5 Werkstofftechnik
Filtern
Dokumenttyp
- Vortrag (87)
- Zeitschriftenartikel (63)
- Beitrag zu einem Tagungsband (17)
- Posterpräsentation (16)
- Forschungsdatensatz (16)
- Buchkapitel (3)
- Corrigendum (1)
- Dissertation (1)
Sprache
- Englisch (204) (entfernen)
Schlagworte
- Ontology (26)
- Creep (24)
- Additive manufacturing (19)
- Microstructure (18)
- Fatigue (12)
- Degradation (11)
- Ti-6Al-4V (11)
- Additive Manufacturing (10)
- Coarsening (10)
- Aging (9)
- Alloy 2618A (9)
- Aluminium (8)
- Crystal plasticity (8)
- EN AW-2618A (8)
- FAIR (8)
- Nickel-base superalloys (8)
- Residual stress (8)
- Transmission electron microscopy (8)
- Anisotropy (7)
- Mechanical testing (7)
- S-phase (7)
- 316L (6)
- Aluminium alloy (6)
- Digitalization (6)
- Semantic Web Technologies (6)
- Thermomechanical fatigue (6)
- AGIL (5)
- Crack growth (5)
- Data Interoperability (5)
- Fe-Al alloys (5)
- Intermetallics (5)
- Iron aluminides (5)
- Knowledge Representation (5)
- LCF (5)
- Laser powder bed fusion (5)
- P92 (5)
- PMD Core Ontology (5)
- Reference data (5)
- Semantic Interoperability (5)
- Shear modulus (5)
- Young's modulus (5)
- AISI 316L (4)
- Aluminum alloys (4)
- Computed Tomography (4)
- Damage (4)
- EBSD (4)
- Elastic modulus (4)
- Electron microscopy (4)
- FAIR data management (4)
- Fatigue crack growth (4)
- Knowledge graph and ontologies (4)
- Low Cycle Fatigue (4)
- Microstrucrue Design (4)
- Plattform MaterialDigital (4)
- Scale-bridging (4)
- Stress relaxation (4)
- Tensile test (4)
- Virtual experiments (4)
- Brinell hardness (3)
- Crack propagation (3)
- Crack tip opening displacement (3)
- Creep behavior (3)
- Creep data (3)
- Creep-fatigue (3)
- Dark-field transmission electron microscopy (3)
- Dark-field transmission electron microscopy (DFTEM) (3)
- Data mapping (3)
- Diffraction (3)
- Ferritic-martensitic steels (3)
- Fractography (3)
- HIP (3)
- High temperature mechanical properties (3)
- Low cycle fatigue (3)
- Mechanical behavior (3)
- Metadata schema (3)
- Microstructure evolution (3)
- Phase-field (3)
- Phase-field simulation (3)
- Precipitation (3)
- Referenzdaten (3)
- Reproducibility (3)
- Single-crystals (3)
- Superalloys (3)
- Syngle Crystal alloy (3)
- Tempered Martensite Ferritic Steels (3)
- Tempered martensite-ferritic steel (3)
- Tensile Test (3)
- Tensile data (3)
- Tensile testing (3)
- Thermo-Mechanical Fatigue (3)
- Additive Fertigung (2)
- Aluminium Alloy (2)
- Aluminum alloy (2)
- CALPHAD (2)
- Casting (2)
- Chemo-mechanical coupling (2)
- Computed tomography (2)
- Concrete (2)
- Continnum damage model (2)
- Copper (2)
- Copper alloys (2)
- Creep-Fatigue (2)
- Cyclic softening (2)
- Data Management (2)
- Data Structures (2)
- Data management (2)
- Dataset (2)
- Density-based Thermodynamics (2)
- Density-based model (2)
- Densty-based Thermodynamics (2)
- Diffusion (2)
- Digital material representation (2)
- Digitization (2)
- Digtial Representation (2)
- Dislocation (2)
- Elasticity (2)
- Electron backscatter diffraction (2)
- Environmentally assisted cracking (2)
- FAIR Data Management (2)
- FAIR data (2)
- Fatigue performance (2)
- Finite element analysis (2)
- Fracture mechanics (2)
- Glass forming (2)
- Hardness (2)
- Heat treatment (2)
- High Cycle Fatigue (2)
- High Temperature Testing (2)
- Joined nickel-based alloys (2)
- Knowledge Graph (2)
- Laser Powder Bed Fusion (2)
- Long-term behavior (2)
- Mass transport (2)
- Material digital (2)
- Materials science (2)
