R. Pflumm, M. Schütze
Increasing demands on technical components for high-temperature applications (e.g. tur-bine blades) promote new developments not only in the field of alloy design, but also in surface engineering. This paper shows that it is possible to structure the surface of intermetallic titanium aluminides in-situ by locally controlled oxidation of the material due to selective doping with fluorine. The aim is to reproduce a shark-skin pattern (parallel riblets with valleys in between) in order to improve the surface aerodynamics. Riblets with widths in the single digit μm range have been generated. The nucleation process, the aspect ratio and the stability of the generated micro-structures are discussed as a function of the substrate composition and the oxidation conditions.