und Energie (HZB) Berlin. The results reveal significant differences in the residual stress states for the different characterization techniques employed, which indicates the dependence of the residual state on the penetration depth in the sample. For the surface residual stresses, longitudinal and transverse stress components from X-ray and synchrotron agree well and the obtained values were around the yield strength of the material. Furthermore, synchrotron mapping disclosed gradients along the width and length of the sample for the longitudinal and transverse stress components. On the other hand, lower residual stresses were found in the bulk of the material measured using neutron diffraction. The longitudinal component was tensile and decreased towards the boundary of the sample. In contrast, the normal component was nearly constant and compressive in nature. The transversal component was almost negligible. The results indicate that a stress re-distribution takes place during the deposition of the consecutive layers. Further investigations are planned to study the phenomenon in detail.
Additive manufacturing (AM) offers an effective solution to the medical sector. It enables the production, on demand, of customised implants which match the patient’s anatomy, with grafts that promote bone growth, as well as surgical guides that help the surgeons.
The objective of this project is to provide a comprehensive basis to enable the safe use of medical AM products with traceable and reliable dimensionalmeasurements. This will guarantee the reliability of medical AM products to notified bodies and facilitate acceptance of AM in the medical sector for a better quality of life.
Glass-ceramics are noted for their unusual combination of properties and manifold commercialized products for consumer and specialized markets. Evolution of novel glass and ceramic processing routes, a plethora of new compositions, and unique exotic nano- and microstructures over the past 60 years led us to review the Definition of glass-ceramics. Well-established and emerging processing methods, such as co-firing, additive manufacturing, and laser patterning are analyzed concerning the core requirements of processing glass-ceramics and the Performance of the final products. In this communication, we propose a revised, updated definition of glass-ceramics, which reads “Glass-ceramics are inorganic, non-metallic materials prepared by controlled crystallization of glasses via different processing methods. They contain at least one type of functional crystalline phase and a residual glass. The volume fraction crystallized may vary from ppm to almost 100%”.
Having been introduced almost two decades ago, Additive Manufacturing (AM) of metals has become industrially viable for a large variety of applications, including aerospace, automotive and medicine. Powder bed techniques such as Selective Laser Melting (SLM) based on layer-by-layer deposition and laser melt enable numerous degrees of freedom for the geometrical design. Developing during the manufacturing process, residual stresses may limit the application of SLM parts by reducing the load bearing capacity as well as induce unwanted distortion depending on the boundary conditions specified in manufacturing.
The residual stress distribution in IN718 elongated prisms produced by SLM was studied non-destructively by means of neutron (bulk) and laboratory X-ray (surface) diffraction. The samples with different scanning strategies, i.e. hatching length, were measured in as-built condition (on a build plate) and after removal from the build plate.
While surface stress fields seem constant for AB condition, X-ray diffraction shows stress gradients along the hatch direction in the RE condition. The stress profiles correlate with the distortion maps obtained by tactile probe measurements.
Neutron diffraction shows bulk stress gradients for all principal components along the main sample directions. We correlate the observed stress patterns with the hatch length, i.e. with its effect on temperature gradients and heat flow. The bulk stress gradients partially disappear after removal from the baseplate.
Together with surface scan utilizing a coordinate-measuring machine (CMM), it is possible to link the stress release to the sample distortion.
We finally propose an explanation of those stress profiles based on the deposition strategy.
We investigated lattice structure manufactured by laser beam melting with computed tomography on difference scales, such as powder scale, strut scale and lattice scale.
The raw powder has been evaluated by means of synchrotron computed tomography (CT) at the BAM-Line (HZB Bessy II, Berlin). Therefore, the particle size distribution and even the pore size distribution was investigated and compared with results received by the producer by means of sieving. Studies with laboratory X-ray CT of porosity and roughness of manufactured struts in dependence of the build angle exhibited the tendency that elongated pores appear solely in a certain range near the edge. The integrity and load-bearing capacity of a lattice structure was investigated by means of in-situ CT during compression. The lattice structure was compressed by 10 % in height with an applied maximum force of 5 kN. We applied digital volume correlation algorithm on volumes of different load steps to quantifies the displacement within the structure.