- Metal seal (2)
- Micromechanical model (2)
- Microstructure-property-correlation (2)
- NFDI (2)
- Neutron diffraction (2)
- Nickel-base alloy (2)
- Notches (2)
- Ontology development (2)
- Ostwald ripening (2)
- PBF-LB/M/316L (2)
- PMD (2)
- PMDco (2)
- Plastic deformation (2)
- Rapid solidification (2)
- S-Phase (2)
- S355 steel sheet (2)
- Semantic Representation (2)
- Semantic web (2)
- Simulation (2)
- Simulation of concrete (2)
- Single-Crystal (2)
- Standard (2)
- Standardization (2)
- Superalloy (2)
- Superconducting magnet (2)
- TEM (2)
- Tensile Properties (2)
- Tensile Test Ontology (2)
- Thermodynamics (2)
- Titanium (2)
- Under cyclic loading (2)
- Viscoplasticity (2)
- Wall thickness (2)
- 3D-finite element modeling (1)
- 9-12% Cr ferritic-martensitic steels (1)
- 9-12%Cr steel (1)
- AM (1)
- Accelerated integration scheme (1)
- Accelerated temporal integration (1)
- Ageing (1)
- Al alloys (1)
- Al-Cu alloy (1)
- Al-Cu-Li alloys (1)
- Al-Cu-Li-alloy (1)
- Al-Li alloys (1)
- Al2CuMg (1)
- Alloy 2818A (1)
- Alloy design (1)
- Alloy microstructure (1)
- Aluminum (1)
- Aluminum Alloy Aging (1)
- Atomistic simulations (1)
- Austenite-to-martensite phase transformation (1)
- Austenitic cast iron (1)
- Austenitischer Stahl (1)
- Automated finite element analysis (1)
- Automated image analysis (1)
- Automation (1)
- Automatische Finite Element Simulation (1)
- Bitter technique (1)
- Calibration (1)
- Carbon steel (1)
- Centrifugal casting (1)
- Characterisation (1)
- Characterization (1)
- Charpy test (1)
- Coefficient of thermal expansion (1)
- Complex borides (1)
- Compositionally complex alloys (1)
- Contact mechanics (1)
- Creep behaviour (1)
- Creep mechanisms (1)
- Creep, Creep Rupture, and Stress Rupture (1)
- Creep-fatigue interaction (1)
- Crystal Defects (1)
- Crystal Plasticity Modelling (1)
- Crystalline defects (1)
- Cyclic loading (1)
- Cyclic oxidation (1)
- DED-L (1)
- Damage Behavior (1)
- Data Exchange (1)
- Data Fusion (1)
- Data Mapping (1)
- Data format (1)
- Data infrastructures (1)
- Data linking (1)
- Data storage (1)
- Data structure (1)
- Defects (1)
- Defects engineering (1)
- Defects phase diagram (1)
- Defects thermodynamics (1)
- Deformation (1)
- Deformation mechanisms (1)
- Die casting (1)
- Differential scanning calorimetry (DSC) (1)
- Diffraction Elastic Constants (1)
- Digital image correlation (1)
- Digital representation (1)
- Digital representations (1)
- Digital workflows (1)
- Dislocations (1)
- Domain Ontology Development (1)
- Dwell periods (1)
- Dwell times (1)
- Dwell-Fatigue (1)
- EN AW 2618A a (1)
- Elastic constants (1)
- Elastic energy (1)
- Electrical resistance (1)
- Electrochemical dressing (1)
- Electronic Lab Notebook (1)
- Electropolishing (1)
- Environment (1)
- Environmental Stress Cracking (1)
- Expanding cavity model (1)
- FAIR Data (1)
- FAIR research data management (1)
- FNCT (1)
- Fatigue crack propagation (1)
- Fatigue damage (1)
- Ferritic–martensitic steel (1)
- Finite elmenet simulation (1)
- Finite-Elemente-Methode (1)
- Fourier series (1)
- Full-Notch Creep Test (1)
- Full-notch creep test (1)
- Fullerite (1)
- GMR (1)
- GMR sensors (1)
- General Chemistry (1)
- General Computer Science (1)
- General Engineering (1)
- General Materials Science (1)
- Grade S960QL steel (1)
- Gradient-enhanced fatigue model (1)
- Grain Boundary Phase Diagram (1)
- Grain Boundary Segregation (1)
- Grain Boundary Spinodal (1)
- Grain boundaries (1)
