Filtern
Erscheinungsjahr
Dokumenttyp
Sprache
- Englisch (45) (entfernen)
Referierte Publikation
- ja (45) (entfernen)
Schlagworte
- Microstructure (8)
- Creep (5)
- Aging (4)
- Fatigue (4)
- Additive Manufacturing (3)
- Cast iron (3)
- Residual stress (3)
- AGIL (2)
- AISI 316L (2)
- Additive manufacturing (2)
- Aluminum alloys (2)
- Cyclic softening (2)
- Elasticity (2)
- Electron microscopy (2)
- Fatigue damage (2)
- GMR (2)
- Metal magnetic memory (2)
- Number density (2)
- Ostwald ripening (2)
- P92 (2)
- Phase-field simulation (2)
- Plastic deformation (2)
- Precipitation (2)
- S-Phase (2)
- Stress relaxation (2)
- Tempered martensite-ferritic steel (2)
- Tensile strength (2)
- Thermo-mechanical fatigue (2)
- Thermomechanical fatigue (2)
- Ti-6Al-4V (2)
- Volume fraction (2)
- 316L (1)
- 9-12%Cr steel (1)
- Acoustic emission (1)
- Advanced ceramic (1)
- Age hardening (1)
- Al-Cu alloy (1)
- Al-Cu-Li-alloy (1)
- Aluminum alloy (1)
- Al‐Cu‐Li‐alloy (1)
- Automated image analysis (1)
- Axial-torsional Loading (1)
- Axial-torsional loading (1)
- Bitter technique (1)
- Brinell hardness (1)
- Carbon capture and storage (CCS) (1)
- Casting skin (1)
- Ceramics (1)
- Characterisation (1)
- Chemo-mechanical coupling (1)
- Computed Tomography (1)
- Corrosion behaviour (1)
- Cracks (1)
- Creep behavior (1)
- Creep strength (1)
- Creep testing (1)
- Creep-fatigue (1)
- Creep-fatigue interaction (1)
- Crystal plasticity (1)
- Damage (1)
- Damage analysis (1)
- Data Interoperability (1)
- Data infrastructures (1)
- Data mapping (1)
- Deformation (1)
- Differential scanning calorimetry (DSC) (1)
- Digital image correlation (1)
- Digital representations (1)
- Digital workflows (1)
- Domain Ontology Development (1)
- Dwell periods (1)
- Dwell times (1)
- EN AW-2618A (1)
- Elastic modulus (1)
- Emission coefficient (1)
- Environment (1)
- Expanding cavity model (1)
- FAIR (1)
- FAIR Data Management (1)
- FAIR research data management (1)
- Fatigue assessment (1)
- Fatigue life time (1)
- Ferritic–martensitic steel (1)
- Fossil fuel power plants (1)
- Fracture (1)
- Gamma titanium aluminide (1)
- Gamma-Titanium Aluminide (1)
- General Computer Science (1)
- General Engineering (1)
- General Materials Science (1)
- Growth kinetics (1)
- Hall-Petch relationship (1)
- Heat resistant steels (1)
- Heat treatment (1)
- High Cycle Fatigue (HCF) (1)
- High efficiency power plants (1)
- Hocheffiziente Kraftwerke (1)
- IN 718 (1)
- In-situ Process Monitoring (1)
- Inconel 718 (1)
- Indentation (1)
- Industrial and Manufacturing Engineering (1)
- Interfacial anisotropy (1)
- Isothermal fatigue (1)
- Knowledge Representation (1)
- Knowledge graphs (1)
- Kohlendioxidabscheidung und -speicherung (CCS) (1)
- Korrosionsverhalten (1)
- Laser Powder Bed Fusion (1)
- Laser Powder Bed Fusion (LPBF) (1)
- Laser beam melting (LBM) (1)
- Laser irradiation (1)
- Laser powder bed fusion (1)
- Laser powder-based directed energy deposition (1)
- Laser-thermal shock (1)
- Life time prediction (1)
- Lifetime (1)
- Long-term aging (1)
- Low carbon steel (1)
- Low cycle fatigue (1)
- Low strain (1)
- Low-cycle fatigue (1)
- Magnetic domain distribution (1)
- Magnetic stray fields (1)
- Magneto-optical sensor (1)
- Magnetomechanical effect (1)
- Materials Testing (1)
- Materials informatics (1)
- Mechanical anisotropy (1)
- Mechanical properties (1)
- Mechanische Eigenschaften (1)
- Metal matrix composites (1)
- Microscopy (1)
