A5025058700- Welding Techniques and Residual Stresses
- Additive Manufacturing Materials and Processes
- Advanced ceramic materials synthesis
- Advanced Surface Polishing Techniques
- High Entropy Alloys Studies
- Hydrogen embrittlement and corrosion behaviors in metals
- Non-Destructive Testing Techniques
- Advanced X-ray and CT Imaging
- Advanced X-ray Imaging Techniques
- Recycling and utilization of industrial and municipal waste in materials production
- Medical Imaging Techniques and Applications
- Corrosion Behavior and Inhibition
- Advanced materials and composites
- Radiation Dose and Imaging
- Aluminum Alloys Composites Properties
- Glass properties and applications
- Bone Tissue Engineering Materials
- X-ray Diffraction in Crystallography
- Nuclear Materials and Properties
- High-Temperature Coating Behaviors
- Composite Material Mechanics
- X-ray Spectroscopy and Fluorescence Analysis
- Crystallography and Radiation Phenomena
- Fire effects on concrete materials
- Electron and X-Ray Spectroscopy Techniques
Physikalisch-Technische Bundesanstalt
2021-2023
Federal Institute For Materials Research and Testing
2017-2023
For the first time, X-ray refraction techniques are proven for identification of void formation in Ti-6Al-4V parts produced by selective laser melting. The topology and volume fraction pores measured samples with different energy density. Unique methods identify kinds defects, characteristic to regions below above optimum density, namely unprocessed powder (unmolten particles, balling effect, fusion defects) from empty keyhole pores. Furthermore, it is possible detect small inhomogeneities...
Abstract Degradation of thermal barrier coatings (TBCs) in gas‐turbine engines due to calcium–magnesium–aluminosilicate (CMAS) glassy deposits from various sources has been a persistent issue since many years. In this study, state the art electron microscopy was correlated with X‐ray refraction techniques elucidate intrusion CMAS into porous structure atmospheric plasma sprayed (APS) TBCs and formation growth cracks under cycling burner rig. Results indicate that sparse nature infiltration...
Abstract The stress–strain behavior of ceramics, such as aluminum titanate, has certain features that are unusual for brittle materials—in particular, a substantial nonlinearity under uniaxial tension, and load–unload hysteresis caused by the sharp increase incremental stiffness at beginning unloading. These observed experimentally attributed to microcracking. Here we compare different degrees titanate materials quantitatively model them. We use advanced mechanical testing observe response...
Abstract Porosity in additively manufactured materials, such as laser powder bed fusion Ti-Al6-V4, can play an important role their mechanical performance. Not only the total porosity but also shape/morphology of individual pores need to be considered. Therefore, it is necessary determine distributions different defect types (especially fusing defects and keyhole pores) dependence on process parameters. We show that synchrotron X-ray refraction radiography allows analysis large samples (up...
Abstract The utilization of additive manufacturing (AM) to fabricate robust structural components relies on understanding the nature internal anomalies or discontinuities, which can compromise integrity. While some discontinuities in AM microstructures stem from similar mechanisms as observed more traditional processes such casting, others are unique process. Discontinuities challenging detect, due their submicron size and orientation dependency. Toward goal improving integrity, minimizing...
While structural ceramics usually display a brittle mechanical behavior, their composites may show nonlinearities, mostly due to microcracking. Herein, the stiffness evolution of sandwich‐like laminate an Al 2 O 3 −15%vol. ZrO matrix reinforced with Nextel 610 fibers is studied as function number cycles N in tension. The composite degrades increasing , indicating However, synchrotron X‐ray refraction radiography shows that internal specific surface such cracks varies differently. A modeling...
Zirconia-based cast refractories are widely used for glass furnace applications. Since they have to withstand harsh chemical as well thermo-mechanical environments, internal stresses and microcracking often present in such materials under operating conditions (sometimes excess of 1700 °C). We studied the evolution thermal (CTE) mechanical (Young’s modulus) properties a function temperature fused-cast refractory containing 94 wt.% monoclinic ZrO2 6 silicate glassy phase. With aid X-ray...
While the problem of identification mechanisms hydrogen‐assisted damage has and is being thoroughly studied, quantitative analysis such still lacks suitable tools. In fact, while, for instance, electron microscopy yields excellent characterization, requires at same time large field‐of‐views high spatial resolution. Synchrotron X‐ray refraction techniques do possess both features. Herein, it shown how synchrotron computed tomography (SXRCT) can quantify induced by hydrogen embrittlement in a...
Carbon fiber composites have been increasingly used in aerospace, military, sports, automotive and other fields due to their excellent properties, including high specific strength, modulus, corrosion resistance, fatigue low thermal expansion coefficient. Interlaminar fracture is a serious failure mode leading loss composite stiffness strength. Discontinuities formed during manufacturing process degrade the life interlaminar resistance of composite. In his study, three approaches were...
Abstract X-ray computed tomography (XCT) is a fast-growing technology for dimensional measurements in industrial applications. However, traceable and efficient methods to determine measurement uncertainties are not available. Guidelines like the VDI/VDE 2630 Part 2.1 suggest at least 20 repetitions of specific task, which feasible standards. Simulation-based approaches task promising, but require closely adjusted model parameters an integration error sources geometrical deviations during...
Abstract The metrological structural resolution (MSR) describes the size of smallest surface feature that can be measured dimensionally with a given accuracy. Several methods to determine MSR for dimensional x-ray CT (dXCT) have been proposed in past, two which are compared and related this publication, i.e. curved-edge based (CEB) profile-based spectral (PBS) method. Both consider structure as being described by single on relevant local scale also suitable application optical or tactile...
3D imaging techniques have an enormous potential to understand the microstructure, its evolution, and link mechanical, thermal, transport properties. In this conference paper we report use of a powerful, yet not so wide-spread, set X-ray based on refraction effects. allows determining internal specific surface (surface per unit volume) in non-destructive fashion, position orientation sensitive, with nanometric detectability. We demonstrate showcases ceramics composite materials, where...