Im Fokus dieser Arbeit steht die computertomographische (CT) Untersuchung (Synchrotron- und Labor-CT) von IN625-Pulver und den daraus gefertigten Streben, welche wiederum zu Gitterstrukturen zusammengesetzt werden. Aufgrund der Filigranität wurde zur Fertigung dieser Proben das pulverbettbasierte selektive Laserschmelzen verwendet.
Porositätsanalysen und Größenverteilungen wurden für das Pulver bei einer rekonstruierten Voxelgröße von 0,5µm ermittelt. 6,0mm lange Streben variierten im Aufbauwinkel von 30° bis 90° zur Bauplattform und zeigten so den Unterschied zwischen Up- und Down-Skin hinsichtlich der Rauigkeit und Porenverteilung. Die Gitterstrukturen konnten in-situ mit bis zu 5,0kN belastet werden, um deren Verformung computertomographisch zu erfassen.
The topic of the presentation consists in some basic considerations on the application of fracture mechanics to fatigue live and strengh prediction of metallic componends manufatured by additive manufacturing. These are based on an approach developed at BAM which comprises elements such as the elastic-plastic modelling of the cyclic crack driving force, a physically meaningfull determination of the initial crack size and multipile crack initiation and propagation due to variations of the local geometry and material charactaristics. Spezial emphasis is put to spezific aspects of materials composed by selectiv laser melting such as surface roughness, porosity and gradiants in the microstructure.
Powder bed -based technologies are amongst the most successful Additive Manufacturing (AM) techniques. "Selective laser sintering/melting" (SLS/SLM) and "binder jetting 3D printing" (3DP) especially are leading AM technologies for metals and polymers, thanks to their high productivity and scalability. In this context, the "layerwise slurry deposition" (LSD) has been developed as a layer deposition method which enables the use of SLS/SLM and 3DP technologies for advanced ceramic materials. LSD consists in the layer-by-layer deposition of a ceramic slurry by means of a doctor blade. Each layer is deposited and dried to achieve a highly packed powder layer, which can be used for SLM or for 3DP. This technique offers high flexibility in the ceramic feedstock used, especially concerning material and particle size, and is capable of producing parts with physical and mechanical properties comparable to traditionally shaped parts. In this presentation, the LSD technique will be introduced and several examples of application to porcelain, SiC and alumina products will be reported.
In powder-based Additive Manufacturing (AM) processes, an object is produced by successively depositing thin layers of a powder material and by inscribing the cross section of the object in each layer. The main methods to inscribe a layer are by binder jetting (also known as powder 3D printing) or by selective laser sintering/melting (SLS/SLM).
Powder-based AM processes have found wide application for several metallic, polymeric and also ceramic materials, due to their advantages in combining flexibility, easy upscaling and (often) good material properties of their products.
The deposition of homogeneous layers is key to the reproducibility of these processes and has a direct influence on the quality of the final parts. Accordingly, powder properties such as particle size distribution, shape, roughness and process related properties such as powder flowability and packing density need to be carefully evaluated.
Due to these requirements, these processes have been so far precluded to find commercial use for certain applications. In the following, two outstanding cases will be presented.
A first example is that powder-based AM processes are widely used for many metallic and polymeric materials, but they find no commercial application for most technical ceramics.
This seemingly contradicting observation is explained by the fact that in powder based AM, a dry flowable powder needs to be used. The processing of technical ceramics in fact typically requires very fine and poorly flowable powder, which makes them not suitable for the standard processes. There have been several approaches to adapt the raw materials to the process (e.g. by granulation), but in order to maintain the superior properties of technical ceramics it seems necessary to follow the opposite approach and adapt the process to the raw materials instead.
This was the motivation for developing the Layerwise Slurry Deposition (LSD), an innovative process for the deposition of powder layers with a high packing density. In the LSD process, a ceramic slurry is deposited to form thin powder layers, rather than using a dry powder. This allows achieving high packing density (55-60%) in the layers after drying. It is also important, that standard ceramic raw materials can be used. When coupled with a printing head or with a laser source, the LSD enables novel AM technologies which are similar to 3D printing or selective laser sintering, but taking advantage of having a highly dense powder bed.
