Non-destructive testing of objects and structures is a valuable tool, especially in cultural heritage where the preservation of the inspected sample is of vital importance. In this paper, a decorative marquetry sample is inspected with three non-destructive testing (NDT) techniques: air-coupled ultrasound, X-ray micro-tomography, and infrared thermography. Results from the three techniques were compared and discussed. X-ray micro-tomography presented the most detailed results. On the other hand, infrared thermography provided interesting results with the advantage of being cheap and easy in the deployment of the NDT method.

This study focuses on the influence of additive manufacturing process strategies on the specimen geometry, porosity, microstructure and mechanical properties as well as their impacts on the design of metamaterials. Filigree additively manufactured NiTi specimens with diameters between 180 and 350 µm and a nominal composition of Ni_50.9Ti_49.1 (at %) were processed by laser powder bed fusion in a first step. Secondly, they structures were characterized by optical and electron microscopy as well as micro tomography to investigate the interrelations between the process parameters, specimen diameters and microstructure. Each specimen was finally tested in a micro tensile machine to acquire the mechanical performance. The process strategy had, besides the resulting specimen diameter, an impact on the microstructure (grain size) without negatively influencing its quality (porosity). All specimens revealed a superelastic response while the critical martensitic phase transition stress decreased with the applied vector length. As a conclusion, and since the design of programmable metamaterials relies on the accuracy of FEM simulations, precise and resource-efficient testing of filigree and complex structures remains an important part of creating a new type of metamaterials with locally adjusted material behavior.

Laser cutting is a suitable manufacturing method for generating complex geometries for sheet metal components. However, their cyclic load capacity is reduced compared to, for example, milled components. This is due to the influence of the laser-cut edge, whose characteristic features act as crack initiation sites, especially resolidified material in the form of burr and melt droplets. Since sheet metal components are often formed into their final geometry after cutting, another important factor influencing fatigue behavior is the effect of the forming process on the laser-cut edge. In particular, the effect of high degrees of deformation has not yet been researched in detail. Accordingly, sheets of AISI 304 were processed by laser cutting and pre-deformed. In the process, α’-martensite content was set to be comparable despite different degrees of deformation. It was found that deformation to high elongations caused a large part of the melt adhesions to fall off, but those still attaching were partially detached and thus formed an initial notch for crack initiation. This significantly lowered the fatigue strength.

Besides electron imaging in Scanning Electron Microscopy (SEM), techniques like Energy Dispersive X-ray spectroscopy (EDX) or Electron Backscatter Diffraction (EBSD) are widely established. With integration of a target holder and a pixelated x-ray detector, x-ray Computed Tomography (CT) in SEM can be realized and extends the modalities of materials characterization in one instrument. For nano-CT mode, an electron beam is focused on a suitable target leading to x-ray emission. While passing through a specimen, x-rays are differently attenuated depending on their material properties and detected by a direct converting x-ray detector afterward. Presented is a SEM-based nano-CT called XRM-II nanoCT and different applications of correlative microscopy using electron imaging, energy dispersive x-ray spectroscopy and CT. Besides multiscale investigation on materials for fuel cells and electrolysers by 3D visualization with micro- and nano-CT, nano-CT characterization of a catalytic converter with additional chemical analysis is depicted. At last, time-resolved imaging of morphology changes in an annealed Al alloy using nano-CT is presented. Results show grain coarsening as well as precipitations in the range of 200 – 1200 nm.