2024-06-20 |
Dr. Christoph Grimme from the DECHEMA Research Institute successfully defended his doctoral thesis on June 17, 2024, titled:
“Yttrium Oxide Nanoparticle-Modified Diffusion Coatings and Their Oxidation, Corrosion, and Wear Behavior.”
The research was carried out as part of a project funded by the German Research Foundation (DFG) and contributes significantly to the protection of nickel-based materials, which are widely used in stationary gas turbines due to their excellent high-temperature properties. However, during the combustion of heavy fuel oil, aggressive vanadium-containing deposits, such as vanadium pentoxide V₂O₅, form on component surfaces and can severely compromise their service life.
Dr. Grimme’s work focused on reducing turbine downtime by directly inhibiting the corrosive deposits on the material surface. For this purpose, yttrium oxide (Y₂O₃) nanoparticles were incorporated into metallic coatings through galvanic co-deposition followed by pack cementation. The developed coatings demonstrated improved oxidation resistance, reduced inward diffusion of harmful species, and a significant increase in corrosion resistance compared to unmodified reference systems.
Particularly promising was the galvanic co-deposition of Y₂O₃ nanoparticles with nickel, which enabled targeted grain refinement and an increased aluminum reservoir through subsequent pack cementation. This significantly prolonged the stability of the protective β-NiAl phase under high-temperature conditions.