The LSD -3D printing, in particular, offers the potential of producing large (> 100 mm) and high quality ceramic parts, with microstructure and properties similar to traditional processing. Moreover, due to the compact powder bed, no support structures are required for fixation of the part in the printing process.
Figure 1 shows the schematics of the working principle of the LSD-3D print and illustrates some examples of the resolution and features achievable.
The second outstanding case here described is the application of powder-based AM in environments with reduced or zero gravity. The vision is to be able to produce repair parts, tools and other objects during a space mission, such as on the International Space Station (ISS), without the need of delivering such parts from Earth or carrying them during the mission. AM technologies are also envisioned to play an important role even for future missions to bring mankind to colonize other planets, be it on Mars or on the Moon. In this situation, reduced gravity is also experienced (the gravitational acceleration is 0.16 g on the Moon and 0.38 g on Mars).
These environments cause the use of AM powder technologies to be very problematic: the powder layers need to be stabilized in order to avoid dispersion of the particles in the chamber. This is impossible for standard AM powder deposition systems, which rely on gravitation to spread the powder.
Also in this case, an innovative approach has been implemented to face this technological challenge. The application of a gas flow through a powder has a very strong effect on its flowability, by generating a force on each particle, which is following the gas flow field. This principle can be applied in a simple setup such as the one shown in Figure 2.
In this setup, the gas flow causes an average pressure on the powder bed in direction of the arrows, generating a stabilizing effect which acts in the same direction of the gravitational force. This effect can be used in addition to normal gravity on Earth to achieve a better stabilization of 3D printed parts in the powder bed. In this case, even a significant increase of packing density of the powder was measured, compared to the same experimental setup without gas flow. This is due to the fact that the force on each single particle follows the gas flow field, which is guiding the particles to settle between the pores of the powder bed, thus achieving an efficient packing.
The same principle can be applied in absence of gravitation, where the gas flow acts to stabilize the powder layers. It has been shown that ceramic powder could be deposited in layers and laser sintered in µ-gravity conditions during a DLR (Deutsches Zentrum für Luft- und Raumfahrt) campaign of parabolic flights, as shown in Figure 2. A follow-up campaign is dedicated to the deposition of metallic (stainless steel) powder in inert atmosphere and to study the effects of laser melting in µ-gravity.
In conclusion, the description of these two example cases shows how the development of novel technological processes can address some of the limitations of standard powder-based AM, in order to enable the use of new materials, such as technical ceramics, or to tackle the challenges of AM in space.
Additive Manufacturing (AM) through the Selective Laser Melting (SLM) route offers ample scope for producing geometrically complex parts compared to the conventional subtractive manufacturing strategies. Nevertheless, the residual stresses which develop during the fabrication can limit application of the SLM components by reducing the load bearing capacity and by inducing unwanted distortion, depending on the boundary conditions specified during manufacturing.
The present study aims at characterizing the residual stress states in the SLM parts using different diffraction methods. The material used is the nickel based superalloy Inconel 718. Microstructure as well as the surface and bulk residual stresses were characterized. For the residual stress analysis, X-ray, synchrotron and neutron diffraction methods were used. The measurements were performed at BAM, at the EDDI beamline of -BESSY II synchrotron- and the E3 line -BER II neutron reactor- of the Helmholtz-Zentrum für Materialien und Energie (HZB) Berlin.
The results reveal significant differences in the residual stress states for the different characterization techniques employed, which indicates a dependence of the residual state on the penetration depth in the sample. For the surface residual stresses, longitudinal and transverse stress components from both X-ray and synchrotron agree well and the obtained values were around the yield strength of the material. Furthermore, synchrotron mapping disclosed gradients along the width and length of the sample for the longitudinal and transverse stress components. On the other hand, lower residual stresses were found in the bulk of the material measured using neutron diffraction. The longitudinal component was tensile and decreased towards the boundary of the sample. In contrast, the normal component was nearly constant and compressive in nature. The transversal component was almost negligible. The results indicate that a stress re-distribution takes place during the deposition of the consecutive layers. Further investigations are planned to study the phenomenon in detail.