- Grain boundary (1)
- Grain boundary phase diagram (1)
- Grain boundary thermodynamics (1)
- Graphic design (1)
- Hardness test (1)
- Hertzian cracks (1)
- High cycle fatigue (1)
- High entropy alloy (1)
- High entropy alloys (1)
- High-Entropy Alloys (1)
- High-entropy alloys (1)
- Hochentropie-Legierung (1)
- Honing (1)
- Honing Stone (1)
- Hot isostatic pressing (HIP) (1)
- IN 718 (1)
- IN718 (1)
- In-Situ Testing (1)
- In-situ Process Monitoring (1)
- In-situ SEM micro shear deformation (1)
- Inconel 718 (1)
- Incremental lifetime models (1)
- Indentation (1)
- Industrial and Manufacturing Engineering (1)
- Interfacial Spinodal (1)
- Interfacial anisotropy (1)
- Interfacial free energy (1)
- Interoperability (1)
- Inverse ostwald ripening (1)
- Investment casting (1)
- Irregular topography (1)
- Knowledge Graphs (1)
- Knowledge graph (1)
- Knowledge graphs (1)
- Knowledge representation (1)
- LMD (1)
- Laser Powder Bed Fusion (LPBF) (1)
- Laser Powder Bed fusion (1)
- Laser Scanning Microscopy (1)
- Laser beam melting (LBM) (1)
- Laser powder-based directed energy deposition (1)
- Layering misalignment (1)
- Legierung mit komplexer Zusammensetzung (1)
- Life cycle (1)
- Lifetime prediction (1)
- Linked open data (1)
- Long-term aging (1)
- Low Cycle Fatigue (LCF) (1)
- Low carbon steel (1)
- Low strain (1)
- Low-Cycle-Fatigue (1)
- Low-cycle fatigue (1)
- Low-cycle fatigue. (1)
- Low-cycle-fatigue behaviour (1)
- Machine learning (1)
- Magnetic domain distribution (1)
- Magnetic stray field (1)
- Magnetic stray fields (1)
- Magnetomechanical effect (1)
- Martensitic transformation (1)
- Mat-o-lab (1)
- Material degradation (1)
- Material modeling (1)
- MaterialDigital (1)
- Materials Chemistry (1)
- Materials Science (1)
- Materials Testing (1)
- Materials informatics (1)
- Materials science and engineering (1)
- Materials testing (1)
- Mechanical Engineering (1)
- Mechanical anisotropy (1)
- Mechanics of Materials (1)
- Mechanistic Modelling (1)
- Mehrskalenmodell (1)
- Metal Magnetic Memory (1)
- Metal magnetic memory (1)
- Metals and Alloys (1)
- Micro computed tomography (1)
- Microstructural evolution (1)
- Microstructure analysis (1)
- Microstructure characterisation (1)
- Microstructure modification (1)
- Mid-Level Ontology for MSE (1)
- Mikrostruktur (1)
- Misfitting precipitate (1)
- Missing acknowledgment (1)
- Model (1)
- Modeling (1)
- Molecular dynamics (1)
- Multiaxial deformation (1)
- NFDI-MatWerk (1)
- Nanocrystalline alloys (1)
- Nanoindentation (1)
- Ni-Resist (1)
- NiTi (1)
- Nickel alloys (1)
- Nickel-base superalloy (1)
- Nimonic 75 (1)
- Non-destructive Materials (1)
- Non-destructive testing (1)
- Normung (1)
- Notch (1)
- Number density (1)
- Ontologies (1)
- Ordering (1)
- Orowan Mechanism (1)
- P92 steels (1)
- PE-HD (1)
- Parametric modeling (1)
- Phase Diagram (1)
- Phase field crystal (1)
- Phase field method (1)
- Phase field model (1)
- Phase field simulation (1)
- Phase stability (1)
- Phase-field model (1)
- Plasticity (1)
- Platform Material Digital (1)
- Platform Material Digital (PMD) (1)
- Platform MaterialDigital (1)
- Platform MaterialDigital (PMD) (1)
- Polyethylene (1)
- Polymer (1)
- Pore (1)
- Pores (1)
- Porosity (1)
- Positron annihilation spectroscopy (1)
- Power plant (1)
- Precipitate shape (1)
- Precipitation Analysis (1)
- Precipitation hardening (1)
- Process development (1)
- Quantitative Precipitation Analysis (1)
- Radii distribution (1)
