5 Werkstofftechnik
Filtern
Dokumenttyp
- Posterpräsentation (118) (entfernen)
Sprache
- Englisch (102)
- Deutsch (15)
- Französisch (1)
Referierte Publikation
- nein (118) (entfernen)
Schlagworte
- Glass (8)
- Additive manufacturing (6)
- Creep (6)
- Degradation (5)
- Microstructure (5)
- Additive Manufacturing (4)
- Coarsening (4)
- Corrosion (4)
- Crack growth (4)
- FAIR (4)
- Transmission electron microscopy (4)
- 316L (3)
- Ab-initio (3)
- Alloy 2618A (3)
- Crystallization (3)
- EBSD (3)
- Fatigue (3)
- Hydrogen (3)
- NTE (3)
- Nanoparticles (3)
- Oxidation (3)
- Soda-lime silicate glass (3)
- Sol-gel (3)
- Solid-state (3)
- TDEP (3)
- VSSA (3)
- Vickers (3)
- Bildanalyse (2)
- Crack Propagation (2)
- Crystal orientation (2)
- DCB (2)
- Dark-field transmission electron microscopy (DFTEM) (2)
- Depth-profiling (2)
- Deuterium (2)
- Electron beam induced modification (2)
- Electron microscopy (2)
- Environmental stress cracking (ESC) (2)
- FIB (2)
- GD-OES (2)
- Gold nanoparticles (2)
- High temperature corrosion (2)
- Imaging techniques (2)
- Inconel 686 (2)
- Iron oxide nanoparticles (2)
- Kikuchi (2)
- LTCC (2)
- Lattice parameters (2)
- Lithium Ion Batteries (2)
- Low Cycle Fatigue (2)
- Machine Learning (2)
- Metadata schema (2)
- Mikroplastik (2)
- NFDI (2)
- Ontologie (2)
- Ontology (2)
- Oxidglas (2)
- Plattform MaterialDigital (2)
- Polymer (2)
- Ratio refinement (2)
- Reference Data (2)
- Reference data (2)
- Referenzdaten (2)
- Research Data Management (2)
- Robotische Glasschmelzanlage (2)
- Sample preparation (2)
- Sandwich (2)
- Selective laser melting (2)
- Semantic Interoperability (2)
- Semantic Web Technologies (2)
- Sintering (2)
- Sulfidation (2)
- Syngle Crystal alloy (2)
- TED-GC-MS (2)
- Ti-6Al-4V (2)
- ToF-SIMS (2)
- Water content (2)
- Water speciation (2)
- 3D (1)
- 3D imaging (1)
- 5G (1)
- AFM (1)
- AISI 304L (1)
- AM (1)
- Abwasser (1)
- Additiv gefertigter Stahl (1)
- Additive Fertigung (1)
- Aggressive environement (1)
- Aggressive environment (1)
- Aging mechanisms (1)
- Al-Cu-Li alloys (1)
- Alkali ions (1)
- Aluminium (1)
- Analysis (1)
- Anhydrite (1)
- Anisotropy (1)
- Artefact (1)
- Atacama Desert (1)
- Atmospheric Plasma Spraying (1)
- Atomic packing factor (1)
- Atomization (1)
- Austenitic stainless steel (1)
- Austenitic steel (1)
- Automation (1)
- BCS (1)
- BTS (1)
- Belebtschlamm (1)
- Bilanzierung (1)
- Bio Ceramics (1)
- Bioactive glass (1)
- Biofilm (1)
- Bioresorbable (1)
- Boden (1)
- Borate glasses (1)
- Brittle / ductile fracture behavior (1)
- Brittle fracture (1)
- CALPHAD (1)
- CALPHAD databases analysis (1)
- CCS (1)
- CMSX4 (1)
- Calcium cobaltite (1)
- Carbon Fiber Reinforced Plastics (1)
- Carbon capture (1)
- Carbon dioxide (1)
- Ceramic (1)
- Chemically Complex Alloy (1)
- Chemometrie (1)
- Chromium oxide (1)
- Co-axial monitoring (1)
- Complex concentrated alloy (CCA) (1)
- Composite (1)
- Computed Tomography (1)
- Corrosion resistance (1)
- Crack (1)
- Crack evolution (1)
- Crack healing (1)
- Crack propagation analysis (1)
- Crystal plasticity (1)
- DED-L (1)
- Dark-field transmission electron microscopy (1)