Virtual-lab-based determination of a macroscopic yield function for additively manufactured parts
(2018)
This work presents a method for the yield function determination of additively manufactured parts of S316L steel. A crystal plasticity model is calibrated with test results and used afterwards to perform so-called virtual experiments, that account for the specific process-related microstructure including crystallographic and morphological textures. These simulations are undertaken on a representative volume element (RVE), that is generated from EBSD/CT-Scans on in-house additively manufactured specimen, considering grain structure and crystal orientations. The results of the virtual experiments are used to determine an anisotropic Barlat yield function, that can be used in a macroscopical continuum-sense afterwards. This scale-bridging approach enables the calculation of large-scale parts, that would be numerically too expensive to be simulated by a crystal plasticity model.
This book fulfills its intention to provide a comprehensive overview on 3D-printing of metals.
The interested reader can get a lot of information about the topics one should deal with when working with additively manufactured metallic parts. It gives a general roadmap where to start, what to learn and how it fits together.
The quality of components made by laser beam melting (LBM) additive manufacturing is naturally influenced by the quality of the powder bed. A packing density < 1 and porosity inside the powder particles lead to intrinsic voids in the powder bed. Since the packing density is determined by the particle size and shape distribution, the determination of these properties is of significant interest to assess the printing process. In this work, the size and shape distribution, the amount of particle’s intrinsic porosity as well as the packing density of micrometric powder used for LBM have been investigated by means of synchrotron X-ray computed tomography (CT). Two different powder batches were investigated: Ti-6Al-4V produced by plasma atomization and Stainless Steel 316L produced by gas atomization. Plasma atomization particles were observed to be more spherical in terms of the mean anisotropy compared to particles produced by gas atomization. The two kinds of particles are comparable in size according to the equivalent diameter. The packing density is lower (i.e. the powder bed contains more voids in between particles) for the Ti-6Al-4V particles. The comparison of the tomographic results with laser diffraction, as another particle size measurements techniques, proved agreement.
Most additive manufacturing processes which produce dense ceramics are nowadays limited in size because of inevitable post-processing steps like for example binder removal in stereolithography. The additive manufacturing of voluminous ceramic parts is realized by powder bed based processes which, however, generate parts with residual porosity. Via infiltration these parts can be processed to dense parts like for example SiC but this is not possible for all ceramics like for example Si3N4. There is a lack of methods for the additive manufacturing of dense voluminous parts for most ceramics.
We have developed a new additive manufacturing technology, the Laser Induced Slip casting (LIS), based on the layerwise deposition of slurries and their local drying by laser radiation. Laser Induced Slip casting generates ceramic green bodies which can be sintered to dense ceramic components like traditional formed ceramic powder compacts. We will introduce the LIS technology, green bodies and sintered parts will be shown and their microstructure and mechanical properties will be discussed.
Most additive manufacturing processes which produce dense ceramics are nowadays limited in size because of inevitable post-processing steps like for example binder removal in stereolithography. The additive manufacturing of voluminous ceramic parts is realized by powder bed based processes which, however, generate parts with residual porosity. Via infiltration these parts can be processed to dense parts like for example SiC but this is not possible for all ceramics like for example Si3N4. There is a lack of methods for the additive manufacturing of dense voluminous parts for most ceramics.
We have developed a new additive manufacturing technology, the Laser Induced Slip casting (LIS), based on the layerwise deposition of slurries and their local drying by laser radiation. Laser Induced Slip casting generates ceramic green bodies which can be sintered to dense ceramic components like traditional formed ceramic powder compacts. We will introduce the LIS technology, green bodies and sintered parts will be shown and their microstructure and mechanical properties will be discussed.
The residual stress distribution in IN718 elongated prisms produced by Selective Laser Melting was studied by means of neutron (bulk) and laboratory X-ray (surface) diffraction.