- Rafting (1)
- Reference Data (1)
- Reference Dataset (1)
- Reference material BCR-425 (1)
- Reheating (1)
- Relaxation fatigue (1)
- Relaxation tests (1)
- Research Data Management (1)
- Residual Stress (1)
- Resonance testing (1)
- Rissausbreitung (1)
- Safety (1)
- Selective laser melting (1)
- Selective laser melting (SLM) (1)
- Semantic Data Integration (1)
- Semantic Interioerability (1)
- Semantic Web (1)
- Semantic Web technologies (1)
- Semantic data integration (1)
- Semantic interoperability (1)
- Shape memory alloy (1)
- Shape memory alloys (1)
- Shear testing (1)
- Single crystal superalloys (1)
- Solidification (1)
- Spinodal Decomposition (1)
- Spinodal decomposition (1)
- Standardisation (1)
- Strain difference (1)
- Strain energy (1)
- Strength (1)
- Stress-strain behavior (1)
- Stress-strain-behavior (1)
- Structural steel (1)
- Structured Data (1)
- Superalloy single crystals (1)
- Superlegierung (1)
- Symmetric dwell periods (1)
- T1 precipitate (1)
- TIG-welding (1)
- TMF (1)
- TMF experiments (1)
- Temperature dependence (1)
- Tempered martensite ferritic steels (1)
- Tensile properties (1)
- Tensile strength (1)
- Tensile stress relaxation (1)
- Texture (1)
- Thermal Cycling (1)
- Thermal expansion (1)
- Thermo-mechanical fatigue (1)
- Thermomechanical Fatigue (TMF) (1)
- Thermomechanische Ermüdung (1)
- Thesaurus (1)
- Thickening (1)
- Tools (1)
- Topography (1)
- Transmission electron microscopy (TEM) (1)
- Vacancies (1)
- Vickers Hardness (1)
- Vickers hardness (1)
- Visual ontology development (1)
- Vocabulary providers (1)
- Volume fraction (1)
- Workshop (1)
- Young`s modulus (1)
- Young´s modulus (1)
- microstructural changes (1)
- γ″ phase (1)
- θ′ phase (1)
- θ′-(Al2Cu) precipitate phase (1)
Organisationseinheit der BAM
- 5.2 Metallische Hochtemperaturwerkstoffe (204) (entfernen)
Paper des Monats
- ja (1)
An improved diffusion model is proposed for pore annihilation during HIP of single-crystal nickel-base superalloys. The model assumes the pore dissolution by emission of vacancies and their sink to the low angle boundaries. Calculation, considering distribution of the pore sizes, predicts the kinetics of pore annihilation similar to the experimental one.
With the introduction of a mass transport mechanism the entire problem is subjected to a time frame that dictates the time-dependent action of soluted species on mechanical properties. A numerical framework within the phase-field approach is presented with an embrittlement-based coupling mechanism. The underlying functionals are expressed in terms of the displacement, mass concentration and crack phase-field. Within the phase-field approach the modelling of sharp crack discontinuities is replaced by a diffusive crack model facilitating crack initiation and complex crack topologies without the requirement of a predefined crack path. The isotropic hardening of the elasto-plastic deformation model and the local fracture criterion are affected by the species concentration. This allows for embrittlement and leads to an accelerated crack propagation. An extended mass transport equation for hydrogen embrittlement, accounting for mechanical stresses and deformations, is implemented. For stabilisation purposes a staggered scheme is applied to solve the system of partial differential equations by a multi-field finite-element method. A thermodynamically consistent coupling relation that accommodates the required mechanisms is presented.