- Data Fusion (1)
- Data Integration (1)
- Data Interoperability (1)
- Data fusion (1)
- Data schema (1)
- Demonstrators (1)
- Density (1)
- Destabilization (1)
- Dielectric Spectroscopy (1)
- Diesel (1)
- Diffraction Enhanced Imaging (1)
- Diffusion coefficient (1)
- Digital material representation (1)
- Digitaler Zwilling (1)
- Digitalisierung (1)
- Digitalization (1)
- Digtial Representation (1)
- Diopside (1)
- Directional grain growth (1)
- Dislocations (1)
- Distributed fiber optic sensors (1)
- EDX (1)
- Electromicroscopy (1)
- Electron Backscatter Diffraction (1)
- Electronic Lab Notebook (1)
- Environmental stress cracking (1)
- FeCr- alloys (1)
- Film depositition (1)
- Focussed ion beam growth (1)
- Fracture Toughness (1)
- Fracture surface analysis (1)
- Fraktografie (1)
- Fresnoit (1)
- Full Notch Creep Test (1)
- Full Notch Creep Test (FNCT) (1)
- Full-Notch Creep Test (FNCT) (1)
- Fused Filament Fabrication (1)
- GFRP (1)
- Gas permeation (1)
- Glas (1)
- GlasDigital (1)
- Glasfaserverstärkter Kunststoff (1)
- Glass ceramic (1)
- Glass composition (1)
- Glass fiber reinforced polymers (1)
- Glass matrix composite (1)
- Glass melt (1)
- Glass structure (1)
- Glass transformation temperature (1)
- Glass-ceramic (1)
- Gypsum (1)
- HDPE Sorption (1)
- HV-Insulation (1)
- Hardness (1)
- Heat Treatment (1)
- High Cycle Fatigue (1)
- High Temperature Testing (1)
- High Voltage Insulation (1)
- High entropy alloy (1)
- High pressure gas storage (1)
- High temperature (1)
- High-density polyethylene (1)
- High-entropy alloys (1)
- High-temperature corrosion (1)
- Hot stage microscopy (1)
- Hydrogen gas (1)
- Hydrogen permeability (1)
- IR (1)
- In situ (1)
- In situ tensile test (1)
- In-situ tomography (1)
- In718 (1)
- Infrarotspektroskopie (1)
- Internal friction (1)
- Interoperability (1)
- Kavitation (1)
- Knowledge Representation (1)
- Knowledge graph and ontologies (1)
- Kontrastierung (1)
- LCF (1)
- LMD (1)
- LTCC multilayer (1)
- Laser Beam Melting (1)
- Laser Cladding (1)
- Laser Powder Bed Fusion (1)
- Laser ablation in liquid (1)
- Laser cladding (1)
- Lightweight materials (1)
- Lithium-ion batteries (1)
- Local landscape evolution (1)
- Long-term behavior (1)
- Low cycle fatigue (1)
- ML (1)
- Manganese oxide (1)
- Material characterization (1)
- Material oxidation (1)
- Mechanical Behavior (1)
- Metal powder characterization (1)
- Metal seal (1)
- Metformin (1)
- Metrology (1)
- Micro computed tomography (1)
- Micromanipulation (1)
- Microplastics (1)
- Microstructure Analysis (1)
- Microstructure analysis (1)
- Mikrostruktur (1)
- Model alloy (1)
- Modeling (1)
- NFDI-MatWerk (1)
- NMR (1)
- Nahinfrarotspektroskopie (1)
- Nano-landscape (1)
- Nano-powder characterization (1)
- Nanomaterial screening (1)
- Non-Destructive Testing (1)
- Optical criterion (1)
- Orientation (1)
- Orientation-dependent microstructure (1)
- Oxide Glasses (1)
- PE-HD (1)
- PMD Core Ontology (1)
- PMDco (1)
- Particle size (1)
- Peem (1)
- Phase-field simulation (1)
- Photocatalysis (1)
- Polyethylene, PE-HD (1)
- Polymer-Ceramic-Composite (1)
