5 Werkstofftechnik
Filtern
Erscheinungsjahr
- 2019 (48) (entfernen)
Dokumenttyp
- Zeitschriftenartikel (48) (entfernen)
Sprache
- Englisch (48)
Referierte Publikation
- ja (48) (entfernen)
Schlagworte
- Corrosion (4)
- Carbon steel (3)
- Crystallization (3)
- 3D printing (2)
- Additive Manufacturing (2)
- Bioactive glass (2)
- Condensate (2)
- Degradation (2)
- Fatigue (2)
- Impurities (2)
- NMR spectroscopy (2)
- Oxidation (2)
- AISI 304L (1)
- Abrasion (1)
- Additive manufacturing (1)
- Alumina (1)
- Aluminosilicate glasses (1)
- Artificial weathering (1)
- Bioceramics (1)
- Biodiesel (1)
- Biogeochemical cycling (1)
- Biomineralisation (1)
- Biopolymer (1)
- Bubble formation (1)
- C. lap-shear (1)
- CCUS (1)
- CFRP (1)
- CO2 (1)
- CO2 separation membranes (1)
- Calcination (1)
- Calcium cobaltite (1)
- Carbon capture (1)
- Carbon capture, utilization and storage technology (1)
- Carbon fibres (1)
- Cavitation (1)
- Cellulose (1)
- Ceramic (1)
- Ceramics (1)
- Chalcogenides (1)
- Characterisation (1)
- Coefficient of thermal expansion (1)
- Contact angle (1)
- Contact fatigue (1)
- Copper vacancies (1)
- Corrosion pits (1)
- Crack arrest (1)
- Crack propagation (1)
- Crosslinking (1)
- Crystal Texture (1)
- Cyclic softening (1)
- D. aging (1)
- D. creep D. viscoelasticity (1)
- Defects (1)
- Deuterium (1)
- Dielectric breakdown (1)
- Diesel (1)
- Diesel Fuel (1)
- Distributed fiber optic sensing (1)
- Ductile iron (1)
- EBSD (1)
- Early oxidation (1)
- Early sulfidation (1)
- Elastic constants (1)
- Electrochemical characterisation (1)
- Electrochemical impedance spectroscopy (1)
- Electron energy (1)
- Electron microscopy (1)
- Energy distribution (1)
- Environment (1)
- Environmentally assisted cracking (1)
- Exposed metal sites (1)
- FSDC (1)
- Fabrication (1)
- Facilitated activation (1)
- Fatigue Testing (1)
- Fatigue crack propagation stages (1)
- Ferritic steels (1)
- Ferritic–martensitic steel (1)
- Finite element analysis (1)
- Four-point bending test (1)
- Fracture (1)
- Fracture mechanics (1)
- Freeze casting (1)
- Friction Stir Welding (1)
- Frozen state photopolymerization (1)
- GFRP (1)
- Geothermal (1)
- Glass (1)
- Glass-ceramic (1)
- Gold (1)
- Grain boundary (1)
- Hierarchical porosities (1)
- High pressure (1)
- High temperature corrosion (1)
- High-temperature oxidation (1)
- High-temperature properties (1)
- High-voltage testing (1)
- Hydrogel (1)
- Hydrogen (1)
- Hydrogen diffusivity (1)
- Hygrothermal (1)
- Impact damage (1)
- In-situ Process Monitoring (1)
- Inclusion cluster (1)
- Inclusion size (1)
- Inconel 625 (1)
- Incremental lifetime models (1)
- Infrared nano AFM (1)
- Infrared spectroscopy (1)
- Intermodulation AFM (1)
- Internal Surfaces (1)
- Internal oxidation (1)
- Interphase (1)
- Ionic porosity (1)
- Iron meteorite (1)
- Kikuchi pattern (1)
- LSD print (1)
- Laser beam melting (1)
- Layerwise slurry deposition (1)
- Long-term storage (1)
- Low cycle fatigue (1)
- MOF-74 (1)
- Magmatic and hydrothermal processes (1)
- Martensite (1)
- Mass transport (1)
- Material degradation (1)
- Micro-shrinkages (1)
- Microhardness (1)
- Mis-match (1)
- Mixed Ca-K-Na phosphates (1)
- Mixed-linkers (1)
- Moisture (1)
- Multiple cracks (1)
- Na and K rhenanites (1)
- Nanocomposites (1)
- Natural (1)
- Neutron diffraction (1)
- Niobium alloying (1)
- Nitride (1)
- Non-destructive Materials (1)
- Non-metallic inclusions (1)
- Orientation relationship (1)
- Oxidation protection (1)
- P92 (1)
- PE-HD Sorption (1)
- Parabolic flight (1)
- Permeability (1)
- Phase diagram (1)
- Phase transformations (1)
- Phase-field (1)
- Phosphate (1)
- Pitting corrosion (1)
- Plastic deformation (1)
- Platinum-group-metals (1)
- Polymer (1)
- Polyurethane (1)
- Pores (1)
- Preceramic polymer (1)
- Pressure-assisted sintering (1)
- Process development (1)
- Processing window (1)
- Pultruded fiber rods (1)
- Relaxation fatigue (1)
- Resonance testing (1)
- SDC (1)
- STEM (1)
- Safety (1)
- Samarium doped ceria (1)
