Filtern
Dokumenttyp
Schlagworte
- Additive manufacturing (13)
- Laser powder bed fusion (8)
- Residual stress (7)
- Additive Manufacturing (6)
- AlSi10Mg alloy (4)
- Computed tomography (4)
- Residual Stress (4)
- X-ray refraction (4)
- AlSi10Mg (3)
- EBSD analysis (3)
- Electron backscatter diffraction (EBSD) (3)
- Fatigue crack growth (3)
- In situ heating (3)
- Laser Powder Bed Fusion (3)
- Neutron diffraction (3)
- Residual stress analysis (3)
- Creep (2)
- Defects (2)
- Diffraction (2)
- Diffraction elastic constants (2)
- Digital image correlation (DIC) (2)
- Electron backscatter diffraction (2)
- Fatigue crack propagation (2)
- Heat treatment (2)
- IN718 (2)
- In-situ heating up to 1400°C (2)
- Inconel 718 (2)
- LPBF (2)
- Microcracking (2)
- Neutron Diffraction (2)
- Refractory materials (2)
- Residual stress state (2)
- Residual stresses (2)
- Sintering (2)
- Synchrotron X-Ray Refraction (2)
- Synchrotron refraction radiography (2)
- Synchrotron µCT and refraction radiography (2)
- Texture (2)
- Thermally induced porosity (2)
- A357-T6 cast aluminum alloy (1)
- A357-T6 casting (1)
- AGIL (1)
- AISI 316L (1)
- AM IN718 (1)
- AM IN718 alloy (1)
- Al-3.85%Mg alloy (1)
- Aluminium alloys (1)
- Aluminum alloy (1)
- Analyzer-based imaging (1)
- As-built LPBF IN718 alloy (1)
- Bench braking sequence (1)
- Bragg-edge neutron 2D imaging (BENI) (1)
- Braking load history (1)
- Bulk properties ageing (1)
- Cellular structures (1)
- Ceramics (1)
- Ceria (1)
- Components influence (1)
- Composite (1)
- Composites (1)
- Compression testing (1)
- Compressive test (1)
- Computed Tomography (1)
- Crack initiation period (1)
- Cracks (1)
- Crystal plasticity finite element modeling (CPFEM) (1)
- Crystallographic descriptor (1)
- Crystallographic texture control (1)
- Cyclic R-curve (1)
- DIC assisted compression (1)
- Damage characterization (1)
- Damage tolerance (1)
- Denoising filter (1)
- Diffraction methods (1)
- Diffraction peak width (1)
- Diffraction-elastic constants (1)
- Diffusion (1)
- Digital image correlation (1)
- Dislocation-climb-controlled creep (1)
- Dislocations (1)
- Distortion (1)
- Distortion upon baseplate removal (1)
- Effect of scanning strategies (1)
- Electron microscopy (1)
- Energy dispersive X Ray diffraction (1)
- Ernel average misorientation (KAM) (1)
- Evolution of bulk properties (1)
- Fatigue performance (1)
- Fatigue strength (1)
- Fractals (1)
- Fractographic observations (1)
- Friction braking (1)
- Geometric descriptor (1)
- Graphite induced hysteresis (1)
- Hystersis (1)
- IN718 PBF-LB/M (1)
- Imaging (1)
- In situ testing (1)
- In-situ (1)
- In-situ heat treatment (1)
- Inconel (1)
- Interfaces (1)
- Interphase residual stress (1)
- Keramik (1)
- Kernel average misorientation (1)
- Kitagawa-Takahashi Diagram (1)
- L-PBF (1)
- L-PBF IN718 material (1)
- Laboratory XµCT (1)
- Laboratory energy-dispersive X-ray diffraction (EDXRD) (1)
- Laminated metal composite (1)
- Laminated metallic composites (1)
- Large Scale Facilities (1)
- Laser Beam Melting (1)
- Laser Powder Bed Melting (1)
- Laser beam melting (1)
- Laser powder bed fusion (LPBF) (1)
- Laser-based additive manufacturing (1)
- Lattice Structure (1)
- Load history (1)
- Macroscopic stress (1)
- Mechanical behavior (1)
- Metal additive manufacturing (MAM) (1)
- Metal matrix composite (1)
- Metallic matrix pad (1)
- Microstructural evolution (1)
- Microstructure (1)
- Microstructure and texture (1)
- Monoclinic to tetragonal transformation (1)
- Near-surface X-ray diffraction (1)
- Neutron and X-ray diffraction (1)
- Neutrons diffraction (1)
- Nickel-based superalloys (1)
- Nonlinear stress-strain curve (1)
- Online Process Monitoring (1)
- PBF-LB/M AlSi10Mg (1)
- PBFLB/M AlSi10Mg alloy (1)
- Phase transformation (1)
- Plasticity (1)
- Pore size (1)
- Porosity growth (1)
- Post processing heat treatment (1)
- Powder analysis (1)
- Powder metallurgy (1)
- Power law and power-law breakdown (1)
- Power-law breakdown (1)
- Propagation modes (1)
- Pure aluminium (1)
- Qquantification and segmentation (1)