- Microstructure evolution (1)
- Miniature specimen (1)
- Misfitting precipitate (1)
- Molybdenum (1)
- Multiaxial deformation (1)
- Multi‐component diffusion (1)
- NDT (1)
- Neutron diffraction (1)
- Nickel-base alloy (1)
- Non-destructive Materials (1)
- Notch (1)
- Ontologies (1)
- Ontology (1)
- P91 (1)
- PBF-LB/M/316L (1)
- Parametric modeling (1)
- Phase‐field modeling (1)
- Precipitate shape (1)
- Precipitates (1)
- Process development (1)
- Radiation thermometry (1)
- Reference data (1)
- Reheating (1)
- Relaxation fatigue (1)
- Reproducibility (1)
- S-phase (1)
- Safety (1)
- Selective laser melting (SLM) (1)
- Semantic Web Technologies (1)
- Shear modulus (1)
- Size effects (1)
- Solid solution softening (1)
- Solid solution strengthening (1)
- Standardisation (1)
- Strain difference (1)
- Stress distribution (1)
- Structural steel (1)
- Symmetric dwell periods (1)
- T1 precipitate (1)
- TIG weld (1)
- TMF (1)
- TNB-V5 (1)
- Temperature dependence (1)
- Temperature measurement (1)
- Tempered martensite ferritic steels (1)
- Tensile Test Ontology (1)
- Tensile properties (1)
- Thermal barrier coating (TBC) (1)
- Thermal shock (1)
- Thermal shock stress (1)
- Thermo-mechanical Fatigue (1)
- Thermography (1)
- Thermomechanical Fatigue (TMF) (1)
- Thermomechanical Fatigue (TMF); High Cycle Fatigue (HCF); Cast iron; Fatigue assessment (1)
- Thermomechanical fatigue (TMF) (1)
- Thickening (1)
- Titanium alloys (1)
- Topography (1)
- Transmission electron microscopy (1)
- Transmission electron microscopy (TEM) (1)
- Visual ontology development (1)
- Vocabulary providers (1)
- Warmfeste Stähle (1)
- Weibull statistics (1)
- Young's modulus (1)
- Yttria stabilized zirconia (1)
- microstructural changes (1)
- γ″ phase (1)
- θ′ phase (1)
- θ′-(Al2Cu) precipitate phase (1)
Organisationseinheit der BAM
- 5 Werkstofftechnik (25)
- 5.2 Metallische Hochtemperaturwerkstoffe (25)
- 8 Zerstörungsfreie Prüfung (9)
- 9 Komponentensicherheit (8)
- 5.1 Mikrostruktur Design und Degradation (7)
- 5.5 Materialmodellierung (6)
- 8.5 Röntgenbildgebung (6)
- 9.6 Additive Fertigung metallischer Komponenten (4)
- 8.0 Abteilungsleitung und andere (3)
- 9.3 Schweißtechnische Fertigungsverfahren (3)
- 9.4 Integrität von Schweißverbindungen (3)
- 1 Analytische Chemie; Referenzmaterialien (1)
- 1.3 Instrumentelle Analytik (1)
- 4 Material und Umwelt (1)
- 4.2 Material-Mikrobiom Wechselwirkungen (1)
- 5.4 Multimateriale Fertigungsprozesse (1)
- 7 Bauwerkssicherheit (1)
- 7.7 Modellierung und Simulation (1)
- 8.4 Akustische und elektromagnetische Verfahren (1)
- S Qualitätsinfrastruktur (1)
- S.0 Abteilungsleitung und andere (1)
- VP Vizepräsident (1)
- VP.1 eScience (1)
MoSi alloys containing up to 1 wt.% Si were fabricated by powder-metallurgical processing and their lattice parameters, elastic constants, densities, grain sizes, strengths, ductilities, and fracture toughness values were measured. The yield strength was insensitive to the grain size, i.e., a HallPetch relationship was not observed. Generally, Si additions caused pronounced solid solution strengthening. However, for small Si concentrations (≤0.1 wt.%) solid solution softening was observed at room temperature and below. With increasing Si concentration, the room temperature ductility and fracture toughness dropped precipitously. This is attributed to the increase in strength and a transition from transgranular to intergranular fracture.