Two deposition hatch lengths were considered. A horizontal plane near the top surface (perpendicular to the building direction) and a vertical plane near the lateral surface (parallel to the building direction) were investigated. Samples both in as-built (AB) condition and removed (RE) from the base plate were characterized.
While surface stress fields seem constant for AB condition, X-ray diffraction shows stress gradients along the hatch direction in the RE condition. The stress profiles correlate with the distortion maps obtained by tactile probe measurements.
Neutron diffraction shows bulk stress gradients for all principal components along the main sample directions. We correlate the observed stress patterns with the hatch length, i.e. with its effect on temperature gradients and heat flow. The bulk stress gradients partially disappear after removal from the baseplate.
The paper deals with the integration of a light emitting diode (LED) into an additive manufactured metal component. Selective laser melting (SLM) and laser metal deposition (LMD) are used. The material used is the chrome-nickel steel 316L. The basic component is manufactured by means of SLM and consists of a solid body and an area with grid structure. The solid body includes a duct in the shape of a groove with a recess for the positioning of the power cable. The LED is embedded in the grid structure via an inlet from the solid body. In further processing, the groove is filled with LMD. Two strategies with different parameter combinations were investigated. It shows that a high energy input near the power cable leads to its destruction. By using multiple parameter combinations during the manufacturing process, this destruction can be prevented. There was a comparison of both strategies with regard to the necessary number of tracks and duration of welding time.
The paper deals with the integration of a light emitting diode (LED) into an additive manufactured metal component. Selective laser melting (SLM) and laser metal deposition (LMD) are used. The material used is the chrome-nickel steel 316L. The basic component is manufactured by means of SLM and consists of a solid body and an area with grid structure. The solid body includes a duct in the shape of a groove with a recess for the positioning of the power cable. The LED is embedded in the grid structure via an inlet from the solid body. In further processing, the groove is filled with LMD. Two strategies with different parameter combinations were investigated. It shows that a high energy input near the power cable leads to its destruction. By using multiple parameter combinations during the manufacturing process, this destruction can be prevented. There was a comparison of both strategies with regard to the necessary number of tracks and duration of welding time.
Compact nuclear magnetic resonance (NMR) instruments make NMR spectroscopy and relaxometry accessible in industrial and harsh environments for reaction characterization and process control. Robust field integration of NMR systems have to face explosion protection or integration into process control systems with short set-up times. This paves the way for industrial automation in real process environments.
The design of failsafe, temperature and pressure resistant flow through cells along with their NMR-specific requirements is an essential cornerstone to enter industrial production plants and fulfill explosion safety requirements. Additionally, if fast reactions are monitored, suitable mixing devices need to be placed in close vicinity to the measuring volume to mix the reactants properly.
NMR-specific requirements aim at full quantitative pre-magnetization and acquisition with maximum sensitivity while reducing sample transfer times and dwell-times. All parameters are individually dependent on the applied NMR instrument.
Luckily, an increasing number of applications are reported together with an increasing variety of commercial equipment. However, these contributions have to be reviewed thoroughly.
The performance of sample flow cells commonly used in online analytics and especially for low-field NMR spectroscopy was experimentally and theoretically investigated by 1H-NMR experiments and numerical simulations. Especially, the applicability of 3D printed zirconium dioxide for innovative flow cell designs was of interest. Here, we demonstrate and discuss an automated test method to determine the critical parameters of flow through cells for quantitative online NMR spectroscopy. The setup is based on randomized setpoints of flow rates in order to reduce temperature related effects. Five flow cells and tubing were assessed and compared for high-field as well as low-field NMR spectrometers.
Due to the advantages of additive manufacturing (AM), it has been increasingly integrated into many industrial sectors.
The application of AM materials for safety-critical parts requires the detailed knowledge about their microstructure stability under thermo-mechanical or mechanical load and knowledge on ageing process mechanisms. Ageing processes are characterized by change of the material microstructure that is to be initially investigated. This work deals with the Investigation of 316L stainless steel manufactured by selective laser melting (SLM). Describing Parameters must be defined and applied on the microstructure of these materials in their initial state and after loads were applied. The findings of this work form the basis for the investigation of AM material ageing.
