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O Hudak, E. Aschauer, V. Dalbauer, O Hunold, M. Arndt, P. Polcik, P. Felfer, H. Riedl:
"Corrosion induced diffusion pathways in thin film materials investigated by atom probe tomography";
Poster: 47th International Conference on Metallurgical Coatings and Thin Films, ICMCTF, San Diego, CA, USA; 2021-04-26 - 2021-04-30.

Corrosion processes are common phenomena in fields of engineering and there is nearly never an instance, where a material is totally inert to its environment and its corrosive nature. Therefore, corrosion and corrosion-resistance are essential variables that play a pivotal role in the development of protective coatings. Ingenuity of next generation PVD coatings has given rise to a wide range of material concepts set out to withstand all kinds of corrosive attacks (e.g. NaCl, HCl, SO3 and O2). While their performance is mostly assessed on descriptors such as mass change, impairment of mechanical properties, or variance in electrochemical surface potential, little work has been dedicated to understand corrosion driven diffusion pathways, specifically on an atomic scale.
This study showcases a systematic approach on highlighting preferred diffusion pathways of corrosive media in arc-PVD thin films. For investigating the effect of grain size, droplet formation and crystallinity on the overall diffusion mechanism, a novel marker architecture was developed. Eliciting chemical and structural changes upon arrival of the diffused media, this marker system facilitates improved application of high-resolution analytical methods, such as APT and TEM, to help identify preferential diffusion paths.

Corrosion Resistance; PVD coatings; Diffusion Pathways; Atom Probe Tomography;