A miniature specimen geometry is presented that allows to extract small samples for tensile creep tests directly from critical components of steam generators in power plants like e.g. superheater tubes. In this way, material can be tested which has been subjected to the full processing chain of the component. The specimens then exhibit all microstructural modifications that are present in the component after the shaping process and heat treatment, and representative mechanical properties are determined. Similarly, specimens can be extracted from pre-corroded test pieces or used components after service to determine the impact of complex aging/loading/oxidation conditions during service on the mechanical properties of the material. The applicability of the miniature specimen test method is demonstrated in a comparative creep study involving standard and miniature specimens of P91 tempered martensite ferritic steel. Test results indicate satisfactory accuracy/repeatability of the method. Comparison with large scale specimen data reveals an influence of specimen size on the obtained creep behavior. These size effects need to be considered for a correct interpretation of results from miniature specimen creep tests.
The uniaxial, torsional and axial-torsional thermomechanical fatigue (TMF) behavior of the near-γ TiAl-alloy TNB-V5 was investigated. TMF tests were performed at 400-800 °C with mechanical strain amplitudes ranging from 0.15% to 0.7%. The tests were conducted thermomechanically in-phase (IP) and out-of-phase (OP).
For the same lifetimes, uniaxial IP tests required the highest strain amplitudes, while OP test conditions were most damaging and needed the lowest strain amplitudes. The Mises equivalent mechanical strain amplitudes of pure torsional tests were found in between uniaxial in-phase and out-of-phase tests for the same lifetimes. The non-proportional multiaxial out-of-phase test showed a lower lifetime at the same equivalent mechanical strain amplitude compared to the other types of tests.
The microstructure has been characterized applying electron microscopy and microstructural parameters such as fraction of twinned grains, grain size, lamellar distance and dislocation density have been quantified.
In recent years, the design and development of materials are strongly interconnected with the development of digital technologies. In this respect, efficient data management is the building block of material digitization and, in the field of materials science and engineering (MSE), effective solutions for data standardization and sharing of different digital resources are needed. Therefore, ontologies are applied that represent a map of MSE concepts and relationships between them. Among different ontology development approaches, graphical editing based on standard conceptual modeling languages is increasingly used due to its intuitiveness and simplicity. This approach is also adopted by the Materials-open-Laboratory project (Mat-o-Lab), which aims to develop domain ontologies and method graphs in accordance with testing standards in the field of MSE. To suit the actual demands of domain experts in the project, Ontopanel was created as a plugin for the popular open-source graphical editor diagrams.net to enable graphical ontology editing. It includes a set of pipeline tools to foster ontology development in diagrams.net, comprising imports and reusage of ontologies, converting diagrams to Web Ontology Language (OWL), verifying diagrams using OWL rules, and mapping data. It reduces learning costs by eliminating the need for domain experts to switch between various tools. Brinell hardness testing is chosen in this study as a use case to demonstrate the utilization of Ontopanel.
Creep-fatigue of P92 in service-like tests with combined stress- and strain-controlled dwell times
(2023)
Complex service-like relaxation- and creep-fatigue tests with strain- and stress-controlled dwells and fatigue cycle durations of approx. 2200 s were performed exemplarily on a grade P92 steel at 620 ◦C in this study. The results indicate deviations in the prevailing creep mechanisms of long-term relaxation and creep dwells, affecting subsequent dwells, load shifts, and the macroscopic softening behavior quite differently. In addition, fracture surfaces and longitudinal metallographic sections reveal intergranular crack growth for complex loading with stress-controlled dwells, whereas complex strain-controlled tests enhance oxidation and transgranular crack propagation. These findings substantiate the limited transferability of relaxation-fatigue to creep-fatigue conditions.