- Re-entrant surface feature (1)
- Refractory (1)
- Refractory zirconia (1)
- Residual stress in AM (1)
- Residual stress measurements (1)
- Röntgen-Refraktion (1)
- SIF evaluation (1)
- Scan strategies (1)
- Scan strategy influence (1)
- Scanning electron microscopy (1)
- Scanning electron microscopy (SEM) (1)
- Selective laser melted materials (1)
- Semi-metallic brake-pad material (1)
- Semi-metallic friction material (1)
- Semi-metallic sintered material (1)
- Short Crack Models (1)
- Si network disintegration (1)
- Stainless Steel (1)
- Statistical image analysis (1)
- Statistically relevant volumes (1)
- Steady-state creep (1)
- Stiffness (1)
- Strain-free lattice references (1)
- Strain-free lattice spacing (1)
- Stress balance (1)
- Stress balance condition (1)
- Stress-relief heat-treatments (1)
- Surface roughness analysis (1)
- Synchrotron Energy Dispersive Diffraction (1)
- Synchrotron X-ray computed tomography (1)
- Synchrotron X-ray diffraction (1)
- Synchrotron X-ray diffraction (SXRD) (1)
- Synchrotron X-ray refraction (1)
- Synchrotron X-ray refraction radiography (1)
- Synchrotron computed tomography (1)
- Synchrotron refraction (1)
- Synchrotron tomography (1)
- Tensile testing (1)
- Thermally induced microcracking (1)
- Thermally induced porosity (TIP) (1)
- Thermography (1)
- Ti-6Al-4V (1)
- Tiatanium (1)
- Torsional fatigue (1)
- Torsional in situ fatigue testing (1)
- Toughening mechanism (1)
- Toughening mechanisms (1)
- Uniaxial compression tests (1)
- Verbundwerkstoffe (1)
- Wear resistance (1)
- X-Ray refraction (1)
- X-ray Computed Tomography (1)
- X-ray Diffraction (1)
- X-ray Refaction radiography (1)
- X-ray analysis (1)
- X-ray and Neutron Diffraction (1)
- X-ray and neutron diffraction (1)
- X-ray synchrotron tomography (1)
- Zirconia (1)
- pure aluminum (1)
- subgrain (1)
Organisationseinheit der BAM
- 8 Zerstörungsfreie Prüfung (58)
- 8.5 Röntgenbildgebung (58)
- 9 Komponentensicherheit (16)
- 9.4 Integrität von Schweißverbindungen (15)
- 5 Werkstofftechnik (5)
- 5.1 Mikrostruktur Design und Degradation (3)
- 5.2 Metallische Hochtemperaturwerkstoffe (2)
- 8.3 Thermografische Verfahren (2)
- 9.0 Abteilungsleitung und andere (2)
- 9.6 Additive Fertigung metallischer Komponenten (2)
Eingeladener Vortrag
- nein (10)
The relationship between residual stresses and microstructure associated with a laser powder bed fusion (LPBF) IN718 alloy has been investigated on specimens produced with three different scanning strategies (unidirectional Y-scan, 90° XY-scan, and 67° Rot-scan). Synchrotron X-ray energy-dispersive diffraction (EDXRD) combined with optical profilometry was used to study residual stress (RS) distribution and distortion upon removal of the specimens from the baseplate. The microstructural characterization of both the bulk and the nearsurface regions was conducted using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). On the top surfaces of the specimens, the highest RS values are observed in the Y-scan specimen and the lowest in the Rot-scan specimen, while the tendency is inversed on the side lateral surfaces. A considerable amount of RS remains in the specimens after their removal from the baseplate, especially in the Y- and Z-direction (short specimen Dimension and building direction (BD), respectively). The distortion measured on the top surface following baseplate thinning and subsequent removal is mainly attributed to the amount of RS released in the build direction. Importantly, it is observed that the additive manufacturing microstructures challenge the use of classic theoretical models for the calculation of diffraction elastic constants (DEC) required for diffraction-based RS analysis. It is found that when the Reuß model is used for the calculation of RS for different crystal planes, as opposed to the conventionally used Kröner model, the results exhibit lower scatter. This is discussed in context of experimental measurements of DEC available in the literature for conventional and additively manufactured Ni-base alloys.