Influence of support configurations on the characteristics of selective laser-melted Inconel 718
(2018)
Samples fabricated using two different support configurations by following identical scan strategies during selective laser melting of superalloy Inconel 718 were characterized in this study. Characterization methods included optical microscopy, electron back-scattered diffraction and x-ray diffraction residual stress measurement. For the scan strategy considered, microstructure and residual stress development in the samples were influenced by the support structures. However, crystallographic texture intensity and the texture components formed within the core part of the samples were almost independent of the support. The formation of finer grains closer to the support as well as within the columnar grain boundaries resulted in randomization and texture intensity reduction by nearly half for the sample built on a lattice support. Heat transfer rates dictated by the support configurations in addition to the scan strategy influenced the microstructure and residual stress development in selective laser-melted Inconel 718 samples.
In-Situ SAXS Techniques
(2018)
Our project's aim is to enhance the capabilities of additive manufacturing techniques, where enabling a Two-Photon-Polymerization (TPP) 3D printer of producing arrays of precisely aligned nanoparticles is of an enormous value. As heterogeneous functional nanostructures with arrays of oriented nanoparticles are very promising in many fields; electrochemistry, energy storage, nanoelectronics among other vital fields.
The feasibility and the convenience of orienting nanoparticles using magnetic, electric fields and ultrasonic vibrations will be systematically investigated, using Small Angle X-ray Scattering (SAXS), since SAXS can provide detailed information about the orientation characteristics of nano-Ensembles. Corresponding to our prerequisites, a set ad hoc functional sample holders, sample stages and other In-Situ SAXS solutions were developed, and incorporated to be compatible with a state-of-the-arts SAXS machine, called Multi-scale Analyzer for Ultrafine Structures (MAUS).
The MAUS has been customized and engineered to serve as a miniaturized synchrotron, and that is exactly what we need.
Experiments attempting to orient superparamagnetic nanoparticles will be discussed, where the outcomes will not only help in understanding the mechanics of field-particle interactions, it will also help in further developing the adequate needed set of corrections to the SAXS data, that is especially regards oriented samples.
Additive Manufacturing (AM) through the Selective Laser Melting (SLM) route offers ample scope for producing geometrically complex parts compared to the conventional subtractive manufacturing strategies. Nevertheless, the residual stresses which develop during the fabrication can limit application of the SLM components by reducing the load bearing capacity and by inducing unwanted distortion, depending on the boundary conditions specified during manufacturing. The present study aims at characterizing the residual stress states in the SLM parts using different diffraction methods. The material used is the nickel based superalloy Inconel 718. Microstructure as well as the surface and bulk residual stresses were characterized.
For the residual stress analysis, X-ray, synchrotron and neutron diffraction methods were used. The measurements were performed at BAM, at the EDDI beamline of -BESSY II synchrotronand the E3 line -BER II neutron reactor- of the Helmholtz-Zentrum für Materialien und Energie (HZB) Berlin. The results reveal significant differences in the residual stress states for the different characterization techniques employed, which indicates the dependence of the residual state on the penetration depth in the sample. For the surface residual stresses, longitudinal and transverse stress components from X-ray and synchrotron agree well and the obtained values were around the yield strength of the material. Furthermore, synchrotron mapping disclosed gradients along the width and length of the sample for the longitudinal and transverse stress components. On the other hand, lower residual stresses were found in the bulk of the material measured using neutron diffraction. The longitudinal component was tensile and decreased towards the boundary of the sample. In contrast, the normal component was nearly constant and compressive in nature. The transversal component was almost negligible. The results indicate that a stress re-distribution takes place during the deposition of the consecutive layers. Further investigations are planned to study the phenomenon in detail.