The article covers data on the Brinell hardness of the forged precipitation-hardened aluminum alloy EN AW-2618A in the initial T61 condition (i. e. slightly underaged) and after isothermal aging for up to 25,0 0 0 h at aging temperatures between 160 °C and 350 °C. In addition, the hardness was determined on specimens after creep testing at 190 °C and various stresses. The hardness decreases with increasing ag- ing time due to the microstructural evolution of the harden- ing precipitates. The drop occurs faster the higher the aging temperature. Aging under creep load additionally accelerates the hardness decrease.
A material family to replace the current superalloys in aeronautical gas turbine engines is
considered to be that of gamma Titanium Aluminide (γ-TiAl) alloys. Structural components in
aeronautical gas turbine engines typically experience large variations in temperatures and multiaxial
states of stress under non-isothermal conditions. The uniaxial, torsional and bi-axial thermomechanical
fatigue (TMF) behaviour of this γ-TiAl alloy have been examined at 400 800°C with
strain amplitudes from 0.15% to 0.7%. The tests were conducted at both in-phase (IP) and out-ofphase
(OP). The effects of TMF on the microstructure were also investigated. For the same
equivalent mechanical strain amplitude uniaxial IP tests showed significantly longer lifetimes than
pure torsional TMF tests. The non-proportional multiaxial OP test showed the lowest lifetimes at
the same equivalent mechanical strain amplitude compared to the other types of tests.
The present work covers the mechanical behaviour of Timetal LCB under fatigue loading and utilizes transmission electron microscopy (TEM) to study the associated microstructural evolution. Fatigue specimens were taken out of LCB wire made for automotive suspension spring manufacturing in a solution treated as well as an additionally aged state. Uniaxial fatigue tests were carried out in total strain control with R = 0.1. Solution treated specimens tested at 3% and 4% maximum total strain showed a saturating force response, which differed from all other total strain controlled tests, and a distinct fracture behaviour. In addition, an increase of the dynamic Young's modulus is observed under these test conditions and in this material state. These findings are interpreted as a deformation induced precipitation of nanosize α- or ω-phase.
In the aged state, the α-phase carries the major part of deformation work, noticeable by distinct α-substructures in fatigued specimen states.
Measurement of spontaneous magnetic stray field signals has been reported to be a promising tool for capturing macro-scale information of deformation states, defects and stress concentration zones in a material structure. This paper offers a new method for self-magnetic leakage field detection using a magneto-optical (MO) hand-held microscope. Its sensor has a dynamic field range between ±0.05 and ±2 kA/m and a lateral optical resolution of approx. 10 µm. We examined flat tensile test specimens of metastable austenitic steel AISI 304. Static tensile tests were repeatedly interrupted at various predetermined states of strain and the magnetic information was measured by the MO system. Comparative measurements using a high-precision magnetic field GMR-sensor, verify the outstanding capability of the MO microscope regarding spatial resolution of magnetic fields.
A study was made on the effect of creep loading on the precipitate radii evolution of the aluminum alloy 2618A.
The overageing process of the alloy was investigated under load at a temperature of 190 °C with stresses between 79 and 181 MPa and compared to stress free isothermal ageing. The precipitates responsible for strength were characterized using dark-field transmission electron microscopy (DFTEM). This allows the experimental Determination of radii distributions of the rod-shaped Al2CuMg precipitates and the evaluation regarding their mean precipitate radius. It was found that the mean precipitate radius enables the comparison of the different microstructural conditions of crept and uncrept samples. The mean precipitate radii of the samples experiencing creep are significantly higher than those of undeformed samples. It was shown that the acquired radii distributions are viable to determine averaged particle radii for comparison of the aged samples. A ripening process including pipe diffusion along dislocations describes the data on coarsening very well for the creep samples.