Thesis defense of Eric Schneider

This work investigates oxidation processes in vanadium-containing AlCrVY(O)N thin films and copper powders used in laser-based powder bed fusion. X-ray diffraction, X-ray absorption near-edge structure spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy were employed to analyse the phase composition, oxidation states, and surface structures of the investigated samples.
For the thin films, it was demonstrated that the deposition method, oxygen content, and cathode power significantly influence both the crystallographic texture of the films and the temperatureinduced oxidation of vanadium. In particular, variations in the oxygen content and the power applied to the vanadium cathode enable the attainable oxidation state of vanadium to be adjusted in a controlled manner.
For the copper powders, the oxidation state was found to have a pronounced effect on the surface morphology and phase evolution. In situ X-ray diffraction measurements further revealed that oxidation and reduction processes are strongly influenced by temperature, the surrounding gas atmosphere, and repeated thermal exposure.
Overall, this work provides a more detailed understanding of the oxidation mechanisms occurring in vanadium-containing thin films and copper powders. The results demonstrate how different process parameters affect the formation of oxide phases and their evolution under thermal exposure. They therefore provide a basis for the further development and optimisation of oxidation-based material concepts.