Development of electron beam physical vapor deposited (EB‐PVD) thermal barrier coatings (TBC) aims at low conductivity, increased temperature capability, and longer life. Considerable progress has been achieved by comprehensive understanding of the evolvement of the porous microstructure in columnar ceramic topcoats and its application to tailoring optimized micro‐structures. New ceramic compositions such as alternative stabilizers in zirconia, hafnia modified coatings, and pyrochlores are addressed. They have demonstrated their potential for future TBC applications. New results of both microstructure and chemistry are presented together with a summary of recent research results.

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Ferromagnetism in certain B2 ordered alloys such as Fe60Al40 can be switched on, and tuned, via antisite disordering of the atomic arrangement. The disordering is accompanied by a ∼1 % increase in the lattice parameter. Here we performed a systematic disordering of B2 Fe60Al40 thin films, and obtained correlations between the order parameter  (S), lattice parameter  (a 0), and the induced saturation magnetization  (M s). As the lattice is gradually disordered, a critical point occurs at 1 − S = 0.6 and a 0 = 2.91 Å, where a sharp increase of the M s is observed. DFT calculations suggest that below the critical point the system magnetically behaves as it would still be fully ordered, whereas above, it is largely the increase of a 0 in the disordered state that determines the M s. The insights obtained here can be useful for achieving tailored magnetic properties in alloys through disordering.

This work studies the modification of commercially available dispersions of intrinsically conductive polymer PEDOT:PSS with a strong base, KOH. It is concluded that addition of base derives a dedoping of the PEDOT chain and increase Seebeck coefficient from 15 µV/K to 90 µV/K. Supportive UV-Vis-NIR spectroscopy was used for tracking the doping level of the polymer. A surface morphology study of the dedoped PEDOT:PSS films was monitored by SEM. It was shown that if KOH is used in excess with respect to the acid component of PEDOT:PSS dispersions, it segregates at the surface forming crystallites. They, however could be easily removed by methanol rinsing without destroying the sample integrity. After material modification, a dispenser-printed polymer unileg-TEG with 61 unicouples was fabricated by printing. The TEG in form of 253 mm-long stripe shows a flexible behavior. At 90 K temperature difference a resulting power output of ~ 100 nW could be measured. We suggest that the low power output is due to a high internal generator resistance.

Gamma titanium aluminides are very interesting for their use in high-performance applications such as aircraft engines due to their low density, high stiffness and favorable high-temperature properties. However, the pronounced brittleness of these intermetallic alloys is a major challenge for their processing through conventional fabrication methods. Additive manufacturing by means of electron beam powder bed fusion (EB-PBF) significantly improves the processability of titanium aluminides due to the high preheating temperatures and facilitates complex components. The objective of this study was to determine a suitable processing window for EB-PBF of the TNM-B1 alloy (Ti-43.5Al-4Nb-1Mo-0.1B), using an increased aluminum content in the powder raw material to compensate for evaporation losses during the process. Design of experiments was used to evaluate the effect of beam current, scan speed, focus offset, line offset and layer thickness on porosity. Top surface roughness was assessed through laser scanning confocal microscopy. Scanning electron microscopy, electron backscatter diffraction (EBSD) and energy-dispersive X-ray spectroscopy (EDX) were used for microstructural investigation and to analyze aluminum loss depending on the volumetric energy density used in EB-PBF. An optimized process parameter set for achieving part densities of 99.9% and smooth top surfaces was derived. The results regarding microstructures and aluminum evaporation suggest a solidification via the β-phase.