Reactive multilayer systems represent an innovative approach for potential usage in chip joining applications. As there are several factors governing the energy release rate and the stored chemical energy, the impact of the morphology and the microstructure on the reaction behavior is of great interest. In the current work, 3D reactive microstructures with nanoscale Al/Ni multilayers were produced by alternating deposition of pure Ni and Al films onto nanostructured Si substrates by magnetron sputtering. In order to elucidate the influence of this 3D morphology on the phase transformation process, the microstructure and the morphology of this system were characterized and compared with a flat reactive multilayer system on a flat Si wafer. The characterization of both systems was carried out before and after a rapid thermal annealing treatment by using scanning and transmission electron microscopy of the cross sections, selected area diffraction analysis, and differential scanning calorimetry. The bent shape of multilayers caused by the complex topography of silicon needles of the nanostructured substrate was found to favor the atomic diffusion at the early stage of phase transformation and the formation of two intermetallic phases Al_0.42Ni_0.58 and AlNi₃, unlike the flat multilayers that formed a single phase AlNi after reaction.

Cemented carbides, or hard metals, are ceramic–metal composites usually consisting of tungsten carbide particles bound by a cobalt-based alloy. They are the backbone materials for the tooling industry, as a direct consequence of the outstanding range of property combinations, depending on their effective microstructural assemblage, i.e., the physical dimensions and relative content of their constitutive phases. Hence, reliable microstructural characterization becomes key for hard metal grade selection and quality control. This work aimed to assess the practical two-dimensional characterization methods for the most important one- and two-phase properties of cemented carbides, i.e., the carbide grain size, phase fraction, carbide contiguity, and binder mean free path. Three different methods—point, line, and area analysis—were implemented to characterize four microstructurally distinct grades. The images were acquired by optical and scanning electron microscopy, with the latter through both secondary and backscattered electrons. Results were critically discussed by comparing the obtained values of properties and the different characterization methodology. Inspection technique combinations were finally ranked based on accuracy, accessibility, and operability considerations. The line method was used to analyze all the properties, the area method, for the one-phase properties, and the point method, for only the phase fraction. It was found that the combination of optical microscopy and the line analysis method was suitable for a direct inspection and rapid estimation for carbides above fine grain size. The most precise results were achieved using line analysis of the images obtained by the backscattered electrons of the scanning electron microscope.

State of the art approaches to produce photocatalytic surfaces generally require multiple processing steps to achieve highly active surfaces. Following recent trends to facilitate the production of active surfaces, this work presents a single‐step method to create porous photocatalytic surfaces via direct laser interference patterning (DLIP) of a titanium substrate with pulses in the picosecond range. The resulting surfaces contain a variety of titanium oxides while both their composition and morphology can be controlled through the laser process parameters. This makes it possible to tailor these surfaces for specific applications such as antimicrobial surfaces, implant materials or water treatment. Surface characterization was executed by applying scanning electron microscopy complemented by focused ion beam cross‐sectioning and energy dispersive X‐ray spectroscopy as well as gracing incidence X‐ray diffractometry. The photocatalytic activity achieved by different laser parameters is assessed by methylene blue degradation under UV‐A light. As DLIP is already established in industrial applications, this approach could greatly facilitate the use of photocatalytic surfaces for water treatment or medical applications, as it does not require nanoparticle synthesis or additional coating steps.

Nickel(Ni)/aluminium(Al) hybrid foams are Al base foams coated with Ni by electrodeposition. Hybrid foams offer an enhanced energy absorption capacity. To ensure a good adhering Ni coating, necessary for a shear resistant interface, the influence of a chemical pre-treatment of the base foam was investigated by a combination of an interface morphology analysis by focused ion beam (FIB) tomography and in situ mechanical testing. The critical energy for interfacial decohesion from these microbending fracture tests in the scanning electron microscope (SEM) were contrasted to and the results validated by depth-resolved measurements of the evolving stresses in the Ni coating during three-point bending tests at the energy-dispersive diffraction (EDDI) beamline at the synchrotron BESSY II. Such a multi-method assessment of the interface decohesion resistance with respect to the interface morphology provides a reliable investigation strategy for further improvement of the interface morphology.