- Sandwich (1)
- Scaffolds (1)
- Scavenging effect of iron (1)
- Scratches (1)
- Silicoborate glasses (1)
- Silicon Carbide (1)
- Simulation (1)
- Sintering (1)
- Soda-lime-silica (1)
- Soda-lime-silica glass (1)
- Sodium ion batteries (1)
- Sol-gel coating (1)
- Sorption (1)
- Spar cap design (1)
- Standardisation (1)
- Statistics (1)
- Steel (1)
- Stress intensity factor (1)
- Stress-strain behavior (1)
- Structural composites (1)
- Structural defects (1)
- Structural health monitoring (1)
- Subcritical crack growth (1)
- Sulfidation (1)
- Superconducting magnet (1)
- Surface treatments (1)
- Swept wavelength interferometry (1)
- Synthesis (1)
- Thermoelectric properties (1)
- Thiol-ene click chemistry (1)
- ToF-SIMS (1)
- Tungsten-Rhenium (1)
- Utilization, and storage (CCUS) technology (1)
- Vickers indentation (1)
- Viscoelastic model (1)
- Viscous sintering (1)
- WAXS (1)
- Water content (1)
- Water speciation (1)
- Wetting (1)
- X-ray absorption spectroscopy (1)
- X-ray refraction (1)
- Young´s modulus (1)
- ZnO (1)
- arbidic austempered ductile iron (1)
- high pressure (1)
- infrared spectroscopy (1)
- phosphate glasses (1)
- water speciation (1)
- µ-gravity (1)
Organisationseinheit der BAM
- 5 Werkstofftechnik (48)
- 5.1 Mikrostruktur Design und Degradation (18)
- 5.6 Glas (11)
- 5.4 Multimateriale Fertigungsprozesse (10)
- 5.3 Polymere Verbundwerkstoffe (7)
- 7 Bauwerkssicherheit (7)
- 9 Komponentensicherheit (7)
- 5.2 Metallische Hochtemperaturwerkstoffe (5)
- 6 Materialchemie (5)
- 7.5 Technische Eigenschaften von Polymerwerkstoffen (4)
Additive manufacturing of SiSiC by layerwise slurry deposition and binder jetting (LSD-print)
(2019)
The current work presents for the first time results on the Additive Manufacturing of SiSiC complex parts based on the Layerwise Slurry Deposition (LSD) process. This technology allows to deposit highly packed powder layers by spreading a ceramic slurry and drying. The capillary forces acting during the process are responsible for the dense powder packing and the good joining between layers. The LSD process can be combined with binder jetting to print 2D cross-sections of an object in each successive layer, thus forming a 3D part. This process is named LSD-print.
By LSD-print and silicon infiltration, SiSiC parts with complex geometries and features down to 1mm and an aspect ratio up to 4:1 could be demonstrated.
The density and morphology were investigated for a large number of samples. Furthermore, the density and the mechanical properties, measured by ball-on-three-balls method, were in all three building directions close to isostatic pressed references.
Modelling of environmentally assisted material degradation in the crack phase-field framework
(2019)
The simulation of crack propagation was conducted with a diffusive crack model in a variational framework. Moreover, the physically sound introduction of mass transport and coupling mechanisms due to environmentally assisted effects could be realised in this framework. The objective consists of the application of the phase-field Approach towards the simulation of environmentally assisted material degradation with the advantage of a non-required predefined crack path and a mesh-independent non-local formulation that facilitates the damage evolution with respect to material softening. The sharp crack is regularised by the introduction of a phase-field order parameter leading to a diffusive crack formulation.
Besides the equations originating from the linear momentum balance an additional evolution equation for the crack phase-field is introduced. Furthermore, mass transport is simulated by a Diffusion equation. The description delivered by the variational phase-field framework is able to simulate crack propagation according to published numerical test cases.
Additionally, the calculation of stress intensity factors is possible as well as crack resistance curves that describe stable crack propagation.