The amount of data generated worldwide is constantly increasing. These data come from a wide variety of sources and systems, are processed differently, have a multitude of formats, and are stored in an untraceable and unstructured manner, predominantly in natural language in data silos. This problem can be equally applied to the heterogeneous research data from materials science and engineering. In this domain, ways and solutions are increasingly being generated to smartly link material data together with their contextual information in a uniform and well-structured manner on platforms, thus making them discoverable, retrievable, and reusable for research and industry. Ontologies play a key role in this context. They enable the sustainable representation of expert knowledge and the semantically structured filling of databases with computer-processable data triples.
In this perspective article, we present the project initiative Materials-open-Laboratory (Mat-o-Lab) that aims to provide a collaborative environment for domain experts to digitize their research results and processes and make them fit for data-driven materials research and development. The overarching challenge is to generate connection points to further link data from other domains to harness the promised potential of big materials data and harvest new knowledge.
A constitutive model for the mechanical behaviour of single crystal Ni-base superalloys under high temperature conditions has been developed in the framework of a Cooretec project in cooperation with Siemens AG, MTU Aero Engines AG and University Bayreuth. In addition to the conventional material properties e.g. elastic constants, the model requires the parameters of the initial microstructure as an input. Thus, the γ’-precipitate size and the channel width of the γ-matrix were obtained from SEM micrographs. The model uses the slip system theory and describes the movement, multiplication and annihilation of dislocations in the channels. Furthermore, the cutting of precipitates is another mechanism contributing to the plastic flow. The evolution of the morphology due to rafting and its effects on the deformation have been implemented according to. The kinematic hardening is introduced as a stress tensor to realistically represent the strain hardening of arbitrary oriented single crystals.
The mechanical behaviour of single crystal specimens has been experimentally investigated in tension tests at different strain rates and in creep tests under various loads. The constitutive model has been calibrated based on the experimental data for temperatures of 950°C and 850°C and the [001] and [111] crystallographic orientations.
Finally, a micromechanical model was created to simulate the creep response of additive manufactured polycrystalline structures. An EBSD image is taken to obtain the grain geometry and their respective orientation. The grain boundaries are discretised using cohesive elements, whereas the single crystal model was applied to each grain in the representative volume. The polycrystal model is generated using Dream3D, NetGen and other software previously developed at the BAM.
The methods of computational damage mechanics are well-established for the description of degradation of materials under monotone loading. An extension to structural damage induced by cyclic loading is however significantly limited. This is due to enormous computational costs required to resolve each load cycle by conventional temporal incremental integration schemes while a typical fatigue loading history comprises between thousands and millions of cycles. Despite the permanent increase of computational resources and algorithmic performance, a successful approach is rather based on the development of novel multiscale in time integration schemes.
A Fourier transformation-based temporal integration (FTTI) is represented, which takes advantage of temporal scale separation incorporated into the cycle jump method. The response fields are approximated by a Fourier series whose coefficients undergo the evolution on a long-time scale. This is correlated with the evolution of the history variables, including damage, by means of the adaptive cycle jump method of various orders. The necessary extrapolation rates are obtained from the underlying solution of a short-time scale problem, which results from the oscillatory boundary condition and fulfills the global equilibrium of the Fourier coefficients. In this way, a remarkable speedup is achieved because the number of cycles to be fully integrated dramatically decreases.
The key idea behind the FTTI method is that the global in space equilibrium problem is linear since it is decoupled from the evolution equations. The latter are solved in the quadrature points under response fields prescribed throughout the whole load cycle. Consequently, integration of a single load cycle is much more efficient than the conventional single scale integration where the global equilibrium iteration and the local iteration of the evolution equations are coupled. This results in an additional speedup of the FTTI method.