- Porosity (1)
- Precipitation (1)
- ProMoAM (1)
- Process Monitoring (1)
- Property simulation (1)
- Prozessmonitoring (1)
- Präparation (1)
- Pulveraktivkohle (1)
- Reference Dataset (1)
- Reference material (1)
- Reference nanomaterials (1)
- Reliable characterization (1)
- Residual stress (1)
- Risswachstum (1)
- Robot-assisted galss melting (1)
- Roboter (1)
- Rotorblätter (1)
- Röntgenbeugung (1)
- Röntgenrefraktion (1)
- S-phase (1)
- SEM (1)
- SIMS (1)
- SLM (1)
- Salt melt (1)
- Sandwichstruktur (1)
- Scale-bridging (1)
- Scanning electron microscopy (SEM) (1)
- Scarf joint repairs (1)
- Schadensanalyse (1)
- Semantic Data (1)
- Silver (1)
- Silver glass paste (1)
- Silver nanoparticle (1)
- Simulation (1)
- Size and size distribution (1)
- Slurry (1)
- Small angle x-ray scattering (1)
- Sodium zinc borate glass (1)
- Sodiumborosilicate glasses (1)
- Soil sample (1)
- Starch (1)
- Starch nanoparticle (1)
- Sulfiding (1)
- Superalloy (1)
- Surface (1)
- Surface Energy (1)
- Surface crystallization (1)
- Surface energy (1)
- Synchrotron (1)
- Synchrotron Tomography (1)
- Synchrotron tomography (1)
- Synthetic air (1)
- TEM (1)
- Tensile Properties (1)
- Thermal Spray (1)
- Thermoanalyse (1)
- Thermodynamic analysis (1)
- Thermoelectric generator design (1)
- Thermoelectric oxides (1)
- Thermogravimetrie (1)
- Thermomechanics (1)
- Time-offlight Diffraction (TOFD) (1)
- Titanium (1)
- Titanium oxide (1)
- Topografie (1)
- Transmission electron microscope (TEM) (1)
- Ultrasonic Testing (1)
- Ultrasound (1)
- VM12 SHC (1)
- Vickers indentation (1)
- Virtual experiments (1)
- Viscosity (1)
- Wind turbine blade shells (1)
- Wind turbine blades (1)
- X-Ray Diffraction (1)
- X-ray refraction (1)
- XRD (1)
- Young´s Modulus (1)
Organisationseinheit der BAM
- 5 Werkstofftechnik (118) (entfernen)
Behälter aus hochdichtem Polyethylen (PE-HD) werden zur Lagerung und für den Transport von Kraftstoffen eingesetzt. Beim Kontakt beider Medien diffundiert der Kraftstoff in das Polymer, erhöht dessen Volumen und Duktilität und ändert damit das Fließverhalten des Polymers unter Zugbelastung. Zudem weist PE-HD in Luft im verstreckten Bereich das sogenannte strain-whitening (Lichtstreuung) auf, während in Diesel gelagertes PE-HD optisch transparent wird. Zur Untersuchung dieses Phänomens wurden ortsaufgelöste Röntgenrefraktion und –diffraktion (Topographie) eingesetzt. Aus Sicht der molekularen Struktur (Diffraktion) weisen die beiden Probentypen keine Unterschiede auf: im verstreckten Bereich liegt eine „Fasertextur“ der Polymerketten in Belastungsrichtung vor, im unverstreckten Bereich nahezu ideale Isotropie. Die für mikroskopische Strukturen empfindliche Röntgenrefraktion zeigt außerdem für die Probe in Luft im verstreckten Bereich eine ausgeprägte Orientierung von Grenzflächen in Zugrichtung, während die in Diesel gelagerte Probe keine Grenzflächen zeigt. In Analogie zum optischen Verhalten bewirken die ähnlichen Brechungsindizes beider Medien im Röntgenbereich, dass eindiffundierter Diesel als Immersionsflüssigkeit die Brechungseigenschaften herabsetzt.
