5 Werkstofftechnik
Filtern
Dokumenttyp
- Posterpräsentation (109) (entfernen)
Sprache
- Englisch (94)
- Deutsch (14)
- Französisch (1)
Referierte Publikation
- nein (109)
Schlagworte
- Glass (8)
- Additive manufacturing (5)
- Creep (5)
- 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)
- 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)
- LTCC (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)
- Polymer (2)
- Reference data (2)
- Referenzdaten (2)
- Robotische Glasschmelzanlage (2)
- Sample preparation (2)
- Sandwich (2)
- Selective laser melting (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 Interoperability (1)
- Data fusion (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)
- Diopside (1)
- Dislocations (1)
- Distributed fiber optic sensors (1)
- EBSD (1)
- EDX (1)
- Electromicroscopy (1)
- Electron Backscatter Diffraction (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)
- GFRP (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 temperature (1)
- High-density polyethylene (1)
- High-entropy alloys (1)
- High-temperature corrosion (1)
- Hot stage microscopy (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)
- Kavitation (1)
- Knowledge Representation (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)
- Mikrostruktur (1)
- Model alloy (1)
- Modeling (1)
- NFDI-MatWerk (1)
- NMR (1)
- Nahinfrarotspektroskopie (1)
- Nano-landscape (1)
- Nano-powder characterization (1)
- Nanomaterial screening (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)
- Photocatalysis (1)
- Plattform MaterialDigital (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 Data (1)
- Reference Dataset (1)
- Reference material (1)
- Reference nanomaterials (1)
- Reliable characterization (1)
- Research Data Management (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 Interoperability (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)
- Titanium (1)
- Titanium oxide (1)
- Topografie (1)
- Transmission electron microscope (TEM) (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 (109)
- 5.1 Mikrostruktur Design und Degradation (30)
- 5.6 Glas (24)
- 5.4 Multimateriale Fertigungsprozesse (21)
- 5.2 Metallische Hochtemperaturwerkstoffe (18)
- 5.3 Polymere Verbundwerkstoffe (15)
- 6 Materialchemie (15)
- 8 Zerstörungsfreie Prüfung (11)
- 8.5 Röntgenbildgebung (10)
- 1 Analytische Chemie; Referenzmaterialien (9)
Additive manufacturing (AM) processes are opening new design possibilities for large scale electrical devices such as power generators. Conventional manufacturing methods use copper rods which are wrapped, vacuum impregnated, bend and welded. These processes are labor-intensive and time-consuming. The introduction of AM methods for manufacturing the copper conductor and electrical insulation can reduce the size of the generator head, the most complex part of the generator.
In this study, the electrical and dielectrical properties of additively deposited ceramic layers are investigated and compared with the properties of conventionally fabricated bulk ceramics. The ceramic layers are thermally deposited by atmospheric plasma spraying of a commercially available alumina powder. Bulk ceramics are fabricated by dry pressing and sintering of the same powder. Microstructure and porosity were analyzed by scanning electron microscopy (SEM). Electrical and dielectrical properties such as DC resistance, dielectric strength, dielectric loss, and relative permittivity were determined according to the standards.
The microstructures of sprayed and sintered alumina show significant differences with respect to grain form and porosity. The density of the bulk ceramic is lower than the density of the sprayed layer due to the coarse particle size (d50 = 33 μm). Therefore, data from dense samples of the same chemical composition but lower particle size alumina powder were used for comparison.
Characterization of early crystallization stages in surface-crystallized diopside glass-ceramics
(2019)
Structure formation in glass-ceramics by means of surface crystallization is a challenging open question and remains elusive to definite answers. In several glass-ceramic systems, oriented crystal layers have been observed at the immediate surface, including diopside and some fresnoite systems. However, it is still open to debate, whether oriented surface crystallization is the result of oriented nucleation or growth selection effects. In the same vein, there is still discussion whether surface nucleation is governed by surface chemistry effects or by defects serving as active nucleation sites.
