High-Temperature Corrosion and Corrosion Protection
The research focus of our team is the behaviour of metallic construction materials and protective coatings systems at high temperatures in oxidizing and mixed simulated operating gas mixtures (e.g. H2/H2O, O2/SO2 etc.) as well as under aggressive deposits. The obtained results are relevant for a large number of practical applications, including concentrated solar power plants, aircraft and stationary gas turbines, chemical industry plants, heating elements and high-temperature solid oxide fuel and electrolyser cells.
Currently investigated material types are martensitic/ferritic/austenitic steels, FeCrAl and Ni-base alloys as well as various types of metallic (aluminide, MCrAlY) and thermal barrier coating systems.
The research projects deal both with basic investigations (e.g. through the use of stable tracers) to clarify corrosion mechanisms and with long-term tests to determine design-relevant data. For a quantitative determination of the corrosion attack, results from thermogravimetric measurements are combined with data from extensive microstructural characterizations of the alloys / coatings and the corrosion products using GDOES, SNMS, Raman spectroscopy, XRD, SEM/EDX/EBSD and TEM. The work on the modelling of corrosion processes includes description of the growth mechanisms of surface scales based on Cr and Al oxide, oxidation induced phase transformations in metallic substrates, as well as prediction of oxidation limited service lifetime of (thin-walled) components and coating systems.