Intermetallic TiAl-alloys are interesting candidates for several high temperature applications because of their properties. Their lower specific weight compared to normally used Ni-based alloys could lead to a weight reduction of nearly 40% for e.g. turbine blades of aero engines which is beneficial in terms of fuel consumption and engine efficiency. A major limitation for the long term use of TiAl-alloys at temperatures above 800°C is their poor oxidation resistance. Small amounts of halogens in the surface of TiAl-components can improve the oxidation resistance drastically. A protective thin alumina scale is formed on the surface of alloys after a halogen treatment instead of a non protective thick mixed oxide scale on untreated surfaces. There are several ways to apply the fluorine to the surface. The results of high temperature oxidation tests of turbine blades for aero engines with and without fluorine treatment in air will be presented in this paper.
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