A5064817479- Additive Manufacturing Materials and Processes
- Welding Techniques and Residual Stresses
- Additive Manufacturing and 3D Printing Technologies
- Complex Network Analysis Techniques
- Advanced X-ray and CT Imaging
- Neural dynamics and brain function
- Functional Brain Connectivity Studies
- Industrial Vision Systems and Defect Detection
- Microstructure and mechanical properties
- Molecular spectroscopy and chirality
- Thermography and Photoacoustic Techniques
- High Temperature Alloys and Creep
- Electron and X-Ray Spectroscopy Techniques
- Nuclear Materials and Properties
- Spectroscopy and Quantum Chemical Studies
- Opinion Dynamics and Social Influence
- Theoretical and Computational Physics
- Semiconductor materials and interfaces
- Aluminum Alloys Composites Properties
- High Entropy Alloys Studies
- Topological and Geometric Data Analysis
- Laser-induced spectroscopy and plasma
Friedrich-Alexander-Universität Erlangen-Nürnberg
2019-2024
One major advantage of additive manufacturing is the high freedom design, which supports fabrication complex structures. However, geometrical features such as combined massive volumes and cellular structures in parts can lead to an uneven heat distribution during processing, resulting different material properties throughout part. In this study, we demonstrate these effects, using a structure consisting three conic shapes with narrow cylinders between hindering flux. We manufacture via...
Abstract Electron beam powder bed fusion (PBF-EB) of Ni-base superalloys such as CMSX-4 is a demanding process. Using conventional PBF-EB machines, process observation done by mounting optical camera systems on viewing windows at the top build chamber. However, concomitant metallization blocks methods with increasing time. Therefore, quality evaluation normally after utilizing visual inspection or subsequent metallurgical analysis. In this work, processed using freely programmable machine an...
Electron beam powder bed fusion offers the unique opportunity to observe process by measuring scattered electrons on a metal detector. This technique is state of art in generating electron optical images build area after melting using single- or multi-detector setups. The enable detection surface defects like porosity material transport reconstructing topography. Internal such as layer-bonding cannot be identified. Many these defects, particularly often originate from an irregular...
The development of a sample environment for in situ x-ray characterization during metal Electron Beam Powder Bed Fusion (PBF-EB), called MiniMelt, is presented. design considerations, the features equipment, and its implementation at synchrotron facility PETRA III Deutsches Elektronen-Synchrotron, Hamburg, Germany, are described. equipment based on commercially available Freemelt ONE PBF-EB system but has been customized with unique process chamber to enable real-time measurements additive...
The deformation behavior of ⟨110⟩-oriented twinned Au nanowires (NWs) with multiple longitudinal coherent twin boundaries (CTBs) under tension is studied using in−situ experiments and molecular dynamics (MD) simulations. NWs show higher yield strength than the single-crystalline similar diameter. Postmortem observations electron microscopy MD simulations that presence CTBs transitions governing mechanism from twinning-mediated in to strongly localized deformation. reveal intersection...
The recent success of the process monitoring method Electron Optical Imaging, applied in additive manufacturing Beam Powder Bed Fusion, necessitates a clear understanding underlying image formation process. Newly developed multi-detector systems enable reconstruction build surface topography in-situ but add complexity to method. This work presents physically based raytracing model, which rationalises effect detector positioning on contrast development and masking. model correctly describes...
Abstract Electron optical imaging is the most promising process monitoring method in electron beam powder bed fusion. State of art modern machines installation a single detector top center build chamber. Exemplary applications are reconstruction digital twins manufactured parts to compare their dimensional accuracy or analysing surface each layer identify features like pores material transport. Multi-detector systems currently under research and have shown great potential reconstructing...
X-ray-computed tomography (CT) is today’s gold standard for the non-destructive evaluation of internal component defects such as cracks and porosity. Using automated standardized algorithms, an analysis can be performed without knowledge shape, location, or size defects. Both measurement are based on fact that has no structures cavities. However, additive manufacturing (AM) hybrid subtractive procedures offer possibility integrating directly during building process. The examination powder...
This work introduces a framework to study the emergence of long time scales in network models brain connectivity, and establishes connection between anomalies spectral dimension Lifshitz tails Laplacian spectrum.
The spectral dimension is a generalization of the Euclidean and quantifies propensity network to transmit diffuse information. We show that, in hierarchical-modular models brain, dynamics are anomalously slow not defined. Inspired by Anderson localization quantum systems, we relate neural activity - essential embed brain functionality spectrum existence an anomalous "Lifshitz dimension". In broader context, our results help shedding light on relationship between structure function biological...