Real-time observation of high- temperature gas corrosion in dry and wet SO2-containing atmosphere
(2019)
Sulfur and water have a fundamental impact on the corrosion rate and potential failure of materials. It is therefore necessary to understand the mechanisms, rates, and potential means of transport, as well as the reactions of these elements with an alloy. This paper investigates the effect of water vapor in the initial stages of SO2 corrosion of an Fe-9Cr-0.5Mn model alloy at 650°C in situ under laboratory conditions using energy-dispersive x-ray diffraction analysis. Two separate experiments were run, one with a 99.5% Ar + 0.5% SO2 atmosphere and one with a 69.5% Ar + 0.5% SO2 + 30% H2O atmosphere. With a wet atmosphere, the alloy formed a scale with decreasing oxygen content towards the scale–alloy interface. Sulfides were identified above and below a (Fe, Cr)3O4 layer in the inner corrosion zone. In contrast to this, the overall scale growth was slower in a dry SO2 atmosphere.
The physical and chemical effects of diesel and biodiesel fuels on two high-density polyethylene (PE-HD) types were investigated. Both semi-crystalline PE-HD are common thermoplastic materials for container and storage tank applications. Biodiesel, a composition of unsaturated fatty acid esters from renewable resources, was chosen as it is regarded a possible green alternative to fossil fuels. The study aims at identifying significant differences between biodiesel and conventional diesel fuels based on the differences in the chemical nature of the two. The physical effects of the fuels on the polymer at first comprises the sorption behavior, i.e. kinetics and final equilibrium concentration. Not only are both fuels absorbed by the amorphous phase of the semi-crystalline PE-HD, they also induce a plasticization effect that modifies the molecular mobility and therefore also the characteristic yielding properties, manifest in the obtained stress-strain curves. The chemical effects related to degradation phenomena is investigated by a long-term storage scenario using partially immersed tensile test specimens in diesel and biodiesel. We were able to confirm the proposed co-oxidation mechanism by Richaud et al. for polyethylene-unsaturated penetrant systems on a larger scale based on practical tensile tests. One of the investigated polyethylene grades subjected to tensile drawing showed a significant loss of plastic deformation and the onset of premature failure after 150 days of storage in biodiesel. Further biodiesel storage showed a systematically reduced elongation at break before necking. None of these effects were observed in diesel. Oxidation of fuels and polymer after progressing storage times were analyzed by the evolution of carbonyl species in FT-IR/ATR spectroscopy.
The crystallization behavior of sodium ion conductive Na2MnP2O7 glass was examined to clarify the crystallization mechanism. The formation of thermodynamically metastable phase, layered Na2MnP2O7, at the surface of the glass occurred. Heat treatment at 430 °C for 3 h lead to surface crystals of Na2MnP2O7 oriented with the (101) direction perpendicular to the sample surface. As the heat treatment temperature increased, the glass-ceramic samples deformed, and the presence numerous micro bubbles due to dissolved water was detected.
An investigation of the two-component phase diagram of the CaNaPO4- CaKPO4system performed using various analysis techniques is reported. The continuous solid solution series of α-CaMPO4 existing above 700 °C undergoes eutectoid decomposition during cooling to β-CaMPO4-based solid solutions enriched with Na and K, and to an intermediate nonstoichiometric compound with an ideal composition of CaK0.6Na0.4PO4. All three compounds exhibit significant volumetric effects associated with first-order phase transitions, with positive volume changes under cooling for the intermediate compound. Increased K content in ceramics based on CaKyNa1-yPO4 compositions enhances the strength properties of those ceramics, including their fracture toughness, which is associated with increased density. Increased K content also has a smaller effect of inducing phase transformations accompanied by strong volume changes.
Chemically modified bioactive glasses based on ICIE16 were prepared with the melt-quenching method using water as a quenching medium. The sinterability of these bioactive glasses was investigated and is discussed in this article. The sintering experiments were conducted with different sintering temperatures, sintering times and heating rates. Those parameters are crucial for dense glass with an amorphous structure. The particle size (d50) of the starting glass powder was determined at 88 μm and kept constant. The pre-pressed glass pellets were cold-isostatically pressed at 300 MPa to a green density of around 63 %. Density development, phase identification, shrinkage behavior and the microstructure were investigated to determine the sinterability of the developed glasses. The glass powders were sintered at different temperatures inside the processing window while crystallization was monitored. The results have shown that the sinterability of the developed glasses strongly dependsonthe proposed chemical additions. The highest density reached was 96 %, which belongs to BP1 glass with sintering conditions of 20 K/min heating rate for 60 min at 750 °C.