In order to help answer these questions, annealing experiments at 850°C have been performed on a MgO·CaO·2SiO2 glass, leading to the crystallization of diopside at the surface. Different annealing durations and surface treatment protocols (i.a. lapping with diamond slurries between 16 µm and 1 µm grain size) have been applied. Particular focus has been put on earliest crystallization stages, with crystal sizes down to about 200 nm. The resultant microstructure has been analyzed by electron backscatter diffraction (EBSD) and two different kinds of textures have been observed, with the a- or b-axis being perpendicular to the sample surface and the c-axis lying in the sample plane. Even at shortest annealing durations, a clear texture was present in the samples. Additionally, selected samples have been investigated with energy-dispersive x-ray spectroscopy in the scanning transmission electron microscope (STEM-EDX). The diopside crystals have been found to exhibit distinguished submicron structure variations and the glass around the crystals was shown to be depleted of Mg.
Introduction
Lithium-ion batteries (LIBs) are one key technology to overcome the climate crisis and energy transition challenges. Demands of electric vehicles on higher capacity and power drives research on innovative cathode and anode materials. These high energy-density LIBs are operated at higher voltages, leading to increased electrolyte decay and the current collectors' degradation. Even though this fundamental corrosion process significantly affects battery performance, insufficient research is being done on the aluminum current collector. Fast and convenient analytical methods are needed for monitoring the aging processes in LIBs.
Methods
In this work glow-discharge optical emission spectrometry (GD-OES) was used for depth profile analysis of aged cathode material. The measurements were performed in pulsed radio frequency mode. Under soft and controlled plasma conditions, high-resolution local determination (in depth) of the elemental composition is possible. Scanning electron microscopy (SEM) combined with a focused ion beam (FIB) cutting and energy dispersive X-ray spectroscopy (EDX) was used to confirm GD-OES results and obtain additional information on elemental distribution.
Results
The aging of coin cells manufactured with different cathode materials (LCO, LMO, NMC111, NMC424, NMC532, NMC622, and NMC811) was studied. GD-OES depth profiling of new and aged cathode materials was performed. Quantitative analysis was possible through calibration with synthetic standards and correction by sputter rate. Different amounts of aluminum deposit on the cathode surface were found for different materials. The deposit has its origin in the corrosion of the aluminum current collector. The results are compatible with results from FIB-EDX. However, GD-OES is a faster and less laborious analytical method. Therefore, it will accelerate research on corrosion processes in high energy-density batteries.
Innovative aspects
- Quantitative depth profiling of cathode material
-Monitoring of corrosion processes in high energy-density lithium-ion batteries
- Systematic investigation of the influence of different cathode materials
Within the perspective of increasing reliability of AM processes, real-time monitoring allows part inspection while it is built and simultaneous defect detection. Further developments of real-time monitoring can also bring to self-regulating process controls. Key points to reach such a goal are the extensive research and knowledge of correlations between sensor signals and their causes in the process.
Multilayer thermoelectric generators are a promising perspective to the conventional π-type generators. Ceramic multilayer technology is well established for production of microelectronics and piezo-stacks. Key features of ceramic multilayer technology are full-automation, cost-effectiveness, and the co-firing of all materials in one single step. This requires similar sintering temperatures of all used materials. The development of multilayer thermoelectric generators is a subject of current research due to the advantages of this technology. One of the challenges is the compatibility of the different materials with respect to the specific design.
The presented study compares three different designs of multilayer generators based on a given set of material properties. Dualleg, unileg and transverse multilayer generators are compared to conventional π-type generators., the designs are evaluated regarding the expected maximum output power and power density using analytical calculations and FEM simulations. Additionally, the complexity of the production process and material requirements are assessed and design optimizations to simplify production are discussed.
Besides the theoretical aspects, unileg multilayer generator prototypes were produced by tape-casting and pressure-assisted sintering. These prototypes are compared to other multilayer generators from literature regarding the power factors of the used material system and the power density. Improvements of the power output by design optimizations are discussed
Additively Manufactured (AM) parts are still far from being used in safety-relevant applications, mainly due to a lack of understanding of the feedstock-process-propertiesperformance relationship. This work aims at providing a characterization of the fatigue behavior of the additively manufactured AISI 316L austenitic stainless steel and a direct comparison with the fatigue performance of the wrought steel. A set of specimens has been produced by laser powder bed fusion (L-PBF) and a second set of specimens has been machined out of hot-rolled plates. The L-PBF material shows a higher fatigue limit and better finite life performance compared to the wrought material, accompanied by an extensive amount of cyclic softening.