Additive manufacturing (AM) offers a range of novel applications. However, the manufacturing process is complex and the production of defect-free parts with a high reliability is still a challenge. Thermography is a valuable tool for process surveillance, especially in metal AM processes. The high process temperatures allow one to use cameras usually operating in the visible spectral range. Here, we compare the results of first measurements during the manufacturing process of a commercial laser metal deposition (LMD) setup using a MWIR camera with those from a VIS high-speed camera with band pass filter in the NIR range.
Additive manufacturing (AM) offers a range of novel applications. However, the manufacturing process is complex and the production of defect-free parts with high reliability and durability is still a challenge. Thermography is a valuable tool for process surveillance, especially in metal AM processes. The high process temperatures allow one to use cameras usually operating in the visible spectral range. Here, we compare the results of measurements during the manufacturing process of a commercial laser metal deposition setup using a mid-wavelength-IR camera with those from a visual spectrum high-speed camera with band pass filter in the near-IR range.
3D-printing or additive manufacturing has many promising and unique advantages. Especially low cost molten polymer Deposition Printers are increasingly populär in the private and educational sector.
Their environmental friendliness can be questioned due to recently reported ultrafine particle and suspected VOC emissions, To further investigate 3D-printing as a potential indoor air pollution source we characterized fine and ultrafine particle emissions from a molten polymer deposition printer producing a 3D object with ten marketable polymer filament materials under controlled conditions in a test chamber. VOC emissions from the filaments have also been compared. Using a straightforward emission model time dependent and averaged particle emission rates were determined. The results indicate that under comparable conditions some filament materials produce mainly ultrafine particles up to an average rate of 1013 per minute. This value is in the upper ränge of typical indoor ultrafine particle sources (e.g. Smoking, frying, candle light, laser printer). The observed material-specific rates differ by five Orders of magnitude. Filament-specific gaseous emissions of organic compounds such as bisphenol A, styrene and others were also detected.
Our results suggest a detailed evaluation of related risks and considering protective measures such as housing and filtering.
Additive manufacturing (AM) opens the route to a range of novel applications.However, the complexity of the manufacturing process poses a challenge for the production of defect-free parts with a high reliability. Since process dynamics and resulting microstructures of AM parts are strongly influenced by the involved temperature fields, thermography is a valuable tool for process surveillance. The high process temperatures in metal AM processes allow one to use cameras usually operating in the visible spectral range to detect the thermally emitted radiation from the process. In our work, we compare the results of first measurements during the manufacturing processes of a commercial laser metal deposition (LMD) setup and a laser beam melting (LBM) setup using a MWIR camera with those from a VIS high-speed camera with band pass filter in the NIR range.
Laser metal deposition (LMD) has been applied as a coating technology for many years. Today, the technologies capacity to produce 3D depositions leads to a new field of application as additive manufacturing method. In this paper, 3D laser metal deposition of titanium alloy Ti-6Al-4V is studied with special regard to the demands of additive manufacturing. Therefore, only the coaxial LMD powder nozzle is used to create the shielding gas atmosphere, which ensures high geometric flexibility. Furthermore, specimen with high aspect ratio and hundreds of layers are manufactured, which represent typical features in additive manufacturing. The presented study contains the following steps: First, cylindrical specimens are manufactured with a standard shell-core build-up strategy and mechanical properties as well as fracture mechanisms are determined. Based on the results, experiments are conducted to improve the build-up strategy and new tensile test specimens are built with the improved strategy. The improved strategy incorporates variable track overlap ratios to achieve a constant growth in the shell and core area. As blanks, lean cylinders comprising more than 240 layers and a height of more than 120mm are manufactured. The specimens are analyzed by X-ray inspection for material defects. Fractured surfaces are observed via scanning electron microscopy and the composition of the surfaces is determined using energy dispersive X-ray spectroscopy. The tensile test results prove mechanical properties close to ASTM F1108 specification for wrought material.
BAM ensures and represents high standards for safety in technology and chemistry. Additive manufacturing (AM) changes the requirements for conventional non-destructive testing (NDT) as new processes of defect creation occur. Especially in safety critical areas, such as aerospace and automotive, new manufacturing processes and materials always require reliability tests and new standards which is a big challenge for NDT.