The performance of the FTTI technique is demonstrated for two different constitutive behaviors: a viscoplastic model with a damage variable governed by the local equivalent viscoplastic strain; a quasi-brittle response where the damage variable is driven by a non-local equivalent strain. The latter is implicitly introduced as proposed by Peerlings. Both, the explicit and implicit extrapolation schemes are validated. The FTTI solutions agree very well with the reference cycle-by -cycle solutions, while significantly reducing the computational costs. The adaptive determination of the jump length can properly recognize the particular responses throughout the fatigue loading history (stationary fatigue, acceleration of fatigue damage when approaching failure) as well as stress redistribution phenomena.
Additive manufacturing (AM) offers significantly greater freedom of design compared to conventional manufacturing processes since the final parts are built layer by layer. This enables metal AM, also known as metal 3D printing, to be utilized for improving efficiency and functionality, for the production of parts with very complex geometries, and rapid prototyping. However, despite many technological advancements made in recent years, several challenges hinder the mass adoption of metal AM. One of these challenges is mechanical anisotropy which describes the dependency of material properties on the material orientation. Therefore, in this work, stainless steel 316L parts produced by laser-based powder bed fusion are used to isolate and understand the root cause of anisotropy in AM parts. Furthermore, an efficient and accurate multiscale numerical framework is presented for predicting the deformation behavior of actual AM parts on the macroscale undergoing large plastic deformations. Finally, a novel constitutive model for the plastic spin is formulated to capture the influence of the microstructure evolution on the material behavior on the macroscale.
Systematic microstructure design requires reliable thermodynamic descriptions of each and all microstructure elements. While such descriptions are well established for most bulk phases, thermodynamic assessment of microstructure defects is challenging because of their individualistic nature. In this paper, a model is devised for assessing grain boundary thermodynamics based on available bulk thermodynamic data. We propose a continuous relative atomic density field and its spatial gradients to describe the grain boundary region with reference to the homogeneous bulk and derive the grain boundary Gibbs free energy functional. The grain boundary segregation isotherm and phase diagram are computed for a regular binary solid solution, and qualitatively benchmarked for the Pt–Au system. The relationships between the grain boundary's atomic density, excess free volume, and misorientation angle are discussed. Combining the current density-based model with available bulk thermodynamic databases enables constructing databases, phase diagrams, and segregation isotherms for grain boundaries, opening possibilities for studying and designing heterogeneous microstructures.
A key limitation of the most constitutive models that reproduce a Degradation of quasi-brittle materials is that they generally do not address issues related to fatigue. One reason is the huge computational costs to resolve each load cycle on the structural level. The goal of this paper is the development of a temporal Integration scheme, which significantly increases the computational efficiency of the finite element method in comparison to conventional temporal integrations.
The essential constituent of the fatigue model is an implicit gradient-enhanced formulation of the damage rate. The evolution of the field variables is computed as amultiscale Fourier series in time.On a microchronological scale attributed to single cycles, the initial boundary value problem is approximated by linear BVPs with respect to the Fourier coefficients. Using the adaptive cycle jump concept, the obtained damage rates are transferred to a coarsermacrochronological scale associated with the duration of material deterioration. The performance of the developedmethod is hence improved due to an efficient numerical treatment of the microchronological problem in combination with the cycle jump technique on the macrochronological scale. Validation examples demonstrate the convergence of the obtained solutions to the reference simulations while significantly reducing the computational costs.
Due to combined cyclic mechanical and thermal loading during operation, the material of exhaust gas conducting components of combustion engines is exposed to thermomechanical fatigue (TMF). This leads to formation and growth of cracks, especially at the most highly stressed points of these components. In order to better predict the service life of cracked components before failure, it is necessary to identify a crack propagation law for the material used. Isothermal crack propagation tests have been carried out at several temperatures with a typical cast iron to identify such a law. The crack length is measured by the potential drop method. The compliance method, fractography and thermographic camera measurements have been used to validate and calibrate the potential drop measurements. Each of the isothermal tests has been simulated using a specially developed FEM-algorithm based on remeshing and remapping. This algorithm has been implemented in python and ABAQUS. Thereby, the crack tip region is modeled by collapsed Quad8 elements. From the individual simulations, the cyclic crack tip opening displacement (ΔCTOD) is extracted and regarded as a potential fracture mechanics parameter which controls the crack growth rate. By combining the data from the experiments and the simulations, the crack propagation law has been identified. Finally, anisothermal crack propagation tests have been performed for validation of the crack growth law.