The phenomenon of expelling nanomaterial from microparticles of different materials, such as Au, WO3 or B2O3 under the influence of a convergent electron beam (CB) of a transmission electron microscope (TEM) was reviewed by Ignacio Gonzalez-Martinez [1]. Converging the e-beam in a TEM means that a high amount of energy enters the microparticle at a very local place and interact with the matter. Obviously, during the convergent beam protocol, no imaging with the electron beam is possible, but at the end, nanoparticles with different appearances lie down next to the microparticle while its size is reduced.
Hence, there is a blind spot in the observation, which we want to fill, as we want to help clarify the nature of the expelling phenomenon. One hypothesis that explains the phenomenon is the so-called damage (of the microparticle) induced by an electric field (DIEF). Within this theory, the material is ionized and expelled in form of ionic waves. Our aim is therefore to fabricate specimens with artificial microlandscapes, as schematically exemplified in figure 1a), using the focused ion beam (FIB) and micromanipulators, as experimental setups to follow the paths of the expelled material.
As a first step towards the fabrication of such specimen, we make experimental feasibility studies for each fabrication method, FIB structuring with Ga+ ion beam and micromanipulated microparticle deposition. Bridges (gray regions in Fig. 1) are created by milling a commercially available electron transparent membrane (silicon oxide or carbon) of a Cu-TEM grid. Platinum or carbon walls (blue features in Fig. 1) are built to stand on those bridges. Microparticles (yellow sphere in Fig. 1) of gold or other material are deposited in the center of the bridges.
Figure 2a) shows four square holes (black area) and between them the residual silicon oxide membrane bridges (dark grey). On top of the bridges, walls (light grey) are deposited. The width of the bridges is different, the walls overlap the holes as well as the distance between the walls is very small, so these and other parameters need to be optimized. Figure 2b) shows a square hole (black) with bridges (white) on the right side on top of a carbon membrane (grey). There are still some obstacles which needs to be eliminated. For instance, the deposition process of the walls is not reliable as visible at the wall on top where a hole arises instead of a wall.
These studies are still in progress and the results are further discussed in terms of the applicability for the DIEF experiment in the TEM.
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.
The ferritic steel 13CrMo4-5 due to good properties with relation to attractive price is frequently use in power plants industry. According EN10028-2 this steel can be used up to 570 °C because of its creep behavior but its corrosion resistance limits the use frequently to lower temperatures, depending on gas temperature and slag formation. The corrosion test were performed in environment containing mixture of gases like: O2, COx, SOx and ashes, with elements e.g. Na, Cl, Ca, Si, C, Fe, Al. Exposure time was respectively 240 h, 1000 h and 4500 h in temperature 600 °C. The oxide scale on the 13CrMo4-5 steel was significant thicker than for In686 coating and the difference increase according for longer exposure time.
The microstructure, chemical and phase composition of the oxide scales were investigated by means of a light microscope, the electron scanning and transmission microscopes (SEM,TEM) equipped with the EDS detectors.
Alkali and alkaline earth chlorides are discussed as heat storage media and are characterized by their low price and high availability. Disadvantages are a high corrosion rate and formation of Cr6+ ions in the melt, as observed in various binary chlorine salt melts. In our work the system NaCl-KCl-MgCl2 is considered. The storage capacity in this salt system is between 2 and 3 MWh per 10 t salt, depending on composition, melting temperature and working temperature. At the same time the system offers a eutectic line, which allows a high variance of the composition and possibly different corrosion rates can be observed. Corrosion tests in melts were carried out and the corrosion layers investigated. The tests with chloride melts on 12% Cr steel show an inner corrosion zone of up to 40 µm depth after 96 hours. The corrosion mechanisms and potential solutions are discussed.