Additive Manufacturing by Selective Laser Melting (SLM) offers an ample scope for producing geometrically complex parts as compared to the traditional subtractive manufacturing strategies. However, the residual stresses (RS) developed during the processing can reduce the load bearing capacity as well as induce unwanted distortion, limiting the life time and the application of SLM parts.
We present two examples of the potential of synchrotron X-ray refraction techniques. First, we focus on the 3D imaging of hydrogen assisted cracks in an EN AW – 6060 aluminium alloy which are otherwise undetected by absorption-based CT. The second work is a quantitative analysis of the damage evolution in an Al/Al2O3 Metal Matrix Composite during interrupted in-situ tensile load.
Due to the complexity of friction materials, the characterization of the tribological properties is prioritised over the bulk material properties even though the tribology is expected to be influenced by the material behaviour. The extent of this relationship is still unknown and further knowledge is required to account for the load history and evolution of the bulk properties. With this view, the compression behaviour and microstructure of a semi-metallic friction material with reduced formulation were investigated before and after a braking program. The thermal loading was monitored with inserted thermocouples. Uniaxial compression tests coupled with Digital Image Correlation (DIC) show significant changes in the worn material, which develops a compression behaviour similar to that of a tri-layered material. The microstructural analysis indicates microcracking of the metallic matrix and carbon diffusion in the Fe-phase. The thermal loading was found to be the key parameter controlling both the friction behaviour and evolution of the material properties. The expected effects of material evolution on the contact uniformity, durability and tribology are discussed.
The quality of components made by laser beam melting (LBM) additive manufacturing is naturally influenced by the quality of the powder bed. A packing density <1 and porosity inside the powder particles lead to intrinsic voids in the powder bed. Since the packing density is determined by the particle size and shape distribution, the determination of these properties is of significant interest to assess the printing process. In this work, the size and shape distribution, the amount of the particle’s intrinsic porosity, as well as the packing density of micrometric powder used for LBM, have been investigated by means of synchrotron X-ray computed tomography (CT). Two different powder batches were investigated: Ti–6Al–4V produced by plasma atomization and stainless steel 316L produced by gas atomization. Plasma atomization particles were observed to be more spherical in terms of the mean anisotropy compared to particles produced by gas atomization. The two kinds of particles were comparable in size according to the equivalent diameter. The packing density was lower (i.e., the powder bed contained more voids in between particles) for the Ti–6Al–4V particles. The comparison of the tomographic results with laser diffraction, as another particle size measurement technique, proved to be in agreement.
This work provides an investigation of the influence of low temperature heat treatments on the fatigue behavior of a PBF-LB AlSi10Mg alloy. Fatigue specimens are produced in form of round bars on a build platform preheated at 200 ◦C. The specimens have been tested in three different conditions: as-built, and after heat treatments at 265 ◦C for 1 h and 300 ◦C for 2 h. Prior to the fatigue testing, the defect distribution is analyzed by means of micro computed tomography. Subsequently, the peak over threshold method is successfully applied to provide a prediction of the size of killer defect. The defect population was of gas porosity type. No clear improvement of the fatigue performance is observed after the heat treatments. The fatigue strength predicted using fracture mechanics-based approaches is in good agreement with the experimental data. Among the studied approaches, short crack models provided the most conservative predictions.