Homogeneous introduction of organic additives is a key of ceramic powder processing. Addition of organics to ceramic slurries holds advantages compared to dry processing like organic content reduction and a more homogeneous additive distribution on the particle surface.
Investigations of the alumina slurries were primarily based on zeta potential measurements and sedimentation analysis by optical centrifugation. Both methods were combined to determine a suitable additive type, amount and composition, whereas the spray drying suitability has been ensured by viscosity measurements. Granules, yielded by spray drying of such ideally dispersed alumina slurries, are mostly hollow and possess a hard shell. Those granules cannot easily be processed and can only hardly be destroyed in the following shaping step, leading to sinter bodies with many defects and poor strength and density.
The precise slurry destabilization, carried out after ideally dispersing the ceramic powder, shows a strong influence on the drying behavior of the granules and hence on the granule properties. A promising degree of destabilization and partial flocculation was quantified by optical centrifugation and resulted in improved granule properties. Spray drying the destabilized alumina slurries yielded homogeneous “non-hollow” granules without the above mentioned hard shell. Sample bodies produced of these granules exhibited a reduction of defect size and number, leading to better results for sinter body density and strength.
The positive effect of the slurry destabilization has been further improved, by exchanging the atomizing unit from a two-fluid one to an ultrasound atomizer with only minor slurry adjustments necessary. The controlled destabilization and ultrasound atomization of the ceramic slurry show excellent transferability for zirconia and even ZTA (zirconia toughened alumina) composite materials.
The introduction of the 5G technology and automotive radar applications moving into higher frequency ranges trigger further miniaturization of LTCC technology (low temperature co-fired ceramics). To assess dimensional tolerances of inner metal structures of an industrially produced LTCC multilayer, computer tomography (CT) scans were evaluated by machine learning segmentation.
The tested multilayer consists of several layers of a glass ceramic substrate with low resistance silver-based vertical interconnect access (VIA). The VIAs are punched into the LTCC green tape and then filled with silver-based pastes before stacking and sintering. These geometries must abide by strict tolerance requirements to ensure the high frequency properties.
This poster presents a method to extract shape and size specific data from these VIAs. For this purpose, 4 measurements, each containing 3 to 4 samples, were segmented using the trainable WEKA segmentation, a non-commercial machine learning tool. The dimensional stability of the VIA can be evaluated regarding the edge-displacement as well as the cross-sectional area. Deviation from the ideal tubular shape is best measured by aspect ratio of each individual layer. The herein described method allows for a fast and semi-automatic analysis of considerable amount of structural data. This data can then be quantified by shape descriptors to illustrate 3-dimensional information in a concise manner. Inter alia, a 45 % periodical change of cross-sectional area is demonstrated.
Despite of the significant advances in additive manufacturing (AM) process optimization there is still a lack of experimental results and understanding regarding the mechanical behavior and its relationship with the microstructural features of AM-parts, especially in loading conditions typical for safety-relevant applications. Within the scope of the presented ongoing investigations, a basic microstructural characterization, tensile tests at room and elevated temperature (400°C) as well as a characterization of the fatigue behavior of additively manufactured Ti-6Al-4V in the low cycle fatigue regime are carried out in the as-built state. After failure, different techniques are used to describe the failure mechanisms of the specimens. The AM-Specimens are provided by the Fraunhofer institute for production systems and design technology and investigated at the BAM following the philosophy of the TF-Project AGIL.
Virtual-lab-based determination of a macroscopic yield function for additively manufactured parts
(2019)
This work aims for a yield function description of additively manufactured parts of S316L steel at the continuum-mechanical macro-scale by means of so-called virtual experiments using a crystal plasticity (CP) model at meso-scale. Additively manufactured parts require the consideration of the specific process-related microstructure, which prevents this material to be macroscopically treated as isotropic, because of crystallographic as well as topological textures. From virtual experiments, yield loci under various loading conditions are simulated. The scale bridging from meso- to macro-scale is realised by the identification of the simulated yield loci as a modified anisotropic Barlat-type yield model representation.
Considerations for nanomaterial identification of powders using volume-specific surface area method
(2019)
The EC’s recommendation for a definition of nanomaterial (2011/696/EU) should allow the identification of a particulate nanomaterial based on the number-based metric criterion according to which at least 50% of the constituent particles have the smallest dimension between 1 and 100 nm. However, it has been recently demonstrated that the implementation of this definition for regulatory purposes is conditioned by the large deviations between the results obtained by different sizing methods or due to practical reasons such as high costs and time-consuming.
For most measurement methods for particle size determination it is necessary to initially disperse the particles in a suitable liquid. However, as the particle size decreases, the adhesion forces increase strongly, making it more difficult to deagglomerate the particles and to assess accurately the result of this process. Therefore, the success of the deagglomeration process substantially determines the measurement uncertainty and hence, the comparability between different methods.
Many common methods such as dynamic light scattering (DLS), centrifugal liquid sedimentation (CLS) or ultrasound attenuation spectroscopy (US) can give good comparable results for the size of nanoparticles, if they are properly separated and stabilized (e.g. in reference suspensions).
In order to avoid the use of hardly available and expensive methods such as SEM / TEM for all powders, an agglomeration-tolerant screening method is useful.
One of the measurement methods well suited to probe the size of particulate powder is the determination of the volume-specific surface area (VSSA) by means of gas adsorption as well as skeletal density. The value of 60 m2/cm3 corresponding to spherical, monodisperse particles with a diameter of 100 nm constitutes the threshold for decisioning if the material is a nano- or non-nanomaterial. The identification of a nanomaterial by VSSA method is accepted by the EU recommendation.
However, the application of the VSSA method was associated also with some limitations. The threshold of 60 m2/cm3 is dependent on the particle shape, so that it changes considerably with the number of nano-dimensions, but also with the degree of sphericity of the particles. For particles containing micro-pores or having a microporous coating, false positive results are induced. Furthermore, broad particle size distributions made necessary to additionally correct the threshold. Based on examples of commercially available ceramic powders, the applicability of the VSSA approach was tested in relation with SEM and TEM measurements. The introduction of a correction term for deviations from sphericity and further additions improved the applicability of VSSA as a screening method.
Up to now, the mechanisms of surface nucleation and surface-induced texture formation are far from being understood. Very few observations of crystal orientation were focused on separately growing surface crystals. In conclusion, no systematic studies on initially oriented crystal growth or nucleation from defined active surface nucleation sites exists. Therefore, the main objective of this just is to advance the basic understanding of the mechanisms of surface-induced microstructure formation in glass ceramics. As a first attempt, we focus on reorientation of separately growing surface crystals during their early growth.
Fiber reinforced polymers (FRPs) are a well established material in lightweight applications, e.g. in automotive, aerospace or wind energy. The FRP components are subjected to multiaxial mechanical as well as hygrothermal loads. Common operation temperatures are in the range of 213 K and 373 K (-60 °C and 100 °C) at a relative humidity of 10% to 90%. In spacecraft applications, the environmental conditions are even more extreme. However, the correlation between multiaxial mechanical loading and harsh environment conditions have to-date not been investigated in detail. The project aims to investigate the fatigue behavior of FRPs dependent on multiaxial mechanical loading, temperature, and humidity. Extensive experimental testing is performed on flat plate and cylindrical tube specimens, accompanied by numerical and analytical calculations.
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.